Fluid-pressure and analogous brake systems – Speed-controlled – Having a valve system responsive to a wheel lock signal
Patent
1998-05-31
1999-10-26
Butler, Douglas C.
Fluid-pressure and analogous brake systems
Speed-controlled
Having a valve system responsive to a wheel lock signal
188356, 188358, 3031141, 3031143, 3031161, 303DIG4, 303 10, B60T 840, B60T 1702
Patent
active
059715006
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to an electronically controllable braking system for motor vehicles with a brake pressure generator unit which can be actuated by a brake pedal, which supplies hydraulic fluid via a hydraulic fluid path to at least one wheel brake of the motor vehicle, a first electromagnetic valve arrangement which is arranged in the hydraulic fluid path between the brake pressure generator and the wheel brake for controlling the pressure build-up, pressure relief and pressure holding phases in the wheel brake, a motor-powered controllable hydraulic pressure source which, in addition to or in lieu of the brake pressure generator, supplies hydraulic fluid to the wheel brake.
From DE 32 19 133 A1 a similar arrangement is known wherein an electric motor for driving a fan of a motor vehicle is additionally employed as the drive of a pump which charges a pressure accumulator for the supply of an auxiliary braking system. The electric motor can additionally be turned on by means of a pressure switch which monitors the accumulator pressure of the pressure accumulator. Moreover, the drive shaft of the electric motor can be coupled to the pump via electromagnetically operable clutches and decoupled from the fan when the pressure accumulator is being charged.
The problem with this arrangement is that the electric motor for driving the fan, for example of a cooling means of the motor vehicle, is usually arranged at a considerable distance from the vehicle braking system so that relatively long pressure lines have to be routed from the pump coupled with the electric motor to the vehicle braking system. Moreover, the two electromagnetically operable clutches are complicated and vulnerable under operating conditions so that the solution as proposed therein is only conditionally suited for a large-scale application under safety and cost aspects.
Nevertheless, there is a demand for a compact and simultaneously safe and economic possibility for a multiple ultilisation of electrical systems which exist in a motor vehicle.
To this end, the invention proposes a motor-powered controllable auxiliary energy source which boosts an actuation of the brake pressure generator by the brake pedal or which effects an actuation of the brake pressure generator in lieu of the brake pedal, with the controllable auxiliary energy source and the controllable hydraulic pressure source being driven by the same motor and being continuously functionally connected with same.
The use of a common motor for the controllable hydraulic source and the controllable auxiliary energy source ensures that long line routings are avoided. Due to the continuous connection via a gear mechanism between the common motor for the controllable hydraulic pressure source and the controllable auxiliary energy source the failure-prone and complicated electromagnetic clutches are omitted.
According to a first embodiment the controllable auxiliary energy source is a pneumatic pump which acts upon a pneumatic brake booster which is coupled with the brake pressure generator. The pneumatic pump may be both an overpressure and a vacuum pump. Depending on whether the pneumatic pump is an overpressure or a vacuum pump, feeding of the auxiliary energy into the pneumatic brake booster is effected into the vacuum chamber or the atmospheric chamber.
The pneumatic pump is preferably a vacuum pump which takes the place of a connection to an intake pipe of an Otto engine.
Preferably, a second controllable valve arrangement is provided between the pneumatic pump and the brake booster by means of which--under the control of an electronic control unit--an actuation of the brake pressure generator can be boosted or an actuation of the brake pressure generator in lieu of the brake pedal can be effected. According to a particularly preferred embodiment the pneumatic pump is either connected with the brake booster, or an inlet and an outlet side of the pneumatic pump can be brought to approximately the same pressure level, depending on the position of the second valve arrangement
REFERENCES:
patent: 3840087 (1974-10-01), Von Loewis et al.
patent: 5547266 (1996-08-01), Beck et al.
patent: 5704694 (1998-01-01), Kozakai
patent: 5855420 (1999-01-01), Lawrence
Lubischer Frank
Voges Dieter
Butler Douglas C.
Lucas Industries Public Limited Company
LandOfFree
Electronically adjustable brake system for motor 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 Electronically adjustable brake system for motor vehicles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electronically adjustable brake system for motor vehicles will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-755475