JPH0343925B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has an irregular cross-sectional strip having a convex or concave cross-sectional shape, that is, a thick portion and a thin portion extending in the longitudinal direction. The present invention relates to a method for manufacturing irregular cross-section strips.

[Conventional technology]

Conventionally, known manufacturing methods of this type include a cutting method, a rolling method, and an intermittent manufacturing method using a V-shaped die and a flat roll.

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.

Furthermore, there are two methods of rolling. One method is to first manufacture a material with a cross-sectional shape similar to the irregular cross-sectional strip to be manufactured by extrusion molding, etc., and then mold this material into a roll having an annular protrusion on the outer periphery and a cylindrical roll. It is manufactured by rolling.

Another method is to sequentially roll a material with a rectangular cross section using a plurality of rolls with different widths of annular protrusions formed on the outer periphery and a plurality of cylindrical rolls paired with each roll. However, by gradually widening the width of the thin portion of the material, a strip of irregular cross section is manufactured.

Furthermore, the cross-sectional manufacturing method includes 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 gradually becomes wider from one end to the other end, and a cylindrical part. By repeatedly passing a material having a rectangular cross section between the flat roll and the V-shaped convex portion from the narrow side several dozen times, and thereby forming a thin wall portion, an irregular cross-sectional strip is formed. (Refer to Japanese Patent Publication No. 7302/1983).

In addition, as shown in Japanese Patent Application Laid-Open No. 54-120269, narrow grooves are formed in the longitudinal direction of the material using rolls, and a flat pressing plate is formed in a substantially triangular shape on one plane with the narrow grooves as a boundary. It is also used to perform subtraction processing.

[Problem that the invention seeks to solve]

Each of the conventional manufacturing methods described above has the following problems.

That is, in the manufacturing method using cutting, a part of the material is shaved off, so there is a problem that material loss is large and the yield is 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 will occur due to the difference in elongation between them. Due to the internal stress caused by this strain, cracks or wrinkles 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, it is very difficult to manufacture such a material, and therefore it is difficult to say that it is a practical manufacturing method. In addition, in the latter manufacturing method, it is possible to prevent the difference in plate thickness due to processing from becoming a difference in elongation only by repeating very local processing, so many pairs of rolling rolls are required. There was a problem with increasing tool costs.

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 manufacturing speed of irregular cross-section strips was slow.

When performing subtraction processing using a triangular press plate, the processing width differs in the longitudinal direction of the material, so the tool (or material) used when performing subtraction processing
Even if the feed pitch is made smaller, unprocessed areas will remain on both sides of the front of the machine, and in order to prevent this from remaining in the final stage, the feed pitch must be made finer.

Therefore, the machining speed inevitably decreases,
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. It is easy 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.

[Purpose of the invention]

This invention was made to solve the above problems, and there is almost no loss of material.
To provide a method for manufacturing a strip of irregular cross-section, which allows manufacturing of raw materials at low cost, low tool costs, improving manufacturing speed, and obtaining products with few defects.

[Structure of the invention]

First, to describe the progress that led to this invention, we decided to adopt a press working method, which is completely different from conventional methods, 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 bulges out in all directions from the pressed portion. 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. The 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 plate thickness of the press part can be reduced. It has been found that most of the elongation due to the press surface occurs in the width direction of the press surface, and almost no elongation occurs in the length direction.

From this, if the part of the material that should become a thin wall part is press-formed with the ratio of the processing width in the longitudinal direction of the material to the processing width in the width direction being a certain level or more, the part that should become a thin part will be pressed in the width direction of the material. Since it mainly elongates in the longitudinal direction and hardly elongates in the longitudinal direction, there is no difference in length between the thick and thin parts, and the above-mentioned cracks and wrinkles can be prevented. This is what we have come to know.

In particular, if the part that is supposed to be a thick part is sandwiched between the tool and the fixed object for forming the part that is supposed to be a thin part, the thickness reduction of the thin part will be equal to that of the thick part. It was also found that the shape of the thick portion extends only in the opposite direction, improving the shape accuracy of the tool-side side surface of the thick portion.

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.

The present invention has been made based on the above findings, and a first manufacturing method is a method for manufacturing an irregular cross-section strip having a thick wall portion and a thin wall portion extending along the longitudinal direction, the method comprising: With only one side of the part in contact with a fixing member fixed in the width direction of the material and its position regulated, press the longitudinal direction of the rectangle along the longitudinal direction of the material using a tool with a flat rectangular pressing surface. While aligning the direction, press the part of the material that is to become the thin wall part so that the processing width in the longitudinal direction of the material is at least three times the processing width in the width direction, and press the part on the side of the fixing member. By repeating this process from the beginning to the other side in the width direction of the material so that the machined surface is continuous, and then repeating this series of press working so that the machined surface is continuous along the longitudinal direction of the material. It is characterized by forming a thin wall portion.

Further, the second method of the present invention is a method for manufacturing a strip of irregular cross-section, which has thick parts extending in the longitudinal direction on both sides in the width direction, and a thin part is formed between these thick parts, With one side of the thick part in contact with a fixing member fixed in the width direction of the material to regulate its position, use a tool with a flat rectangular pressing surface to press the longitudinal direction of the rectangle along the longitudinal direction of the material. While matching the direction, the part that should be the thin part of the material,
Pressing is performed so that the processing width in the longitudinal direction of the material is at least three times the processing width in the width direction, and this pressing is performed so that the processing surface is continuous from the side of the member to the other side in the width direction of the material. The process was repeated, and in the process, when performing press working at the end position of the other side, the fixing member was removed and the other side of the material was newly brought into contact with the fixing member fixed in the width direction of the material. Further, the thin wall portion is formed by performing the press working at the end position and repeating the above series of press working so that the processed surface is continuous along the longitudinal direction of the material.

Furthermore, in the third method of the present invention, after forming the thin-walled part as in the first method, the pressed part and the non-pressed part are drawn out so that their thickness reduction rates are the same. It is characterized by being processed or rolled.

Note that the machining width above refers to the width of the part where the tool and the material come into contact, and when the entire surface of a rectangular tool is in contact with the material, the vertical and horizontal widths of the tool are equal to the longitudinal and width directions of the material, respectively. Corresponds to the processing width. However, when the width of the material to be press-worked is narrower than the width of the tool, the width to be press-worked becomes the processing width in the width direction.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. The embodiment shown in this figure is for manufacturing a strip of irregular cross section with a concave 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 its thickness T is the same as the thick part of the finished product, the irregular cross section strip. being done.

On the other hand, the press surface 2a of the tool 2 has a rectangular shape, and the length ratio of the long side to the short side of the press surface 2a is set to 3 or more. Note that it is desirable that the tool width W is set to be at least twice the thickness T of the material 1.

In order to press-form the material 1 with the tool 2 to form the thin section 1b having an irregular cross-section, first, the material 1 is press-formed using the tool 2.
One side of the is brought into contact with the fixed object 3 to regulate the position.

Then, the longitudinal direction of the press surface 2a of the tool 2 is aligned with the longitudinal direction of the material 1, and the fixed object 3
The distance between the tool 2 and the tool 2 is set equal to the width of the portion 1a that should be the thick wall portion (hereinafter referred to as the thick wall portion),
Place tool 2.

Next, using the tool 2, a portion of the portion 1b of the material 1 that is to become a thin wall portion (hereinafter referred to as the thin wall portion) on the fixed object 3 side is pressed. At this time, thick portion 1a
Since the sides of are restrained by the fixed object 3,
The elongation of the material 1 due to press working occurs toward the side edge of the material on the opposite side from the fixed object 3. Therefore, the side wall of the thick wall portion 1a on the side of the fixed object 3 that is in contact with the tool 2 is formed in a shape corresponding to the tool 2, that is, in this example, as a steep vertical surface.

Next, as shown in FIG. 1c, the tool 2 is moved to the side opposite to the fixed object 3, and the unprocessed portion of the thin wall portion 1b is pressed. The amount of movement of the tool 2 is preferably such that a portion of the machined surface overlaps before and after the movement.

In the example shown in this figure, one processing cycle in the width direction of the thin section 1b is completed by repeating the press processing a total of two times in the width direction, so when the second press processing is performed to process the end position in the width direction, To do this, once the contact between the fixed object 3 and the tool 1 is released, another fixed object is newly brought into contact with the opposite side of the material 1 to regulate the position, and then press working is performed at the end position. . If the width of the thin portion 1b is wide and the one processing cycle consists of three or more presses, the same operation is performed at the end position in the width direction.

Then, the elongation of the material 1 due to the press working at the end position occurs toward the side edge of the material on the opposite side from the fixed object 3, so that the side wall of the thick part 1a on the fixed object 3 side that is in contact with the tool 2 2, that is, in this example, it is formed as a steep vertical surface, and as a result, the thin wall portion 1b of both thick wall portions 1a
The shape accuracy of both side walls is improved.

Next, when the press working of a part of the longitudinal direction of the material 1 is completed in the width direction, the material 1 is relatively moved in the longitudinal direction, and the unprocessed part following the processed part is processed in the same cycle as above. Press. In this case, the amount of movement of the material 1 is also set to such an extent that a portion of the tool 2 overlaps.

Then, by repeating the above pressing process, a strip of irregular cross section is manufactured.

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.

In addition, in this method, after pressing the thin wall portion 1b on the fixed object 3 side with one side of the material 1 in contact with the fixed object 3, the other side of the material 1 is pressed against the fixed object 3. Since the other side of the thin wall portion 1b is pressed, the shape accuracy of the side walls of both the thick wall portions 1a on the thin wall portion 1b side is improved as described above.

On the other hand, for example, if both sides of the material 1 are pressed without regulating the position, the material 1 will stretch toward both sides, so in FIG.
As shown in the figure, incompletely pressed parts appear on both sides of the tool 2, and the machined surface of the thick part 1a cannot be made into the required shape corresponding to the tool 2. In addition, when the above-mentioned series of pressing is performed with both sides of the material 1 in contact with a fixed object, if the width of the thin-walled portion 1b is wide, the irregular cross-section strip may be warped due to stretching in the width direction, or the longitudinal The result is that the material stretches in the direction and bends.

In addition, in the above example, pressing was repeated twice in the width direction, but in the present invention, pressing was repeated 3 times in the width direction.
It may be configured to repeat pressing more than once.

Alternatively, the pressing in the width direction may be performed until the side edge of the material 1 is reached, a thin portion reaching one side edge of the material 1 is formed, and the thick portion 1a may be formed only on one side of the material 1.

Further, in the above example, the production of the irregular cross-section strip is completed in the state of press working, but after press working, the thick part and the thin part 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.

If 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 it is necessary to crush these to make the surface of the irregular cross-section strip smoother. I can do it.

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

〔Effect of the invention〕

As explained above, according to the first manufacturing method according to the present invention, a thin section of the material is processed using a tool having a flat rectangular pressing surface, so that the processing width in the longitudinal direction of the material is Pressing is repeated in the width direction so that the width is at least three times the processing width in the width direction, and this series of press processing is then repeated along the longitudinal direction of the material, so the processing width of the thin section is Even if is wide,
There is almost no material loss of the material, the material is easy to manufacture, the tool cost is low, the production speed of irregular cross-section strips can be improved, and products without defects can be obtained. It will be done.

In addition, in this method, compared to the above-mentioned press processing, the part that should be the thinner part mainly extends in the width direction of the material and less in the longitudinal direction, so there is no space between the thick part and the thin part in the longitudinal direction. Differences in elongation rates are less likely to occur, and bending, cracking, and wrinkles of the material can be prevented.In addition, during the above-mentioned pressing, only one side of the material is brought into contact with the fixing member to regulate its position. Therefore, even though the thin portion extends in the width direction, the side surface of the thin portion of the thick portion can be formed into a cross-sectional shape that accurately corresponds to the shape of the tool.

Further, in the second method of the present invention, in addition to the effects of the first manufacturing method, the thin-walled portions are sequentially pressed from the fixed object side with only one side of the material in contact with the fixed member and the position regulated. After processing, at the end position, the other side of the material is brought into contact with a fixed object and the other side of the thin section is pressed, so when forming a pair of thick sections on both sides of the material, This has the advantage that the shape accuracy of each side wall on the thin-walled side of the pair of thick-walled portions is improved.

Furthermore, according to the third method of the present invention, after the press working according to the first method, rolling is performed while simultaneously maintaining the thickness reduction rate of the portion that is to be a thick wall portion and the portion that is to be a thin wall portion. Since processing or drawing is performed, 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.

[Brief explanation of drawings]

FIGS. 1A to 1C are front views for explaining each step of an embodiment of the present invention. 1...Material, 1a...Part that should become a thick part (thick part), 1b...Part that should become a thin part (thin part), 2...Tool, 2a...Press surface, 3...Fixation object (fixed member).

Claims (1)

[Claims] 1. A method for manufacturing a strip of irregular cross-section having a thick wall portion and a thin wall portion extending along the longitudinal direction, wherein only one side of the thick wall portion is fixed relative to the width direction of the material. Using a tool with a flat rectangular pressing surface, while the longitudinal direction of the rectangle is aligned with the longitudinal direction of the material,
The part of the material that is to become a thin section is press-formed so that the processing width in the longitudinal direction of the material is at least three times the processing width in the width direction, and this pressing is carried out from the side of the fixing member in the width direction of the material. Toward the other side, the process is repeated so that the processed surface is continuous, and then this series of press working is repeated in the longitudinal direction of the material so that the processed surface is continuous, thereby forming a thin wall part. A method for manufacturing a strip of irregular cross section characterized by: 2. A method for manufacturing an irregular cross-section strip having thick wall portions extending in the longitudinal direction on both sides in the width direction and a thin wall portion between these thick wall portions, wherein only one side of the thick wall portion is made of a material. While the tool is in contact with a fixing member fixed in the width direction and its position is regulated, a tool with a flat rectangular pressing surface is used to press the thin wall of the material while aligning the longitudinal direction of the rectangle with the longitudinal direction of the material. The part that is to become a part is pressed so that the processing width in the longitudinal direction of the material is at least three times the processing width in the width direction, and this pressing is directed from the side of the member to the other side in the width direction of the material. The process is repeated so that the processed surface is continuous, and in the process, when performing press working at the end position of the other side, the fixing member is removed and only the other side of the material is fixed in the width direction of the material. After making new contact with the member and regulating the position, pressing is performed at the end position, and the above series of pressing is repeated so that the machined surface is continuous along the longitudinal direction of the material, thereby forming a thin part. 1. A method of manufacturing a strip of irregular cross section, the method comprising: forming a strip of irregular cross section. 3. A method for manufacturing a strip of irregular cross-section having a thick walled portion and a thin walled portion extending along the longitudinal direction, wherein only one side of the thick walled portion is brought into contact with a fixing member fixed in the width direction of the material. In this state, using a tool with a rectangular flat pressing surface, the machined width in the longitudinal direction of the material is adjusted to the thinner part of the material while aligning the longitudinal direction of the rectangle with the longitudinal direction of the material. Pressing is performed so that the width is at least three times the processing width in the width direction, and this pressing is repeated from the fixed member side to the other side of the material in the width direction so that the processing surface is continuous, and then After forming a thin part by repeating this series of press working so that the machined surface is continuous along the longitudinal direction of the material, the thickness reduction rate of the pressed part and the non-pressed part is the same. 1. A method for manufacturing a strip of irregular cross-section, which comprises drawing or rolling the strip so that the strip has a different shape.