JP2007167883A - Method for manufacturing metallic tubular member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a metallic tubular member by which restruck articles having highly accurate and stable shape is obtained and the cost of a die is reduced while being made correspond to a plurality of kinds of formed articles. <P>SOLUTION: By forming a planar straight-line parts 8 in the end parts of the formed articles 20, providing a recessed part 13 where is matched with the outer peripheral surface 8c including the straight line part 8 of the formed articles 20 on an upper die 11 and providing a projecting part 14 where is matched with the end parts 8a of the straight-line parts 8 and the inner peripheral surfaces 8b of the straight-line parts 8 of the formed articles 20 on a lower die 12, the restriking work is performed in the state where the straight-line parts 8 of the formed articles 20 are supported with the recessed part 13 of the upper die 11 and the projecting part 14 of the lower die 12 while inserting the formed articles 20 between the upper die 11 and the lower die 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a metallic tubular member.

Conventionally, the end of the foam product is flattened by re-striking the end of the foam product while sandwiching the foam product with the half-shaped metal tubular member between the upper mold and the lower mold. The technique of the manufacturing method of the metal tubular member which formed the prepared wrist-like goods and welded the edge parts by making the said wrist-like goods into a pair is known (refer patent document 1).
Japanese Patent Laid-Open No. 10-329503

  However, as in the case of the conventional invention, the accuracy of parts is improved when the thickness of the foam product is 10 mm or more. However, when the thickness of the foam product is as thin as 0.5 to 1.0 mm, the foam The end of the product is deformed by the residual stress when it is press-molded, or it is deformed by the thermal stress when the end is gas-cut after press-molding. In this case, the so-called springback occurs in which the end of the foam product returns to the original shape before compression, and when the amount of wrist-like is excessive, the end of the foam product is buckled and cracked, There was a problem that a highly accurate and stable shape like a re-like product could not be obtained.

  Further, in the conventional invention, there is a problem that the lower mold contacting the inner peripheral surface of the foam product cannot cope with a plurality of types of foam products, and the mold cost is increased due to an increase in size.

  The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to obtain a highly accurate and stable shape-like product and to cope with a plurality of types of foam products. Another object of the present invention is to provide a method for manufacturing a metal tubular member that can reduce mold costs.

  In the invention according to claim 1 of the present invention, the end of the foam product is subjected to a re-striking process while sandwiching a foam product having a half-shaped metal tubular member between the upper mold and the lower mold. In the method of manufacturing a metal tubular member in which a wrist-like product in which the ends of the foam product are arranged flat is formed, and the ends of the wrist-like product are welded to each other as a pair, a flat plate is formed on the end of the foam product. The upper mold is provided with a recess that matches the outer peripheral surface including the linear part of the foam product, and the lower mold has an end part of the linear part of the foam product and an inner peripheral surface of the linear part. The convex part is provided with a convex part that matches the upper mold and the lower mold, and the linear part of the foam product is supported by the concave part of the upper mold and the convex part of the lower mold. It is characterized by being processed like.

  In the invention according to claim 1 of the present invention, a foam product having a shape in which a metal tubular member is halved is sandwiched between an upper mold and a lower mold, and an end portion of the foam product is subjected to restric processing. In the method of manufacturing a metal tubular member in which a wrist-like product in which the ends of the foam product are flattened is formed, and the ends are welded to each other as a pair, the end of the foam product A flat linear portion is formed on the upper die, and a concave portion that matches an outer peripheral surface including the linear portion of the foam product is provided on the upper die, and an end portion of the linear portion of the foam product and a linear portion of the lower die are provided on the lower die. Protrusions that match the inner peripheral surface are provided, and the foam product is sandwiched between the upper die and the lower die, and the linear portion of the foam product is supported by the concave portions of the upper die and the convex portions of the lower die. The restructuring process is performed in a state, so the restructuring of a highly accurate and stable shape It is possible to obtain a click products, while coping with a plurality of types of forms products can reduce mold costs.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1 will be described below.
1 is a plan view of a foam product 20 according to a first embodiment of the present invention, FIG. 2 is a bottom view thereof, FIG. 3 is a front view thereof, FIG. 4 is an end view taken along line S4-S4 of FIG. FIG. 6 is an end view taken along line S5-S5 in FIG. 6, and FIG. 6 is an end view taken along line S6-S6 in FIG.

  FIG. 7 is a diagram for explaining a press molding processing apparatus used for manufacturing the foam product 20 of the first embodiment, FIG. 8 is a diagram for explaining manufacturing of the foam product 20 by the press molding processing apparatus, and FIG. It is a figure explaining the cutting | disconnection of the edge part of this foam article.

  FIG. 10 is a diagram for explaining the wrist-like processing apparatus used for manufacturing the wrist-like product according to the first embodiment, FIG. 11 is a diagram for explaining the manufacturing of the wrist-like product by the wrist-like processing apparatus, and FIG. 12 is the first embodiment. FIG. 6 is an enlarged view of a main part of the figure, and is a diagram for explaining an action at the time of wrist-like processing.

  13 is a plan view of the wrist-like product 30 of the first embodiment, FIG. 14 is a bottom view thereof, FIG. 15 is a diagram for explaining the joining of the wrist-like products 10 and 30 of the first embodiment, and FIG. b) is an end view taken along line S16-S16, FIG. 17 is an end view taken along line S17-S17 in FIG. 15B, and FIG. 18 is an end view taken along line S18-S18 in FIG.

In order to manufacture the metallic tubular member A of the first embodiment, first, using a known press forming apparatus 2 described later, a material 1 made of a stainless steel flat plate having a thickness of 0.5 to 1.0 mm, The foam article 20 shown in FIGS. 1-6 is formed.
The foam product 20 of the first embodiment is composed of straight portions 20a and 20b having both ends in the longitudinal direction having a semicircular cross section, and a bulging portion having a substantially triangular cross section curved at the center in the longitudinal direction. 20c. The cross-sectional shape of the foam product 20 can be set as appropriate.

  As shown in FIG. 7, the press molding apparatus 2 matches the upper mold 4 having the recess 3 having a shape that matches the outer peripheral surface of the foam product 20 to be manufactured, and the inner peripheral surface of the foam product 20 to be manufactured. A lower die 6 having a convex portion 5 having a shape, a pair of chuck mechanisms 7a and 7b, an unillustrated driving device capable of stopping the upper and lower dies 4 and 6 close to and away from each other, and a pair of chuck mechanisms 7a and 7b It is comprised from the drive device outside a figure which moves this to an up-down direction. Note that these drive devices employ general pneumatic or hydraulic cylinders.

Then, as shown in FIG. 8A, the chuck mechanism 7a, 7b is moved upward by a driving device (not shown), and the material 1 is sandwiched between the lower end portion of the upper mold 4 and FIG. As shown in (b), the raw material 1 is press-molded by moving the lower die 6 upward by a driving device (not shown) and causing the convex portion 5 to enter the concave portion 3 of the upper die 4.
At this time, the check mechanisms 7a and 7b may be loosened so that the material 1 is gradually fed between the concave portion 3 and the convex portion 5 of the upper and lower molds 4 and 6.

Next, as shown in FIG. 9, the press-molded material 1 is cut at a predetermined cutting position to obtain a foam product 20 having flat linear portions 8 at both ends.
At this time, the cutting position, in other words, the length of the linear portion 8 is set so that the cross-sectional circumferential length of the foam product 20 is 101% to 101.5% of the wrist-like product 10 to be manufactured.

Next, the wrist-like product 10 is obtained by subjecting the foam product 20 to a rest-like processing using a wrist-like processing device 9 described later.
As shown in FIG. 10, the wrist-like processing device 9 includes an upper mold 11, a lower mold 12, and upper and lower molds 11, 12 that are stopped from being close to and separated from each other and can be stopped. Note that this drive device employs a general pneumatic or hydraulic cylinder.

The upper mold 11 is formed with a concave portion 13 having a shape matching the outer peripheral surface including the straight portion 8 of the foam product 20.
On the other hand, the lower mold 12 has the same thickness W1 and length W2 as the thickness and width of the straight portion 8 of the foam product 20 from the main body 12a, and the end portion 8a and the straight portion 8 of the straight portion 8 of the foam product 20 The convex portions 14 having a shape matching the inside are formed in pairs.

  Then, as shown in FIG. 11, the both linear portions 8 of the foam product 20 are matched with the convex portion 14 of the lower mold 12, and the lower mold 12 is made to enter the concave portion 13 of the upper mold together with the foam product 20. The wrist-like product 10 is obtained by subjecting the foam product 20 between the upper and lower molds 11 and 12.

  At this time, as shown in FIG. 12, at both ends of the foam product 20, the end portion 8 a of the straight portion 8 and the inner peripheral surface 8 b of the straight portion 8 are the pressing surface 14 a and the convex portion of the convex portion 14 of the lower mold 12. Since the outer peripheral surface 8c of the linear portion 8 contacts the concave portion 13 of the upper mold 11, the outer peripheral surface 8c and the inner peripheral surface 8b of the foam product 20 are connected to the concave portion 13 and the convex portion. The foam product 20 is compressed in a substantially U-shaped cross-sectional direction (illustrated by a wavy arrow in FIG. 10) by pressing the end portion 8a of the straight portion 8 with the pressing surface 14a of the convex portion 14 while being supported by the side surface 14a. Thus, the end portion 8a of the straight portion 8 can be flattened.

Here, in the conventional invention, the end portion of the foam product is deformed by the residual stress at the time of press forming, or deformed by the thermal stress at the time of gas cutting the end portion after the press forming process. If the amount of re-striking is insufficient in the subsequent re-striking process, a so-called springback occurs in which the end of the foam product returns to its original shape before compression, and if the re-striking amount is excessive, the foam product As a result, there is a problem that a highly accurate and stable re-stoic product cannot be obtained.
As a result of experiments with conventional products, a springback of 3.0 mm on average occurred, and a maximum of 4.8 mm of springback occurred in the bulging portion 20c.

  However, in the method for manufacturing the metal tubular member A of the first embodiment, as described above, the outer peripheral surface 8c and the inner peripheral surface 8b of the linear portion 8 of the foam article 20 are supported by the side surface 14a of the concave portion 13 and the convex portion 14. However, the end surface 8a of the straight portion 8 is pressed by the pressing surface 14a of the convex portion 14 to compress the foam product 20 in a substantially U-shaped cross-sectional direction, so that it buckles inwardly on the end portion of the foam product 20. The stress in the direction can be relieved, whereby the end of the foam product 20 can be prevented from bending inward and buckling / cracking, and the foam product 20 can be entirely compressed to be formed into a stable shape.

  Further, since the convex portion 14 of the lower mold 12 does not need to be brought into contact with the foam product 20 except for the end portion 8a of the straight portion 8 and the inner peripheral surface 8b of the straight portion 8, it can be made compact and the die cost can be reduced. Can be reduced.

  Moreover, since it does not depend on the cross-sectional shape of the foam product 20, it can deal with a plurality of types of foam products 20 having different cross-sectional shapes.

  Finally, a wrist-like product 30 symmetrical to the wrist-like product 10 shown in FIGS. 13 and 14 is formed using the press processing device 2 and the wrist-like processing device 9 similar to the above, and as shown in FIG. A desired metal tubular member A is obtained by welding X the end portions 8a of the straight portions 8 of the pair of foam articles 10 and 30 (see FIGS. 16 to 18).

  Here, Table 1 shows the test results of the re-striking process by varying the re-striking amount (compression ratio) with respect to the cross-sectional circumference of the foam product 20 before the re-striking process. The foam product 20 used in the test was made of stainless steel (SUS304) with a thickness of 0.5 mm, and the same result was obtained for the foam product 30.

As is apparent from Table 1, when 0% ≦ restriction amount (compression ratio) <1.0%, the springback amount does not become smaller than 1.0 mm, and as a result, the pair of foam articles 10,30 When the end portions 8a of the straight portions 8 are joined together, there is a possibility that a gap of 2 mm or more is generated and welding cannot be performed satisfactorily.
On the other hand, when the amount of re-striking was set to> 1.5%, the straight part 8 of the foam product 20 was cracked or broken.
Similar results were obtained when the thickness of the foam product 20 was tested in place of 0.5 to 1.0 mm.

  Therefore, as an actual product, when the amount of re-striking is 1.0 to 1.5% of the cross-sectional circumference of the foam product 20 before re-striking, the re-stried product 10 having the highest product accuracy and reliability is obtained. Obtainable.

Next, the effect will be described.
As described above, in the method for manufacturing the metallic tubular member A according to the first embodiment, the foam product 20 having a shape in which the metallic tubular member A is divided in half is used as the upper mold 11 and the lower mold 12. The end portion of the foam product 20 is subjected to a wrist-like process while being sandwiched between them, thereby forming the wrist-like product 10 in which the end portion of the foam product 20 is flattened, and the wrist-like products 10 and 30 are paired as ends. In the manufacturing method of the metal tubular member A in which the parts are welded together, the flat linear portion 8 is formed at the end of the foam product 20, and the upper mold 11 is formed on the outer peripheral surface 8 c including the linear portion 8 of the foam product 20. A matching concave portion 13 is provided, and the lower die 12 is provided with a convex portion 14 that matches the end portion 8a of the linear portion 8 of the foam product 20 and the inner peripheral surface 8b of the linear portion 8, and the foam product 20 is connected to the upper die 11 and the lower die 12. The straight line of the foam product 20 while sandwiched between the mold 12 8 is supported by the concave portion 13 of the upper mold 11 and the convex portion 14 of the lower mold 12, so that a highly accurate and stable shape of the wrist-like product 10 can be obtained. The mold cost can be reduced while corresponding to the foam product 20.

  Further, when the foam product 20 is made of stainless steel and the thickness thereof is set to 0.5 mm to 1.0 mm, the amount of the re-striking of the foam product 20 by the re-slicing process is determined by the sectional circumference of the foam product 20 before the re-striking process. Since the length is set to 1.0 to 1.5%, it is possible to obtain a product 10 having a product quality and reliability.

Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and design changes and the like within the scope not departing from the gist of the present invention are included in the present invention.
For example, the upper molds 4 and 11 may be combined.
Further, the thickness, the cross-sectional shape, the length W2 of the straight portion 8 and the like of the foam product 20 can be set as appropriate. For example, it is conceivable to set the straight portion 8 only in a portion where the deformation amount of the end portion is large. .

It is a top view of the foam article 20 of Example 1 of this invention. It is a bottom view of the foam article 20 of Example 1 of this invention. It is a front view of the foam article 20 of Example 1 of this invention. FIG. 4 is an end view taken along line S4-S4 in FIG. 3. FIG. 4 is an end view taken along line S5-S5 in FIG. 3. FIG. 4 is an end view taken along line S6-S6 of FIG. It is a figure explaining the press molding processing apparatus used for manufacture of the foam article 20 of the present Example 1. FIG. It is a figure explaining manufacture of the foam article 20 by a press molding processing apparatus. It is a figure explaining the cutting | disconnection of the edge part of the foam goods of the present Example 1. FIG. It is a figure explaining the wrist-like processing apparatus used for manufacture of the wrist-like goods of the present Example 1. FIG. It is a figure explaining manufacture of a wrist-like article by a wrist-like processing device. It is a principal part enlarged view of the present Example 1, and is a figure explaining the effect | action at the time of a wrist-like process. 3 is a plan view of the wrist-like product 30 according to the first embodiment. FIG. It is a bottom view of the wrist-like product 30 of the first embodiment. It is a figure explaining joining of wristlike goods 10 and 30 of this example 1. FIG. It is an end elevation in the S16-S16 line of Drawing 15 (b). It is an end elevation in S17-S17 line of Drawing 15 (b). It is an end elevation in S18-S18 line of Drawing 15 (b).

Explanation of symbols

A Metal tubular member 1 Material 2 Press molding processing device 20, 30 Foam product 20a, 20b Straight portion 20c Swelling portion 3, 13 Concavity 4, 11 Upper die 5, 14 Convex portion 6, 12 Lower die 12a Main body 7a, 7b Chuck mechanism 8 Linear portion 8a (Linear portion) End portion 8b (Linear portion) Inner peripheral surface 8c (Linear portion) Outer peripheral surface 9 Wrist-like processing device 10 Wrist-like product 14a (Convex portion) Press surface 14b (Convex portion) Side)

Claims (1)

The end of the foam product was flattened by re-striking the end of the foam product while sandwiching the foam product with the half-shaped metal tubular member between the upper mold and the lower mold. Forming restorative products,
In the method of manufacturing a metal tubular member in which the ends are welded together as a pair of the wrist-like product,
A flat linear portion is formed at the end of the foam product,
The upper mold is provided with a recess that matches the outer peripheral surface including the straight portion of the foam product,
Providing the lower mold with a convex portion that matches the end of the straight portion of the foam product and the inner peripheral surface of the straight portion,
It is characterized in that the foam product is restricked in a state where the linear part of the foam product is supported by the concave portion of the upper die and the convex portion of the lower die while sandwiching the foam product between the upper die and the lower die. A method for producing a metal tubular member.

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