The study of the working conditions of drivers indicates the significant importance of the parameters of the internal environment in the car. These parameters only with greater or lesser probability correspond to the established standards, which allows us to extend the concept of reliability to the system that provides the conditions for the habitability of people in a car. In some cases, operational observations are indirect evidence of its insufficient reliability. According to the results of a survey of a large number of professional drivers about the influence of internal environmental factors, the temperature regime in the cab was negatively assessed (hot in summer, cold in winter) - 49% of drivers; the presence of toxic substances (air pollution by exhaust gases) - 60%; vibration influence - 45%, noise -
56% of surveyed drivers.
1.13.1. Climate comfort
Abnormal climatic conditions in the car cabin have a harmful effect on the health of the driver and are one of the reasons contributing to the occurrence of an accident. Under the influence of high or low temperature in the cab, the driver's attention is dulled, visual acuity decreases, reaction time increases, fatigue sets in quickly, errors and miscalculations appear that can lead to an accident.
One of the requirements of occupational safety and health is to exclude the possibility of penetration into the driver's cab of spent
gases that contain a number of toxic components, including carbon monoxide. Depending on the proportion of carbon monoxide in the air and the duration
the driver's work in such an atmosphere, the impact is different.
The most characteristic signs of minor poisoning are drowsiness, fatigue, intellectual passivity, impaired
spatial coordination of movements, errors in determining the distance and an increase in the latent period during sensorimotor reactions. Studies have shown that only a small
amount of carbon monoxide to cause some people to experience a burning sensation, intoxication, headache, drowsiness and disorientation, i.e. such deviations that can lead to an exit from the road, an unexpected turn of the steering wheel, falling asleep.
Carbon monoxide is sucked into the passenger compartment along with exhaust gases when technical malfunctions car. Deprived of any odor and color, carbon monoxide remains perfectly clean for a long time.
inconspicuous. At the same time, a working person is poisoned three times faster than a person who is at rest.
It should be borne in mind that carbon monoxide enters the driver's workplace also along with exhaust gases emitted by engines of other vehicles. This is especially dangerous for drivers of passenger cars - taxis, city buses and trucks, systematically working in conditions of intensive and dense traffic of vehicles in cities, the highways of which are filled with exhaust gases.
Studies of the air environment in driver's cabins and passenger compartments of buses showed that in some cases the content of carbon monoxide reaches 125 mg/m3, which is several times higher than the maximum permissible concentration for the driver's working area. Therefore, long-term driving of a car exceeding 8 hours in urban conditions is extremely dangerous due to the possibility of poisoning the driver with carbon monoxide.
Conditions in which a person does not experience overheating or hypothermia, sudden movement of air and other unpleasant sensations can be considered thermally comfortable. Comfortable conditions in winter are somewhat different from the same conditions in summer, which is associated with the use of different clothes by a person. The main factors that determine the thermal state of a person are temperature, humidity and air velocity, temperature and properties of the surfaces surrounding a person. With various combinations of these factors, it is possible to create equally comfortable conditions in the summer and winter periods of operation. In view of the variety of features of heat transfer between the human body and the external environment, the choice of a single criterion that characterizes comfortable conditions and is a function of environmental parameters is a difficult task. Therefore, comfortable conditions are usually expressed as a set of indicators that limit individual parameters: temperature, humidity, air speed, maximum air temperature difference in the body and outside it, temperature of surrounding surfaces (floor, walls, ceiling), radiation level, air supply to a limited room (body , cabin) per person per unit time or air exchange rate.
Comfortable values of air temperature and humidity recommended by various researchers differ somewhat. Yes, Institute of Hygiene
performing light work, the air temperature in winter
20...22°C, in summer +23...25°C at its relative humidity of 40...60%.
Permissible air temperature is +28°C at the same humidity and low speed (about 0.1 m/s).
According to the results of French researchers, for light winter work, an air temperature of +18 ... 20 ° C is recommended with a humidity of 50 ... 85%, and
for summer +24...28 °С at air humidity 35...65%.
According to other foreign data, car drivers must work at lower temperatures (+15 ... 17 ° C in the winter period of operation and
18...20°C in summer) at a relative air humidity of 30...60% and
the speed of its movement is 0.1 m/s. In addition, the temperature difference between the outside air and inside the body during the summer period should not exceed 10 ° C. The temperature difference inside the limited volume of the body in order to avoid human colds should not exceed 2 ... 3 ° C.
Depending on the working conditions, to ensure comfortable conditions, the temperature in winter can be taken equal to + 21 ° С with mild
work, +18.5°C for moderate, +16°C for severe.
At present, microclimatic conditions on cars are regulated in Russia.
So, for cars, the air temperature in the cab (body) in summer should not be higher than +28 C, in winter (at an outside temperature of -20 ° C) - at least + 14 ° C. In summer, when driving a car at a speed of 30
km/h, the difference between the internal and external air temperatures at the level of the driver's head should not be more than 3°С at an external temperature of +28°С and more than 5°С at an external temperature of +40°С. In winter time in the zone
positioning of the legs, belt and head of the driver should ensure the temperature is not lower than +15°C at an outside temperature of -25°C and not lower than +10°C at an outside temperature of -40°C.
Humidity in the cabin should be 30 ... 70%. The supply of fresh air to the cabin must be at least 30 m3/h per person, the speed of air movement in the cabin and the car interior is 0.5...1.5 m/s. The maximum concentration of dust in the cabin (cabin) should not exceed 5 mg/m3.
Ventilation system devices must create an excess pressure of at least 10 Pa in a closed cabin.
The maximum concentration of dust in the cabin (cabin) should not exceed 5 mg/m3.
The maximum permissible concentrations of harmful substances in the air of the working areas of the passenger compartment and the cab of the car are regulated by GOST R 51206 - 98 for cars, in particular: carbon monoxide (CO) - 20 mg / m3; nitrogen oxides in terms of NO2 – 5 mg/m3; total hydrocarbons (Сn Нm) – 300 mg/m3; acrolein (С2Н3СНО) – 0.2 mg/m3.
The concentration of gasoline vapors in the cabin and cabin of the vehicle should not exceed 100 mg/m3.
The temperature regime in the cabin (body) can be approximately
calculated according to the heat balance equation, according to which the air temperature in the cabin (body) remains constant:
The flow of heat into the cabin from various sources. AT
In most cases, the heat balance of the cabin (cabin) is determined by a number of factors, the main of which are: the number of people in the cabin (cabin) and
quantity of heat
QH coming from them; quantity of heat,
coming through transparent barriers
(mainly from
solar radiation) and opaque fences
(quantity of heat,
coming from the engine
Qeng, transmissions
QTP, hydraulic equipment
electrical equipment fan.
In this way,
QEO) and together with outside air
QVN supplied
ΣQi QCh QCh QP.O QNP.O QDV QTR QGO QEO QVN 0
It should be noted that the heat balance terms included in the equation should be taken into account algebraically, i.e. with a positive sign when heat is released into the cabin and with a negative sign when it is removed from the cabin. Obviously, the heat balance condition is met if the amount of heat entering the cabin is equal to the amount of heat removed from it.
Temperature conditions and air mobility in the cabins of vehicles are provided by heating, ventilation and air conditioning systems.
Currently, there are various ventilation and heating systems for cabins and car interiors, which differ in the layout and design of individual units. The most economical and widely used
modern cars is a heating system that uses the heat of liquid cooling of the engine. The combination of heating systems and general ventilation of the cabin allows you to increase the efficiency of the entire complex of devices for ensuring the microclimate in the cabin throughout the year.
Heating and ventilation systems differ mainly in the location of the air intake on the outer surface of the car, the type of fan used and its location relative to the radiator
heater (at the inlet or outlet of the radiator), the type of radiator used (tubular-lamellar, tubular-tape, with an intensified surface, matrix, etc.), control method
the operation of the heater, the presence or absence of a bypass air duct,
recirculation channel, etc.
The intake of air from outside the cab into the heater is carried out in the place of the minimum dust content of the air and the maximum dynamic pressure,
occurring while the vehicle is in motion. In trucks, the air intake is located on the cab roof. Water-repellent partitions, blinds and covers are installed in the air intake,
powered from inside the cab.
An axial fan is used to provide air supply to the cabin and overcome the aerodynamic resistance of the radiator and air ducts.
radial, diametrical, diagonal or other type. Currently, the most widely used double-console radial fan, as it has a relatively small size with a large
performance.
DC motors are used to drive the fan. The speed of rotation of the electric motor and, accordingly, the fan impeller is regulated by a two- or three-stage variable resistor included in the power supply circuit of the electric motor.
The heat output of the heater and its
aerodynamic drag. To increase the efficiency of heat transfer from the radiator, the shape of its channels through which air moves is complicated, various turbulators are used.
A decisive role in the effective uniform distribution of temperatures and air velocities in the cabin is played by the air distributor. The air distributor nozzles are made in various shapes: rectangular,
round, oval, etc. They are placed in front of the windshield, near the door windows, in the center of the instrument panel, at the driver's feet and in other places determined by the requirements for the distribution of fresh air
flows in the cab.
In the nozzles, various dampers, rotary shutters,
control plates, etc. The drive for dampers and rotary shutters is most often located directly in the air distributor housing.
Air ducts to the air distributor are made of sheet steel, rubber hoses, corrugated plastic pipes, etc. AT
some cars use cabin parts, the cavity of the instrument panel as air ducts. However, such a design of air ducts is irrational, since tightness is not ensured and air consumption increases. Vehicle traffic safety is largely
depends on reliable and effective protection of the windshield from fogging and freezing, which is achieved by uniform blowing of warm air and heating to a temperature above the dew point.
Such glass protection is structurally simple, does not impair its optical properties, but requires an increase in the ventilation system performance and a high heat capacity of the glass. The effectiveness of glass jet protection against
fogging is determined by the temperature and air velocity at the outlet of the nozzle located in front of the glass edge. The higher the air velocity at the outlet of the nozzle, the lower the temperature in the glass zone differs from
temperature at the nozzle outlet.
The layout of the ventilation and heating system depends on the design of the vehicle, cab, individual components and their placement.
At present, air conditioners have become widespread - devices for
artificial cooling of the air entering the cabin (body). According to the principle of operation, air conditioners are divided into compression, air-cooled, thermoelectric and evaporative. Automatic control of the heater operation mode of some vehicles is carried out by changing the flow rate of liquid or air through the heater radiator. With automatic control by changing
air flow parallel to the radiator, a bypass air channel is made, in which a controlled damper is installed.
As already noted, an important place in the ventilation system of the cabin (body)
the car is occupied by cleaning the ventilation air from dust.
The most common way is to clean the ventilation air using filters made of cardboard, synthetic fiber materials,
modified polyurethane foam, etc. However, in order to effectively use such filters, which are characterized by low dust capacity, with fewer maintenance,
dust concentration at the filter inlet. For preliminary air purification, inertial type dust separators are installed at the inlet to the filter with continuous removal of trapped dust.
The basic principles of ventilation air dedusting are based on the use of one or more mechanisms for the deposition of dust particles from the air: the inertial separation effect and the effects of engagement and
deposition.
Inertial sedimentation is carried out with the curvilinear movement of dusty air under the action of centrifugal and Coriolis forces. On the
The settling surface is discarded by particles whose mass or velocity are significant and cannot follow the flow line around the obstacle along with the air. Inertial settling is manifested and
when the obstacles are the filling elements of filters made of fibrous materials, the ends of flat sheets of inertial louvered grilles, etc.
When dusty air moves through the porous partition of the particle,
suspended in the air, linger on it, and the air completely passes through it. Studies of the filtration process are aimed at establishing the dependence of the efficiency of dust collection and aerodynamic resistance on the structural characteristics of porous partitions, dust properties and air flow regime.
The process of air purification in fibrous filters occurs in two stages.
At the first stage, particles are deposited in a clean filter without structural changes in the porous partition. In this case, changes in the thickness and composition of the dust layer are not significant and can be neglected. At the second stage, continuous structural changes in the dust layer and further deposition of particles in a significant amount occur. This changes the dust collection efficiency of the filter and its aerodynamic resistance, which complicates the calculation of the filtration process. The second stage is complex and little studied; under operating conditions, it is this stage that determines the efficiency of the filter, since the first stage is very short-lived. Of the variety of filter materials used in the filters of the cabin ventilation air dedusting system, three groups can be distinguished: woven from natural, synthetic and mineral fibers; non-woven - felt, paper, cardboard, needle-punched materials, etc.; cellular - polyurethane foam, sponge rubber, etc.
For the manufacture of filters, materials of organic origin and artificial are used. Organic materials include cotton, wool. They have low heat resistance, high moisture capacity. A common disadvantage of all filter materials of organic origin is their susceptibility to putrefactive processes and the negative effects of moisture. Synthetic and mineral materials include: nitron, which has a high resistance to temperatures, acids and alkalis; chlorane having low heat resistance but high chemical resistance; capron, characterized by high resistance to abrasion; oxalon having high heat resistance; glass fiber and asbestos, which are distinguished by high heat resistance, etc. The filter material made of lavsan has high rates of dust-catching, strength and regeneration parameters.
Wide application in filters with pulsed air purge during filter regeneration has received non-woven needle-punched polyester
filter materials. These materials are obtained by compacting the fibers, followed by stitching or needle punching.
The disadvantage of such filter materials is the passage of more
fine dust particles through the holes formed by the needles.
A significant disadvantage of filters made of any filter material is the need to replace them or Maintenance with the aim of
regeneration (recovery) of the filter material. Partial filter regeneration can be carried out directly in the ventilation system by back blowing the filter material with purified air from the vehicle cabin or by local jet air blowing
from a compressor with preliminary purification of compressed air from water vapor and oil.
Design of filters made of woven or non-woven filter media
for cabin ventilation systems should have a maximum filtration surface with minimum dimensions and aerodynamic resistance. Installing the filter in the cabin and changing it should be convenient and ensure reliable tightness around the filter perimeter.
1.13.2. Vibration comfort
From the point of view of reaction to mechanical excitations, a person is a kind of mechanical system. At the same time, various internal organs and individual parts of the human body can be considered as masses interconnected by elastic bonds with the inclusion of parallel resistances.
Relative movements of parts of the human body lead to stresses in the ligaments between these parts and mutual impact and pressure.
Such a viscoelastic mechanical system has natural frequencies and rather pronounced resonant properties. resonant
the frequencies of individual parts of the human body are as follows: head - 12 ... 27 Hz,
throat - 6...27 Hz, rib cage- 2 ... 12 Hz, legs and arms - 2 ... 8 Hz, lumbar spine - 4 ... 14 Hz, stomach - 4 ... 12 Hz. The degree of harmful effects of vibrations on the human body depends on the frequency, duration and direction of vibration, individual characteristics of a person.
Long fluctuations of a person with a frequency of 3 ... 5 Hz adversely affect the vestibular apparatus, the cardiovascular system and cause motion sickness. Oscillations with a frequency of 1.5 ... 11 Hz cause disorders due to resonant vibrations of the head, stomach, intestines and, ultimately, the whole body. With fluctuations with a frequency of 11 ... 45 Hz, vision deteriorates, nausea and vomiting occur, and the normal activity of other organs is disrupted. Fluctuations with a frequency of more than 45 Hz cause damage to the vessels of the brain, a disorder of blood circulation and higher nervous activity occurs, followed by the development of a vibration disease. Since vibration under constant exposure has an adverse effect on the human body, it is normalized.
The general approach to normalizing vibration is to limit the vibration acceleration or vibration velocity measured at the driver's workplace to
depending on the direction of the vibration, its frequency and duration.
Note that the smooth running of the machine is characterized by general vibration,
transmitted through the supporting surfaces to the body of a seated person. Local vibration is transmitted through the hands of a person from the controls of the machine, and its influence is less significant.
The dependence of the mean square value of the vertical
vibration acceleration az of a seated person as a function of the oscillation frequency at its constant vibration loading is shown in fig. 1.13.1 (curves of "equal thickening"), from which it can be seen that in the frequency range f = 2 ... 8 Hz, the sensitivity of the human body to vibration increases.
The reason for this lies precisely in the resonant vibrations of various parts of the human body and its internal organs. Most curves
"equal thickening" obtained by exposing the human body to harmonic vibration. With random vibration, the curves of "equal thickening" in different frequency ranges have a common character, but
quantitatively different from harmonic vibration.
Hygienic assessment of vibration is carried out by one of three methods:
frequency (spectral) analysis; integral estimate by frequency and
"dose of vibration".
In the case of separate-frequency analysis, the normalized parameters are the root-mean-square values of vibration velocity V and their logarithmic levels Lv or vibration acceleration az for local vibration in octave frequency bands, and for general vibration - in octave or one-third octave frequency bands. When normalizing vibration, "equal thickening" curves were first taken into account in ISO 2631-78. The standard establishes the permissible mean square values of vibration acceleration in one-third octave bands
|
frequencies in the range of geometric mean frequencies of 1...80 Hz at various durations of vibration action. ISO 2631-78 provides for the evaluation of both harmonic and random vibration. In this case, the direction of the general vibration is usually estimated along the axes of the orthogonal coordinate system (x - longitudinal, y - transverse, z - vertical).
Rice. 1.13.1. Equal Condensation Curves for Harmonic Vibration:
1 - threshold of sensations; 2 - the beginning of discomfort
A similar approach to vibration regulation is used in GOST
12.1.012-90, the provisions of which are the basis for determining the criterion and indicators of the smooth running of cars.
The concept of “safety” was introduced as a criterion for smooth running, not
causing health problems for the driver.
Ride ratings are usually assigned according to the output value, which is the vertical vibration acceleration az or the vertical vibration velocity Vz determined from the driver's seat. It should be noted here that when assessing the vibration load on a person, the vibration acceleration is the preferred output value. For sanitary standardization and control, the vibration intensity is estimated by the root mean square
az value
vertical vibration acceleration, as well as its logarithmic
Threshold RMS vertical
vibration acceleration.
RMS value az
called "controlled"
parameter", and the smoothness of the machine is determined with constant vibration in the frequency range of 0.7 ... 22.4 Hz.
In the integral assessment, a frequency-corrected value of the controlled parameter is obtained, which takes into account the ambiguity of human perception of vibration with a different spectrum
frequencies. Frequency-corrected value of the controlled parameter az
and its logarithmic level
determined from expressions:
|
|
|
|
|
|
|
|
|
|
~ ∑ (k zi a zi) ;
10 lg ∑100.1(Lazi Lkzj) ,
– root mean square value of the controlled parameter
and its logarithmic level in the i-th octave or one-third octave band;
- weighting factor for the root mean square value
controlled parameter and its logarithmic level in the i-th band
kzi i ; n is the number of bands in the normalized frequency range.
The values of the weight coefficients are given in Table 1.13.1.
Table 1.13.1
The average value of the frequency of a third octave and
One third octave frequency band
Octave Bandwidth
octave bands
According to sanitary standards, with a shift duration of 8 hours and general vibration, the standard mean square value of vertical vibration acceleration is 0.56 m/s2, and its logarithmic level is 115 dB.
When determining the vibration load on a person using the vibration spectrum, the normalized indicators are the root mean square value of vibration acceleration or its logarithmic level in one-third octave and octave frequency bands.
Permissible values of spectral indicators of vibration load per person are given in Table. 1.13.2.
Table 1.13.2
Sanitary standards for spectral indicators of vibration load for vertical vibration acceleration
geometric
Standard average
quadratic value
Regulatory
logarithmic
one-third octave frequency value
vibration acceleration
vibration acceleration
and octave
third octave
frequency band
Octave
frequency band
third octave
frequency band n
In the case of applying the integral and separate-frequency methods for assessing the vibration load on a person, one can come to different results. As a priority, it is recommended to use the method of separate-frequency (spectral) assessment of the vibration load.
At present, normative indicators of the smoothness of the movement of machines, such as vibration accelerations and
vibration velocities in the vertical and horizontal planes, set differentially for different vibration frequencies.
The latter are grouped into seven octave bands with an average geometric frequency from 1 to 63 Hz (Table 1.13.3.).
Table 1.13.3
Normative indicators of the smoothness of the movement of transport vehicles
Parameter
Vibration velocity,
Average geometric oscillation frequency, Hz
1 2 4 8 16 31,5 6
vertical horizontal Vibration acceleration, m/s2: vertical horizontal
On a number of special wheeled and tracked vehicles operated in difficult road conditions, where the amplitudes of the microprofile are significant, it is difficult to ensure the values of the ride smoothness indicators regulated for transport technology. Therefore, for such machines, standard indicators of smooth running are set at a lower level (Table 1).
Table 1.13.4
Normative indicators of smoothness for machines operating in difficult road conditions
Acceleration in the workplace
driver - (operator)
Vertical:
root mean square maximum from episodic
tremors
maximum from rotary shocks
Horizontal RMS
Transport traction
Ride comfort standards for trucks, buses, cars, trailers and semi-trailers are defined for three types of sections of the NAMI polygon:
I – cement dynamometric road with r.m.s. value of roughness heights 0.006 m;
II - cobblestone paved road without potholes with RMS
roughness values 0.011 m;
III - cobblestone road with potholes with r.m.s. roughness values of 0.029 m.
Vehicle smoothness standards established by OST 37.001.291-84,
are given in table. 1.13.5, 1.13.6, 1.13.7.
To improve the smooth running of cars, the following measures are used:
The choice of the layout scheme of the car, ensuring the independence of oscillations on the front and rear suspension sprung mass of the machine;
The choice of the optimal characteristics of the elasticity of the suspension;
Ensuring the optimal ratio of rigidity of the front and rear suspensions of the car;
Reducing the mass of unsprung parts;
Suspension of the cab and driver's seat of a truck and road train.
Table 1.13.5
Limit technical standards for smooth running of trucks
Corrected values of vibration accelerations on seats, m/s2, no more
horizontal
RMS values of vertical
vibration accelerations in
road vertical
al longitudinal
characteristic points of the sprung part, m/s2, no more
Table 1.13.6
Limit technical standards for smooth running of passenger cars
The corrected values of vibration accelerations on the driver's seats and
Road type
passengers, m/s2, no more
vertical horizontal
Table 1.13.7
Limit technical standards for the smooth running of buses
Corrected values of vibration accelerations on bus seats, m/s2, no more
urban other types
driver passengers driver and passengers
1.13.3. Acoustic comfort
Various noises occur in the cab of the car, which adversely affect the driver's performance. First of all, the auditory function suffers, but noise phenomena, having cumulative properties (i.e., properties to accumulate in the body), depress nervous system, at the same time, psychophysiological functions change, the speed and accuracy of movements are significantly reduced. Noise causes negative emotions, under its influence the driver develops absent-mindedness, apathy, memory impairment. The impact of noise on a person can be subdivided depending on the intensity and spectrum of noise into the following groups:
Highly loud noise with levels of 120 ... 140 dB and above - regardless of the spectrum, it can cause mechanical damage to the hearing organs and cause severe damage to the body;
Strong noise with levels of 100 ... 120 dB at low frequencies, above 90 dB at medium frequencies and above 75 ... 85 dB at high frequencies - causes irreversible changes in the hearing organs, and with prolonged exposure it can be
the cause of a number of diseases and, first of all, the nervous system;
Noise at lower levels of 60 ... 75 dB at medium and high frequencies has a harmful effect on the nervous system of a person engaged in work that requires concentrated attention, to which work belongs
car driver.
Sanitary standards divide noise into three classes and set an acceptable level for them:
Class 1 - low-frequency noise (the largest components in the spectrum are located below the frequency of 350 Hz, above which the levels decrease) with an allowable level of 90 ... 100 dB;
Class 2 - mid-frequency noise (the highest levels in the spectrum
located below the frequency of 800 Hz, above which the levels decrease) with an allowable level of 85 ... 90 dB;
Class 3 - high-frequency noise (the highest levels in the spectrum are located above the frequency of 800 Hz) with an allowable level of 75 ... 85 dB.
Thus, the noise is called low-frequency when the oscillation frequency is not
more than 400 Hz, mid-frequency - 400 ... 1000 Hz, high-frequency - more
1000 Hz. At the same time, according to the frequency of the spectrum, noise is classified into broadband, including almost all frequencies of sound pressure (the level is measured in dBA), and narrow-band (the level is measured in dB).
Although the frequency of acoustic sound vibrations is in the range of 20 ... 20,000
Hz, its normalization in dB is carried out in octave bands with a frequency of 63 ...
8000 Hz constant noise. The characteristic of intermittent and broadband noise is equivalent in energy and perception
human ear sound level in dBA.
Permissible indoor noise levels for vehicles on
GOST R 51616 - 2000 are given in table. 1.13.8.
It should be noted that the permissible levels of internal noise in the cabin or saloon are set regardless of whether there is one source here.
noise or more. Obviously, if the sound power emitted by one source satisfies the maximum permissible sound pressure level at the workplace, then when installing several such sources
the indicated maximum allowable level will be exceeded due to the sum of their effects. As a result general level noise is determined by the law of energy summation.
Table 1.13.8
Permissible levels of internal noise of vehicles
Permissible
motor vehicle
Cars and buses for the transport of passengers
sound level, dB A
M 1, except for wagon models or
half-bonnet body layout
M 1 - models with wagon or 80
semi-bonnet body layout.
M 3 , except models with
the location of the engine in front of or next to the place
driver: 78 in the driver's workplace 80 in the passenger area of class II buses 82
in the passenger area of class I buses
Models with arrangement 80
engine in front of or next to the driver's seat:
at the driver's workplace and in the passenger 80
indoors
Vehicles for the transport of goods
N1 gross weight up to 2 t 80
N1 GVW from 2 to 3.5 t 82
N3 , except models,
intended for international and 80
intercity transportation
Models for international and 80
intercity transportation
Trailers designed for the transport of passengers 80
Total noise level, dBA, from several identical sources
LΣ L1 10 lg⋅ n ,
L1 – noise level of one source, dBA;
n is the number of noise sources.
With the simultaneous action of two sources with different sound pressure levels, the total noise level
LΣ La ∆L ,
– the largest of the two summed noise levels;
∆L – additive depending on the difference in noise levels between two sources
∆L values
depending on the difference between the noise levels of the two sources
> Lb) are given below:
|
La − Lb , dBA…..0 1 |
|||
|
∆L , dBA…...3 2.5 |
Obviously, if the noise level of one source is higher than that of another by
8 ... 10 dBA, then the noise of a more intense source will prevail, since
in this case, the addition ∆L
very small.
The total noise level of sources of different intensity is determined by the expression
−0.1∆L1,n
Σ 1 10 log 1 10
... 10 ,
L1 - the highest noise level of one of the sources;
∆L1, 2 − L1 − L2 ;
∆L1.3 L1 − L3 ; ∆L1,n L1 − Ln ⋅ L2 , L3 ,...., Ln
Noise levels
2nd, 3rd, ..., nth sources, respectively). Calculation of the noise level, dB A,
with a change in the distance to the source is performed by the formula
Lr Lu − 201gr − 8 ,
– source noise level; r is the distance from the noise source to
the object of his perception,
The total noise of a moving vehicle is made up of the noise generated by the engine, aggregates, the vehicle body and its components, the noise of auxiliary equipment and tire rolling, as well as the noise from the air flow.
Noise in a particular source is generated by certain physical phenomena, among which the most characteristic in a car are:
impact interaction of bodies; friction of surfaces; forced vibrations of solid bodies; vibration of parts and assemblies; pressure pulsation in pneumatic and hydraulic systems.
In general, vehicle noise sources can be divided into the following:
Mechanical - engine internal combustion, body parts,
transmission, suspension, panels, tires, tracks, exhaust system;
Hydromechanical - torque converters, fluid couplings, hydraulic pumps,
hydraulic motors;
Electromagnetic - generators, electric motors;
Aerodynamic - intake and exhaust system of an internal combustion engine, fans.
Noise has a complex structure and is made up of noise from individual sources. The most intense sources of noise are:
structural engine noise (mechanical and combustion noise), intake and system noise, exhaust system and exhaust system noise, cooling fan noise, transmission noise, tire rolling noise (tire noise), body noise. Many years of research have established that the main sources of noise in a car include an internal combustion engine, transmission elements, tires, and aerodynamic noise. Body panels are a secondary source of noise. Additional sources include noise from engine attachments, some transmission elements, electric motors, heaters, window blowing, slamming doors, etc.
The listed sources generate mechanical and acoustic vibrations, different in frequency and intensity. The nature of the frequency spectrum
disturbances is very difficult to analyze due to the overlap and frequency interconnection of work processes and disturbances from transmission elements, running gear, aerodynamic processes, etc.,
and also in view of the fact that many sources are both causative agents of mechanical and acoustic vibrations. In the vibration spectra of the main transmission units and noise, mainly
harmonic components from the main excitation sources
(engine and transmission).
The dynamic interaction of parts of the vehicle's assemblies generates vibrational energy, which, propagating from vibration sources,
creates the sound field of a car, tractor, i.e. car noise.
In accordance with this, the following ways can be outlined to reduce the intensity of noise:
Reducing the vibration activity of aggregates, i.e. decrease in the level of vibrational energy generated in the source;
Taking measures to reduce the intensity of fluctuations in the way of their
distribution;
Impact on the process of radiation and transmission of vibrations to attached parts, i.e. reduction of their vibroacoustic activity.
Reducing the vibration activity of the source is achieved by improving the kinematic properties of vehicle systems and selecting parameters mechanical systems so that their resonant frequencies are
as far as possible from the frequency range containing the operating frequencies of the units, as well as reducing to a minimum the levels of oscillations at the reference points and minimizing the amplitudes of forced oscillations. Noise reduction can be achieved by creating a low noise process
combustion, improving the vibroacoustic characteristics of body parts, assemblies, introducing damping into their design, improving the design and manufacturing quality of movable
parts, increasing the acoustic efficiency of intake and exhaust silencers, etc.
Fight against noise and vibrations during their distribution in the process
radiation and transmission of vibrational energy to attached parts and
aggregates can be carried out by "detuning" the system of bearing elements from resonant states by means of vibration isolation, vibration damping and vibration damping.
Vibration isolation - the choice of such parameters of mechanical systems that provide localization of vibrations in a certain area of the car without
its further distribution.
Vibration damping - the use of systems that actively dissipate the energy of vibrations of vibrating surfaces, as well as the use of materials with a large decrement
attenuation.
Vibration damping is the use in units tuned to a certain frequency and shape of vibrations, systems operating in antiphase.
Suppression of noise at the very source of its occurrence is an active method of noise suppression and the most radical means of combating noise. However, in many cases this method, for one reason or another, is not
can be applied. Then you have to resort to passive methods of noise protection - this is vibration damping of surfaces, sound absorption, sound insulation.
Soundproofing refers to the reduction of sound (noise) entering the receiver due to reflection from obstacles in the transmission path. The soundproofing effect always occurs when the passage of sound
waves through the interface between two different media. The greater the energy of the reflected waves, the less the energy of the transmitted ones and, consequently, the greater the soundproofing ability of the interface between the media. The more sound energy is absorbed by the barrier, the higher its sound-absorbing
ability.
Noise caused by medium and high frequency vibrations is transmitted to the cabin mainly through the air. To reduce this transmission, a special
pay attention to sealing the cabin, identifying and eliminating acoustic holes (acoustic holes). Acoustic holes can be through and non-through slots, technological holes, areas with
low sound insulation, significantly worsening the overall sound insulation of the structure.
From the point of view of the characteristics of the transmission of sound energy, there are
large and small acoustic openings. A large acoustic hole is characterized by a large ratio of the linear dimensions of the hole to the length of the sound wave incident on the hole compared to unity. In practice, we can assume that sound waves pass through a large acoustic hole according to the laws of geometric acoustics, and the sound energy passed through the hole is proportional to its area. Each hole category has one or more effective methods their elimination.
To determine effective ways to reduce noise, it is necessary to know the most intense sources of noise, to carry out their separation, as well as
determine the need and magnitude of reducing the levels of each of them.
Having the results of separation of sources and their levels, it is possible to determine the sequence of finishing the car in terms of noise.
test questions
1. For what purpose is the safety of the design of vehicles regulated?
2. What are the main properties that determine the safety of the design of vehicles
3. By what criteria is the impact of active vehicle safety on safety determined? traffic?
4. What is the relationship between vehicle weight and risk
injury in an accident for its passengers?
5. What determines the width of the dynamic corridor during curvilinear motion?
6. What are the size classes for cars sold in Europe?
with GOST R 52051-2003?
8. What forces act on a car accelerating uphill?
9. What changes in the technical condition of the car affect its traction dynamics and how?
10. What is the dynamic factor of a car?
11. What is called transverse stability car?
12. What is called the longitudinal stability of the car?
13. What is vehicle directional stability?
14. What are the main technical requirements (test methods)
apply to the braking properties of vehicles?
15. What standards regulate the stability and controllability of vehicles as properties of active safety?
16. What types of stability tests do you know?
17. What indicators are evaluated during the "stabilization" test?
18. What types of car steering exist?
19. For what technical reasons is it possible to lose control of the car?
20. What is braking distances car?
21. How a Type 0 test is carried out brake systems Vehicle?
22. What indicators determine the requirements for tires and wheels?
23. Specify the main characteristics of coupling devices.
24. What devices are used for information support of vehicles?
25. What are the technical requirements for lighting and light signaling devices?
The study of the working conditions of drivers indicates the significant importance of the parameters of the internal environment in the car. These parameters only with greater or lesser probability correspond to the established standards, which allows us to extend the concept of reliability to the system that provides the conditions for the habitability of people in a car.
In some cases, operational observations are indirect evidence of its insufficient reliability. According to the results of a survey of 4 drivers of this car about the influence of internal environmental factors, the temperature regime in the cab was negatively assessed (hot in summer, cold in winter) - 75% of drivers; the presence of toxic substances (air pollution with exhaust gases) - 75%; influence of vibrations - 75%, noise - 75%.
Abnormal climatic conditions in the car cabin have a harmful effect on the health of the driver and are one of the reasons contributing to the occurrence of an accident. Under the influence of high or low temperature in the cab, the driver's attention is dulled, visual acuity decreases, reaction time increases, fatigue sets in quickly, errors and miscalculations appear that can lead to an accident.
A survey was also conducted on the state of noise in the car interior and 100% of the respondents stated the presence of mid-frequency noise from the low quality of the interior plastic, which causes increased irritation during the trip, although they do not exceed noise class 2 according to GOST R 51616 - 2000.
Based on the above, I conclude that the driver's comfort in the car is significantly low, which leads to a decrease in the active safety of the car.
3. Vehicle passive safety systems
Passive safety includes many elements, and one of the main ones is the seat belt. The second most important element of passive safety is the car body. Its front or rear part should, by crushing, dissipate the released impact energy as much as possible, and the central part of the body should provide as much space as possible for the passengers of the car to survive. Interior materials should not only be pleasant to the touch and pleasing to the eye, if necessary, they should soften the blow as much as possible. At the same time, they should not crack, so that their fragments do not cause additional damage to passengers.
After the impact, the car's gas tank must not ignite or crack in order to avoid spilling fuel on the road. Great importance is attached to doorways and locks. As accident statistics show, the most severe injuries, often incompatible with life, are received by passengers who fell out of the opened car doors. At the same time, after an accident, locks and doors should open easily without the use of additional equipment to ensure quick and timely evacuation of people in the cabin.
Composed of a number of factors, often contradictory, passive safety serves to achieve one main task - in the event of an accident, regardless of its severity, do everything possible to save the lives of people in the car.
Based on the study of the safety of the ZAZ 1102 car by the magazine Autoreview No. 3 of 2004. "The hood as a murder weapon"
(A crash test of this car was carried out. The nature and severity of the damage received by Tavria left no doubt about the outcome of the collision for this car.
The front part of Tavria was thoroughly crumpled - 62 cm on the left side. At the same time, the entire front part noticeably shifted to the left, two solid folds appeared on the roof - the body went like a screw. Crashed and thrown out on impact windshield, the driver's door jammed in the opening.
The base of the A-pillar shifted back by 33 cm, to which the spare wheel contributed - it advanced part of the engine shield into the cabin, and the hard plastic instrument panel shifted back and cracked slightly to the left of the center, forming sharp injury-prone edges. With the steering column and the driver's seat, miracles happened at all. The column moved to the right so that wheel it turned out to be almost in the middle and at the same time it shifted inward by 14 cm. The left seat moved forward by 13 cm, and in addition it was strongly skewed to the left. This happened due to the fact that the power structure of the floor of the body in the area of \u200b\u200bfastening the front seats turned out to be too flimsy - the floor went in waves, bent the seat slide, and they opened up without holding the seat. Together with the deformation of the floor, this reduced the space for the feet and legs, and in addition, after the mannequin bounced back, his head missed the headrest, which is fraught with damage to the cervical vertebrae.
It is also unpleasant that the locks-latches of the rear seat back from the impact opened up and allowed it to fold. The decoded data from the dummy's sensors showed that the total level of overloads that acted on the dummy's head for 20 ms turned out to be higher than the permissible one.)
Imagine our surprise when, while watching high-speed filming, we saw a strange and terrible picture: the hard object that the driver hit his head turned out to be ... the hood! Even during the first inspection of the body, we noticed that the emergency latch of the hood on the left side did not work. The right hook did its job, and the left hook just came off "with meat" upon impact! In general, this is not surprising - the hook is cantilevered to the motor shield, and in the event of a collision, all spot welding points (there are four of them) worked to break away. The hook came off already after 30 milliseconds, and over the next 60 ms, the sharp edge of the hood pierced the windshield, which led to its sweeping out of the opening and shifted into the cabin towards the dummy. The high-speed filming footage clearly shows how the mannequin hit its face on the sharp edge of the hood. And this despite the fact that the belts were tightened as much as is hardly possible during normal driving.
An analysis of the residual deformation of the car body showed that Tavria has a weaker power structure of the body, seat and steering column.
Fatigue is a condition that has arisen under the influence of the work done and affects the level of performance.
Fatigue is a complex and varied phenomenon. Often it does not directly affect the performance of labor activity, but manifests itself in a different way. For example, labor operations that used to be performed easily, without any tension, automatically, after a few hours of work require additional effort, special attention. The rate of fatigue development depends on many factors: dynamic and static adaptation, visual comfort, working environment, etc.
Fatigue has a decisive influence on the driver's ability to navigate correctly, quickly and safely in a traffic situation. Decreased performance due to fatigue is not a purely physiological phenomenon. As numerous studies have shown, an important role in the processes of fatigue belongs to psychological factors, the tension of the human nervous system.
In the practice of the driver of a car (tractor) there are:
Natural fatigue, the effects of which disappear the next day;
Excessive fatigue arising from improper organization of work;
A harmful fatigue, the effects of which do not disappear on the second day, but imperceptibly accumulate and remain unconscious for a long time, until they suddenly appear.
The main factors causing driver fatigue and other deviations during work are as follows:
Duration of continuous driving of the car (tractor);
The psycho-physiological state of the driver before leaving for a flight or leaving for a shift;
Driving a car (tractor) at night;
Monotony and monotony of driving;
Working conditions at the driver's workplace.
The most objective evidence of driver fatigue when driving a car is the number of accidents depending on the duration of movement and other conditions associated with fatigue. A clear dependence of the number of road accidents and accidents on the duration of work has been established.
The driver's psychophysiological state before departure has no less influence on the driver's fatigue. It worsens from lack of sleep and the load of the driver before starting work (mental stress, conflict unnerving environment, mental trauma).
Increased driver fatigue occurs when driving at night.
With monotonous and monotonous movement, a particularly dangerous type of fatigue occurs, which causes a inhibited state of the higher nervous activity of the driver and can lead to weakness, drowsiness and falling asleep at the wheel. This condition occurs as a result of prolonged repetition of the same action.
No less important factors that accelerate fatigue are the working conditions at the driver’s workplace (working position, rhythm and pace of work, work breaks), the microclimate at the driver’s workplace (temperature, pressure, air humidity, gas pollution, lighting, radiation) and noise and vibration levels.
A fishing rod or a long key is a hijacking method when attackers use a wave system designed for special services. Relaying the key signal allows you to open the car, even if the owner is at a considerable distance. Ways to deal with this type of theft.
During operation, scratches appear on the windows of the car from wipers, scrapers and other small abrasives. Scratches and abrasions can significantly reduce the driver's visibility while driving, especially in the evening. In order not to change the glass, you can try to polish it yourself.
Soundproofing car doors can significantly reduce the level extraneous sounds in the cabin. The procedure for installing Shumka is not so complicated, so you can even make it right with your own hands. What materials are commonly used for sound insulation, what are the positive and negative sides has installation Shumkov for doors.
50% of car owners produce independent soundproofing of a car, while the other half orders this service in specialized workshops. Is it really so difficult to make a noise in a car with your own hands, what materials should be used. How much material is needed and what types are better to use.
It is useful to study the rating of the most stolen cars in Russia for all car owners, as well as for those who are just going to purchase a vehicle. The article contains statistics of car thefts since 2014. Fresh data for 2018, by the number of thefts in general and by specific gravity.
Double glazing your car will help you avoid constant fines for the installed tinting. Having once spent a certain amount of money, you can forget about the problem forever. But it is advisable to approach the choice of the contractor responsibly in order to avoid problems with double glazing in the future.
Since the vehicle is a source of increased danger, there is a list of malfunctions, in the event of which the driver does not have the right to use the vehicle at all. There is also a list of malfunctions with which the car can independently continue to move to the place where the breakdown is repaired.
Did you smell gasoline in your car? It is necessary to calculate the place of the leak, because you should not joke with gasoline. There can be several reasons for the smell. First you need to figure out exactly at what moment it appears, and even then start the search. It may start to smell when the engine is started, and then the smell disappears. We are trying to figure out what is causing the smell of gasoline in the car.
Due to the fact that once a law was passed on the permissible level of tinted car windows, drivers had such a problem as removing the tint. You can make it in several ways - on your own, or by contacting the workshop. Removing tint on your own is not so difficult, it is enough to know how to do it correctly.
Many people have heard the expression preheater engine. Its main function becomes clear from the name - facilitating the winter start of the car. There are many different heaters from different manufacturers. According to the type of implementation, they can be divided into two: autonomous and electric. You can learn about each of them from this article.
One of the necessary and important improvements in the car, without a doubt, is such a device as an autonomous interior heater. Thanks to this device, the required temperature can be maintained in the cabin, without the need to start the engine. Such a unit is in greatest demand among truckers, as it allows you to relax on the road under much more comfortable conditions.
Such a device as anti-sleep allows the driver to avoid an emergency if he is tired and starts to fall asleep at the wheel. The sharp, piercing signal that the device emits, as soon as the head leans forward, will wake anyone up. Although by and large, it is best not to tempt fate and not hope for a device, but simply stop and relax.
Tinting, whatever it may be, reduces visibility and increases the possibility of an emergency. Therefore, permissible light transmission standards have been introduced, and drivers who violate these requirements are fined. One option to avoid punishment is electro tinting. What it is and how it works, read in this publication.
One of additional options designed to increase the comfort of the driver and passengers is heated seats. The option is purely seasonal, but very popular. In luxury trim levels, heated seats are present by default, while others can install it on their own, with their own hands.
The rain sensor is optional and is designed to make life easier for the driver and increase the level of comfort. There is no need to turn the wipers on and off on your own, the sensor turns them on automatically as soon as water gets on the windshield.
The safety of the driver and passengers of the car is a very important issue, and when it comes to children, there can be no compromise at all. For the greatest safety of children, the driver must use special child seats, which are fastened using the existing belts, or the isofix system, if available. What is it and in what machines is available, read the article.
Many motorists, entering a turn at a decent speed, experienced the feeling that a little more and the car would roll over. This is due to the effect of centrifugal and other forces on the car. In the fight against the possibility of a car overturning, manufacturers complete them with various systems that prevent rollovers.
Transporting a bicycle by car is often difficult, especially when the car is no different. large sizes. What can we say about how to transport several bicycles at once. To do this, there are various mounts on the towbar of a car, both factory-made (flexfix from opel) and many other solutions.
This article will focus on a special type of glass tinting, which is provided by the manufacturer. skoda cars. It's called sunset and can be applied directly at the factory. Do we need such an option, is it worth overpaying our hard-earned money for it and what is the use of it - let's try to figure it out.
Heat-shielding glazing, its other name is athermal, protects the car interior from overheating. This is achieved with the help of various additives in the manufacture of glass. Athermal glasses are used by skoda car manufacturers and a number of others. Also recently, tinting with athermal films is gaining popularity.
Owners of Skoda brand cars are probably familiar with such a concept as the varioflex system. This is a very convenient implementation of the interior space of the cabin, thanks to which the rear row seats can be folded in various variations, and if necessary, completely removed. The varioflex system allows you to make passenger car almost complete truck.
It is already difficult to imagine a modern car without such an option as air conditioning. A great variety of them have been invented, and each is good in its own way. This article will focus on the principle of operation of all such systems, and on a semi-automatic air conditioner, which is called Climate (climatic).
For maximum comfort of the driver and passengers, there are a great many different systems. One of these is the seat ventilation system. On expensive cars maximum configuration this option is becoming more and more common. But this does not mean that a person with an average income cannot afford seat ventilation. It is possible to install it yourself.
Cars equipped with keyless access systems make life much easier for the driver. There is no need to arm or disarm the car - the smart key system does all this perfectly. It is enough that the electronic key is in the pocket, and then the driver will be identified as the rightful owner vehicle.
Power windows is the dream of any owner of a domestic vehicle. If now modern VAZ models are equipped with this option already from the factory, then on the classics, for example, the same 2107, you will have to install the window regulator yourself. The article contains information about all possible types window regulators and their device.
What on-board computer in a car, for what purposes it is installed and why it is so popular among car owners. The answer is simple - this device allows you to control many parameters of the car, notify the owner of malfunctions, and generally make life easier for the owner of the vehicle.
Why do we need a projection display (head up) and to what extent it is able to facilitate driving, as well as to protect all road users as much as possible. Modern electronic means, one of which is a display capable of projecting instrument readings onto the windshield, do an excellent job of increasing safety and comfort.
Surely many of us, at least once, had to fall under such heavy rain that even the windshield wipers could not cope with the streams of water pouring from the sky. And what could be worse than a fine drizzle that makes the wipers work continuously, and the view still leaves much to be desired. Modern technologies make it possible to treat car windows with an “anti-rain” agent, from the action of which water simply rolls off the glass.
System exchange rate stability, or dynamic stabilization of the car, is necessary in order to prevent uncontrolled skidding at the time of sudden braking, or loss of traction of one of the wheels. Based on the readings of multiple sensors, the system ensures that the driver does not get into an emergency due to road conditions or your inexperience.
Noise isolation excites the minds of many car owners, which is not surprising. After all, who doesn’t want to drive a car without hearing the noise of the wheels, enjoy the silence, or let’s say the music in the cabin, which is not drowned out by the rustle of gravel under the wheels and the roar of passing cars. Yesterday, the soundproofing procedure was long and expensive, but today, thanks to the advent of liquid rubber, it is available to everyone.
It is difficult to overestimate the importance of such a system as assistance during descent and ascent. It is especially needed, and even necessary, for novice drivers who experience problems just when they need to move uphill. Having many names, depending on the manufacturer, the principle of operation of this system remains unchanged.
In the struggle for road safety, humanity is increasingly improving the filling of the car in order to achieve comfort and safety. Long travel times invariably affect the driver's condition, and sometimes driver fatigue leads to fatal consequences.
What is voice control of a car is not difficult to guess from the name of this option. The article will tell you exactly how you can implement the work of such a system, it also contains information about how the voice control system has evolved over time, and how the very first differs from the latest developments in this area.
What kind of miracle is an active head restraint and is there any benefit from it for the driver. Let's try to figure this out. Numerous tests have proven that an active head restraint significantly reduces the risk of damage to the driver's cervical vertebrae in a rear impact. So far, this security system is not common at all, but we think over time everything will change, and equipping a car with active head restraints will become the norm.
The surround view system in the car is another step towards road safety. This system allows you to monitor the traffic situation around the car in real time. This is achieved through video cameras and proximity sensors installed in a circle. Each manufacturer names their systems differently, but they have the same basic principle of operation.
What forwarding trunk represent everyone, at least the majority of car owners. How important and necessary to have this type of trunk for those who travel by car is a moot point. The article describes its main advantages, and also contains information on how you can independently make a trunk from improvised means.
There are a lot of road signs, and the driver has only two eyes, so it can be difficult to keep track of everyone. To facilitate the control of the traffic situation, a device such as a traffic sign recognition system was invented. It will warn the driver that it is necessary to observe the speed limit on this section of the road, or that overtaking is prohibited here. The system is very useful, but as practice shows, it does not always work as it should.
Man has always sought to automate certain processes as much as possible, and driving is no exception. This article will focus on such a system as park assist. The automatic parking system is able to park the car on its own, without any human intervention. Whether there is a driver in the car or not, the vehicle will find a free space and park the car.
Many sooner or later face the problem when the heating completely stops working. rear window. This happens most often due to the breakage of the filaments, which provide this very heating. Let's take a look at the most simple ways restoration of glass heating, which is within the power of any motorist with straight arms.
We have already found out what an immobilizer is and for what purposes it is needed in a car. In this article, let's discuss when and how a device such as an immobilizer bypass is required. It is clear that this anti-theft protection system can turn against you in case of key loss, program failure or equipment breakdown. This is where the knowledge of how you can turn off the immobilizer comes in handy.
An immobilizer is an anti-theft tool for a car that works on the principle of blocking certain features of the car, individual components or assemblies, which in turn leads to the immobilization of the vehicle. And since hijackers rarely use tow trucks and other loading equipment when stealing, the chances that a car equipped with an immobilizer will remain with the owner are quite high.
What is a parking sensor and is it necessary to install it. Quite a lot of varieties of parking sensors have already been invented, with and without cameras, with monitors built into the rear-view mirrors and without them, but the essence of the device remains unchanged - it is designed to make life easier for the driver, especially for a beginner. It is a kind of third eye. How it works and how to install it, read in this article.
A central lock in a car is an indispensable thing, and it is found, in our time, on the vast majority of cars. What role does the central lock play, on what principle its work is organized can be found in this article.
Do you buckle up while driving? More and more people in our time, realizing that courage can go sideways, began to take care of themselves first of all and fasten their seat belts. And this is very correct. How the procession of seat belts began, what were the first of them, and what the evolution of safety has led to today - about this and more in this article.
If the car is not comfortable, then after traveling especially for a long distance or in case of standing idle in traffic jams, it will cause you fatigue and irritation. Russian roads, unfortunately, leave much to be desired and not all brands of cars can boast of comfort and convenience.
But it must be admitted that most modern cars have become better in terms of reliability, quality and comfort. However, there are models that have a huge advantage over other brands in terms of comfort. We offer you our rating of the most comfortable cars. selected for comfort while driving, sound insulation, the convenience of the driver's seat and front passenger seat. We intentionally excluded compact small cars from our list, sports cars and convertibles, which, by definition, cannot be perfectly comfortable due to their size or design features.
Also, having familiarized yourself with the best cars for comfort, you can also find out if these models are, as well as what kind they have by clicking on the photo or model name.
A6 is very convenient and comfortable. A trip in this car will appeal to even the most experienced driver.
This year's new Impala model has become modern big sedan. Spacious interior, comfortable, quiet and pleasant to drive. Draw attention to the large and spacious front seats. They are pleasant to the touch and perfectly support the lower back and unload the back, which allows you to comfortably cover long distances.
One of best sedans on the market. Space and comfortthe main merit of computer engineersChrysler. The top trim is the best. Management of all functions of the car is very convenient. Various amenities, luxury items and silence during the trip will not let you get tired behind the wheel. The car is especially ideal on the highway, where you will not hear the loud work of the engine and the sound of tires.See also:
The highest comfort is available in the car of the maximum complete set. The cabin is quiet. Noise comes from
climate control ventilation. Also, some noise will bother you for several minutes after starting the engine in cold weather. After warming up, you will not hear the sound of the motor. front seats correct form and very comfortable, thanks to the support of the lower back. It is worth noting that it leather seats hold your back better than fabric chairs. Plus, cloth-trimmed seats are somewhat stiffer than leather, which can lead to fatigue during long traffic jams.See also:
Complete silence in the cabin. Even at high speed, no wind noise is heard. The interior of the Lexus ES is thought out to the smallest detail.
Comfort is maximum. Expensive interior trim pleasantly surprises with its textures. The ES models have very quiet engines and expensive noise insulation. The seats are distinguished by their comfort thanks to their width and balanced softness.Reliability Rating
Lexus LS The flagship sedan provides both driver and passengers with comfort and a relaxing ride over any distance. The LS on the road won't be a problem on any road. Noise isolation is top notch. Absorption of extraneous noise is perfect. The smooth running of the car and excellent handling are the main advantage of this model. All seats are very comfortable and luxurious.