Fluid-pressure and analogous brake systems – Multiple systems – Fluid pressure and electric
Patent
1994-10-26
1996-04-09
Ballato, Josie
Fluid-pressure and analogous brake systems
Multiple systems
Fluid pressure and electric
303155, B60T 1366
Patent
active
055055265
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a brake pressure control method in a vehicle brake system equipped with an electronically adjustable brake pressure booster, with which an actuating speed of the brake pedal is determined and brake pressure boosting effected in response to the same.
Such a method is known from DE 40 28 290 C1. In that case it is suggested to shorten the distance to stop a motor vehicle in critical driving situations (especially during so-called panic braking) by drawing upon the actuating speed of the brake pedal as a criterion to release automatic application of the brakes. To accomplish that, a per se known brake pressure booster is used which generates brake pressures at the vehicle brakes which no longer are determined exclusively by the force produced at the pedal by the driver of the vehicle, but instead by other criteria, especially by a comparison between the actuating speed of the brake pedal and a threshold value. If the brake pedal actuating speed surpasses a threshold value, the braking operation is released automatically and brake pressure is built up to a level higher than the pressure that would result from the position of the brake pedal alone.
With this prior art, the brake pressure at the individual vehicle brakes is not controlled but rather regulated. An increased brake pressure is built up in response to the actuating speed of the brake pedal so that additional brake pressure beyond the brake pressure resulting from the instantaneous pedal position of the brake pedal is generated (when the above mentioned threshold value is exceeded), and this pressure, for instance, may be proportional to the maximum actuating speed of the brake pedal which occurred.
Those skilled in the art are familiar with the art of adjusting random or automatically controlled higher pressure values in vehicle brakes, in addition to the hydraulic pressure produced by the master cylinder of a brake system. For example, DE 39 43 002 A1 describes a vehicle brake system comprising a brake pressure booster and another valve, controlled electrically, which is provided in addition to the conventional mechanical operating valve of the brake pressure booster so as to adjust the brake pressure booster (and thus the braking force) in response to control signals provided by a data processing means. DE-GM 92 02 154, too, describes an electronically adjustable brake pressure booster.
In the description below, the above prior art is assumed to be known, especially the art of brake pressure boosters and their electronic control, such as by means of electronically controlled valves is assumed to be known.
In accordance with the prior art, therefore, particularly those means must be started from as being known with which brake pressure boosters, such as boosters operating with a pressure difference, are controllable by means of an additional, electromagnetically operable, control valve such that brake pressure boosting is effected which differs from purely mechanically adjusted brake pressure boosting, differing more specifically in accordance with the electronic control commands for the electromagnetically operable control valve of the brake pressure booster.
Brake pressure control which makes use of a brake pressure booster, ideally, could consist in measuring the force produced by the driver of the vehicle at the brake pedal and deriving a control signal for the brake pressure booster according to a given function, with the aid of this force, and generating corresponding brake pressure at the wheels which are to be retarded (if desired, under the conditions of antilock control). However, it is very expensive to mount a force sensor in addition at the master cylinder of a brake system.
Investigations of the behavior of motor vehicle drivers have shown that in critical driving conditions (particularly during so-called panic braking) involuntary false behavior often occurs. During the initial phase of a braking operation, very frequently the brake pedal, although being applied sufficiently quick
REFERENCES:
patent: 4610484 (1986-09-01), Amberg et al.
patent: 4678243 (1987-07-01), Leiber
patent: 4914917 (1990-04-01), Schonlau
patent: 5158343 (1992-10-01), Reichelt et al.
Ballato Josie
Lucas Industries Public Limited Company
LandOfFree
Adjusting actual brake pressure to match stored pressure values does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Adjusting actual brake pressure to match stored pressure values , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adjusting actual brake pressure to match stored pressure values will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-134665