JP6741224B2 - Joint pipe manufacturing method and processing apparatus suitable for the same - 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 configuration in which a plurality of flat flange-shaped bead portions are provided on the outer periphery of the pipe body. The bead portion is formed by compressing the tubular body in its axial direction. With such a configuration, it is possible to mount the O-ring for sealing between the plurality of bead portions and to position the O-ring, and it is necessary to separately use a dedicated member for positioning the O-ring. Can be eliminated.

However, in the above-mentioned prior art, there is still room for improvement as described below.

That is, in the above-mentioned conventional technique, as a method of forming the above-mentioned flange-shaped bead portion, first, the portions of the tubular body which are separated from each other are clamped by two clamp members, and the two clamp members are brought close to each other, A means for compressing the tubular body in the axial direction is adopted. However, according to such means, since the compressive force in the axial direction is simply applied to the pipe body, the pipe body should be deformed so as to bulge outward in the radial direction in a substantially uniform manner at each place. Is not easy. A considerable amount of compressive force is required to form the bead portion. Further, when the compressive force acts on the tubular body in a non-uniform manner, problems such as the bead portion being distorted or being formed at a position deviated from the center of the tubular body are likely to occur. .. Such a problem becomes more remarkable when the thickness of the tubular body is large and the tubular body is difficult to be deformed, and the yield is deteriorated.

Furthermore, in the prior art, when forming a plurality of bead portions, the bead portions are individually formed. For example, when forming two bead portions, two clamping members are attached to two portions of the tubular body. The work of compressing in the axial direction is repeated twice. At that time, it is necessary to change the clamp position of the tubular body by the clamp member between the first work and the second work. Therefore, in the related art, there is a problem that the work efficiency when forming the plurality of bead portions is poor.

Japanese Patent No. 2974134

The present invention was devised under the circumstances as described above, and it is possible to easily and appropriately manufacture a joint pipe in which a flange-shaped bead portion is formed on the outer periphery of a pipe body as compared with the conventional art. It is an object of the present invention to provide a possible joint pipe manufacturing method and a processing apparatus suitable for carrying out this manufacturing method.

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

In the method for manufacturing a joint pipe provided by the first aspect of the present invention, a flange-shaped bead portion is formed on the outer circumference of the tubular body by compressing at least a portion of the tubular body in the axial length direction. A method for producing a joint pipe having a compression step of, wherein at least one of the bead portions is formed in the pipe body, wherein the pipe is expanded using a pipe expanding device before the compression step. There is a pipe expanding step of pressing the body radially outward from the inside thereof to form a bulging portion that bulges radially outward in the tube body, and in the compressing step, the bulging portion is formed into the tube body. In the axial direction, and the pipe expanding step is performed in a state in which both regions of the pipe body on the distal side and the base end side of the pipe body are clamped by two clamp members with respect to the pipe pipe portion to be expanded. The compression of the bulging portion in the compression step is performed by moving at least one of the two clamp members so as to approach the other side .

With such a configuration, the following effects can be obtained.
That is, the portion of the tube body where the bead portion is formed is formed as a bulge portion that is bulged outward in the radial direction of the tube body in advance by the tube expanding step before the compression step is performed. It is possible to appropriately eliminate or suppress the difficulty of expanding the tubular body outward in the radial direction. It is also possible to reduce the compressive force required to form the bulge portion as a flange-shaped bead portion. Further, when the compressive force acts in a non-uniform manner on the pipe body, it is possible to prevent problems such as a bead portion having a distorted shape or being formed at a position deviated from the center of the pipe body. is there. For this reason, it is possible to easily and appropriately manufacture the joint pipe including the bead portion and improve the yield.
Further, according to such a configuration, when both the tube expanding step and the compressing step are performed, the tube body may be kept clamped by the two clamp members, and the work efficiency can be improved.

In the present invention, preferably, the bulging portion has an arcuate cross-section whose diameter increases from the widthwise both ends of the bulging portion toward the widthwise central portion, and is continuously connected in the circumferential direction of the tubular body. It is a formed ring.

With such a configuration, when the bulging portion is compressed in the axial direction, it is possible to further facilitate and ensure that the flange-shaped bead portion is formed into a substantially uniform shape over the entire circumference of the tubular body. Can be planned.

In the present invention, preferably, in the pipe expanding step, a plurality of bulges are formed as the bulges, and in the compression step, each of the bulges is simultaneously compressed in the axial direction of the tubular body. Then, a joint pipe having a plurality of bead portions as the bead portion is manufactured.

With such a configuration, it is possible to efficiently manufacture the joint pipe having the plurality of bead portions.

In the present invention, preferably, the pipe expanding device has an expandable/deformable portion divided into a plurality of segments around a central axis, and the expandable/deformable portion has a larger area than the other parts of the expandable/deformable portion. Also, a split punch in which a plurality of convex portions whose outer diameters or outer widths are partially increased are arranged side by side in the axial direction, and the tubular body in a state of being inserted inside the expansion/contraction deformable portion. A mandrel having a wedge portion capable of pushing the plurality of segments outward in the radial direction by displacing the plurality of segments in the axial direction, is used. The plurality of convex portions press the tubular body radially outward from the inside thereof.

According to such a configuration, it is possible to appropriately and simultaneously form a plurality of bulges on the tubular body by using the tube expanding device having a relatively simple configuration.

In the present invention, preferably, when the pipe body is clamped by the two clamp members, a region near a tip end portion of the pipe body is made to protrude forward of the two clamp members, and the compression step is performed. In above, the operation of moving at least one of the two clamp members so as to approach the other side is performed by pressing the one clamp member using a pressing device, and at the time of this pressing, the tubular body is pressed. By pressing the tip portion of the tube by the pressing device, a flange-shaped additional bead portion is formed on the outer periphery of the tip portion of the tubular body, and in addition to the bead portion, a joint further provided with the additional bead portion. Manufacture tubes.

With such a configuration, it is possible to efficiently and appropriately manufacture a joint pipe in which, in addition to the bead portion, an additional bead portion is formed at the tip portion of the tubular body.

A processing device provided by the second aspect of the present invention is a clamping device capable of clamping and holding a pipe body, a pipe expanding device capable of expanding the pipe body, and a distal end portion of the pipe body being pressed toward a proximal end side. And a clamp device capable of pressing, wherein the clamp device clamps a main clamp member and a region closer to the tip end portion of the tubular body than the main clamp member, and is opposed to the main clamp member. A sub-clamp member movable in the axial direction of the tubular body, wherein the tube expanding device includes a portion of the tubular body clamped by the main clamp member and a portion clamped by the sub-clamp member. It is possible to expand the non-clamping portion located between and the bulge portion that bulges outward in the radial direction, and in the pressing device, the region near the tip end portion of the tubular body is more than the sub-clamping member. Also in the setting state of projecting forward, each of the distal end portion of the tubular body and the sub-clamp member can be simultaneously pressed against the proximal end portion side of the tubular body, and by the pressing operation of the pressing device, the non- The clamp portion is compressed between the sub clamp member and the main clamp member, and the bulge portion can be formed as a flange-shaped bead portion, and a region near the tip end portion of the tubular body is provided with the pressing device and the pressing device. It is characterized in that it is compressed between itself and the sub-clamp member and can be formed as an additional bead portion in the form of a flange.

With such a configuration, it is possible to efficiently and appropriately carry out the method for manufacturing the joint pipe provided by the first aspect of the present invention. Further, it is possible to manufacture a joint pipe further including an additional bead portion in addition to the bead portion.

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 a pipe expanding device used in the method for manufacturing a joint pipe of the present invention, and (b) is a sectional view taken along line Ib-Ib of (a). FIG. 3 is a side view showing an example of a split punch and a mandrel used in the tube expanding device of FIG. 1. 1A is an enlarged cross-sectional view taken along the line IIIa-IIIa of FIG. 1B, and FIG. 1B is an enlarged cross-sectional view showing an example of the operating state of FIG. (A) is a side sectional view showing an example of a pipe expanding step in the method for manufacturing a joint pipe of the present invention, and (b) is an enlarged sectional view of a main part of (a). It is a side sectional view showing an example of a processing device for performing a compression process in a manufacturing method of a joint pipe of the present invention. (A) is a side sectional view showing an example of a compression process performed using the processing apparatus shown in FIG. 5, and (b) is an enlarged sectional view of a main part of (a). FIG. 7 is a main-portion cross-sectional view showing an example of a pipe joint structure configured using a joint pipe manufactured through the steps shown in FIGS. 4 and 6. (A)-(c) is a principal part sectional view which shows the other example of the joint pipe manufactured by the method of this invention.

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

[Composition of joint pipe]
FIG. 7 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 has two bead portions 11 and one additional bead portion 12 (referred to as a flare portion) on the outer periphery of a pipe body 10 (joint pipe body portion) made of copper or other metal. In some cases) is formed. Each of the bead portion 11 and the additional bead portion 12 has a flat flange shape protruding outward in the radial direction of the tubular body 10, and an O-ring 98 for sealing is mounted between them, and the bead portion is provided. The O-ring 98 is prevented from coming off by 11 and the additional bead portion 12.

The pipe joint structure D has a configuration in which the joint pipe 1 is inserted into a socket portion 91 formed at an end portion of the pipe body 90 to be connected, and both portions of the bead portion 11 and the flange portion 91a of the socket portion 91 are , Is engaged 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 91, and the connection state between the pipe body 90 to be connected and the joint pipe 1 is appropriately 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.

[Processing equipment used in manufacturing method of joint pipe]
The joint pipe 1 described above is manufactured through a pipe expanding process and a compressing process described later. At that time, for example, a processing device in which the clamp device A and the tube expanding device B shown in FIG. 1 and the pressing device C shown in FIG. 5 are combined is used. These configurations will be described below.

In FIG. 1, the clamp device A includes main and sub clamp members 3A and 3B for clamping the tubular body 10. Each of the main and sub clamp members 3A and 3B is divided in two in the vertical direction, and the tube body 10 can be clamped from both upper and lower sides thereof. The sub-clamp member 3B is movable in the axial direction of the tube body 10 relative to the main clamp member 3A, and in a normal state where no load is applied from the tube expanding device B, the clamping device is generated by the elastic force of the spring 20. It is pressed to the front side of A and is in contact with the stopper portion 21. In this state, a gap is formed between the front wall portion 30 of the main clamp member 3A and the rear wall portion 31 of the sub clamp member 3B, and the main and sub clamp members 3A and 3B of the tubular body 10 clamp the respective gaps. A non-clamping portion 13 (a region not clamped by the clamp members 3A and 3B) is provided between the formed regions.

The tube expanding device B includes a base member 40, a split punch 5 for tube expanding, a mandrel 41, a positioning pin 42, a guide 43 for the positioning pin 42, and a support member 44 that supports the guide 43. The base member 40 is attached to an actuator such as a hydraulic cylinder (not shown), so that the entire tube expanding device B can reciprocate in the horizontal direction facing the clamp device A.

The split punch 5 is a tubular member for pressing the tubular body 10 radially outward from the inside thereof, and a mandrel 41 is slidably inserted therein (see also FIG. 2). The split punch 5 has a plurality of slits 50 formed along the longitudinal direction thereof. As a result, as shown in FIG. 3, 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. The expansion/contraction deformable portion 51 is deformable. For example, two convex portions 52 are formed adjacent to the expandable/contractible deformable portion 51. Each convex portion 52 is a smooth convex curved surface, and is a substantially annular shape (interrupted at the position of the slit 50) extending in the circumferential direction of the expansion/contraction 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 FIGS. 3A to 3B, the wedge portions 41a push the plurality of segments 51a outward in the radial direction. It is possible (see also FIG. 4). 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, but as shown in FIG. 4, when the positioning pin 42 comes into contact with the front wall portion 30 of the main clamp member 3A, the spring of the spring 48 springs. It is possible to retreat to the base member 40 side against the force generated. As a result, the mandrel 41 moves forward relative to the split die punch 5 and expands the outer diameter or outer width of the tip of the split die punch 5.

In FIG. 5, the pressing device C has a structure in which a pressing punch 61 is connected and fixed to a holder 60, and a die 62 is externally fitted to a portion near the tip of the punch 61. Like the base member 40 of the tube expanding device B, the holder 60 is attached to an actuator such as a hydraulic cylinder (not shown), so that the entire pressing device C reciprocates in the horizontal direction facing the clamping device A. You are free. The punch 61 has a step portion 61a, and the tip portion of the tube body 10 can be horizontally pressed by the step portion 61a.

The die 62 serves to assist the formation of the additional bead portion 12 when the punch 61 is advanced, and is a member for pressing the sub-clamp member 3B of the clamp device A toward the base end side of the tubular body 10. .. The die 62 is slidably fitted onto the pressing punch 61, and is constantly biased forward by a spring 63. A concave portion 62a is formed on the front end surface of the die 62, and when the front end portion of the tubular body 10 is pressed and deformed by the punch 61, the periphery of this deformed portion is covered by the inner peripheral surface of the concave portion 62a. At the same time, one side surface of the deformed portion is pressed by the side wall of the recess 62a. As a result, the region near the tip of the tube body 10 can be compressed as shown in FIG. 6B, and the additional bead portion 12 can be formed.

In the clamp device A, when the additional bead portion 12 is formed, the sub-clamp member 3B is pressed by the die 62 and retracts. As a result, the non-clamping portion 13 of the tubular body 10 (the formation location of the bulging portion 11a described later) is compressed between the main and sub clamp members 3A and 3B, and the bead portion 11 can be formed. At this time, the rear wall portion 31 of the sub clamp member 3B comes into contact with the front wall portion 30 of the main clamp member 3A to prevent the sub clamp member 3B from retracting beyond a certain level.

[Method of manufacturing joint pipe]
In order to manufacture the joint pipe 1, first, the pipe expanding process for the pipe body 10 is executed. This tube expanding step is performed by advancing the tube expanding device B toward the tube body 10, as shown in FIG. When setting the tube body 10 in the clamp device A, the tube expansion target portion of the tube body 10 is set as the non-clamp portion 13. When the mandrel 41 is moved forward with the expandable/deformable portion 51 of the split die punch 5 arranged inside the non-clamping portion 13, the outer diameter or outer width of the expandable/deformable portion 51 increases, and the tubular body 10 is expanded. Is expanded. As a result of this expansion, the tube body 10 is formed with two bulges 11a having an arcuate cross-section whose outer diameter increases from the widthwise ends toward the center.

In the compression step after the tube expanding step described above, as shown in FIGS. 5 and 6, while the tube body 10 described above is placed in the clamp device A, the pressing device C is used in front of the tube expanding device B instead of the tube expanding device B. Place and execute. More specifically, as shown in FIG. 6, the pressing device C is moved forward so that a part of the punch 61 enters the tubular body 10, and the tip portion of the tubular body 10 is moved in the axial direction by the step portion 61a. Press. At the same time, the die 62 is also used to press the sub clamp member 3B. Then, the two bulging portions 11a described above are deformed so that the amount of bulging outward in the radial direction is further increased, and then clamped by the main and sub clamp members 3A and 3B to form a flat flange shape. It is formed as two bead portions 11. On the other hand, the region near the tip of the tube body 10 swells outward in the radial direction and then is pinched between the side wall of the recess 62a of the die 62 and the sub-clamp member 3B, so that the flat bead-shaped additional bead portion is formed. Formed as twelve.

According to the series of operation steps described above, the two bead portions 11 are formed by compressing the two bulging portions 11a formed in the tube expanding step, and therefore, without providing such bulging portions 11a, simply Compared with the case where the tube body 10 is only compressed in the axial direction, the bead portion 11 can be formed smoothly and easily, and the risk that the bead portion 11 is formed in a distorted state can be reduced. It is possible. Further, it is possible to reduce the force required to compress the pipe body 10 in the compression process.

In the compression step described above, the two bulging portions 11a can be simultaneously formed as the bead portion 11 by the work of advancing the punch 61 and the die 62 of the pressing device C once, and the additional bead portion 12 is also formed. It can be formed at the same time. Therefore, the work efficiency is good, and the manufacturing cost can be reduced. In addition, when the pipe body 10 is transferred from the pipe expanding process to the compressing process, the pipe body 10 may remain clamped by the clamp device A, and it is not necessary to transfer the pipe body 10 to another clamp device. Therefore, work efficiency can be further improved.

FIG. 8 shows another embodiment of the present invention.
As shown in FIGS. 7A and 7B, the flange-shaped bead portions 11 may be formed by arranging three or more, or by providing only one. The specific number is not limited to two. Therefore, the specific number of the bulge portions 11a formed in the pipe expanding step for forming the bead portion 11 is not limited.
In the configuration shown in FIG. 3C, the additional bead portion 12 is not formed near the tip of the tubular body 10. In the present invention, such a configuration is also possible.

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 processing apparatus according to the present invention can be modified in various ways.

The tube expanding device is not limited to the type in which the split die punch is expanded and contracted by the mandrel, and it is also possible to use a type in which the split die punch (split die) is expanded and contracted by utilizing fluid pressure, for example. .. As a means for compressing the bulging portion formed on the tubular body in the axial direction, a pressing device having a different configuration from the pressing device described above can be used.
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, when a flange-shaped bead portion is formed at the end of a relatively long-sized heat transfer tube that constitutes a heat exchanger, and this portion is used for connection with another piping member, this heat transfer tube is It is included in the concept of the joint pipe in the present invention. The specific configuration of the pipe joint structure constructed using the joint pipe is not limited.

A Clamping device B Pipe expanding device C Pressing device 1 Joint pipe 10 Tubular body 11 Bead portion 11a Bulging portion 12 Additional bead portion 13 Non-clamping portion 3A, 3B Main and sub clamping members (two clamping members)
41 Mandrel 41a Wedge part 5 Split type punch 51 Expansion/contraction deformable part 51a Segment (expansion/contraction deformable part)
61 Punch (of pressing device)
62 die (of pressing device)

Claims (6)

By compressing at least a portion of the tubular body in the axial direction in the axial direction, there is a compression step of forming a flange-shaped bead portion on the outer periphery of the tubular body,
A method for manufacturing a joint pipe in which at least one bead portion is formed in the pipe body,
Prior to the compression step, there is a tube expanding step of pressing the tube body radially outward from the inside using a tube expanding device to form a bulge portion that bulges radially outward in the tube body. ,
In the compression step, compressing the bulging portion in the axial direction of the tubular body ,
The pipe expanding step is performed in a state where both the regions on the tip side and the base end side of the pipe body with respect to the pipe expansion target portion of the pipe body are clamped using two clamp members,
The method of manufacturing a joint pipe , wherein the compression of the bulge portion in the compression step is performed by moving at least one of the two clamp members so as to approach the other side . It is a manufacturing method of the joint pipe according to claim 1,
The bulging portion has an arcuate cross-section with a diameter increasing from the widthwise both ends of the bulging portion toward the center in the widthwise direction, and is an annular shape formed in series in the circumferential direction of the tubular body, Manufacturing method of joint pipe. It is a manufacturing method of the joint pipe according to claim 1 or 2,
In the pipe expanding step, a plurality of bulges are formed as the bulges.
In the compression step, each of the plurality of bulging portions is simultaneously compressed in the axial direction of the tubular body,
A method for manufacturing a joint pipe, which comprises manufacturing a joint pipe having a plurality of bead portions as the bead portion. It is a manufacturing method of the joint pipe according to claim 3,
As the tube expanding device,
It has an expandable/contractible deformable portion divided into a plurality of segments around the central axis, and the expandable/contractible deformable portion has an outer diameter or an outer width partially larger than those of other portions of the expandable/contractible deformable portion. A plurality of convex portions are provided side by side in the axial direction, and a split punch,
A mandrel having a wedge portion capable of pushing the plurality of segments radially outward by displacing the plurality of segments in the axial direction of the tubular body while being inserted inside the expandable/deformable portion,
Use the one with
In the pipe expanding step, a method for manufacturing a joint pipe, wherein the plurality of convex portions of the expandable/deformable portion press the pipe body radially outward from the inside thereof. A method for manufacturing the joint pipe according to any one of claims 1 to 4, comprising:
When the tube body is clamped by the two clamp members, a region near the tip end portion of the tube body is set to be in a state of projecting forward of the two clamp members,
In the compression step, the operation of moving at least one of the two clamp members so as to approach the other side is performed by pressing the one clamp member using a pressing device, and at the time of pressing, the operation is performed. By pressing the tip portion of the tubular body also by the pressing device, to form a flange-shaped additional bead portion on the outer periphery of the tip portion of the tubular body,
A method for manufacturing a joint pipe, which comprises manufacturing a joint pipe further including the additional bead portion in addition to the bead portion . A clamp device that can hold the pipe in a clamp,
A pipe expanding device capable of expanding the pipe body,
A pressing device capable of pressing the distal end of the tubular body toward the proximal end,
Is equipped with
The clamp device clamps a main clamp member and a region closer to the tip end portion of the pipe body than the main clamp member, and is movable in the axial direction of the pipe body relative to the main clamp member. And a clamp member,
The pipe expanding device expands a non-clamping portion of the pipe body located between a portion clamped by the main clamp member and a portion clamped by the sub clamp member and expands radially outward. It is possible to form a bulge,
In the pressing device, in a setting state in which a region near a tip end portion of the tubular body projects forward from the sub-clamp member, the tip end portion of the tubular body and the sub-clamp member are respectively attached to a base end portion side of the tubular body. It is possible to press at the same time,
By the pressing operation by the pressing device, the non-clamp portion is compressed between the sub-clamp member and the main clamp member, and the bulge portion can be formed as a flange-shaped bead portion, and The processing device, wherein the region near the tip portion is compressed between the pressing device and the sub-clamping member, and can be formed as an additional bead portion having a flange shape.

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