Diaphragm valve

Abstract

A diaphragm valve (1) is provided with: a valve housing (10) having a first flow path (11), a second flow path (12), and a valve seat (15); a cover body (20) which is screwed on the valve box (10); a valve rod (30) which can perform rotation operation of screw joint with the cover body (20) in a manner of being capable of rising and falling; a joint (40) connected to the valve stem (30) and having a screw shaft (42) along the valve stem (30); a fixed seat (50) which is screwed to the screw shaft (42) and which opens and closes between the first flow path (11) and the second flow path (12) by coming into contact with and separating from the valve seat (15); and an annular diaphragm (60) through which the screw shaft (42) is inserted. An outer peripheral edge portion (61) of the diaphragm (60) is mechanically fastened and fixed between the valve housing (10) and the cover body (20), and an inner peripheral edge portion (62) of the diaphragm (60) is mechanically fastened and fixed between the joint (40) and the fixing seat (50).

Description

Technical Field

[0001] The present invention relates to a diaphragm valve for regulating the flow rate of a fluid flowing in a flow path and for opening and closing the flow path. Background Art

[0002] At present, a metal diaphragm valve is known as a diaphragm valve (see Patent Document 1), in which a metal diaphragm (diaphragm) is arranged between a thrust button that is raised and lowered via a valve stem by the rotation of a handle and a valve seat provided in a valve box. The diaphragm is shaped such that its periphery is sealed by the valve box and its central portion bulges upward (toward the thrust button).

[0003] This metal diaphragm valve is used in semiconductor manufacturing equipment, etc., and is constructed so that a thrust button that is lowered by operating a handle presses the diaphragm and makes it abut against a valve seat. On the other hand, the thrust button rises by operating the handle, thereby releasing the pressure on the diaphragm by the thrust button, causing the diaphragm to restore itself to its original shape, thereby separating the diaphragm from the valve seat. By moving the diaphragm in this way, the flow rate is regulated.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent document 1: (Japanese) Patent Application Publication No. 8-105554. Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] However, in the metal diaphragm valve described in Patent Document 1, the diaphragm is configured to separate from the valve seat by self-restoration. Therefore, it is difficult to achieve a larger flow rate by forcibly separating the diaphragm from the valve seat beyond the self-restoration of the diaphragm.

[0009] Here, for example, the diaphragm may be welded to the push button, and the diaphragm may be forced to leave the valve seat by the rise of the push button. However, welding is required in the manufacture of metal diaphragm valves, and it is difficult to reduce the manufacturing cost.

[0010] An object of the present invention is to provide a diaphragm valve that can forcibly operate a diaphragm to achieve a large flow rate and can suppress manufacturing costs.

[0011] Technical solutions for solving technical problems

[0012] The diaphragm valve of the present invention comprises: a main body, which has a first flow path, a second flow path and a valve seat; a cover body, which is screwed and installed on the main body; a valve stem, which can be screwed and rotated relative to the cover body to be raised and lowered; a joint, which is connected to the valve stem and has a screwing axis along the valve stem; a fixed seat, which is screwed on the screwing axis and contacts and separates relative to the valve seat to open and close the first flow path and the second flow path; an annular diaphragm, through which the screwing axis is inserted; the outer peripheral edge of the diaphragm is mechanically fastened and fixed between the main body and the cover body, and the inner peripheral edge of the diaphragm is mechanically fastened and fixed between the joint and the fixed seat.

[0013] According to the diaphragm valve of the present invention, the inner peripheral edge of the diaphragm is fastened and fixed between the joint and the fixed seat, so that the diaphragm can be forcibly raised and lowered as the valve stem is raised and lowered. For example, compared with the case of the diaphragm valve that uses the self-recovery of the diaphragm to adjust the flow rate, the flow path can be opened beyond the self-recovery of the diaphragm, so that a large flow rate can be achieved. In addition, both the outer peripheral edge and the inner peripheral edge of the diaphragm are mechanically fastened and fixed, so there is no need to weld the diaphragm to the joint, etc., and the manufacturing cost of the diaphragm valve can be suppressed.

[0014] In the diaphragm valve of the present invention, it can also be set that the joint has: a joint body, which has the threaded shaft; an abutment body, which can be rotatable relative to the joint body to allow the threaded shaft to be inserted and abuts against the diaphragm; the outer diameter dimension of the abutment body is set to the same dimension as the outer diameter dimension of the joint body.

[0015] According to such a structure, when the fixing seat is screwed to the screw shaft of the joint body, the fixing seat and the abutment body rotate together with the diaphragm, thereby reducing the friction between the diaphragm, the joint and the fixing seat. In addition, the outer diameter of the abutment body is set to the same size as the outer diameter of the joint body, so that when the joint and the valve stem are lifted and lowered together, the abutment area of ​​the abutment body relative to the diaphragm can be increased within the range where the abutment body does not interfere with the cover body, etc. Therefore, the diaphragm that bears the pressure of the fluid flowing inside the body can be supported by the aforementioned larger abutment area of ​​the abutment body.

[0016] In the diaphragm valve of the present invention, it may also be that the joint comprises: a joint body, which has the threaded shaft; an abutment body, which is rotatable relative to the joint body for the threaded shaft to be inserted and abuts against the diaphragm; the main body and the cover body fasten and fix the outer peripheral edge of the diaphragm in a manner that the diaphragm is inclined upward toward the joint side, and the abutment body comprises: a planar receiving surface, which receives the diaphragm; a convex curved surface, which is continuous with the outer periphery of the receiving surface.

[0017] According to such a structure, when the joint is lowered so that the receiving surface of the abutment body is arranged below the fastening and fixing position of the outer peripheral edge portion of the diaphragm, the portion on the inner side is bent obliquely downward toward the joint side compared to the portion on the outer side of the diaphragm that is fastened and fixed on the outer peripheral edge portion in a manner obliquely upward toward the joint side. However, the aforementioned convex surface is formed on the abutment body, so that stress concentration on the diaphragm can be suppressed.

[0018] In the diaphragm valve of the present invention, the joint may also include: a joint body, which has the threaded shaft; an abutment body, which is rotatable relative to the joint body for the threaded shaft to be inserted and abuts against the diaphragm; the fixed seat has a threaded hole that is opened on its upper surface and for the threaded shaft to be threaded, and a conical surface that is inclined upward toward the threaded shaft side is formed on the abutment body, the upper surface of the fixed seat forms an acute angle with the continuous corner of the threaded hole, and is overlapped in the up and down directions relative to the conical surface.

[0019] According to such a structure, the inner peripheral edge of the diaphragm can be firmly fixed by fitting the corner of the fixing seat between the tapered surface of the abutment body and the screw shaft, and the risk of fluid leakage can be further reduced even without welding as described above.

[0020] Furthermore, by fastening and fixing the inner peripheral edge of the diaphragm in this manner, the fastened and fixed portion has a shape that is inclined downward toward the outer peripheral side. Therefore, when the inner peripheral edge of the diaphragm is lowered, the shape of the diaphragm can be prevented from being reversed upside down to generate abnormal noise, and the durability of the diaphragm can be improved.

[0021] In the diaphragm valve of the present invention, the original shape of the diaphragm may be an annular flat plate, and the inner peripheral edge of the diaphragm may be arranged above or below the outer peripheral edge of the diaphragm as the joint and the fixing seat are raised and lowered.

[0022] According to such a structure, the inner peripheral edge of the diaphragm whose original shape is an annular flat plate can be forcibly arranged at an upper position or a lower position compared to the outer peripheral edge. Thus, for example, compared with the case of using a dome-shaped diaphragm whose original shape bulges upward, the generation of abnormal noise can be further suppressed.

[0023] According to the present invention, it is possible to provide a diaphragm valve that can forcibly operate the diaphragm to achieve a larger flow rate and that can suppress the manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a perspective view showing a diaphragm valve according to an embodiment of the present invention.

[0025] Figure 2It is a longitudinal sectional view showing the diaphragm valve in the open state according to the above embodiment.

[0026] Figure 3 It is a longitudinal sectional view showing an intermediate state of the diaphragm valve according to the above embodiment.

[0027] Figure 4 is a longitudinal sectional view showing the closed state of the diaphragm valve according to the above embodiment

[0028] Figure 5 It is an enlarged schematic diagram showing the main parts of the diaphragm valve in the open state according to the above embodiment.

[0029] Figure 6 It is an enlarged schematic diagram showing a main part of the diaphragm valve in an intermediate state according to the above embodiment.

[0030] Figure 7 It is an enlarged schematic diagram showing the main parts of the diaphragm valve in the closed state according to the above embodiment. DETAILED DESCRIPTION

[0031] [Structure of this embodiment]

[0032] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0033] exist Figures 1 to 4 The diaphragm valve 1 of this embodiment is a metal diaphragm valve that controls the flow rate of various fluids in semiconductor manufacturing equipment and the like, and is a large flow type valve that pursues a high Cv value. The diaphragm valve 1 is made of metal and has a valve box 10 as a main body, a cover body 20 screwed and installed on the valve box 10, a valve stem 30 screwed to the cover body 20 so as to be able to be raised and lowered, a joint 40 connected to the valve stem 30 and having a screw shaft 42 along the valve stem 30, a fixing seat 50 screwed to the screw shaft 42, and an annular diaphragm 60 through which the screw shaft 42 is inserted. A handle 70 for rotating the valve stem 30 is installed on the valve stem 30.

[0034] In the following description, the left-right direction of the diaphragm valve 1 is set as the X-axis direction, the front-back direction of the diaphragm valve 1 is set as the Y-axis direction, and the up-down direction of the diaphragm valve 1 is set as the Z-axis direction. The X-, Y-, and Z-axis directions are orthogonal to each other. It should be noted that in this embodiment, for the convenience of description, the up-down, down-down, left-down, and right-down directions of the diaphragm valve 1 are determined, but the up-down, down-down, left-down, and right-down directions may be different depending on the actual setting direction.

[0035] The valve box 10 has a first flow path 11 on the inlet side where a fluid flows in, a second flow path 12 on the outlet side where a fluid flows out, and a rising portion 13 forming a chamber 131 that connects the first flow path 11 and the second flow path 12 .

[0036] In the present embodiment, the first flow path 11 is formed into an L-shaped cross-section, with an end portion on one side in the X-axis direction opening at a position protruding from the outer peripheral surface 14 of the valve box 10, and an end portion on the other side in the X-axis direction opening at a substantially central portion on the bottom surface 132 forming the chamber 131, and a valve seat 15 is formed at the periphery of the opening so as to protrude slightly upward from the bottom surface 132.

[0037] In the present embodiment, the second flow path 12 is formed in a substantially "<" shape in cross section, and the end portion located on one side in the X-axis direction opens at the bottom surface 132 and the inner peripheral surface 133 forming the chamber 131, and is located on the other side in the X-axis direction compared to the end portion on the other side of the first flow path 11. The end portion located on the other side in the X-axis direction of the second flow path 12 opens at a position protruding from the outer peripheral surface 14 of the valve box 10.

[0038] The rising portion 13 is composed of a cylindrical portion rising from the periphery of the chamber 131 in the Z-axis direction, and an internal thread portion 135 for screwing the cover body 20 is formed in the upper portion 134 of the rising portion 13, and the wall of the lower portion 136 of the rising portion 13 becomes thicker toward the inner peripheral side compared with the upper portion 134. An annular section 137 is formed between the upper portion 134 and the lower portion 136 of the rising portion 13. An annular groove portion that overlaps with the annular protrusion 239 of the diaphragm pressing ring 235 described later in the Z-axis direction is formed in the annular section 137.

[0039] The cover body 20 is formed in a cylindrical shape, and in this embodiment, it integrally includes an upper annular cover portion 21, an intermediate annular cover portion 22, and a lower annular cover portion 23, and a diaphragm pressing ring 235 is provided on the lower annular cover portion 23. In the cover body 20, the outer diameter of the intermediate annular cover portion 22 is formed larger than the outer diameter of the upper annular cover portion 21, the outer diameter of the lower annular cover portion 23 is formed larger than the outer diameter of the intermediate annular cover portion 22, and the inner diameter of the lower annular cover portion 23 is formed larger than the inner diameter of the upper annular cover portion 21 and the intermediate annular cover portion 22.

[0040] The marking portion 71 is embedded in the outer peripheral portion 211 of the upper annular cover portion 21 in a manner that allows rotation around an axis along the Z-axis direction. The inner peripheral portion of the upper annular cover portion 21 is formed as an internal thread portion 212 for the valve stem 30 to be screwed. The marking portion 71 is configured to display opening (OPEN) and closing (CLOSE) marks on its upper surface, and the above marks can be seen from the hole 72 formed in the handle 70. The marking portion 71 is formed to be concave-convexly engaged with the handle 70 at a predetermined position in the above-mentioned rotation direction, and rotates together with the handle 70 in the engaged state.

[0041] The inner peripheral portion 222 of the intermediate annular cover portion 22 is in sliding contact with the valve stem 30 that can be raised and lowered in the Z-axis direction.

[0042] The outer peripheral portion of the lower annular cover 23 is formed as an external thread portion 231 that is threadedly engaged with the upper portion 134 of the rising portion 13. The inner diameter of the inner peripheral portion 232 of the lower annular cover 23 is formed to be larger than the outer diameter of the joint 40. The lower annular cover 23 is provided with the diaphragm pressing ring 235.

[0043] The diaphragm pressing ring 235 includes a cylindrical portion 236 disposed between the inner circumferential portion 232 and the joint 40, and a hollow disk-shaped pressing ring portion 237 extending from the lower end of the cylindrical portion 236 toward the outer circumferential side. Figure 5 ) is inclined upward from the outer peripheral side to the inner peripheral side (joint 40 side). An annular protrusion 239 protruding downward is formed at the lower portion of the outer peripheral edge of the diaphragm pressing ring 235, and the external threaded portion 231 of the lower annular cover portion 23 is screwed into the internal threaded portion 135 of the valve box 10, thereby mechanically fastening and fixing the outer peripheral edge portion 61 of the diaphragm 60 between the aforementioned annular protrusion 239 and the annular segment portion 137 of the rising portion 13 (screw-in fixing in this embodiment). Here, the annular protrusion 239 of the diaphragm pressing ring 235 provided on the cover body 20 overlaps with the aforementioned groove portion in the annular segment portion 137 of the valve box 10 in the Z-axis direction, and clamps the outer peripheral edge portion 61 of the diaphragm 60 between the annular segment portion 137. Therefore, the outer peripheral edge portion 61 of the diaphragm 60 is fastened and fixed by the valve box 10 and the cover body 20 in a manner that the diaphragm 60 is inclined upward toward the joint 40 side. It should be noted that the outer peripheral edge portion 61 of the diaphragm 60 is not welded to the annular protrusion 239 and the annular step portion 137 .

[0044] The valve stem 30 extends along the Z-axis direction and has a valve stem upper portion 31 and a valve stem lower portion 32. The valve stem upper portion 31 is formed with an external threaded portion 311 screwed with the internal threaded portion 212 of the upper annular cover portion 21 on the outer periphery. The outer periphery of the valve stem lower portion 32 is in sliding contact with the inner periphery 222 of the intermediate annular cover portion 22 so as to be able to be raised and lowered. In this embodiment, an O-ring is embedded in the outer periphery of the valve stem lower portion 32. A handle 70 is installed at the upper end portion 33 of the valve stem 30, and a joint 40 is installed at the lower end portion 34 thereof.

[0045] The joint 40 includes a joint body 41 including a threaded shaft 42 and a recess 43 , and an abutment body 45 (piece) through which the threaded shaft 42 is rotatably inserted and which abuts against the diaphragm 60 .

[0046] The joint body 41 is formed into a short cylindrical body except for the screw shaft 42 and the recess 43. The screw shaft 42 extends downward from the lower surface of the short cylindrical body, and an external thread is formed on its outer peripheral surface. The screw shaft 42 is arranged on the rotation axis along the Z-axis direction of the valve stem 30. The recess 43 is open on the upper surface of the short cylindrical body, and the lower end 34 of the valve stem 30 is rotatably embedded. The joint body 41 has a larger outer diameter than the outer dimensions of the valve stem 30.

[0047] The abutment body 45 is formed of a metal annular plate. Figure 5 As shown, the contact body 45 has an upper surface 451, a lower surface 452, an inner peripheral surface 453 and an outer peripheral surface 454, and the lower surface 452 constitutes a planar receiving surface for receiving the diaphragm 60. Figures 5 to 7 As shown, the contact body 45 is formed with a tapered surface 455 which is continuous with the lower surface 452 and the inner peripheral surface 453 and inclined upwardly toward the screwed shaft 42. In addition, the contact body 45 is formed with a convex curved surface 456 which is continuous with the lower surface 452 (the outer periphery of the receiving surface) and the outer peripheral surface 454 and convexly curved toward the outer peripheral side. The outer diameter dimension of the contact body 45 is set to the same dimension as the outer diameter dimension of the joint body 41.

[0048] A sealing ring 51 capable of abutting against the valve seat 15 is mounted on the fixed seat 50, and a screw hole 52 is formed on the fixed seat 50, and the screw hole 52 has an internal thread formed on the inner peripheral surface to be screwed with the external thread of the screw shaft 42. The screw hole 52 opens on the upper surface 53 of the fixed seat 50. The upper surface 53 of the fixed seat 50 is inclined downward from the screw shaft 42 side (inner peripheral side) toward the rising portion 13 side (outer peripheral side), and is formed in the form of a shape along the diaphragm 60 when the valve stem 30 rises. The upper surface 53 and the corner 54 continuous with the screw hole 52 are set to an acute angle smaller than 90°, and are overlapped with the aforementioned tapered surface 455 in the Z-axis direction. Here, the inner peripheral edge 62 of the diaphragm 60 is pressed upward by the corner 54 and its vicinity, and abuts against the abutment body 45 at a position closer to the outer peripheral side than the corner 54. Therefore, the inner peripheral edge 62 of the diaphragm 60 is mechanically fastened and fixed (screwed in this embodiment) so that the diaphragm 60 is tilted downward toward the outer peripheral side. It should be noted that the inner peripheral edge 62 of the diaphragm 60 is not welded to either the joint 40 or the fixing seat 50 .

[0049] The diaphragm 60 is made of metal, and its original shape is an annular flat plate, and it can be elastically deformed in the Z-axis direction. The outer peripheral edge 61 of the diaphragm 60 is installed by screwing the cover body 20 and the valve box 10, thereby, the diaphragm 60 is mechanically fastened and fixed between the valve box 10 and the cover body 20 in a manner that is obliquely upward toward the joint 40 side, without being welded. In addition, the inner peripheral edge 62 of the diaphragm 60 is installed by screwing the fixing seat 50 and the joint 40, thereby, the diaphragm 60 is mechanically fastened and fixed between the joint 40 and the fixing seat 50 in a manner that is obliquely downward toward the outer peripheral side. The tightening force relative to the outer peripheral edge 61 and the inner peripheral edge 62 of the diaphragm 60 is appropriately set according to the size within a range that does not cause fluid leakage and the diaphragm does not cause excessive crushing. The diaphragm 60 divides the space of the chamber 131.

[0050] Next, the opening and closing operation of the diaphragm valve 1 will be described.

[0051] Figure 2 and Figure 5 Indicates the open state of the diaphragm valve 1, Figure 3 and Figure 6 Indicates the intermediate state of the diaphragm valve 1, Figure 4 and Figure 7 Indicates the closed state of the diaphragm valve 1. In the open state, the sealing ring 51 of the fixed seat 50 is arranged to move upward from the valve seat 15 of the valve box 10, and the first flow path 11 and the second flow path 12 are connected to each other via the space of the chamber 131. In the intermediate state, the fixed seat 50 is arranged closer to the valve seat 15 than in the open state, and the flow path connecting the first flow path 11 and the second flow path 12 is throttled in the space of the chamber 131. In the closed state, the sealing ring 51 of the fixed seat 50 contacts the valve seat 15, blocking the first flow path 11 and the second flow path 12.

[0052] [Close Action]

[0053] First, in the Figure 2 and Figure 5 In the diaphragm valve 1 in the open state shown, the handle 70 is rotated around the axis of the valve stem 30 to rotate the valve stem 30. The valve stem 30 descends due to the rotation, the joint 40 and the fixed seat 50 descend without rotating, and the abutment body 45 of the joint 40 presses the inner peripheral edge 62 of the diaphragm 60 downward, so that the diaphragm valve 1 passes through Figure 3 and Figure 6 The intermediate state shown becomes Figure 4 and Figure 7 The closed state is shown. Figure 6 In the intermediate state, the position of the inner peripheral edge portion 62 is at a substantially equal height position (upper and lower positions) relative to the position of the outer peripheral edge portion 61. Figure 7In the closed state, the inner peripheral edge portion 62 is arranged at a lower position relative to the outer peripheral edge portion 61. When the position of the inner peripheral edge portion 62 in the intermediate state is taken as the reference position, in the closed state, the position of the inner peripheral edge portion 62 is arranged at a lower position less than 1 mm downward compared to the reference position. Furthermore, in the intermediate state and the closed state, the abutment body 45 is arranged at a position protruding downward compared to the inner peripheral side portion of the pressure ring portion 237 of the diaphragm pressure ring 235. Figure 6 The intermediate state and Figure 7 In the closed state, the lower surface 452 of the abutment body 45 receives the inner peripheral edge 62 of the diaphragm 60 from above, and the convex curved surface 456 can abut against the diaphragm 60 in a manner that does not cause stress concentration on the diaphragm 60. The diaphragm 60 is uniquely fastened and fixed with its outer peripheral edge 61 and inner peripheral edge 62 as described above, so that in the intermediate state and the closed state, the outer peripheral edge 61 is inclined upward toward the inner peripheral side, and the middle part of the inner peripheral edge 62 side is inclined downward toward the inner peripheral side compared to the outer peripheral edge 61, and the inner peripheral edge 62 on the inner peripheral side is more gently inclined than the middle part. By forcibly bending the diaphragm 60 in a unique shape in this way, it is difficult for the diaphragm 60 to emit abnormal noises such as clicking when the diaphragm valve 1 is operated to the open state and the closed state. Furthermore, the corner portion 54 is arranged to overlap the tapered surface 455 in the Z-axis direction, so that even without welding, the inner peripheral edge portion 62 of the diaphragm 60 can be firmly fastened and fixed by the inner peripheral side portion of the abutment body 45 and the fixing seat 50. It should be noted that in the present embodiment, the forced deformation of the diaphragm 60 based on the rotation of the handle 70 when closing the flow path is performed within a range where the diaphragm 60 does not undergo plastic deformation but can undergo elastic deformation. By limiting the deformation to this range, for example, the diaphragm 60 can be prevented from undergoing plastic deformation and reducing durability.

[0054] In this way, the fixing seat 50 of the diaphragm valve 1 comes into contact with the valve seat 15 , closing the first flow path 11 and the second flow path 12 .

[0055] [Open Action]

[0056] First, in the Figure 4 and Figure 7 In the diaphragm valve 1 in the closed state shown, the handle 70 is rotated in the opposite direction around the axis of the valve stem 30, so that the valve stem 30 rotates in the opposite direction. The valve stem 30 rises due to this rotation, and the joint 40 and the fixing seat 50 rise without rotating. The fixing seat 50 presses the inner peripheral edge 62 of the diaphragm 60 upward, and the diaphragm valve 1 is in Figure 3 and Figure 6 The intermediate state shown in FIG. 1 further exceeds the self-recovery of the diaphragm 60 and is forced upward, thereby becoming Figure 2 and Figure 5The open state is shown. In this open state, the diaphragm 60 is significantly separated from the valve seat 15 compared to the case where the diaphragm 60 self-recovers upward, so that the connecting area between the first flow path 11 and the second flow path 12 can be expanded to achieve a further increase in flow rate. It should be noted that in the present embodiment, the forced deformation of the diaphragm 60 based on the rotation of the handle 70 when the flow path is opened is performed within the range where the diaphragm 60 does not undergo plastic deformation but can undergo elastic deformation. By limiting the deformation to this range, for example, the plastic deformation of the diaphragm 60 and the reduction in durability can be suppressed. Figure 5 In the open state, the position of the inner peripheral edge portion 62 is arranged at an upper position relative to the position of the outer peripheral edge portion 61. In addition, in the open state, the lower surface 452 of the abutment body 45 is arranged at an upper and lower position roughly along the inner peripheral side portion of the pressure ring portion 237 of the diaphragm pressure ring 235, and the upper surface 53 of the fixed seat 50 receives the inner peripheral edge portion 62 of the diaphragm 60 from below. In addition, in the open state, the diaphragm 60 becomes a roughly dome shape that is inclined upward from the outer peripheral edge portion 61 to the inner peripheral edge portion 62. When the position of the inner peripheral edge portion 62 in the intermediate state is taken as the reference position, in the open state, the position of the inner peripheral edge portion 62 is arranged at an upper position that is upward within a range of 1 to 2 mm compared to the reference position.

[0057] In this way, in the diaphragm valve 1 , the fixing seat 50 is separated from the valve seat 15 , so that the first flow path 11 and the second flow path 12 communicate with each other.

[0058] As described in the diaphragm valve 1 of the present embodiment, the inventors conducted stress analysis on the shape of the parts that mechanically clamp the diaphragm 60 in the diaphragm valve 1 for a large flow rate with a large stroke in which the diaphragm 60 is fixed to the joint 40 instead of being welded to the joint 40, and invented a diaphragm valve 1 that combines stroke, sealing, and durability.

[0059] [Effects of this embodiment]

[0060] In the present embodiment, in the diaphragm valve 1, the outer peripheral edge 61 of the diaphragm 60 is mechanically fastened and fixed between the valve box 10 and the cover body 20, and the inner peripheral edge 62 of the diaphragm 60 is mechanically fastened and fixed between the joint 40 and the fixing seat 50, so that the diaphragm 60 can be forcibly raised and lowered along with the raising and lowering of the valve stem 30. For example, compared with the case of the diaphragm valve that uses the self-restoration of the diaphragm to adjust the flow rate as described above, the flow path can be opened in a manner that exceeds the self-restoration of the diaphragm 60, thereby achieving a further increase in flow rate. In addition, since both the outer peripheral edge 61 and the inner peripheral edge 62 of the diaphragm 60 are mechanically fastened and fixed, it is not necessary to weld the diaphragm 60 to the joint 40, etc., and the manufacturing cost of the diaphragm valve 1 can be reduced.

[0061] In the present embodiment, the outer diameter of the abutment body 45 is set to be the same as the outer diameter of the joint body 41. Therefore, when the fixing seat 50 is screwed to the screw shaft 42 of the joint body 41, the fixing seat 50 and the abutment body 45 rotate together with the diaphragm 60, thereby reducing the friction between the diaphragm 60 and the joint 40 and the fixing seat 50. In addition, the outer diameter of the abutment body 45 is set to be the same as the outer diameter of the joint body 41. Therefore, when the joint 40 and the valve stem 30 are raised and lowered together, the abutment area between the abutment body 45 and the diaphragm 60 can be increased within a range where the abutment body 45 does not interfere with the cover body 20 and the like. Therefore, the diaphragm 60 that receives the pressure of the fluid flowing inside the valve box 10 can be received by the aforementioned large abutment area of ​​the abutment body 45.

[0062] In the present embodiment, in particular, the valve box 10 and the cover body 20 fasten and fix the outer peripheral edge portion 61 of the diaphragm 60 in a manner that the diaphragm 60 is inclined upward toward the joint 40 side, and the abutment body 45 has a lower surface 452 as a planar receiving surface for receiving the diaphragm 60, and a convex curved surface 456 that is continuous with the outer periphery of the lower surface 452. Therefore, when the lower surface 452 of the abutment body 45 is arranged below the fastening and fixing position of the outer peripheral edge portion 61 of the diaphragm 60 due to the lowering of the joint 40, the inner peripheral portion of the diaphragm 60 is bent obliquely upward toward the joint 40 side compared to the outer peripheral portion of the diaphragm 60 fastened and fixed in a manner that the outer peripheral edge portion 61 is inclined upward toward the joint 40 side. However, the aforementioned convex curved surface 456 is formed on the abutment body 45, so that stress concentration on the diaphragm 60 can be suppressed.

[0063] In this embodiment, in particular, the abutment body 45 is formed with a tapered surface 455 that is inclined upward obliquely toward the screw-engaging shaft 42 side, and the upper surface 53 of the fixing seat 50 and the corner 54 that is continuous with the screw-engaging hole 52 form an acute angle, and are arranged to overlap with the tapered surface 455 in the Z-axis direction, so that the inner peripheral edge 62 of the diaphragm 60 can be firmly fastened and fixed in a manner that the corner 54 of the fixing seat 50 is embedded between the tapered surface 455 of the abutment body 45 and the screw-engaging shaft 42, and even if the inner peripheral edge 62 is not welded, the hidden danger of fluid leakage can be further reduced. In addition, the inner peripheral edge 62 of the diaphragm 60 is fastened and fixed in this way, so that the fastened and fixed part has a shape that is inclined downward obliquely toward the outer peripheral side. Therefore, when the inner peripheral edge 62 of the diaphragm 60 is lowered, the shape of the diaphragm 60 can be suppressed from being turned upside down and generating abnormal noise, and the durability of the diaphragm 60 can be improved.

[0064] In the present embodiment, the original shape of the diaphragm 60 is an annular flat plate, and the inner peripheral edge portion 62 of the diaphragm 60 is arranged at an upper position or a lower position compared to the outer peripheral edge portion 61 of the diaphragm 60 as the joint 40 and the fixing seat 50 rise and fall. Therefore, the inner peripheral edge portion 62 of the diaphragm 60 whose original shape is an annular flat plate is forcibly arranged at an upper position or a lower position compared to the outer peripheral edge portion 61. Therefore, compared with the case of using a dome-shaped diaphragm whose original shape bulges upward, the generation of abnormal noise can be further suppressed.

[0065] [Modifications]

[0066] In the above-mentioned embodiment, the outer diameter dimension of the abutment body 45 is set to be the same as the outer diameter dimension of the joint body 41, but it is not limited to this. For example, it can also be set to a size smaller than the outer diameter dimension of the joint body 41, and as long as it is a structure that does not hinder the lifting and lowering work of the joint body 41, the outer diameter dimension of the abutment body 45 can be set to a size larger than the outer diameter dimension of the joint body 41.

[0067] In the above embodiment, the outer diameter of the fixing seat 50 is larger than the outer diameter of the joint 40 , but the present invention is not limited thereto and the outer diameter may be equal to or smaller than the outer diameter.

[0068] In the above embodiment, the joint 40 is configured such that the abutment 45 is rotatably provided relative to the joint body 41, and when the fixing seat 50 is screwed to the screwing shaft 42, the abutment 45 rotates together with the diaphragm 60, which can suppress the friction with the diaphragm 60, but even without considering this point, the diaphragm valve 1 can be configured, and the abutment 45 can be formed integrally with the joint body 41. The integrally formed joint 40 has a portion equivalent to the abutment 45 (not rotatable).

[0069] In the above-mentioned embodiment, the inner peripheral edge portion 62 of the diaphragm 60 is firmly fastened by the tapered surface 455 of the aforementioned abutment body 45 and the acute angle corner 54 of the fixing seat 50. However, such tapered surface 455 and acute angle corner 54 may be omitted, and these structures may be omitted as long as the inner peripheral edge portion 62 of the diaphragm 60 can be fastened and fixed without welding.

[0070] In the above-mentioned embodiment, the valve box 10 and the cover body 20 fasten and fix the outer peripheral edge portion 61 of the diaphragm 60 in such a manner that the diaphragm 60 is inclined upward toward the joint 40 side. During the movement of the diaphragm 60, even if the inner peripheral edge portion 62 of the diaphragm 60 is arranged at a lower position relative to the outer peripheral edge portion 61, the abnormal sound caused by the flipping of the diaphragm 60 can be suppressed. However, when it is not necessary to suppress such abnormal sound, the valve box 10 and the cover body 20 may not fasten and fix the outer peripheral edge portion 61 of the diaphragm 60 in the aforementioned direction, for example, the diaphragm 60 may be fastened and fixed in a horizontal direction.

[0071] In the above embodiment, the convex surface 456 is formed on the contact body 45 . However, if there is no problem in the operation of the diaphragm 60 even without the convex surface 456 , the convex surface 456 may be omitted.

[0072] In the above embodiment, the diaphragm valve 1 is described as a large flow rate type metal diaphragm valve used in semiconductor manufacturing equipment and the like, but it can also be used in the liquid crystal market in addition to the semiconductor market.

[0073] Description of Reference Numerals

[0074] 1… diaphragm valve; 10… valve box (main body); 11… first flow path; 12… second flow path; 13… rising portion; 131… chamber; 132… bottom surface; 133, 453… inner peripheral surface; 134… upper side portion; 135, 212… internal thread portion; 136… lower side portion; 137… annular segment portion; 14… outer peripheral surface; 15… valve seat; 20… cover body; 21… upper side annular cover portion; 211… outer peripheral portion; 22… middle annular cover portion; 222, 232… inner peripheral portion; 23… lower side annular cover portion; 231, 311… external thread portion; 235… diaphragm pressure ring; 236… cylindrical 237…pressure ring; 238, 452…lower surface; 239…annular protrusion; 30…valve stem; 31…upper part of valve stem; 32…lower part of valve stem; 33…upper end; 34…lower end; 40…connector; 41…connector body; 42…screw-on shaft; 43…recess; 45…abutment body; 451, 53…upper surface; 454…outer peripheral surface; 455…conical surface; 456…convex curved surface; 50…fixing seat; 51…seal ring; 52…screw-on hole; 54…corner; 60…diaphragm; 61…outer peripheral edge; 62…inner peripheral edge; 70…handle; 71…marking portion; 72…hole.

Claims

1. A diaphragm valve, comprising: a main body having a first flow path, a second flow path and a valve seat; A cover body, which is screwed and installed on the main body; A valve stem capable of rotating and being screwed to the cover body so as to be liftable; a connector connected to the valve stem and having a threaded axis along the valve stem; a fixed seat, which is screwed to the screw-in shaft and contacts and separates from the valve seat to open and close the first flow path and the second flow path; an annular diaphragm through which the threaded shaft is inserted; The outer peripheral edge of the diaphragm is mechanically fastened and fixed between the main body and the cover body. The inner peripheral edge of the diaphragm is mechanically fastened and fixed between the joint and the fixing seat.

2. The diaphragm valve according to claim 1, wherein: The connector has: a joint body having the threaded shaft; an abutment body that allows the threaded shaft to be inserted through the abutment body so as to be rotatable relative to the joint body and abuts against the diaphragm; The outer diameter dimension of the abutment body is set to be the same as the outer diameter dimension of the joint body.

3. The diaphragm valve according to claim 1 or 2, wherein: The connector has: a joint body having the threaded shaft; an abutment body that allows the threaded shaft to be inserted through the abutment body so as to be rotatable relative to the joint body and abuts against the diaphragm; The main body and the cover body fasten and fix the outer peripheral edge of the diaphragm in a manner that the diaphragm is inclined upward toward the joint side. The abutment body has: A planar receiving surface receiving the diaphragm; The convex curved surface is continuous with the outer periphery of the receiving surface.

4. The diaphragm valve according to any one of claims 1 to 3, wherein: The connector has: a joint body having the threaded shaft; an abutment body that allows the threaded shaft to be inserted through the abutment body so as to be rotatable relative to the joint body and abuts against the diaphragm; The fixing seat has a screw hole which is opened on its upper surface and for screwing the screw shaft. The abutment body is formed with a tapered surface that is inclined obliquely upward toward the screw-engaging shaft side. The upper surface of the fixing seat forms an acute angle with a corner portion continuous with the screw hole, and the fixing seat is arranged to overlap with the tapered surface in the up-down direction.

5. The diaphragm valve according to claim 4, wherein: The original shape of the diaphragm is an annular flat plate. The inner peripheral edge of the diaphragm is arranged at an upper position or a lower position than the outer peripheral edge of the diaphragm as the joint and the fixing seat are raised and lowered.

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