| 摘要 |
PURPOSE:To prevent a windshield pane from vibrating, by applying a vibration exciting force having the same phase as that of vibration transmitted from an engine or the like to the windshield pane and having a phase reverse to that of the transmitted vibration, to cancel out both vibrations in a vector-like manner when vibration is transmitted from the engine or the like to the windshield pane. CONSTITUTION:Vibration from an engine E, acting upon an automobile windshield pane 10 has a largest intensity when it is produced by detonation during combustion cycle. Accordingly, a vibration detecting means 1 detects transmitted vibration with reference to ignition pulses of a distributor 6 for each engine cylinder. Further, vibration detected by the means 1 is reversed in its phase by a phase compensating circuit 2 and is then delivered to an amplifier circuit 3. Then, an electromagnetic vibration exciter 4 vibrates the automobile windshield pane 10 through a plunger 4b in association with the energization of an electromagnetic coil 4a in accordance with the amplified output of the amplifier circuit 3. Thereby it is possible to cancel out the forced vibration transmitted from the engine E with the vibration transmitted from the electromagnet vibration exciter 4 in a vector-like manner to eliminate vibration.
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