The correct operation of the hydraulic retarder

Hydraulic retarder is a powerful tool to improve driving safety, but it must be used correctly to maximize its effect.

• The gears of the hydraulic retarder can be divided into constant speed gears and brake gears

Judging from the mainstream hydraulic retarder products on the market, the gears of the hydraulic retarder can be roughly divided into constant speed gear and brake gear (the retarder brand is different, and the specific gear setting may be slightly different) .

Generally speaking, most of the hydraulic retardation in the first gear is set to a constant speed gear, which is similar to the "fixed speed cruise" mode of a car, which is to keep the vehicle speed constant above the set value (for example, the vehicle speed before going downhill is 50km/h, enter the downhill and open the constant speed gear, the vehicle will maintain a speed of about 50km/h, and the retarder will monitor the speed of the vehicle downhill in real time to control the braking power of the retarder, and stabilize the speed at 50km/h. h).

Once the vehicle speed is less than the set speed of 50km/h, the retarder will automatically exit the working state. If the vehicle speed exceeds the set speed at this time, the retarder will continue to enter the working state to control the vehicle speed in real time.

It should be noted that: constant speed gear is generally suitable for long downhill road scenes. In addition, according to the retarder's requirements for engine speed, when using a constant speed gear, it is generally necessary to maintain the engine speed above 1500 rpm.

If the engine rotates below 1500 rpm when using the constant speed gear, the retarder's braking work is likely to be reduced or withdrawn. We should use the gearbox downshift method to increase the engine speed so that the retarder continues to work normally .

If the gravity of the vehicle is too high when the vehicle is going downhill, the speed of the vehicle will continue to increase when using the constant speed gear. At this time, the brake pedal should be stepped on to assist the vehicle to decelerate, instead of directly shifting the retarder handle to the maximum gear.

The 2-5 gear (or 2-4 gear) of the hydraulic retarder is a forced retard gear, which can be used on downhill and flat roads. According to the road conditions and vehicle speed, shift the handle one by one to select the appropriate gear to slow down the vehicle. The lowest gear corresponds to the lowest braking torque (generally 25%), and the highest gear corresponds to 100% braking torque. In the process of downhill, our card friends can increase or decrease the deceleration force of the retarder to maintain the smooth speed of the vehicle.

The high brake gears (4 gears and 5 gears) have a very large braking torque, and long-term use of the highest gear is likely to cause poor engine heat dissipation. Therefore, the brake gear (especially the highest gear) is generally only used for short-distance braking that requires deceleration, and the constant speed gear is generally used for long downhill conditions.

Under special conditions, if the vehicle needs to decelerate quickly, you can turn the retarder handle to the maximum gear. At this moment, the hydraulic retarder will retard the vehicle with the maximum braking torque, but the water temperature will rise sharply. It will exit at high temperature within ten seconds and lose braking force.

Since the retarder acts on the front of the vehicle instead of the trailer, when the maximum braking torque is used, the braking force of the front part of the vehicle will suddenly become too large, which is likely to cause a dangerous situation. We must use it with caution. It is strictly forbidden to use it in rainy and snowy weather or the road is slippery or icy.

• During the use of the hydraulic retarder, the following issues should be paid attention to:

1. The retarder is only an auxiliary braking device, and the brakes are still required for emergency braking and parking.

2. Try to use a constant speed gear, so that the hydraulic retarder automatically adjusts the braking force according to the set speed and the current speed to achieve the purpose of constant speed downhill.

3. When using the hydraulic retarder, you must increase the braking force step by step, and you must not go directly from the zero gear to the highest gear, and do not skip gears.

4. Choose a suitable gear and let the engine speed reach more than 1500 rpm, so that the heat dissipation system of the engine can effectively dissipate the heat slowly transferred from the liquid to the air.

5. Although the work of the retarder is not affected when the gearbox is in neutral, because the speed of the vehicle is low (about 800-1000 rpm) when the vehicle is in neutral, the water circulation of the engine is slow at this time, and the retarder is used for tens of seconds. The water temperature of the clock engine may rise, causing the retarder to exit. Therefore, the gearbox cannot be in neutral when the retarder is in use.

6. Don't overload, any component has a range that it can bear when designing.

7. The hydraulic buffer can basically be regarded as a wear-free auxiliary brake component, so its maintenance are very simple. We only need to replace the oil and filter according to the requirements of the vehicle type and workload.

8. Pay attention to the working conditions of retarder, and it is forbidden to use it on icy and snowy roads!