JP2014166645A - Method for manufacturing metallic structure material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a metallic structure material in which first and second plate-like parts are jointed via a corner part and the corner part is reinforced suitably, with high manufacturing efficiency and at a low cost.SOLUTION: A method for manufacturing a metallic structure material 1 in which first and second plate-like parts 11 and 12 are jointed via a corner part C, includes the steps of: heating a part 14 serving as the corner part C of a metal plate 1A serving as a raw material; press-working the metal plate 1A by using dies 20-22 to form the heated part 14 as a swollen part 15, and cooling the swollen part 15 for quenching by using the dies 20-22; and bending the boundary part between the swollen part 15 and the second plate-like part 12 so that the swollen part 15 becomes the corner part C, and a portion connected to both sides of the swollen part 15 becomes the first and second plate-like parts 11 and 12.

Description

  The present invention relates to a method for suitably producing a metal structural material having a cross-sectional hat shape, a cross-sectional L-shape, or other shapes used as a structural material for automobiles and building structures.

A metal structural material having a hat-shaped cross section is often used as a vehicle body component of a vehicle such as an automobile. Conventionally, as a method for producing such a metal structure material, for example, there is a method described in Patent Document 1.
In the method described in this document, a flat metal plate as a raw material is pressed into a cross-sectional hat shape. In this case, a partial Z of the metal plate is flattened by repeating partial pressing. The corner part of the shape folded in the shape of a letter is formed. According to such a configuration, it is possible to increase the rigidity of the corner portion and to increase the strength of the entire metal structural material.

  However, the prior art has the following problems.

First, in the case of manufacturing a metal structural material, when it is desired to quench the corner portion where stress tends to concentrate for the purpose of further improving the strength while reducing the overall thickness and weight. There is. However, conventionally, if the corner portion is heated and cooled to be quenched after the corner portion is formed, the corner portion may be distorted and the entire metal structure may be deformed. On the other hand, if quenching is performed before the corner portion is formed, there is a problem that the formability at the time of forming the corner portion deteriorates and the corner portion forming operation becomes difficult.
Secondly, in the prior art, it is necessary to press the metal plate a plurality of times so that a part of the metal plate is folded back into a flat Z shape. For this reason, since there are many press work processes and productivity is not so favorable, there also exists a malfunction that manufacturing cost becomes expensive.

Japanese Patent No. 4983733

  The present invention has been conceived under the circumstances described above, and has a structure in which the first and second plate-like portions are connected via the corner portion, and the corner portion is appropriately reinforced. It is an object of the present invention to provide a method for producing a metal structural material capable of producing the metal structural material shown in (1) with a low number of work steps with high production efficiency and at a low cost.

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

The method for producing a metal structure material provided by the present invention is a metal structure having a structure in which the first and second plate-like portions are connected via a corner portion by processing a metal plate as a raw material. A method for manufacturing a material, comprising: a heating step of heating a portion of the metal plate that is formed as the corner portion; and pressing the metal plate using a mold. The heated portion is formed as a bulging portion bulging in the thickness direction of the metal plate, and the bulging portion is quenched by cooling the bulging portion using the mold. The die quenching step to be applied, and the metal plate, the bulging portion as the corner portion, and the portions connected to both sides of the bulging portion as the first and second plate-like portions, A boundary portion between the bulging portion and the second plate-like portion It is characterized in that it has a bending step of bending, the a.

According to such a configuration, the following effects can be obtained.
First, the metal structural material manufactured by the above method has a bulged portion formed in the corner portion to increase the rigidity, and the bulged portion is quenched. For this reason, the strength of the corner portion is increased efficiently, and it is possible to appropriately obtain a high-strength metal structural member while suppressing the increase in the overall thickness and weight.
Second, the formation and quenching of the bulges located at the corners are performed simultaneously. Unlike the prior art, it is not necessary to press the metal plate many times, and the number of processing steps can be reduced. Therefore, the productivity of the metal structural material can be improved, and the manufacturing cost can be suitably reduced.

  In the present invention, preferably, in the die quench step, the metal plate is compressed in the width direction to increase the thickness of the bulging portion.

  According to such a structure, the rigidity of a corner part can be improved further.

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

It is a perspective view which shows an example of the metal structure material manufactured by the manufacturing method of this invention. (A)-(e) is explanatory drawing which shows an example of the manufacturing method of the metal structural material which concerns on this invention. (A), (b) is principal part sectional drawing which shows the other example of this invention. It is a perspective view which shows the other example of the metal structural material used as the application object of this invention.

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

First, the metal structural member 1 of FIG. 1 manufactured by the manufacturing method of the present invention will be described.
This metal structural member 1 is a member having a hat-shaped cross section, and is used as, for example, a vehicle body component (including a reinforcing member) of an automobile. The metal structural member 1 includes a first plate-like portion 11 as an upper plate portion, a second plate-like portion 12 as a pair of left and right side plate portions, and the first and second plate-like portions 11, 12 and a pair of corner portions C that are located in the middle of 12 and integrally connect them. The third plate-like portion 13 is continuously connected to the lower portion of the second plate-like portion 12 in a bent state. As will be understood from the manufacturing method described later, the corner portion C is a portion that has been increased in thickness and has been subjected to quenching treatment.

  Next, an example of the manufacturing method of the metal structural member 1 will be described with reference to FIG.

  First, a rectangular plate-shaped metal plate 1A (steel plate) as shown in FIG. 2A is prepared as a raw material of the metal structural member 1, and the corner portion C is formed in a later step of the metal plate 1A. Two portions 14 (two strip-shaped regions) to be heated are locally heated. This heating can be performed by, for example, heating by energization or high frequency heating, but the specific heating method is not limited. The heating temperature is a temperature at which quenching described later can be performed, and is, for example, 850 to 900 ° C.

  Next, as shown in FIG. 2 (b), two bulging portions 15 are formed on the metal plate 1A using the upper dies 20, 21 and the lower die 22 which are press dies. Die quenching for quenching the bulging portion 15 is performed. As a result, a metal plate 1A having a form as shown in FIG.

  This point will be described in more detail. First, the lower mold 22 shown in FIG. 2B has a flat upper surface portion for receiving the entire lower surface of the metal plate 1A. On the other hand, the upper mold 20 is for pressing a region near the center in the width direction of the metal plate 1A, and has a pair of left and right concave grooves 20a with downward openings on the lower surface thereof. The concave groove 20a is aligned directly above the two heating portions 14 of the metal plate 1A. The pair of upper molds 21 are for contacting the left and right end surfaces 19 of the metal plate 1A and pressing the both end surfaces 19 toward the center of the metal plate 1A. When the metal plate 1A is compressed in the left-right width direction by the pair of upper molds 21, the two heating portions 14 bulge (raise) so as to enter the concave groove portion 20a by being compressed and deformed, and the two strips are expanded. A protruding portion 15 is formed. Since each bulging portion 15 is formed by compressive deformation in the left-right width direction, the bulging portion 15 is a portion where the thickness is increased (the thickness is larger than the other portions of the metal plate 1A).

  On the other hand, the upper mold | type 20 and the lower mold | type 22 are equipped with the water flow path (not shown) for cooling inside, for example, and have the cooling function with respect to the metal plate 1A. As a result, the bulging portion 15 can be formed on the metal plate 1A, and at the same time, the bulging portion 15 can be cooled and quenched. In FIG. 2 (b), the groove 20a has a rectangular cross section, and a gap is formed between the inner wall of the groove 20a and the outer surface of the bulged portion 15, but preferably the groove 20a has a cross-sectional shape (for example, a semicircular shape) corresponding to the outer surface of the bulging portion 15, and the inner wall of the recessed groove portion 20a contacts the outer surface of the bulging portion 15, so that the bulging portion 15 is efficiently cooled. It is comprised so that it may be performed (FIG. 3 mentioned later is also the same).

  Thereafter, the metal plate 1A of FIG. 2C is subjected to bending as shown in FIGS. This bending process is performed by pushing down the second plate-like portion 12 using a pair of dies 32 in a state where the first plate-like portion 11 is sandwiched between the upper and lower dies 30 and 31. Since the bulging portion 15 is hardened and has a higher hardness than other portions, the boundary between the bulging portion 15 and the second plate-like portion 12 is obtained according to the bending process. The portion can be bent so that the second plate-like portion 12 extends downward from one end of the bulging portion 15. In this bending process, the third plate-like portion 13 can also be formed. However, the third plate-like portion 13 may be formed in a separate process.

  Through the series of steps as described above, the metal structural member 1 shown in FIG. 1 can be appropriately manufactured, and the following operation is obtained.

  That is, in the metal structural material 1, each corner portion C is quenched, and the corner portion C has the bulging portion 15, so that the strength is increased. In particular, in the present embodiment, as described with reference to FIG. 2B, the bulging portion 15 is a portion where the thickness is increased, and therefore the strength of the corner portion C is further increased. . For this reason, it is possible to efficiently increase the strength while appropriately suppressing an increase in the overall thickness and weight of the metal structural member 1, and a vehicle body component member that is required to have a light weight and a high strength performance. It will be suitable for use as such.

In the manufacturing method described above, the formation and quenching of the bulging portion 15 located at the corner portion C are performed simultaneously. Further, when forming the bulging portion 15, it is not necessary to repeatedly press the metal plate 1A many times. The total number of work steps from the heating step of the metal plate 1A shown in FIG. 2A to the bending step of the metal plate 1A shown in FIG. Therefore,
The productivity of the metal structural member 1 is good and the manufacturing cost can be reduced.

  3 and 4 show another embodiment of the present invention. In these drawings, elements that are the same as or similar to those in the above embodiment are given the same reference numerals as in the above embodiment.

  In the embodiment shown in FIG. 3, as means for performing die quenching on the metal plate 1 </ b> A, a pair of convex portions 22 a are formed on the lower mold 22, and the heating portion 14 of the metal plate 1 </ b> A is pressed by these convex portions 22 a. doing. According to such means, as shown in FIG. 5B, the heated portion 14 is projected to the concave portion 20a side of the upper mold 20 by the pressing action of the convex portion 22a to form the bulging portion 15A. be able to. Of course, the bulging portion 15A can be cooled and quenched. According to the present embodiment, although it is difficult to increase the thickness of the bulging portion 15A, it is possible to appropriately increase the strength of this portion by forming the bulging portion 15A and quenching it. .

  The metal structural member 1 ′ shown in FIG. 4 has a substantially L-shaped cross section, and the entire configuration is such that each of the first and second plate-like parts 11, 12 has one corner C. It is a connected configuration. The present invention can also be applied to the case of manufacturing the metal structural member 1 ′ having such a configuration. Note that the manufacturing process of the metal structural member 1 ′ is basically different from the process described with reference to FIG. 2 in that only one bulging portion 15 is provided. Since the configuration is the same, it is omitted.

  The metal structural material to which the present invention is applied is a metal structural material having a structure in which the first and second plate-like portions are connected via a corner portion, and the entire metal structural material is as described above. The structure may be such that a part of the metal structural material is as described above. The specific number of the first and second plate-like parts and corner parts is not limited. As the plate-like portion, in addition to the first and second plate-like portions, a third or fourth plate-like portion may be further provided. In the case where a plurality of corner portions are formed in a metal structural material, it is not necessary to form bulge portions in all the corner portions and to perform quenching.

  The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each step of the method for manufacturing a metal structural material according to the present invention can be variously changed within the intended scope of the present invention.

C corner portion 1, 1 ′ metal structural material 1 </ b> A metal plate 11, 12 first and second plate-like portion 14 heating part 15, 15 </ b> A bulging portion 20-22 type 30-32 type

Claims (2)

A method for producing a metal structural material having a structure in which the first and second plate-like portions are connected via a corner portion by processing a metal plate as a material,
Of the metal plate, a heating step of heating a portion formed as the corner portion;
By pressing the metal plate using a mold, the heated portion of the metal plate is formed as a bulging portion that bulges in the thickness direction of the metal plate, and the mold is A die quench step of quenching the bulging portion by cooling the bulging portion using,
Of the metal plate, the bulging part and the bulging part are used as the corner part and the parts connected to both sides of the bulging part are the first and second plate-like parts. A bending step of bending a boundary portion with the second plate-shaped portion;
A method for producing a metal structural material, comprising: It is a manufacturing method of the metal structure material according to claim 1,
In the die quench step, the metal plate is compressed in the width direction to increase the thickness of the bulged portion, and the method for manufacturing a metal structural material.

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