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EP-4306341-B1 - TRAILER STABILIZATION SYSTEM FOR A VEHICLE TRAILER WITH ROTATIONAL SPEED SENSOR

EP4306341B1EP 4306341 B1EP4306341 B1EP 4306341B1EP-4306341-B1

Inventors

  • STRASSER, JOSEF
  • Feichtner, Michael

Dates

Publication Date
20260513
Application Date
20230706

Claims (6)

  1. Trailer stabilisation system for a vehicle trailer, comprising - a rotational speed detection device for determining the rotational speed of at least one trailer wheel (53), wherein the rotational speed detection device comprises a pole wheel (25, 25', 25"), which is connected to a brake hub (24) or brake drum of a wheel brake of the vehicle trailer, and at least one rotational speed sensor (51) that interacts with the pole wheel (25, 25', 25"), - an electronic controller (44), which is connected to the rotational speed detection device, for controlling at least one brake actuator (19) to produce a brake force and to brake the at least one trailer wheel (53) by means of the wheel brake as a function of the detected rotational speed of the trailer wheel (53), characterised in that the rotational speed sensor (51) is attached to a sensor holder (56), which is attached to a stub axle (5) of a trailer axle, said stub axle (5) serving to mount the brake hub (24) or brake drum, and in that the pole wheel has a substantially L-shaped cross-section, wherein a plurality of depressions (42) are arranged in a vertical limb (41) of the pole wheel (25), wherein connecting bars (43) are located between the depressions (42), wherein the depressions (42) and connecting bars (43) are arranged relative to the rotational speed sensor such that they are led past the rotational speed sensor and cause changes in the magnetic field there.
  2. Trailer stabilisation system according to claim 1, characterised in that the sensor holder (56) has a clamping device in the form of a clamp (57) for encompassing the stub axle (5) and for retaining the sensor holder (56) on the stub axle (5).
  3. Trailer stabilisation system according to claim 2, characterised in that one half (57b) of the clamp (57) is integrally connected to an arm (59), which extends from the clamp (57) to the pole wheel (25, 25', 25").
  4. Trailer stabilisation system for a vehicle trailer, comprising - a rotational speed detection device for determining the rotational speed of at least one trailer wheel (53), wherein the rotational speed detection device comprises a pole wheel (25, 25', 25"), which is connected a brake hub (24) or brake drum of a wheel brake of the vehicle trailer, and at least one rotational speed sensor that interacts with the pole wheel (25, 25', 25"), - an electronic controller (44), which is connected to the rotational speed detection device, for controlling at least one brake actuator (19) to produce a brake force and to brake the at least one trailer wheel (53) by means of the wheel brake as a function of the detected rotational speed of the trailer wheel (53), characterised in that the rotational speed sensor (51) is attached to a sensor holder (54) which is attached to a cable insertion fitting (35) of a brake carrier plate (34), and in that the pole wheel has a substantially L-shaped cross-section, wherein a plurality of depressions (42) are arranged in a vertical limb (41) of the pole wheel (25), wherein connecting bars (43) are located between the depressions (42), wherein the depressions (42) and connecting bars (43) are arranged relative to the rotational speed sensor such that they are led past the rotational speed sensor and cause changes in the magnetic field there.
  5. Trailer stabilisation system according to claim 4, characterised in that the cable insertion fitting (35) has a first holding shell (35a), which is attached to the brake carrier plate (34), and a second holding shell (35b), which is detachably connected to the first holding shell (35a), wherein the sensor holder (54) is attached to the detachable second holding shell (35b).
  6. Trailer stabilisation system for a vehicle trailer, comprising - a rotational speed detecting device for determining the rotational speed of at least one trailer wheel (53), wherein the rotational speed detection device comprises a pole wheel (25, 25', 25"), which is connected to the brake hub (24) or brake drum of a wheel brake of the vehicle trailer, and at least one rotational speed sensor (51) that interacts with the pole wheel (25, 25', 25"), - an electronic controller (44), which connected to the rotational speed detection device, for controlling at least one brake actuator (19) to produce a brake force and to brake the at least one trailer wheel (53) by means of the wheel brake as a function of the detected rotational speed of the trailer wheel (53), characterised in that the rotational speed sensor (51) is attached to a sensor holder (60), which is attached to a brake carrier plate (34) in the region of a viewing hole (61), provided in the brake carrier plate (34), in such a way that the rotational speed sensor (51) is directed through the viewing hole (61) towards the pole wheel (25, 25', 25"), and in that the pole wheel has a substantially L-shaped cross-section, wherein a plurality of depressions (42) are arranged in a vertical limb (41) of the pole wheel (25), wherein connecting bars (43) are located between the depressions (42), wherein the depressions (42) and connecting bars (43) are arranged relative to the rotational speed sensor such that they are led past the rotational speed sensor and cause changes in the magnetic field there.

Description

The invention relates to a trailer stabilization system for a vehicle trailer, in particular for a caravan, transport or boat trailer, according to the preamble of claims 1, 4 and 6. Trailer stabilization systems of this type are known to prevent unstable driving conditions of the trailer, especially swaying movements. This is achieved by applying the wheel brakes of the trailer when swaying occurs, thus straightening the vehicle combination and counteracting the swaying motion. The detection of swaying movements is usually achieved using acceleration sensors, which send corresponding swaying signals to an electronic control unit for controlling a brake actuator. In braking systems with In mechanical brake force transmission, the braking force generated by the brake actuator is then transmitted to the wheel brakes, for example by means of cables in the form of Bowden cables. It is of utmost importance that the braking force transmitted to the wheel brakes, i.e., the brake clamping force, does not cause the trailer wheels to lock up. As is well known, locked trailer wheels prevent sufficient lateral forces from being transmitted to the road surface, which can intensify swaying movements and cause the trailer to break away sideways. This is particularly critical if the trailer wheel that is subjected to greater stress due to the trailer's rolling movements locks up. Whether a trailer wheel locks up depends heavily on the load and thus the trailer's weight, as well as the road surface and its coefficient of friction. With light, unloaded trailers and slippery surfaces, such as snow and ice, even relatively low braking forces can cause the trailer wheels to lock. With heavy, loaded trailers and surfaces with good grip, locking of the trailer wheels only occurs at higher braking forces. In known trailer stabilization systems for overrun-braked trailers that operate without regard to the load, the brake clamping force is constant and calibrated to the trailer's unladen weight. The use of such trailer stabilization systems is therefore limited to trailers with a relatively small difference between unladen weight and permissible total weight. From the EP 3176042 A1 A trailer stabilization system is already known that measures the axle load of the trailer to adjust the brake application forces to the trailer's load. However, this system does not take into account the friction between the road surface and the trailer wheels, so even with this system, locking of a trailer wheel when the stabilization system intervenes cannot always be reliably prevented. From the DE 202021102632 U1 A trailer stabilization system according to the preamble of claims 1, 4, and 6 is already known. This system uses a pulse detection device arranged in the area of the brake hub or brake drum, comprising a pole wheel and a magnetic field sensor, to detect the rotational speed of a trailer wheel and to control the brake actuator depending on the detected rotational speed. This also allows for the detection of a trailer wheel locking up. The pole wheel is equipped with permanent magnets attached to a cup-shaped carrier that can be mounted between the rim of the trailer wheel and an outer end face of the brake hub or brake drum. Further details regarding the method of mounting the magnetic field sensor are not provided in this document. Furthermore, it is from WO 2018/219 894 A1 a known flywheel which is part of an anti-lock braking system of a motor vehicle. The invention is based on the objective of creating a trailer stabilization system of the type mentioned above, in which the speed sensor of the speed detection device, which interacts with the flywheel, can be attached to the vehicle trailer in the simplest, most space-saving and preferably retrofittable way possible. This problem is solved according to the invention by a trailer stabilization system with the features of claims 1, 4 and 6. Advantageous embodiments of the invention are described in the further claims. The trailer stabilization system according to the invention comprises a speed detection device for determining the rotational speed of at least one trailer wheel, wherein the speed detection device comprises a pole wheel connected to a brake hub or brake drum of a wheel brake of the vehicle trailer, and at least one speed sensor interacting with the pole wheel. Furthermore, the trailer stabilization system comprises an electronic control unit connected to the speed detection device for controlling at least one brake actuator to generate a braking force and to brake the at least one trailer wheel by means of the wheel brake depending on the detected rotational speed of the trailer wheel. Furthermore, in the trailer stabilization system according to claim 1, the speed sensor is attached to a sensor holder which is attached to an axle stub of a trailer axle which serves to support the brake hub or brake drum. According to an advantageous embodiment, the sensor holder has a cla