Valve device

Abstract

This valve device provides an improved controllability while achieving high flow rates. [Solution] The valve device 100 according to the present invention includes a flow path forming block 1 having a recess 14 that communicates with a fluid inlet passage 12 and a fluid outlet passage 13; a valve seat 2 provided in the recess 14, having a first fluid supply passage 23 located on the outer circumference side of the inner valve seat 22 and a second fluid supply passage that communicates the first fluid supply passage 23 and the fluid outlet passage 13; a valve body mechanism 3 having a valve body 31 and a third fluid supply passage formed thereon; and a drive actuator 4 provided in the flow path forming block 1 that drives the valve body mechanism 3 so that the valve body 31 seats or separates from the valve seat 2. In the closed state of the valve device 100, a recess 223 is formed between the inner valve seat 22 and the valve body 31 of the valve seat 2, and the third fluid supply passage supplies fluid from the fluid inlet passage 12 to the recess 223.

Description

Technical Field

[0001] The present invention relates to a valve device.

Background Art

[0002] Patent Document 1 discloses a valve device that opens and closes a valve by driving a valve element.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the valve device described in Patent Document 1, in the closed state of the valve device, the fluid from the fluid inflow passage cannot be supplied to the cavity formed between the valve element and the valve seat. Therefore, when the valve device is switched from the closed state to the open state, the movement of the valve element deteriorates, and there is a problem that the controllability of the valve device decreases.

[0005] Therefore, the present invention has been made by paying attention to this problem, and an object thereof is to provide a valve device that can improve controllability while realizing a large flow rate of the valve device.

Means for Solving the Problems

[0006] According to one aspect of the present invention, a valve device is provided, comprising: a fluid inlet passage; a fluid outlet passage; a flow path forming block having a communication chamber communicating with the fluid inlet passage and the fluid outlet passage; a valve seat provided in the communication chamber, having an annular first fluid supply passage located on the outer circumference of the central part and a second fluid supply passage communicating the first fluid supply passage and the fluid outlet passage; a valve body mechanism having a valve body and a third fluid supply passage formed thereon; and a drive actuator provided in the flow path forming block for driving the valve body mechanism so that the valve body seats or dissipates from the valve seat, wherein in the closed state of the valve device, a cavity is formed between the entire central part of the valve seat and the valve body, and in the closed state of the valve device, the third fluid supply passage supplies fluid from the fluid inlet passage to the cavity. [Effects of the Invention]

[0007] According to this embodiment, it is possible to improve the controllability of the valve device while achieving a high flow rate. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a cross-sectional view showing the closed state of the valve device according to this embodiment. [Figure 2] Figure 2 is an enlarged cross-sectional view showing an enlarged view of the main components of the valve device in the closed state as shown in Figure 1. [Figure 3] Figure 3 is an enlarged cross-sectional view showing the main components of the valve device in the open state according to this embodiment, corresponding to Figure 2. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention (hereinafter referred to as "these embodiments") will be described with reference to the attached drawings. Throughout this specification, the same elements will be denoted by the same reference numerals.

[0010] (Configuration of the valve device) First, the valve device 100 according to this embodiment will be described with reference to Figures 1 and 2.

[0011] Figure 1 is a cross-sectional view showing the valve device 100 in the closed state according to this embodiment. Figure 2 is an enlarged cross-sectional view showing an enlarged view of the main components of the valve device 100 in the closed state in Figure 1.

[0012] As shown in Figure 1, the valve device 100 according to this embodiment is a valve device used in a fluid supply unit as a fluid supply means for supplying process gas or the like as a fluid from a fluid supply source (not shown) to semiconductor manufacturing equipment (CVD equipment, sputtering equipment, etching equipment, etc. / not shown). In this embodiment, the valve device 100 is composed of a normally open (i.e., normally open) solenoid valve, but is not limited to this, and may be composed of, for example, an air-supplied drive valve or a piezoelectric drive valve. As shown in Figures 1 and 2, the valve device 100 comprises a flow path forming block 1, a valve seat 2, a valve body mechanism 3, a drive actuator 4, and a support block 5. The drive actuator 4 is attached to the flow path forming block 1 by the support block 5 and bolts (not shown).

[0013] As shown in Figures 1 and 2, the flow path forming block 1 comprises a block body 11, a fluid inlet flow path 12 and a fluid outlet flow path 13 formed in the block body 11, and a recess 14 as a communication chamber formed on the upper surface of one side of the block body 11 so as to connect the outlet end, which is one end of the fluid inlet flow path 12, with the inlet end, which is one end of the fluid outlet flow path 13. The support block 5 is erected from the upper surface of the block body 11 so as to be located on the outer circumference side of the recess 14.

[0014] As shown in Figures 1 and 2, the recess 14 has a first communication chamber 141 formed to communicate with the outlet end of the fluid inflow passage 12 and to be close to the support block 5, and a second communication chamber 142 formed to communicate the first communication chamber 141 and the inflow end of the fluid outflow passage 13 and to be spaced away from the support block 5. The first communication chamber 141 and the second communication chamber 142 are arranged in order from top to bottom so as to be coaxial. The diameter of the first communication chamber 141 is formed to be larger than the diameter of the second communication chamber 142. On the other hand, an internal thread is formed on the circumferential surface of the second communication chamber 142.

[0015] As shown in Figures 1 and 2, the valve seat 2 is housed in the recess 14 (specifically, both the first communication chamber 141 and the second communication chamber 142) and has a cylindrical outer valve seat 21 and an inner valve seat 22 as a central part housed inside the outer valve seat 21.

[0016] As shown in Figure 2, the outer valve seat 21 has a male thread 211 formed on its outer circumferential surface so as to screw into the female thread of the second communication chamber 142, a flange 212 formed on its outer circumferential surface so as to rest on the bottom of the first communication chamber 141 (i.e., the step formed between the first communication chamber 141 and the second communication chamber 142), a large-diameter chamber 213 formed on the inside of the outer valve seat 21 so as to be close to the valve body 31 of the valve body mechanism 3 (described later), and a part formed on the inside of the outer valve seat 21 so as to be spaced away from the valve body 31. The valve seat 213 has a small diameter chamber 214, a gasket housing chamber 215 formed on the inside of the outer valve seat 21 so as to be located between the small diameter chamber 214 and the bottom of the second communication chamber 142 (i.e., the step formed between the second communication chamber 142 and the inlet end of the fluid outflow passage), an annular (specifically, circular) outer surface 216 formed to face the valve body mechanism 3, and an annular (specifically, circular) outer seat surface 217 formed to protrude from the outer surface 216 toward the valve body mechanism 3 side (i.e., toward the valve body 31 side). The large diameter chamber 213, the small diameter chamber 214, and the gasket housing chamber 215 are arranged in order from top to bottom so as to be formed coaxially.

[0017] As shown in Figure 2, the inner valve seat 22 includes a cylindrical body 221 that is press-fitted and fixed into the small-diameter chamber 214, a lid 222 provided at one end of the cylindrical body 221 facing the valve body 31, a recess 223 formed on the side of the lid 222 facing the valve body, an annular inner seat surface 224 formed to be located on the outer circumference of the recess 223, a plurality of through holes 225 formed in the cylindrical body 221 so as to penetrate the cylindrical body 221, and a projection 226 formed on the outer circumference of the cylindrical body 221 so as to rest on the bottom of the large-diameter chamber 213 (i.e., the step formed between the large-diameter chamber 213 and the small-diameter chamber 214). Note that the lid 222 does not have a through hole formed through it.

[0018] And when the cylindrical body 221 of the inner valve seat 22 is pressed into the small-diameter chamber 214 of the outer valve seat 21, An annular (specifically, circular) first fluid supply channel 23 is formed on the outer circumference of the inner valve seat 22. Specifically, in this state, an annular (specifically, circular) first fluid supply channel 23 is formed between the outer valve seat 21 (specifically, the large-diameter chamber 213) and the inner valve seat 22 (specifically, the outer surface of the cylindrical body 221). This makes it easy to form the first fluid supply channel 23 between the outer valve seat 21 and the inner valve seat 22. Also, in a plan view, the annular (specifically, circular) first fluid supply channel 23 is formed between the outer seat surface 217 and the inner seat surface 224. As described above, since the valve seat 2 is composed of separate outer valve seat 21 and inner valve seat 22, an annular first fluid supply channel 23 where a high flow rate is required can be easily manufactured.

[0019] A second fluid supply channel 24 is formed in the internal valve seat 22, connecting the first fluid supply channel 23 and the inlet end of the fluid outlet channel 13. The second fluid supply channel 24 is composed of multiple through holes 225 and the inside of the cylindrical body 221. This allows the second fluid supply channel 24 to be easily formed simply by forming multiple through holes 225 in the cylindrical body 221. The process gas, as a fluid, from the first fluid supply channel 23 is then supplied to the inlet end of the fluid outlet channel 13, sequentially passing through the multiple through holes 225 and the inside of the cylindrical body 221.

[0020] The gasket housing chamber 215 houses a gasket 25. And the cylindrical body 221 of the inner valve seat 22 is press-fitted into the small-diameter chamber 214 such that the protruding portion 226 is placed on the bottom of the large-diameter chamber 213. Thereby, the axial direction (downward in FIGS. 1 and 2) positioning of the inner valve seat 22 with respect to the outer valve seat 21 can be facilitated. And in this state, the outer seat surface 217 and the inner seat surface 224 are flush. Thereby, since the lower surface as the opposing surface of the valve body 31 facing the valve seat 2 can be made a flat surface, the valve body 31 can be easily manufactured. Note that a depression 223 as a cavity is formed in the whole inside of the annular (specifically, circular-ring-shaped) inner seat surface 224. Further, in this state, the gasket 25 housed in the gasket housing chamber 215 is pressed between a step formed between the small-diameter chamber 214 and the gasket housing chamber 215 and the bottom of the second communication chamber 142. Thereby, the airtightness of the entire valve seat 2 can be improved.

[0021] In the present embodiment, the inner valve seat 22 is fixed to the outer valve seat 21 by press-fitting, but is not limited thereto. For example, it may be fixed to the outer valve seat 21 by screwing.

[0022] Also, in the present embodiment, both the outer seat surface 217 and the inner seat surface 224 protrude from the outer peripheral surface 216 and are provided so as to be able to contact the valve body 31, but are not limited thereto. For example, both may be provided so as to be flush with the outer peripheral surface 216. In this case, the valve body 31 is provided with an annular (specifically, circular-ring-shaped) protrusion protruding toward the valve seat 2 side. In the closed valve state of the valve device 100, the annular protrusion contacts both the outer seat surface 217 and the inner seat surface 224. In other words, in the closed valve state of the valve device 100, the annular protrusion is seated on both the outer seat surface 217 and the inner seat surface 224.

[0023] As shown in Figures 1 and 2, the valve body mechanism 3 includes a valve body 31 housed in a recess 14 (specifically, a first communication chamber 141) and provided to be seatable on or off with respect to the valve seat 2, and a valve body holding member 32 connected to a plunger 41 of the drive actuator 4 (described later) to hold the valve body 31.

[0024] As shown in Figure 2, the valve body 31 has a tapered portion 311 formed to be close to the valve seat 2, a large-diameter portion 312 formed to be spaced away from the valve seat 2, and a communication hole 313 that serves as a communication passage and penetrates both the tapered portion 311 and the large-diameter portion 312. The tapered portion 311 and the large-diameter portion 312 are arranged in order from bottom to top so as to be formed coaxially.

[0025] As shown in Figure 2, when the valve device 100 is in the closed state (i.e., when the valve body 31 is seated on the seating surface of the valve seat 2 (specifically, the outer seat surface 217 and the inner seat surface 224)), a cavity is formed between the valve body 31 and the inner valve seat 22 (specifically, the cover 222). In this embodiment, the cavity is composed of a recess 223, but is not limited to this, and may be composed of, for example, a recess formed on the opposite side of the valve body 31 facing the inner valve seat 22. Also, when the valve device 100 is in the closed state, the communication hole 313 is in communication with the recess 223.

[0026] Furthermore, in this embodiment, the communication hole 313 is composed of a single through hole formed in the center of the valve body 31, but it is not limited to this, and may be composed of, for example, multiple through holes formed in the valve body 31. The communication hole 313 only needs to perform the function of connecting the upper surface (specifically, the upper surface of the large-diameter portion 312) and the lower surface (specifically, the lower surface of the tapered portion 311) of the valve body 31.

[0027] As shown in Figure 2, the valve body retaining member 32 includes a first valve body retaining frame 321 connected to the plunger 41, a second valve body retaining frame 322 that screws into the first valve body retaining frame 321, and a leaf spring 323 as a biasing means housed between the first valve body retaining frame 321 and the valve body 31.

[0028] As shown in Figure 2, the first valve body retaining frame 321 includes a bottomed cylindrical body 321a with male threads formed on its outer circumferential surface and an opening facing toward the valve seat 2 side (downward side in Figures 1 and 2), a columnar portion 321b protruding from the bottom of the bottomed cylindrical body 321a toward the plunger 41 side (upward side in Figures 1 and 2), a male threaded portion 321c protruding from the tip of the columnar portion 321b toward the plunger 41 side (upward side in Figures 1 and 2), and a plurality of through holes 321d located on the outer circumferential side of the columnar portion 321b and formed in the bottom of the bottomed cylindrical body 321a so as to penetrate the bottom of the bottomed cylindrical body 321a. The columnar portion 321b and the male threaded portion 321c are formed coaxially. Furthermore, since the columnar portion 321b is formed to have a diameter larger than the diameter of the male threaded portion 321c, a step is formed between the columnar portion 321b and the male threaded portion 321c.

[0029] Then, with the first valve body retaining frame 321 connected to the plunger 41 (specifically, the male threaded portion 321c is screwed into the plunger 41), a clearance C is formed between the bottomed cylindrical body 321a and the retaining member 46 of the drive actuator 4 (specifically, the second retaining frame 462), which will be described later, serving as a fluid passage. Multiple through holes 321d connect the clearance C to the inside of the bottomed cylindrical body 321a.

[0030] As shown in Figure 2, the second valve body retaining frame 322 has a ring portion 322a and an internal thread 322b that is erected from the outer circumference of the ring portion 322a.

[0031] When the male threaded portion and female threaded portion 322b of the bottomed cylindrical body 321a are screwed together, the valve body 31 is held by the valve body holding member 32 such that the tapered portion 311 fits inside the ring portion 322a and the large-diameter portion 312 (specifically, the portion of the large-diameter portion 312 that protrudes radially (i.e., perpendicular to the axial direction) from the outer circumferential surface of the tapered portion 311) rests on the inner edge of the ring portion 322a. In this state, a housing space S for housing the leaf spring 323 is formed between the valve body 31 and the bottomed cylindrical body 321a.

[0032] In this embodiment, the clearance C, through hole 321d, containment space S, and communication hole 313 constitute a third fluid supply channel that supplies process gas from the fluid inlet channel 12 to the recess 223 when the valve device 100 is in the closed state. As a result, the process gas from the fluid inlet channel 12 is supplied to the recess 223 sequentially via the clearance C, through hole 321d, containment space S, and communication hole 313, so that when the valve device 100 is in the closed state, the pressure difference between both sides of the valve body 31 (specifically, between the opposing side of the valve body 31 facing the valve seat 2 (the lower side in Figures 1 and 2) and the opposite side of the valve body 31 that is opposite to the opposing side (the upper side in Figures 1 and 2)) can be kept to a minimum. As a result, when the valve device 100 is switched from the closed state to the open state, the load on the valve body 31 is reduced, the movement of the valve body 31 is improved, and the controllability of the valve device 100 can be improved.

[0033] Furthermore, when the valve device 100 is in the closed state, a gap A is formed between the second valve body retaining frame 322 (specifically, the ring portion 322a) and the outer circumferential surface 216. In other words, when the valve device 100 is in the closed state, the ring portion 322a and the outer circumferential surface 216 are not in contact. As a result, when the valve device 100 is in the closed state, the process gas from the fluid inflow passage 12 is supplied to the gap A, and the pressure difference between both sides of the valve body mechanism 3 can be kept to a minimum when the valve device 100 is in the closed state. As a result, the movement of the valve body 31 becomes smoother when the valve device 100 is switched from the closed state to the open state, and the controllability of the valve device 100 can be further improved.

[0034] As shown in Figures 1 and 2, the drive actuator 4 is an electromagnetic actuator that drives the valve mechanism 3 so that the valve body 31 sits on or off the valve seat 2 (specifically, the outer seat surface 217 and the inner seat surface 224). Furthermore, the drive actuator 4 includes a plunger 41 connected to a valve body holding member 32 (specifically, a first valve body holding frame 321), a guide cylinder 42 that guides the plunger 41 so that it can move along the axial direction, a core 43 located above the plunger 41 and the guide cylinder 42 and connected to the plunger 41, a coil 44 wound around the outer circumference of the core 43, a case 45 supported by a support block 5 so as to house the plunger 41, the guide cylinder 42, the core 43 and the coil 44, etc., a holding member 46 fixed so as to be sandwiched between the case 45 and the block body 11 and also sandwiching a part of the guide cylinder 42, and a spring 47 as a biasing means provided between the lower end of the guide cylinder 42 and a step formed between the columnar portion 321b and the male screw portion 321c.

[0035] The spring 47 is provided to bias the valve body mechanism 3 toward the plunger 41 side of the drive actuator 4 (upward side in Figures 1 and 2). As a result, when the valve device 100 is in the open state, the valve body 31 is separated from the seating surface of the valve seat 2 (specifically, the outer seating surface 217 and the inner seating surface 224) by the biasing force of the spring 47.

[0036] The retaining member 46 has a first retaining frame 461, part of which is sandwiched between the case 45 and the block body 11, and a second retaining frame 462, which is provided to screw into the first retaining frame 461. Part of the guide cylinder 42 is sandwiched between the first retaining frame 461 and the second retaining frame 462, which are screwed together with the outer edge of the spring 47.

[0037] (Operation of the valve device) Next, the operation of the valve device 100 according to this embodiment will be described with reference to Figures 2 and 3.

[0038] Figure 3 is an enlarged cross-sectional view showing the main components of the valve device 100 in the open state according to this embodiment, corresponding to Figure 2.

[0039] When no current is supplied to the coil 44 of the drive actuator 4, as shown in Figure 3, the valve body 31 is separated from the seating surface of the valve seat 2 (specifically, the outer seating surface 217 and the inner seating surface 224) by the biasing force of the spring 47, as described above. This makes it possible to realize a normally open valve device 100. At this time, a fluid passage is formed between the valve body 31 and the seating surface of the valve seat 2 (specifically, the outer seating surface 217 and the inner seating surface 224). And since the upper end of the first fluid supply passage 23 is open, the valve device 100 is in an open state. As a result, the process gas supplied from the fluid inlet channel 12 to the recess 223 via the third fluid supply channel (i.e., the process gas located inside the annular first fluid supply channel 23) is supplied to the first fluid supply channel 23 via the inner seat surface 224, while the process gas supplied from the fluid inlet channel 12 to the gap A (i.e., the process gas located outside the annular first fluid supply channel 23) is supplied to the first fluid supply channel 23 via the outer seat surface 217. This makes it possible to increase the flow rate of the valve device 100. Note that in the open state, the clearance C becomes narrower than in the closed state, but it does not disappear.

[0040] On the other hand, when fluid is supplied to the coil 44 of the drive actuator 4, as shown in Figure 2, the core 43 is displaced, pushing down both the plunger 41 and the valve body mechanism 3 against the biasing force of the spring 47. The valve body 31 is then seated on the seating surface of the valve seat 2 (specifically, the outer seating surface 217 and the inner seating surface 224). As a result, the upper end of the first fluid supply passage 23 is blocked by the valve body 31, and the valve device 100 is in a closed state.

[0041] (Effects and Benefits) Next, the effects and benefits of the above-described embodiment will be explained.

[0042] The valve device 100 according to the above embodiment includes a fluid inlet passage 12, a fluid outlet passage 13, a flow path forming block 1 having a recess 14 (communication chamber) that communicates with the fluid inlet passage 12 and the fluid outlet passage 13, a valve seat 2 provided in the recess 14, having an annular (specifically, circular) first fluid supply passage 23 located on the outer circumference of the inner valve seat 22 (central part) and a second fluid supply passage 24 that communicates the first fluid supply passage 23 and the fluid outlet passage 13, and a third fluid supply passage The valve device 100 includes a valve body mechanism 3 having a valve body 31, and a drive actuator 4 provided in the flow path forming block 1 that drives the valve body mechanism 3 so that the valve body 31 seats or separates from the valve seat 2. When the valve device 100 is in the closed state, a recess 223 (cavity) is formed between the entire inner valve seat 22 of the valve seat 2 and the valve body 31, and when the valve device 100 is in the closed state, the third fluid supply flow path supplies process gas (fluid) from the fluid inflow flow path 12 into the recess 223.

[0043] With this configuration, when the valve device 100 is in the closed state, a recess 223 is formed between the inner valve seat 22 of the valve seat 2 and the valve body 31. The third fluid supply channel supplies process gas from the fluid inflow channel 12 to the recess 223. Therefore, when the valve device 100 is in the closed state, the pressure difference between both sides of the valve body 31 (specifically, between the opposing side of the valve body 31 facing the valve seat 2 (the lower side in Figures 1 and 2) and the opposite side of the valve body 31 that is opposite to the opposing side (the upper side in Figures 1 and 2)) can be kept to a minimum. As a result, when the valve device 100 is switched from the closed state to the open state, the load on the valve body 31 is reduced, the movement of the valve body 31 is improved, and the controllability of the valve device 100 can be improved.

[0044] When the valve device 100 is in the open state, the process gas supplied from the fluid inlet passage 12 to the recess 223 via the third fluid supply passage (i.e., the process gas located inside the annular first fluid supply passage 23) is supplied to the first fluid supply passage 23, and the process gas supplied from the fluid inlet passage 12 to the outer circumference of the recess 223 (i.e., the process gas located outside the annular first fluid supply passage 23) is supplied to the first fluid supply passage 23. This makes it possible to increase the flow rate of the valve device 100.

[0045] Furthermore, in the embodiment described above, the valve seat 2 has a cylindrical outer valve seat 21 provided in the recess 14 and an inner valve seat 22 housed inside the outer valve seat 21, the first fluid supply passage 23 is located between the outer valve seat 21 and the inner valve seat 22, and the second fluid supply passage 24 is formed in the inner valve seat 22, with the central part being composed of the inner valve seat 22.

[0046] With this configuration, since the valve seat 2 is composed of a separate outer valve seat 21 and an inner valve seat 22, a first fluid supply channel 23 can be easily formed between the outer valve seat 21 and the inner valve seat 22.

[0047] Furthermore, in the embodiment described above, a recess 223 is formed on the side of the inner valve seat 22 that faces the valve body 31, and the cavity is configured to have the recess 223, and the recess 223 is provided so as not to communicate with the first fluid supply passage 23 when the valve device 100 is in the closed state.

[0048] With this configuration, a cavity can be easily formed by forming the recess 223 on the side of the inner valve seat 22 that faces the valve body 31. Furthermore, since a cavity can be formed simply by forming the recess 223 in the inner valve seat 22, the lower surface of the valve body 31 that faces the valve seat 2 can be made flat, thus making it easy to manufacture the valve body 31.

[0049] Furthermore, in the embodiment described above, the outer valve seat 21 has an outer seat surface 217 that is provided so as to be able to contact the valve body 31, and the inner valve seat 22 has an inner seat surface 224 that is provided so as to be able to contact the valve body 31, and the outer seat surface 217 and the inner seat surface 224 are flush with each other.

[0050] With this configuration, the lower surface of the valve body 31 facing the valve seat 2 can be made flat, making it easy to manufacture the valve body 31.

[0051] Furthermore, in the embodiment described above, the outer valve seat 21 further has an outer peripheral surface 216 located on the outer peripheral side of the outer seat surface 217, the valve body mechanism 3 is connected to the drive actuator 4 and has a valve body holding member 32 that holds the valve body 31, and a gap A is formed between the outer peripheral surface 216 and the valve body holding member 32.

[0052] With this configuration, when the valve device 100 is in the closed state, the process gas from the fluid inflow passage 12 is supplied to the gap A, so that the pressure difference between both sides of the valve body mechanism 3 can be kept to a minimum when the valve device 100 is in the closed state. As a result, the movement of the valve body 31 becomes smoother when the valve device 100 is switched from the closed state to the open state, and the controllability of the valve device 100 can be further improved.

[0053] Furthermore, in the embodiment described above, the outer valve seat 21 has a large-diameter chamber 213 formed inside the outer valve seat 21 so as to be close to the valve body 31, and a small-diameter chamber 214 formed inside the outer valve seat 21 so as to be spaced away from the valve body 31. The first fluid supply passage 23 is located between the large-diameter chamber 213 and the inner valve seat 22, and the inner valve seat 22 is press-fitted into the small-diameter chamber 214 and fixed in place.

[0054] This configuration makes it possible to achieve both the positioning of the inner valve seat 22 relative to the outer valve seat 21 and the formation of the first fluid supply channel 23.

[0055] Furthermore, in the embodiment described above, the inner valve seat 22 has a cylindrical body 221 that is press-fitted and fixed into the small-diameter chamber 214, and a lid 222 provided at one end of the cylindrical body 221 facing the valve body 31. The second fluid supply passage is configured to have a through hole 225 formed in the cylindrical body 221 so as to communicate with the first fluid supply passage 23 and the inside of the cylindrical body 221, and the central part in which the recess 223 is formed is made up of the lid 222.

[0056] In this configuration, the second fluid supply channel 24 is composed of multiple through holes 225 and the inside of the cylindrical body 221. This allows the second fluid supply channel 24 to be easily formed simply by creating multiple through holes 225 in the cylindrical body 221. The process gas from the first fluid supply channel 23 is then supplied to the inlet end of the fluid outlet channel 13, sequentially passing through the multiple through holes 225 and the inside of the cylindrical body 221.

[0057] Furthermore, in the embodiment described above, the valve body mechanism 3 is connected to the drive actuator 4 and has a valve body holding member 32 that holds the valve body 31, and the third fluid supply passage has a communication hole 313 (communication passage) formed in the valve body 31 so as to communicate with the recess 223.

[0058] With this configuration, process gas from the fluid inlet passage 12 is supplied to the recess 223 via the communication hole 313, etc., so that when the valve device 100 is in the closed state, the pressure difference between both sides of the valve body 31 (specifically, between the opposing side of the valve body 31 facing the valve seat 2 (the lower side in Figures 1 and 2) and the opposite side of the valve body 31 that is opposite to the opposing side (the upper side in Figures 1 and 2)) can be kept to a minimum. As a result, when the valve device 100 is switched from the closed state to the open state, the load on the valve body 31 is reduced, the movement of the valve body 31 is improved, and the controllability of the valve device 100 can be improved.

[0059] Although this embodiment has been described above, the above-described embodiment only illustrates a part of the application of the present invention, and is not intended to limit the technical scope of the present invention to the specific configurations of the above-described embodiment. [Explanation of Symbols]

[0060] 1. Flow channel forming block 2 valve seats 3. Valve mechanism 4 Drive actuators 12 Fluid inflow channel 13 Fluid Outlet Channel 14 Recess (communication chamber) 22 Inner valve seat (center) 23 First fluid supply channel 24 Second fluid supply channel 31 Valve body 100 Valve device 223 Cavity

Claims

1. A valve device, A fluid inflow channel, a fluid outflow channel, and a flow path forming block having a communication chamber that communicates with the fluid inflow channel and the fluid outflow channel, A valve seat provided in the communication chamber, having an annular first fluid supply channel located on the outer circumference of the central part and a second fluid supply channel connecting the first fluid supply channel and the fluid outlet channel, A valve mechanism having a valve body is formed in which a third fluid supply channel is formed, The flow path forming block includes a drive actuator that drives the valve mechanism so that the valve body seats or separates from the valve seat, In the closed state of the valve device, a cavity is formed between the entire central portion of the valve seat and the valve body. In the closed state of the valve device, the third fluid supply channel supplies fluid from the fluid inflow channel to the cavity. Valve device.

2. The aforementioned valve seat is A cylindrical outer valve seat provided in the aforementioned communication chamber, It has an inner valve seat housed inside the outer valve seat, The first fluid supply channel is located between the outer valve seat and the inner valve seat, The second fluid supply channel is formed in the inner valve seat, The central portion is composed of the inner valve seat. The valve device according to claim 1.

3. A recess is formed on the side of the inner valve seat that faces the valve body. The cavity is configured to have the recess, The recess is provided so as not to communicate with the first fluid supply passage when the valve device is in the closed state. The valve device according to claim 2.

4. The outer valve seat has an outer seat surface that is provided so as to be able to contact the valve body, The inner valve seat has an inner seat surface that is provided so as to be able to contact the valve body, The outer seating surface and the inner seating surface are flush with each other. The valve device according to claim 2.

5. The outer valve seat further has an outer peripheral surface located on the outer peripheral side of the outer seat surface, The valve mechanism is connected to the drive actuator and has a valve body holding member that holds the valve body. A gap is formed between the outer circumferential surface and the valve body holding member. The valve device according to claim 4.

6. The aforementioned outer valve seat is A large-diameter chamber formed on the inside of the outer valve seat so as to be in close proximity to the valve body, It has a small-diameter chamber formed on the inside of the outer valve seat so as to be spaced apart from the valve body, The first fluid supply channel is located between the large-diameter chamber and the internal valve seat. The inner valve seat is press-fitted and fixed into the small-diameter chamber. The valve device according to claim 2.

7. The aforementioned internal valve seat is A cylindrical body pressed into and fixed in the aforementioned small-diameter chamber, The cylindrical body has a cover provided at one end facing the valve body, The second fluid supply channel is configured to have a through hole formed in the cylindrical body so as to communicate with the first fluid supply channel and the inside of the cylindrical body, The central part is composed of the lid, The valve device according to claim 6.

8. The valve mechanism is connected to the drive actuator and has a valve body holding member that holds the valve body. The third fluid supply channel has a communication channel formed in the valve body so as to communicate with the cavity. The valve device according to claim 1.

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