JP2974049B2 - Method for processing dent in pipe and processing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming a recess in a pipe suitable for forming a locking recess in, for example, a headrest stay of an automobile.

[0002]

2. Description of the Related Art For example, as shown in FIG. 8 (a), a headrest stay 1 of an automobile is selectively engaged with a ratchet pawl of a ratchet mechanism (not shown) for vertically adjusting a headrest (not shown). Are formed at a plurality of locations on the stay portion at predetermined intervals.

Conventionally, when forming the recess 2 in the headrest stay 1 as described above, for example, as shown in FIG. 8B, a headrest stay 1 that is bent and formed so as to have a downward substantially U-shape is formed. At least a part (three places in this example) of the outer periphery of the pipe 3 which is a material to be processed is formed by forming a groove 4 having a substantially V-shape as a first step processing by light press processing or the like. I do. Then, in such a pipe 3, as shown in FIG. 8 (c), mechanical cutting using an appropriate cutting jig as a second step processing is performed on the groove 4 formed by the light press working. The recess 2 having a required shape is formed by processing.

Here, such a headrest stay 1
The pipe 3 is a material having a projection 5 at an appropriate place as shown in FIG. 9 by, for example, forming a strip-shaped sheet material in a widthwise direction by roll forming and sequentially seam-welding the seam. It is formed and prepared with.
The projection 5 formed by such seam welding is the same as the second projection described above.
It is removed by mechanical cutting of the step or by applying a forming process such as pressing.

[0005]

However, in the above-mentioned conventional processing method, two-stage pressing and mechanical cutting are required for forming the recess 2 in the pipe material 3 to be the headrest stay 1. Since these processing steps are mixed, there is a problem in workability such as work efficiency. Further, since the cutting blade used for the mechanical cutting process is worn out, replacement is required after an appropriate period, running costs are always incurred, and there is a problem that the cost is increased as a whole.

Further, in the above-mentioned conventional processing method, since the outer peripheral portion of the stay 1 and the formed portion of the recess 2 are cut by mechanical cutting, the wall thickness is reduced and the strength of the stay 1 is reduced. there were. In particular, when the thickness of the stay 1 is locally reduced, or when wrinkles occur due to buckling or the like, the distortion and stress in the dent forming portion become unbalanced, and not only can the desired dent shape not be obtained, but also In some cases, cracks or breaks may occur, and there is a problem in strength such as a decrease in cross-sectional strength.

The present invention has been made in view of such circumstances, and it is possible to easily and appropriately form a recess having a desired shape at a desired position of a pipe by a single press working, and to improve work efficiency. It is an object of the present invention to obtain a method for processing a dent in a pipe and a processing apparatus therefor, which can improve the quality of the pipe.

[0008]

In order to respond to such a demand, a method for forming a dent in a pipe according to the present invention comprises inserting a metal core supporting the inner surface of the pipe into a pipe to be formed.
A punch die for holding a pipe between the upper die and the lower die corresponding to the core metal and holding the same, and forming a recess movably installed in the die of the forming die, is pressed through a die holder. Simultaneously pressurizing, in the method for forming a recess in a pipe at a predetermined location on the outer periphery of the pipe, a concave portion corresponding to a concave portion of a portion pressed by a punch die, The groove in the circumferential direction that allows relative rotation of the portion corresponding to the recess of the pipe continuously, and the relative movement in the axial direction of the portion corresponding to the recess on the pipe side continuously to the groove. Forming a groove in the axial direction to allow, forming a recess of a predetermined shape at a predetermined location on the outer periphery of the pipe, then rotating the cored bar and pulling it out of the pipe,
In addition, by opening the upper mold and the lower mold, a recess is formed in a predetermined position of the pipe in a predetermined shape.

Further, the present invention provides a pipe dent processing apparatus for forming a dent in at least a part of an outer periphery of a pipe, wherein the dent is inserted into a pipe to be formed and supports the inner surface of the pipe. A core having a concave portion corresponding to the above, an upper die and a lower die for holding the pipe in which the core is inserted from above and below, and a concave shape movably installed in the mold. Punch type,
A mold presser for supporting the one molding die during press working with the punch die, and a core corresponding to the depression of the portion pressed by the punch die, A circumferential groove portion that allows relative rotation of a portion corresponding to the pipe-side recess continuously, and an axial relative movement of a portion corresponding to the pipe-side recess continuously to the groove portion The groove is formed in the axial direction to allow the above.

[0010]

According to the present invention, a core metal for supporting the inner surface of a pipe is inserted into a pipe having a recess formed in at least a part of the outer periphery of the pipe which is a forming material, and an upper die and a lower die corresponding to the core metal are inserted. A punch mold that holds a pipe between the mold and holds it, and forms a dent that is movably installed in the lower mold,
Pressing is performed simultaneously with press working through the mold holder, forming a recess of a predetermined shape at a predetermined location on the outer periphery of the pipe, and then rotating the core metal through the groove to pull it out of the pipe, and the upper die and the lower die Can be opened to form a recess having a predetermined shape at a predetermined location of the pipe.

[0011]

1 to 7 show an embodiment of a method and an apparatus for forming a dent in a pipe according to the present invention. In these figures, reference numeral 10 denotes a pipe which is a material for forming, Reference numeral 11 denotes a metal core inserted into the inside and supporting the inner surface of the pipe. As is clear from FIGS. 2 to 5, the metal core 11 has a chuck portion 11a held by a chuck (not shown) of the dent processing device 20. A portion 11b of the cored bar 11 inserted into the pipe 10 supports the inner surface of the pipe 10 and has portions 14 and 14 in the figure corresponding to the recesses 12 and 13 formed at predetermined locations of the pipe 10. As shown by, a concave portion serving as a concave forming receiving portion is formed.

In such a core metal 11 for forming, the recesses 14 and 14 corresponding to the recesses 12 and 13 are formed in portions pressed by punches 23 and 24 described later, and the pipe 10 Circumferential grooves 15, 15 which allow relative rotation of the portions corresponding to the side recesses 12, 13 and the recesses 1 on the pipe 10 side continuous with the grooves 15, 15.
It is formed in a shape having an axial groove 16 that allows relative movement in the axial direction of portions corresponding to 2 and 13. In short, the core metal 11 has recesses 14, 14 serving as receiving portions at the time of forming the dent, and grooves 15, 15 capable of rotating the core metal 11 by escaping the protrusion into the pipe 10 after the molding.
And a portion that escapes from the protrusion when the core metal 11 is pulled out may be formed to be recessed from the outer diameter portion.

In FIGS. 4 and 5, reference numeral 17 denotes an arc-shaped groove formed by being recessed at a position shifted from the above-mentioned grooves 15 and 15 by substantially half a circle. 9 is a recess for escaping the projecting portion 5 protruding inward when the pipe 10 is formed by seam welding as shown in FIG. 9, and allows rotation of the core bar 11 within a predetermined angle range, and 11 are formed along the axial direction so as to allow 11 axial movements.

In this embodiment, one of the recesses 12 and 13 formed on the outer periphery of the pipe 10 has a tapered surface on one side, and the other is formed as a simple recess. However, the present invention is not limited to this, and it is needless to say that a material having an appropriate shape may be formed.

The core metal 11 of the dent processing device 20 for the pipe 10 has a dent 1 on at least a part of the outer periphery of the pipe 10.
2 and 13 are inserted into the recessed pipe 10 to support the inner surface of the pipe 10 and have recesses 14 and 14 corresponding to the recesses 12 and 13. The upper mold 21 and the lower mold 2 having semicircular grooves 21a and 22a for the pipe 10 for holding the pipe 10 into which the core metal 11 is inserted by pressing the pipe 10 from above and below.
2, a punching die 23, 24 for forming a concave shape movably installed in one of the upper die 21 and the lower die 22; in this embodiment, a lower die 22; A mold presser 25 is provided for supporting the lower mold 22, which is one of the molding dies, during press working with the molds 23 and 24.

Here, as shown in FIG. 6, a part of the semi-circular groove 22a of the lower die 22 is provided with the punch dies 23, 24.
The insertion holes 26a and 26b are formed in accordance with the shape of. Further, these punch dies 23 and 24 are
The upper part of the pipe 10 is held by the push-out pins 27a and 27b of the push-out member 27 disposed below the pipe 10 so as to locally press a part of the outer peripheral portion of the pipe 10, and The recesses 12 and 13 are formed in the pipe 10 by press working with the groove portions 14 and 14 which are formed by pressing.

In FIG. 7, reference numeral 29a denotes a combination pin 30 for positioning and combining the upper mold 21 and the lower mold 22.
The holes 29b are holes for screws 31 for assembling the die holder 25 to the lower die 22.

According to the above configuration, the dents 12 and 13 formed in the pipe 10 can be formed by the processing device 20 and the punch dies 23 and 24 having a simple structure. It can be performed very easily and reliably by one-step pressing. Therefore, pipe 1
The recesses 12 and 13 can be formed very easily and surely with respect to 0, so that the working efficiency can be greatly improved. Further, it is possible to eliminate a problem such as a decrease in cross-sectional strength, which has been a problem due to forming by press working after performing conventional cutting.

In particular, according to the present invention, the metal core 11 for supporting the inner surface of the pipe 10 is inserted into the pipe 10 in which the recesses 12 and 13 are formed in at least a part of the outer periphery.
The punches 23 and 24 which hold the pipe 10 between the upper die 21 and the lower die 22 corresponding thereto and hold the pipe 10, and which are formed movably in the die of the lower die 22 are formed by the die holder 27.
And pressurizing simultaneously with the press working to form recesses 12 and 13 of a predetermined shape at predetermined locations on the outer periphery of the pipe 10.

After the molding, the core 11 can be rotated by a predetermined angle in a required direction, and can be pulled out of the pipe 10 through the grooves 15, 15, 16, 17. By opening the upper mold 21 and the lower mold 22, the pipe 1 in which the recesses 12 and 13 having a predetermined shape are formed at predetermined positions of the pipe 10.
The recesses 12 and 13 can be easily and appropriately formed on the outer periphery of the pipe 10 by a single-step press process, although the molding process is simple. It is possible to improve work efficiency in processing. Further, it is possible to eliminate a problem such as a decrease in cross-sectional strength, which has been a problem due to forming by press working after performing conventional cutting.

According to the above-described configuration, the lower die 22 and the punch dies 23 and 24 are appropriately changed to cope with a difference in the number and positions of the dents due to a difference in specifications of the headrest stays. This structure has the advantage that the number of molds can be reduced as compared with a case where the molds and the like are entirely changed. In the above-described embodiment, any one of the molds is the lower mold 22.
The upper mold 21 can be used, and the molding dies can have left and right mold structures.

It should be noted that the method and apparatus 20 for recessing a pipe according to the present invention are not limited to the structure of the embodiment described above, and it is needless to say that the shape and structure of each part can be appropriately modified and changed. For example, the shapes of the punch dies 23 and 24 and the driving means thereof can be freely changed. That is, the punch dies 23 and 24 can be freely driven by an appropriate fluid pressure cylinder mechanism or the like instead of being pressed by the pushing member 27.

In the above-described embodiment, the recess of the present invention is used for forming a locking recess in, for example, a headrest stay of an automobile. However, the present invention is not limited to this, and it is necessary to form an appropriate recess. The effect can be exhibited in forming a thin pipe 10 having a certain thickness.

[0024]

As described above, according to the method for forming a dent in a pipe according to the present invention, a core for supporting the inner surface of a pipe is inserted into a pipe to be formed, and an upper die corresponding to the core is formed. Pressing and holding a pipe between the lower mold and the punch, which forms a dent that is movably installed in the mold of the molding die, presses simultaneously with press working via a mold holder, and pressurizes the outer periphery of the pipe. In a method for forming a dent in a pipe, a dent having a predetermined shape is formed at a predetermined position. In the core metal, a dent corresponding to a dent of a portion to be pressed by a punch die is formed. A circumferential groove portion that allows relative rotation of a corresponding portion, and an axial groove portion that allows an axial relative movement of a portion corresponding to the recess on the pipe side are formed continuously with the groove portion. At a predetermined location on the outer periphery of the pipe. After forming the shape of the recess, the core is rotated to be drawn out of the pipe, and the upper mold and the lower mold are opened to form a recess of a predetermined shape at a predetermined position of the pipe. Because of the configuration, various excellent effects listed below are exhibited despite simple molding processing.

That is, according to the present invention, it is possible to easily and appropriately form the dent on the outer periphery of the pipe by one-step press working, and it is possible to improve the working efficiency in forming the dent. Further, it is possible to eliminate a problem such as a decrease in cross-sectional strength, which has been a problem due to forming by press working after performing conventional cutting.

In particular, according to the present invention, as a core metal to be inserted into a pipe, a part pressurized by a punch mold has a concave part corresponding to the concave part and a part corresponding to the concave part on the pipe side continuously to the concave part. By using a circumferential groove that allows relative rotation and an axial groove that allows relative movement in the axial direction of a portion corresponding to the recess on the pipe side continuous to the groove, It is extremely easy to remove the cored bar from the pipe after use.

According to the apparatus for forming a dent in a pipe according to the present invention, in a processing apparatus for forming a dent in at least a part of the outer periphery of a pipe, the apparatus is inserted into the pipe to be formed and supports the inner surface of the pipe. A metal core having a concave portion corresponding to the concave portion, an upper die and a lower die for holding the pipe inserted with the core metal from above and below, and a concave shape movably installed in the mold of the molding die; A punch die to be formed, and a die holder for supporting the one of the forming dies at the time of press working with the punch die. And a groove in the circumferential direction that allows relative rotation of a portion corresponding to the recess on the pipe side continuous with the recess, and an axis of a portion corresponding to the recess on the pipe side continuous to the groove portion One Because of the axial groove that allows relative movement of the pipe, it has an excellent effect that, despite its simple structure, it is possible to form the dent in the pipe extremely easily and reliably. Play.

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of a method for processing a dent in a pipe and an apparatus for processing the same according to the present invention.

FIG. 2 is a schematic side view showing a method for processing a dent in a pipe according to the present invention and a core used in the processing apparatus.

FIG. 3 is a schematic sectional view showing in detail a portion IIIA and IIIB in FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is a sectional view taken along line VV of FIG. 2;

FIG. 6 is a schematic exploded perspective view showing one embodiment of a pipe dent processing apparatus according to the present invention.

FIG. 7 is a schematic sectional view of a pipe dent processing apparatus according to the present invention.

FIG. 8A is a schematic view of a headrest stay to which a conventional method of forming a recess in a pipe is applied, and FIG. 8B is a cross-sectional view of a main part showing a state where a first-stage cutting process is performed in forming a recess. (C) is a sectional view of an essential part showing a state in which the pipe of (b) is subjected to a second-stage press working.

FIG. 9 is a cross-sectional view of a main part of a pipe material forming a headrest stay to which a conventional method of forming a recess in a pipe is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Headrest stay 10 Pipe 11 Core 12 Depression 13 Depression 14 Depression serving as a receiving portion for molding 15 Circumferential groove 16 Axial groove 20 Depression processing device 21 Upper die 21a Semicircular groove 22 Lower die 22a Semicircular groove Reference Signs List 23 punch die 24 punch die 25 die holder 26a insertion hole 26b insertion hole 27 extrusion member 27a extrusion pin 27b extrusion pin

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigeru Hattori 771 Kozono, Ayase-shi, Kanagawa Ikeda Bussan Co., Ltd. (56) References JP-A-6-31350 (JP, A) JP-A-61-232022 ( JP, A) JP-A-6-246363 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B21D 17/02 B21D 22/02 B21D 22/04

Claims (2)

(57) [Claims] 1. A mold for supporting an inner surface of a pipe is inserted into a pipe to be formed, and the pipe is pressed and held between an upper mold and a lower mold corresponding to the core, and the mold of the mold is formed. A punch mold for forming a recess movably installed in the press, pressurizing simultaneously with press working via a mold holder, and a method for forming a recess of a predetermined shape at a predetermined location on the outer periphery of the pipe, wherein the method for forming a recess into a pipe comprises: A concave portion corresponding to a concave portion of a portion pressed by a punch die, a circumferential groove portion allowing a relative rotation of a portion corresponding to the concave portion of the pipe continuously to the concave portion; Forming a groove in the axial direction allowing relative movement in the axial direction of a portion corresponding to the recess on the pipe side, forming a recess of a predetermined shape at a predetermined location on the outer periphery of the pipe, and then forming the core. Rotate the gold and pull it out of the pipe By opening the mold the upper and lower molds and, recess machining method of the pipe, characterized in that to perform the shaping of the recess with a predetermined shape to a predetermined position of the pipe. 2. A processing apparatus for forming a recess in at least a part of an outer periphery of a pipe, comprising: a metal core inserted into a pipe to be subjected to the forming process, supporting a pipe inner surface, and having a recess corresponding to the recess; An upper die and a lower die that hold the pipe into which the gold is inserted by pressing from above and below, a punch die that forms a concave shape that is movably installed in the die of the forming die, and a press die that is formed by the punch die. With a mold holder that supports one of the molding dies, a metal core inserted into a pipe to be subjected to the molding processing is provided,
A concave portion corresponding to the concave portion of the portion to be pressed by the punch die, a circumferential groove portion allowing the relative rotation of the portion corresponding to the concave portion on the pipe side continuously to the concave portion, An apparatus for machining a dent in a pipe, wherein an axial groove is formed to allow relative movement in the axial direction of a portion corresponding to the dent on the pipe side.