Abstract: An anti-lock braking control system is described in which the braking pressure cycle is filtered by limiting the minimum time period of each brake pressure cycle. The period from the time a brake pressure release phase is initiated until the next brake pressure release phase is called for is timed. If the time is less than a predetermined value, the brake pressure is held constant until the minimum time period has expired.
Type:
Grant
Filed:
December 11, 1987
Date of Patent:
April 25, 1989
Assignees:
General Motors Corporation, Delco Electronics Corporation
Inventors:
Peter J. Spadafora, Philip M. Headley, Alan J. Lee, Jill G. Hersberger
Abstract: A hydraulic brake system for automotive vehicles with a master brake cylinder (1) connected to an unpressurized reservoir and with a brake line (13, 14) connected to a working chamber (4, 5) of the master brake cylinder and leading to pressure control valves of a brake slip control device (40). The pressure control valves are followed by at least one wheel brake (18, 19) with the working chamber (4, 5) of the master brake cylinder (1) being connectable to a pressure medium source (29) upon the start of the brake slip control device. To ensure that in brake systems of different vehicle types, the wheel brakes of which have clearances differing in size, the same master brake cylinder can be used without the master brake cylinder having an undesired long pedal travel and thus a great overall length.
Abstract: A valve assembly for an anti-skid brake system has at least two valves disposed parallel to one another. Both valves are embodied in the manner of check valves having closing springs. To open the valves, there is an armature displaceable by an electromagnet; the armature opens the first valve automatically via a rigid opening tappet and opens the second valve, via another opening tappet and a spring associated with it, only when a pressure urging the second valve in the closing direction does not exceed a preselected pressure difference relative to an armature chamber. This has the advantage that despite the high pressure drop, the quantity of pressure fluid per unit of time that flows through the valve assembly does not exceed a preselected threashold value in the anti-skid regulation situation; on the other hand, without anti-skid operation, a rapid buildup of brake pressure is possible by furnishing a larger flow cross section.
Abstract: A slip-controlled brake system for automotive vehicles including provision of a static brake circuit into which pressure fluid out of a dynamic pressure fluid circuit can be introduced during slip control via a multi-directional control valve. The master cylinder assembly connected for this purpose to a hydraulic brake power booster comprises a partition or floating piston designed as a stepped piston and isolating the two working chambers of the master cylinder. The large step of the floating piston is sealingly guided in the master cylinder bore, the working chamber in front of the large step communicating by way of a pressure fluid conduit with the booster chamber and with the brake circuit of the wheel brakes of the rear wheels.