CN201909074U - Direct-operated water pressure overflow valve with damping piston - Google Patents

Abstract

The utility model relates to a direct-acting water pressure overflow valve with a damping piston. Including the end cover and the valve seat, valve core, left spring seat, guide sleeve, spring, right spring seat and pressure regulating screw arranged in sequence in the valve body; there are annular grooves and cross holes in the valve seat, and the valve core is set on In the axial through hole of the valve seat, a countersunk groove is provided at the end of the valve core, and the cylindrical surface of the tail of the valve core forms a guiding surface with the axial through hole of the valve seat, and forms a cone valve structure with the valve port formed by the valve seat; The valve core is in contact with the left spring seat; the left spring seat is guided by the inner hole of the guide sleeve. The screw rod is threadedly connected with the valve body. The utility model is suitable for a pressure control element in a medium-high pressure water hydraulic system with seawater, fresh water, high water base, etc. as working media. Compared with similar valves, it has simple structure, convenient processing, small leakage, small vibration, low noise, good cavitation resistance and high working stability.

Description

A direct-acting water pressure relief valve with a damping piston

technical field

The utility model relates to a pressure control element in a water hydraulic system, in particular to a direct-acting hydraulic overflow valve with a damping piston, which belongs to the valve class and is suitable for intermediate valves with seawater, fresh water, seawater base, etc. as working media. Pressure control elements in high pressure water hydraulic systems.

Background technique

Relief valve is a commonly used pressure control component in hydraulic system, which can be used as constant pressure relief valve or safety valve. Oil is often used as the working medium in the hydraulic system, and when the overflow valve is used in water (including seawater, fresh water or high water base, etc.) medium, a series of technical problems will arise. ①Because the gasification pressure of water is much higher than that of mineral oil, when water flows at a high speed at the valve port, the local pressure of the flow field will be lower than the gasification pressure of water, and then cavitation will occur, causing the material at the valve port to be affected by gas corrosion, thereby reducing the working reliability and life of the valve; ②Due to the low viscosity and poor lubricity of water, the friction between the valve core and the valve seat and the leakage at the valve port are serious; ③The density and elastic modulus of water are higher than those of minerals. If the oil is large, the "water hammer" phenomenon is serious; ④The radial force caused by the uneven flow of the medium at the valve port and the deviation of the spring force from the axis of the valve core makes the valve core polarized. ⑤ The structure of the hydraulic pressure relief valve is complicated, the processing difficulty increases, and the production cost is high.

Huazhong University of Science and Technology has developed a hydraulic direct-acting relief valve with an oil-gas shock absorbing device. The relief valve spool is equipped with an oil-gas spring, which is composed of an air chamber, an upper oil chamber and a lower oil chamber. The spool moves When the hydraulic oil passes through the small damping hole to form a damping force, at the same time the hydraulic oil can improve the lubrication conditions of the spool, and the movement of the spool has a guiding effect. However, there is still oil in the valve, which is not a pure water medium, the vibration of the valve core is relatively severe, and the noise is very loud; moreover, the structure of the valve is relatively complicated, and the processing cost is relatively high.

The rear end of the direct-acting hydraulic pressure relief valve produced by Danfoss company in Denmark has a damping chamber, which improves the working stability of the valve to a certain extent. However, the valve is prone to polarization, and the resulting vibration noise and working stability still exist. Moreover, the material used in this valve is not suitable for seawater, but only suitable for less corrosive media such as fresh water and seawater.

Utility model content

The utility model provides a direct-acting hydraulic overflow valve with a damping piston, which is used to solve the above-mentioned technical problems existing in the direct-acting overflow valve, works in a water medium environment, improves the working stability of the valve, reduces Valve port leakage, cavitation, vibration, noise, increased corrosion resistance, simplified structure, easy processing, and cost saving.

The technical scheme of the utility model is as follows:

A direct-acting water pressure overflow valve with a damping piston of the utility model includes an end cover and a valve seat, a valve core, a left spring seat, a guide sleeve, a spring, a right spring seat, a pressure regulating valve arranged in sequence in the valve body. Screw; the valve seat has an annular groove in the radial direction, and a cross hole in the axial and radial directions, which is used to increase the flow area at the water inlet and reduce the flow rate and noise of the water inside the overflow valve. Improve the reliability and service life of the relief valve; the valve core is set in the axial through hole of the valve seat, the end of the valve core is provided with a countersunk groove, the countersunk groove and the end cover form a damping chamber, the cylindrical surface of the tail of the valve core is in contact with the The axial through hole of the valve seat forms a guide surface, and forms a cone valve structure with the valve port formed by the valve seat; The force acts on the valve core evenly; the left spring seat is guided by the inner hole of the guide sleeve, and there is a small flow hole on the guide sleeve, and an annular groove is opened on the right side; The pressure screw is threaded to the valve body; the end cover is connected to the valve body through 4 bolts, and the water inlet and outlet on the valve body are connected to other components of the hydraulic system by plate connection or pipe connection.

Among them, the spool acts as a damping piston. A T-shaped elongated through hole is opened in the valve core along the axial direction and radial direction, and communicates with the countersunk groove at the end thereof. On the one hand, it is to facilitate the processing of the slender hole; on the other hand, the countersunk groove and the end cover form a damping chamber, and the pressure change in the damping chamber when the valve core moves is used to increase the motion damping of the valve core and improve the valve core's performance. Work stability, so the spool acts as a damping piston at the same time; at the same time, the tail end of the spool is designed with a guiding cylindrical surface, which forms a matching gap with the inner hole of the valve seat, provides guidance for the movement of the spool, and can reduce the spool in the valve. Polarization during work.

The contact port between the valve seat and the valve core is an annular stepped hole, so that the valve seat and the valve core form a two-stage throttling valve port structure. That is, when the relief valve works under a relatively high pressure state, the contact port between the valve seat and the valve core is designed as a countersunk groove, and then the through hole is processed, so that a two-stage throttling is formed between the valve seat and the valve core. The structure of the mouth can reduce the hazards of cavitation and leakage.

In addition, the outer cylindrical surface at the tail end of the valve core can also be milled and flattened, so that the high-pressure water at the inlet can act on the bottom of the piston. That is, there is no need to open T-shaped through holes along its radial and axial directions. On the one hand, it plays a damping role when the poppet valve is opened or closed, which is used to improve the stability of the poppet valve; on the other hand, it is used to ensure that the poppet valve will not tilt after opening, so as to improve the static characteristics of the poppet valve.

The valve seat and the valve core are matched with soft-hard materials, wherein the valve seat is made of aluminum bronze or engineering plastic with low hardness, and the valve core is made of strengthened stainless steel material.

The valve body is provided with an annular groove at the outlet, which can effectively increase the flow area at the outlet, reduce the flow velocity at the outlet, and increase the service life.

Compared with the structure of other direct-acting overflow valves, the utility model provides a direct-acting water pressure overflow valve with a damping piston. The utility model has a simple structure, is easy to process, and saves costs.

Description of drawings

Fig. 1 is a structural diagram of a direct-acting hydraulic overflow valve with a damping piston of the present invention.

Fig. 2 is the embodiment of the utility model valve seat and valve core secondary throttling valve port.

Fig. 3 is a structure diagram of another embodiment in which the spool of the utility model acts as a damping piston.

Fig. 4 is a sectional view of A-A in Fig. 3 .

In the figure: 1, end cover, 2, valve seat, 3, spool (damping piston), 4, left spring seat, 5, guide sleeve, 6, valve body, 7, spring, 8, right spring seat, 9, Pressure regulating screw, P, water inlet, O, water outlet.

Detailed ways

Below in conjunction with accompanying drawing 1-4, the utility model is further described by embodiment.

Example 1

As shown in Figure 1, the overflow valve includes an end cover 1 and a valve seat 2, a valve core 3, a left spring seat 4, a guide sleeve 5, a spring 7, a right spring seat 8, a pressure regulating Screw 9; the valve seat 2 has an annular groove in the radial direction, and has a cross hole in the axial and radial direction, and the valve core 3 has a T-shaped elongated through hole in the axial and radial direction. The countersunk groove at the end communicates, the countersunk groove and the end cover 1 form a damping chamber, the valve core 3 is inside the valve seat 2, and the cylindrical surface of its tail forms a guide surface with the axial through hole of the valve seat 2, which is connected with the valve seat 2. The formed valve port is a cone valve structure; the valve core 3 and the left spring seat 4 contact and cooperate to transmit the pressure regulating spring force, and the contact surface of the two is a spherical surface; the left spring seat 4 is guided by the inner hole of the guide sleeve 5, and the guide sleeve 5 There is a small hole for flow on the top, and an annular groove is opened on the right side; the pressure regulating screw 9 is threadedly connected with the valve body 6, and the inlet and outlet of the overflow valve can adopt a plate connection or a pipe connection structure.

When installing, put the right spring seat 8, spring 7, and left spring seat 4 into the valve body 6 first to ensure that the spring 7 is located between the left and right spring seats, and the guide sleeve 5 is positioned against the internal steps of the valve body 6 and passes through the left spring seat 4. Insert the valve core 3 into the inner hole of the valve seat 2, then put the two together into the valve body 6, and then install the end cover 1 on the end surface of the valve body 6 through bolts, so that the end of the valve seat 2 presses the guide sleeve 5. Finally, screw the pressure regulating screw 9 into the valve body 6 from the right end. The lower bottom surface of the valve body 6 is provided with an installation threaded hole, which is convenient for connecting the overflow valve with other elements of the hydraulic system.

When working, high-pressure water enters the annular groove and cross hole of the valve seat 2 from the water inlet P, and then flows through the slender through hole of the valve core 3 to the countersink groove at the end, and the liquid pressure acts on the valve seat through the countersink groove. On the spool 3, when the hydraulic pressure is greater than the working pressure set by the pressure regulating spring 7, the spool 3 opens, the water flows out through the valve port, and then flows into the spring chamber through the flow hole of the guide sleeve 5, and finally flows out from the water outlet. O flow out. The pressure of the water inlet P can be set by changing the pre-compression of the pressure regulating spring 7 . During the adjustment process of the spool 3, the guiding surface of the valve seat 2 can suppress the polarization when the spool is opened, and the guiding surface of the guiding sleeve 5 can relieve the eccentricity of the spring. The hole can reduce the pressure change and improve the damping effect of the valve core when it moves, thereby improving the service life of the valve seat and the working stability of the valve core.

Example 2

Accompanying drawing 2 is the embodiment of the utility model valve seat and valve core secondary throttling valve port. That is, when the relief valve works under a relatively high pressure state, the contact port between the valve seat 2 and the valve core 3 is designed as a countersunk groove and then the through hole is processed, so that a two-stage pressure is formed between the valve seat and the valve core. The structure of the orifice can reduce the hazards of cavitation and leakage.

Example 3

Accompanying drawing 3-4 is another embodiment that the spool of the present utility model plays damping piston effect. That is, there is no need to open T-shaped through holes along its radial and axial directions, and the outer cylindrical surface of the tail end of the valve core 3 is milled and flattened, so that the high-pressure water at the water inlet directly enters from here and acts on the bottom of the piston. On the one hand, it plays a damping role when the poppet valve is opened or closed, which is used to improve the stability of the poppet valve; on the other hand, it is used to ensure that the poppet valve will not tilt after opening, so as to improve the static characteristics of the poppet valve.

Claims (6)

1. A direct-acting water pressure relief valve with a damping piston, comprising an end cover (1) and a valve seat (2), a valve core (3), a left spring seat ( 4), guide sleeve (5), spring (7), right spring seat (8), pressure regulating screw (9); there is an annular groove in the valve seat (2) along the radial direction, and along its axial and radial direction There is a cross hole, the valve core (3) is set in the axial through hole of the valve seat (2), the end of the valve core (3) is provided with a countersunk groove, and the countersunk groove and the end cover (1) form a damping chamber , the cylindrical surface at the tail of the valve core (3) forms a guiding surface with the axial through hole of the valve seat (2), and forms a cone valve structure with the valve port formed by the valve seat (2); the valve core (3) and the left spring The seat (4) contacts and cooperates to transmit the pressure regulating spring force, and the contact surface of the two is a spherical surface; the left spring seat (4) is guided by the inner hole of the guide sleeve (5), and the guide sleeve (5) is provided with a flow hole. The right side has an annular groove; the spring (7) is located between the left and right spring seats; the pressure regulating screw rod (9) is threadedly connected with the valve body (6). 2. A direct-acting hydraulic relief valve with a damping piston as claimed in claim 1, characterized in that: the spool (3) has a T-shaped elongated through hole along the axial and radial directions, and It communicates with the countersink at the end. 3. A direct-acting hydraulic relief valve with a damping piston as claimed in claim 1, characterized in that: the contact port between the valve seat (2) and the valve core (3) is an annular step hole, so that the valve seat (2) and the spool (3) form a secondary throttling valve port structure. 4. A direct-acting hydraulic overflow valve with a damping piston as claimed in claim 1, characterized in that: the outer cylindrical surface of the tail end of the valve core (3) is a milled and flattened structure, so that the high-pressure water at the inlet can This acts on the bottom of the piston. 5. A direct-acting hydraulic pressure relief valve with a damping piston according to any one of claims 1-4, characterized in that: the end cover (1) and the valve body (6) are connected by 4 bolts , the water inlet (P) and the water outlet (O) on the valve body (6) and other components of the hydraulic system adopt plate connection or pipe connection. 6. A direct-acting water pressure relief valve with a damping piston according to any one of claims 1-4, characterized in that: the valve seat (2) and the valve core (3) are made of soft-hard materials Matching, the valve seat is made of aluminum bronze or engineering plastic with low hardness, and the valve core is made of reinforced stainless steel.

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