JP4065826B2 - Manufacturing method of branch connection pipe - Google Patents

Description

  The present invention relates to a method for manufacturing a branch connection pipe in which a sub hose is connected to a main hose.

  Conventionally, as this kind of branch connection pipe, the technique of Patent Document 1 used for a hose for an engine radiator is known. The branch connection pipe is obtained by branching the sub hose from the main hose, and includes a branch connection portion in which a rubber material is injected and molded between the base of the sub hose and the main hose.

  FIG. 15 is an explanatory view illustrating a process of forming the branch connection portion 106 of the branch hose. In FIG. 15, in order to form the branch connection portion 106, the main hose 102 and the sub hose 104 are set on the main passage core 112 and the sub passage core 114, respectively, and held in a T-shape. At this time, the sub-passage core 114 is set by being brought into contact with the upper part of the main-passage core 112 or by fitting into the recess of the main-passage core 112. Then, after setting the main hose 102 in which the main passage core 112 and the sub-passage core 114 are set and the molding die 116 having the cavity 116a surrounding the connecting portion of the sub hose 104, the mold is clamped. In this state, a rubber material is injected into the cavity 116 a and further vulcanized to form the branch connection portion 106, and the sub hose 104 is integrated with the main hose 102. Then, after releasing the molding die 116, the sub-passage core 114 is extracted from above the sub-hose 104, and the main-passage core 112 is extracted from the main hose 102 in the axial direction. Is connected to the auxiliary hose 104 via the branch connection portion 106.

JP 2001-182848 A

  However, in the step of forming the branch connection portion 106, when inserting the secondary passage core 114 into the secondary hose 104 or when removing the secondary passage core 114 from the secondary hose 104, it is long in the narrow passage of the secondary hose 104. There is a problem in that workability is poor because the sub-passage core 114 must be inserted or removed over a distance. Further, there is a problem that burrs are generated at the mating surface between the end portion of the sub-passage core 114 and the main-passage core 112, and a troublesome work for removing the burrs is required.

  SUMMARY OF THE INVENTION The present invention solves the above-described problems of the prior art, and an object thereof is to provide a method for manufacturing a branch connection pipe with improved workability in setting / resetting the core.

The present invention made to solve the above problems
Preparing a main hose having a main passage and a branch port connected to the main passage and formed in the peripheral wall of the hose;
A sub hose preparation step of preparing a sub hose connected to the branch port and having a sub passage having a smaller passage area than the main passage;
A core setting step for setting a core in the main passage and the sub-passage;
A mold setting step of setting a molding die so as to surround a connection portion of the main hose and the sub hose with the core set in a cavity;
An injection step of injecting a rubber material into the cavity;
After the injection step, a mold release step of releasing the main hose and sub hose from the molding die and the core;
In the manufacturing method of the branch connection pipe provided with
As the above-mentioned core, the core for the main passage formed in the cylinder which followed the inner wall of the above-mentioned main hose by the 1st divided body divided along the axial direction and the 2nd divided body, the above-mentioned 2nd Using the core for the auxiliary passage projecting on the outer peripheral surface of the divided body and following the inner wall of the auxiliary hose,
In the center core setting step, the second split body is moved in the axial direction in the main passage and then moved in a direction crossing the axial direction, thereby penetrating the sub-pass center through the branch port. Are set in the sub-passage, and then the first divided body is inserted into the main passage and integrated with the second divided body, whereby the main passage core is inserted into the main passage. With the process of setting
In the releasing step, after the first divided body is removed from the main passage, the second divided body is moved in the direction intersecting the axial direction and then moved in the axial direction, thereby moving the sub-passage. And a step of removing from the main passage.

  In the branch connection pipe according to the present invention, the sub hose is connected to the main hose via the branch connection portion. That is, after setting the core to the main hose and sub hose, set the connecting part in the molding die so that it is surrounded by the cavity, and inject the rubber material into the cavity to make the sub hose into the branch of the main hose. After that, the molding die and the core are released.

  In such a process, in order to set the center core to the main hose and the sub hose, the second divided body is moved in the direction crossing the axial direction after moving in the axial direction in the main passage, thereby making the middle for the sub passage. The core is set in the sub-passage, and the first divided body is inserted into the main passage. In this way, the sub-passage core can be inserted into or removed from the main passage of the large-diameter main hose, not from the small-diameter sub-hose, so that the workability is excellent.

  Moreover, as a suitable aspect of the core, a configuration is provided that includes a guide mechanism that guides the first divided body in the axial direction with respect to the second divided body over the first divided body and the second divided body. Can be taken. With this configuration, the first divided body can be smoothly moved without causing a positional shift with respect to the second divided body.

  Further, as the center core, a structure in which the second divided body and the sub-pass center core are integrally formed can be used. With this configuration, the sub-passage core is not configured to be fitted to the upper portion of the second divided body, but is integrally joined. Therefore, there is no gap therebetween, and therefore, after the rubber material is injected, Does not occur.

  The sub-passage core can be configured to include a core body projecting from the upper surface of the second divided body and a moving body provided so as to be able to project and retract from the core body in the axial direction. . According to this configuration, since the movable body can be extended from the core body and inserted into the auxiliary hose further, the auxiliary hose is not crushed by the injection pressure of the rubber material forming the branch connection portion. The branch connection part covering the end of the can be made long. Therefore, the strength of connecting the secondary hose by the branch connection portion to the main hose is increased, and the pressure resistance and durability of the branch connection portion can be improved.

  In order to further clarify the configuration and operation of the present invention described above, preferred embodiments of the present invention will be described below.

A. First Embodiment (1) Schematic Configuration of Branch Hose 10 FIG. 1 is a front view showing a branch hose 10 according to a first embodiment of the present invention, in which an automobile engine and a radiator (not shown) are connected. The location where the sub hose 30 is branched from the main hose 20 is shown. FIG. 2 is a sectional end view of the branch hose 10 cut. The main hose 20 is connected to the lower part of the radiator at one end and connected to the engine at the other end, while the auxiliary hose 30 is connected to the reservoir at the other end. The main hose 20 and the sub hose 30 are connected by a branch connection portion 40.

  The main hose 20 includes an inner tube layer 21 and an outer tube layer 22 made of an EPDM rubber material, and a main passage 21a through which a cooling medium flows. A thread layer 23 is interposed between the inner tube layer 21 and the outer tube layer 22 to reinforce the main hose 20. A branch port 25 is opened at the branch portion of the main hose 20 and the peripheral wall of the hose.

  The auxiliary hose 30 has substantially the same configuration as the main hose 20 except that the diameter is 1/3 to 1/2 that of the main hose 20. That is, even in the secondary hose 30, it is formed of an EPDM rubber material, and the inner tube layer 31, the outer tube layer 32, and the thread layer 33 are laminated, and the inner tube layer 31 is used as the sub passage 31a. Further, a flange 34 extended in the radial direction is formed at the connection end of the sub hose 30. The lower surface of the flange 34 is bent in a direction perpendicular to the longitudinal direction of the auxiliary hose 30, and the thread layer 33 is also bent in the radial direction along the lower surface in the flange 34.

 The branch connection portion 40 fixes the sub hose 30 to the main hose 20 and connects the main passage 21a to the sub passage 31a. The branch connection portion 40 is formed by embedding the end portion of the sub hose 30 including the flange 34 and surrounding the part of the main hose 20 by injection molding of EPDM rubber.

  In the branch hose 10 having such a connection structure, a flange 34 is formed at the end of the sub hose 30, and the flange 34 is expanded in a direction perpendicular to the longitudinal direction and embedded in the branch connection 40. Therefore, it acts as a retaining for the main hose 20, and a large bonding strength can be obtained.

(2) Manufacturing method of branch hose 10 Next, the manufacturing method of the said branch hose 10 is demonstrated. This manufacturing method includes a manufacturing process of the main hose 20 and the sub hose 30 and a forming process of the branch connection portion 40 that connects the sub hose 30 to the main hose 20.

(2) -1 Manufacturing Process of Main Hose 20 and Sub-Hose 30 As shown in FIG. 3, first, an unvulcanized hose extrudate HA for forming the main hose 20 is manufactured and the sub-hose 30 is formed. To produce an unvulcanized hose extrudate HB. The hose extrudates HA and HB are manufactured by a normal method, that is, by winding a reinforcing yarn for forming the yarn layers 23 and 33 in a spiral manner while extruding a rubber material by an extruder. Here, as the shapes of the hose extrudates HA and HB, for example, the inner diameter of the hose extrudate HA is 27 to 37 mm, the thickness is 4.0 to 5.0 mm, and the inner diameter of the hose extrudate HB is 5.8 to 16 mm. It can be.

  Subsequently, the hose extrudate HB is vulcanized and simultaneously brazed so that the end of the sub hose 30 becomes the flange 34. FIG. 4 is an explanatory diagram for explaining the step of brazing. The brazing process is performed using the terminal forming jig 50. As shown in FIG. 4A, the terminal forming jig 50 includes a supporting plate 51, a supporting jig 53 having a center core 52 protruding from the central upper surface of the supporting plate 51, and a pressing jig 54. I have.

  In order to braze the flange 34 using the terminal forming jig 50, as shown in FIG. 4 (B), the hose extrudate HB is inserted into the center core 52 of the terminal forming jig 50, and the hose extrusion is further performed. The end of the body HB is pressed against the support plate 51 to shape the flare HBa. Subsequently, as shown in FIG. 4C, the pressing jig 54 is externally mounted on the outer periphery of the hose extrudate HB through the insertion hole 54 a of the pressing jig 54, and the flare HBa is attached by the pressing jig 54. It is crushed by pinching with the support plate 51. At this time, the thread layer 33 in the hose extrudate HB moves slightly inward at the connection end of the hose extrudate HB. In this state, the hose extrudate HB is vulcanized with a vulcanizer (not shown). Thereby, the hose extrudate HB becomes the sub hose 30 having the flange 34. At this time, since the yarn end of the yarn layer 33 is sandwiched between the support plate 51 and the pressing jig 54, it is filled with rubber and is not exposed to the outside.

(2) -2 Center core setting process Next, the process of connecting the sub hose 30 to the main hose 20 is performed. FIG. 5 is a perspective view showing the core mechanism 60 before being set on the main hose 20. The center core mechanism 60 is a mold that is inserted into the main hose 20 and constitutes a part of the molding die. The center core 61 for the main path and a sub-projecting projection on the upper part of the center core 61 for the main path. And a passage core 64.

  The main passage core 61 includes a first divided body 62, a second divided body 63, and a connection mechanism 65 that connects the first divided body 62 and one end of the second divided body 63. It has. The first divided body 62 has a sector shape that is divided along the axial direction and is larger than a semicircular cross section, and has an outer shape that is substantially the same as a part of the inner wall of the main passage 21 a of the main hose 20. A guide groove 62 a is formed on the upper surface of the main core 61 for the main passage. The second divided body 63 has a fan shape smaller than a semicircular cross section divided along the axial direction, and has the same circular cross section slightly smaller than the inner wall of the main passage 21a when combined with the first divided body 62. Configure. A guide protrusion 63 a is formed at the lower portion of the second divided body 63. The guide protrusion 63a is fitted in the guide groove 62a so as to be slidable in the axial direction, thereby constituting a guide mechanism in which the first divided body 62 is slidably guided with respect to the second divided body 63. .

  The second divided body 63 is formed with a sub-passage core 64. The sub-passage core 64 is a core that is inserted into the sub-passage 31 a of the sub-hose 30 to support the sub-hose 30. A recess 63b for placing a placement rubber SR, which will be described later, is formed around the sub-passage core 64.

  The coupling mechanism 65 is a mechanism for coupling and fixing the first divided body 62 and the second divided body 63, and includes a locking projection 65 a provided at an end of the first divided body 62, and a coupling screw. 65b. That is, the locking projection 65a hits the end surface of the second divided body 63 and is positioned, and the connecting screw 65b is screwed from the second divided body 63 to the first divided body 62, so that the second The divided body 63 is connected and fixed to the first divided body 62.

  Next, a process of setting the core mechanism 60 to the main hose 20 and the sub hose 30 will be described. FIG. 6 is an explanatory diagram for explaining the operation of setting the center core to the main hose 20. As shown in FIG. 6 (A), the second divided body 63 is inserted into the main passage 21a of the main hose 20, and the second divided body 63 is moved upward as shown in FIG. 6 (B). Thus, the sub-passage core 64 is inserted into the branch port 25 and the arc surface of the second divided body 63 is aligned with the inner peripheral wall of the main hose 20. Subsequently, after the guide groove 62a of the first divided body 62 is fitted to the guide protrusion 63a of the second divided body 63 shown in FIG. 6 (C), the first divided body 62 is moved into the main hose 20. Then, the outer peripheral surface of the first divided body 62 is made to follow the inner peripheral wall of the main hose 20. Subsequently, the second divided body 63 is fixed to the first divided body 62 by screwing the connecting screw 65b (see FIG. 5) or by inserting a connecting pin (not shown). FIG. 7 is an explanatory view for explaining a step of forming a branch connection portion by the molding die 70. As shown in FIG. 7, the rubber SR is set from the branch port 25 into the recess 63b, and the auxiliary hose 30 is inserted into the auxiliary passage core 64 and set.

(2) -3 Injection Molding Process FIG. 8 is a cross-sectional view cut in a direction perpendicular to the main hose 20, and FIG. 9 is a cross-sectional view taken along line 9-9 of FIG. The injection molding process is performed using a molding die 70. The molding die 70 is constituted by a split mold of the molds 71a and 71b, and includes a cavity 72 for forming the branch connection portion 40 together with the main passage core 61 by the molds 71a and 71b. In this step, the main hose 20 and the sub hose 30 set in the core mechanism 60 are set in the cavity 72, and then the mold is clamped. In this state, a rubber material is injected from the resin supply mechanism 74 into the cavity 72 and further vulcanized.

(3) -4 Mold Release Process This process is the reverse of the above-described core setting process after the molds 71a and 71b of the molding die 70 are opened. That is, the connecting screw 65b (see FIG. 5) is separated by loosening the first divided body 62 with respect to the second divided body 63. If a connecting pin is used instead of the connecting screw 65b, it is removed. Thereafter, the first divided body 62 is removed from the main passage 21a, and the second divided body 63 is moved in the direction crossing the axial direction and then moved in the axial direction, thereby moving the auxiliary passage 31a and the main passage. Unplug from 21a. Thereby, the branch hose 10 in which the sub hose 30 shown in FIG. 1 is connected to the main hose 20 by the branch connection portion 40 is formed.

(3) Effects of the Example The configuration of the above example provides the following effects in addition to the effects described above.
(3) -1 Since the sub-passage core 64 can be extracted from the large-diameter main hose 20 instead of the small-diameter sub-hose 30, workability is improved.

(3) -2 The sub-passage core 64 is not configured to abut or fit to the upper surface of the second divided body 63, but is formed integrally with the upper portion of the second divided body 63. , There are no gaps between them, and therefore no burrs.

B. Second Embodiment FIGS. 10 and 11 show a second embodiment. FIG. 10 is a sectional view of the molding die cut in a direction perpendicular to the main hose. FIG. 11 is a line 11-11 in FIG. FIG. The second embodiment has a feature in a configuration in which a part of the sub-passage core 64B is projected and retracted in the axial direction. That is, the sub-passage core 64B includes a core body 64Ba integrally formed on the upper surface of the second divided body 63B, and a moving body 64Bb protruding and retracting in the axial direction with respect to the core body 64Ba. Constitutes the cylinder. A storage chamber 64Bc is formed in the core body 64Ba, and a moving body 64Bb is fitted in the storage chamber 64Bc so as to be movable in the vertical direction. The storage chamber 64Bc is connected to the gas flow path 64Bf. The gas flow path 64Bf passes through the second divided body 63B in the axial direction and is connected to a gas supply means (not shown). The compressed gas is supplied to the storage chamber 64Bc via the gas supply means. It is configured to be discharged. When the gas is supplied / discharged to / from the storage chamber 64Bc by the gas supply means, the moving body 64Bb appears and disappears with respect to the core main body 64Ba. Moreover, the upper end part of center core main body 64Ba is the front-end | tip expansion part 64Bg which expands the lower end of the sub hose 30B in flare form. The tip extension 64Bg acts as a weir that prevents the rubber material supplied into the cavity 72B from flowing toward the moving body 64Bb.

  FIG. 12 is an explanatory view for explaining the setting process of the core mechanism. In this step, the step of FIG. 6 described in the first embodiment, that is, the sub-passage core 64B is inserted into the branch port 25, and the main-passage core 61B is inserted and integrated, and the placing rubber is inserted. It is the same process until it is set (FIGS. 12A to 12C). Further, in the second embodiment, as shown in FIG. 12D, the compressed gas is supplied into the storage chamber 64Bc through the gas flow path 64Bf to move the moving body 64Bb upward. The moving body 64Bb rises until it hits the stopper 64Bh and is removed from the core body 64Ba. In this state, the moving body 64Bb extends from the upper end of the core main body 64Ba. Then, as shown in FIGS. 10 and 11, the auxiliary hose 30 </ b> B is inserted into the extended moving body 64 </ b> Bb and the core body 64 </ b> Ba. Subsequently, after mold clamping, a rubber material is injected into the cavity 72B. The rubber material injected into the cavity 72B reaches the vicinity of the upper end of the moving body 64Bb along the outer wall of the sub hose 30B, and reaches the tip extension portion 64Bg along the inner wall of the sub hose 30B. It does not flow to the tip side, that is, the connecting portion between the core body 64Ba and the moving body 64Bb. Then, after filling the cavity 72B with the rubber material, it is vulcanized.

  Subsequently, after releasing the molding die 70B, the first divided body 62B of the main passage core 61B is removed from the main hose 20, and gas is further introduced into the sub hose 30B from the opening front end side of the sub hose 30B. While supplying, gas is discharged | emitted from storage chamber 64Bc. At this time, the sub hose 30B is expanded by supplying gas into the sub hose 30B, and a gap is formed between the inner wall of the sub hose 30B and the core body 64Ba and the moving body 64Bb. Can move to. Further, the sub-passage core 64B is moved in the axial direction integrally with the second divided body 63B, and further, the second divided body 63B is moved in the axial direction to be pulled out from the main hose 20.

  In the above embodiment, since the moving body 64Bb is extended from the core body 64Ba and inserted further into the sub hose 30B, the sub hose 30B is driven by the injection pressure of the rubber material forming the branch connection portion 40B. The branch connection part 40B which covers the edge part of the sub hose 30B can be lengthened without being crushed. Therefore, the strength of connecting the sub hose 30B to the main hose 20 by the branch connection portion 40B is increased, and the pressure resistance and durability of the branch connection portion 40B can be improved.

  Further, in the step of removing the moving body 64Bb from the sub hose 30B, the step of supplying the gas from the tip opening of the sub hose 30B to expand the sub hose 30B is taken. Friction with the sub hose 30B can be reduced, and the moving body 64Bb and the sub passage center core 64B can be easily pulled out from the sub hose 30B.

  Further, the tip extension portion 64Bg formed at the tip of the core body 64Ba is dammed so that the rubber material injected into the cavity 72B does not reach between the core body 64Ba and the moving body 64Bb. It is hard to generate burr. Accordingly, not only does the hindrance to the operation of moving the moving body 64Bb backward, but burrs are not left in the flow path of the sub hose 30B.

C. Third Embodiment FIG. 13 is a cross-sectional view of a molding die according to a third embodiment cut in a direction perpendicular to the main hose. The third embodiment is characterized by a mechanism for mechanically driving the moving body of the second embodiment. That is, the moving body 64Ce is configured to be spline-fitted so as to be movable in the axial direction with respect to the core main body 64Ca and to be projected and retracted by the drive mechanism 64Cj. The drive mechanism 64Cj includes a drive shaft 64Cj-1 that passes through the second divided body 63C and is connected to a motor (not shown), a gear 64Cj-2 that is fixed to the tip of the drive shaft 64Cj-1, and a gear 64Cj. -2 meshed with the gear -2 and a driven shaft 64Cj-4 fixed to the gear 64Cj-3. The outer peripheral portion of the distal end of the driven shaft 64Cj-4 is a screw, and is screwed into a screw formed on the axis of the moving body 64Ce. In this configuration, when the drive shaft 64Cj-1 is rotationally driven, the gear 64Cj-2 rotates integrally, the gear 64Cj-3 meshed with the gear 64Cj-2 is rotated, and the driven shaft 64Cj-4 is further rotated. The screw on the outer periphery of the shaft is screwed into the screw of the moving body 64Ce by the rotation of the driven shaft 64Cj-4, but the movement of the moving body 64Ce is restricted by the spline fitting to the center core body 64Ca. To move forward and backward in the axial direction. Even with such a mechanical configuration, the moving body 64Ce of the sub-passage core 64C can be made to appear and disappear in the axial direction.

  The present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

(1) In the above embodiment, the rubber secondary hose has been described. However, the present invention is not limited to this, and all or a part of the secondary hose is constituted by a resin connection pipe, and the connection pipe is connected to one end of the branch connection part. The structure which embeds and fixes and connects a hose to the other end part of this connecting pipe may be sufficient.

(2) Although the auxiliary hose has been described as being connected in a direction perpendicular to the axial direction of the main hose as in the above-described embodiment, it is not limited thereto, and the sub hose is connected at an inclined angle if a branch path is formed. It may be a configuration.

(3) In the above embodiment, the configuration in which the flange 34 is formed at the tip of the sub hose 30 shown in FIG. 2 has been described. However, the configuration is not limited thereto, and the tip shape of the sub hose may be a straight shape. In this case, as shown in the cross section of the branch hose 10C in FIG. 14, the inner extension portion 41C constituting a part of the branch connection portion 40 covers the main hose 20C and the inner side of the end portion of the sub hose 30C. The connection with the sub hose 30C can be firmly connected.

It is a front view which shows the branch hose concerning the 1st Example of this invention. It is sectional drawing which shows a branch hose. It is sectional drawing which shows a hose extrusion body. It is explanatory drawing explaining the process of brazing to a hose extrusion body. It is a perspective view which shows the center mechanism before being set to the main hose. It is explanatory drawing explaining the process of setting a center core mechanism to a branch hose. It is explanatory drawing explaining the injection molding process by rubber | gum. It is sectional drawing which cut | disconnected the metal mold | die for shaping | molding at the right angle direction with the main hose. FIG. 9 is a cross-sectional view taken along line 9-9 in FIG. It is sectional drawing which cut | disconnected the metal mold | die used for the manufacturing process of the branch hose concerning a 2nd Example at a right angle direction with respect to the main hose. It is sectional drawing in alignment with 11-11 of FIG. It is explanatory drawing explaining the setting process of a center core mechanism. It is sectional drawing which cut | disconnected the metal mold | die concerning 3rd Example in the axial direction of the main hose. It is sectional drawing which cut | disconnected the branch hose concerning another Example. It is explanatory drawing explaining the process of forming the branch connection part of the branch hose concerning a prior art.

Explanation of symbols

10 ... Branch hose 20 ... Main hose 21 ... Inner pipe layer 21a ... Main passage 22 ... Outer pipe layer 23 ... Thread layer 25 ... Branch 30 ... Sub hose 30B ... Sub-hose 31 ... Inner pipe layer 31a ... Sub-passage 32 ... Outer pipe layer 33 ... Thread layer 34 ... Flange 40 ... Branch connection 40B ... Branch connection Part 50 ... Terminal forming jig 51 ... Support plate 52 ... Center 53 ... Support jig 54 ... Pressing jig 54a ... Insertion hole 60 ... Center core mechanism 61. .. Core core for main passage 61B ... Center core for main passage 62 ... First divided body 62B ... First divided body 62a ... Guide groove 63 ... Second divided body 63B ... second divided body 63C ... second divided body 63a ... guide protrusion 63b ... recessed portion 64 ... center for auxiliary passage 64Cj-1 ... drive shaft 64Cj-2 ... gear 64Cj-3 ... gear 64Cj-4 ... driven shaft 64B ... sub-passage core 64Ba ... core core body 64Bb ... moving body 64Bc ... Storage chamber 64Bf ... Gas flow path 64Bg ... End extension 64Bh ... Stopper 64C ... Middle core for secondary passage 64Ca ... Core body 64Ce ... Moving body 64Cj. Drive mechanism 65 ... Connection mechanism 65a ... Locking projection 65b ... Connection screw 70 ... Mold for molding 70B ... Mold for molding 71a, 71b ... Mold 72 ... Cavity 72B ... Cavity 74 ... Resin supply mechanism HA, HB ... Hose extrudate HBa ... Flare SR ... Rubber

Claims (4)

Preparing a main hose (20) having a main passage (21a) and a branch port (25) connected to the main passage (21a) and formed in the peripheral wall of the hose;
A sub hose preparation step of preparing a sub hose (30) connected to the branch port (25) and having a sub passage (31a) having a smaller passage area than the main passage (21a);
A core setting step of setting a core in the main passage (21a) and the sub-passage (31a);
A mold setting step of setting a molding die (70) so as to surround a connection portion of the main hose (20) and the sub hose (30) set with the core with a cavity (72);
An injection step of injecting a rubber material into the cavity (72);
A mold release step of releasing the main hose (20) and the sub hose (30) from the molding die (70) and the core, after the injection step;
In the manufacturing method of the branch connection pipe provided with
A main passage formed as a cylinder that follows the inner wall of the main hose (20) by the first divided body (62) and the second divided body (63) divided along the axial direction as the center. Using a middle core for use (61) and a middle core for sub-passage (64) projecting on the outer peripheral surface of the second divided body (63) and following the inner wall of the sub-hose (30),
In the center core setting step, the second split body (63) is moved in the main passage (21a) in the axial direction and then moved in a direction intersecting the axial direction, whereby the sub-passage core ( 64) passes through the branch port (25) and is set in the auxiliary passage (31a), and then the first divided body (62) is inserted into the main passage (21a) and the second passage is inserted. A step of setting the core for the main passage (61) in the main passage (21a) by being integrated with the divided body (63) of
In the mold release step, the first divided body (62) is removed from the main passage (21a), and then the second divided body (63) is moved in a direction intersecting the axial direction, and then the shaft is moved. A branch connecting pipe manufacturing method comprising the step of pulling out from the sub passage (31a) and the main passage (21a) by moving in a direction. In the manufacturing method of the branch connection pipe of Claim 1,
As the center, the first divided body (62) and the second divided body (63) are arranged at a portion where the first divided body (62) and the second divided body (63) are in contact with each other. The manufacturing method of the branch connection pipe using what was provided with the guide mechanism guided to the said axial direction with respect to said. In the manufacturing method of the branch connection pipe of Claim 1 or Claim 2,
A method for manufacturing a branch connection pipe, wherein the second core (63) and the sub-passage core (64) are integrally formed as the core. In the manufacturing method of the branch connection pipe in any one of Claims 1 thru | or 3,
The sub-passage core includes a core main body (64Ba) protruding from the upper surface of the second divided body (63B), and a movable body (64Bb) provided so as to be able to protrude and retract in the axial direction from the core main body (64Ba). And a branch connecting pipe manufacturing method.

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