JP2011189388A - Deformed cross-sectional bar with uneven pattern, and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost deformed cross-sectional bar reducing the weight thereof and ensuring the strength thereof, having flanges on both ends, and preferably having a stepped shape in the plate thickness direction, and a method for manufacturing the same. <P>SOLUTION: An uneven shape is imparted to the entire area or a partial area of an outer surface and/or an inner surface of a deformed cross-sectional bar having flanges on both ends. In the method for forming and imparting the uneven shape, a roller having a profile according to the predetermined sectional shape and a roller having an uneven pattern on its surface are arranged in a four-way rolling mill and the uneven shape is formed and imparted by the rolling. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a modified cross-section strip having a step shape in the plate width direction by forming flanges at both ends having predetermined strength even if the plate thickness is reduced, and a method for manufacturing the same.

A deformed cross-section having flanges at both ends and having a step shape in the width direction of the plate is widely used, for example, in transportation equipment such as automobiles and rails of sliding doors in houses.
Such an irregular cross-section strip is formed by rolling or roll forming using a grooved roll or a roll with a convex strip provided with a groove or convex strip having a desired shape on the surface. The deformed cross-section formed into a desired shape by rolling or roll forming as described above is slit to a predetermined length, and after performing predetermined processing such as bending processing, it is mounted as a slide door rail by welding, bolts, etc. It is fixed to.

  Of the slide door rails shown above, in the transportation equipment field, particularly in the automobile field, it is desired to reduce the weight from the viewpoint of improving the fuel consumption accompanying the recent global warming countermeasures. As measures for reducing the weight, it is possible to reduce the thickness of the irregular cross-section strips. However, since the strength is reduced only by reducing the thickness, it is necessary to make it more than the strength of the current parts.

In this way, as a method of realizing weight reduction and strength securing of parts, the material type and plate thickness should be such that a high strength material is used in a part requiring strength and a relatively low strength material is used in other parts. A so-called tailored blank method is generally applied in which the materials are joined by welding and used as a material.
Patent Document 1 proposes a method for increasing the strength by rolling.

JP 2001-234325 A

However, when the tailored blank method is used, there is a problem in that the number of welding processes increases and the cost increases.
In addition, the proposal of Patent Document 1 is a method of increasing the strength by processing a concavo-convex pattern on an electrolytic copper foil, and then crushing and hardening the emboss with a flat roll. If this method is used, the number of steps such as welding will not increase, but since the portion processed into a concavo-convex pattern is crushed by rolling, the step of the concavo-convex pattern remains, making it difficult to install it on a pedestal or join other parts The problem of becoming.

It is also possible to roll or roll-form a material that has been rolled and hardened partially in a straight line with a grooved roll into a deformed cross section, but it is partially thin, so it is formed into a deformed cross section. In some cases, stress concentrates on the portion, and cracks and buckling easily occur.
Furthermore, in the case where a necessary portion is work-hardened by rolling after being formed into a deformed cross section, buckling tends to occur because the deformation state in the rolling direction during rolling is partially different.

  The present invention has been devised to solve such problems, and has a low-cost structure having flanges at both ends capable of achieving weight reduction and ensuring strength and having a step shape in the plate width direction. An object is to provide an irregular cross section and a method for producing the same.

  In order to achieve the object, the irregular cross-section with uneven pattern according to the present invention is characterized in that an irregular cross-section having flanges at both ends is provided with an uneven shape on the outer surface and / or inner surface of the irregular cross-section. It is said. Moreover, you may give uneven | corrugated shape to the partial area | region of the outer surface and / or inner surface of an irregular cross-section. Furthermore, the cross-sectional shape of the irregular cross-section is preferably M-shaped.

As a manufacturing method, through a four-sided rolling mill in which a pair of upper and lower horizontal rolls and a pair of smooth left and right vertical rolls having a profile corresponding to a predetermined cross-sectional shape are arranged adjacent to each other, a cross-sectional shape having flanges at both ends is provided. After forming, as a pair of upper and lower horizontal rolls constituting the four-sided rolling mill, an uneven pattern is imparted to the upper and / or lower rolls using the entire surface or a partially uneven surface. It is characterized by that. Moreover, as a roll which gives a concavo-convex pattern, as a pair of left and right vertical rolls constituting a four-sided roll mill, use a roll whose right and / or left roll has a concavo-convex shape on the entire surface or partially. Also good.
In addition, in order to give a concavo-convex pattern, as a pair of upper and lower horizontal rolls and a pair of left and right vertical rolls constituting the four-sided rolling mill, the upper and / or lower rolls and the right and / or left rolls are surfaced. Needless to say, the whole or part of the surface can be made uneven.

In the irregular cross-section with uneven pattern, which has flanges at both ends of the present invention, and preferably has a stepped shape by the plate width method, the uneven pattern is given to the outer surface and / or the inner surface by rolling. The portion provided with the concavo-convex pattern is work-hardened, whereby the strength of the irregular cross-section strip can be improved. Moreover, since it is also possible to give a concavo-convex pattern partially, only the area | region required as intensity | strength can be work-hardened. Since these effects can be exerted even if the plate thickness is reduced, it is possible to realize light weight and secure strength of the irregular cross-section strip.
In addition, as a manufacturing method, since a concave and convex pattern is imparted using a four-sided rolling mill after forming a flange shape at both ends and preferably a step shape in the sheet width direction, it is uniform without causing cracks and buckling. Therefore, it is possible to form a concavo-convex pattern with various dimensions, and to obtain a stable processed shape and work hardening characteristics.

The figure shows (a) an M-shape and (b) a U-shape with irregular cross-sections that have flanges at both ends and are stepped in the plate width direction. The figure which shows the state which used the rail-shaped cross section which has a flange in both ends and becomes a step shape in the board width direction with a rail. The schematic of the equipment which manufactures the irregular cross-section with an uneven pattern. The figure explaining the condition of the 1st preforming. The figure explaining the condition of the 2nd preforming. The figure which shows the rolling to a M-shaped profile section. The figure which shows an example of the irregular cross-section with an uneven | corrugated pattern of this invention. The figure which shows an example of the uneven | corrugated pattern of the irregular cross-section with an uneven | corrugated pattern of this invention. The figure which shows provision of the uneven | corrugated pattern to the irregular cross-section of this invention. The figure which showed the flange strength evaluation of the irregular cross-section with an uneven | corrugated pattern of a present Example. The figure which showed the plastic strength evaluation in the three-point bending of the irregular cross-section with an uneven | corrugated pattern of a present Example.

The inventors of the present invention have made various studies in order to reduce the weight and secure the strength of the deformed cross-section strip having flanges at both ends and having a step shape in the plate width direction. As a result, the present invention was completed by finding that work hardening was imparted by applying a concavo-convex pattern to the outer surface and / or inner surface by rolling, thereby ensuring strength.
Details will be described below.

  Specifically, the modified cross-section strip 1 having flanges at both ends and having a step shape in the plate width direction has an M-shaped or U-shaped cross-section as shown in FIG. The rail 2 is used in the state shown in FIG. In this case, the wheel 3 that moves inside the deformed cross section 1 is installed and moved as needed. The wheel is guided by the flange 4 portion of the deformed cross section, and the wheel 3 is attached to the end surface 5 of the flange 4. It is also used in such a way that it is installed and moved. Therefore, when the wheel 3 is installed on the end surface 5 of the flange 4, a force is applied to the flange 4 to prevent the wheel 3 from being removed. It will work. In other words, the portion of the modified cross section 1 that requires strength is the flange 4.

However, in order to reduce the weight, it is necessary to reduce the thickness of the irregular cross-section strip. However, since the strength is reduced by that amount, it is necessary to perform a process to compensate for it. As a method for the treatment, a method of improving the deformation resistance by work hardening is effective, and this makes it possible to ensure the strength even when the thickness is reduced.
As a method of work hardening, it is effective to form irregular shaped strips having flanges at both ends and having a stepped shape in the plate width direction, and then to make the surface of the irregular shaped strips uneven by rolling. According to this rolling, since it is a partial reduction, a shape with good quality can be obtained without causing buckling during rolling. The area for rolling the concavo-convex pattern may be the entire outer surface, the entire inner surface, or the entire inner / outer surface of the irregular cross-section strip, or may be a partial area around the flange and its surroundings. It is possible to select appropriately according to.

As a manufacturing method, it is optimal to use an integrated manufacturing process in consideration of manufacturing costs. In other words, since the concave and convex pattern is applied by rolling, if the step shape in the width direction of the both ends and the step shape in the plate width direction and the concave and convex pattern are continuously applied, it is possible to manufacture in the same process. Can be suppressed.
In addition, it has a flange at both ends and has a step in the plate width direction. Specifically, it is M-shaped or U-shaped in cross-section, but when this shape is formed by rolling, the width direction of the material Thrust force acts on However, if a four-way roll mill in which a pair of upper and lower horizontal rolls and a pair of smooth left and right vertical rolls are arranged adjacent to each other is used, the movement of the raw material due to the thrust force can be suppressed, and stable rolling becomes possible.
As shown in FIG. 3, the rolling roll in this method is composed of a first preform with a side roll from the upstream side, a second preform formed with upper and lower two-way rolls, and a first four-roll mill. A pair of upper and lower horizontal rolls having profiles corresponding to flanges at both ends and a step shape are arranged, and a roll corresponding to a predetermined uneven pattern is arranged on the second-stage four-sided rolling mill.
Hereinafter, a series of these forming methods will be described by taking an M-shaped irregular cross section as an example.

M-shaped irregular cross-section strips cannot be formed into flanges at both ends due to insufficient material flow into the roll gap when a rectangular cross-section blank is directly formed by a four-way roll mill. Therefore, it is necessary to bend the raw material plate in the plate width direction in advance before forming into a substantially M shape by a four-sided roll mill.
As a means for bending, a two-stage preforming is adopted.
First, as shown in FIG. 4, first preforming is performed in which C warpage is imparted by reduction in the plate width direction by a side roll having a substantially V-shaped groove on a flat material plate.

Next, the center of the plate to which the C warp is applied is formed by an upper roll having convex portions at both ends and a lower roll having a convex portion having an upper flat portion whose width is narrower than the interval between the convex portions. Contrary to the C warp, a second preforming is performed that curves upward.
Specifically, as shown in FIG. 5, the C warp is caused by a lower roll provided with a convex portion having an upper flat portion at the center while restraining both ends of the material plate with an upper roll provided with convex portions at both ends. The center of the plate provided with is curved upward, and is shaped so as to have a W-shaped cross section in which curved portions are formed only at both ends.

After the second pre-forming is completed, a material plate having a W-shaped cross section is formed into an M-shape by a four-sided rolling mill shown in FIG.
At this time, a gap for flange formation was provided between the left and right vertical rolls as well as the end of the upper horizontal roll constituting the four-sided rolling mill, and the gap was provided to both ends of the material plate. The curved portion can easily enter, and the flange can be easily formed. In addition, a so-called M-shaped deformed section having a step shape in the plate width direction along the profile of the upper and lower rolls can be obtained.

The irregular cross section formed into an M shape is given a predetermined uneven pattern by a second-stage four-sided rolling mill shown in FIG. For the provision of the uneven pattern, a roll formed with an uneven pattern is arranged on the required part as a pair of upper and lower horizontal rolls of a four-sided rolling mill, and the rolling rate is set to be uniform in the sheet width direction during rolling. A rough pattern.
The concave / convex pattern may be applied to the entire front and rear surfaces and the side surfaces of the flange in the plate width direction, or may be partially applied to necessary portions.

  An M-shaped irregular cross section strip 6 shown in FIG. 7 was formed using a material strip having a rectangular cross section with a material width of SCM415 and a plate width of 22 mm. As shown in FIG. 8, the uneven pattern imparted to the irregular cross-section 6 and the arrangement thereof are an uneven pattern in which the flange 4 is a staggered arrangement having a diameter of 0.5 mm, a depth of 0.1 mm, and a pitch of 1 mm between the circles. Was granted. The forming and applying method is performed by an apparatus composed of two four-way roll rolling stands from the upstream side of the apparatus as shown in FIG. 9, and is formed into an M-shape by the four-sided roll rolling stand 7 upstream of the apparatus, and the four sides behind it. A concave-convex pattern was imparted to the lower surface side by a pair of left and right vertical rolls having the convex shape of the roll rolling stand 8 on the surface. The plate thickness of the material strip is based on 1.0 mm which does not give the uneven pattern, and when the uneven pattern is given, the plate thickness t in FIG. 7 is changed from 0.95 to 0.7 mm at a 0.05 mm pitch.

The strength evaluation on quality of the M-shaped irregular cross-section strips provided with the concavo-convex pattern was compared in terms of cross-sectional hardness. Since it is difficult to directly measure the strength evaluation of the flange 4 in the evaluation method, the region provided with the concavo-convex pattern is the product of the cross-sectional hardness and the plate thickness of the portion squeezed by the application (recessed section strip recess), and the reduction The product of the cross-sectional hardness and the plate thickness of the portion that is not formed (the convex portion of the irregular cross-section strip) was measured at three locations, and the average values of the measured values were compared.
The hardness of SCM415 which is a material strip is 130HV.
As a result of molding with the raw steel strip of each plate thickness, it was possible to form the M-shaped irregular cross-section strip 6 shown in FIG. Further, as shown in FIG. 10, the strength evaluation result of the flange 4 showed the same value as the plate thickness of 1 mm, which is a base to which the uneven pattern is not applied, up to a material plate thickness of 0.9 mm. That is, it has been found that it is possible to reduce the weight to 10% and ensure the strength.

  Further, a comparison of the plastic strength of the M-shaped irregular cross-section strips provided with the concavo-convex pattern produced as a prototype was compared with the plastic strength by three-point bending shown in FIG. In the comparison of plastic strength by three-point bending, if the base plate thickness is 1.0 mm, the strength can be improved by about 5%, and the base plate thickness is thin. It was found that the strength could be improved.

1: Profile section 2: Rail
3: Wheel
4: Flange
5: End face
6, 7: Pre-molding stand
8, 9: Four-way roll rolling stand

Claims (5)

  An irregular cross-section having flanges at both ends, wherein an irregular shape is provided on the outer surface and / or the inner surface of the irregular cross-section.   The irregular cross-section with a concavo-convex pattern according to claim 1, wherein a concavo-convex shape is imparted to an outer surface and / or a partial region of the inner surface of the irregular cross-section.   The deformed cross-section with a concavo-convex pattern according to claim 1 or 2, wherein the cross-sectional shape of the deformed cross-section is M-shaped.   After forming the material into a cross-sectional shape having flanges at both ends through a four-way roll mill in which a pair of upper and lower horizontal rolls and a pair of smooth left and right vertical rolls having a profile corresponding to a predetermined cross-sectional shape are arranged adjacently, As a pair of upper and lower horizontal rolls constituting a roll rolling mill, a concavo-convex pattern is imparted to the upper and / or lower rolls using the entire surface or a partially uneven surface. Manufacturing method of irregular cross section with uneven pattern. After forming the material into a cross-sectional shape having flanges at both ends through a four-way roll mill in which a pair of upper and lower horizontal rolls and a pair of smooth left and right vertical rolls having a profile corresponding to a predetermined cross-sectional shape are arranged adjacently, As the pair of left and right vertical rolls constituting the roll mill, the right and / or left roll is provided with a concavo-convex pattern by using the entire surface or a partially uneven surface. A manufacturing method for irregular cross sections with patterns.

Images