JP7829645B2 - plumbing equipment - Google Patents

Description

This invention relates to piping equipment that has a fluid passage inside and constitutes part of a piping system.

In various industrial sectors such as chemical plants, semiconductor manufacturing, food processing, medical, and biotechnology, various piping devices are used as part of the piping system, such as valves and fluid mixers, which have internal flow paths to facilitate fluid circulation. In particular, piping devices in the semiconductor manufacturing sector often use highly toxic substances like strong acids as chemicals, so sealing structures—so-called external sealing structures—are employed to prevent leakage of these chemicals.

Generally, such external seal structures are constructed by combining machined parts. However, in such structures, even slight distortion of the contacting surfaces due to machining errors can create gaps, forming stagnant areas within the flow path and leading to reduced yield. Therefore, when closing a recess formed in a flow path and opening to the outside with another component, it is common to sandwich an elastic component such as a diaphragm or packing between the opposing surfaces of the two components to seal the gap without creating any gaps. Furthermore, when it is not possible to sandwich a component like a diaphragm between the opposing surfaces of the two components, methods such as heating the contacting surfaces of the two components above their melting point and welding them together, as seen in the flow control valve described in Patent Document 1, may be employed.

Patent No. 7146204

As described in Patent Document 1, in a method of welding two contact members by heating their contact surfaces together, the materials of each member are heated above their melting point and become fluid. Therefore, when the two contact surfaces are pressed together, the fluidized material may leak out from between the two members into the flow path, forming a stepped portion. Such stepped portions can cause stagnation of the chemical solution within the flow path, similarly leading to a decrease in yield.

Therefore, the objective of the present invention is to solve the problems of the prior art by connecting two components in piping equipment without gaps and without creating any steps or uneven surfaces.

In view of the above objectives, the present invention provides a piping device comprising: a main body formed from a first fluororesin material and having a first interface; a joining member formed from a second fluororesin material and having a second interface; and an intermediate member formed from a heat-fusible third fluororesin material and integrally molded with the joining member via the second interface, wherein the main body has a recess opening to the first interface, and an annular cylindrical wall portion protruding from the first interface by a length less than the thickness of the intermediate member is provided around the opening of the recess, wherein the first and second fluororesin materials are non-fusible fluororesin materials that exhibit non-melting properties at the melting point of the third fluororesin material, the first and second fluororesin materials are made of the same type of fluororesin material or different types of fluororesin material, and the inner circumferential surface and top surface of the cylindrical wall portion are molded integrally with the intermediate member, with at least the tip portion of the cylindrical wall portion sinking into and embedded in the intermediate member, and a space portion is formed by the intermediate member and the recess.

In the above-described piping equipment, the first fluororesin material forming the main body and the second fluororesin material forming the joining member are made of fluororesin materials that exhibit non-melting properties 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 member can maintain their shape, and it is possible to mold the intermediate member and the main body together as an integrated unit with at least a portion of the cylindrical wall portion provided along the opening of the recess in the main body sinking into the intermediate member. As described above, if the intermediate member and the main body are molded together as an integrated unit with at least the tip portion of the annular cylindrical wall portion provided in the main body sinking into the intermediate member which is integrally molded with the joining member, then at least the inner circumferential surface and tip surface (top surface) of the tip portion of the cylindrical wall portion of the main body will be integrated with the intermediate member which is integrally molded with the joining member. As a result, even if a gap exists between the first interface of the main body and the intermediate member, the space between the cylindrical wall of the main body and the intermediate member is reliably sealed. Therefore, 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 connecting member, reliably preventing fluid leakage from the space. Furthermore, since the cylindrical wall is formed along the periphery of the opening of the recess, no step is formed at the connection between the main body and the intermediate member in the space, and no stagnation occurs. In this application, the state in which the tip of the cylindrical wall is submerged in the intermediate member means that at least the tip surface (top surface) and inner circumferential surface of the cylindrical wall are in contact with the intermediate member without any gaps, and includes the state in which the outer circumferential surface of the cylindrical wall is not in contact with the intermediate member.

In the above-described piping device, the main body may be configured to have an inflow channel and an outflow channel that communicate with the space.

In the above-mentioned piping equipment, it is preferable that the intermediate member be in the form of a film or a plate.

Furthermore, the thickness of the intermediate member can be in the range of 50 μm to 100 mm. In this case, the length of the portion of the cylindrical wall that is recessed into the intermediate member can be in the range of 0.5 μm to 95 mm.

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

According to the piping device of the present invention, even if a gap exists between the first interface surface of the main body and the intermediate member, the space between the cylindrical wall portion of the main body and the intermediate member is reliably sealed. Therefore, the space formed by the recess of the main body, the intermediate member, and the joint member integrally molded thereto is sealed from the outside between the main body, the intermediate member, and the joint member, reliably preventing fluid in the space from leaking to the outside through the space between the main body, the intermediate member, and the joint member. Furthermore, since the cylindrical wall portion is formed along the periphery of the opening of the recess, no step is formed at the connection between the main body and the intermediate member in the space, and no stagnant areas are created.

This is a perspective view showing the overall configuration of a vortex-type fluid mixer, which is one embodiment of the piping equipment according to the present invention. Figure 1 is a plan view of the piping equipment shown, viewed from above. This is a cross-sectional view of the piping equipment along the line III-III shown in Figure 2. Figure 1 is an explanatory diagram showing an example of the procedure for manufacturing the piping equipment shown. Figure 1 is an explanatory diagram showing an example of the procedure for manufacturing the piping equipment shown. Figure 1 is an explanatory diagram showing an example of the procedure for manufacturing the piping equipment shown.

Hereinafter, embodiments of the piping equipment according to the present invention will be described with reference to the drawings.
First, with reference to Figures 1 to 3, the overall configuration of a vortex-type fluid mixer 11, which is an example of piping equipment according to the present invention, will be described.

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

The main body 13 has a recess 19 that opens into the first interface surface 13a, and an annular cylindrical wall portion 21 is provided around the opening of the recess 19 into the first interface surface 13a, i.e., along the periphery, protruding from the first interface surface 13a by a length shorter than the thickness of the intermediate member. The inner circumferential surface of the recess 19 and the inner circumferential surface of the cylindrical wall portion 21 are formed to be smoothly connected and flush. Furthermore, the intermediate member 17, which is integrally molded with the joining member 15, is integrally molded with the main body 13 on the first interface surface 13a side, such that at least the tip of the annular cylindrical wall portion 21 sinks into and is embedded in the intermediate member 17. The length of the cylindrical wall portion 21 that sinks into and is embedded in the intermediate member 17 is shorter than the thickness of the intermediate member 17, and can be in the range of, for example, 0.5 μm to 95 mm. However, the length of the cylindrical wall portion 21 that sinks into and is embedded in 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 it. In this application, the state in which the tip of the cylindrical wall portion 21 sinks into and is embedded in the intermediate member 17 means a state in which at least the tip surface (top surface) and the inner circumferential surface of the cylindrical wall portion 21 are in contact with the intermediate member 17 without any gaps, and includes a state in which the outer circumferential surface of the cylindrical wall portion 21 is not in contact with the intermediate member 17.

Thus, the recess 19 of the main body 13 is closed to the opening to the first interface surface 13a by the intermediate member 17, which is integrally molded with the joining member 15, thereby forming a space. The main body 13 and the intermediate member 17 are molded such that at least the inner circumferential surface and the top surface of the tip portion 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 exists between the first interface surface 13a of the main body 13 and the intermediate member 17, the space between the annular cylindrical wall portion 21 of the main body 13 and the intermediate member 17 is reliably sealed (i.e., sealed), thus reliably preventing leakage of fluid from the internal space through the joint between the main body 13 and the joining member 15.

The third fluororesin material forming the intermediate member 17 is a heat-fusible fluororesin material that can be joined to other resin materials by heating above its melting point, melting, and then cooling and solidifying. 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-fusible) fluororesin materials that do not melt at the melting point of the third fluororesin material and maintain their shape.

As a sparingly soluble (non-meltable) fluororesin material, for example, a fluororesin material having a melting point higher than the melting point of the third fluororesin material, or a fluororesin that does not completely melt even when heated to its melting point and becomes gel-like, can be used. Furthermore, the first and second fluororesin materials may be the same type of fluororesin material or different types of fluororesin materials, as long as they exhibit non-meltable properties 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.

In this application, "piping equipment" refers to equipment that has a fluid passage inside and constitutes part of the piping, and includes, for example, valve devices and fluid mixers. In the embodiments shown in Figures 1 to 3, a vortex-type fluid mixer 11 is exemplified as piping equipment according to the present invention, and the space formed by the recess 19 of the main body 13 and the joining member 15 and intermediate member 17 that constitute the lid member is used as the vortex chamber 23. The recess 19 is a roughly cylindrical space with a roughly circular cross-section. Furthermore, a projection 25 is provided on the bottom surface of the recess 19 of the main body 13 (the ceiling surface of the space in the embodiments shown in Figures 1 to 3) that protrudes from the center of the bottom surface. The projection 25 has a roughly cylindrical shape with a roughly circular cross-section, and an annular space is formed around the projection 25. Furthermore, the main body 13 has a first fluid supply passage 29 extending tangentially to the inner circumferential surface of the recess 19 from the first inlet connection end 27 and in the horizontal direction in the figure, communicating with the recess 19; a second fluid supply passage 33 extending vertically in the figure from the second inlet connection end 31 and connected to the middle portion of the first fluid supply passage 29; and a fluid discharge passage 37 extending horizontally in the figure from the outlet connection end 35, then curving downward at approximately a right angle, passing through the protrusion 25 and connecting to the recess 19. The first fluid supply passage 29 and the second fluid supply passage 33 constitute an inflow passage communicating with the space, i.e., the vortex chamber 23, and the fluid discharge passage 37 constitutes an outflow 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 through it.

In this type of vortex-type fluid mixer 11, the main fluid supplied to the first fluid supply passage 29 merges with the additive fluid supplied from the second fluid supply passage 33, which is connected to the first fluid supply passage 29, and is supplied to the vortex chamber 23. The merged fluids form a vortex within the vortex chamber 23, mix under the action of the vortex, and are then discharged through the fluid discharge passage 37. In the vortex-type fluid mixer 11 shown in Figures 1 to 3, a projection 25 is provided protruding from the center of the bottom surface of the recess 19, and the fluid discharge passage 37 extends through the projection 25. However, the position of the projection 25 is not limited to the center of the bottom surface of the recess 19; it is sufficient that at least a portion of the fluid supplied from the first fluid supply passage 29 collides with the projection 25. Furthermore, the fluid discharge passage 37 may be connected to the recess 19 without passing through the projection 25, as long as it can discharge the fluid in the vortex chamber 23; the projection 25 may not even be provided.

In the vortex-type fluid mixer 11, at least the inner circumferential surface and the tip surface (top surface) of the cylindrical wall portion 21, which is provided along the periphery of the opening of the recess 19 in the main body 13, are integrally molded with the intermediate member 17, which forms part of the lid member. Since the space between the main body 13 and the lid member is sealed, it is possible to reliably prevent the fluid in the vortex chamber 23, which is formed by the space created by the recess 19 and the lid member, from leaking to the outside from between the main body 13 and the lid member.

Next, with reference to Figures 4 to 6, an example of a method for manufacturing the vortex-type fluid mixer 11 shown in Figures 1 to 3 will be described. Here, it is assumed that the intermediate member 17 of the vortex-type fluid mixer 11 is formed from PFA, a third fluororesin material with heat-sealing properties; the main body 13 is formed from PTFE, a first fluororesin material that exhibits non-melting properties at the melting point of PFA; and the joining member 15 is formed from PTFE, a second fluororesin material that exhibits non-melting properties at the melting point of PFA.

First, as shown in Figure 4, a recess 19 is created on the bottom surface 39a of a rectangular parallelepiped first blank body 39, which is compression-molded from PTFE, by cutting. This recess 19 has a projection 25 that opens downward and protrudes downward from the top surface. An annular cylindrical wall portion 21 is created along the periphery of the opening of the recess 19 to the bottom surface 39a, protruding from the first interface surface 13a, such that its inner surface is smoothly connected to the inner surface of the recess 19 and is flush with it. This forms the cylindrical wall portion 21 protruding from the first interface surface 13a. Next, a first fluid supply passage 29 is created by cutting, extending horizontally from the first side surface 39b of the first blank body 39 so as to be connected tangentially to the outer surface of the recess 19. A second fluid supply passage 33 is created by cutting, extending vertically (up and down) from the top surface 39c of the first blank body 39, and connected to the middle part of the first fluid supply passage 29. Furthermore, by machining, a fluid passage extending horizontally from the second side surface 39d of the first blank body 39, which is opposite the first side surface 39b, is created, and a fluid passage extending upward through the protrusion 25 is also created. The two created fluid passages are then connected to form a fluid discharge passage 37.

Next, a recess 43 opening upwards is created on the top surface 41a of the second rectangular parallelepiped blank body 41, which is compression-molded from PTFE, by machining. The recess 43 is manufactured such that the length (depth) from the bottom surface of the recess 43 to the opening is greater than the length (i.e., height) of the cylindrical wall portion 21 protruding from the first interface surface 13a. Next, a film-like or plate-like resin assembly 45, formed from PFA, is placed inside the recess 43 of the second blank body 41. The resin assembly 45 is manufactured such that its height is less than the depth of the recess 43, so that it does not protrude above the recess 43 when placed inside. The resin assembly 45 may be manufactured by machining, extrusion molding, or injection molding, or by filling the recess 43 with PFA powder or pellets.

Next, the first blank body 39 is placed on top of the second blank body 41, which contains the resin assembly 45 in the recess 43, so that the cylindrical wall portion 21 formed on the first blank body 39 is in contact with the resin assembly 45. Furthermore, the first blank body 39, the second blank body 41, and the resin assembly 45, positioned in this state, are placed in a heating furnace and heated to at least above the melting point of the third fluororesin material, PFA. As a result, the first blank body 39 and the second blank body 41, formed from the first fluororesin material and the second fluororesin material, which is poorly soluble PTFE, do not gel and melt even if heated above the melting point of PTFE, and thus maintain the shape of the cylindrical wall portion 21 and the recess 43. On the other hand, the resin assembly 45, formed from the heat-sealable third fluororesin material, PFA, melts and becomes fluid because it has been heated above its melting point. Since the PTFE, the second fluororesin material forming the recess 43, is poorly soluble and the second blank body 41 maintains its shape, the resin assembly 45 remains within the recess 43 even when it melts. Furthermore, when the resin assembly 45 melts, as shown in Figure 5, the cylindrical wall portion 21 formed on the blank body 39 sinks into the resin assembly 45 until the first interface surface 13a formed on the shape-retaining first blank body 39 contacts the top surface 41a of the second blank body 41. Since the height of the cylindrical wall portion 21 is shorter than the depth of the recess 43, when the first interface surface 13a formed on the first blank body 39 contacts the top surface 41a of the second blank body 41, the tip surface of the cylindrical wall portion 21 formed on the first blank body 39 does not contact the bottom surface of the recess 43 formed on the second blank body 41. When cooled in this state, at least the tip of the cylindrical wall portion 21 does not penetrate the resin assembly 45, but sinks and becomes embedded within the resin assembly 45. In this state, the resin assembly 45 and the first blank body 39 are integrally molded and fused together, and the resin assembly 45 and the second blank body 41 are integrally molded and fused together. In the state where the resin assembly 45 and the second blank body 41 are integrally molded and fused together, the bottom surface of the recess 43 of the second blank body 41, which is in contact with the bottom surface of the resin assembly 45, forms the second interface surface 15a.

Next, the vortex-type fluid mixer 11 can be manufactured as shown in Figure 6 by machining the first blank body 39, the second blank body 41, and the resin assembly 45, which are integrally molded and fused together. Specifically, the main body 13 is manufactured by machining to create the first inlet connection end 27, the second inlet connection end 31, and the outlet connection end 35 at the ends of the fluid supply passage 29, the second fluid supply passage 33, and the fluid discharge passage 37 of the first blank body 39, respectively. Furthermore, the joining member 15 and the intermediate member 17 (i.e., the lid member), which are integrally molded via the second interface 15a, are manufactured by machining the sides and bottom of the second blank body 41 and the resin assembly 45 until they are flush with the outer circumferential surface of the cylindrical wall portion 21. In the vortex-type fluid mixer 11 thus constructed, the bottom surface of the first blank body 39 surrounding the cylindrical wall portion 21 constitutes the first interface surface 13a, and the top surface of the joining member 15 that contacts the bottom surface of the intermediate member 17 (the portion produced from the bottom surface of the recess 43 of the second blank body 41) constitutes the second interface surface 15a.

The cylindrical wall portion 21 of the main body 13 is integrally molded and fused with the intermediate member 17 without penetrating the intermediate member 17, which is formed integrally with the joining member 15. At least the tip portion is embedded and embedded within the intermediate member 17. This ensures that the recess 19 of the main body 13 is sealed by the joining member 15 and the intermediate member 17, forming the space that constitutes the vortex chamber 23. Furthermore, since the tip portion of the cylindrical wall portion 21 is integrally molded with the intermediate member 17 at least on its inner circumferential surface and tip surface (top surface), the space between the main body 13, the joining member 15, and the intermediate member 17 is reliably sealed, preventing fluid in the internal space from leaking to the outside from between the main body 13, the joining member 15, and the intermediate member 17. Additionally, since the cylindrical wall portion 21 sinks into the resin assembly 45, which forms the intermediate member 17, in a molten state, a step is formed at the connection point between the cylindrical wall portion 21 and the intermediate member 17, preventing the formation of a stagnant area.

The present invention has been described above with reference to the illustrated embodiment of the fluid device of the present invention, the vortex-type fluid mixer 11. However, the present invention is not limited to the illustrated embodiment. For example, in the illustrated embodiment, the vortex-type fluid mixer 11 is exemplified as a piping device according to the present invention. Piping device refers to a device that has a fluid flow path inside and is used as part of piping, and includes, for example, valve devices and fluid mixers. Also, in the illustrated embodiment, PTFE is used as the first and second fluororesin materials, and PFA is used as the third fluororesin material. However, the first, second, and third fluororesin materials are not limited to these. Furthermore, the manufacturing method of the vortex-type fluid mixer 11, which is an example of a 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.

11 Vortex-type fluid mixer 13 Main body 13a First interface 15 Joining member 15a Second interface 17 Intermediate member 19 Recess 21 Cylinder wall

Claims (7)

A body formed from a first fluororesin material and having a first interface,
A joining member formed from a second fluororesin material and having a second interface,
An intermediate member formed from a heat-fusible third fluororesin material and integrally molded with the joining member via the second interface,
A piping device comprising: the main body having a recess opening to the first interface; an annular cylindrical wall portion protruding from the first interface by a length less than the thickness of the intermediate member being provided around the opening of the recess; the first fluororesin material and the second fluororesin material being non-meltable fluororesin materials exhibiting non-melting properties at the melting point of the third fluororesin material; the first fluororesin material and the second fluororesin material being made of the same type of fluororesin material or different types of fluororesin material; the inner circumferential surface and top surface of the cylindrical wall portion being molded integrally with the intermediate member, with at least the tip portion of the cylindrical wall portion being submerged and embedded in the intermediate member; and a space being formed by the intermediate member and the recess. The piping device according to claim 1, wherein the main body has an inflow channel and an outflow channel that communicate with the space. The piping device according to claim 2, wherein the intermediate member is in the form of a film or a plate. The piping equipment according to any one of claims 1 to 3, wherein the thickness of the intermediate member is in the range of 50 μm to 100 mm. The piping device according to claim 4, wherein the length of the portion of the cylindrical wall that is recessed into the intermediate member is in the range of 0.5 μm to 95 mm. The piping equipment according to any one of claims 1 to 3, wherein the first fluororesin material and the second fluororesin material are PTFE. The piping equipment according to claim 6, wherein the third fluororesin material is PFA or modified PTFE.