Reaction force mechanism for brake power servo booster
AssigneeJidosha Kiki Co., Ltd.
InventorMichio Kobayashi
Life of this patent
Estimating the term…
Abstract
A reaction force mechanism for a brake power booster includes an elastic member (53) which forms a hydraulic pressure reaction force chamber (50) and is spaced from an end surface (17d) of an input shaft (17) by a predetermined distance (.delta.) so that braking hydraulic pressure is not immediately detected by a driver. In addition, a passage (57) normally provides communication between the hydraulic pressure reaction force chamber and a primary side pressure chamber (45) of the master cylinder, and, alternatively, provides communication between the hydraulic pressure reaction force chamber and a secondary side pressure chamber (46) of the master cylinder when no hydraulic pressure is established in the primary side pressure chamber of the master cylinder.
Claims18
A reaction force mechanism for a brake power booster, comprising:
- a power piston (4) slidably disposed in a shell (1);
- a master cylinder (2) connected to said shell on a brake pedal side;
- an output shaft (32) for linking said power piston with a second piston (31) of said master cylinder;
- an elastic member (53) situated between said output shaft (32) and an input shaft (17), and forming a boundary of a first hydraulic pressure reaction force chamber (50) and capable of being elastically deformed upon reception of pressure in said first hydraulic pressure chamber;
- a passage (57) for providing communication between said first hydraulic pressure chamber and a second pressure chamber (45) of said master cylinder;
- said input shaft (17) having an end surface (17d) disposed in opposition to said elastic member with a predetermined distance (.delta.) therebetween, said elastic member being made to abut against said end surface when it is elastically deformed so that the pressure in said first hydraulic pressure chamber is transmitted to said input shaft;
- and
- a valve mechanism (15) linked to said input shaft so as to be actuated to generate a fluid pressure difference between a front side and a rear side of said power piston.
A reaction force mechanism for a brake power booster, comprising:
- a power piston (4) slidably disposed in a shell (1);
- a two-system master cylinder (2) connected to said shell on a brake pedal side;
- an input shaft (17) passing through said master cylinder;
- a valve mechanism (15) linked to said input shaft so as to be actuated to generate a fluid pressure difference between a front side and a rear side of said power piston;
- an output shaft (32) for linking said power piston with a primary side piston (31) of said master cylinder on its primary side;
- a passage (57) which normally opens into a pressure chamber (45) of said master cylinder on its primary side;
- means for opening said passage to another pressure chamber (46) of said master cylinder on its secondary side in an abnormal case where no hydraulic pressure is established in said primary side pressure chamber and hydraulic pressure is established in said another pressure chamber (46) upon generation of said fluid pressure difference between said front and rear sides of said power piston.
Dependencies are inferred from the claim text.