JP3210186U - 2-port valve - Google Patents

Abstract

Provided is a two-port valve capable of preventing a seal member from being deteriorated by suppressing adhesion of deposits to a seal member. In a two-port valve, a first seal member 15 that hermetically seals around a flow path opening 12a when the first flow path opening 12a is closed by a valve body 20 is provided in the valve seat 10, and the entire seal member is provided. In the direction of the axis L1, the base end of the opening wall is more than the distal end 16a of the opening wall 16 forming the first flow path opening 12a and the edge 13b closest to the valve seat among the peripheral edges of the second flow path opening 13a. Retreated to the side. [Selection] Figure 3

Description

  The present invention relates to a two-port valve for use, for example, in a semiconductor manufacturing apparatus for decompressing a vacuum chamber using a process gas.

  In a semiconductor manufacturing apparatus, when a film formation process is performed on a semiconductor substrate using a process gas, the process is performed in a vacuum chamber. At that time, a vacuum pump is used for decompression of the vacuum chamber, and a two-port valve is used to open and close an external flow path connecting the vacuum pump and the vacuum chamber. For example, as shown in Patent Document 1, the 2-port valve includes a first port portion for connection to a vacuum chamber, a second port portion for connection to a vacuum pump, and a flow connection between the two port portions. A passage, a valve seat provided on the first port portion side in the flow path, and a valve body that contacts and separates from the valve seat are provided, and a seal member is attached to the valve body.

  By the way, in such a two-port valve, since the opening of the seal member and the first port portion opened to the flow path is opposed to each other, when the valve is opened by separating the valve body from the valve seat, The process gas flowing in from the port portion directly hits the seal member attached to the valve body. Therefore, deposits such as by-products (products other than the products formed by film formation) are likely to adhere to the seal member, which may lead to a decrease in the sealing performance of the seal member.

JP 2006-329881 A

  Therefore, a technical problem of the present invention is to provide a two-port valve that can prevent the sealing performance of the seal member from being deteriorated by suppressing adhesion of deposits to the seal member.

  In order to achieve the above object, a two-port valve of the present invention has a main valve portion and a valve drive portion that are continuous in the axial direction, and the main valve portion is a primary port portion that is opened in the axial direction, A secondary side port portion established in a direction orthogonal to the axis, and a valve housing having a flow path portion connecting these two port portions, and a first flow opened in the flow path portion in the primary side port portion A valve seat formed so as to surround the passage opening; and a valve body that opens and closes the first flow path opening in contact with and away from the valve seat, and the valve drive unit drives the valve body in the axial direction. Thus, the valve body is a two-port valve that contacts and separates from the valve seat, and the first flow path opening extends in the axial direction from the inner peripheral side of the valve seat toward the flow path portion side. The valve seat is formed by an upright annular opening wall, and the valve seat is a first shaft on which the valve body comes in contact with and separates from the first seat. And the opening wall projects in the axial direction from the top end of the first seal member toward the flow path portion, and the valve body It has the escape part for avoiding interference with the said opening wall at the time of contact | abutting to 1 seal member, It is characterized by the above-mentioned.

In this case, the secondary port portion has a second flow passage opening opened in the flow passage portion, and an end closest to the valve seat among the peripheral edges of the second flow passage opening in the axial direction. It is desirable that the edge is located on the channel portion side with respect to the top end of the first seal member.
The valve housing includes a primary housing portion having the primary port portion, and a housing main body portion having the secondary port portion and the flow passage portion, and the flow passage portion is the housing main body portion. It is preferable that a portion of the inner peripheral wall adjacent to the valve seat is formed in a tapered shape that is reduced in diameter from the flow path portion toward the valve seat.
In this case, the primary housing part and the housing body part are formed separately from each other, the valve seat is formed in the primary housing part, and the valve housing includes the primary housing part and the housing body part. It is preferable that they are formed by interconnecting each other.

In a preferred embodiment of the two-port valve, a surface of the valve body facing the valve seat includes an annular convex portion, and a surface of the annular convex portion facing the valve seat is the first surface. A seal surface that contacts and separates from the seal member is formed.
In this case, preferably, the escape portion is formed by a concave portion surrounded by the annular convex portion.

In a preferred embodiment of the two-port valve, a valve shaft extending in the axial direction is fixed to a surface of the valve body facing the valve driving unit, and the valve driving unit is connected to the valve shaft. And a cylinder chamber for reciprocating the piston in the axial direction, and the main valve portion and the valve drive portion are inserted through the valve shaft in an airtight and slidable manner. The holes are connected to each other by a connecting member penetrating in the axial direction, and the flow path portion of the main valve portion and the cylinder chamber of the valve driving portion are airtightly partitioned by the connecting member.
At this time, it is preferable that the surface of the valve body facing the valve driving portion side is in contact with the connecting member when the first flow passage opening is opened, and between the flow passage portion and the insertion hole. A second seal member for hermetically sealing is provided so as to surround the valve shaft.
More preferably, when the second seal member is in contact with the connecting member, the entire valve body is closest to the connecting member at the periphery of the second flow path opening in the axial direction. It is located closer to the connecting member than the edge.
More preferably, the cylinder chamber is partitioned by the piston in the axial direction into a first pressure chamber on the connecting member side and a second pressure chamber on the opposite side to the first pressure chamber. The pressure chambers are each provided with ports for supplying and discharging compressed fluid, and the compressed fluid leaked from the first pressure chamber beyond the seal member of the insertion hole to the atmosphere is inserted into the insertion hole. A through hole for discharging is provided.
More preferably, an end of the valve shaft opposite to the valve body is penetrated through a cylinder housing forming the cylinder chamber in the axial direction so as to be airtight and slidable. An indicator that moves in and out of the cylinder housing as the valve body reciprocates is attached, and the piston is sandwiched between the valve shaft and the indicator and fixed to the valve shaft. .

  According to this device, the first flow path opening in the primary port portion is formed by the annular opening wall erected in the axial direction from the inner peripheral side of the valve seat toward the flow path side, and the valve seat Has a first seal member that contacts and separates the valve body so as to surround the opening wall, and the opening wall projects in the axial direction from the top end of the first seal member to the flow path side. ing. Therefore, it is possible to prevent the fluid flowing from the primary side port portion toward the secondary side port portion from directly hitting the seal member attached to the valve body, and to suppress the adhesion of deposits to the seal member. Thus, it is possible to prevent the sealing performance of the sealing member from being lowered.

It is sectional drawing of the valve closing state which shows embodiment of the 2 port valve which concerns on this invention. It is sectional drawing of the valve opening state of the 2 port valve of FIG. It is a principal part fracture | rupture enlarged view of FIG.

  Hereinafter, an embodiment of a two-port valve according to the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, the two-port valve 1 according to the present embodiment includes a main valve portion 2 including a valve seat 10 and a valve body 20 that contacts and separates from the valve seat 10, and the valve body 20. The main valve portion 2 is arranged on the first end side and the valve drive portion 3 is arranged on the second end side in the direction of the axis L1, and these are mutually connected. It is configured by connecting.

  The main valve section 2 is opened in the direction of the axis L1, and is opened in the direction of the axis L2 orthogonal to the primary port section 12 for connecting to a vacuum chamber or the like of a semiconductor manufacturing apparatus (not shown). The valve housing 5 is formed with a secondary side port portion 13 for connection to a vacuum pump (not shown) and a flow path portion 11 that connects and communicates between the port portions 12 and 13. Yes. The valve housing 5 includes a primary housing part 6 in which a primary port part 12 is formed, and a housing body part 7 in which a secondary port part 13 and a flow path part 11 are formed. At this time, the primary housing 6 and the housing body 7 are formed separately, and the valve housing 5 is configured such that the primary housing 6 and the housing body 7 are mutually connected via a seal member. It is configured by connecting in an airtight manner.

  On the flow passage 11 side (boundary between the flow passage portion 11 and the primary port portion 12) of the primary housing portion 6, the first flow passage opening 12a of the primary side port portion 12 opened to the flow passage portion 11 is provided. The valve seat 10 is formed so as to surround the periphery of the first flow path opening 12a. As shown in FIG. 3, an annular groove 14 is formed in the valve seat 10, and an annular first seal member 15 made of a synthetic resin such as rubber is fitted in the groove 14. It is. The valve body 20 contacts and separates from the first seal member 15 so that the first flow path opening 12a is opened and closed. That is, in the two-port valve 1, the sealing member 15 for ensuring the airtightness between the primary port portion 12 and the flow passage portion 11 when the first flow passage opening 12 a is closed is provided in the valve body 20. It is provided in the valve seat 10 without.

  Furthermore, as shown in FIG. 3, from the inner peripheral side in the radial direction of the valve seat 10, an annular and cylindrical opening wall 16 is erected in the direction of the axis L1 toward the flow path portion 11 side. The region surrounded by the tip 16a of the opening wall 16 forms the first flow path opening 12a. And the 1st seal member 15 of the said valve seat 10 is arrange | positioned so that the circumference | surroundings may be surrounded on the outer peripheral side of the opening wall 16 which forms the said 1st flow-path opening 12a. At this time, the opening wall 16 has an opening direction of the valve body 20 with respect to the flow path section 11 (that is, the flow path section) in the direction of the axis L1 relative to the top end 15a of the seal member 15 with which the valve body 20 abuts. 11 side). In other words, the entirety of the first seal member 15 (that is, the entirety of the valve seat 10) is more than the opening wall 16 in the direction of the axis L1 than the first flow path opening 12a (that is, the tip 16a of the opening wall 16). It is arranged at a position retracted to the base end side.

  By doing so, it is avoided that the gas flow such as the process gas flowing into the flow path portion 11 from the first flow path opening 12a through the primary side port portion 12 directly hits the first seal member 15 as it is. be able to. Therefore, it is possible to suppress deposits such as by-products (products other than the products formed by film formation) included in the fluid from adhering to and depositing on the first seal member 15. As a result, the life of the first seal member 15 can be extended, and the airtightness when the first flow path opening 12a is closed by the valve body 20 can be maintained longer. In the primary side port portion 12, the inner diameter of the opening wall 16, that is, the diameter of the first flow path opening 12a of the axis L1, and the inner diameter of the portion connected to the inner peripheral surface of the opening wall 16 are equal to each other. Yes.

  On the other hand, the housing body portion 7 is formed hollow, and the flow passage portion 11 is formed by the inner peripheral wall thereof, and the first opening portion 17 and the second opening portion 18 are respectively provided at both ends in the direction of the axis L1. Have. And as mentioned above, the primary side housing part 6 provided with the said primary side port part 12 is attached to the said 1st opening part 17 airtightly via the sealing member. Further, a connecting member 30 described later is fitted into the second opening 18 in an airtight manner via a seal member.

  Further, the secondary port portion 13 is opened between the first opening portion 17 and the second opening portion 18 in the housing main body portion 7 along a direction orthogonal to the first port portion 12. Yes. A second flow passage opening 13 a of the secondary port portion 13 that opens to the flow passage portion 11 is formed at a boundary between the inner peripheral wall of the flow passage portion 11 and the secondary port portion 13. . At this time, in the direction of the axis L1, the edge 13b closest to the valve seat 10 out of the peripheral edge of the second flow path opening 13a is the top end 15a of the first seal member 15 or the tip 16a of the opening wall 16. It is located in the opening direction of valve body 20 (namely, channel part 11 side). Further, in the direction of the axis L <b> 2, the end edge 13 b is located on the outer peripheral side with respect to the valve seat 10.

  And the site | part adjacent to the said valve seat 10 in the internal peripheral wall of the said flow-path part 11 is the cyclic | annular shape diameter-reduced toward the said valve seat 10 from the said flow-path part 11 side (namely, the said 2nd opening part 18 side). A tapered surface 7a is formed. Thereby, the inner peripheral wall extending between the end edge 13b of the second flow path opening 13a and the valve seat 10 also forms the tapered surface 7a.

  As described above, in the present embodiment, an annular groove having a bottom surface formed by the valve seat 10 including the first seal member 15 and a side wall formed by the opening wall 16 and the tapered surface 7a is the primary groove. The second port opening 13a is formed on the outer peripheral side of the first port opening 12a of the side port portion 12, and in the direction of the axis L1, the entire second channel opening 13a is opened in the valve body 20 rather than the concave groove. That is, it is arranged on the second opening 18 side. Therefore, the flow of the fluid flowing in from the first flow path opening 12a and flowing out from the second flow path opening 13a directly hits the first seal member 15 of the valve seat 10 with respect to the flow path portion 11. Can be suppressed. Even if the flow of the fluid flows into the groove, the taper surface 7a promptly guides the groove to the outside of the groove or the second flow path opening 13a, and enters the groove. The retention of fluid can be suppressed.

  The valve body 20 is formed in a circular disk shape or a substantially cylindrical shape, and is provided on the axis L1. The first facing surface 21 facing the valve seat 10 side of the valve body 20 has an opening wall 16 when the first flow path opening 12a is closed, that is, when the valve body 20 contacts the first seal member. Has an escape portion 22 for avoiding interference with the. The first opposing surface 21 includes an annular convex portion 23, and the first opposing surface 21 that faces the valve seat 10 in the annular convex portion 23 contacts and separates from the first seal member 15. A sealing surface 24 is formed. The escape portion 22 is formed by a concave portion surrounded by the annular convex portion 23.

  On the other hand, the second facing surface 25 of the valve body 20 facing the valve driving unit 3 faces the connecting member 30. In the center of the second facing surface 25, a valve shaft 26 extending in the direction of the axis L1 is fixedly provided. That is, the valve body 20 and the valve shaft 26 are molded integrally, and the valve body 20 is provided at the tip of the valve shaft 26. In addition, an annular dovetail groove 27 is formed on the second facing surface 25 so as to surround the valve shaft 26, and the dovetail groove 27 is connected to the connection when the first flow path opening 12a is opened. An annular second seal member 28 that contacts the member 30 is fitted. When the first flow path opening 12a is opened, the entire valve element 20 is more than the edge 13c closest to the connecting member 30 at the periphery of the second flow path opening 13a in the direction of the axis L1. It is located on the connecting member 30 side. Thereby, when the first flow path opening 12a is opened, the flow of fluid in the flow path portion 11 can be more smoothly guided from the first flow path opening 12a to the second flow path opening 13a. It becomes.

  The connecting member 30 has a first surface 31a facing the second facing surface 25 side (that is, the flow channel portion 11 side) of the valve body 20 at both ends in the direction of the axis L1, and a back surface facing the first surface 31a. And a second surface 31b facing the valve drive unit 3 side. Between the first surface 31a and the second surface 31b, an insertion hole 32 is inserted through the valve shaft 26 in the direction of the axis L1 so as to be airtight and slidable. Here, the first surface 31a forms an inner wall of the flow path portion 11 and partitions the flow path portion 11 in an airtight manner. Then, when the first flow path opening 12a is opened, the second seal member 26 of the valve body 20 abuts on the first surface 31a, so that the gap between the flow path portion 11 and the insertion hole 32 is established. It can be hermetically sealed. A scraper 33 that prevents foreign matter such as sludge adhering to the surface of the valve shaft 26 from entering the insertion hole 32, a bearing member 36 that slidably supports the valve shaft 26, and the insertion A third seal member 35 that hermetically seals between the hole 32 and the valve shaft 26 is sequentially provided from the first surface side 31a toward the second surface side 31b.

  On the other hand, the valve drive unit 3 includes a piston 41 fixed to the valve shaft 26, a cylinder chamber 40 for reciprocating the piston 41 in the direction of the axis L1, and the cylinder chamber 40 formed therein. The cylinder housing 8 is provided. The cylinder housing 8 has a second opening 18 on the connecting member 30 side in the direction of the axis L1, and similarly, the cylinder chamber 40 is also open on the connecting member 30 side. Then, the second surface 31b side of the connecting member 30 is fitted into the opening 18 in an airtight manner. As a result, the cylinder chamber 40 of the valve driving unit 3 is airtightly sealed by the second surface 31b of the connecting member 30. It is partitioned. In this manner, the main valve portion 2 and the valve driving portion 3, that is, the valve housing 5 and the cylinder housing 8 are airtightly connected by the connecting member 30 interposed therebetween.

  The cylinder chamber 40 is partitioned by the piston 41 in the direction of the axis L1 into a first pressure chamber 42 located on the second surface side 31b of the connecting member 30 and a second pressure chamber 43 on the opposite side thereof. In these pressure chambers 42 and 43, a first port 44 and a second port 45 for supplying and discharging a compressed fluid as a pilot fluid are respectively opened. The compressed fluid is supplied to and discharged from the pressure chambers 42 and 43 through the ports 44 and 45, and the piston 41 is reciprocated in the direction of the axis L1 in the cylinder chamber 40, whereby the valve body 20 is moved in the direction of the axis L1. The first flow path opening 12a can be opened and closed by reciprocating.

  In the insertion hole 32, the fluid from the first pressure chamber side is sealed to the first pressure chamber 42 side (that is, the second surface 31b side) from the third seal member 35. A lip-shaped seal member 34 that allows fluid flow from the opposite side is provided. Between the lip-shaped seal member 34 and the third seal member 35, the compressed fluid leaking from the first pressure chamber 42 over the lip-shaped seal member 34 and into the insertion hole 32 is released to the atmosphere. A through-hole 37 for escaping is opened through the connecting member in the radial direction.

  Further, from the end of the valve shaft 26 opposite to the valve body 20, that is, from the base end located in the second pressure chamber 43 of the valve shaft 26, the primary port portion 12 and the secondary side are connected. An indicator 46 formed in the shape of an elongated round bar for displaying the state of communication with the port portion 13 extends coaxially with the valve shaft 24 in the direction of the axis L1. Further, the cylinder housing 8 is provided with a through hole 47 that penetrates between the second pressure chamber 43 and the outside on the axis L1. The indicator 46 is inserted into the through-hole 47 so as to be airtight and slidable, and the valve body 20 moves in and out of the cylinder housing 8 as the valve body 20 reciprocates.

Specifically, in a state where the valve body 20 is in contact with the first seal member 15 of the valve seat 10 and the primary port portion 12 and the secondary port portion 13 are blocked, the indicator The whole is hidden in the cylinder housing, and conversely, the valve body is separated from the valve seat, and the second seal member abuts against the first surface of the connecting member, so that the primary port portion and the secondary port portion are In this state, the tip of the indicator 46 projects from the cylinder housing.
Here, the base end portion of the indicator 46 is connected to the base end portion of the valve shaft 26 by means such as screwing, and the piston 41 is connected to the valve shaft 26 on the axis L1. It is sandwiched between the base end portion and the base end portion of the indicator 46 and is fixedly attached to the valve shaft.

  In operating the two-port valve 1, the compressed fluid was exhausted from the first pressure chamber 42 through the first port 44 and the compressed fluid was supplied to the second pressure chamber 43 through the second port 45. Sometimes, the seal surface 24 of the valve body 20 abuts on the first seal member 15 of the valve seat 10, so that the primary port portion 12 and the secondary port portion 13 are blocked. Conversely, when the compressed fluid is supplied to the first pressure chamber 42 through the first port 44 and the compressed fluid is exhausted from the second pressure chamber 43 through the second port 45, the sealing surface 24 of the valve body 20 is The primary side port portion 12 and the secondary side port are separated from the first seal member 15 of the valve seat 10 and the second seal member 28 of the valve body 20 abuts on the first surface 31 a of the connecting member 30. Communication with the unit 13 is established.

  As described above, according to the two-port valve 1 according to the present embodiment, when the first flow path opening 12a is closed by the valve body 20, the first seal member 15 that hermetically seals the periphery of the flow path opening 12a is provided on the valve seat 10. In addition, the entire seal member 15 is arranged in the direction of the axis L1 more than the tip 16a of the opening wall 16 that forms the first flow path opening 12a and the edge 13b of the second flow path opening 13a. The first seal member 15 is directly exposed to the flow of fluid such as process gas that has flowed into the flow path portion 11 from the first flow path opening 12a because it is disposed at a position retracted to the proximal end side of the opening wall 16. Can be suppressed. As a result, adhesion of deposits to the first seal member 15 is suppressed, and deterioration of the sealing performance of the first seal member 15 can be prevented.

As mentioned above, although one embodiment of the two-port valve according to the present invention has been described in detail, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the claims of the utility model registration. Needless to say, various design changes are possible.
For example, the second seal member is not necessarily provided on the valve body as in the present embodiment, and may be provided on the first surface 31 a of the connecting member 30.

DESCRIPTION OF SYMBOLS 1 2 port valve 2 Main valve part 3 Valve drive part 5 Valve housing 6 Primary side housing part 7 Housing main-body part 7a Tapered surface 8 Cylinder housing 10 Valve seat 11 Flow path part 12 Primary side port part 12a 1st flow path opening 13 2 Secondary port portion 13a Second flow path openings 13b, 13c End edge 15 First seal member 15a Top end 16 of first seal member Open wall 16a Open wall tip 20 Valve element 21 First facing surface 22 Escape portion 23 Annular convex portion 24 sealing surface 25 second opposing surface 26 valve shaft 28 second sealing member 30 connecting member 31a first surface 31b of connecting member second surface 32 of connecting member insertion hole 34 lip-shaped sealing member 37 through hole 40 cylinder chamber 41 piston 42 First pressure chamber 43 Second pressure chamber 46 Indicator L1, L2 Axis

Claims (11)

It has a main valve part and a valve drive part that are continuous in the axial direction,
The main valve portion includes a primary port portion established in the axial direction, a secondary port portion established in a direction orthogonal to the axial line, and a flow path portion connecting these two port portions. A housing, a valve seat formed so as to surround the first flow passage opening opened in the flow passage portion in the primary side port portion, and a valve body for opening and closing the first flow passage opening in contact with and away from the valve seat And
A two-port valve in which the valve element is driven to and away from the valve seat by driving the valve element in the axial direction by the valve driving unit;
The first flow path opening is formed by an annular opening wall erected in the axial direction from the inner peripheral side of the valve seat toward the flow path part side,
The valve seat has a first seal member that contacts and separates the valve body so as to surround the opening wall,
The opening wall protrudes toward the flow path part from the top end of the first seal member in the axial direction,
The valve body has an escape portion for avoiding interference with the opening wall at the time of contact with the first seal member.
It is characterized by that. The two-port valve according to claim 1,
The secondary port portion has a second flow path opening opened in the flow path portion;
In the axial direction, the edge closest to the valve seat among the peripheral edges of the second flow path opening is located closer to the flow path part than the top end of the first seal member.
It is characterized by that. The two-port valve according to claim 1 or 2,
The valve housing is composed of a primary housing part having the primary port part, a housing body part having the secondary port part and the flow path part,
The flow path part is formed by an inner peripheral wall of the housing body part,
The portion adjacent to the valve seat on the inner peripheral wall is formed in a tapered shape that decreases in diameter from the flow path side toward the valve seat.
It is characterized by that. The two-port valve according to claim 3, wherein
The primary housing part and the housing body part are formed separately from each other,
The valve seat is formed on the primary housing part,
The valve housing is formed by interconnecting the primary side housing part and the housing body part,
It is characterized by that. The two-port valve according to claim 1 or 2,
The face of the valve body facing the valve seat includes an annular convex portion,
The surface facing the valve seat in the annular convex portion forms a seal surface that comes into contact with and separates from the first seal member.
It is characterized by that. The two-port valve according to claim 5,
The escape portion is formed by a concave portion surrounded by the annular convex portion.
It is characterized by that. The two-port valve according to claim 1 or 2,
A valve shaft extending in the axial direction is fixed to a surface of the valve body facing the valve driving unit,
The valve drive unit has a piston fixed to the valve shaft, and a cylinder chamber for reciprocating the piston in the axial direction.
The main valve portion and the valve driving portion are connected to each other by a connecting member having an insertion hole through which the valve shaft is inserted in an airtight and slidable manner in the axial direction.
The connecting member divides the flow path portion of the main valve portion and the cylinder chamber of the valve drive portion in an airtight manner, respectively.
It is characterized by that. The two-port valve according to claim 7,
A surface of the valve body facing the valve drive unit side is configured to abut against the connection member when the first flow path opening is opened, so that the flow path part and the insertion hole are hermetically sealed. A second seal member is provided to surround the valve shaft;
It is characterized by that. A two-port valve according to claim 8,
When the second seal member is in contact with the connecting member, the entire valve element is connected to the peripheral edge of the second flow path opening in the axial direction more than the edge closest to the connecting member. Located on the member side,
It is characterized by that. The two-port valve according to claim 9, wherein
The cylinder chamber is partitioned by the piston in the axial direction into a first pressure chamber on the connecting member side and a second pressure chamber on the opposite side to the first pressure chamber,
Each of these pressure chambers has a port for supplying and discharging compressed fluid.
The insertion hole is provided with a through hole for discharging the compressed fluid leaking from the first pressure chamber beyond the sealing member of the insertion hole to the atmosphere.
It is characterized by that. The two-port valve according to claim 10,
At the end of the valve shaft opposite to the valve body, a cylinder housing that forms the cylinder chamber is pierced in an airtight and slidable manner in the axial direction so that the valve body can be reciprocated by the valve drive section. Along with the indicator that goes in and out of the cylinder housing is attached,
The piston is clamped between the valve shaft and the indicator and fixed to the valve shaft;
It is characterized by that.

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