JP2005125757A - Method for producing tube resin joint and tube resin joint produced by the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a tube resin joint which improves sealing properties by uniformly fusion-bonding the molding parts of the joint side terminal part of a tube and a resin joint member and makes the design of the shapes and wall thicknesses of a heating tube and a joint part have a degree of freedom and the tube resin joint produced by the method. <P>SOLUTION: First, a core bar 4 of the same diameter is inserted by a prescribed length into the joint side terminal part 1a of a tube body 1, the vicinity of the joint side terminal part 1a of the tube body 1 is set in an approximately middle part between the upper mold 3a and lower mold 3b of a split mold 3, and the molds are clamped. After that, the joint side terminal part 1a of the tube body 1 and a space part X between the core bar 4 and the split mold 3, namely a molten resin material W is injected from an injection hole 5 into molding recesses 6a and 6b for molding the connection part 2a and screw connection part 2b of the joint member 2. After the curing of the resin material W, the split mold 3 is released while being divided, and a product Wx in which the tube body 1 and the joint member 2 are integrated is demolded from the split mold 3. The core bar 4 is extracted from the joint side terminal part 1a of the tube main body 1 to finish molding work. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a tube resin joint manufacturing method and a tube resin joint manufactured by the manufacturing method, and more specifically, uniform bonding of a molded portion between a joint side end portion of a resin tube and a resin joint member. The present invention relates to a tube resin joint manufacturing method and a tube resin joint manufactured by the manufacturing method capable of improving sealing performance and allowing flexibility in designing the shape and thickness of the tube and the joint portion. It is.

  Conventionally, as a structure of a pipe joint, for example, a connection between a joint body and a tubular body (tube or the like) includes a threaded portion of a push-in tubular body inserted through the tubular body and a threaded portion formed in the joint body. A screwed structure or a nut portion for tightening the screw portion at the connection portion is provided (for example, see Patent Document 1).

  As another connecting pipe structure, a structure in which a tubular body made of a fluorine-based resin and a cylindrical joint member made of a fluorine-based resin are integrally formed by heat fusion has been proposed (for example, a patent) Reference 2).

  However, in the case of the former pipe joint structure, the sealing performance at the connection part between the joint body and the cylindrical body is poor, and the nut part for tightening has a problem that the whole joint becomes large and the cost increases. was there. Therefore, the entire apparatus including the pipe using such a joint structure has a problem of low reliability related to leakage, large size, and high cost.

Further, the latter connection pipe structure needs to melt and fuse the tubular body and the tubular joint member, but it can melt and fuse only the contact portion between the tubular body and the joint member. There is a problem that it is difficult to cause leakage of a fluid flowing in the tube due to insufficient fusion. For this reason, the whole apparatus including piping using such a joint has a problem of low reliability regarding leakage.
JP-A-6-272794 Japanese Utility Model Publication No. 6-63994

  This invention pays attention to such conventional problems, and improves the sealing performance by uniformly fusing the molded portion of the tube joint side end portion and the resin joint member, and further, the shape of the heating tube and the joint portion. The tube resin joint manufacturing method that can be manufactured at low cost because it can be integrated with the tube at the same time as the molding of the joint member when mass production is possible. An object of the present invention is to provide a tube resin joint manufactured by the manufacturing method.

  In order to achieve the above object, the present invention provides a tube resin joint manufacturing method in which a metal core is inserted into a joint-side end portion of a tube body, and the vicinity of the joint-side end portion of the tube body is placed in a split mold. After disposing and clamping, the molten resin material is injection-molded into the joint-side end portion of the tube main body and the space between the core metal and the split mold, and after the resin material is cured, it is demolded and the tube The gist is to integrally form the main body and the joint member.

  Further, another method of manufacturing the tube resin joint of the present invention is to expand the joint side end portion of the tube body in advance, and insert a cored bar from the joint side end portion of the tube body expanded in this state, After the vicinity of the joint-side end portion is placed in the split mold and clamped, the molten resin material is injection-molded in the space between the inner surface of the split mold and the core metal of the joint-side end portion of the tube body. Then, after the resin material is cured with respect to the tube main body, it is demolded to integrally form the tube main body and the joint member.

  Here, the inner surface or outer surface of the joint-side end portion of the tube main body, or the inner and outer surfaces and the resin-made joint member are integrally formed.

  Further, the tube body and the joint member are made of tetrafluoroethylene-perfluorovinylether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer. A thermoplastic fluororesin such as coalescence (ETFE) or polyvinylidene fluoride (PVDF) is used.

  Further, the gist of the tube resin joint of the present invention is that a joint member made of resin is integrally formed by injection molding at the joint side end portion of the tube main body.

  The tube body can be made into a multilayer structure by using a resin material for the inner surface layer and the outer surface layer, or a multilayer structure by interposing a gas barrier layer between the resin inner surface layer and the outer surface layer. It is. Further, the joint member formed integrally with the tube main body integrally forms a flange portion for fixing with the counterpart device via the fastening member, and a seal member is provided at the contact portion of the flange portion with the counterpart device. Is provided.

The present invention has the following excellent effects by being configured as described above.
(a) Since it is molded integrally by injection molding, it is possible to apply appropriate pressure during molding, and the temperature of the fused part can be made uniform, so the joint side end of the tube body and the resin joint The molded part can be fused uniformly with the member, and the sealing performance can be improved.
(b) Since it is integrally molded by injection molding, there is no restriction to heat the connection part between the joint side end part of the tube body and the resin joint member from the outside, and the shape of the connection part and the thickness of the tube The thickness can be designed compactly and freely.
(c) When mass-produced, it can be produced at low cost because it can be integrated with the tube simultaneously with the formation of the joint member.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view of a tube resin joint showing a first embodiment of the present invention. 1 is a tube body, 2 is a joint member integrally formed by injection molding on a joint-side end portion 1a of the tube body 1. Is shown.

  The tube body 1 is made of a rubber material or resin material that can be melted with a resin material, and the joint member 2 has a connecting portion 2a and a screw coupling portion 2b that are integrally formed of the resin material. As an embodiment of the present invention, a tube main body 1 and a joint member 2 are connected to a tetrafluoroethylene-perfluorovinylether copolymer (PFA), a tetrafluoroethylene-hexafluoropropylene copolymer (FEP), four A thermoplastic fluororesin such as fluorinated ethylene-ethylene copolymer (ETFE) or polyvinylidene fluoride (PVDF) is used.

  The tube body 1 is not limited to a single-layer structure, and may be a multi-layer structure using a fluororesin for the inner surface layer and a resin material such as nylon for the outer surface layer, or ethylene vinyl between the inner surface layer and the outer surface layer. It is also possible to form a multilayer structure by interposing a gas barrier layer made of a resin material such as an alcohol copolymer (EVOH).

  Furthermore, it is desirable that the tube body 1 and the joint member 2 are made of the same resin material or a material having a higher melting point than the resin material of the tube body 1.

  In addition, when a tube having an inner surface layer made of a fluorine-based resin and an outer surface layer made of a general-purpose resin such as nylon is used and the joint is formed of a fluororesin, the inner surface layer of the tube and the resin material of the joint are welded in this embodiment Therefore, it does not come into contact with the outer surface layer of the tube that flows inside the piping, and does not attack the outer surface layer of the tube even when a corrosive fluid is used. Piping without impurity elution can be obtained.

  In addition, when a material having poor water resistance such as ethylene vinyl alcohol copolymer (EVOH) is used for the intermediate layer, in this embodiment, since the fluid flowing inside the pipe does not contact the intermediate layer, Even if the fluid containing it is made to flow, performance degradation can be eliminated.

Next, a method for manufacturing a tube resin joint will be described with reference to FIGS.
2 and 3 show a side view and a cross-sectional view taken along the line AA of the core metal 4 having the same diameter as the split mold 3 for injection molding for integrally molding the tube body 1 and the joint member 2. The split mold 3 is divided into an upper mold 3a and a lower mold 3b, an injection hole 5 is formed in a part of the divided surface S, and inner surfaces of the upper mold 3a and the lower mold 3b. Are formed with concave portions 6a and 6b for molding the connecting portion 2a of the joint member 2 and the screw connecting portion 2b.

  In this invention, as shown in FIG. 4, first, a core bar 4 having the same diameter is inserted into the joint-side end portion 1 a of the tube body 1 for a predetermined length, and the vicinity of the joint-side end portion 1 a of the tube body 1 is divided. The mold 3 is clamped by being disposed at substantially the center of the upper mold 3a and the lower mold 3b.

  After that, as shown in FIG. 5, the joint-side end portion 1a of the tube main body 1 and the space portion X between the core metal 4 and the split mold 3, that is, the connection portion 2a of the joint member 2 and the screw connection portion 2b are formed. After injecting the molten resin material W from the injection hole 5 into the molding recesses 6a and 6b for curing, and the resin material W is cured, the split mold 3 is split and opened as shown in FIG. The product Wx in which the tube body 1 and the joint member 2 are integrated is removed from the split mold 3. And as shown in FIG. 7, the metal core 4 is pulled out from the joint side terminal part 1a of the tube main body 1, and a shaping | molding operation is completed.

  At the time of molding, the tube main body 4 is held for a certain period of time in the split mold 3 heated to a predetermined temperature in a state where the core metal 4 is inserted into the joint-side end portion 1a of the tube main body 1 for a predetermined length. The joint member 2 is molded at the same time that the temperature of 1 is raised and the resin material W melted by injection molding is brought into contact with the tube body 1 in this state.

  Since the tube resin joint is integrally formed by injection molding in this way, it is possible to apply an appropriate pressure at the time of molding, and the temperature of the fused portion can be made uniform. It is possible to uniformly fuse the molded portion with the connecting portion 2a of the resin joint member 2 and improve the sealing performance. Moreover, there is no restriction | limiting which heats the connection part 2a of the joint side terminal part 1a of the tube main body 1 and the resin-made coupling members 2 from the outside, The shape of the connection part 2a and the screw connection part 2b, and the thickness of the tube main body 1 are determined. Compact and free design.

  Next, FIGS. 8-14 shows 2nd Embodiment of this invention, and this embodiment integrally connects the inner and outer surface of the joint side terminal part 1a of the tube main body 1, and the connection part 2a of the joint member 2. FIG. Molded.

  That is, in this embodiment, the cored bar 4 having a small diameter portion 4a formed in part is used, and the molten resin material W is covered with the inner surface side and the outer surface side of the joint side terminal portion 1a of the tube body 1. It is comprised so that it may shape | mold integrally.

  In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the manufacturing method is omitted.

  As a manufacturing method of the second embodiment, as shown in FIGS. 9 to 11, one end of a cored bar 4 having a small diameter portion 4 a formed on a part of the joint-side end portion 1 a of the tube body 1 has a predetermined length. The tube body 1 is inserted and the vicinity of the joint-side end portion 1a of the tube body 1 is disposed in the substantially central portion of the upper die 3a and the lower die 3b of the split mold 3 and clamped.

  After that, as shown in FIG. 12, the joint-side end portion 1a of the tube main body 1 and the space portion X between the core metal 4 and the split mold 3, that is, the connection portion 2a and the screw connection portion 2b of the joint member 2 are formed. The molten resin material W is injected from the injection hole 5 into the molding recesses 6a and 6b. Then, the melted resin material W flows so as to cover the inner surface side and the outer surface side of the joint-side end portion 1 a of the tube body 1 by the small diameter portion 4 a of the core metal 4, and further into the entire space portion X of the split mold 3. Filled.

  And after the resin material W hardens | cures, as shown in FIG. 13, the division | segmentation metal mold | die 3 is divided | segmented and it open | releases in the state, The product Wx with which the tube main body 1 and the coupling member 2 were integrated is divided | segmented metal mold | die 3 Then, as shown in FIG. 14, the cored bar 4 is pulled out from the joint-side end portion 1a of the tube main body 1 to complete the molding operation.

  Since other configurations and operations are the same as those in the first embodiment, the same reference numerals are given and description thereof is omitted.

  Next, FIG. 15 to FIG. 21 show a third embodiment of the present invention. This embodiment shows a modification of the second embodiment, and uses a straight cored bar 4 without a step. In this way, the inner surface of the tube main body 1 and the inner surface of the connecting portion 2a of the joint member 2 are formed to be flush with each other.

  That is, in this embodiment, by using a straight cored bar 4, the cored bar 4 can be easily removed after injection molding, and the inner diameter of the joint-side end portion 1 a of the tube body 1 is reduced. In addition, the flow resistance of the fluid can be reduced, and a multi-layer tube can also be used.

  In the following description, the same constituent elements as those in the second embodiment are denoted by the same reference numerals, and the manufacturing method is omitted.

  As shown in FIG. 18, in the manufacturing method of the third embodiment, the joint-side terminal portion 1a of the tube main body 1 is expanded in advance, and in this state, the joint-side end portion 1a of the tube main body 1 is expanded from the core-side terminal portion 1a. One end of the tube body 1 is inserted for a predetermined length, and the vicinity of the joint-side end portion 1a of the tube main body 1 is disposed in a substantially central portion of the upper mold 3a and the lower mold 3b of the split mold 3 and clamped. The split mold 3 is preferably heated to a predetermined temperature using a temperature control device, and the dimensions of the pipe expansion of the joint-side end portion 1a are the same as that of the expanded part when the split mold 3 is closed. It is desirable that the outer diameter is in contact with the inner surface of the split mold 3.

  Thereafter, as shown in FIG. 19, the space X between the inner surface of the split mold 3 of the joint-side end portion 1a of the tube main body 1 and the cored bar 4, that is, the connection portion 2a and the screw connection portion 2b of the joint member 2 The molten resin material W is injected from the injection hole 5 into the molding recesses 6a and 6b. Then, the melted resin material W flows along the surface of the core metal 4 into the inner surface side of the joint-side end portion 1a of the tube body 1, and is caused by heat conduction from the split mold 3 that has been temperature-controlled in advance by a temperature adjusting device. The expanded portion of the joint-side end portion 1a of the heated tube body 1 is further heated by the temperature of the molten resin material W and expanded by the pressure of the injected resin material W, so that the upper mold of the split mold 3 It deform | transforms and crimps | bonds to the form along the form of 3a and the lower mold | type 3b.

  In such a state, the resin material W is filled in the entire space portion X of the split mold 3 so that the inner surface of the tube body 1 whose inner surface is in a molten state or close to melting and the injected resin material W are integrated. Are welded.

  In addition, when the injected resin material W spreads thinly on the inner surface of the tube body 1 as in the second embodiment, the volume of the injected resin material W is small and the heat capacity is small. The tube body 1 may not be heated sufficiently and cannot be welded sufficiently. However, in the embodiment of the present invention, since the joint-side end portion 1a of the tube body 1 is expanded in advance, the injected resin material W Since it goes around the inner surface of the tube body 1 in large quantities, it has a heat capacity and welding occurs sufficiently.

  Thus, after the filled resin material W is hardened, the cored bar 4 is drawn from the joint-side end portion 1a of the tube main body 1 to complete the molding operation as shown in FIG. In this case, as described above, by using a straight cored bar 4, the cored bar 4 can be easily removed after injection molding.

  Then, as shown in FIG. 21, the divided mold 3 is opened with the upper mold 3 a and the lower mold 3 b divided, and the product Wx in which the tube body 1 and the joint member 2 are integrated is separated from the divided mold 3. Demold to complete the molding operation. Since other configurations and operations are the same as those in the second embodiment, the same reference numerals are given and description thereof is omitted.

  In addition, the resin material of the surface which contacts fluid by using resin of the near characteristic, such as making the resin material used for the inner surface of a multilayer tube, and the resin material to be injection-molded into fluororesin into the embodiment of this invention. It is also possible to have the same characteristics.

  In addition, since the divided mold 3 is preheated, it may be possible that the resin material W is not cured early after the injection molding of the resin material W. In this case, the resin material W has a higher melting point than the resin material of the tube body 1. By using the material, the injection resin material is quickly cured while heating to the state where the inner surface of the tube body 1 is melted or close to melting, so that the molding speed can be increased.

  According to the third embodiment as described above, by using a straight cored bar 4, the cored bar 4 can be easily pulled out after injection molding, and the joint-side terminal portion 1 a of the tube body 1 is used. The flow resistance of the fluid can be reduced without reducing the inner diameter of the tube, and it can also be applied to a multilayer tube. Moreover, since the joint side terminal part 1a of the tube main body 1 is expanded in advance, a sufficient volume of the resin material W can be passed around the inner surface of the tube main body 1, and welding can be performed stably. In addition, when a multilayer tube is used, the inner surface can be made of only a fluororesin, so that the characteristics with respect to the fluid can be made uniform.

  Next, FIGS. 22 to 28 show a fourth embodiment of the present invention. This embodiment is for fixing a mating device (not shown) to one end of the joint member 2 as shown in FIGS. A flange portion 2c is integrally formed, and through-holes 7a and 7b for inserting fastening members such as bolts are formed on the side surface of the flange portion 2c, and a contact portion of the flange portion 2c with a counterpart device is formed. 8, a seal member 9 such as an O-ring is provided.

  The mold 10 for molding the tube resin joint of this embodiment is composed of a first mold 10a and a second mold 10b that are divided into two parts that can be engaged with each other, and a part of the dividing surface S. Is formed with a through hole 11a for inserting the joint-side end portion 1a of the tube body 1 and the flange portion 2c inside the divided first mold 10a. And a concave portion 11b is formed on the inner surface of the second mold 10b. A cored bar 12 that fits into the joint-side end portion 1a of the tube main body 1 is formed in the center portion, Protrusions 13a and 13b for forming the through holes 7a and 7b are integrally formed. Further, a projection 14 for forming a recess 13 for fitting the seal member 9 is formed on the inner surface of the second mold 10b.

  As a manufacturing method of this fourth embodiment, as shown in FIGS. 25 to 28, first, the joint side terminal portion 1a of the tube body 1 is inserted through the through hole 11a of the first mold 10a divided into two, The core metal 12 formed on the inner surface of the second mold 10b is inserted into the joint-side end portion 1a of the tube body 1 for a predetermined length, and the first mold 10a and the second mold 10b are connected as shown in FIG. Clamp the mold.

  Thereafter, as shown in FIG. 27, the molten resin material W is injected from the injection hole 5 into the joint-side end portion 1 a of the tube main body 1 and the space X between the core metal 12 and the mold 10. Then, the molten resin material W is filled in the entire space X as shown in FIG.

  Then, after the resin material W is cured, as shown in FIG. 28, the first mold 10a and the second mold 10b divided into two parts are opened in a divided state, and the joint side terminal of the tube body 1 is opened. The cored bar 12 is pulled out from the part 1a, and the product Wx in which the tube body 1 and the joint member 2 including the flange part 2c are integrated is removed from the split mold 3 to complete the molding operation.

  Since other configurations and operations are the same as those in the first embodiment, the same reference numerals are given and description thereof is omitted.

It is sectional drawing of the tube resin coupling which shows 1st Embodiment of this invention. It is a side view of the split mold for shape | molding a tube resin coupling. It is AA arrow sectional drawing of FIG. 2 which inserted the core metal into the division | segmentation metal mold | die. It is sectional process drawing of the state which has arrange | positioned the tube main body and the core metal in the division mold. It is sectional process drawing of the state which injected and filled the resin material in the division mold. It is sectional process drawing of the state which divided | segmented the division mold. It is sectional process drawing of the state which made the product in which the tube main body and the coupling member were integrated removed from the split mold. It is sectional drawing of the tube resin coupling which shows 2nd Embodiment of this invention. It is a side view of the split mold for shape | molding the tube resin coupling of 2nd Embodiment. It is the BB arrow sectional drawing of FIG. 9 which inserted the core metal into the division | segmentation metal mold | die. It is sectional process drawing of the state which has arrange | positioned the tube main body and the core metal in the division mold. It is sectional process drawing of the state which injected and filled the resin material in the division mold. It is sectional process drawing of the state which divided | segmented the division mold. It is sectional process drawing of the state which made the product in which the tube main body and the coupling member were integrated removed from the split mold. It is sectional drawing of the tube resin coupling which shows 3rd Embodiment of this invention. It is a side view of the split mold for shape | molding the tube resin coupling of 3rd Embodiment. It is CC arrow sectional drawing of FIG. 16 which inserted the core metal into the split mold. It is sectional process drawing of the state which has arrange | positioned the tube main body and the core metal in the division mold. It is sectional process drawing of the state which injected and filled the resin material in the division mold. It is sectional process drawing of the state which divided | segmented the division mold. It is sectional process drawing of the state which made the product in which the tube main body and the coupling member were integrated removed from the split mold. It is sectional drawing of the tube resin coupling which shows 4th Embodiment of this invention. It is a side view of a tube resin joint. It is a side view of the metal mold | die for shape | molding the tube resin coupling of 4th Embodiment. It is DD sectional view taken on the line of FIG. It is sectional process drawing of the state which has arrange | positioned the tube main body and the core metal in the metal mold | die. It is sectional process drawing of the state which injected and filled the resin material in the metal mold | die. It is sectional process drawing of the state which made many products with which the tube main body and the coupling member were integrated removed from the metal mold | die.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tube main body 1a Joint side terminal part 2 Joint member 2a Connection part 2b Screw connection part 2c Flange part 3 Split mold 3a Upper mold 3b Lower mold 4 Core metal 4a Small diameter part 5 Injection hole 6a, 6b Molding recessed part 7a, 7b Through hole 8 Contact part 9 Seal member 10 Mold 10a First mold 10b Second mold 11a Through hole 11b Recess 12 Core metal 13a, 13b Projection 13 Recess 14 Projection S Dividing surface X Space part W Resin material Wx Product

Claims (8)

After inserting the core metal into the joint side terminal portion of the tube main body, disposing the vicinity of the joint side terminal portion of the tube main body in the split mold and clamping, the joint side terminal portion of the tube main body and the core metal A method for manufacturing a tube resin joint, in which a molten resin material is injection-molded in a space with a split mold, and after the resin material is cured, the tube body and a joint member are integrally molded by demolding. Expand the joint side end of the tube body in advance, insert the cored bar from the joint side end of the tube body expanded in this state, and place the vicinity of the joint side end of the tube body in the split mold. After the mold is clamped, the molten resin material is injection-molded into the space between the inner surface of the split mold of the joint end of the tube body and the core metal, and the resin material is cured on the tube body, and then demolded. A method for manufacturing a tube resin joint, in which a tube body and a joint member are integrally formed. The method for manufacturing a tube resin joint according to claim 1 or 2, wherein an inner surface or an outer surface of the joint side end portion of the tube main body or an inner and outer surface and a resin joint member are integrally formed. The method for manufacturing a tube resin joint according to claim 1, 2 or 3, wherein a thermoplastic fluororesin is used for the tube body and the joint member. A tube resin joint formed by integrally molding a resin joint member to the joint side end portion of the tube body by injection molding. The tube resin joint according to claim 5, wherein the tube main body has a multilayer structure using a resin material for an inner surface layer and an outer surface layer. The tube resin joint according to claim 5, wherein the tube body has a multilayer structure in which a gas barrier layer is interposed between an inner surface layer and an outer surface layer made of resin. The joint member formed integrally with the tube main body integrally forms a flange portion for fixing with a counterpart device via a fastening member, and a seal member is provided at a contact portion of the flange portion with the counterpart device. The tube resin joint according to claim 5, 6 or 7.

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