JP4849990B2 - Diaphragm flow control valve - Google Patents

Description

  The present invention relates to a diaphragm-type flow rate control valve that adjusts the flow rate of water flowing through a main water channel by changing the opening of a main valve composed of a diaphragm valve.

Conventionally, it has a main valve composed of a diaphragm valve that is provided on the main water channel and changes the opening degree, and an annular main valve seat that is configured at the tip of the cylindrical part, and according to the opening degree of the main valve A diaphragm type flow control valve for performing flow control is known.
For example, this type of diaphragm type flow control valve is disclosed in Patent Document 1 below.

FIG. 11 shows a specific example of this type of diaphragm type flow control valve.
In the figure, 200 is a main water channel, 202 is a main valve made of a diaphragm valve provided on the main water channel 200, 204 is an annular main valve seat composed of a tip portion of a cylindrical portion 206, and 200a is a main valve seat. A primary inflow water channel 200 b in the water channel 200 is a secondary outflow water channel in the main water channel 200 formed inside the cylindrical portion 206.

The main valve 202 is composed of a rubber diaphragm membrane 208 and a hard main valve body 210 made of resin or the like, and the outer peripheral end of the diaphragm membrane 208 is held in a fixed state. To move (displace) in the axial direction to change the opening, thereby changing the flow rate of the water flowing through the main water channel 200.
In this diaphragm type flow control valve, when the main valve 202 is seated on the main valve seat 204, the main water channel 200 is closed and water does not flow.

On the other hand, when the main valve 202 is separated from the main valve seat 204, the main water channel 200 is opened, water flows, and water from the inflow water channel 200a passes over the main valve seat 204 and flows into the outflow water channel 200b, and further downstream. Supplied to the side.
Further, the flow rate of the water flowing through the main water channel 200 is increased or decreased according to the movement amount (displacement amount) of the main valve 202 in the axial direction, that is, according to the opening degree of the main valve 202. That is, the flow rate is adjusted.

  The flow control valve shown in FIG. 11 is a pilot type valve, and 212 is formed behind the main valve 202, and a back pressure that acts on the main valve 202 as a pressing force in the valve closing direction. The chamber 214 is a small introduction hole for introducing the water in the primary inflow water channel 200a in the main water channel 200 into the back pressure chamber 212 to increase the pressure of the back pressure chamber 212, and 216 is the back pressure chamber 212 and the secondary side. The pilot water channel 218 is provided through the main valve 202 so as to communicate with the outflow water channel 200b and draws water from the back pressure chamber 212 to the outflow water channel 200b to reduce the pressure in the back pressure chamber 212. A pilot valve 220 opens and closes the pilot valve seat.

  By the way, in this kind of diaphragm type flow control valve, the main valve 202 tilts as shown in FIG. 11 based on the non-uniform action of the water flow with respect to the main valve 202 and the flow control is smooth. There was a problem that there was a case where it was not done.

Therefore, in this type of diaphragm type flow rate control valve, regardless of whether it is a pilot type or not, the main valve guide that guides the main valve 202 when moving is used as the main valve 202. The unit 210 is provided so as to move integrally.
By providing such a main valve guide in the main valve 202, it is possible to prevent the main valve 202 from tilting to some extent.

However, when such a main valve guide is provided, it is normal to ensure a fitting clearance (annular gap) between the outer peripheral surface of the main valve guide and the inner peripheral surface of the cylindrical portion. Since the main valve guide can be slightly inclined within the clearance, the inclination of the main valve cannot be completely prevented.
For this reason, there arises a problem that a rapid flow rate change occurs due to the inclination of the main valve in the small flow rate region at the end of the closing operation of the main valve or at the start of the valve opening operation, that is, just before water stoppage or at the start of water supply.

JP-A-4-302790

  The present invention is based on the above circumstances, and solves the problem of rapid flow rate changes due to the inclination of the main valve in the small flow rate range just before stopping water supply or at the start of water supply, and performs continuous and smooth flow rate change. It is an object of the present invention to provide a diaphragm type flow rate control valve that can be used.

Thus, according to the first aspect of the present invention, (a) a main valve comprising a diaphragm valve provided on the main water channel to change the opening degree, and (b) an annular main valve formed at the tip of the cylindrical portion. A seat, and (c) a main valve guide that is provided in a state of moving integrally with the main valve and that fits into the cylindrical portion and guides the main valve during movement. In a diaphragm type flow control valve that adjusts the flow rate according to the opening, a diameter is formed on the outer peripheral surface of the main valve guide on the movable side or the inner peripheral surface of the cylindrical portion on the fixed side at a position on the main water channel. An elastic ring having elasticity in the direction is mounted, and the elastic ring has a radially outward elastic force within a moving range from a closed position of the main valve to a position opened by a set minute distance. These main valves are in elastic contact with the outer surface of the main valve guide so as to be slidable relative to the outer surface of the main valve guide or with a radially inward elastic force While blocking the annular gap between the outer peripheral surface and the inner peripheral surface of the cylindrical portion of the id, the elastic ring, when moved to the position the main valve is opened the set minute distance above the cylindrical portion or the main valve guide And the blocking action on the annular gap disappears, and after the disappearance of the blocking action on the annular gap by the elastic ring, the opening between the main valve and the main valve seat is changed. It is characterized in that the flow rate is adjusted .

  According to a second aspect of the present invention, in the first aspect, the flow rate control valve is (a) formed behind the main valve so that the internal pressure acts on the main valve as a pressing force in the valve closing direction. A pressure chamber, and (b) an introduction small hole for introducing water in the primary inflow water channel in the main water channel into the back pressure chamber to increase the pressure of the back pressure chamber, and (c) the back pressure chamber and the A pilot water channel that is provided through the main valve so as to communicate with a secondary side outflow water channel in the main water channel, and draws water from the back pressure chamber into the outflow water channel to reduce the pressure in the back pressure chamber. And (d) a pilot valve that moves forward and backward in the same direction as the main valve to control the opening of the pilot water channel, and moves the main valve forward and backward following the forward and backward movement of the pilot valve. It is a pilot type valve for adjusting the flow rate of the main water channel.

Effects and effects of the invention

  As described above, the present invention attaches an elastic ring to the outer peripheral surface of the main valve guide or the inner peripheral surface of the cylindrical portion, and the elastic ring is attached to the inner peripheral surface of the cylindrical portion by the elastic force in the radial direction of the elastic ring. On the other hand, it is elastically contacted with the outer peripheral surface of the main valve guide so as to be slidable relative to the outer peripheral surface of the main valve guide. It is designed to block in the direction of the heart.

  In the flow control valve of the present invention, in the small flow rate range just before the stoppage of water or at the start of water supply, the annular clearance between the main valve guide and the cylindrical portion is formed by the blocking action of the annular clearance by the elastic ring. The flow path to be closed is substantially closed or the flow rate is significantly reduced.

In other words, this elastic ring serves as an auxiliary valve for the main valve, and eliminates or significantly restricts the flow of the flow path formed by the annular gap in the small flow rate region.
Therefore, even if the main valve is tilted in the small flow rate region, it is possible to avoid a sudden flow rate change in the small flow rate region due to the tilt, and it is possible to ensure a continuous and smooth flow rate change.

In the present invention, the elastic ring serving as the auxiliary valve does not necessarily completely close (seal) the flow path between the main valve guide and the cylinder portion, and causes some leakage. It may be a thing.
However, the leakage is smaller than the amount of change in flow rate caused by the inclination of the main valve in the small flow rate region.

  The present invention is a pilot-type flow control valve, more specifically, a back pressure chamber formed behind the main valve and acting as a pressing force in the valve closing direction against the main valve, and the pressure in the back pressure chamber is increased. A pilot water channel that drains water from the back pressure chamber and reduces the pressure, and a pilot valve that moves forward and backward in the same direction as the main valve to control the opening of the pilot water channel. The main valve can be moved forward and backward following the forward / backward movement to provide a pilot-type valve that adjusts the flow rate of the main channel (claim 2).

As the elastic ring has a slit in the circumferential direction of the predetermined portion, Ki out using a C-ring to elastically deform in the radial direction based on the cut, or also as an elastic ring O-ring made of a rubber elastic body Ru can be used.

  Next, an embodiment when the present invention is applied to a pilot type diaphragm type flow control device will be described in detail with reference to the drawings.

1 and 2, reference numerals 10 and 12 respectively denote a first member and a second member constituting a valve body, and the second member 12 further includes an upper part 14, a lower part 16 and an intermediate part 18 each having a cylindrical shape. They are assembled in the axial direction.
Here, the second member 12, that is, the upper part 14, the lower part 16, and the intermediate part 18 are all made of resin.
Further, a cylindrical portion (tubular portion) 22 is integrally formed with the lower portion 16 together with a rectifying portion 64 described later.

Reference numeral 20 denotes a main water channel, and a main valve 26 composed of a diaphragm valve described later is provided on the main water channel 20. In the figure, 20a is a primary inflow water channel in the main water channel 20, 20b is a secondary outflow water channel formed on the inner side of the cylindrical portion 22, and 54 represents a terminal outlet.
A front end portion (upper end portion in the figure) of the cylindrical portion 22 is configured as a main valve seat 24 having an annular shape, and forms a part of the primary inflow water passage 20 a on the outer peripheral side of the cylindrical portion 22. An inflow chamber 50 is formed.

The main valve 26 composed of the diaphragm valve performs opening / closing and opening degree adjustment of the main water channel 20 (hereinafter simply referred to as opening degree adjustment including opening / closing and opening degree adjustment of the main water channel 20), and also serves as a seal member. It consists of a diaphragm film 28 made of an elastic body made of rubber and a hard main valve body 30.
In the main valve 26, the outer peripheral end portion of the diaphragm film 28 is held in a fixed state by a valve body, and the central portion thereof moves forward and backward (displaces) in the axial direction (vertical direction in the figure), and the main valve seat 24 And the opening degree of the main water channel 20 is changed.

Specifically, the main valve 26 shuts off the main water channel 20 by being seated on the main valve seat 24, and opens the main water channel 20 by being separated upward from the main valve seat 24 in the figure.
Further, the opening degree is changed in accordance with the distance from the main valve seat 24 to adjust the flow rate of water flowing through the main water channel 20, that is, the feed water flow rate.

A back pressure chamber 32 is formed behind the upper side of the main valve 26 in the figure.
The back pressure chamber 32 causes the internal pressure to act on the main valve 26 as a pressing force in the downward valve closing direction in the figure.
The main valve 26 is provided with a small introduction hole 33 that passes through the main valve 26 and allows the inflow chamber 50 and the back pressure chamber 32 to communicate with each other.
The introduction small hole 33 leads the water from the inflow chamber 50 to the back pressure chamber 32 and increases the pressure of the back pressure chamber 32.

The main valve 26 is also provided with a pilot water channel 34 as a water drainage channel that passes through the main valve 26 and communicates the back pressure chamber 32 and the outflow water channel 20b.
The pilot water channel 34 reduces the pressure in the back pressure chamber 32 by drawing water in the back pressure chamber 32 to the outflow water channel 20b.

As shown in FIGS. 3 and 4, the main valve 26 is also provided with a through-hole 36 penetrating in the axial direction at the center thereof, and a pilot valve 35 is inserted therethrough, and this pilot valve Between the outer peripheral surface of the valve 35 and the inner peripheral surface of the through-hole 36, the pilot water channel 34 having an annular shape with a narrow passage width is formed.
The main valve 26 is integrally provided with a pilot valve seat 37 that forms an annular shape around the axis of the main valve 26 along the inner peripheral surface of the through hole 36.
Reference numeral 38 denotes a seal portion in the pilot valve seat 37, which holds an O-ring 40 as an elastic seal ring having an annular shape inside the annular groove.

The pilot valve 35 is fitted to the pilot valve seat 37 so as to be movable back and forth in the vertical direction in the figure along the axis of the main valve 26.
Specifically, the pilot valve 35 has a circular cross section and has a seal portion 42 having the same outer diameter in the vertical direction, that is, the forward and backward direction in the figure, and an annular recess 44 on the lower side (lower side in the figure). is doing.
Each end portion in the axial direction of the annular recess 44 is a tapered surface 46 that gradually becomes smaller in diameter toward the smallest diameter portion of the recess 44, and a step is provided at each end portion on the large diameter side of the tapered surface 46. Attached portions 48 and 49 are formed.

1 and 3 show the state of the pilot valve 35 when the water is stopped. At this time, the pilot valve 35 has a seal portion 42 having a diameter over the entire circumference with respect to the pilot valve seat 37 via the O-ring 40. In this state, the pilot valve 35 and the pilot valve seat 37 are sealed in a watertight manner.
At this time, the main valve 26 is seated on the main valve seat 24, and the main water channel 20 is closed.

On the other hand, FIGS. 2 and 4 show the state of maximum water discharge. At this time, the pilot valve 35 is in a state in which the seal portion 42 is separated from the pilot valve seat 37, and a minute gap is formed between them. Yes.
At this time, the main valve 26 is largely separated upward from the main valve seat 24 in the figure, and the main water channel 20 is largely opened.

5 and 6 show the action at the time of flow adjustment (flow rate adjustment) by the movement of the pilot valve 35.
In this embodiment, when the pilot valve 35 moves backward from the water stop state of FIGS. 1 and 3 upward in the figure, the gap between the pilot valve 35 and the pilot valve seat 37 becomes large, and the inside of the back pressure chamber 32 is increased. A large amount of water escapes to the outflow water channel 20b side through the pilot water channel 34, and the pressure in the back pressure chamber 32 decreases.
Therefore, as shown in FIG. 5I, the main valve 26 moves backward in the figure due to the pressure difference with the inflow chamber 50, and the pressure in the inflow chamber 50 and the back pressure chamber 32 are balanced. The backward movement of the main valve 26 stops.
By the backward movement of the main valve 26, the gap between the main valve 26 and the main valve seat 24 becomes large, and water flows out from the inflow chamber 50 toward the outflow water channel 20b.

  From this state, when the pilot valve 35 is further moved backward in the figure, the main valve 26 follows the backward movement of the pilot valve 35 so that the pressure in the back pressure chamber 32 and the pressure in the inflow chamber 50 are balanced. Then, it moves backward, further increasing the opening of the main water channel 20 and increasing the flow rate of water flowing through the main water channel 20 (see FIGS. 5 (II) and (III)).

  On the other hand, when the pilot valve 35 moves forward downward in the drawing as shown in FIG. 6 (I), between the pilot valve 35 and the pilot valve seat 37, more specifically, the seal portion 42 and the pilot valve seat in the pilot valve 35. 37, the gap between the O-ring 40 and the pilot water channel 34 is reduced, and the amount of water flowing from the back pressure chamber 32 to the outflow water channel 20b is reduced. The pressure of 32 increases.

For this reason, the main valve 26 moves forward downward in the figure due to the increased pressure, and stops at a position where the pressure of the back pressure chamber 32 and the pressure of the inflow chamber 50 are balanced (see FIG. 6 (II)). ).
At this time, the gap between the main valve 26 and the main valve seat 24 is reduced, that is, the opening of the main water channel 20 is reduced, and the flow rate of water flowing through the main water channel 20 is reduced.

  When the pilot valve 35 further moves downward in the figure from this state, the opening of the main water channel 20 is further reduced, and the flow rate of the flowing water is further reduced (see FIG. 6 (III)). Further, when the pilot valve 35 further moves forward, the water stop state shown in FIGS. 1 and 3 is obtained.

1 and 2, reference numeral 56 denotes a drive shaft. The drive shaft 56 extends in the axial direction with a uniform circular cross section and a uniform outer diameter, and the above-described pilot valve 35 is integrally formed at the bottom of the drawing. ing.
In these drawings, reference numeral 58 denotes a rotary operation unit. Between the operation unit 58 and the drive shaft 56, the rotation of the operation unit 58 causes the drive shaft 60 to advance and retract by screw feed according to the operation amount. A flow control mechanism (not shown) that moves the pilot valve 35 forward and backward in the vertical direction in the drawing and changes its position is incorporated.

That is, in this embodiment, when the operation unit 58 is rotated, the pilot valve 35 moves up and down in the drawing in accordance with the amount of rotation, and the main valve 26 is displaced following this.
As a result, the flow rate of water flowing through the main water channel 20 is adjusted.
The drive shaft 56 and the back pressure chamber 32 are sealed watertight by an O-ring 61.
Further, the second member 16 and the first member 10 in the valve body are sealed in a watertight manner by an O-ring 62.

The inflow chamber 50 is provided with a rectifying unit 64 that acts on the main valve 26 after adjusting the flow of water from the inflow water passage 20 a in the axial direction of the main valve 26.
The rectifying unit 64 is also made of resin and is integrally formed with the lower portion 16 of the second member 12.

The rectifying unit 64 includes a guide plate 66 that is provided at a predetermined pitch in the circumferential direction and extends radially in the radial direction, and a guide plate 68 that is concentric with the cylindrical portion 22 and is partitioned by them. In addition, a large number of rectifying paths 70A on the inner peripheral side and a large number of rectifying paths 70B on the outer peripheral side are provided.
Here, as shown in FIGS. 3 and 4, each of the rectifying paths 70 </ b> A and 70 </ b> B extends in the axial direction of the main valve 26, and an upper end and a lower end are opened inside the inflow chamber 50.

The rectifying unit 64 operates as follows.
That is, when such a rectifying unit 64 is not provided, the flow of water that flows laterally into the inflow chamber 50 hits the cylindrical portion 22 or the outer peripheral wall of the inflow chamber 50 and becomes a vertical and upward flow. Although it acts on the valve 26, at this time, the flow of water is totally unsatisfactory in the inflow chamber 50 due to resistance to abrupt water flow and changes in the direction of the water, causing strong and weak water flow. Accordingly, the momentum of the flow of water acting on the main valve 26 is also uneven in each part.

However, in this embodiment, since the rectification | straightening part 64 is provided, the non-equalization of the flow of the water in the inflow chamber 50 is suppressed.
As a result, the water flow is adjusted to flow in the axial direction over the entire circumference, and is then applied to the main valve 26.

In this embodiment, the main valve body 30 of the main valve 26 formed of a diaphragm valve is integrally formed with a main valve guide 74 that fits inside the cylindrical portion 22 and guides the main valve 26 during movement. .
Here, as shown in the partially enlarged view of FIG. 4, the main valve guide 74 includes a disk-shaped upper portion 74-1 having a predetermined thickness in the axial direction, that is, a vertical direction, and a plate extending radially from the central portion. And a predetermined annular gap is formed between the outer peripheral surface of the upper portion 74-1 and the inner peripheral surface of the cylindrical portion 22 in a state of being fitted into the cylindrical portion 22. To do.

In this embodiment, as shown in FIGS. 3 and 4, an annular groove 76 is formed on the outer peripheral surface of the main valve guide 74, and there is a cut at a predetermined position in the circumferential direction as shown in FIG. An elastic C ring (elastic ring) 80 made of resin or metal having 78 is attached, and the elastic C ring 80 applied when the main valve id 74 is fitted into the cylindrical portion 22 is elastically fitted to the inner peripheral surface of the cylindrical portion 22. It ’s like that.
That is, the outer peripheral surface of the elastic C ring 80 is in elastic contact with the inner peripheral surface of the cylindrical portion 22 so as to be slidable in the axial direction of the main valve 26, that is, in the moving direction. It is.

Here, the elastic C-ring 80 has an outer diameter slightly larger than the inner diameter of the cylindrical portion 22 in the free shape state shown in FIG. 4, and when the main valve guide 74 is fitted into the cylindrical portion 22, The elastic C-ring 80 is forcibly elastically deformed in the reduced diameter direction on the inner peripheral surface of the cylindrical portion 22.
That is, when the main valve guide 74 is fitted into the cylindrical portion 22 and the elastic C-ring 80 is fitted to the inner peripheral surface of the cylindrical portion 22, the elastic C-ring 80 has its outer peripheral surface moved to the cylindrical portion 22 by its own elastic force. The outer circumferential surface of the main valve guide 74 and the inner circumferential surface of the cylindrical portion 22 are blocked and sealed in the axial direction.

However, the elastic C-ring 80 has a cut 78 at a predetermined position in the circumferential direction, and allows water to leak at the cut 78.
However, the amount of leakage is very small, and as will be described later, the main valve 26 is inclined in a small flow rate range immediately before the main valve 26 is closed (immediately when the water is stopped) or when the valve is opened (when water supply is started). Therefore, the flow rate is smaller than the change amount of the flow rate caused by this (however, the flow rate change amount when the elastic C-ring 78 is not provided).

The elastic C-ring 78 is connected to the main valve guide 74 so as to maintain an elastic contact state with the inner peripheral surface of the cylindrical portion 22 within a movement range from the closed position of the main valve 26 to a position opened by a set minute distance. The assembly position is determined.
Here, the set minute distance can be determined within a movement range until the inclination of the main valve 26 is almost eliminated.
As shown in FIGS. 3 and 4, the main valve seat 24 has a curved cross-sectional shape, and the inner peripheral portion has an elastic C-ring 78 in the free-form state of FIG. A fitting guide 82 for reducing the diameter and fitting the cylindrical portion 22 is formed.

FIG. 7 specifically shows the operation of the elastic C-ring 80.
First, FIG. 7 (I) shows a state when the water is stopped. From this state, the pilot valve 35 moves upward and the seal portion 42 is slightly separated upward from the O-ring 40 of the pilot valve seat 38 (FIG. 7). 7 (II)), a gap is generated there, and the water in the back pressure chamber 32 leaks through the pilot water channel 34 to the outflow water channel 20b. The amount of leakage at this time is very small.

FIG. 8 shows the relationship between the rotation angle of the operation unit 58 and the flow rate of water corresponding thereto. In FIG. 8, A represents the change in flow rate in the present embodiment, and B represents the elastic C-ring 80. The change in flow rate when not provided (comparative example) is shown.
Thus, a minute amount of water outflow occurs in the portion A-1 in the figure, but the water outflow in this A-1 is the amount of water outflow in the state of FIG. The amount of water leakage from the water channel 34 is shown.
At this point, the main valve 26 is still closed.

When the pilot valve 35 is further slightly lifted from this state, the main valve 26 follows this and tends to leave the main valve seat 24.
At this time, the main valve 26 does not operate uniformly over the entire circumference, and is likely to be inclined due to, for example, non-uniformity in the flow of water acting on the main valve 26.
The portion represented by B-2 in FIG. 8 is a portion where the flow rate has changed abruptly due to the inclination of the main valve 26.

In this embodiment, however, the elastic C-ring 80 is in elastic contact with the inner peripheral surface of the cylindrical portion 22 in this state, and the radial gap between the main valve guide 74 and the cylindrical portion 22 is filled. In this way, even if the main valve 22 is tilted, there is no sudden change in the flow rate.
A portion represented by A-2 in FIG. 8 represents a state in which the flow rate is slightly increased by the inclination of the main valve 22. Here, the minute flow rate increase is caused by the cut 78 of the elastic C-ring 80.
As indicated by A-2 in the figure, in this embodiment, even if the main valve 26 is tilted, a rapid flow rate change does not occur, and the flow rate change is extremely slight and smooth.

When the pilot valve 35 is further lifted from the state shown in FIG. 7 (III), the main valve 26 rises following this.
At this time, the elastic C-ring 80 is detached from the cylindrical portion 22 and returns to the original free shape. And the flow volume of the water which flows through the main water channel 20 is changed according to the amount of raises of the main valve 26 after this, ie, the valve opening amount. In FIG. 8, A-3 represents the state of flow rate change at this time.
The flow rate change at this time is almost the same as B-3 in the flow rate change curve of B in FIG. That is, it is almost the same as when no elastic C-ring is provided.

Incidentally, the movement from lowering the pilot valve 35 to lowering the main valve 26 following the pilot valve 35 until the valve is in the maximum open state is closed.
At this time, the flow rate in the main channel 20 changes from A-3 to A-2 and from A-2 to A-1 in FIG.

  In the flow control valve of this embodiment, the annular gap between the main valve guide 74 and the cylindrical portion 22 is blocked by the elastic C-ring 80 in the small flow rate range just before stopping water supply or at the start of water supply. Therefore, even if the main valve 26 is inclined in the small flow rate region, it is avoided that a rapid flow rate change occurs in the small flow rate region due to the inclination. Thus, a continuous and smooth flow rate change can be ensured.

  Further, since the elastic C-ring 80 can be elastically deformed in the radial direction in the annular groove 76, it seals the annular gap between the main valve guide 74 and the cylindrical portion 22, and on the inner peripheral surface of the cylindrical portion 22. When moving along the axial direction along the axis, the outer diameter is changed along the inner diameter of the cylindrical portion 22 and smoothly deformed following the shape of the inner peripheral surface of the cylindrical portion 22 to slide the inner surface. can do.

FIG. 9 shows another embodiment of the present invention.
In this example, an O-ring 84 made of a rubber elastic body is used instead of the elastic C-ring 80 as an elastic ring.
However, the O-ring 84 is in the free form state shown in FIG. 9 (II), and the outer diameter is larger than the inner diameter of the cylindrical portion 22, and the inner diameter is annular when mounted in the annular groove 76. The diameter of the groove 76 is slightly larger than the outer diameter of the groove bottom, and an annular gap is formed between the groove 76 and the groove bottom.
Here, the O-ring 84 has a continuous annular shape that is continuous in the circumferential direction.
In this example as well, the same effect as in the first embodiment can be obtained.

However, in this embodiment, since the O-ring 84 as an elastic ring has a continuous annular shape that is continuous in the circumferential direction, in the state where the O-ring 84 is in elastic contact with the inner peripheral surface of the cylindrical portion 22, The flow path formed by the annular gap between the valve guide 74 and the cylindrical portion 22 is blocked without leakage in the axial direction and is in a sealed state.
Therefore, the portion A-2 in the flow rate change curve A in FIG. 8 changes at a flow rate level substantially the same as the flow rate level of A-1.

  In this embodiment, since a gap is secured between the inner periphery of the O-ring 84 and the groove bottom of the annular groove 76, the O-ring 84 is moved from the state shown in FIG. When the O-ring 84 is elastically fitted, the deformation resistance in the radial direction of the O-ring 84 is small. Therefore, when the O-ring 84 slides in the moving direction of the main valve 26 with respect to the inner peripheral surface of the cylindrical portion 22, that is, in the axial direction. The sliding resistance can be kept small.

FIG. 10 shows still another embodiment of the present invention.
In this example, an annular groove 76 is formed on the cylindrical portion 22 side, that is, on the inner peripheral surface thereof, and an elastic C ring 80 is attached thereto, and the inner peripheral surface of the elastic C ring 80 is connected to the main valve guide 74. This is an example in which an outer peripheral surface is elastically pressed to fill a gap between them and seal.

In this example, the elastic C-ring 80 has a shape shown in FIG. 10B in a free-form state, that is, the inner diameter is smaller than the outer diameter of the main valve guide 74, and the main valve guide 74 moves downward in the figure. When the elastic C ring 80 is elastically fitted to the outer peripheral surface of the main valve guide 74, the main valve guide 74 is elastically expanded outward in the radial direction, and the elastic force causes the inner peripheral surface of the elastic C ring 80 to be main. The valve guide 74 is pressed inward in the radial direction against the outer peripheral surface of the valve guide 74 to make elastic contact.
Here, the elastic C-ring 80 is used as the elastic ring, but an O-ring 84 may be used instead. In this case, however, the inner diameter in the free-form state is smaller than the outer diameter of the main valve guide 74.

Although the embodiment of the present invention has been described in detail above, this is merely an example.
For example, as shown in FIG. 11, the present invention can be applied to a pilot type flow control valve of a type in which the pilot valve is pressed against the pilot valve seat of the main valve in their moving direction, that is, in the axial direction. For example, the present invention can be configured in various forms without departing from the spirit of the present invention.

It is the figure which represented the flow regulating valve of one Embodiment of this invention in the water stop state. It is the figure which represented the same embodiment in the valve opening state. It is the figure which expanded and showed the principal part of FIG. It is the figure which expanded and showed the principal part of FIG. It is effect | action explanatory drawing which showed the flow volume adjustment effect | action of the embodiment. FIG. 6 is an operation explanatory diagram following FIG. 5. It is action | operation explanatory drawing of the elastic C-ring of the embodiment. It is the figure which showed the flow volume change of the embodiment with the flow volume change of the comparative example. It is the figure which showed the principal part of other embodiment of this invention. It is the figure which showed the principal part of other embodiment of this invention. It is the figure which showed an example of the conventional flow control valve.

Explanation of symbols

20 Main water channel 20a Primary inflow water channel 20b Secondary outflow water channel 22 Cylindrical part (cylinder part)
24 main valve seat 26 main valve 32 back pressure chamber 33 introduction small hole 34 pilot water channel 35 pilot valve 74 main valve guide 78 cut 80 elastic C ring 84 O ring

Claims (2)

(B) a main valve composed of a diaphragm valve provided on the main water channel to change the opening; (b) an annular main valve seat formed at the tip of the cylindrical part; and (c) the main valve. A diaphragm that is provided in a state of moving integrally, and that is fitted into the cylindrical portion to guide the movement of the main valve, and adjusts the flow rate according to the opening of the main valve Type flow control valve
At the position on the main water channel, an outer peripheral surface of the main valve guide on the movable side or an inner peripheral surface of the cylindrical portion on the fixed side is attached with an elastic ring having radial elasticity,
The elastic ring has a radially outward elastic force on the inner peripheral surface of the cylindrical portion or a radially inward elastic force within a moving range from the closed position of the main valve to a position opened by a small distance. While elastically contacting the outer peripheral surface of the main valve guide so as to be relatively slidable, the annular clearance between the outer peripheral surface of the main valve guide and the inner peripheral surface of the cylindrical portion is blocked ,
When the main valve moves to a position opened more than the set micro distance, the elastic ring is separated from the cylindrical portion or the main valve guide, and the blocking action on the annular gap is lost.
A diaphragm type flow rate adjustment , wherein the flow rate is adjusted in accordance with an opening degree between the main valve and the main valve seat after disappearance of a blocking action on the annular gap by the elastic ring. valve.   2. The back pressure chamber according to claim 1, wherein the flow control valve is (a) a back pressure chamber formed behind the main valve and acting as a pressing force in the valve closing direction on the main valve; An introduction small hole for increasing the pressure of the back pressure chamber by introducing the water of the primary inflow water channel in the main water channel into the back pressure chamber; and (c) a secondary side of the back pressure chamber and the main water channel. A pilot water channel provided through the main valve so as to communicate with an outflow water channel, and drawing water from the back pressure chamber into the outflow water channel to reduce the pressure in the back pressure chamber; and (d) the main water channel A pilot valve that moves forward and backward in the same direction as the valve to control the opening degree of the pilot water channel, and adjusts the flow rate of the main water channel by moving the main valve forward and backward following the forward and backward movement of the pilot valve. A diaphragm type flow control valve characterized by being a pilot type valve.

Images