WO2022079790A1

WO2022079790A1 - Flow rate control valve

Info

Publication number: WO2022079790A1
Application number: PCT/JP2020/038598
Authority: WO
Inventors: 実菱川; 正和今西
Original assignee: タイム技研株式会社
Priority date: 2020-10-13
Filing date: 2020-10-13
Publication date: 2022-04-21
Also published as: JP7305237B2; JPWO2022079790A1

Abstract

Provided is a flow rate control valve that enables high turndown by achieving extremely low flow rate control that conventional needle valves are not capable of. A flow rate control valve 1 includes: a valve chamber 22; a first port 20 and a second port 21 that communicate with the valve chamber 22; a valve seat 18 provided in a valve opening 19 of the second port 21; a valve body 25 that is seated on the valve seat 18; and a driving unit 13 that connects to the valve body 25 and allows the position of the valve body 25 to move in the valve opening/closing direction, wherein the valve body 25 is provided with a plug 14 insertable into the valve opening 19 at the center and with a sponge 16 being interposed between the valve body 25 and the valve seat 18 so as to be seated on the valve seat 18 while surrounding the circumference of the plug 14.

Description

Flow control valve

The technique disclosed in this application mainly relates to a flow rate control valve that controls the flow rate of air, fuel gas, etc.

Conventionally, a flow rate control valve using a needle valve is disclosed in Patent Document 1 and the like.

Patent Document 1 describes a valve body having a primary port and a secondary port communicating with the valve chamber and having a valve seat at the communication valve port of the partition wall on the secondary port side, and a valve opening valve seat of the valve body. A stepping motor provided with a needle valve that can move the position in the valve opening / closing direction that is rotated by energization of the stator coil, and a valve operating mechanism that opens / closes the needle valve by the screw feed action of the rotation of the stepping motor. An electric flow control valve comprising the above is disclosed.

Japanese Patent No. 3181118

In the flow rate control valve using the needle valve disclosed in Patent Document 1 and the like, low flow rate control is possible by lengthening the needle and reducing the inclination angle of the inclined tapered surface.

However, in the flow rate control valve using these conventional needle valves, there is a limit to the lower limit flow rate at which the flow rate can be controlled, and there is a problem that it is difficult to stably control the flow rate even at a smaller minute flow rate. Therefore, there is a limit to the amount of turndown, which is the difference between the maximum and minimum flow rates that can be controlled.

The technique disclosed in the present application has been proposed in view of the above problems, and is a flow control valve that enables control of an extremely small flow rate, which was not possible with a conventional needle valve, and realizes a large turndown. The purpose is to provide.

In order to achieve the above object, the flow control valve according to claim 1 includes a valve chamber, a primary port and a secondary port communicating with the valve chamber, a valve seat provided at the valve port of the secondary port, and a valve seat. It consists of a valve body that sits down and a drive unit that connects to the valve body and allows the valve body to move its position in the valve opening / closing direction. In a flow control valve that controls the flow rate of passing fluid, the valve body is provided with a plug that can be inserted into the valve port of the secondary port in the center, and between the valve body and the valve seat, a hole that sits on the valve seat is porous. It is characterized in that it is provided with a quality elastic body intervening.

The flow rate control valve according to claim 2 is the flow rate control valve according to claim 1, wherein the elastic body has a cylindrical shape whose inner diameter is larger than the maximum diameter of the plug, and is around the plug between the valve body and the valve seat. The upper end surface of the elastic body is provided so as to be fixed to the plug.

The flow rate control valve according to claim 3 is the flow rate control valve according to claim 1, wherein the elastic body has a cylindrical shape whose inner diameter is larger than the maximum diameter of the plug, and is plugged between the plug of the valve body and the valve seat. The lower end surface of the elastic body is provided so as to surround the periphery of the valve seat so as to be fixed to the upper surface of the valve seat.

The flow control valve according to claim 4 is the flow control valve according to claim 1, wherein the valve port has an upper valve port into which a plug can be inserted and slidable, and a valve seat on which an elastic body is seated. The elastic body has a columnar shape or a polygonal column shape having an outer diameter smaller than the opening diameter of the upper valve opening and larger than the opening diameter of the lower valve opening, and is under the plug of the valve body. It is characterized in that the upper end surface of the elastic body is provided so as to be fixed to the lower end surface of the plug so as to be interposed between the end surface and the valve seat.

The flow rate control valve according to claim 5 is the flow rate control valve according to any one of claims 1 to 4, wherein the elastic body is a sponge made of a synthetic rubber material.

The flow rate control valve according to claim 6 is the flow rate control valve according to any one of claims 1 to 5, wherein the drive unit moves and controls the valve body to a position in the valve opening / closing direction by a stepping motor. do.

In the flow control valve according to claim 1, a valve body having a plug that can be inserted into the valve port of the secondary port at the center is moved in the direction of the valve seat by the drive unit, and is interposed between the valve body and the valve seat. The valve opening can be closed by the elastic body by seating the elastic body on the valve seat and further compressing the elastic body completely to make the volume of the pores of the elastic body zero. Then, with the lower end surface of the elastic body in contact with the valve seat, the valve body is moved up and down with respect to the valve seat to compress / release the elastic member to increase or decrease the volume of the holes in the elastic body. This makes it possible to control an extremely small flow rate, which was not possible with conventional needle valves. In addition, with the elastic body isolated from the valve seat, the plug of the valve body is inserted / isolated from the valve opening, and the plug is completely isolated from the valve opening, so that the flow rate is equivalent to that of the conventional needle valve. Flow rate control is also possible. As a result, the difference between the minimum flow rate and the maximum flow rate whose flow rate can be controlled becomes large, and a large turndown can be realized.

In the flow control valve according to claims 2 and 3, the elastic body has a cylindrical shape whose inner diameter is larger than the maximum diameter of the plug, and is interposed between the valve body and the valve seat so as to surround the plug and under the plug. By fixing it to the end face or the upper surface of the valve seat, the elastic body is completely compressed when the valve is closed, the volume of the pores of the elastic body is reduced to zero, and the valve opening is securely closed by the elastic body. Can be done. Further, with the elastic body in contact with the valve seat, the valve body is moved up and down with respect to the valve seat to compress / release the elastic member, and the volume of the holes in the elastic body is increased or decreased to make it extremely small. Allows control of flow rate. In addition, since the elastic body intervenes so as to surround the plug, the relationship between the amount of movement of the valve body and the flow rate of the fluid passing through the valve port becomes substantially constant, and control of an extremely small flow rate is easy and stable. It will be possible.

The flow control valve according to claim 4 is provided with an upper valve port in which a plug is inserted and slidable, and a lower valve port in which a valve seat on which an elastic body is seated is provided at an upper end portion. Then, the elastic body has a cylindrical shape or a polygonal column shape whose outer diameter is smaller than the opening diameter of the upper valve opening and is larger than the opening diameter of the lower valve opening, and is interposed between the lower end surface of the plug of the valve body and the valve seat. However, the upper end surface of the elastic body is fixed to the lower end surface of the plug. Therefore, by moving the valve body up and down, the elastic body is seated on the valve seat provided at the upper end of the lower valve port and is in contact with the valve seat. When the plug is separated from the valve seat provided at the upper end portion, the plug moves the upper valve port up and down or separates it from the upper valve port to control an extremely small flow rate as in the flow control valve according to claims 1 to 3. At the same time, it is possible to control the flow rate equivalent to that of a conventional needle valve.

In the flow control valve according to claim 5, the cost of parts can be reduced by forming the elastic body with a sponge made of a synthetic rubber material.

In the flow rate control valve according to claim 6, since the movement of the valve body can be finely controlled by using a stepping motor for the drive unit, the flow rate of the fluid passing through the valve opening can be finely controlled. ..

It is sectional drawing in the closed state of the flow rate control valve which is one Embodiment which concerns on this invention. It is sectional drawing in the opened state of the flow rate control valve which is one Embodiment which concerns on this invention. (A) top view and (B) front view of a plug (corresponding to a needle) constituting a valve body according to the present invention. (A) top view and (B) front view of a sponge (corresponding to an elastic body) constituting a valve body according to the present invention. It is a figure explaining the relationship between the movement amount (stroke) of a valve body, and a flow rate. It is sectional drawing in the opened state of the flow rate control valve which is another embodiment (the 1) which concerns on this invention. FIG. 6 is a diagram illustrating a state of movement of the valve body in the embodiment according to FIG. It is sectional drawing in the opened state of the flow rate control valve which is another embodiment (the 2) which concerns on this invention. FIG. 8 is a diagram illustrating a state of movement of the valve body in the embodiment according to FIG. It is a figure explaining the flow rate control valve which is another Embodiment (3), (4) and (5) which concerns on this invention.

First, the flow rate control valve 1, which is an embodiment of the present invention, will be described with reference to the drawings.

1 and 2 show a flow rate control valve 1 according to an embodiment of the present invention, which is interposed in a gas supply path to a burner or the like, and FIG. 1 is a cross-sectional view in a closed state. , FIG. 2 is a cross-sectional view in a valve open state.

As shown in FIG. 1, the flow rate control valve 1 is incorporated in a body 10 that forms a flow path for a fluid such as gas. The body 10 is provided with a valve chamber 22 in which the valve body 25 of the flow control valve 1 is housed, and a primary port 20 and a secondary port 21 communicating with the valve chamber 22. A valve port 19 is provided between the valve chamber 22 and the secondary port 21, and a valve seat 18 on which the valve body 25 of the flow control valve 1 is seated is provided on the upper end surface of the valve port 19. The lower surface of the body 10 is supported by the lower plate 11 via the packing 24 which is an elastic material, and the sealed state between the body 10 and the lower plate 11 is maintained.

The flow control valve 1 includes a drive unit 13 composed of a stepping motor, gears, etc. (not shown), a shaft 15 that moves in the vertical direction with respect to the drawing by the stepping motor, gears, etc. in the drive unit 13. It is composed of a valve body 25 connected to the lower end of the shaft 15 and a coil spring 17 for urging the valve body 25 downward in the drawing (valve closing direction). In the present embodiment, the valve body 25 has a plug 14 having a truncated cone-shaped protrusion that protrudes toward the lower part of the drawing and can penetrate the valve opening 19, and a cylindrical shape that surrounds the outer peripheral surface of the protrusion of the plug 14. It is composed of a sponge 16 of the above. The drive unit 13 is assembled while maintaining a sealed state with respect to the body 10 via an O-ring 23 interposed between the upper plate 12 and the body 10. The plug 14 of the valve body 25 is provided so as to be insertable into the valve opening 19, and the lower end portion of the sponge 16 is seated on the valve seat 18. In this embodiment, a stepping motor is used for the drive unit 13, but the drive unit 13 only needs to be able to control the movement of the shaft 15 up and down with respect to the drawing, and a DC motor, a geared motor, an actuator, and the like are also used. It is possible.

Here, the plug 14 and the sponge 16 constituting the valve body 25, which is a feature of the present invention, will be described with reference to FIGS. 3 and 4.

FIG. 3A is a top view of the plug 14, and FIG. 3B is a front view of the plug 14. As shown in FIG. 3B, the plug 14 is directed from the upper part of the drawing toward the columnar plug connecting portion 14a connected to the shaft 15, the cylindrical plug supporting portion 14b supporting the coil spring 17, and the lower part of the drawing. It is composed of a plug body 14d having a substantially truncated cone shape whose diameter gradually decreases. Further, a screw hole 14c for attaching to the shaft 15 is provided at the upper end portion of the plug connecting portion 14a. The maximum diameter of the plug body 14d is set to be slightly smaller than the opening diameter of the valve port 19, so that the plug body 14d can be inserted / isolated from the valve port 19.

FIG. 4A is a top view of the sponge 16, and FIG. 4B is a front view of the sponge 16. As shown in FIG. 4, the sponge 16 is formed in a cylindrical shape having an inner peripheral surface 16a. The outer diameter of the cylindrical portion of the sponge 16 is substantially the same as the outer diameter of the plug support portion 14b of the plug 14, and the inner diameter of the inner peripheral surface 16a of the sponge 16 is slightly larger than the maximum diameter of the plug body 14d of the plug 14. It is set. As a result, the sponge 16 is fixed to the lower surface of the plug support portion 14b of the plug 14 so as to surround the outer periphery of the plug body 14d of the plug 14. In the present embodiment, the sponge 16 is formed of a porous elastic member made of a synthetic rubber material, but the material is not limited to the synthetic rubber material, and the compression / release of the sponge 16 causes porous pores. Other materials can be used as long as the sum of the volumes can be increased or decreased.

Next, the closed state and the open state of the flow rate control valve 1 will be described.

As shown in FIG. 1, in the closed state of the flow control valve 1, the shaft 15 is moved to the lower side of the drawing by the drive unit 13. As a result, the sponge 16 of the valve body 25 is seated on the valve seat 18, and the plug 14 of the valve body 25 (specifically, the plug body 14d) is inserted into the valve opening 19. Then, when the shaft 15 is further moved downward and the sponge 16 is compressed until the sum of the volumes of the porous pores of the sponge 16 becomes zero, the valve opening 19 is sealed by the sponge 16 and the valve is closed. Become.

Further, as shown in FIG. 2, in the valve open state of the flow control valve 1, the shaft 15 is moved upward in the drawing by the drive unit 13 as shown by the arrow (1). As a result, the valve body 25 moves upward against the urging force of the coil spring 17, the sponge 16 of the valve body 25 is isolated from the valve seat 18, and the plug 14 of the valve body 25 (specifically, the plug body 14d) is also. Separated from the valve port 19, the flow control valve 1 is opened, and the primary port 20 and the secondary port 21 communicate with each other via the valve chamber 22 and the valve port 19.

Next, the effect of the valve body 25 including the plug 14 of the flow rate control valve 1 and the sponge 16 according to the present invention will be described with reference to FIG.

In FIGS. 5 (A) to 5 (E), the flow control valve 1 is moved upward by the drive unit 13 from the closed state ((A) in FIG. 5), and the plug 14 (valve body 25) is moved upward. Is illustrated in a state in which is gradually moved upward (valve opening direction). The state of (A) in FIG. 5 is set to zero stroke (S (A) = 0), and (B) to (E) of FIG. 5 are (B) of FIG. 5, respectively, with respect to (A) of FIG. ) Is the stroke S (B), FIG. 5 (C) is the stroke S (C), FIG. 5 (D) is the stroke S (D), FIG. 5 (E) is the stroke S (E), and the plug 14. It is a figure which showed the state which moved upward gradually.

FIG. 5 (F) shows a fluid that opens and flows through the valve opening 19 due to the stroke (distance in which the plug 14 moves upward from the state of FIG. 5 (A)) and the movement of the plug 14 (upward). It is a graph which showed the relationship with the flow rate of. The black circles (“●”) in the graph of FIG. 5 (F) are the strokes (S (A), S (B), S (C), in each state of FIGS. 5 (A) to (E). It is a point showing the flow rate (F (A), F (B), F (C), F (D), F (E)) with respect to S (D), S (E)). In the states (A) to (C) of FIG. 5, the sponge 16 is compressed / released with the lower end surface of the sponge 16 in contact with the valve seat 18. In this state, the flow rate of the fluid flowing through the valve port 19 is substantially proportional to the sum of the volumes of the porous pores of the sponge 16, so that the stroke is along the line (1) of FIG. Change. This makes it possible to control an extremely small flow rate compared to the conventional needle valve. When the lower end surface of the sponge 16 is isolated from the valve seat 18 (states (C) to (E) in FIG. 5), the stroke is substantially proportional to the stroke size of the plug 14 as in the conventional needle valve. On the other hand, it changes along the line (2) of FIG. 5 (F). This makes it possible to control the flow rate equivalent to that of a conventional needle valve.

As described above, in the flow rate control valve 1 according to the present invention, the flow rate of the fluid flowing through the valve port 19 is as shown in FIG. 5 with respect to the stroke when the lower end surface of the sponge 16 is in contact with the valve seat 18. Since it changes along the line (1) of F), it is possible to control an extremely small flow rate as compared with the conventional needle valve (line (2) of (F) in FIG. 5), and the lower end surface of the sponge 16 is a valve. When isolated from the seat 18, the flow rate of the fluid flowing through the valve port 19 changes with respect to the stroke along the line (2) of FIG. 5 (F) like the conventional needle valve, and thus the conventional needle valve. It is possible to control up to a large flow rate equivalent to that of the above, and as a result, the difference between the minimum flow rate and the maximum flow rate that can be controlled by the flow rate becomes large, and a large turndown can be realized.

Here, the flow rate control valve 1 is an example of a flow rate control valve, the valve chamber 22 is an example of a valve chamber, the primary port 20 is an example of a primary port, and the secondary port 21 is an example of a secondary port. , The valve seat 18 is an example of a valve seat, the valve body 25 is an example of a valve body, the valve port 19 is an example of a valve port, the drive unit 13 is an example of a drive unit, and the plug 14 is an example of a plug. As an example, the sponge 16 is an example of a porous elastic body.

Although the embodiments of the present invention have been described in detail above, these are merely examples, and the present invention is not to be interpreted in a limited manner by the specific description in the embodiment, and those skilled in the art are skilled in the art. It can be carried out in an embodiment in which various changes, modifications, improvements, etc. are added based on knowledge, and all of them are within the scope of the present invention as long as such embodiments do not deviate from the gist of the present invention. It should be understood that it is contained in.

FIG. 6 shows a cross-sectional view of the flow rate control valve 100 according to another embodiment (No. 1) of the present invention in a valve open state. In the flow rate control valve 1 of the above embodiment, the sponge 16 is fixed to the plug 14 constituting the valve body 25, but the arrangement of the sponge is not limited to this, as in the flow rate control valve 100 shown in FIG. , The sponge 116 may be fixedly arranged on the upper surface of the valve seat 118. Like the sponge 16 on the flow control valve 1, the sponge 116 has a cylindrical shape whose inner diameter is larger than the maximum diameter of the plug body 114a of the plug 114, and the valve seat 118 surrounds the outer peripheral surface of the plug body 114a of the plug 114. Placed on the top surface.

FIG. 7 is a diagram illustrating a state of movement of the plug 114 of the valve body over the flow control valve 100. In FIG. 7A, as in the case of FIG. 5A, the sponge 116 is completely compressed by the plug 114, the volume of the pores of the sponge 116 is set to zero, and the valve is closed. The stroke of the plug 114 is set to zero (S1 (A) = 0), and (B) to (E) in FIG. 7 indicate each state in which the plug 114 is gradually moved upward (valve opening direction) (stroke S1 (B)). , Stroke S1 (C), Stroke S1 (D), Stroke S1 (E)). While the sponge 116 is in contact with the plug 114 ((A) to (C) in FIG. 7), the flow rate of the fluid flowing through the valve port 119 is that of the porous sponge 116, as in the case of the flow control valve 1. Since it is substantially proportional to the sum of the volumes of the vacancies, it changes with respect to the stroke, for example, as shown in the line (1) of FIG. 5 (F) above, and the sponge 116 is isolated from the plug 114 (FIG. 7). In (C) to (E), the stroke changes, for example, as shown in the line (2) of FIG. 5 (F). Therefore, even with the flow rate control valve 100 in which the sponge 116 is fixed to the upper surface of the valve seat 118, it is possible to control an extremely small flow rate as in the flow rate control valve 1, so that the difference between the minimum flow rate and the maximum flow rate that can be controlled by the flow rate. Becomes larger, and a large turndown can be realized.

FIG. 8 shows a cross-sectional view of the flow rate control valve 200 according to another embodiment (No. 2) of the present invention in a valve open state. As shown in FIG. 8, in the flow control valve 200, the sponge 216, which is a feature of the present invention, is fixedly provided on the lower end surface of the plug 214, and the valve body 225 is composed of the plug 214 and the sponge 216. Further, the valve port includes an upper valve port 226 into which the plug 214 can be inserted and slidable, and a lower valve port 219 having a valve seat 218 on which the lower end surface of the sponge 216 is seated. The sponge 216 adopts a cylindrical sponge having an outer diameter smaller than the opening diameter of the upper valve port 226 and larger than the opening diameter of the lower valve port 216. Here, the shape of the sponge 216 is not limited to the cylindrical shape, but may be a polygonal prism shape.

FIG. 9 is a diagram illustrating a state of movement of the plug 214 of the valve body pertaining to the flow control valve 200. FIG. 9A shows a state in which the sponge 216 is completely compressed by the plug 214 and the volume of the pores of the sponge 216 is set to zero to close the valve, as in the case of FIG. 5A. The stroke of the plug 214 is set to zero (S2 (A) = 0), and (B) to (E) in FIG. 9 indicate each state in which the plug 214 is gradually moved upward (valve opening direction) (stroke S2 (B). ), Stroke S2 (C), Stroke S2 (D), Stroke S2 (E)). While the lower end surface of the sponge 216 is in contact with the valve seat 218 ((A) to (C) in FIG. 9), the flow rate of the fluid flowing through the valve port 219 is the sponge 216, as in the case of the flow rate control valve 1. Since it is substantially proportional to the sum of the volumes of the porous pores of the above, the sponge 216 changes with respect to the stroke, for example, as shown in the line (1) of FIG. 5 (F) above, and the sponge 216 is separated from the valve seat 218. In the state ((C) to (E) of FIG. 9), the plug 214 moves the upper valve port 226 and further separates from the upper valve port 226. It changes like the line (2) of (F). Therefore, in the flow rate control valve 200, as in the flow rate control valve 1, it is possible to control an extremely small flow rate, so that the difference between the minimum flow rate and the maximum flow rate in which the flow rate can be controlled becomes large, and a large turndown can be realized. It will be possible.

In the

flow control valves

1 and 100, 200, the sponge (16, 116, 216) was compressed to seal and close the valve port (19, 119, 219), but the sponge was compressed depending on the material of the sponge. Even if it is made, the valve opening may not be completely sealed. In that case, a sealing member made of an elastic member may be added separately from the sponge.

FIG. 10 is a diagram showing another embodiment (No. 3), (No. 4), and (No. 5) to which a seal member is added. 10 (A) and 10 (B) are cross sections of the flow control valve 300 (the third embodiment) in which a seal member is added to the flow control valve 1 of the above embodiment when the valve is closed and the valve is opened. It is a figure, (C) and (D) of FIG. It is sectional drawing at the time of a valve. Each of the sealing

members

330 and 430 has a cylindrical shape whose inner diameter is larger than the outer peripheral diameter of each of the

plugs

314 and 414, and when the valve is closed, as shown in FIGS. 10A and 10C, the respective valves are formed. It sits on seats 318 and 418 so that each valve can be completely sealed. As shown in FIG. 10, the flow rate control valve 300 and the flow rate control valve 400 are provided with a sponge 316 and a sponge 416.

Further, the seal member is not limited to the cylindrical seal member such as the

seal members

330 and 430, and is, for example, the flow rate control valve 500 (embodiment (No. 5)) shown in FIG. 10 (E). The O-ring 530 may be adopted. A concave groove 514a that fits into the O-ring 530 is provided on the outer peripheral portion of the upper end of the plug 514, the O-ring 530 can be mounted, and the valve opening can be sealed by the O-ring 530.

1,100,200,300,400,500 ...

Flow control valve

10, 110, 210 ... Body 11 ... Lower plate 12 ... Upper plate 13 ...

Drive unit

14, 114, 214, 314, 414, 514・・ Plug 15 ・・

Shaft

16, 116, 216, 316, 416 ・・ Sponge 17 ・・

Coil spring

18, 118, 218, 318, 418 ・・

Valve seat

19, 119, 219, 226 ・・ Valve port 20 ・・Primary port 21 ... Secondary port 22 ... Valve chamber 23 ... O-ring 24 ...

Packing

25, 225 ... Valve body

Claims

Valve room and
The primary and secondary ports that communicate with the valve chamber,
The valve seat provided at the valve opening of the secondary port and
The valve body that sits on the valve seat and
It consists of a drive unit that is connected to the valve body and allows the valve body to move its position in the valve opening / closing direction.
In a flow rate control valve that controls the flow rate of a fluid passing through the valve port by controlling the increase / decrease in the opening degree of the valve body and the valve port of the secondary port.
The valve body is provided with a plug that can be inserted into the valve port of the secondary port in the center.
A flow control valve characterized in that a porous elastic body seated on the valve seat is interposed between the valve body and the valve seat.
The elastic body has a cylindrical shape having an inner diameter larger than the maximum diameter of the plug, is interposed between the valve body and the valve seat so as to surround the plug, and the upper end surface of the elastic body is the above-mentioned elastic body. The flow rate control valve according to claim 1, wherein the flow control valve is provided by being fixed to a plug.
The elastic body has a cylindrical shape having an inner diameter larger than the maximum diameter of the plug, and is interposed between the plug and the valve seat of the valve body so as to surround the plug, and the lower end surface of the elastic body. The flow rate control valve according to claim 1, wherein the valve seat is fixedly provided on the upper surface of the valve seat.
The valve port includes an upper valve port into which the plug can be inserted and slidable, and a lower valve port having a valve seat on which the elastic body is seated at an upper end portion.
The elastic body has a cylindrical shape or a polygonal column shape having an outer diameter smaller than the opening diameter of the upper valve port and larger than the opening diameter of the lower valve port, and the lower end surface of the plug of the valve body and the valve. The flow control valve according to claim 1, wherein the upper end surface of the elastic body is interposed between the seat and fixed to the lower end surface of the plug.
The flow rate control valve according to any one of claims 1 to 4, wherein the elastic body is a sponge made of a synthetic rubber material.
The flow rate control valve according to any one of claims 1 to 5, wherein the drive unit moves and controls the valve body to a position in the valve opening / closing direction by a stepping motor.