JP6741223B2 - Method and device for manufacturing joint pipe - Google Patents

Description

The present invention relates to a technique for suitably manufacturing a joint pipe that can be connected to various piping members for flowing hot water, fluid devices, and the like.

As a specific example of the joint pipe, there is one described in Patent Document 1.
The joint pipe described in the document has a flange-shaped bead portion formed on the outer periphery of the tip end portion of the pipe body, and a ring-shaped spacer is externally fitted and fixed at a position separated from the bead portion. Has been done. The bead portion is formed by compressing a region near the tip end portion of the tubular body in the axial direction thereof. The spacer is fixed by expanding a portion of the tubular body corresponding to the spacer and engaging the expanded portion with the inner peripheral surface portion of the spacer.
In the joint pipe having such a structure, an O-ring for sealing can be attached and positioned between the bead portion and the spacer, and a dedicated member for positioning the O-ring is separately provided. It is possible to eliminate the need to use. The spacer can also be used as a portion for engaging an appropriate engaging member when the joint pipe is connected to another pipe member to prevent the pipe from coming off.

However, conventionally, there is still room for improvement as described below.
That is, in the conventional art, the step of forming the bead portion at the tip of the tubular body and the tube expanding step for fixing the spacer are actually performed separately. Therefore, the manufacturing efficiency of the joint pipe is not so good, and there is room for improvement in increasing the manufacturing efficiency and reducing the manufacturing cost.

Japanese Patent No. 4973275 (FIGS. 3 and 9)

The present invention was devised under the circumstances as described above, and efficiently and properly manufactures a joint pipe including a flange-shaped bead portion and a protruding portion that engages with an externally fitted spacer. It is an object of the present invention to provide a joint pipe manufacturing method capable of performing the above, and a joint pipe manufacturing apparatus suitable for carrying out this manufacturing method.

In order to solve the above problems, the present invention takes the following technical means.

A method for manufacturing a joint pipe provided by the first aspect of the present invention uses a processing device having a reciprocating pressing member, and advances the pressing member to move the tip end portion of the tubular body in the axial direction. Corresponding to a bead portion forming step of forming a flange-shaped bead portion on the outer periphery of the tip end portion of the tubular body by pressing the tubular body, and a ring-shaped spacer fitted on the tubular body out of the tubular body. A spacer fixing step of forming a protruding portion that protrudes outward in the radial direction and engages with the spacer at a location, and for manufacturing a joint pipe in which the bead portion and the protruding portion are provided. In the method, as the processing device, a split die for pipe expansion having a expandable/contractible deformable portion divided into a plurality of segments around a central axis, and the split punch inserted inside the expandable/deformable portion, A mandrel capable of expanding and contracting the expandable/deformable portion by moving relative to the die punch ; and a split punch attached to the pressing member so as to project forward from the front surface of the pressing member. A cylindrical member externally fitted to the split die punch so that a radial gap that allows expansion/contraction deformation of the expansion/contraction deformable portion is formed between When the pressing member is advanced to perform the bead portion forming step, the cylindrical member is arranged in the tubular body, and the region from the bead portion of the tubular body to the spacer is the tubular body. While preventing the body from being deformed inward in the radial direction, the split punch is inserted into the tubular body, and the advance of the pressing member and the cylindrical member is stopped. It is characterized in that the outer diameter or the outer width of the expansion/contraction deformable portion is enlarged by advancing the split punch relative to the split punch, and the spacer fixing step is executed.

With such a configuration, not only the two steps of the bead portion forming step and the spacer fixing step are performed at the same time, but also the above-mentioned two steps include the pressing member and the mandrel included in one processing apparatus. Since it is performed by moving it forward, it is possible to eliminate the need for complicated operation mechanisms and complicated operation control. Therefore, the joint pipe including the flange-shaped bead portion and the spacer fitted and fixed to the outside can be efficiently and appropriately and easily manufactured, and the manufacturing cost of the joint pipe can be reduced. Is.

In the present invention, preferably, the inner peripheral surface portion of the spacer, a pair of inward projections that are located at intervals in the axial direction of the tubular body, and that project inward in the radial direction, An inward concave portion formed between a pair of inward convex portions is provided, and in the spacer fixing step, the protruding portion is formed into an arcuate cross section and is inserted into the inward concave portion.

With such a configuration, the protruding portion of the tubular body and the spacer can be appropriately engaged with each other so as not to cause a large displacement or rattling of the spacer.

A joint pipe manufacturing apparatus provided by the second aspect of the present invention is a clamp device capable of clamping and holding a tubular body in a state in which a ring-shaped spacer is externally fitted at a location separated from a tip portion of the tubular body, A pressure member reciprocally movable in the axial direction of the tubular body is provided, and when the pressing member advances, the tip end portion of the tubular body is pressed in the axial length direction to form a flange shape on the outer periphery of the distal end portion of the tubular body. And a processing device capable of forming a bead part of the pipe, and the processing device includes a split die for pipe expansion having an expansion/contraction deformable part divided into a plurality of segments around a central axis, and the expansion/contraction. A mandrel that is inserted inside the deformable portion and that is capable of expanding and contracting the expandable/deformable portion by moving relative to the split die punch, and the mandrel that protrudes forward from the front surface portion of the pressing member. A cylindrical member attached to the pressing member and externally fitted to the split die punch so that a radial gap is formed between the split die punch and the split die to allow the expandable/deformable portion to expand/contract. And further, when the pressing member advances and a forming operation of the bead portion is executed, the cylindrical member is arranged in the tubular body, and the spacer is provided from the bead portion of the tubular body. Is prevented from being deformed inward in the radial direction of the pipe body, the split punch enters the pipe body, and the pressing member and the cylindrical member are moved forward. In the stopped state, the mandrel moves forward relative to the split punch to increase the outer diameter or outer width of the expansion/contraction deformable portion, and the spacer out of the tubular body is fitted on the tubular body. It is characterized in that the portion corresponding to the above can be projected outward in the radial direction.

According to the joint pipe manufacturing apparatus having such a configuration, the joint pipe manufacturing method provided by the first aspect of the present invention can be suitably implemented, and the joint pipe manufacturing method of the present invention has been described. The same effect as can be obtained.

Other features and advantages of the present invention will become more apparent from the following description of the embodiments of the invention with reference to the accompanying drawings.

(a) is a plane sectional view showing an example of the joint pipe manufacturing apparatus of the present invention, and (b) is an Ib-Ib sectional view of (a). (A) is a side sectional view showing an example of an operating state of the joint pipe manufacturing apparatus shown in FIG. 1, and (b) is an enlarged sectional view of a main part of (a). It is a side view which shows an example of the split-type punch and mandrel used in the joint pipe manufacturing apparatus of FIG. 1A is an enlarged cross-sectional view taken along the line IVa-IVa of FIG. 1B, and FIG. 1B is an enlarged cross-sectional view showing an example of the operating state of FIG. It is a principal part sectional view which shows the joint pipe manufactured through the process shown in FIG. 2, and its usage example.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

[Composition of joint pipe]
FIG. 5 shows an example of a joint pipe to be manufactured according to the present invention and a pipe joint structure using the joint pipe.
In the figure, the joint pipe 1 may be referred to as a flat flange-shaped bead portion 12 (flare portion) on the outer periphery of the tip of a pipe body 10 (joint pipe body portion) made of copper or other metal. ) Is formed and a ring-shaped spacer 8 is externally fitted and fixed at a position separated from the bead portion 12.
A pair of inward projecting portions 80 protruding inward in the radial direction are formed on the inner peripheral surface of the spacer 8 at intervals in the axial direction of the tubular body 10, and the pair of inward projecting portions 80 are formed. An inward recess 81 is provided between the two. An annular protruding portion 11 protruding in an arcuate cross section is formed on the inner side of the spacer 8 in the tubular body 10, and the protruding portion 11 enters (engages) in the inward recess 81. With such an engaging structure, the spacer 8 is positioned and fixed. An O-ring 98 for sealing is attached between the bead portion 12 and the spacer 8.

The pipe joint structure D is configured such that the joint pipe 1 is inserted into the socket portion 91 formed at the end portion of the pipe body 90 to be connected, and both the one end portion of the spacer 8 and the flange portion 91a of the socket portion 91 are formed. The portion engages with the engagement pieces 92a, 92b of the engagement member 92 and is sandwiched between the engagement pieces 92a, 92b. As a result, the joint pipe 1 is prevented from coming off from the socket portion 91, and the connection state between the pipe body 90 to be connected and the joint pipe 1 is maintained. The pipe joint structure D is applied to, for example, a pipe portion for hot water flow in a hot water supply device, but it is not limited to this.

[Joint pipe manufacturing equipment]
The joint pipe manufacturing apparatus S shown in FIG. 1 is configured by combining a clamp apparatus A and a processing apparatus B.
The clamp device A can clamp and hold the pipe body 10 while the spacer 8 is fitted on the pipe body 10, and can clamp the pipe body 10 from the upper and lower sides. 3 (3a, 3b).

The processing device B has both a function as a pressing device that presses the tip portion of the pipe body 10 and a function as a pipe expanding device that expands the pipe body 10. Specifically, the processing apparatus B includes a base member 40, a split die 5 for expanding a pipe, a mandrel 41, a positioning pin 42, a pressing member 6 (pressing die), and a supporting member 44 that supports the pressing member 6. And so on. The base member 40 is attached to an actuator such as a hydraulic cylinder (not shown), so that the entire processing device B can reciprocate in the horizontal direction (axial direction of the tubular body 10) facing the clamp device A. Is.

The split punch 5 is a tubular member for pressing the tubular body 10 radially outward from the inside thereof, and the mandrel 41 is slidably inserted into the inside thereof (see also FIG. 3). The split punch 5 has a plurality of slits 50 formed along the longitudinal direction thereof. As a result, as shown in FIG. 4, the split punch 5 is divided into a plurality of segments 51a around its central axis, and the portion of the split punch 5 near the tip in the axial direction is expanded and contracted in the radial direction. It is a deformable expansion/contraction deformable portion 51. A convex portion 52 is formed on the outer circumference of the tip end portion of the expandable/contractible deformable portion 51. The convex portion 52 is a convex curved surface whose outer peripheral surface is smooth,
Further, it is a substantially annular shape (interrupted at the position of the slit 50) extending in the circumferential direction of the expandable/contractible deformable portion 51.

The tip of the mandrel 41 has, for example, a conical shape, and is formed as a wedge portion 41a whose diameter or width increases from the tip to the base end side. The wedge portion 41a expands and contracts the split punch 5. It is located inside the deformable portion 51. Therefore, when the mandrel 41 is moved relative to the split punch 5 and moved forward, as shown in FIG. 4A to FIG. 4B, the wedge portions 41 a push the plurality of segments 51 a outward in the radial direction. It is movable (see also FIG. 2).

In FIG. 1, the mandrel 41 is fixed to the front surface of the base member 40 using a pressing member 45, while the split punch 5 is provided on the front side of the base member 40 so as to be capable of reciprocating. It is held by the movable member 46, and the rear surface thereof is pressed by the pressing member 47. The movable member 46 is biased forward by a spring 48. Therefore, when the processing device B advances, as shown in FIG. 2, the positioning pin 42 abuts on the front wall portion 30 of the clamp member 3, and the positioning pin 42 and the movable member 46 are prevented from further moving forward. At this point, the split die punch 5 also does not advance any further, and the split die punch 5 is positioned at a position overlapping the spacer 8.

On the other hand, the base member 40 and the member fixedly connected to the base member 40 can be further advanced by the dimension L shown in FIG. 1 after the positioning pin 42 contacts the front wall portion 30 of the clamp member 3. Is. As a result, as shown in FIG. 2, the mandrel 41 advances relative to the split die punch 5 and expands the outer diameter or outer width of the tip portion of the split die punch 5. By this operation, it is possible to expand the tubular body 10 and form the above-mentioned protruding portion 11. When the mandrel 41 is moved forward, the pressing member 6 can be moved forward as well.

The pressing member 6 is a portion for forming the bead portion 12, and a front wall portion 60 thereof is provided with a concave portion 61 forming a peripheral wall and a side wall. When the pressing member 6 moves forward in a state in which the region near the distal end portion of the tube body 10 projects toward the front of the clamp member 3, the side wall of the recess 61 can press the distal end portion of the tube body 10 in the axial direction. .. Due to this pressing, the region near the tip of the tube body 10 is deformed so as to bulge outward in the radial direction. The periphery of the deformed portion is covered by the peripheral wall portion of the recess 61, and the deformed portion is clamped by both the side wall of the recess 61 and the front wall portion 30 of the clamp member 3 in the axial direction of the tubular body 10. To be done. As a result, the region near the tip of the tube body 10 can be compressed as shown in FIG. 2B to form the bead portion 12. The pressing member 6 is provided with a cylindrical member 68 that enters the tube body 10 when the pressing member 6 moves forward. The cylindrical member 68 is provided when the tip portion of the tube body 10 is pressed. A member for preventing the region near the tip of the tube body 10 from being deformed inward in the radial direction, ensuring that the region is expanded outward in the radial direction, and stably forming the bead portion 12. is there. The cylindrical member 68 also prevents the O-ring mounting portion provided between the bead portion 12 and the spacer 8 from being deformed.

[Method of manufacturing joint pipe]
In order to manufacture the joint pipe 1, in the set state of the pipe body 10 and the spacer 8 shown in FIG. 1, the front wall portion 60 of the pressing member 6 becomes the front wall portion 30 of the clamp member 3 as shown in FIG. The processing device B is moved forward until it abuts. By the forward movement of the processing apparatus B, the bead portion forming step of forming the bead portion 12 and the spacer fixing step of forming the protruding portion 11 engaging with the spacer 8 are simultaneously performed.

Specifically, the bead portion forming step includes an operation of pushing the tip portion of the tubular body 10 by the side wall of the recess 61 formed in the pushing member 6. By this operation, as described above, the region near the tip end portion of the tubular body 10 is compressed so as to bulge outward in the radial direction, and this compressive deformation is generated between the side wall of the concave portion 61 and the front wall portion 30 of the clamp member 3. The bead portion 12 can be formed by sandwiching the two. On the other hand, the spacer fixing step includes an operation of advancing the mandrel 41 so as to face the split die 5 for pipe expansion. By this operation, as described above, it is possible to expand the tubular body 10 by increasing the outer diameter or the outer width of the expandable/contractible deformable portion 51 and form the protruding portion 11 that engages with the spacer 8.

According to the manufacturing method described above, the joint pipe 1 shown in FIG. 5 can be appropriately manufactured. Since the bead portion forming step and the spacer fixing step can be performed at the same time only by advancing the processing apparatus B toward the pipe body 10, the manufacturing work of the joint pipe 1 is facilitated and speeded up, It is possible to preferably improve the productivity and reduce the manufacturing cost. Further, the overall structure of the joint pipe manufacturing apparatus S can be simplified, and the cost of production equipment can be reduced. Since the protrusion 11 can be inserted into the inward recess 81 of the spacer 8 with a small gap, it is also possible to appropriately suppress the rattling and displacement of the spacer 8.

The present invention is not limited to the contents of the above-mentioned embodiment. The specific configuration of each step of the method for manufacturing a joint pipe according to the present invention can be variously changed within the scope intended by the present invention. The specific configuration of each part of the joint pipe manufacturing apparatus according to the present invention can be modified in various ways.

In the present invention, the projecting portion of the tubular body may be formed to project outward in the radial direction of the tubular body and be formed so as to engage with the spacer. The spacer may be a ring-shaped member externally fitted to the tubular body. Moreover, although it is preferable that the spacer has a configuration in which a concave portion for engaging with the protruding portion of the tubular body is formed in the inner peripheral surface portion, the present invention is not limited to this.
The pressing member of the processing device may be any member that can press the tip portion of the tubular body, and is not limited to the block shape. Further, the pressing member can be configured by combining a plurality of members.
The joint pipe according to the present invention may be of any material, straight pipe, curved pipe (L-shaped pipe, U-shaped pipe, etc.), and its specific length is not limited. For example, by applying the configuration intended by the present invention to the end portion of a relatively long-sized heat transfer tube that constitutes a heat exchanger, a pipe joint structure that can be connected to other piping members or the like is configured. If obtained, this heat transfer tube is included in the concept of the joint tube in the present invention. The specific configuration of the pipe joint structure constructed using the joint pipe is not limited.
The fixing of the spacer in the present invention means a state in which some positioning is regulated by engaging with the protrusion formed on the pipe body, and the spacer is prevented from being displaced at all. It is not limited to the case where it is firmly fixed to the body. Although it is not so preferable, the spacer may have some displacement or rattling.

A Clamping device B Machining device S Joint pipe manufacturing device 1 Joint pipe 10 Tubular body 11 Protruding portion 12 Bead portion 41 Mandrel 41a Wedge portion 50 Split punch 51 Expansion/contraction deformable portion 51a Segment (expansion/contraction deformable portion)
6 pressing member 8 spacer 80 inward convex 81 inward concave

Claims (3)

By using a processing device equipped with a reciprocally movable pressing member and advancing the pressing member to press the distal end portion of the tubular body in the axial direction, a flange-shaped outer periphery of the distal end portion of the tubular body is formed. A bead portion forming step of forming a bead portion,
Of the tubular body, a spacer fixing step of forming a projecting portion that projects outward in the radial direction and engages with the spacer, at a location corresponding to the ring-shaped spacer externally fitted to the tubular body
Has
A method for manufacturing a joint pipe provided with the bead portion and the protrusion, comprising:
As the processing device, a split die punch for expanding having a expandable/deformable portion divided into a plurality of segments around a central axis, and a die insertable inside the expandable/deformable portion, and facing the split die punch. The expansion/contraction is mounted between the mandrel that allows the expansion/contraction deformable portion to expand/contract by moving and the pressing member attached to the front surface of the pressing member so as to project to the front thereof. Using a processing device further comprising: a cylindrical member externally fitted to the split punch so that a radial gap that allows expansion and contraction of the deformable portion is formed ,
When the pressing member is advanced to perform the bead portion forming step, the cylindrical member is arranged in the tubular body, and the region from the bead portion of the tubular body to the spacer is the tubular body. Prevents deformation inward of the body in the radial direction,
The expansion/contraction deformable portion is caused by advancing the mandrel relative to the split die punch in a state where the split die punch is inserted into the tubular body and the advancement of the pressing member and the cylindrical member is stopped. A method of manufacturing a joint pipe, wherein the spacer fixing step is performed by increasing the outer diameter or the outer width of the joint tube. It is a manufacturing method of the joint pipe according to claim 1,
The inner peripheral surface portion of the spacer, a pair of inward convex portions, which are located at intervals in the axial direction of the tubular body and project inward in the radial direction, and a pair of these inward convex portions. Is provided with an inwardly facing recess formed between
In the spacer fixing step, the method for manufacturing a joint pipe, wherein the projecting portion is formed into an arcuate cross section and is inserted into the inward recess. A clamp device capable of clamping and holding the tubular body in a state where a ring-shaped spacer is externally fitted at a location separated from the tip portion of the tubular body,
A pressure member reciprocally movable in the axial direction of the tubular body is provided, and when the pressing member advances, the tip end portion of the tubular body is pressed in the axial length direction to form a flange shape on the outer periphery of the distal end portion of the tubular body. A processing device capable of forming a bead part of
Is equipped with
The processing device is
A split punch for pipe expansion having an expandable/contractible deformable portion divided into a plurality of segments around a central axis,
A mandrel that is inserted inside the expandable/deformable portion and that is capable of expanding/contracting the expandable/deformable portion by moving relative to the split punch.
A radial gap, which is attached to the pressing member so as to project from the front surface of the pressing member to the front thereof, and which allows expansion/contraction deformation of the expansion/contraction deformable portion is formed between the pressing die and the split die. A cylindrical member externally fitted to the split punch,
Is further equipped with
When the pressing member advances and the operation of forming the bead portion is executed, the cylindrical member is arranged in the pipe body, and a region from the bead portion of the pipe body to the spacer is formed in the pipe body. It is possible to prevent deformation to the inner side in the radial direction of the body,
In the state where the split punch enters the tubular body and the advance of the pressing member and the cylindrical member is stopped, the mandrel moves forward relative to the split punch to expand and contract the deformable portion. The outer diameter or the outer width is enlarged, and the portion of the tubular body corresponding to the spacer fitted on the tubular body can be projected outward in the radial direction. , Joint pipe manufacturing equipment.

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