An electric motor-driven brake apparatus has speed reduction mechanisms transmitting rotational force of an electric motor, a ball screw mechanism converting rotational force of the speed reduction mechanisms into a thrust, a piston propelled by the ball screw mechanism, and a caliper movably supporting the piston. The ball screw mechanism has a base nut non-rotatably supported relative to the caliper. The ball screw mechanism further has a push rod receiving rotational force from the speed reduction mechanisms. The push rod is movable relative to the base nut in the axial direction of the push rod. Consequently, it is possible to reduce the axial length of the cylinder portion of the caliper body, and hence possible to attain a size reduction. Accordingly, it is possible to improve the mountability of the electric motor-driven brake apparatus 1 onto vehicles.

A cable includes a plurality of electric wires, a tape member wound around the plurality of electric wires, and a jacket that covers an outer periphery of the tape member and includes an urethane-based resin. The tape member includes a nonwoven fabric including one of a polyester, a polypropylene, an aramid fiber, a nylon, an acrylic fiber and a glass fiber. An air permeability of the nonwoven fabric is not less than 30 cc/cm.sup.2/sec.

A motion conversion mechanism includes a shaft having an external thread and a cylinder having an internal thread that is screwed with the external thread. The motion conversion mechanism converts rotating motion of one of the shaft and the cylinder into linear motion of the other of the shaft and the cylinder. The cylinder is provided with two internal thread portions, each having the internal thread, such that a threadless portion is interposed between the two internal thread portions in an axial direction.

Provided is an electric brake including: a brake mechanism configured to transmit, based on a braking request, a thrust force generated through drive of an electric motor to a piston configured to move brake pads to be pressed against a disc rotor; and an ECU for rear electric brake configured to control the drive of the electric motor, and to move, in a non-braking state, the piston to a predetermined clearance position at which a clearance between each of the brake pads and the disc rotor is a predetermined amount. The ECU for rear electric brake is configured to drive the electric motor so that a period from generation of the braking request to a start of the pressing of the disc rotor by the brake pads is a predetermined period regardless of a position of the piston at a time when the braking request is generated.

A disk brake apparatus includes a piston thrust mechanism disposed in a caliper and including a thrust member configured to thrust a piston by an electric motor, and a piston holding mechanism configured to hold the thrust piston. When the piston holding mechanism release the holding of the thrust piston, the controller acquires a hydraulic pressure supplied to the caliper. If the hydraulic pressure is a predetermined value or higher, the controller determines whether a thrust force generated by the electric motor is released based on a time period from issue of an instruction to release the holding of the piston and a start of driving of the electric motor. If the hydraulic pressure is lower than the predetermined value, the controller determines whether the thrust force generated by the electric motor is released based on a change status of a current for driving the electric motor.

An electromechanical brake booster for a brake system of a vehicle includes: a booster housing; and a valve element, which is situated in a continuous receiving opening of the booster housing in a manner that allows an adjustment in relation to the booster housing, and which has a continuous central opening within which a valve piston is positioned or able to be positioned in a manner that allows an adjustment in relation to the valve element such that a driver-applied brake force is transmittable via an input rod to an output rod. In addition, a ball segment is situated or developed on the valve element, which contacts a conical seat of a disk of the electromechanical brake booster situated between the ball segment and the booster housing so as to allow an adjustment in relation to the booster housing.

A brake device includes a control device which performs feedback control using a braking force of a linear motion mechanism as a controlled variable. The control device includes a computing unit for computing an operating quantity (voltage applied to an electric motor) for canceling out fluctuations in braking force, and a frequency detector for detecting the frequency of the operating quantity. The control device further includes an operating quantity limiting unit which limits the operating quantity according to a predetermined parameter when the detected frequency is higher than a predetermined frequency threshold (i.e. when the detected frequency is in a high-frequency range in which the permissible value of the braking force fluctuations is high). Thus, it is possible to reduce the output of the electric motor within a range in which the braking force fluctuations does not exceed the permissible value, thereby reducing the power consumption.

A redundant control system is applied to a brake-by-wire (BBW) system. The redundant control system applied to the BBW system includes electromechanical brakes (EMBs) provided at wheels of a vehicle and configured to perform brake control of the vehicle, controllers connected to the EMBs, respectively, and a local gateway on a first communication line configured to receive information on the vehicle and a command of a driver and to transmit the information on the vehicle and the command of the driver to the controllers, where the controllers are configured to receive the information on the vehicle and the command of the driver through a second communication line.

The present disclosure relates to an electromechanical actuation unit for a motor vehicle brake comprising: at least one electromechanical actuation device for actuating at least one brake shoe of the motor vehicle brake. The electromechanical actuation device has at least drive element and at least one drive spindle, wherein the at least one drive element drives the at least one drive spindle. The electromechanical actuation device has at least one elastic element, the at least one elastic element being elastically deformable for a parking brake function.

Disclosed is an electronic parking brake system including an electronic parking brake provided to provide a clamping force necessary for parking a vehicle by a motor, a warning unit provided to warn a failure of the electronic parking brake, a current sensor provided to detect a current of the motor, and a controller electrically connected to the current sensor, wherein the controller determines whether a clamping force is generated depending on the motor current in a parking operation, counts a clamping force non-generation time when the clamping force is not generated, and warns a suspected failure of the electronic parking brake through the warning unit when the clamping force non-generation time elapses a preliminary failure detection time set shorter than a failure detection time of the electronic parking brake.