US-20260124663-A1 - PRESS WORKING APPARATUS

US20260124663A1US 20260124663 A1US20260124663 A1US 20260124663A1US-20260124663-A1

Abstract

A press working apparatus of the present disclosure is a press working apparatus that performs press working on a workpiece, including a punch including a press surface and a side surface connected to the press surface, a die on which the workpiece is placed, the die including a hollow portion in which the punch is to be inserted, a position sensor that detects a position of the punch, a vibration sensor that detects a vibration of the die, and a controller that controls the punch, the die, the position sensor, and the vibration sensor, wherein the controller generates a vibration waveform indicating a relationship between the vibration detected by the vibration sensor and a time after the punch reaches a bottom dead center, and calculates a first wear amount of the side surface of the punch based on the vibration waveform.

Inventors

Hideaki Hamada

Assignees

PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20251107
Priority Date: 20230523

Claims (12)

1 . A press working apparatus that performs press working on a workpiece, the press working apparatus comprising: a punch including a press surface and a side surface connected to the press surface; a die on which the workpiece is placed, the die including a hollow portion in which the punch is to be inserted; a position sensor that detects a position of the punch; a vibration sensor that detects a vibration of the die; and a controller that controls the punch, the die, the position sensor, and the vibration sensor, wherein the controller: generates a vibration waveform indicating a relationship between the vibration detected by the vibration sensor and a time after the punch reaches a bottom dead center; and calculates a first wear amount of the side surface of the punch based on the vibration waveform.
2 . The press working apparatus according to claim 1 , wherein the vibration waveform indicates a change in vibration in a predetermined period from when the punch starts to rise from the bottom dead center as detected by the position sensor.
3 . The press working apparatus according to claim 1 , wherein the controller determines that polishing of the punch is necessary when the first wear amount has exceeded a first threshold value.
4 . The press working apparatus according to claim 1 , further comprising a load sensor that detects a load applied to the punch, wherein the controller: generates a load waveform indicating a relationship between the load detected by the load sensor and a time from a start of press working; and calculates a second wear amount of the side surface of the punch based on a part of the load waveform during a period from completion of working on the workpiece until the punch reaches the bottom dead center.
5 . The press working apparatus according to claim 4 , wherein whether polishing of the punch is necessary is determined based on one or two wear amounts selected from the first wear amount and the second wear amount, the one or two wear amounts including at least the second wear amount.
6 . The press working apparatus according to claim 5 , wherein the controller: calculates a third wear amount of the side surface of the punch based on a part of the load waveform in a predetermined period from when the punch starts to rise from the bottom dead center; and determines whether polishing of the punch is necessary based on one or two or more wear amounts selected from the first wear amount, the second wear amount, and the third wear amount, the one or two or more wear amounts including at least the third wear amount.
7 . The press working apparatus according to claim 6 , wherein the controller determines that polishing of the punch is necessary when at least one of the second wear amount and the third wear amount has exceeded a predetermined second threshold value.
8 . The press working apparatus according to claim 6 , wherein the controller determines that polishing of the punch is necessary when a largest value among the first wear amount, the second wear amount, and the third wear amount has exceeded a predetermined threshold value.
9 . The press working apparatus according to claim 1 , wherein the vibration sensor includes a plurality of vibration sensors.
10 . The press working apparatus according to claim 9 , wherein the plurality of vibration sensors is disposed at equal intervals around the hollow portion of the die.
11 . The press working apparatus according to claim 9 , wherein the controller calculates a wear position of the punch based on a plurality of load waveforms each indicating a relationship between the vibration detected by corresponding one of the plurality of vibration sensors and time.
12 . The press working apparatus according to claim 4 , wherein the load sensor includes a plurality of load sensors.

Description

TECHNICAL FIELD The present disclosure relates to a press working apparatus. BACKGROUND ART In press working for punching a plate-shaped workpiece, there has been known a device for measuring working resistance generated when the workpiece is punched. In a punching characteristic measurement apparatus described in PTL 1, a temporal change in deformation of a frame at the time of punching is converted into an electric signal to measure a punching force. CITATION LIST Patent Literature PTL 1: Unexamined Japanese Patent Publication No. S62-40938 SUMMARY OF THE INVENTION A press working apparatus according to one aspect of the present disclosure is a press working apparatus that performs press working on a workpiece, the press working apparatus including: a punch including a press surface and a side surface connected to the press surface; a die on which the workpiece is placed, the die including a hollow portion in which the punch is to be inserted; a position sensor that detects a position of the punch; a vibration sensor that detects a vibration of the die; and a controller that controls the punch, the die, the position sensor, and the vibration sensor, wherein the controller: generates a vibration waveform indicating a relationship between the vibration detected by the vibration sensor and a time after the punch reaches a bottom dead center; and calculates a first wear amount of the side surface of the punch based on the vibration waveform. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating a press working apparatus according to a first exemplary embodiment of the present disclosure. FIG. 2 is a schematic diagram illustrating a bottom dead center state of a punch of the press working apparatus in FIG. 1. FIG. 3 is a top view illustrating a vibration sensor of the press working apparatus in FIG. 1. FIG. 4 is a flowchart for describing processing of calculating the wear amount of a side surface of the punch in the press working apparatus. FIG. 5A is a schematic diagram illustrating a step of punching a workpiece with a press working apparatus. FIG. 5B is a schematic diagram illustrating a step of punching the workpiece with the press working apparatus. FIG. 5C is a schematic diagram illustrating a step of punching the workpiece with the press working apparatus. FIG. 5D is a schematic diagram illustrating a step of punching the workpiece with the press working apparatus. FIG. 5E is a schematic diagram illustrating a step of punching the workpiece with the press working apparatus. FIG. 5F is a schematic diagram illustrating a step of punching the workpiece with the press working apparatus. FIG. 5G is a schematic diagram illustrating a step of punching the workpiece with the press working apparatus. FIG. 6 is a graph illustrating a relationship between a load (left vertical axis) detected by four vibration sensors, a position (right vertical axis) from a bottom dead center of punch 1, and time in punching. FIG. 7A is a graph illustrating a vibration waveform generated when wear of the punch of FIG. 6 has not progressed. FIG. 7B is a graph illustrating a vibration waveform generated when wear of the punch of FIG. 6 has progressed. FIG. 8 is a graph illustrating an example of a relationship between maximum value Asb of vibration of a die and a first wear amount of a side surface of the punch in period Tsb0. FIG. 9 is a schematic diagram illustrating a press working apparatus according to a second exemplary embodiment. FIG. 10 is a schematic diagram illustrating a state where a punch of the press working apparatus in FIG. 9 is at a bottom dead center. FIG. 11 is a top view illustrating a load sensor of the press working apparatus in FIG. 9. FIG. 12 is a flowchart for describing processing of calculating the wear amount of a side surface of the punch in the press working apparatus in FIG. 9. FIG. 13 is a graph in which load waveforms generated based on loads detected by four load sensors and vibration waveforms generated based on vibrations detected by the four vibration sensors illustrated in FIG. 6 are arranged. FIG. 14 is a graph in which a load waveform and a vibration waveform generated when the wear of the punch has not progressed are superimposed on a load waveform and a vibration waveform generated when the wear of the punch has progressed in FIG. 13. FIG. 15 is a graph illustrating an example of a relationship between maximum value Ps of the load applied to the punch and a second wear amount of the side surface of the punch in period Ts0. FIG. 16 is a graph illustrating an example of a relationship between maximum value Psb of the load of the punch and a third wear amount of the side surface of the punch in period Tsb0. DESCRIPTION OF EMBODIMENT Background to Present Disclosure Press working of performing punching on a plate-shaped workpiece is generally a technique capable of obtaining a predetermined shape by pressing a workpiece loaded on a die with a stripper, pushing a part of