Nissan Motor Company Limited

Kazuaki Shimizu

Hitoshi Kubota

Haruhiko Iizuka

Hiroyuki Asano

Terukiyo Murakami

Yoshinori Katayama

Yuichi Abe

Yoshio Otsuka

Tetu Yamazaki

Toshio Yama

Hitoshi Kuboto

Yoshio Fukai

Shunichi Toshida

There is proved a driving force control system which comprises device for measuring operating state of the vehicle brake system and generating an output signal, and device for controlling a driving force upon a predetermined condition being fulfilled after the output signal has indicated a predetermined operating state of the vehicle brake system.

Driving force control system

A hydraulic pressure control valve assembly for a hydraulic brake system for a wheeled vehicle, comprises a proportioning valve having a plunger which is axially movable in a direction against a spring in response to application of a hydraulic pressure to a fluid inlet port to control the magnitude of hydraulic pressure in a fluid outlet port, and a deceleration sensing valve responsive to a deceleration of the vehicle the degree of which exceeds a predetermined value. The deceleration sensing valve has a piston which supports an end of the spring and is sealingly disposed in a chamber to define a sealed expandable chamber which is communicable with the fluid inlet port to enable the expandable chamber to contain a fluid the pressure of which is changeable in accordance with the degree of the deceleration of the vehicle. Biasing means is arranged in the valve assembly to bias the plunger to move axially in the other direction when the magnitude of hydraulic pressure in the sealed expandable chamber exceeds a predetermined value causing the piston to move toward the plunger beyond a predetermined distance against the spring.

Hydraulic pressure control valve assembly for automotive hydraulic brake

An enclosed space which constitutes part of an operating chamber of a cylinder is left between a piston and the bottom of the cylinder or between a piston and another piston when the piston is brought into contact with the bottom or the other piston. At least one groove or recess is formed in either the piston or the bottom, or in either the piston or the other piston so that communication between the enclosed space and a fluid port of the cylinder is not blocked even when the piston is brought into contact with the bottom or the other piston.

Disc brake

A hydraulic pressure control valve assembly comprising a proportioning valve and a deceleration sensing valve is such arranged that when the magnitude of hydraulic pressure in an expandable chamber of the deceleration sensing valve exceeds a predetermined value in response to rapid deceleration of the vehicle, a piston associated with the expandable chamber is brought into contact with a plunger of the proportioning valve thereby suppressing the axial movement of the plunger in a direction toward the piston. Thus, under this condition, the normal operation of the proportioning valve stops so that the hydraulic pressure in the fluid inlet port is supplied to the fluid outlet port, keeping the pressure unchanged.

An anti-skid device is provided with valving which establishes a first normal pressure transmission path between the master cylinder and the wheel brake cylinders via which an anti-skid pressure reduction can be effected to prevent lock up of the wheels and a second fail safe pressure transmission path which is established in place of the first path upon a malfunction or the like in a source of hydraulic pressure associated with the anti-skid device. The valving is characterized by a valve which is held open (establishing the first pressure transmission path) by abutment with a spool formed with a bore therein. The bore is closed at this time by the stem of the valve which seats in the mouth thereof until the spool moves in response to pump failure or the like to first allow the valve to seat (closing the first path) and subsequently move sufficiently to bring the stem out of contact with the bore mouth (opening the second fail safe path without overlap with the first).

Hydraulic anti-skid device

Locking means locks an expansion valve in a position in which the expansion valve provides communication between the master cylinder and a brake unit when hydraulic fluid pressure is not generated by a pump so that a bypass valve and a differential valve can be omitted and air can be purged without providing an air bleed device.

A stop locks an expansion valve of the anti-skid device in a position in which the expansion valve provides communication between a first passage located upstream of the expansion valve and a second passage interconnecting the expansion valve and a bypass valve during air bleeding, and an air bleed provides communication between the second passage and the atmosphere.

In the case of pump failure a spool valve instantly connects a pressurized fluid accumulator with the servo motor which assistingly activates the master cylinder and isolates a power steering mechanism fluidly connected to the servo motor so that only the power brake is temporarily operable but with stepwise decreasing effectiveness.

Motor vehicle power assisted braking system

A check valve is integrally formed on one end of an expansion valve slidably disposed in a first stepped bore and arranged to cut communication between the master cylinder and the brake units upon the pressure of the hydraulic fluid biasing the expansion valve to a first normal position being reduced due to either a signal from a computing circuit indicating a dangerously high rate of deceleration or cessation of the supply of pressurized hydraulic fluid. The movement of the expansion valve from its normal position permits the fluid in the brake units to pressure reducingly expand. A differential valve integrally connected to a by-pass valve maintains a fail safe pressure transmission path closed until cessation of the supply of pressurized fluid whereupon the master cylinder is directly connected with the brake units and a regulator valve slidably disposed in a third stepped bore formed in the by-pass valve is responsive to the change of both the master cylinder pressure and the supplied pressurized fluid to modulate the pressure biasing the expansion valve to its normal position.

Anti skid control valve

The invention provides a disc brake in which a tongue on a yoke is securely received in a blind bore formed in a piston of a hydraulic actuator by means of a pair of insert members of a resilient material. The insert members have grooves, respectively, for receiving the tongue. Each insert member has a part-cylindrical surface and the undistorted radius of curvature of the part-cylindrical surface of each insert member is greater than the radius of curvature of a cylindrical wall of the blind bore to permit easy insertion, during assembly, of the pair of insert members into the blind bore. When the tongue is inserted into the grooves of the insert members disposed in the blind bore, the part-cylindrical surfaces of the insert members are urged into firm engagement with the cylindrical wall and the insert members are caused to be distorted in such a manner as to urge the side walls of the grooves into firm engagement with the tongue.

A disc brake comprises a yoke which transmits the force developed by the piston to the indirectly actuated friction pad of the brake. The yoke has an indirectly actuated friction pad contacting bent edge which is arc-shaped and which bears along the edge thereof on the indirectly actuated friction pad so as to cause the contacting bent edge to firmly urge the indirectly actuated friction pad into a braking function during brake application.

Closed loop type disc brake

A friction pad of a disc brake is indirectly actuated through a yoke to move between brake application and brake release positions with respect to a braking disc. Supports on the yoke each have elastomeric bushings arranged to slidingly receive a collar on a rod fixed to the stationary hydraulic cylinder so as to guide the yoke in its movements. The elastomeric bushings are so configured that the elastomeric bearings slide over the collars with less frictional resistance during brake application movement than during brake release movement.

Elastomeric bushing clearance device for a closed-loop disc brake

Elastic members are disposed between yoke and the torque absorbing structure of a spot-type disc brake, the elastic members reacting against the yoke under actuated conditions only when an indirectly actuated friction pad is worn to such an extent that the yoke travels towards the face of a brake disc in excess of preselected distance, thereby to abruptly make the stroke of a brake pedal large so as to give a warning of danger to a driver that the friction pad is worn to a dangerous extent.

Growing community of inventors

Fujisawa, Japan

Kazuaki Shimizu