Excavator main relief valve accessories introduction

The excavator safety valve is installed on the main control valve, usually two. This valve sets the maximum pressure at which the entire hydraulic system works. When the system pressure exceeds the set pressure of the main gun, the main gun opens the oil tank, and the hydraulic oil returns to the oil tank to protect the entire hydraulic system and avoid excessive pressure in the oil circuit.

Excavator main safety valve The figure below shows the physical and structural diagram model of the main safety valve

As well as the understanding of its principle, the structure is two relief valves, which can reduce the change of the system pressure at the instantaneous pressure peak.

The schematic diagram of the main relief valve structure is shown in the figure below

Red is system pressure at work. When the pressure is greater than the set pressure, the white cone valve opens, and the pressure oil in the purple valve sleeve returns to the oil tank through the valve body, which is the green part.

This is because the purple closes the hole of the damping valve sleeve, and the pressure oil cannot be quickly added to the oil leakage of the purple valve sleeve, causing the purple valve set pressure to be lower than the system pressure, and the system pressure opens the working system of the valve sleeve purple, and the oil communicates directly with the oil tank , The effect of decompression.

After the main gun pressure is lower than the set pressure, the poppet valve is closed, the pressure valve sleeve is equal to the purple, the purple valve is set under the spring force, and the pressure relief oil system pressure is kept at the set pressure to adjust the yellow force in the oil. Section, increase set pressure cone valve, force effect. This set after 6 – 8 seconds.