Regulator

Abstract

The diaphragm member 15 receives a receiving part 151a of the front end surface of the shaft part 145 of the valve body 14, and is provided with a concave spherical surface 151b having a first radius at a portion facing the front end surface, the center of the concave spherical surface 151b being located on the central axis CL11 of the shaft part 145. The first radius is equal to or greater than 20% of the diameter D11 of the shaft part 145 subtracted from the diameter D11 of the shaft part 145. The part of the front end face opposite to the concave spherical surface 151b is a convex spherical surface 144 formed by subtracting a second radius by 2-5% of the first radius from the first radius.

Description

Technical Field

[0001] The present invention relates to a regulator. Background Art

[0002] In existing semiconductor manufacturing processes, for example, when controlling fluids such as pure water and chemical solutions used for wafer film formation processing, a regulator disclosed in Patent Document 1 is used for pressure control. The regulator of the related prior art is described as follows. Figure 28 For illustration. Figure 28 The cross-sectional view of the prior art regulator 50 is shown.

[0003] The regulator 50 is successively connected from the upstream end with: an input port 59, an upstream end fluid chamber 52, a valve hole 54, a downstream end fluid chamber 53, and an output port 60, forming a series of flow paths.

[0004] A valve body 51 is accommodated in the upstream end fluid chamber 52. The valve body 51 can move in the up-and-down direction in the figure and come into contact with / separate from an annular valve seat 55 provided around the valve hole 54.

[0005] A compression coil spring 58 is disposed on the lower end side of the valve body 51 in the figure. By the biasing force of the compression coil spring 58, the valve body 51 is biased in the direction of contacting the annular valve seat 55 (closing direction). In addition, the valve body 51 has a cylindrical shaft portion 511 that extends from the upstream end fluid chamber 52 through the valve hole 54 to the downstream end fluid chamber 53 in the contact / separation direction. The front end face 512 of the shaft portion 511 forms a convex spherical surface having a diameter approximately the same as that of the shaft portion 511. Therefore, the shaft portion 511 can be detachably and loosely fitted into a receiving portion 571 of a diaphragm member 57 accommodated in the downstream end fluid chamber 53. The receiving portion 571 of the diaphragm member 57 forms a concave spherical surface having a diameter approximately the same as that of the shaft portion 511.

[0006] The diaphragm member 57 can change its position in the contact / separation direction in accordance with the pneumatic air pressure supplied to the pressure acting chamber 56.

[0007] The regulator 50 configured as described above can adjust the distance (i.e., the opening degree) of the valve body 51 relative to the annular valve seat 55 by achieving a balance between the pneumatic air pressure supplied to the pressure acting chamber 56 and the biasing force of the compression coil spring 58.

[0008] Here, a detailed description will be given of the place where the valve body 51 is detachably and loosely fitted to the diaphragm member 57. For example, if back pressure is received from the end of the output port 60, causing the pressure in the downstream fluid chamber 53 to rapidly increase, the diaphragm member 57 will be pushed upward in the figure (i.e., the closing direction). At this time, if the valve body 51 and the diaphragm member 57 are connected in a non-detachable state, as the diaphragm member 57 is pushed upward in the closing direction, the valve body 51 will move in the closing direction, resulting in the possibility of excessive interference with the annular valve seat 55. Since excessive interference between the valve body 51 and the annular valve seat 55 can cause dust due to wear and the like, it is best to avoid it.

[0009] Here, if the valve body 51 and the diaphragm member 57 are made detachable, even if the pressure in the downstream fluid chamber 53 rapidly increases, causing the diaphragm member 57 to be pushed upward in the closing direction, the diaphragm member 57 will still separate from the valve body 51 and move alone in the closing direction. Therefore, since the valve body 51 does not move in the closing direction, excessive interference with the annular valve seat 55 can be prevented. In addition, since the valve body 51 and the diaphragm member 57 are liquid contact members that come into contact with the control fluid, a fluorine-based synthetic resin with high corrosion resistance (such as PTFE, PFA), etc. is used as the material. [Prior Art Documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Laid-Open No. 2021-89070 Summary of the Invention Problems to be Solved by the Invention

[0011] However, the above-described regulator has the following problems. As described above, if the valve body 51 is detachably and loosely fitted to the diaphragm member 57, there is a possibility of dust generation due to repeated contact / separation between the front end face 512 of the shaft portion 511 and the receiving portion 571 of the diaphragm member 57.

[0012] The reason for this dust generation can be considered that when the front end face 512 contacts the receiving portion 571, excessive stress is generated on the contact surface and sliding occurs on the front end face 512.

[0013] First, an explanation will be given of the stress generated on the contact surface when the front end face 512 contacts the receiving portion 571. Figure 29The figure shows the result of a finite element method analysis of the stress generated at the contact surface between the valve body 51 and the diaphragm member 57 (the contact surface between the front end surface 512 and the receiving portion 571) in the prior art. This analysis assumes that the materials of the valve body 51 and the diaphragm member 57 are both PTFE, and uses the biasing force of the compression coil spring 58 to bring the front end surface 512 into contact with the receiving portion 571. The value of the generated stress is represented by the length and color depth of the colored bars. That is, the longer the length of the colored bar, the greater the generated stress, and the darker the color of the colored bar, the greater the generated stress.

[0014] The generated stress is higher towards the central axis CL51 of the shaft portion 511 and is maximum near the center of the shaft portion 511. The maximum stress value is 10.92 MPa. Considering that the compressive strength of PTFE is about 10 MPa and about 5 MPa in a high-temperature environment (for example, when controlling the fluid temperature at 90°C), the analysis result indicates that in the state where the front end surface 512 of the valve body 51 is in contact with the receiving portion 571 of the diaphragm member 57, a stress equal to or greater than the compressive strength of the material will act. Therefore, if the front end surface 512 and the receiving portion 571 repeatedly come into contact / separate, there is a possibility of plastic deformation occurring in the shaft portion 511 and the receiving portion 571. The occurrence of plastic deformation will damage the contact surface between the valve body 51 and the diaphragm member 57, leading to the cause of dust generation.

[0015] Next, the sliding of the front end surface 512 that occurs when the front end surface 512 comes into contact with the receiving portion 571 will be described. Figure 30 The figure shows the result of a finite element method analysis of the sliding of the front end surface 512 of the shaft portion 511 in the prior art. Assuming that the materials of the valve body 51 and the diaphragm member 57 are both PTFE, and using the biasing force of the compression coil spring 58 to bring the front end surface 512 into contact with the receiving portion 571, which is the same as in the above stress analysis. The magnitude of the sliding amount is represented by the length and color depth of the colored bars. That is, the longer the length of the colored bar, the greater the sliding amount, and the darker the color of the colored bar, the greater the sliding amount. In addition, the extending direction of the colored bar represents the sliding direction. When the colored bar extends towards the end of the shaft portion 145, it indicates that sliding occurs towards the end of the central axis CL51 (inward sliding).

[0016] The sliding that occurs is as Figure 30 shown, and the overall sliding is inward. The sliding amount gradually increases as it moves away from the central axis CL51 and reaches a maximum value near the middle position between the central axis CL51 and the outer periphery of the shaft portion 511. However, if it exceeds this maximum value, the sliding amount gradually decreases as it moves towards the outer periphery. The range of the sliding amount that occurs is 0 - 2.9 μm.

[0017] If sliding occurs in this way, there is a possibility of repeated sliding between the front end face 512 and the receiving portion 571 due to the repeated abutment / separation between the front end face 512 and the receiving portion 571. The repeated sliding will cause dust to rise at the contact surface between the valve body 51 and the diaphragm member 57.

[0018] The dust rising at the contact surface between the valve body 51 and the diaphragm member 57 causes fine dust to be mixed into the control fluid. If fine dust is mixed into the control fluid, problems such as poor wafer manufacturing may occur, leading to a possible reduction in semiconductor manufacturing efficiency.

[0019] The present invention has been completed in view of the above problems, and an object thereof is to provide a regulator that can prevent dust from rising at the contact portion between the valve body and the diaphragm member. (Technical means for solving the problem)

[0020] To solve the above problems, the regulator according to one aspect of the present invention has the following configuration.

[0021] (1) A regulator, comprising: an upstream end fluid chamber housed in a valve body, a downstream end fluid chamber located at the downstream end of the upstream end fluid chamber, a valve hole connecting the upstream end fluid chamber and the downstream end fluid chamber, a ring-shaped valve seat provided along the periphery of the valve hole and capable of abutting / separating from the valve body, and a diaphragm member housed in the downstream end fluid chamber and capable of changing its position in the abutting / separating direction in accordance with the pressure of pneumatic air; wherein, the valve body has a cylindrical shaft portion extending from the upstream end fluid chamber through the valve hole to the downstream end fluid chamber in the abutting / separating direction; the shaft portion is detachably and loosely fitted with a receiving portion of the diaphragm member that receives the front end face of the shaft portion; the valve body is provided with a biasing device on the opposite side of the diaphragm member end for applying a biasing pressure to the valve body in the direction of abutting the ring-shaped valve seat; the opening degree of the valve body is adjusted by the balance between the pressure of the pneumatic air and the biasing pressure; wherein, the receiving portion is provided with a concave spherical surface centered on the central axis of the shaft portion and formed by a first radius at a portion opposite to the front end face; the first radius is a value equal to or greater than the value obtained by subtracting 20% of the diameter from the diameter of the shaft portion; the front end face is provided with a convex spherical surface formed by a second radius obtained by subtracting 2 to 5% of the first radius from the first radius at a portion opposite to the concave spherical surface.

[0022] According to the above adjuster, since the first radius is a value greater than or equal to the value obtained by subtracting 20% of the above diameter from the shaft diameter, the stress generated at the contact surface when the valve body contacts the diaphragm member can be suppressed to 10 MPa or less. For example, if the valve body or the diaphragm member is made of PTFE or PFA with high corrosion resistance, the compressive strength of PTFE is about 10 MPa and the compressive strength of PFA is about 15 MPa. Among them, even if PTFE with a lower compressive strength is selected, as described above, the stress generated at the contact surface can still be suppressed to 10 MPa or less, so that plastic deformation, damage, and dust generation of the valve body and the diaphragm member can be prevented.

[0023] Furthermore, according to the above adjuster, since the first radius is a value greater than or equal to the value obtained by subtracting 20% of the above diameter from the shaft diameter, when comparing the sliding amount of the shaft at the contact surface between the valve body and the diaphragm member according to the maximum value, it can be suppressed to 30% or less of the existing value. By suppressing the sliding amount of the shaft to be lower than the existing value, dust generation can be suppressed.

[0024] As described above, if the stress and sliding amount generated at the above contact surface can be suppressed, the possibility of dust generation at the contact surface can be reduced. Therefore, it is possible to prevent fine dust from mixing into the control fluid and reduce the semiconductor manufacturing efficiency.

[0025] (2) In the adjuster described in (1), preferably, the first radius is a value less than or equal to the value obtained by adding 20% of the above diameter to the diameter of the above shaft. Therefore, it is possible to ensure that the stress generated at the contact surface between the valve body and the diaphragm member is suppressed to 10 MPa or less, and plastic deformation, damage, and dust generation of the valve body and the diaphragm member can be prevented.

[0026] (3) In the adjuster described in (2), preferably, the first radius is a value greater than or equal to the value obtained by subtracting 10% of the above diameter from the shaft diameter and less than or equal to the value obtained by adding 10% of the above diameter to the shaft diameter. Therefore, when the valve body contacts the diaphragm member, the stress generated at the contact surface can be suppressed to 5 MPa or less. The compressive strength of PTFE can be considered to be about 5 MPa in a high-temperature environment (for example, the control fluid temperature is 90 °C). By suppressing the stress generated at the contact surface when the valve body contacts the diaphragm member to 5 MPa or less, even in a high-temperature environment, plastic deformation, damage, and dust generation of the valve body and the diaphragm member can be prevented.

[0027] (4) The adjuster according to any one of (1) to (3), wherein the second radius is preferably a value obtained by subtracting 3 to 4% of the first radius from the first radius. Thus, it is possible to ensure a reduction in the stress generated at the contact surface between the valve body and the diaphragm member. For example, if the second radius is set to a value greater than the value obtained by subtracting 2% of the first radius from the first radius, the degree of freedom of the valve body shaft portion in the receiving portion of the diaphragm member becomes small. Assuming that the valve body tilts during the opening and closing operation, the tilt cannot be absorbed, resulting in the possibility of generating excessive stress at the above contact surface. On the other hand, if the second radius is set to a value significantly less than the value obtained by subtracting 4% of the first radius from the first radius, the valve body shaft portion will not sufficiently abut against the receiving portion of the diaphragm member, leading to the possibility of the central axis of the shaft portion shifting. Therefore, as described above, the second radius is preferably a value obtained by subtracting 3 to 4% of the first radius from the first radius.

[0028] In addition, for the above adjuster, the entire front end surface of the shaft portion may be a convex spherical surface, but it is also possible (5) The adjuster according to (1), wherein the receiving portion has, on the periphery of the concave spherical surface, a concave curved surface formed with a radius smaller than the first radius and tangent to the concave spherical surface; the front end surface has, on the periphery of the convex spherical surface and at a portion opposite to the concave curved surface, a convex curved surface formed with a radius smaller than the second radius and tangent to the convex spherical surface. Further, it is also possible in (6) The adjuster according to (1), wherein the receiving portion has a first flat surface on the tangent line of the concave spherical surface on the periphery of the concave spherical surface; the front end surface has a second flat surface on the tangent line of the convex spherical surface on the periphery of the convex spherical surface and at a portion opposite to the first flat surface.

[0029] (7) The adjuster according to any one of (1) to (6), wherein the receiving portion has a cylindrical wall facing the outer peripheral surface of the shaft portion, and there is a gap between the cylindrical wall and the outer peripheral surface of the shaft portion, and the size of the gap is preferably 3 to 5% of the diameter of the shaft portion.

[0030] According to the adjuster described in (7), since the receiving portion has a cylindrical wall facing the outer peripheral surface of the shaft portion, the cylindrical wall can ensure preventing the axis of the shaft portion from shifting.

[0031] Furthermore, if the shaft portion is pressed against the receiving portion by the biasing force of the biasing device, the shaft portion will be compressed, which may cause the shaft portion to deform in the direction of increasing diameter. However, according to the adjuster described in (7), since there is a gap between the cylindrical wall and the outer peripheral surface of the shaft portion, even if the diameter of the shaft portion is compressed and thickened, interference between the cylindrical wall and the shaft portion can be prevented. By preventing interference, dust generation due to friction between the shaft portion and the cylindrical wall can be prevented. Here, the size of the gap is preferably 3 to 5% of the diameter of the shaft portion. The reason is that if the size of the gap is greater than 5% of the diameter of the shaft portion, it is impossible to ensure prevention of the offset of the central axis of the shaft portion. If it is less than 3% of the diameter of the shaft portion, there is still a possibility of interfering with the cylindrical wall even when the shaft portion is compressed and thickened. In addition, the so-called "gap" here is obtained by subtracting the diameter of the shaft portion from the diameter of the cylindrical wall and dividing the result by 2 assuming that the shaft portion and the cylindrical wall are coaxial.

[0032] (8) In the adjuster described in any one of (1) to (7), preferably, a non-contact portion that does not contact the concave spherical surface is provided coaxially with the shaft portion at the vertex portion of the convex spherical surface; the diameter of the non-contact portion does not exceed 1 / 20 of the diameter of the shaft portion.

[0033] The convex spherical surface can be formed by cutting or injection molding. When formed by cutting, the machining speed at the vertex portion of the convex spherical surface becomes zero, and there is a possibility of generating burrs. If it contacts the concave spherical surface in a state with burrs, it may become a cause of dust generation. Therefore, in the adjuster described in (7), by previously setting the vertex portion of the convex spherical surface as a non-contact portion, dust generation can be prevented. In addition, when the convex spherical surface is formed by injection molding, if the gate is located on the surface of the convex spherical surface, there is a possibility that the effect of suppressing the stress and sliding amount generated at the contact surface cannot be fully obtained when the valve body contacts the diaphragm member. Here, in the adjuster described in (7), by setting the vertex portion of the convex spherical surface as a non-contact portion, a gate can be provided at the non-contact portion without affecting the above effect. However, the diameter of the non-contact portion is preferably not more than 1 / 20 of the diameter of the shaft portion. The reason is that if the diameter of the non-contact portion exceeds 1 / 20 of the diameter of the shaft portion, the surface area of the convex spherical surface will be relatively narrow, and the above effect of suppressing stress and sliding amount cannot be fully obtained. [Advantages of the Invention]

[0034] According to the adjuster of the present invention, dust generation at the contact portion between the valve body and the diaphragm member can be prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a cross-sectional view of the adjuster; Figure 2 is Figure 1 a partially enlarged view of part A of Figure 3 is Figure 2Partial enlarged view of part B; Figure 4 It is a result diagram of performing finite element method analysis on the stress generated at the contact surface between the valve body and the diaphragm member in the first embodiment; Figure 5 It is a result diagram of performing finite element method analysis on the sliding of the front end face of the shaft portion in the first embodiment; Figure 6 It is a result diagram of performing finite element method analysis on the stress generated at the contact surface between the valve body and the diaphragm member for the first comparison object; Figure 7 It is a result diagram of performing finite element method analysis on the sliding of the front end face of the shaft portion for the first comparison object; Figure 8 It is a result diagram of performing finite element method analysis on the stress generated at the contact surface between the valve body and the diaphragm member for the second comparison object; Figure 9 It is a result diagram of performing finite element method analysis on the sliding of the front end face of the shaft portion for the second comparison object; Figure 10 It is a result diagram of performing finite element method analysis on the stress generated at the contact surface between the valve body and the diaphragm member for the third comparison object; Figure 11 It is a result diagram of performing finite element method analysis on the sliding of the front end face of the shaft portion for the third comparison object; Figure 12 It is a result diagram of performing finite element method analysis on the stress generated at the contact surface between the valve body and the diaphragm member for the fourth comparison object; Figure 13 It is a result diagram of performing finite element method analysis on the sliding of the front end face of the shaft portion for the fourth comparison object; Figure 14 It is a comparison diagram of the maximum stress value using finite element method analysis; Figure 15 It is a comparison diagram of the sliding amount range using finite element method analysis; Figure 16 It is an enlarged view of the contact portion between the valve body and the diaphragm member in the second embodiment, corresponding to Figure 2 the figure; Figure 17 It is Figure 16 Partial enlarged view of part C; Figure 18 It is a result diagram of performing finite element method analysis on the stress generated at the contact surface between the valve body and the diaphragm member in the second embodiment; Figure 19 It is a result diagram of performing finite element method analysis on the sliding of the front end face of the shaft portion in the second embodiment; Figure 20 is an enlarged view of the contact portion between the valve body and the diaphragm member of the third embodiment, corresponding to Figure 2 the figure; Figure 21 is the result diagram of the finite element method analysis performed on the stress generated on the contact surface between the valve body and the diaphragm member in the third embodiment; Figure 22 is the result diagram of the finite element method analysis performed on the sliding of the front end surface of the shaft portion in the third embodiment; Figure 23 is an enlarged view of the contact portion between the valve body and the diaphragm member of the third embodiment, corresponding to Figure 2 the figure; Figure 24 is the result diagram of the finite element method analysis performed on the stress generated on the contact surface between the valve body and the diaphragm member in the fourth embodiment; Figure 25 is the result diagram of the finite element method analysis performed on the sliding of the front end surface of the shaft portion in the fourth embodiment; Figure 26 is the comparison diagram of the maximum stress values analyzed by the finite element method for each embodiment; Figure 27 is the comparison diagram of the sliding amount ranges analyzed by the finite element method for each embodiment; Figure 28 is a cross-sectional view of the prior art regulator; Figure 29 is the result diagram of the finite element method analysis performed on the stress generated on the contact surface between the valve body and the diaphragm member in the prior art; Figure 30 is the result diagram of the finite element method analysis performed on the sliding of the front end surface of the shaft portion in the prior art; Figure 31 is the explanatory diagram of the forces acting on the valve body and the diaphragm member when the valve body and the diaphragm member are in contact in the first embodiment; and Figure 32 is the explanatory diagram of the forces acting on the valve body and the diaphragm member when the valve body and the diaphragm member are in contact in the prior art. Embodiments of the Invention

[0036] Embodiments of the regulator of the present invention will be described in detail with reference to the drawings. Figure 1 A cross-sectional view of the regulator 1 is shown. Additionally, Figure 1 the up and down directions in

[0037] (Regarding the configuration of the regulator) The regulator 1 of the present embodiment is a pressure control machine that performs pressure control on liquids such as chemical solutions and pure water (hereinafter referred to as "control fluids") used in semiconductor manufacturing steps (such as film formation processing of wafers).

[0038] The regulator 1 is as shown in Figure 1 and includes: a valve body 11, an upper cover 12, and a lower cover 13. The upper cover 12 and the lower cover 13 are assembled to the valve body 11 in a manner of sandwiching the valve body 11 in sequence from the up-and-down direction in the figure (the same direction as the opening and closing direction of the valve body 14 described later). In addition, since the valve body 11 is a liquid contact member through which the control fluid flows internally, it is formed of a fluorine-based synthetic resin with high corrosion resistance. On the other hand, the upper cover 12 and the lower cover 13, which are not liquid contact members, are formed of, for example, polypropylene resin.

[0039] The valve body 11 is formed with: an input port 111 for inputting the control fluid, and an output port 112 for outputting the control fluid. The input port 111 is connected to a supply source of the control fluid (not shown), and the control fluid is input into the regulator 1 from the supply source. The output port 112 is connected to, for example, a nozzle (not shown), and the control fluid output from the regulator 1 is dripped onto a wafer or the like.

[0040] In the valve body 11, an upstream end fluid chamber 113 is formed through the end face on the side of the valve body 11 close to the lower cover 13 ( Figure 1 the lower end face in ) upward through the upper cover 12. The upstream end fluid chamber 113 forms a space in an approximately conical trapezoid shape. The upstream end fluid chamber 113 is communicated with the input port 111 through the input flow path 111a. In addition, a valve hole 114 is formed through the inner surface 113a on the side of the upstream end fluid chamber 113 close to the upper cover 12. The valve hole 114 is coaxial with the upstream end fluid chamber 113. An annular valve seat 115 protrudes along the periphery of the valve hole 114 on the inner surface 113a of the upstream end fluid chamber 113. The front end of the annular valve seat 115 is flat and forms a contact surface for abutting a valve body 14 described later.

[0041] In addition, in the valve body 11, from the end face on the side of the valve body 11 close to the upper cover 12 ( Figure 1The upper end surface thereof) faces downward to one side of the lower cover 13, and an opening 116 of an approximately cylindrical space is formed therethrough. The opening 116 is coaxially arranged with the upstream end fluid chamber 113 and the valve hole 114. In addition, the opening 116 is partitioned into two chambers in the opening and closing direction by a diaphragm member 15 described later. That is, it is partitioned into a downstream end fluid chamber 116a and a pressure acting chamber 116b. The downstream end fluid chamber 116a communicates with the upstream end fluid chamber 113 through the valve hole 114. In addition, the downstream end fluid chamber 116a communicates with the output port 112 through the output flow path 112a. Therefore, the valve body 11 forms a series of flow paths from the input port 111 to the output port 112 by means of the input flow path 111a, the upstream end fluid chamber 113, the valve hole 114, the downstream end fluid chamber 116a, and the output flow path 112a.

[0042] An approximately cylindrical valve body 14 that can reciprocate in the opening and closing direction is received in the upstream end fluid chamber 113. Since the valve body 14 is a liquid contact member, it is formed of a highly corrosion-resistant material such as a fluorine-based synthetic resin (PTFE, PFA).

[0043] A diameter-expanded portion 141 with a larger diameter at the central portion in the axial direction is formed in the valve body 14. The end surface of the diameter-expanded portion 141 facing the valve seat 115a is an abutting surface that abuts against the annular valve seat 115. Therefore, when the regulator 1 is in the closed valve state, the valve body 14 and the annular valve seat 115 are abutted against each other in a plane. Accordingly, if the abutting surface of the valve body 14 abuts against the annular valve seat 115, the flow path from the input port 111 to the output port 112 is blocked. On the other hand, if the abutting surface is away from the valve seat 115a, the flow path from the input port 111 to the output port 112 is in a communicating state.

[0044] Furthermore, an end portion of the valve body 14 on the side close to the lower cover 13 is provided with a film portion 142 integrally formed with the valve body 14 and a fixing portion 143 formed around the film portion 142. The fixing portion 143 is clamped by the valve body 11 and the lower cover 13, so the valve body 14 is fixed coaxially with the upstream end fluid chamber 113. The film portion 142 can be elastically deformed as the valve body 14 reciprocates in the opening and closing direction.

[0045] The valve body 14 is provided with a shaft portion 145 protruding from the diameter-expanded portion 141 toward the upper cover 12. The shaft portion 145 extends through the valve hole 114 to the downstream end fluid chamber 116a. The front end portion of the shaft portion 145 is detachably and loosely fitted to the diaphragm member 15. The diaphragm member 15 is formed in an approximately disc shape. In addition, since the diaphragm member 15 is a liquid contact member, it is formed of a highly corrosion-resistant material such as a fluorine-based synthetic resin.

[0046] The diaphragm member 15 is composed of a central portion 151, a thin film portion 152 formed around the central portion 151, and an annular fixing portion 153 formed around the thin film portion 152. A receiving portion 151a is provided through the center of the end face of the central portion 151 on the side close to the valve body 14. The receiving portion 151a is designed to be coaxially aligned with the shaft portion 145 of the valve body 14, and the front end portion of the shaft portion 145 is loosely fitted therein. The so-called "loose fitting" means that when the valve body 14 moves in the closing direction (the upward direction in the figure), it is positioned so that the central axis position does not shift, but it can move away when a force is applied in the direction away from the diaphragm member 15 and the valve body 14.

[0047] The fixing portion 153 of the diaphragm member 15 is clamped between the upper cover 12 and the valve body 11, so the diaphragm member 15 is fixed. By this fixation, the central portion 151 can reciprocate in the opening and closing directions together with the valve body 14 while elastically deforming the thin film portion 152. An O-ring 19 is provided between the fixing portion 153 and the upper cover 12 to keep the pressure acting chamber 116b airtight.

[0048] An inlet 121 communicating with the pressure acting chamber 116b is formed in the upper cover 12, so that pneumatic air can be supplied to the pressure acting chamber 116b via the inlet 121. Then, in accordance with the pressure of the pneumatic air supplied to the pressure acting chamber 116b, the position of the central portion 151 of the diaphragm member 15 in the opening and closing directions is changed. When the central portion 151 moves in the opening direction ( Figure 1 the downward direction in the figure), as the central portion 151 moves, the valve body 14 is pushed downward in the opening direction to be in the valve open state.

[0049] A spring receiving chamber 131 in the shape of an approximate cylinder is formed coaxially with the valve body 14 in the lower cover 13. The spring receiving chamber 131 is sandwiched between the thin film portion 142 of the valve body 14 and is located on the opposite side of the upstream end fluid chamber 113. A compression coil spring 16 is housed in the spring receiving chamber 131.

[0050] Furthermore, a concave guide portion 132 is provided coaxially with the valve body 14 in the spring receiving chamber 131. A support member 17 that supports the valve body 14 from the lower cover 13 is inserted into the guide portion 132. The compression coil spring 16 abuts against a flange portion 171 provided on the outer peripheral surface of the support member 17 protruding. Therefore, the support member 17 is biased toward the valve body 11 side (the upper direction in the figure).

[0051] Furthermore, the support member 17 is inserted into the lower end portion of the valve body 14 in a groove 172 formed through the upper end surface of the valve body 14, thus supporting the valve body 14. Since the support member 17 is biased upward by a compression coil spring 16, the valve body 14 supported by the support member 17 is also biased upward. That is, the valve body 14 is biased in the closing direction toward the annular valve seat 115. Then, when the valve body 14 moves in the opening direction, it moves against the biasing force of the compression coil spring 16. That is, the position adjustment of the valve body 14 is performed by balancing the pressure of the pneumatic air supplied to the pressure application chamber 116b and the biasing force of the compression coil spring 16. The so-called "position adjustment of the valve body 14" refers to adjusting the distance between the valve body 14 and the annular valve seat 115 (opening adjustment).

[0052] Furthermore, a sliding portion 173 inserted into the guide portion 132 is provided at an end portion (the lower end portion in the figure) of the support member 17 on the side facing the valve body 14. The abutting / separating movement of the valve body 14 against the annular valve seat 115 is guided by the guide portion 132 with the sliding portion 173 inserted therein.

[0053] Next, regarding the loose fitting portion between the shaft portion 145 of the valve body 14 and the diaphragm member 15, use Figure 2 and Figure 3 will be described in more detail. Figure 2 Shown is Figure 1 a partially enlarged view of portion A of Figure 3 Shown is Figure 2 a partially enlarged view of portion B of

[0054] As described above, the diaphragm member 15 (central portion 151) has a receiving portion 151a for receiving the front end surface of the shaft portion 145 of the valve body 14. The receiving portion 151a has a hole-blocking shape and is in a state of being abutted by the front end surface of the shaft portion 145. Therefore, the portion of the receiving portion 151a abutted by the front end surface of the shaft portion 145 is provided as a concave spherical surface 151b. The center position CP11 of the concave spherical surface 151b is designed to be located on the central axis CL11 of the shaft portion 145. In addition, the radius SR11 (first radius) of the concave spherical surface 151b is preferably not less than a value obtained by subtracting 20% of the diameter D11 of the shaft portion 145 from the diameter D11 value, and not more than a value obtained by adding 20% of the diameter D11 of the shaft portion 145 to the diameter D11 value, more preferably not less than a value obtained by subtracting 10% of the diameter D11 of the shaft portion 145 from the diameter D11 value, and not more than a value obtained by adding 10% of the diameter D11 of the shaft portion 145 to the diameter D11 value. In this embodiment, the diameter D11 of the shaft portion 145 is set to 4 mm, and the radius SR11 is set to 4 mm, the same as the diameter. In addition, the numerical values listed here are merely examples for reference only.

[0055] Furthermore, outside the concave spherical surface 151b in the receiving portion 151a, a cylindrical wall 151c facing the outer peripheral surface of the shaft portion 145 is formed. The diameter D12 of the cylindrical wall 151c is set such that the gap C11 between the cylindrical wall 151c and the outer peripheral surface of the shaft portion 145 becomes a predetermined size. That is, the size of the gap C11 is set to 3 to 5% of the diameter D11 of the shaft portion 145. In the present embodiment, since the diameter of the shaft portion 145 is set to 4 mm, it is preferable to set the gap C11 to 0.12 to 0.2 mm. In addition, the so-called "gap C11" here is the value obtained by subtracting the diameter D11 of the shaft portion 145 from the diameter D12 of the cylindrical wall 151c and then dividing by 2 assuming that the shaft portion 145 and the cylindrical wall 151c are coaxial.

[0056] In the shaft portion 145 loosely fitted in the receiving portion 151a as described above, a convex spherical surface 144 is provided on the front end surface facing the concave spherical surface 151b. The center position of the convex spherical surface 144 is designed to be the same as the center position CP11 of the concave spherical surface 151b in a state where the convex spherical surface 144 is in contact with the concave spherical surface 151b. In addition, the radius SR12 (second radius) of the convex spherical surface 144 is preferably a value obtained by subtracting 2 to 5% of the radius SR11 from the radius SR11 of the concave spherical surface 151b, and more preferably a value obtained by subtracting 3 to 4% of the radius SR11 from the radius SR11. In the present embodiment, the radius SR11 of the concave spherical surface 151b is set to 4 mm, and the radius SR12 of the convex spherical surface 144 is set to 3.85 mm. In addition, the values listed here are merely examples.

[0057] Furthermore, as Figure 3 shown, a counterbore 146 is drilled coaxially with the shaft portion 145 on the front end surface of the shaft portion 145. By drilling the counterbore 146, a non-contact portion 147 that is not in contact with the concave spherical surface 151b is formed in the vertex portion of the convex spherical surface 144 by an amount corresponding to the diameter D13 of the counterbore 146. The diameter D13 of the counterbore 146 (that is, the diameter of the non-contact portion 147) is preferably not more than 1 / 20 of the diameter D11 of the shaft portion 145. In the present embodiment, the diameter D11 of the shaft portion 145 is set to 4 mm, and the diameter D13 is set to 0.2 mm. In addition, the values listed here are merely examples. In addition, Figure 3 the size of the diameter D13 of the counterbore 146 in

[0058] (Regarding the function and effect of the adjuster) The adjuster 1 can stabilize the control fluid pressure output from the output port 112 by adjusting the pressure of the pneumatic air supplied to the pressure application chamber 116b.

[0059] If pneumatic air at any pressure is supplied to the regulator 1 to make the pressure in the pressure application chamber 116b positive, the regulator 1 is in an open valve state. Accordingly, a control fluid is output from the regulator 1. In this case, for example, if the amount of the control fluid used is increased by using a nozzle at the downstream end of the regulator 1, the pressure in the downstream fluid chamber 116a decreases. If the pressure in the downstream fluid chamber 116a is less than the pneumatic air pressure supplied to the pressure application chamber 116b, the film portion 152 of the diaphragm member 15 deforms toward the side of the downstream fluid chamber 116a. Then, the diaphragm member 15 moves to a position where the pressure in the downstream fluid chamber 116a, the biasing force of the compression coil spring 16, and the pressure in the pressure application chamber 116b are balanced. Along with this, the opening degree of the valve body 14 becomes larger. On the other hand, if the amount of the control fluid used is decreased by using a nozzle at the downstream end of the regulator 1, the pressure in the downstream fluid chamber 116a increases. If the pressure in the downstream fluid chamber 116a is greater than the pneumatic air pressure supplied to the pressure application chamber 116b, the film portion 152 of the diaphragm member 15 deforms toward the side of the pressure application chamber 116b. Then, the diaphragm member 15 moves to a position where the pressure in the downstream fluid chamber 116a, the biasing force of the compression coil spring 16, and the pressure in the pressure application chamber 116b are balanced. Along with this, the opening degree of the valve body 14 becomes smaller.

[0060] Accordingly, in accordance with the pressure balance among the pneumatic air pressure supplied to the pressure application chamber 116b, the pressure in the downstream fluid chamber 116a, and the biasing force of the compression coil spring 16, the diaphragm member 15 elastically deforms the film portion 152 while changing its position in the opening / closing direction. Therefore, by adjusting the position of the valve body 14 in the opening / closing direction, the pressure of the control fluid output from the output port 112 can be stabilized. In addition, if the supply of the pneumatic air to the pressure application chamber 116b is stopped, the valve body 14 is moved to a position where it abuts against the annular valve seat 115 by the biasing force of the compression coil spring 16, and the flow of the control fluid is blocked.

[0061] Furthermore, since the shaft portion 145 of the valve body 14 is loosely fitted in a separable manner to the receiving portion 151a of the diaphragm member 15, excessive interference between the valve body 14 and the annular valve seat 115 can be prevented.

[0062] To explain in detail, for example, if the regulator 1 receives a back pressure from the end of the output port 112 and the pressure in the downstream fluid chamber 116a rapidly increases, the diaphragm member 15 is pushed upward (i.e., in the closing direction) in Figure 1 . At this time, if the valve body 14 and the diaphragm member 15 are connected in an inseparable state, as the diaphragm member 15 is pushed upward in the closing direction, the valve body 14 also moves in the closing direction, which may cause excessive interference with the annular valve seat 115. Since the excessive interference between the valve body 14 and the annular valve seat 115 causes dust due to wear and the like, this is not preferable.

[0063] However, in the adjuster 1 of the present embodiment, since the shaft portion 145 of the valve body 14 is detachably and loosely fitted into the receiving portion 151a of the diaphragm member 15, even if the pressure in the downstream end fluid chamber 116a rapidly increases, causing the diaphragm member 15 to be pushed upward in the closing direction, the diaphragm member 15 will separate from the valve body 14 and move independently in the closing direction. Therefore, the valve body 14 will not move in the closing direction, so excessive interference with the annular valve seat 115 can be prevented.

[0064] If the shaft portion 145 of the valve body 14 is detachably and loosely fitted into the receiving portion 151a of the diaphragm member 15, there is a possibility that the front end face of the shaft portion 145 and the receiving portion 151a will repeatedly come into contact with and move away from each other. However, since a convex spherical surface 144 is provided on the front end face of the shaft portion 145 and a concave spherical surface 151b is provided in the receiving portion 151a, excessive stress can be prevented from being generated on the contact surface between the convex spherical surface 144 and the concave spherical surface 151b, and sliding can be prevented from occurring on the front end face of the shaft portion 145. Therefore, even if the front end face of the shaft portion 145 and the receiving portion 151a repeatedly come into contact with and move away from each other, dust generation can be prevented.

[0065] First, the results of a finite element method analysis of the stress generated on the contact surface (the contact surface between the convex spherical surface 144 and the concave spherical surface 151b) between the valve body 14 and the diaphragm member 15 will be described. Figure 4 Shown is the result diagram of a finite element method analysis of the stress generated on the contact surface (the contact surface between the convex spherical surface 144 and the concave spherical surface 151b) between the valve body 14 and the diaphragm member 15 in the first embodiment.

[0066] Furthermore, in order to compare with the results of the above finite element method analysis, the finite element method analysis was performed by changing the radius SR11 of the concave spherical surface 151b and the radius SR12 of the convex spherical surface 144.

[0067] The first comparison object was to set the radius SR11 of the concave spherical surface 151b to 3 mm and the radius SR12 of the convex spherical surface 144 to 2.9 mm, and perform a finite element method analysis. Figure 6 Shown is the result diagram of a finite element method analysis of the stress generated on the contact surface between the valve body 14 and the diaphragm member 15 for the first comparison object.

[0068] Furthermore, the second comparison object was to set the radius SR11 of the concave spherical surface 151b to 5 mm and the radius SR12 of the convex spherical surface 144 to 4.82 mm, and perform a finite element method analysis. Figure 8 Shown is the result diagram of a finite element method analysis of the stress generated on the contact surface between the valve body 14 and the diaphragm member 15 for the second comparison object.

[0069] Furthermore, for the third comparison object, the radius SR11 of the concave spherical surface 151b was set to 6 mm, and the radius SR12 of the convex spherical surface 144 was set to 5.80 mm, and a finite element method analysis was performed. Figure 10 Shown is the third comparison object, which is a result diagram of performing a finite element method analysis on the stress generated on the contact surface between the valve body 14 and the diaphragm member 15.

[0070] Furthermore, for the fourth comparison object, it was assumed that the valve body 14 and the diaphragm member 15 were in contact with each other on a flat surface, and a finite element method analysis was performed. Figure 12 Shown is the fourth comparison object, which is a result diagram of performing a finite element method analysis on the stress generated on the contact surface between the valve body 14 and the diaphragm member 15.

[0071] In these analyses, it was assumed that the materials of the valve body 14 and the diaphragm member 15 were both PTFE, and in a state where the convex spherical surface 144 was pressed against the concave spherical surface 151b by the biasing force of the compression coil spring 16. Moreover, the value of the generated stress was represented by the length and the depth of color of the colored bar. That is, the longer the length of the colored bar, the greater the generated stress, and the darker the color of the colored bar, the greater the generated stress.

[0072] Hereinafter, the results of the analysis will be described. In the present embodiment, as Figure 4 shown, the stress increases near the center axis CL11 and near the periphery of the convex spherical surface 144. In particular, the maximum stress is generated near the periphery of the convex spherical surface, and the value is 4.48 Mpa.

[0073] For the first comparison object, as Figure 6 shown, the maximum stress is generated near the center axis CL11, but as the distance from the center axis CL11 increases, the stress gradually decreases. The maximum stress value is 7.28 Mpa.

[0074] For the second comparison object, as Figure 8 shown, the stress increases near the center axis CL11 and near the periphery of the convex spherical surface 144. In particular, the maximum stress is generated near the periphery of the convex spherical surface, and the value is 7.64 Mpa.

[0075] For the third comparison object, as Figure 10 shown, the stress increases near the center axis CL11 and near the periphery of the convex spherical surface 144. In particular, the maximum stress is generated near the periphery of the convex spherical surface, and the value is 8.27 Mpa.

[0076] For the fourth comparison object, as Figure 12 shown, as the distance from the center axis CL11 increases, the stress gradually rises, and the maximum stress is generated at the peripheral portion of the convex spherical surface 144. The maximum stress value is 12.12 Mpa.

[0077] Next, the results of the finite element method analysis for the sliding of the front end surface of the shaft portion 145 when the valve body 14 contacts the diaphragm member 15 (the convex spherical surface 144 contacts the concave spherical surface 151b) will be described. This analysis is the same as the above stress analysis. Assuming that the materials of the valve body 14 and the diaphragm member 15 are both PTFE, the biasing force of the compression coil spring 16 is used to make the front end surface of the shaft portion 145 press against the receiving portion 151a of the diaphragm member 15.

[0078] Figure 5 Shown is the result diagram of the finite element method analysis for the sliding of the front end surface of the shaft portion 145 in the first embodiment. In addition, the finite element method analysis is similarly performed for the above first to fourth comparison objects. Figure 7 Shown is the result diagram of the finite element method analysis for the sliding of the front end surface of the shaft portion 145 in the first comparison object. Figure 9 Shown is the result diagram of the finite element method analysis for the sliding of the front end surface of the shaft portion 145 in the second comparison object. Figure 11 Shown is the result diagram of the finite element method analysis for the sliding of the front end surface of the shaft portion 145 in the third comparison object. Figure 13 Shown is the result diagram of the finite element method analysis for the sliding of the front end surface of the shaft portion 145 in the fourth comparison object. These analysis results are represented by the length and color depth of the colored bar to indicate the amount of sliding generated. That is, the longer the length of the colored bar, the greater the amount of sliding, and the darker the color of the colored bar, the greater the amount of sliding. In addition, the extending direction of the colored bar indicates the sliding direction. Specifically, the place where the colored bar extends toward the end of the shaft portion 145 indicates the generation of sliding toward the end of the central axis CL11 (inward sliding), and the place where the colored bar extends toward the end of the central portion 151 indicates the generation of sliding toward the opposite end of the central axis CL11 (outward sliding). In addition, the following will describe that the inward sliding amount is set as a positive value and the outward sliding amount is set as a negative value, but the magnitude of the sliding amount is judged using the absolute value. That is, for example, when comparing a sliding amount of 0.3 μm and a sliding amount of -0.5 μm, the sliding amount of -0.5 μm is judged as the larger sliding amount.

[0079] Next, the analysis results will be described. In this embodiment, as Figure 5 shown, the outward sliding, inward sliding, outward sliding, and inward sliding from the end of the central axis CL11 are alternately distributed, and as the distance from the central axis CL11 increases, the sliding amount gradually becomes larger. The range of the generated sliding amount is -0.052 to 0.094 μm, and an inward sliding is generated on average.

[0080] The first comparison object is as Figure 7As shown, the whole produces an inward sliding. The sliding amount gradually increases as it moves away from the central axis CL11, and reaches the maximum value at a position closer to the outer periphery than the middle position between the central axis CL11 and the outer periphery. Then, for the part exceeding this maximum value, the sliding amount gradually decreases as it moves towards the outer periphery. The range of the generated sliding amount is 0 to 0.7 μm.

[0081] The second comparison object is as Figure 9 shown. The whole produces an outward sliding. The sliding amount gradually increases as it moves away from the central axis CL11, and reaches the maximum value near the middle position between the central axis CL11 and the outer periphery of the shaft portion 145. Then, for the part exceeding this maximum value, the sliding amount gradually decreases as it moves towards the outer periphery. The range of the generated sliding amount is -0.33 to 0 μm.

[0082] The third comparison object is as Figure 11 shown. The whole produces an outward sliding. The sliding amount gradually increases as it moves away from the central axis CL11, and reaches the maximum value at a position closer to the outer periphery than the middle position between the central axis CL11 and the outer periphery. Then, for the part exceeding this maximum value, the sliding amount gradually decreases as it moves towards the outer periphery. The range of the generated sliding amount is -0.86 to 0 μm.

[0083] The fourth comparison object is as Figure 13 shown. The whole produces an outward sliding. The sliding amount gradually increases as it moves away from the central axis CL11, and reaches the maximum value near the outer peripheral part. The range of the generated sliding amount is -5.76 to 0 μm.

[0084] Arranging the above analysis results, as Figure 14 shown in Figure 15 . Figure 14 Shown is a comparison graph of the maximum stress values obtained by finite element method analysis. The vertical axis represents the maximum stress value, and the horizontal axis represents the radius SR11 value of the concave spherical surface 151b.

[0085] When the value of the concave spherical surface SR is 2 mm, it represents the analysis result obtained by using the prior art adjuster 50 (refer to Figure 28 ). The maximum stress value generated at the contact area between the front end face 512 (convex spherical surface) of the shaft portion 511 and the receiving portion 571 (concave spherical surface) of the diaphragm member 57 of the adjuster 50 is 10.92 MPa.

[0086] When the value of the concave spherical surface SR is 3 mm, it represents the analysis result obtained by using the first comparison object. The maximum stress value is 7.28 Mpa, which is about 67% of that of the prior art adjuster 50.

[0087] When the value of the concave spherical surface SR is 4 mm, it represents the analysis result obtained by using the present embodiment. The maximum stress value is 4.48 Mpa, which is less than about half of that of the prior art adjuster 50.

[0088] The value of the concave spherical surface SR being 5 mm represents the analysis result using the second comparison object. The maximum stress value is 7.64 Mpa, which is about 70% of that of the prior art adjuster 50.

[0089] The value of the concave spherical surface SR being 6 mm represents the analysis result using the third comparison object. The maximum stress value is 8.27 Mpa, which is about 76% of that of the prior art adjuster 50.

[0090] The value of the concave spherical surface SR being ∞ represents the meaning of flatness, which is the analysis result using the fourth comparison object. The maximum stress value is 12.12 Mpa, which is higher than that of the prior art adjuster 50.

[0091] Figure 15 Shown is a comparison graph of the sliding amount range analyzed using the finite element method. The vertical axis represents the sliding amount, and the horizontal axis represents the radius SR11 value of the concave spherical surface 151b.

[0092] The value of the concave spherical surface SR being 2 mm represents the analysis result using the prior art adjuster 50 (refer to Figure 28 ). The range of the sliding amount generated on the front end face of the shaft portion 511 is 0 - 2.9 μm, and an inward sliding is generated.

[0093] The value of the concave spherical surface SR being 3 mm represents the analysis result using the first comparison object. The range of the sliding amount generated on the front end face of the shaft portion 145 is 0 - 0.7 μm, and an inward sliding is generated. In addition, when comparing the magnitudes of the sliding amounts based on the maximum value, it is about 24% of the existing one.

[0094] The value of the concave spherical surface SR being 4 mm represents the analysis result using this embodiment. The range of the sliding amount generated on the front end face of the shaft portion 145 is -0.052 - 0.094 μm, and an inward sliding is generated on average. In addition, when comparing the magnitudes of the sliding amounts based on the maximum value, it is about 3% of the existing one.

[0095] The value of the concave spherical surface SR being 5 mm represents the analysis result using the second comparison object. The range of the sliding amount generated on the front end face of the shaft portion 145 is -0.33 - 0 μm, and an outward sliding is generated. In addition, when comparing the magnitudes of the sliding amounts based on the maximum value, it is about 11% of the existing one.

[0096] The value of the concave spherical surface SR being 6 mm represents the analysis result using the third comparison object. The range of the sliding amount generated on the front end face of the shaft portion 145 is -0.86 - 0 μm, and an outward sliding is generated. In addition, when comparing the magnitudes of the sliding amounts based on the maximum value, it is about 30% of the existing one.

[0097] When the value of the concave spherical surface SR is ∞, it means flatness, which is the analysis result using the fourth comparison object. The range of the sliding amount generated on the front end surface of the shaft portion 145 is -5.76 to 0 μm, and an outward sliding is generated. In addition, when comparing the magnitudes of the sliding amounts based on the maximum value, it is greater than the existing one.

[0098] Based on the above analysis results, considering that the compressive strength of the PTFE material of the valve body 14 and the diaphragm member 15 is about 10 Mpa, the radius SR11 of the concave spherical surface 151b is 3 to 5 mm, because the maximum stress value is less than 10 Mpa, so it is better. In addition, considering the tolerance, the radius SR11 is preferably a value greater than the value obtained by subtracting 20% of the diameter D11 of the shaft portion 145 from the diameter D11 of the shaft portion 145 and less than the value obtained by adding 20% of the diameter D11 of the shaft portion 145 to the diameter D11 of the shaft portion 145. In addition, when the radius SR11 of the concave spherical surface 151b is 6 mm, if only comparing the maximum stress values, there is not much difference between when the radius SR11 is 3 mm and 5 mm, but in terms of the larger outward sliding amount generated on the front end surface of the shaft portion 145, it is not better. The reason is that the inward sliding has an aligning effect on the axis of the shaft portion 145, and relatively, the outward sliding may cause the axis of the shaft portion 145 to deviate.

[0099] Furthermore, since it can be considered that the compressive strength of PTFE is about 5 MPa in a high-temperature environment (for example, the temperature of the control fluid is 90 °C), considering this phenomenon, the radius SR11 of the concave spherical surface 151b is preferably the same as the diameter D11 of the shaft portion 145, which is also 4 mm. In addition, considering the tolerance, the radius SR11 is preferably a value greater than the value obtained by subtracting 10% of the diameter D11 of the shaft portion 145 from the diameter D11 of the shaft portion 145 and less than the value obtained by adding 10% of the diameter D11 of the shaft portion 145 to the diameter D11 of the shaft portion 145.

[0100] The mechanism for reducing the sliding amount can be considered as follows. Figure 31 Shown is the first embodiment, which is an explanatory diagram of the forces acting on the valve body 14 and the diaphragm member 15 when they are in contact. Figure 32 Shown is the prior art, which is an explanatory diagram of the forces acting on the valve body 51 and the diaphragm member 57 when they are in contact. In addition, Figure 31 、 Figure 32 Both are shown separately for the valve bodies 14, 51 and the diaphragm members 15, 57 for easy understanding of the explanation.

[0101] A compression coil spring 58 (refer to Figure 28 ) applies a biasing force F31 and a reaction force F32 of the biasing force F31 to the mutually contacting diaphragm member 57 and valve body 51.

[0102] The diaphragm member 57 is subjected to the biasing force F31 of the compression coil spring 58 and its reaction force F32, and a compressive force F33 in the vertical direction is applied. Due to this compressive force F33, a force F34 that tends to expand outward in the radial direction is generated in the diaphragm member 57 with the central axis CL51 as the center. In addition, a reaction force F35 generated by the contact of the shaft portion 511 is generated on the surface of the receiving portion 571 (at a distance X from the central axis CL51), and this reaction force F35 is decomposed to generate a tangential force F36. This force F36 becomes a force that tends to expand the receiving portion 571 outward in the radial direction with the central axis CL51 as the center.

[0103] Furthermore, the shaft portion 511 of the valve body 51 is subjected to the biasing force F31 of the compression coil spring 58 and its reaction force F32, and a compressive force F37 in the vertical direction is applied. Due to this compressive force F37, a force F38 that tends to expand outward in the radial direction is generated in the shaft portion 511 with the central axis CL51 as the center. In addition, a contact force F39 on the receiving portion 571 is generated on the front end surface 512 of the shaft portion 511 (at a distance X from the central axis CL51), and this contact force F39 is decomposed to generate a tangential force F40. This force F40 becomes a force that tends to contract the front end surface 512 of the shaft portion 511 inward in the radial direction with the central axis CL51 as the center.

[0104] As a result of performing a finite element method analysis on the sliding of the front end surface of the shaft portion 511, an inward sliding occurs (refer to Figure 30 ). This phenomenon is considered to be due to the fact that the amount of deformation of the shaft portion 511 inward in the radial direction caused by the force that tends to contract inward in the radial direction is larger than the amount of deformation of the receiving portion 571 and the shaft portion 511 outward in the radial direction caused by the force that tends to expand outward in the radial direction.

[0105] On the other hand, the adjuster 1 of the present embodiment will be described. The compression coil spring 16 (refer to Figure 1 ) biasing force F11 and the reaction force F12 of the biasing force F11 are applied to the diaphragm member 15 and the valve body 14 that are in contact with each other.

[0106] By applying the biasing force F11 of the compression coil spring 16 and its reaction force F12 to the diaphragm member 15, a compressive force F13 in the vertical direction is applied. Using this compressive force F13, a force F14 that tends to expand outward in the radial direction is generated in the diaphragm member 15 with the central axis CL11 as the center. In addition, a reaction force F15 generated by the contact with the shaft portion 145 is generated on the concave spherical surface 151b of the receiving portion 151a (at a distance X from the central axis CL51), and this reaction force F15 is decomposed to generate a tangential force F16. This force F16 becomes a force that tends to expand the receiving portion 151a outward in the radial direction with the central axis CL11 as the center.

[0107] Furthermore, the shaft portion 145 of the valve body 14 is subjected to the biasing force F11 of the compression coil spring 16 and its reaction force F12, and a compressive force F17 in the vertical direction is applied. By means of this compressive force F17, a force F18 is generated in the shaft portion 145 that tends to expand outward in the radial direction about the central axis CL11. In addition, a contact force F19 against the receiving portion 151a is generated on the convex spherical surface 144 (at a distance X from the central axis CL11) on the front end surface of the shaft portion 145, and this contact force F19 is decomposed to generate a tangential force F20. This force F20 becomes a force that tends to contract the convex spherical surface 144 of the shaft portion 145 inward in the radial direction about the central axis CL11.

[0108] As a result of performing a finite element method analysis on the sliding of the front end surface of the shaft portion 145, an inward sliding occurs on average (see Figure 5 ). This phenomenon is considered to be because the amount of deformation of the shaft portion 145 inward in the radial direction caused by the force that tends to contract inward in the radial direction is larger than the amount of deformation of the receiving portion 151a and the shaft portion 145 outward in the radial direction caused by the force that tends to expand outward in the radial direction.

[0109] However, when comparing the magnitudes of the sliding amounts based on the maximum values, it is significantly reduced to about 3% of the existing value. This phenomenon is considered to be due to setting the radius SR11 of the concave spherical surface 151b to be greater than the value obtained by subtracting 20% of the diameter D11 of the shaft portion 145 from the diameter D11 of the shaft portion 145 and less than the value obtained by adding 20% of the diameter D11 of the shaft portion 145 to the diameter D11 of the shaft portion 145, or setting it to be greater than the value obtained by subtracting 10% of the diameter D11 of the shaft portion 145 from the diameter D11 of the shaft portion 145 and less than the value obtained by adding 10% of the diameter D11 of the shaft portion 145 to the diameter D11 of the shaft portion 145, so that the reaction force F15 generated on the concave spherical surface 151b becomes an angle close to perpendicular to the concave spherical surface 151b, thereby reducing the force that tends to expand outward in the radial direction, and because the contact force F19 generated on the convex spherical surface 144 becomes an angle close to perpendicular to the convex spherical surface 144, thereby reducing the force that tends to contract inward in the radial direction. By reducing the force in the radial direction, the amount of deformation in the radial direction can be reduced, and this phenomenon will consequently reduce the sliding amount.

[0110] As described above, the adjuster 1 of the present embodiment has: (1) an upstream end fluid chamber 113 housed in the valve body 14, a downstream end fluid chamber 116a located at the downstream end of the upstream end fluid chamber 113, a valve hole 114 connecting the upstream end fluid chamber 113 and the downstream end fluid chamber 116a, an annular valve seat 115 provided along the periphery of the valve hole 114 and capable of abutting / separating from the valve body 14, and a diaphragm member 15 housed in the downstream end fluid chamber 116a and capable of changing its position in the abutting / separating direction in accordance with the pressure of pneumatic air; and the valve body 14 has a cylindrical shaft portion 145 extending from the upstream end fluid chamber 113 through the valve hole 114 to the downstream end fluid chamber 116a in the abutting / separating direction; the shaft portion 145 is loosely and detachably fitted with a receiving portion 151a of the diaphragm member 15 that receives the front end face; on the opposite side of the valve body 14 facing the diaphragm member 15, a biasing device (such as a compression coil spring 16) that applies a biasing force to the valve body 14 in the direction of abutting against the annular valve seat 115 is provided; the opening degree of the valve body 14 is adjusted by the balance between the pressure of pneumatic air and the biasing force; wherein, the receiving portion 151a is provided with a concave spherical surface 151b centered on the central axis CL11 of the shaft portion 145 and formed by a first radius (radius SR11) at a portion opposite to the front end face; the first radius (radius SR11) is a value equal to or greater than the value obtained by subtracting 20% of the diameter D11 of the shaft portion 145 from the diameter D11; the front end face is provided with a convex spherical surface 144 formed by a second radius (radius SR12) obtained by subtracting 2-5% of the first radius (radius SR11) from the first radius (radius SR11) at a portion opposite to the concave spherical surface 115b.

[0111] According to the above adjuster 1, since the first radius (radius SR11) is a value equal to or greater than the value obtained by subtracting 20% of the diameter D11 of the shaft portion 145 from the diameter D11, the stress generated at the contact surface when the valve body 14 and the diaphragm member 15 are in contact can be suppressed to 10 MPa or less. For example, if the valve body 14 or the diaphragm member 15 is made of PTFE or PFA with high corrosion resistance, the compressive strength of PTFE is about 10 MPa and the compressive strength of PFA is about 15 MPa. Among them, even if PTFE with a lower compressive strength is selected, as described above, the stress generated at the contact surface can still be suppressed to 10 MPa or less, so that plastic deformation, damage, and dust generation of the valve body 14 and the diaphragm member 15 can be prevented.

[0112] Furthermore, according to the above adjuster 1, since the first radius (radius SR11) is a value equal to or greater than the value obtained by subtracting 20% of the diameter D11 of the shaft portion 145 from the diameter D11, when comparing the sliding amount of the shaft portion 145 at the contact surface between the valve body 14 and the diaphragm member 15 according to the maximum value, it can be suppressed to 30% or less of the existing value. By suppressing the sliding amount of the shaft portion 145, dust generation can be suppressed.

[0113] As described above, if the stress and sliding amount generated at the above contact surface can be suppressed, the possibility of dust generation at the contact surface can be reduced. Therefore, it is possible to prevent dust from mixing into the control fluid and the reduction of semiconductor manufacturing efficiency.

[0114] (2) The adjuster 1 described in (1), wherein the first radius (radius SR11) is preferably not more than a value obtained by adding 20% of the diameter D11 to the diameter D11 of the shaft portion 145. Therefore, it is possible to ensure that the stress generated at the contact surface between the valve body 14 and the diaphragm member 15 is suppressed to 10 MPa or less, and it is possible to prevent plastic deformation, damage, and dust generation of the valve body 14 and the diaphragm member 15.

[0115] (3) The adjuster 1 described in (2), wherein the first radius (radius SR11) is preferably not less than a value obtained by subtracting 10% of the diameter value D11 from the diameter D11 of the shaft portion 145 and not more than a value obtained by adding 10% of the diameter D11 to the diameter of the shaft portion 145. Therefore, when the valve body 14 and the diaphragm member 15 are in contact with each other, the stress generated at the contact surface can be suppressed to 5 MPa or less. The compressive strength of PTFE is considered to be about 5 MPa in a high-temperature environment (for example, the temperature of the control fluid is 90 °C). By suppressing the stress generated at the contact surface when the valve body 14 and the diaphragm member 15 are in contact with each other to 5 MPa or less, even in a high-temperature environment, it is possible to prevent plastic deformation, damage, and dust generation of the valve body 14 and the diaphragm member 15.

[0116] (4) The adjuster 1 described in any one of (1) to (3), wherein the second radius (radius SR12) is preferably a value obtained by subtracting 3 to 4% of the first radius (radius SR11) from the first radius (radius SR11). Therefore, it is possible to ensure a reduction in the stress generated at the contact surface between the valve body 14 and the diaphragm member 15. For example, if the second radius (radius SR12) is set to be greater than a value obtained by subtracting 2% of the first radius (radius SR11) from the first radius (radius SR11), the degree of freedom of the shaft portion 145 of the valve body 14 in the receiving portion 151a of the diaphragm member 15 becomes smaller. Assuming that the valve body 14 is inclined during the opening and closing operation, the inclination cannot be absorbed, resulting in the possibility of generating excessive stress at the above contact surface. On the other hand, if the second radius (radius SR12) is set to be less than a value obtained by subtracting 4% of the first radius (radius SR11) from the first radius (radius SR11), the shaft portion 145 of the valve body 14 will not sufficiently abut against the receiving portion 151a of the diaphragm member 15, and there is a possibility that the central axis CL11 of the shaft portion 145 will shift. Therefore, as described above, the second radius (radius SR12) is preferably a value obtained by subtracting 3 to 4% of the first radius (radius SR11) from the first radius (radius SR11).

[0117] (7) The adjuster 1 described in any one of (1) to (6), wherein the receiving portion 151a has a cylindrical wall 151c facing the outer peripheral surface of the shaft portion 145, and there is a gap C11 between the cylindrical wall 151c and the outer peripheral surface of the shaft portion 145. The size of the gap C11 is preferably 3 to 5% of the diameter D11 of the shaft portion 145.

[0118] According to the adjuster described in (7), since the receiving portion 151a has a cylindrical wall 151c facing the outer peripheral surface of the shaft portion 145, the cylindrical wall 151c can be used to ensure that the central axis CL11 of the shaft portion 145 does not shift.

[0119] Furthermore, if the shaft portion 145 is pressed against the receiving portion 151a by the biasing force of the biasing device (compression coil spring 16), the shaft portion 145 will be compressed, resulting in the possibility that the shaft portion 145 will deform in the direction of increasing diameter. However, according to the adjuster 1 described in (7), since there is a gap C11 between the cylindrical wall 151c and the outer peripheral surface of the shaft portion 145, even when the diameter of the shaft portion 145 is compressed and thickened, interference between the cylindrical wall 151c and the shaft portion 145 can be prevented. By preventing interference, dust generation due to friction between the shaft portion 145 and the cylindrical wall 151c can be prevented. Here, the size of the above gap C11 is preferably 3 to 5% of the diameter D11 of the shaft portion 145. The reason is that if the size of the gap C11 is greater than 5% of the diameter of the shaft portion 145, ensuring that the central axis CL11 of the shaft portion 145 does not shift, and if it is less than 3% of the diameter D11 of the shaft portion 145, even when the shaft portion 145 is compressed and thickened, there is still a possibility of interfering with the cylindrical wall 151c. In addition, the so-called "gap C11" here is obtained by subtracting the diameter D11 of the shaft portion 145 from the diameter D12 of the cylindrical wall 151c and then dividing by 2 assuming that the shaft portion 145 and the cylindrical wall 151c are coaxial.

[0120] (8) The adjuster 1 described in any one of (1) to (7) preferably has a non-contact portion 147 that is not in contact with the concave spherical surface 151b provided coaxially with the shaft portion 145 at the vertex of the convex spherical surface 144; the diameter D13 of the non-contact portion 147 does not exceed 1 / 20 of the diameter D11 of the shaft portion 145.

[0121] The convex spherical surface 144 is assumed to be formed by cutting or injection molding. When formed by cutting, the machining speed at the vertex portion of the convex spherical surface 144 becomes zero, and there is a possibility of generating burrs. If it contacts the concave spherical surface 151b in a state with burrs, it may become a cause of dust generation. Therefore, as in the adjuster 1 described in (7), by previously setting the vertex portion of the convex spherical surface 144 as the non-contact portion 147, dust generation can be prevented. In addition, when the convex spherical surface 144 is formed by injection molding, if the gate is located on the surface of the convex spherical surface 144, when the valve body 14 contacts the diaphragm member 15, there is a possibility that the effect of suppressing the stress and sliding amount generated at the contact surface cannot be fully obtained. Here, by using the adjuster 1 described in (7) to set the vertex portion of the convex spherical surface 144 as the non-contact portion 147, the gate can be provided at the non-contact portion 147 without affecting the above effect. However, the diameter D13 of the non-contact portion 147 is preferably not more than 1 / 20 of the diameter D11 of the shaft portion 145. The reason is that if the diameter D13 of the non-contact portion 147 exceeds 1 / 20 of the diameter D11 of the shaft portion 145, the surface area of the convex spherical surface 144 will be relatively narrowed, and the above effect of suppressing stress and sliding amount cannot be fully obtained.

[0122] (Second Embodiment) Next, regarding the adjuster of the second embodiment, only the differences from the adjuster of the first embodiment will be described using Figure 16 for illustration. Figure 16 An enlarged view of the contact portion between the valve body 24 and the diaphragm member 25 in the second embodiment corresponds to Figure 2 the figure.

[0123] The difference between the adjuster of the second embodiment and the adjuster of the first embodiment is only in the shapes of the receiving portion and the front end surface of the shaft portion. The receiving portion 251a of the diaphragm member 25, as shown in Figure 16 has: a concave spherical surface 251b and a concave curved surface 251c provided on the periphery of the concave spherical surface 251b.

[0124] The concave spherical surface 251b is arranged within an angular range A11 with respect to the central position CP21 centered on the central axis CL21 of the shaft portion 245 of the valve body 24. The angle A11 is preferably within a range of 24 degrees ± 1 degree centered on the central position CP21. In addition, the radius SR21 (first radius) of the concave spherical surface 151b is preferably a value greater than or equal to the value obtained by subtracting 20% of the diameter D21 of the shaft portion 245 from the diameter D21. The upper limit value of the radius SR21 is determined by the above-mentioned angle A11 and the radius SR22 of the concave curved surface 251c that is set to be tangent to and continuous with the concave spherical surface 151b. In the present embodiment, the diameter D21 of the shaft portion 145 is set to 4 mm, and the radius SR21 is set to 6 mm. Additionally, the values listed here are merely examples. Moreover, the range of the concave spherical surface 251b is the range indicated by the angle A11.

[0125] The concave curved surface 251c is set to be tangent to and continuous with the concave spherical surface 251b, and the radius R22 is set to be smaller than the radius SR21 of the concave spherical surface 251b. Specifically, it is preferably a value obtained by subtracting 60 - 65% of the radius SR21 from the radius SR21. In the present embodiment, the radius R22 is set to 2.2 mm. Additionally, the values listed here are merely examples.

[0126] The front end surface of the shaft portion 245 of the valve body 24 that is loosely fitted into the receiving portion 251a as described above is formed by: a convex spherical surface 244 provided at a portion opposite to the concave spherical surface 251b, and a convex curved surface 246 provided on the periphery of the convex spherical surface 244 and opposite to the concave curved surface 251c.

[0127] The central position of the convex spherical surface 244 is designed to be the same as the central position CP21 of the concave spherical surface 251b in a state where the convex spherical surface 244 is in contact with the concave spherical surface 251b. In addition, the radius SR23 (second radius) of the convex spherical surface 244 is preferably a value obtained by subtracting 2 - 5% of the radius SR21 of the concave spherical surface 251b from the radius SR21, and more preferably a value obtained by subtracting 3 - 4% of the radius SR21 from the radius SR21. In the present embodiment, the radius SR21 of the concave spherical surface 251b is set to 6 mm, and the radius SR23 of the convex spherical surface 244 is set to 5.6 mm. Additionally, the values listed here are merely examples.

[0128] The convex curved surface 246 is set to be tangent to and continuous with the convex spherical surface 244, and the radius R24 is set to be much smaller than the radius SR23 of the convex spherical surface 244. Specifically, the gap C21 (refer to Figure 17 ) between the outer edge of the convex curved surface 246 and the concave curved surface 251c is preferably set to be 0.02 or more and 0.03 or less in the initial state. In the present embodiment, the radius R24 is set to 2.05 mm. Additionally, the values listed here are merely examples.

[0129] For the regulator configured as described above, analysis is performed using the finite element method in the same manner as the regulator 1 of the first embodiment. Figure 18 Shown is the second embodiment, which is a result graph of performing a finite element method analysis on the stress generated at the contact surface between the valve body 24 and the diaphragm member 25. In addition, Figure 19 Shown is the second embodiment, which is a result graph of performing a finite element method analysis on the sliding of the front end surface of the shaft portion 245.

[0130] First, the analysis results of the stress will be described. As Figure 18 shown, the maximum stress is generated near the central axis CL21, and as the distance from the central axis CL21 increases, the stress gradually decreases. The stress is at its lowest value near the connection of the tangential continuous convex surface 246 and the convex spherical surface 244, and if it exceeds this point, the stress gradually increases towards the outer peripheral portion. The maximum stress value is 6.15 Mpa.

[0131] Next, the analysis results of the sliding amount will be described. As Figure 19 shown, an outward sliding is generated on the central axis CL21 side, and an inward sliding is generated on the outer peripheral portion of the shaft portion 245. The range of the generated sliding amount is -0.235 to 0.122 μm, and the average is a slightly outward sliding.

[0132] The above analysis results are compared with the analysis results of the prior art regulator 50 and the regulator 1 of the first embodiment. Figure 26 Shown is a comparison graph of the maximum stress values obtained by performing finite element method analysis for each configuration. Figure 27 Shown is a comparison graph of the sliding amount ranges obtained by performing finite element method analysis for each configuration.

[0133] As Figure 26 shown, the maximum stress value of the second embodiment is 6.15 Mpa, which is about 56% of that of the prior art regulator 50. In addition, as Figure 27 shown, the range of the sliding amount generated on the front end surface of the shaft portion 245 in the second embodiment is -0.235 to 0.122 μm, and when compared by the maximum value, it is about 8% of the existing one. From the above results, although the stress value and the sliding amount are slightly larger compared to the regulator 1 of the first embodiment, when compared to the prior art regulator 50, the mitigation of the stress value and the mitigation of the sliding amount are both significantly reduced, so it can be said to have the effect of preventing dust emission.

[0134] (Third Embodiment) Next, for the regulator of the third embodiment, only the differences from the regulator of the first embodiment will be described using Figure 20 this. Figure 20The figure shows an enlarged view of the contact portion between the valve body 34 and the diaphragm member 35 of the third embodiment, corresponding to Figure 2 of the figure.

[0135] Between the adjuster of the third embodiment and the adjuster of the first embodiment, only the shape of the receiving portion and the front end face of the shaft portion is different. The receiving portion 351a of the diaphragm member 35 is as Figure 20 shown, and includes: a concave spherical surface 351b, and a first flat surface 351c provided on the periphery of the concave spherical surface 351b.

[0136] The central position CP31 of the concave spherical surface 351b is designed to be located on the central axis CL31 of the shaft portion 345 of the valve body 34. In addition, the radius SR31 (first radius) of the concave spherical surface 351b is preferably not less than a value obtained by subtracting 20% of the diameter D31 of the shaft portion 345 from the diameter D31 of the shaft portion 345 and not more than a value obtained by adding 20% of the diameter D31 of the shaft portion 345 to the diameter D31 of the shaft portion 345, more preferably not less than a value obtained by subtracting 10% of the diameter D31 of the shaft portion 345 from the diameter D31 of the shaft portion 345 and not more than a value obtained by adding 10% of the diameter D31 of the shaft portion 345 to the diameter D31 of the shaft portion 345. In this embodiment, the diameter D31 of the shaft portion 345 is set to 4 mm, and the radius SR31 is set to 4 mm. In addition, the values listed here are only examples at best. In addition, the range of the concave spherical surface 351b is the range shown by the angle A21. The angle A21 is preferably 40 degrees ± 1 degree centered on the central position CP31.

[0137] The first flat surface 351c is provided on the tangent line of the concave spherical surface 351b, and the angle A31 with respect to the central axis CL31 of the shaft portion 345 is set to 70 degrees. In addition, the angle A31 is appropriately set so that the radius SR31 falls within the above range.

[0138] The front end face of the shaft portion 345 of the valve body 34 that is loosely fitted to the receiving portion 351a as described above is formed by: a convex spherical surface 344 provided at a portion opposite to the concave spherical surface 351b, and a second flat surface 346 provided on the periphery of the convex spherical surface 344 and opposite to the first flat surface 351c.

[0139] The central position of the convex spherical surface 344 is designed to be the same as the central position CP31 of the concave spherical surface 351b in a state where the convex spherical surface 344 is in contact with the concave spherical surface 351b. In addition, the radius SR33 (second radius) of the convex spherical surface 344 is preferably a value obtained by subtracting 2 to 5% of the radius SR31 of the concave spherical surface 351b from the radius SR31 of the concave spherical surface 351b, more preferably a value obtained by subtracting 3 to 4% of the radius SR31 of the concave spherical surface 351b from the radius SR31 of the concave spherical surface 351b. In this embodiment, the radius SR31 of the concave spherical surface 351b is set to 4 mm, and the radius SR33 of the convex spherical surface 344 is set to 3.85 mm. In addition, the values listed here are only examples at best.

[0140] The second flat surface 346 is disposed on the tangent line of the convex spherical surface 344, and the angle A32 with respect to the central axis CL31 of the shaft portion 345 is set to 69.25 degrees. In addition, the angle A32 is appropriately set to be less than the angle A31, and the radius SR33 is within the above range.

[0141] For the adjuster configured as described above, similar to the adjuster 1 of the first embodiment, analysis is performed using the finite element method. Figure 21 Shown is the third embodiment, which is a result diagram of performing finite element method analysis on the stress generated at the contact surface between the valve body 34 and the diaphragm member 35. In addition, Figure 22 Shown is the third embodiment, which is a result diagram of performing finite element method analysis on the sliding of the front end surface of the shaft portion 345.

[0142] First, the analysis results of the stress will be described. As Figure 21 shown, the stress becomes high near the central axis CL31 and near the periphery of the shaft portion 345. In particular, the maximum stress is generated near the periphery of the shaft portion 345, and the value is 6.82 Mpa.

[0143] Next, the analysis results of the sliding amount will be described. As Figure 22 shown, outward sliding occurs as a whole, and as the distance from the central axis CL31 increases, the sliding amount gradually increases. The range of the generated sliding amount is -0.311 to 0.045 μm.

[0144] The above analysis results are compared with the analysis results of the existing adjuster 50 and the adjuster 1 of the first embodiment.

[0145] As Figure 26 shown, the maximum stress value of the third embodiment is 6.82 Mpa, which is about 63% of that of the existing adjuster 50. In addition, as Figure 27 shown, the range of the sliding amount generated on the front end surface of the shaft portion 345 in the second embodiment is -0.311 to 0.045 μm. When comparing the maximum values of the sliding amounts, it is about 11% of the existing one. From the above results, although the stress value and the sliding amount are slightly larger compared to the adjuster 1 of the first embodiment, if compared to the existing adjuster 50, the mitigation of both the stress value and the sliding amount is significantly reduced. Therefore, it can be said that it has the effect of preventing dust generation.

[0146] (Fourth Embodiment) Next, for the adjuster of the fourth embodiment, only the differences from the adjuster of the first embodiment will be described using Figure 23 this. Figure 23 Shown is an enlarged view of the contact portion between the valve body 44 and the diaphragm member 45 of the third embodiment, corresponding to Figure 2 the figure.

[0147] For the adjuster 1 of the first embodiment, the receiving portion 151a has a cylindrical wall 151c facing the outer peripheral surface of the shaft portion 145, which can ensure preventing the axis of the shaft portion 145 from shifting. However, it is not necessarily required to provide the cylindrical wall 151c. For example, Figure 23 as shown, the cylindrical wall 151c is not provided, but the convex spherical surface 444 of the front end surface of the shaft portion 445 of the valve body 44 is made to abut against the concave spherical surface 451b of the receiving portion 451a of the diaphragm member 45. In this case, a thickened portion 446 having a diameter larger than other portions is provided at the front end portion of the shaft portion 445. By providing the thickened portion 446, the width W11 of the convex spherical surface 444 is larger than the width W12 of the concave spherical surface 451b, so that the axis shift of the shaft portion can be absorbed. In addition, the radius SR42 of the convex spherical surface 444 and the radius SR41 of the concave spherical surface 451b are the same as those in the first embodiment.

[0148] For the adjuster configured as described above, analysis is performed in the same manner as the adjuster 1 of the first embodiment using the finite element method. Figure 24 As shown in the fourth embodiment, the figure shows the result of finite element method analysis of the stress generated on the contact surface between the valve body 44 and the diaphragm member 45. In addition, Figure 25 as shown in the fourth embodiment, the figure shows the result of finite element method analysis of the sliding on the front end surface of the shaft portion 445.

[0149] First, the analysis result of the stress will be described. As Figure 24 shown, the maximum stress is generated near the central axis CL31, and the stress gradually decreases as it moves away from the central axis CL41. The stress rises at the outermost periphery of the contact portion between the convex spherical surface 444 and the concave spherical surface 451b. The maximum stress value is 4.47 Mpa.

[0150] Next, the analysis result of the sliding amount will be described. As Figure 25 shown, an inward sliding is generated near the central axis CL41, and the outward sliding amount becomes larger on the outer peripheral side of the concave spherical surface 451b. The range of the generated sliding amount is -0.160 to 0.128 μm.

[0151] The above analysis results are compared with the analysis results of the existing adjuster 50 and the adjuster 1 of the first embodiment.

[0152] As Figure 26 shown, the maximum stress value of the fourth embodiment is 4.47 Mpa, which is about 41% of the existing adjuster 50. In addition, as Figure 27As shown, the range of the sliding amount generated on the front end face of the shaft portion 445 in the second embodiment is -0.160 to 0.128 μm. When comparing the magnitudes of the sliding amounts based on the maximum value, it is approximately 5% of the existing one. From the above results, when comparing with the adjuster 1 of the first embodiment, the stress values and the sliding amounts are the same, and it can be said to have the effect of preventing dust from flying.

[0153] In addition, the above embodiments are merely illustrative and do not limit the present invention. Therefore, the present invention can of course be variously improved and modified without departing from the gist. For example, although the non-contact portion 147 on the front end face of the shaft portion 145 is formed by the counterbore 146, the non-contact portion 147 can also be provided by setting the vertex portion of the convex spherical surface 144 as a flat surface. In addition, in the above embodiments, the materials of the valve body 14 and the diaphragm member 15 are described as PTFE, but it is not limited thereto. Even other fluorine-based synthetic resins (such as PFA) can similarly suppress dust from flying. Description of reference numerals

[0154] 1 - Adjuster; 14 - Valve body; 15 - Diaphragm member; 16 - Compression coil spring (an example of a biasing device); 113 - Upstream end fluid chamber; 114 - Valve hole; 115 - Annular valve seat; 116a - Downstream end fluid chamber; 144 - Convex spherical surface; 145 - Shaft portion; 151a - Receiving portion; 151b - Concave spherical surface.

Claims

1. An adjuster, comprising: An upstream fluid chamber, which is housed in the valve body; A downstream fluid chamber, which is located at the downstream end of the upstream fluid chamber; A valve hole, which connects the upstream fluid chamber and the downstream fluid chamber; An annular valve seat, which is arranged along the periphery of the valve hole and can abut / separate from the valve body; and A diaphragm member, which is housed in the downstream fluid chamber and can change its position along the abut / separate direction in cooperation with the pressure of pneumatic air; The valve body has a cylindrical shaft portion that extends from the upstream fluid chamber through the valve hole to the downstream fluid chamber along the abut / separate direction; The shaft portion is detachably and loosely fitted with a receiving portion of the diaphragm member that receives the front end face of the shaft portion; On the opposite side of the valve body adjacent to the diaphragm member, a biasing device is provided that applies a biasing force to the valve body in the direction of abutting the annular valve seat; The opening degree of the valve body is adjusted by the balance between the pressure of the pneumatic air and the biasing force; Wherein, At a portion of the receiving portion facing the front end surface, there is a concave spherical surface centered on the central axis of the shaft portion and formed by a first radius; The first radius is a value greater than the value obtained by subtracting 20% of the diameter from the diameter of the shaft portion; At a portion of the front end surface facing the concave spherical surface, there is a convex spherical surface formed by a second radius obtained by subtracting 2-5% of the first radius from the first radius.

2. The adjuster according to claim 1, wherein, The first radius is a value less than or equal to the value obtained by adding 20% of the diameter to the diameter of the shaft portion.

3. The adjuster according to claim 2, wherein, The first radius is a value greater than the value obtained by subtracting 10% of the diameter from the diameter of the shaft portion and less than or equal to the value obtained by adding 10% of the diameter to the diameter of the shaft portion.

4. The adjuster according to any one of claims 1-3, wherein, The second radius is a value obtained by subtracting 3-4% of the first radius from the first radius.

5. The adjuster according to claim 1, wherein, The receiving portion has, at the periphery of the concave spherical surface, a concave curved surface formed by a radius smaller than the first radius and tangent to the concave spherical surface; The front end surface has, at the periphery of the convex spherical surface and at a portion facing the concave curved surface, a convex curved surface formed by a radius smaller than the second radius and tangent to the convex spherical surface.

6. The adjuster according to claim 1, wherein, The receiving portion has a first flat surface on the tangent line of the concave spherical surface at the periphery of the concave spherical surface; The front end surface has a second flat surface on the tangent line of the convex spherical surface at the periphery of the convex spherical surface and at a portion facing the first flat surface.

7. The adjuster according to claim 1, wherein, The receiving portion has a cylindrical wall facing the outer peripheral surface of the shaft portion; There is a gap between the cylindrical wall and the outer peripheral surface of the shaft portion; The size of the gap is 3-5% of the diameter of the shaft portion.

8. The adjuster according to claim 1, wherein, At the vertex of the convex spherical surface, a non-contact portion not in contact with the concave spherical surface is provided coaxially with the shaft portion; The diameter of the non-contact portion does not exceed 1 / 20 of the diameter of the shaft portion.

Images