To increase the detection precision of the position of a workpiece for spot welding.
The position detection device includes: a physical quantity detection section 4 for detecting a motor torque T of the servo motor 24 when the servo motor 24 allows one of the pair of movable electrodes 21 to approach a surface of the workpiece so that the one of the pair of movable electrodes 21 abuts against the surface of the workpiece; position detection sections 13a, 24a for detecting positions of the pair of movable electrodes 21; storage sections 3, 4 for storing the motor torque T detected by the physical quantity detection section 4 and a value detected by the position detection sections 13a, 24a; and computation sections 3, 4 for calculating a contact start time at which the one of the pair of movable electrodes 21 comes into contact with the surface of the workpiece based on time-series data of the motor torque T stored in the storage sections 3, 4, and computing a position of the workpiece at the contact start time based on the value detected by the position detected sections 13a, 24a stored in the storage sections 3, 4.
AOKI TOSHIMICHI
HATADA MASANOBU
NISHIMURA AKINORI
| JPH06218554A | 1994-08-09 | |||
| JPH0764615A | 1995-03-10 | |||
| JPH0929453A | 1997-02-04 | |||
| JPH106025A | 1998-01-13 | |||
| JPH10128552A | 1998-05-19 | |||
| JPH10249539A | 1998-09-22 | |||
| JPH11104849A | 1999-04-20 | |||
| JP2001129670A | 2001-05-15 | |||
| JP2002035951A | 2002-02-05 | |||
| JP2002283059A | 2002-10-02 | |||
| JP2005021896A | 2005-01-27 | |||
| JP2008307595A | 2008-12-25 |
Jun Tsuruta
Tetsuro Shimada
Ryuichi Nishimura
Hirose Shigeki
Kazuo Maejima
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