Motor vehicles – Having four wheels driven – With differential means for driving two wheel sets at...
Patent
1986-04-24
1988-10-04
Love, John J.
Motor vehicles
Having four wheels driven
With differential means for driving two wheel sets at...
747105, 180252, B60K 1735
Patent
active
047750260
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention concerns the actuation of a differential lock controlled by signals originating outside the lock.
BACKGROUND OF THE INVENTION
It is known how to actuate locking differentials by monitoring differences of speed rotation (similar to anti-blocking systems). Thus, a catalog of the SIGE Company, Vimercate (Italy) shows an "electronic locking differential" whose operating principle utilizes two speed-of-rotation sensors on the two wheels of shaft stubs, respectively, whose signals are compared electronically and then converted to an engagement signal for an electronically operable locking clutch. This type of construction is particularly unsatisfactory for vehicles with additionally clutchable drive axles for the following diverse reasons:
(a) The first reason is that the shifting principle exemplified by the SIGE catalog causes actuation of the lock immediately when a predetermined difference of rotational speed is reached, regardless of the cause. The synchronous rotation of the wheels thus attained leads again to a release of the lock. Therefore, a reactivation can occur immediately and it can, at an appropriate configuration of the terrain, come to a continuous actuation and deactuation which severely stresses the locking means. One attempts to counter this problem by means of an actuation delay. However, the problem will still divert a driver's attention.
(b) One needs, in addition, to two sensing positions, a relatively sensitive and complex electronic conversion means because an engagement point for an electrical coupling operated with switching current cannot be preset with mechanical exactitude.
(c) Furthermore, the prevention of accidental activation and deactivation of the lock during driving conditions when it is not desired (e.g. release of lock during turning of a tractor on strongly inclined, irregular terrain) based on comparison of speed of rotation is not attainable with absolute certainty. The reason for such uncertainty may be traced to the many influences of load distribution or terrain properties which are never exactly determinable in advance upon the release of the engagement actuation.
(d) Finally, the installation of two electronic measuring sensors to be attuned to each other on the two drive shafts increases or multiplies the problems of assembly, protection from damage, and inspection.
It is an objective of the present invention to advance the state of the art in such manner than an engagement means is created less complex and less prone to malfunction in an actuation range exactly predeterminable, easily installed, where the driver can clearly foresee the occurrence of the engagement point, and steer accordingly.
SUMMARY OF THE INVENTION
According to this invention an actuator device is provided for a differential lock which is controlled by a signal originating outside the differential lock, with a signal generator (7) actuated upon at an immediately sensed value of a steering angle excursion (L) due to an excursion of a displaceable steering element (5, 20) with respect to an axle housing (2) wherein the improvement comprises the signal generator (7) being mounted embedded in a construction element (2, 3) rigidly connected to the axle housing (2) so as to provide protection against impact, dirt and damage, and wherein a locking differential (10) comprises an electrically actuatable coupling (11) in an electrical switching circuit of the signal generator (7) whereby connection cables (31) are brought to said signal generator through the axle housing (2).
The accomplishment of the invention objective is based on the fact that for the actuation of the differential lock there is no need for two sensors and an electronic evaluation device for differences either in speed of rotation or of torque to actuate the differential lock. Instead, there is now a single YES-NO electrical engagement signal immediately scannable, if possible, by galvanic means. The foregoing arises directly from a mechanical change of the steering geometry, wherein the si
REFERENCES:
patent: 2803150 (1957-08-01), Fisher
patent: 2874790 (1959-02-01), Hennessey
patent: 4162712 (1979-07-01), Nelson
patent: 4523494 (1985-06-01), Sparks et al.
patent: 4559847 (1985-12-01), Newendorp et al.
patent: 4570509 (1986-02-01), Nighswonger
International Application (PCT), WO 81/02049, Published Jul. 23, 1981, (Avery).
Sige Catalog, Brevetti Ing. Colombo SPA "Elektronisches Selbstsperrdifferential".
Dziuba Peter
Ehrlinger Friedrich
Keller Walter
Sollbach Gerhard
Dubno Herbert
Love John J.
Watts Charles R.
Zahnradfabrik Friedrichshafen AG
LandOfFree
Actuation of a differential lock does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Actuation of a differential lock, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Actuation of a differential lock will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2151561