Generally speaking, due to different operating environments and conditions, the application principles of automobile engine and construction machinery engine (hereinafter referred to as industrial machine) are different.
In daily life, our requirements for cars are fast, stable and able to cope with short-term bad road conditions; In addition, the cooling condition of automobile engine is complex, which needs to face long-distance uphill and downhill, has strict requirements on emission and noise, and has high requirements on economic use. Therefore, for vehicle machines, we require good acceleration, large reserve power, steep torque curve, large reserve torque and so on.
The excavator needs to operate continuously and deal with various complex sudden working conditions, but the speed requirement is not high. The working machine requires continuous constant power and many operating conditions, and the reliability of continuous operation is required to be high; The acceleration performance requirements are not high, and they are basically high-speed operation conditions, among which loaders and forklifts are special, and there are many acceleration and deceleration conditions. Because there is no upwind cooling condition for vehicle engine, it has high requirements for cooling performance and low requirements for emission.
According to the working conditions and use requirements of the above engines, the two machines have different characteristics:
1. Different calibration speeds
The calibration speed of automobile engine is high, because the vehicle machine does not often run in the high-speed area for a long time, while the industrial machine needs to often run in the high-speed area.
2. Governor control is different
The resistance of cars is predictable, such as bad roads, steep slopes, etc. In many cases, the load change of the excavator is unpredictable. For example, during excavation, it is impossible to know what the underground geology or ground conditions are, so the excavator engine is controlled by the whole process governor. Therefore, under the traditional mechanical governor control of fuel injection pump, vehicle engine is controlled by two-stage governor, while industrial engine is controlled by whole process governor. Although the acceleration response is not as flexible as bipolar governor, the ability of engine to overcome resistance is higher than two-stage governor.
3. Different noise reduction requirements
Automobile engines have high requirements for noise reduction. For noise, automobile machines can often make an issue on the silencing and noise shielding of exhaust emission to reduce noise emission. As long as the noise does not exceed the standard in the specified parts, they can pass the acceptance. Excavator engines are not strictly required in this regard.
4. Different requirements for machine weight
For the power and weight ratio of the machine, the vehicle requires smooth and light driving, so the vehicle machine requires lightweight, so as to reduce the vehicle's servicing quality and reduce fuel consumption. Due to the work demand of excavator, it is not high to this point, and sometimes even need to increase the counterweight.
