A drive assembly having a motor accommodating bore for an electric motor, the bore being directed perpendicularly into an end face of a block-like accommodating body, and having a motor housing for accommodating a bearing provided for a motor shaft of the electric motor the bearing being fixed in an end-side motor housing section which extends into the motor accommodating bore. The invention provides for the electric motor to be frictionally fixed and centered in the motor accommodating bore by a motor holder that is fastened to the end-side motor housing section and projects into the motor accommodating bore.

An electric motor (2) is controlled according to the stroke of an input rod (30) moved in response to an operation of a brake pedal. The rotation of the electric motor is transmitted through a belt transmission mechanism (45) to a ball-screw mechanism (38) to propel a primary piston (10), thereby generating a brake hydraulic pressure in a master cylinder (4). The belt transmission mechanism has pulleys (45A, 45B), one of which is secured to an output shaft of the electric motor. The output shaft and a nut member (39) of the ball-screw mechanism are held by bearings (42A, 42B and 42C) secured to a rear housing (3B) which is a single member. Thus, before an electric motor-driven booster (1) is assembled, the belt transmission mechanism can be subassembled to the rear housing. Therefore, a belt (46) can be adjusted for tension in the state of a subassembly.

A brake device having an electric parking brake function, capable of appropriately performing stepwise increase control for a clamping force. A control unit including a computing circuit (20), a memory (21), and each motor drive circuit (23) of a parking brake control device (19) includes a stepwise increase control unit configured to increase the clamping force generated by brake pads (33) to a disc rotor (4) in a stepwise manner. When start of contact between the disc rotor (4) and the brake pads (33) caused by feeding of power from the parking brake control device (19) to an electric motor (43B) is detected based on a motor current from a current sensor unit (24), the stepwise increase control unit performs control for repeatedly feeding and stopping power to the electric motor (43B) to increase the clamping force in a stepwise manner in accordance with a predefined processing procedure.

A brake device having an electric parking brake function, capable of appropriately performing stepwise increase control for a clamping force. A control unit including a computing circuit (20), a memory (21), and each motor drive circuit (23) of a parking brake control device (19) includes a stepwise increase control unit configured to increase the clamping force generated by brake pads (33) to a disc rotor (4) in a stepwise manner. When start of contact between the disc rotor (4) and the brake pads (33) caused by feeding of power from the parking brake control device (19) to an electric motor (43B) is detected based on a motor current from a current sensor unit (24), the stepwise increase control unit performs control for repeatedly feeding and stopping power to the electric motor (43B) to increase the clamping force in a stepwise manner in accordance with a predefined processing procedure.

A method of calibrating a solenoid actuated valve includes: providing a brake system including a fluid pressure source: providing a valve having a solenoid, and wherein the valve is in fluid communication with the fluid pressure source; operating the fluid pressure source to provide a constant flow of fluid to the valve; energizing the solenoid of the valve with a constant current such that fluid flows through the valve; measuring the pressure of the fluid flowing at the valve; adjusting the current sent to the solenoid until a predetermined pressure has been obtained; storing a nominal current value of the current required to obtain the predetermined pressure; and calibrating the valve by adding a correction offset factor to the nominal current value for future actuation of the solenoid of the valve.

An immobilizer arrangement for a motor vehicle includes a brake that can be electrically actuated by at least one motor. The motor is controlled by a brake control, and with an immobilizer control that serves for activating and deactivating the immobilizer of the motor vehicle. The immobilizer control is configured to receive an authorization for deactivating the immobilizer from a user identification device. With the brake serving as the immobilizer, at least one current path is provided for actuating the motor, which is coupled to the immobilizer control.

A control device for an electric parking brake controls a motor for driving a friction member of the electric parking brake. The control device includes a processing unit which starts the motor in order to drive the friction member to a direction for placing the electric parking brake in a locked state; measures a current value of the motor in an operating state thereof; determines a cut-off current value from the measured current value of the motor according to a predetermined rule defining a correlation between the cut-off current value of the motor, by which a braking force necessary for the electric parking brake in the locked state is generated, and an increasing rate of the current; and stops the motor when the current value of the motor reaches the determined cut-off current value.

A motor initialization method for an electric booster brake system may include: determining, by a control unit, whether a key on signal of a vehicle is inputted; turning on a warning light and determining a battery voltage state of the vehicle, when the key on signal is inputted; and performing a motor initialization mode according to the determined battery voltage state.

A motor initialization method for an electric booster brake system may include: determining, by a control unit, whether a key on signal of a vehicle is inputted; turning on a warning light and determining a battery voltage state of the vehicle, when the key on signal is inputted; and performing a motor initialization mode according to the determined battery voltage state.

A braking system having an electromechanical braking function may include a compound caliper device including a motor and configured to press a pair of brake pads against a brake disk, a hydraulic pressure producer including a master hydraulic line receiving oil from a master cylinder, a master valve configured to open and close the master hydraulic line, a caliper hydraulic line connected to the compound caliper device, and a hydraulic pump configured to increase hydraulic pressure supplied to the compound caliper device, and a brake controller to control the motor and the hydraulic pressure producer, in which the brake controller is configured to close the master valve and decrease clamping force of the brake pads applied by the motor when a conversion condition for converting a parking brake stage into a primary brake stage is satisfied.