3.9. MINI TRACTOR STARTING SYSTEM
Schematic diagram of the electrical equipment of the microtractor TZ-4K-14
As an example of the electrical equipment of a mini-tractor equipped with a diesel engine with electric start and having lighting and switching devices, consider the electrical circuit of the TZ-4K-14 microtractor, which is much more complicated than all those discussed above. As a source of electric current (see Fig. 3.35), a battery 17 and a DC generator 18 are used. The battery is located under the instrument panel of the microtractor and feeds the starter 19 when the engine is started. The 150 W generator is located on the left side of the engine front cover. The system has a voltage of 12 V and is used to power various devices and systems, as well as charge the battery. The generator rotor is driven by a V-belt from camshaft engine. The same belt is also used to drive the cooling fan. Belt tension is adjusted by turning the alternator, which has
the ability to change its position relative to the front crankcase cover.
The DC Regulator Relay 15 consists of three separate relays: a reverse current relay, a voltage regulator and a current limiter. The reverse current relay is used to automatically connect the battery to the generator if the voltage at the generator terminals reaches 12 V. In this case, the battery is being charged. At a lower voltage, this circuit breaks, protecting the battery from discharging to the generator. The voltage regulator is used to stabilize the voltage at the terminals of the generator when changing its speed or load in the circuit of consumers of electric current. The current limiter protects the generator from overloads that occur when a large number of consumers or a discharged battery are connected to it. When overloaded, the current in the generator armature windings increases significantly, which leads to their overheating and failure.
The electrical equipment of the microtractor has a mass switch 16 and an electric start button 20. Battery charging is controlled by a signal lamp 21. The inclusion of the electrical system of the microtractor into operation is carried out by a special lock-switch 22, which has three key positions, which ensures the operation of the devices from the generator or from the battery. Fuses 6 protect the devices of the electrical system from high voltage. For ease of maintenance, a portable lamp can be connected to the electrical system through socket 5. Electric horn
4 is connected to the current source through the signal on button 3. Headlights 1 and 24, direction indicators 2 and 23 are connected to the electrical system through three-and. four-terminal blocks 25 and 26. The direction indicator switch 8 is connected to the electrical system through a switch 7 and a terminal box 9, to which a lamp 14 is connected, signaling the operation of the direction indicators. Direction indicators 10, 13 and parking lights are connected to the system through a five-terminal block 11. A seven-pin socket 12 is used to connect the trailer's electrical equipment.
When checking and adjusting the central gear, the following is done:
1. Preparatory work
Clean the transmission of dust and dirt. Drain transmission oil. Flush the inside of the housing with diesel fuel.
2. Checking and adjusting the clearance in the bearing 7205 of the drive bevel gear shaft.
Move the drive bevel gear with a crowbar, and at the same time, the normal axial movement should not exceed 0.1 mm (measured with an indicator) and, if necessary, adjust. Disconnect the main and additional gearboxes. Unscrew the lock nut on the front end of the drive bevel gear shaft (Fig.4-5). While tightening the adjusting nut, turn the drive bevel gear by hand until noticeable resistance is felt. Lock the nut.
3. Checking and adjusting the clearance in the bearings 7306 of the central gear shaft.
Rest the indicator leg against the end face of the crown of the driven bevel gear. Moving the driven bevel gear with a crowbar to the left and right, the redistribution of the arrow span is observed. Normal axial movement should not exceed 0.15mm and be adjusted if necessary. By turning the driven bevel gear, add or decrease the bearing shims 7306 installed on the two ends of the central gear shaft until noticeable resistance is felt (Fig. 4-6).
4. Checking the imprint of gear engagement.
When checking, pay special attention to
Table 4-1
4.3. Brake adjustment
4.3.1. Pedal free play adjustment.
Normal gap between brake shoe and the drum is 0.5-0.7mm, which corresponds to a pedal free play of 30-40mm (Fig.4-8).
When adjusting the free play of the pedal, lower the locknuts 2 (Fig.4-8,4-9) of the brake rod, screwing (if the pedal travel needs to be reduced) or unscrewing (if the pedal travel needs to be increased) the rod into the adjusting fork, sets the required pedal travel ( Fig.4-10). And tighten the lock nuts.
Fig.4-8 Brake pedal free travel adjustment:
1,4-levers; 2- locknuts; 3-sleeve.
4.3.2. Checking and adjusting the left and right brakes. The braking performance of both brakes must be the same. Otherwise, emergency braking during high-speed traffic may cause an accident due to uneven braking.
Slip track difference rear wheels should not exceed 400 mm during emergency braking of the tractor at high speed on a horizontal section of the road. Adjust if necessary.
When adjusting, it is expedient to achieve simultaneous braking by increasing the gap of the brake having better braking efficiency, rather than reducing the gap of the brake with poorer efficiency.
4.4 Adjusting the front axle and steering
4.4.1. Front axle adjustment
The most characteristic deviations from normal operation running system- wobbling and vibrations of the wheels. Possible reasons: Bearing misalignment due to worn tapered roller bearings. Therefore, it is necessary to periodically check and adjust the clearance in the bearings.
When adjusting from the raised front wheels, unscrew three bolts, remove the wheel hub cap, tighten the bearings, and then loosen the castellated nut by 1/16 - 1/8 of a turn so that the axial clearance of the bearings is within 0.1-0.2 mm. When the wheel is turned by hand, it turns easily and without noticeable wobbling. Fasten the slotted nut and replace the cap.
4.4.2. Adjustment of a convergence of forward wheels.
Toe-in is defined as a kind of distance between the wheels in front and behind at the level of their centers. The normal value of tractor convergence is 4~12mm.
During operation of the tractor, the amount of convergence of the front wheels changes. Failure to check and adjust toe-in in time can lead to wheel impact and oscillation, and consequently, difficulty in steering control and increased wear on tire treads.
Fig.4-11 Adjusting convergencea.
Rear wheel spacing b. Distance between wheels in front
Toe-in is adjusted by changing the length of the tie rod.
4.3. steering wheel free play adjustment.
Tractor free wheeling 15? -20? and should not exceed 30?.
If the free play of the relay wheel exceeds the allowable one, it is necessary to determine the malfunction of the mechanisms included in steering and adjust them.
4.4.3.1. Ball joint adjustment.
Replace the trunnion, or socket and cap, when the gap formed due to heavy wear is too large and cannot be compensated by the action of the springs.
4.4.3.2. Adjusting the axial clearance of the rotary shaft (Fig.4-12)
Fig.4-12 Steering:
1- steering wheel; 2- steering shaft; 3- top cover; 4- gasket; 5- steering housing; 6- worm rotary; 7- bottom cover; 8- bipod steering; 9- worm sector; 10- fastening bolt; 11- side cover; 12- lock gasket; 13 adjusting gaskets; 14-sleeve of the regulating core; 15 - dust cover.
5.1. The electrical equipment of the Xingtai-200/220 tractor consists of a battery, a generator, a starting motor, a relay-regulator, etc. The tractor has two headlights, one rear headlight, front pointer turn signal, two rear brake lights and a turn signal (Figure 5-1).
5.2. The electrical equipment of the Xingtai-120 tractor consists of a generator, two front and one rear lights (Fig. 5-2).
Fig.5-1 Electrical equipment diagram:
1- accumulator battery; 2- front headlight; 3- direction indicator; 4-generator; 5- starter; 6- fuse; 7- current indicator; 8- sound signal switch; 9 - switch; 10- relay-regulator; 11- rear headlight; 12- socket; 13- brake light rear; 14 - brake light switch; 15- sound signal switch; 16 - turn indicator switch; 17-switch; 18 flasher.
1-headlight rear; 2- switch; 3- generator; 4- headlight front right; 5- headlight front and left.
Applications
ATTACHMENT 1
Attachment diagram
The dimensions of the plunger lifting mechanism are given.
APPENDIX 2
Tightening torque of the main threaded connections.
Detailed technical descriptionFig.1 MOTOR CONTROL MECHANISM
1 ENGINE CONTROL MECHANISM
Name | Designation | Quantity |
|
Ball head assembly | |||
Welded handle assembly | |||
Bolt М8х16 | |||
Bolt М8х30 | |||
Clamp clamp | |||
Bracket welded assy | |||
clamping lever | |||
Cotter pin 2x10 | |||
Connecting plug | |||
Finger B5x25 | |||
NutM12x1.25 | |||
Spring bush guide | |||
Excelerator spring pressure | |||
Disk leading | |||
It is hard to imagine agriculture without the use of special equipment. But most private farmers cannot afford to buy a mini tractor. On small land plots, you can get by with hand tools, but on an area of \u200b\u200bmore than 1 hectare this will not be enough. homemade tractor not inferior in efficiency to most factory models.
The main types of homemade tractors
Due to the high fuel consumption, weight and dimensions, the use of large and powerful tractors in a small area is inconvenient and irrational. Their manufacture requires accurate calculations, which, without engineering skills, are difficult to perform at home.
A mini-tractor is considered a multifunctional technique and is capable of processing up to 10 hectares of area. This is enough for private farming. It should be suitable not only for gardening, but also for cleaning snow, transporting goods and removing garbage. When designing your design, you should take these features into account.
There are 2 approaches to building your own tractor:
- Re-equipment of finished agricultural machinery. In the vast majority, a walk-behind tractor is used as the basis, to which a frame with an additional pair of wheels and a driver's seat is attached. This method allows you to quickly and with minimal effort to build a simple and functional tractor.
- Complete production. It is used in the absence of a base or with specific requirements for technology. In this case, the chassis is designed and manufactured independently, and components are selected based on financial capabilities and design features.
Some enthusiasts build steam tractors. A separate boiler allows the use of almost any type of combustible fuel. This type of energy conversion was common in the 1900s. Due to low efficiency, bulky design and short power reserve steam engines cannot compete with ICE. The use of outdated technologies in agriculture is costly and used for entertainment.
Tractor manufacturing features
Home-made equipment has the most simplified scheme, and in its manufacture, components and assemblies from other equipment are used. The goal is to obtain a cheap and reliable design. Assembly requires basic tool handling skills and minimal technical knowledge.
When designing your own structure, you should use parts with minimal modifications. Spare parts should be readily available and inexpensive. A large number of homemade elements in the design will increase the cost and duration of the repair.
Performing accurate calculations of strength and loads is almost impossible at home, so the frame and other load-bearing components of the structure are made with a large margin of safety.
If you have drawings and the necessary equipment, you can make a tractor yourself in 3 months.
Preparation of drawings
Before purchasing and preparing units, it is necessary to draw up a draft of the future tractor. As a basis, you can take drawings of finished models. The parts that you have may differ from those declared, and it will not be difficult to change the finished design scheme. There are ready-made solutions for any modifications.
If it is not possible to use the finished project, then you need to prepare rough sketches yourself. During the assembly process, the layout of the elements may change, but you must understand how the individual nodes will be located.
A mini tractor is exactly the same agricultural equipment as a tractor, but with a slightly lower performance, which is sacrificed for the sake of maneuverability and economy. In addition, some specimens are so light that they are transported in a trailer. Small tractors perform all the same tasks as higher class counterparts. They can also be attached attachments for processing and fertilizing the soil, cleaning the territory and transporting various goods. In addition, in many tractors, even those made independently, there is a rotation drive auxiliary units and hydraulics.
It differs from a walk-behind tractor, first of all, in that it is a full-fledged agricultural machinery. Of course, a powerful walk-behind tractor also has considerable functionality, but when managing it, you have to walk all the time. This is very tiring, especially when processing a large area of arable land. And by making it a self-propelled machine, even the smallest, the operator gets tired much less.
Understanding all the advantages of minitractors, domestic inventors create with their skillful hands, sometimes first-class specimens, and on the Internet you can now find many descriptions, diagrams and even ready-made drawings of such homemade products.
Designs of mini tractors
For the most part, amateur designers in the manufacture of a tractor simply remake some serial product, adding some components and eliminating others. This is an easy way, but it is not always feasible, because. a complete machine must be available.
And the design of homemade tractors created from scratch is individual in each case, so today the variety of solutions just rolls over.
For example, the frame for a minitractor is made integral and breaking (called a “break”), the turn is made with steerable wheels and onboard, the layout is classic or in the form of separate modules that allow you to change the purpose of the device. Install hydraulic system and power take-off shaft.
Tractor from the manufacturer at the price of a homemade product - the whole the lineup. We buy good attachments for a home-made agricultural machine at the link. We read in this article - the easiest way to assemble a mini tractor from a walk-behind tractor.
The homemade mini tractor offered below is one of the easiest to manufacture and allows you to get by with the available materials and parts.
But, of course, for those who are going to do something themselves, with their own hands, it is recommended to have technical skills, the ability to work with a tool and read drawings. And, most importantly, to have a lot of time and a great desire to do it.
Frame
It is made from rolled metal. Calculations for strength are a thankless task (and in this case, not necessary), so you just need to lay in advance a multiple stock. Based on this, apply a channel from No. 6 to 12 - best solution for homemade mini tractor. It is not worth doing any “recesses” and “roundings” of the units, because. this will greatly complicate and increase the cost of the project. The usual flat "ladder" is simple and accessible to many.
As practice shows for a homemade tractor, it is more useful to use a larger rolled channel (up to 20) as the front and rear traverses (crossbars), because. subsequently, it is to these traverses that various working bodies and auxiliary equipment are attached. And it is better to have it shelves inside. Channel spars (longitudinal beams) can be positioned both inside and outside. Fuel lines and lines are laid inside the spars, which are naturally protected.
In shape, the simplest frame design for homemade is a rectangle with two or more traverses, but a frame in the form of a trapezoid will have much greater rigidity. The width in the front part should be smaller to accommodate the minimum dimensions of the steered wheels, as well as to be able to observe the movement strictly along the arable row. The joints of the spars and traverses must be strengthened by welding scarves.
Layout
The relative arrangement of the units of any tractor has historically developed a long time ago.
Classic layout self-propelled machine next: the engine is located in front, longitudinally, above the front axle. A gearbox is connected to it through a clutch, followed by a transfer case and a drive axle behind it. Between themselves, the shafts of the units are connected using cardans and (or) couplings.
Following this scheme will the best option when creating a mini tractor, because allows you to apply existing aggregates without changing them.
According to the experience of many creators of homemade tractors, it is better to assemble the units “in place”, without doing unnecessary drawing and calculations. The best option is to place all the main components and homemade mechanisms on the finished frame by installing them on temporary supports (conveniently - on wooden blocks), and, having found the best mutual position, make mounting brackets. But we must not forget that all components on a homemade tractor must be mounted through supports that dampen vibrations (rubber cushions). It is best to borrow them from the same equipment from which the unit was taken. Another important factor must be taken into account. This is weight distribution, i.e. distribution full weight minitractor on the front and rear axles. The most acceptable option - 60% of the weight falls on the drive wheels, 40% - on the driven ones.
Homemade engine
From the point of view of thrust-to-weight ratio, weight, accessibility and low cost of repair, it is most logical to use an engine from VAZ cars of classic models - from 2101 to 2107 when manufacturing a tractor in "home" conditions. They can be found in good condition at the price of scrap metal. With luck, one machine can become a donor of most parts for a mini tractor.
The motor with clutch and gearbox is fixed as a single unit, which simplifies the work on a homemade tractor and saves the creator from many difficulties. Be sure to install a fan impeller on the shaft of the water pump ("pump"), even if it was not there. After all, the speeds of agricultural machinery are much lower than those of automobiles, so the operating mode of the minitractor motor is the same as when standing in a traffic jam, which is considered difficult for any engine. Therefore, the radiator of the cooling system of a homemade tractor needs forced airflow.
Transmission
As mentioned above, it is desirable to install power plant for a complete do-it-yourself. In this case, what will later become a mini tractor will already have at least four gears forward and one reverse. It remains only to agree on the optimal tractor engine speed and the desired speed. For this, a transfer case from any all-wheel drive car will be quite enough. The most suitable option is UAZ. By the way, the previously considered components can also be used from UAZ, but they are heavier, the consumption of the resulting tractor will be higher, and all its power will rarely be used.
A good element for connecting the shafts is an elastic coupling, which is installed on the output shaft of the VAZ gearbox. Having made a flange to transfer case, you can do without an intermediate cardan. But from the "razdatka" to the drive axle, the cardan is required, because. the loads there are significantly higher, and the clutch will not withstand them.
When building a tractor on your own, it is best to use the drive axle also from a UAZ car that has final drives. This will increase, firstly, traction, and secondly, ground clearance (which is desirable to bring up to 450 mm). The required track size of a home-made mini tractor is obtained by cutting the stockings of the bridge (narrowing it) or by making spacers for attaching the wheels (expanding it), because. the nominal gauge of the UAZ is 1445mm, which does not coincide with the accepted ranges for agricultural vehicles (1260-1285, 1350-1370, 1490-1515, 1790-1815).
Chassis and propulsion
This system for the considered home-made mini tractor almost completely repeats the similar one for tractors manufactured by the industry and differs from the automobile one in some ways. important points. The main difference is the absence rear suspension, i.e., the drive axle is not attached to the frame on the springs, but is rigidly fixed to it. This must be done if it is planned to make not only the tractor itself, but also all the agricultural implements for it with which it is supposed to be used. Since attachments such as plows, harrows, mowers and others, attached to the back of a homemade mini tractor, are very heavily loaded rear axle and, if present on the last rear suspension, will quickly render it unusable. Front axle on a homemade tractor, it can also be installed without suspension, comfort will not decrease significantly. It is convenient to use forks as pivot pins cardan joints trucks (ZIL, KAMAZ, KrAZ), spare parts for which can be found in car fleets and metal receiving stations. Two forks are welded to the beam, or directly to the frame, observing alignment, and two reciprocal - to knuckles donor vehicle. The steering trapezoid, together with the steering mechanism, is also entirely borrowed.
The braking system in her automotive form"It makes no sense to use it on a tractor made by oneself, because not those speeds. Just the parking brake is enough. However, the mechanism is driven not from a lever, but from a pedal with a fixed pressed position. Then the homemade product can be slowed down in motion, and fixed in the parking lot. Wheels are best used from agricultural machines, because. they have the desired tread, but it is quite possible to adapt tires from SUVs or light trucks by cutting the desired tread pattern onto them (preferably a herringbone, for self-cleaning). Tire pressures are selected empirically to find the optimal combination of comfort and performance.
Electrician on a homemade tractor
You can use any parts from anything, the main thing is that the voltage of the generator and consumers match. We must not forget that the battery is a container with acid, so it must be very firmly fixed. The recommended solution is to place it under the seat of the minitractor in a special box, or simply in a fence.
Headlights and marker lights, as well as brake lights are desirable elements, but not mandatory, because. You can only exploit the result of your labors away from other transport.
Road traffic
Not all homemade mini tractor designers go to public roads. And rightly so, because in our country, a number of stringent requirements are listed that must be met by vehicles moving along them. Even if everything turned out well, and the product meets all the requirements, certification will be necessary to confirm this, which is very expensive.
Therefore, it is forbidden to drive on the roads on a homemade tractor. If you have to deliver it to the place of work, then it is better to do it on a trailer. This is one of the reasons why they are trying to make homemade products easier.
Electrical equipment of the tractor T-40 designed to start the engine and work safely at night when performing transport or agricultural work. The electrical equipment is implemented on a single-wire system, in which the metal parts of the tractor (“mass”) serve as a negative wire.
The rated voltage in the tractor electrical system is 12 V. The sources of electric current are connected by negative terminals to the ground.
Electrical equipment T-40 consists of the following units and devices:
1. DC generator equipped with a relay-regulator and batteries, which are a source of electric current.
2. Starter with relay and starter switch that performs the function starting device engine.
3. Direction indicators, dimensions, rear and front lights, ceiling light, brake light, license plate light, fan belt break warning light, as well as a portable lamp are used for light signaling and lighting.
4. An ammeter that displays the strength of the discharge or charging current.
5. Sound signal equipped with a switch.
6. Connection panels and wires, ground switch and fuse.
Scheme of electrical equipment of the tractor T-40 with a starter:1 - lamp-indicator of turns and dimensions; 2 - headlight; 3 - connecting panel; 4 - sound signal; 5 — cockpit cover; 6 - switch for ceiling and fan; 7 - fan; 8 - wiper; 9 - oil temperature indicator sensor; 10 - generator; 11 - glow plug; 12 - switch "mass"; 13 - battery; 14 - starter; 15 - starter relay; 16 - control lamp direction indicators; 17 - switch direction indicators; 18 - central light switch; 19 - headlight switch; 20 - high beam control lamp; 21 - signal switch; 22 — a control lamp of the switch of "weight"; 23 - oil temperature gauge; 24 - diesel start blocking switch with the gear engaged; 25 - control element; 26 - portable lamp; 27 - portable lamp socket; 28 - additional resistance; 29 - glow plug and starter switch; 30 - current indicator; 31 - switch "stop"; 32 - taillight switch; 33 - instrument panel lighting lamps; 34 - breaker direction indicators; 35 - fuse; 36 — lamp-indicator of turns, dimensions and brake signal; 37 - taillight; 38 - socket; 39 - license plate light. Designation of wire colors on the diagram: B - white; G - blue (blue); W - yellow; Z - green; K - red; Kch - brown; F - purple; H - black. Next to the designation of the coloring, the cross section of the wires is indicated by numbers. Wire sections not indicated in the diagram 0.75 mm².
Scheme of electrical equipment of the T-40 tractor with a starting unit: 1 - lamp-indicator of turns and dimensions; 2 - headlight; 3 - connecting panel; 4 - sound signal; 5 — cockpit cover; 6 - switch for ceiling and fan; 7 - fan; 8 - wiper; 9 - oil temperature indicator sensor; 10 - generator; 11 - spark plug; 12 - glow plug; 13 - switch "mass"; 14 - battery; 15 - starter starting unit; 16 - magneto; 17— control lamp of direction indicators; 18 - switch direction indicators; 19 - central light switch; 20 - headlight switch; 21 - high beam control lamp; 22 - signal switch; 23 — a control lamp of the switch of "weight"; 24 - oil temperature gauge; 25 - switch to stop the starting unit; 26 - diesel start blocking switch with the gear engaged; 27 - control element; 28 - portable lamp; 29 - portable lamp socket; 30 - glow plug switch; 31 - additional resistance; 32 - starter switch of the starting unit; 33 - current indicator; 34 - taillight switch; 35 — a lamp of illumination of a panel of devices; 36 - breaker direction indicators; 37 - fuse; 38 - switch "stop"; 39 — lamp-indicator of turns, dimensions and brake signal; 40 - taillight; 41 - socket; 42 - license plate light. The designation of the colors of the wires in the diagram above.
The central switch is required to turn on parking lights and tractor lighting. The front lights are used to indicate the dimensions of the tractor and give turn signals, the rear lights serve as indicators of dimensions, as well as turns and a brake signal.
The headlights, together with the lamps, are mounted on a single bracket, fixed on the front beam of the tractor. The wings of the rear wheels are equipped with rear lights and reflectors that reflect light from the headlights of the vehicle behind.
To start the engine, the T-40 tractor can be equipped with a starting unit, a starter switch and a button to turn it off. There is a switch in the gearbox housing that prevents the engine from starting when the gear is engaged.