JPS5667657A - Brake master cylinder - Google Patents

Abstract

PURPOSE: To control the increase of stepping force in high-pressure generation region as well as make pedal stroke small by increasing the discharge of fluid for the moving amount of piston in the early period of braking operation, while reducing it in later period.

CONSTITUTION: When a rod 55 is moved to the left, piston parts 7 and 11 moves to the left and the pressure of chambers 12 and 13 rise. By the pressure, a valve 36 is closed and the connection between the chambers 12 and 13 and a reservoir 23 is closed. When the piston 7 moves further, the fluid of the chamber 12 flows into the chamber 13 through a hole 42 and the lip 40 of a seal 41 because the pressure rise of the chamber 12 is greater than that of the chamber 13, and then the fluid is sent, together with the fluid of the chamber 13, to a liquid pressure actuator. Thus, a comparatively large amount of fluid for the moving amount of the piston 7 is sent. When the pressure of the chamber 12 reaches a given value, a valve 24 is opened by the pressure, the chamber 12 is connected through a port 19 to the reservoir 23, and then the fluid of the chamber 12 flows into the reservoir 23. Therefore, the moving force of the piston 7 is made small.

COPYRIGHT: (C)1981,JPO&Japio