Valve

Abstract

Provided is a valve with which the sealing performance of a seal part between an orifice plate and a member clamping the orifice plate can be ensured.　The valve comprises: a body having an accommodation recess in which a first inflow path and a first outflow path open to a bottom surface; an orifice plate; an inner member in which a second inflow path and a second outflow path are formed; and a fixing ring for pressing the inner member toward the bottom surface. The first outflow path opens at the center of the bottom surface of the accommodation recess, and an annular plate support surface and an abutted surface are formed around the first outflow path. The second outflow path opens at the center of a lower surface of the inner member, and an annular pressing surface and an abutting surface are formed around the second outflow path. An annular pressing protrusion is provided on the pressing surface. During a process in which the fixing ring is fastened into the accommodation recess and the abutting surface is fitted tightly to the abutted surface, the pressing protrusion presses the orifice plate so that the seal part between the orifice plate and the body and inner member is sealed.

Description

valve

[0001] The present disclosure relates to a valve incorporating an orifice.

[0002] In semiconductor manufacturing processes, for example, in microprocesses such as ALD (Atomic Layer Deposition) and ALE (Atomic Layer Etching), a pressure-type flow control device having an orifice-integrated valve is used to supply an accurately metered amount of processing gas to a processing chamber in a short time. In the orifice-integrated valve of Patent Document 1, an orifice plate is placed on a body, and a seat valve body, inner disk, diaphragm, etc. are placed on the orifice plate, and a bonnet is screwed to the body, so that the orifice plate is sealed and fixed by the protrusions of the valve seat body.

[0003] Patent No. 4137267

[0004] Some pressure-type flow control devices with built-in orifice valves have a flow rate self-diagnosis function that performs a self-diagnosis to check for abnormalities in the controlled flow rate due to orifice clogging, corrosion, etc. The flow rate self-diagnosis function detects the presence or absence of abnormalities by comparing the initial pressure drop characteristics of the device with the pressure drop characteristics at the time of diagnosis. When investigating the cause of abnormalities diagnosed by the flow rate self-diagnosis function in conventional built-in orifice valves, it was inferred that the cause of the abnormality was changes in the amount of leakage generated from the orifice plate seal, which had low surface contact and deformed (bent) over time. For this reason, it is necessary to ensure that the orifice plate does not deform and that surface contact and sealing properties are maintained between the orifice plate and the clamping part that holds it.

[0005] In order to ensure that the seal between the orifice plate and the member that presses it has appropriate surface contact and sealing performance, it is also necessary to manage the tightening torque of the bonnet to the body. In this case, even if the same torque is applied, the tightening angle may differ depending on the roughness of the surfaces of the screw joint between the bonnet and the body, which may result in a large tightening force being applied to the orifice plate, causing it to deform, or insufficient tightening force being applied to members such as the orifice plate, resulting in insufficient sealing performance. For this reason, it is necessary to uniformly apply the force to the orifice plate.

[0006] Therefore, one object of the present disclosure is to provide a valve that can ensure surface contact and sealing performance of the seal portion between the orifice plate and the member that clamps it.

[0007] In order to achieve the above object, one aspect of the present invention provides a valve comprising: a body having a recessed portion in which a first inlet passage and a first outlet passage are formed, the recessed portion opening to the top surface and the first inlet passage and the first outlet passage opening to the bottom surface; an orifice plate disposed on the bottom surface of the recessed portion and having an orifice formed therein; an inner member disposed within the recessed portion and having a second inlet passage communicating with the first inlet passage and a second outlet passage communicating with the first outlet passage formed therein; and a fixing ring disposed above the inner member and threadedly engaged with a threaded portion formed on the inner surface of the recessed portion to press the inner member toward the bottom surface. The first outlet passage opens at the center of the bottom surface of the accommodating recess, around which an annular plate support surface and an abutment surface are formed in this order, and the second outlet passage opens at the center of the lower surface of the inner member, around which an annular pressing surface and an abutment surface are formed in this order, and the pressing surface is provided with an annular pressing protrusion, and in the process of tightening the fixing ring into the accommodating recess and the abutment surface coming into close contact with the abutment surface, the pressing protrusion presses the orifice plate, thereby sealing the seal between the orifice plate and the body and the inner member.

[0008] An annular relief groove may be formed on the outer peripheral edge of the plate support surface, and the outer peripheral edge of the orifice plate may be pressed by the pressing protrusion and bent toward the relief groove.

[0009] The pressing protrusion before being deformed by pressing the orifice plate has an outer edge that is arc-shaped in cross section, and is located between a first position and a second position in the radial direction of the pressing surface, the first position being a position where the top of the pressing protrusion before being deformed is located slightly outside the inner end of the escape groove in the radial direction, and the second position being a position where the inner end of the pressing protrusion before being deformed is located slightly inside the inner end of the escape groove in the radial direction.

[0010] The device may further include a gasket disposed on the bottom surface of the accommodating recess and having through holes communicating with the first inlet passage and the second inlet passage, wherein the bottom surface of the accommodating recess is provided with a first annular protrusion surrounding the opening of the first inlet passage and the opening of the first outlet passage, and the lower surface of the inner member is provided with a second annular protrusion surrounding the opening of the second inlet passage and the opening of the second outlet passage, and when the fixing ring is tightened into the accommodating recess, the first protrusion bites into the lower surface of the gasket and the second protrusion bites into the upper surface of the gasket, thereby forming a seal in each case.

[0011] According to the present invention, it is possible to provide a valve that can ensure the sealing performance of the seal portion between the orifice plate and the member that presses it.

[0012] FIG. 2 is a cross-sectional view of a valve according to an embodiment of the present disclosure. FIG. 3 is an enlarged cross-sectional view of a main portion of the valve 1 of FIG. 1. FIG. 4 is a perspective view of an orifice plate. (a) is a perspective view of an inner member, and (b) is a cross-sectional view of the inner member. (a) is a perspective view of a fixing ring, and (b) is a cross-sectional view of the fixing ring. FIG. 5 is a plan view of a thrust ring. FIG. 6 is an explanatory diagram of the positional relationship between a pressing protrusion of the inner member and an escape groove of the body. FIG. 7 is a diagram showing a state in which the outer peripheral edge of the orifice plate is pressed by the pressing protrusion and bent toward the escape groove.

[0013] A valve according to an embodiment of the present disclosure will be described with reference to the drawings.

[0014] Fig. 1 is a cross-sectional view of a valve 1 according to this embodiment in a closed state. Fig. 2 is an enlarged cross-sectional view of a main portion of the valve 1 shown in Fig. 1. The valve 1 according to this embodiment is a diaphragm valve with a built-in orifice.

[0015] The valve 1 is, for example, a diaphragm valve, and includes a body 2 and an actuator 3. In the following description, the actuator 3 side of the valve 1 will be referred to as the upper side, and the body 2 side of the valve 1 will be referred to as the lower side.

[0016] The body portion 2 includes a body 10 , a gasket 15 , an orifice plate 20 , an inner member 30 , a valve seat 40 , a fixing ring 50 , a thrust ring 60 , a diaphragm 70 , and a pressure adapter 80 .

[0017] The body 10 is formed in a block shape from a metal material such as stainless steel. The body 10 has a first inlet passage 11 and a first outlet passage 12 formed therein, and is provided with an accommodating recess 13 having a circular cross-sectional hole that opens to the top surface of the body 10. In this embodiment, the gasket 15, orifice plate 20, inner member 30, valve seat 40, fixing ring 50, thrust ring 60, diaphragm 70, and presser adapter 80 constitute valve elements.

[0018] The bottom surface of the accommodation recess 13 has a first outlet passage 12 opening in the center, and is surrounded by a ring-shaped plate support surface 13a, a cylindrical portion 13b, an annular recess 13c, and an abutted surface 13d, which are concentrically formed in this order. The plate support surface 13a is flat, and an annular relief groove 13e (see FIG. 7) is formed on its outer periphery. The cylindrical portion 13b is configured to protrude upward. The first inlet passage 11 opens on a bottom surface 13f of the annular recess 13c, and an annular first protrusion 13g is provided. The first protrusion 13g is located outside the opening. The abutted surface 13d is flat and abuts against a later-described abutting surface 30c of the inner member 30. A female thread portion 13h is formed on the inner peripheral surface of the upper portion of the accommodation recess 13. The surfaces that constitute the plate support surface 13 a , the cylindrical portion 13 b , the annular recess 13 c , and the abutted surface 13 d correspond to the bottom surface of the accommodation recess 13 .

[0019] The gasket 15 is an annular member made of a soft material, and in this embodiment is made of a metal such as annealed stainless steel. That is, the gasket 15 is made of a metal that is softer than the body 10 and the inner member 30. The gasket 15 is disposed in the annular recess 13c and has a through hole 15a that communicates with the first inlet passage 11. Because the gasket 15 is made of a soft material, when the valve element is fixed to the body 10, the first protrusion 13g bites into the lower surface 15b of the gasket 15, thereby sealing the connection between the first inlet passage 11 and the through hole 15a.

[0020] 3 is a perspective view of the orifice plate 20. As shown in FIGS. 2 and 3, the orifice plate 20 is disposed on the body 10 and has an orifice 20a formed therein that communicates with the first outlet passage 12. The orifice plate 20 is a thin disk made of a metal such as stainless steel, and has the orifice 20a formed in its center. The orifice plate 20 is disposed on the plate support surface 13a of the installation recess 13 and is fixed by being sandwiched between the plate support surface 13a and the pressing surface 30a of the inner member 30. The orifice plate 20 is configured to narrow the opening of the second outlet passage 32 of the inner member 30. Although only one orifice 20a is formed in the orifice plate 20, multiple orifices may be formed.

[0021] 4(a) and 4(b) are a perspective view and a cross-sectional view of the inner member 30. As shown in FIGS. 2 and 4, the inner member 30 is disposed within the mounting recess 13 and is positioned above the gasket 15 and the orifice plate 20. The inner member 30 has four second inlet passages 31 and one second outlet passage 32. Each second inlet passage 31 communicates with the first inlet passage 11 via a through-hole 15a. The second outlet passage 32 communicates with the first outlet passage 12 via an orifice 20a. The inner member 30 is made of a metal such as stainless steel having the same hardness as the body 10 and has a stepped cylindrical shape with a large-diameter portion 33 and a small-diameter portion 34 located inside the large-diameter portion 33 and having an upper end that protrudes upward. The outer peripheral surface of the large-diameter portion 33 fits into the inner peripheral surface of the lower portion of the mounting recess 13 of the body 10, thereby positioning the inner member 30 relative to the body 10.

[0022] The second outflow passage 32 penetrates the center of the inner member 30. The second outflow passage 32 opens in the center of the underside of the inner member 30, and an annular pressing surface 30a, an annular recess 30b, and an abutment surface 30c are concentrically formed around it in this order. The pressing surface 30a is flat, and an annular pressing protrusion 30d is provided on its outer periphery. The second inflow passage 31 opens into the bottom surface 30e of the annular recess 30b, and an annular second protrusion 30f is provided to surround the opening. The second protrusion 30f faces the first protrusion 13g along its entire circumference in the vertical direction. The annular recess 30b forms a protrusion 30g that protrudes downward from the center of the bottom of the inner member 30. The pressing surface 30a and the pressing protrusion 30d are formed on the protrusion 30g. The protrusion 30g is inserted into the cylindrical portion 13b when the valve element is fixed to the body 10. The surfaces that form the pressing surface 30a, the annular recess 30b, and the abutting surface 30c correspond to the lower surface of the inner member 30.

[0023] The abutment surface 30c is flat and abuts against the abutted surface 13d of the body 10 when the valve element is fixed to the body 10. The pressing protrusion 30d is configured to press against the upper surface 20b of the orifice plate 20 to seal the connection between the second outflow path 32 and the first outflow path 12. The second protrusion 30f is configured to bite into the upper surface 15c of the gasket 15 to seal the connection between the second inflow path 31 and the through hole 15a. Before pressing against the orifice plate 20, the pressing protrusion 30d has an outer edge that is arc-shaped in cross section (see FIG. 7). The pressing protrusion 30d deforms when pressing against the orifice plate 20 and bending the outer peripheral edge 20c (see FIG. 8).

[0024] A second outlet passage 32 opens in the center of the upper surface of the inner member 30, and is surrounded by a circular seat placement groove 30h, an annular outlet groove 30i, a diaphragm support portion 30j, and an annular upper end surface 30k, all of which are concentrically formed in this order. Four second inlet passages 31 are formed at equal intervals around the circumference. Each second inlet passage 31 has its lower end opening into the annular recess 30b and its upper end opening into the annular outlet groove 30i. The number of second inlet passages 31 may be one or more. Each second inlet passage 31 slopes inward as it extends upward. The lower end of each second inlet passage 31 communicates with the first inlet passage 11 of the body 10 via the through-hole 15a of the gasket 15.

[0025] The valve seat 40 is an annular member provided around the opening of the second outflow passage 32 on the upper surface of the inner member 30. The valve seat 40 is made of, for example, fluororesin (PTFE). The valve seat 40 is fitted into a seat placement groove 30h in the inner member 30.

[0026] 5(a) and 5(b) are a perspective view and a cross-sectional view of the retainer ring 50. As shown in FIGS. 2 and 5, the retainer ring 50 is made of a metal such as stainless steel and has a generally circular ring shape. A male thread portion 50a is formed on the outer peripheral surface of the retainer ring 50, and a double hex structure that engages with a rotary tool is formed on the inner peripheral surface 50b. A plate accommodating recess 50c is formed on the underside of the retainer ring 50. Two thrust rings 60 are accommodated in the plate accommodating recess 50c.

[0027] 6 is a plan view of the thrust ring 60. The thrust ring 60 is a generally washer-shaped stainless steel plate coated with a sliding material. When the valve element is secured to the body 10, the thrust ring 60 reduces friction during rotation caused by tightening with the fixing ring 50, and prevents co-rotation of the inner member 30. The thrust ring 60 is not limited to a stainless steel plate coated with a sliding material, and any material that can reduce friction during rotation of the fixing ring 50 may be used. The thrust ring 60 may be made of, for example, a synthetic resin material with excellent sliding properties, or may be a thrust bearing.

[0028] As shown in FIG. 2 , the diaphragm 70 is disposed on the inner member 30 and is a member that opens or closes communication between the second inlet channel 31 and the second outlet channel 32 by separating from or contacting the valve seat 40. The diaphragm 70 is formed by laminating thin metal plates, such as special stainless steel, and thin nickel-cobalt alloy plates, with the center portion bulging upward. The diaphragm 70 is supported by the diaphragm support portion 30j of the inner member 30 and is fixed by being pressed by the lower portion 4a of the bonnet 4 of the actuator 3 via a ring-shaped presser adapter 80. The diaphragm 70 defines a portion of the flow path and is elastically deformed by being pressed by the diaphragm presser 6. When the diaphragm 70 contacts the valve seat 40, the flow path is closed. When the diaphragm 70 moves away from the valve seat 40, the flow path is opened.

[0029] As shown in FIG. 1, the actuator 3 includes a bonnet 4 , an actuator cap 5 , a diaphragm holder 6 , a stem 7 , a piston 8 , and a compression coil spring 9 .

[0030] The bonnet 4 is generally cylindrical and has a lower portion 4a, an intermediate portion 4b, and an upper portion 4c. The lower portion 4a is inserted into the body 10, and the outer periphery of the upper end of the lower portion 4a is screwed onto the body 10, thereby fixing the bonnet 4 to the body 10. The lower portion 4a penetrates the inner circumferential surface 50b of the fixing ring 50, and its lower end surface presses against the presser adapter 80. The intermediate portion 4b is located above the lower portion 4a and has an outer shape like a hexagonal pillar. The upper portion 4c is provided to extend upward from the outer edge of the intermediate portion 4b.

[0031] The actuator cap 5 is generally cylindrical with a lid and includes an outer cylinder 5a, an upper cover 5b, and an inner cylinder 5c. The actuator cap 5 is fixed to the bonnet 4 by screwing the lower end of the outer cylinder 5a into the upper part 4c of the bonnet 4. The upper cover 5b is provided to cover the upper end of the outer cylinder 5a. The inner cylinder 5c is connected to the inner end of the upper cover 5b. The bonnet 4 and the actuator cap 5 form an accommodation space 5d that accommodates the piston 8 and the compression coil spring 9.

[0032] The diaphragm retainer 6 is provided above the diaphragm 70 and is supported by the lower part 4a of the bonnet 4 so as to be movable in the vertical direction. The stem 7 is supported by the middle part 4b of the bonnet 4 so as to be movable in the vertical direction, and is configured to open and close the flow path by moving toward and away from the diaphragm 70.

[0033] The piston 8 is integral with the stem 7, provided above the stem 7, and supported by the bonnet 4 and actuator cap 5 so as to be vertically movable. The piston 8 has a base 8a and an upper protrusion 8b. The base 8a is generally disk-shaped, and the stem 7 is integrally provided on its underside. The upper protrusion 8b is generally cylindrical and extends upward from the upper surface of the base 8a. A pressure chamber 8c is defined by the lower surface of the base 8a of the piston 8 and the upper surface of the middle portion 4b of the bonnet 4. The piston 8 has a drive fluid introduction passage 8d extending from its upper end to the pressure chamber 8c. A compression coil spring 9 is disposed between the lower surface of the upper lid portion 5b of the actuator cap 5 and the upper surface of the base 8a of the piston 8, and constantly biases the piston 8 downward.

[0034] When driving fluid is supplied to the valve 1, the driving fluid passes through the driving fluid inlet passage 8d and flows into the pressure chamber 8c. When the driving fluid flows into the pressure chamber 8c, the piston 8 rises against the biasing force of the compression coil spring 9. As a result, the piston 8, which has the stem 7 at its tip, moves to its top dead center, and the elastic force of the diaphragm 70 and the pressure of the fluid (gas) move the diaphragm retainer 6 upward, connecting the second inlet passage 31 and the second outlet passage 32, and the valve 1 enters an open state.

[0035] Next, the positional relationship between the pressing protrusion 30d and the relief groove 13e of the body 10 before the orifice plate 20 is pressed and deformed will be described with reference to FIG.

[0036] FIG. 7 is an explanatory diagram of the positional relationship between the pressing protrusion 30d and the relief groove 13e of the body 10 before pressing the orifice plate 20. The outer diameter of the orifice plate 20 is configured to be larger than the outer shape of the plate support surface 13a, and the outer peripheral edge 20c of the orifice plate 20 is located on the relief groove 13e. The pressing protrusion 30d has an arc-shaped outer edge in a cross-sectional view. For example, the position of the pressing protrusion 30d provided on the pressing surface 30a before deformation is the innermost (centerward) position shown in FIG. 7(a) and the outermost (outside) position shown in FIG. 7(b). The pressing protrusion 30d shown in FIG. 7(a) is provided on the pressing surface 30a such that its apex P1 is located slightly outside the inner end X of the relief groove 13e (the outer end of the plate support surface 13a) in the radial direction of the pressing surface 30a. The pressing protrusion 30d shown in Fig. 7(b) is provided on the pressing surface 30a so that the inner end P2 of the pressing protrusion 30d is located slightly inside the inner end X of the relief groove 13e. In this embodiment, the pressing protrusion 30d is preferably provided between the position shown in Fig. 7(a) (first position) and the position shown in Fig. 7(b) (second position) in the radial direction of the pressing surface 30a.

[0037] Next, the assembly procedure for the valve 1 will be described with reference to FIGS.

[0038] The orifice plate 20 is placed on the plate support surface 13a of the accommodating recess 13. The gasket 15 is placed in the annular recess 13c of the accommodating recess 13. The valve seat 40 is fitted into the seat placement groove 30h of the inner member 30. This inner member 30 is placed in the accommodating recess 13 of the body 10. At this time, the protruding portion 30g of the inner member 30 is inserted into the cylindrical portion 13b. Two thrust rings 60 are placed on the annular upper end surface 30k of the inner member 30. The male thread portion 50a of the fixing ring 50 is threaded into the female thread portion 13h of the accommodating recess 13, and the fixing ring 50 is tightened until the abutting surface 30c of the inner member 30 abuts against the abutted surface 13d of the body 10, thereby fixing the gasket 15, orifice plate 20, and inner member 30 to the body 10.

[0039] The diaphragm 70 is placed on the diaphragm support portion 30j of the inner member 30, the presser adapter 80 is placed on the diaphragm 70, and the bonnet 4 of the actuator 3 is screwed into the female thread portion 13h of the accommodation recess 13. In this way, the valve 1 of this embodiment is assembled.

[0040] When tightening of the fixing ring 50 begins, the second protrusion 30f of the inner member 30 contacts the upper surface 15c of the gasket 15, but the pressing protrusion 30d of the inner member 30 does not contact the orifice plate 20. After the fixing ring 50 is tightened and the first protrusion 13g and the second protrusion 30f bite into the gasket 15, the pressing protrusion 30d contacts the upper surface 20b of the orifice plate 20 (see FIGS. 7(a) and 7(b)). When the fixing ring 50 is tightened further, the outer peripheral edge 20c of the orifice plate 20 is pressed by the pressing protrusion 30d and bent toward the relief groove 13e (see FIGS. 8(a) and 8(b)). At this time, the pressing protrusion 30d is crushed and deformed from the shape shown in FIG. 7. The fastening of the fixing ring 50 is completed by fastening the fixing ring 50 until the pressing surface 30a of the inner member 30 comes into close contact with the upper surface 20b of the orifice plate 20 and the abutting surface 30c of the inner member 30 abuts against the abutted surface 13d of the body 10. In Fig. 8(a), the positional relationship between the pressing protrusion 30d and the relief groove 13e corresponds to Fig. 7(a), and in Fig. 8(b), the positional relationship between the pressing protrusion 30d and the relief groove 13e corresponds to Fig. 7(b).

[0041] As described above, in the valve 1 of this embodiment, the sealing of the seal portion between the orifice plate 20 and the body 10 and inner member 30 is completed by tightening the fixing ring 50 until the abutting surface 30c of the inner member 30 comes into close contact with the abutted surface 13d of the body 10. This makes it possible to easily ensure the sealing of the seal portion between the orifice plate 20 and the member that clamps it, without the need for torque management or the like. This makes it easy to make the sealing of the seal portion uniform between different valves 1. In this embodiment, tolerances are set so that the sealing portion between the orifice plate 20 and the body 10 and inner member 30 is reliably sealed during the process from when the pressing protrusion 30d comes into contact with the upper surface 20b of the orifice plate 20 until the abutting surface 30c comes into close contact with the abutted surface 13d. The tolerances in question are the tolerance (build-up tolerance) between the plate support surface 13a and the abutment surface 13d of the body 10, the tolerance (build-up tolerance) of the thickness of the orifice plate 20, and the tolerance (build-up tolerance) between the pressing surface 30a and the abutment surface 30c of the inner member 30.

[0042] An annular relief groove 13e is formed on the outer peripheral edge of the plate support surface 13a, and the outer peripheral edge 20c of the orifice plate 20 is pressed by the pressing protrusion 30d and bent toward the relief groove 13e. This improves surface contact, improves sealing performance, and suppresses deformation of the orifice plate 20.

[0043] The pressing protrusion 30d is provided between a first position and a second position in the radial direction of the pressing surface 30a. The first position is a position where the top P1 of the pressing protrusion 30d is located slightly outward from the inner end X of the relief groove 13e in the radial direction of the pressing surface 30a. The second position is a position where the inner end P2 of the pressing protrusion 30d is located slightly inward from the inner end X of the relief groove 13e in the radial direction of the pressing surface 30a. This improves surface contact, thereby improving sealing performance and suppressing deformation of the orifice plate 20.

[0044] When the fixing ring 50 is tightened into the receiving recess 13, the first protrusion 13g bites into the lower surface 15b of the gasket 15, and the second protrusion 30f bites into the upper surface 15c of the gasket 15, thereby forming a seal. This allows the sealing of the sealing portion of the orifice plate 20 and the sealing portion of the gasket 15 to be performed simultaneously.

[0045] The present disclosure is not limited to the above-described embodiments, and those skilled in the art may make various additions, modifications, etc. within the scope of the present disclosure.

[0046] For example, the gasket 15 is made of a metal such as annealed stainless steel, but if heat resistance is not required as much, a resin material such as fluororesin (PCTFE) may be used. The thrust ring 60 is used to reduce friction of the fixing ring 50, but if co-rotation of the inner member 30 does not occur, the thrust ring 60 does not have to be used.

[0047] 1: Valve 10: Body 11: First inlet passage 12: First outlet passage 13: Receiving recess 13a: Plate support surface, 13b: Cylindrical portion, 13c: Annular recess, 13d: Contact surface, 13e: Relief groove, 13g: First protrusion, 13h: Female thread portion 15: Gasket 15b: Lower surface, 15c: Upper surface 20: Orifice plate 20a: Orifice, 20c: Outer periphery 30: Inner member 30a: Pressing surface, 30b: Annular recess, 30c: Contact surface, 30d: Pressing protrusion, 30f: Second protrusion, 31: Second inlet passage, 32: Second outlet passage 50: Fixing ring P1: Top of pressing protrusion P2: Inner end of pressing protrusion X: Inner end of relief groove

Claims

1. A valve comprising: a body having a first inlet passage and a first outlet passage formed therein, and a receiving recess that opens on an upper surface and through which the first inlet passage and the first outlet passage open on a bottom surface; an orifice plate disposed on the bottom surface of the receiving recess and having an orifice formed therein; an inner member disposed in the receiving recess and having a second inlet passage communicating with the first inlet passage and a second outlet passage communicating with the first outlet passage formed therein; and a fixing ring positioned above the inner member and screwed into a screw portion formed on an inner peripheral surface of the receiving recess to press the inner member toward the bottom surface, wherein the first outlet passage opens at the center of the bottom surface of the receiving recess, and an annular plate support surface and an abutting surface are formed in this order around the first outlet passage; a second outlet passage opens at the center of the lower surface of the inner member, and an annular pressing surface and an abutting surface are formed in this order around the second outlet passage, and an annular pressing protrusion is provided on the pressing surface; and in a process of tightening the fixing ring with respect to the receiving recess so that the abutting surface is in close contact with the abutting surface, the pressing protrusion presses the orifice plate so that a seal portion between the orifice plate, the body, and the inner member is sealed.

2. The valve according to claim 1, wherein an annular relief groove is formed at an outer peripheral edge of the plate support surface, and an outer peripheral edge portion of the orifice plate is bent toward the relief groove side by being pressed by the pressing protrusion.

3. The valve according to claim 2, wherein the pressing protrusion before pressing and deforming the orifice plate has an outer edge that is arcuate in a cross-sectional view, and is provided between a first position and a second position in a radial direction of the pressing surface, the first position being a position where a top portion of the pressing protrusion before deformation is slightly outside the inner end of the relief groove in the radial direction, and the second position being a position where an inner end of the pressing protrusion before deformation is slightly inside the inner end of the relief groove in the radial direction.

4. Further provided with a gasket disposed on the bottom surface of the accommodation recess and having a through hole communicating with the first inflow path and the second inflow path, An annular first protrusion is provided on the bottom surface of the accommodation recess so as to surround the opening of the first inflow path and the opening of the first outflow path, An annular second protrusion is provided on the lower surface of the inner member so as to surround the opening of the second inflow path and the opening of the second outflow path, When the fixing ring is tightened with respect to the accommodation recess, the first protrusion bites into the lower surface of the gasket, and the second protrusion bites into the upper surface of the gasket, and seals are respectively formed. The valve according to claim 1, wherein the valve is configured as described above.

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