JPS6116204B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of Application] The present invention relates to prevention of pocket waves in wide-width cold forming of thin steel sheets. The "pocket wave" referred to here is a thin steel plate with a wide cross section (hereinafter referred to as a thin plate). It refers to irregular wrinkles that occur periodically on the surface due to shallow flexures that appear wavy. Among these, minute wrinkles that occur in the longitudinal direction at the end of the cross section are sometimes called "edge waves." In addition to these edge waves, fine wavy irregularities that occur in the longitudinal direction near the bends are also referred to as "edge waves." I〕
Although it is sometimes called this, it also includes this waist. Pocket waves are generally referred to as ``bulging convex surfaces'' and ``deflection concave surfaces.'' They are moved in a longitudinal straight line, and the depth of the concave and the height of the convexity on the line are totaled, and 1/2 of the total value is It is also represented by the symbol hw (unit
Described in mm/m). The "width shifting amount" of the plate to be formed is "1/2 of the difference in width of the molded product before and after passing through a pair of upper and lower forming rolls." The term width refers to the width of the web being formed, not the board width itself. Thin steel plates, that is, thin plates, include ordinary steel plates, plated steel plates, silicon steel plates, stainless steel plates,
Refers to clad steel plates and other thin plates. Pocket waves are generated in scattered areas in FIG. [Conventional technology] Conventional wide-width cold forming processes thin sheets using tandem rolls. For example, the bending angle can be gradually increased from a flat plate between 10 rolls, and the required shape and dimensions can be formed in the 10th roll.In the 9th roll, the product is formed taking into account the spring back, and in the 10th roll, Adding even more precise and precise molding. At the roll exit of each stage, equal stress is applied to each roll, that is, equal deformation energy is applied to maintain the degree of forming uniformly and to obtain a product with the desired size. For example, when an angle of about 80 degrees is required for corner bending, from the flat plate to the 5th step, each roll should be bent at an angle of about 10 degrees, and at the 5th step, as will be explained later in Figure 4.
Bend it at 45 to 50 degrees, then gently deform it at an appropriate angle of 5 to 10 degrees from the 6th to 9th tier, and decide the bending angle of each tier based on empirical rules. The 10th roll used for this forming is driven by a single line shaft and a single power device.
The information is transmitted to each corrugated roll, and each corrugated roll changes the speed slightly, for example, by 0.01 to 1.0% depending on the application, at the roll circumferential speed, and forms the thin plate to be processed between the upper roll and the lower roll. . First, based on the above principles, we examined the intermediate processing at the exit of each forming roll.
If anything is incorrect, adjust it and try again. In this case, when pocket waves occur, it is difficult to plan how many stages of roll forming should be done and how to adjust them. It is not easy to increase the number of stages, so if conditions for direct mass production can be obtained with an existing, say 10 stage forming roll, in a reasonable initial confirmation trial, workability will be improved with extremely good efficiency. Products with accurate and highly accurate shapes and dimensions can be obtained, and as a result, product costs can be reduced and products with good desired shapes and dimensions can be obtained. [Problems to be solved by conventional technology] In light of the current state of the conventional technology, the present invention attempts a rational molding method at the beginning of its planning, examines the results of the trial, and promptly begins mass production. The aim is to provide products with low cost and good quality. To achieve this purpose, the structure and forming method of common tandem rolls are improved. In recent years, thin sheet products have been required to be more diverse, and the thickness of the sheet has been reduced, the width of the sheet has been increased, and the bending radius of the bending corner has been minimized. The challenge is to provide a highly efficient manufacturing method and device that can perform molding that does not occur and that can improve and effectively use existing conventional equipment. [Technical means for solving the problem] The present invention plans and trials a forming process that is considered appropriate, measures the amount of pocket waves (hw) at the exit of each corrugated roll, and calculates the amount of width closing and plate thickness. Each roll stage is driven to supply the energy required for uniform processing, forming, and the roll stage number indicating the maximum value of the pocket wave generating corrugated roll is found. Next, one existing line shaft is divided at the exit of the roll stage number, and the first drive device (existing one) is used for up to the roll stage, and from the roll stage next to the roll stage to the 10th roll stage. First line shaft (existing division)
In the divided second line shaft, the first and second two independent drive devices and the first and second two drive devices are respectively driven by a second drive device that is independent of the first drive device. Form with a line shaft. Also, the ratio of the number of rotations of the second line shaft to the number of rotations of the first line shaft, N2/N1, is 1.15 to 1.2.
(times). In addition, the bending radius formed by the forming rolls is made smaller, the width closing angle is made steeper, and the flat portion is made larger. FIG. 2A shows a conventional arrangement, and FIG. 2B shows an explanatory diagram showing the arrangement of this embodiment. Example 1 Next, one example of the present invention will be described based on the drawings. FIG. 1 shows a plan view of an improved tandem roll consisting of 10 stages of forming rolls with the middle section omitted, according to an embodiment of the present invention. The first forming section includes a first drive device AA, a motor 23, a variable speed reduction device 9, a transmission device 8, a first line shaft device 7, and a required number of stages forming roll device. The second molding part is
It consists of a second drive device BB, a motor 33, a variable speed reduction device 19, a transmission device 18, a second line shaft device 17, and a required number of stages forming roll device.
Axis 03 indicated by a dotted line in part B indicated by an arrow in the middle part is
The original axis is shown after dividing and removing one line shaft. 20, 25, 30 in the figure are base plates, 21 and 3
1 is an operating handle, and 26 and 36 are drive shafts. The forming roll device equipped with the thin plate device 6 at the front end and the formed body straightening machine 16 at the rear end has first forming sections S ₁ , S ₂ , S ₃ , S ₄ , S ₅ , S ₆ and S _{7 .} The second molded part consists of S ₈ , S ₉ and S ₁₀ . The circumferential speed of each roll is arbitrarily selected depending on the purpose of use within the range of 0.01 to 1.0%, and is driven in a tensile manner. In the embodiment shown in this figure, the first forming device has seven-stage rolls, and the second forming device has three-stage rolls. The original thin plate is advanced from the charging device 6 between the rolls 1 and 2 of the roll stand S ₁ and is formed.
The first forming is completed between rolls 1 and 2 of the _S7 roll stand. Next, it advances between the rolls 11 and 12 of the roll stand S ₈ of the second forming device, and the upper and lower rolls 11 and 12 of the final stand S ₁₀ .
Perform finishing molding between. The results of _{the series} of tests were as follows:
Suitable molding was achieved when N2/N1 was 1.15 to 1.2 times. FIG. 2 is a partially enlarged side view of the roll stand _S10 of the second forming device. Other stands, e.g.
S ₁ also has a similar structure. Example 2 Molding is carried out using the apparatus of Example 1. The 10-stage tandem cold roll forming device consists of a shaft 7 with a diameter of 30 mm, a roll stand width of 250 mm, a variable speed reduction motor of 15 HP, and a lower shaft driven and an upper shaft driven roll. The sample material is
According to JIS-SPCC-SD, the thickness of the thin plate is 0.5 mm, and the ratio of web width Ww/plate thickness t is 96,
There are four types: 144, 192, and 240. Fig. 6A shows the product board width W and web width Ww, and Fig. 6B shows the partially enlarged shape of the convex portion of the bent portion and the bending radius R. Front views of the 10-roll intermediate forming process are shown in Figures 5A and 5B. In order to clarify the cause of pocket waves, we changed the maximum width approach, the ratio of web width to sheet thickness, the forming roll drive method, the number of rolls, the amount of unreasonable deformation during work, and the elimination of pocket waves that occurred. Next, the case where the molding is performed will be explained. As will be explained in other embodiments, pocket waves are not generated when Ww/t is 96 or less. Occurs at 192 or higher. Preferably it is 96 or less.

[Effect]

A first forming device is used for first forming with a first driving device,
A thin plate that is subjected to second forming in a second forming device using a second drive device, with the rotation speed of the second line shaft being in the range of 1.1 to 1.3 times, preferably 1.15 to 1.2 times, the rotation speed of the first line shaft. In the case of wide-width cold rolling of , the generation of pocket waves is minimized when the maximum width shift is 1.2 mm or less and the ratio of web width to plate thickness to be formed is smaller than 144 mm/m, preferably smaller than 96 mm/m. The premise is to rationalize the amount of deformation and avoid excessive forming. The forming roll to be divided can be determined by finding a roll that generates a prominent pocket wave. [Effects] The method and apparatus of the present invention as described above can minimize or completely eliminate pocket wave generation, resulting in high quality molding, improved workability, and lower costs.

[Brief explanation of the drawing]

FIG. 1A is a plan view of an embodiment of the present invention, and FIG. 1B is a plan view of an embodiment of the present invention.
The figure is a side view of the forming roll stand (same as the conventional one). In Figure 2A, Figure A is an explanatory diagram of the layout of the conventional method, Figure B is an explanatory diagram of the layout of the present invention, Figures 3A and B are illustrations of the mode of pocket wave generation, and Figure 4 is a 10-tier roll. The deformation angle and bending shape for each are shown. Figures 5A and 5B are partially enlarged front sectional views showing the intermediate process of molding, Figures 6A and 6B are explanatory diagrams of the final molded product, and Figure 7A is deformation at each stage according to the conventional method. Fig. 7B is an explanatory diagram showing the measured values by the method and device of the present invention using the least squares method, and Figs. 8A and 8B are relationship diagrams between line shaft rotational speed and pocket wave reduction. . DESCRIPTION OF SYMBOLS 1, 11... Forming roll, 2, 12... Roll support body, _S1 , _S10 ... Roll stand, 7, 17... Line shaft, 8, 18... Drive wheel, 6... Charging device,
16... Correction device, 26, 36... Drive shaft, C-C,
D-D...roll center, _W1 , _W2 , _W3 , _W4 ...web, W...maximum width of plate, Ww...width of processed web,
WR ₁ , WR ₂ , WR ₃ , WR ₄ ... Bending radius of the bent part, N ₁ , N ₂ ... Rotation speed, 01 ... Relationship curve obtained by least squares method.

Claims (1)

[Scope of Claims] 1. In forming by advancing between each forming roll of a tandem roll device, the measurement value during the process of forming a thin steel plate with line shaft drive rolls is (a) The ratio of web width to plate thickness is 144
mm/m or less, preferably 96 mm/m or less, and (b) the maximum width shift amount is 1.2 mm or less, and the pocket wave measurement value is at the rear of the roll that is protruding compared to the values of other rolls, A first forming process in which the line shaft is separated and divided into one for the front part and one for the rear part to form two independent line shafts, and the first line shaft for the front part drives up to the roll showing the protrusion value, a second forming process in which the rear line shaft drives a roll after the protrusion value roll, and the thin steel plate to be processed is roughly formed in the first forming process;
A method for wide-width cold forming of a thin steel sheet, characterized in that finishing forming is performed in the second forming process, and tension is applied to the object to be formed. 2 Forming is performed by advancing between upper and lower rolls in a tandem roll machine device, and includes a support roll stand for a central shaft into which a pair of vertically opposed forming rolls is fitted, and a line shaft drive device for driving the central shaft. , the one line shaft of the forming roll device formed by combining these is divided into two independent drive first forming device and second forming device each formed by two independent first and second line shafts; The thin film is characterized in that the ratio N2/N1 of the shaft rotational speed N1 of the first line shaft of the first forming device to the shaft rotational speed N2 of the second line shaft of the second forming device is 1.15 to 1.2 times. Equipment for wide cold forming of steel plates.