Title:
消磁方法
Document Type and Number:
Japanese Patent JP7217898
Kind Code:
B2
Abstract:
To process a workpiece while an electromagnetic chuck using an electromagnet is magnetized to adsorb the workpiece and cause demagnetizing current to flow through the coil of the electromagnet when the workpiece is detached, thereby performing demagnetization of the workpiece in a short time.SOLUTION: In a method of performing excitation by applying an alternating magnetic field using a coil of an electromagnetic chuck, a commercial power supply is stored in a capacitor, and a DC voltage which is 1.414 times as large as a commercial power supply voltage is alternately switched over time and applied to the coil as a pulse voltage, and a pulse voltage which is successively attenuated by setting the pulse width of a first wave of demagnetization and an attenuation rate of an alternating pulse is applied to supply an alternating current whose current peak value successively decreases linearly. When the pulse voltage width to be applied is 0.01 second or less, the minimum pulse width is switched to 1/10 or less, and a voltage pulse having a pulse width of 0.01 second to 0.0005 second is applied to the coil, thereby causing a minute alternating attenuated current to flow through the coil of the electromagnetic chuck.SELECTED DRAWING: Figure 3
Inventors:
Yoshiharu Watanabe
Application Number:
JP2021066934A
Publication Date:
February 06, 2023
Filing Date:
April 12, 2021
Export Citation:
Assignee:
Hishi Ko Co., Ltd.
International Classes:
H01F13/00; H01F7/20
Domestic Patent References:
| JP2000357611A | ||||
| JP5198436A | ||||
| JP2006288082A | ||||
| JP62097308A | ||||
| JP2006261226A | ||||
| JP2003303716A | ||||
| JP2016532862A | ||||
| JP2116445A | ||||
| JP2002353045A |
Attorney, Agent or Firm:
Nakagawa International Patent Office
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