JPH10156959A - Bent rubber pipe having a plurality of openings, and bent rubber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bent rubber pipe which enables connection of three or more passages provided in an apparatus by a single rubber pipe and also to obtain a manufacturing method enabling manufacture of the bent rubber pipe. SOLUTION: A bent rubber pipe is manufactured so that a main passage of which the opposite ends are opened by a first opening and a second opening and a sub-passage branched outward from the main passage and opened sideward are molded integrally. In a clamping process, a first mold tool 5 and a second mold tool 9 are brought into contact with each other, a pipe external shape hole corresponding to the outside surface of the bent rubber pipe is formed thereby and a core body C corresponding to the main passage and the sub-passage is disposed fixedly in the pipe external shape hole. In a molding process, a rubber material is molded in a cavity formed by the pipe external shape hole and the core body C. In a workpiece takeout process, the bent rubber pipe provided with the core body C is taken out from the cavity and vulcanized by a vulcanizing process. In a core body takeout process, the core body C is taken out from the vulcanized bent rubber pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bent rubber pipe formed of a rubber material, and this bent rubber pipe is used as a flow path member for connecting fluid flow paths of various fluids.

[0002]

2. Description of the Related Art A conventional bent rubber pipe 90 is shown in FIG.
As shown in FIG. According to FIG. 34, one end is opened to the right through a first opening 90A, and the other end is opened in a lower side through a second opening 90B to form a "shape".
According to FIG. 35, one end of the first opening 9 is located on the right side.
0A, and the other end is also opened to the right through a second opening 90B. That is, in the conventional bent rubber pipe, only both ends are opened. The bent rubber pipe is manufactured through a kneading step, a forming step, a cutting step, a mandrel inserting step, a vulcanizing step, and a mandrel removing step. That is, in the kneading step, the raw rubber made of natural rubber (NR) or synthetic rubber (SR) is squeezed or mixed. In the forming step, the material is formed into a continuous pipe shape by extrusion, calendering, or the like. In the cutting step, the continuous rubber pipe is cut to a desired constant length. In the mandrel insertion step, the mandrel has a shape (final shape) corresponding to the bent flow path, and this mandrel is inserted into the rubber pipe cut in the cutting step. In the vulcanization step, the rubber pipe into which the mandrel is inserted is heated to form a strong bond between rubber molecules, thereby reducing plastic flow over a wide temperature range and increasing elasticity and tensile strength. Then, in the mandrel removing step, by removing the mandrel from the inside of the rubber pipe, a bent rubber pipe having both ends opened as shown in FIGS. 34 and 35 is manufactured.

[0003]

According to such a conventional bent rubber pipe, the opening is provided only at both ends and is not provided with an opening other than both ends. According to the above description, when connecting a plurality of (three or more) flow paths provided in a device using a bent rubber pipe, it is impossible to connect the flow paths with a single bent rubber pipe. It was necessary to prepare a rubber pipe, and it was difficult to reduce the manufacturing cost.

[0004] Further, in the conventional manufacturing method of inserting a mandrel into a rubber pipe, it has been extremely difficult to manufacture a bent rubber pipe having three or more openings. This is because it is extremely difficult to insert and remove the mandrel into the rubber pipe.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a bent rubber pipe capable of connecting three or more flow paths provided in equipment with a single bent rubber pipe. To provide. Another object of the present invention is to provide a method for manufacturing a bent rubber pipe that enables the manufacture of the bent rubber pipe.

[0006]

In order to achieve the above object, a bent rubber pipe having a plurality of openings according to the present invention has a first end at one end.
A main flow path in which an opening is opened and a second opening connected to the first opening is opened at the other end; a sub-flow path having one or more side openings that branch and open sideways from the main flow path; The first feature is that the main flow passage and the sub flow passage are integrally formed of a rubber material.

Further, the method of manufacturing a bent rubber pipe having a plurality of openings according to the present invention comprises: a main channel core having a shape corresponding to the main channel; a sub-channel core having a shape corresponding to the sub-channel; A core body in which a sub-flow path core is detachably mounted on the main flow path core; and a first groove corresponding to one side surface of the outer shape of the bent rubber pipe is formed in the first contact surface. A first mold;
A second mold in which a second groove corresponding to the other side surface of the outer shape of the bent rubber pipe is formed in a second contact surface abutting on the first contact surface; By contacting the first contact surface with the second contact surface of the second mold, the first groove and the second groove are formed.
Forming a pipe outer hole corresponding to the outer side surface of the bent rubber pipe by the groove and fixing and arranging a core in the pipe outer hole; and a cavity formed by the pipe outer hole and the core. A molding step of molding a bent rubber pipe by enclosing a rubber material; separating a first mold and a second mold and taking out a bent rubber pipe having a core body in a cavity; A second feature is that a vulcanizing step of heating and vulcanizing the bent rubber pipe provided with the core body; and a core body removing step of pulling out and removing the core body from the bent rubber pipe.

In addition, a main flow path core having a shape corresponding to the main flow path and a sub flow path core having a shape corresponding to the sub flow path S are provided. A core body removably disposed; a first mold having a first groove corresponding to one side surface of the outer shape of the bent rubber pipe formed in the first contact surface; and the first contact surface A second mold having a second groove corresponding to the other side surface of the outer shape of the bent rubber pipe formed on a second contact surface abutting on the second mold, and a first contact surface of the first mold. The second of the second mold
Forming a pipe contour hole corresponding to the outer face of the bent rubber pipe by the first groove and the second groove by abutting the contact surface of the core, and fixing the core body in the pipe contour hole. A molding step of molding a bent rubber pipe by enclosing a rubber material in a cavity formed by a pipe outer hole and a core; and heating and vulcanizing the formed bent rubber pipe in the cavity. A sulfurization step;
A work take-out step of separating the first mold and the second mold and taking out a bent rubber pipe provided with a core body in the cavity; a core body take-out step of pulling out and taking out a core body from the bent rubber pipe; This is a third feature.

In addition to the second and third features, a fourth feature is that the rubber material is injected into the cavity in the molding step.

Further, in addition to the second and third features, the molding step includes a first step of disposing a first plate-like rubber material in a first groove of a first mold; A second method in which the core is pressed and arranged on the plate-like rubber material and the core is fixedly arranged in the first groove.
Placing a second plate-like rubber material on the core, pressing the second groove of the second mold toward the first groove of the first mold, and setting the second mold to the second mold. A fifth step is to perform a third step of contacting with one mold.

[0011] In addition to the second and third features, the distal end of the sub-flow path core has a contact portion having a concave portion that opens toward the distal end side and is in contact with the outer periphery of the main flow path core. This is a sixth feature.

In addition to the above-mentioned second and third features, an abutting portion is provided at the end of the sub-flow channel core, through which an insertion hole through which the main flow channel core can be inserted is formed. This is the seventh feature.

In addition to the second and third features, the rear end of the main flow path core and the rear end of the sub flow path core are formed by pipe outer holes formed by a first mold and a second mold. Extending through an extension extending further outward, the extension is connected to the first
A core support groove connected to the first groove of the mold;
The fact that the core was held by the core supporting groove connected to the groove
The feature of.

In addition to the eighth feature, an extension formed at the rear end of the core of the main flow path and an extension formed at the rear end of the core of the sub flow path may be formed by a first mold. A ninth feature is that the holding member is pressed and held toward the core supporting groove by a pressing member arranged on the first contact surface.

Still further, in addition to the ninth feature, the pressing member is formed by a plate spring made of a plate-like spring material, and one end of the plate spring is fixedly arranged on the first contact surface of the first mold. The tenth feature is that the other end is elastically abutted on the extension of the main flow channel core and the extension of the sub flow channel core.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a bent rubber pipe having a plurality of openings according to the present invention will be described below. 1 is a longitudinal sectional view showing a first embodiment of a bent rubber pipe having a plurality of openings (hereinafter simply referred to as a bent rubber pipe), FIG. 2 is a perspective view of FIG. 1, and FIG. 3 is a longitudinal section showing a second embodiment of the bent rubber pipe. 4 is a longitudinal sectional view showing a third embodiment of the bent rubber pipe, FIG. 5 is a longitudinal sectional view showing a fourth embodiment of the bent rubber pipe, FIG. 6 is a perspective view of FIG. 5 of the bent rubber pipe, and FIG. FIG. 8 is a longitudinal sectional view showing a fifth embodiment of the bent rubber pipe, FIG. 9 is a longitudinal sectional view showing the seventh embodiment of the bent rubber pipe, and FIG. FIG. 16 is a longitudinal sectional view showing an eighth embodiment of the present invention.

FIGS. 1 and 2 show a first example of a bent rubber pipe.
An example will be described. Reference numeral 1 denotes a bent rubber pipe having three or more openings (hereinafter, simply referred to as a bent rubber pipe), and includes the following. M is a main flow path, and a first opening 1A opening rightward in FIG. 1 is provided at an upper end A thereof, and a second opening 1B opening leftward in FIG. Provided. In other words,
The upper part of the main flow path M is bent rightward, and the first opening 1A
To open to the right, and the lower part bends to the left,
The opening 1B is opened to the left.

The sub flow path S having one or more side openings is branched from the main flow path M to the side. In this example, two sub-channels S are provided, a first sub-channel S1 is provided above, and a second sub-channel S is provided below the first sub-channel S1.
2 are provided. The first sub flow path S1 is branched from above the main flow path M, extends rightward, and has a first side opening 2
A opens rightward. Further, the second sub flow path S2 is
Below the first sub flow path S1, it branches off from the main flow path M, extends leftward, and opens leftward by the second side opening 2B.

That is, the bent rubber pipe 1 in this embodiment
Is formed by the main flow path M and the sub flow path S, and one end A above the linear main flow path M is bent rightward to form the first opening 1
A opens rightward, and the other end B below the linear main flow path M bends leftward, and opens leftward through the second opening 1B. Further, the first sub flow path S1 is branched right from the upper side of the main flow path M so as to be understood to the right side.
A opens rightward, a second sub-flow path S2 branches leftward from a main flow path M located at a position lower than the first sub-flow path S1, and is leftward by a second side opening 2B. Open to

The bent rubber pipe 1 is manufactured by the following method. In the manufacture, first, a core C is prepared. FIGS. 11 and 1 show the core C.
This will be described with reference to FIGS. FIG. 11 is a perspective view showing a state in which the assembly of the core C is completed, and FIG.
1, FIG. 13 is a longitudinal sectional view taken along line DD of FIG. 12, FIG. 14 is a longitudinal sectional view taken along line EE of FIG.
It is.

The core C is formed by a main flow channel core Cm having a shape corresponding to the main flow channel M and a sub flow channel core Cs having a shape corresponding to the sub flow channel S. The core Cs is removably disposed on the main channel core Cm. More specifically, the main channel core Cm has a linear shape, and its upper portion is bent and extends rightward. The extended right end Cma has a length protruding further rightward from the first opening 1A of the bent rubber pipe 1. This first
The portion protruding from the opening 1A is called an extension Ct. on the other hand,
The lower part of the linear main flow path core Cm is bent and extends leftward. The extended left end Cmb has a length protruding further leftward from the second opening 1B of the bent rubber pipe 1, and a portion projecting from the second opening 1B is referred to as an extended portion Ct.

The sub-channel core Cs has a first sub-channel core Cs1 having a shape corresponding to the first sub-channel S1, and a second sub-channel core Cs1 having a shape corresponding to the second sub-channel S2. Sub-channel core Cs2
And is composed of Right end C of first sub-flow path core Cs1
s1a has a length protruding further rightward from the first side opening 2A of the first sub flow path S1, and a contact portion 3 is formed at the left end Cs1b. The portion projecting from the first side opening 2A is called an extension Ct.

The contact portion 3 will be described in detail with reference to FIG. The contact portion 3 is formed such that a concave portion 3A having a shape similar to the outer periphery of the main flow channel core Cm opens leftward so as to be detachably contacted with the outer circumference of the main flow channel core Cm. According to this example, the cross section of the main flow path core Cm is circular, and the shape of the concave portion 3A of the contact portion 3 is a semicircular shape that opens leftward. Thus, when the first sub-flow channel core Cs1 moves to the left, the concave portion 3A of the contact portion 3 is mounted in contact with the right outer periphery of the main flow channel core Cm. On the other hand, when the first sub-flow channel core Cs1 is moved rightward from the contact state, the recess 3A of the contact portion 3 is separated from the right outer periphery of the main flow channel core Cm, and the mounting is released. Therefore, the first sub-flow channel core Cs1 is detachably mounted on the main flow channel core Cm.

The left end Cs2b of the second sub-flow path core Cs2
Has a length protruding further leftward from the second side opening 2B of the second sub flow path S2, and a contact portion 3 is formed at the right end Cs2a. The portion projecting from the second side opening 2B is referred to as an extension Ct.

The contact portion 3 will be described in detail with reference to FIG. The contact portion 3 is formed such that a concave portion 3A having a shape similar to the outer periphery of the main flow channel core Cm is opened rightward so as to be detachably contacted with the outer circumference of the main flow channel core Cm. According to this example, the cross section of the main flow path core Cm is circular, and the shape of the concave portion 3A of the contact portion 3 is a semicircular shape that opens rightward. When the second sub-flow channel core Cs2 moves to the right, the concave portion 3A of the contact portion 3 is mounted in contact with the left outer periphery of the main flow channel core Cm. On the other hand, when the second sub-flow path core Cs2 is moved leftward from the contact state, the recess 3A of the contact part 3 is separated from the left outer periphery of the main flow path core Cm, and the mounting is released. Accordingly, the second sub-flow channel core Cs2 is detachably disposed with respect to the main flow channel core Cm.

The first sub-flow path core Cs1 is
Is moved to the left at a position corresponding to the sub-channel S1 of
A concave portion 3A that opens to the left of the contact portion 3 is mounted in contact with the right outer periphery of the main channel core Cm. On the other hand, the second
Is moved to the right at a position corresponding to the second sub-flow path S2, and a concave portion 3A opening rightward of the contact portion 3 is formed on the left side of the main flow-path core Cm. It is mounted in contact with the outer periphery of.

As described above, the first sub-flow channel core Cs1 and the second sub-flow channel core Cs2 are mounted on the main flow channel core Cm to form the core C. The core C is well shown in FIGS.

In manufacturing the second mold, the first mold 5
And a second mold 9 are prepared. The first mold 5 is shown in FIG. 15 and will be described with reference to the drawings. In the first mold 5,
A first contact surface 5A having a planar shape is formed upward, and a first groove 5B corresponding to one side surface 1C of the outer shape of the bent rubber pipe 1 is formed in the first contact surface 5A. You. The one side surface 1C of the outer shape refers to the outer shape of the bent rubber pipe 1 having a semicircular cross section of the lower half when the bent rubber pipe 1 is divided into two parts at the center of the longitudinal section.

Also, the first opening 1A, the second opening 1B, the first side opening 2A, the second side opening 2 of the bent rubber pipe 1
B, respectively, from the first open groove end 5B1, the second open groove end 5B2, the first side open groove end 5B3, and the second side open groove end 5B4 of the first groove 5B corresponding to B. A core support groove 5C for holding one side of each of the extensions Ct of the core C outside the extension Ct is continuously provided and formed. The core support groove 5C is formed in the first contact surface 5A with a semicircular cross section.

Further, a first groove 5B is formed on the first contact surface 5A.
A first relief groove 5D is formed to surround the outer periphery of. A first connection groove 5E having a small width h and slightly lower than the first contact surface 5A is formed between the first groove 5B and the first clearance groove 5D.

Reference numeral 6 denotes a pressing member disposed on the first contact surface 5A. One end of the pressing member 6 is the first contact surface 5.
A is fixedly arranged on A, and the other end is arranged facing core body supporting groove 5C. For example, the pressing member 6 is formed of a plate-like spring material and disposed on the first contact surface 5A, one end 6A of which is fixedly disposed on the first contact surface 5A by a screw 7, and the other. The free end of the end 6B is the core supporting groove 5C.
It is arranged facing.

Reference numeral 8 denotes a positioning pin for positioning and supporting the first mold 5 and the second mold 9, and is formed by projecting at four places on the first contact surface 5A.

The second mold 9 is arranged to face the first mold 5. The second mold 9 includes a first contact surface 5A of the first mold 5.
A second contact surface 9A having a planar shape is formed downwardly, and a second groove 9B corresponding to the other side surface 1D of the outer shape of the bent rubber pipe 1 is formed in the second contact surface 9A. Drilled. The other side 1D of the outer shape is a bent rubber pipe 1
Is the outer shape of the bent rubber pipe 1 having a semicircular cross section of the upper half when the is divided into two at the center of the vertical cross section.

The first opening 1A, the second opening 1B, the first side opening 2A, and the second side opening 2 of the bent rubber pipe 1 are also provided.
B, a first opening groove end, a second opening groove end (both not shown), and a first side opening groove end 9 of the second groove 9B corresponding to B.
B3 (shown in FIG. 17), second side opening groove end 9B
4 (shown in FIG. 18), a core support groove 9C is provided continuously to hold the other side of each extension Ct of the core C outward. You. The core supporting groove 9C has a semicircular cross section and has a second contact surface 9C.
A is drilled.

Further, a second groove 9B is formed in the second contact surface 9A.
A second clearance groove 9D is formed to surround the outer periphery of the second groove 9D. A second connection groove 9E having a minute width h and slightly lower than the second contact surface 9A is formed between the second groove 9B and the second clearance groove 9D.

In short, the second contact surface 9A of the second mold 9
A second groove 9B facing the first groove 5B and formed on the first contact surface 5A of the first mold 5;
C, a core supporting groove 9C facing the C, and a first relief groove 5D
A second escape groove 9D facing the first connection groove 5E and a second connection groove 9E facing the first connection groove 5E are formed.

The second contact surface 9A of the second mold 9 has
When the first contact surface 5A of the first mold 5 comes into contact with the second contact surface 9A, the pressing member 6 arranged on the first contact surface 5A
A pressing member escape groove 9F is formed to prevent the contact member 9 from contacting the second contact surface 9A. The pressing member escape groove 9F is shown in FIG.
7, shown in FIG.

Further, the positioning pin 8 of the first mold 5 is inserted into the second mold 9, and a positioning hole 9 G for positioning and positioning the second mold 9 on the first mold 5 is formed. Is established. The positioning holes 9G are shown in FIG.

Next, a method for manufacturing a bent rubber pipe will be described. The bent rubber pipe 1 is performed by a mold clamping step, a molding step, a work removal step, a vulcanization step, and a core body removal step.

The first mold 5 and the second mold 9 are initially arranged apart from each other between the contact surfaces 5A and 9A.
In the first groove 5B of the mold 5, a core body C in which a first sub-flow path core Cs1 and a second sub-flow path core Cs2 are mounted on a main flow path core Cm is arranged. At this time, the extending portions Ct of the outer portions of the main flow channel core Cm and the first and second sub flow channel cores Cs1 and Cs2 extend further outward from the first groove 5B. Outer extension Ct of children Cm, Cs1, Cs2
Are supported and arranged in the core support groove 5C of the first mold 5. At this time, when the upper portion of each extension Ct of each core Cm, Cs1, Cs2 is elastically pressed toward the core support groove 5C by the other end 6B of the pressing member 6, the first groove of the core C is formed. 5B can be accurately positioned in the vertical direction. Further, in such a case, the right end Cma and the left end Cmb of the main flow path core Cm and the first sub flow path core Cs1
Right end Cs1a, left end Cs2 of second sub-flow path core Cs2
b is brought into contact with the outer end 5F of each core support groove 5C in which they are arranged, the core C in the first groove 5B
Can be positioned more accurately.

FIG. 16 shows a state where the first mold 5 and the second mold 9 are separated from each other and the core C is not arranged in the first groove 5B of the first mold 5. FIG. 17 shows a state in which the first mold 5 and the second mold 9 are separated from each other,
The core C is arranged in the groove 5B, and the extending portion Ct extending outward of the first sub-flow path core Cs1 is formed in the core supporting groove 5C.
And a state where the extension portion Ct is pressed by the pressing member 6.

FIG. 18 shows a state where the core C is disposed in the first groove 5B of the first die 5 and the second sub-dial is provided when the first die 5 and the second die 9 are separated from each other. A state where the outwardly extending portion Ct of the channel core Cs2 is arranged in the core body supporting groove 5C and the extending portion Ct is pressed by the pressing member 6 is shown.

Then, the first mold 5 in the above-described state
Is brought into contact with the second contact surface 9A of the second mold 9, and the mold clamping step is performed. According to this mold clamping step, each extension portion Ct of the core C is held between the core support groove 5C of the first mold 5 and the core support groove 9C of the second mold 9, and the first groove is formed. 5B and the second groove 9B form a pipe outer shape hole P corresponding to the outer side surface of the bent rubber pipe 1 and a core C disposed inside the pipe outer shape hole P.
The core C forms the cavity C.

On the other hand, a first escape groove 5D of the first mold 5 and a second escape groove 9D of the second mold 9 form an escape hole R surrounding the outer periphery of the cavity V. The cavity V includes a first connection groove 5E of the first mold 5 and a second connection groove 5E.
Connection hole T formed by second connection groove 9E of mold 9
Contacted by The cavities V, the relief holes R and the connection holes T are well shown in FIGS.

Next, a molding step is performed. In this molding step, the rubber material in a kneaded state is directed into the cavity C through the first mold 5, the second mold 9, or gate holes (not shown) provided in the contact surfaces 5A and 9A thereof. According to this, the rubber material filled in the cavity C flows into the escape hole R through the connection hole T, whereby the rubber material is securely filled in the cavity V. it can.

Next, a work removal step is performed. The workpiece removal step is a step of separating the first mold 5 and the second mold 9 to open the mold, and removing a molded bent rubber pipe in the first groove 5B of the first mold 5; Immediately after being removed from the mold, the bent rubber pipe is in an unvulcanized state, in a state where the core C is disposed inside, and a relief formed by an escape hole R outside the bent rubber pipe. And a connecting portion connecting the relief portion and the bent rubber pipe. Since the escape portion is connected to the bent rubber pipe via a thin connection portion, the escape portion including the connection portion is more easily removed than the bent rubber pipe by applying an external force to the escape portion. The step of removing the escape portion may be performed immediately after the work take-out step, or may be performed after the vulcanization step described later is completed.

FIG. 21 is a longitudinal sectional view of the bent rubber pipe in a state where the escape portion has been removed in the work take-out step. FIG. 22 is a longitudinal sectional view taken along line FF of FIG.
FIG. 23 is a vertical sectional view taken along line GG of FIG.
As clearly shown in the drawing, the core C is still disposed in the bent rubber pipe in the work removal process.

Next, a vulcanization step is performed. Vulcanization is the process of heating a rubber material in an unvulcanized state to create strong bonds between rubber molecules, reduce plastic flow over a wide temperature range, and increase elasticity and tensile strength. In addition, a bent rubber pipe in an unvulcanized state and provided with a core C is subjected to heat treatment.

Next, a core removing step is performed. The core removal step is a step of removing the core C from the vulcanized bent rubber pipe. First, the first sub-flow path core Cs1 is taken out from the bent rubber pipe to the right in FIG. The rightward movement of the first sub-flow channel core Cs1 is because the concave portion 3A of the contact portion 3 has a semicircular shape and is disposed in contact with the right outside of the main flow channel core Cm. Can be easily removed. At the time of the removal, the outer shape of the contact portion 3 is larger than that of the first sub-flow path core Cs1, but the contact portion having a partially larger shape because the bent rubber pipe has elasticity. The removal of the part 3 is not hindered. Second, the second sub-flow path core Cs2 is taken out from the bent rubber pipe to the left in FIG. The movement of the second sub-flow channel core Cs2 to the left is because the concave portion 3A of the contact portion 3 has a semicircular shape and is disposed in contact with the left outer side of the main flow channel core Cm. Can be easily removed. In addition, at the time of such removal, the outer shape of the contact portion 3 is larger than the second sub-flow path core Cs2. However, since the bent rubber pipe has elasticity and expands at the time of removal, it is partially. The removal of the contact portion 3 having a large shape is not hindered. Third, the core Cm of the main flow path is taken out of the bent rubber pipe. In taking out the main channel core Cm, the main channel core Cm is easily taken out because the first sub-channel core Cs1 and the second sub-channel core Cs2 have already been taken out. It is.

As described above, from the inside of the vulcanized bent rubber pipe, the first sub-flow path core Cs1 and the second sub-flow path core Cs
The core body C including the core s2 and the main channel core Cm is taken out. According to this, the main channel M having the first opening 1A at one end A and the second opening 1B at the other end B is formed. It is formed by a main flow path core Cm, branches off from the main flow path M,
A first sub-flow path S1 in which the side opening 2A is opened is formed by the first sub-flow path core Cs1, which branches off from the main flow path M, and a second sub-flow path in which the second side opening 2B opens. Since the flow path S2 is formed by the second sub-flow path core Cs2, the bent rubber pipe 1 having a plurality of openings shown in FIG. 1 can be provided.

Next, another method of manufacturing the bent rubber pipe will be described. This manufacturing method is performed by a mold clamping step, a forming step, a vulcanizing step, a work removing step, and a core body removing step. In the present manufacturing method, the mold clamping step and the forming step are performed in the same manner as in the aforementioned manufacturing method. The vulcanization step is performed as follows after the molding step. In the vulcanizing step, in the molding step, a rubber material is sealed in a cavity V formed by the first mold 5 and the second mold 9, and the first mold 5 and the second mold 9 are combined. This is performed in a mold-clamped state. Heat corresponding to the vulcanization temperature is applied to the dies 5 and 9, and the bent rubber pipe in the cavity V is heated and vulcanized.

Next, in a work removing step, a bent rubber pipe which has been vulcanized and has a core body C is removed from the dies 5 and 9.

Next, the core body removing step is performed in the same manner as described above, and the bent rubber pipe 1 having a plurality of openings shown in FIG. 1 can be provided.

According to the present manufacturing method, since the bent rubber pipes in the dies 5 and 9 are directly heated by heating the dies 5 and 9, the bent rubber pipes removed from the dies 5 and 9 are vulcanized. Since the number of steps to be carried into the apparatus can be greatly reduced, the production efficiency of the bent rubber pipe can be improved, which is effective in reducing the manufacturing cost. Although the mold of the present embodiment has a single cavity, a plurality of cavities are provided for production.

In the above-mentioned manufacturing method, the rubber material is injected into the cavity V in the molding step, but the following molding step may be used. The molds 5, 9 and the core C have the same structure as the above embodiment. In the first step of the molding step, the first plate-like rubber material J1 in a kneaded state is inserted and arranged into the first groove 5B of the first mold 5. This is shown in FIG. 24, and the first relief groove 5D
A part of the first plate-like rubber material J1 may be inserted therein. In the second step, the core C is disposed on the first plate-like rubber material J1 and the core C is inserted into the first groove 5.
B, each extension of the core C is disposed in contact with the core support groove of the first mold 5, and the core C is placed in the first groove 5.
It is fixedly arranged in B. This is shown in FIG.
The extension and the core support groove are not shown. In the third step, the second plate-like rubber material J2 in a further kneaded state is placed on the first plate-like rubber material J1 and the core C.
In this state (this is shown in FIG. 26), the second mold 9 is brought into contact with the first mold 5. According to the above description, the rubber material filled in the cavity V flows into the escape hole R through the connection hole R, and the rubber material can be reliably sealed in the cavity V.

According to such a molding step, at the time of molding, the plate-like rubber material may be simply placed on the mold, so that the rubber material is injected into the cavity V using an injection machine or the like. Compared to the molding method of sealing by encapsulation, the molding is extremely easy, and the injection molding machine required for performing injection molding or the need for drilling gate holes in the mold is unnecessary, reducing the manufacturing cost It is effective in doing. In particular, such a bent rubber pipe is used for multi-cavity production in order to enhance its production effect. However, the elimination of the gate hole in such multi-cavity production makes the mold design for multi-cavity extremely easy. That can be done.

The embodiment of the bent rubber pipe 1 is shown in FIG.
However, as shown in FIG. 3, one end A side of the main flow path M turns rightward, the first opening 1A opens rightward, and the other end B side of the main flow path M turns rightward. Second opening 1
A bent rubber pipe 1 in which B opens rightward, the sub flow path S branches rightward from the main flow path M, and the side opening 2A opens rightward. As shown in FIG. 4, one end A of the main flow path M is turned rightward, the first opening 1A is opened rightward, the other end B side of the main flow path M is turned leftward, and the second opening 1B is turned leftward. And the first sub flow path S1 branches rightward from the main flow path M,
The first side opening 2A opens rightward, and the second sub flow path S2
Is bent from the main flow path M to the right, and the second side opening 2B is opened to the right. Can also be manufactured by the above manufacturing method.

Next, a core body suitable for manufacturing the bent rubber pipe shown in FIGS. 5, 7, 8, 9, and 10 will be described. In FIG. 5, the main flow path M extends vertically in the figure, and one end A thereof is bent to the right, and the first opening 1A is formed.
Open rightward, the other end B extends downward, and a second opening 1B opens downward. Also, from the top of the main flow path M, the first
Sub-channel S1 branches rightward, and the first side opening 2A opens rightward. Furthermore, the second sub flow path S2 branches leftward from the main flow path M below the first sub flow path S1, and the second side opening 2B opens leftward.

In FIG. 7, the main flow path M extends vertically in the figure, one end A turns rightward, the first opening 1A opens rightward, the other end B extends downward, and the second opening 1B extends downward. Open toward. Further, the first sub flow path S1 branches rightward from the main flow path M, and the first side opening 2A opens rightward.

In FIG. 8, the main flow path M extends vertically in the figure, with one end A opening upward through the first opening 1A and the other end B opening downward through the second opening 1B. I do. Further, the first sub flow path S1 branches rightward from the main flow path M, and the first side opening 2A opens rightward.

In FIG. 9, the main flow path M extends vertically in the figure, and one end A opens upward through the first opening 1A, and the other end B opens downward through the second opening 1B. I do. Further, the first sub flow path S1 branches rightward from above the main flow path M, and the first side opening 2A opens rightward. Further, the second sub flow path S2 branches leftward from the main flow path M below the first sub flow path S1, and the second sub flow path S2 branches to the left.
Side opening 2B opens leftward.

In FIG. 10, the main flow path M extends vertically in the figure, with one end A opening upward through the first opening 1A and the other end B opening downward through the second opening 1B. I do. In addition, the first sub flow path S1 is located from above the main flow path M.
Branch rightward, and the first side opening 2A opens rightward. Further, the second sub flow path S2 branches rightward from the main flow path M below the first sub flow path S1, and the second side opening 2B opens rightward.

What can be said in common in the bent rubber pipes 1 shown in FIGS. 5 to 10 is that at least one opening of the main flow path M opens along the longitudinal axis of the main flow path M. That is, at least the second opening 1B of the main flow path M opens downward along the longitudinal axis of the main flow path M.

A core C suitable for manufacturing the above-mentioned bent rubber pipe 1 will be described below by taking the bent rubber pipe 1 shown in FIG. 5 as an example. FIG. 28 is a perspective view showing a state where the assembly of the core C is completed. FIG. 29 is a sectional view of FIG.
FIG. FIG. 30 is a longitudinal sectional view taken along line LL of FIG. The main flow path core Cm has a linear shape,
The upper portion bends and extends rightward. The extended right end Cma has a length protruding further rightward from the first opening 1A of the bent rubber pipe 1. The portion protruding from the first opening 1A is called an extension Ct.
On the other hand, the lower part of the linear main flow path core Cm extends toward the lower end. The extended lower end Cmb has a length projecting further downward from the second opening 1B of the bent rubber pipe 1, and a portion projecting from the second opening 1B is referred to as an extended portion Ct.

The sub-channel core Cs has a first sub-channel core Cs1 having a shape corresponding to the first sub-channel S1, and a second sub-channel core Cs1 having a shape corresponding to the second sub-channel S2. Sub-channel core Cs2
And is composed of Right end C of first sub-flow path core Cs1
s1a has a length protruding further rightward from the first side opening 2A of the first sub flow path S1, and a contact portion 3 is formed at the left end Cs1b. The portion projecting from the first side opening 2A is called an extension Ct.

The contact portion 3 will be described in detail with reference to FIG. The contact portion 3 is provided with an insertion hole 3D having a shape similar to the outer periphery of the main channel core Cm so as to be detachably inserted into the outer periphery of the main channel core Cm. According to this example, the cross section of the main flow path core Cm is circular, and the shape of the insertion hole 3D of the contact portion 3 is circular. Thus, the main channel core Cm is inserted into the insertion hole 3D of the contact portion 3.

The left end Cs2b of the second sub-flow path core Cs2
Has a length protruding further leftward from the second side opening 2B of the second sub flow path S2, and a contact portion 3 is formed at the right end Cs2a. The portion projecting from the second side opening 2B is referred to as an extension Ct.

The contact portion 3 will be described in detail with reference to FIG. The contact portion 3 is provided with an insertion hole 3D having a shape similar to the outer periphery of the main channel core Cm so as to be detachably inserted into the outer periphery of the main channel core Cm. According to this example, the cross section of the main flow path core Cm is circular, and the shape of the insertion hole 3D of the contact portion 3 is circular. Thus, the main channel core Cm is inserted into the insertion hole 3D of the contact portion 3.

Then, the first sub-flow path core Cs1 is
The insertion hole 3D of the contact portion 3 is inserted into the main flow channel core Cm at a position corresponding to the sub flow channel S1, while the second sub flow channel core Cs2 is inserted into the second sub flow channel S2. At a corresponding position, the insertion hole 3D of the contact portion 3 is inserted and arranged in the main flow path core Cm.

As described above, the core member C is formed by mounting the first sub-channel core Cs1 and the second sub-channel core Cs2 on the main channel core Cm. Core C is best shown in FIG.

The core C is arranged in the pipe outer hole P formed by the first die 5 and the second die 9 in the above-described manufacturing method to form the cavities V. Each extension part Ct of the child body C is clamped and fixed by the core supporting groove 5C of the first die 5 and the second die 9.

FIGS. 31, 32 and 33 show a state in which the molding is performed by the above-described manufacturing method and the molding is taken out of the mold.

In order to take out the core C from the bent rubber pipe in the completed molding state, first, the core Cm in the main flow path is moved to the position shown in FIG.
1, the first sub-flow channel core Cs1 is taken out to the right side, and then the second sub-flow channel core Cs1 is taken out.
Take out s2 to the left. In this way, the main flow path core Cm can be taken out upward because of the main flow path core Cm.
Are inserted through the insertion hole 3D of the first sub-flow channel core Cs1 and inserted through the insertion hole 3D of the second sub-flow channel core Cs2, and the upward movement of the main flow channel core is allowed. Because it is done.

According to the use of the core C, the extension Ct of the main flow path core Cm and the first and second sub-flow path cores Cs1 and Cs2 constituting the core C are formed. The entire circumference of the main flow path core Cm is combined with the first and second sub flow path cores Cs1 and Cs2 in combination with being sandwiched by the core supporting grooves 5C of the first die 5 and the second die 9. According to this, the main flow path core Cm for forming a particularly long flow path can be more accurately arranged in the pipe outer shape hole P, and the bent rubber pipe 1 can be guided. Is effective in forming a uniform thickness.

[0075]

As described above, according to the bent rubber pipe of the present invention, the main passage having the first opening at one end and the second opening at the other end, and one or more sides branched from the main passage. Since the secondary flow path having the one opening and the secondary flow path are integrally formed of a rubber material, the bent rubber pipe can be provided as a single pipe with a bent rubber pipe having three or more openings. In addition, a plurality of flow paths can be connected at a time by a single bent rubber pipe, whereby the number of parts and the number of assembling steps can be reduced, and flow path connection in equipment can be performed at low cost. In addition, the elimination of the need for a plurality of bent rubber pipes facilitates piping design for piping, and has greatly improved the flexibility of piping in a region where piping space is limited, such as in automobile equipment.

In the method for manufacturing a bent rubber pipe,
It consists of a main flow channel core having a shape corresponding to the main flow channel, and a sub flow channel core corresponding to the sub flow channel, and these are detachably arranged to form a core body. In a mold clamping step with the two molds, a core is fixedly arranged in a pipe outer shape hole formed by the first groove and the second groove, and a cavity corresponding to a bent rubber pipe is formed. In the molding process, a rubber material is sealed in the cavity to form a bent rubber pipe,
In the work take-out step, the mold is opened to take out the bent rubber pipe with the core, and in the vulcanization step, the bent rubber pipe with the core is vulcanized, and in the core take-out step, from within the bent rubber pipe. The bent rubber pipe having a plurality of (three or more) openings could be manufactured very easily by the above-described process from which the core was taken out.

Further, in the molding step, in a state in which the rubber material is sealed in the cavity and molded, the molded bent rubber pipe in the cavity is heated by heating the mold to vulcanize the bent rubber pipe. Removing the unvulcanized bent rubber pipes from the mold and putting them into a vulcanizer to vulcanize is abolished, so efficient vulcanization work can be performed and the production efficiency of the bent rubber pipes can be reduced. The manufacturing cost was greatly reduced and the manufacturing cost was reduced.

In addition, according to the injection of the rubber material into the cavity in the molding step, it is possible to mold the bent rubber pipe by using a conventional injection molding machine, and it is possible to use a special new injection apparatus. There is no need to use

The molding step includes a first step of disposing a first plate-like rubber material in a first groove of a first mold, and a pressing and disposing of a core body on the first plate-like rubber material. According to the first step, the core is fixedly arranged in the first groove, and the third step of contacting the second mold with the first plate-shaped rubber material and the upper part of the core is performed. Since it is not necessary to form a gate hole connected to each cavity in the mold for performing the injection molding, it is particularly easy to manufacture the mold and suitable for taking a large number of bent rubber pipes.

In order to detachably mount the sub-channel core on the main channel core, a concave portion is provided at the tip of the sub-channel core, which is in contact with the outer periphery of the main channel core. According to the contact with the road core, the main flow passage and the sub flow passage are communicated with each other at the contact portion between the main flow passage core and the concave portion, and the contact between the concave portion and the main flow passage core is released. By taking out the channel core, the main channel core can be easily taken out from the bent rubber pipe.

According to the insertion of the main passage core into the insertion hole at the tip of the sub passage core, the mold for the main passage core and the sub passage core is inserted. Is more accurately positioned in the cavity, which is effective in uniformly forming the thickness of the bent rubber pipe.

Further, according to the fact that the extending portions of the main flow path core and the sub flow path core are sandwiched by the core supporting grooves of the first and second molds, the main flow path core and the sub flow path The positioning of the core in the cavity of the mold is performed more accurately, which is effective in uniformly forming the thickness of the bent rubber pipe.

Further, according to the fact that the extending portions of the main channel core and the sub channel core are pressed by the pressing member and pressed and held in the core supporting groove of the first mold, At the time of clamping with the second mold, the core does not move in the core support groove and is reliably positioned and supported in the core support groove. Since the core is held between the core supporting grooves of the two dies, the main flow path core and the sub flow path core can be positioned more accurately in the cavities of the die. This is effective in uniformly forming the thickness of the rubber pipe.

Further, the pressing member is formed of a plate-like spring material, the rear end is fixed to the first mold, and the front end is elastically attached to the extension of the main channel core and the sub channel core. According to the contact, the extending portion of each core can be reliably pressed toward the core supporting groove by the pressing member having an extremely simple structure, and furthermore, the extension of each core by the pressing member can be achieved. It is convenient that the protrusion can be easily pressed and released.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a bent rubber pipe having a plurality of openings according to the present invention.

FIG. 2 is a perspective view of FIG. 1;

FIG. 3 is a longitudinal sectional view showing a second embodiment of a bent rubber pipe having a plurality of openings according to the present invention.

FIG. 4 is a longitudinal sectional view showing a third embodiment of a bent rubber pipe having a plurality of openings according to the present invention.

FIG. 5 is a longitudinal sectional view showing a fourth embodiment of a bent rubber pipe having a plurality of openings according to the present invention.

FIG. 6 is a perspective view of FIG. 5;

FIG. 7 is a longitudinal sectional view showing a fifth embodiment of a bent rubber pipe having a plurality of openings according to the present invention.

FIG. 8 is a longitudinal sectional view showing a sixth embodiment of a bent rubber pipe having a plurality of openings according to the present invention.

FIG. 9 is a longitudinal sectional view showing a seventh embodiment of a bent rubber pipe having a plurality of openings according to the present invention.

FIG. 10 is a longitudinal sectional view showing an eighth embodiment of a bent rubber pipe having a plurality of openings according to the present invention.

FIG. 11 is a perspective view of a core used in the method of manufacturing a bent rubber pipe according to the present invention.

FIG. 12 is an upper plan view of the core body of FIG. 11;

FIG. 13 is a longitudinal sectional view taken along line DD of FIG. 11;

FIG. 14 is a longitudinal sectional view taken along line EE of FIG. 11;

FIG. 15 is a perspective view of a first mold used in the method for manufacturing a bent rubber pipe of the present invention.

FIG. 16 is a perspective view showing an arrangement state of a first die, a second die, and a core used in the method of manufacturing a bent rubber pipe of the present invention.

FIG. 17 is a longitudinal sectional view of the first sub-flow path core along the longitudinal axis in the mold open state of the method for manufacturing a bent rubber pipe of the present invention.

FIG. 18 is a longitudinal sectional view of the second sub-flow path core along the longitudinal axis in the mold open state of the method for manufacturing a bent rubber pipe of the present invention.

FIG. 19 is a longitudinal sectional view of a first sub-flow path core along a longitudinal axis in a mold clamping state of the method of manufacturing a bent rubber pipe of the present invention.

FIG. 20 is a longitudinal sectional view of a second sub-flow path core along a longitudinal axis in a mold clamping state of the method of manufacturing a bent rubber pipe of the present invention.

FIG. 21 shows a method for manufacturing a bent rubber pipe according to the present invention.
FIG. 4 is a longitudinal sectional view showing a state in which a core is arranged and molded in a bent rubber pipe.

FIG. 22 is a longitudinal sectional view taken along line FF of FIG. 21;

FIG. 23 is a longitudinal sectional view taken along line GG of FIG. 21.

FIG. 24 is a longitudinal sectional view of an essential part showing a first step of another embodiment of another forming method in the method of manufacturing a bent rubber pipe of the present invention.

FIG. 25 is a longitudinal sectional view showing a main part of another embodiment of the method of manufacturing a bent rubber pipe according to the present invention, showing a second step thereof.

FIG. 26 is a longitudinal sectional view of a main part showing a third step of the embodiment of another forming method in the method of manufacturing a bent rubber pipe of the present invention.

FIG. 27 is a vertical cross-sectional view of a principal part showing a fourth step of an example of another forming method in the method of manufacturing a bent rubber pipe of the present invention.

FIG. 28 is a perspective view showing another embodiment of the core used in the method of manufacturing a bent rubber pipe of the present invention.

FIG. 29 is a longitudinal sectional view taken along line KK of FIG. 28.

30 is a vertical sectional view taken along line LL in FIG. 28.

FIG. 31 is a longitudinal sectional view of a bent rubber pipe including a core formed by using the core shown in FIG. 28;

FIG. 32 is a longitudinal sectional view taken along line WW of FIG. 31;

FIG. 33 is a longitudinal sectional view taken along line XX of FIG. 31.

FIG. 34 is a longitudinal sectional view showing an example of a conventional bent rubber pipe.

FIG. 35 is a longitudinal sectional view showing another example of a conventional bent rubber pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bent rubber pipe 1A 1st opening 1B 2nd opening 2A 1st side opening 2B 2nd side opening 3 Contact part 3A recessed part 5 1st metallic mold 5A 1st contact surface 5B 1st groove 5C core Body support groove 6 Pressing member 9 Second mold 9A Second contact surface 9B Second groove 9C Core support groove M Main flow path S Sub flow path C Core body Cm Main flow path core Cs Sub flow path core P Pipe outer hole V Cavity J1 First plate-shaped rubber material J2 Second plate-shaped rubber material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29L 23:00

Claims (10)

[Claims] 1. A first opening 1A is opened at one end A and the other end B
A main flow path M having a second opening 1B connected to the first opening 1A; and a sub-flow path S having one or more side openings 2A and 2B branching open from the main flow path M to the side. ,
A bent rubber pipe having a plurality of openings in which the main flow path M and the sub flow path S are integrally formed of a rubber material. 2. A main flow channel core Cm having a shape corresponding to the main flow channel M, and a sub flow channel core C having a shape corresponding to the sub flow channel S.
and a core body C in which the sub flow path core Cs is detachably attached to the main flow path core Cm; on the first contact surface 5A, on one side surface 1C of the outer shape of the bent rubber pipe 1; Corresponding first groove 5
A second die 9B corresponding to the other side surface 1D of the outer shape of the bent rubber pipe 1 is formed on the first die 5 in which B is perforated; and on the second contact surface 9A contacting the first contact surface 5A. A second die 9 perforated; a first contact surface 5A of the first die 5 and a second die 9;
By making contact with the second contact surface 9A of the mold 9, the first groove 5B and the second groove 9B form a pipe external hole P corresponding to the outer surface of the bent rubber pipe 1 and the pipe external hole P A mold clamping step of fixedly disposing the core C in the inside;
A molding step of molding a bent rubber pipe by enclosing a rubber material in a cavity V formed by the pipe outer shape hole P and the core body C; separating the first mold 5 and the second mold 9 from each other;
A work removal step of taking out a bent rubber pipe provided with a core C in a cavity V; a vulcanizing step of heating and vulcanizing the bent rubber pipe provided with a core C; A method for producing a bent rubber pipe, comprising: 3. A main flow channel core Cm having a shape corresponding to the main flow channel M, and a sub flow channel core C having a shape corresponding to the sub flow channel S.
and a core body C in which the sub flow path core Cs is detachably attached to the main flow path core Cm; on the first contact surface 5A, on one side surface 1C of the outer shape of the bent rubber pipe 1; Corresponding first groove 5
A second die 9B corresponding to the other side surface 1D of the outer shape of the bent rubber pipe 1 is formed on the first die 5 in which B is perforated; and on the second contact surface 9A contacting the first contact surface 5A. A second die 9 perforated; a first contact surface 5A of the first die 5 and a second die 9;
By making contact with the second contact surface 9A of the mold 9, the first groove 5B and the second groove 9B form a pipe external hole P corresponding to the outer surface of the bent rubber pipe 1 and the pipe external hole P A mold clamping step of fixedly disposing the core C in the inside;
A molding step of molding a bent rubber pipe by enclosing a rubber material in a cavity V formed by a pipe outer hole P and a core C; and heating and vulcanizing the formed bent rubber pipe in the cavity V Vulcanizing step; first mold 5
And a second mold 9 are separated from each other, and a work take-out step of taking out the bent rubber pipe provided with the core C in the cavity V; A method for producing a bent rubber pipe. 4. The method for manufacturing a bent rubber pipe according to claim 2, wherein in the molding step, a rubber material is injected into the cavity V. 5. The forming step includes: placing a first plate-like rubber material J1 in a first groove 5B of a first mold 5; and said first plate-like rubber material J1. A second step of pressing and arranging the core C on the core C and fixedly arranging the core C in the first groove 5B; and disposing a second plate-like rubber material J2 on the core C, The second groove 9B of the second mold 9 is connected to the first groove 5 of the first mold 5.
4. The method for manufacturing a bent rubber pipe according to claim 2, further comprising a third step of pressing the second mold 9 against the first mold 5 by pressing the mold toward B. 6. A contact portion 3 having a concave portion 3A which is open toward the distal end and which is in contact with the outer periphery of the main flow channel core Cm is provided at the distal end of the sub flow channel core Cs. 2
A method for producing a bent rubber pipe according to claim 3. 7. An abutting portion 3 having a through hole 3D through which a main flow channel core Cm can be inserted is provided at a tip of the sub flow channel core Cs. Item 4. A method for producing a bent rubber pipe according to Item 3. 8. The rear end of the main flow channel core Cm and the rear end of the sub flow channel core Cs are located outward of the pipe outer shape hole P formed by the first mold 5 and the second mold 9. The extending portion Ct extends through the extending portion Ct, and the extending portion Ct is connected to the core supporting groove 5C connected to the first groove 5B of the first mold 5 and the second groove 9B of the second mold 9. The method for manufacturing a bent rubber pipe according to claim 2 or 3, wherein the bent rubber pipe is sandwiched by a core supporting groove (9C) continuous with the core. 9. The extension part Ct formed at the rear end of the main flow path core Cm and the extension part Ct formed at the rear end of the sub flow path core Cs 9. The method of manufacturing a bent rubber pipe according to claim 8, wherein the pressing member 6 disposed on the first contact surface 5A presses and holds the pressing member 6 toward the core supporting groove 5C. 10. The pressing member 6 is formed by a leaf spring made of a leaf spring material, and one end 6A of the leaf spring is connected to the first spring.
The other end 6B is fixedly arranged on the first contact surface 5A of the mold 5 and the other end 6B is elastically contacted with the extension Ct of the main flow channel core Cm and the extension Ct of the sub flow channel core Cs. The method for producing a bent rubber pipe according to claim 9, wherein