Hydraulic multi-way directional valve is referred to as multi-way valve. It is based on two or more directional valves. It integrates different safety valves, one-way valves, diverter valves, overload valves, brake valves, charge valves, etc. Multi-functional integrated valve of function valve, which can control multiple actuators. Because of its compact structure, simple pipeline connection, small pressure loss, and easy installation, it has been widely used in construction machinery14.
Multi-way valve has two functions of flow and direction control, which can be divided into different categories according to different classification methods.
The following introduces various forms of multi-way valves:
(1) According to the structure of the valve body, the multi-way valve can be divided into integral type and split type. In general, a group of multi-way valves is composed of multiple directional valves, and each directional valve is a unit. As shown in Figure 1.3, the integral multi-way valve is to install each directional valve and some auxiliary valves on a valve body. The overall structure is compact, the pressure loss is small, the weight is light, the processing surface is small, the flow rate is high, and the pressure is high; but its versatility is poor, and the internal flow channel is formed by precision casting. Large quantities of machinery. As shown in Figure 1.4, the split-type multi-way valve is assembled with bolts according to the use requirements. It has strong versatility, but it has many machined surfaces, and there is more possibility of oil leakage.
(2) According to the oil connection between the directional valves, it can be divided into parallel, series, series-parallel and composite oil circuits, as shown in Figure 1.5. Figure 1.5a) is a parallel type, the pressure oil in the oil inlet of the parallel oil multi-way valve can directly enter the oil inlet chamber of each directional valve, and the oil return chamber of each directional valve directly leads to the multi-way valve The total oil return port. Each interlock valve can be operated independently, but when the compound operation is performed, it can be preferentially operated when the load is small. Figure 1.5b) is a tandem type. The oil inlet chamber of the tandem valve of the tandem oil multi-way valve is connected to the oil return chamber of the previous tandem valve. The pressure is the sum of the pressure of each actuator, so the operating resistance is large. Figure 1.5c) is a series-parallel type. The oil inlet chamber of each valve of a series-parallel oil multi-way valve is connected in series. With this kind of oil circuit connection, when the previous directional valve is operated, the next one cannot work, and it can ensure that the previous one valve takes priority action. The oil path of the compound oil path multi-way valve is formed by combining the above two or three.
