JP2011112209A - Seal structure of flow control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal structure of a flow control valve, capable of reducing sliding resistance as much as possible while satisfactorily sealing a gap between a valve element and an axial sliding surface of a valve housing when seal is needed. <P>SOLUTION: In a pressure balance valve which is configured to reduce inflow rates of water and hot water by moving a balance valve element 76 along an axial sliding surface 86 of a valve housing 66 to change openings of a water inflow passage 72 and a hot water inlet passage 74, seal members 92, 94 which seal gaps caused by a fitting clearance C between the axial sliding surface 86 and a water-side valve element 82 and hot water-side valve element 84 of the pressure balance valve are formed of flexible membrane-like members. The seal members 92, 94 are pressed and closely fitted onto corresponding seal wall surfaces 100, 102 by hydraulic pressure introduced to the gaps to seal the gaps. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a seal structure for a flow rate control valve that controls the flow rate of a liquid by moving the valve body along the axial sliding surface of the valve housing and changing the opening of the liquid passage. The present invention relates to a seal structure that seals a gap between a moving surface.

As a typical example of this kind of flow control valve, there is a pressure balance valve arranged on the upstream side of the mixing valve body in the hot and cold mixing valve.
This pressure balance valve moves the valve body by the differential pressure between the water inflow pressure and the hot water inflow pressure, and supplies the water outflow pressure and hot water outflow pressure to the hot water mixing valve as the same pressure. To work.

FIG. 14 shows a specific example thereof.
In the figure, reference numeral 200 denotes a valve housing of a hot and cold mixing valve comprising a cylindrical (here, cylindrical) inner cylinder, in which a mixing valve body 202 is accommodated so as to be movable in the left-right direction, that is, in the axial direction.
The mixing valve body 202 has a water side valve body 204 and a hot water side valve body 206 that move integrally in the axial direction.

In this hot water / water mixing valve, water flows into the interior of the water side valve body 204 and the hot water side valve body 206 from the water inlet 208 formed in the valve housing 200 through the subsequent water inflow passage 210. In addition, hot water is caused to flow from the hot water inlet 212 formed in the valve housing 200 through the hot water inflow passage 214 that follows.
The inflowing water and hot water are mixed in the mixing chamber 216, and the mixed water flows out from the outflow portion 218 to be discharged from a predetermined water discharge portion.

  The mixing valve body 202 changes the opening degree of the water side valve body 204 and the hot water side valve body 206, that is, the opening degree of each of the water inflow passage 210 and the hot water inflow passage 214 in a reverse relationship. Then, the mixing ratio of the flowing water and hot water is changed. That is, the temperature of the mixed water is changed.

A temperature-sensitive spring 217 made of a shape memory alloy is provided in the mixing chamber 216, and its urging force is applied to the mixing valve body 202 in the left direction in the figure.
Also, the biasing force of the bias spring 219 made of a normal metal coil spring is exerted on the mixing valve body 202 in the right direction in the drawing, that is, in the direction opposite to the biasing force by the temperature-sensitive spring 217. Is moved in the left-right direction, that is, in the axial direction in the figure, to a position where the urging force leftward in the figure by the temperature-sensitive spring 217 and the rightward urging force in the figure by the bias spring 219 are balanced (to a balanced position). .

  Specifically, if the temperature of the mixed water is higher than the set temperature, the temperature sensing spring 217 expands to increase the leftward biasing force in the figure, and the balance between the biasing force of the temperature sensing spring 217 and the biasing spring 219 is balanced. The position is shifted to the left in the figure, and the mixing valve body 202 is moved in the left direction in the figure.

Conversely, if the mixed water temperature is lower than the set temperature, the temperature sensing spring 217 contracts to weaken the biasing force, and the balance position of the biasing force by the temperature sensing spring 217 and the biasing spring 219 is shifted to the right side in the figure. The mixing valve body 202 is moved in the right direction in the figure.
As a result, the amount of inflowing water and hot water is changed, and the temperature of the mixed water is automatically adjusted to the set temperature.
The water side valve body 204 abuts on a water side valve seat 220 formed in the valve housing 200 and closes, and the hot water side valve body 206 abuts on a hot water side valve seat 222 formed in the valve housing 200. Close the valve.

  Reference numeral 224 denotes a valve housing of a pressure balance valve comprising a cylindrical (here, cylindrical) outer cylinder, and the balance valve body 226 is formed in an annular space formed between the valve housing 200 of the hot water / water mixing valve. Is provided so as to be movable in the left-right direction, that is, in the axial direction.

The balance valve body 226 has a partition portion 236 at an intermediate portion in the axial direction.
The partition part 236 is slidably fitted to the valve housings 224 and 200, and the partition part 236 allows the annular space between the valve housings 224 and 200 to flow into the water inflow on the valve housing 224 side. A water side chamber communicated with the passage 230 and the water inflow passage 210 on the hot water mixing valve side, a hot water inflow passage 234 on the valve housing 224 side, and the hot water inflow passage 214 on the hot water mixing valve side. It is divided into a hot water side room.

  The balance valve body 226 is integrally provided with a water side valve body 238 and a hot water side valve body 240 on the left and right sides of the partition portion 236 in the figure, and these are fitted to the inner peripheral surface of the valve housing 224. The inner peripheral surface of the valve housing 224 is used as an axial sliding surface 242 and moves together with the partition 236 in the left-right direction in the axial direction.

  Here, the water side valve body 238 functions to adjust the inflow amount of water by expanding or narrowing the opening degree of the water inflow passage 230, and the hot water side valve body 240 has an opening degree of the hot water inflow passage 234. Is made narrower or wider to adjust the amount of inflow of hot water from the hot water inflow passage 234.

  In this pressure balance valve, the balance valve body 226 has the same pressure receiving area in the axial direction with respect to the water side chamber and the hot water side chamber, so that the inflow liquid pressure of water is higher than the inflow liquid pressure of hot water, and the hydraulic pressure Pc of the water side chamber. Is higher than the hydraulic pressure Ph in the hot water side chamber, the balance valve body 226 moves to the right in the figure by the differential pressure, the water side valve body 238 narrows the opening of the water inflow passage 230, and the hot water side valve The body 240 changes the opening degree of the hot water inflow passage 234 to be widened.

  As a result, the amount of water inflow from the water inflow passage 230 is reduced, the amount of hot water inflow from the hot water inflow passage 234 is increased, and the hydraulic pressure Pc in the water side chamber and the hydraulic pressure Ph in the hot water side chamber are equalized. Then, the balance valve body 226 stops there, and supplies water and hot water from the water side chamber and the hot water side chamber to the hot water / mixing valve side at the same hydraulic pressure.

  Specifically, water and hot water are supplied into the hot water mixing valve through the water inlet 208 of the valve housing 200 of the hot water mixing valve, the water inflow passage 210 that follows, and the hot water inlet 212 and the hot water inflow passage 214 that follows. To do.

  By the way, in the pressure balance valve, the balance valve body 226 is controlled based on the differential pressure between the inflow fluid pressure of water and the inflow fluid pressure of hot water, that is, the differential pressure between the fluid pressure Pc in the water side chamber and the fluid pressure Ph in the hot water side chamber. It is necessary to move to the balance position lightly with good responsiveness. Therefore, as shown in an enlarged view in FIG. 15, between the outer peripheral surface of the balance valve body 226 and the inner peripheral surface of the valve housing 224, that is, the sliding surface 242. A predetermined fitting clearance C is ensured.

  In this case, if the gap formed between the water-side valve body 238 and the sliding surface 242 is not sealed based on the clearance C, the water inflow occurs even when the water-side valve body 238 is closed. The water from the passage 230 goes around to the water side chamber through the gap. That is, water from the water inflow passage 230 leaks from the gap into the water side chamber.

  Similarly, if the gap formed between the hot water side valve body 240 and the sliding surface 242 is not sealed based on the clearance C, even if the hot water side valve body 240 is closed, the hot water inlet passage 234 Hot water wraps around the hot water side room through the gap. That is, hot water from the hot water inflow passage 234 leaks from the gap into the hot water side chamber.

Therefore, it is necessary to seal the gap between the water side valve body 238 and the sliding surface 242 and the gap between the hot water side valve body 240 and the sliding surface 242, respectively.
As the seal structure, a resin seal ring 244 that seals between the partition portion and the sliding surface of the valve housing in the one disclosed in Patent Document 1 below is used, and this is slid with the water side valve body 238. It is conceivable to use a seal structure used for sealing between the surface 242 and sealing between the hot water side valve body 240 and the sliding surface 242.

  The resin seal ring 244 has a circular ring shape as shown in an enlarged view in FIG. 14B, and the side surfaces 244A and 244B and the outer peripheral surface 244C in the axial direction each form a flat surface. In addition, an oblique notch 245 is provided at a predetermined position in the circumferential direction, the seal ring 244 can be elastically deformed in the radial direction by the notch 245, and the seal ring 244 is pushed and expanded in the radial direction by the notch 245 to be predetermined. It can be attached to the valve body.

As shown in an enlarged view in FIG. 15, when this seal ring 244 is fitted in the groove of the water side valve body 238 and the hot water side valve body 240, the side surface 244A or 244B in the axial direction is While contacting the corresponding groove side surface 246A or 246B and bringing the flat outer peripheral surface 244C into contact with the sliding surface 242, the water-side valve element 238 based on the clearance C and the sliding surface 242 are brought into contact with each other. The gap between the hot water side valve body 240 and the sliding surface 242 is sealed.
In this example, seal rings 244 are also mounted on the outer peripheral side and inner peripheral side of the partition portion 236.

  In the sealing structure using the resin seal ring 244, an O-ring is used to seal between the water side valve body 238 and the sliding surface 242 and between the hot water side valve body 240 and the sliding surface 242. However, the sliding resistance cannot be sufficiently reduced when the balance valve body 226 slides.

Thus, when such sliding resistance occurs, the pressure balance effect due to the axial movement of the balance valve body 226 is adversely affected, and the operation accuracy of the pressure balance valve is deteriorated.
In addition, since the cut 245 is provided in the seal ring 244, leakage at the cut 245 cannot be avoided, which also causes a deterioration in the operation accuracy of the pressure balance valve.
Thus, if the operation accuracy of the pressure balance valve deteriorates, water and hot water cannot be supplied to the downstream hot water mixing valve at the same pressure, and the hot water mixing valve cannot perform the hot water mixing operation accurately. End up.

  Therefore, especially when the above-mentioned leakage is a serious problem when the valve is closed, a gap generated between the water side valve body 238 and the sliding surface 242 based on the clearance C, the hot water side valve body 240 and the sliding surface 242 Therefore, there has been a demand for a seal structure that can satisfactorily seal the gap generated between the two and reduce the sliding resistance as much as possible.

A similar problem is that the sealing structure between the water-side valve body 204 and the hot-water side valve body 206 of the mixing valve body 202 and the corresponding inner peripheral surface of the valve housing 200, that is, the axial sliding surface 248 in the hot water / water mixing valve. Also exists.
In FIG. 14, an O-ring 250 is used as a seal for this purpose. In this case, when the water side valve body 204 and the hot water side valve body 206 of the mixing valve body 202 move in the left-right direction, that is, in the axial direction in the figure. A large sliding resistance is generated.

  The water side valve body 204 and the hot water side valve body 206 of the mixing valve body 202, that is, a valve for adjusting the temperature of the mixed water by moving in the axial direction so as to balance the urging forces of the springs acting in the opposite directions in the axial direction. If such a large sliding resistance occurs in the body, the sliding resistance adversely affects the balance action of these valve bodies, and the temperature of the mixed water cannot be adjusted accurately.

Therefore, in the sealing structure between the water side valve body 204 and the sliding surface 248 and between the hot water side valve body 206 and the sliding surface 248 in the mixing valve body 202, the above-mentioned leakage is a serious problem. There has been a need for a seal structure that can seal the gaps well and sometimes reduce the sliding resistance as much as possible.
In addition to these valves, other flow control valves for controlling the flow rate of liquid by moving the valve body along the axial sliding surface of the valve housing and changing the opening of the liquid passage, particularly the valve body On the other hand, there is a demand for a similar seal structure in a valve in which forces opposite to each other in the axial direction act on each other and the valve body moves in the axial direction so as to balance these forces.

  Patent Document 2 listed below uses a rubber U-packing as a sealing member between a mixing valve body in a hot and cold mixing valve with an automatic temperature control function and a corresponding axial sliding surface. However, when such a U-packing is used as a seal member, it is necessary to elastically deform the U-packing against the water pressure when the valve body is moved. The problem of adding resistance to movement arises.

JP 11-51219 A Japanese Utility Model Publication No. 6-69549

  The present invention is based on the above circumstances, and when necessary, it is possible to satisfactorily seal the gap between the valve body and the axial sliding surface of the valve housing, and to minimize the sliding resistance. The object of the present invention is to provide a seal structure for a flow rate control valve that can be reduced.

  Thus, according to the first aspect of the present invention, there is provided a seal structure of a flow rate control valve for controlling the flow rate of the liquid by moving the valve body along the axial sliding surface of the valve housing and changing the opening of the liquid passage. A flexible membrane member is used as a seal member that seals a gap between the valve body and the sliding surface, and the seal member is attached to a corresponding seal wall surface by a hydraulic pressure introduced into the gap. It is characterized by being pressed and brought into close contact and sealed.

  According to a second aspect of the present invention, in the first aspect, the seal wall surface is a surface in a direction intersecting the axial direction, and the gap is sealed in the axial direction by the seal member. It is characterized by.

  According to a third aspect of the present invention, in any one of the first and second aspects, the flow control valve is a valve that moves the valve body to a valve closing position to close the liquid passage, and at least the valve body of the valve body is closed. In the valve closing position, the seal member is tightly sealed to the seal wall surface.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the sealing member seals the seal wall in close contact with the valve body while moving from the fully open side to the fully closed side. .

According to a fifth aspect of the present invention, in any one of the third and fourth aspects, the flow control valve is configured such that the valve body moves along the sliding surface so that the valve bodies are opposite to each other in the axial direction. The liquid pressure applied to the direction or / and the urging force of the elastic body operate to balance.
Here, balancing the hydraulic pressure and / or the urging force of the elastic body means that the urging force of the elastic body and the urging force of the elastic body are balanced when the hydraulic pressure and the hydraulic pressure applied in opposite directions to each other in the axial direction are balanced. Is balanced, it means that both the hydraulic pressure and the urging force of the elastic body are balanced.

  According to a sixth aspect of the present invention, in the fifth aspect, the valve body is moved by a differential pressure between the inflow liquid pressure of water and the inflow liquid pressure of hot water, so that the outflow liquid pressure of water and the outflow liquid pressure of hot water are equalized. A water-side valve body and / or a hot water-side valve body in the valve body of the pressure balance valve to be flowed out and the seal member is a gap between the water-side valve body and the sliding surface of the valve housing or / And a gap between the hot water valve body and the sliding surface is sealed.

  According to a seventh aspect of the present invention, in the fifth aspect, the flow control valve is a hot water mixing valve with an automatic temperature control function, and the valve body is a water side valve body and / or a hot water side valve body in the mixing valve body. And the sealing member seals a gap between the water side valve element and the sliding surface of the valve housing or / and a gap between the hot water side valve element and the sliding surface. Features.

  According to an eighth aspect of the present invention, in any one of the first and second aspects, the flow rate control valve includes a primary side hydraulic pressure and a secondary side hydraulic pressure applied in an opposite direction to the valve body in an axial direction. A constant flow valve that controls the flow rate of the liquid flowing through the liquid passage to a constant flow rate so that the differential pressure of the valve body is constant, at least at the constant flow acting position of the valve body It is characterized in that a member is brought into close contact with the seal wall surface for sealing.

  A ninth aspect of the present invention is characterized in that, in the eighth aspect, the seal member is tightly sealed to the seal wall surface while the valve body moves toward the constant flow rate operation position. To do.

  According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the flexible film-like sealing member is made of an elastic material.

  According to an eleventh aspect, in any one of the first to tenth aspects, the seal wall surface is provided on both the valve housing and the valve body, while the seal member extends over the valve housing side and the valve body side. Each of the valve housing side and the valve body side is non-fixed and is movable relative to the valve housing side and the valve body side, and the sealing member is moved by the fluid pressure introduced into the gap. It is characterized in that both the sealing wall surfaces are brought into close contact with each other for sealing.

  According to a twelfth aspect of the present invention, in any one of the first to tenth aspects, the seal member is fixedly attached to one of the valve housing side or the valve body side, and the seal wall surface provided on the other side is The seal member is brought into close contact with the liquid pressure introduced into the gap and sealed.

  According to a thirteenth aspect of the present invention, in any one of the third and fourth aspects, the seal member is fixedly attached to one of the valve housing side or the valve body side, and the seal wall surface provided on the other side The sealing member is brought into close contact with the fluid pressure introduced into the gap and sealed, and the mounting position of the sealing member is provided on the other side when the valve body is positioned at the valve closing position. The valve body is separated from the sealing wall surface in the valve closing direction.

  According to a fourteenth aspect of the present invention, in any one of the eighth and ninth aspects, the seal member is fixedly attached to one of the valve housing side or the valve body side, and the seal wall surface provided on the other side is The sealing member is brought into close contact with the fluid pressure introduced into the gap and the sealing member is attached to the other when the valve body is located at the constant flow rate operating position. It is characterized in that the valve body is located at a position spaced apart from the valve body on the side of the constant flow rate operation position.

Effects and effects of the invention

  As described above, the present invention uses a flexible membrane member as a seal member for sealing the gap between the valve body and the axial sliding surface of the valve housing, and the hydraulic pressure introduced into the gap. The seal member is pressed against the corresponding seal wall surface so as to be in close contact with the seal wall surface.

The present invention uses a hydraulic pressure introduced between a valve body and a sliding surface to seal a sealing member against a corresponding sealing wall surface in a close contact state. In this case, the sealing member is flexible. Therefore, a sufficiently large surface pressure can be applied to the seal member, and the seal member is sealed based on its flexibility by the surface pressure. It can adhere well to the wall surface, thereby ensuring good sealing performance.
In this case, the flow control valve can be a cylindrical valve.

The sealing wall surface may be a surface intersecting the axial direction, for example, a surface perpendicular to the axial direction, and the clearance may be sealed in the axial direction by a sealing member (claim). Item 2).
The seal structure according to the second aspect can be configured such that only the seal in the axial direction is performed without performing the seal in the direction perpendicular to the axis such as the radial direction.

The leakage of the liquid from the gap between the axial sliding surface of the valve housing and the valve body is the above when the valve body is open, that is, when the liquid passage is large. Since the ratio of the flow rate of leakage from the gap is small, it is not a big problem.
On the other hand, when the opening degree of the valve body is small, that is, when the throttle for the liquid flow in the liquid passage is large, the ratio of the leakage flow rate to the total flow rate becomes large, which is a big problem.

  For example, as defined in claim 3, when the valve body is a valve that moves to the valve closing position and closes the liquid passage, the liquid leaks from the gap even though the valve body is closed. That is a big problem.

  Alternatively, as defined in claim 8, when the valve body is a constant flow valve that restricts the flow of the liquid passage and performs a constant flow rate action, the valve body moves from the fully open side to the fully closed side to reach the constant flow rate action position. In spite of the constant flow rate action, the constant flow rate action cannot be performed accurately if there is a leak from the gap.

  In particular, when the valve body reaches the closed position as described above, or when the opening degree of the liquid passage is greatly reduced, the pressure drop on the upstream side of the valve body causes the valve body to be greatly opened. As a result, the hydraulic pressure introduced into the gap increases as a result of the smaller size, and the amount of leakage from the gap also increases.

  However, according to the present invention, the liquid pressure introduced into the gap is utilized and the flexibility of the seal member is utilized to press the seal against the corresponding seal wall surface. When the valve body is closed, or when the valve body is in a position where constant flow rate action is performed, the sealing member is pressed against the seal wall surface to cause the valve body to open. When the valve is in the valved state, it is possible not to perform sealing with the seal member.

In this case, the sealing member is in close contact with the sealing wall surface during the movement of the valve body from the fully open side to the fully closed side, in particular, the way to the valve closing position or the way to the constant flow rate operation position. (Claim 4 and Claim 9).
By doing so, sliding resistance due to the seal of the seal member does not occur until the valve body reaches the valve closing position or the constant flow rate operation position, and the valve body is moved lightly along the sliding surface. It becomes possible.

The seal structure according to claims 3 and 4 is configured such that the valve body moves by using the difference between the hydraulic pressure applied to the valve body in the opposite directions in the axial direction and / or the biasing force of the elastic body as a driving force, and balances them. The present invention is suitable for application to a flow control valve that operates in the following manner (Claim 5), and is particularly effective when applied to a pressure balance valve defined in Claim 6.
As a result, it is possible to satisfactorily prevent the sliding resistance during movement of the valve body and the leakage of liquid from the gap from adversely affecting the balance action of the valve body.

  The seal structure according to claim 5 is also a seal structure for a gap between the water side valve element and / or the hot water side valve element and the sliding surface of the valve housing in the mixing valve element of the hot water mixing valve with an automatic temperature control function. It is suitable to apply to (claim 7).

In the present invention, the flexible film-like sealing member can be made of an elastic material (elastomer) such as rubber (claim 10).
By configuring the seal member with such an elastic material, when surface pressure is applied to the seal member with the hydraulic pressure introduced into the gap, the seal wall surface of the seal member is elastically deformed to cause the seal wall surface to be sealed. Can be sufficiently adhered to each other, and the sealing performance can be further enhanced.

  In the present invention, seal wall surfaces are provided on both the valve housing and the valve body, and the seal member is unfixed across the valve housing side and the valve body side and on each of the valve housing side and the valve body side. The seal member is provided so as to be relatively movable on the valve housing side and the valve body side, and the seal member is brought into close contact with both seal wall surfaces by the fluid pressure introduced into the gap, so that sealing can be performed. ).

  Alternatively, according to claim 12, the seal member is fixedly attached to one of the valve housing side or the valve body side, and the seal member is pressed against the seal wall surface provided on the other side by the hydraulic pressure introduced into the gap in a sealed state. (Claim 12).

Thus, when the sealing member is attached to one side in a fixed state, the following advantages are obtained.
When the seal member is provided in a non-fixed state according to claim 11, the seal member may be irregularly deformed by the flow of the liquid in the gap, which may cause a case where the seal function cannot be sufficiently performed. However, according to the twelfth aspect, it is possible to prevent such inconveniences by providing the sealing member in a fixed state on one side.

  In this way, when the sealing member is fixed to one side, when the valve body moves to the valve closing position and closes the liquid passage, the mounting position of the sealing member is indicated as the valve body closing position. It can be set as the position spaced apart in the valve-closing direction of the valve body with respect to the other seal wall surface.

  Alternatively, when the flow control valve is a constant flow valve and the valve element does not reach the valve closing position and the liquid passage is opened with a certain amount, the fixed flow rate action is performed. When the body is located at the constant flow rate action position, the valve body can be positioned away from the other seal wall surface toward the constant flow rate action position side of the valve body (claim 14).

  According to the thirteenth and fourteenth aspects, the sealing member attached in a fixed state obstructs the movement of the valve body in the valve closing direction at the attachment position, and the valve body is the target valve closing. It is possible to prevent the movement to the direction position or the constant flow rate operation position.

It is sectional drawing which showed the hot-water mixing valve and pressure balance valve as a flow control valve which has the seal structure of one Embodiment of this invention. It is a principal part enlarged view of the embodiment. It is operation | movement explanatory drawing of the embodiment. It is the figure which expanded and showed the principal part of FIG. It is the figure which showed the sealing characteristic of this embodiment compared with the prior art example. It is the figure which showed the principal part of the seal structure of other embodiment of this invention. It is the figure which showed the principal part of the seal structure of further another embodiment of this invention. It is explanatory drawing shown in order to demonstrate the advantage of one Embodiment of this invention. It is the figure which showed the principal part of the seal structure of further another embodiment of this invention. It is the figure which showed the principal part of the seal structure of further another embodiment of this invention. It is the figure which showed the principal part of the seal structure of further another embodiment of this invention. It is a figure of other embodiment of this invention. It is a figure of other embodiment of this invention. It is a figure of the flow control valve which has the conventional seal structure. It is a principal part enlarged view of FIG.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, 10 is a valve housing of a hot / cold mixing valve comprising a cylindrical (here, cylindrical) inner cylinder, in which a mixing valve body 12 is accommodated so as to be movable in the left-right direction in the axial direction. .
This mixing valve body 12 has a water-side valve body 14 and a hot water-side valve body 16 that are spaced apart in the left-right direction in the axial view, and a shaft-like connecting portion 18 that connects them. They are integrally movable in the left-right direction in the figure.

In this hot water / water mixing valve, water flows in from the water inlet 20 formed in the valve housing 10 to the inside through the water inflow passage 22 that follows, with the water side valve element 14 and the hot water side valve element 16 opened. In addition, hot water is caused to flow from the hot water inlet 24 formed in the valve housing 10 into the interior through the hot water inflow passage 26 that follows.
The inflowing water and hot water are mixed in the mixing chamber 28, and the mixed water flows out from the outflow part 30 and is discharged from a predetermined water discharge part.

  The mixing valve body 12 changes the valve opening degrees of the water side valve body 14 and the hot water side valve body 16, that is, the respective opening degrees of the water inflow passage 22 and the hot water inflow passage 26 in a reverse relationship. Then, the mixing ratio of the flowing water and hot water is changed. That is, the temperature of the mixed water is changed.

A temperature-sensitive spring 32 made of a shape memory alloy is provided in the mixing chamber 28, and its urging force is exerted on the mixing valve body 12 leftward in the figure.
Also, the biasing force of the bias spring 34 made of a normal metal coil spring is exerted on the mixing valve body 12 in the right direction in the drawing, that is, in the direction opposite to the biasing direction by the temperature-sensitive spring 32.
The mixing valve body 12 is in a position where the urging force in the left direction in the figure by the temperature-sensitive spring 32 and the urging force in the right direction in the figure by the bias spring 34 are balanced (in a balanced position). Moved to.

  Specifically, if the temperature of the mixed water is higher than the set temperature, the temperature sensing spring 32 expands to increase the urging force in the left direction in the figure, and the balance between the urging force of the temperature sensing spring 32 and the urging force of the bias spring 34 is balanced. The position is shifted to the left in the figure, and the mixing valve body 12 is moved in the left direction in the figure.

On the contrary, if the temperature of the mixed water is lower than the set temperature, the temperature sensing spring 32 contracts and weakens the urging force, and the balance position of the urging force by the temperature sensing spring 32 and the urging force by the bias spring 34 is shifted to the right side in the figure. Then, the mixing valve body 12 is moved in the right direction in the figure.
As a result, the inflow amount of the inflowing water and hot water is changed, and the temperature of the mixed water is automatically adjusted to the set temperature.

The water side valve element 14 contacts and closes the water side valve seat 36 formed in the valve housing 10, and the hot water side valve element 16 contacts the hot water side valve seat 38 formed in the valve housing 10. Close the valve.
The valve housing 10 of the hot and cold water mixing valve is provided with an annular projecting portion 40 projecting to the right at the left position in the drawing. This protrusion 40 constitutes a part of a valve housing in a pressure balance valve described later.

  As shown in FIG. 2, annular grooves 35 and 37 are provided on the outer peripheral surfaces of the cylindrical water-side valve body 14 and the hot water-side valve body 16 as seal members. O-rings 39 and 41 are held, and the water-side valve body 14 and the hot-water side valve body 16 are placed there through the O-rings 39 and 41, with the inner peripheral surface of the valve housing 10 as a sliding surface 43. It is fitted in a watertight and slidable manner in the axial direction.

  Reference numeral 42 denotes a drive mechanism housing that houses therein a drive mechanism for driving the mixing valve body 12. A drive shaft 44 extending in the left-right direction in the drawing is provided in the center of the housing, and the drive shaft 44 is mixed. The valve body 12 is coupled to the connecting portion 18 in a state of integral movement.

An operation shaft portion 46 is connected to a handle (not shown) in an integrally rotated state. The operation shaft portion 46 is integrally provided with a large-diameter cylindrical portion 48 inside the housing 42.
A female screw portion 50 is provided on the inner peripheral surface of the cylindrical portion 48, and the male screw portion 54 on the outer peripheral surface of the cylindrical advance / retreat member 52 is screwed into the female screw portion 50, so that the operation shaft portion 46, By the rotation of the cylindrical portion 48, the advance / retreat member 52 is moved forward and backward in the horizontal direction in the drawing by screw feed.

  A cylindrical engagement member 56 is coupled to the forward / backward member 52 so as to be movable relative to the forward / backward member 52 in the horizontal direction in the drawing. The bias spring 34 is interposed between the inward flange-shaped spring receiver 58 and the stepped portion 60 of the advance / retreat member 52 in a compressed state.

An annular engagement portion 62 that protrudes radially outward is provided at the right end of the advance / retreat member 52 in the drawing, while a radially inward flange-like shape is provided at the left end of the engagement member 56 in the drawing. An engaging portion 64 is provided, and the engaging portions 62 and 64 are engaged in the axial direction.
The engaging portion 62 of the advancing / retracting member 52 is movable relative to the engaging member 56 between the engaging portion 64 of the engaging member 56 and the flange-shaped spring receiver 58.

In this hot and cold water mixing valve, the temperature of the mixed water is set or changed by rotating the operation shaft portion 46.
At this time, due to the rotation of the cylindrical portion 48 integrated with the operation shaft portion 46, the advance / retreat member 52 moves back and forth in the left-right direction in the drawing, and the position of the mixing valve body 12 changes in the left-right direction in the drawing.

Specifically, when the operation shaft portion 46 is rotated to the high temperature side, the advance / retreat member 52 moves forward to the right in the drawing by screw feed, compressing the bias spring 34 and increasing its urging force.
As a result, the balance position of the biasing force of the bias spring 34 and the temperature sensitive spring 32 shifts to the right in the drawing, and the mixing valve body 12 is moved in the same direction.

On the other hand, when the operating shaft portion 46 is rotated in the opposite direction, the advancing / retracting member 52 moves backward in the left direction in the figure to extend the bias spring 34 and reduces the biasing force of the bias spring 34. Let
Thereby, the balance position of the urging force of the bias spring 34 and the temperature sensitive spring 32 is shifted to the left in the figure, and the mixing valve body 12 is shifted in the same direction.

  In this state, the mixing valve body 12 finely moves in the left-right direction in the figure according to the increase / decrease of the mixed water temperature, lowers or increases the mixed water temperature toward the set temperature, and automatically increases the mixed water temperature. Adjust to the set temperature.

Specifically, if the mixed water temperature is higher than the set temperature, the mixing valve body 12 slightly moves to the left in the figure due to the increase in the urging force of the temperature sensing spring 32, and the mixed water temperature is lowered toward the set temperature.
On the contrary, if the mixed water temperature is lower than the set temperature, the temperature sensing spring 32 contracts to weaken the urging force, and here, the mixed valve body 12 slightly moves to the right in the figure to raise the mixed water temperature toward the set temperature. Let

A pressure balance valve is disposed on the upstream side of the mixing valve body 12 in the hot and cold mixing valve.
In the figure, reference numeral 66 denotes a valve housing of a pressure balance valve comprising a cylindrical (here, cylindrical) outer cylinder. The valve housing 66 includes a water inlet 68 and a hot water inlet 70 at positions separated in the axial direction, and these A continuous water inflow passage 72 and a hot water inflow passage 74 are formed.

  In an annular space formed inside the valve housing 66 and between the valve housing 10 of the hot and cold water mixing valve, a cylindrical balance valve body 76 is provided so as to be movable in the left-right direction in the axial direction. Yes.

The balance valve body 76 is provided with a partition portion 78 at an intermediate portion in the axial direction.
As shown in detail in FIG. 2, the partition 78 is slidably fitted to the valve housings 66 and 10, and the annular portion between the valve housings 66 and 10 is formed by the partition 78. The water side chamber 79 communicated with the water inflow passage 72 of the valve housing 66 and the water inflow passage 22 of the valve housing 10, and the hot water communicated with the hot water inflow passage 74 of the valve housing 66 and the hot water inflow passage 26 of the valve housing 10. It is partitioned into a side chamber 80.

  The balance valve body 76 has a water side valve body 82 and a hot water side valve body 84 on the left side and the right side of the partition 78 in the figure, and the water side valve body 82 and the hot water side valve body 84 are connected to each other. The valve housing 66 is fitted to the inner peripheral surface of the valve housing 66, and the inner peripheral surface of the valve housing 66 is moved in the left-right direction together with the partitioning portion 78 with the sliding surface 86 in the axial direction.

  Here, the water side valve element 82 functions to adjust the amount of water inflow by expanding or narrowing the opening of the water inflow path 72, and the hot water side valve element 84 opens the hot water inflow path 74. By changing the degree narrower or wider, the amount of hot water flowing in from the hot water inflow passage 74 is adjusted.

  In this pressure balance valve, the balance valve body 76 has the same pressure receiving area in the axial direction with respect to the water side chamber 79 and the hot water side chamber 80, so that the inflow liquid pressure of water is higher than the liquid pressure of hot water. If the pressure Pc is higher than the hydraulic pressure Ph in the hot water side chamber 80, the balance valve body 76 moves rightward in the figure due to the hydraulic pressure difference, and the water side valve body 82 narrows the opening of the water inflow passage 72. The hot water side valve element 84 changes the opening degree of the hot water inflow passage 74 to be widened.

  As a result, the amount of water inflow from the water inflow passage 72 decreases, the amount of hot water inflow from the hot water inflow passage 74 increases, and the hydraulic pressure Pc in the water side chamber 79 and the hydraulic pressure Ph in the hot water side chamber 80 are equally balanced. Then, the balance valve body 76 stops there, and supplies the hot water / water mixing valve side from the water side chamber 79 and the hot water side chamber 80 with the same hydraulic pressure as water and hot water.

  Specifically, water and hot water are supplied into the hot water mixing valve through the water inlet 20 of the valve housing 10 of the hot water mixing valve and the subsequent water inflow passage 22, and the hot water inlet 24 and the subsequent hot water inflow passage 26. Supply with equal hydraulic pressure.

  In this embodiment, the water-side valve body 82 contacts and closes the water-side valve seat 88 formed in the valve housing 66, and the hot-water side valve body 84 is formed in the valve housing 66. The valve abuts 90 and closes.

  In this embodiment, the balance valve body 76 is fitted to the sliding surface 86 on the inner peripheral surface of the valve housing 66 with a predetermined fitting clearance C, and the water side valve body 82 and the hot water side valve body 84 are fitted. On the outer peripheral side, annular seal members 92 and 94 for sealing a gap based on the fitting clearance are provided.

In the present embodiment, flexible membrane members are used as the seal members 92 and 94. Here, the sealing members 92 and 94 are made of an elastic material (elastomer) such as rubber.
The seal members 92, 94 are oriented in a direction perpendicular to the axis, the outer peripheral end is fixedly attached to the valve housing 66, and the inner peripheral end is a sliding surface 86 of the inner peripheral surface of the valve housing 66. Projecting inward in the radial direction.

On the other hand, annular grooves 96, 98 are provided on the outer peripheral surfaces of the water side valve body 82 and the hot water side valve body 84, and the inner peripheral side portions of the seal members 92, 94 are inserted into the annular grooves 96, 98. ing.
Here, the seal members 92 and 94 are provided in a non-contact state with respect to the groove bottom surfaces of the annular grooves 96 and 98.

  The water-side seal member 92 is attached to an annular position when the water-side valve element 82 comes into contact with the water-side valve seat 88 and closes as shown in FIG. 4 (II). The seal wall 100 in the direction perpendicular to the axis formed by the groove side surface of the groove 96 is positioned on the right side in the drawing, that is, the position separated in the valve closing direction of the water side valve element 82.

Similarly, when the hot water side valve body 84 comes into contact with the hot water side valve seat 90 to be in the valve closing position, the hot water side seal member 94 is attached in the direction perpendicular to the axis formed by the groove side surface of the annular groove 98. The wall surface 102 is spaced from the hot water side valve body 84 in the valve closing direction.
Note that seal members 104 and 106 having the same configuration are also provided on the outer peripheral side and the inner peripheral side of the partition portion 78.

Here, the outer peripheral side sealing member 104 is fixed to the partitioning portion 78 at the inner peripheral end, and the inner peripheral sealing member 106 is fixed to the partitioning portion 78 at the outer peripheral side. It protrudes radially outward and inward.
Correspondingly, annular grooves 108 and 110 are provided in the valve housings 66 and 10, and seal members 104 and 106 are inserted into the annular grooves 108 and 110, respectively.

However, the seal member 104 on the outer peripheral side seals the pair of groove side surfaces in the annular groove 108 as a seal wall surface 112 in the direction perpendicular to the axis.
Further, the seal member 106 on the inner peripheral side seals the pair of groove side surfaces of the annular groove 110 of the valve housing 10 in the hot water / water mixing valve in close contact with each other with the seal wall surface 114 in the direction perpendicular to the axis.

  Specifically, when the balance valve body 76 moves to the right in FIG. 2 and the water-side valve body 82 closes, the seal member 104 comes into close contact with the seal wall surface 112 on the right side in FIG. None, and when the partition 78 moves to the left in the drawing to the full and the hot water side valve body 84 abuts on the hot water side valve seat 90 and closes, the seal member 104 is the seal wall surface on the left side of the annular groove 108 in the drawing. It is in close contact with 112 and performs a sealing action.

  On the other hand, when the water-side valve element 82 is closed, the inner circumferential side seal member 106 is in close contact with the seal wall 114 on the right side of the annular groove 110 in the drawing to seal the gap between the partition portion 78 and the valve housing 10. Further, when the hot water side valve body 84 is closed, the sealing wall functions in close contact with the seal wall surface 114 on the left side in the drawing.

Next, the operation of this embodiment will be described.
FIG. 3I shows that the balance valve body 76 opens the water side valve body 82 and the hot water side valve body 84, and the hydraulic pressure Pc of the water side chamber 79 and the hydraulic pressure Ph of the hot water side chamber 80 are the same. It shows the action state when balancing. At this time, the water-side seal member 92 is in a state of being separated from the seal wall surface 100 of the water-side valve element 82 to the right side in the drawing as shown in FIG. The gap based on the fitting clearance C with the surface 86 does not seal, and similarly, the hot water side seal member 94 also does not seal the gap between the hot water side valve body 84 and the sliding surface 86. Accordingly, the water flowing in from the water inflow passage 72 can flow into the water side chamber 79 through the gap, and similarly, the hot water from the hot water inflow passage 74 can also flow into the hot water side chamber 80 through the gap.
However, since the water inflow passage 72 and the hot water inflow passage 74 are largely opened in the state of FIG. 3 (I), the liquid pressure Pc and the liquid in the hot water side chamber 80 even if such water and hot water wraps around. The pressure Ph is the same pressure, and no particular trouble occurs.
On the other hand, the balance valve element 76 operating to balance the hydraulic pressure Pc of the water side chamber and the hydraulic pressure Ph of the hot water side chamber in this way does not receive any sliding resistance due to the seal members 92 and 94. Balance operation can be performed lightly.

On the other hand, for example, when the hydraulic pressure Pc in the water side chamber 79 becomes excessive with respect to the hydraulic pressure Ph in the hot water side chamber 80, the water side valve element 82 is in a state where the flow of water from the water inflow passage 72 is greatly reduced. As a result, as shown in FIG. 3 (II), the water side valve element 82 comes into contact with the water side valve seat 88 to be closed.
At this time, the water-side seal member 92 is pushed leftward in the figure by the water-side hydraulic pressure introduced into the gap between the water-side valve element 82 and the sliding surface 86, and is shown in FIG. 3 (II). In this way, the water-side valve body 82 is brought into close contact with the seal wall surface 100. As a result, the seal member 92 seals the gap between the water side valve element 82 and the sliding surface 86, and prevents water from the water inflow passage 72 from flowing into the water side chamber 79 through the gap.

In this embodiment, when the water-side valve element 82 is close to the valve closing position, that is, just before the valve is closed, the pressure drop on the upstream side of the water-side valve element 82 is caused when the water-side valve element 82 is largely opened. As a result, the hydraulic pressure introduced into the gap between the water-side valve element 82 and the sliding surface 86, that is, the hydraulic pressure acting on the seal member 92 increases.
On the other hand, since the sealing member 92 is made of an elastic material and has flexibility, the water-side valve element 82 is closed before the water-side valve element 82 is completely closed. On the way, the seal member 92 is pressed against the seal wall surface 100 in a close contact state to perform a sealing action.

  Therefore, in this embodiment, when the most serious problem is that the water from the water inflow passage 72 leaks into the water side chamber 79 through the clearance C, the seal member 92 performs the sealing action of the clearance at an appropriate timing. Prevents water leakage to the water side chamber 79.

  In this embodiment, the sealing wall surface 100 is also attached when the sealing member 92 is attached to the valve housing 66 when the water side valve element 82 is closed as shown in FIGS. 3 (II) and 4 (II). Since the seal member 92 is located at the right side in the drawing, that is, at a position separated in the valve closing direction of the water side valve element 82, the seal member 92 hinders the movement of the water side valve element 82 to the valve closing position at the mounting position. It has the advantage that there is no fear of becoming.

  As shown in FIG. 8A, when the sealing member 92 is attached to the valve housing 66, the sealing member 92 contacts the sealing wall surface 100 before the water-side valve element 82 reaches the valve closing position. If it is in the position, the seal member 92 may hinder further movement of the water side valve element 82 in the valve closing direction, but the mounting position of the seal member 92 is the position as shown in FIG. Therefore, it is possible to satisfactorily avoid the occurrence of such inconvenience.

  The operation when the sealing member 92 seals the gap between the water side valve body 82 and the sliding surface 86 has been described above. However, the hot water side sealing member 94 is formed between the hot water side valve body 84 and the sliding surface 86. The action when sealing the gap between them is basically the same.

FIG. 5 shows the sealing characteristics of the sealing structure of the present embodiment in comparison with the conventional example using the resin ring 204 of FIG. 14 as a sealing member.
The horizontal axis in FIG. 5 indicates the valve opening degree of the water side valve element 82, and the vertical axis indicates the flow rate Q of water flowing into the water side chamber 79.
As shown in FIG. 5, the leakage of water through the gap between the water side valve element 82 and the sliding surface 86 is caused by the leakage of hot water through the gap between the hot water side valve element 84 and the sliding surface 86. The same applies to leakage), which is particularly problematic when the valve opening of the water-side valve element 82 becomes small.

  Specifically, in the case of the conventional seal structure, when the water side valve element 82 moves in the valve closing direction and the valve opening degree becomes smaller than a certain value, that is, the water flow from the water inflow passage 72 becomes larger than a certain value. Water leakage becomes a problem at the stage where it is greatly squeezed.

  Specifically, even when the water side valve element 82 moves in the valve closing direction and reaches the valve closing position, a certain amount of water still leaks, and even when the water side valve element 82 is closed, It is not possible to reduce or eliminate water leakage from the inflow passage 72 toward the hot water / mixing valve.

However, according to the seal structure of the present embodiment, the movement of the water side valve element 82 continues until the water side valve element 82 closes due to the movement of the water side valve element 82 in the valve closing direction. Thus, it is possible to reduce the flow of water from the water inflow passage 72 to the hot water mixing valve side, and finally, it is possible to stop the inflow of water into the water side chamber 79 without water leakage.
The sealing structure between the hot water valve body 84 and the sliding surface 86 is the same as described above.

  The above is an example in which the seal members 92 and 94 are fixedly attached to the valve housing 66 side. However, the seal members 92 and 94 are also provided on the valve housing 66 side, the water side valve element 82 and the hot water side valve. It is also possible that the body 84 is not fixed and is provided so as to be relatively movable with respect to them.

  The functions of the water-side seal member 92 and the hot water-side seal member 94 are basically the same. Therefore, the water-side seal member 92, that is, between the water-side valve element 82 and the sliding surface 86 will be described below. The gap seal structure will be described below as an example.

FIG. 6 shows an example.
In this example, an annular groove 116 is provided also on the valve housing 66 side, and the seal member 92 extends over the water side valve body 82 and the valve housing 66 and to either the valve housing 66 or the water side valve body 82. However, they are not fixed and are provided so as to be movable relative to them. The outer peripheral portion is inserted into the annular groove 116, the inner peripheral portion is inserted into the annular groove 96, and the water side valve element 82 is inserted. The seal member 92 is moved to near the valve closing position, and the sealing wall surface 100 of the annular groove 96 and the annular groove 116 are hydraulically introduced into the gap between the sliding surface 86 and the water side valve body 82. In this example, both the sealing wall surface 118 and the sealing wall surface 118 are pressed in close contact with each other to cause a sealing action.
It should be noted that the axial positional relationship between the seal wall surface 100 on the water side valve element 82 side and the seal wall surface 118 on the valve housing 66 side may be different from the above example.

FIG. 7 shows an example.
In the example of FIGS. 7A and 7A, the axial position of the seal wall surface 118 on the valve housing 66 side is positioned on the left side in the drawing with respect to the seal wall surface 100 of the water side valve element 82 with respect to the example of FIG. On the contrary, the example of FIG. 7B shows an example in which the axial position of the seal wall surface 118 is positioned on the right side of the seal wall surface 100 of the water side valve element 82 in the drawing. ing.

  The above example is an example in the case where the annular groove 116 on the valve housing 66 side is provided independently of the water inflow passage 72, and such an annular groove 116 is shown in FIG. 7B. It is also possible to provide the water inflow passage 72 in a continuous form.

When the seal member 92 is provided in a non-fixed and free state with respect to the valve housing 66 and the water-side valve element 82 as described above, the water due to the clearance C as shown in FIG. The flow of water flowing into the gap between the side valve body 82 and the sliding surface 86 may cause the seal member 92 to be irregularly deformed, and the seal member 92 may not be able to exert a sealing action. There is.
However, as shown in FIGS. 1 to 4, such a problem can be prevented by attaching the seal member 92 to the valve housing 66 in a fixed state.

The above is an example in which the water-side valve body 82 is brought into contact with the water-side valve seat 88 to close it, but as shown in FIG. 9, the water-side valve seat 88 is provided on the valve housing 66 side. It is also possible to close the water-side valve element 82 without bringing it into contact with the water-side valve seat 88 without providing it.
FIG. 9A shows a specific example. In this example, the water side valve element 82 is closed without contact with the water side valve seat.
In this case, in order to define the valve closing position of the water side valve body 82, the water side valve body 82 and the valve housing 66 are provided with stopper portions 120, 122 and brought into contact with each other to thereby contact the water side valve body 82. Is stopped at the valve closing position.

When the sealing member 92 is provided in a fixed state, it can be attached to the water side valve element 82 in a fixed state.
FIG. 10 shows an example in that case.
In this example, the water-side valve seat 88 on the valve housing 66 side is provided so as to protrude downward in the figure, while the water-side valve body 82 projects a contact portion 124 against the water-side valve seat 88 upward. In addition, a water passage 128 is provided in the water side valve body 82, and water flowing in from the water inflow passage 72 flows into the inside through the passage 128 and a gap between the water side valve seat 88 and the contact portion 124. It is supposed to let you.

  The seal member 92 is fixedly attached to the inner peripheral side with respect to the water side valve element 82, and the outer peripheral side portion is inserted into an annular groove 116 formed in the valve housing 66, and this is inserted into the water side. When the valve body 82 is closed or just before the valve body 82 is pressed against the seal wall surface 118 in a close contact state, a sealing action is performed.

  In the above embodiment, the sealing structure of the present invention is provided between the water side valve body 82 and the valve housing 66 of the pressure balance valve and between the hot water side valve body 84 and the valve housing 66. The seal structure may be provided between the water side valve body 14 of the mixing valve body 12 and the valve housing 10 of the hot water / water mixing valve in the hot water / water mixing valve of FIG. 1 or between the hot water side valve body 16 and the valve housing 10. Is possible.

  FIG. 11 shows an example in which the seal structure of the present invention is applied between the water-side valve element 14 and the valve housing 10 as a representative example. However, even when the seal structure of the present invention is applied between the hot water side valve body 16 and the valve housing 10, it is basically the same as the seal structure shown in FIG. 1 except that the left and right are reversed.

In the seal structure shown in FIG. 11, the annular groove 96 in the above example is provided in the water side valve body 14 in the mixing valve body 12, and one seal member 92 is fixedly attached to the valve housing 10 side of the hot water mixing valve. Thus, the inner peripheral side is inserted into the annular groove 96, and the inserted portion is pressed against the seal wall surface 100 of the annular groove 96 to effect sealing.
The other points are basically the same as the seal structure between the water-side valve element 82 and the valve housing 66 in the balance valve element 76 described above.

12 and 13 show an example in which the present invention is applied as a seal structure in a constant flow valve.
In the drawing, 130 is a valve body having a cylindrical shape of a constant flow valve, and 132 is a valve housing.
The valve body 130 moves in the left-right direction in the drawing in the axial direction with the inner peripheral surface of the valve housing 132 as an axial sliding surface 134 to perform a constant flow rate action.

The valve body 130 is provided with an opening 136 through which liquid flows from the primary side to the secondary side.
Also the valve body 130, the primary-side pressure receiving surface 138 for receiving the fluid pressure _{P 1} on the primary side, the secondary side pressure receiving surface 140 for receiving the fluid pressure _{P 2} on the secondary side.
The urging force of the spring 142 is exerted on the valve body 130 in the left direction in the drawing, that is, in the direction in which the secondary hydraulic pressure P ₂ acts on the secondary pressure receiving surface 140.

In the constant differential pressure type constant flow valve of this example, the primary side hydraulic pressure P ₁ acting to the right in the figure with respect to the valve element 130 and the secondary side hydraulic pressure P ₂ acting to the left in the figure with respect to the valve element 130. , And the valve body 130 moves in the left-right direction in the drawing so as to balance the leftward biasing force of the spring 142 in the drawing.

That is, when the secondary pressure P ₂ increases, the valve body 130 moves to the left in the figure, and the restriction on the flow of the liquid flowing out from the liquid passage 146 formed between the valve seat 144 and the secondary side is reduced. The hydraulic pressure P ₂ is lowered, the differential pressure between the primary hydraulic force P ₁ and the secondary hydraulic force P ₂ is kept constant, and the rightward force and the leftward force on the valve body 130 are balanced.

Further, when the secondary pressure P ₂ decreases, the valve body 130 moves to the right in the figure to increase the throttle for the liquid flow in the liquid passage 146 and increase the secondary pressure P _{2 to} increase P ₁ and P ₂ . Is maintained constant, and the rightward force and the leftward force on the valve body 130 are balanced.
In this constant flow valve, the flow rate of the liquid flowing through the opening 136 is given by the following equation (1).

However, in Formula (1), Q is a flow rate, A is the flow path area of the opening 136, C is a constant, and ρ is the specific gravity of water.
Thus, in this constant flow valve, since the differential pressure P ₁ -P ₂ is kept constant, the flow rate flowing through the opening 136 is kept constant.

In this example, the inner peripheral side of the seal member 152 similar to the above is attached to the outer peripheral side of the valve body 130 in a fixed state.
On the other hand, an annular groove 148 is formed on the valve housing 132 side, and an outer peripheral side portion of the seal member 152 is inserted therein.
In this constant flow valve seal structure, the seal member 152 is in close contact with the seal wall surface 150 in the direction perpendicular to the axis of the annular groove 148 immediately before the valve body 130 moves rightward in the drawing to perform the constant flow action. Perform the action.

  That is, also in this constant flow valve, a clearance C is secured between the valve body 130 and the axial sliding surface 134 of the valve housing 132 in order to ensure smooth movement of the valve body 130, and If leakage of liquid from the gap between the valve body 130 and the sliding surface 134 due to the clearance C occurs, the constant flow rate action due to the operation of the valve body 130 cannot be performed accurately. A structure is provided between the valve body 130 and the valve housing 132. The valve body 130 moves rightward in the drawing from the state in which the valve body 130 is largely opened toward the valve seat 144, and immediately before reaching the constant flow rate operation position, The sealing member 152 is pressed against the sealing wall surface 150 in a close contact state with the hydraulic pressure introduced into the gap between the body 130 and the sliding surface 134 to cause a sealing action, and the liquid flowing downstream by the leakage of the liquid from the gap Flow rate , And has to prevent from becoming greater than the constant flow rate was set.

FIG. 13 also shows an example in which the seal structure of the present invention is applied to a constant flow valve. In the example shown in FIG. 13, the opening 136 is a fixing member provided in the flow path separately from the valve body 130. 154.
Further, a back pressure chamber 158 communicating with the primary side through the communication passage 156 is formed behind the right side of the valve body 130 in the figure, and the primary side hydraulic pressure P ₁ is guided there. .

Thus, the primary hydraulic pressure P _{1 of the} back pressure chamber 158 acts on the valve body 130 in the left direction in the figure with respect to the primary pressure receiving surface 138, and the secondary side with respect to the secondary pressure receiving surface 140. hydraulic P ₂ acts in the figure right.
Further, the urging force of the spring 142 is applied to the valve body 130 in the right direction in the figure.

Also in the constant flow valve shown in FIG. 13, the valve body 130 moves in the left-right direction in the figure so as to make the differential pressure between the primary side hydraulic pressure P ₁ and the secondary side hydraulic pressure P ₂ constant. The flow rate of the liquid flowing out downstream from the passage 146 is throttled, and the throttle action keeps the differential pressure between the primary side hydraulic pressure P ₁ and the secondary side hydraulic pressure P ₂ constant, and passes through the opening 136. The flow rate of the flowing liquid is made constant.

  Thus, in this constant flow valve, the above-described sealing structure is applied between the valve body 130 and the valve housing 132, the valve body 130 approaches the valve seat 144 and restricts the flow of the liquid passage 146, and the constant flow action is performed. When reaching the position immediately before or at the position just before that, the leakage of liquid from the gap due to the fitting clearance C between the valve body 130 and the valve housing 132 is prevented.

Although the embodiment of the present invention has been described in detail above, this is merely an example.
For example, in the present invention, a mixing valve body of a hot and cold water mixing valve with an automatic temperature control function is operated by water pressure driving or hot water pressure driving to adjust the temperature of the mixed water. It is also possible to apply as a seal structure between the valve body and the valve housing.

As a hot water mixing valve, a back pressure chamber is formed behind a water side valve body integrally formed with the mixing valve body, water in the primary side water channel is introduced there through a small introduction hole, and the mixing valve body The mixing valve body is moved in a balance between the pressing force in the valve closing direction by the back pressure chamber and the pressing force in the valve opening direction by the hydraulic pressure of the water supply on the primary side. By providing a pilot water channel to flow out and changing the opening of the pilot water channel by moving the pilot valve body forward and backward, the hydraulic pressure in the back pressure chamber is increased or decreased, thereby mixing following the movement direction of the pilot valve body A hot water mixing valve of the type that moves the valve body in the same direction, or a back pressure chamber formed behind the hot water side valve body that is integrated with the mixing valve body, and the primary hot water through the introduction small hole there. Introduce hot water from the road and move the pilot valve body in the same way as above. Conventionally known is a hot water / water mixing valve of a type in which the mixing valve body is moved to follow, and a seal structure between the water side valve body and / or the hot water side valve body and the valve housing in such a hot water / water mixing valve. It is also possible to apply the seal structure of the present invention.
In the above embodiment, the seal wall surface is a surface perpendicular to the axis. However, in some cases, the seal wall surface can be formed as a surface in a direction intersecting the axial direction other than the direction perpendicular to the axis. For example, the present invention can be configured in various forms without departing from the spirit of the present invention.

10, 66, 132 Valve housing 12 Mixing valve body 14, 82 Water side valve body 16, 84 Hot water side valve body 22, 72 Water inflow passage 26, 74 Hot water inflow passage 32 Temperature sensitive spring 34 Bias spring 43, 86, 134 Sliding Moving surface 76 Balance valve element 92, 94, 104, 106, 152 Seal member 100, 102, 112, 114, 118, 150 Seal wall 128 Path 130 Valve element 146 Liquid path C Fitting clearance

Claims (14)

A seal structure for a flow rate control valve that moves the valve body along the axial sliding surface of the valve housing and changes the opening of the liquid passage to control the flow rate of the liquid, wherein the valve body and the sliding surface A flexible membrane-like member is used as a seal member for sealing the gap between the two and the seal member, and the seal member is pressed against the corresponding seal wall surface with the hydraulic pressure introduced into the gap to be sealed. A flow control valve seal structure characterized by that.   2. The flow control valve according to claim 1, wherein the seal wall surface is a surface in a direction intersecting the axial direction, and the gap is sealed in the axial direction by the seal member. Seal structure.   The flow rate control valve according to any one of claims 1 and 2, wherein the valve body is a valve that moves to a valve closing position to close the liquid passage, and at least in the valve closing position of the valve body the seal member. Is a seal structure for a flow control valve, wherein the seal wall is in close contact with the seal wall surface.   4. The seal structure for a flow control valve according to claim 3, wherein the seal member is in close contact with the seal wall surface while the valve body is moving from the fully open side to the fully closed side.   The flow rate control valve according to any one of claims 3 and 4, wherein the valve body moves along the sliding surface, so that the hydraulic pressure applied to the valve body in opposite directions to each other or / And a flow rate control valve seal structure which operates so as to balance the urging force of the elastic body.   6. The pressure balance valve according to claim 5, wherein the valve body is moved by a differential pressure between the inflow liquid pressure of water and the inflow liquid pressure of hot water to equalize the outflow liquid pressure of water and the outflow liquid pressure of hot water. A water-side valve body and / or a hot water-side valve body, and the seal member includes a gap between the water-side valve body and the sliding surface of the valve housing or / and the hot water-side valve body. A seal structure for a flow rate control valve, which seals a gap between the sliding surface.   In Claim 5, the flow control valve is a hot and cold water mixing valve with an automatic temperature control function, and the valve body is a water side valve body or / and a hot water side valve body in a mixing valve body, and the seal member is A flow control valve characterized by sealing a gap between the water side valve element and the sliding surface of the valve housing or / and a gap between the hot water side valve element and the sliding surface. Seal structure.   3. The flow rate control valve according to claim 1, wherein the flow rate control valve makes a differential pressure between a primary side hydraulic pressure and a secondary side hydraulic pressure applied in an axial direction opposite to the valve body constant. And a constant flow valve that controls the flow rate of the liquid flowing through the liquid passage to a constant flow rate, wherein the seal member is in close contact with the seal wall surface at least at a constant flow action position of the valve body. A flow rate control valve sealing structure characterized by being sealed.   9. The seal structure for a flow control valve according to claim 8, wherein the seal member is in close contact with the seal wall surface while the valve body is moving toward the constant flow rate operation position. .   The flow rate control valve seal structure according to claim 1, wherein the flexible film-like seal member is made of an elastic material.   In any one of Claims 1-10, while providing the said seal wall surface in both the said valve housing and the said valve body, the said sealing member straddles these valve housing sides and a valve body side, and this valve housing side and Non-fixed with respect to each of the valve body side and provided so as to be relatively movable with respect to the valve housing side and the valve body side, and the seal member is brought into close contact with both the seal wall surfaces by the fluid pressure introduced into the gap. The flow control valve sealing structure is characterized by being sealed.   11. The hydraulic pressure according to claim 1, wherein the seal member is fixedly attached to one of the valve housing side and the valve body side, and is introduced into the gap with respect to the seal wall surface provided on the other side. A seal structure for a flow rate control valve, wherein the seal member is brought into close contact with the seal. 5. The liquid according to claim 3, wherein the seal member is fixedly attached to one of the valve housing side and the valve body side, and is introduced into the gap with respect to the seal wall surface provided on the other side. The seal member is brought into close contact with pressure and sealed,
The attachment position of the seal member is a position separated in the valve closing direction of the valve body from the seal wall surface provided on the other when the valve body is located at the valve closing position. The flow control valve seal structure. 10. The hydraulic pressure according to claim 8, wherein the seal member is fixedly attached to one of the valve housing side and the valve body side, and is introduced into the gap with respect to the seal wall surface provided on the other side. The seal member is closely attached and sealed,
The mounting position of the seal member is a position separated from the seal wall surface provided on the other side toward the constant flow rate action position side of the valve body when the valve body is located at the constant flow rate action position. A flow rate control valve seal structure characterized by being made.

Images