Advics Co., Ltd.

Shin Sasaki

Hiroshi Kondo

Masahiko Kamiya

Daizo Oba

Fumitoshi Koyama

Moriharu Sakai

Yasuhito Sekihara

Fumiyoshi Ariki

Kazuyuki Kobayashi

Jun Oonishi

Shota Watanabe

Takahiro Miyagi

A hydraulic unit for a vehicle brake apparatus having a master cylinder and a wheel cylinder includes a housing formed with a pipe line connecting between the master cylinder and the wheel cylinder, a pump disposed in the housing for sucking and discharging a brake fluid to boost pressure of the brake fluid, and a reservoir piston disposed in a hole formed in the housing so as to be movable slidably back and forth, the reservoir piston partitioning a reservoir chamber within the hole for temporarily storing the brake fluid discharged from the wheel cylinder. The hydraulic unit further includes a cover disposed in the hole to close one end on an atmospheric side of the hole, the cover being formed with a fluid reservoir chamber for storing the brake fluid leaking from the pump.

Hydraulic unit for vehicle brake apparatus

A brake fluid pressure controlling actuator is equipped with a block, an electric device secured to the block, and a casing attached to the block, and a board support with a stay. The brake fluid pressure controlling actuator is designed to have the board support disposed in the casing and also have a circuit board placed in contact with the stay of the board support. The stay of the board support serves to firmly hold a portion of the circuit board around a through-hole formed in the circuit board when a terminal of an electric device is press-fitted into the through-hole, thereby minimizing the degree of bending of the circuit board to ensure the stability in electrically connecting the electric device to the circuit board.

Brake fluid pressure controlling actuator

To minimize the amount of air that may enter the damper chamber in a normally closed solenoid valve to stably maintain the damper capacity, the normally closed solenoid valve has a valve housing and a movable element. A cylinder having an open end is formed in one of the valve housing and the movable element. The cylinder has an inner diameter smaller than the outer diameter of a trunk of the movable element. A piston provided on the other of the valve chamber and the movable element is movable relative to the cylinder as the movable member moves. The piston is inserted into the cylinder through its open end to define a damper chamber between the piston and the cylinder. A restricted passage is formed between the damper chamber and the valve chamber through which hydraulic fluid can be moved between the valve chamber and the damper chamber.

Normally closed solenoid valve

A hydraulic unit is provided with a housing having two planar portions neighboring at a predetermined angle between them. At least one opening is formed on each of the planar portions. For example, one opening and at least two openings are formed on the two planar portions, respectively. A protective tape is adhered to the two planar portions of the housing for covering each opening formed on each of the two planar portions. The protective tape is cut by a laser beam, for example, to be separated into at least each one of a part for covering one opening and a part for covering at least two openings.

Hydraulic unit

A pressure regulating reservoir is structured such that a major diameter portion of a shaft contacts a bottom surface of a valve seat, whereas a top surface of a piston does not contact an upper end surface of a wall forming a reservoir chamber in a housing. Therefore, a lift amount of a ball valve can be set using a portion above the major diameter portion of the shaft that contacts the bottom surface of the valve seat. That is, the lift amount can be set using only a dimension in the axial direction of a minor diameter portion of the shaft.

Pressure regulating reservoir and vehicular braking apparatus using it

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 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.

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Okazaki, Japan

Shin Sasaki