Sheet metal processing methods
The method forms relief holes as cutting slits using a laser beam to address finishing accuracy and deformation issues in sheet metal processing, enhancing coining precision and reducing defects.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- AMADA CO LTD
- Filing Date
- 2025-01-16
- Publication Date
- 2026-07-29
AI Technical Summary
Existing sheet metal processing methods form wide relief holes that affect finishing accuracy and can cause deformation and defects during coining, especially in long products, and laser contour cutting risks the relief hole getting stuck on the workpiece.
Forming relief holes as cutting slits along the contour line using a laser beam, followed by coining and cutting out the product with a laser beam, to maintain finishing accuracy and prevent deformation.
The method maintains finishing accuracy and reduces defects by forming relief holes as cutting slits, preventing relative deviation and sticking issues, thus ensuring precise coining results.
Smart Images
Figure 2026122646000001_ABST
Abstract
Description
Technical Field
[0004] , , , , , ,
[0003] , , , ,
[0001] The present invention relates to a sheet metal processing method.
Background Art
[0002] In Patent Document 1, when coining is performed on the edge of a part cut out from a sheet metal workpiece to form a product, in order to eliminate burrs, the inclination on the draft surface side, and ensure flatness, a relief hole is formed by punching in a die along its contour outside the part that will become the product.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] Conventionally, as described in Patent Document 1, in order to absorb the elongation of the material generated by coining or suppress the deformation of the workpiece itself generated by coining, a relief hole has been formed in advance. Since this relief hole is formed by punching with a die or contour cutting with a laser, the width of the relief hole is relatively wide. Therefore, the range between the relief hole and the part that will become the product is likely to be excessively deformed by coining, and a relative deviation may occur in the positional relationship between the die and the material during coining, which may affect the finishing accuracy of coining. In particular, when the product is long, it is necessary to form a long relief hole, and the part between the relief hole and the product is more likely to be deformed, and the influence on the finishing accuracy of coining becomes more significant. Further, when the relief hole is formed by laser contour cutting, the longer and thinner the relief hole becomes, the more likely it is that the outer edge of the part to be removed as the relief hole gets caught on the workpiece and cannot be removed. Therefore, in a sheet metal processing method involving coining, it is desired that the relief hole can be formed so as to hardly affect the finishing accuracy of coining and hardly cause problems. [Means for solving the problem]
[0005] A first aspect of one or more embodiments is a sheet metal processing method in which, in a sheet metal workpiece, a cutting slit is formed by a laser beam along the contour line as a relief hole in the area outside the contour line of the product to be cut from the workpiece, coining is performed in the area including the contour line, and the contour line is cut with a laser beam to cut out the product. [Effects of the Invention]
[0006] According to one or more embodiments of the sheet metal processing method, relief holes can be formed in a way that does not significantly affect the finishing accuracy of the coining and is less prone to defects. [Brief explanation of the drawing]
[0007] [Figure 1] Figure 1 is a first plan view illustrating a first aspect of a sheet metal processing method according to one or more embodiments of the present invention. [Figure 2] Figure 2 is a second plan view illustrating the first embodiment. [Figure 3A] Figure 3A is a cross-sectional view taken at the S3A-S3A position in Figure 1. [Figure 3B] Figure 3B is a cross-sectional view taken at the S3B-S3B position in Figure 4. [Figure 3C] Figure 3C is an enlarged plan view of section A in Figure 4. [Figure 4] Figure 4 is a third plan view illustrating the first embodiment. [Figure 5A] Figure 5A is a plan view of product P obtained in the first embodiment. [Figure 5B] Figure 5B is a cross-sectional view of the S5B-S5B position in Figure 5A. [Figure 6A] Figure 6A is a plan view showing the relief hole 1B of the modified example 1. [Figure 6B] Figure 6B is a plan view showing the relief hole 1C of modified example 2. [Figure 6C] Figure 6C is a plan view showing the relief hole 1D of modified example 3. [Modes for carrying out the invention]
[0008] A first embodiment of a sheet metal processing method according to one or more embodiments of the present invention will be described with reference to Figures 1 to 5B. Figure 1 is a first plan view illustrating the first embodiment of a sheet metal processing method according to one or more embodiments of the present invention. Figure 2 is a second plan view illustrating the first embodiment. Figure 3A is a cross-sectional view at position S3A-S3A in Figure 1. Figure 3B is a cross-sectional view at position S3B-S3B in Figure 4. Figure 3B is an enlarged plan view of part A in Figure 4. Figure 4 is a third plan view illustrating the first embodiment. Figure 5A is a plan view of product P obtained in the first embodiment. Figure 5B is a cross-sectional view at position S5B-S5B in Figure 5A.
[0009] The first embodiment of the sheet metal processing method comprises, in this order, a relief hole formation process, a coining process, and a product P cutting process, as major classifications of processing steps for a sheet metal workpiece W. Figure 1 is a plan view showing the state of the workpiece W after the relief hole formation process. In Figure 1, the workpiece W is a sheet metal, and the rectangular dashed line is the contour line LN of the portion of the workpiece W that will become the product P. The contour line LN becomes the cutting line (cutting line) that is cut by a laser beam in the product P cutting process. In the workpiece W shown in Figure 1, the relief hole 1 is formed in the outer part of the portion that will become the product P, along the long side LNa of the pair of long sides of the contour line LN that is on the side where coining is performed.
[0010] The relief hole section 1 is formed in two rows. Specifically, it consists of a first row of relief holes 1a formed intermittently and a second row of relief holes 1b formed intermittently on the outer edge side of the first row of relief holes 1a. The first row of relief holes 1a is parallel to the long side LNa at a distance d1, and the second row of relief holes 1b is formed parallel to the first row of relief holes 1a at a distance d2.
[0011] The first row of relief holes 1a are formed in a plurality of numbers with the same length, separated from each other by a distance La in the longitudinal direction. In this example, there are four first row relief holes 1a. The second row of relief holes 1b are formed at the same length and at the same longitudinal position as the first row of relief holes 1a. That is, the first row and the second row have intermittent parts (connected parts) at the same position in the longitudinal direction. The longitudinal length of the intermittent part is indicated by the distance La.
[0012] The first row of relief holes 1a and the second row of relief holes 1b are formed as cut slits obtained by scanning a laser beam in one direction rather than by cutting the contour of the hole. For example, the first row of relief holes 1a are formed as cut slits scanned from left to right in FIG. 1 (see arrow DR1), and after turning back at the right end (see arrow DR2), the second row of relief holes 1b are formed as cut slits scanned from right to left in FIG. 1 (see arrow DR3). That is, it is formed in a so-called single stroke.
[0013] Specific dimensional examples are as follows. Length Lp of product P: 300 mm Distance La: 10 mm Distances d1, d2: 2 mm Widths ta, tb of the relief holes (widths of the cut slits): 0.12 mm These values are for example only, and can be appropriately changed according to the thickness and material of the workpiece W, as well as the specifications of the product P and coining. The widths ta, tb can be adjusted in scale, for example, by adjusting the focal length of the laser processing head. Therefore, the widths ta, tb can be set with high precision and reproducibility at a fine width. Note that FIGS. 1 and subsequent figures are schematic diagrams and are not drawn in the ratio of these dimensions.
[0014] FIG. 2 is a diagram showing the coining range M which is the approximate range of coining performed on the workpiece W. In this example, the range M is set at four locations so as to straddle the long side LNa of the contour line LN.
[0015] The cross-section of the relief hole portion 1 before coining is shown in Fig. 3A. After coining is performed on this workpiece W, the cross-sectional view is shown in Fig. 3B, the plan view is shown in Fig. 4, and the enlarged view of part A in Fig. 4 is shown in Fig. 3C. As shown in each figure, in this example, coining is performed by striking a coining die with a triangular cross-sectional shape from above to form a triangular recess as shown in Fig. 3B at the corresponding part of the workpiece W. Due to this coining, the material undergoes plastic flow, and as shown in Fig. 3C, a protruding portion 2m that protrudes into the first row of relief holes 1a is formed.
[0016] When the protruding amount of the protruding portion 2m exceeds the width ta of the first row of relief holes 1a, the protruding portion 2m abuts on the narrow portion Wa between the first row of relief holes 1a and the second row of relief holes 1b, and deforms this by a distance Lb in the outer edge direction. Therefore, the energy of plastic flow is consumed, and excessive protrusion of the protruding portion 2m is suppressed. As a result, there is no deviation in the relative positional relationship between the coining die and the workpiece W, and the finishing accuracy of coining is maintained.
[0017] When the energy of plastic flow is even greater and the deformation of the narrow portion Wa exceeds the width tb of the second row of relief holes 1b, the narrow portion Wa abuts on the outer edge portion Wb and the energy of plastic flow is further consumed, further suppressing excessive protrusion of the protruding portion 2m and highly maintaining the finishing accuracy of coining.
[0018] The product cutting process after coining is cutting along the contour line LN by a laser beam. Thereby, the product P shown in Fig. 5A is cut out. Since the long side LNa of the contour line LN is set at the center in the width direction of the indentation portion 2, a coining formation portion 2a that is an inclined surface is formed on the product P.
[0019] As described above, in the first embodiment, the relief hole 1 is formed by a slit created by a single cut of the laser beam. Therefore, a space is secured as a relief for the protrusion 2m that will be generated by the plastic flow that occurs during coining, and if the amount of protrusion is excessive, it immediately comes into contact with the narrow space Wa, appropriately suppressing the size and amount of the protrusion 2m. As a result, the coining die does not slip relative to the workpiece W during the subsequent coining process, and the finishing accuracy of the coining is maintained.
[0020] Furthermore, since both the first row relief holes 1a and the second row relief holes 1b are formed by cutting slits of the laser beam rather than by contour cutting of the laser beam, there are no punched-out sections, and the problem of relief holes getting stuck and not coming out does not occur.
[0021] The configuration of the relief holes in relief hole section 1 is not limited to the configuration in which the positions of the discontinuing portions are the same in the two rows described above, and can be modified. Relief hole sections 1B to 1D of modified examples 1 to 3 will be described with reference to Figures 6A to 6C, respectively.
[0022] (Variations 1-3: Second to fourth forms) As shown in Figure 6A, a second embodiment (modification 1) may be a relief hole section 1B consisting of only one row of relief holes 1Ba. Also, as shown in Figure 6B, a third embodiment (modification 2) may be a relief hole section 1C having a first row of relief holes 1Ca and a second row of relief holes 1Cb, with the discontinuance between the first and second rows in a staggered position. Furthermore, a fourth embodiment (modification 3) may be a relief hole section 1D having three rows of relief holes, such as the first row of relief holes 1Da to the third row of relief holes 1Dc, as shown in Figure 6C. There may be four or more rows. In addition, the first to fourth embodiments may be combined to the extent possible.
[0023] The relief holes 1 can be formed to correspond to each side on which coining is performed, in accordance with the shape of the contour line LN. Furthermore, if the corresponding contour line LN is relatively short, the relief holes 1 may be formed with a single cutting slit for one of the rows without forming the discontinuous section DB.
[0024] The coining range M set along the long side LNa is not limited to the four locations described above, but can be set at any position and length. For example, it may be set at one location along the long side LNa, and that one location may extend along part or all of the long side LNa. Furthermore, even if the range M is set over the entire long side LNa, the energy of the plastic flow generated by coining at a position parallel to the intermittent portion DB of the relief hole 1 is absorbed by deforming the relief hole near the intermittent portion DB, thus maintaining a high level of finishing accuracy for the coining.
[0025] As described in detail above, the first aspect of one or more embodiments of the present invention is a sheet metal processing method in which, in a sheet metal workpiece W, a cutting slit is formed as a relief hole portion 1 by a laser beam along the contour line LN in the outer portion of the contour line LN of the product P to be cut out from the workpiece W, coining is performed in the area M including the contour line LN, and the contour line LN is cut with a laser beam to cut out the product P.
[0026] According to this first embodiment, the relief hole portion 1 can be formed in a way that does not significantly affect the finishing accuracy of the coining and is less prone to defects.
[0027] In the first embodiment, the relief hole portion 1 may be formed by one row or multiple rows of cutting slits parallel to the contour line LN.
[0028] This makes it possible to form an optimal relief hole 1 according to the specifications of product P and the coining specifications.
[0029] Furthermore, the relief hole portion 1 may be formed by multiple rows of cutting slits, with each row consisting of multiple intermittently formed cutting slits.
[0030] This makes it possible to form a more optimal relief hole 1 according to the specifications of product P and the coining specifications.
[0031] The intermittent portions DB of the multiple intermittently formed cutting slits may be arranged in a staggered pattern in the multiple rows.
[0032] This also makes it possible to form a more optimal relief hole 1 according to the specifications of product P and the coining specifications.
[0033] In the first embodiment, the widths ta and tb of the cutting slits may be set by adjusting the focal length of the laser beam.
[0034] This allows the widths ta and tb of the cutting slits to be set with fine widths, high precision, and with good reproducibility. [Explanation of Symbols]
[0035] 1,1B,1C,1D Escape holes 1a,1Ca First row escape holes 1b, 1Cb, 1Db Second row escape holes 1Dc Third row escape hole 1Ba escape hole 2. Impacted area 2a Coining forming section 2m protrusion d1,d2,La,Lb distance DB Interruption Section LN contour line LNa Long side Lp length M (Coining) range P product ta,tb width Double job Wa narrow section Wb outer edge
Claims
1. A sheet metal processing method comprising forming a cutting slit by laser beam as a relief hole along the contour line in the outer portion of the contour line of a sheet metal workpiece, performing coining in the area including the contour line, and cutting the contour line with a laser beam to cut out the product.
2. The sheet metal processing method according to claim 1, wherein the relief hole portion is formed by one row or multiple rows of cutting slits parallel to the contour line.
3. The sheet metal processing method according to claim 2, wherein the relief hole is formed by multiple rows of cutting slits, and each row is made up of multiple intermittently formed cutting slits.
4. The sheet metal processing method according to claim 3, wherein the intermittent portions of the multiple intermittently formed cutting slits are arranged in a staggered pattern in multiple rows.
5. The sheet metal processing method according to any one of claims 1 to 4, wherein the width of the cutting slit is set by adjusting the focal length of the laser beam.