Regarding the principle of the four-way valve

Structure and working principle of the four-way directional valve: 1. Composition of the four-way directional valve The four-way directional valve is mainly composed of a four-way pneumatic directional valve (main valve), an electromagnetic directional valve (control valve), and capillaries. The main valve contains a movable valve core made up of a slider and a piston. There are holes at both ends of the main valve body, allowing the capillaries at those ends to be connected to the space inside the valve body. Pistons are fixed to each end of the slider, and the spaces on either side of the pistons can be connected through exhaust holes on the pistons. The control valve consists of a valve body and an electromagnetic coil. There is a needle-type valve core inside the valve body. Three (or four) capillaries connect the main valve and the control valve, forming the entire four-way directional control valve. The working principle of the four-way directional control valve is as follows: the port (4) of the main valve is connected to the high-pressure exhaust port of the compressor, while port (2) is connected to the low-pressure suction port of the compressor. The two nozzles at (1) and (3) are connected to the exhaust port of the evaporator and the intake port of the condenser, respectively. As shown in the diagram, (3) is connected to the inlet of the condenser, and (1) is connected to the outlet of the evaporator. When the solenoid valve is not powered, the system operates in cooling mode. Due to the action of spring 1, the control valve’s spool moves to the left end, ending up in a released position; at this time, capillaries E and C are connected. Since E is connected to the low-pressure intake pipe, both the capillary C and the space on the left side inside the main valve are at low pressure. High-pressure gas enters the main valve through port 4, and through the exhaust hole of piston I, the space on the right side inside the main valve becomes high pressure, which pushes the valve core of the main valve to the left. As a result, port 2 becomes connected to port 1 and port 4 becomes connected to port 3, thus establishing a refrigeration cycle in the system.

This post was last edited by wdj_fbi on 2009-9-17 16:57: 1 in, 3 out? By using a 5-way valve and blocking one oil port, it becomes 1 inlet and 3 outlets

Haha, what kind of four-way valve? There are many different structures for four-way valves. The type you mentioned, with one inlet and three outlets, where each of the three outlets needs to be controlled separately – what’s the point of using a four-way valve then? Isn’t it the same as having a single bus line from which three branches emerge, each controlled by a control valve? The simplest four-way valve works by, under the control of a control system, changing it from 1/2 way to 2/3 way, or from 3/4 way to 1/4 way (no diagram needed). There are various ways of controlling it: cylinders, electromagnets, hydraulics… anything that can make the valve rotate will do.

I want to see if I can cut costs..

It’s a matter of how many times it can be actuated; the key is that the function is determined by the design of the valve core in the actuation unit