Aisin Seiki Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Takumi Nishimura

Nobuyasu Nakanishi

Noboru Noguchi

Tadao Saito

Yoshiharu Adachi

Hirochika Shibata

Hiroaki Takeuchi

Masamoto Ando

Hiromu Kuromitsu

Akira Shirai

Toshiyuki Kondo

Takashi Fujii

Tadao Saitoh

An anti-skid apparatus for installation in a vehicle braking system between a master cylinder and a wheel brake cylinder. The anti-skid apparatus includes a hydraulic power pressure source connected to a fluid reservoir of the master cylinder to produce a hydraulic power pressure higher than a braking pressure applied to the wheel brake cylinder from the master cylinder, a regulator valve connected to the pressure source to control the power pressure in dependence upon a hydraulic pressure created in the master cylinder in braking operation, a first switchover valve disposed within a braking circuit connecting the master cylinder to the wheel brake cylinder and being arranged to be intermittently activated when a road wheel tends to be locked, the first switchover valve being connected to the reservoir to connect the wheel brake cylinder to the reservoir in its activated condition, a second switchover valve disposed within the braking circuit between the master cylinder and the first switchover valve and being arranged to be activated when the road wheel tends to be locked, a second switchover valve being connected to the regulator valve to interrupt the flow of pressurized fluid from the master cylinder and permit the flow of pressurized fluid from the regulator valve to the wheel brake cylinder through the first switchover valve.

Anti-skid apparatus for automotive vehicle

An actuator is disclosed for use in an anti-skid brake system for wheeled vehicles. A first valve is disposed in a pressure line to selectively divide the pressure line into two separate lines. Also included is an electric motor, a pump driven by the electric motor, an accumulator adapted to accumulate fluid pressure generated by the pump, a control piston reciprocating under the fluid pressure to open and close the first valve, a second valve adapted to supply the fluid pressure to the control piston upon normal rolling of wheels so as to move the control piston to a non-operative position while excluding the fluid pressure from the control piston when the wheels are likely to lock up, and a third valve having first and second valves and controlling the fluid pressure to be supplied to a hydraulic chamber in response to depression and release of a brake pedal. In this arrangement, a relief valve is provided in a seat member of the first valve so that when the fluid pressure exceeds a predetermined upper limit, it is opened to introduce hydraulic fluid to a drain line through the second valve.

Actuator for use in an anti-skid system

A brake fluid pressure control valve assembly includes a body having a single cylinder bore communicating inlet and outlet ports connected to a brake master cylinder and wheel brake cylinder, respectively. The cylinder bore accommodates the components of two separate valves, namely first, second and third seat members and first and second valve elements brought into and out of contact with seat surfaces of these seat members, as well as a spring interposed between the two valve elements, a pressure reducing piston and a by-pass piston. First and second passageways arranged in parallel each interconnect the inlet and outlet ports through two serially arranged valve cavities in the cylinder bore and are opened and closed in a prescribed manner by the two valves in cooperation with the spring and pistons. The third seat member has seal rings fitted in first and second annular grooves formed in its outer periphery for providing a seal between the outer periphery of the third seat member and wall surfaces of axially extending bores in the first and second seat members. The outer diameter of the third seat member is smaller than the inner diameter of the first and second seat members so that the inner peripheral portions of the these seat members will not be contacted by the third seat member. The first and second seat members are joined to each other by a pin press fitted into opposing holes formed in opposing end faces of these seat members.

Valve assembly for brake fluid pressure control

An anti-skid device for motor vehicles provided with a hydraulic circuit for connecting the brake master cylinder with the wheelbrake cylinder has a first valve for dividing the hydraulic circuit into two sections, a second valve for supplying the hydraulic pressure to the pressure reducing piston and a third valve having two valve sections for controlling the hydraulic pressure supplied to a working fluid chamber so as to prevent it from exceeding a predetermined degree. The third valve is constructed so that a fluid chamber defined by both the slidable valve members and fixed valve members of the two valve sections is formed therein so as to be communicated with the working fluid chamber side circuit through an orifice, in order to prevent the generation of strange sounds from the third valve during its operation by damper action of the fluid chamber.

Actuator of anti-skid device for motor vehicles

An anti-skid device for motor vehicles provided with a hydraulic circuit for connecting the brake master cylinder with the wheelbrake cylinder has a valve dividing the hydraulic circuit into a brake master cylinder side section and a wheelbrake cylinder side circuit section, the two circuit sections being arranged so as to act against each other. Two floating pistons make slidable reciprocating movement respectively according to the pressure difference between the two hydraulic circuit sections and the spring force. The anti-skid device causes the brake pedal to generate a vibration of adequate degree at the time of anti-skid operation in any road condition so that the drive can recognize the actuation of anti-skid.

Anti-skid device for motor vehicles

A brake fluid pressure control valve assembly includes a body having a single cylinder bore communicating inlet and outlet ports connected to a brake master cylinder and wheel brake cylinder, respectively. The cylinder bore accommodates the components of two separate valves, namely first, second and third seat members and first and second valve elements brought into and out of contact with seat surfaces of these seat members, as well as a spring interposed between the two valve bodies, a pressure reducing piston and a by-pass piston. First and second passageways arranged in parallel each interconnect the inlet and outlet ports through two serially arranged valve cavities in the cylinder bore and are opened and closed in a prescribed manner by the two valves in cooperation with the spring and pistons. The third seat member has seal rings fitted in first and second annular grooves formed in its outer periphery for providing a seal between the outer periphery of the third seat member and wall surfaces of axially extending bores in the first and second seat members. The diameter of first and second end portions outwardly of the first and second annular grooves, respectively, of the third seat member is such that these end portions will not contact the wall surfaces of the axially extending bores of the first and second seat members, respectively.

A hydraulic anti-skid apparatus for installation in a vehicle braking system includes a cut-off valve disposed within a braking circuit connecting a master cylinder to a wheel brake cylinder, a piston arranged to be applied at opposite ends thereof with a braking pressure from the master cylinder and a hydraulic power pressure from a power pressure source and being associated with the cut-off valve to open the cut-off valve while the power pressure is applied thereto and to be displaced by the braking pressure when released from the power pressure to close the cut-off valve and subsequently to increase a capacity downstream of the cut-off valve, a first changeover valve arranged to normally apply the power pressure to the piston and to exhaust the power pressure when a road wheel tends to be locked, and a second changeover valve arranged to permit the power pressure applied to the piston through the first changeover valve when the master cylinder is operated and to exhaust the power pressure therethrough when the master cylinder is released from its operation. The second changeover valve is loaded to maintain the pressure acting on the piston at a low level while the master cylinder is inoperative.

Hydraulic anti-skid apparatus for automotive vehicles

An anti-skid braking control system which includes an actuator disposed in a braking fluid pressure circuit for controlling a braking fluid pressure. The actuator includes a body having a cylinder with one end closed by a closure member, an inlet port defined in the body and opening into the cylinder, the inlet port being connected through the braking fluid pressure circuit to a brake master cylinder, an outlet port defined in the body and opening into the cylinder, the outlet being connected through the braking fluid pressure circuit to a wheel brake actuating cylinder, a first valve disposed centrally in the cylinder between the inlet and outlet ports for cutting off fluid communication therebetween, a first piston disposed in one side of the cylinder and having an end on which a power fluid pressure from a fluid pressure source acts and an opposite end exposed in the braking fluid pressure circuit for engaging the first valve, the first piston being responsive to the power fluid pressure for moving the first valve to vary the volume of the braking fluid pressure circuit, a second piston disposed in an opposite side of the cylinder and having an end on which the power fluid pressure acts and actuatable by the braking fluid pressure in response to failure of the power fluid pressure, and a second valve for communicating the inlet and outlet ports directly with each other in response to operation of the second piston.

Anti-skid braking control system

An antiskid apparatus for an automotive vehicle having a master cylinder connected to wheel cylinders via respective brake lines, and a pressure regulating valve in a power hydraulic pressure line connecting an accumulator with a directional control valve, which is installed in a power hydraulic pressure line connecting the accumulator with a hydraulic pressure control piston. When the brake is applied, the pressure regulating valve is operable, in dependence upon master cylinder hydraulic pressure delivered by each wheel cylinder, to reduce power hydraulic pressure supplied by the accumulator to a hydraulic pressure higher, by a predetermined amount, than the master cylinder hydraulic pressure, and to deliver this reduced hydraulic pressure to each directional control valve. When the brake is not applied, the pressure regulating valve cuts off communication between the accumulator and each directional control valve and brings the hydraulic pressure in a hydraulic pressure line leading to a fluid chamber of the control piston to a value not higher than a set value through the directional control valve. Thus, the fluid chamber is supplied with hydraulic pressure reduced to a predetermined value to suppress a pressure change that occurs in the fluid chamber when the apparatus is operated, thereby reducing shock and noise and making it easier to control the operation of the apparatus.

Antiskid apparatus for vehicles

A hydraulic anti-skid apparatus for use in a vehicle braking system comprises a cut-off valve disposed within a braking circuit connecting a master cylinder to a wheel brake cylinder, a bypass valve disposed within a bypass passage of the braking circuit, and first and second pistons respectively arranged to control opening and closing operations of the cut-off valve and the bypass valve. A main body for the anti-skid apparatus is formed with a single cylinder the one end of which is closed by a closure member fixed thereto. To simplify the anti-skid apparatus in construction, the cut-off valve and the bypass valve are coaxially arranged within the single cylinder to be controlled by the first and second pistons respectively.

An actuator of an antiskid system for a vehicle and which includes a cut-off valve for selectively dividing a hydraulic pressure circuit connecting together a brake master cylinder and a wheel brake cylinder of the vehicle into a brake master cylinder-side hydraulic pressure circuit portion and a wheel brake cylinder-side hydraulic pressure circuit portion.

Actuator of antiskid system for vehicle

An actuator adapted to be used with the antiskid device of a vehicle and which includes cutoff valves which are capable of dividing each of the brake lines connecting the brake master cylinder of the vehicle to each brake cylinder at the wheels into two. The actuator further includes an electric motor and a high-pressure pump driven by the motor for forcing brake fluid into an accumulator. The brake fluid is also used as a mechanism for reducing braking effort when such are almost locked, i.e., for unlocking the wheels. The accumulator stores this unlocking fluid which is sufficiently pressurized to be greater than the maximum pressure that the brake fluid is under for braking action. Each piston taking the form of a right circular cylinder is advanced by the brake fluid and is withdrawn by the unlocking fluid supplied from the accumulator, so that the piston closes and opens the corresponding cutoff valve.

Actuator for antiskid device of vehicle

An anti-skid brake control system which includes a method and apparatus for anti-skid brake control of the vehicle utilizing a first and second electromagnetic valves that controls operation of the at least one rear wheel and at least one rear brake of the vehicle which includes the steps of registering a first predetermined rear wheel rotational velocity standard and a predetermined rear wheel receleration rate upon braking of the vehicle, registering an actual rear wheel deceleration rate of the vehicle, establishing a predetermined velocity differential for operation of the first electromagnetic valve, establishing a second predetermined rear wheel rotational velocity standard, calculating a time period for changing from the first velocity standard to the second velocity standard, comparing the predetermined deceleration rate with the actual deceleration rate, comparing the predetermined velocity differential with the difference between the first and second velocity standards when the actual deceleration rate is less than the predetermined deceleration rate, energizing the first electromagnetic valve when the difference between the first and second velocity standards is equal to the predetermined velocity differential, and automatically controlling operation of the rear brake by energizing and de-energizing the first and second electromagnetic valve by comparison of the time period of energizing the first electromagnetic valve with the calculated time period for changing from the first velocity standard to the second velocity standard.

Anti-skid brake control system for automobiles

A powered brake system for vehicles including wheel brake cylinders, a pump powered hydraulic pressure source, a reservoir hydraulically connected to the pump powered hydraulic pressure source, a control valve interposed between the wheel brake cylinders and the pump powered hydraulic pressure source for controlling the fluid pressure to the wheel brake cylinders, a valve interposed between the reservoir and the control valve for connecting the wheel brake cylinders to either one of the reservoir and the control valve, and an orifice valve interposed between the control valve and the valve for slowly supplying the fluid pressure from the control valve to the valve just when the fluid pressure of the control valve reaches the point where the pressure is higher than that of the wheel brake cylinders.

Growing community of inventors

Chiryu, Japan

Takumi Nishimura