The directional control valve is referred to as the directional valve. In terms of working principle, the directional control valve uses the relative movement of the valve core in the valve body to control the opening and closing of the valve port and the size of the valve port, so as to realize the control of pressure, flow and direction, and flow through the valve port. The flow rate is related to the pressure difference before and after the valve port and the valve port area, and always satisfies the pressure-flow equation. Depending on the purpose, directional control valves can be divided into two categories: check valves and reversing valves.
1. One-way valve.
The one-way valve is also called a check valve, and its function is to make the oil flow only in one direction. According to the different spool structure, one-way valve can be divided into two types: ball valve type and poppet valve type. Figure 5-1 shows the structure of two check valves and the symbols of check valves. The ball valve spool has a simple structure, but it is easy to cause poor sealing due to friction, and is only used in low pressure applications. The poppet valve type is used more and has better sealing performance. According to the channel in the valve, it can be divided into straight-through type and right-angle type. The straight-through liquid flow resistance is small, and it is more convenient to replace the spring. Generally, a tubular connection is used; while the right-angle type can be used for a tubular connection. Plate connection or flange connection can also be used.
The main function of the spring in the one-way valve is to help the valve close quickly when there is no oil flow through or when the oil is flowing backwards. But it also increases the resistance when the valve is opened, and becomes the main part of the pressure loss when the oil flows through the one-way valve. The spring should be made softer without affecting the sensitivity and reliability of the valve. 'Generally, the opening pressure of the one-way valve is 0.035-0.05MPa, and the pressure loss when the whole flow passes through is about 0.1-0.3MPa.
2. Reversing valve.
The function of the reversing valve is to use the relative movement of the spool and the valve body to connect, close the oil circuit or change the flow direction of the oil to the actuator, so that the actuator can start, stop or change the direction of movement.
Reversing valve classification: The reversing valve is divided into rotary valve type and slide valve type according to the structure; according to the number of working positions of the valve core, there are two-position, three-position and multi-position, etc.; according to the number of inlet and outlet channels, there are two-way and three-way , four-way and five-way, etc.; manual, motor, electric, hydraulic and electro-hydraulic, etc. are divided according to the operation and control method; pipe type, plate type and flange type are divided according to the installation method. The situation of the reversing valve is much more complicated than that of the one-way valve. If you are interested, you can get more information on the official website of Hanjiu.
Hanjiu Technology Co., Ltd. is a company specializing in the production of hydraulic products, and they have accumulated more than ten years of experience in this field. Hanjiu can produce at least 100,000 directional control valves every year. These valves will eventually be sold to more than 30 countries in the world, especially in the US market, relying on Hanjiu's strong business network! Because the directional control valves produced by Hanjiu are not only of good quality, but also cost-effective, such characteristics determine that their products will be very popular no matter where they are.
If you are interested in buying a directional control valve, then come to the official website of Hanjiu, where there are the most complete products and the most thoughtful service. www.hjhydraulic.com welcome your visit!
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