Fluid-pressure and analogous brake systems – Speed-controlled – Having a valve system responsive to a wheel lock signal
Patent
1988-08-16
1990-05-15
Kashnikow, Andres
Fluid-pressure and analogous brake systems
Speed-controlled
Having a valve system responsive to a wheel lock signal
303103, 36442603, 36442602, B60T 864, B60T 860
Patent
active
049252534
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates generally to a method and corresponding apparatus for automatically actuating a vehicle wheel brake with the aim of preventing the wheel from skidding in conjunction with braking and acceleration. More specifically, the present invention relates to such a method wherein the instantaneous speed of rotation of the wheel is sensed and the instantaneous absolute speed variation is calculated, after which the wheel brake is automatically released or actuated depending upon the sensed conditions.
According to the aforementioned brake actuation method, the wheel brake is automatically released during braking of the vehicle when the speed of rotation of the wheel reduces so that its absolute speed variation is greater than a predetermined maximum permissible value. The wheel brake is also automatically released during braking when the speed of rotation of the wheel approaches zero and the vehicle is still in motion. The wheel brake is applied automatically during vehicle braking when the speed of rotation of the wheel has increased to a predetermined reducing value after the brake has previously been released.
During vehicle acceleration, the wheel brake is applied automatically when the speed of rotation of the wheel increases so that its absolute speed variation is greater than the aforementioned predetermined maximum permissible value. The wheel brake is released automatically during acceleration of the vehicle when the speed of rotation of the wheel has fallen to a predetermined increasing value after the brake has been applied.
The wheel brake of the aforementioned brake actuation method remains unaffected and is not subject to automatic actuation when the absolute variation in the speed of rotation of the wheel is less than the aforementioned predetermined maximum permissible value. Also, the wheel brake is applied on braking once a predetermined period has elapsed since the brake was released, and is released on acceleration once a predetermined period has elapsed since the brake was applied.
U.S. Pat. No. 3,917,353 contains an exhaustive description of the above-mentioned method and a system which operates in accordance therewith, including discussion of the difficulties which are associated with braking. A system which proposes to resolve similar problems during both braking and acceleration is described in U.S. Pat. No. 3,584,921.
U.S. Pat. No. 3,958,834 discloses the re-application of a brake during braking once a predetermined period has elapsed since the brake was released automatically, without the unbraked wheel having previously reached an acceleration threshold.
While the above-mentioned system operates satisfactorily when the friction between the road surface and the wheel remains substantially constant, i.e., the road surface is either slippery or coarse, it has been found that the required braking distance for such a system becomes unnecessarily long under variable road conditions, due to an inability of the system to take account of and provide effective braking under such variable conditions.
SUMMARY OF THE INVENTION
The object of the present invention is to make available a method of preventing the wheel of the vehicle from skidding during both braking and acceleration.
The present invention provides an improved brake actuation method and apparatus, wherein the aforementioned period for automatic brake application reckoned from an automatic release during braking is calculated as a percentage increment of time to be added to the period between a previous release and application of the brake during braking. Likewise, the aforementioned period for automatic brake release reckoned from an automatic application during acceleration is calculated as a percentage increment of time to be added to the period between a previous application and release of the brake during acceleration.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described below in more detail with reference to the accompanying drawing, in which:
FIG. 1 is a flow ch
REFERENCES:
patent: Re31383 (1983-09-01), Leiber et al.
patent: 3584921 (1971-06-01), Crawford
patent: 3790227 (1974-02-01), Dozier
patent: 3820855 (1974-06-01), Salotti et al.
patent: 3888550 (1975-06-01), Reinecke et al.
patent: 3917353 (1975-11-01), Swiden et al.
patent: 3958834 (1976-05-01), Takeuchi et al.
patent: 4230376 (1980-10-01), Brearley et al.
patent: 4327948 (1982-05-01), Beck et al.
patent: 4430714 (1984-02-01), Matsuda et al.
patent: 4480309 (1984-10-01), Burckhardt et al.
patent: 4484280 (1984-11-01), Brugger et al.
patent: 4635031 (1987-01-01), Blomberg et al.
patent: 4681374 (1987-07-01), Nakomara et al.
Ahlersmeyer David L.
Hoffman John F.
Jeffers Albert L.
Kashnikow Andres
Newholm Timothy
LandOfFree
Method and arrangement of automatically actuating a vehicle whee does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and arrangement of automatically actuating a vehicle whee, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and arrangement of automatically actuating a vehicle whee will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-617654