Abstract: A combined service and parking brake apparatus includes a piston which forms a hydraulic chamber within a cylinder portion; a brake lining which, when pressed by the piston, brakes rotation of a disc rotor; a second piston which divides the hydraulic changer into a first hydraulic chamber and a second hydraulic chamber; a friction clutch which allows rotation of the second piston when the second piston is held at its home position and which disables rotation of the second piston when the second piston moves by a predetermined distance toward the second hydraulic chamber; an adjuster including an internal-thread portion and an external-thread portion and adapted to adjust the clearance between the pistons in accordance with the amount of wear of the brake lining; and a changeover valve for establishing and shutting off the communication between the first hydraulic chamber and the second hydraulic chamber.

Abstract: There is a case where first and second pressurizing units press different portions of friction members to a brake disc so as to press the friction members to the brake disc with predetermined pressing force, thereby generating braking force. When the brake noise is generated, a distribution ratio of the pressing force is changed by changing at least one of the pressing force generated by the first pressurizing unit and the pressing force generated by the second pressurizing unit. Accordingly, when the friction member contacts the brake disc, it is possible to change pressure distributions between first portions and second portions, whereby the brake noise is reduced or suppressed.

Abstract: A wedge-operated brake apparatus includes a piston for generating a braking force when axially driven, an actuator for generating a linear brake-actuating input, and a wedge transmission mechanism for converting the linear brake-actuating input into a brake-actuating output in the axial direction of the piston. The brake-actuating output is transmitted to the piston so as to drive the piston to thereby generate a braking force. The wedge transmission mechanism includes a first plate member which moves together with the piston, a second plate member disposed in opposition to the first plate member and fixedly secured to a housing, a wedge member disposed between the first and second plate members and engaging respective engaging surfaces of the first and second plate members via rollers, and a holder for rotatably holding the rollers and holding the wedge member while allowing linear movement of the wedge member.

Abstract: A braking force is generated by using a rotation of an electric motor to move a piston, which presses friction members onto a rotor. The displacement of the piston is controlled such that a detection value of a resolver becomes a target value. In the case of brake noise due to vibration of the rotor, the displacement of the friction members with respect to the rotor fluctuates in connection with the rotation of the rotor, leading to fluctuations in a rotational amount of the electric motor. Therefore, in a simple method and apparatus, brake noise can be detected based upon the magnitude of the fluctuation amount in the detection value of the resolver.

Abstract: A combined service and parking brake apparatus includes a piston which forms a hydraulic chamber within a cylinder portion; a brake lining which, when pressed by the piston, brakes rotation of a disc rotor; a second piston which divides the hydraulic changer into a first hydraulic chamber and a second hydraulic chamber; a friction clutch which allows rotation of the second piston when the second piston is held at its home position and which disables rotation of the second piston when the second piston moves by a predetermined distance toward the second hydraulic chamber; an adjuster including an internal-thread portion and an external-thread portion and adapted to adjust the clearance between the pistons in accordance with the amount of wear of the brake lining; and a changeover valve for establishing and shutting off the communication between the first hydraulic chamber and the second hydraulic chamber.

Abstract: A brake squeal control device is proposed which carries out squeal control by specifying travel state and temperature conditions in which brake noise tends to be produced. The brake squeal control device is adapted to feed detection signals from a sensor group that indicates the travel state of the vehicle from a stepping force sensor or wheel speed sensors, and a sensor group that indicates the temperature state from an engine cooling water temperature sensor, a car compartment temperature sensor, a caliper temperature sensor or an outer air temperature sensor to a control circuit. If conditions corresponding to an “in-the-cold” and “first-in-the-morning” states are detected by computing in the control circuit, a solenoid valve is turned on and off to suppress brake squeals.

Abstract: A brake squeal control device is proposed in which specific control for reducing brake squeals can be carried out to meet the will of a driver, and squeal control conditions for starting squeal reduction can be set individually to meet the requirements of drivers. Signals from wheel speed sensors, which indicate travel state, a hydraulic pressure sensor in a hydraulic circuit, which indicates the braking state, interior and exterior temperature sensors, which indicate the temperature state, and a manual switch operated by the will of a driver are sent to a control circuit. Conditions when squeals which the driver wishes to reduce or eliminate are produced, are stored in the control circuit, and when certain data are prepared, thereafter, by detecting the conditions at the time of generation, automatic squeal control is carried out.

Abstract: An output signal that accords with a rotation speed of a brake rotor of a respective wheel is output by a vehicle wheel speed sensor. A noise frequency identification portion identifies a frequency component that corresponds to brake noise from this output signal. It is possible, for example, to identify a frequency component that corresponds to brake squeal by performing fast Fourier transform (FFT) calculation for the vehicle wheel speed. Further, a noise detection portion determines that brake noise is being generated when the frequency component identified by the noise frequency identification portion is equal to or more than a predetermined value.

Abstract: A vehicle brake device having a hydraulic pressure generating source is proposed which can reliably prevent dragging and ensure the initial response of brakes during braking. In a brake fluid supply passage from the master cylinder to the wheel cylinder, a brake fluid circulating passage having a hydraulic pressure generating source is provided. A detector for detecting whether the brake pedal is being operated, and a detector for detecting dragging of the brake pads are provided, and only when dragging is detected while the brake pedal is not being operated, the hydraulic pressure generating source is actuated for a predetermined time with a supply valve provided in the brake fluid circulating passage closed and a return valve open to suck brake fluid in the wheel cylinder and increase the distances between the brake pads and the disk rotor, thereby reliably preventing dragging.

Abstract: A brake noise detecting portion detects brake noise generated in respective wheels by braking operation in a vehicle by a normal friction brake device in a vehicle running state. When the brake noise is detected in at least one of the wheels, if a brake-noise generation wheel in which the brake noise is generated is at least one of first left and right wheels, first target braking force is reduced by a first brake noise suppression variation amount, whereby it becomes new first target braking force. The new first target braking force is then applied to the first left and right wheels. If the brake-noise generation wheel is at least one of the second left and right wheels, second target braking force is reduced by a second brake noise suppression variation amount, whereby it becomes new second target braking force. The new second target braking force is applied to the second left and right wheels.

Abstract: In a case where a generation of a brake noise is detected at least one of the front and rear wheels on the left side and on the right side, respectively, the vehicle brake system selects a wheel where the generation of the brake noise is detected as a noise generating single-wheel. Then the vehicle brake system reduces target braking force for the noise generating wheel by a predetermined amount, thereby reducing or suppressing the brake noise in the noise generating wheel. At the same time, the vehicle brake system increases target braking force for one of the front and rear wheels which is other than the noise generating wheel by the amount equivalent to the predetermined amount mentioned above. Accordingly, while the deviation of the braking force from the optimal distribution between the front and the rear of the vehicle is reduced, the driver does not feel an unpleasant sensation due to an abnormal vehicle behavior and the like.

Abstract: There is a case where first and second pressurizing units press different portions of friction members to a brake disc so as to press the friction members to the brake disc with predetermined pressing force, thereby generating braking force. When the brake noise is generated, a distribution ratio of the pressing force is changed by changing at least one of the pressing force generated by the first pressurizing unit and the pressing force generated by the second pressurizing unit. Accordingly, when the friction member contacts the brake disc, it is possible to change pressure distributions between first portions and second portions, whereby the brake noise is reduced or suppressed.

Abstract: A vehicle brake device having a hydraulic pressure generating source is proposed which can reliably prevent dragging and ensure the initial response of brakes during braking. In a brake fluid supply passage from the master cylinder to the wheel cylinder, a brake fluid circulating passage having a hydraulic pressure generating source is provided. A detector for detecting whether the brake pedal is being operated, and a detector for detecting dragging of the brake pads are provided, and only when dragging is detected while the brake pedal is not being operated, the hydraulic pressure generating source is actuated for a predetermined time with a supply valve provided in the brake fluid circulating passage closed and a return valve open to suck brake fluid in the wheel cylinder and increase the distances between the brake pads and the disk rotor, thereby reliably preventing dragging.

Abstract: An output signal that accords with a rotation speed of a brake rotor of a respective wheel is output by a vehicle wheel speed sensor. A noise frequency identification portion identifies a frequency component that corresponds to brake noise from this output signal. It is possible, for example, to identify a frequency component that corresponds to brake squeal by performing fast Fourier transform (FFT) calculation for the vehicle wheel speed. Further, a noise detection portion determines that brake noise is being generated when the frequency component identified by the noise frequency identification portion is equal to or more than a predetermined value.

Abstract: A braking force is generated by using a rotation of an electric motor to move a piston, which presses friction members onto a rotor. The displacement of the piston is controlled such that a detection value of a resolver becomes a target value. In the case of brake noise due to vibration of the rotor, the displacement of the friction members with respect to the rotor fluctuates in connection with the rotation of the rotor, leading to fluctuations in a rotational amount of the electric motor. Therefore, brake noise can be detected based upon the magnitude of the fluctuation amount in the detection value of the resolver.

Abstract: Master cylinder pressure generated in a master cylinder is transmitted to wheel cylinders through a linear valve that generates a differential pressure proportional to the amount of current supplied, and respective increase control valves. As a result, a braking force is generated. Brake fluid discharged from the wheel cylinders is, for example, reserved in a pressure regulating reservoir. The brake fluid sucked up from the pressure regulating reservoir by a pump is discharged to the downstream side of the linear valve, and then the fluid is again returned to the pressure regulating reservoir. When existence of brake noise is detected, dither control of the linear valve is executed. By setting a dither frequency to 500 Hz to 1 kHz which is lower than a resonance frequency of a caliper, pulsation for suppressing brake noise can be applied to the wheel cylinder pressure.

Abstract: The aim is to reliably detect abnormality of a brake device with a simple structure without providing a special detecting means. A pump for generating brake hydraulic pressure of a hydraulic brake device is driven when the ignition switch for starting the vehicle is closed. The rise time of the output of a brake hydraulic pressure detecting means provided in the hydraulic brake device is detected, and it is determined that uneven wear of the pads has occurred if the rise time is longer than a predetermined time. An alarm lamp is turned on to notify abnormality. Thereby it is possible to accurately detect abnormality of the brake device before the driver drives the vehicle without providing a special detecting means.

Abstract: A brake squeal control device is proposed in which specific control for reducing brake squeals can be carried out to meet the will of a driver, and squeal control conditions for starting squeal reduction can be set individually to meet the requirements of drivers. Signals from wheel speed sensors, which indicate travel state, a hydraulic pressure sensor in a hydraulic circuit, which indicates the braking state, interior and exterior temperature sensors, which indicate the temperature state, and a manual switch operated by the will of a driver are sent to a control circuit. Conditions when squeals which the driver wishes to reduce or eliminate are produced, are stored in the control circuit, and when certain data are prepared, thereafter, by detecting the conditions at the time of generation, automatic squeal control is carried out.

Abstract: A brake squeal control device is proposed which carries out squeal control by specifying travel state and temperature conditions in which brake noise tends to be produced. The brake squeal control device is adapted to feed detection signals from a sensor group that indicates the travel state of the vehicle from a stepping force sensor or wheel speed sensors, and a sensor group that indicates the temperature state from an engine cooling water temperature sensor, a car compartment temperature sensor, a caliper temperature sensor or an outer air temperature sensor to a control circuit. If conditions corresponding to an “in-the-cold” and “first-in-the-morning” states are detected by computing in the control circuit, a solenoid valve is turned on and off to suppress brake squeals.

Abstract: An electric brake apparatus includes an electric motor which generates a rotational drive force. A gear train is driven by the electric motor and generates a rotational drive force. A screw feed mechanism is driven by the gear train and converts the rotational drive force from the gear train into a linear drive force. A wedge transmission mechanism is driven by the screw feed mechanism and converts the linear drive force from the screw feed mechanism into a linear drive force transverse to the linear drive force from the screw feed mechanism. A piston is driven by the wedge transmission mechanism in an axial direction of the piston and generates a braking force.