| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a negative pressure estimating device for estimating negative pressure in a booster without increasing its cost. <P>SOLUTION: The negative pressure estimating device 1 includes a pedal stroke amount detecting means 2a for detecting a pedal stroke amount ST of a brake pedal 20, a volume calculating means 2b for calculating a volume Vh in a transformation chamber 13 of the booster 3 in accordance with the pedal stroke amount ST, and a negative pressure calculating means 2c for calculating pressure Pt in a constant pressure chamber 14 of the booster 3 in accordance with the volume Vh and calculating negative pressure in the booster 3 in accordance with the pressure Pt and atmospheric pressure Pa. <P>COPYRIGHT: (C)2011,JPO&INPIT |
