The body of the remote control valve (pilot valve) has an oil inlet P (primary pressure) and an oil outlet T (oil tank). In addition, the secondary pressure (secondary pressure) can be obtained through the oil port 1, the oil port 2, the oil port 3, and the oil port 4 on the bottom surface. Its structure is shown in Figure 1-83, port
and port size are shown in Table 1-16, and the hydraulic circuit diagram of modern excavator is shown in Figure 1-84.
The structure of the pilot valve is shown on the 1-83 (b) section. The pressure reducing valve is installed in a vertical hole in the valve body.
Reducing valve is composed of spool, spring setting secondary pressure, return spring, stop block, spring seat and gasket. The spring for setting the secondary pressure-generally the preset pressure is 5~20.5kgf/cm2 (according to different models). The spool is pushed against the push rod by the return spring.
When the push rod is pushed down by the handle, the spring seat simultaneously lowers and changes the setting of the secondary pressure spring.
