The three-position four-way reversing valve consists of a two-position four-way reversing valve and a rest position. The three-position four-way reversing valve has a variety of neutral functions (as shown in the figure, the neutral function is M-type). In the working position shown in the figure, the oil inlet P is connected with the working port B, and the working port A is connected with the oil return port T.. The three-position four-way reversing valve can be a slide valve structure or an on-off valve structure.
The three-position four-way reversing valve is in the static position, at which time the oil inlet P is communicated with the oil return port T, and the working oil ports A and B are closed. Because the oil at the outlet of the hydraulic pump flows to the oil tank, this working position is called hydraulic pump unloading or hydraulic pump bypass. When the hydraulic pump is empty, its working pressure is only the resistance loss of the three-position four-way reversing valve, which will not cause the system to heat up.
When the three-position four-way reversing valve reverses to the right, the oil inlet P is connected with the working oil port A, and the working oil port B is connected with the oil return port T. ..
When the three-position four-way reversing valve is in the static position, the oil at the outlet of the hydraulic pump flows back to the oil tank through the bypass oil path. When the three-position four-way reversing valve is driven, the piston rod of the hydraulic cylinder extends out, and the one-way valve is used to protect the hydraulic pump.
Extended data:
Three-position four-way electromagnetic directional valve is a new product developed for G series forklift trucks, which has obtained national patent. It is an essential component for electro-hydraulic reversing of various forklifts. In order to ensure the quality, the ex-factory test standard of solenoid valve is completely in accordance with international standards: it meets the performance requirements under the harsh conditions of oil temperature 130 degrees and rated voltage negative 15%.
The three-position four-way electromagnetic directional valve has three shortcomings, such as large volume, poor anti-vibration and waterproof performance, and its application environment is greatly limited. The new three-position four-way electromagnetic directional valve has been greatly improved in structural design, process design and material selection. Compared with the traditional solenoid valve, its volume is reduced by 1/3, and it has strong shockproof and waterproof performance.
The six-way reversing valve is mainly composed of valve body, sealing assembly, cam, valve stem, handle and valve cover. The valve is driven by the handle, which drives the stem and cam to rotate. The cam has the functions of positioning, driving and locking the opening and closing of the sealing assembly.
Turn the handle counterclockwise, and the two groups of sealing components respectively close the two channels at the lower end under the action of the cam, and the two channels at the upper end are respectively communicated with the inlet of the pipeline device. On the contrary, the two channels at the upper end are closed, and the two channels at the lower end are communicated with the inlet of the pipeline device, thus realizing uninterrupted commutation.
Baidu encyclopedia-three-position four-way electromagnetic reversing valve