RUNNING CONTROL DEVICE FOR CAR

摘要

PURPOSE:To improve the responsiveness of a running control device for a car and simplify its structure by providing a piezoelectric piston in the pressure chamber of a wheel cylinder and also providing a moving wall that forms a chamber filled with the control oil with low viscosity even at low temperatures at the master cylinder side of a switching control valve. CONSTITUTION:A piezoelectric piston mechanism 26 is installed at the inner part of a wheel cylinder 17 and this piezoelectric piston mechanism 26 is formed by being covered with an expandable moving body 27 on which two or more thin plate type piezoelectric elements 261 and 262 are stacked. In addition, the wheel cylinder 17 is connected to a hydraulic control room 19 through an oil path 18 and a switching control valve 23 is interposed in the oil path 18. The hydraulic control room 19 is partitioned into first and second chambers 191 and 192 by a bellowsphragm 19. The first chamber 191 is connected to a master cylinder. The second chamber 192 is connected to the wheel cylinder. As a result, the chamber is filled with the control oil with low viscosity even at low temperatures and its response is improved even at low temperatures. In addition, the hydraulic pressure at the time when the wheels are locked is controlled by the piezoelectric piston mechanism 26 and the control valve 23.