Abstract: Provided is a piston push rod assembly which can prevent discomfort from being imparted during the operation of a brake pedal by a driver. A piston push rod assembly, wherein: a second piston is provided with a piston slide section which is housed in a cylinder and which slides relative to the cylinder, and a connection tube section which is connected to a push rod; the piston slide section is covered by metal plating; the connection tube section has a non-plated section; and the second piston and the push rod are connected by the caulking of the connection tube section when the push rod has been inserted inside the connection tube section.

Abstract: Provided is a stroke simulator capable of suppressing occurrence of inclination of a piston with respect to a sliding surface formed in a cylinder. The stroke simulator includes a simulator piston which is displaced by sliding on a sliding surface formed in a first cylinder, and a first return spring which is housed in the first cylinder and applies, to the simulator piston, a reaction force which is generated by an elastic deformation of the spring under a pressing force due to a displacement of the simulator piston, and generates the reaction force which is applied to the simulator piston as a brake reaction force for a brake operating element. The stroke simulator is characterized in that a cup seal for sealing a gap formed between the sliding surface and the simulator piston is mounted in the middle in the axial direction of the sliding surface.

Abstract: A cylinder device includes a regulation mechanism that regulates separation distance between a front piston and a rear piston. A spring seat member of the regulation mechanism includes a spring reception part that projects toward a retainer side to receive a rear end of a spring, a cup seal holding part that projects on an opposite side from the retainer to hold a cup seal arranged on the rear piston, and a projection part that projects on the opposite side from the retainer. The projection part becomes abuttable on the retainer by a stroke of the rear piston if the spring reception part and the cup seal holding part are installed reversely-oriented on the rear piston.

Abstract: A cylinder device includes a regulation mechanism that regulates separation distance between a front piston and a rear piston. A spring seat member of the regulation mechanism includes a spring reception part that projects toward a retainer side to receive a rear end of a spring, a cup seal holding part that projects on an opposite side from the retainer to hold a cup seal arranged on the rear piston, and a projection part that projects on the opposite side from the retainer. The projection part becomes abuttable on the retainer by a stroke of the rear piston if the spring reception part and the cup seal holding part are installed reversely-oriented on the rear piston.

Abstract: Provided is a piston push rod assembly which can prevent discomfort from being imparted during the operation of a brake pedal by a driver. A piston push rod assembly, wherein: a second piston is provided with a piston slide section which is housed in a cylinder and which slides relative to the cylinder, and a connection tube section which is connected to a push rod; the piston slide section is covered by metal plating; the connection tube section has a non-plated section; and the second piston and the push rod are connected by the caulking of the connection tube section when the push rod has been inserted inside the connection tube section.

Abstract: Provided is a stroke simulator capable of suppressing occurrence of inclination of a piston with respect to a sliding surface formed in a cylinder. The stroke simulator includes a simulator piston which is displaced by sliding on a sliding surface formed in a first cylinder, and a first return spring which is housed in the first cylinder and applies, to the simulator piston, a reaction force which is generated by an elastic deformation of the spring under a pressing force due to a displacement of the simulator piston, and generates the reaction force which is applied to the simulator piston as a brake reaction force for a brake operating element. The stroke simulator is characterized in that a cup seal for sealing a gap formed between the sliding surface and the simulator piston is mounted in the middle in the axial direction of the sliding surface.

Abstract: A pressure regulating valve unit 7 is configured to be electrically driven according to a detection value of a detection unit 74 adapted to detect an amount of brake application effort made by a brake operation member 5 so as to switch states of the vehicle brake apparatus between a state where a boosted hydraulic pressure chamber 9 is made to communicate with a hydraulic pressure generating source 6 while a communication between the boosted hydraulic pressure chamber 9 and a reservoir R is interrupted, a state where the communication between the boosted pressure chamber 9 and the hydraulic pressure generating source 6 is interrupted while the boosted pressure chamber 9 is made to communicate with the reservoir R, and a state where the boosted hydraulic pressure chamber 9 is disconnected from both the hydraulic pressure generating source 6 and the reservoir R.

Abstract: A normally opened solenoid valve includes: a coil; a fixed core; a movable core; a valve seat located at one of openings of a through hole formed in the fixed core; and a valve body inserted into the through hole. The valve body includes: a shaft part inserted into the through hole and pressed by the movable core; a valve part seated on or separated from the valve seat; and a connection part configured to connect the shaft part with the valve part. The connection part includes a conical portion increased in diameter toward the shaft part from the valve part. A plurality of reduced thickness portions, each having a concave shape as viewed in an axial direction, are formed in the conical portion. The reduced thickness portions are located at equal intervals in a circumferential direction of the conical portion.

Abstract: A pressure regulating valve unit is configured to regulate the output hydraulic pressure of a hydraulic pressure generating source through electrical control for application to a boosted hydraulic pressure chamber, and a release valve is interposed between the boosted hydraulic pressure chamber and a reservoir which is adapted to the hydraulic pressure in the boosted hydraulic pressure chamber to the reservoir side when the pressure regulating valve unit fails.

Abstract: A normally opened solenoid valve includes: a coil; a fixed core; a movable core; a valve seat located at one of openings of a through hole formed in the fixed core; and a valve body inserted into the through hole. The valve body includes: a shaft part inserted into the through hole and pressed by the movable core; a valve part seated on or separated from the valve seat; and a connection part configured to connect the shaft part with the valve part. The connection part includes a conical portion increased in diameter toward the shaft part from the valve part. A plurality of reduced thickness portions, each having a concave shape as viewed in an axial direction, are formed in the conical portion. The reduced thickness portions are located at equal intervals in a circumferential direction of the conical portion.

Abstract: A fluid pressure booster includes: a control piston in which brake operation input acts in an advancing direction, and reaction based on fluid pressure of a booster fluid pressure generation chamber that generates fluid pressure for actuating a master piston acts in a retracting direction; a pressure increasing valve provided between the booster fluid pressure generation chamber and a fluid pressure generation source so as to open at the time of advance of the control piston and close at the time of retraction of the control piston; and a pressure reducing valve provided between a release chamber and the booster fluid pressure generation chamber so as to close at the time of the advance of the control piston and open at the time of the retraction of the control piston.

Abstract: A pressure regulating valve unit 7 is configured to regulate the output hydraulic pressure of a hydraulic pressure generating source 6 through electrical control for application to a boosted hydraulic pressure chamber 9, and a release valve 103 is interposed between the boosted hydraulic pressure chamber 9 and a reservoir R which is adapted to the hydraulic pressure in the boosted hydraulic pressure chamber 9 to the reservoir R side when the pressure regulating valve unit 7 fails.

Abstract: A pressure regulating valve unit 7 is configured to be electrically driven according to a detection value of a detection unit 74 adapted to detect an amount of brake application effort made by a brake operation member 5 so as to switch states of the vehicle brake apparatus between a state where a boosted hydraulic pressure chamber 9 is made to communicate with a hydraulic pressure generating source 6 while a communication between the boosted hydraulic pressure chamber 9 and a reservoir R is interrupted, a state where the communication between the boosted pressure chamber 9 and the hydraulic pressure generating source 6 is interrupted while the boosted pressure chamber 9 is made to communicate with the reservoir R, and a state where the boosted hydraulic pressure chamber 9 is disconnected from both the hydraulic pressure generating source 6 and the reservoir R.

Abstract: A vehicle braking system having a hydraulic booster which applies output hydraulic pressure of a hydraulic power source to a boosted hydraulic pressure chamber after regulating the output hydraulic pressure as a control piston balances a reaction force generated by hydraulic pressure of the boosted hydraulic pressure chamber with brake operating input. The boosted hydraulic pressure chamber faces a rear face of a master piston of a master cylinder; and a brake stroke simulator installed between a brake operating member and the control piston. The hydraulic booster includes a backup piston slidably housed in a casing with its front face turned to the boosted hydraulic pressure chamber and which can directly push the master piston in response to operation of the brake operating member when the hydraulic pressure of the boosted hydraulic pressure chamber decreases. The control piston and the brake stroke simulator are contained in the backup piston.

Abstract: A vehicle braking device includes a stroke simulator provided between a control piston of a fluid pressure booster and a brake operation member, wherein the control piston has an inner peripheral surface partially including a tapered surface with a decreasing diameter toward the front. The stroke simulator includes an input member housed in the control piston slidably in an axial direction backward of the tapered surface and connected to the brake operation member, and an elastic body interposed between the input member and the control piston and housed in the control piston. The elastic body has a cylindrical shape so as to be elastically deformed according to an action of an axial compressive force along with an advancing operation of the input member, and prevented from being deformed sequentially from the front by restraint with the tapered surface according to an increase in the axial compressive force.

Abstract: There is provided a vehicle braking device in which a front outer periphery of a backup piston that can directly press a master piston from behind when output fluid pressure from a fluid pressure generation source is reduced is fluid-tightly and slidably fitted to a short cylindrical separator, a sleeve forming an annular channel between itself and an outer periphery of the backup piston is placed backward of the separator, and annular seal members for sealing front and rear sides of the annular passage are mounted between the separator and the backup piston, and between the sleeve and the backup piston. The seal member for sealing a front side of the annular passage is mounted to an inner periphery of the separator so as to come into repulsive contact with the outer periphery of the backup piston. The seal member for sealing a rear side of the annular passage is mounted to the outer periphery of the backup piston so as to come into repulsive contact with an inner periphery of the sleeve.

Abstract: There is provided a vehicle braking device in which a front outer periphery of a backup piston that can directly press a master piston from behind when output fluid pressure from a fluid pressure generation source is reduced is fluid-tightly and slidably fitted to a short cylindrical separator, a sleeve forming an annular channel between itself and an outer periphery of the backup piston is placed backward of the separator, and annular seal members for sealing front and rear sides of the annular passage are mounted between the separator and the backup piston, and between the sleeve and the backup piston. The seal member for sealing a front side of the annular passage is mounted to an inner periphery of the separator so as to come into repulsive contact with the outer periphery of the backup piston. The seal member for sealing a rear side of the annular passage is mounted to the outer periphery of the backup piston so as to come into repulsive contact with an inner periphery of the sleeve.

Abstract: A vehicle braking device includes a stroke simulator provided between a control piston of a fluid pressure booster and a brake operation member, wherein the control piston has an inner peripheral surface partially including a tapered surface with a decreasing diameter toward the front. The stroke simulator includes an input member housed in the control piston slidably in an axial direction backward of the tapered surface and connected to the brake operation member, and an elastic body interposed between the input member and the control piston and housed in the control piston. The elastic body has a cylindrical shape so as to be elastically deformed according to an action of an axial compressive force along with an advancing operation of the input member, and prevented from being deformed sequentially from the front by restraint with the tapered surface according to an increase in the axial compressive force.

Abstract: A fluid pressure booster includes: a control piston in which brake operation input acts in an advancing direction, and reaction based on fluid pressure of a booster fluid pressure generation chamber that generates fluid pressure for actuating a master piston acts in a retracting direction; a pressure increasing valve provided between the booster fluid pressure generation chamber and a fluid pressure generation source so as to open at the time of advance of the control piston and close at the time of retraction of the control piston; and a pressure reducing valve provided between a release chamber and the booster fluid pressure generation chamber so as to close at the time of the advance of the control piston and open at the time of the retraction of the control piston.

Abstract: In a vehicle braking system, a backup piston pushes a master piston directly from behind when hydraulic pressure of a boosted hydraulic pressure chamber decreases. The backup piston has a piston body which is slidably fitted in a casing, and a pusher which is slidably fitted in the casing with a seal diameter smaller than seal diameters of the master piston and the piston body and which extends to the front end of the piston body, to push the master piston from behind. An annular input chamber communicated with a hydraulic power source is formed between the backup piston and the casing. When the pusher pushes the master piston forward, amount of volume increased in the boosted hydraulic pressure chamber is set to be substantially equal to amount of volume decreased in the input chamber. Thus, it is possible to avoid increase in the hydraulic pressure of the boosted hydraulic pressure chamber during forward movement of the backup piston, using a simple configuration with a reduced number of parts.