| 摘要 |
PURPOSE:To prevent seizure due to heating between a disc and a friction plate by disposing a temperature detecting element close to a disc of an electromagnetic coil portion in an electromagnetic clutch device, and demagnetizing the electromagnetic coil portion when the element detects an abnormal rise in temperature. CONSTITUTION:When an ignition switch 20 and a cooler switch are closed in operating an air conditioner, a disc 9 is adsorbed to a friction plate 11 by applying a current to a coil 5, so that the rotation of a pulley 2 is transmitted to a compressor body 1. When in this condition, the disc is not rotated by a support plate 8 because of an abnormality such as seizure caused by oil return failure due to leakage of coolant of the compressor body 1, slipping is caused between the disc 9 and the friction plate 11, and the temperature at that portion rises. When the temperature becomes more than a fixed value, the internal resistance of the temperature detecting element 15 is lowered to excite a relay 17, and a normally closed contact point 18 is opened to shut off the current to the coil 5, so that the clutch is disengaged. |
