| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately detect the operation speed of a brake operation member based on an increase gradient of master cylinder hydraulic pressure, regardless of the size of booster negative pressure, in a brake device with a vacuum booster. <P>SOLUTION: The increase gradient to time of the master cylinder hydraulic pressure becomes larger than a small case when the operation speed of the brake operation member is large, and becomes larger than a case near to atmospheric pressure when booster negative pressure is near to vacuum. When the operation speed of the brake operation member is the same, the increase gradient of the master cylinder hydraulic pressure becomes larger than the case near to the atmospheric pressure when the booster negative pressure is near to the vacuum. Based on the above situations, a threshold value is determined based on the booster negative pressure, and when comparing with the increase gradient of the master cylinder hydraulic pressure, the operation speed of the brake operation member can be accurately detected regardless of the size of the booster negative pressure. <P>COPYRIGHT: (C)2011,JPO&INPIT |
