The invention relates to an improved plunger assembly for a vehicle brake system. The plunger assembly is operable as a pressure source to control brake fluid pressure supplied to one or more wheel brakes. The plunger assembly comprises a housing defining a cylinder; a reversible motor supported by the housing and having a rotor; and a linear actuator such as a ball screw/nut mechanism driven by the motor. A plunger head is mounted in the cylinder and driven by the linear actuator in first and second opposite directions. Improvements include an elastomeric tubular torque coupler connected to a ball screw/nut anti-rotation member; and a clamped connection at an inner race of a motor bearing for securing the rotor to the ball screw/nut component.

The invention relates to an improved plunger assembly for a vehicle brake system. The plunger assembly is operable as a pressure source to control brake fluid pressure supplied to one or more wheel brakes. The plunger assembly comprises a housing defining a cylinder; a reversible motor supported by the housing and having a rotor; and a linear actuator such as a ball screw/nut mechanism driven by the motor. A plunger head is mounted in the cylinder and driven by the linear actuator in first and second opposite directions. Improvements include a linear actuator rotationally supported on the housing by a bearing to actuate the plunger head connection to a ball screw.

The invention relates to an improved plunger assembly for a vehicle brake system. The plunger assembly is operable as a pressure source to control brake fluid pressure supplied to one or more wheel brakes. The plunger assembly comprises a housing defining a cylinder; a reversible motor supported by the housing and having a rotor; and a linear actuator such as a ball screw/nut mechanism driven by the motor. A plunger head is mounted in the cylinder and driven by the linear actuator in first and second opposite directions. Improvements include, the cylinder projecting from one side of a housing with an end cap covering the projecting end of the cylinder and is secured to the housing block in a generally coaxial relationship with the cylinder. The cylinder and the end cap cooperate to define a fluid passageway between the end of the cylinder and at least one fluid passageway provided in the housing block. The plunger head may include a stop cushion assembly. The stop cushion assembly provides for a cushioned stop if the end of the piston head engages the fixed structure of the plunger assembly in the event of power loss.

A vehicle brake system includes a dual acting plunger assembly. The dual acting plunger assembly comprises a housing, an anti-rotation tube secured to a ball screw assembly, and a torque coupler. The torque coupler is attached between the housing and anti-rotation tube, wherein the torque coupler allows rotation between the housing and the anti-rotation tube.

A brake control device includes an electric pump, a pressure adjustment valve that adjusts a hydraulic pressure of a brake fluid discharged by the electric pump to an adjustment hydraulic pressure and supplies the brake fluid in a rear wheel cylinder, and a master unit provided with a servo chamber into which brake fluid at the adjustment hydraulic pressure is supplied and in which the adjustment hydraulic pressure is converted into a forward force of a master piston, and a master chamber fluidically separated from the servo chamber by the master piston and connected to the front wheel cylinder and in which a rearward force converted from the hydraulic pressure in the front wheel cylinder and is applied to the master piston. Also included is an input unit provided with an input chamber and a simulator, and a controller configured to control the electric pump and the pressure adjustment valve.

This hydraulic braking device is provided with: a tubular cylinder; an assisting piston, which is housed in the cylinder so as to be able to move reciprocally, faces a reservoir formed inside the cylinder, and assists a master piston, in a master cylinder, that generates hydraulic pressure for generating a braking force by reciprocally moving from one side to the other as a result of a fluid flowing into the reservoir from a supply source; and a seal member, which is elastically deformable and which seals the reservoir. When the assisting piston is at a location on one side, the reservoir is compartmentalized into a first chamber that communicates with the supply source, and a second chamber that communicates with the first chamber through a restricting flow passage, and the seal member seals the second chamber.

A method for operating a vehicle brake system including a brake booster and an electronic traction control device, which is used as a fallback level in a malfunction of the brake booster. The position of an accelerator pedal is ascertained when a malfunction of the brake booster is detected, and under the precondition that the accelerator pedal is released, a predefined initial pressure is built up in a pressure chamber of a master brake cylinder of the vehicle brake system with the aid of the traction control device so that a deceleration of the vehicle is induced. A control unit which is designed to carry out the method, and a vehicle having a vehicle brake system and a control unit, are also described.

According to the embodiment of the present disclosure, it provides an inspection valve installed at a flow path connecting a reservoir to a chamber of a master cylinder, comprising: a housing at which a bore is formed and having one side at which an inlet hole is formed; a plunger provided to be movable along the bore of the housing; a seat member configured to close one side of the bore and through which an outlet hole passes; and an elastic member having one side supported by the plunger and the other side supported by the seat member, wherein the plunger is provided to block the outlet hole when a hydraulic pressure flowing in through the inlet hole is greater than an elastic force of the elastic member. Also, according to the embodiment of the present disclosure, it provides an inspection valve installed at a bypass flow path connecting a front side of a check valve to a rear side thereof at a reservoir flow path connecting a reservoir to a master cylinder, comprising: a housing at which a bore is formed and having one side at which an inlet hole communicating with the master cylinder is formed; a plunger provided to be movable along the bore of the housing; a seat member configured to close one side of the bore and through which an outlet hole communicating with the reservoir passes; and an elastic member having one side supported by the plunger and the other side supported by the seat member, wherein the check valve is provided at the reservoir flow path and enables fluid to flow in a direction from the reservoir to the master cylinder, and the plunger is provided to block the outlet hole when a hydraulic pressure flowing in through the inlet hole is greater than an elastic force of the elastic member.

A deflection control apparatus is provided with: a controller programmed to: a determine whether or not a vehicle is about depart from a driving lane, perform a deflection control of supplying a brake fluid pressure to at least one of brake mechanisms provided for corresponding wheels so that a yaw moment in a direction of avoiding departure of the vehicle is applied to the vehicle, if it is determined that the vehicle is about to depart, arithmetically operate a departure angle of the vehicle, and arithmetically operate a boost trajectory for boosting the brake fluid pressure to a target brake fluid pressure on condition that the departure angle is greater than a predetermined angle. The controller is programed to perform the deflection control after boosting in advance the brake fluid pressure associated with the at least one of the plurality of brake mechanism, on the basis of the boost trajectory.

A method is described for operating a hydraulic braking device of a vehicle, in particular a motor vehicle, including at least one brake booster, which sets a brake boost as a function of a driver's braking command. It is provided that the driver's braking command is ascertained via a vacuum sensor assigned to a pneumatic brake booster and a hydraulic brake boost is set.