Abstract:
To control the braking pressure in the wheel brakes of a slip-controlled hydraulic brake system for automotive vehicles with all-wheel drive and with lockable or automatically locking differentials (2, 3), a circuit configuration is provided which influences the variation of the vehicle reference speed (v.sub.REF). This is to say, in the event of the wheel (v.sub.Rn) which is momentarily decisive for the formation of references becoming instable, the reference speed (v.sub.REF) will first be declined with a relatively flat gradient which corresponds to a vehicle deceleration at a low frictional coefficient. A decrease of the vehicle reference speed (v.sub.REF) with a very steep gradient will follow after a predetermined period of time (T.sub.1). This decrease is continued until the vehicle reference speed (v.sub.REF) reaches the decisive wheel speed again or falls thereunder. To avoid oscillations, the change-over of the reference (v.sub.REF) after the attainment of the wheel speed curves (v.sub.Rn) will not be effected until after a predetermined time of delay (T.sub.2 or T.sub.3).
Abstract:
To monitor and control the pressure in the auxiliary pressure supply system of a hydraulic motor vehicle brake system, a circuit arrangement is employed which is provided with a door-contact switch (24) which closes when the driver's door of the motor car is opened and which at a pressure in the auxiliary pressure supply system (11-16) below the telltale threshold activates the hydraulic pump (11) irrespective of the activation of the ignition. Moreover, a holding circuit (25, 26, 30, D30) is provided through which, after closure of the driver's door, the hydraulic pump (11) continues to operate until the telltale pressure threshold or responding threshold is reached or exceeded.
Abstract:
An anti-lock hydraulic brake system is described wherein a throttle valve has a restrictive flow condition which becomes effective in the brake line in the event of brake slip control. Pumps for reapply pressure deliver fluid to the wheel brake via this restriction and regulating the pressure in the wheel brake is performed by control of an outlet valve. The throttle valve is operated hydraulically by various arrangements including the application of pump pressure, or by wheel brake pressure applied upon opening of the outlet valve at the start of an anti-lock control cycle.
Abstract:
An anti-lock-controlled hydraulic brake system is described having a pump (9) and a master brake cylinder (1). An arrangement for controlling the pump pressure is integrated in the master brake cylinder ( 1 ) and consists of the combination of a connection of the pump to the master cylinder and reservoir, and a primary seal (30, 34) cooperating with a compensating hole (36) in the master cylinder wall. The seal (30, 34) consists of an elastic ring (37) lying on the inside and of a slide ring (38) lying on the outside. The necessary communication between the storage reservoir ( 7 ) and the brake circuits, which enables the brake circuits to be resupplied via a non-return valve, is effected via the nonreturn valves (10, 11) of the pump (9). The double seal can be backed by a secondary seal (41) which completely seals the working chamber against leakage flow past the primary ring seal.
Abstract:
In a hydraulic brake system for automotive vehicles with an electronically controlled brake force distribution and with anti-lock control, the rear-wheel brakes are connected via inlet valves (5, 7) closed in their inactive position. Placed in parallel to these valves is an arrangement (13, 14; 13', 14') which is substantially composed of the series connection of a brake force regulator (17, 18, 17', 18') with a throttle (15, 16) or a multiple-way valve (21, 22) which is open in its inactive position.
Abstract:
A slip-controlled brake system for automotive vehicles equipped with a deceleration-sensitively actuated brake pressure modulator (1) comprising a shaft (7) rotating together with the wheel (6) and an inert mass (8) arranged on said shaft. If a critical wheel deceleration is exceeded, the inert mass (8) is axially displaced on the shaft (7) by an arrangement comprising a ball (10) and an inclined ramp (9), and the brake pressure in the wheel brake (5) of the associated wheel (6) is, by way of a lever (16) actuating a brake pressure control valve (17), thus controlled, that is maintained and/or reduced. The rotating inert mass (8) which, due to its inertia, at first continues to run at unreduced speed when the control action sets in, is slowed down to the rotational speed of the shaft (7) by a force depending on the instantaneous brake pressure in the wheel brake (5). During the control phase, the reference quantity (v.sub.REF) relevant to the control action is, thereby, adapted to the instantaneous brake pressure and thus to the instantaneous friction coefficient existing between the road surface and the controlled wheel (6).
Abstract:
An anti-lock hydraulic brake system equipped with one plunger system (7, 8) each per brake circuit (I, II) for the purpose of pressure control, that is, slip control. Serving as an auxiliary-pressure source is a hydraulic pump (9) which is driven electromotively, preferably through the starter motor (10), and which comprises hydraulically isolated circuits for the individual plunger systems. The plunger systems are each controlled by one two-way/two-position directional control valve (21, 22) which is actuatable electromagnetically and is controllable as a function of the signals obtained by wheel sensors (24 to 27) and processed in an electronic controller (23). A valve piston (47, 48) in conjunction with a valve member (55, 56) and a channel (53, 54) closable by this valve member opens in the plunger system (7, 8) a connection to a pressure-fluid return line (19, 20) as soon as the braking pressure has decreased to a predetermined low threshold value and thereby prevents low pressure in the brake system. The hydraulic pump (9) is in operation only during the control. A strong resetting spring (45, 46) ensures that the normal brake function will be regained immediately on failure of the auxiliary pressure.
Abstract:
A pump having a simple and compact construction which permits leakage test of the pressure valve both outside and inside the pump housing, and, if necessary, ensures ease of replacement of individual parts, such as replacement of the pressure valve or the valve seat member, if leakage occurs during testing. The peripheral surface of the valve seat member facing the cover has a conical chamfer onto which an annular projection of the cover is movable into sealing abutment and is radially expandable to provide a press fit engagement.
Abstract:
In a hydraulic brake system for automotive vehicles with an electronically controlled brake force distribution and with anti-lock control, the rear-wheel brakes are connected via inlet valves (5, 7) closed in their inactive position. Placed in parallel to these valves is an arrangement (13, 14; 13', 14') which is substantially composed of the series connection of a brake force regulator (17, 18, 17', 18') with a throttle (15, 16) or a multiple-way valve (21, 22) which is open in its inactive position.
Abstract:
A circuit configuration for a brake system with anti-lock control and traction slip control comprising, wheel sensors for generating electric signals representing the wheel rotational behavior and circuits for the cornering identification is provided such that lateral reference speeds (13, 14) are formed by virtue of selection circuits (8, 9) which select leading wheel speed according to specific criteria, and by virtue of a filter means (10, 11) whose time constants (12) are variable. A difference signal (DVS) is formed of the lateral references speeds (SRG.sub.L, SRG.sub.R), the magnitude of which is variable by inverse feedback. This difference signal (DVS) serves to actuate an adaptation circuit (18) as a function of the vehicle reference speed (V.sub.REF). The adaptation circuit influences on the control thresholds of the anti-lock control and traction slip control to adapt the control to the particularities of cornering.