EFRD-G03 & EFRD-G06 Proportional Electro-Hydraulic Relief And Plow Control Valve

Introduction to electro-hydraulic proportional valve:

 

Electro-hydraulic proportional valve is called proportional valve for short. Ordinary hydraulic valve can only preset the way of the liquid flow pressure, flow rate for constant control. But when equipment requirements in the process of work of hydraulic system pressure, flow parameters to adjust or continuous control, for example. Hold bench when the job is feed to the slow, fast, slow speed to realize continuous change of feed, or in a certain accuracy simulate a curve of optimal control force control. The ordinary hydraulic valve are not achieve them. At this time can be electro-hydraulic proportional valve control of the hydraulic system.

 

Electro-hydraulic proportional valve is a kind of valve which continuously and proportionally controls the direction, flow and pressure of hydraulic system according to the input electrical signal. Tashan electro-mechanical proportional conversion device and hydraulic control valve body are composed of two major parts. The former continuously converts the input electrical signal into mechanical force and displacement output in proportion, while the latter continuously output pressure and flow in proportion after receiving such mechanical force and displacement.

 

The development of electro-hydraulic proportional valve has two main ways one is to replace the traditional hydraulic valve with proportional electromagnet manual adjustment device or replace the common electromagnet development; Second, the electro-hydraulic servo valve simplifies the structure and reduces the precision. The proportion valve that introduces below all points to former, it is the mainstream of current proportion valve. Interchangeable with common hydraulic valves.

 

The structure of proportional solenoid valve is shown in figure 5-27. Proportional electromagnet is dc electromagnet, but it is different from ordinary dc electromagnet. The armature of ordinary dc electromagnet has only two working positions of suction and disconnection, and there is almost no air gap in the magnetic circuit during the suction. It is composed of pole shoe 1, coil 2, shell 5 and armature 10. Magnetic field is generated after energizing in coil 2 due to the presence of magnetic isolation ring 4. Make the main part of the magnetic force line pass through armature 10, air gap and pole shoe 1, and form the pole shoe at the return junction to generate a suction gate on the armature with a certain current in the coil. The suction varies with the distance between pole shoe 1 and armature. However, the change of the position of the armature varies little with the change of its suction force in the proper travel of the air gap.

 

The armature of proportional electromagnet is designed to work in this travel. So. By changing the current in the coil, you can get the suction proportional to it on the armature. Using proportional electromagnet instead of screw handle to adjust the hydraulic valve, can make the output force or flow and input current corresponding to proportional change.

 

Proportional valve for analog control, is between the ordinary switch control and servo control control mode, it is also particularly suitable for

 

Renovation or modification of equipment. So that the level of automatic control equipment greatly improved. They make up a large proportion of the modern fluid system

 

Compared with the ordinary hydraulic valve. Proportional valve advantage is: (1) can easily achieve remote control: (2) can continuously, in proportion to the control of the hydraulic system pressure and flow. In this way, the position, speed and force of the actuator can be continuously controlled, and the impact of pressure and speed change can be prevented or reduced. Oil path simplification, the number of components is small.

 

Proportional valve is suitable for both the requirements of continuous control of the expansion force, flow and direction.

 

Proportional valve is also divided into pressure valve, flow valve and direction valve several categories. Recently there has been a trend towards functional complexity.