CN-122008058-A - Abnormal state detection method and polishing device

Abstract

The application provides an abnormal state detection method and a polishing device, which can detect the generation of abnormal state related to a workpiece based on the load state of a polishing surface. In a polishing device (1) provided with a polishing tool (10) pressed against the surface of a glass plate (G) and a driving unit (20) for driving the polishing tool (10) to rotate, the abnormal state detection method monitors the load current value of the driving unit (20), and detects the occurrence of an abnormal state related to the glass plate (G) based on the fact that the time change of the load current value is different from the normal state.

Inventors

• LIANG CHANGHUAN
• ZHENG ZEQIU
• PEI CHANGHE

Assignees

• ＡＧＣ株式会社

Dates

Publication Date

20260512

Application Date

20251110

Priority Date

20241111

Claims (10)

1. 1. An abnormal state detection method, wherein, In a polishing apparatus comprising a polishing tool pressed against a surface of a plate-like workpiece and a driving section for driving the polishing tool to rotate relative to the plate-like workpiece, The load current value of the driving section is monitored, Detecting occurrence of an abnormal state related to the flat plate-like workpiece based on a case where a time change of the load current value is different from a normal state.
2. 2. The abnormal state detection method according to claim 1, wherein, Detecting occurrence of the abnormal state when the load current value exceeds an overload threshold value determined based on an average value of the normal state.
3. 3. The abnormal state detection method according to claim 1, wherein, The time variation of the load current value in the normal state includes a periodic waveform, In the case where the load current value deviates from a certain range determined based on the average value of the normal state and the amplitude of the periodic waveform, the generation of the abnormal state is detected.
4. 4. The abnormal state detection method according to claim 3, wherein, When the load current value is deviated from the predetermined range and returns to the predetermined range within a predetermined time based on the wavelength of the periodic waveform, the occurrence of the abnormal state is not detected, and when the load current value is not returned to the predetermined range within the predetermined time, the occurrence of the abnormal state is detected.
5. 5. The abnormal state detection method according to claim 2, wherein, The overload threshold includes a threshold for alarm and a threshold for stop that is greater than the threshold for alarm, When the load current value exceeds the alarm threshold value, an alarm is issued, When the load current value exceeds the stop threshold value, the driving unit is stopped.
6. 6. The abnormal state detection method according to claim 4, wherein, The predetermined time includes a predetermined time for alarm and a predetermined time for stop longer than the predetermined time for alarm, After the load current value deviates from the certain range, When the alarm does not return to the certain range within the prescribed time for alarm, And stopping the driving unit when the vehicle does not return to the predetermined range within the predetermined time for stopping.
7. 7. The abnormal state detection method according to claim 1, wherein, When the load current value exceeds a load threshold value which is determined based on the center value with an average value of the load current values in the normal state as the center value, occurrence of an abnormal state is detected.
8. 8. The abnormal state detection method according to claim 1, wherein, When the load current value deviates from a predetermined range defined based on the peak value with the maximum value of the absolute value of the load current value in the normal state as the peak value, the occurrence of an abnormal state is detected.
9. 9. The abnormal state detection method according to any one of claims 1 to 8, wherein, Detecting the occurrence of an abnormal state associated with the flat plate-like work made of a glass plate.
10. 10. A polishing device is provided with: a polishing tool pressed against the surface of the flat workpiece; A driving section that drives the polishing tool to rotate; A monitor part for monitoring the load current value of the drive part, and And a detection unit configured to detect occurrence of an abnormal state associated with the flat plate-like workpiece based on a temporal change in the load current value.

Description

Abnormal state detection method and polishing device Technical Field The present invention relates to an abnormal state detection method and a polishing apparatus. Background For example, in various kinds of processing of glass plates used for flat panel displays (FPD: FLAT PANEL DISPLAY) such as LCDs (Liquid CRYSTAL DISPLAY: liquid crystal displays) and OLEDs (Organic Light-Emitting diodes), damage such as breakage may occur in the glass plates. Therefore, as a polishing apparatus for polishing a glass plate, an apparatus having a function of detecting breakage of the glass plate in advance is known. Patent document 1 discloses an abnormality detection device provided with an AE sensor provided on a processing table for processing an upper object to be processed, the device detecting an elastic wave from the object to be processed through a liquid interposed between the AE sensor and the object to be processed, and an abnormality detection unit for determining the presence or absence of an abnormality in the object to be processed based on a detection signal from the AE sensor, the AE sensor being disposed directly below a position where the object to be processed is placed on the processing table. Non-patent document 1 discloses that by specifying the relationship between the change in power (current) of a machining machine and the machining load and studying the influence on the power (current) during unstable machining, the main shaft current during machining is measured to estimate the tangential resistance and the grinding burn and the clogging ratio. [ Prior Art literature ] [ Patent literature ] [ Patent document 1] Japanese patent laid-open No. 2020-185659 [ Non-patent literature ] Non-patent document 1 mountain health Medium, ministry Chi Hong, zeng Tian, in the future, "observation of processing load due to electric power variation of processing machine during grinding", carinu county Industrial technology center research report, no.20,2023 Disclosure of Invention [ Problem to be solved by the invention ] In the conventional polishing apparatus, since the load state of the polished surface of the workpiece to be polished is not sufficiently considered, it is difficult to appropriately detect an abnormal state that may occur at the time of polishing. The present invention has been made in view of the above circumstances, and an object thereof is to provide an abnormal state detection method and a polishing apparatus capable of detecting occurrence of an abnormal state related to a workpiece based on a load state of a polishing surface. [ Means for solving the problems ] One embodiment of the present invention is configured as follows. In a polishing apparatus including a polishing tool pressed against a surface of a flat workpiece and a driving unit for driving the polishing tool to rotate, a load current value of the driving unit is monitored, and occurrence of an abnormal state related to the flat workpiece is detected based on a time change of the load current value being different from a normal state. One embodiment of the present invention is configured as follows. A polishing device is provided with a polishing tool pressed against the surface of a flat workpiece, a driving unit that drives the polishing tool to rotate, a monitoring unit that monitors the load current value of the driving unit, and a detection unit that detects the occurrence of an abnormal state associated with the flat workpiece based on the temporal change of the load current value. [ Effect of the invention ] According to the present invention, the occurrence of an abnormal state related to the workpiece can be detected based on the load state of the polishing surface. Drawings Fig. 1 is a schematic view of a polishing apparatus according to a first embodiment of the present invention. Fig. 2 is a perspective view showing a state in which a polishing tool polishes a glass plate in the polishing apparatus of the first embodiment. Fig. 3 is a schematic diagram showing a processing concept of a method for detecting an abnormal state of a glass plate in the control device according to the first embodiment. Fig. 4 is a flowchart showing steps of the first detection method. Fig. 5 is a flowchart showing steps of the second detection method. Fig. 6 is a graph showing an example of the load current value in the normal state. Fig. 7 is a graph showing an example of behavior of a load current value when an abnormal state is generated in relation to a glass plate in the polishing apparatus according to the first embodiment, (a) shows an example in which a broken glass is generated after a crack is generated in the glass plate and the load current value is temporarily decreased, and then the load current value is increased, (B) shows an example in which a crack is generated in the glass plate but broken glass is not generated and the load current value is decreased, and (C) shows an example in which a crack and broken glass are gene