JP2005000928A - Tube machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tube machining apparatus with which loads on a tubular stock tube and a mandrel is suppressed when expanding the stock tube. <P>SOLUTION: Mandrel pieces 12, 14, 16 and 18 are connected in series by a wire 20. End parts of the wire 20 is connected to a drum 22. When the drum 22 is rotated in the direction of an arrow, the wire 20 is wound around the drum 22. As the wire 20 is wound, the mandrel pieces 12, 14, 16 and 18 are inserted into a tube hole 28a of a stock tube 28 in the ascending order of the size to successively expand the tube. Since the shape of a rear face 18b of the mandrel piece 18 at the tail end is equal to the sectional shape of the tube hole of a product, and when the mandrel piece 18 at the tail end passes through the tube hole 28a, the sectional shape of the tube hole 28a becomes the sectional shape of the tube hole of the product. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube processing apparatus, and more particularly to an apparatus for processing a tube material by expanding the diameter of the tube hole by passing a mandrel through the tube hole of the tube material.
[0002]
2. Description of the Related Art Hydroforming (hydraulic bulge forming) technology that expands a pipe hole by feeding a pressurized liquid into the pipe hole in order to process the pipe material by expanding the pipe hole of the pipe material It has been known. According to the hydroforming technique, it can be processed into various tube shapes, but has the problem that the equipment is large and expensive. On the other hand, the technique of processing the pipe material by expanding the diameter of the pipe hole by passing the mandrel through the pipe hole of the pipe material can be implemented with relatively simple equipment.
Patent Document 1 discloses a technique in which a tube expansion head formed at the head of a mandrel is attached, the mandrel is pushed from behind, and the tube expansion head passes through a tube hole of a tube material.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-68331
In the processing apparatus disclosed in Patent Document 1, the diameter of the tube hole is increased by pushing a tube expansion head attached to the head of the mandrel into the tube hole. In the conventional technique, when the tube expansion head passes, the tube material is expanded to the cross-sectional shape of the tube expansion head all at once, so that a large pressure is applied to the wall of the tube material. In addition, the burden on the tube expansion head is large, and the tube expansion head may be worn or damaged.
The present invention provides a tube processing apparatus that can reduce a burden on a tube material and a mandrel when expanding the diameter of a tube hole.
[0005]
[Means for Solving the Problems, Actions and Effects] The pipe processing apparatus according to the present invention allows a plurality of mandrel pieces to be connected in series and flexibly in order to expand the hole of the pipe material into a pipe product. A connected mandrel and a mandrel feeding mechanism for feeding the mandrel and sequentially passing a plurality of mandrel pieces through the tube hole of the tube material are provided. The following conditions are satisfied.
(1) The cross-sectional shape of each mandrel piece is enlarged from the front side to the rear side.
(2) The cross-sectional shape of the front end of the leading mandrel piece does not exceed the cross-sectional shape of the tube hole of the tube material.
(3) The cross-sectional shape of the rear end of the leading mandrel piece exceeds the cross-sectional shape of the tube hole of the tube material,
(4) The cross-sectional shape of the front end of the second and subsequent mandrel pieces does not exceed the cross-sectional shape of the rear end of the mandrel piece located immediately before.
(5) The cross-sectional shape of the rear end of each mandrel piece is gradually enlarged from the leading mandrel piece toward the rear mandrel piece.
[0006]
According to the conditions (1), (3), and (4), it is possible to expand the diameter of the tube material for each mandrel piece, and as the plurality of mandrel pieces sequentially pass through the tube holes of the tube material. The pipe material is expanded in multiple stages. The tube material and mandrel piece are not burdened at once.
Moreover, the diameter expansion process by each mandrel piece is smoothly started by the conditions of said (2) and (4), and an excessive burden is not applied to a pipe | tube raw material or a mandrel piece.
According to this apparatus, it is possible to perform pipe processing without imposing a large burden on the pipe material or mandrel piece. The tube material can be expanded in multiple stages, and the burden on the tube material can be reduced. In addition, since the tube is expanded by a plurality of mandrel pieces, the burden is distributed to the plurality of mandrel pieces, and a specific load is not applied to the specific mandrel piece.
Since the mandrel of the present invention is configured by connecting a plurality of mandrel pieces in series and in a freely bendable manner, the diameter can be expanded while following the bent tube. The shape range of pipes that can be processed is wide.
[0007]
In addition, the mandrel described in JP-A-7-68331 also has a plurality of mandrel pieces connected in series and flexibly. However, the mandrel described in Japanese Patent Application Laid-Open No. 7-68331 is for pushing the tube expansion head attached to the head into the tube hole, and the mandrel itself does not expand the tube hole. A plurality of mandrel pieces are connected in series and bendably so that the tube expansion head can be pushed into the bent tube hole, but the mandrel piece itself is narrower than the tube hole, and the diameter of the tube hole is increased. It is not what you do. The tube expansion head for expanding the diameter of the tube hole is not divided into a plurality of pieces and connected in series and flexibly.
In the present invention, a mandrel corresponding to a tube expanding head for expanding the diameter of a tube hole is divided into a plurality of pieces and connected in series and flexibly, which is completely different from that described in JP-A-7-68331. To do. In the technique described in JP-A-7-68331, the conditions (1), (3) to (5) are not satisfied.
[0008]
It is preferable to further include a mold for restraining the outer wall of the bent pipe being processed from the outside. By using a mold, it is possible to follow the inner shape of the mold at the same time as expanding the diameter in multiple stages by passing through the mandrel pieces in order, and simultaneously forming the bent shape (outer shape) of the pipe product It becomes possible to do.
[0009]
When the outer wall of the bending tube being processed is constrained by a mold, the mandrel pieces can be sequentially passed through the tube holes by pulling wires extending through the plurality of mandrel pieces. In this case, the mandrel feeding mechanism can be configured by the wire winding device.
When the mandrel piece group is passed through the tube hole by pulling, the device can be configured much more easily than by pushing the mandrel piece group through the tube hole. A wire may be used in place of the bendable mandrel described in JP-A-7-68331.
[0010]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.
(Mode 1) The plurality of mandrel pieces are arranged at a predetermined interval.
(Mode 2) The plurality of mandrel pieces are connected in series by a wire.
(Mode 3) Each mandrel piece is tiltable with respect to the wire.
(Mode 4) When the wire between the mandrel pieces is bent, adjacent mandrel pieces are bent.
(Mode 5) A wire connecting a plurality of mandrel pieces extends further forward from the leading mandrel piece, and when the wires are pulled forward, the connected mandrel pieces pass through the tube hole.
[0011]
DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described with reference to FIGS. FIG. 1 is a schematic cross-sectional view of a tube processing apparatus 2 of the present embodiment that processes a tube material 28, FIG. 2 is a perspective view of the tube material before processing, and FIG. 3 is a tube after bending processing. 4 is a perspective view of the pipe product after the diameter expansion processing, and FIG. 5 is a schematic perspective view of the molds 24 and 26 of the pipe processing apparatus 2.
A pipe processing apparatus 2 shown in FIG. 1 is an apparatus for forming a pipe product as shown in FIG. 4 by performing pipe expansion processing on a bent pipe material (see FIG. 3). The bent tube material is formed by applying a bending process or the like to a metal straight tube material (see FIG. 2) in the previous process.
[0012]
The tube processing apparatus 2 shown in FIG. 1 includes a mandrel 10, an upper mold 24, a lower mold 26, a wire 20, a drum 22 around which the wire 20 is wound. The mandrel 10 includes a plurality of mandrel pieces 12, 14, 16, and 18, and the mandrel piece groups 12, 14, 16, and 18 are connected to each other in series and bendable by wires 20. The front end of the wire 20 is connected to the drum 22. The drum 22 is rotationally driven by a motor (not shown). When the drum 22 is driven to rotate in the direction of the arrow by the motor, the wire 20 is wound around the drum 22.
[0013]
The mandrel pieces 12, 14, 16, and 18 are attached to the wire 20 at the center, and can be tilted with respect to the wire 20 without moving relative to the wire 20 to the left in the drawing. The mandrel pieces 12, 14, 16, 18 can be freely tilted with respect to each other.
The right direction in the figure of the mandrel 10 is referred to as the head, and the left direction in the figure is referred to as the rear. Further, the right direction in the figure of each mandrel piece 12, 14, 16, 18 is defined as the front, and the left direction in the figure is defined as the rear.
[0014]
Each mandrel piece 12, 14, 16, 18 satisfies the following relationship.
(1) The rear surface of each mandrel piece 12, 14, 16, 18 is larger than the front surface. That is, each mandrel piece 12, 14, 16, 18 expands from the front side toward the rear side.
(2) The size of the front surface 12a of the leading mandrel piece 12 is slightly smaller than the size of the cross section of the tube hole 28a.
(3) The size of the rear surface 12b of the leading mandrel piece 12 is slightly larger than the size of the cross section of the tube hole 28a.
(4) The size of the front surface 14 a of the second mandrel piece 14 is slightly smaller than the size of the rear surface 12 b of the leading mandrel piece 12. The size of the front surface 16 a of the third mandrel piece 16 is slightly smaller than the size of the rear surface 14 b of the second mandrel piece 14. The size of the front surface 18 a of the fourth mandrel piece 18 is slightly smaller than the size of the rear surface 16 b of the third mandrel piece 16. That is, the cross-sectional shape of the front end of the second and subsequent mandrel pieces does not exceed the cross-sectional shape of the rear end of the mandrel piece located immediately before.
(5) The size of the rear surface 14b of the second mandrel piece 14 is slightly larger than the size of the rear surface 12b of the leading mandrel piece 12. The size of the rear surface 16 b of the third mandrel piece 16 is slightly larger than the size of the rear surface 14 b of the second mandrel piece 14. The size of the rear surface 18 b of the fourth mandrel piece 18 is slightly larger than the size of the rear surface 16 b of the third mandrel piece 16. That is, the cross-sectional shape of the rear end of each mandrel piece is sequentially enlarged from the leading mandrel piece toward the rear mandrel piece.
[0015]
The mold shown in FIG. 5 includes an upper mold 24 and a lower mold 26. A recess 24 a is formed in the upper mold 24, and a recess 26 a is formed in the lower mold 26. When the upper mold 24 and the lower mold 26 are combined, a space of a product shape (see FIG. 4) bent by the recesses 24a and 26a is formed. The pipe material 28 is accommodated in this space and the pipe expansion process is performed.
[0016]
The tube material 28 is sandwiched between the upper mold 24 and the lower mold 26, and the mandrel 10 is passed through the tube hole 28a, thereby expanding the diameter of the tube hole 28a and expanding the tube material 28. At the same time, the outer shape of the tube material 28 is made to follow the shape of the concave portions 24a and 26a of the mold, and the bent shape of the tube product is simultaneously formed.
[0017]
The processing procedure will be described below. The wire 20 extending forward from the mandrel piece 12 is inserted from one end (left side in the figure) of the tube hole 28a of the tube material 28, and the tip of the wire 20 is drawn out from the other end (right side in the figure) of the tube hole 28a. Connecting. When a motor (not shown) is driven, the drum 22 is rotationally driven in the direction of the arrow, and the wire 20 is wound around the drum 22. Mandrel pieces 12, 14, 16, and 18 are connected to the wire 20, and when the wire 20 is wound around the drum 22, the mandrel pieces 12, 14, 16, and 18 are moved in the right direction (the direction of the arrow) in the figure. Moving.
[0018]
Since the front surface 12a of the leading mandrel piece 12 is slightly smaller than the tube hole 28a of the tube material 28, the mandrel piece 12 is smoothly inserted into the tube hole 28a as the wire 20 is wound around the drum 22. . The cross-sectional shape of the mandrel pieces 12, 14, 16, 18 increases toward the rear. The rear surface 12b of the mandrel piece 12 is larger than the tube hole 28a. Therefore, when the mandrel piece 12 is inserted and passed to the rear part, the tube material 28 is successively expanded to the size of the rear surface 12b.
Subsequently, since the front surface 14a of the mandrel piece 14 connected immediately after is slightly smaller than the size of the rear surface 12b of the mandrel piece 12, the mandrel piece 12 is expanded as the wire 20 is wound around the drum 22. Is smoothly inserted into the pipe hole 28a. When the mandrel piece 14 is inserted and passed to the rear, the tube material 28 is successively expanded to the size of the rear surface 14b.
Subsequently, since the front surface 16a of the mandrel piece 16 connected immediately after is slightly smaller than the size of the rear surface 14b of the mandrel piece 14, the mandrel piece 14 is expanded as the wire 20 is wound around the drum 22. Is smoothly inserted into the pipe hole 28a. When the mandrel piece 16 is inserted and passed to the rear, the tube material 28 is successively expanded to the size of the rear surface 16b.
Subsequently, the mandrel piece 18 that is immediately after and connected to the rearmost part has a front surface 18a slightly smaller than the size of the rear surface 16b of the mandrel piece 16, so that the wire 20 is wound around the drum 22. The mandrel piece 16 is smoothly inserted into the expanded tube hole 28a. The shape of the rear surface 18b of the mandrel piece 18 is equal to the sectional shape of the tube hole of the product (see FIG. 4). When the mandrel piece 18 is inserted to the rear and passes through the tube hole 28a, the tube hole 28a is successively expanded to the cross-sectional shape of the product tube hole.
[0019]
When the leading mandrel piece is inserted into the tube material, the size of the cross-sectional shape of the mandrel piece is slightly smaller than the tube hole of the tube material, so that the mandrel piece is inserted without difficulty. Since the mandrel piece is enlarged toward the rear part, when the mandrel piece is inserted to the rear part, the tube material is slightly expanded. Subsequently, the mandrel piece connected immediately after is inserted without difficulty because the front part does not exceed the size of the rear part of the immediately preceding mandrel piece, but when this mandrel piece is inserted to the rear part, the tube material tube The hole is further expanded. Subsequently, when the mandrel piece connected immediately after is inserted to the rear, the tube hole is further expanded. In this way, a plurality of mandrel pieces are inserted into the tube hole of the tube material in ascending order, and each time the tube is expanded little by little. Since the cross-sectional shape of the rear part of the mandrel piece at the end is equal to the cross-sectional shape of the product hole, when the last mandrel piece passes through the pipe hole, the cross-sectional shape of the pipe material hole becomes the cross-section of the product hole. It becomes a shape.
[0020]
Further, the pipe expansion process is performed in a state of being sandwiched between the upper mold 24 and the lower mold 26. When the mandrel pieces 12, 14, 16, 18 pass through the tube hole 28a, the outer peripheral surface of the tube material 28 is pressed against the recess 24a of the upper die 24 and the recess 26a of the lower die 26. Since the product shape (see FIG. 4) is formed by the recess 24a and the recess 26a, the outer peripheral surface of the tube material 28 pressed against the recess 24a and the recess 26a is formed into a product shape. As a result, stable tube expansion processing can be performed and the outer shape of the product can be molded. That is, according to the tube processing apparatus of the present embodiment, the tube material 28 can be simultaneously formed from inside and outside the tube hole 28a.
[0021]
As described above, by using the tube processing apparatus of this embodiment, the tube material 28 can be gradually expanded, and the burden on the tube material 28 can be reduced. In addition, since the pipes are expanded by all the mandrel pieces 12, 14, 16, and 18 constituting the mandrel 10, the burden is distributed to all the mandrel pieces 12, 14, 16, and 18, and a burden that is biased to a specific mandrel piece only. There is no hanging. The burden on the entire mandrel 10 can be reduced, and the occurrence of wear and damage can be suppressed.
[0022]
Further, since the entire tube material 28 is also supported from the outer peripheral surface side, the tube expansion work by the mandrel 10 is stabilized, and highly accurate tube expansion can be performed. In addition, since the tube material 28 is sandwiched and accommodated in the product-shaped molds 24 and 26 and expanded, the outside of the tube material 28 can be molded simultaneously with the expansion of the tube hole 28a.
For example, when a straight pipe (see FIG. 2) is subjected to a bending bending process to form a curved pipe (see FIG. 3), the pipe may be slightly flattened at the bent portion. In such a case, when tube expansion processing is performed by the tube processing apparatus of the present embodiment, since the tube material is formed from inside and outside, some flatness is eliminated, and it is possible to form into a good shape.
[0023]
Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
For example, although a wire is preferable as a member for connecting a plurality of mandrel pieces, it is not particularly limited as long as it is a member that can connect the mandrels so as to be bent.
As for the means for moving the mandrel piece inserted into the tube hole of the tube material, since a plurality of mandrel pieces are connected by a wire in the embodiment, a method of winding the wire with a drum driven by a motor is taken. However, an appropriate means should just be used by the member which connects a mandrel piece, and it does not specifically limit.
In the embodiment, the mandrel has four mandrel pieces, but the number of mandrel pieces constituting the mandrel is not limited to this.
Although the cross-sectional shape of the product in the examples is rectangular, the tube processing apparatus of the present invention can be used when a product having a shape other than a rectangle is formed.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a pipe processing apparatus of this embodiment and a pipe material being processed.
FIG. 2 is a perspective view of a tube material before processing.
FIG. 3 is a perspective view of a pipe material after bending.
FIG. 4 is a perspective view of a tube material after tube expansion.
FIG. 5 is a perspective view of a mold of a pipe processing apparatus.
[Explanation of symbols]
10: Mandrel 12, 14, 16, 18: Mandrel piece 20: Wire 22: Drum 24: Upper mold 26: Lower mold 28: Tube material, 28a: Tube hole

Claims (3)

A device that expands the diameter of the tube material and processes it into a tube product.
A mandrel in which a plurality of mandrel pieces are connected in series and flexibly;
A mandrel feed mechanism that sends the mandrel and sequentially passes a plurality of mandrel pieces through the tube hole of the tube material,
The cross-sectional shape of each mandrel piece is expanding from the front side to the rear side,
The cross-sectional shape of the front end of the first mandrel piece does not exceed the cross-sectional shape of the tube hole of the tube material,
The cross-sectional shape of the rear end of the leading mandrel piece exceeds the cross-sectional shape of the tube hole of the tube material,
The cross-sectional shape of the front end of the second and subsequent mandrel pieces does not exceed the cross-sectional shape of the rear end of the mandrel piece located immediately before,
A tube processing apparatus, wherein a cross-sectional shape of a rear end of each mandrel piece is sequentially enlarged from a leading mandrel piece toward a rear mandrel piece. The pipe processing apparatus according to claim 1, further comprising a mold for restraining an outer wall of the bent pipe being processed from the outside. The tube processing apparatus according to claim 2, wherein the mandrel feeding mechanism includes a winding device that winds a wire extending through a plurality of mandrel pieces.

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