Abstract: The present disclosure provides a disk brake capable of making it easier for the piston to return than conventional ones when the brake is released from a state where the brake is applied. In the disk brake, the seal groove 5 includes a front wall 51, a rear wall 52 farther from the brake rotor than the front wall 51 in the axial direction Dl, and a bottom wall 53 extending along the axial direction Dl between the rear wall 52 and the front wall 51. The bottom wall 53 includes a front bottom wall 53a adjacent to the front wall 51 and a rear bottom wall 53b adjacent to the rear wall 52. The rear bottom wall 53b has a depth d2 from the inner circumferential surface 42a of the cylinder 42, the depth d2 being larger than a dimension d3 of the uncompressed piston seal 6 in the direction of the depth d2 and being larger than a depth d1 from the inner circumferential surface 42a of the cylinder 42 of the front bottom wall 53a.

Abstract: The present disclosure provides a disk brake capable of making it easier for the piston to return than conventional ones when the brake is released from a state where the brake is applied. In the disk brake, the seal groove 5 includes a front wall 51, a rear wall 52 farther from the brake rotor than the front wall 51 in the axial direction D1, and a bottom wall 53 extending along the axial direction D1 between the rear wall 52 and the front wall 51. The bottom wall 53 includes a front bottom wall 53a adjacent to the front wall 51 and a rear bottom wall 53b adjacent to the rear wall 52. The rear bottom wall 53b has a depth d2 from the inner circumferential surface 42a of the cylinder 42, the depth d2 being larger than a dimension d3 of the uncompressed piston seal 6 in the direction of the depth d2 and being larger than a depth d1 from the inner circumferential surface 42a of the cylinder 42 of the front bottom wall 53a.

Abstract: A disk brake allowing a connector terminal (255) and a joining terminal (256) to be easily positioned in a width direction thereof and a direction toward an opening portion of a housing, because the joining terminal fixed to one end of a harness includes individual protruding portions (265) and a pair of biasing portions (264). Further, due to each of the biasing portions, the connector terminal and the joining terminal can be brought into close contact with each other. Further, due to the protruding portions of the joining terminal, an end (258A) of the connector terminal and an end (268A) of a contact surface portion (263) can be brought into alignment with each other, which facilitates formation of such a welded portion (266) that extends over the respective ends, and thus achieves a secure connection between the connector terminal and the joining terminal.

Abstract: A disk brake allowing a connector terminal (255) and a joining terminal (256) to be easily positioned in a width direction thereof and a direction toward an opening portion of a housing, because the joining terminal fixed to one end of a harness includes individual protruding portions (265) and a pair of biasing portions (264). Further, due to each of the biasing portions, the connector terminal and the joining terminal can be brought into close contact with each other.

Abstract: In an electric motor-driven booster, a sharp change of reaction force to an operation of a brake pedal is reduced to improve the brake pedal operation feeling. Operation of the brake pedal causes an input rod (34) and an input piston (32) to advance, and an electric motor (40) is driven according to the movement of the input piston to propel a primary piston (10) through a ball-screw mechanism, thereby generating a desired brake hydraulic pressure in a master cylinder. At this time, the input piston receives the hydraulic pressure in the master cylinder to feed back a part of reaction force during braking to the brake pedal. When the brake pedal is further depressed after the output of the electric motor has reached a maximum output and the primary piston 10 has stopped, a lock nut abuts against a movable spring retainer and compresses a reaction force spring.

Abstract: In response to depression of a brake pedal (6), an electric brake (5) mounted on the rear side starts to generate a braking force at the time of stroke h1 before a fluid pressure brake (4) mounted on the front side starts to generate a braking force when the stroke reaches stroke h2. Accordingly, the rear side is able to generate a braking force prior to the front side, whereby it is possible to reduce a rigid feeling, and therefore improve the pedal feeling.

Abstract: In an electric motor-driven booster, a sharp change of reaction force to an operation of a brake pedal is reduced to improve the brake pedal operation feeling. Operation of the brake pedal causes an input rod (34) and an input piston (32) to advance, and an electric motor (40) is driven according to the movement of the input piston to propel a primary piston (10) through a ball-screw mechanism, thereby generating a desired brake hydraulic pressure in a master cylinder. At this time, the input piston receives the hydraulic pressure in the master cylinder to feed back a part of reaction force during braking to the brake pedal. When the brake pedal is further depressed after the output of the electric motor has reached a maximum output and the primary piston 10 has stopped, a lock nut abuts against a movable spring retainer and compresses a reaction force spring.

Abstract: In a brake system, when setting a control origin position for a resolver for detecting a moved position of a booster piston, communication between a master cylinder and wheel cylinders is interrupted by cut valves. Thereafter, the booster piston is moved forward by an electric actuator in a direction in which a hydraulic pressure is generated so that a position detected by the resolver upon detection of generation of the hydraulic pressure by a hydraulic pressure sensor (position at a time of generation of hydraulic pressure) is obtained. A position obtained by moving backward the position at the time of generation of hydraulic pressure by a predetermined amount is set as the control origin position.

Abstract: In the normal condition, a braking force is generated by directly supplying to a disk brake a fluid pressure generated in a master cylinder in response to an operation of a brake pedal. In addition, a braking force can be generated by supplying a fluid pressure to the disk brake by actuating a hydraulic pump motor by a controller. When a knock-back occurs due to, for example, rapid turning of a vehicle, a piston is allowed to be displaced backward so that uneven wear of a brake pad and a disk rotor can be prevented. After that, when a cause for the knock-back is eliminated, the piston is caused to move forward and a pad clearance is adjusted by actuating the pump motor by the controller so that deterioration of the responsiveness can be prevented.

Abstract: An electro mechanical brake apparatus is provided, in which a counter-measure for the heat of the driving circuit is much improved when configured to be integrated with an electric circuit. An electric circuit portion is provided by sandwiching a motor with brake pads, and a power module is provided so that a heat dissipating surface is opposed to the inner surface of the metallic outer case of the electric circuit portion, and a control circuit board is disposed at the motor side for the power module.

Abstract: In a brake system, when setting a control origin position for a resolver for detecting a moved position of a booster piston, communication between a master cylinder and wheel cylinders is interrupted by cut valves. Thereafter, the booster piston is moved forward by an electric actuator in a direction in which a hydraulic pressure is generated so that a position detected by the resolver upon detection of generation of the hydraulic pressure by a hydraulic pressure sensor (position at a time of generation of hydraulic pressure) is obtained. A position obtained by moving backward the position at the time of generation of hydraulic pressure by a predetermined amount is set as the control origin position.

Abstract: An electric disk brake is capable of determining an abnormality of a parking brake mechanism while the parking brake mechanism is in operation. A brake force is generated in the following manner. A rotation of an electric motor is slowed down by a differential speed reducing mechanism, and is converted into a linear motion by a ball ramp mechanism so as to advance a piston, which then presses a brake pad against a disk rotor to generate a brake force. A parking brake mechanism can lock a rotation of a rotor of the electric motor and maintain a braked state by rotating an engagement pawl through a plunger of a solenoid and causing the engagement pawl to be engaged with a ratchet wheel coupled to the rotor of the electric motor. A play is provided at a coupling portion of the engagement pawl and the plunger.

Abstract: An object of the present invention is to provide an electric disk brake capable of determining an abnormality of a parking brake mechanism while the parking brake mechanism is in operation. A brake force is generated in the following manner. A rotation of an electric motor is slowed down by a differential speed reducing mechanism, and is converted into a linear motion by a ball ramp mechanism so as to advance a piston, which then presses a brake pad against a disk rotor to generate a brake force. A parking brake mechanism can lock a rotation of a rotor of the electric motor and maintain a braked state by rotating an engagement pawl through a plunger of a solenoid and causing the engagement pawl to be engaged with a ratchet wheel coupled to the rotor of the electric motor. A play is provided at a coupling portion of the engagement pawl and the plunger.

Abstract: An object of the present invention is to provide a brake device in which brake feeling can be improved. In response to depression of a brake pedal 6, an electric brake 5 mounted on the rear side starts to generate a braking force at the time of stroke h1 before a fluid pressure brake 4 mounted on the front side starts to generate a braking force when the stroke reaches stroke h2. In the conventional art, the braking force on the rear side is set according to the fluid pressure on the front side, and braking can be controlled only by the response of the fluid pressure. In the conventional art, an invalid stroke is long, and when the stroke enters a braking force zone where a braking force is generated according to a pedal stroke, the braking force suddenly increases relative to an advance of the stroke (rigid impression), whereby the driver often feels discomfort and pedal feeling is deteriorated.

Abstract: In the normal condition, a braking force is generated by directly supplying to a disk brake a fluid pressure generated in a master cylinder in response to an operation of a brake pedal. In addition, a braking force can be generated by supplying a fluid pressure to the disk brake by actuating a hydraulic pump motor by a controller. When a knock-back occurs due to, for example, rapid turning of a vehicle, a piston is allowed to be displaced backward so that uneven wear of a brake pad and a disk rotor can be prevented. After that, when a cause for the knock-back is eliminated, the piston is caused to move forward and a pad clearance is adjusted by actuating the pump motor by the controller so that deterioration of the responsiveness can be prevented.

Abstract: An electro mechanical brake apparatus is provided, in which a counter-measure for the heat of the driving circuit is much improved when configured to be integrated with an electric circuit. An electric circuit portion is provided by sandwiching a motor with brake pads, and a power module is provided so that a heat dissipating surface is opposed to the inner surface of the metallic outer case of the electric circuit portion, and a control circuit board is disposed at the motor side for the power module.

Abstract: A device for detecting a fault in a solenoid valve prevents a feeding system from supplying a drive current to a solenoid valve coil which actuates the solenoid valve from being damaged at the time of detection of the fault. The feeding system is provided with a first switch installed between one end of the solenoid valve coil and a battery, a second switch installed between the other end of the solenoid valve coil and a ground, and a plurality of wires for connecting the battery, the first and second switches and the solenoid valve coil. A test power supply system is connected to one end or the other end of the solenoid valve coil and supplies a micro test current to the solenoid valve coil when a current from the battery to the solenoid valve coil is cut off.