Patent ID: 8661811
Filing Date: 2014-03-04
Classification: B60T

Abstract:
1. A vehicle brake device comprising: a fluid pressure booster including a control piston having a front end wall formed at its front end and formed in a bottomed cylindrical shape, the fluid pressure booster being configured to adjust and apply a fluid pressure of a fluid pressure generating source to a boosting fluid pressure chamber in accordance with the operation of the control piston in the axial direction so that a reaction force based on a fluid pressure of the boosting fluid pressure chamber is equal to a brake operation input from a brake operation member; and a stroke simulator including: a master cylinder is operated in accordance with the fluid pressure of the boosting fluid pressure chamber; the elastic body is formed such that the circulation of the operation fluid is permitted from the front end to the rear end of the elastic body until a filling rate of the elastic body reaches a predetermined value in a filling area where deformation of the elastic body is stopped by restraint of the control piston in the state where a forward stroke of the control piston is less than at least the predetermined stroke, but the circulation of the operation fluid is stopped when the filling rate reaches the predetermined value or more; and the elastic body is formed such that a circulation path is formed in at least one of a gap between the inner peripheral portion of the control piston and the outer peripheral portion of the elastic body, a gap between the front end wall of the control piston or the slide member and the front end of the elastic body, a gap between the simulator piston and the rear end of the elastic body, and a gap between the outer peripheral portion of the guide shaft and the inner peripheral portion of the elastic body, where the circulation path is formed to be closed when the elastic body comes into close contact with at least one of the inner peripheral portion of the control piston, the outer peripheral portion of the guide shaft, the front end wall of the control piston or the slide member, and the simulator piston, and is used to permit the circulation of the operation fluid from the front end to the rear end of the elastic body.