| 摘要 |
PURPOSE:To contrive to enhance braking efficiency, by a method wherein a brake device comprising a plurality of brake oil pressure chambers connected to brakes for front and rear wheels is provided with a means for automatically relieving and restoring a braking force for front wheels by an antilock device to avoid locking. CONSTITUTION:At braking by simultaneously operating a lever 1 and a pedal 2, a return spring 262 is compressed at the time of starting the movement of a piston 152 to generate an oil pressure in the brake oil pressure chamber 172. After the oil pressure reaches a predetermined value, a return spring 261 is compressed, and a brake piston 151 is moved forwards to generates an oil pressure in the brake oil pressure chamber 171. The oil pressure in the chamber 172 is transmitted to the brake Br for the rear wheels after being reduced by the function of a proportional pressure reducing valve V, while the oil pressure in the chamber 171 is directly transmittd to the brake Bf for the front wheels. When the front wheels tend to be locked, a signal from a front-wheel speed sensor closes a normally open type control valve 49 and opens a normally closed type control valve 48, so that the pressure oil in a pressure accumulator Ac is supplied into a control oil pressure chamber 42, a control piston 40 retracts the piston 151 against the braking force, the pressure in the chamber 171 is reduced, and the braking force of the brake Bf is reduced, preventing the locking phenomenon. |
