What are the faults of crawler bulldozer that can’t walk normally?

During routine work, the crawler bulldozer failed.For example, walking errant, not walking, fast block walking errant and other problems, among which walking errant is one of the common fault phenomena of crawler bulldozer, such faults are usually related to the walking motor, crawler and hydraulic pump and other components.

First, the caterpillar bulldozer running deviation fault

1. The bulldozer runs off track

2. The bulldozer quickly blocks the running deviation

Second, crawler bulldozer inspection sequence

bulldozer

1. Walking and running sideways

(1) Check the track, measure the tension of the left and right sides of the track the same, eliminate the track fault.

(2) When the crawler bulldozer is operated in a straight line, the result is also off-track, thus the fault of the main hydraulic pump can be eliminated.

(3) Forward and backward are running in the same direction, so the oil seal fault of the central rotary joint can be eliminated.

(4) Measure the pressure of the walking motor on both sides. The pressure on one side is 28Mpa, and the pressure on the other side is 34Mpa.

(5) The main safety valve is suspected to fail because of the different pressure of the two sides of the walking motor.After further inspection and analysis, it is found that the spring in the main safety valve absorbs the temperature of hydraulic oil in the operation process, which leads to the temperature rise and the elastic force decrease, resulting in the decrease of the original set pressure of the side walking motor, and finally leads to the deviation of the crawler bulldozer.After replacing the spring of the main safety valve to make the pressure of both sides of the walking motor equal, the equipment operation will return to normal.

2. Fast block walking deviation

Check the hydraulic main pump.

The fault of the main hydraulic pump can be ruled out because the working device of the crawler bulldozer (arm, bucket rod and bucket) and the rotary device are all working

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Prevention of cavitation failure of hydraulic cylinder in construction machinery

When we repair the hydraulic cylinder of construction machinery, we can see the inner wall of the hydraulic cylinder, the piston or the piston rod surface has some honeycombed holes, which are caused by cavitation.The harm of hydraulic cylinder cavitation is quite large, it will lead to the black surface, and even the phenomenon of supporting ring and sealing ring burning, resulting in the internal leakage of the hydraulic cylinder.When cavitation and other types of corrosion work together, it will accelerate the corrosion speed of the main parts of the hydraulic cylinder several times or even dozens of times, so as to seriously affect the normal use of construction machinery.Therefore, it is very necessary to prevent the cavitation of hydraulic cylinder.


(1) strictly close the selection of hydraulic oil
(2) prevent the oil temperature from being too high and reduce the hydraulic impact
(3) keep the normal clearance of the joint surface of the hydraulic components
(4) pay attention to the exhaust during maintenance

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Luoyang Roader Machinery Equipment : independent market development

The ROADER company is a professional production of construction machinery, agricultural machinery enterprises. The ROADER machinery in addition to providing independent development with independent intellectual property rights of engineering machinery can also provide the machines designed by ROADER and manufactured by SINOMARCH (OEM) such as: YTO bulldozers, forklifts, wheel loaders, excavators,  diesel engines, YTO tractors and road rollers, motor graders, drag the concrete pump, pump truck, asphalt mixing station, mining equipment, hydraulic baler and other mechanical products.

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ROADER has a strategic cooperation with Hyundai Robotics

ROADER and Hyundai Robotics, adheres to the creative wisdom, positive will, strong driving force of the modern spirit, comprehensive development in the Chinese market.

ROADER has a strategic cooperation with Hyundai Robotics

 

Modern robot

ROADER has a strategic cooperation
Both teams will give full play to the modern in spot welding, arc welding robot and up-down material, coating and other mature application scenarios, to provide intelligent solutions for automation for cars and car parts, electronic appliances, rail transportation, household appliances, elevators, mechanical processing and other industries.

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ROADER road roller is trusted by users

ROADER road roller

Recently, 4.5 tons of single steel wheel vibratory roller is produced and manufactured by Luoyang ROADER Company, which has been sent to all over the country.

Luoyang ROADER 4.5ton single steel wheel vibratory roller is one of the leading export-oriented products of small tonnage high-end roller, which is especially favored by users in countries and regions along the “One Belt And One Road” and has been exported to more than 70 countries and regions overseas. This machine is mainly suitable for the compaction of non-cohesive materials of base layer and sub-base layer, such as gravel, gravel, sand mixture, sandy soil and rock, etc. It is the ideal compacting equipment for the construction of high-grade highways, railways, airports, ports, DAMS and large industrial sites. In recent years, it has been gradually trusted by more and more high-end users in China.

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How to maintain the loader

Loaders are used for filling and digging of roadbed engineering, aggregate and loading of asphalt mixture and cement concrete yard. In order to maintain the normal operation of the loader and prolong its service life, the various components of the loader must be systematically and carefully inspected, adjusted and cleaned to create good working conditions for the normal operation of the loader and prevent early wear and tear of the loader. All kinds of failures, give full play to the performance of the loader. Therefore, various maintenance work must be done carefully before and during the use of the loader.

First of all, the vehicle must be maintained in accordance with the requirements in the loader manual. It takes about 60 hours for the new car to travel in. During the travel in period, the following must be done:

ZL50D-Ⅱ-wheel-loader

1. Read the manual of the loader carefully and pay attention to every precaution in the manual.

2. During the running-in period, forward gears and backward gears, each gear should be evenly arranged for running-in. The load weight during the running-in period shall not exceed 70% of the rated load.

3. Pay attention to the lubrication of the machine and replace or add lubricating oil at the specified time.

4. You must always pay attention to the temperature of the gearbox, torque converter, front and rear axles, wheels and brake drums. If there is overheating, find out the reason and eliminate it.

5. During the walk-in period, it is advisable to load loose materials, and do not proceed too violently or hastily.

6. Check the temperature and connection of each component of the electrical system, power supply status of the generator, lighting and other working conditions.

7. Comprehensively check the tightening of bolts and nuts of each key component of the loader (engine, axle box, rim, drive shaft, etc.).

8. After the running-in period expires, clean the transmission oil pan filter, replace with new oil; and change the engine oil and transaxle oil.

Secondly, the loader should be regularly maintained according to the following stages:

ZL20 wheel loader

Check the engine oil level, fuel tank oil level, water tank water level, brake fluid every day (every 10 hours) around the machine visually for any abnormalities and three leaks; check lights and gauges; check tire pressure and lubrication of each hinge Condition: Check the tightening condition of the bolts in key parts.

Every half month (every 100 hours), in addition to repeating the above daily inspection items, it is also necessary to clean the diesel tank fuel filter, engine cylinder head and torque converter oil cooler; check the battery liquid level and apply a thin layer of windshield on the joints ; Be sure to replace the front and rear drive axle gear oil.

Every month (every 250 hours), in addition to repeating the above half-month inspection items, check the tightening torque of the rim fixing bolts; check the front and rear axle oil levels; check the working device and the front and rear frame for cracks in the stressed welds; check Adjust the foot brake and emergency parking brake. It is important to check the engine: check the engine fan belt, compressor and generator belts for tightness and damage; check the engine intake system air filter service indicator, if the indicator yellow piston rises to the red area, it should be cleaned or replaced Air cleaner element.

In addition to repeating the above monthly inspection items every three months (every 500 hours), the connecting bolts of the front and rear axles and the frame must be checked and tightened; the engine oil must be replaced, and the oil filter element must be replaced: check the engine valve clearance and clean the diesel tank to refuel and Suction filter; check the steering system, the empty stroke of the steering wheel.

Every six months (every 1000 hours), in addition to repeating the above inspection items every three months, it is also necessary to check and replace the transmission oil, clean the oil filter and oil pan; check the operation of the engine, and replace the diesel filter of the engine; Check various temperature gauges and pressure gauges; replace the drive axle gear oil and the oil return filter element of the hydraulic oil tank; check the brake booster and replace the brake oil.

Every year (every 2000 hours), in addition to repeating the above semi-annual inspection items, the engine must be overhauled according to the diesel engine manual; the transmission and the oil and hydraulic oil for the front and rear axles; check the working conditions of the foot brake and parking brake, If necessary, disassemble and check the friction lining wear. Clean and check the seals and springs of the brake booster, replace the brake fluid, and check the sensitivity of the brake; check the flexibility of the steering system by measuring the natural settlement of the cylinder, checking the sealing of the distribution valve and the working cylinder; checking the working device , Frame, and rim welds.

Finally, pay attention to the following points in the use of the loader:

X200PWZ-606-small-loader

1. When replacing hydraulic oil, brake fluid, gear oil and lubricating oil, you must use the model specified by the loader manufacturer. Pay special attention to the different types of brake fluids that cannot be mixed.

2. In winter (generally the temperature is below -5°C), the engine should be warmed up before starting, and the engine should be warmed up to above 30-40°C before starting. The water tank should be filled with antifreeze (for vehicles that do not use antifreeze in winter, all the cooling water in the water tank, engine block, and heater must be drained when the machine is not working).

3. It is strictly forbidden for the user to modify the loader without authorization, and the manufacturer is not responsible for the quality problems caused by the modified bow.

4. The diesel used by the loader must be pure and precipitated for at least 72 hours. The diesel grade should meet the specified requirements.

5. The hydraulic transmission oil used in the gearbox and torque converter, and the hydraulic oil used in the hydraulic system must be clean.

6. Diesel engine outlet water temperature is higher than 60°C and engine oil temperature is higher than 50°C before full load operation is allowed. Engine water temperature and engine oil temperature during operation should not exceed 95°C. The oil temperature of the torque converter does not exceed 120°C. It should be stopped for cooling when the oil temperature exceeds the allowable value for heavy-duty operation.

7. The power of the diesel engine used by the loader decreases with the increase in altitude, ambient temperature and relative temperature. For this reason, when using the loader, you must pay attention to the local environmental conditions. According to the “Diesel Engine Operation and Maintenance Manual” The requirements in the power correction table give the actual power of the diesel engine under local conditions.

The above is all the introduction about the maintenance of the loader. We hope that through our sharing, the majority of users will have a new understanding of the maintenance of the loader, and regular and reasonable maintenance of the loader will extend its service cycle.

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What are the differences between bulldozers and loaders?

Although loaders and bulldozers belong to the same industry, the two are different. Loaders are used for earth-moving construction machinery, while bulldozers are used for earth-moving construction machinery. In addition, it can also be seen literally that the main role of the loader is loading and unloading, and the bulldozer is clearing land, roads and other buildings. There are many differences between the two. Today, bulldozer manufacturers will share with you what are the differences between loaders and bulldozers.

The definition of loaders and bulldozers

Bulldozer is a kind of construction vehicle. Composed of torque converter, transmission and other components, it is divided into crawler bulldozer, tire bulldozer, etc. In addition, the bulldozer is capable of independently completing the work of digging, transporting and unloading soil, and is characterized by flexible operation, convenient rotation, small working surface required, and fast driving speed. It is used for site cleaning or leveling, excavation of small deep foundation pits and backfilling, pushing and building subgrades of small height, etc.

Loader is a kind of earthwork construction machinery widely used in construction projects such as highways, railways, construction, hydropower, ports, mines, etc. It is mainly used for shoveling bulk materials such as soil, sand, lime, and coal, and can also be used for ore , Hard soil, etc. for light shoveling operations. Different auxiliary working devices can also be used for bulldozing, lifting and other materials such as wood loading and unloading operations. Moreover, loaders are often used for filling and excavating roadbed engineering, aggregate and loading of asphalt mixtures and cement concrete yards. In addition, it can also carry out operations such as pushing the soil, leveling the ground, and pulling other machinery.

The difference between loader and bulldozer

SINOMACH-T80-3-bulldozer,80hp-crawler-bulldozer

1. Different classification methods

The classification of bulldozers is based on the walking mode. Bulldozers can be divided into crawler type and tire type. Crawler-type bulldozers have high adhesion traction, low ground contact pressure (0.04 to 0.13MPa), strong climbing ability, but low driving speed. Wheeled bulldozers have high traveling speed, flexible maneuverability, short operating cycle time, convenient transportation and transfer, but low traction, which is suitable for situations that require frequent change of construction sites and field work. The other classification is classified by purpose, which can be divided into general-purpose and special-purpose. The universal type is a model that is produced according to standards and is widely used in earth and stone engineering.

Loaders are classified according to different engine power, transmission mode, walking system structure, and loading method. One of the commonly used types is the single bucket loader. According to engine power, the power is less than 74kw for small loaders; the power is 74～147kw for medium loaders; the power is between 147～515kw for large loaders, and the power is greater than 515kw for extra large loaders. Divided by transmission type, hydraulic mechanical transmission, small shock and vibration, long life of transmission parts, convenient operation, automatic adjustment between vehicle speed and external load, generally used in medium and large loaders; hydraulic transmission is stepless speed regulation , The operation is simple, but the startability is poor, generally only used on small loaders; and the electric drive can also be stepless speed regulation, reliable work, simple maintenance, high cost, generally used on large loaders. There are also uses in the classification, and it can be seen that the use is also very important. So what are the different uses of the two.

2. Different uses

A bulldozer is a road construction machine loaded with a bulldozer shovel in front of the tractor, used for bulldozing and leveling construction sites. For example, in road construction, bulldozers can complete the treatment of the roadbed base, take soil from the roadside and add an embankment with a building height of no more than 1 meter, and shovel and transfer along the center line of the road. The soil builds a roadbed of half embankment and half trench. In addition, bulldozers can also be used to level the ground, accumulate loose materials, and remove obstacles in the work area.

In addition, special types of bulldozers are used in specific working conditions. There are wetland bulldozers and marshland bulldozers that use triangular wide crawler plates to reduce the ground pressure, amphibious bulldozers, underwater bulldozers, cabin bulldozers, and unmanned Driving bulldozers, high prototypes and bulldozers operating under high humidity conditions, etc.

Loaders are mainly used for shoveling, loading, unloading, transporting soil and stones and other bulk materials, and can also perform light shoveling operations on rocks and hard soils. If you change to a different working device, you can also complete the work of bulldozing, lifting, loading and unloading other materials. In highway construction, it is mainly used for filling and excavation of roadbed engineering, aggregate and loading of asphalt and cement concrete yard. Because it has the advantages of fast working speed, good maneuverability, and light operation, it has developed rapidly and has become the main machine in earth and stone construction.

YTO-YD320-crawler-hydraulic-bulldozer

3. The working principle is different

The working principle of bulldozers is based on the transmission system. Bulldozers use mechanical transmission or hydraulic mechanical transmission system with hydraulic torque converter, and a few use hydraulic transmission system. Among them, the crawler bulldozer is mainly composed of engine, transmission system, working device, electrical part, cab and hood. Among them, the mechanical and hydraulic transmission system includes hydraulic torque converter, coupling assembly, planetary gear type power shift transmission, central transmission, steering clutch and brake, final drive and walking system.

The power output is driven by gear transmission and spline connection to drive the working pump in the hydraulic system of the working device, the variable speed pump of the variable torque hydraulic system, and the steering pump of the steering brake hydraulic system; the sprocket represents the final drive of the secondary spur gear transmission Mechanism (including left and right final drive assembly); track shoe includes the walking system including track assembly, trolley frame and suspension assembly.

YTO-YD160S-crawler-bulldozer-for-wet-earth-use

The working principle of the loader is realized by the movement of its working device. The working device is composed of bucket, boom, connecting rod, rocker arm and bucket cylinder, boom cylinder, etc., and the entire working device It is hinged on the frame. The bucket is hinged with the bucket cylinder through a connecting rod and a rocker arm for loading and unloading materials. The boom is hinged with the frame and the boom cylinder to lift the bucket. However, the turning of the bucket and the lifting of the boom need to be operated by hydraulic pressure.

The above is an introduction to the difference between a loader and a bulldozer. Generally speaking, the difference between a bulldozer and a loader is: bulldozers are more suitable for shallow excavation and short transportation of earth. The main purpose of loader is to load trucks, but it can also be used for multiple purposes. The main machinery in stone construction.

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Tractor operation skills

In recent years, agricultural mechanization at home and abroad has entered a new stage of rapid development. At the same time, the safe driving operation technology of tractor drivers has become an important subject that cannot be ignored. The essentials of tractor operation, as the main link of tractor safe driving operation, is the content that every tractor driver must learn, know, and know.

1. Getting started

There are three keys to the start of the tractor: one is the size of the gas pedal; the second is the timing to relax the brake; the third is the cooperation of the accelerator and the clutch. When starting, first step on the brake pedal with your right foot, step on the clutch pedal with your left foot, shift the gear into low gear, then step on the accelerator pedal slowly with the forefoot of your right foot, and slowly release the clutch pedal with your left foot until the engine sounds When there is a change or the body shakes a little, quickly raise the right heel, release the brake pedal, and then slightly depress the accelerator pedal. In this way, the tractor can start smoothly. The key here is the coordination of the left foot and the right foot.

Note that the process of engaging the clutch should be fast and then slow. When starting, the clutch should not be lifted sharply. The clutch pedal should be loosened slowly. When driving, be careful not to step on the clutch pedal to avoid early wear of the clutch friction plate. The clutch has a semi-disengaged state, which reduces the wear time of the clutch friction.

MG704

2. Change gears

If the low gear shifts to the high gear, refuel first to increase the speed. Then, step on the clutch pedal and quickly move the gear lever to a higher gear. But if you switch from high gear to low gear, you should use two-leg clutch and one-leg oil control. Namely: reduce the accelerator first] to reduce the vehicle speed, then disconnect the clutch, and quickly shift the gear, and then raise the clutch pedal to put the lower gear. Finally, refuel steadily and the gear shift is complete. When the driver changes gears, he should keep his eyes on the front instead of lowering his head to shift gears. Because the moment when the vehicle is moving, the head is lowered and the gear is changed, accidents are prone to occur. At the same time, you must keep your body straight and not swing your upper body with your hands to relax your upper body naturally.

Note when shifting gears: Do not look left or right, or look down at the shift lever, and do not push or pull the shift lever to avoid damage to the gear. Pay attention to step by step when shifting, and can’t go beyond the gear. When changing gears, you should also pay attention to that, when changing the forward or reverse direction, you can shift gears only after the standby motor car has stopped. Changing gears actually changes the ratio of the engine speed to the speed of the drive shaft. The lower the gear, the greater the speed ratio. The torque and traction are also greater.

YTO-ME354

Conversely, the higher the gear, the smaller the torque and traction. Therefore, when the tractor is running, when the movement resistance increases and the traction force is required, the low gear should be selected. First gear and second gear can be used for temporary overload. For example, a low gear should be selected when going up and downhill to keep the vehicle speed even, and gear shifting is forbidden in the middle to avoid slipping caused by improper operation. The low-speed gear has low vehicle speed, high engine speed, faster temperature rise, higher fuel consumption, and increased driving costs. Therefore, the time to resist low-speed driving should be as short as possible. The middle gear is a transitional gear from low gear to high gear or from high gear to low gear. Usually, it is used when there is difficulty in crossing, turning, bridge or passing.

When the road conditions are good and the engine has sufficient power, a high gear should be selected. High-speed gear travels fast and saves fuel, but traffic safety must be ensured. When a tractor is driving, it needs to constantly change its driving speed as the environmental conditions change. Therefore, timely, accurate and rapid gear shifts play a great role in prolonging the service life of the locomotive, maintaining stable driving, and saving fuel.

3. Turn

When turning, slow down first before turning. For beginners, it is not allowed to turn sharply at high speed. If you need to make a sharp turn, you must follow the principle of “slow down, whistle, and drive on the right”. When making a slow turn, you should turn the steering wheel early and turn the steering wheel less frequently. When turning sharp turns, turn the steering wheel late and turn the steering wheel more. When turning small turns, you can use unilateral braking to assist you at low speeds. In addition, when turning, do not get too close to the inside. You should turn the steering wheel according to the degree of curvature and the distance of the roadside obstacles so that the inside rear wheels can pass smoothly and prevent the rear wheels from crossing the road and encountering obstacles.

4. Reversing

When the tractor is driving backwards, it is necessary to use the rearview mirror, keep the mind focused, and use the low-oil door to decelerate, and must take care of the front and back, pay close attention to the presence of people and obstacles, and be ready to stop at any time. First of all, ensure that there is enough space for reversing. If the tractor needs to change direction when turning in reverse, the turning direction of the steering wheel should be consistent with the direction to be turned, so that the turning radius of the front turning in the original direction is smaller than the turning radius of the trailer, and the trailer can change direction. When the trailer turns, turn the steering wheel back to the right, so that the front of the trailer can be reversed straight in the same direction as the trailer.

5. Brakes

When braking slowly, first reduce the accelerator, use the engine to brake, reduce the vehicle speed, and use the brake to brake intermittently. When braking suddenly, you should quickly step on the brake pedal, and then disconnect the clutch to stop within a short distance.

6. Parking

When temporarily stopping, the clutch and brake pedals can be depressed at the same time to realize temporary parking. When parking for a long time, after stepping on the clutch and brake pedal, lock the brake pedal and the engine stops. When parking, pay attention to first reduce the throttle and reduce the driving speed. Depress the clutch pedal again, place the shift lever in the neutral position, and depress the brake pedal to achieve a safe stop. After getting off the truck, use stones or bricks to hold the wheels against the tractor to prevent the tractor from slipping behind.

The above is the relevant introduction about tractor operation skills. With the rapid development of agricultural mechanization, more and more users buy tractors at home and abroad. Only when the tractor is used and operated correctly can the efficiency of the tractor be fully utilized, the use cost is reduced, and the tractor is extended life.

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Common faults and solutions of small road rollers

Small road rollers are widely used in the edge compaction work of various roads and the second highway compaction. It is a common road compaction machine in our daily life. For people doing engineering, the normal use of the road roller is to ensure the workload The premise is that once the roller fails, the construction period will be delayed. Next, the roller manufacturer will explain to you some common faults and their solutions that are often encountered in the use of small rollers, so that you can repair them in time if there is a failure in use.

1. Common faults of the steering wheel of the road rollers

1. During the operation of the small roller, the steering wheel rotates, swings left and right, and shakes a lot. It is necessary to check whether the position of the rotor and the transmission coupling are correspondingly reasonable or the screws are loose.

2. Broken, deformed and worn dial pins, or broken, deformed, open, or worn transmission linkage shafts will cause the steering wheel to not turn and increase the pressure.

3. When the small road roller automatically deviates during driving, or the vehicle deviates from the direction after turning the steering wheel, check the two-way cushion valve and spring for debris.

2. Common faults in the power system of the road rollers

2Y6X8B static road roller

(1)The engine can’t start?

First of all, we must first analyze the reasons why the engine cannot start: a. Is the fuel used up? b. Is the fuel filter blocked? c. Whether the fuel pipe is leaking. d. The battery is leaking and discharged or the connection is not good.

Then we have to eliminate these reasons one by one: a. Fill the fuel bottle to eliminate the air in the system. b. Replace the filter. c. Check and prohibit tightening of all connections. d. Clamp the electric clamp and check the cable.

(2)The engine is difficult to start or the working power is unstable?

Reasons: a. The battery voltage is too low, and the battery clamps are loose or oxidized, causing the starter to rotate too slowly. b. Engine oil with too much viscosity, especially in winter. c. The fuel supply is not smooth. In winter, paraffin wax will cause blockage of the fuel system. d. Incorrect valve clearance. e. The fuel injector is defective. f. The turbocharger is defective. g. The dry air filter is dirty. h. The vacuum switch is faulty. i. The throttle cable is too tight.

Remedy: a. Check the battery, clean the two clamps to clamp and apply oil to the clamps. b. Use suitable engine oil. c. Replace the fuel filter, check all the fuel pipes, and change to winter fuel when it is cold. d. Adjust the valve clearance. e. Clean or replace. f. Check the vacuum switch. g. Adjust or replace the throttle cable.

(3)The engine overheats or stops suddenly?

Reason: a. The cooling fins of the cylinder and the radiator on the top of the cylinder are blocked by dirt. b. The fuel injector is defective. c. The injection pump is not adjusted correctly. d. The cooling air flow is restricted. e. The fan belt is too loose or broken.

Remedy: a. Clean the radiator cooling fins, especially the vertical fins on the top of the cylinder. b. Have a home inspection. c. Have a home inspection. e. Clean the cooling air delivery pipe. f. Check the belt or replace the belt.

(4)Exhaust too much smoke?

Analysis of the reasons: a. Too much oil. b. The dry air filter is dirty. c. The piston is burned or broken, resulting in insufficient compression plough. d. Incorrect valve clearance.

Remedy: a. Exclude too much oil. b. Clean or replace the filter. c. Inspection by professional personnel. d. Adjust the valve clearance.

(5)Engine oil leakage

It may be due to the large abrasion of the components of the small roller, which leads to the lack of tightness; the quality of the fuel itself and the concentration is not up to the standard; the sealing components have problems; the drive shaft has a large gap. When the hydraulic system of a small roller is running, the pump body is overheated: it may be due to a problem with the pump body, such as extra suction and exhaust; the pump body is damaged and leaks.

(6)The system pressure is not up to or there is no pressure

It may be that the unloading port of the pilot relief valve of the small roller is not blocked, resulting in no pressure in the control oil or no pressure in the hydraulic pump. During construction, the operating frequency of the small rollers suddenly decreases or the oil discharge failure occurs. This phenomenon may be caused by the following reasons: insufficient fuel consumption of the small rollers; relatively large wear and tear of related parts and failure of coordination; limited performance of some machines.

3. Common failure problems of road rollers

LT210 road roller

(1)The small roller cannot change speed when walking

The speed change mechanism of the roller is divided into two kinds, one is to realize the speed change by a variable motor, and the other is to realize the speed change by a fixed motor and a gearbox.

a. The variable motor mechanism is unable to change speed because the displacement control mechanism of the variable motor cannot be opened normally or malfunctions. First, check whether the walking speed control switch is good, whether the variable speed solenoid valve is normal, and measure the circuit at the solenoid valve. Unobstructed, to ensure that the solenoid valve can be opened smoothly and connected to the variable speed control oil circuit to ensure that its pressure is normal (its pressure is the replenishment pressure). If the top is cut well, the motor is damaged.

b. The quantitative motor gearbox mechanism cannot change speed. The judgment is relatively simple. If the working pressure of the quantitative motor is normal, the gearbox is damaged, and the gearbox can be changed by restoring it.

(2)What is the reason why the small vibratory roller does not vibrate

The reason why small vibratory rollers do not vibrate is mostly due to a problem with the shaft of the thrower. Many of these problems are also caused by some small problems when welding the thrower. Another reason is the problem of the electromagnetic clutch. In addition, if there is a problem with the throttle cable of a small roller with a gasoline engine, the roller will not vibrate.

(3)The parking brake of small rollers fails

The reason analysis should start from the composition, structure and working principle of the parking brake system of the roller. Wet disc brakes are used in the rear axle and front wheel reducer of small rollers, which rely on the friction between the friction plates to generate braking. Torque; if the roller parking brake fails, it must be caused by the slippage of the brake friction plate, which can be analyzed according to its composition, structure and working principle. The braking torque of the brake depends on the surface number of the friction lining, the average radius of the friction lining and the size of the friction force. The surface number and the average radius of the friction lining are designed and manufactured and cannot be changed during the braking process. Then, the brake slip must be caused by the reduced friction.

The pressing force of the brake pressure plate is generated by the pressing spring. If the elastic force of the pressing spring is reduced due to fatigue or plastic deformation caused by heat, the pressing performance of the pressing spring will attenuate. If the brake friction plate becomes thin after wear, The compression spring stretches, according to the inverse relationship between the compression spring force and its free length, so the spring force will decrease, causing the brake to slip. The frictional force of a friction brake depends on the pressure of the pressure plate and also has a great relationship with the friction coefficient of the friction plate. The brake friction lining should have a relatively large friction coefficient. If the friction lining is used for a long time, the friction surface is ablated and hardened, there is oil or moisture, the friction coefficient will be reduced, which will cause the brake to slip.

(4)Heat dissipation of small rollers

For technicians operating small rollers, it should be understood that poor heat dissipation results when the machine is working will directly affect the life of the machine or cause damage to parts.

When a small roller encounters excessive coolant temperature and the hydraulic system cannot dissipate heat normally, it should be judged whether the coolant temperature and the temperature of the heat sink are normal, and the coolant in the heat sink should be replaced. If the high temperature phenomenon occurs again after the coolant is replaced, it should be the leakage of the built-in liquid storage tank of the cooling box, and the parts in the cooling box need to be cleaned or replaced in time.

(5)The fuel line air has air

The diesel engine of the road roller stalled due to lack of diesel in the fuel tank during use. After the diesel engine is turned off, although diesel is added to the fuel tank, air has been in the diesel pipeline at this time, and the fuel supply cannot be restored using a hand oil pump.

In order to remove the air in the diesel pipeline and make the diesel engine start smoothly, we adopt the following methods: First, find a small basin and hold a fixed amount of diesel, and place it at a position slightly higher than the diesel pump; second, connect the fuel tank Remove the diesel pipe of the hand oil pump, and this small basin of diesel oil; again, pump the diesel with the hand oil pump to remove the air in the low-pressure oil circuit; finally, install the diesel pipe connecting the fuel tank to the hand oil pump and test the machine. The diesel engine started normally.

(6)The solenoid valve is damaged

If it is difficult to start a diesel engine, it will take a long time for each start before the diesel engine can barely start. We preliminarily believed that it was caused by poor atomization of the fuel injector, but the inspection of the fuel injector and the fuel injection pump were all good. When the solenoid valve was checked again, it was found that the solenoid was not attractive.

When we remove the start solenoid valve and pull the oil valve stem connecting the fuel injection pump and the solenoid valve by hand, the diesel engine can start smoothly, which shows that the solenoid valve has been damaged. As new solenoid valves are temporarily not available in the nearby market, we use thin copper wires to bind the fuel injection pump stem to prevent it from returning, and thicken the solenoid valve gasket to prevent the fuel injection pump stem hole Oil leaks from the mouth. After the above treatment, the solenoid valve is installed and the roller is put into use, and the new solenoid valve can be replaced after purchasing.

LT218B

(7)Deformation repair method of front wheel support

When a small roller failed to start, in order to start the roller, a loader was used to push it on the spot. As a result, the box supporting the front wheel of the roller was deformed, and the welding of the front fork and the vertical shaft was misaligned. The roller cannot be used.

Usually the front wheel box, vertical axle and front fork must be disassembled to repair the fault, but this repair is time-consuming and laborious. To this end, we adopted the following simple recovery methods:

First, adjust the front wheel to the front direction;

Secondly, pad the front wheel, front wheel frame and front fork beam with wood so that the front wheel does not rotate when turning the steering wheel;

Once again, turn the steering wheel, remember the total number of turns of the steering wheel, turn to the limit position and then turn back to half the total number of turns, the misaligned front fork and the shaft sleeve of the vertical shaft can return to the correct position; then, remove the front wheel The 14 fixing bolts on both sides of the box are used to lift the front wheel box about 400mm with a jack to leave the front wheel axle;

Finally, use electric welding to weld the vertical shaft sleeve firmly, loosen the jack, drop the front wheel fork, and assemble the front wheel frame with the front wheel shaft. In this way, only one person can adjust the deformation of the front wheel frame in place.

(8)Repair method for poor positioning of shift lever

The positioning pin of the shift lever of the small roller is easy to fall out or be cut off, resulting in the shift lever cannot be positioned. The locating pin has a diameter of 4mm and is used to prevent the shift lever from rotating.

To solve this problem, we adopt the following methods:

First, expand the diameter of the gear lever pin hole to 5mm and tap the M6 ​​internal thread;

Second, modify the width of the shift lever pin groove to 6mm;

Finally, configure one M6 screw and one M6 nut, screw the screw into the seat pin hole, and lock the nut after returning it half a turn.

(9)Solution to oil leakage of sealing ring

The vibrating valve of the roller leaked oil. After replacing the Y-shaped sealing ring, oil leaks occurred after a short period of use. The inspection found that after long-term use of the vibrating valve, the valve core upper cover and the valve core were severely worn.
To solve this problem, we adopt the method of adding O-shaped or flat-shaped sealing ring, that is, installing O-shaped or flat-shaped sealing ring in the groove of Y-shaped sealing ring. The vibration valve did not leak oil after the sealing ring was installed, which proved that the method achieved good results.

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How to choose a tractor correctly?

With the rapid development of society and the continuous improvement of technology, small tractors are gradually emerging in agriculture and are widely used. Choosing a suitable small tractor will lay the foundation for the smooth progress of agricultural production. So, what are the tractor models and how should we buy them?

Tractor model

There are three types of tractors: walking tractors, wheeled tractors and crawler tractors; according to power, they can be divided into large, medium and small tractors. Among them, the walking tractor is a small tractor with a power of 11kW (15 horsepower) or less. It is mainly suitable for farmland operations and short-distance transportation operations on small fields. It is more commonly used in southern rural areas.

Wheeled tractors are divided into belt drive and power output shaft drive. The belt drive is generally a small four-wheel tractor with a power of 8.8kW～14.7kW (12 horsepower to 20 horsepower); the power output shaft drive is large, Medium-sized tractors, the power is above 14.7kW (20 horsepower), with the demand of production, the power of tractors is getting bigger and bigger.

Wheeled tractors are mainly used for farmland operations or transportation operations in rural areas in northern my country. Among them, large wheeled tractors are suitable for use in large-area farmland production and can greatly improve production efficiency. Because crawler tractors can be equipped with bulldozers, they are generally used in farmland infrastructure and water conservancy projects. All agricultural tractors are powered by diesel engines.

How to choose a tractor

YTO-X1204

1. The choice of the form of the whole machine

Small tractors with belt drive are usually called small four-wheel tractors. In recent years, there are mainly two types of small four-wheel tractors on the market: 11.0kW (15 horsepower) and 13.2kW (18 horsepower). Small four-wheel tractors of 14.7kW (20 hp) and 8.8 kW (12 hp) are less on the market. There are two types of diesel engines installed on small four-wheel tractors, one is evaporative water-cooled diesel engines, and the other is circulating water-cooled diesel engines. Because these two types of diesel engines have different structures and parts cannot be interchanged, you should choose the diesel engine type commonly used in your area when buying a tractor. This is very important for future repairs and maintenance.

2. Choose famous brand products

As the brand-name products are recognized by the public in long-term use or approved by authoritative departments (such as products with the agricultural machinery promotion license of the Ministry of Agriculture), their product quality is reliable, the performance is advanced, the product coverage is large, and the after-sales service is good.

3. Check the appearance

(1) The paint of the shell should be bright and even, without peeling or falling off, and the hand feel smooth and flat.

(2) The surface of the casting should be smooth, without cracks and sand holes that can be seen by the naked eye, the appearance of the sheet metal should be smooth, and the surface of the electroplated part should be bright and free of rust.

(3) The surface of the tire should be smooth, with regular patterns and no blisters or cracks.

4. Check whether the safety protection devices and safety warning signs are complete

(1) Check the starting shaft end of the engine, the end of the shaft head cannot protrude from the surface of the engine box body. To prevent danger when people approach when the engine is running.

(2) The pulley and belt must have a protective cover. To prevent danger when people approach when the engine is running.

(3) There should be a protective cover on the exhaust pipe. To prevent the operator from being burned when accidentally touched.

(4) The steps and pedals on the car should have anti-skid nets and raised edges or ribs. In order to prevent the driver from slipping when getting on and off the car, causing fall injuries.

(5) The shaft head of the power output shaft must have a guard. To prevent danger when people approach when the engine is running.

(6) On the operating device whose operating direction is not obvious, there should be signs indicating the direction. To prevent misoperation.

X1004

5. Check the control mechanism

(1) The throttle and lever are connected reliably, and there is no sticking when trying to step on.

(2) Push and pull the main and auxiliary gear levers (shift levers) according to the operating regulations to confirm their reliability.

(3) When the front wheel of the steering wheel is stationary, its free turning angle should not be too large, but less than 30 degrees.

6. Test run

(1) Check the engine oil height, add diesel oil and cooling water.

(2) When the ambient temperature is higher than 5℃, start three times in a row, and two of them should start smoothly within 30 seconds.

(3) Run for 10 minutes at medium throttle and observe the exhaust smoke and engine sound to be continuous and stable.

(4) After 10 minutes, reduce the throttle as much as possible and run at low speed (idle speed), and the engine sound should be steady.

(5) Increase the throttle gradually, and the engine sound should be stable. When the throttle is at the maximum, the exhaust pipe does not emit black smoke.

7. Stop for water and oil leakage inspection

Observe that there should be no drips and flow marks on the joint surface of each rotating part. There should be no wetness on the joint surface.

Precautions for buying a tractor

1604

1. Check and verify random attachments, certificates and documents

Product qualification certificate, agricultural machinery promotion license stamp, “three guarantees” certificate (service card), instruction manual, maintenance manual and accessories.

2. Ask for an invoice

After purchasing the goods, take the initiative to ask the seller for the invoice formally printed by the finance and taxation department.

In summary, it is about all the relevant content about tractor purchase. I hope it will be helpful to everyone when buying tractors. In fact, only in accordance with the corresponding purchase standards, we can definitely purchase our favorite tractors.

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