JP2005028437A - Method and apparatus for trimming of aluminum or aluminum alloy sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for trimming of an aluminum or aluminum alloy sheet which can suppress occurrence of a dent and a paint defect through suppression of abrasion particle generation, by preventing generation of burrs easily and reliably while preventing shearing defects, without causing increase in production steps. <P>SOLUTION: An upper face of lower die 6 and a lower face of a press plate 2 are bent respectively at the matching point of their edge parts, so that the edge part of an aluminum alloy sheet 1 is bent. Therefore, the portion of aluminum alloy sheet 1 to be trimmed is tilted at an angle θ to the moving direction of the upper die 5, that is vertically downward (arrow 3), at the cutting line position. The tilting angle θ is 50-80°. Thus, though the upper die 5 makes a reciprocative shearing motion downward and upward, the problem such as occurrence of burrs and shearing defects on the edge of the aluminum alloy sheet 1 is suppressed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention forms aluminum or aluminum alloy plates (hereinafter collectively referred to as aluminum alloy plates) used for automobile panels and parts thereof, electrical equipment, precision parts, etc., and then removes the edges of the formed plates. The present invention relates to a trimming method and a trimming device used for the trimming method.

  Conventionally, when a molded product is obtained from a plate-shaped material by press processing, after performing molding processing on the material, trimming processing is performed to remove the edge of the molded plate, and unnecessary portions (hereinafter referred to as scrap portions) are formed from the molded plate. Are removed to leave the molded product shape part. In the trimming process, the shaped part is generally pressed against the lower blade and fixed by a member, and the molded plate is shear-cut (sheared) with the upper blade and the lower blade to remove the scrap part.

  FIG. 4 is a schematic diagram showing a conventional typical trimming apparatus. The molded plate 7 after molding is sandwiched between the lower blade 10 and the pressing plate 8 at the molding portion, and the portion to be removed is protruded from the lower blade 10 and supported by the lower blade 10 and the pressing plate 8. To do. Thereafter, the upper blade 9 is processed, and an unnecessary portion (scrap portion) of the aluminum alloy molded plate 7 is shear-cut by shearing with the upper blade 9 and the lower blade 10. The upper blade 9 is then lifted, and the scrap portion is trimmed and removed by a press operation in which the upper blade 9 reciprocates once.

  Thus, in the conventional shearing process, the angle formed by the surface of the portion to be sheared and the moving direction 11 of the upper blade is 90 °, and the molding plate 7 is sheared in a direction perpendicular to the surface. The molded product after trimming is used as a panel or a part constituting an automobile or the like after undergoing a bending process, an assembly process, a painting process, and the like.

  However, by shear cutting, burr may occur on the end face after shearing, which may be lost and wear powder may be generated. The generated abrasion powder adheres to the molded product shape part and the molding die of the workpiece, and forms irregularities called stars on the surface of the molded product. If there are irregularities on the surface of the molded product, color unevenness in which the painted surface does not become a uniform color, that is, unevenness in the coating, will occur in the subsequent painting process. For this reason, when a star is formed, the surface of the molded product is polished to remove irregularities. In this case, if there are many molded products that need to be reworked, this may cause a decrease in productivity. For this reason, various studies have been made so far that no abrasion powder is generated during trimming.

  Japanese Patent No. 290889 includes a trim line and a cut line that is formed along a cut line that intersects the trim line, and the scrap line is pushed by a plurality of push bars. A method of performing trimming according to the above has been proposed (Patent Document 1). In this method, after a groove is formed at a predetermined position of the molded product, trimming is performed using the groove as a separation tip, so that an unnecessary portion is reliably separated from the molded product shape portion through the groove. Thus, burr is prevented from occurring on the molded product shape portion side.

  In recent years, demands for weight reduction of automobiles have increased, and aluminum alloy plates have been used as automobile panel materials instead of conventional steel sheets. However, even when an aluminum alloy plate is used, the process from forming to trimming is not changed.

Japanese Patent No. 29088989

  However, when trimming a molded product formed from an aluminum alloy plate, if the trimming is performed under the same conditions as a conventional steel plate, burr is likely to occur after trimming because the burr generation behavior differs between the steel plate and the aluminum plate. There is a problem. For this reason, in the case of an aluminum alloy plate, abrasion powder is more easily generated than the steel plate, and the occurrence rate of unevenness after coating increases.

  The present invention has been made in view of such a problem, and prevents the generation of burr and suppresses the generation of wear powder without causing an increase in the number of man-hours and preventing a shear failure and easily and reliably. An object of the present invention is to provide a trimming method and a trimming apparatus for aluminum or an aluminum alloy plate that can suppress the occurrence of star marks and coating defects.

  A trimming method for an aluminum or aluminum alloy plate according to the present invention is a portion to be sheared in a trimming method for an aluminum or aluminum alloy plate in which a formed plate made of aluminum or an aluminum alloy plate is trimmed by shearing an upper blade and a lower blade. Is bent so as to form an angle of 50 to 80 ° with respect to the moving direction of the upper blade, and then trimmed by shearing between the upper blade and the lower blade.

  Further, the trimming device for aluminum or aluminum alloy plate according to the present invention includes a lower blade that supports a formed portion of the formed aluminum or aluminum alloy plate from below, a lower blade that presses the formed portion from above, and the lower blade A pressing member that supports the molding portion between the upper blade and the upper blade that lowers and trims the molding plate by shearing between the lower blade and the lower blade and the pressing member are formed by the molding. It is characterized in that it has a shape that bends the part to be sheared when the part is clamped so as to form an angle of 50 to 80 ° with respect to the moving direction of the upper blade.

  As described in detail above, according to the present invention, when trimming an aluminum alloy plate, the portion to be trimmed is bent and inclined so as to form an angle θ of 50 to 80 ° with respect to the shearing direction. The occurrence of rusting can be suppressed, coating failure caused by the occurrence of burr can be suppressed, shearing failure can be prevented, and trimming can be performed with high productivity.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a schematic view showing the structure of a trimming mold of the trimming apparatus of this embodiment.

  The aluminum alloy plate 1 after forming such as press forming is sandwiched between a lower die (lower blade) 6 and a pressing plate 2. The lower die 6 is fixedly installed, and the molding part of the aluminum alloy plate 1 is positioned on the lower die 6, and the presser plate 2 is lowered on the aluminum die plate 1, and the aluminum is formed between the presser plate 2 and the lower die 6. The alloy plate 1 is clamped. The upper die (upper blade) 5 moves vertically downward so as to slide on the lower die 6 as indicated by an arrow 3, and the aluminum alloy plate 1 is sheared between the upper die 5 and the lower die 6. Unnecessary portions (scrap portions) protruding from above the lower mold 6 are sheared and removed.

  In the present embodiment, the upper surface of the lower mold 6 and the lower surface of the pressing plate 2 are bent at locations where the edge portions thereof are aligned, whereby the edge portion of the aluminum alloy plate 1 is bent. The portion to be trimmed 1 is inclined at an angle of θ with respect to the moving direction of the upper mold 5, that is, vertically downward (arrow 3) at the cutting line position. The inclination angle θ is 50 to 80 °.

  In the present embodiment configured as described above, when the upper die 5 is lowered and the trimming portion of the aluminum alloy plate 1 is cut with the lower die 6 by shearing, the trimming portion is moved by the upper die 5. Since it is inclined at an angle of θ with respect to the direction (vertically downward), even if the upper die 5 reciprocates once in the descending and ascending shearing operations, the end of the aluminum alloy plate 1 is burred and sheared poorly, etc. The occurrence of the inconvenience is suppressed.

  At this time, when the angle θ is 80 ° or more, as in the case of the conventional 90 °, the effect of suppressing burr at the time of trimming cannot be obtained. In addition, when the angle θ is less than 50 °, not only the effect of suppressing burr during trimming is saturated, but also the angle is too small and shear failure is likely to occur during processing. Therefore, the bending angle θ of the edge of the aluminum alloy plate is set to 50 to 80 ° with respect to the moving direction of the upper mold.

  Hereinafter, the effect of the embodiment that satisfies the claims of the present invention will be specifically described in comparison with a comparative example that is out of the scope of the present invention. FIG. 2 is a plan view showing the dimensions of the molded plate after molding, and FIG. 3 is a perspective view showing the dimensions of the pressing plate 2 (plate pressing pad) in FIG. The presser plate 2 presses a forming part (vertical 200 mm, horizontal 300 mm) of the forming plate, and has a thickness of 30 mm. The molded plate has a trimming portion having a width of 30 mm on the four sides of the molded portion.

  The molded plate to be trimmed is an aluminum alloy plate made of JIS 5052-O and has a thickness of 1 mm. The upper mold and the lower mold are JIS FCD-55 mold steels. For θ, various bending angles of the pressing plate and the surface of the lower die were prepared. At the time of trimming, the lower die and the pressing plate were changed variously, and 1000 trimming tests were performed per condition. Then, the trimmed molded product was painted using a paint for automobile painting, and the occurrence of burr on the end face was evaluated by obtaining the painting defect rate. In addition, the presence or absence of shear failure during trimming was also evaluated.

  Regarding the shear failure, when the shearing failure occurred in the test material less than 50 times out of 1000 times, it was evaluated as ◯, and when it was 50 times or more, ×. The coating failure rate was evaluated by the occurrence rate when a coating failure occurred by visually observing the molded product after coating. The evaluation criteria were ○ when the incidence of poor coating was less than 2%, and x when 2% or more.

  Table 1 below shows the test results of the shear failure and the coating failure rate.

  As shown in Table 1, in Examples 3 to 5, since the angle θ satisfies 50 to 80 °, the shear failure and the coating failure were extremely small. Less paint failure indicates very little burr. On the other hand, Comparative Example 1 was a case where shearing was performed perpendicularly to the surface of the aluminum alloy plate as in the prior art, but the coating defect rate was as high as 50.5%. Further, in Comparative Example 2, since θ was as large as 82 ° and the inclination was small, generation of burr could not be suppressed, and wear powder was generated at the time of trimming processing, so the occurrence rate of defects after painting was large. Since Comparative Example 6 had a small angle θ and a large inclination, the shear failure rate was high.

It is a schematic diagram which shows the trimming apparatus of the aluminum or aluminum alloy plate which concerns on embodiment of this invention. It is a top view which shows the dimension of the shaping | molding part and trimming part of a shaping | molding board. It is a perspective view which shows the dimension of a pressing board. It is a schematic diagram which shows the conventional trimming apparatus.

Explanation of symbols

1, 7; Aluminum alloy plates 2, 8; Presser plates 5, 9; Upper die 6, 10; Lower die

Claims (2)

In a trimming method of an aluminum or aluminum alloy plate in which a formed plate made of aluminum or an aluminum alloy plate is trimmed by shearing an upper blade and a lower blade, the portion to be sheared is 50 to 80 ° with respect to the moving direction of the upper blade A method for trimming an aluminum or aluminum alloy plate, wherein the trimming is performed by shearing the upper blade and the lower blade after bending to form an angle of. A lower blade that supports the molded portion of the aluminum or aluminum alloy molded plate after molding from below, a pressing member that presses the molded portion from above and supports the molded portion between the lower blade, and lowers An upper blade that trims the molded plate by shearing with the lower blade, and the lower blade and the pressing member have a portion to be sheared when the molded portion is sandwiched between the upper blade and the upper blade. An aluminum or aluminum alloy plate trimming apparatus having a shape that is bent so as to form an angle of 50 to 80 ° with respect to a moving direction.

Images