Method for operating a braking device of a trailer

Abstract

Method for operating a braking device (22) of a trailer (10), in which: - the braking device (22) comprises: ◯ at least one wheel brake (24) by means of which at least one associated vehicle wheel (14) of the trailer (10) can be braked; ◯ at least one brake cable (28) which has a cable sheath (30) and a brake cable (32) which runs at least partially in the cable sheath (30), by means of which the wheel brake (24) can be actuated to brake the vehicle wheel (14); and ◯ a drive (36) by means of which one end (E) of the cable sheath (30) is translationally movable relative to the brake cable (32); and - a rotational speed of the vehicle wheel (14) is detected by means of a rotational speed sensor (46), wherein the end (E) of the cable sheath (30) is moved translationally relative to the brake cable (32) by means of the drive (36) as a function of the detected rotational speed; characterized in that: - in a first step (S1) of the method, the end (E) of the cable sheath (30) is moved translationally relative to the brake cable (32) by means of the drive (36) in such a way that the vehicle wheel (14) is braked; and - if it is detected by detecting the rotational speed that, as a result of the braking of the vehicle wheel (14) taking place in the first step (S1), the rotational speed is lower than a threshold value and / or a decrease in the rotational speed is greater than a comparison value, in a second step (S2) of the method following the first step (S1), the end (E) of the cable sheath (30) is moved translationally relative to the brake cable (32) by means of the drive (36) in such a way that the vehicle wheel (14) is braked by means of the wheel brake (24), and: o the speed becomes greater than or equal to the threshold value and / or the decrease in speed becomes less than or equal to the reference value.

Description

[0001] The invention relates to a method for operating a braking device of a trailer according to the preamble of patent claim 1.

[0002] DE 20 2006 004 679 U1 discloses a braking device for stabilizing vehicle trailers during rolling movements, wherein the respective vehicle trailer has a braking force transmission device, in particular in the form of a brake linkage and at least one brake cable. The brake cable has a cable sheath and a brake cable guided in the cable sheath, which is connected to the braking force transmission device by means of a connecting element designed, for example, as a balance beam, while the cable sheath is attached to an abutment at its end adjacent to the connecting element. Also provided are a rolling motion sensor, a control device, and an actuator that can be operatively connected to the at least one brake cable.It is provided that the abutment for the at least one cable pull sheath is arranged movably and is operatively connected to the actuator so that the abutment can be moved by the actuator in the longitudinal direction of the brake cable.

[0003] DE 20 2022 103 880 U1 discloses a trailer stabilization system for a vehicle trailer. DE 10 2022 133 945 A1 discloses a locking device and an ABS braking system. DE 20 2004 006 324 U1 discloses a braking system for a vehicle trailer.

[0004] The object of the present invention is to provide a method for operating a braking device of a trailer so that a particularly advantageous operation of the trailer can be realized.

[0005] This object is achieved according to the invention by a method having the features of patent claim 1. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0006] The invention relates to a method for operating a braking device of a trailer. In the method, the braking device has at least one wheel brake, designed for example as a friction brake, by means of which at least one vehicle wheel of the trailer assigned to the wheel brake can be braked. In other words, in its fully manufactured state, the trailer has the braking device. Furthermore, the trailer has, for example in its fully manufactured state, at least or exactly one vehicle axle, which is also simply referred to as an axle. The vehicle axle has at least or exactly two vehicle wheels arranged on opposite sides of the trailer in the transverse direction of the trailer, namely the aforementioned vehicle wheel as the first vehicle wheel and a second vehicle wheel. The trailer is a vehicle, in particular a land vehicle.When reference is made above and below to the vehicle wheel, this means the first vehicle wheel unless otherwise stated. The aforementioned wheel brake is also referred to as the first wheel brake. When reference is made above and below to the wheel brake, this means the first wheel brake unless otherwise stated. For example, the braking device has a second wheel brake assigned to the second vehicle wheel, wherein the previous and following statements regarding the first vehicle wheel and the first wheel brake are also readily transferable to the second vehicle wheel and the second wheel brake, and vice versa. The respective vehicle wheel is a respective ground contact element of the trailer, which can be or is supported on a ground downwards in the vertical direction of the trailer via the respective ground contact element.If the trailer is driven along the ground, for example by pushing or pulling the trailer along the ground by means of a towing vehicle that is coupled to the trailer in an articulated manner, while the trailer is supported on the ground downwards in the vertical direction of the trailer via the respective ground contact element, the respective ground contact element rolls, in particular directly, on the ground.

[0007] The braking device has at least one brake cable assigned to the wheel brake, also simply referred to as a cable pull. The brake cable has a cable pull casing, also referred to as a sleeve, sleeve or cable pull sleeve, and a brake cable, also simply referred to as a cable, which runs at least partially in the cable pull casing, i.e. inside the cable pull casing and is guided, for example, in the cable pull casing and through the cable pull casing. Very particularly, the brake cable is to be understood as a traction means which is inherently pliable, i.e., unstable in shape, when viewed on its own, and via which preferably only tensile forces, but not compressive forces, can be transmitted. The wheel brake can be actuated by means of the brake cable to brake the vehicle wheel. In particular, the wheel brake can be actuated by means of the brake cable in such a way that a tensile force can be exerted or is exerted on the brake cable.In other words, the wheel brake can be actuated via the brake cable, for example, by pulling on the brake cable. The braking device can have a braking force transmission device, in particular in the form of a brake linkage, wherein, for example, the brake cable can be connected or is connected to the braking force transmission device by means of a connecting element, in particular a balance beam. A force, in particular designed as a tensile force, can be transmitted from the braking force transmission device to the brake cable via the connecting element in order to actuate the wheel brake by means of the brake cable, i.e. via the brake cable, and thus to brake the associated vehicle wheel. Very particularly, the trailer can be designed as an overrun-braked trailer. In other words, it is conceivable for the braking device to comprise an overrun brake, which, for example, has the aforementioned braking force transmission device.If, for example, a towing vehicle which is coupled to the trailer in particular in an articulated manner brakes, this - as is sufficiently known from the general state of the art - activates, for example, the overrun brake, whereby the brake force transmission device exerts the aforementioned force, in particular in the form of a tensile force, on the brake cable, in particular via the connecting element, whereby the wheel brake is actuated via the brake cable and the vehicle wheel is thus braked.

[0008] In the method, the braking device also has a drive by means of which one end of the cable sheath is translationally movable, i.e., displaceable, relative to the brake cable and in particular along the brake cable, i.e., for example, in the longitudinal direction of the brake cable. This is already known, for example, from DE 20 2006 004 679 U1 and described therein.

[0009] The drive is also referred to as an actuator. The drive can be an electric drive, and therefore an electrically operated drive. It is also conceivable for the drive to be a pneumatically and / or hydraulically actuated or operable drive. In general, the term drive is understood to mean, for example, an actuator by means of which the said end of the cable pull casing can be moved translationally relative to the brake cable. As already described in DE 20 2006 004 679 U1, the wheel brake can be actuated by means of the drive-induced or effectable translational movement of the end of the cable pull casing relative to the brake cable, in particular without the brake force transmission device exerting a force on the brake cable via the connecting element and thus in particular without the overrun brake being activated.This is achieved or can be achieved by changing a laying path, also known as the laying radius or laying distance, along which the brake cable extends or runs, in particular from the connecting element to the wheel brake, in particular to a fixed brake carrier of the wheel brake, through the translational movement of the end of the cable sheath, which can be effected or caused by the drive and occurs relative to the brake cable. This results in the brake cable being displaced in the cable sheath, and in particular relative to the cable sheath, by the same amount by which the cable sheath is moved translationally relative to the brake cable by means of the drive, i.e., displaced.

[0010] In order to be able to realize particularly advantageous, and in particular particularly safe, operation of the trailer, it is provided according to the invention that a speed sensor detects the speed of the vehicle wheel, which can rotate at the speed about a wheel rotation axis, in particular relative to a chassis of the trailer, or rotates at the speed about the wheel rotation axis, in particular relative to the chassis. Furthermore, it is provided according to the invention that the end of the cable pull sleeve is moved translationally, i.e. displaced, relative to the brake cable by means of the drive as a function of the detected speed. For example, an electronic computing device, also referred to as a control unit, is provided, which can be a component of the trailer, in particular of the braking device.The speed sensor, which is also referred to as the first sensor, provides, for example, a signal, in particular an electrical signal, which is also referred to as the first signal and characterizes the speed detected by the speed sensor. The electronic computing device can receive the signal, whereby, for example, the electronic computing device can or does control the drive depending on the signal, i.e. depending on the detected speed. By controlling the drive in this way, the drive moves the end of the cable sheath translationally relative to the brake cable, whereby the end of the cable sheath is moved translationally relative to the brake cable depending on the detected speed. As already explained above, the wheel brake can be actuated by the translational movement of the end of the cable sheath relative to the brake cable, and the vehicle wheel can subsequently be braked.Generally speaking, a translational movement of the end of the cable sheath, caused or achievable by the drive and occurring relative to the brake cable, can influence the actuation of the wheel brake, in particular caused or achievable by the brake cable, and thus a braking of the vehicle wheel caused or achievable by the wheel brake. The invention now makes it possible to influence the actuation of the wheel brake as a function of the rotational speed of the vehicle wheel, thereby counteracting, for example, an initially excessively strong or excessively weak braking of the vehicle wheel, for example resulting from an actuation of the wheel brake caused by the brake cable or from a displacement of the end of the cable sheath relative to the brake cable.If, for example, it is determined from the recorded speed that the vehicle wheel is (still) rotating excessively fast, meaning that the speed is higher than desired, it can be concluded that the vehicle wheel is not being braked sufficiently and the end of the cable sheath can then be translated relative to the brake cable by means of the drive in such a way that the vehicle wheel is braked more strongly and the speed is subsequently reduced.However, if it is determined, for example based on the detected speed, that the speed is lower than desired and is, for example, 0, so that it is determined that the vehicle wheel is not (or no longer) rotating and is therefore blocked, the end of the cable sheath can then be moved translationally relative to the brake cable, for example by means of the drive, in such a way that the vehicle wheel is braked less strongly and subsequently rotates (again), and the speed therefore increases (again) and in particular becomes greater than 0. In particular, the method according to the invention makes it possible to advantageously, in particular safely, operate, in particular drive, the trailer with different trailer weights.In other words, the method according to the invention makes it possible to operate, in particular drive, the trailer particularly advantageously, and in particular particularly safely, both when the trailer has a first weight and when the trailer has a second weight that is greater than the first weight. These different weights of the trailer can arise, for example, from different loading states of the trailer. If the trailer is unloaded, for example, the trailer has the first weight, which can be, for example, 1,400 kilograms or 600 kilograms. If, however, the trailer is loaded, in particular heavily loaded, the trailer has the second weight, which is, for example, 1,800 kilograms, greater than the first weight.Such significant differences in the weight of the trailer arise, for example, when the trailer is used to transport heavy objects or living creatures such as horses. If no appropriate countermeasures are taken, these different weights can lead to different behavior of the vehicle trailer, particularly when braking the vehicle trailer, i.e. when braking the vehicle wheel. If, for example, the trailer has the second weight, the vehicle wheel must be braked more sharply than if the trailer has the first weight in order to decelerate the trailer in the same way, i.e. with the same force. In other words, if, for example, the vehicle wheel is braked as hard when the trailer has the second weight as if the trailer had the first weight, this can lead to insufficient deceleration, and therefore to deceleration of the trailer.If, on the other hand, for example, the vehicle wheel is braked as hard when the trailer has the first weight, i.e. braked as hard as if the trailer had the second weight, this could lead to undesired locking of the vehicle wheel, and thus to the speed being 0, i.e. rotation of the vehicle wheel about the wheel's axis of rotation and relative to the chassis is prevented. Both can be undesirable. One possibility for adapting the strength of braking of the vehicle wheel that can be effected or caused by the wheel brake to different trailer weights, i.e. to the respective current weight of the trailer, as required, would be to use a scale, for example, by means of which the current weight of the trailer in particular can be measured, i.e. recorded.As a result, it would be possible, for example, to use the drive to move the end of the cable sheath translationally relative to the brake cable depending on the weight detected by the scale. However, such a scale is weight-intensive and cost-intensive, and detecting the weight of the trailer using the scale is technically complex. To avoid the problems and disadvantages mentioned above, the rotational speed of the vehicle wheel is detected by the rotational speed sensor, and the drive is used to move the end of the cable sheath translationally relative to the brake cable depending on the detected speed. The invention is based on the idea that the current weight of the trailer, in particular, affects the rotational speed of the vehicle wheel when the vehicle wheel is braked. In other words, it has been found that the rotational speed of the vehicle wheel is an indicator of the weight of the trailer.The invention thus makes it possible to counteract excessive and undesirably weak braking of the vehicle wheel and excessive and undesirably strong braking of the vehicle wheel by means of the drive displacing, i.e. moving translationally, the end of the cable sheath relative to the brake cable as a function of the detected rotational speed.

[0011] In order to be able to realize particularly advantageous, in particular particularly safe, operation of the trailer, it is provided in the invention that in a first step of the method, the end of the cable sheath is moved translationally relative to the brake cable by means of the drive in such a way that the vehicle wheel is braked, i.e. that the wheel brake is actuated in such a way that the vehicle wheel is braked by means of the wheel brake. In particular, it is provided that in the first step of the method, the end of the cable sheath is moved translationally relative to the brake cable by means of the drive in such a way that the vehicle wheel is locked, i.e. that the wheel brake is actuated in such a way that the vehicle wheel is locked by means of the wheel brake.Blocking the vehicle wheel means that the current speed of the vehicle wheel is 0, i.e. rotation of the vehicle wheel around the wheel rotation axis and relative to the trailer chassis is prevented.

[0012] If, based on the detection of the rotational speed, it is detected that the rotational speed is lower than a threshold value as a result of the braking of the vehicle wheel occurring in the first step and / or that a decrease in the rotational speed is greater than a comparison value, in a second step of the method which follows the first step chronologically, the end of the cable sheath is moved translationally relative to the brake cable by means of the drive in such a way that the rotational speed is greater than or equal to the threshold value and / or the decrease in the rotational speed is less than or equal to the comparison value. The feature that the decrease in the rotational speed is greater than the comparison value is to be understood in particular to mean that the absolute value of the decrease is greater than the comparison value. In particular, a gradient of the rotational speed, also referred to as the rotational speed gradient, which becomes lower, i.e. decreases, with the gradient as a result of the braking of the vehicle wheel occurring or brought about in the first step.Thus, for example, a decrease in speed is to be understood as a deceleration in the angle of rotation, that is to say in particular a negative acceleration in the angle of rotation, wherein, for example, if the absolute value of the deceleration in the angle of rotation or the acceleration in the angle of rotation is greater than the comparison value, in the second step the end of the cable sheath is moved translationally relative to the brake cable by means of the drive in such a way that the absolute value becomes less than or equal to the comparison value. The threshold value and / or the comparison value are stored, for example, in an electrical or electronic data memory of the electronic computing device. In particular, it is provided that, in particular by means of the electronic computing device, the detected speed is compared with the threshold value and / or the decrease in speed is compared with the comparison value.If this comparison shows that the speed, in particular its absolute value, is lower than the threshold value and / or that the decrease in the speed, in particular the absolute value of the decrease in the speed, is greater than the comparison value, then in the second step of the method, the end of the cable sheath is moved translationally relative to the brake cable by means of the drive in such a way that the speed is greater than or equal to the threshold value and / or the decrease in the speed is less than or equal to the comparison value.

[0013] In particular, it can be provided that when, based on the detection of the rotational speed, a locking of the vehicle wheel is determined, or the locking resulting from the braking of the vehicle wheel in the first step, the end of the cable pull sleeve is moved translationally relative to the brake cable by means of the drive in the second step of the method following the first step, in particular depending on the detected rotational speed, in such a way that the locking of the vehicle wheel resulting from the braking of the vehicle wheel in the first step is canceled.

[0014] The translational movement of the cable sheath occurring relative to the brake cable in the first step can, but does not necessarily have to, be dependent on the rotational speed. In particular, it is provided that the translational movement of the cable sheath occurring relative to the brake cable in the first step occurs at least or exclusively as a function of a rolling movement of the vehicle trailer, i.e. is carried out, wherein, for example, the rolling movement is detected by means of a sensor device, in particular of the trailer and very particularly of the braking device. In other words, for example, at least one measured variable can be measured, i.e. detected, by the said sensor device, which, for example, characterizes the said rolling movement of the trailer.The sensor device can, for example, have a speed sensor and / or at least one second sensor which is different from the speed sensor and is provided additionally, by means of which the measured variable is detected, i.e. measured. For example, the second sensor can be an acceleration sensor and / or comprise at least one acceleration sensor. Alternatively or additionally, the second sensor can, for example, be a yaw rate sensor and / or comprise a yaw rate sensor. By means of the acceleration sensor, for example, in particular an acceleration of the trailer can be detected as the measured variable. By means of the yaw rate sensor, for example, in particular a yaw rate of the trailer, in particular about its vertical direction of the vehicle, can be measured, i.e. detected.This design makes it possible to effectively and efficiently counteract unwanted locking of the vehicle wheel or undesirably strong braking of the vehicle wheel, as needed, so that the locking can be eliminated or the vehicle wheel can be prevented from locking. At the same time, for example, unwanted swaying of the trailer can be counteracted, thus ensuring particularly safe trailer operation.

[0015] The invention also provides that in the second step of the method, the end of the cable sheath is moved translationally relative to the brake cable by means of the drive, in particular depending on the detected speed, in such a way that the vehicle wheel is braked by means of the wheel brake and, in addition, at least one further effect is brought about, in particular in a targeted manner. The further effect comprises that the speed, in particular its absolute value, becomes greater than or equal to the threshold value. Alternatively or additionally, the further effect comprises that the decrease in the speed, in particular the absolute value of the decrease in the speed, becomes less than or equal to the comparison value. In particular, it can preferably be provided that in the second step of the method, the end of the cable sheath is moved translationally relative to the brake cable by means of the drive, in particular depending on the detected speed, in such a way thatthat the locking of the vehicle wheel resulting from the braking of the vehicle wheel in the first step is canceled and the vehicle wheel is braked, in particular further, by means of the wheel brake. In other words, in the first step of the method, for example, the vehicle wheel is braked, but excessively or undesirably strongly, so that the rotational speed is lower than the threshold value and / or the decrease in the rotational speed, i.e. in particular the absolute value of the decrease in the rotational speed, is greater than the comparison value and / or the vehicle wheel locks. This is detected by detecting the rotational speed. Subsequently, in the second step of the method, the end of the cable sheath is moved translationally relative to the brake cable by means of the drive in such a way that the rotational speed becomes greater than or equal to the threshold value and / or the decrease in the rotational speed,that is, the absolute value of the decrease in the speed becomes less than or equal to the comparison value and / or the locking of the vehicle wheel occurring in the first step is cancelled, so that locking of the vehicle wheel is avoided and / or so that, for example, the vehicle wheel rotates or can rotate (again) at a speed greater than 0, however, it is preferably provided that in the second step of the method, the end of the cable sheath is not moved translationally relative to the brake cable by means of the drive in such a way that braking of the vehicle wheel is avoided in the second step of the method, but preferably in the second step of the method, the end of the cable sheath is moved translationally relative to the brake cable by means of the drive in such a way thatthat the wheel locking occurring in the first step or resulting from the first step is eliminated and / or the rotational speed becomes greater than or equal to the threshold value and / or the decrease becomes less than or equal to the comparison value, but the wheel is (still) braked. In other words, in the second step of the method, the vehicle wheel is braked by means of the wheel brake in such a way that the vehicle wheel does not lock, i.e., the vehicle wheel rotates about the wheel rotation axis relative to the chassis, thus the rotational speed is greater than 0 and / or the rotational speed becomes greater than or equal to the threshold value and / or the decrease becomes less than or equal to the comparison value. This can, for example, prevent undesired locking of the vehicle wheel.At the same time, the aforementioned swaying motion of the trailer can be counteracted. This allows for particularly safe operation of the trailer. Preferably, the threshold value, in particular its absolute value, is a value other than zero. Preferably, the comparison value, in particular its absolute value, is a value other than zero.

[0016] A further embodiment is characterized in that in the first step of the method, the end of the cable pull sleeve is moved translationally relative to the brake cable by a first distance, also referred to as the first distance, in a first direction by means of the drive. Furthermore, it is preferably provided that in the second step of the method, the end of the cable pull sleeve is moved translationally relative to the brake cable by a second distance, which is shorter than the first distance and is also referred to as the second distance, in a second direction opposite to the first direction. It is conceivable that both the first direction and the second direction coincide with a straight line.This embodiment, for example, can eliminate wheel locking, but still allow the vehicle wheel to be braked, particularly while the vehicle wheel rotates around the wheel's axis of rotation relative to the chassis at a higher speed than zero, so that the aforementioned swaying motion of the trailer can be advantageously counteracted. This allows for particularly safe operation of the trailer.

[0017] In a further, particularly advantageous embodiment of the invention, it is provided that the at least one measurement variable characterizing the rolling movement of the trailer is detected by means of the at least one sensor provided in addition to the speed sensor, which is also referred to as the second sensor.

[0018] It has proven particularly advantageous if, in the second step of the method, the end of the cable pull casing is moved translationally relative to the brake cable by means of the drive as a function of the detected measured variable in such a way that the rotational speed becomes greater than or equal to the threshold value and / or the decrease in rotational speed becomes less than or equal to the comparison value. In particular, it is preferably provided that, in the second step of the method, the end of the cable pull casing is moved translationally relative to the brake cable by means of the drive as a function of the detected measured variable in such a way that the locking of the vehicle wheel resulting from the braking of the vehicle wheel in the first step is canceled.This ensures that the vehicle wheel is braked as strongly as possible, yet as gently as necessary, in order to effectively and efficiently counteract the trailer's swaying motion, while also preventing unwanted locking of the vehicle wheel. Since this occurs depending on the vehicle wheel's speed, the trailer can be operated safely with varying trailer weights. In other words, the invention counteracts unwanted swaying motions of the trailer, thus preventing undesirable trailer driving conditions, especially when the trailers have varying weights.

[0019] In order to prevent unwanted locking of the vehicle wheel and at the same time to be able to advantageously counteract the swaying movement so that particularly safe operation of the trailer can be realized, a further embodiment of the invention provides that in the second step of the method, the end of the cable pull sleeve is moved translationally relative to the brake cable by means of the drive as a function of the measured variable in such a way that the vehicle wheel is braked. This means that in the second step of the method, the vehicle wheel is braked, while at the same time the vehicle wheel is allowed to rotate about the wheel rotation axis relative to the chassis at a speed greater than 0. This advantageously prevents unfavorable driving conditions of the trailer, so that particularly safe operation can be ensured.

[0020] A further embodiment is characterized in that a path, also referred to as the distance, by which the end of the cable sheath is moved translationally relative to the brake cable by means of the drive, is varied.

[0021] It has proven particularly advantageous if the path is varied depending on the detected speed. If, for example, the speed has a first speed value, the end of the cable sheath is moved translationally relative to the brake cable by a first movement path, for example by means of the drive. If, for example, the speed has a second speed value that is different from the first speed value, the end of the cable sheath is moved translationally relative to the brake cable by a second movement path that is different from the first movement path, for example by means of the drive. In this way, the braking of the vehicle wheel can be influenced as needed, which can result in particularly advantageous operation of the trailer.

[0022] In a further, particularly advantageous embodiment of the invention, the travel is varied depending on the measured variable. This makes it possible to effectively and efficiently counteract the trailer's swaying movement, while simultaneously preventing unwanted locking of the vehicle wheel. This ensures particularly safe operation of the trailer.

[0023] Finally, it has proven particularly advantageous that the electronic computing device determines a driving speed of the trailer, also simply referred to as the speed, which, for example, travels along the aforementioned ground at the driving speed during the method. The driving speed is determined, for example, as a function of the detected engine speed. Furthermore, it is conceivable that, alternatively or additionally, the driving speed is detected by means of at least one further sensor provided in addition to the engine speed sensor and in addition to the second sensor. In this case, it is preferably provided that the end of the cable pull sleeve is moved translationally relative to the brake cable by means of the drive as a function of the determined driving speed.In other words, the vehicle speed is taken into account when moving the end of the cable sheath, allowing the braking of the vehicle wheel to be adjusted as needed. This allows for particularly safe operation.

[0024] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective specified combinations, but also in other combinations or on their own, without departing from the scope of the invention.

[0025] The drawing shows: Fig. 1 a schematic and partially sectioned view of a trailer; and Fig. 2 a flowchart illustrating a method for operating a braking device of the trailer.

[0026] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0027] Fig. 1 shows a fragmentary, schematic and partially sectioned view of a trailer 10. The trailer 10 is a vehicle which is braked as a land vehicle. Fig. 1, the trailer 10 has exactly one vehicle axle 12, which has exactly two vehicle wheels, namely a first vehicle wheel 14 and a second vehicle wheel 16. The trailer 10 also has a chassis 18. Connected to the chassis 18 is, for example, a platform of the trailer 10 (not shown in the figures), the platform of which provides, for example, at least one loading area. Objects and / or living beings such as horses, for example, to be transported by means of the trailer 10 can be parked on the loading area. The respective vehicle wheel 14, 16 is held at least indirectly on the chassis 18 and is rotatable about a respective wheel rotation axis D1, D2 relative to the chassis 18. The vehicle wheels 14 and 16 are ground contact elements by means of which the trailer 10 can be or is supported downwards on a ground along its vertical direction.In this case, the vehicle's vertical direction runs perpendicular to the image plane of . Fig. 1 and is illustrated by a double arrow 20. The trailer 10 can be coupled, in particular in an articulated manner, to a towing vehicle such as a motor vehicle. If the trailer 10 is driven along the ground, for example, by being pulled or pushed along the ground by the towing vehicle while the trailer 10 is supported downwards on the ground via the ground contact elements in the vertical direction of the trailer 10, the ground contact elements roll, in particular directly, along the ground.

[0028] The trailer 10 has a Fig. 1 particularly schematically illustrated braking device 22, by means of which the vehicle wheels 14 and 16 and thus the trailer 10 can be braked. In the following, Fig. 1 and Fig. 2 describes a method for operating the braking device 22 of the trailer 10. The braking device 22 has a first wheel brake 24 assigned to the vehicle wheel 14 and a second wheel brake 26 assigned to the vehicle wheel 16. The respective vehicle wheel 14, 16 can be braked by means of the respective wheel brake 24, 26 assigned to the respective vehicle wheel 14, 16. This is to be understood in particular that by braking the respective vehicle wheel 14, 16, a respective speed at which the respective vehicle wheel 14, 16 rotates about the respective wheel rotation axis D1, D2 relative to the chassis 18 is reduced. The trailer 10 and the aforementioned method are described below with reference to the vehicle wheel 14, the wheel brake 24, and the wheel rotation axis D1.The previous and following statements regarding the vehicle wheel 14, the wheel rotation axis D1 and the wheel brake 24 can also be readily applied to the vehicle wheel 16, the wheel brake 26 and the wheel rotation axis D2 and vice versa.

[0029] The braking device 22 has at least one brake cable 28 assigned to the wheel brake 24, which has a cable sheath 30, also referred to as a sleeve, cable sleeve or sheath, and a brake cable 32, which runs at least partially in the cable sheath 30. For example, the brake cable 32 is guided in the cable sheath 30 and by means of the cable sheath 30. Preferably, the brake cable 32 is flexible, that is, dimensionally unstable. Furthermore, it is preferably provided that the cable sheath 30 is flexible, that is, dimensionally unstable. By means of the brake cable 32, the wheel brake 24 can be actuated to brake the vehicle wheel 14. For this purpose, for example, a brake force transmission device 34 is provided, which can, for example, be a component of the braking device 22. The brake force transmission device 34 is or comprises, for example, an overrun brake. For example, if the trailer 10 is first driven along its Fig. 1 by a double arrow 38 by means of the towing vehicle and thereby driven, in particular, along the ground. If the towing vehicle then brakes, for example, the overrun brake is activated, for example. As a result, the brake force transmission device 34 exerts a force, in particular a tensile force, on the brake cable 32, which is thereby moved, for example, relative to the chassis 18, in particular at least translationally. This actuates the wheel brake 24, thereby braking the vehicle wheel 14.

[0030] The braking device 22 further comprises a drive 36, also referred to as an actuator, by means of which one end E of the cable pull sheath 30 can be moved translationally, i.e. displaced, relative to the brake cable 32 and in particular also relative to the chassis 18. If, for example, the end E is displaced relative to the brake cable 32 by means of the drive 36, in particular during a movement of a first point of the brake cable 32 relative to the chassis 18 and a movement of a second point of the brake cable 32 relative to the chassis 18 is omitted, which is coupled, for example, at its first point to the brake force transmission device 34 and at its second point to the wheel brake 24, a laying path, also referred to as the laying radius or laying distance, along which the brake cable 32 runs, in particular between the aforementioned points on the brake cable 32, is thereby changed.By means of the drive 36 effected or brought about and translational movement of the end E relative to the brake cable 32, a braking of the vehicle wheel 14 effected or brought about by means of the wheel brake 24 can be influenced, in particular in the following way: If, for example, the end E is displaced by means of the drive 36 relative to the brake cable 32 in a first direction illustrated by an arrow 40, i.e. moved translationally, the wheel brake 24 is actuated as a result, for example, whereby the vehicle wheel 14 is braked.If, for example, the end E is displaced relative to the brake cable 32 in a second direction opposite to the first direction and illustrated by an arrow 42 by means of the drive 36, this at least reduces or cancels out actuation of the wheel brake 24, as a result of which, for example, an initial braking of the vehicle wheel 14 brought about by means of the wheel brake 24 is at least reduced or canceled out. In the present case, the directions illustrated by the arrows 40 and 42 run along a common straight line. In other words, the directions coincide with the straight line which, in the present case, runs parallel to the vehicle longitudinal direction (double arrow 38). Fig. 1, the first direction runs from front to rear in the vehicle longitudinal direction of the trailer 10, and the second direction accordingly runs from rear to front in the vehicle longitudinal direction of the trailer 10. In particular, the drive 36 can displace the end E independently of the braking force transmission device 34. For example, the aforementioned first point of the brake cable 32 is a first end of the brake cable 32 or is arranged at a first end of the brake cable 32. For example, alternatively or additionally, the aforementioned second point of the brake cable 32 is a second end of the brake cable 32 or is arranged at a second end of the brake cable 32, wherein the second end is opposite the first end.

[0031] In Fig. 1 also shows, particularly schematically, an electronic computing device 44, also referred to as a control unit, by means of which, for example, the method is carried out. The electronic computing device 44 is, for example, a component of the trailer 10, in particular of the braking device 22.

[0032] In order to be able to realize particularly advantageous, and in particular particularly safe, operation of the trailer 10, especially when the trailer 10 has different, significantly different weights, the method provides that a rotational speed of the vehicle wheel 14 is detected by means of a rotational speed sensor 46, which is rotatable or rotates at the stated rotational speed about the wheel rotation axis D1 relative to the chassis 18. Furthermore, the method provides that the end E of the cable pull sleeve 30 is displaced, and thus moved translationally, relative to the brake cable 32 by means of the drive 36 as a function of the detected rotational speed.

[0033] Fig.2 shows a flow chart to illustrate the method. In a first step S1 of the method, the end E of the cable sheath 30 is moved translationally relative to the brake cable 32 by means of the drive 36 in such a way that the vehicle wheel is braked. If, based on the detection of the rotational speed of the vehicle wheel 14, a locking of the vehicle wheel 14 resulting from the braking of the vehicle wheel 14 in the first step S1 is determined, in a second step S2 of the method following the first step S1, the end E of the cable sheath 30 is moved translationally relative to the brake cable 32 by means of the drive 36 in such a way that the locking of the vehicle wheel resulting from the braking of the vehicle wheel 14 in the first step S1 is canceled, thus the vehicle wheel 14 rotates (again) about the wheel rotation axis D1 relative to the chassis 18 and thus the rotational speed becomes or is greater than 0.

[0034] Preferably, it is provided that in the second step S2 of the method, the end E of the cable sheath 30 is moved translationally relative to the brake cable 32 by means of the drive 36 in such a way that the locking of the vehicle wheel 14 resulting from the braking of the vehicle wheel 14 in the first step S1 is canceled and the vehicle wheel 14 is braked, in particular further, by means of the wheel brake 24, i.e., decelerated. Thus, it is provided, for example, that in the first step S1 of the method, the end E of the cable sheath 30 is moved translationally relative to the brake cable 32 by a first distance in the first direction (arrow 40) by means of the drive 36. In the second step S2 of the method, for example, the end E is moved translationally relative to the brake cable 32 by a second distance that is smaller than the first distance in the second direction opposite the first direction (arrow 42).On the one hand, this can cancel the locking of the vehicle wheel 14. On the other hand, this can, for example, also and / or still counteract a swaying movement which is or was counteracted in the first step S1 by the vehicle wheel 14 being or was braking in the first step S1, in the second step S2, since in the second step S2 the locking of the vehicle wheel 4 is canceled, but the vehicle wheel 14 is, in particular, still braked. The aforementioned swaying movement is a swaying movement of the trailer 10, and by counteracting the swaying movement both in the first step S1 and in the second step S2, the probability of an unfavorable or even more unfavorable driving condition of the trailer 10 can be kept particularly low.

Claims

[1] Method for operating a braking device (22) of a trailer (10), in which: - the braking device (22) comprises: ◯ at least one wheel brake (24) by means of which at least one associated vehicle wheel (14) of the trailer (10) can be braked; ◯ at least one brake cable (28) which has a cable sheath (30) and a brake cable (32) which runs at least partially in the cable sheath (30), by means of which the wheel brake (24) can be actuated to brake the vehicle wheel (14); and ◯ a drive (36) by means of which one end (E) of the cable sheath (30) is translationally movable relative to the brake cable (32); and - a rotational speed of the vehicle wheel (14) is detected by means of a rotational speed sensor (46), wherein the end (E) of the cable sheath (30) is moved translationally relative to the brake cable (32) by means of the drive (36) as a function of the detected rotational speed; characterized by , that: - in a first step (S1) of the method, the end (E) of the cable sheath (30) is moved translationally relative to the brake cable (32) by means of the drive (36) in such a way that the vehicle wheel (14) is braked; and - if it is detected by detecting the rotational speed that, as a result of the braking of the vehicle wheel (14) taking place in the first step (S1), the rotational speed is lower than a threshold value and / or a decrease in the rotational speed is greater than a comparison value, in a second step (S2) of the method following the first step (S1), the end (E) of the cable sheath (30) is moved translationally relative to the brake cable (32) by means of the drive (36) in such a way that the vehicle wheel (14) is braked by means of the wheel brake (24), and: o the speed becomes greater than or equal to the threshold value and / or the decrease in speed becomes less than or equal to the reference value. [2] Method according to claim 1, characterized by , that: - in the first step (S1) of the method, the end (E) of the cable sheath (30) is moved translationally relative to the brake cable (32) by a first distance in a first direction (40) by means of the drive (36); and - in the second step (S2) of the method, by means of the drive (36), the end (E) of the cable pull sheath (30) is moved translationally relative to the brake cable (32) by a second path which is smaller than the first path in a second direction (42) opposite to the first direction (40). [3] Method according to one of the preceding claims, characterized by that at least one measurement variable characterizing a rolling movement of the trailer (10) is detected by means of at least one sensor provided in addition to the speed sensor (46). [4] Method according to claim 3, characterized bythat in the second step (S2) of the method, the end (E) of the cable sheath (30) is moved translationally relative to the brake cable (32) by means of the drive (36) as a function of the measured variable in such a way that the rotational speed becomes greater than or equal to the threshold value and / or the decrease in the rotational speed becomes less than or equal to the comparison value. [5] Method according to claim 4 or claim 3, characterized by that in the second step (S2) of the method, by means of the drive (36), the end (E) of the cable sheath (30) is moved translationally relative to the brake cable (32) as a function of the measured variable in such a way that the vehicle wheel (14) is braked. [6] Method according to one of the preceding claims, characterized by that a path by which the end (E) of the cable sheath (30) is moved translationally relative to the brake cable (32) by means of the drive (36) is varied. [7] Method according to claim 6, characterized bythat the path is varied depending on the detected speed. [8] Method according to claim 6 or 7 when referred back to one of claims 3 to 5, characterized by that the path is varied depending on the measured value. [9] Method according to one of the preceding claims, characterized by that a driving speed of the trailer (10) is determined by means of an electronic computing device (44), wherein the end (E) of the cable pull sheath (30) is moved translationally relative to the brake cable (32) by means of the drive (36) as a function of the determined driving speed.

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