Aisin Seiki Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Yoshiharu Adachi

Nobuyasu Nakanishi

Noboru Noguchi

Takumi Nishimura

Toshio Kondo

Hiroaki Takeuchi

Hiroshi Uemura

Masamoto Ando

Hiromu Kuromitsu

Juichi Shibatani

Fumio Fujimori

Takashi Nagashima

Tadao Saito

Hirochika Shibata

Kazutaka Kuwana

Tsuyoshi Yoshida

Hiroshi Toda

Akira Shirai

Hiroyuki Oka

Harumi Ohori

Asao Kozakai

Masashi Sawada

Katsuki Takayama

Kiyonobu Nagamori

Shingo Watanabe

Fumio Nakagawa

Ryuichi Sakakibara

Uichiro Kobashi

Masahiro Kito

Toshiya Shibata

Tadao Saitoh

Masuo Yamashita

A brake pressure control device for use in an anti-skid control system decreases the slipping of a car wheel by reducing the car wheel brake pressure when the slipping of the car wheel against the road surface is excessive at the time of applying a brake pressure to the car wheel brake. The brake pressure control device includes a valve body having a first input port, a second input port, an output port, a spool valve with an annular recess communicating the ports, a spring biasing the spool valve toward a first position, a pressure chamber connected to the output port for applying pressure to the spool to move the spool toward a second portion and an electric coil for applying a force to move the spool toward the first position. Thus, the car wheel brake pressure can be controlled in proportion to the current supplied to the coil.

Brake pressure control device

An anti-skid apparatus for installation in a vehicle braking system having a master cylinder, a wheel brake cylinder and a primary fluid passage connecting these cylinders includes a changeover valve disposed in the primary fluid passage to selectively communicate the wheel brake cylinder with the master cylinder or with a reservoir, and a fluid pump for pumping a brake fluid from the reservoir and returning it to a portion of the primary fluid passage between the master cylinder and the changeover valve. The anti-skid apparatus further includes a control valve disposed in that portion of the primary fluid passage. The control valve comprises a piston slidably disposed in a housing, and a valve member slidably disposed in the piston and seatable on a valve seat with a cutout formed thereon. The control valve allows a flow of the brake fluid from the master cylinder and/or the fluid pump to the wheel brake cylinder through the changeover valve without restriction in normal braking operation. In the anti-skid operation, the control valve allows a restricted flow of the brake fluid through the cutout to reduce the increasing speed of the hydraulic pressure in the wheel brake cylinder.

Anti-skid apparatus for an automotive vehicle

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

A disc brake assembly includes a stationary support member mounted on a vehicle body structure and having at least one support pin fixed thereto, a caliper member slidably supported on the support pin to be movable in an axial direction, and a tubular elastic boot arranged in surrounding relationship with the support pin to enclose a sliding portion on the same. To protect the elastic boot, a cylindrical elastic protector is arranged to contain therein the elastic boot, the elastic protector having one end coupled with a member such as a washer or a cup-shaped member fixed to the outer end of the support pin and the other end pressed into contact with an end face of the support portion of the caliper member.

Pin boot protector in disc brake assembly

A brake pressure control system for a wheeled vehicle includes a swingable lever pivotally mounted at a first end portion thereof to a sprung mass of the vehicle such as a body frame, a first tension coil spring connected at a first end thereof to the sprung mass and at a second end thereof to a second end portion of the swingable lever to bias the lever toward the sprung mass, a second tension coil spring connected at a first end thereof to an unsprung mass of the vehicle such as a wheel axle and at a second end thereof to the second end portion of the swingable lever to bias the lever against the biasing force of the first spring, a bushing rotatably mounted on the second end portion of the swingable lever, the bushing being formed with a first support portion for retaining the second end of the first spring and a second support portion for retaining the second end of the second spring, and a modulator valve secured to the sprung mass and incorporated in a hydraulic connection between a master cylinder and a wheel brake cylinder, the modulator valve having a spring-loaded valve member which is carried on the swingable lever to be applied with a biasing force proportional to the vehicle load.

Brake pressure control system of vehicle load responsive type

An anti-skid apparatus in a vehicle braking system including a bypass circuit connected in parallel with a braking circuit between a master cylinder and a wheel brake cylinder, wherein a fluid pump is disposed within the bypass circuit and connected to a fluid reservoir to produce a hydraulic power pressure, a first switchover valve is disposed within both the circuits to permit the flow of fluid passing through the braking circuit in its deactivated condition and to interrupt the braking circuit and connect the brake cylinder to the reservoir through the bypass circuit in its activated condition, a second switchover valve is disposed between the master cylinder and the first switchover valve to permit the flow of fluid passing through the braking circuit while the first switchover valve is maintained in its deactivated conidition and to interrupt the braking circuit and connect the pump to the brake cylinder in response to a decrease of the brake cylinder pressure caused by activation of the first switchover valve, a regulator valve is disposed within the bypass circuit between the pump and the second switchover valve to control the power pressure in dependence upon the master cylinder pressure, and a relief valve is disposed within the bypass circuit to maintain the power pressure at a predetermined value.

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 sealing boot for use in a disc brake assembly which includes a stationary support member having a support pin fixed thereto, and a caliper member having a boss portion slidably supported on the support pin. The sealing boot includes a bellows portion integrally formed at the opposite ends thereof with an outside cylindrical sealing portion coupled over the support pin and an inside cylindrical sealing portion coupled within an annular groove in the boss portion, the inside sealing portion being formed at its outer circumference with a first annular projection in contact with the bottom surface of the annular groove and at its inner circumference with a second annular projection sliding in contact with the support pin. The first annular projection of the inside sealing portion is formed at its one side with a steep annular surface directed outwardly and at its other side with a gentle slope annular surface and has a rounded annular head in contact with the bottom surface of the annular groove. The second annular projection is slightly displaced relative to the first annular projection.

Sealing boot for use in disc brake assembly

In a disc brake assembly of the pin slide type including a stationary support member mounted on a vehicle body structure and having at least one support pin secured thereto, a caliper member having a boss portion slidably supported on the support pin to be movable in an axial direction, and a tubular elastic boot arranged in surrounding relationship with the support pin to enclose a sliding portion on the same, a cylindrical protector with a closed end is arranged in surrounding relationship with the tubular elastic boot and fixed in place by engagement with the outer end portion of the support pin or a member secured thereto in such a way to contain therein the tubular elastic boot, the outer end portion of the support pin and its associated members.

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 regulator valve for a hydraulic anti-skid apparatus and which includes a housing provided with a first inlet port for connection to a fluid pump and the anti-skid apparatus, a second inlet port for connection to a master cylinder, and an outlet port for connection to a fluid reservoir, a regulator piston reciprocably disposed within the housing to form a first fluid chamber in open communication with the first inlet and outlet ports and a second fluid chamber in open communication with the second inlet port, and a spring loaded annular valve seat member arranged within the first fluid chamber to cooperate with a valve part of the piston so as to control the fluid flow from the first inlet port to the outlet port in response to the difference in pressure between the fluid chambers. A support member is arranged within the first fluid chamber formed therein with an axial bore in which a large diameter portion of the piston is slidably disposed to form a third annular fluid chamber. The support member is further formed with an orifice for effecting the fluid flow between the first and third fluid chambers in response to axial movement of the piston.

Regulator valve for hydraulic anti-skid apparatus

In a brake pressure control device having an inlet port for connection to a master cylinder and an outlet port for connection to a wheel brake cylinder, a differential piston cooperates with a first annular valve seat arranged in a first passage between the inlet and outlet ports, and an inertia-controlled valve element contained within a valve chamber formed in a second passage between the inlet and outlet ports to cooperate with a second annular valve seat fixed to one end portion of the piston. The one end portion of the piston is formed therein with a passage arranged to permit fluid flow passing through the second valve seat between the valve chamber and the outlet port. In such an arrangement, the valve element rests in place to be spaced from the second valve seat when the deceleration is below a predetermined value, the valve element being engaged with the second valve seat when subjected to the deceleration in excess of the predetermined value, and the piston is displaced against a spring load acting thereto to increase the space between the second valve seat and the valve element before the deceleration reaches the predetermined value under a heavy loaded condition of the vehicle.

Brake pressure control device for vehicle braking systems

A hydraulic system for a vehicle having an open-center hydraulic brake booster powered by an engine-driven single rotary pump with an unloader valve into which is incorporated a bypass valve to enable a fluid flow to bypass the unloader valve into the brake booster. The invention contemplates the use of the bypass valve for such purpose as pressurizing the fluid circuit upstream of the bypass valve for storaging fluid in a fluid storage member under pressure in case of rest position of the booster for actuating the booster when the pump failed.

Hydraulic system for a vehicle

A fluid pressure operated electrical switch has a piston element subject to an operating fluid pressure on its acting end face for actuating an electrical switch. The switch employs a limiting member for limiting motion of the piston element to a predetermined extent in order to prevent the switch from being damaged due to overstroke of the piston element. The limiting member includes a flange at the rearmost end of the piston element and an annular shoulder in a bushing which is closely fitted within a port of a switch body for the operating fluid pressure. The piston element is loosely fit in the bushing with the flange in engagement within the shoulder of the bushing such that the flange and shoulder cooperate to provide limitation of the stroke of the piston element.

Growing community of inventors

Gamagori, Japan

Yoshiharu Adachi