JP7305237B2 - flow control valve - Google Patents

Description

The technology disclosed in the present application mainly relates to a flow control valve that controls the flow rate of air, fuel gas, and the like.

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

In Patent Document 1, a valve body having a primary port and a secondary port communicating with a valve chamber and a valve seat provided at the communication valve port of the secondary port side partition wall and a valve body contacting and separating from the valve seat of the valve port. a stepping motor provided with a rotor which is rotated by the energization and excitation of a stator coil and is movable in the valve opening/closing direction; and a valve operating mechanism for opening and closing the needle valve by a screw feeding action caused by the rotation of the stepping motor. A motorized flow control valve is disclosed comprising:

Japanese Patent No. 3181118

In the flow control valve using a needle valve disclosed in Patent Document 1 and the like, the needle is made longer and the inclination angle of the inclined tapered surface is made smaller, thereby making it possible to control the flow rate at a low flow rate.

However, with these conventional flow control valves using a needle valve, there is a limit to the lower limit of the flow rate that can be controlled, and there is a problem that it is difficult to stably control a very small flow rate. Therefore, there is a limit to the amount of turndown, which is the difference between the maximum controllable flow rate and the minimum controllable flow rate.

The technology disclosed in the present application has been proposed in view of the above problems, and provides a flow control valve that enables control of an extremely small flow rate, which was impossible with conventional needle valves, and realizes a large turndown. intended to provide

In order to achieve the above object, the flow control valve according to claim 1 comprises 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 It consists of a seated valve disc and a drive unit that is connected to the valve disc and allows the position of the valve disc to move in the valve opening/closing direction. In a flow control valve that controls the flow rate of a passing fluid, the valve body has a plug that can be inserted into the valve opening of the secondary port at the center. / A releasing porous elastic body is interposed, and the elastic body is compressed by the movement of the valve body in a state in which the valve body moves toward the valve seat and the elastic body is in contact with both the valve body and the valve seat. /Released to enable control of an extremely small flow rate of the fluid, and the valve body is moved in the direction opposite to the valve seat direction and the elastic body is isolated from either the valve body or the valve seat. It is characterized in that the plug moves inside the valve port according to the movement of the body, making it possible to control a flow rate greater than the microscopic flow rate of the fluid.

The flow control valve according to claim 2 is the flow control valve according to claim 1, wherein the elastic body has a cylindrical shape with an inner diameter larger than the maximum diameter of the plug, and the elastic body is positioned between the valve body and the valve seat around the plug. and the upper end surface of the elastic body is fixedly attached to the plug.

A flow control valve according to claim 3 is the flow control valve according to claim 1, wherein the elastic body has a cylindrical shape with an inner diameter larger than the maximum diameter of the plug, and the plug is positioned between the plug and the valve seat of the valve body. and the lower end surface of the elastic body is 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 opening includes an upper valve opening 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 or polygonal prism shape with 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 is below the plug of the valve body The plug is interposed between the end face and the valve seat, and the upper end face of the elastic body is fixed to the lower end face of the plug.

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

A flow control valve according to claim 6 is the flow control valve according to any one of claims 1 to 5, wherein the drive unit controls movement of 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, the valve body provided with the plug that can be inserted into the valve opening of the secondary port is moved toward the valve seat by the driving part, and is interposed between the valve body and the valve seat. The elastic body is brought into contact with both the valve body and the valve seat, and the valve body moves toward the valve seat to completely compress the elastic body, so that the total volume of the pores in the elastic body becomes zero. By doing so, the valve opening can be closed by the elastic body. Then, in a state in which the two opposing end surfaces of the elastic body are in contact with the valve body and the valve seat, the valve body is moved toward or away from the valve seat, compressing or releasing the elastic member, thereby compressing or releasing the elastic body. By increasing or decreasing the total volume of the holes in the valve, it is possible to variably control an extremely small flow rate, which was impossible with the conventional needle valve. In addition, the valve body is moved in a direction opposite to the direction of the valve seat by the driving part, and one of the two opposing end surfaces of the elastic body is isolated from either the valve body or the valve seat, and the valve body is moved. By inserting/separating the plug from the valve orifice and completely isolating the plug from the valve orifice, variable control of the flow rate equivalent to that of the conventional needle valve becomes possible. As a result, the difference between the minimum flow rate and the maximum flow rate at which the flow rate can be controlled becomes large, making it possible to realize a large turndown.

In the flow control valves according to claims 2 and 3, the elastic body has a cylindrical shape with an inner diameter 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 the To securely close a valve port by means of an elastic body, which is fixed to an end face or an upper surface of a valve seat, so that the elastic body is completely compressed when the valve is closed, and the volume of the holes in the elastic body is reduced to zero. can be done. Furthermore, while the elastic body is 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, thereby increasing or decreasing the volume of the pores of the elastic body. Allows control of flow rate. In addition, since the elastic body surrounds the periphery of 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, making it easy and stable to control an extremely small flow rate. to make it possible.

The flow control valve according to claim 4 comprises an upper valve opening into which a plug can be inserted and slidable, and a lower valve opening having a valve seat on which an elastic member is seated at the upper end. The elastic body has a columnar or polygonal columnar shape with 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 is interposed between the lower end surface of the plug of the valve body and the valve seat. The upper end face of the elastic body is fixed to the lower end face of the plug. Therefore, by moving the valve body up and down, when the elastic body is seated and abuts against the valve seat provided at the upper end of the lower valve port, compression/release of the elastic member causes the elastic body to move to the lower valve port. When the plug is separated from the valve seat provided at the upper end, the plug vertically moves the upper valve port or separates it from the upper valve port. In addition, it is possible to control the flow rate equivalent to that of the conventional needle valve.

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

In the flow control valve according to claim 6, the movement of the valve body can be finely controlled by using a stepping motor in the driving part, so that the flow rate of the fluid passing through the valve port can be finely controlled. .

1 is a cross-sectional view of a flow control valve according to an embodiment of the present invention in a closed state; FIG. 1 is a cross-sectional view of a flow control valve in an open state according to an embodiment of the present invention; FIG. It is (A) a top view of the plug (equivalent to a needle) which comprises the valve body concerning this invention, and (B) is a front view. FIG. 4A is a top view of a sponge (corresponding to an elastic body) constituting the valve body according to the present invention, and FIG. 4B is a front view thereof. It is a figure explaining the relationship between the moving amount|distance (stroke) of a valve body, and flow volume. FIG. 4 is a cross-sectional view of the flow control valve of another embodiment (Part 1) of the present invention in the open state; 7A and 7B are diagrams for explaining the state of movement of the valve body in the embodiment according to FIG. 6; FIG. 7 is a cross-sectional view of a flow control valve in another embodiment (part 2) of the present invention in an open state; FIG. 9 is a diagram for explaining the state of movement of the valve body in the embodiment according to FIG. 8; It is a figure explaining the flow control valve which is other embodiment (the 3rd), (the 4th), and (the 5th) concerning this invention.

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

FIGS. 1 and 2 show a flow 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 of the valve closed state. , and FIG. 2 is a sectional view in the valve open state.

As shown in FIG. 1, the flow control valve 1 is incorporated in a body 10 forming a flow path for fluid such as gas. The body 10 is provided with a valve chamber 22 in which a valve element 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 through a packing 24 made of 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 and gears (not shown), a shaft 15 that moves vertically with respect to the drawing by the stepping motor and gears 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 that biases the valve body 25 downward in the drawing (in the valve closing direction). In this embodiment, the valve body 25 includes a plug 14 having a truncated conical protruding portion that protrudes downward in the drawing and can penetrate the valve port 19, and a cylindrical shape that surrounds the outer peripheral surface of the protruding portion of the plug 14. and a sponge 16. The driving portion 13 is assembled to the body 10 in a sealed state 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 port 19 , and the lower end of the sponge 16 is seated on the valve seat 18 . In the present embodiment, a stepping motor is used as the drive unit 13, but the drive unit 13 only needs to be able to control the vertical movement of the shaft 15 with respect to the drawing, and a DC motor, geared motor, actuator, or the like is also used. It is possible.

Here, the plug 14 and the sponge 16 that constitute the valve body 25, which are the features 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. FIG. As shown in FIG. 3B, the plug 14 includes, from the top of the drawing, a columnar plug connecting portion 14a that connects to the shaft 15, a columnar plug supporting portion 14b that supports the coil spring 17, and downward of the drawing. The plug body 14d has a substantially truncated conical shape with a gradually decreasing diameter. Further, a screw hole 14c for attachment to the shaft 15 is provided at the upper end of the plug connection portion 14a. The maximum diameter of the plug body 14 d is set slightly smaller than the opening diameter of the valve port 19 , so that the plug body 14 d can be inserted/separated from the valve port 19 .

4A is a top view of the sponge 16, and FIG. 4B is a front view of the sponge 16. FIG. 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 main body 14d of the plug 14. is set. Thereby, the sponge 16 is fixed to the lower surface of the plug supporting portion 14b of the plug 14 so as to surround the outer periphery of the plug main body 14d of the plug 14. As shown in FIG. In this embodiment, the sponge 16 is formed of a porous elastic member made of synthetic rubber material, but the material is not limited to the synthetic rubber material, and compression/release of the sponge 16 creates 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 open state of the flow control valve 1 will be described.

As shown in FIG. 1 , when the flow control valve 1 is closed, the driving portion 13 moves the shaft 15 downward in the drawing. As a result, the sponge 16 of the valve body 25 is seated on the valve seat 18 , and the plug 14 (specifically, the plug body 14 d ) of the valve body 25 is inserted into the valve port 19 . 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, when the flow control valve 1 is open, the driving portion 13 moves the shaft 15 upward in the drawing as indicated by an arrow (1). As a result, the valve body 25 moves upward against the biasing force of the coil spring 17, the sponge 16 of the valve body 25 is separated from the valve seat 18, and the plug 14 (more specifically, the plug body 14d) of the valve body 25 is also moved upward. Isolated 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 composed of the plug 14 and the sponge 16 of the flow control valve 1 according to the present invention will be described with reference to FIG.

5A to 5E, the flow control valve 1 is moved upward from the closed state (FIG. 5A), the shaft 15 is moved upward by the drive unit 13, and the plug 14 (valve body 25) is opened. is gradually moved upward (valve opening direction). The state of (A) in FIG. 5 is assumed to be zero stroke (S(A)=0), and (B) to (E) in FIG. 5 correspond to (A) in FIG. ), the stroke S (C) in FIG. 5C, the stroke S (D) in FIG. 5D, the stroke S (E) in FIG. 5E, and the plug 14 is a diagram showing a state in which the is gradually moved upward.

FIG. 5F shows the stroke (the distance that the plug 14 moves upward from the state of FIG. is a graph showing the relationship with the flow rate of The black circles (“●”) in the graph of FIG. 5(F) indicate the strokes (S(A), S(B), S(C), 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)). 5A to 5C, the sponge 16 is compressed/released while the lower end surface of the sponge 16 is in contact with the valve seat 18. As shown in FIG. In this state, the flow rate of the fluid flowing through the valve port 19 is approximately proportional to the total volume of the porous pores of the sponge 16. Change. This allows control of very small flow rates relative to conventional needle valves. When the lower end surface of the sponge 16 is separated from the valve seat 18 (states (C) to (E) in FIG. 5), the stroke is approximately proportional to the stroke of the plug 14 as in the conventional needle valve. , changes along line (2) in FIG. 5(F). This makes it possible to control a flow rate equivalent to that of a conventional needle valve.

As described above, in the flow control valve 1 according to the present invention, the flow rate of the fluid flowing through the valve port 19 is ( F) changes along the line (1), so it is possible to control a very small flow rate compared to a conventional needle valve (line (2) of (F) in FIG. 5), and the lower end surface of the sponge 16 is a valve. Isolating from seat 18, the flow rate of fluid through valve port 19 varies with stroke along line (2) in FIG. As a result, the difference between the minimum flow rate and the maximum flow rate that can be controlled becomes large, making it possible to realize a large turndown.

Here, the flow control valve 1 is an example of a flow 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 driving portion 13 is an example of a driving portion, and the plug 14 is a plug. It is an example, and 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 only examples, and the present invention is not to be construed in any limited way by the specific descriptions in such embodiments. It can be implemented in embodiments with various changes, modifications, improvements, etc. based on knowledge, and as long as such embodiments do not depart from the spirit of the present invention, all are within the scope of the present invention. should be understood to be included in the

FIG. 6 shows a cross-sectional view of a flow control valve 100 according to another embodiment (Part 1) of the present invention in the open state. In the flow control valve 1 of the above-described embodiment, the sponge 16 is fixed to the plug 14 that constitutes the valve body 25, but the arrangement of the sponge is not limited to this, and is similar to that of the flow control valve 100 shown in FIG. , the sponge 116 may be fixedly placed on the upper surface of the valve seat 118 . Similar to the sponge 16 applied to the flow control valve 1, the sponge 116 has a cylindrical shape with an inner diameter larger than the maximum diameter of the plug body 114a of the plug 114. The valve seat 118 surrounds the outer periphery of the plug body 114a of the plug 114. Placed on top.

7A and 7B are diagrams for explaining the state of movement of the plug 114 of the valve body on the flow control valve 100. FIG. FIG. 7A shows a state in which the sponge 116 is completely compressed by the plug 114, the sum of the pore volumes of the sponge 116 is zeroed, and the valve is closed, as in FIG. 5A. The stroke of the plug 114 in this case is zero (S1(A)=0), and the states (stroke S1( B), stroke S1 (C), stroke S1 (D), and stroke S1 (E)). While the sponge 116 is in contact with the plug 114 (FIGS. 7A to 7C), as in the case of the flow control valve 1, the flow rate of the fluid flowing through the valve port 119 is Since it is approximately proportional to the total volume of the pores, it changes with respect to the stroke, for example, as shown by line (1) in (F) of FIG. From (C) to (E) in (1)), the line (2) in (F) of FIG. 5 changes with respect to the stroke, for example. Therefore, even with the flow 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 with the flow control valve 1. becomes large, and a large turndown can be realized.

FIG. 8 shows a cross-sectional view of a flow control valve 200 according to another embodiment (Part 2) of the present invention in the open state. As shown in FIG. 8, in flow control valve 200, sponge 216, which is a feature of the present invention, is fixed to the lower end surface of plug 214, and plug 214 and sponge 216 constitute valve body 225. As shown in FIG. The valve port includes an upper valve port 226 into which the plug 214 can be inserted and slid, 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 employs 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 a columnar shape, and may be a polygonal columnar shape.

9A and 9B are diagrams for explaining the state of movement of the plug 214 of the valve body on the flow control valve 200. FIG. FIG. 9(A) is the same as FIG. 5(A) above, in which the sponge 216 is completely compressed by the plug 214 and the sum of the pore volumes of the sponge 216 is zero, and the valve is closed. The stroke of the plug 214 in this case is assumed to be zero (S2(A)=0), and each state (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 is separated from the valve seat 218 by changing, for example, the line (1) in FIG. 9(C) to (E)), the plug 214 moves through the upper valve port 226 and further separates from the upper valve port 226. It changes like line (2) in (F). Therefore, in the flow control valve 200, as in the flow control valve 1, it is possible to control a very small flow rate, so that the difference between the minimum flow rate and the maximum flow rate that can be controlled becomes large, and a large turndown can be realized. be possible.

In the flow control valves 1 and 100, 200, the sponge (16, 116, 216) is compressed to seal the valve opening (19, 119, 219) to close the valve. In some cases, it may not be possible to completely seal the valve opening. In that case, a sealing member made of an elastic member may be added separately from the sponge.

FIG. 10 shows other embodiments (part 3), (part 4) and (part 5) in which seal members are added. FIGS. 10A and 10B show, as an example, cross sections of a flow control valve 300 (embodiment (3)) obtained by adding a seal member to the flow control valve 1 of the above embodiment when the valve is closed and when the valve is opened. FIGS. 10C and 10D show, as an example, when a flow control valve 400 (embodiment (4)) obtained by adding a sealing member to the flow control valve 200 of the above embodiment is closed and opened. It is a sectional view at the time of valve. Both of the sealing members 330 and 430 have a cylindrical shape whose inner diameter is larger than the outer diameter of the respective plugs 314 and 414, and when the valve is closed, as shown in FIGS. Seats 318 and 418 are seated so that each valve port can be completely sealed. The flow control valve 300 and the flow control valve 400 are provided with sponges 316 and 416 as shown in FIG.

Further, the sealing member is not limited to a cylindrical sealing member such as the sealing members 330 and 430, and is, for example, a flow control valve 500 (embodiment (5)) shown in FIG. 10(E). Alternatively, an O-ring 530 may be employed. A recessed groove 514a for fitting an O-ring 530 is provided on the outer peripheral portion of the upper end of the plug 514, and the O-ring 530 is mounted so that the O-ring 530 can seal the valve opening.

Reference Signs List 1, 100, 200, 300, 400, 500 Flow control valves 10, 110, 210 Body 11 Lower plate 12 Upper plate 13 Actuator 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 (6)

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;
a valve body seated on the valve seat;
a drive unit connected to the valve body and capable of moving the valve body in the valve opening/closing direction;
In a flow control valve that controls the opening degree of the valve body and the valve opening of the secondary opening to increase or decrease the flow rate of the fluid passing through the valve opening,
The valve body has a plug that can be inserted into the valve opening of the secondary port at the center,
Between the valve body and the valve seat, a porous elastic body that is compressed/released by the movement of the valve body is interposed,
In a state in which the valve body moves toward the valve seat and the elastic body is in contact with both the valve body and the valve seat, the movement of the valve body compresses/releases the elastic body, so that the fluid becomes extremely small. It is possible to control the flow rate of
With the valve body moving in the direction opposite to the valve seat direction and the elastic body isolated from either the valve body or the valve seat, the plug moves within the valve port due to the movement of the valve body. and enables control of a flow rate larger than the extremely minute flow rate of the fluid. The elastic body has a cylindrical shape with an inner diameter 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. 2. The flow control valve of claim 1, wherein the flow control valve is fixedly attached to the plug. The elastic body has a cylindrical shape with 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. 2. The flow control valve according to claim 1, wherein 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 slid, and a lower valve port having a valve seat on which the elastic body is seated at the upper end,
The elastic body has a columnar shape or a polygonal columnar shape with an outer diameter smaller than the opening diameter of the upper valve port and larger than the opening diameter of the lower valve port. 2. The flow control valve according to claim 1, wherein the upper end face of said elastic body is fixed to the lower end face of said plug. 5. The flow control valve according to any one of claims 1 to 4, wherein said elastic body is a synthetic rubber sponge. 6. The flow control valve according to any one of claims 1 to 5, wherein the drive unit controls movement of the valve body to a position in the valve opening/closing direction by a stepping motor.

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