Manufacturing method for molded products

Abstract

To provide a manufacturing method of a formed product capable of detecting a defect in the formed product when an abnormality occurs in a mold.SOLUTION: When a formed product (31, 31A) is manufactured by performing press working on a conductive member (ribbon material 3) by using an upper mold (punch 1) and a lower mold (die 2), a closed circuit (missing detection structure 10) including the upper mold and the lower mold contacting with each other via the formed product is formed. A resistance value of the closed circuit is measured and an abnormality in press working is detected on the basis of the measured resistance value.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a molded product.

Background Art

[0002] The punching device of Patent Document 1 is a punching device that punches a workpiece into a predetermined shape by a punch and a die, and includes a detection device and a determination device. The detection device acquires horizontal component forces in two orthogonal axes in a plane orthogonal to an axis along the punching direction by the punch. The determination device determines the presence or absence of a defect in the punch or the die based on the horizontal component forces acquired by the detection device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the punching device detects an abnormality in the component force, it can determine whether the punch or the die is defective and estimate the possibility that the quality of the punched workpiece deteriorates. However, since the punching device cannot determine whether a defect actually occurs in the workpiece, a process in which an operator or the like visually checks the workpiece for defects is required.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for manufacturing a molded product capable of detecting a defect in the molded product when an abnormality occurs in the mold.

Means for Solving the Problems

[0006] In order to achieve the above object, the method for manufacturing a molded product according to the present invention is characterized by the following. 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. death , 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. [Effects of the Invention]

[0007] The method for manufacturing molded articles according to the present invention has the effect of detecting defects in molded articles when an abnormality occurs in the mold.

[0008] The present invention has been briefly described above. Furthermore, the details of the present invention will be further clarified by referring to the attached drawings and reading through the embodiments for carrying out the invention described below (hereinafter referred to as "embodiments"). [Brief explanation of the drawing]

[0009] [Figure 1] 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] Figure 2 is an enlarged view of section A in Figure 1. [Figure 3] Figure 3 shows a normal punch and a molded product of a predetermined shape punched out by this punch. [Figure 4] Figure 4 shows a damaged punch and a molded product punched out by this punch. [Modes for carrying out the invention]

[0010] Specific embodiments of the present invention will be described below with reference to the figures.

[0011] Figure 1 is a schematic diagram showing an example of a defect detection structure used in the method for manufacturing molded products according to the present invention, and Figure 2 is an enlarged view of part 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.

[0012] Power supply unit 4 supplies power to the closed circuit, and current measuring device 5 measures and displays the current value 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.

[0013] 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. In other words, 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.

[0014] The determination unit 9 pre-stores a threshold range determined based on the current measurement results when there is no abnormality in the press work, i.e., under normal conditions, and receives the measurement result from the current measuring device 5. The determination unit 9 compares the stored threshold range with the input measurement result, and if the measurement result is outside the threshold range under normal conditions, it determines that there is an abnormality in the press work and outputs the determination result. Operators can recognize whether there is an abnormality in the press work based on the determination result output by the determination unit 9. Operators can also determine whether there is an abnormality in the press work by looking at the value displayed on the current measuring device 5.

[0015] FIG. 3 is a view showing a normal punch 11 and a molded product 31 having a predetermined shape punched out of this punch 11, and FIG. 4 is a view showing a defective punch 11A and a molded product 31A punched out of this punch 11A. As shown in FIG. 4, the defective punch 11A has a defective portion 12 at a position facing the ribbon material 3. Therefore, the defective punch 11A does not punch out the ribbon material 3 into a predetermined shape, and a defective portion 32 also exists in the molded product 31A punched out of this punch 11A.

[0016] Since there is a defective portion 32 in the molded product 31A punched out by the defective punch 11A, the volume is different from that of the molded product 31 having the predetermined shape shown in FIG. 3. For this reason, for example, when the resistance value of the normally punched molded product 31 is 10 mΩ or less, if the resistance value of the punched molded product 31A is 12 mΩ, it will be different from the normal threshold range. Therefore, the value displayed on the current measuring device 5 is different from the value displayed during normal operation. Therefore, an operator or the like can determine that the ribbon material 3 has not been punched into a predetermined shape by looking at the value of the current measuring device 5. For this reason, an operator or the like can detect an abnormality such as a defect in the punch 11A or the die 2 without visually checking the molded product 31A.

[0017] When the current measuring device 5 measures, for example, the temporal change of the current value from the time when the punch 1 and the die 2 contact the ribbon material 3 until the molded product 31 is completely separated from the remaining portion of the ribbon material 3 and the punching is completed, the determination unit 9 may detect an abnormality based on the waveform of the measurement result. In this case, the determination unit 9 may store the normal waveform in advance, and may detect an abnormality, for example, when the similarity between the waveform of the measurement result and the waveform during the market time is less than a threshold value as a result of comparing the waveform of the measurement result with the waveform during the market time. Also, an operator or the like can detect an abnormality by looking at the waveform of the measurement result by the current measuring device 5 and based on the comparison with the normal waveform.

[0018] According to the defect detection structure 10, since the measured value displayed on the current measuring device 5 varies depending on the volume of the molded product 31 in which a part of the ribbon material 3 is punched out, abnormalities in the press working by the punch 1 and the die 2 during the production of the molded product 31 can be detected based on the value of the current measuring device 5. Therefore, an operator or the like can detect abnormalities such as defects in the punch 1 or the die 2 without visually checking the molded product 31. Examples of abnormalities in the press working may include defects, wear of the punch 1 or the die 2, adhesion of foreign matter to the punch 1 or the die 2, etc.

[0019] According to the defect detection structure 10, since abnormalities in the press working by the punch 1 and the die 2 are detected based on the value of the current measuring device 5, automation of the processing step becomes easy and cost reduction is possible.

[0020] Further, according to the defect detection structure 10, since it is possible to electrically detect that the molded product is different from the predetermined shape, generation of defective products can be immediately detected. Therefore, even when the punch 1 or the die 2 is likely to be damaged, for example, when fine processing is required for a thick plate, generation of defective products can be instantaneously detected, so that the number of manufactured defective products can be reduced.

[0021] Note that the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. can be made as appropriate. In addition, the material, shape, dimensions, numerical values, form, number, arrangement location, etc. of each component in the above-described embodiments are arbitrary as long as the present invention can be achieved, and are not limited.

[0022] In the above embodiment, when the measured value of the current measuring device 5 is different from the threshold range during normal operation, that is, outside the threshold range in the case where there is no abnormality in the press working, an abnormality in the press working is detected. However, not limited to the current value, an abnormality may be detected by measuring the resistance value or voltage value of the closed circuit.

[0023] Also, in the above embodiment, an example of punching is shown, but the defect detection structure 10 can also be applied to press working such as bending.

[0024] Here, the features of the embodiments of the manufacturing method for molded articles according to the present invention described above are briefly summarized and listed below in [1] to [3].

[0025] [1] A method for manufacturing molded products (31, 31A) in which a conductive member (ribbon material 3) is press-formed using an upper die (punch 1) and a lower die (die 2), A closed circuit (defect detection structure 10) 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, A method for manufacturing a molded product, which detects an abnormality in the press working process based on the measured resistance value.

[0026] According to the manufacturing method for molded products with the configuration described in [1] above, abnormalities in the press working process, i.e., defects or foreign matter adhesion in at least one of the upper die, lower die, or molded product, can be electrically detected without visually inspecting the molded product. If defects or foreign matter adhesion occur in the upper or lower die, abnormalities such as chipping will occur in the molded product. In this case, the volume of the molded product will differ from that of a normal product, and the resistance value of the molded product will differ from that of a normal product. In addition, the volume of at least one of the upper or lower die will also differ from that of a normal product. Therefore, the resistance value of the closed circuit can be measured, and abnormalities in the press working process can be detected based on the measured value. In this way, the condition of the molded product, i.e., whether or not the molded product is defective, can be electrically detected, eliminating the need for workers to visually inspect the molded product. Consequently, automation of the processing process becomes easier, and the manufacturing cost of molded products can be reduced.

[0027] [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. The method for manufacturing a molded product as described in [1] above.

[0028] [3] Based on the time change of the measured resistance value, the abnormality is detected. The method for manufacturing a molded product as described in [1] above. [Explanation of Symbols]

[0029] 1 punch 2 Dies 3 Ribbon material 4 Power supply 5 Current measuring device 6, 7, 8 Electrical Circuits 9 Judgment section 10. Missing data detection structure 11, 11A Punch 31, 31A molded product 12, 32 Missing locations

Claims

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.

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