JP-7856972-B2 - Manufacturing method for molded products

Inventors

• 高橋 一栄
• 久保 考広
• 山梨 潔昭
• 宮田 猛

Assignees

• 矢崎総業株式会社
• 山梨金属工業株式会社

Dates

Publication Date

20260512

Application Date

20220622

Claims (3)

1. In a method for manufacturing molded products, in which a conductive member is press-formed using an upper and lower die, A closed circuit is formed including the upper mold and the lower mold that are in contact with each other via the molded product. The resistance value of the closed circuit is measured, Based on the measured resistance value, an abnormality in the press working process is detected . In the closed circuit, the upper die and the lower die each contact only both sides of the molded product that are opposite to each other along the pressing direction of the press work. A method for manufacturing molded products.
2. If the measured resistance value is outside the threshold range based on the resistance value when there is no abnormality in the press work, the abnormality is detected. A method for manufacturing a molded article as described in claim 1.
3. Based on the time change of the measured resistance value, the abnormality is detected. A method for manufacturing a molded article as described in claim 1.

Description

This invention relates to a method for manufacturing molded articles. The punching apparatus described in Patent Document 1 is a punching apparatus that punches a workpiece into a predetermined shape using a punch and a die, and comprises a detection device and a determination device. The detection device acquires the horizontal force component on two orthogonal axes in a plane perpendicular to the axis along the punching direction by the punch. The determination device determines whether or not there is a defect in the punch or die based on the horizontal force component acquired by the detection device. Japanese Patent Publication No. 2021-45771 Figure 1 is a schematic diagram showing an example of a defect detection structure used in the method for manufacturing molded articles according to the present invention.Figure 2 is an enlarged view of section A in Figure 1.Figure 3 shows a normal punch and a molded product of a predetermined shape punched out by this punch.Figure 4 shows a damaged punch and a molded product punched out by this punch. Specific embodiments of the present invention will be described below with reference to the figures. Figure 1 is a schematic diagram showing an example of a defect detection structure used in the manufacturing method of a molded product according to the present invention, and Figure 2 is an enlarged view of portion A in Figure 1. As shown in Figure 1, the defect detection structure 10 comprises a punch 1, a die 2, a long conductive ribbon material 3, a power supply device 4, a current measuring device 5, electrical circuits 6, 7, and 8, and a determination unit 9. The punch 1 and die 2 punch out a portion of the ribbon material 3 into a predetermined shape to manufacture a molded product 31. Power supply unit 4 supplies power to the closed circuit, and current measuring device 5 measures and displays the current flowing through the closed circuit. Electrical circuit 6 electrically connects power supply unit 4 and punch 1, electrical circuit 7 electrically connects die 2 and current measuring device 5, and electrical circuit 8 electrically connects current measuring device 5 and power supply unit 4. Specifically, as shown in Figure 2, the punch 1 and die 2 are in contact with each other via a molded product 31 in which a portion of the ribbon material 3 has been punched out, forming a closed circuit including the power supply 4, the current measuring device 5, and electrical circuits 6, 7, and 8. That is, the defect detection structure 10 has a closed circuit including the punch 1, die 2, and ribbon material 3. In this closed circuit, the value displayed on the current measuring device 5 fluctuates due to the resistance of the punch 1, die 2, and ribbon material 3. The current measuring device 5 can measure and display the temporal change in the current value flowing through the closed circuit. The determination unit 9 pre-stores a threshold range determined based on the current measurement results under normal conditions (i.e., when there are no abnormalities in the press working process), and receives the measurement results from the current measuring device 5. The determination unit 9 compares the stored threshold range with the input measurement results. If the measurement results fall outside the normal threshold range, it determines that there is an abnormality in the press working process and outputs the determination result. Operators can recognize the presence or absence of an abnormality in the press working process based on the determination result output by the determination unit 9. Furthermore, operators can also determine the presence or absence of an abnormality in the press working process by looking at the value displayed on the current measuring device 5. Figure 3 shows a normal punch 11 and a molded product 31 of a predetermined shape punched by this punch 11, while Figure 4 shows a damaged punch 11A and a molded product 31A punched by this punch 11A. As shown in Figure 4, the damaged punch 11A has a missing portion 12 at the position facing the ribbon material 3. Therefore, the damaged punch 11A cannot punch the ribbon material 3 into the predetermined shape, and the molded product 31A punched by this punch 11A also has a missing portion 32. The molded product 31A punched out by the defective punch 11A has a defect 32, resulting in a different volume from the molded product 31 of the predetermined shape shown in Figure 3. Therefore, for example, if the resistance value of a normally punched molded product 31 is 10 mΩ or less, and the resistance value of the punched molded product 31A is 12 mΩ, this differs from the normal threshold range. Consequently, the value displayed on the current measuring device 5 will differ from the value displayed under normal conditions. Therefore, operators can determine that the ribbon material 3 has not been punched out into the predetermined shape by looking at the value on the current measuring device 5. Thus, ope