Whether the hydraulic retarder is worth installing
With the continuous development of the domestic transportation industry, the requirements for vehicle production technology are more and more strict, a variety of vehicle "artifact" gradually appeared in people's eyes, hydraulic retarder is one of them.
Hydraulic retarder, also known as hydraulic deceleration device, can realize deceleration braking under non-emergency braking that can be predicted in advance, such as long downhill, so as to reduce the use of brake and avoid braking failure caused by long time braking.
According to JT/T1178.2 previously issued by the Ministry of Transportation, from September 1, 2020, new tractors must be fitted with hydraulic retarders or other auxiliary braking devices.
But in reality, many owners are not willing to install liquid slow, in addition to the price is expensive, can not see the long-term return, part of the problem is not clear about liquid slow. Today, we will start from the basic knowledge of liquid retarder, operation matters, maintenance three areas, to answer the owners of the relevant questions about the hydraulic retarder.
1. What is the hydraulic retarder?
Semi Trailer supplier says Hydraulic retarder is a reduction device, can slow down the vehicle through the hydraulic device, and engine brake, exhaust brake belong to the vehicle auxiliary brake device.
2. Working principle of hydraulic retarder
The structure of hydraulic retarder is composed of rotor, stator, working cavity, oil storage tank, heat exchanger and other large components.
When slowing is needed, the retarder control system will pump the retarder in the oil storage box into the working chamber between the stator and the rotor. The rotor rotates with the drive shaft, the stator is fixed on the retarder shell, and the rotor is driven by the drive shaft to drive the retarder oil to rotate together. Retarder oil has a certain viscosity, so that the rotor is subjected to the stator's stagnation resistance, at this time the rotor speed will slow down, the transmission shaft speed will also slow down, the speed slows down, to slow the effect.
3. Classification of hydraulic retarder
According to the different medium, liquid retardation can be divided into oil medium liquid retardation and water medium liquid retardation. However, at present, there are still technical difficulties to overcome in water medium liquid retardation, so the liquid retardation in the market is mainly oil medium. In terms of price, the liquid price of oil as the medium is about 15,000 to 30,000 yuan, and the liquid price of water as the medium is about 30,000 to 50,000 yuan.
According to the different installation methods, the liquid retarder can be divided into series retarder, parallel retarder and independent retarder. Among them, serial-type liquid retarder is suitable for vehicles with sufficient chassis space, such as tractors or heavy trucks. It is worth noting that serial-type liquid retarder can not be installed after the force takeout; Parallel liquid slow suitable for compact space light truck, medium truck or special vehicles, later installation may need to modify the transmission; Independent liquid retarder suitable for installation in the middle of the girder, can be applied to any vehicle.
4. Higher fuel consumption after slow installation? No. Compared with the traditional water spraying device, the dead weight of the liquid slow can be reduced by 1t-1.5t or so, the weight is lighter, the volume is smaller, and the fuel consumption is more conducive to saving.
In addition, the service life of brake pads and tires of vehicles installed with hydraulic retarder has also been extended to a certain extent, which can reduce the number of replacement and save the cost of comprehensive vehicles.
5. Do you need other auxiliary braking methods after installing the hydraulic retarder?
According to the data and practical driving experience, the hydraulic retarder is enough to undertake 80% of the braking task in the vehicle running, and can not use other auxiliary braking mode under the condition of meeting the requirements. But if the vehicle running conditions are special, liquid retardation can not fully meet the braking needs, it can also be used with other auxiliary braking devices.
6. Can hydraulic retarder replace brake?
No! The function of hydraulic retarder is to realize deceleration braking by braking torque in tollstation, traffic light, traffic jam, mountain road and other non-emergency braking situations that can be predicted in advance, but deceleration is not equal to stopping, and it still needs to rely on the brake pedal when necessary. In addition, when the speed is slow, because the braking torque is small, the hydraulic retarder may stop working, therefore, the hydraulic retarder can not completely replace the brake.
7. How to distinguish the tap position of liquid slow?
Liquid slow can probably be divided into two types: constant speed gear and slow speed gear (different brands lead to different gear Settings, generally 1 gear constant speed gear 2-4/5 gear deceleration gear).
Constant speed gear, which is similar to "constant cruise" mode, is to keep the speed of the vehicle above the set value. Once the vehicle speed is less than the set speed, the liquid slow will automatically exit the working state, if the vehicle speed exceeds the set speed, the liquid slow will continue to enter the working state, real-time control of the vehicle speed.
Slow gear, according to road conditions and vehicle speed, shift the handle one by one, select the appropriate gear to slow down the vehicle, the lowest gear corresponds to the lowest braking torque (generally 25%), the highest gear corresponds to 100% braking torque.
8. How to operate constant speed gear?
When you want to use constant speed, hang the gearbox into a relatively low gear (ensure the engine speed is above 1500 RPM), and hang the retarder into constant speed gear (usually first gear) at the speed you think is appropriate.
9. Why should it be kept above 1500 RPM?
General liquid slow manufacturers recommend the use of liquid slow, the engine speed is maintained at more than 1500 RPM, the purpose is to let the engine cooling system can timely and effectively transfer the heat from the liquid slow "dispose", if the engine speed is below 1500 RPM, the brake work of the liquid slow is likely to become smaller or exit.
10. Why can't the liquid slow up to the highest level?
Braking torque provided by retarder is very high. If pulled to the highest level, the liquid retarder suddenly reaches the maximum braking torque, not only the water temperature will rise sharply, the retarder will exit at high temperature within ten seconds, and the braking force will be lost. At the same time, the braking force of the front part will suddenly be larger, which is likely to lead to the occurrence of dangerous phenomena such as pushing head.
The retarder has provided different gears according to the gradual rise of braking torque, and the owner can gradually pull down the retarder to provide stable and reasonable braking torque.
In special situations, if the vehicle needs to slow down quickly, the handle of the retarder can be set to the highest level, but other braking means should be taken to prevent danger.
11, why rain, snow, ice, turning road conditions can not use liquid slow?
Generally speaking, the hydraulic retarded braking torque acts on the driving wheel through the drive shaft, which results in the limitation of braking force supply. In extreme weather such as rain, snow, ice and so on, the road friction coefficient decreases. In order to be in case, the hydraulic retarder should be used cautiously.
12. Can the hydraulic retarder be turned off and stopped immediately after use?
A: Yes, the hydraulic retarder depends on the engine coolant as the main heat dissipation medium, and can be stopped directly after use.
13. Can the gearbox be hung into neutral when using liquid retarded?
No. Although the gearbox is in neutral state, the work of retarder is not affected, but because the vehicle is in neutral state, the speed is low, the engine water circulation is slow, the engine water temperature may rise for dozens of seconds when the liquid retards are used, resulting in the liquid retards exit, so the gearbox cannot be in neutral when the liquid retards are used.
14. Is the liquid retarder mounted on the traction car or the semi-trailer?
Because the liquid retarder needs to use the vehicle's own cooling system and transmission system, the hydraulic retarder is mostly installed near the transmission. There are also cases of installing liquid retarder on the trailer in China. The main way is to change the first axle of the trailer from the support bridge without power device to the drive axle with the main reducer, and the installed liquid retarder is the independent liquid retarder. Such cases are rare and need to be tested by market observation.
15. Does the hydraulic retarder need additional battery?
No need, hydraulic retarder as long as the controller and control valve need very weak control current, no additional requirements for power supply.
16, where is the noise in the use of liquid slow?
In the process of using the hydraulic retarder, there is the sound of the liquid impact, and the exhaust is also reduced by the muffler.
17. Is fluid retardation the same as engine braking?
Not the same, the engine braking mainly exists exhaust braking, deflating braking and compression release braking three kinds, liquid retarder braking is retarder braking, braking torque is greater than the engine braking.
18. How to choose slow oil?
Hydraulic retarder is an efficient energy conversion device, which requires higher shear resistance, flash point and viscosity of the oil. It is best to select special oil according to the user manual.
19. Does liquid retardation require special maintenance?
Hydraulic retarder can be basically regarded as non-wear auxiliary brake parts, its maintenance and maintenance is very simple, the owner only needs to replace the oil and filter element according to the vehicle type and work load.
20, after the installation of liquid slow is once and for all?
No, any vehicle parts have the prescribed range of bearing capacity, the owner also needs to comply with the use, if there is overload or road conditions are too bad, simply relying on the hydraulic retarder may also exist unreliable situation, but also need to be used carefully with other braking devices.
1. What is the hydraulic retarder?
Semi Trailer supplier says Hydraulic retarder is a reduction device, can slow down the vehicle through the hydraulic device, and engine brake, exhaust brake belong to the vehicle auxiliary brake device.
2. Working principle of hydraulic retarder
The structure of hydraulic retarder is composed of rotor, stator, working cavity, oil storage tank, heat exchanger and other large components.
When slowing is needed, the retarder control system will pump the retarder in the oil storage box into the working chamber between the stator and the rotor. The rotor rotates with the drive shaft, the stator is fixed on the retarder shell, and the rotor is driven by the drive shaft to drive the retarder oil to rotate together. Retarder oil has a certain viscosity, so that the rotor is subjected to the stator's stagnation resistance, at this time the rotor speed will slow down, the transmission shaft speed will also slow down, the speed slows down, to slow the effect.
3. Classification of hydraulic retarder
According to the different medium, liquid retardation can be divided into oil medium liquid retardation and water medium liquid retardation. However, at present, there are still technical difficulties to overcome in water medium liquid retardation, so the liquid retardation in the market is mainly oil medium. In terms of price, the liquid price of oil as the medium is about 15,000 to 30,000 yuan, and the liquid price of water as the medium is about 30,000 to 50,000 yuan.
According to the different installation methods, the liquid retarder can be divided into series retarder, parallel retarder and independent retarder. Among them, serial-type liquid retarder is suitable for vehicles with sufficient chassis space, such as tractors or heavy trucks. It is worth noting that serial-type liquid retarder can not be installed after the force takeout; Parallel liquid slow suitable for compact space light truck, medium truck or special vehicles, later installation may need to modify the transmission; Independent liquid retarder suitable for installation in the middle of the girder, can be applied to any vehicle.
4. Higher fuel consumption after slow installation? No. Compared with the traditional water spraying device, the dead weight of the liquid slow can be reduced by 1t-1.5t or so, the weight is lighter, the volume is smaller, and the fuel consumption is more conducive to saving.
In addition, the service life of brake pads and tires of vehicles installed with hydraulic retarder has also been extended to a certain extent, which can reduce the number of replacement and save the cost of comprehensive vehicles.
5. Do you need other auxiliary braking methods after installing the hydraulic retarder?
According to the data and practical driving experience, the hydraulic retarder is enough to undertake 80% of the braking task in the vehicle running, and can not use other auxiliary braking mode under the condition of meeting the requirements. But if the vehicle running conditions are special, liquid retardation can not fully meet the braking needs, it can also be used with other auxiliary braking devices.
6. Can hydraulic retarder replace brake?
No! The function of hydraulic retarder is to realize deceleration braking by braking torque in tollstation, traffic light, traffic jam, mountain road and other non-emergency braking situations that can be predicted in advance, but deceleration is not equal to stopping, and it still needs to rely on the brake pedal when necessary. In addition, when the speed is slow, because the braking torque is small, the hydraulic retarder may stop working, therefore, the hydraulic retarder can not completely replace the brake.
7. How to distinguish the tap position of liquid slow?
Liquid slow can probably be divided into two types: constant speed gear and slow speed gear (different brands lead to different gear Settings, generally 1 gear constant speed gear 2-4/5 gear deceleration gear).
Constant speed gear, which is similar to "constant cruise" mode, is to keep the speed of the vehicle above the set value. Once the vehicle speed is less than the set speed, the liquid slow will automatically exit the working state, if the vehicle speed exceeds the set speed, the liquid slow will continue to enter the working state, real-time control of the vehicle speed.
Slow gear, according to road conditions and vehicle speed, shift the handle one by one, select the appropriate gear to slow down the vehicle, the lowest gear corresponds to the lowest braking torque (generally 25%), the highest gear corresponds to 100% braking torque.
8. How to operate constant speed gear?
When you want to use constant speed, hang the gearbox into a relatively low gear (ensure the engine speed is above 1500 RPM), and hang the retarder into constant speed gear (usually first gear) at the speed you think is appropriate.
9. Why should it be kept above 1500 RPM?
General liquid slow manufacturers recommend the use of liquid slow, the engine speed is maintained at more than 1500 RPM, the purpose is to let the engine cooling system can timely and effectively transfer the heat from the liquid slow "dispose", if the engine speed is below 1500 RPM, the brake work of the liquid slow is likely to become smaller or exit.
10. Why can't the liquid slow up to the highest level?
Braking torque provided by retarder is very high. If pulled to the highest level, the liquid retarder suddenly reaches the maximum braking torque, not only the water temperature will rise sharply, the retarder will exit at high temperature within ten seconds, and the braking force will be lost. At the same time, the braking force of the front part will suddenly be larger, which is likely to lead to the occurrence of dangerous phenomena such as pushing head.
The retarder has provided different gears according to the gradual rise of braking torque, and the owner can gradually pull down the retarder to provide stable and reasonable braking torque.
In special situations, if the vehicle needs to slow down quickly, the handle of the retarder can be set to the highest level, but other braking means should be taken to prevent danger.
11, why rain, snow, ice, turning road conditions can not use liquid slow?
Generally speaking, the hydraulic retarded braking torque acts on the driving wheel through the drive shaft, which results in the limitation of braking force supply. In extreme weather such as rain, snow, ice and so on, the road friction coefficient decreases. In order to be in case, the hydraulic retarder should be used cautiously.
12. Can the hydraulic retarder be turned off and stopped immediately after use?
A: Yes, the hydraulic retarder depends on the engine coolant as the main heat dissipation medium, and can be stopped directly after use.
13. Can the gearbox be hung into neutral when using liquid retarded?
No. Although the gearbox is in neutral state, the work of retarder is not affected, but because the vehicle is in neutral state, the speed is low, the engine water circulation is slow, the engine water temperature may rise for dozens of seconds when the liquid retards are used, resulting in the liquid retards exit, so the gearbox cannot be in neutral when the liquid retards are used.
14. Is the liquid retarder mounted on the traction car or the semi-trailer?
Because the liquid retarder needs to use the vehicle's own cooling system and transmission system, the hydraulic retarder is mostly installed near the transmission. There are also cases of installing liquid retarder on the trailer in China. The main way is to change the first axle of the trailer from the support bridge without power device to the drive axle with the main reducer, and the installed liquid retarder is the independent liquid retarder. Such cases are rare and need to be tested by market observation.
15. Does the hydraulic retarder need additional battery?
No need, hydraulic retarder as long as the controller and control valve need very weak control current, no additional requirements for power supply.
16, where is the noise in the use of liquid slow?
In the process of using the hydraulic retarder, there is the sound of the liquid impact, and the exhaust is also reduced by the muffler.
17. Is fluid retardation the same as engine braking?
Not the same, the engine braking mainly exists exhaust braking, deflating braking and compression release braking three kinds, liquid retarder braking is retarder braking, braking torque is greater than the engine braking.
18. How to choose slow oil?
Hydraulic retarder is an efficient energy conversion device, which requires higher shear resistance, flash point and viscosity of the oil. It is best to select special oil according to the user manual.
19. Does liquid retardation require special maintenance?
Hydraulic retarder can be basically regarded as non-wear auxiliary brake parts, its maintenance and maintenance is very simple, the owner only needs to replace the oil and filter element according to the vehicle type and work load.
20, after the installation of liquid slow is once and for all?
No, any vehicle parts have the prescribed range of bearing capacity, the owner also needs to comply with the use, if there is overload or road conditions are too bad, simply relying on the hydraulic retarder may also exist unreliable situation, but also need to be used carefully with other braking devices.