JP5979231B2 - Fitting mold and method for manufacturing a joint using the same - Google Patents

Description

  The present invention relates to a joint mold for molding a joint used in a water supply system or a hot water system piping system, and a method of manufacturing a joint using the same.

  Conventionally, in this type of joint, a seal member is mounted between the joint body and the pipe inserted into the joint body in order to maintain water tightness. As a method for maintaining the water tightness as described above, there are an outer diameter sealing method for sealing the outer peripheral side of the pipe and an inner diameter sealing method for sealing the inner peripheral side of the pipe. Usually, the pipe is stored with its outer peripheral surface exposed. For this reason, the foreign material and the damage | wound exist in the outer peripheral surface of a pipe. For this reason, in the case of the outer diameter sealing method, when the pipe is connected to the joint, water may leak due to foreign matters or scratches attached to the pipe. On the other hand, in the case of the inner diameter sealing method, since the sealing is performed on the inner peripheral surface of the pipe, such water leakage does not occur. The joint of the inner diameter seal system has a pipe insertion space between the outer cylinder part and the inner cylinder part. In addition, a fitting groove is provided on the outer peripheral surface of the inner cylinder portion, and a sealing member is fitted in the fitting groove.

  This type of inner diameter seal type pipe joint is disclosed in Patent Document 1. A pipe joint consists of a joint main body which constitutes the whole channel, and an outer skin which covers a joint main body. The joint body is formed by injection molding. The outer skin is formed in the joint body by inserting the joint body into the mold and injecting the outer skin resin. According to this structure, the joint main body and outer skin which comprise a pipe joint are separate members. It is also necessary to insert-mold after molding the joint body and to form the outer skin on the outside of the joint body. For this reason, the structure of a pipe joint becomes complicated and the manufacturing method of a pipe joint also becomes complicated. Therefore, there is a demand for a joint in which the inner tube portion and the outer tube portion are integrated with the joint body and easy to manufacture.

  As such a joint, a pipe joint described in Patent Document 2 is known. The pipe joint disclosed in this document includes a joint base having an inner cylinder portion inserted along the inner peripheral surface of the pipe. An outer cylinder part is integrally formed on the joint base so as to cover the inner cylinder part. A water-stopping O-ring as a sealing member and an oxygen-impermeable O-ring are fitted side by side in a groove formed on the outer peripheral surface of the inner cylinder portion. The joint base is provided with a cap that prevents the pipe dropout prevention member from coming off.

  Patent document 3 is disclosing the plug-in type pipe joint. The pipe joint disclosed in this document is provided with a confirmation hole for confirming the tip position of a pipe inserted into the joint. The pipe joint has a double cylinder composed of an inner cylinder and an outer cylinder. A gap into which the connection pipe is inserted is formed between the inner cylinder and the outer cylinder. A seal ring is fitted into a groove formed on the outer peripheral surface of the inner cylinder. A confirmation hole is provided at a position where the seal ring can be viewed from the outside in the outer cylinder. The confirmation hole is a long hole extending in the axial direction of the pipe joint.

  By the way, according to the joint described in Patent Document 2, after mounting the water-stopping O-ring and the oxygen-impermeable O-ring on the inner cylindrical portion, the water-stopping O-ring is externally provided due to the presence of the outer cylindrical portion. It is difficult to visually recognize the oxygen-impermeable O-ring. For this reason, there is a risk of forgetting to attach the seal member to the inner cylinder portion. In this case, when a pipe is connected to the joint and water is passed, water leaks from the joint. Furthermore, since the groove is provided on the outer peripheral surface of the inner cylinder part, it is difficult to integrally mold the inner cylinder part and the outer cylinder part at the same time. For this reason, the outer cylinder part is divided into a main body part and a part facing the circumferential groove of the inner cylinder part, and is formed in two stages. However, with this manufacturing method, the mold becomes complicated and the number of manufacturing steps increases.

  According to the pipe joint described in Patent Document 3, the entire width of the seal ring can be visually recognized from the confirmation hole. However, since the width of the confirmation hole is shorter than the length of the seal ring, the seal ring cannot be visually recognized from the confirmation hole over the entire circumference. That is, it is impossible to check the seal ring over the entire circumference as to whether or not there is a scratch on a part of the seal ring and whether or not dust or dust is attached to the seal ring. Further, when the seal ring is not attached, the entire circumference of the seal ring groove cannot be visually confirmed. For this reason, the presence or absence of flash formed in the groove for the seal ring during molding cannot be confirmed over the entire circumference of the groove.

  When manufacturing this pipe joint, first, an inner cylinder having a seal ring groove is formed integrally with the joint body. Thereafter, the outer cylinder formed separately from the joint body is screwed into the joint body to integrate both members. Therefore, it is necessary to prepare a mold for the joint body and a mold for the outer cylinder separately, and it is also necessary to form the joint body and the outer cylinder part separately and assemble them. Therefore, manufacture of a pipe joint is troublesome.

JP 2005-233363 A JP 2008-95899 A JP-A-2005-48916

  An object of the present invention is to provide a forming die for a joint that has a simple configuration and can easily form a joint, and a method for manufacturing a joint using the same.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a joint mold for injecting molten resin into a cavity formed inside to mold a joint. The joint has a synthetic resin joint body, and the joint body is integrally formed with an inner cylinder part and an outer cylinder part that form an insertion space into which a pipe is inserted, and a seal member is fitted on the outer peripheral surface of the inner cylinder part. The groove between the pipe and the inner cylindrical portion inserted into the insertion space is sealed by the seal member fitted in the fitting groove, and the fitting groove and the fitting are fitted in the outer cylindrical portion. A pair of visual recognition windows for visually confirming the seal member fitted in the groove is provided from the outside, and one visual recognition window is provided at each position facing the outer cylinder portion. The joint is configured such that the entire circumference and the entire width of the fitting groove can be visually recognized through the visual recognition window when the seal member is not attached. The mold for joint has a fixed side split mold and a movable side split mold that form a cavity, and a core assembled to the fixed side split mold and the movable side split mold. The fixed side split mold and the movable side split mold Forming the outer peripheral surface of the joint body, the core forming the outer cylinder part, the inner cylinder part, the fitting groove and the viewing window, and the core is formed with an insertion hole for inserting the protruding mold, Forms the fitting groove and the viewing window.

  According to this configuration, the joint mold has the fixed side split mold, the movable side split mold, the core, and the protruding mold that is inserted into the insertion hole of the core. Further, the core with the protruding mold inserted into the insertion hole is disposed in the fixed split mold, the movable split mold is closed to the fixed split mold, and the molten resin is injected into the cavities in both split molds. If it does in this way, shaping | molding of a coupling main body will be completed in a short process and a short time by simple operation. Therefore, the configuration is simple, and the joint can be easily and quickly formed.

  In the above-described joint molding die, the protruding die is preferably assembled to the core, or provided in the fixed-side split mold and the movable-side split mold.

  In the above-described joint mold, it is preferable that a protrusion for forming the fitting groove is provided at the end of the protrusion mold.

  In the above-described joint mold, the protrusion is preferably formed in a semicircular shape.

  In the above-described joint molding die, the viewing window is formed in a front square shape, and the length and width of the protruding mold forming the viewing window are set to be larger than the length and width of the protrusion forming the fitting groove. It is preferable.

  In order to achieve the above object, according to a second aspect of the present invention, a method of manufacturing a joint using a joint mold is provided. This manufacturing method includes a step of inserting a protruding die into an insertion hole of a core, a step of assembling the core to a fixed side split die, a movable side split die and a fixed side split die, and clamping. And a step of injecting molten resin into a cavity in a mold and molding a joint.

The perspective view which shows the state which assembled | attached the protrusion type | mold to the core of the shaping | molding die for couplings which concerns on 1st Embodiment of this invention, and has arrange | positioned above the stationary-side split type | mold. The perspective view which decomposes | disassembles and shows a core and a protrusion type | mold. The perspective view which shows the state which assembled | attached the core to the fixed side division type and has arrange | positioned the movable side division type above the fixed side division type. Sectional drawing which shows the state which closed the movable side division type to the fixed side division type. Sectional drawing which shows the state which injected molten resin in the cavity. The perspective view which shows the state which released the movable side split mold from the fixed side split mold after shaping | molding. The perspective view which shows the molded object taken out with the core from the split mold. The perspective view which shows the coupling main body obtained by removing a protrusion type | mold and a core from the molded object of FIG. (A) is a plan view of the joint body, (b) is a front view of the joint body, and (c) is a right side view of the joint body. The perspective view which shows the state in which components and a pipe are assembled | attached to a coupling main body. Sectional drawing which shows the state which connected the pipe to the coupling. FIG. 9 is a perspective view showing a joint mold according to a second embodiment of the present invention, in which a protruding mold is provided on a fixed-side split mold, and a core is disposed above the fixed-side split mold. The perspective view which shows the state which assembled | attached the core in the fixed side division type, and has arrange | positioned the movable side division type above the fixed side division type. The perspective view which shows the state which released the movable side split mold from the fixed side split mold after shaping | molding. The perspective view which shows the molded object taken out with the core from the split mold. The perspective view which shows the state which removed the core from the molded object of FIG. The perspective view which shows the core and protrusion type | mold which comprise the shaping | molding die for couplings concerning 3rd Embodiment of this invention. The perspective view which shows the state which has arrange | positioned the core which assembled | attached the protrusion type | mold above the fixed side division | segmentation type | mold. (A) is a plan view of the joint body, (b) is a front view of the joint body, and (c) is a right side view of the joint body.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS.

  As shown in FIGS. 9A to 9C, the joint body 11 includes a pair of cylindrical pipe connecting portions 13 to which the resin pipe 12 is connected. Each pipe connection part 13 is provided so as to face the opposite direction. The joint body 11 is made of a synthetic resin containing rubber, specifically, a polyphenylene sulfide resin (PPS resin) mixed with rubber. The resin pipe 12 is made of a synthetic resin such as polyolefin (crosslinked polyethylene, polybutene, etc.). Since each of the pair of pipe connection portions 13 has the same configuration, only one of the pipe connection portions 13 will be described.

  As shown in FIGS. 10 and 11, the joint main body 11 is integrally formed with an inner cylinder portion 15 and an outer cylinder portion 16. The inner cylinder part 15 and the outer cylinder part 16 form an insertion space 14 into which the resin pipe 12 is inserted. A pair of fitting grooves 17 are provided side by side on the outer peripheral surface of the inner cylinder portion 15. A seal member 18 made of ethylene-propylene-diene copolymer rubber (EPDM) is fitted in each of the pair of fitting grooves 17. The seal member 18 seals between the inner peripheral surface of the resin pipe 12 inserted into the insertion space 14 and the outer peripheral surface of the inner cylindrical portion 15. The pair of fitting grooves 17 are disposed on the inner side of the outer end of the outer cylinder portion 16 in order to suppress the length of the joint body 11. The space in the inner cylinder portion 15 is a flow path 19 through which a fluid such as water flows.

  A cylindrical spacer 20 is inserted into the insertion space 14. When the resin pipe 12 is inserted into the insertion space 14, the spacer 20 comes into close contact with the outer peripheral surface of the resin pipe 12. The spacer 20 is made of a transparent resin such as a polyamide resin. According to this configuration, the inside of the spacer 20 can be seen through, and entry of dust into the insertion space 14 is blocked.

  In the vicinity of the outer end of the spacer 20, a retaining mechanism 21 is provided for holding the resin pipe 12 inserted into the insertion space 14 so as not to come off. The retaining mechanism 21 includes a retaining ring 22 made of stainless steel or the like. A plurality of retaining pieces 22 a projecting obliquely are formed on the inner peripheral portion of the retaining ring 22. The retaining piece 22a bites into the outer peripheral portion of the resin pipe 12 inserted into the insertion space 14, and holds the resin pipe 12 so as not to come off.

  The retaining ring 22 is sandwiched between a PPS cap 23 and a pressing ring 24 made of polyacetal resin (POM) that covers the outer cylinder portion 16. A locking recess 23 a is provided on the inner peripheral surface of the cap 23. The locking ridge 16a of the outer cylinder portion 16 is locked to the locking recess 23a. Thereby, the cap 23 is attached to the outer cylinder part 16. By forming the cap 23 with a transparent resin, the seal member 18 can be visually recognized through the cap 23, a viewing window 25 described later, and the spacer 20.

  A split ring 26 made of PPS is interposed between the retaining ring 22 and the cap 23. By the split ring 26, the inclination angle of the retaining piece 22a is maintained. A retaining mechanism 21 for the resin pipe 12 is configured by the retaining ring 22, the holding ring 24, the cap 23, the split ring 26, and the like.

  An insertion guide 27 made of polypropylene resin (PP) is disposed in the insertion space 14. The insertion guide 27 is pressed against the distal end surface of the resin pipe 12 to guide insertion of the resin pipe 12. The insertion guide 27 is formed in a C-ring shape. The insertion guide 27 can be expanded and contracted. A cap cover 28 made of stainless steel is attached to the outer peripheral surface of the cap 23. The cap cover 28 holds the outer cylinder portion 16 so as not to come out of the cap 23.

  A pair of viewing windows 25 are provided in the outer cylinder portion 16. The visual recognition window 25 is used to look into the fitting groove 17 of the inner cylinder part 15 or the seal member 18 fitted into the fitting groove 17 from the outside. One viewing window 25 is provided at a position facing each other on the peripheral surface of the outer cylinder portion 16. The visual recognition window 25 is formed by notching the outer cylinder part 16 inward along the axial direction from the outer end thereof. The visual recognition window 25 is formed in a front square shape. The state of the fitting groove 17 of the inner cylinder part 15 and whether or not the sealing member 18 is attached to the fitting groove 17 can be confirmed from the outside by the visual recognition window 25. It is also possible to check whether or not the seal member 18 is fitted in a proper position and whether or not there are scratches, dust, dust, or the like on the surface of the seal member 18.

  As shown in FIG. 9B, the length Y of the viewing window 25 in the radial direction of the outer cylinder portion 16 (length viewed from the front) is the length of the fitting groove 17 in the radial direction of the inner cylinder portion 15. It is set to y or more. Further, the width D of the visual recognition window 25 in the axial direction of the outer cylinder portion 16 is set to be equal to or larger than the width d of the fitting groove 17 in the axial direction of the inner cylinder portion 15. By setting the length Y and the width D of the viewing window 25 as described above, the entire circumferential direction and the entire width direction of the fitting groove 17 can be seen from the viewing window 25 and the fitting window 17 is mounted. The entire circumferential direction and the entire width direction of the seal member 18 can also be visually confirmed.

  If a flash exists in the fitting groove 17, the watertightness between the inner cylinder portion 15 and the seal member 18 is impaired. For this reason, it is necessary to visually check the entire fitting groove 17 from the viewing window 25 to confirm the presence or absence of flash. In addition, when a flash exists, it is possible to remove the flash by inserting a tool from the viewing window 25. One engaging recess 29 is formed on each of both sides of the viewing window 25.

  As shown in FIG. 10, one protrusion 30 is provided at each position facing the outer end of the spacer 20. One engaging convex portion 31 is formed on each of both side surfaces of each protrusion 30. When the spacer 20 is inserted into the insertion space 14, the protrusion 30 is engaged with the visual recognition window 25, and the engagement protrusion 31 is engaged with the engagement recess 29. In this way, the spacer 20 is held so as not to come off from the joint body 11.

  In addition, a confirmation hole 32 for confirming the resin pipe 12 inserted into the insertion space 14 is formed in the outer cylinder portion 16. The confirmation hole 32 is provided at the same position as the viewing window 25 in the circumferential direction of the outer cylinder portion 16. The joint 10 is configured by assembling the seal member 18, the spacer 20, the retaining mechanism 21, the cap 23, and the like to the joint body 11.

  When the resin pipe 12 is inserted into the insertion space 14, the inner end of the resin pipe 12 is guided by the insertion guide 27 and held by the retaining mechanism 21 so as not to be detached. Thus, the resin pipe 12 is connected to each of the pipe connecting portions 13 of the joint body 11.

  Next, a joint mold for manufacturing the joint 10 will be described.

  As shown in FIGS. 1 to 3, the joint molding die 40 includes a fixed-side split die 41 and a movable-side split die 43 that is disposed to face the fixed-side split die 41. As shown in FIG. 4, each of the split dies 41 and 43 is provided with a cavity 44 for forming the outer peripheral surface of the pair of outer tube portions 16 facing in opposite directions. The outer peripheral surface of the joint body 11 is molded by closing both the split dies 41 and 43 and injecting molten resin into the cavity 44.

  When the movable side split mold 43 is clamped to the fixed side split mold 41, a core receiving recess 46 is formed inside them. A pair of cores 45 are disposed in the core housing recess 46 so as to face each other so as to form the inner cylinder part 15 and the outer cylinder part 16. A flange 47 is provided at the outer end of the core 45. An annular recess 48 extending in the axial direction of the core 45 is formed at the inner end of the core 45. The annular recess 48 is for forming the inner cylinder portion 15. An insertion hole 49 penetrating in a direction orthogonal to the axis of the core 45 is provided in an intermediate portion of the core 45.

  The protruding mold 50 is inserted into the insertion hole 49 of the core 45. A semicircular arc surface 51 is formed at the inner peripheral end of the protruding mold 50. The semicircular arc surface 51 is provided with a pair of protrusions 52 for forming the fitting groove 17 on the outer peripheral surface of the inner cylinder portion 15. A pair of protruding molds 50 are inserted into the insertion holes 49 of the core 45 and are brought into contact with each other. Accordingly, a circumferential surface is formed by the semicircular arc surfaces 51 of the two protruding molds 50, and the fitting groove 17 is formed by the protrusion 52. The inner surface of the movable side split mold 43 has the same shape as the inner surface of the fixed side split mold 41.

  At the outer end of the projecting mold 50, a bulging portion 53 for forming the viewing window 25 of the outer cylinder portion 16 in a notch shape is provided. Protrusions 56 for forming the engagement recesses 29 of the outer cylinder part 16 are provided on both sides of the protrusion mold 50. On the other hand, a protruding type accommodation recess 54 is formed on the inner surface of the fixed-side split mold 41. When the core 45 to which the protruding mold 50 is assembled is accommodated in the fixed-side split mold 41, the protruding mold 50 is fitted into the protruding mold accommodating recess 54. Then, after the protruding mold 50 in which the core 45 is inserted into the insertion hole 49 is accommodated in the protruding mold receiving recess 54, the movable side split mold 43 and the fixed side split mold 41 are closed to perform molding. Thereby, a notch-like viewing window 25 is formed in the outer cylinder portion 16 of the joint body 11.

  As described above, the visual recognition window 25 is formed by the protruding mold 50, and the fitting groove 17 is formed by the protrusion 52 provided on the semicircular arc surface 51 of the protruding mold 50. From this, the length Y of the visual recognition window 25 is larger than the length y of the fitting groove 17, and the width D of the visual recognition window 25 is larger than the width d of the fitting groove 17.

  Further, a confirmation hole forming convex portion 55 extending in the circumferential direction is provided on the inner surface of the fixed-side split mold 41. The confirmation hole forming convex portion 55 is disposed on the inner side along the axial direction than the protruding type accommodating concave portion 54. The confirmation hole forming convex portion 55 is for forming the confirmation hole 32 in the joint body 11.

  Next, the manufacturing method of said coupling 10 is demonstrated with an effect | action.

  As shown in FIG. 2, first, a pair of protrusion type | molds 50 are each inserted and inserted from the up-down direction with respect to the insertion hole 49 of the core 45. As shown in FIG. At this time, the pair of protruding molds 50 are inserted to the vicinity of the center of the insertion hole 49. Thereby, both protrusion type | molds 50 are easily assembled | attached with respect to the core 45. FIG. Next, as shown in FIG. 1, the pair of cores 45 to which the protruding molds 50 are assembled are housed in the core housing recesses 46 of the fixed-side split mold 41. Note that a protruding type accommodation recess 54 is formed on the inner surface of the fixed-side split mold 41. For this reason, the core 45 to which the protruding mold 50 is assembled can be smoothly accommodated in the fixed-side split mold 41 by fitting the protruding mold 50 into the protruding mold accommodating recess 54.

  Thereafter, as shown in FIGS. 3 and 4, the movable side split mold 43 is closed with respect to the fixed side split mold 41. Thereby, the cavity 44 is formed in both the split dies 41 and 43. Then, as shown in FIGS. 5 and 6, molten resin (PPS resin) is injected into the cavity 44 from the gate 57 to mold the joint body 11. By the cavity 44, the outer cylinder part 16, the inner cylinder part 15, the visual recognition window 25, the fitting groove 17, and the confirmation hole 32 of the joint body 11 are simultaneously formed.

  As shown in FIG. 6, after cooling, the movable side split mold 43 is released from the fixed side split mold 41. Subsequently, as shown in FIG. 7, the formed joint body 11 is taken out from the fixed-side split mold 41 together with the core 45 and the protruding mold 50. At this time, the joint body 11 can be taken out together with the core 45 without difficulty. Then, as shown in FIG. 8, after the pair of protruding dies 50 are pulled out from the insertion hole 49 of the core 45 in the vertical direction, the core 45 is pulled out using the flange 47. In this case, since there is no undercut portion in the joint body 11 with respect to the core 45 and the protruding mold 50, the core 45 can be smoothly released from the protruding mold 50. Thus, the joint body 11 shown in FIGS. 9A to 9C is formed. The joint 10 is completed by assembling the seal member 18, the spacer 20, the retaining mechanism 21, the cap 23, and the like to the joint body 11.

  As described above, according to the first embodiment, the following effects can be obtained.

  (1) The joint molding die 40 includes a fixed-side split die 41 and a movable-side split die 43, and a core 45 assembled to both split dies 41 and 43. Both split dies 41 and 43 form the outer peripheral surface of the joint body 11, and the core 45 forms the outer cylinder part 16, the inner cylinder part 15, the fitting groove 17, and the viewing window 25 of the joint body 11. An insertion hole 49 is formed in the core 45. A protruding mold 50 for forming the fitting groove 17 and the viewing window 25 is inserted into the insertion hole 49. According to this configuration, the core 45 in which the protruding mold 50 is inserted into the insertion hole 49 is disposed in the fixed-side split mold 41, and both the split molds 41 and 43 are clamped to inject the molten resin, The joint body 11 is formed. Therefore, the molding of the joint body 11 is completed in a short process and in a short time by a simple operation without using the slide core.

  (2) The protruding mold 50 is assembled in the insertion hole 49 of the core 45. For this reason, it is possible to easily assemble the protruding mold 50 with respect to the core 45 or release the protruding mold 50 by simply inserting and removing the protruding mold 50 into and from the insertion hole 49 of the core 45.

  (3) A protrusion 52 for forming the fitting groove 17 is provided on the inner peripheral end of the protruding mold 50. Therefore, the fitting groove 17 can be formed on the outer peripheral surface of the inner cylinder portion 15 by the protrusion 52 of the protruding die 50 assembled to the core 45.

  (4) The protrusion 52 of the protruding mold 50 is formed in a semicircular shape. Therefore, the annular fitting groove 17 can be formed by the pair of protrusions 52.

  (5) The visual recognition window 25 is formed in a front square shape. The length and width of the protruding mold 50 that forms the viewing window 25 are set to be larger than the length and width of the protrusion 52 that forms the fitting groove 17. For this reason, the visual recognition window 25 can be formed larger than the fitting groove 17. Therefore, the entire fitting groove 17 can be viewed from the viewing window 25.

(6) When the joint body 11 is manufactured using the joint mold 40, first, the protruding mold 50 is inserted into the insertion hole 49 of the core 45. In this state, after the core 45 is assembled to the fixed-side split mold 41, the movable-side split mold 43 is closed to the fixed-side split mold 41, and the molten resin is injected into the cavity 44. In this way, the joint body 11 can be quickly manufactured only by performing a simple molding operation.
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, portions that are different from the first embodiment will be mainly described, and description of the same portions will be omitted.

  As shown in FIG. 12, the protruding mold 50 is provided in each protruding mold accommodating recess 54 of the fixed side split mold 41 and the movable side split mold 43. In this case, when the core 45 is accommodated in the fixed-side split mold 41, the protruding mold 50 of the fixed-side split mold 41 is inserted into the insertion hole 49 of the core 45. Further, when both the split dies 41 and 43 are clamped, the protruding die 50 of the movable split die 43 is inserted into the insertion hole 49 of the core 45.

  When manufacturing the joint 10, as shown in FIG. 12, first, the core 45 is accommodated in the fixed-side split mold 41. At this time, the protruding mold 50 of the fixed-side split mold 41 is inserted into the insertion hole 49 of the core 45. In this state, the movable side split mold 43 is closed to the fixed side split mold 41 as shown in FIG. Also at this time, the protruding mold 50 of the movable side split mold 43 is inserted into the insertion hole 49 of the core 45. Next, the molten resin is injected into the cavity 44 in each of the closed split molds 41 and 43.

  After that, as shown in FIG. 14, the movable side split mold 43 is released from the fixed side split mold 41. Further, as shown in FIG. 15, the joint body 11 is taken out together with the core 45 from the fixed side split mold 41. Then, as shown in FIG. 16, the joint body 11 is formed by extracting the core 45 from the joint body 11.

Therefore, according to the second embodiment, the protruding mold 50 is integrated with the split molds 41 and 43. For this reason, the number of members constituting the joint mold 40 can be reduced. Moreover, since the process of previously assembling the protruding mold 50 to the core 45 is omitted, the joint body 11 can be quickly formed.
(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. Also in the third embodiment, portions that are different from the first embodiment will be mainly described, and description of the same portions will be omitted.

  As shown in FIGS. 19A to 19C, the visual recognition window 25 is formed not in a cutout but in a front square shape. Each length of the visual recognition window 25 in the axial direction and the radial direction of the outer cylinder part 16 is set to be larger than each length of the fitting groove 17 in the axial direction and the radial direction of the outer cylinder part 16.

  As shown in FIG. 17, the bulging portion 53 and the protruding portion 56 are omitted from the protruding mold 50. The protruding mold 50 is inserted into the insertion hole 49 of the core 45.

  When manufacturing the joint main body 11, as shown in FIG. 17, first, the pair of protruding molds 50 are inserted into the insertion holes 49 of the core 45 from the up and down direction and assembled. Next, as shown in FIG. 18, the core 45 to which the protruding mold 50 is assembled is accommodated in the fixed-side split mold 41. Then, the joint main body 11 is shape | molded according to the procedure similar to 1st Embodiment.

  Therefore, according to the third embodiment, the front rectangular viewing window 25 can be easily and quickly manufactured in the outer cylinder portion 16 of the joint body 11 using the joint molding die 40 having a simple configuration.

  Each embodiment may be changed as follows.

  -You may form the visual recognition window 25 and the confirmation hole 32 in the position which differs 90 degree | times along the circumferential direction of the outer cylinder part 16, respectively. In this case, the insertion hole 49 of the core 45 is provided at a position different from the first embodiment by 90 degrees along the circumferential direction, and the protruding-type receiving recesses 54 of the fixed-side split mold 41 and the movable-side split mold 43 are provided. It may be formed so as to correspond to the insertion hole 49 of the core 45.

  In the first embodiment and the second embodiment, both side surfaces extending in the axial direction of the viewing window 25 may be tapered surfaces in which the width between both side surfaces becomes narrower toward the outer end of the outer cylinder portion 16. In this case, both side surfaces of the protruding die 50 are formed in a tapered shape.

  -The pipe connection part 13 of the coupling main body 11 is good also as a three-way branch and a four-way branch. In this case, three or four cores 45 are accommodated in both split dies 41 and 43.

  -You may change the number of the fitting grooves 17 of the inner cylinder part 15, and the sealing member 18 to 1 or 3 or more. In this case, the number of the protrusions 52 of the protruding mold 50 is also changed to 1 or 3 or more according to the number of the fitting grooves 17 and the seal members 18.

  -You may change the front shape of the visual recognition window 25 into an oval or arbitrary polygons. In this case, according to the shape of the viewing window 25, the shape of the protruding mold 50 is also changed to an oval or an arbitrary polygon.

  The material forming the joint body 11 may be a synthetic resin (engineering plastic) such as polyacetal (POM), polyphthalamide (PPA), or polyphenylsulfone (PPSU).

  In addition to the resin pipe 12, a soft metal pipe such as a copper pipe may be used.

  DESCRIPTION OF SYMBOLS 10 ... Joint, 11 ... Joint main body, 12 ... Resin pipe, 14 ... Insertion space, 15 ... Inner cylinder part, 16 ... Outer cylinder part, 17 ... Insertion groove, 18 ... Seal member, 25 ... Viewing window, 40 ... Mold for joint, 41 ... Fixed side split mold, 43 ... Movable side split mold, 44 ... Cavity, 45 ... Core, 49 ... Insertion hole, 50 ... Projection mold, 52 ... Projection, Y ... Radial direction of viewing window , Y: length in the radial direction of the fitting groove, D: width in the axial direction of the viewing window, d: width in the axial direction of the fitting groove.

Claims (6)

A fitting mold for injecting molten resin into a cavity formed inside to form a joint, wherein the joint includes a synthetic resin joint body, and a pipe is inserted into the joint body. An inner cylinder part and an outer cylinder part that form a space are integrally formed, and an outer circumferential surface of the inner cylinder part is provided with a fitting groove into which a sealing member is fitted, and the sealing member fitted into the fitting groove To seal between the pipe inserted into the insertion space and the inner cylinder part, and the outer cylinder part to visually recognize the fitting groove and the sealing member fitted in the fitting groove from the outside. A pair of viewing windows are provided, and each of the viewing windows is provided at a position opposed to the outer cylinder portion, and the joint is inserted into the fitting groove when the seal member is not mounted via the viewing window. Molds for joints that are configured so that the entire circumference and width can be visually confirmed There,
The joint mold includes a fixed-side split mold and a movable-side split mold that form the cavity, and a core that is assembled to the fixed-side split mold and the movable-side split mold.
The fixed side split mold and the movable side split mold form an outer peripheral surface of the joint body,
The core molds the outer cylinder part, the inner cylinder part, the fitting groove and the visual recognition window,
The core is formed with an insertion hole for inserting the protruding mold,
The protruding mold is characterized in that the fitting groove and the viewing window are formed.
Mold for fittings. 2. The joint molding die according to claim 1, wherein the protruding die is assembled to the core or is provided in the fixed side split die and the movable side split die. 3. The joint molding die according to claim 1, wherein a protrusion for molding the fitting groove is provided at an end of the projection die. The said protrusion is formed in the semicircle shape, The shaping | molding die for joints of Claim 3 characterized by the above-mentioned. The viewing window is formed in a front square shape,
5. The length and width of the protruding mold that forms the visual recognition window are set to be larger than the length and width of the protrusion that forms the fitting groove. The molding die for a joint according to one item. A method for producing a joint using the joint mold according to any one of claims 1 to 5,
Inserting a protruding mold into the insertion hole of the core;
Assembling the core into the fixed-side split mold;
And a step of closing the movable side split mold to a fixed side split mold, and injecting molten resin into a cavity in the joint mold, and molding the joint.

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