Brakes – With condition indicator – Electrical
Patent
1992-02-26
1994-01-18
Butler, Douglas C.
Brakes
With condition indicator
Electrical
188 7342, 188 7343, 188181T, 303112, B60T 852, F16D 55224
Patent
active
052793940
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a disc brake comprising two pads which are adapted to be pressed against the brake disc on both sides and which are supported on a vehicle-fixed support with respect to a force generated when the brake pads bear on the brake disc, and at least one force sensor arranged in the path of the force between one of the brake pads and the support for measuring the brake torque.
Such a disc brake is known from EP 0 221 299 A2, cf. therein in particular FIG. 4. In the latter, on the support plate of a brake lining in a sliding caliper brake a torque sensor is provided which is arranged in the path of force of the frictional force (so-called peripheral force) generated by brake friction between the brake disc and the friction linings and the vehicle-fixed support.
In addition, the invention proceeds from prior art as known from EP 0 229 618 A2. The disclosure content of that publication is expressly made part of the content of the present application. The sliding caliper spot-type disc brake for motor vehicles described therein has a sliding caliper which is displaceably mounted with respect to a vehicle-fixed support, two brake pads which act on the brake disc on both sides and have support plates for brake linings on their sides remote from the brake disc, a hydraulic piston-cylinder assembly in the sliding caliper which acts directly on one of the two brake pads and on the other brake pad via the sliding caliper, and a slide guide between the support and the sliding caliper. It is distinguished in that one of the lining support plates is supported solely at the sliding caliper and the other solely at the piston of the piston-cylinder assembly and that between the piston or a component fixedly connected therewith and the support a further slide guide is provided. However, this known disc brake does not include any measuring device for determining the brake torque.
In progressive braking, knowledge of the brake torque actually generated braking by friction is extremely desirable.
U.S. Pat No. 2,183,700 discloses a direct measurement of the brake torque in a drum brake. For the measurement therein, an eccentric pin is arranged between the brake pads and a frictional force generated on braking effects a turning of the pin. The rotary force acting on the pin is proportional to the actually generated brake torque but is independent of the actuating force applied by means of the brake pedal. Said pin turning on generation of a brake torque is provided with a means which on rotation thereof acts on an electrical circuit in such a manner that a signal is emitted which is proportional to the rotation and thus to the brake torque.
This prior art is already based on the recognition that the brake torque actually generated on braking is in no way always a clear function of the hydraulic pressure generated in the brake cylinder with the brake pedal. The causes of the absence of such a clear relationship may be very varied and extend from defective brakes through worn brake linings up to changes in the coefficient of friction between the brake disc (or the brake drum) and the brake pads due to different temperatures.
Exact knowledge of the actual magnitude of the brake torque generated by friction can serve a variety of purposes; in particular, the brake torque can be used to control the brake system, to monitor the latter, to determine the road adhesion coefficient, to control the drive engine, to control the starting coupling (cf aforementioned EP 0 221 299 A2), to control the switching stages of the vehicle transmission and for connecting or disconnecting drive axles.
The direct measurement of the brake torque is particularly significant as a reliable means for monitoring the function of brakes. Except for the brake torque, all the parameters measurable in a brake can erroneously simulate a functioning brake during a measurement. In contrast, the measurement of the brake torque is the most direct and most reliable way of monitoring the function of a brake. In particular, the direct measurement of brak
REFERENCES:
patent: 2183700 (1939-12-01), Sinclair
patent: 3166159 (1965-01-01), Burnett
patent: 3689121 (1972-09-01), Kawabe et al.
patent: 4666021 (1987-05-01), Messersmith
patent: 4679668 (1987-07-01), Washizu et al.
patent: 4716994 (1988-01-01), Iwamoto
patent: 4775033 (1988-10-01), Heibel
Research Disclosure, No. 270, Oct. 1986.
Patent Abstracts of Japan, vol. 12, No. 292 Aug. 10, 1988 and JP-A-63 068449 Mar. 28, 1988.
Wollenweber Karl-Heinz
Zimmermann Dieter
Butler Douglas C.
Lucas Industries Public Limited Company
LandOfFree
Disc brake does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Disc brake, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Disc brake will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1131730