Pressed product manufacturing method

Abstract

This disclosure provides a method for manufacturing press-formed products that can suppress the peeling of markings used for moldability evaluation. [Solution] The press-formed product manufacturing method according to the present disclosure is a press-formed product manufacturing method that manufactures a press-formed product by press-forming a metal sheet 1, comprising the steps of forming a plurality of recesses 11 on the surface of the metal sheet 1, forming a press-formed product by press-forming the metal sheet 1, and measuring the amount of positional change of the recesses 11 between the metal sheet 1 and the press-formed product.

Description

Technical Field

[0006]

[0001] This disclosure relates to a method for manufacturing press-worked products.

Background Art

[0002] In the process of manufacturing press-worked products by pressing a metal sheet, formability evaluations such as measurement of the amount of deformation and detection of cracks in the press-worked products are performed. For example, in Patent Document 1, a plurality of markings are applied to the surface of the metal sheet before pressing, and formability evaluation is performed based on the amount of position change of the markings before and after pressing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Regarding the manufacturing method disclosed in Patent Document 1, the inventors have found the following problems. Depending on the location of the metal sheet, due to the contact between the surface of the metal sheet and the processing surface of the press die, the markings applied to the surface of the metal sheet are subjected to high surface pressure and slide. As a result, the markings may peel off, and there is a risk that the measurement of the marking position after pressing cannot be accurately performed.

[0005] The present invention has been made to solve such problems, and an object thereof is to provide a method for manufacturing press-worked products capable of suppressing peeling of markings for formability evaluation.

Means for Solving the Problems

[0006] The press-formed product manufacturing method according to this disclosure is a press-formed product manufacturing method for manufacturing a press-formed product by press-forming a metal sheet, comprising the steps of: forming a plurality of recesses on the surface of the metal sheet; forming a press-formed product by press-forming the metal sheet; and measuring the amount of positional change of the recesses between the metal sheet and the press-formed product.

[0007] The method further includes the step of applying dot-shaped markings to the bottom surfaces of the multiple recesses, and the measuring step may measure the amount of change in the position of the markings.

[0008] The measurement step may involve measuring the amount of position change using optical measuring means.

[0009] The step of forming the recess may be performed by cutting. [Effects of the Invention]

[0010] This disclosure provides a method for manufacturing press-formed products that can suppress the peeling of markings used for moldability evaluation. [Brief explanation of the drawing]

[0011] [Figure 1] This is a cross-sectional view of a metal plate illustrating a method for marking a metal plate according to Embodiment 1. [Figure 2] This is a cross-sectional view showing an example of a metal sheet being pressed according to Embodiment 1. [Figure 3] This is a cross-sectional view showing another example of a metal sheet being press-formed according to Embodiment 1. [Figure 4] This is a flowchart of the press-formed product manufacturing method according to Embodiment 1. [Figure 5] This is a cross-sectional view showing an example of a metal sheet being press-formed according to Embodiment 2. [Figure 6] This is a flowchart of the press-formed product manufacturing method according to Embodiment 2. [Modes for carrying out the invention]

[0012] The following describes specific embodiments of this disclosure in detail with reference to the drawings. However, this disclosure is not limited to the following embodiments. Also, for clarity, the following descriptions and drawings have been simplified as appropriate.

[0013] (Embodiment 1) <Method for marking on metal plates> First, the method of marking a metal plate according to Embodiment 1 will be described with reference to Figures 1 to 3. Figure 1 is a cross-sectional view of a metal plate for illustrating the method of marking a metal plate according to Embodiment 1. Figure 2 is a cross-sectional view showing an example of a metal plate during press working according to Embodiment 1. Figure 3 is a cross-sectional view showing another example of a metal plate during press working according to Embodiment 1.

[0014] First, the surface of the metal plate 1 in the state shown in Figure 1(a) is cut at predetermined intervals. As a result, as shown in Figure 1(b), a plurality of recesses 11 are formed on the surface of the metal plate 1 at predetermined intervals. The cutting process can be performed by, for example, laser cutting or milling, and either method may be used.

[0015] Next, dot printing is performed on the bottom surface 12 of the recess 11 of the metal plate 1 in the state shown in Figure 1(b). As a result, dot-shaped markings 13 are applied to the bottom surface 12 of the recess 11 of the metal plate 1, as shown in Figure 1(c). Examples of methods for dot printing include electrolytic etching, photoetching, ink transfer, and laser processing, and any of these methods may be used.

[0016] As shown in FIG. 1(c), even when the metal plate 1 with the marking 13 applied to the bottom surface 12 of the recess 11 is press-worked by the upper die T1 and the lower die T2, which are dies for press-working, as shown in FIGS. 2 and 3, a gap is generated between the marking 13 and the processing surface of the upper die T1 or the lower die T2. Therefore, the marking 13 does not contact the processing surface of the upper die T1 or the lower die T2. Accordingly, during the press-working, the marking 13 does not slide, and peeling of the marking 13 is suppressed.

[0017] In addition, in the first embodiment, although the recess 11 and the marking 13 are formed only on one surface of the metal plate 1, the recess 11 and the marking 13 may be formed on both surfaces of the metal plate 1.

[0018] <Manufacturing method> Subsequently, the press-worked product manufacturing method according to the first embodiment will be described. FIG. 4 is a flowchart of the press-worked product manufacturing method according to the first embodiment.

[0019] First, a plurality of recesses 11 are formed on the surface of the metal plate 1 (step S101). Next, dot-shaped markings 13 are applied to the bottom surfaces 12 of the plurality of recesses 11 (step S102).

[0020] Next, the metal plate 1 with the marking 13 is press-worked to form a press-worked product (step S103). Note that before performing this step S103, the position of the marking 13 on the metal plate 1 before the press-working may be measured in advance by an existing optical measuring device.

[0021] Next, the amount of change in the position of the marking 13 between the metal plate 1 before the press-working and the metal plate 1 after the press-working (i.e., the press-worked product) is measured (step S104). Based on the measured amount of change in the position of the marking 13, formability evaluation such as measurement of the amount of deformation of the press-worked product and detection of cracks can be performed.

[0022] As described above, in the press-formed product manufacturing method according to this embodiment 1, a gap is created between the processing surface of the press-formed die and the marking 13 by applying a dot-shaped marking 13 to the bottom surface 12 of the recess 11 of the metal plate 1, thereby suppressing the peeling of the marking 13.

[0023] (Embodiment 2) <Method for marking on metal plates> Next, with reference to Figures 1 and 5, a method for marking a metal plate according to Embodiment 2 will be described. Figure 5 is a cross-sectional view showing an example of a metal plate during press working according to Embodiment 2.

[0024] First, similar to Embodiment 1, cutting is performed at predetermined intervals on the surface of the metal plate 1 in the state shown in Figure 1(a). As a result, a plurality of recesses 11 are formed at predetermined intervals on the surface of the metal plate 1, as shown in Figure 1(b). In this second embodiment, dot printing is not performed, and the recessed area 11 is used as a marking. That is, in this second embodiment, the metal plate 1 in the state shown in Figure 1(b) is press-formed to create a press-formed product.

[0025] As shown in Figure 1(b), a metal plate 1 having a recess 11, when pressed using an upper die T1 and a lower die T2, which are press-working dies, a gap is created between the bottom surface 12 of the recess 11 and the processed surface of the upper die T1 or the lower die T2, as shown in Figure 5. Therefore, the bottom surface 12 does not come into contact with the processed surface of the upper die T1 or the lower die T2. Consequently, during press-working, the bottom surface 12 does not slide, maintaining its surface quality and making it suitable for use as a marking.

[0026] In this embodiment 2, the recess 11 is formed on only one side of the metal plate 1, but the recess 11 may be formed on both sides of the metal plate 1.

[0027] <Manufacturing method> Next, we will describe the press-formed product manufacturing method according to Embodiment 2. Figure 6 is a flowchart of the press-formed product manufacturing method according to Embodiment 2.

[0028] First, a plurality of recesses 11 are formed on the surface of the metal plate 1 (step S201).

[0029] Next, the metal plate 1 with the recess 11 formed on it is press-formed to create a press-formed product (step S202). Before performing step S202, the position of the recess 11 on the metal plate 1 before press-forming may be measured in advance using an existing optical measuring instrument.

[0030] Next, the amount of positional change of the recesses 11 between the metal sheet 1 before press working and the metal sheet 1 after press working (i.e., the press-worked product) is measured (step S203). Based on the measured amount of positional change of the recesses 11, formability evaluations such as measuring the amount of deformation of the press-worked product and detecting cracks can be performed.

[0031] As described above, the press-formed product manufacturing method according to this second embodiment utilizes the recess 11 of the metal sheet 1 as a marking. Even when press-formed by a die, a gap is created between the bottom surface 12 of the recess 11 and the processing surface of the die. Therefore, the bottom surface 12 does not come into contact with the processing surface of the die. Consequently, during press-formation, the bottom surface 12 does not slide, maintaining its surface quality and can be used as a marking.

[0032] It should be noted that the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. This application claims priority based on Japanese Patent Application No. 2024-179919, filed on 15 October 2024, and incorporates all of its disclosures herein. [Explanation of symbols]

[0033] 1 metal plate 11 recess 12. Base 13 Markings T1 upper mold T2 lower mold

Claims

1. A method for manufacturing press-formed products by press-forming a metal sheet, The steps include forming a plurality of recesses on the surface of the metal plate, The steps include: pressing the aforementioned metal plate to form a pressed product; The method includes the step of measuring the amount of change in the position of the recess between the metal plate and the pressed product. A method for manufacturing press-formed products.

2. The method further includes the step of applying dot-shaped markings to the bottom surfaces of the multiple recesses, The measurement step involves measuring the amount of change in the position of the marking. The method for manufacturing a press-formed product according to claim 1.

3. The measurement step involves measuring the amount of position change using optical measuring means. A method for manufacturing a press-formed product according to claim 1 or 2.

4. The step of forming the recess is to form the recess by cutting. The method for manufacturing a press-formed product according to claim 3.

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