Fluid-pressure and analogous brake systems – Speed-controlled – Having a valve system responsive to a wheel lock signal
Patent
1992-04-23
1993-10-12
Butler, Douglas C.
Fluid-pressure and analogous brake systems
Speed-controlled
Having a valve system responsive to a wheel lock signal
3031161, 3031191, 303900, B60T 840, B60T 842, B60T 844
Patent
active
052519716
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
This invention relates to an anti-lock-controlled brake system for automotive vehicles.
Such a brake system is already known from patent application, official Ser. No. P 40 15 884.5. If, within the scope of an anti-lock control operation, in this brake system, the braking pressure or rather the volume in the wheel brake threatened by a lock-up is reduced by means of actuating the inlet and outlet valves the electronic control unit simultaneously will cause the auxiliary pressure pump to start in order to provide the auxiliary pressure. The auxiliary pressure will switch a locking valve into its locking position so that the braking pressure generator will be separated from the pump pressure prevailing in the main pressure line. Due to the pressure limiting valve preadjusted via a compression spring as well as because of the hydraulic connection of the pressure limiting valve with the wheel brake on the front axle and because of the hydraulic communication towards the auxiliary pressure pump the pump pressure will automatically regulate itself in dependence on the wheel brake pressure active at the pressure limiting valve as well as in dependence on the spring-force-adjusted hydraulic prepressure. Consequently, the pressure limiting valve will adjust the pump pressure to the respective wheel brake pressure plus the adjusted prepressure of the effective compression spring. Thus, in case of need, on the one hand, pressure build-up of the auxiliary pressure pump can take place at a quicker rate as, due to the inventive hydraulic operating position, a relatively smaller pressure has to be overcome. On the other hand, the noise emission of the inlet valve is markedly reduced as the pressure difference at the inlet valve cannot be higher than the compression-spring-generated prepressure of the pressure limiting valve.
As compared with the generic brake system, this invention has the advantage that the return line is no longer connected to the open storage reservoir but rather communicates with the master cylinder whereby an accumulator system connected to the auxiliary pressure pump is controlled in an economically reasonable manner in dependence on the actual wheel brake volume requirements or rather on the actually required wheel brake pressure.
It is thus an object of this invention to further develop an anti-lock-controlled brake system of the type referred to at the beginning such as to enable a brake-slip-dependent adaptation of the auxiliary pressure supply to the actual pressure medium requirements in the wheel brake in a brake system decoupled from the storage reservoir.
SUMMARY OF THE INVENTION
According to this invention this object is solved by controlling the accumulator pressure or rather the volume of a closed hydraulic system via a pressure medium accumulator, connected to the pressure limiting valve, in dependence on the wheel brake pressure so as to meet the actual requirements.
The pressure medium accumulator is preferably formed by connecting two pressure accumulator pistons in tandem both in terms of construction and of action, the two pistons facing each other with a common space therebetween. Via the operation of the pressure limiting valve, this will cause an indirect hydraulic effect of the pressure level, adjusted at the wheel brake, on the pressure accumulator and this, on its part, will cause the second pressure accumulator piston to perform a stroke movement independent of the first pressure accumulator piston movement.
A spring element is interposed between the two facing pressure accumulator pistons in order to effect a spring-characteristic-dependent sequential control of the second pressure accumulator piston acting as a high pressure accumulator section.
A structurally compact and, hence, integral combination of the two pressure accumulator pistons with the spring element is achieved by mounting in a common pressure accumulator housing.
A non-return valve, locking in the direction of the auxiliary pressure pump, and a throttle are arranged in the hy
REFERENCES:
patent: 4618189 (1986-10-01), Nakanishi et al.
patent: 4699435 (1987-10-01), Wupper
patent: 5094511 (1992-03-01), Becker et al.
patent: 5152586 (1992-10-01), Burgdorf
Japanese Abstract, vol. 10, No. 105 (M-471) (2162) Apr. 19, 1986.
Japanese Abstract, vol. 10, No. 118 (M-475) (2175) May 2, 1986.
Reinartz Hans-Dieter
Steffes Helmut
Alfred Teves GmbH
Butler Douglas C.
Lewis J. Gordon
Seitter Robert P.
LandOfFree
Anti-lock controlled brake system for automotive vehicles does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Anti-lock controlled brake system for automotive vehicles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Anti-lock controlled brake system for automotive vehicles will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1900064