First of all, I would like to thank all colleagues and masters who provided us with information and comrades who fought in the front line.
Masters; A XCMG 230 excavator has a serious speed loss, but the engine does not emit black smoke. What is the fault of speed loss and flameout?
Hitachi 270-3, moving the bucket, stick, holding the car, walking on the left and turning on the right, the engine speed is very serious. What is the reason?
Colleagues often ask such questions in this regard. We checked the information in this regard and sorted it out as follows to attract jade. Take pc-200-6 as an example.
Power -... Plunger pump -... Main control valve - action effector energy conversion: kinetic energy ----- pressure potential energy ----------- kinetic energy has four automatic control feedback between pump and power and between man-machine, some positive feedback and some negative feedback, so as to achieve man-machine interactive control, power matching with pump power and meet the requirements of different working conditions.
1. Power speed - PC EPC valve - PC valve -... - pump flow, which is positive feedback
2. Operator action amplitude - pls pressure - LS valve - pump flow, which is positive feedback
3. Small and large external load pressure... PC valve - the flow of the pump, which is negative feedback. 4. Automatic speed oil control inside the power, slow speed - large oil volume, which is negative feedback. When lifting the boom, the working conditions are: high pressure, large flow, when extending the boom and bucket cylinder, the working conditions are: high pressure, small flow, and when rotating and walking, the working conditions are: low pressure, If the output of the pump, power and main control valve cannot meet the above working conditions due to various reasons, it will cause the vehicle to slow down or shut down. (because people's reaction speed is far less than the speed of positive and negative feedback regulation, the machine works normally. Once the machine fails, it will cause the above car to stall or stall). This is a complex feedback regulation process, which affects several positive and negative feedback regulation, so it is difficult to analyze and draw a correct conclusion.
