Views:4 Author:Site Editor Publish Time: 2017-04-05 Origin:Site
In general, due to the difference in the environment and conditions of use, the difference in the use environment between the engine of a vehicle engine and a construction machine [referred to as an industrial machine] is basically:
First, the automotive machine requires good acceleration, large reserve power, steep torque curve [reserve torque], high torque reserve in common speed range [so as to overcome the steep road, muddy, soft roadbed and other harsh road conditions], and does not require long The time of full power output (especially mountain road conditions, one will uphill, one will downhill, changing conditions), in general, predictable load conditions are more [such as the predictability of the ramp, resistance Large road conditions can accelerate the sprint in advance]; basic is based on 15 minutes and one hour of continuous power; engine cooling conditions are more complex [long climbs and long distances downhill]; on the engine's variable altitude conditions The requirements are more stringent (sometimes from heavy-lifting at low altitudes to high-altitude areas, and from no-load downhills to low-altitude areas all the way from high altitudes), the emission and noise requirements are more stringent; the economical requirements are higher;
Second, industrial machines require continuous constant power [even full power] operating conditions, and require high reliability for continuous operation [essentially 12 hours continuous power] Acceleration performance requirements are not high, but require the engine to overcome sudden unpredictable The resistance [load] has a stronger ability, basically high-speed operation conditions [more special for loaders and forklifts, more acceleration and deceleration conditions], high cooling performance requirements [because there is no wind cooling condition of vehicle], and emission requirements It is not high [lagging behind the car machine] and pays more attention to economical use;
According to the operating conditions and usage requirements of the above engines, the two machines have different characteristics:
Vehicles are generally rated on the nameplate for 15 minutes or one hour of continuous power. Generally, they are about 10% larger than 12 hours of power.
In other words, the power marked on the nameplate cannot be used as an industrial machine and must be reduced by about 10%;
In general, the vehicle's calibration speed is higher, because the vehicle does not often run in the high-speed area for a long time, but the machine needs to operate in the high-speed area often;
Vehicle resistance is predictable in many cases, such as: bad roads, steep slopes, etc.; and in many cases, the load changes of industrial machines are unpredictable. For example, in the excavation, who knows that there is something under the ground? In the simplest case, agricultural tractors with complex working conditions are fuel governors that are full governors!
Therefore, under the control of the traditional fuel pump mechanical governor, the vehicle is controlled by a two-stage governor, and the industrial machine is controlled by a full governor. Although the acceleration response is not as flexible as the two-governor, the engine overcomes the resistance. Ability to be higher than two-speed governors;
Similarly, in electronically controlled engines, changes in software are also used to adapt to the operating conditions of the engine. The use of software control is more convenient than designing mechanical governors!
For the changes in the use of the environment, automotive machine often make a fuss about the configuration of the turbocharger, generally can use the exhaust valve to control the boost pressure is too high to meet the drastic altitude changes, using variable speed cooling fan To adjust the cooling intensity under different operating conditions (In the past, it was said that the automotive machine could not have this condition, and the cooling fan design was based on the operating condition of the maximum cooling intensity.)
Workers can only make a fuss about increasing supercharging pressure and reducing machine load. Some superchargers also have exhaust valves, which are often adapted by car machines.
For noise, vehicle engines can often make a fuss about noise emission and noise shielding of exhaust emissions to reduce noise emissions. Anyway, as long as the noise is not exceeded in the specified location, acceptance can be achieved;
Workers' machines are not strictly required in this respect. For example, CAT machines require that the driver's ear noise is not more than 75 dB at full power [domestic machines can be much lower in demand, as if they are 82 dB];
With regard to fuel economy, vehicle-mounted vehicles can be matched with the driving system to achieve higher economic efficiency, and the working machine has shortcomings due to operating conditions. For example, hydraulic transmission and hydraulic transmission are far from purely mechanical transmissions. The efficiency is high, and even the most primitive belt drive has high efficiency. The current hybrid drive is mainly for this purpose, so the overall fuel economy is not high, and it is difficult to make a larger range of improvement in the short term;
For the power and weight ratio of the machine, the car machine is required to be lightweight in order to reduce the car's service quality and reduce fuel consumption (the ratio of the current quality of the advanced diesel engine has reached 1.5:1, that is, the weight of the 1KW power is 1.5kg) ;
Worker machines are not sensitive to this, and sometimes they need to be weighted.
Taken together, if you change from a car machine to a machine, you need to:
Reduce the speed, control the whole speed governor, reduce the power usage, change the gear ratio of the fan to suit the working conditions of the industrial machine