Nippondenso Co., Ltd.

Denso Corporation

Nippon Soken, Inc.

Haruhiko Uno

Toshihiro Takei

Yuzo Imoto

Yoshiyuki Hattori

Taku Itoh

Hideo Wakata

Yuzuru Sudani

Mitsuo Inagaki

Kenji Takeda

Motoyoshi Ando

Hiroyuki Nakane

Tetuya Izumi

Maki Kawamura

In an electromagnetic valve, a maximum distance between a movable core and a fixed core is set to be larger than a movable stroke of a movable rod moving together with the movable core. Therefore, a movable stroke of the movable core is set by a movable stroke of the movable rod, and the movable core always does not contact the fixed core. Accordingly, a vibration of the fixed core can be restricted and noise caused in the electromagnetic valve can be reduced. Further, because the movable core is movable without having an unnecessary moving stroke, a responsive performance of the electromagnetic valve relative to an electrical switching can be improved.

Electromagnetic valve and assembling method

A solenoid valve has a solenoid, a control valve having a spool, a seat member having an oil hole whose one end communicates with a control pressure chamber between the seat member and the spool, a supply passage through which a second supply port communicates via a control orifice with the control pressure chamber and a drain passage through which the other end of the oil hole is able to communicate with the second drain port. A second orifice or a slit, whose cross sectional opening area is smaller than that of the control orifice, is formed in the supply passage at a periphery of the seat member that comes in contact with the spool so that a flow amount of the oil supplied to and ejected from the control pressure chamber through the supply and drain passages after the spool contacts the seat member is smaller than that before the spool contacts the seat member.

Solenoid valve

In a pressure regulation valve having a main spool and a sub-spool slidably housed in the main spool, the main spool is at a position where pilot pressure force balances with a sum of pressure force of a feedback chamber and spring biasing force, when the pilot pressure is below a given value, so that normal output pressure proportional to pilot pressure is supplied to a hydraulic servo for driving a clutch of an automatic transmission, and, when the pilot pressure exceeds the given value, the sub-spool moves to a position where the feedback chamber communicates with a drain so that the main spool moves to a position where maximum output pressure equal to supply pressure source is supplied.

Pressure regulation valve

A braking apparatus for a vehicle has a booster for receiving, as a pilot pressure, a pressure of a master cylinder and for regulating a pressure from an auxiliary pressure source to a level predetermined times the pilot pressure. The booster is provided with an initial pressure raising mechanism for causing the booster to output a predetermined initial pressure in response to an initial actuation of a brake pedal.

Braking apparatus for vehicle

A brake control system for effectively properly performing a braking hydraulic pressure distribution between a front wheel and a rear wheel or a left wheel and a right wheel of a motor vehicle including a master cylinder for generating a hydraulic pressure in response to depression of a brake pedal thereof and applying the hydraulic pressure through first and second braking passages to first and second wheel braking cylinders. This brake control system has first and second pressure control devices respectively coupled to a braking pressure source for allowing the output hydraulic pressures to be regulated independently of each other under control of a control unit. The output of the first pressure control device is coupled through the first braking passage to the first wheel braking cylinder and the output of the second pressure control device is coupled through the second braking passage to the second wheel braking cylinder. The control unit determines first and second target braking pressures to the first and second wheel braking cylinders on the basis of the hydraulic pressure in the master cylinder. The determined first and second target braking pressures are respectively corrected on the basis of the vehicle acceleration and wheel slip ratios.

Brake control system for controlling a braking force to each wheel of a

A braking system having a pressure modulator which, during normal braking operation, delivers a fluid pressure which is a predetermined multiple of a fluid pressure generated by the master cylinder to a wheel cylinder. The pressure modulator has a solenoid actuator which is energized during braking force proportioning and anti-skid operations to reduce the delivery pressure. In a preferred embodiment, the pressure modulator further includes another solenoid actuator for increasing the delivery pressure during braking force proportioning operation and for delivering fluid pressure during traction control operation.

Braking system with power brake, braking force proportioning, anti-skid,

Wheel cylinders supplied with oil pressure from a master cylinder are respectively provided in brake mechanism provided in wheels of a vehicle. The wheel cylinder has a brake piston provided to form a first fluid chamber to supply oil pressure from the master cylinder, and a brake piston driven by the oil pressure of the first fluid chamber. The wheel cylinder has a piston mechanism formed by laminating thin plate shaped piezoelectric elements, and the piston mechanism is controlled to be expanded or contracted by controlling the voltage applied to the piezoelectric elements to vary the volume of the first fluid chamber. Cut-off valves are provided in passages for supplying the oil pressure from the master cylinder to the wheel cylinders, a check valve for allowing only the work oil to flow from the master cylinder to the wheel cylinder in parallel with the cut-off valve to control to expand the piston in the state the oil pressure is generated from the master cylinder and the cut-off valve is closed to control to further strengthen the oil pressure in the first fluid chamber.

Growing community of inventors

Okazaki, Japan

Haruhiko Uno