RU2735121C2 - Self-acting valve - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to mechanisms used in compressor and vacuum equipment operating under pressure. Self-acting valve comprises a centrally-symmetric body having a longitudinal cylindrical air passage, axis of which coincides with the axis of the body, an annular projection serving as a valve seat located on the side of air supply into the valve and protruding into the cylindrical channel, a plurality of longitudinal recesses made in the body, located along the cylindrical channel perimeter in the form of camomile with a gap relative to each other and extending to the annular projection, valve plate having a bearing surface which repeats the valve seat shape, a spring for pressing the valve plate to the seat, cylindrical spring displacement limiter having a diameter exceeding the inlet diameter of the cylindrical channel and fixed by means of a pin in the cylindrical channel on the side of outlet of air from the valve, opposite to the annular projection, means for adjusting spring force arranged on cylindrical spring displacement limiter, wherein total area of flow section of recesses is equal to or greater than flow area of cylindrical channel.

EFFECT: providing minimum gas-dynamic resistance to direct gas flow.

6 cl, 6 dwg

Description

Technology area

The present invention relates to mechanical engineering, to devices used in compressor and vacuum technology, to mechanisms operating under pressure, and more specifically to a self-acting valve.

The invention can be used in devices for pumping liquids and gases, in the automotive industry, aviation, medicine and household appliances.

State of the art

Self-acting valves are among the most critical components of piston machines. They have a significant impact on the two most important characteristics of any piston mechanism - efficiency and reliability. A number of requirements are imposed on them, which are very difficult to satisfy at the same time.

Self-acting valves should provide as little gas-dynamic resistance as possible to the flow of gas flowing through them, have a developed flow area, open under the influence of a small pressure difference before and after the valve, and when open, work without vibrations of moving elements.

Therefore, various valve designs have appeared, but all of them do not meet the specified technical requirements.

Known spherical self-acting poppet valves (see, for example, Piston compressors. Textbook for universities. Leningrad "Engineering", 1987, pp. 197-198), consisting of a saddle with a smoothly rounded sealing edge, valve discs, usually stamped from sheet , the surface of which is the mating of the spherical outer part with the flat central biasing spring and the valve lift stop. Poppet valves are available with a flat disc. The disadvantages of poppet valves include poor utilization of the available area, resulting in increased pressure losses and large dead space. For these reasons, the use of such valves is limited.

As the closest technical solution, a poppet valve disclosed in patent RU 2064089 C1 (published 06/20/1996) is considered, which consists of a seat, to the sealing edge of which is pressed by a spring and pressure from the cylinder side, a plate having a spherical surface on the spring side and a support surface made along the radius, which smoothly connects the spherical surface of the saddle with the spherical surface of the lift limiter, which has a flat support surface and mills (windows). The specified poppet valve has an insufficiently developed flow area, therefore, during operation, it has significant gas-dynamic resistance to the flow. In addition, it should be noted the unstable position of the valve in the flow due to the lack of guides, which leads to undesirable vibrations of the moving elements and, as a consequence, to an increase in the energy spent on pushing the gas and a decrease in the efficiency of the compressor.

The essence of the invention

The technical objective of the present invention is to provide a self-acting valve that provides a minimum gas-dynamic resistance to a direct gas flow and has a good response when closing, more reliable and easier to manufacture.

The technical problem posed was solved by creating a self-acting valve that contains

a centrally symmetric metal casing with a longitudinal cylindrical channel for air passage, the axis of which coincides with the axis of the casing,

an annular lip serving as a valve seat located on the side of the air supply to the valve and protruding into the cylindrical channel,

a plurality of longitudinal grooves made in the body, located along the perimeter of the cylindrical channel in the form of a camomile with a gap relative to each other and reaching an annular protrusion,

a valve disc having a bearing surface that follows the shape of the valve seat,

a spring designed to press the valve disc against the seat,

a cylindrical limiter for spring displacement, having a diameter equal to the diameter of the cylindrical channel and fixed in the cylindrical channel from the side of the air outlet from the valve, opposite to the annular protrusion,

means for adjusting the spring force, located on the cylindrical limiter of the spring movement,

the total flow area of the recesses is equal to or greater than the flow area of the cylindrical channel.

Preferably, the valve seat seating surface is a tapered surface, the taper angle of which is directed towards the side of the air supply to the body.

It is advisable that the valve disc is made in the form of a profiled aerodynamic disc.

Preferably, the means for adjusting the spring force comprises a screw with a locknut moving through a threaded hole in the cylindrical spring stop and a thrust washer, with which one end of the spring interacts, to which the screw force is transmitted.

It is advisable that the cylindrical limiter for the movement of the spring is fixed in the cylindrical channel by means of fastening elements.

The technical effect achieved by the claimed invention is that the proposed self-acting valve provides a minimum gas-dynamic resistance to the direct gas flow and has a good quick response when closing, is more reliable compared to known valves and is easy to manufacture.

Brief Description of Drawings

In the following, the invention is illustrated by the preferred variants of its embodiment with reference to the accompanying drawings, in which:

FIG. 1 shows a self-acting valve in open position (cross-section) according to the invention;

FIG. 2 shows a section along the line P-P in FIG. 1;

FIG. 3 shows an aerodynamically shaped valve disc;

FIG. 4 shows a cylindrical spring travel stop;

FIG. 5 shows a frusto-conical valve disc;

FIG. 6 shows a self-acting valve in a closed position (cross-section) according to the invention.

Description of preferred embodiments of the invention

The self-acting valve 1 (Fig. 1), according to the invention, contains a centrally symmetric body 2 having a longitudinal cylindrical channel 3 for the passage of air, the axis o-o of which coincides with the axis of the body 2.

An annular protrusion 4 serving as a seat 5 of valve 1 is located on the side A of the air supply to the valve and protrudes into the cylindrical channel 3.

In the body 2, a plurality of longitudinal recesses 6 (Fig. 2) are made, located along the perimeter of the cylindrical channel 3 in the form of a camomile with a gap 7 relative to each other and reaching the annular protrusion 4.

The valve disc 8 (Fig. 3) has a support surface 9 that follows the shape of the valve seat 5.

There is a spring 10 designed to press the disc 8 against the seat 5.

The cylindrical limiter 11 for the movement of the spring has a diameter that exceeds the inlet diameter of the cylindrical channel 3, and is fixed by means of a pin 12 (Fig. 4) in the housing 2 from the side B of the air outlet from the valve, opposite to the annular protrusion 4.

The valve contains means 13 for adjusting the spring force, located on the cylindrical limiter 11 of the spring movement.

In this case, the total flow area of the recesses 6 is equal to or greater than the flow area of the cylindrical channel 3.

The support surface of the valve seat 5 is a tapered surface, the taper angle of which is directed to the A side of the air supply to the body 2.

In another embodiment, the valve disc is truncated cone (FIG. 5).

Valve elements are made of metal and / or composite material.

Due to the fact that the seat 5 and the adjacent surface of the disc 8 are made conical relative to the central hole 3, the most tight fit of the disc 8 of the valve to the seat 5 and a decrease in the rebound effect is ensured, since centering is achieved at the moment of closing the valve 1. The conical surface of the seat 5 and the disc 8 valves in the contact zone improve the tightness of the connection.

The means 13 for adjusting the spring force comprises a screw 14 with a lock nut 15, which moves through a threaded hole 16 in the cylindrical limiter 11 of the spring movement, and a thrust washer 17, with which one end of the spring 10 interacts, to which the force of the screw 14 is transmitted.

The self-acting valve 1 has an aerodynamic shape towards the flow and serves as a guide for air flow through the channels 6 surrounding the valve, which makes it possible to reduce turbulence in the flow expansion zone.

The profiled, aerodynamically shaped valve disc straightens the flow and reduces turbulence, thereby lowering the dynamic resistance of the valve and reducing its vibration, as well as increasing the response time.

It should be noted that the said self-acting valve is easy to manufacture.

Self-acting valve 1 operates as follows.

The flow of liquid or gas acts on the valve from the side A of the seat 5 and raises the plate 8 compressing the thrust spring 10, thereby freeing the passage through the side recesses 6. The distance to which the valve plate 8 rises depends on the gas pressure and the stiffness of the thrust spring 10, the position of which can be changed by means of a regulating device 13, which sets the initial valve response threshold.

In the closed position of the valve (Fig. 6), when the flow changes direction, the valve disc 8 is pressed against the seat 5, the channel 3 is closed and the flow stops. The proposed valve can protect pressure devices, i.e. serves as a safety mechanism in case of abnormal fluctuations in gas pressure, leading to the destruction of the object.

Industrial applicability

The self-acting valve can be used in reciprocating compressors, in devices for pumping liquids and gases, in engine building, in aviation, in medicine as a vascular valve and in household appliances, for example, in pumps as a pressure relief valve and as a check valve in pipelines ...

Claims (6)

1. A self-acting valve containing a centrally symmetric body, having a longitudinal cylindrical channel for air passage, the axis of which coincides with the axis of the body, an annular protrusion serving as a valve seat located on the side of the air supply to the valve and protruding into the cylindrical channel, a plurality of made in the body longitudinal grooves located along the perimeter of the cylindrical channel in the form of a camomile with a gap relative to each other and reaching an annular protrusion, a valve disc having a support surface that repeats the shape of the valve seat, a spring designed to press the valve disc against the seat, a cylindrical spring travel stop having diameter exceeding the inlet diameter of the cylindrical channel and fixed by means of a pin in the cylindrical channel on the side of the air outlet from the valve, opposite to the annular protrusion, means for adjusting the spring force, located on the cylindrical limiter of the spring movement, while the total the flow area of the recesses is equal to or greater than the flow area of the cylindrical channel. 2. A self-acting valve according to claim 1, characterized in that the supporting surface of the valve seat is a conical surface, the taper angle of which is directed towards the side of air supply to the body. 3. A self-acting valve according to claim 1, characterized in that the valve plate is made in the form of a profiled aerodynamic disk. 4. A self-acting valve according to claim 1, characterized in that the means for adjusting the spring force comprises a screw with a locknut moving through a threaded hole in the cylindrical spring travel stop and a thrust washer, with which one end of the spring interacts, to which the screw force is transmitted. 5. The self-acting valve of claim. 1, characterized in that the cylindrical limiter for the movement of the spring is fixed in the cylindrical channel by means of fasteners. 6. Self-acting valve according to claim 1, characterized in that the valve elements are made of metal and / or composite material.

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