As a mainstream brand in the excavator market, Kobelco excavators have always been favored by Chinese people. Its excellent working performance, ultra-low fuel consumption and failure rate are important factors for Japanese excavators to occupy the market. Although the excavator brand is good, it will cause trouble to the excavator if it is not properly maintained.
1. Model: Kobelco SK270XD-10
2. Anomaly investigation:
(1) Reverse the phenomenon of replacing the hose in the main control room of the large pump.
(2) Exchange the hose between the main pump valve and the central joint-the condition remains unchanged.
(3) Switch the negative control signal line and go straight (not biased).
(4) During operation, there is a pressure of 8~10kgf/cm2 in the negative control line.
(5) The second pressure of the pilot is 0K.
(6) It is judged that the main control fault is not good, but there is still no improvement after replacement (NO GOOD).
3. Analysis of the cause of the failure:
(1) Measurement-the pressure of the lower return line, there is a pressure of 8~10 kg f/m2.
(2) The one-way valve is 0K.
(3) After removing the return filter element, the return pressure drops, and the pressure of the negative control line drops to 2~3kgf/cm2 during operation.
Walking becomes straight.
Reason: The back pressure is generated due to the clogging of the return filter element, which leads to the generation of negative control pressure.
4. Troubleshooting method:
(1) Replace the return filter element.
(2) Clean up the hydraulic oil or renew it.
