JPS602933B2 - Cold roll forming method for shaped steel - Google Patents

Description

[Detailed Description of the Invention] The present invention utilizes a roll-forming method with a large number of roll stands to form C-shaped steel, channel steel, guardrails, automobile bumpers, and other shaped steel whose flange portions have open surfaces and rise. The present invention relates to a method of forming rolls of different lengths.

When a metal strip is cold roll-formed into a desired shape with an irregular cross-section through a number of roll stands, it is necessary to use a straightening machine or the like to form a molded product that is straight in the longitudinal direction, or to form a molded product that is constant in the longitudinal direction. When forming a molded product that has a C-shaped cross section with a curvature of , and the flanges have different rising lengths, a flat roll is usually used for the bottom part of the shaped steel product. FIG. 1 shows the above-described shaped steel sections with different flange rises. When this section steel is formed by the flower shown in FIG. 2, the flower No. In 1, the bottom part of the section steel corresponding to A indicates the flat part and is formed by the horizontal part of the rolls, the rising part B is formed by upper and lower rolls with an angle of 3, and the rising part C is formed by upper and lower rolls with an angle of only Q. It had been.

And Flower No. 2.No. 3 and molded No.
4, the desired molded product shown in FIG. 1 was completed. This shows one forming form; in reality, many more stands are used, and even in the case of forming channel steel, usually 10 to 1 stands are required. With this forming method, NO. 1 to N
O. 1 to No. Since the band is passed through the stand continuously to the stand 2, twisting occurs in the longitudinal direction of the strip between the stands where it is formed.In order to achieve the desired forming, the rising angle Q and 3 for passing through the stand once must be adjusted. We tried to make the distortion form as balanced as possible to prevent twisting in the longitudinal direction, but due to the thickness and height of the form, we could not solve the problem by adjusting the Q of the rise per pass and the 8 angles. . The present invention has been made to solve these drawbacks, and when forming a section steel with upper and lower rolls during the forming of a section steel having flanges with different rising heights on both sides of the cross section, the cross section of the rolls forming approximately the central part is The shape of the roll surface is represented by a curve, and the roll portion forming the vicinity of the corner has a straight roll shape, so that the desired formed cross section without twisting can be achieved by forming. The present inventors have discovered that the present invention provides a cold roll forming method having an irregularly shaped open cross section.

The present invention will be explained using figures.

FIG. 3 shows an embodiment of the method for forming a shaped steel according to the present invention. This is a flower diagram for forming a section steel having the same shape as shown in FIG. In other words, A' is the part that will become the bottom part of the shaped steel, and B' and ○ indicate the rising flange parts on both sides, respectively, but the upper and lower forming rolls make the part that will be flat as a shaped product with the lower roll convex in the center part. It is characterized by a forming method in which the upper roll forms a curved shape, a straight line shape at both ends, a concave curved shape at the center, and a linear roll shape at both ends while forming the rising part. By using such a forming method, the strip plate that becomes the section steel during forming is subjected to elongation strain in the central portion, and as a result, the balance of strain with the rising portions on both sides is maintained, and twisting does not occur in the longitudinal direction.

This is thought to be because the central part of the strain-balanced outer shape forms a constant radius, which increases the stability of the shape with steel properties compared to a flat case like a follower. FIG. 3 merely shows an embodiment of the present invention, and the process is NO. 1~No.
Although the product is completed as a shaped steel product in step 4, in actual implementation, for example, a channel steel with a cross-sectional bottom width of 6 mm, one side of the rising edge is 2 mm, the other side is 45 mm thick, and the thickness of 23 mm is formed using the method of the present invention. When molding using a 7-stage cold roll stand was required. When the shaped steel product was cut into four pieces, there was no twisting in the longitudinal direction and the dimensional accuracy was good. As an embodiment of the present invention, a case is shown in which the open part of the flange with a rising cross section is molded upward, but even if it is molded downward or sideways, it will be a nearly middle-resistance part with respect to the open part of the strip shape material in the middle of forming. Any roll shape may be used as long as the bottom is always convex and the vicinity of the corners are straight.

FIG. 4 is a flower diagram showing another embodiment of the present invention.

Product cross section section steel No. In order to mold No. 7. 1~N
o. Molding is performed through the cross-sectional deformation steps up to No. 6. 1.No. Part 2 and No. 4.No. The method of the present invention is applied to part 5. That is, in FIG. 4, a, a' are the central curved parts, b, b', d
, d' is a flower diagram showing the cross-sectional shape of the roll at the portion forming the corner portion of the section steel. Of course, this embodiment does not show the actual number of roll stands used during the actual implementation, but only shows the state of a part of the method of the present invention which is applied depending on the state of the flower during molding.

・ As explained above, by using the forming method of the present invention when roll forming a section having an open cross section such as a section steel, longitudinal twisting can occur even in the formed materials having side upright flanges of different heights. The effect of forming steel sections with accurate dimensions is great.

[Brief explanation of drawings]

Fig. 1 is a cross section of channel steel, Fig. 2 is an embodiment of the flower of the conventional cold roll forming method, Fig. 3 is a flower diagram showing the embodiment of the present invention, and Fig. 4 is an application of the present invention. It is a flower diagram. Figure 'Figure 2 Figure 3 Blind Figure 4

Claims (1)

[Claims] 1 Open faces of section steel with different rising lengths in cold roll forming process where the steel is continuously roll-formed from a strip through multiple roll stands and has rising flanges on both sides and a flat central part. In order to keep the distortion in the part including the corner with a curved line, the roll surface is curved in the cross-sectional shape of the roll at approximately the center of the upper and lower rolls, and the roll surface forming the vicinity of the corner is curved in the cross-sectional shape of the roll. A cold roll forming method for shaped steel, characterized in that forming is performed using rolls with straight roll surfaces.