PURPOSE: To prevent pulsation in reverse direction, pump noise, and vibration by providing a bypassed check valve in parallel with a restriction located between a master cylinder and a No.2 liquid inlet to always enable supply of hydraulic pressure of liquid to the No.2 inlet of a modulator.
CONSTITUTION: Though an output liquid from a pump 5 is fed back slightly to a master cylinder through a restriction 10 in a line C5 by generation of an anti-lock signal, noise due to pulsation, etc., is suppressed by the restriction 10. Also the liquid fed to a No.2 inlet 8 of a modulator 4 by a check valve 11 includes that from the pump 9 as well as the liquid from a master cylinder 1 through a bypass line C6. Accordingly, even if an expansion chamber 12 is empty, liquid is fed continuously from the master cylinder 1 to a No.2 inlet 8 through the check valve 11 to enable metal edge control at the No.2 inlet 8. Thus the No.1 inlet 7 can always be kept in a shut-off condition during the anti-lock operation.
MAEKAWA AKIO
SEGAWA TARO