JPH04220131A - Manufacture of deformed section bar - Google Patents

Abstract

PURPOSE:To prevent the bending or wrinkles of the deformed section bar and to improve the precision of the shapes of both side surface of the thick wall part. CONSTITUTION:The tool 2 is made with the pressing surface 2a in a rectangular shape, the ratio of the long to the short side of the pressing surface 2a is set to be over three. The longitudinal direction of each pressing surfaces 2a, 2a of a pair of tools 2, 2 are aligned with the longitudinal direction of the stock, and also the mutual distance D is set equal to the width of the part 1a to be made the thick wall part. Next, the parts 1b, 1b to be made the thin wall part of the stock 1 are worked with the tools 2, 2 at the same time. Further, the tools 2, 2 are moved stepwise to each side edge of lateral direction of the stock 1, worked by pressing successively to the unworked parts of the thin wall part 1b. In such a way, when the pressing of the part of the longitudinal direction of the stock 1 is completed, the stock 1 is moved relatively, and the worked parts following the processed part is worked by pressing from the thick wall part 1a side in the same way. By repeating these series pressing to the longitudinal direction, the deformed shape is manufactured.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a strip of irregular cross section, which has a thick wall portion extending in the longitudinal direction at the center portion in the width direction, and has thin wall portions that are relatively thin on both sides of the thick wall portion. Regarding the manufacturing method.

0002

2. Description of the Related Art Hitherto, known methods for producing this type of irregular cross-section strip include cutting, rolling, and intermittent production using V-shaped dies and flat rolls.

[0003] In the cutting method, a strip of irregular cross section is manufactured by cutting off a part of a material having a rectangular cross section and the same thickness as the thick part to form a thin part.

[0004] Furthermore, there are two methods of rolling. One method is to manufacture a material having a cross-sectional shape similar to the irregular cross-sectional strip to be manufactured in advance by extrusion molding or the like, and then roll this material with a roll having an annular protrusion on the outer periphery and a cylindrical roll. It is manufactured by Another method is to sequentially roll a material having a rectangular cross section using a plurality of rolls having annular protrusions formed on the outer periphery having different widths and a plurality of cylindrical rolls paired with each roll. A strip of irregular cross section is manufactured by gradually widening the width of the thin portion of the material.

Furthermore, the cross-sectional manufacturing method uses a V-shaped die having a flat plate part and a V-shaped convex part on the upper surface of the flat plate part whose width becomes gradually wider from one end to the other end, and a cylindrical die. A material with a rectangular cross section is repeatedly passed between the flat roll and the V-shaped convex part from the narrow side several dozen times, thereby forming a thin part, thereby forming an irregular cross-sectional strip. (Special Publication Act, 1973-7)
(See Publication No. 302).

[0006] Furthermore, as shown in Japanese Patent Application Laid-Open No. 120269/1983, a thin groove is formed in the longitudinal direction of the material using a roll, and one plane of the flat plate is shaped approximately triangularly with the narrow groove as a boundary. Thickness reduction processing is also performed using a pressing plate.

[0007]

[Problems to be Solved by the Invention] Each of the conventional manufacturing methods described above has the following problems. In other words, in manufacturing methods using cutting, a portion of the material is removed, resulting in large material loss.
There was a problem that the yield rate deteriorated.

In addition, there are two manufacturing methods using rolling processing, but in the former manufacturing method, unless the thickness reduction rate of the thick and thin parts is the same, distortion due to the difference in elongation will occur between them. The internal stress caused by this strain causes cracks, wrinkles, etc. to occur in the manufactured irregular cross-section strip. Therefore, when manufacturing the material, it is necessary to accurately form a portion that is to be a thick wall portion and a portion that is to be a thin wall portion so that the difference in thickness between them is a predetermined value. However, manufacturing such materials is extremely difficult.
Therefore, it was difficult to say that it was a realistic manufacturing method. Also,
In the latter manufacturing method, it is possible to eliminate the differences in plate thickness due to processing from differences in elongation only by repeating very localized processing, so many pairs of rolling rolls are required, which increases tool costs. There was a problem.

Furthermore, in the intermittent manufacturing method, it is necessary to move the roll forward and backward relative to the material several dozen times. Here, when the roll is retracted, no machining is performed, so the time required for retraction becomes loss time. For this reason, there was a problem in that the production speed of irregular cross-section strips was slow.

[0010] When performing thickness reduction processing using a triangular pressing plate, the processing width differs in the longitudinal direction of the material, so the feed pitch of the tool (or material) when performing thickness reduction processing must be made smaller. However, in order to avoid leaving unprocessed areas on both sides of the front of the process,
The feed pitch must be made finer. therefore,
Machining speed is inevitably low, resulting in poor efficiency. In addition, the part that receives extremely narrow indentation at the front of the tool (near the apex of the triangle) is then pressed by the wide part of the tool, so the material undergoes complex three-dimensional deformation. , tends to have defects such as cracks inside or on the surface. Furthermore, there are other problems such as severe wear at the front end of the tool.

[0011] This invention was made to solve the above-mentioned problems; (1) there is almost no loss of material, (2)
The object of the present invention is to provide a method for manufacturing irregular cross-section strips that is inexpensive to manufacture materials, ■ has low tool costs, can improve manufacturing speed, and can yield products with fewer defects. shall be.

[0012] First, to describe the progress that led to the present invention, we decided to adopt a press working method, which is completely different from the conventional method, as a method for forming the thin wall portion. According to press working, there is no need to scrape off the material, and it is only necessary to use a material that has the same thickness as the thick part of the finished product and a rectangular cross-section, making the material manufacturing inexpensive. Because it can be done.

However, in press working, the reduced plate thickness of the pressed portion causes the pressed portion to bulge out in all directions. For this reason, if a part of the material that should be a thin part is simply pressed, a difference in length will occur between the unprocessed thick part and the processed thin part. Internal stress caused by the difference may cause wrinkles or cracks in the thin wall portion.

As a result of intensive research on this point, we found that if a press tool with a rectangular press surface is used and the ratio L/W of the length L and width W of the press surface is set to a certain value or more, the press part can be It was found that most of the elongation due to the reduction in plate thickness appeared in the width direction of the press surface, and almost no elongation appeared in the length direction. From this, if the ratio of the processing width in the longitudinal direction of the material to the processing width in the width direction is set to a certain level or more, the part that should become the thin part of the material will only be formed in the width direction of the material. Since it does not elongate or elongate in the longitudinal direction, there is no difference in the elongation rate in the longitudinal direction between the thick part and the thin part, and it is possible to prevent the above-mentioned cracks and wrinkles caused by the difference in elongation rate. I have come to the knowledge that it is possible.

In particular, if both sides of the part that is to become the thick part are pressed simultaneously using a pair of symmetrically arranged tools,
It was also found that the reduced thickness of the thin portion extends only in the direction from the thick portion side toward both side edges of the material, and the accuracy of the cross-sectional shape of both side surfaces of the thick portion is improved. Note that the ratio L/W of the processing width L in the longitudinal direction of the material and the processing width W in the width direction is 3 or more, preferably 5 or more.

[0016]

[Means for Solving the Problems] The present invention has been made based on the above-mentioned findings, and the first manufacturing method of the present invention has a thick wall portion extending in the longitudinal direction at the center portion in the width direction; A method for manufacturing a strip with an irregular cross section in which both sides of a thick wall section are relatively thin wall sections, and the method includes flat presses having the same dimensions and forming a rectangle with a ratio of the length of the long side to the short side of 3 or more. A pair of tools each having a surface and arranged symmetrically on both sides of the part to be the thick part are used to draw the long sides of the press surfaces on the side facing the tool into imaginary lines that become both edges of the thick part. Both sides of the thick-walled part are pressed at the same time in accordance with each of the above, and each tool is moved away from the thick-walled part in stages in the width direction of the material, and the press-forming is repeated at the same time so that the machined surfaces are continuous. After this, the above-described series of press working is further repeated so that the processed surfaces are continuous along the longitudinal direction of the material, thereby forming a pair of thin-walled parts.

Further, in the second manufacturing method of the present invention, after forming the pair of thin-walled parts as described above, the pressed part and the non-pressed part are made to have the same thickness reduction rate. It is characterized by being subjected to drawing or rolling processing.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. It should be noted that this example is for manufacturing a strip of irregular cross section with a convex cross section.

First, the material 1 and tool 2 used in this example will be explained. The material 1 has a rectangular cross section, and the thickness T1 is the same as the thick part of the finished product. The width W1 is set to be equal to the width of the irregular cross-section strip that is a completed product after completion of press working. On the other hand, the press surface 2a of the tool 2 has a rectangular shape, and the ratio of the lengths of the long sides and short sides of the press surface 2a is
(L2/W2) is set to 3 or more. Note that it is desirable that the tool width W2 be set to at least twice the thickness T1 of the material 1.

When press-forming the material 1 with the tool 2 to produce a strip of irregular cross-section, the pair of tools 2, 2 are aligned so that the longitudinal direction of each pressing surface 2a, 2a coincides with the longitudinal direction of the material, They are arranged so that the distance D between them is set equal to the width of a portion 1a that is to become a thick portion (hereinafter referred to as a thick portion).

Next, as shown in FIG. 2, parts 1b, 1b of the material 1 that are to become thin parts (hereinafter referred to as thin parts) are simultaneously pressed using tools 2, 2. At this time,
Since the thick portion 1a is restrained simultaneously by the two tools 2, 2, the elongation of the material 1 due to the press does not occur toward the thick portion 1a, but only toward both side edges of the material 1. Therefore, both side walls of the thick portion 1a are formed in a shape that matches the cross-sectional shape of the tool 2, that is, in this example, are formed as steep vertical surfaces. On the other hand, on the side surface of each tool 2 opposite to the thick part 1a, an incompletely press-formed part is created as shown by the symbol P due to the extension in the width direction, and the shape matches the cross-sectional shape of the tool 2. cannot be processed.

Next, as shown in FIGS. 3 and 4, the tools 2, 2 are moved stepwise to each side edge in the width direction of the material 1, and the unprocessed portions of the thin portion 1b are successively pressed. Note that the amount of movement of the tool 2 is preferably such that a portion of the tool 2 overlaps before and after the movement.

When a part of the press working in the longitudinal direction of the material 1 is completed in this way, the material 1 is relatively moved in the direction of the arrow in FIG. Pressing is performed from the meat part 1a side. In this case, the amount of material movement in the longitudinal direction is also set to such an extent that the tools 2 partially overlap. Then, by repeating the above series of press working in the longitudinal direction, a strip of irregular cross section is manufactured.

[0024] In this embodiment, the tools 2, 2
is moved in the width direction of the material 1, but instead of moving the tools 2, 2, a plurality of pairs of tools with different intervals may be arranged in the longitudinal direction of the material.

[0025] However, in the above embodiment, since the material 1 is pressed without being cut, almost no material loss occurs. Furthermore, since a rectangular material is used, the material can be easily manufactured. Furthermore, since only one pair of tools is basically required, tool costs can be kept low. Moreover, since it is not necessary to feed the material in the opposite direction to the feeding direction for processing, the manufacturing speed can be improved.

Furthermore, in this method, due to the above-described press working, the portions 1a that are to become each thin wall portion mainly extend in the width direction of the material and hardly extend in the longitudinal direction, so that the thick wall portion 1a and the thin wall portion 1a are separated from each other. There is no difference in elongation rate in the longitudinal direction in the portion 1b, and the occurrence of bending, cracking, wrinkles, etc. in the irregular cross-section strip due to the difference in elongation rate can be prevented, and on both sides of the thick part 1a,
Since the press work is repeated symmetrically and simultaneously with respect to the center line of the thick part 1a, the center line position of the thick part 1a does not bend in the width direction of the material 1 due to extension in the width direction, which improves the accuracy of subsequent press work. There is no risk of deterioration. Furthermore, since both side surfaces of the thick portion 1a can be processed into a shape corresponding to the cross-sectional shape of each tool 2, the accuracy of the cross-sectional shape of the irregular cross-sectional strip is improved, and there is no need to modify the shape after pressing. It also has

[0027] In the above embodiment, the production of the irregular cross-section strip is completed during press working, but after press working, the thick and thin parts may be rolled at the same time. In this case, it goes without saying that the thickness reduction rate of the thick portion and the thin portion should be the same.

When the above-mentioned rolling process is performed after press working, minute lines representing the outline of the tool will appear in the thin wall part during press working, but these can be crushed to make the surface of the irregular cross-section strip smoother. It can be done.

[0029] Note that drawing may be performed instead of this rolling, and similar effects can be obtained in such a case.

[0030]

Effects of the Invention As explained above, according to the first manufacturing method of the present invention, flat press surfaces having the same dimensions and having a rectangular shape with a length ratio of long side to short side of 3 or more can be manufactured. Using a pair of tools, both sides of the thick part are simultaneously pressed by aligning the long sides of the pressing surfaces on the side facing the tool with the respective imaginary lines forming both side edges of the thick part. After repeatedly pressing the tools at the same time so that the machined surface is continuous while gradually separating the tools from the thick part in the width direction of the material, the above series of press working is further performed along the longitudinal direction of the material. Because the process is repeated so that the processed surface is continuous, even when the processing width of thin-walled parts is wide, there is almost no loss of material, and the material is easy to manufacture.
The following effects can be obtained: (1) tool costs are low, (2) manufacturing speed of irregular cross-section strips can be improved, and (2) products without defects can be obtained.

[0031] Furthermore, in this method, due to the above-mentioned press working, the parts that are to become each thin-walled part mainly extend in the width direction of the material and hardly extend in the longitudinal direction, so that the thick-walled part and the thin-walled part are separated. There is no difference in elongation rate in the longitudinal direction, and bending, cracking, and wrinkles of the irregular cross-section strip due to the difference in elongation rate in the longitudinal direction can be prevented. On the other hand, since the press working is repeated symmetrically and simultaneously, the center line position of the thick portion will not be bent in the width direction of the material due to its extension in the width direction, and there is no risk of reducing the accuracy of subsequent press working. Furthermore, since the thin-walled part extends from the thick-walled part to both edges of the material by press working, both sides of the thick-walled part can be machined into a shape that corresponds to the cross-sectional shape of each tool, and the cross-sectional shape of the irregular cross-sectional strip It also has the advantage of increasing accuracy.

On the other hand, in the second manufacturing method of the present invention, after the press working according to the first manufacturing method, the thickness reduction rate of the part to be the thick part and the part to be the thin part is maintained at the same rate. Since the rolling or drawing process is carried out in the same state, in addition to the effect of the first method, it is possible to produce a strip of irregular cross-section having a smooth surface without streaks or the like. It will be done.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the steps of the same embodiment.

FIG. 3 is a sectional view showing the steps of the same embodiment.

FIG. 4 is a cross-sectional view showing the steps of the same embodiment.

[Explanation of symbols]

1 Material 1a Part that should be a thick part (thick part) 1b Part that should be a thin part (thin part) 2 Tool 2a Press surface

Claims (2)

[Claims] (1) A method for manufacturing an irregular cross-section strip having a thick wall portion extending in the longitudinal direction at the center portion in the width direction, and having relatively thin wall portions on both sides of the thick wall portion, the long side Each of the above-mentioned parts is pressed using a pair of tools arranged symmetrically on both sides of the part to be the thick part, each having flat pressing surfaces of the same size and forming a rectangular shape with a length ratio of 3 and the short side length or more. Pressing both sides of the thick wall at the same time by aligning the long sides of the pressing surface facing the tool with the imaginary lines on both sides of the thick wall, and then using each tool to remove the material from the thick wall. Pressing is repeatedly performed at the same time so that the processed surfaces are continuous while being separated in stages in the width direction, and then the above series of press processing is further repeated so that the processed surfaces are continuous along the longitudinal direction of the material. 1. A method of manufacturing a strip of irregular cross-section, characterized by forming a pair of thin-walled portions. (2) A method for manufacturing an irregular cross-section strip having a thick wall portion extending in the longitudinal direction at the center portion in the width direction, and having relatively thin wall portions on both sides of the thick wall portion, the long side Each of the above-mentioned parts is pressed using a pair of tools arranged symmetrically on both sides of the part to be the thick part, each having flat pressing surfaces of the same size and forming a rectangular shape with a length ratio of 3 and the short side length or more. Pressing both sides of the thick wall at the same time by aligning the long sides of the pressing surface facing the tool with the imaginary lines on both sides of the thick wall, and then using each tool to remove the material from the thick wall. After repeatedly performing press working at the same time so that the machined surface is continuous while separating the parts in stages in the width direction, the above series of press working is further repeated so that the machined surface is continuous along the longitudinal direction of the material. manufacturing a strip of irregular cross-section, characterized in that a pair of thin-walled parts are formed by this process, and the pressed part and the non-pressed part are drawn or rolled so that their thickness reduction rates are the same. Method.