JPH0729371U - Flow control valve - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a small and simple water control valve that can be installed in a flow path. [Structure] An elastic membrane 3 which partitions a flow path and has a primary passage hole 15 formed in the center, and a partition wall 7 which partitions a flow passage on the downstream side and has a secondary passage hole 14 are provided. The partition wall 7 is provided with a valve seat 4 having a distance from the elastic membrane 3
The flow rate is controlled by changing the distance from the valve seat 4 by the displacement of.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a flow valve that controls a fluid flow rate to a constant amount with respect to fluctuations in supply pressure.

[0002]

[Prior art]

 Generally, gas appliances and the like incorporate a flow rate control valve (hereinafter referred to as a control valve) that controls the gas flow rate to a constant amount. This control valve plays the role of ensuring a stable combustion gas amount even if the supply pressure of the gas fluctuates. As an example, the constant flow valve disclosed in Japanese Utility Model Laid-Open No. 2-47330 will be described with reference to FIG.

The control valve 40 has a substantially cylindrical lid 43 having a gas inflow portion and a substantially cylindrical main body 45 having a gas outflow portion faced by their flange surfaces 44, 45, and a diaphragm valve 54 therebetween. It is fixed by sandwiching. Therefore, the primary chamber 42 is formed on the upstream side of the diaphragm valve 54, and the secondary chamber 46 is formed on the main body 45 side. A valve seat 51 facing the diaphragm valve 54 and having a gap is provided in the center of the main body 45, and a communication hole 50 for guiding gas to the outlet is formed in the center of the valve seat 51. The communication hole 50 serves as a flow path for guiding the controlled gas to the outlet, and is therefore sufficiently large. A spring 47 is provided on the outer periphery surrounding the valve seat 51 and urges the diaphragm valve 54 in the valve opening direction. The diaphragm valve 54 has a through hole 53 located outside the abutting portion of the spring 47, and the gas in the primary chamber 42 flows into the secondary chamber 46 through the through hole 53.

When the gas pressure P0 is applied to the primary chamber 42, the gas passes through the through hole 53, flows into the secondary chamber 46, becomes the pressure P1, and then passes through the gap between the diaphragm valve 54 and the valve seat 51. The pressure becomes P2. The diaphragm valve 54 receives the pressure difference between P0 and P1 on the pressure receiving surface and acts in the valve closing direction (downward direction in the drawing). On the other hand, the diaphragm valve 54 is operated by the spring 47 in the valve opening direction.

When the supply pressure P0 increases and the pressure of P1 also increases and the flow rate increases, the differential pressure between P0 and P1 also increases because the through hole 53 is a fixed flow path. Therefore, the force due to the differential pressure overcomes the force of the vane 47 and narrows the gap between the diaphragm valve 54 and the valve seat 51. Further, when the supply pressure P0 decreases and the pressure P2 decreases and the flow rate decreases, the pressure difference between P0 and P1 also decreases because the through hole 53 is a fixed flow path. Therefore, the force due to the differential pressure loses the force of the spring 47 and widens the gap between the diaphragm valve 54 and the valve seat 51.

When the passage resistance of the valve seat 51 after the communication hole 50 decreases and the flow rate increases, the pressure of P2 decreases and the differential pressure between P0 and P1 increases. Therefore, the force due to the differential pressure overcomes the force of the spring 47 and narrows the gap between the diaphragm valve 54 and the valve seat 51.

When the passage resistance of the valve seat 51 after the communication hole 50 increases and the flow rate decreases, the pressure of P2 increases and the pressure difference between P0 and P1 decreases. Therefore, the force due to the differential pressure loses the force of the spring 47 and widens the gap between the diaphragm valve 54 and the valve seat 51. From the above, the diaphragm valve 54 acts so as to balance the force acting on the pressure receiving surface in the valve closing direction with the pressure difference between P0 and P1 and the force acting on the diaphragm valve 54 in the valve opening direction by the spring 47. Therefore, if the load of the spring 47 is constant, the pressure difference between P0 and P1 is also constant, and the flow rate through the through hole 53 is constant.

[0008]

[Problems to be solved by the device]

 However, even if the above control valve is used as it is to control the flow rate, various inconveniences actually occur. For example, a spring receiver is required to evenly apply a spring load to the diaphragm valve, a guide for preventing deformation of the through hole, and a member for preventing deformation of the valve seat abutting portion of the diaphragm valve. Will be required. Also, since the through hole is eccentrically opened outside the valve seat abutting portion of the diaphragm valve, the diaphragm valve is prone to tilting and is unstable, and there is a problem that stable performance is difficult to obtain. In addition, since the diaphragm is sandwiched to maintain airtightness, there is a risk of fluid leakage to the outside due to poor sealing at the flange surface. It is an object of the control valve of the present invention to solve the above problems and provide an inexpensive, small-sized, simple-structured control valve.

[0009]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the flow valve of the present invention divides the flow passage and also has an elastic membrane having a primary passage hole formed in the center and a downstream passage that faces the elastic membrane and divides the flow passage. A partition wall having a secondary passage hole formed therein, and a valve seat having a gap between the primary passage hole peripheral portion and the primary passage hole facing the primary passage hole of the elastic membrane is provided on the partition wall, and the displacement of the elastic membrane causes the valve seat to move. The gist is to change the gap between the peripheral portion of the primary passage hole and the valve seat.

The flow valve of the second invention is the flow valve of the first invention, wherein a communication hole having a diameter smaller than the primary passage hole faces the primary passage hole of the elastic membrane in the central portion of the valve seat. The main point is that they are formed.

According to a third aspect of the present invention, in the flow valve according to the first or second aspect, the valve seat is screwed into the partition wall, and the screwing position adjustment adjusts the peripheral position of the primary passage hole and the valve seat. The point is that the gap between and is finely adjusted.

[0012]

[Action]

 The control valve of the present invention having the above structure operates by utilizing the elastic force of the elastic film. The fluid passes through the primary passage hole in the center of the elastic membrane, passes through the gap with the valve seat, and is discharged to the downstream side of the control valve through the secondary passage hole provided in the partition wall. At this time, when the fluid passes through the primary passage hole in the center of the elastic film, a pressure difference is generated before and after the elastic film, and the elastic film is deformed in the downstream direction depending on the degree of the pressure difference. The larger the pressure difference, the smaller the gap between the elastic membrane and the facing valve seat, and the smaller the pressure difference, the larger the gap between the elastic membrane and the valve seat. Therefore, if the supply pressure changes, the opening degree between the elastic membrane and the valve seat changes, and the flow rate is controlled to a predetermined amount.

Further, in the control valve of the second invention, the fluid passing through the primary passage hole of the elastic membrane passes through not only the secondary passage hole but also the communication hole provided in the central portion of the valve seat. Therefore, even if the fluid supply pressure becomes too large and the gap between the elastic membrane and the valve seat is closed, the flow path of the communication hole is always ensured and the fluid flow does not stop.

Further, in the control valve of the third invention, since the valve seat is screwed into the partition wall, the clearance between the peripheral edge portion of the primary passage hole of the elastic membrane and the valve seat can be finely adjusted for mass production. It is possible to make the control valve that matches the target performance by absorbing the variation in individual performance.

[0015]

【Example】

 In order to further clarify the structure and operation of the present invention described above, a preferred embodiment of the flow rate control valve of the present invention will be described below. FIG. 1 shows a gas flow rate control valve as an example. The gas flow rate control valve 1 (hereinafter, simply referred to as a control valve) is arranged in the middle of the gas pipeline GP, and includes a case 2, an elastic membrane 3, a valve seat 4, a seat retainer 5, and a ring 6. To be done.

The case 2 is a substantially cylindrical body that fits into the gas flow passage, and has a partition wall 7 that divides the flow passage on the downstream side (lower side in the drawing). A screw hole 8 is formed in the center of the partition wall, and the valve seat 4 is screwed into the screw hole 8 to be mounted. A step portion 11 is formed on the inner cylindrical wall surface 10 of the case 2 by changing the wall thickness. The elastic film 3 is placed on the step portion 11, and the elastic film 3 is fixed by the ring 6 via the sheet retainer 5.

The elastic film 3 is made of an elastic material such as rubber and is formed into a disc shape, and a hole 15 (hereinafter, referred to as a primary passage hole) through which a gas passes is provided in the center thereof.

The valve seat 4 has a seat portion 12 facing the elastic film 3 and has a gap close to the primary passage hole 15 of the elastic film 3. A communication hole 13 is formed in the center of the seat portion 12 of the valve seat 4 so as to communicate downstream. The screw-in type valve seat 4 can be moved back and forth by a screwdriver or the like, and the clearance between the valve seat 4 and the elastic film 3 can be finely adjusted.

The partition wall 7 of the case 2, which is the mounting surface of the valve seat 4, has a hole 14 (hereinafter referred to as a secondary passage hole) having a sufficient area as a flow passage for the gas downstream. , Multiple openings are provided to surround the valve seat 4.

As described above, the control valve of the present embodiment is configured as a single unit in which the ring 6, the sheet retainer 5, the elastic membrane 3, and the valve seat 4 are sequentially installed in the case 2 from the upstream side, It is attached to a step portion formed in the pipe line GP and is fixed by a ring 20.

Next, the operation of the control valve will be described. FIG. 2 shows the operating state of the control valve, and FIG. 3 shows the control characteristics of the control valve. For convenience of explanation, the upstream side with the elastic film 3 interposed is the first chamber 16, the room between the elastic film 3 and the partition wall 7 of the case 2 is the second chamber 17, and the downstream side with the partition wall 7 as the boundary. Call it the third room 18. The state of (a) of FIG. 2 shows the state on the section A on the flow characteristic of FIG. 3, and the state of (b) corresponds to the state on the section B of the flow characteristic.

In FIG. 2A, when the gas passes through the primary passage hole 15 of the elastic film 3 due to the supply pressure P0 from the first chamber 16 side, the gas enters the second chamber 17 and is depressurized to the pressure P1. A part of the gas sent to the second chamber 17 enters the third chamber 18 as a fixed flow path that passes through the communication hole 13 of the valve seat 4, and the rest of the gas passes through the gap between the elastic membrane 3 and the valve seat 4. After passing through, it enters the third chamber 18 through the secondary passage hole 14 of the case and merges. Therefore, the gas pressure becomes P2, and the flow rate becomes Q0. The force exerted on the elastic membrane 3 depends on the pressure difference between the first chamber 16 and the second chamber 17, and if the force is smaller than the elastic force of the elastic membrane 3, the elastic membrane 3 does not deform. For this reason, the flow rate changes in proportion to the supply gas pressure over the section A on the flow rate characteristic of FIG.

When the supply pressure P0 from the first chamber 16 side further rises, the differential pressure between the first chamber 16 and the second chamber 17 increases, and the force applied to the elastic film 3 becomes larger than the elastic force. Therefore, as shown in FIG. 2B, the elastic film 3 is deformed without maintaining a stationary state, and the opening degree between the elastic film 3 and the valve seat 4 is narrowed. When the supply pressure P0 decreases, the pressure difference between the first chamber 16 and the second chamber 17 decreases, and the elastic force of the elastic membrane 3 increases the opening degree of the gap between the upper and the valve seat 4. Therefore, the opening degree of the gap between the elastic membrane 3 and the valve seat 4 is changed according to the fluctuation of the supply pressure. As a result, the flow rate changes over the section B on the flow rate characteristic in FIG. 3 regardless of the supply pressure, and the downstream flow rate Q0 is controlled to a constant value.

When the passage resistance after the communication hole 13 of the valve seat 4 decreases and the flow rate increases, the differential pressure between P0 and P1 increases, and the force applied to the elastic membrane 3 is larger than the elastic force. Become. Therefore, the opening degree of the gap between the elastic film 3 and the valve seat 4 is narrowed. On the contrary, when the passage resistance after the communication hole 13 of the valve seat 4 increases and the flow rate decreases, the differential pressure between P0 and P1 decreases, and the elastic force between the elastic membrane 3 and the valve seat 4 is lost due to the elastic force. The opening of the gap is widened to control the flow rate Q0 to a constant value. The elastic membrane 3 receives the pressure difference between P0 and P1 on the pressure receiving surface and widens the gap by the force acting in the direction of narrowing the opening degree of the gap between the elastic membrane 3 and the valve seat 4 and its own elastic force. It works to balance the force acting in the direction. Therefore, if the elastic force is constant, the differential pressure between P0 and P1 is also constant, and the flow rate Q0 passing through the primary passage hole 15 is also constant.

In the unlikely event that the gas supply pressure P0 exceeds the desired control range and becomes excessively large, the force exerted on the elastic film 3 due to the differential pressure between the first chamber 16 and the second chamber 17 is elastic. Much bigger than power. Therefore, the elastic film 3 is largely deformed to close the opening of the gap with the valve seat 4, but the gas passes through the fixed flow passage of the communication hole 13 of the valve seat 4 and enters the third chamber 18. Because it flows, the gas flow does not stop. Therefore, the problem that the gas supply pressure P0 becomes temporarily excessive for some reason and the stopped state continues does not occur.

In order to make the flow rate characteristic ideal, the elastic force of the elastic film 3, the primary passage hole diameter of the elastic film 3, the pressure receiving area of the elastic film 3, the thickness of the elastic film 3, the shape of the sheet portion of the elastic film 3, Seat diameter of valve seat 4, seat portion shape of valve seat 4, communication hole diameter of valve seat 4, secondary passage hole diameter of case 2, secondary passage hole position of case 2, elastic membrane 3 and seat of valve seat 4 The gaps between the parts are optimally selected.

The valve seat 4 is screwed into the case 2, and the opening degree with the elastic film 3 can be finely adjusted by a driver or the like. Therefore, the accuracy of the flow rate characteristics during mass production can be further improved. Also, even for devices having different flow rates, other parts can be made common by only adjusting the clearance of the valve seat 4 or replacing the valve seat 4. In addition, it is more convenient to adjust by installing an adjustment port from the outside of the flow path in the state where it is built into the equipment. Also, since the entire unit can be built into the flow path as it is, there is no restriction on the space of the built-in equipment. However, any flow path can be easily changed to a flow rate controlled flow path. Furthermore, it will be compact and easy to handle, and will be versatile. In addition, since it is built into the flow channel as it is, there is no connection part in contact with the outside air, and there is no possibility of gas leaking to the outside. Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments and can be implemented in various modes. For example, the material of the elastic film 3 is not limited to rubber or the like, and various materials such as synthetic resin can be used. Further, the invention is not limited to the control of the gas flow rate, and may be applied to the control of the flow rate of liquid such as water and oil.

[0028]

[Effect of device]

 As described above in detail, the flow control valve of the present invention has a small number of parts, is small in size, and can perform flow control at low cost. Further, since it is incorporated into the flow path, the space of the equipment to be incorporated is not restricted, and since there is no connecting portion that contacts the outside air, fluid does not leak out of the flow path.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a flow rate control valve as one embodiment.

FIG. 2 is an explanatory diagram of the operation.

FIG. 3 is a flow rate characteristic diagram.

FIG. 4 is a schematic configuration diagram of a flow control valve as a conventional example.

[Explanation of symbols]

 1 Gas Flow Control Valve 2 Case 3 Elastic Membrane 4 Valve Seat 7 Partition Wall

Claims (3)

[Scope of utility model registration request] 1. An elastic membrane that divides a flow passage and has a primary passage hole formed in the center, and a partition wall that faces the elastic membrane and divides the downstream passage and also has a secondary passage hole. The partition wall is provided with a valve seat facing the primary passage hole of the elastic membrane and having a gap with the peripheral edge portion of the primary passage hole, and the displacement of the elastic membrane forms a gap between the peripheral edge portion of the primary passage hole and the valve seat. A flow control valve characterized by being changed. 2. The flow rate according to claim 1, wherein a communication hole having a diameter smaller than that of the primary passage hole is formed in a central portion of the valve seat so as to face the primary passage hole of the elastic film. Control valve. 3. The valve seat according to claim 1, wherein the valve seat is screwed into the partition wall and the clearance between the peripheral edge portion of the primary passage hole and the valve seat is finely adjusted by adjusting the screwing position. Item 2. The flow control valve according to item 2.