Advics Co., Ltd.

Denso Corporation

Daizo Oba

Takashi Murayama

Masahiko Kamiya

Hiroshi Kondo

Shin Sasaki

Takeshi Fuchida

Moriharu Sakai

Koichi Hashida

Hiroyuki Shinkai

Hideaki Higashimura

Toshiya Morikawa

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.

Combined service and parking brake apparatus

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.

Vehicle brake system for preventing brake noise

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. When the wedge member moves linearly, the holder moves, while being guided by the first and second plate members.

Wedge-operated brake apparatus

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.

Vehicular braking apparatus and method

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.

Vehicle brake squeal control device

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.

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.

Brake noise detection device

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.

Vehicle brake device

In a pump equipment having plural rotary pumps, the respective discharge ports of the rotary pumps are located at the points which are nearly symmetrical with respect to the center axis of the drive shaft to counterbalance each other the respective reaction forces against the drive shaft to be produced by the high pressure at the respective discharge ports. The respective discharge fluid conduits, in case of the first and second pumps, are located at the points which are opposite each other, more preferably, different at an angle of 180 degrees each other, with respect to the center axis of the drive shaft to limit the bending of the drive shaft. As a method for assembling the pump equipment, the peripheral border between respective cylindrical members piled up for constituting the casing is tentatively welded by laser beam at first and, then, all around the peripheral borders are finally welded.

Pump equipment with plural rotary pumps and method for assembling same

In a pump equipment having one or more rotary pumps for hydraulic circuit, the intake port is communicated with the shaft hole for inserting the drive shaft and fluid flows through the shaft hole to a fluid groove provided in inner surfaces of the pump room for the purpose of lubrication. To prevent fluid leakage to outside, first and second oil seals are disposed for filling the clearance between the drive shaft and the shaft hole and, preferably, a communicating conduit is provided between the first and second oil seals to transmit the fluid leaked through the first oil seal to a low pressure fluid conduit of the hydraulic circuit. In particular, in the pump equipment having plural rotary pumps, the respective discharge ports of the rotary pumps are located at the points which are nearly symmetrical with respect to the center axis of the drive shaft to counterbalance each other, the reaction forces against the drive shaft to be produced by the high pressure at the respective discharge ports.

Pump equipment and method for assembling same

In a pump equipment having one or more rotary pumps for a hydraulic circuit, the intake port is communicated with the shaft hole for inserting the drive shaft and fluid flows through the shaft hole to a fluid groove provided in inner surfaces of the pump room for the purpose of lubrication. To prevent fluid leakage to the outside, first and second oil seals are disposed for filling the clearance between the drive shaft and the shaft hole and, preferably, a communicating conduit is provided between the first and second oil seals to transmit the fluid leaked through the first oil seal to a low pressure fluid conduit of the hydraulic circuit. In particular, in the pump equipment having plural rotary pumps, the respective discharge ports of the rotary pumps are located at the points which are nearly symmetrical with respect to the center axis of the drive shaft to counterbalance each other, the reaction forces against the drive shaft to be produced by the high pressure at the respective discharge ports.

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Kariya, Japan

Daizo Oba