Piping equipment

Abstract

This piping equipment comprises: a main body (13) that is formed from a first fluororesin material and has a first boundary surface (13a); a joining member (15) that is formed from a second fluororesin material and has a second boundary surface (15a); and an intermediate member (17) that is formed from a third fluororesin material and is formed integrally with the joining member (15) via the second boundary surface (15a). The main body (13) has a recessed part (19) that opens at the first boundary surface (13a), and a cylindrical wall part (21) that is provided around the opening of the recessed part (19) and protrudes by a length shorter than the thickness of the intermediate member (17). The first fluororesin material and the second fluororesin material are non-meltable fluororesin materials that are non-meltable at the melting point of the third fluororesin material. The intermediate member (17) is formed integrally with the main body (13) in a state in which at least a tip of the cylindrical wall part (21) sinks and is embedded in the intermediate member, and a space is formed by the intermediate member and the recessed part.

Description

plumbing equipment

[0001] The present invention relates to a piping device that has a flow path therein through which a fluid flows and that constitutes a part of a piping system.

[0002] In various industrial fields such as chemical plants, semiconductor manufacturing, food, medical, and biotechnology, various piping devices, such as valve devices and fluid mixers, which have internal flow paths and are used as part of piping, are used to circulate fluids. In particular, piping devices in the semiconductor manufacturing field often use strong acids, which are highly toxic chemicals, and therefore employ a seal structure that prevents chemical liquids from leaking to the outside, a so-called external seal structure.

[0003] Typically, such external seal structures are constructed by assembling machined parts. However, even slight distortion of the abutting surfaces due to machining errors in such structures can create gaps and stagnate the fluid flow path, resulting in reduced yields. For this reason, when a recess formed in a part of the flow path and opening to the outside is closed with another member, a resilient member such as a diaphragm or packing is often sandwiched between the opposing surfaces of the two components to seal the gap between the two components. Furthermore, when a member such as a diaphragm cannot be sandwiched between the opposing surfaces of the two components, a method such as heating the abutting surfaces of the two components above their melting point and welding them together to form a single unit is sometimes employed, as in the flow control valve described in Patent Document 1.

[0004] Patent No. 7146204

[0005] In the method of heating and fusing the contact surfaces of two contacting members as described in Patent Document 1, the material of each member is heated above its melting point and fluidized, and when the two contact surfaces are pressed together, the fluidized material may spill out from between the two members into the flow path, forming a step. Such a step may cause a stagnation of the chemical solution in the flow path, which also reduces yield.

[0006] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problems present in the prior art by connecting two members in a piping device without creating a gap or a step.

[0007] In view of the above object, the present invention provides a piping device comprising: a main body formed from a first fluororesin material and having a first boundary surface; a joining member formed from a second fluororesin material and having a second boundary surface; and an intermediate member formed from a heat-fusible third fluororesin material and integrally molded with the joining member via the second boundary surface, wherein the main body has a recess that opens to the first boundary surface, and an annular cylindrical wall portion that protrudes from the first boundary surface by a length that is shorter than the thickness of the intermediate member is provided around the opening of the recess, the first fluororesin material and the second fluororesin material are inmeltable fluororesin materials that are inmeltable at the melting point of the third fluororesin material, and at least a tip end of the cylindrical wall portion is sunk and embedded in the intermediate member, and an inner circumferential surface and a top surface of the cylindrical wall portion are molded integrally with the intermediate member, and a space is formed by the intermediate member and the recess.

[0008] In the above-described piping device, the first fluororesin material forming the main body and the second fluororesin material forming the joining members are made of fluororesin materials that are non-meltable at the melting point of the third fluororesin material forming the intermediate member. Therefore, even when heated to the melting point of the third fluororesin material, the main body and the joining members can maintain their shapes, and the intermediate member and the main body (more specifically, the cylindrical wall portion) can be integrally molded with each other in a state where at least a portion of the cylindrical wall portion provided around the opening of the recess in the main body is sunk and embedded in the intermediate member. As described above, if the intermediate member and the main body are integrally molded with each other in a state where at least the tip end portion of the annular cylindrical wall portion provided on the main body is sunk and embedded in the intermediate member integrally molded with the joining members, then at least the inner circumferential surface and the tip end surface (top surface) of the tip end portion of the cylindrical wall portion of the main body are integral with the intermediate member integrally molded with the joining members. As a result, even if a gap occurs between the first boundary surface of the main body and the intermediate member, the space formed by the recess of the main body and the intermediate member is sealed from the outside between the main body, the intermediate member, and the joining member, and fluid in the space is reliably prevented from leaking to the outside. Note that, in this application, a state in which the tip end of the cylindrical wall portion is sunk into the intermediate member means a state in which at least the tip end surface (top surface) and inner peripheral surface of the cylindrical wall portion are in contact with the intermediate member without any gaps, and also includes a state in which the outer peripheral surface of the cylindrical wall portion is not in contact with the intermediate member.

[0009] In the above-described piping device, it is preferable that the cylindrical wall portion is provided along the periphery of the opening of the recess and is formed to be flush with the inner peripheral surface of the recess. If the cylindrical wall portion is provided along the periphery of the opening of the recess and is formed to be flush with the inner peripheral surface of the recess, no step is formed in the space at the connection portion between the main body and the intermediate member, and no stagnation portion is generated.

[0010] In the above-described piping device, an inlet flow passage and an outlet flow passage communicating with the space portion may be formed in the main body.

[0011] In the above-described piping device, it is preferable that the intermediate member is in the form of a film or a plate.

[0012] The thickness of the intermediate member may be in the range of 50 μm to 100 mm, and in this case, the length of the portion of the cylindrical wall portion that sinks into the intermediate member may be in the range of 0.5 μm to 95 mm.

[0013] In one embodiment, the first fluororesin material and the second fluororesin material may be PTFE, and in this case, the third fluororesin material is preferably PFA or modified PTFE.

[0014] According to the piping device of the present invention, even if a gap occurs between the first boundary surface of the main body and the intermediate member, the space between the tubular wall portion of the main body and the intermediate member is reliably sealed, so that the space formed by the recess of the main body, the intermediate member, and the joining member molded integrally therewith is sealed from the outside between the main body, the intermediate member, and the joining member, and fluid in the space is reliably prevented from leaking to the outside through between the main body, the intermediate member, and the joining member.

[0015] Fig. 1 is a perspective view showing the overall configuration of a vortex fluid mixer which is one embodiment of the piping device according to the present invention. Fig. 2 is a plan view of the piping device shown in Fig. 1 as seen from above. Fig. 3 is a cross-sectional view of the piping device taken along line III-III shown in Fig. 2. Fig. 4 is an explanatory diagram showing an example of a procedure for manufacturing the piping device shown in Fig. 1. Fig. 5 is an explanatory diagram showing an example of a procedure for manufacturing the piping device shown in Fig. 1. Fig. 6 is an explanatory diagram showing an example of a procedure for manufacturing the piping device shown in Fig. 1.

[0016] Hereinafter, an embodiment of a piping device according to the present invention will be described with reference to the drawings. First, the overall configuration of a vortex fluid mixer 11, which is an example of a piping device according to the present invention, will be described with reference to Figs. 1 to 3.

[0017] The piping device according to the present invention comprises a main body 13 formed from a first fluororesin material and having a first boundary surface 13a, a joining member 15 formed from a second fluororesin material and having a second boundary surface 15a, and an intermediate member 17 formed from a third fluororesin material and interposed between the main body 13 and the joining member 15, the intermediate member 17 being integrally molded and joined to the joining member 15 via the second boundary surface 15a. The intermediate member 17 is in the form of a film or plate, and its thickness can be in the range of 50 μm to 100 mm, for example.

[0018] The main body 13 is formed with a recess 19 that opens to the first boundary surface 13a, and is provided with an annular cylindrical wall portion 21 that protrudes from the first boundary surface 13a by a length shorter than the thickness of the intermediate member along the periphery, i.e., the periphery, of the opening of the recess 19 to the first boundary surface 13a. The inner peripheral surfaces of the recess 19 and the cylindrical wall portion 21 are smoothly connected and formed flush. The intermediate member 17, which is molded integrally with the joining member 15, is molded integrally with the main body 13 on the first boundary surface 13a side, with at least the tip of the annular cylindrical wall portion 21 sinking into the intermediate member 17. The length of the cylindrical wall portion 21 that sinks into the intermediate member 17 is shorter than the thickness of the intermediate member 17 and can be in the range of 0.5 μm to 95 mm, for example. However, the length of the cylindrical wall portion 21 that sinks into the intermediate member 17 is not limited to the above range as long as it is shorter than the thickness of the intermediate member 17 and at least the tip surface (top surface) of the cylindrical wall portion 21 is in contact with the intermediate member 17 and does not penetrate the intermediate member 17. In this application, the state in which the tip portion of the cylindrical wall portion 21 is sunk into the intermediate member 17 means a state in which at least the tip surface (top surface) and the inner peripheral surface of the cylindrical wall portion 21 are in contact with the intermediate member 17 without any gaps, and also includes a state in which the outer peripheral surface of the cylindrical wall portion 21 is not in contact with the intermediate member 17.

[0019] In this way, the recess 19 of the main body 13 forms a space by closing the opening to the first boundary surface 13a with the intermediate member 17 molded integrally with the joining member 15, and the main body 13 and the intermediate member 17 are molded such that at least the inner circumferential surface and top surface of the tip of the annular cylindrical wall portion 21 of the main body 13 are integrated with the intermediate member 17. As a result, even if a gap occurs between the first boundary surface 13a of the main body 13 and the intermediate member 17, the annular cylindrical wall portion 21 of the main body 13 and the intermediate member 17 are reliably sealed (i.e., sealed), so that leakage of fluid from the internal space through the joint between the main body 13 and the joining member 15 can be reliably prevented.

[0020] The third fluororesin material forming the intermediate member 17 is made of a heat-fusible fluororesin material that can be joined to other resin materials by being heated to or above its melting point to melt and then cooling and solidifying, while the first fluororesin material forming the main body 13 and the second fluororesin material forming the joining member 15 are made of sparingly soluble (non-meltable) fluororesin materials that do not melt at the melting point of the third fluororesin material and are therefore able to maintain their shape.

[0021] Examples of the hardly soluble (non-meltable) fluororesin material include a fluororesin material having a melting point higher than that of the third fluororesin material, and a fluororesin that gels and does not completely melt even when heated to its melting point. Furthermore, the first and second fluororesin materials may be the same or different types of fluororesin materials, as long as they are non-meltable at the melting point of the third fluororesin material. For example, the first and second fluororesin materials may be polytetrafluoroethylene (PTFE), and the third fluororesin material may be perfluoroalkoxyalkane (PFA) or modified PTFE.

[0022] In this application, the term "piping equipment" refers to equipment that has a fluid flow path therein and constitutes part of a pipe, and includes, for example, a valve device, a fluid mixer, etc. In the embodiment shown in FIGS. 1 to 3 , a vortex fluid mixer 11 is exemplified as the piping equipment according to the present invention, and a space formed by a recess 19 in a main body 13 and a joining member 15 and an intermediate member 17 that constitute a cover member is used as a vortex chamber 23. The recess 19 is a generally cylindrical space having a generally circular cross section. In addition, a protrusion 25 protruding from the center of the bottom surface is provided on the bottom surface of the recess 19 in the main body 13 (the ceiling surface of the space in the embodiment shown in FIGS. 1 to 3 ). The protrusion 25 has a generally cylindrical shape with a generally circular cross section, and an annular space is formed around the protrusion 25. Furthermore, the main body 13 is formed with a first fluid supply passage 29 extending from the first inlet connection end 27 in a direction tangential to the inner circumferential surface of the recess 19 and in the horizontal direction in the figure to communicate with the recess 19, a second fluid supply passage 33 extending from the second inlet connection end 31 in the vertical direction in the figure to connect to an intermediate portion of the first fluid supply passage 29, and a fluid discharge passage 37 extending from the outlet connection end 35 in the horizontal direction in the figure and then curving downward at a substantially right angle to penetrate the protrusion 25 to connect to the recess 19. The first fluid supply passage 29 and the second fluid supply passage 33 form an inlet flow passage communicating with the space, i.e., the vortex chamber 23, and the fluid discharge passage 37 forms an outlet flow passage communicating with the space, i.e., the vortex chamber 23. The protrusion 25 is positioned so that the fluid flowing from the first fluid supply passage 29 into the vortex chamber 23 collides with the protrusion 25 and flows out.

[0023] In this vortex fluid mixer 11, the main fluid supplied to the first fluid supply channel 29 is joined with the additive fluid supplied from the second fluid supply channel 33 connected to the first fluid supply channel 29, and the joined fluids are supplied to the vortex chamber 23. The joined fluids form a vortex in the vortex chamber 23, are mixed by the action of the vortex, and are then discharged from the fluid discharge channel 37. In the vortex fluid mixer 11 shown in FIGS. 1 to 3, a protrusion 25 protruding from the center of the bottom surface of the recess 19 is provided, and the fluid discharge channel 37 extends through the protrusion 25. However, the position of the protrusion 25 is not limited to the center of the bottom surface of the recess 19, as long as at least a portion of the fluid supplied from the first fluid supply channel 29 collides with the protrusion 25. Furthermore, as long as the fluid in the vortex chamber 23 can be discharged, the fluid discharge channel 37 may be connected to the recess 19 without passing through the protrusion 25, and the protrusion 25 may not be provided.

[0024] In the vortex fluid mixer 11, at least the inner peripheral surface and tip surface (top surface) of the cylindrical wall portion 21 provided along the periphery of the opening of the recess 19 of the main body 13 are molded integrally with the intermediate member 17 that forms part of the lid member, and the space between the main body 13 and the lid member is sealed, so that the fluid in the vortex chamber 23, which is formed by the space formed by the recess 19 and the lid member, can be reliably prevented from leaking to the outside from between the main body 13 and the lid member.

[0025] Next, an example of a method for manufacturing the vortex fluid mixer 11 shown in Figures 1 to 3 will be described with reference to Figures 4 to 6. Here, it is assumed that the intermediate member 17 of the vortex fluid mixer 11 is formed from PFA, which is a heat-fusible third fluororesin material, the main body 13 is formed from PTFE, which is a first fluororesin material that is hardly soluble (non-meltable) and non-meltable at the melting point of PFA, which is the third fluororesin material, and the joining member 15 is formed from PTFE, which is a second fluororesin material that is hardly soluble and non-meltable at the melting point of PFA, which is the third fluororesin material.

[0026] First, as shown in Fig. 4, a recess 19 is formed by cutting the bottom surface 39a of a rectangular parallelepiped first blank 39 compression-molded from PTFE. The recess 19 has a downward opening and a protrusion 25 that protrudes downward from the top surface. An annular cylindrical wall 21 is then formed around the opening of the bottom surface 39a of the recess 19, protruding from the first boundary surface 13a so that its inner circumferential surface is smoothly connected to and flush with the inner circumferential surface of the recess 19. This results in the cylindrical wall 21 protruding from the first boundary surface 13a. Next, a first fluid supply channel 29 is formed by cutting, extending horizontally from the first side surface 39b of the first blank 39 to connect tangentially to the outer circumferential surface of the recess 19. A second fluid supply channel 33 is then formed by cutting the top surface 39c of the first blank 39, extending vertically (up and down). The second fluid supply channel 33 is connected to an intermediate portion of the first fluid supply channel 29. Furthermore, by cutting, a fluid passage extending horizontally from the second side surface 39d of the first blank body 39 opposite the first side surface 39b is created, and a fluid passage extending upward through the protrusion 25 is created, and the two created fluid passages are connected to create a fluid discharge path 37.

[0027] Next, an upwardly opening recess 43 is created by cutting on the top surface 41a of a rectangular parallelepiped second blank 41 compression-molded from PTFE. The recess 43 is created so that the length (depth) from the bottom surface of the recess 43 to the opening is longer than the length (i.e., height) of the cylindrical wall portion 21 protruding from the first boundary surface 13a. Next, a film-like or plate-like resin aggregate 45 made of PFA is placed in the recess 43 of the second blank 41. The resin aggregate 45 is created so that its height is shorter than the depth of the recess 43, so that when placed in the recess 43, the resin aggregate 45 does not protrude above the recess 43. The resin aggregate 45 may be created by cutting, extrusion molding, or injection molding, or may be created by filling the recess 43 with PFA powder or pellets.

[0028] Next, the first blank 39 is placed on the second blank 41 with the resin assembly 45 housed in the recess 43 so that the cylindrical wall 21 formed on the first blank 39 contacts the resin assembly 45. The first blank 39, second blank 41, and resin assembly 45 arranged in this state are then placed in a heating furnace and heated to at least the melting point of the third fluororesin material, PFA. The first blank 39 and second blank 41, which are made of the first and second fluororesin materials, the sparingly soluble PTFE, do not gel and melt even when heated to the melting point of PTFE, and therefore maintain the shapes of the cylindrical wall 21 and the recess 43. Meanwhile, the resin assembly 45, which is made of the heat-fusible third fluororesin material, PFA, is heated to the melting point and melts. Because PTFE, the second fluororesin material forming the recess 43, is hardly soluble and the second blank 41 maintains its shape, the resin assembly 45 is retained in the recess 43 even when melted. Furthermore, when the resin assembly 45 melts, the cylindrical wall 21 formed on the first blank 39, which maintains its shape, sinks into the resin assembly 45 until the first boundary surface 13a formed on the blank 39 contacts the top surface 41a of the second blank 41, as shown in FIG. 5 . Because the height of the cylindrical wall 21 is shorter than the depth of the recess 43, when the first boundary surface 13a formed on the first blank 39 contacts the top surface 41a of the second blank 41, the leading end surface of the cylindrical wall 21 formed on the first blank 39 does not contact the bottom surface of the recess 43 formed on the second blank 41. When cooled in this state, the resin assembly 45 and the first blank 39 are integrally molded and fused together, and the resin assembly 45 and the second blank 41 are also integrally molded and fused together, with at least the tip of the cylindrical wall portion 21 not penetrating the resin assembly 45 but sinking into and embedded in the resin assembly 45. When the resin assembly 45 and the second blank 41 are integrally molded and fused together, the bottom surface of the recess 43 of the second blank 41 that contacts the bottom surface of the resin assembly 45 forms the second boundary surface 15a.

[0029] Next, the first blank 39, the second blank 41, and the resin assembly 45, which are integrally molded and fused together, are cut to produce the vortex fluid mixer 11, as shown in Fig. 6. Specifically, the first inlet connection end 27, the second inlet connection end 31, and the outlet connection end 35 are cut at the ends of the fluid supply path 29, the second fluid supply path 33, and the fluid discharge path 37 of the first blank 39, respectively, to produce the main body 13. Furthermore, the side and bottom portions of the second blank 41 and the resin assembly 45 are cut until they are flush with the outer circumferential surface of the cylindrical wall portion 21, to produce the joining member 15 and the intermediate member 17 (i.e., the lid member) which are integrally molded via the second boundary surface 15a. In the vortex fluid mixer 11 thus manufactured, the bottom surface of the first blank body 39 around the cylindrical wall portion 21 constitutes the first boundary surface 13a, and the top surface of the joining member 15 that contacts the bottom surface of the intermediate member 17 (the portion formed from the bottom surface of the recess 43 of the second blank body 41) constitutes the second boundary surface 15a.

[0030] The cylindrical wall portion 21 of the main body 13 is molded integrally with the intermediate member 17, which is formed integrally with the joining member 15, and fused thereto with at least its tip portion sinking into and embedded in the intermediate member 17 without penetrating the intermediate member 17. This seals the recess 19 of the main body 13 with the joining member 15 and the intermediate member 17, forming a space that forms the vortex chamber 23. Furthermore, because at least the inner circumferential surface and the tip surface (top surface) of the tip portion of the cylindrical wall portion 21 are molded integrally with the intermediate member 17, the gap between the main body 13 and the joining member 15 and the intermediate member 17 is reliably sealed, preventing fluid in the internal space from leaking out from between the main body 13 and the joining member 15 and the intermediate member 17. Furthermore, because the cylindrical wall portion 21 sinks into the resin assembly 45 that forms the intermediate member 17 in a molten state, it is possible to prevent a step from being formed at the connection portion between the cylindrical wall portion 21 and the intermediate member 17, thereby preventing a stagnation portion from occurring.

[0031] The present invention has been described above with reference to the illustrated vortex fluid mixer 11, which is an embodiment of the fluid equipment of the present invention. However, the present invention is not limited to the illustrated embodiment. For example, in the illustrated embodiment, the vortex fluid mixer 11 is used as an example of a piping device according to the present invention. However, piping devices refer to devices that have a fluid flow path therein and are used as part of piping, and include, for example, valve devices and fluid mixers. Furthermore, in the illustrated embodiment, PTFE is used as the first fluororesin material and the second fluororesin material, and PFA is used as the third fluororesin material, but the first fluororesin material, the second fluororesin material, and the third fluororesin material are not limited to these. Furthermore, the manufacturing method of the vortex fluid mixer 11, which is an example of the piping device of the present invention, is merely illustrative, and the manufacturing method is not limited as long as it satisfies the configuration of the piping device of the present invention.

[0032] REFERENCE SIGNS LIST 11 vortex fluid mixer 13 main body 13a first boundary surface 15 joining member 15a second boundary surface 17 intermediate member 19 recess 21 cylindrical wall portion

Claims

1. A piping device comprising: a main body formed from a first fluororesin material and having a first boundary surface; a joining member formed from a second fluororesin material and having a second boundary surface; and an intermediate member formed from a heat-fusible third fluororesin material and molded integrally with the joining member via the second boundary surface, wherein the main body has a recess that opens to the first boundary surface, and a ring-shaped cylindrical wall portion that protrudes from the first boundary surface by a length that is shorter than the thickness of the intermediate member is provided around the opening of the recess, the first fluororesin material and the second fluororesin material are inmeltable fluororesin materials that are inmeltable at the melting point of the third fluororesin material, at least the tip of the cylindrical wall portion is sunk and embedded in the intermediate member, and the inner circumferential surface and top surface of the cylindrical wall portion are molded integrally with the intermediate member, and a space is formed by the intermediate member and the recess.

2. The piping device according to claim 1, wherein the cylindrical wall portion is provided along the periphery of the opening of the recess and is formed to be flush with the inner peripheral surface of the recess.

3. The piping device according to claim 2, wherein the main body is formed with an inlet flow passage and an outlet flow passage communicating with the space.

4. The piping device according to claim 3, wherein the intermediate member is in the form of a film or a plate.

5. A piping device according to any one of claims 1 to 4, wherein the thickness of the intermediate member is in the range of 50 µm to 100 mm.

6. The piping device according to claim 5, wherein the length of the portion of the cylindrical wall portion that sinks into the intermediate member is in the range of 0.5 μm to 95 mm.

7. A piping device according to any one of claims 1 to 4, wherein the first fluororesin material and the second fluororesin material are PTFE.

8. The piping device according to claim 7, wherein the third fluororesin material is PFA or modified PTFE.

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