When the P port into the oil, the hydraulic oil through the valve core 3 priority supply to the CF port. When the diverter does not work, the CF port is closed, then the pressure of the LS port is zero, the right end of the spool into the oil, hydraulic pressure acting on the right end of the spool, Forklift Loader to overcome the spring 2 pre-pressure, so that the spool to the left, At this point P port and EF port connected to the pump oil flow to the working system to go, in order to achieve double pump confluence. Forklift Loader When the steering gear is operated, the CF port is connected with the steering cylinder through the diverter and the steering pump is used to enter the steering cylinder to turn the loader. The pressure signal of the LS port acts on the left end of the spool through the throttle hole. The pressure at the right end is lower than the pressure at the outlet of the diverter, Forklift Loader and the spool moves to the right when the steering speed is large due to the change of the pressure difference between the left and right of the spool and the spring.
When the steering load exceeds the rated value, the pressure oil of the LS port opens the steering valve 1, the LS port is depressurized, the spool is shifted left, Forklift Loader and the steering pump is supplied to the working system. When the working system does not work, the multi-way valve in the neutral position unloading.
Load Sensing Full Hydraulic Steering and Preferential Valve Steering System When the operating system is in high pressure and low flow operation, Forklift Loader the fluid that is merged into the working system is redundant, and the steering system is subjected to the same high pressure as the working system. To this end on the basis of the preferred valve, increased the high pressure unloading part, it became a priority unloading valve.
The priority unloading valve structure is mainly composed of unloading safety valve, check valve spring, equivalent unloading check valve, unloading spool, Forklift Loader unloading valve spring and so on. Its working principle shown in Figure 2b, when the working system is in high pressure state, EF port is also in high pressure state, high pressure oil open equivalent unloading check valve 3 and unloading safety valve 1 contact; when the pressure exceeds the unloading safety valve When the pressure is set, the unloading safety valve is opened and the oil return to the oil is released from the oil trail b to the left end of the unloading spool 4 to overcome the spring force of the unloading valve spring 5, Forklift Loader the unloading spool is shifted right, the high pressure oil of the EF port is directly unloaded by the T port Fuel tank.
The priority of the high-pressure valve can not unload the problem, to achieve a high pressure and low flow conditions, saving energy. However, Forklift Loader it should be noted that when the system is not working, that is, when the loader is in high-speed transport state, the steering pump to oil is still through the multi-way valve unloading, and this work in the loader is often present, The low pressure unloading structure on the basis of high pressure unloading.