JPH10132094A - Double seal valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double seal valve which has a sufficient durability to a temporary operation of an excessive pressure, and can carry out the connection and the disconnection to a valve element easily. SOLUTION: This double seal valve furnishes two valve elements 11 and 12 operating independently, and a valve seat 30 having two valve seat surfaces 31 and 32 conbined with the valve elements 11 and 12 respectively, and it has a valve mechanism which can seal doubly between flow passages 2A and 2B partitioned by the valve seat and the valve elements, by abutting the valve element 11 and 21 to the corresponding valve seats 31 and 32. In this case, to the abutting parts of the valve elements with the corresponding valve seat surfaces, seal members 14 and 24 with the hardness more than the Shore hardness 85 are provided, and to the valve elements 11 and 21, retainers 13 and 23 to hold the seal member 14 and 24 are provided, as well as groves 11g and 21g to receive the seal members 14 and 24 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double seal valve having a valve mechanism capable of double sealing between both sides partitioned by a valve body and a valve seat when the valve is closed.

[0002]

2. Description of the Related Art A so-called double-seal valve mechanism in which a double-sided seal between a valve body and a valve seat when a valve is closed can be double-sealed is conventionally known. This valve mechanism basically includes two valve bodies that can operate independently of each other, and a valve seat having two valve seat surfaces respectively combined with these valve bodies. By contacting each with the valve seat surface, it is possible to double seal between both sides partitioned by the valve seat and the valve body, for example,
2. Description of the Related Art In a device or a plant handling fluid foods and beverages, a valve mechanism such as a so-called anti-mixing valve is used to prevent mixing of two liquids by doubly sealing between different flow paths.

FIGS. 6 to 8 are a series of cross-sectional explanatory views for explaining the valve mechanism of a conventional double seal valve and its operation. As shown in these figures, in the double seal valve, two parallel flow paths 102A and 102B respectively connected to different pipes (not shown) provided outside the valve communicate with the valve box. The two flow paths 10
A valve seat 130 is arranged between 2A and 102B. This valve seat 130 has two independently operated valve elements 111 and 121.
And two valve seat surfaces 131 and 132 respectively combined with
Is provided. On the other hand, the contact portions of the respective valve elements 111 and 121 with the corresponding valve seat surfaces 131 and 132 are made of relatively soft synthetic rubber having a Shore hardness of about 70 (for example, a so-called fluorine rubber such as Viton). Ring-shaped sealing member 114,
124 are mounted. A ring-shaped seal member 124 'made of the same synthetic rubber material is also attached to the lower end of the second valve body 121 located on the upper side in the figure. Each of these seal members 114, 124, 124 'is press-fitted into a ring groove formed on the valve body side.

In the valve mechanism configured as described above, the two valve bodies 111 and 121 are provided with the corresponding valve seat surfaces 131 and 13 respectively.
In the fully closed state in which the valve abuts on the valve 2 (see FIG. 6), the two flow paths 102A and 102B partitioned by the valve bodies 111 and 121 and the valve seat 130 are double sealed. Become. This double seal valve is normally used in this state, and different types of fluids flow through the flow paths 102A and 102B. When the valve is opened, first, as shown in FIG. 7, the first valve body 111 located on the lower side in the figure moves upward until it is stopped against the second valve body 121 on the upper side, and the seal member is opened. Due to the sealing action of 124 ', the space 109 (leak chamber) formed between the valve bodies 111 and 121 is closed to the flow path. After that,
Both valve bodies 111 and 121 move upward integrally, and are brought into a completely open state (see FIG. 8).

[0005]

However, in the above-mentioned conventional double seal valve, the seal members 114, 124, 124 'are provided.
There are the following problems related to the material.
That is, there is a case where the pressure in the pipeline is temporarily increased to the design use pressure or more due to an erroneous operation of a piping system in which the valve is interposed or a so-called water hammer, and in such a case, a synthetic rubber sealing member is used. A compressive load exceeding the design strength acts on 114, 124, 124 ', and the sealing members 114, 124, 1
As a result of the crushing of 24 ', the sealing members 114, 12
4,124 'has an extremely short life.

As a material for the sealing member for the valve or the pipe, synthetic rubber is generally widely used, and a commercially available synthetic rubber having a Shore hardness of 70 is available. And those with a Shore hardness of 90. In addition, the numerical value indicating the hardness of the synthetic rubber is, for manufacturing reasons such as blending of raw materials,
Usually, a variation of about ± 5 is inevitably included as an allowable range (for example, see JIS: B2403). However, in the conventional double seal valve, the sealing members 114, 124, and 12 are used, for example, for the purpose of securing the mountability to a ring groove provided on the valve body side.
As 4 ', synthetic rubber having a Shore hardness of 70 is usually used, and seal members 114, 124, 1 of such a material are used.
In the case of 24 ′, generally, when the pressure is increased by about 15 kgf / cm ² or more, the sealing performance is greatly impaired,
It has been experienced that the life expectancy becomes extremely short.

[0007] In a piping system such as a plant or a plant that handles fluid foods or beverages in which the double seal valve mechanism as described above is commonly used, the design operating pressure is usually It is about 3 to 8 kgf / cm ² . Then, it is preferable to allow about three times the pressure (8 kgf / cm ² ) in the line with the highest pressure for the above-mentioned erroneous operation and water hammer. Further, even when an excessive compressive load is temporarily applied to the sealing member, if the resulting compression set is minute and is about 2% or less, the sealing property is not particularly impaired even in subsequent continuous use. On the other hand, if it exceeds this value, it is known that depending on the working pressure, there is a case where the sealing property in subsequent continuous use may be uneasy.

The inventor of the present application has conducted intensive studies, and as a result, as a material for the sealing member, a conventional Shore hardness of 70 was used.
When a high-hardness elastomer (for example, synthetic rubber such as fluoro rubber having a Shore hardness of 90) is used instead of the synthetic rubber of
It has been found that even when a pressure of about 30 kgf / cm ² is applied to the seal member, the seal member is not crushed, and the sealing property can be sufficiently maintained even after continued use. Also, when a fluorine-based resin such as ethylene tetrafluoride is used as the material of the seal member, extremely high compression resistance can be obtained because of its high Shore hardness (Shore hardness: about Hs = 130). It has been found that sufficient sealing properties can be ensured as a sealing member for a double seal valve.

Incidentally, the conventional double seal valve has the following problems in connection with the mounting structure of the seal members 114, 124, 124 '. That is, the ring groove in which each of the sealing members 114, 124, 124 'is mounted has both functions of receiving and holding (preventing falling-off) the sealing members 114, 124, 124', and therefore, usually has a peripheral edge of its cross section. The shape is formed so as to form a reverse taper or wedge shape of a certain degree or more.
4, 124 'is press-fitted into the ring groove having such a sectional shape. For this reason, it is very difficult to attach and detach the seal members 114, 124, and 124 '.
Old seal members 114 and 12 pressed into the ring grooves
4, 124 'is removed and new sealing members 114, 12 are removed.
At the time of mounting 4,124 ', even a skilled worker needs a long and careful operation.

[0010] The present invention has been made in view of the above technical problem, and even when an excessive pressure temporarily acts,
It is an object of the present invention to provide a double seal valve having a sufficient durability against this and a seal member capable of being easily attached to and detached from a valve element.

[0011]

Therefore, the invention according to claim 1 of the present application (hereinafter referred to as a first invention) has two valve bodies which can operate independently of each other, A valve seat having two valve seat surfaces to be combined, and by abutting each of the valve bodies on the corresponding valve seat surface, a double space is provided between both sides partitioned by the valve seat and the valve body. Assuming a double seal valve having a valve mechanism capable of sealing, a seal member having a Shore hardness of 85 or more is provided at a contact portion of each valve body with a corresponding valve seat surface. It is characterized by having been done.

Here, the Shore hardness of the seal member is set to 8
The reason for setting it to 5 or more is that in the case of a general synthetic rubber as a sealing material, a substantially available sealing material has a Shore hardness of 7
0 (± 5) and 90 (± 5) Shore hardness, and those with 70 (± 5) Shore hardness have a relatively low pressure (for example, about 15 kgf / cm ² ). The seal member is crushed due to the mechanical action, the sealing performance is greatly impaired, and there is a case where the life is extremely shortened. On the other hand, when a material having a Shore hardness of 85 or more is used, the seal member High pressure (eg 30kgf / c
This is because the sealing member is not crushed even if the pressure is applied to about m ² ), and the sealing property can be sufficiently maintained even in subsequent continuous use.

Further, the invention according to claim 2 of the present application (hereinafter referred to as “the invention”)
A second invention) comprises two valve bodies that can operate independently of each other, and a valve seat having two valve seat surfaces respectively combined with these valve bodies, and the valve bodies correspond to the corresponding valve bodies. Assuming a double seal valve having a valve mechanism capable of doubly sealing between both sides partitioned by the valve seat and the valve body by making contact with the seat surface, A seal member having a compression resistance of 2% or less with respect to a compressive stress of 24 kgf / cm ² or more is provided at a contact portion with a corresponding valve seat surface. Things.

Here, the compression resistance of the seal member is
The reason why the compression set is set to 2% or less with respect to the compression stress of 24 kgf / cm ² or more is that the double seal valve mechanism is commonly used for a piping system of a device or plant for handling fluid foods and beverages. Then, the design working pressure is
A 3~8kgf / cm ² or so, relative to the erroneous operation of the pipeline and water hammer or the like, about three times the pressure of the most value in the high pressure line ^{(8kgf / cm 2) (24kgf} /
cm ² ) is preferable, and even if an excessive compressive load is temporarily applied to the seal member, if the resulting compression set is minute and 2% or less, even in subsequent continuous use. The reason for this is that the sealing property is not particularly impaired. On the other hand, when the value exceeds this value, there is a case where the sealing property in continuous use afterwards may be uneasy.

Further, the invention according to claim 3 of the present application (hereinafter referred to as “the invention”)
According to a third aspect of the present invention, in the first or second aspect, the seal member is made of a fluororesin.

Further, the invention according to claim 4 of the present application (hereinafter, referred to as the invention)
A fourth invention) comprises two valve bodies which can operate independently of each other, and a valve seat having two valve seat surfaces respectively combined with these valve bodies, and the valve bodies correspond to the corresponding valve. Assuming a double seal valve having a valve mechanism capable of doubly sealing between both sides partitioned by the valve seat and the valve body by being in contact with the seat surface, Is provided with a groove for receiving a seal member provided in a contact portion with a corresponding valve seat surface, and a holding member for holding the seal member received in the groove is provided. It was done.

Further, the invention according to claim 5 of the present application (hereinafter referred to as “the invention”)
According to a fifth aspect of the present invention, in the fourth aspect, the seal member disposed on at least one of the valve elements can contact the corresponding valve seat surface and also contact the other valve element. It is characterized by the following.

Further, the invention according to claim 6 of the present application is further provided.
(Hereinafter, referred to as a sixth invention) is characterized in that, in the fourth or fifth invention, the holding member is detachably provided to the valve body.

Furthermore, the invention according to claim 7 of the present application.
(Hereinafter, referred to as a seventh invention) is the flow passage according to any one of the first to sixth inventions, wherein the valve body in which the valve bodies and the valve seats are incorporated is connected to different pipes. The valve seat is disposed between these flow paths, and the respective flow paths are double-sealed by bringing each valve body into contact with a corresponding valve seat surface. Things.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention applied to, for example, a so-called mixing prevention valve will be described in detail with reference to the accompanying drawings. The anti-mixing valve according to the present embodiment is used, for example, in an apparatus or a plant that handles a fluid food or beverage having a design maximum working pressure of about 8 [kgf / cm ² ] or less. Except for a part, such as a material and a structure of a seal portion between a valve body and a valve seat, the basic configuration and operation are the same as those conventionally well known.

FIG. 1 is an explanatory longitudinal sectional view schematically showing the entire configuration of a mixing prevention valve 1 as a double seal valve according to the present embodiment. As shown in this figure, in the mixing prevention valve 1, two parallel flow paths (a first flow path 2A and a second flow path 2A, respectively) connected to different pipes (not shown) provided outside the valve. 2B) is provided so as to communicate with the valve box 2,
A valve seat 30 is arranged between the two flow paths 2A and 2B. Note that different types of fluids are usually flowed in these two flow paths 2A and 2B. Two valve bodies (a first valve body 11 and a second valve body 21) that can operate independently of each other are combined with the valve seat 30. Further, valve stems 12 and 22 are more preferably integrally connected to the valve bodies 11 and 21, respectively.
0,20 are formed. The second valve body unit 2
The zero valve stem 22 is slidably fitted to the outer periphery of the valve stem 12 of the first valve body unit 10.

On the upper part of the valve box 2, each valve body unit 1
An actuator 40 for driving 0,20 is mounted via the top cover 5. The actuator 40 is, for example, an air-operated type. In normal use in which different types of fluids are flowing in the two flow paths 2A and 2B, the valve bodies 11 and 21 are actuated by the urging forces of the compression springs 41 and 42. Are both seated and pressed on the valve seat 30, and the space between the two flow paths 2A and 2B is closed. FIG. 1 shows this normal use state. The detailed configuration of the valve seat 30 and each of the valve bodies 11 and 21 will be described later.

In this state, as shown in detail in FIG.
A space 9 (leak chamber) is formed between the first and second valve bodies 11 and 21, and the leak chamber 9 is provided in the leak passage 1 provided in the first valve body unit 10.
It communicates with the atmosphere side (outside of the valve) through 9. Therefore, the valve seat 3 is required for either of the two valve bodies 11 and 21.
If a leak occurs between the leak chamber 9 and the leak passage 1,
It leaks out of the valve via 9 and by monitoring this, it is possible to detect the occurrence of a leak and which valve element has a leak.

The first valve body unit 10 is preferably provided with a cleaning liquid passage 18 at a stem portion opposite to the leak passage 19, and the cleaning liquid is supplied from the cleaning liquid introduction plug 18P into the passage 18. By introducing,
The cleaning liquid is spouted into the leak chamber 9 through the communication hole 18h (see FIGS. 2 to 4) and a nozzle hole 23h provided in a retainer 23 described later.
The liquid-contacting part is effectively cleaned.

On the other hand, when the two channels 2A and 2B are communicated after use in the normal state, operation air having a predetermined pressure is introduced into the air chamber 44 from the air inlet 43. By the pressure of the operation air, first, the first valve body unit 10 is pulled up and the first valve body 11 is opened against the urging force of the compression spring 41. Then, when it is pulled up by a predetermined amount, as shown in FIG. 3, the upper surface side of the first valve body 11 is stopped against the lower surface side of the second valve body 21, and thereafter, both compression springs 41, 4
1 and the second valve body unit 1 while resisting the urging force of
0, 20 are pulled up integrally, and the second valve body 21 is also opened. In this way, the two valve bodies 11, 21 are completely separated from the valve seat 30, and a communication state between the two flow paths 2A, 2B is obtained (see FIG. 4).

The basic structure and operation of the mixing prevention valve 1 according to the present embodiment are as described above.
As described above, they are the same as those conventionally well known. Therefore, further detailed description and illustration of the basic configuration and operation of the mixing prevention valve 1 will be omitted.

Next, each valve body 11, 2 of the mixing prevention valve 1 will be described.
The configuration of the seal between the valve seat 1 and the valve seat 30 will be described. As can be clearly seen from FIGS.
The valve seat 30 arranged between A and 2B has two valve seat surfaces (a first valve seat surface 31 and a second valve seat surface 32) respectively combined with two valve bodies 11 and 21 which can operate independently. have. In the present embodiment, the seal members (the first seal member 14 and the second seal member 24) provided at the contact portions of the respective valve elements 11 and 21 with the corresponding valve seat surfaces 31 and 32 include:
Conventional synthetic rubber with a Shore hardness of 70 (for example, fluoro rubber)
A seal member having higher compressive strength was used in place of the seal member. Specifically, a material having a compression resistance of 2 [%] or less with respect to a compressive stress of 24 [kgf / cm ² ] or more was used.

By using the seal members 14 and 24 having such compression resistance, the maximum operating pressure of the piping system in which the mixing prevention valve 1 is used (in the case where the mixing prevention valve 1 is used due to erroneous operation of the piping system or occurrence of a water hammer or the like). 8 kgf / cm ² ) about 3
Even if the pressure is doubled temporarily, the permanent set of the pressure is very small, and the sealability is not particularly deteriorated in the subsequent continuous use of the seal members 14 and 24. That is, as described above, even when an excessive compression load is temporarily applied to the seal member, if the resulting compression set is small and is about 2% or less, the sealing property is maintained even after continued use. Since there is no particular impairment, sufficient durability can be obtained against the temporary action of excessive pressure. Therefore, the maintenance period for exchanging the seal members 14 and 24 can be set sufficiently long as compared with the conventional case where the synthetic rubber seal members 114, 124 and 124 'are used.

The sealing member having such compression resistance characteristics includes:
It can be obtained by using, for example, a high-hardness elastomer or resin having a Shore hardness of 90 (± 5) or more (that is, 85 or more). Mixing prevention valve 1 according to the present embodiment
When a high-hardness elastomer (for example, fluoro rubber having a Shore hardness of 90) is used for the seal members 14 and 24,
Even when the pressure in the flow path increased to 30 [kgf / cm ² ], it was confirmed that the sealing member was not crushed at all and the sealing performance was not impaired. In the present embodiment, for example, a fluorine-based resin, more preferably, a tetrafluoroethylene resin (PTFE) is used as a seal material. In the case of the sealing member made of the tetrafluoroethylene resin, the compression set is suppressed to 1% or less, and about 50% is set.
It was confirmed that it could withstand compressive stress up to [kgf / cm ² ]. The Shore hardness of the sealing member made of the tetrafluoroethylene resin was about 130.

Each of the valve bodies 11 and 21 receives a seal member (first seal member 14 and second seal member 24) disposed at a contact portion with the corresponding valve seat surface 31 and 32. Ring-shaped grooves 11g and 21g are provided. In the present embodiment, the peripheral shape of the cross section of each of the grooves 11g and 21g is formed in a substantially U-shape that is open on one side, and each seal member 1 having a fitting portion having a cross-sectional shape suitable for this.
4, 24 are relatively loosely fitted and accommodated in the respective grooves 11g, 21g. In addition, the sealing member 14,
When the material 24 is made of a high-hardness elastomer or resin, particularly a fluorine-based resin, the hardness is much higher than that of a conventional synthetic rubber having a Shore hardness of 70. It is extremely difficult to attach / detach to / from the reverse tapered or wedge-shaped groove even if the skill of the operator is high and special jigs and tools are used.

Each of the valve body units 10 and 20 has a corresponding one of the sealing members 14 and 2 housed in the grooves 11g and 21g.
A retainer (first retainer 13, second retainer 23) is provided as a holding member for holding the fourth member 4. The first
The retainer 13 is more preferably the first valve body unit 1
0 screw connection 17 located at the end of the valve stem 12
1 (see FIG. 1), the first seal member 14 is held in the groove 11g by being fixedly fastened to the valve stem 12. Lock nuts 7, 7 for detent and drop prevention are screwed to the outside of the screw joint 17 between the retainer 13 and the valve stem 12. Incidentally, between the first seal member 14 and the surface of the groove portion 11g of the first valve body 11 and between the first retainer 13 and the first valve body 11, in order to prevent leakage passing therebetween. For example, "0" -rings 15 and 16 made of synthetic rubber (Shore hardness 70) such as Viton are provided.

On the other hand, the second retainer 23 is more preferably fastened and fixed to the valve body 21 by a screw connection portion 27 located on the inner diameter side of the end of the second valve body 21. 2 The seal member 24 is held in the groove 21g. The second seal member 24 and the groove 21 of the second valve body 21
A "0" -ring 25 made of synthetic rubber such as Viton is disposed between the g surface and the surface of the g to prevent leakage therethrough. Further, as can be clearly understood from FIG. 5, for example, a pair of notches 23 s is provided on the inner peripheral portion of the second retainer 23, and the protruding pins 28 protruding from the second valve body 21 side are provided with the notches. By fitting into one of the parts 23s, the detent of the second retainer 23 is prevented and the second retainer 23 is prevented from falling off.

As described above, the grooves 11g and 21g for receiving the sealing members 14 and 24 are provided in the respective valve elements 11 and 21 and the retainers 13 for holding the sealing members 14 and 24 received in the grooves 11g and 21g. , 23,
Even when the seal members 14, 24 are relatively loosely fitted and stored in the respective groove portions 11g, 21g, the respective seal members 14, 24 are firmly fixed in the groove portions 11g, 21g by the respective retainers 13, 23. Can be held.
That is, the receiving and holding (prevention of falling off) of the seal members 14 and 24 are performed by separate members, so that both of these functions are conventionally performed by the ring grooves of the valve body. , 24 are not mounted in the grooves in an excessively press-fitted state, and the mounting of the seal members 14, 24 can be performed much easier.

Further, in particular, each of the retainers 13, 23
Are connected to the respective valve elements 11 and 21 by screw connections 17 and 27, respectively.
It is provided so that it can be easily attached to and detached from
Not only the mounting work but also the removing work of the seal members 14 and 24 can be performed very easily.
14, 124, and 124 'are 111g, 121g, and 121g in the ring groove having a cross-sectional peripheral edge shape of a reverse taper or wedge.
The maintainability can be greatly improved as compared with the case where g ′ is mounted in a press-fitted state.

Further, in the present embodiment, the valve element 11,
21 (in the present embodiment, the second
The second seal member 24 disposed on the valve body 21) is formed to be wide and abuts the corresponding valve seat surface 32 and also abuts on the upper surface of the other valve body (the first valve body 11). When the valve is open (see FIGS. 3 and 4),
When the lower surface of the second seal member 24 comes into contact with the upper surface of the first valve body 11, the leak chamber 9
Closed to B. Therefore, conventionally, the sealing member 124 that contacts the corresponding valve seat surface 132 and the other valve body 1
Compared to a case where the seal member 124 ′ abutting on 11 is provided separately, the number of parts is reduced, and the number of steps for mounting or removing the seal member is reduced.

As described above, according to the present embodiment, in order to surely prevent mixing of the two liquids flowing through the respective flow paths 2A and 2B, mixing prevention in which securing of sealing property is particularly emphasized. In the valve 1, the durability of the sealing portion can be greatly increased, and the mounting or detaching operation of the sealing members 14, 24 can be performed extremely easily, thereby improving the assembling property or the maintenance property. A great effect can be achieved above.

The present invention is not limited to the above embodiment. For example, the present invention is not limited to the mixing prevention valve, but may be applied to other types of double seal valves employing a double seal valve mechanism. Can be applied effectively. Also, various improvements and modifications of the present invention may be made without departing from the gist thereof.
It goes without saying that deformation or change in design is possible.

[0038]

According to the first aspect of the present invention, in the double seal valve, the seal member provided at the contact portion of each of the valve bodies with the corresponding valve seat surface has a Shore hardness of 85 or more. Conventionally, since a sealing member having a hardness of
Even if excessive pressure is applied temporarily, as in the case of using synthetic rubber of No. 0, it is possible to provide sufficient durability without crushing and losing the sealing property. it can. As a result, the maintenance period for replacing the seal member can be made longer.

According to the second aspect of the present invention, in the double seal valve, the compression resistance of the seal member provided at the contact portion of each valve body with the corresponding valve seat surface is as follows: 24k
Compression set of ^{2 for} gf / cm ² or more compressive stress
% Or less, a pressure three times higher than the maximum working pressure (8 kgf / cm ² ) of the piping system in which such a double seal valve is normally used due to erroneous operation of the piping system or occurrence of water hammer etc. , The permanent set is very small, and the sealing performance is not particularly deteriorated in the subsequent continuous use of the sealing member. That is, even when an excessive pressure is temporarily applied, sufficient durability can be imparted thereto, and the maintenance period for replacing the seal member can be further lengthened.

Further, according to the third aspect of the present invention, basically the same effects as those of the first or second aspect can be obtained. In particular, since the seal member is made of a fluorine-based resin, the above-described compression resistance can be obtained more reliably and sufficiently.

According to the fourth aspect of the present invention, in the double seal valve, each valve element is provided with a groove for receiving the seal member, and holds the seal member received in the groove. Since the holding member is provided, the receiving and holding (prevention of falling off) of the sealing member are performed by separate members, so that both of these functions are conventionally performed by the ring groove of the valve body as in the case where the ring groove of the valve body is used. In addition, the seal member is not mounted in the groove in an unreasonable press-fit state, so that the seal member can be mounted much more easily.

Further, according to the fifth aspect of the present invention, basically the same effects as those of the fourth aspect can be obtained. In addition, since the seal member disposed on at least one of the valve bodies abuts the corresponding valve seat surface and can also abut the other valve body, conventionally, the corresponding valve seat surface Compared to the case where the contacting seal member and the seal member contacting the other valve body are provided separately,
The number of parts is reduced, and the number of sealing member mounting operations is reduced.

Further, according to the sixth invention of the present application,
Basically, the same effects as those of the fourth or fifth invention can be obtained. In addition, since the holding member is provided so as to be detachable from the valve body, not only the mounting operation but also the removal operation of the sealing member can be performed extremely easily, and the maintainability can be greatly improved. it can.

Further, according to the seventh invention of the present application,
Basically, the same effect as any one of the first to sixth inventions can be obtained. In particular, specifically, the valve box includes flow paths connected to different pipes,
By contacting each valve body with the corresponding valve seat surface, the above-mentioned flow passages are double-sealed.For example, the present invention can be applied to a mixing prevention valve or the like. In order to surely prevent such a problem, in the valve in which maintaining and securing the sealing property is particularly important, the mounting or detaching operation of the sealing member can be performed extremely easily, and in order to improve the assembling property or the maintainability thereof. A great effect can be achieved.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing an entire configuration of a double seal valve according to an embodiment of the present invention.

FIG. 2 is an explanatory longitudinal sectional view showing a completely closed state of the valve mechanism of the double seal valve.

FIG. 3 is an explanatory longitudinal sectional view showing an initial state of the valve mechanism of the double seal valve.

FIG. 4 is an explanatory longitudinal sectional view showing a fully opened state of the valve mechanism of the double seal valve.

FIG. 5 is an explanatory cross-sectional view of the retainer and the valve body shown along the line VV in FIG. 2;

FIG. 6 is an explanatory longitudinal sectional view showing a completely closed state of a conventional valve mechanism of a double seal valve.

FIG. 7 is an explanatory longitudinal sectional view showing an initial state of the valve opening of the conventional valve mechanism.

FIG. 8 is an explanatory longitudinal sectional view showing the fully opened state of the conventional valve mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Mixing prevention valve (double seal valve) 2 ... Valve box 2A, 2B ... 1st, 2nd flow path 11, 21 ... 1st, 2nd valve body 11g, 21g ... Groove part 13, 23 ... 1st, 1st 2 retainer (holding member) 14, 24 ... first and second seal members 30 ... valve seats 31, 32 ... first and second valve seat surfaces

Claims (7)

[Claims] 1. A valve seat comprising two valve bodies which can operate independently of each other, and a valve seat having two valve seats respectively combined with these valve bodies, wherein each of said valve bodies is provided on a corresponding valve seat surface. A double seal valve having a valve mechanism capable of double sealing between both sides partitioned by the valve seat and the valve body by being brought into contact with each other, wherein a corresponding valve of each of the valve bodies is provided. A double seal valve, wherein a seal member having a Shore hardness of 85 or more is provided at a contact portion with a seat surface. 2. A fuel cell system comprising: two valve bodies which can operate independently of each other; and a valve seat having two valve seats respectively combined with these valve bodies, wherein each of said valve bodies is provided on a corresponding valve seat surface. A double seal valve having a valve mechanism capable of double sealing between both sides partitioned by the valve seat and the valve body by being brought into contact with each other, wherein a corresponding valve of each of the valve bodies is provided. 24kg in the contact part with the seat
2% compression set for compressive stress of f / cm ² or more
A double seal valve, wherein a seal member having the following compression resistance is provided. 3. The double seal valve according to claim 1, wherein the seal member is made of a fluorine-based resin. 4. A vehicle comprising two valve bodies which can operate independently of each other, and a valve seat having two valve seats respectively combined with these valve bodies, wherein each of said valve bodies is provided on a corresponding valve seat surface. A double seal valve having a valve mechanism capable of double sealing between both sides partitioned by the valve seat and the valve body by being brought into contact with each other. A groove for receiving a seal member provided in a contact portion with a valve seat surface, and a holding member for holding the seal member received in the groove is provided. Seal valve. 5. The valve according to claim 4, wherein a seal member disposed on at least one of the valve bodies is in contact with a corresponding valve seat surface and can also contact the other valve body. Double seal valve. 6. The double seal valve according to claim 4, wherein the holding member is provided so as to be detachable from the valve body. 7. The valve box in which each of the valve bodies and the valve seats are incorporated has a flow path connected to a different pipe, and the valve seat is disposed between these flow paths. Abut on the corresponding valve seat surfaces,
The double seal valve according to any one of claims 1 to 6, wherein a double seal is provided between the flow paths.