| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic brake device including an electric motor control device to make PWM control of an electric motor to drive a hydraulic pump, wherein noise emission is prevented and the lifetime is prolonged. SOLUTION: In case the demand running condition of a vehicle is the normal, the frequency of PWM control is made 20 kHz which is greater than the max. audible frequency, and noise emission is prevented. In the case of the demand running condition is as requiring quick braking, a demand output of an electric motor 18 is large, which enlarges the heat emitting amount of a switching element 40. However, the driver is in tension in the quick brake requiring condition, and noise emission gives no problem, and it is considered as the noise admissible condition. The frequency is made 500 Hz which is below the max. audible frequency, and heat emission of the switching element 40 can be suppressed and the lifetime be prolonged.
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