JP2006194388A - Check valve - Google Patents

Abstract

【Task】
Without applying biasing force such as spring force, self-weight, rubber elastic force, etc. to press the valve body against the valve seat, this effectively reduces the valve opening pressure, that is, cracking pressure when the gas flows in the positive direction. Provide a zero check valve.
[Solution]
The inlet side body 11 and the outlet side body 12 constitute a housing, and a circular sheet is formed in the space of a minute gap in the axial direction between the wall surface 24 of the inlet side body 11 and the abutting wall surface 34 of the outlet side body 12. When the valve body 13 is arranged and a flow in the opposite direction occurs, the valve body 13 is crimped to the wall surface 24 using the wall surface adhesion phenomenon by the flow of gas flowing between the valve body 13 and the wall surface 24. Thus, the discharge port 23 opened in the wall surface 24 is closed, and the flow of gas in the reverse direction is blocked.
[Selection] Figure 5

Description

  The present invention relates to a check valve, and more particularly to a check valve that allows a gas or liquid to flow only in one direction and blocks the flow in the reverse direction.

  Conventionally, check valves have been widely used to control the flow direction of gas or liquid. The check valve is arranged such that the valve body is arranged in the body so as to be able to contact and separate from the valve seat, and the valve body is pressure-bonded to the valve seat by the weight of the spring or the valve body itself. .

  In such a check valve, the forward flow overcomes the biasing force of the spring or the dead weight of the valve body to separate the valve body from the valve seat, thereby generating a flow. On the other hand, in the reverse flow, in order to generate pressure in the same direction as the bias pressure, the valve body is pressed against the valve seat and the flow is blocked. With such a structure, a forward flow is allowed and a reverse flow is blocked.

  In this type of conventional check valve, the valve body is pressed against the valve seat by the elastic restoring force of the spring, the weight of the valve body itself, or the elastic force of rubber. Since the fluid pressure in the positive direction flows against this force, a pressure that overcomes the bias force applied to the valve body and opens the valve body is required. This pressure is called cracking pressure. That is, the cracking pressure refers to a force for opening the valve body.

  Therefore, from this, the operating pressure of the check valve must be equal to or higher than the cracking pressure, and fluid below the cracking pressure is blocked not only in the reverse direction but also in the forward direction. Although the check valve using the weight of the valve body itself can reduce the cracking pressure, the check pressure cannot be reduced to zero. Further, when the bias force for generating the cracking pressure depends on the weight of the valve body, there is a problem that the cracking pressure varies depending on the position and posture of the check valve. Further, the method of pressure-bonding the valve body to the valve seat using the elastic force of rubber has a disadvantage that the cracking pressure is not stable because the elastic force is unstable.

  An object of the present invention is to provide a check valve that does not apply a biasing force to a valve body that is pressed against a valve seat and performs a blocking operation.

  Another object of the present invention is to provide a check valve which can substantially reduce the pressure required to open the valve body by the forward flow, that is, the cracking pressure.

  Still another object of the present invention is to provide a check valve capable of following high-speed operation.

  Yet another object of the present invention is to provide a check valve having high durability.

  Still another object of the present invention is to provide a check valve that can reliably control the flow of a minute amount of gas.

  The above-described problems and other problems of the present invention will be made clear by the technical idea and embodiments of the present invention described below.

In the main invention of the present application, the valve body is arranged in a free state so as to be able to contact and separate from the wall surface where the fluid discharge port opens,
The forward flow discharged from the discharge port separates the valve body from the wall surface,
The reverse flow sucked into the discharge port relates to a check valve characterized in that the valve body is pressure-bonded to the wall surface by a wall surface adhesion phenomenon, and the valve body closes the discharge port.

  Here, the gap between the valve body and the wall surface when spaced apart from the wall surface is the gap between the wall surface and the valve body when an adhering flow is generated in the reverse flow. It may be. In addition, the wall surface and the valve body may have a length in the flow direction so as to generate an attached flow between the wall surface and the valve body when flowing in the opposite direction. The valve body may be a flexible sheet or film. The valve body is a flexible circular sheet or film, and the cross section is arranged in a circular space, and the forward flow is caused by a gap between the outer peripheral portion of the valve body and the inner peripheral surface of the space. It may be allowed to flow through.

  A preferred embodiment of the present invention uses a wall surface adhesion phenomenon which is one of the properties of fluid flow, and thereby opens and closes the valve body, and includes a reaction force of the spring and the weight of the valve body, The cracking pressure is made substantially zero without using a biasing force such as the elastic force of rubber.

  If a flow in the reverse direction occurs here and the valve body is sufficiently away from the opposing wall surface, the fluid will only adhere to one of the surfaces and the check valve will operate. That is, the valve closing operation does not occur. When the wall surface and a flexible valve body such as a diaphragm seal are brought close to each other, the fluid flow that has adhered to only one side works to adhere to the other portion. As a result, the valve body arranged in a free state is attracted to the wall surface, and in the reverse flow, the downstream pressure flows into the portion on the opposite side of the attachment surface of the valve body. A pressure difference is generated between the upstream side and the downstream side of the flow, and the valve body is pressed against the wall surface by this pressure difference, and the closing operation is performed.

  In order to achieve such an operation, the gap between the wall surface and the valve body is sufficiently narrow that the influence of the attached flow is generated on both the wall surface and the valve body, and the wall surface is Therefore, it is necessary that the valve body has a sufficient length in the flow direction so as to be generated, and that the valve body has a sufficient length in the flow direction so that the attached flow can be generated.

  According to the check valve of this aspect, since the valve body is not given a biasing force such as a spring, its own weight, or an elastic force of rubber, the pressure that opens the valve body by the forward flow, that is, the cracking pressure is substantially reduced. Can be made zero. Further, since the movable part of the valve body can be made extremely light, it is possible to follow high-speed operation and exhibit high durability.

  The main invention of the present application is that the valve body is arranged in a free state so as to be able to contact and separate from the wall surface where the fluid discharge port opens, and the flow in the positive direction discharged from the discharge port On the other hand, the flow in the reverse direction in which the valve body is sucked into the discharge port is formed by pressing the valve body against the wall surface by the wall surface adhesion phenomenon and closing the discharge port.

  Therefore, according to such a check valve, when a forward flow discharged from the discharge port is generated, the valve body is separated from the wall surface, so that a passage through which the fluid flows is formed, and the fluid flows. To flow. On the other hand, when a flow in the reverse direction occurs, the valve body is pressure-bonded to the wall surface due to the wall surface flow phenomenon, so that the discharge port formed on the wall surface is closed by the valve body. Therefore, the reverse flow is blocked by the valve body. Since the reverse flow blocking operation utilizes the wall surface adhesion phenomenon of the valve body accompanying the reverse flow, a bias that resists the forward flow with respect to the valve body. There is no need to give power. Therefore, it is not necessary to allow the flow in the positive direction against the bias force as described above, and the pressure required to generate the flow in the positive direction, that is, the cracking pressure can be made substantially zero. Allows flow control of an amount of fluid.

  The present invention will be described below with reference to the illustrated embodiments. As shown in FIG. 1, the check valve according to the present embodiment includes an inlet side body 11, an outlet side body 12, and a circular valve body 13 interposed therebetween. A protrusion 14 having a columnar shape is formed at the front end portion of the outlet side body 12, and a male screw 15 is formed at the base of the protrusion 14, and the protrusion 14 is formed inside the recess 16 of the inlet side body 11. While being inserted, the male screw 15 is screwed onto the female screw 17 formed on the inner peripheral surface of the recess 16 so that the pair of bodies 11 and 12 are assembled together (FIGS. 4 and 4). 5).

  The inlet side body 11 is made of brass and has a substantially hexagonal columnar shape as shown in FIG. 2, and an inlet port 21 is formed at one end and in the center. An internal thread 22 is formed at the base side of the inlet port 21. A pipe line on the inlet side is inserted into the inlet port 21 and is screwed onto the female screw 22. The front end of the inlet port 21 is closed, and a discharge port 23 composed of a plurality of small holes is formed at the closed bottom. The discharge port 23 is opened in the wall surface 24 that forms the bottom surface of the recess 16.

  The outlet body 12 is also made of brass, and an outlet port 28 is formed at the center of one end thereof as shown in FIG. The outlet port 28 communicates with the center hole 29. A circumferential groove 30 is formed on the outer peripheral surface of the protrusion 14, and, for example, four radial holes 31 are formed so that the inner circumferential bottom of the circumferential groove 30 communicates with the center hole 29. A holding groove 32 is formed on the rear side of the circumferential groove 30 of the protrusion 14, and an O-ring 33 is held in the holding groove 32. A portion on the tip end side of the protrusion 14 is a contact wall surface 34.

  The inlet side body 11 shown in FIG. 2 and the outlet side body 12 shown in FIG. 3 are combined, the protrusion 14 of the outlet side body 12 is inserted into the recess 16 of the inlet side body 11, and the male screw 15 is connected to the female screw 17. This check valve is assembled as shown in FIGS. 4 and 5 by screwing. Here, the valve body 13 is, for example, a sheet of flexible fluoro rubber (trade name Viton), and in the present embodiment, a valve having a thickness of 0.15 mm is used. Here, the valve body 13 is disposed between the inlet-side body 11 and the outlet-side body 12 and in a gap portion between the wall surface 24 of the inlet-side body 11 and the abutting wall surface 34 of the outlet-side body 12. The Moreover, the valve body 13 does not have any support and is arranged in a free state.

  In the configuration as described above, the forward flow, that is, the flow of fluid, for example, gas, from the inlet port 21 of the inlet side body 11 to the outlet port 28 of the outlet side body 12, as shown in FIG. Flows through the discharge port 23 to the gap between the wall surface 24 on which the valve element 13 is disposed and the contact wall surface 34. Due to the pressure of the gas at this time, the valve body 13 is brought into a pressure-bonded state against the abutting wall surface 34 of the tip end portion of the protrusion 14 of the outlet side body 12. The gas flows through the gap between the outer peripheral portion of the valve body 13 and the inner peripheral portion of the concave portion 16 of the inlet side body 11 to the peripheral groove 30 of the protrusion 14 of the outlet side body 12, and from this peripheral groove 30. It flows through the radial holes 31 to the central hole 29 of the outlet side body 12 and then flows through the outlet port 28. That is, with respect to the flow in the positive direction, the gas flow is allowed in a state where the valve body 13 made of a circular diaphragm sheet is pressed against the contact wall surface 34.

  On the other hand, the flow in the reverse direction, that is, the flow from the outlet port 28 to the inlet port 21, as shown in FIG. Gas reaches the circumferential groove 30 of the protrusion 14, and then passes through a gap between the outer peripheral portion of the valve body 13 and the inner peripheral surface of the recessed portion 16, and the gas further flows between the valve body 13 and the wall surface 24. After flowing into the gap, it flows from the discharge port 23 to the inlet port 21.

  At this time, a wall surface adhesion phenomenon occurs, and the gas flow adheres to the wall surface 24 of the recess 16 of the inlet side body 11 and the valve body 13 which are minute spaces in the axial direction. Here, since the wall surface 24 does not move due to the flow of gas, the valve element 13 arranged in a free state comes close to the wall surface 24. Accordingly, the resistance of the gap between the valve body 13 and the wall surface 24 that forms the flow path in the reverse direction increases, thereby increasing the gas pressure in the space between the valve body 13 and the contact wall surface 34. As the pressure rises, the valve body 13 receives a leftward force in FIG. 5, and the valve body 13 is pressure-bonded to the wall surface 24 of the recess 16 of the inlet side body 11 due to such a pressure difference. The discharge port 23 opened to 24 is closed. This therefore blocks the reverse flow. These series of operations are performed instantaneously.

  When the gas flows in the opposite direction, if the wall surface 24 of the inlet side body 11 and the valve body 13 are sufficiently separated, the gas only adheres to and flows through only one of the wall surface 24 and the valve body 13. For this reason, the above-described check valve closing operation does not occur. When the gap between the wall surface 24 of the body 11 on the inlet side and the valve body 13 is reduced, the flow of gas that has flowed while adhering only to one side flows so as to adhere to the wall surface 24 and the valve body 13 on both sides. To do. As a result, the valve body 13 supported in a free state is attracted to the wall surface 24 of the inlet side body 11, and for this reason, the pressure on the wall surface 24 side of the valve body 13 is brought into contact with the valve body 13 and the contact wall surface 34. , The pressure difference is generated on both sides of the valve body 13, and the valve closing operation in which the valve body 13 is crimped to the wall surface 24 is performed.

  Therefore, in order to perform the non-return operation by the wall surface adhesion phenomenon as described above, the gap between the wall surface 24 and the valve body 13 is affected by both the wall surface 24 and the valve body 13 due to the influence of the gas adhesion flow. It is necessary for the valve body 13 to be close to the wall surface 24 to such an extent. In the present embodiment, when a rubber sheet having a diameter of 30 mm and a thickness of 0.15 mm is used as the valve body 13, the gap between the valve body 13 and the wall surface 24 is set to 0.8 mm. In general, when used for air or a gas substantially equivalent to air, the gap is preferably set to a value of about 0.5 to 1.5 mm. If it is smaller than the range, the gas flow becomes insufficient, and if it is larger than the range, the check operation due to the wall surface adhesion phenomenon does not operate smoothly.

  Further, in order for the valve body 13 to be crimped to the wall surface 24 by the flow in the reverse direction, the wall surface 24 needs to have a dimension that is sufficiently long with respect to the gas flow direction to the extent that an adhering flow can be generated. It is necessary to be sufficiently long in the radial direction with respect to the outlet 23. Similarly, the valve body 13 needs to have a sufficient length in the flow direction so that an attached flow can be generated. Further, a gap between the outer peripheral portion of the valve body 13 and the inner peripheral surface of the concave portion 16 of the inlet body 11 is a gas passage, and in this embodiment, the value is set to a value of 0.225 mm. ing. When set to approximately this value, there is a function of centering the valve body 13 by the flow of gas and maintaining the center thereof substantially coincident with the axis of the check valve. In general, the gap is preferably 0.2 to 1.0 mm when, for example, a valve body 13 having a diameter of 30 mm is used. If it is smaller than this range, the gas flow rate becomes small, and if it is larger than this range, there is a possibility that the stable position holding of the valve body 13 is not sufficient.

  Such a check valve utilizes the wall surface adhesion phenomenon, which is one of the properties of fluid flow, and thereby opens and closes the valve body 13. Therefore, it is not necessary to apply a spring, self-weight, elastic force, or the like for applying a biasing force for closing to the valve body 13. Therefore, the cracking pressure for overcoming the above pressure and performing the valve opening operation can be made substantially zero. In addition, a very thin and flexible sheet or film can be used as the valve body 13, and since it is held in a free state, the movable part becomes extremely light and can follow high-speed operation. In addition, high durability is produced.

  Although the present invention has been described above with reference to the illustrated embodiments, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the technical idea of the invention included in the present application. For example, although the above embodiment is a check valve for gas, the present invention can also be used as a check valve for liquid.

  The present invention can be widely used as a check valve for controlling the flow in the direction of gas or liquid, particularly for blocking the flow in the reverse direction.

It is a disassembled perspective view which shows the structure of the whole check valve. It is the front view and longitudinal cross-sectional view of the part of an entrance side body. It is the longitudinal cross-sectional view and rear view of an exit side body. It is a longitudinal section showing the internal structure of a check valve when gas flows in the forward direction. It is a longitudinal cross-sectional view which shows the internal structure of a non-return valve when gas is made to flow in the reverse direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Inlet side body 12 Outlet side body 13 Valve body 14 Protrusion part 15 Male thread 16 Recessed part 17 Female thread 21 Inlet port 22 Female thread 23 Discharge port (small hole)
24 Wall 28 Exit port 29 Center hole 30 Circumferential groove 31 Radial hole 32 Holding groove 33 O-ring 34 Abutting wall

Claims (5)

The valve body is arranged in a free state so as to be able to contact and separate from the wall surface where the fluid discharge port opens,
The forward flow discharged from the discharge port separates the valve body from the wall surface,
The reverse flow sucked into the discharge port presses the valve body against the wall surface by a wall surface adhesion phenomenon, and the valve body closes the discharge port.   The gap between the valve body and the wall surface when spaced apart most from the wall surface is a gap in which an adhering flow is generated in both the wall surface and the valve body during a reverse flow. The check valve according to claim 1.   The length of the flow direction is such that the wall surface and the valve body have a length in the flow direction so as to generate an adhering flow between the wall surface and the valve body when flowing in opposite directions. The check valve described.     The check valve according to claim 1, wherein the valve body is a flexible sheet or film. The valve body is a flexible circular sheet or film, and the cross section is disposed in a circular space, and the forward flow passes through a gap between the outer peripheral portion of the valve body and the inner peripheral surface of the space. The check valve according to claim 1, wherein the check valve flows.

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