Trailer coupling device

Abstract

The invention discloses a trailer connecting device. The technical problems that in the prior art, a trailer connecting device is poor in locking effect and not compact enough in structure are solved. The trailer connecting device comprises a bearing frame, a trailer hook, a driving shaft, a transmission part, a locking actuating part, a locking element and a locking keeping part, the bearing frame comprises a sleeve with a guide hole, the trailer hook comprises a supporting seat with at least one pair of outer rotation stopping grooves, the supporting seat is connected to the outer side of the sleeve in a pivoted mode, and the locking element is arranged on the supporting seat. The locking actuating piece is provided with an inner rotation stopping groove and locking platforms arranged on the two sides of the inner rotation stopping groove in the circumferential direction, the locking element moves along the guide hole, and the locking maintaining piece is arranged between the locking actuating piece and the transmission piece to transmit torque force and can be compressed by relative pivoting of the locking actuating piece and the transmission piece to store energy. The pivot locking device has a first locking state and a second locking state following the first locking state, and in the second locking state, the locking retaining piece is kept compressed to load a pre-tightening torque on the locking actuating piece, and the locking platform is maintained to stop the locking element.

Description

Technical Field

[0001] This invention relates to the field of vehicle connector technology, and in particular to trailer coupling devices. Background Technology

[0002] A trailer hitch includes a base and a trailer hook mounted on the base. The base is mounted on a vehicle, and the trailer hook is used for vehicle rescue, such as towing a vehicle when it is damaged and cannot be started.

[0003] Existing electric trailer hitch couplings typically include a base, a trailer hook, a motor, and a drive unit connecting the motor and the trailer hook. The motor's operation drives the drive unit to rotate the trailer hook, allowing it to switch between a working position and a retracted position. Electric trailer hitch couplings usually also need to have locking and unlocking functions: the trailer hook is locked when it is in the working or retracted position, and unlocked when it needs to switch between the two positions.

[0004] Some technical solutions related to trailer coupling devices have been disclosed in the prior art, such as the Chinese invention patent application with publication number CN119749121A entitled "Trailer Hook and Automobile". It realizes the locking and unlocking of the tow hook through a locking component (steel ball), a locking groove on the hook body and a receiving groove on the slider, and realizes the switching between the working position and the storage position of the tow hook through a drive shaft, a retaining inclined surface on the slider and an elastic component (spring).

[0005] However, in this technical solution, on the one hand, the elastic element is in a relaxed state when locked, which means that under the action of a large external force, the elastic element is prone to compression and the slider is prone to displacement, resulting in the tow hook not being able to be locked properly; on the other hand, the trailer coupling device needs to reserve additional axial movement space for the slider and elastic element, which is not conducive to the compact design of the trailer coupling device. Summary of the Invention

[0006] This invention proposes a trailer coupling device to overcome the shortcomings of the prior art, thereby solving the technical problems of poor locking effect and insufficient compact structure of the existing trailer coupling device.

[0007] To achieve the above technical objectives, the trailer coupling device proposed in this invention includes: A support frame for securing to a vehicle body includes a sleeve with guide holes; A trailer hitch includes a support seat having at least two external anti-rotation grooves, the support seat being pivotally connected to the outside of the sleeve, allowing the trailer hitch to pivotally switch between a stowed position and a working position relative to the support frame; A pivot drive device, which is disposed within the sleeve, includes a drive shaft and a transmission component that is drively connected to the drive shaft; A pivoting locking device includes a locking actuator, a locking element, and a locking retainer. The locking actuator is pivotally mounted on a drive shaft. The locking actuator has an inner anti-rotation groove and locking platforms disposed on both sides of the inner anti-rotation groove in the circumferential direction. The locking element is disposed in a guide hole and can move along the guide hole. The locking retainer is configured between the locking actuator and the transmission element to transmit torque force and can be compressed and stored by the relative pivoting of the two. The pivot locking device has: In the first locking state, the drive shaft drives the transmission component and the locking actuator to pivot synchronously. The locking element is pushed by the locking actuator and partially enters one of the outer anti-rotation grooves along the guide hole and is stopped by the locking platform to lock the trailer hook in the storage position or the working position. In the second locking state, following the first locking state, the drive shaft drives the transmission component to pivot relative to the locking actuator to compress the locking retainer. In the compressed state, the locking retainer applies a preload torque to the locking actuator to maintain the locking platform's stop on the locking element.

[0008] The trailer coupling device proposed in this invention includes a support frame, a trailer hook, a pivot drive device, and a pivot locking device. The trailer hook can pivot relative to the support frame. The pivot locking device moves under the drive of the pivot drive device. The pivot locking device can lock the trailer hook in the storage position or the working position in the first locking state. The pivot locking device can also maintain the stop of the locking platform on the locking element by compressing the locking retainer in the second locking state following the first locking state. In this case, any external force that attempts to push the locking element out of the outer anti-rotation groove must first overcome the preload of the locking retainer which is already in the compressed state. This is difficult to achieve with normal external force, thus ensuring the reliability of the trailer hook locking. Secondly, the locking retainer compresses and stores energy through the relative pivoting of the locking actuator and the transmission. Therefore, the locking retainer is compressed and reset in the circumferential direction of the locking actuator and the transmission. This means that the trailer coupling does not need to reserve space in the axial direction for the compression and reset of the locking retainer, making the trailer coupling more compact in the axial direction.

[0009] Preferably, the outer peripheral surface of the locking actuator is partially recessed to form the inner anti-rotation groove, and two locking platforms are formed on the outer peripheral surface that gradually extends radially outward from both sides of the inner anti-rotation groove in a direction away from the inner anti-rotation groove. One of the two locking platforms stops the locking element at the storage position of the trailer hook, and the other stops the locking element at the working position of the trailer hook.

[0010] By adopting the aforementioned technical solution, two locking platforms are set to lock the trailer hooks in the storage position and the working position respectively. The two locking platforms are set on both sides of the inner anti-rotation groove. This means that the locking actuator only needs to rotate a small angle to lock the trailer hook. That is, when locking the trailer hooks in the storage position and the working position, the locking actuator only needs to spend a small amount of time to complete the locking, which greatly improves the locking efficiency. Secondly, the locking platform gradually extends radially outward in the direction away from the inner anti-rotation groove. When the two sides of the locking element abut against the bottom wall of the locking platform and the outer anti-rotation groove respectively, this arrangement of the locking platform restricts the further rotation of the locking platform towards the outer anti-rotation groove, which also restricts the further rotation of the locking actuator relative to the sleeve. This allows the locking retainer to compress and store energy under the torque force transmitted by the transmission component. The pivot locking device has good locking performance in the second locking state.

[0011] Preferably, the locking platform is configured as one of the following: an inclined surface, a spiral trajectory surface, or an involute trajectory surface extending circumferentially along the outer peripheral surface of the locking actuator.

[0012] Using the aforementioned technical solution, several specific structures constituting the locking platform are disclosed.

[0013] Preferably, both the locking actuator and the transmission member are configured as discs and arranged axially along the drive shaft. The disc surface of the locking actuator has first stop portions distributed in pairs at intervals in the circumferential direction, and the disc surface of the transmission member has second stop portions distributed in pairs at intervals in the circumferential direction. When the trailer hook is in the retracted position, the drive shaft drives the transmission component to pivot relative to the locking actuator, causing one of the circumferentially misaligned first and second stop portions to compress the locking retainer. When the trailer hook is in the working position, the drive shaft drives the transmission component to pivot relative to the locking actuator, causing another set of circumferentially misaligned first and second stops to compress the locking retainer.

[0014] Using the aforementioned technical solution, a first stop and a second stop are respectively provided on the disc surface of the locking actuator and the disc surface of the transmission component. The first stop and the second stop are used to transmit torque circumferentially between the locking actuator and the transmission component through the locking retainer. At the same time, since the rotation direction of the trailer hook for locking in the storage position and the working position is different, the first stop and the second stop are both distributed in pairs circumferentially at intervals, so that the pivot locking device can compress the locking retainer in different rotation directions, ensuring that the pivot locking device can lock the trailer hook in the storage position and the working position.

[0015] Preferably, the locking actuator has a first groove on its disc surface, the two ends of the first groove defining a pair of first stops, and a portion of the locking retainer is housed in the first groove. The transmission member has a second groove on its disc surface, the two ends of the second groove defining a pair of second stops, and a portion of the locking retainer is housed in the second groove.

[0016] By adopting the aforementioned technical solution, on the one hand, the locking retainer is accommodated and limited by the closing of the first groove and the second groove, which prevents the locking retainer from disengaging from the first stop and the second stop under the action of preload torque, thereby improving the reliability of the pivot locking device; on the other hand, the two ends of the first groove define a pair of first stop portions and the two ends of the second groove define a pair of second stop portions, which also eliminates the need to set stop portions separately in the first groove and the second groove, thereby reducing the cost of the locking actuator.

[0017] Preferably, the transmission component and the locking retaining component are provided in two sets and are compactly distributed on both sides of the axial direction of the locking actuator, and the drive shaft drives the two sets of transmission components to rotate in the same direction.

[0018] By adopting the aforementioned technical solution, the forces at both ends of the locking actuator along the axial direction are balanced.

[0019] Preferably, the locking retainer is one or a combination of a helical spring, a torsion spring, and a rubber spring.

[0020] Using the aforementioned technical solution, several specific types of elastic devices constituting locking and retaining members are disclosed.

[0021] Preferably, the trailer hook has a gravity balance position between the storage position and the working position. After unlocking, the trailer hook pivots downward to the gravity balance position by its own weight and synchronizes its rotation speed by means of the same-direction rotation of the drive shaft.

[0022] With the aforementioned technical solution, this configuration of the trailer hitch means that the trailer hitch rotates downwards and then upwards to retract from its working position to its storage position, rather than rotating upwards and then downwards. This makes it easier for the trailer hitch to be hidden under the vehicle, and the vehicle interior does not need to sacrifice space to avoid the rotation path of the trailer hitch. The rotation of the trailer hitch is also less likely to collide with items inside the vehicle. At the same time, during the downward pivoting process of the trailer hitch to the gravity balance position, the trailer hitch's own weight can provide the pivoting force of the trailer hitch, which can reduce the output torque of the drive shaft.

[0023] Preferably, a clutch mechanism is also included, wherein the clutch mechanism is configured as follows: When the trailer hitch is locked in the retracted or working position, disconnect the power connection between the drive shaft and the support. Once the trailer hitch is unlocked in the retracted or working position, a power connection is established between the drive shaft and the support until the trailer hitch is locked again.

[0024] By adopting the aforementioned technical solution, since the power connection between the drive shaft and the support is cut off when the trailer hook is locked, the further rotation of the drive shaft compression locking retainer is prevented from causing the trailer hook to rotate further, thus allowing the trailer hook to remain stationary in the working or retracted position. At the same time, the external force acting on the trailer hook will not be transmitted to the drive shaft, thus avoiding the impact of external force on the drive shaft. Furthermore, after the trailer hook is unlocked in the retracted or working position, the power connection between the drive shaft and the support is established, ensuring that the trailer hook can pivot between the retracted or working position under the support of the drive shaft or the torque force of the drive shaft.

[0025] Preferably, the clutch mechanism includes: A fixed guide component is fixed to the support frame, and the fixed guide component is provided with a first stepped track extending circumferentially. A movable guide component is connected to the drive shaft and rotates with the drive shaft; the movable guide component is provided with an axially arranged pin hole. A drive pin passes through a pin hole and can move along the pin hole; The rotation of the movable guide component causes one end of the transmission pin to slide along the first stepped track, while the other end of the transmission pin engages or disengages with the support seat.

[0026] Using the aforementioned technical solution, the specific structure of the clutch mechanism is disclosed.

[0027] Preferably, the drive shaft includes a main shaft and a bushing fitted outside the main shaft. The main shaft has two circumferentially spaced main shaft protrusions, the bushing has two circumferentially spaced bushing protrusions, and the transmission component has two circumferentially spaced transmission protrusions. The two main shaft protrusions and the two bushing protrusions are circumferentially alternating and can rotate relative to each other, the two bushing protrusions and the two transmission protrusions are circumferentially alternating and can rotate relative to each other, and the two main shaft protrusions and the two transmission protrusions are axially misaligned. When the trailer hitch is unlocked in the storage or working position, the main shaft rotates relative to the bushing for a first idle stroke. After the first idle stroke is completed, the main shaft drives the bushing to rotate relative to the transmission component for a second idle stroke.

[0028] By adopting the aforementioned technical solution, a free stroke is set, so that the rotation of the drive shaft is only a small angle of rotation of the drive transmission component, and the rotation of the locking actuator is also only a small angle. This enables the locking actuator to complete the locking in a short time when the trailer hook is locked in the storage position or the working position. At the same time, the smaller rotation angle of the transmission components and locking actuators means that the locking retainer has a smaller compression stroke, which allows the locking retainer to have a larger spring constant (also known as the elasticity coefficient or spring constant), thereby providing a larger preload torque. Furthermore, the smaller rotation angle of the transmission component and the locking actuator reduces the friction between the locking actuator, the transmission component and the sleeve caused by the rotation of the locking actuator and the transmission component, thereby increasing the service life of the locking actuator, the transmission component and the sleeve. Finally, since the transmission between the main shaft, bushing and transmission components is achieved by radial protrusions, and since the protrusions have thickness, the free travel between any two that are transmitting in opposition is necessarily less than 180°. However, by setting a first free travel and a second free travel, the free travel between the drive shaft and the transmission components can be greater than 180°, so that the trailer hitch can have more pivoting travel options for different vehicle models.

[0029] Preferably, the pivot drive device further includes a motor drive unit for driving the spindle to rotate in both directions. The motor drive unit is equipped with a self-locking mechanism, which is used to restrict the spindle from being driven to rotate by the load when the motor drive unit is not in operation. In the second locking state, the main shaft protrusion, bushing protrusion, and transmission protrusion abut against each other in sequence, and the compression state of the locking retainer is maintained by the self-locking force of the self-locking mechanism.

[0030] By adopting the aforementioned technical solution, a self-locking force is provided through a self-locking mechanism. When the spindle does not output torque, the locking retainer in the second locking state can be kept in a compressed state by the self-locking force, and the pivot drive device does not need to continuously output torque.

[0031] Preferably, the self-locking mechanism is configured as one of the following structures: The self-locking mechanism is a braking element provided on the output shaft of the motor drive unit. When the motor drive unit is not running, the output shaft is restricted from rotation by friction engagement of the braking element. The self-locking mechanism is a worm gear assembly of a motor drive unit. The worm wheel in the worm gear assembly is connected to the main shaft for transmission. The helical teeth of the worm and the teeth of the worm wheel form a one-way friction self-locking mechanism, which allows the worm to drive the worm wheel but the worm wheel cannot drive the worm.

[0032] Using the aforementioned technical solution, several specific implementation methods of the self-locking mechanism are disclosed.

[0033] Preferably, the device also includes a stroke sensor and a triggering component, wherein the triggering component is driven to rotate by a transmission component, and the stroke sensor outputs an electrical signal in response to the action of the triggering component.

[0034] Using the aforementioned technical solution, the stroke sensor can be triggered by the triggering component to determine whether the trailer hitch is in the storage position or the working position.

[0035] Preferably, the triggering component includes an axially extending safety pin, the inner peripheral wall of the sleeve is provided with an axially extending outer pin groove, and the locking actuator is correspondingly provided with an inner pin groove. During the first and second idle strokes, the safety pin is inserted into the outer pin groove and the inner pin groove to limit the locking actuator. When the trailer hook is locked in the storage position or the working position, the safety pin is disengaged from the inner pin groove.

[0036] By adopting the aforementioned technical solution, on the one hand, the safety pin is inserted into the outer pin groove and the inner pin groove to limit and lock the actuator, providing additional protection for the limiting of the locking actuator; on the other hand, when the trailer hook is locked in the storage position or the working position, the safety pin is withdrawn from the inner pin groove, so that the locking actuator can rotate relative to the sleeve, thereby cooperating with the locking element to lock the trailer hook under the action of the torque force transmitted from the locking retaining member.

[0037] Preferably, the triggering component includes a radially protruding shoulder, and the transmission component is provided with a circumferentially extending second stepped track. The shoulder is biased on the second stepped track by an elastic biasing element, and the relative sliding of the shoulder on the second stepped track causes the triggering component to generate axial displacement along the outer pin groove.

[0038] The aforementioned technical solution discloses a specific structure for driving the rotation of the transmission component to trigger the action of the component. These features and advantages of the present invention will be revealed in detail in the following specific embodiments and accompanying drawings. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the trailer coupling device in an embodiment of the present invention; Figure 2 This is an exploded view of the trailer coupling device in an embodiment of the present invention; Figure 3 This is a schematic diagram of the pivot drive device and the pivot locking device in an embodiment of the present invention; Figure 4 This is an exploded view of the pivot drive device and pivot locking device in an embodiment of the present invention; Figure 5 This is a partial cross-sectional view of the pivot drive device and the pivot locking device in an embodiment of the present invention; Figure 6 This is a partial view of the locking element and locking actuator in an embodiment of the present invention; Figure 7 This is another partial view of the locking element and locking actuator in an embodiment of the present invention; Figure 8This is an exploded view of the drive shaft and transmission components in an embodiment of the present invention; Figure 9 This is a schematic diagram of the drive shaft and transmission components working together and the idle stroke in an embodiment of the present invention; Figure 10 This is an exploded view of the support frame, trailer hitch, and clutch mechanism in an embodiment of the present invention; Figure 11 This is a schematic diagram of the fixed guide component being fixed to the support frame in an embodiment of the present invention; Figure 12 This is an exploded view of the support frame, triggering component, and stroke sensor in an embodiment of the present invention; Figure 13 for Figure 12 Enlarged view of point A in the middle; Figure 14 This is a schematic diagram of the trailer hook of the trailer coupling device in the storage position in the locked state in an embodiment of the present invention; Figure 15 This is a cross-sectional view of the trailer hook of the trailer coupling device in the embodiment of the present invention in the locked state in the storage position; Figure 16 for Figure 15 Enlarged view of point B in the middle; Figure 17 This is a schematic diagram showing the position of the clutch mechanism when the trailer hook is locked in the storage position in an embodiment of the present invention; Figure 18 This is a cross-sectional view of the clutch mechanism position when the trailer hook is locked in the storage position in an embodiment of the present invention; Figure 19 This is a partial view of the triggering component and the stroke sensor when the trailer hook is locked in the stowed position in an embodiment of the present invention; Figure 20 This is another partial view of the triggering component and the travel sensor when the trailer hook is locked in the retracted position in an embodiment of the present invention; Figure 21 This is a schematic diagram of the trailer hook of the trailer coupling device in the storage position in the unlocked state in an embodiment of the present invention; Figure 22 This is a cross-sectional view of the trailer hook of the trailer coupling device in the embodiment of the present invention in the unlocked state in the storage position; Figure 23 This is a schematic diagram showing the position of the clutch mechanism when the trailer hitch is unlocked in the stowed position in an embodiment of the present invention; Figure 24 This is a cross-sectional view of the clutch mechanism position when the trailer hitch is unlocked in the stowed position in an embodiment of the present invention; Figure 25 This is a partial view of the triggering component and travel sensor when the trailer hitch is unlocked in the stowed position, according to an embodiment of the present invention. Figure 26 This is another partial view of the triggering component and travel sensor when the trailer hitch is unlocked in the stowed position, according to an embodiment of the present invention; Figure 27 This is a schematic diagram of the trailer hook of the trailer coupling device in the working position in an embodiment of the present invention being in a locked state; Figure 28 This is a cross-sectional view of the trailer hook of the trailer coupling device in the embodiment of the present invention in the locked state in the working position; Figure 29 This is a schematic diagram of the clutch mechanism position when the trailer hook is locked in the working position in an embodiment of the present invention; Figure 30 This is a cross-sectional view of the clutch mechanism position when the trailer hook is locked in the working position in an embodiment of the present invention; Figure 31 This is a partial view of the triggering component and the stroke sensor when the trailer hook is locked in the working position in an embodiment of the present invention; Figure 32 This is another partial view of the triggering component and the stroke sensor when the trailer hook is locked in the working position in an embodiment of the present invention; Figure 33 This is a schematic diagram showing the trailer hook of the trailer coupling device in a position of gravity equilibrium in an embodiment of the present invention; Figure 34 This is a cross-sectional view of the trailer hook of the trailer coupling device in an embodiment of the present invention in a position of gravity equilibrium; Figure 35 This is a schematic diagram of the clutch mechanism when the trailer hitch is in the gravity equilibrium position according to an embodiment of the present invention; Figure 36 This is a partial view of the triggering component and the stroke sensor when the trailer hook is in the gravity equilibrium position in an embodiment of the present invention; Figure 37 This is a schematic diagram of a trailer coupling device having multiple locking elements in an embodiment of the present invention; Figure 38 This is another schematic diagram of a trailer coupling device having multiple locking elements in an embodiment of the present invention.

[0040] Figure label: 100. Support frame; 110. Sleeve; 111. Guide hole; 112. Outer pin groove; 200. Trailer hook; 210. Support seat; 211. External anti-rotation groove; 220. End cover; 221. Transmission groove; 300, pivot drive device; 310, drive shaft; 311, main shaft; 311a, main shaft protrusion; 312, bushing; 312a, bushing protrusion; 320, transmission component; 321, second stop; 322, second groove; 323, transmission protrusion; 324, second stepped track; 324a, top surface; 324b, slope; 324c, bottom surface; 325, first shaft end face; 326, boss. 400, pivot locking device; 410, locking actuator; 411, inner anti-rotation groove; 412, locking platform; 412a, transition section; 413, first stop portion; 414, first groove; 415, inner pin groove; 420, locking element; 430, locking retainer. 500, clutch mechanism; 510, fixed guide component; 511, first stepped track; 511a, guide platform; 511b, transition track; 511c, low-position track; 512, track groove; 520, movable guide component; 521, pin hole; 530, transmission pin. 600. Triggering component; 610. Safety pin; 620. Shoulder; 630. Flexible biasing element; 700. Stroke sensor. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of the present invention and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of the present invention.

[0042] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" or "a number" means two or more, unless otherwise expressly defined.

[0044] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] The trailer coupling device proposed in this embodiment of the invention, in Figure 14 , Figure 15 , Figure 17 , Figure 19 to Figure 21 The image shows the trailer hitch in its stowed position. Figure 25 to Figure 27 The image shows the trailer hitch in its working position. Figure 31 to Figure 33 The image shows the trailer hook pivoting to an intermediate position between the two positions mentioned above.

[0046] like Figure 1 to Figure 7 , Figure 14 to Figure 17 , Figure 21 to Figure 23 , Figure 27 to Figure 29 , Figure 33 to Figure 35 As shown, the trailer coupling device includes a carrier frame 100, a trailer hitch 200, a pivot drive mechanism 300, and a pivot locking mechanism 400. The carrier frame 100 is used to secure itself to a vehicle body (e.g., a rear bumper, a beam), and includes a sleeve 110 with guide holes 111. The trailer hitch 200 includes a support 210 with two external anti-rotation grooves 211, which is pivotally connected to the outside of the sleeve 110, allowing the trailer hitch 200 to pivotally switch between a stowed position and a working position relative to the carrier frame 100.

[0047] The support frame 100 is fixed to the bumper of the vehicle body using existing connection methods. The guide hole 111 extends radially along the sleeve 110.

[0048] The pivot drive device 300 is disposed inside the sleeve 110. The pivot drive device 300 includes a drive shaft 310 and a transmission component 320 that is drively connected to the drive shaft 310.

[0049] The pivoting locking device 400 includes a locking actuator 410, a locking element 420, and a locking retainer 430. The locking actuator 410 is pivotally mounted on a drive shaft 310 and has an inner anti-rotation groove 411 and locking platforms 412 disposed on both sides of the inner anti-rotation groove 411 circumferentially. The locking element 420 is disposed in a guide hole 111 and is movable along the guide hole 111. The locking retainer 430 is disposed between the locking actuator 410 and the drive element 320 to transmit torque, and the locking retainer 430 can be compressed and stored by the relative pivoting of the locking actuator 410 and the drive element 320.

[0050] The pivot locking device 400 has an unlocked state and a locked state. For example, Figure 14 to Figure 16 As shown, the trailer hitch is in the retracted position and the pivot locking device 400 is in the locked state; as Figure 21 , Figure 22 As shown, the trailer hitch is in the retracted position and the pivot locking device 400 is in the unlocked state; Figure 27 , Figure 28 As shown, the trailer hitch is in the working position and the pivot locking device 400 is in the locked state.

[0051] In the locked state, the trailer hitch 200 is locked in either the storage or working position. In the unlocked state, the trailer hitch 200 can pivot relative to the support frame 100 between the storage and working positions.

[0052] The locking state includes a first locking state and a second locking state.

[0053] In the first locked state, the drive shaft 310 drives the transmission component 320 and the locking actuator 410 to pivot synchronously. The locking element 420 is pushed by the locking actuator 410 and partially enters one of the outer anti-rotation grooves 211 along the guide hole 111 and is stopped by the locking platform 412 to lock the trailer hook 200 in the storage position or the working position.

[0054] The second locking state, which follows the first locking state, is referenced. Figure 7 , Figure 14 to Figure 16 The drive shaft 310 drives the transmission component 320 to pivot relative to the locking actuator 410 to compress the locking retainer 430. The compressed locking retainer 430 applies a preload torque to the locking actuator 410 to maintain the stop of the locking platform 412 on the locking element 420.

[0055] In the first and second locking states, the transmission member 320 is restricted by the drive shaft 310, so that the preload torque of the locking retainer 430 will not drive the transmission member 320 to rotate in the opposite direction.

[0056] In the second locking state, one side of the locking element 420 abuts against the bottom wall of the outer anti-rotation groove 211, and the other side abuts against the locking platform 412. Thus, the pre-tightening torque of the locking retainer 430 firmly holds the locking platform 412, the locking element 420 and the outer anti-rotation groove 211 in place. As long as the transmission component 320 does not rotate in the opposite direction, the support seat 210 cannot rotate relative to the sleeve 110, thereby locking the trailer hook 200 in the current position.

[0057] like Figure 6 , Figure 7 , Figure 16 As shown, the outer peripheral surface of the locking actuator 410 is partially recessed to form an inner anti-rotation groove 411. On a portion of the outer peripheral surface of the locking actuator 410, a locking platform 412 is formed on each side of the inner anti-rotation groove 411. The two locking platforms 412 are formed by gradually extending radially outward from both circumferential sides of the inner anti-rotation groove 411 in a direction away from the inner anti-rotation groove 411. One of the two locking platforms 412 stops the locking element 420 at the storage position of the trailer hook 200, and the other stops the locking element 420 at the working position of the trailer hook 200.

[0058] The inner anti-rotation groove 411 includes a groove bottom and a groove wall that gradually transitions from the groove bottom to the outer peripheral surface of the locking actuator 410. A transition section 412a is also provided on the outer peripheral surface of the locking actuator 410, connecting the groove wall of the inner anti-rotation groove 411 and the locking platform 412. The linear distance between the locking platform 412 and the rotation axis of the locking actuator 410 gradually increases, causing the locking platform 412 to gradually extend radially outward.

[0059] As the locking actuator 410 rotates, the groove wall of the inner anti-rotation groove 411 can push the locking element 430 to move towards the outer anti-rotation groove 211 along the extension direction of the guide hole 111. The groove wall of the inner anti-rotation groove 411 can also limit the depth to which the locking element 430 retracts into the guide hole 111, so that at least a portion of the locking element 430 extends into the guide hole 111 and engages with the outer anti-rotation groove 211. The transition section 412a is used to engage with the groove wall of the inner anti-rotation groove 411, so that the locking element 430 can smoothly transition to the locking platform 412.

[0060] like Figure 16 As shown, the locking platform 412 extends radially outward in a direction away from the inner anti-rotation groove 411, serving two purposes.

[0061] The first function is that the locking platform 412 stops the locking element 420 and pushes the locking element 420 towards the bottom of the outer anti-rotation groove 211. Since the sleeve 110 is fixed, the locking platform 412 gradually extends radially outward, so that the straight distance between the support point of the locking platform 412 on the locking element 420 and the bottom of the outer anti-rotation groove 211 gradually decreases. When the straight distance decreases to a certain value, the locking platform 412, the locking element 420, and the outer anti-rotation groove 211 are completely locked together, and the locking actuator 410 can no longer rotate. As a result, the locking retainer 420 is compressed under the drive of the transmission member 320 and transmits the preload torque to the locking actuator 410, thereby locking the pivot locking device 400 in the second locking state.

[0062] The second function is that when the pivot locking device 400 switches from the locked state to the unlocked state, the drive shaft 310 drives the transmission component 320 to rotate in the opposite direction. The force of the rotation of the trailer hook 200 is transmitted to the locking element 430 through the groove wall of the outer anti-rotation groove 211, so that the locking element 430 generates a force acting on the locking platform 412. The direction of this force is the normal direction of the position on the locking platform 412 that contacts the locking element 430. Since the locking platform 412 gradually extends radially inward in the direction close to the inner anti-rotation groove 411, the force can be decomposed into two mutually perpendicular forces. One force points to the center of the locking actuator 410, and the other force constitutes a thrust that pushes the locking actuator 410 to rotate. This allows the rotation of the trailer hook 200 to push the locking actuator 410 to rotate through the locking element 430, so that the locking element 430 can disengage from the outer anti-rotation groove 211 and engage with the inner anti-rotation groove 421.

[0063] Preferably, the locking platform 412 is configured as an inclined surface that extends circumferentially along the outer peripheral surface of the locking actuator 410.

[0064] In some other embodiments, the locking platform 412 may also be configured as a helical trajectory surface or an involute trajectory surface extending circumferentially along the outer peripheral surface of the locking actuator 410.

[0065] like Figure 6 , Figure 7 As shown, the locking element 420 is constructed as a sphere.

[0066] In some other embodiments, the locking element 420 may also be constructed as a cylinder, or an ellipsoid, or a combination of the above shapes.

[0067] like Figure 4 to Figure 7 As shown, there is one locking element 420 and one corresponding guide hole 111.

[0068] In some other embodiments, multiple locking elements 420 may be provided. The multiple locking elements 420 are spaced apart circumferentially on the sleeve 110, and the central angle formed by any two adjacent locking elements 420 relative to the rotation axis of the sleeve 110 is different from the central angle formed by other two adjacent locking elements 420 relative to the rotation axis of the sleeve 110. A corresponding number of guide holes 111 are provided, corresponding to the number of locking elements 420. The locking elements 420 can return to the guide holes 111 under their own weight or by the pushing of the outer anti-rotation grooves 211. The number of outer anti-rotation grooves 211 is twice the number of locking elements 420, with two outer anti-rotation grooves 211 forming a group that mates with one locking element 420.

[0069] For example, such as Figure 37 , Figure 38 As shown, there are three locking elements 420. The central angle formed by two adjacent locking elements 420 relative to the rotation axis of the sleeve 110 is 110°, the central angle formed by two other adjacent locking elements 420 relative to the rotation axis of the sleeve 110 is 120°, and the central angle formed by two other adjacent locking elements 420 relative to the rotation axis of the sleeve 110 is 130°. The positions of the six outer anti-rotation grooves 211 correspond to the three locking elements 420, so that when the trailer hook 200 is in the working position, the three locking elements 420 extend into the three outer anti-rotation grooves respectively, and when the trailer hook 200 is in the storage position, the three locking elements 420 extend into the other three outer anti-rotation grooves respectively.

[0070] When the trailer hook 200 rotates between the working position and the storage position, when one locking element 420 corresponds to one of the six outer anti-rotation grooves 211, the other two locking elements 420 are blocked by the inner wall of the support seat 210 and cannot fall into either outer anti-rotation groove 211. That is, at any position during the pivoting process of the trailer hook 200, only one locking element 420 can fall into one of the outer anti-rotation grooves 211. This means that during the pivoting process of the trailer hook 200, apart from the weight of the trailer hook 200 itself, the pivoting drive device 300 only needs to overcome the resistance of the outer anti-rotation groove 211 pushing one locking element 420 back to the guide hole 111 and the inner anti-rotation groove 411, thereby reducing the pivoting resistance of the trailer hook 200 and reducing the probability of the trailer hook 200 getting stuck during the pivoting process.

[0071] In this way, the pivot locking device 400 can provide locking force at multiple positions in the circumferential direction, so that the locking actuator 410 and the trailer hook 200 are subjected to uniform force in the circumferential direction, and the locking force is distributed, so that the size and thickness of the components providing the locking force in the pivot locking device 400 can be reduced accordingly.

[0072] Understandably, the locking element 420 can also be set to two or more.

[0073] The locking retainer 430 includes a locking group consisting of three locking units, which are circumferentially spaced on one side of the locking actuator 410 in the axial direction. The three locking units in one locking group together transmit torque between the locking actuator 410 and the transmission member 320, and together apply preload torque to the locking actuator 410 in the second locking state.

[0074] In the unlocked state, the locking element 420 is almost completely located in the guide hole 111, and the rotation direction of the support 210 is not obstructed by the locking element 420, allowing the trailer hook 200 to pivot relative to the support frame 100 between the storage position and the working position. The locking element 420 can return to the guide hole 111 under its own weight, or it can return to the guide hole 111 under the push of the outer anti-rotation groove 211 and be stopped by the inner wall of the support 210 and held in the guide hole 111.

[0075] The trailer hook 200 has a hook body 201 at its end. When the trailer hook 200 is in the retracted position, the hook body 201 is hidden inside the vehicle body. When the trailer hook 200 is in the working position, the trailer hook 200 pivots to the working position, and the hook body 201 pivotally flips out from inside the vehicle body and is exposed outside the vehicle body, making it easy to hook up.

[0076] like Figure 2 , Figure 4 As shown, the locking retainer 430 is a helical spring.

[0077] In some other embodiments, the locking retainer 430 may also be a torsion spring, or a rubber spring, or a combination of the above springs.

[0078] like Figure 4 , Figure 5 As shown, both the locking actuator 410 and the transmission member 320 are disc-shaped and arranged axially along the drive shaft 310. The disc surface of the locking actuator 410 has pairs of first stops 413 spaced apart circumferentially, and the disc surface of the transmission member 320 has pairs of second stops 321 spaced apart circumferentially. When the trailer hitch 200 is in the retracted position, the drive shaft 310 drives the transmission member 320 to pivot relative to the locking actuator 410, causing one set of circumferentially misaligned first stops 413 and second stops 321 to engage and compress the locking retainer 430. When the trailer hitch 200 is in the working position, the drive shaft 310 drives the transmission member 320 to pivot relative to the locking actuator 410, causing another set of circumferentially misaligned first stops 413 and second stops 321 to engage and compress the locking retainer 430.

[0079] The first stop portion 413 includes a first stop portion 413a and a first stop portion 413b, and the second stop portion 321 includes a second stop portion 321a and a second stop portion 321b.

[0080] like Figure 4 , Figure 5 As shown, the locking actuator 410 has a first groove 414 on its disc surface, and the two ends of the first groove 414 define a pair of first stop portions 413. A portion of the locking retainer 430 is received in the first groove 414. The transmission member 320 has a second groove 322 on its disc surface, and the two ends of the second groove 322 define a pair of second stop portions 321. A portion of the locking retainer 430 is received in the second groove 322.

[0081] In order to accommodate the three locking units, three first grooves 414 are provided and are circumferentially spaced on the disk surface of the locking actuator 410. Correspondingly, three second grooves 322 are also provided and are circumferentially spaced on the disk surface of the transmission member 320. A cavity for accommodating one of the three locking units is formed between the first grooves 414 and the second grooves 322 that are axially adjacent on the locking actuator 410 and the transmission member 320.

[0082] The locking retainer 430 is pre-tightened by the relative movement of the first stop portion 413a and the second stop portion 321b compressing the size of the cavity, or by the relative movement of the first stop portion 413b and the second stop portion 321a compressing the size of the cavity. When the first stop portion 413a and the second stop portion 321a are side by side, or when the first stop portion 413b and the second stop portion 321b are side by side, the locking retainer 430 is in a released state, that is, the pivot locking device 400 is in an unlocked state.

[0083] It is understandable that the locking assembly consists of three locking units in order to reduce the preload of each locking unit and to balance the forces on the locking actuator 410 and the transmission member 320 in the circumferential direction. The number of locking units can also be set to other quantities, and correspondingly, the number of the first groove 414 and the second groove 322 can also be set to other quantities.

[0084] like Figure 2 , Figure 4 , Figure 5 As shown, the transmission component 320 is configured as two sets, with the two sets of transmission components 320 respectively disposed on both sides of the locking actuator 410 along the axial direction. The two sets of transmission components 320 are compactly distributed on both sides of the locking actuator 410, and the locking retaining component 430 correspondingly includes two locking groups, which are also compactly distributed on both sides of the locking actuator 410 along the axial direction. The transmission component 320 limits one locking group between the transmission component 320 and the locking actuator 410, and the drive shaft 310 drives the two sets of transmission components 320 to rotate in the same direction, so that the forces on both ends of the locking actuator 410 along the axial direction are balanced.

[0085] The locking actuator 410 has a locking group on each of its two axial sides, meaning that the locking retainer 430 includes six locking units.

[0086] like Figure 10 , Figure 11 , Figure 17 , Figure 18 , Figure 23 , Figure 24 , Figure 29 , Figure 30 As shown, the trailer coupling device also includes a clutch mechanism 500, which is configured as follows: When the trailer hitch 200 is locked in the storage or working position, the power connection between the drive shaft 310 and the support 210 is cut off. When the trailer hitch 200 is unlocked in the storage or working position, a power connection is established between the drive shaft 310 and the support 210 until the trailer hitch 200 is locked again.

[0087] The clutch mechanism 500 establishes a power connection between the drive shaft 310 and the support seat 210, allowing the trailer hook 200 to pivot between the working position and the retracted position under the rotational torque of the drive shaft 310 or supported by the rotation of the drive shaft 310. The clutch mechanism 500 disconnects the power connection between the drive shaft 310 and the support seat 210, enabling the trailer hook 200 to remain stationary in the working or retracted position. The actual position of the trailer hook 200 will not change due to the rotation of the pre-tightening locking retainer 430 of the drive shaft 310. Simultaneously, external forces acting on the trailer hook 200 will not be transmitted to the drive shaft 310, preventing impact on the drive shaft 310.

[0088] like Figure 10 , Figure 11 , Figure 17 , Figure 18 , Figure 23 , Figure 24 , Figure 29 , Figure 30 As shown, the specific structure of the clutch mechanism 500 is described below. The clutch mechanism 500 includes a fixed guide component 510, a movable guide component 520, and a transmission pin 530. The fixed guide component 510 is fixed to the support frame 100 and has a first stepped track 511 extending circumferentially. The movable guide component 520 is connected to the drive shaft 310 and rotates with the drive shaft 310. The movable guide component 520 has an axially arranged pin hole 521. The transmission pin 530 passes through the pin hole 521 and can move along the pin hole 521. The rotation of the movable guide component 520 causes one end of the transmission pin 530 to slide along the first stepped track 511, and the other end of the transmission pin 530 to engage or disengage from the support seat 210.

[0089] In this embodiment, the trailer hook 200 further includes an end cap 220 fixedly connected to the support base 210, and the end cap 220 is provided with a transmission groove 221 that engages with the transmission pin 530. The fixing guide member 510 is disc-shaped, and the fixing guide member 510 and the end cap 220 are spaced parallel to each other in the axial direction of the trailer coupling device. The fixing guide member 510 has an outer surface facing the end cap 220, and a circumferentially extending track groove 512 is formed in a local position on the outer surface. The two ends of the first stepped track 511 are respectively connected to the two ends of the track groove 512 in the circumferential direction.

[0090] The end cap 220 can be screwed onto the support 210. In some other embodiments, the end cap 220 can be integrally formed onto the support 210.

[0091] The movable guide component 520 is strip-shaped and has a connecting hole for transmission connection with the drive shaft 310. This connecting hole is polygonal so that the movable guide component 520 and the drive shaft 310 rotate synchronously. In some other embodiments, the movable guide component 520 and the drive shaft 310 may also use a keyway fit for synchronous rotation.

[0092] A portion of the first stepped track 511 is recessed relative to the outer surface of the fixed guide member 510 in a direction away from the end cover 220. The first stepped track 511 includes a guide platform 511a, a transition track 511b, and a low-position track 511c. The guide platform 511a is in a high position, the low-position track 511c is in a low position, and the transition track 511b transitions from high to low between the guide platform 511a and the low-position track 511c. Thus, the drive pin 530 can be axially guided to move between the guide platform 511a, the transition track 511b, and the low-position track 511c.

[0093] Among them, the guide platform 511a is part of the outer surface of the fixed guide component 510.

[0094] When one end of the transmission pin 530 moves to the guide platform 511a, the other end of the transmission pin extends into the transmission groove 221 and drives the end cover 220. At this time, the clutch device drives the drive shaft 310 and the support seat 210.

[0095] When one end of the transmission pin 530 moves to the lower track 511c, the other end of the transmission pin separates from the transmission groove 221. At this time, the clutch device separates the drive shaft 310 and the support seat 210.

[0096] It should be noted that in this embodiment, when one end of the transmission pin 530 is supported on the guide platform 511a and the other end is engaged in the transmission groove 221, at least one of the transmission pin 530, the guide platform 511a, and the end cap 220 undergoes elastic deformation. This elastic deformation allows the transmission pin 530 to move to the position of the transition track 511b and then elastically reset so that one end of the transmission pin 530 can engage with the transition track 511b and completely disengage from the transmission groove 221 under the drive of the movable guide component 520.

[0097] It can be understood that this elastic deformation does not need to be large, only that the transmission pin 530 can engage with the transition track 511b when it is disengaged from the guide platform 511a.

[0098] In some other embodiments, the pin hole 521 may be set to be inclined so that the drive pin 530 can engage with the transition track 511b under its own gravity when it is disengaged from the guide platform 511a.

[0099] like Figure 11 As shown, there are two track grooves 512 and two corresponding first stepped tracks 511. The two first stepped tracks 511 are respectively engaged with the transmission pins 530 to drive the trailer hooks 200 in the working position and the storage position to engage or disengage.

[0100] In some other embodiments, there may be only one track groove 512, and a corresponding first stepped track 511. When the transmission pin 530 moves outside the track groove 512, the clutch mechanism 500 engages with the trailer hook 200. When the transmission pin 530 moves inside the track groove 512, the clutch mechanism 500 disengages from the trailer hook 200.

[0101] It should be noted that one end wall of each of the two track grooves 512 can limit the movement distance of the transmission pin 530, thereby preventing the drive shaft 310 from excessively compressing the locking retainer 430. The two track grooves 512 can also prevent the fixed guide component 510 from having too many hollow positions, which would lead to a decrease in the strength of the fixed guide component 510.

[0102] It should be further explained that since the transmission pin 530 is driven by the movable guide component 520, and the movable guide component 520 is provided with an axially arranged pin hole 521 to guide the axial movement of the transmission pin 530, the track groove 512 is unnecessary. The track groove 512 is an auxiliary structure produced by integrally forming the first stepped track 511 on the fixed guide component 510 using a stamping and stretching process.

[0103] In some other embodiments, there may be two drive pins 530, and the movable guide component 520 is provided with two corresponding pin holes 521. The two drive pins 530 move on circles with different radii. Correspondingly, the first stepped track 511 is provided in two sets to respectively engage the two drive pins 530, and the end cover 220 is provided with drive grooves 221 that respectively engage with the two pin holes 521.

[0104] like Figure 8 , Figure 9 As shown, the specific structure of the drive shaft 310 and the transmission method between the drive shaft 310 and the transmission component 320 are described. The drive shaft 310 includes a main shaft 311 and a bushing 312 fitted outside the main shaft 311. The main shaft 311 has two circumferentially spaced main shaft protrusions 311a, the bushing 312 has two circumferentially spaced bushing protrusions 312a, and the transmission component 320 has two circumferentially spaced transmission protrusions 323. The two main shaft protrusions 311a and the two bushing protrusions 312a are circumferentially alternating and can rotate relative to each other, the two bushing protrusions 312a and the two transmission protrusions 323 are circumferentially alternating and can rotate relative to each other, and the two main shaft protrusions 311a and the two transmission protrusions 323 are axially misaligned. When the trailer hook 200 is unlocked in the storage or working position, the main shaft 311 rotates relative to the bushing 312 for a first idle stroke. After the first idle stroke ends, the main shaft 311 drives the bushing 312 to rotate relative to the transmission component 320 for a second idle stroke.

[0105] Two main shaft protrusions 311a are partially radially outward at the central position in the axial direction of the main shaft 311, and are symmetrically distributed on both sides of the main shaft 311. A hollow bushing 312 is fitted onto the outside of the main shaft 311. Two bushing protrusions 312a are symmetrically radially inward in the bushing 312, and also symmetrically outward at both ends in the axial direction of the bushing 312. The transmission component 320 includes a through hole for connecting the main shaft 311, and two transmission protrusions 323 symmetrically protrude radially inward from the inner wall of the through hole. The main shaft protrusions 311a abut against the radially inwardly protruding portion of the bushing protrusions 312a in the bushing 312, and the transmission protrusions 323 abut against the axially outwardly protruding portion of the bushing protrusions 312a in the bushing 312.

[0106] Two main shaft protrusions 311a and two bushing protrusions 312a are circumferentially alternately distributed, allowing the main shaft 311 to rotate relative to the bushing 312. When the two main shaft protrusions 311a abut against the two bushing protrusions 312a respectively, the main shaft 311 drives the bushing 312 to rotate. Two bushing protrusions 312a and two transmission protrusions 323 are circumferentially alternately distributed, allowing the bushing 312 to rotate relative to the transmission component 320. When the two bushing protrusions 312a abut against the two transmission protrusions 323 respectively, the bushing 312 drives the transmission component 320 to rotate.

[0107] The two main shaft protrusions 311a and the two transmission protrusions 323 are axially misaligned, so that the rotation of the main shaft protrusions 311a is not directly transmitted to the transmission protrusions 323. The transmission component 320 is driven to rotate by the bushing 312 driven by the main shaft 311.

[0108] There is a circumferential gap between the inwardly protruding portions of the main shaft protrusion 311a and the bushing protrusion 312a. When the main shaft protrusion 311a and the bushing protrusion 312a abut each other in one of the rotational directions (e.g., clockwise), the main shaft 311 rotates in the opposite direction (e.g., counterclockwise). The main shaft protrusion 311a needs to eliminate the circumferential gap between itself and the bushing protrusion 312a before it abuts the bushing protrusion 312a for transmission. The circumferential gap between the inwardly protruding portions of the main shaft protrusion 311a and the bushing protrusion 312a results in a first free stroke between the main shaft 311 and the bushing 312a.

[0109] The bushing protrusion 312a has a circumferential gap between the outwardly protruding portion of the bushing 312 on the shaft and the transmission protrusion 323. Accordingly, the circumferential gap between the bushing protrusion 312a and the transmission protrusion 323 allows for a second free stroke between the bushing 312 and the transmission member 320.

[0110] In conjunction with the aforementioned embodiments, a free stroke is set so that the rotation of the drive shaft 310 is only a small angle of rotation of the drive transmission component 320, and the rotation of the locking actuator 410 is also only a small angle. This enables the locking actuator 410 to complete the locking in a short time when the trailer hook 200 is locked in the storage position or the working position.

[0111] At the same time, the smaller rotation angle of the transmission component 320 and the locking actuator 410 means that the locking retainer 430 has a smaller compression stroke, which allows the locking retainer 430 to have a larger stiffness coefficient (also known as the elasticity coefficient or spring constant), thereby providing a larger preload torque.

[0112] Furthermore, the smaller rotation angle of the transmission component 320 and the locking actuator 410 also reduces the friction between the locking actuator 410, the transmission component 320 and the sleeve 110 due to rotation, thereby increasing the service life of the locking actuator 410, the transmission component 320 and the sleeve 110.

[0113] Finally, since the transmission between the main shaft 311, bushing 312 and transmission component 320 is achieved by radial protrusions, and since the protrusions have thickness, the free travel between any two parts that are in contact with each other is necessarily less than 180°. However, the first free travel and the second free travel between the drive shaft 310 and the transmission component 320 of the present invention are formed on two circumferences respectively. Therefore, the first free travel and the second free travel can be superimposed on each other, so that the free travel between the drive shaft 310 and the transmission component 320 can be greater than 180°. Thus, the trailer hook 200 can have more pivoting travel options for different vehicle models.

[0114] It should be noted that when assembling the pivot drive device 300, in order to avoid interference between the protrusions, the main shaft 311 and the bushing 312 that are connected by a sleeve should be connected and installed into the locking actuator 410 first, and then the transmission component 320 should be connected and installed on the main shaft 311.

[0115] The pivot drive device 300 also includes a motor drive unit for driving the spindle 311 to rotate in both directions. The motor drive unit is equipped with a self-locking mechanism to restrict the spindle 311 from being driven to rotate by a load when the motor drive unit is not in operation. In the second locked state, the spindle protrusion 311a, the bushing protrusion 312a, and the transmission protrusion 323 abut against each other in sequence, and the self-locking force of the self-locking mechanism maintains the compression state of the locking retainer 430.

[0116] The self-locking mechanism provides the self-locking force, so that the locking retainer 430 in the second locking state can be kept in the compressed state when the spindle 311 does not output torque, and the pivot drive 300 does not need to continuously output torque.

[0117] In one embodiment, a specific structure of the self-locking mechanism is disclosed. The self-locking mechanism is configured as a worm gear assembly driven by a motor-driven unit. The worm gear in the worm gear assembly is connected to the main shaft 311. The helical teeth of the worm and the teeth of the worm gear form a one-way frictional self-locking mechanism, allowing the worm to drive the worm gear while preventing the worm gear from driving the worm. The self-locking of the worm gear and worm is achieved by the thread helix angle being smaller than the friction angle.

[0118] In other embodiments, another specific structure of the self-locking mechanism is disclosed, wherein the mechanism itself is configured as a braking element disposed on the output shaft of the motor drive unit. When the motor drive unit is not in operation, the output shaft is restricted from rotation by frictional engagement of the braking element. Specifically, the braking element can be referenced to the friction ring in Chinese Utility Model Patent Publication No. CN215634557U, entitled "Self-locking Device, Motor with Self-locking Function, and Linear Brake." The braking element can also be referenced to the friction ring in Chinese Invention Patent Application Publication No. CN113653782A, entitled "Self-locking Device and Linear Actuator Applicable to Motors."

[0119] like Figure 12 , Figure 13 As shown, the trailer coupling device also includes a stroke sensor 700 and a triggering component 600. The triggering component 600 is driven to rotate by the transmission component 320, and the stroke sensor 700 outputs an electrical signal in response to the action of the triggering component 600.

[0120] The triggering component 600 is configured to trigger the stroke sensor 700 when the pivot locking device 400 is in the second locking state, and the triggering component 600 is driven to trigger the stroke sensor 700 when the trailer hook 200 is in the retracted position or the working position. The sensing signal of the stroke sensor 700 can be used to determine whether the trailer hook 200 is in the working position or the retracted position.

[0121] It should be noted that, in the second locking state, the locking platform 412, the locking element 420, and the outer anti-rotation groove 211 are completely locked together. At this time, the motor drive unit is in a stalled state, and the current of the motor drive unit increases. The motor drive unit can be stopped by changing the current of the motor drive unit or by controlling the current threshold of the motor drive unit.

[0122] like Figure 12 , Figure 13 As shown, the triggering component 600 includes an axially extending safety pin 610. The inner peripheral wall of the sleeve 110 is provided with an axially extending outer pin groove 112. The locking actuator 410 is correspondingly provided with an inner pin groove 415. During the first and second idle strokes, the safety pin 610 is inserted into the outer pin groove 112 and the inner pin groove 415 to limit the locking actuator 410. When the trailer hook 200 is locked in the storage position or the working position, the safety pin 610 is disengaged from the inner pin groove 415.

[0123] During the first and second free strokes, the locking element 420 can disengage from the locking platform 412 and partially enter the inner anti-rotation groove 411 to limit the locking actuator 410. When the safety pin 610 is inserted into the outer pin groove 112 and the inner pin groove 415, the groove wall of the inner pin groove 415 can be stopped by the safety pin 610, which also plays a role in assisting to limit the locking actuator 410.

[0124] like Figure 12 , Figure 13 As shown, the triggering component 600 includes a radially protruding shoulder 620, and the transmission component 320 is provided with a circumferentially extending second stepped track 324. The shoulder 620 is biased on the second stepped track 324 by an elastic biasing element 630. The relative sliding of the shoulder 620 on the second stepped track 324 causes the triggering component 600 to generate axial displacement along the outer pin groove 112.

[0125] One end of the elastic bias element 630 is elastically pre-tightened between the shoulder 620 and the housing of the stroke sensor 700. The housing of the stroke sensor 700 is fixed to the vehicle body (e.g., rear bumper or beam), such that the end of the elastic bias element 630 away from the shoulder 620 is essentially fixed. The shoulder 620 is radially protruding onto the safety pin 610, and a load-bearing portion is formed on the safety pin 610 to bear the pre-tightening force of the elastic bias element 630. Thus, the elastic bias element 630 can push the trigger member 600 to move in the direction of the transmission member 320, and the elastic bias element 630 can be compressed by the trigger member 600 to store energy.

[0126] In this embodiment, the elastic bias element 630 can be a helical spring.

[0127] In some other embodiments, the elastic biasing element 630 may also be a torsion spring, or a rubber spring, or a combination of the above springs.

[0128] The second stepped track 324 is disposed on the transmission member 320. The transmission member 320 includes a first shaft end face 325 adjacent to the stroke sensor 700 and a boss 326 that circumferentially protrudes axially from the first shaft end face 325. The second stepped track 324 includes a top surface 324a, a slope surface 324b, and a bottom surface 324c. The top surface 324a is part of the upper surface of the boss 326, the bottom surface 324c is part of the first shaft end face 325, and the slope surface 324b connects the top surface 324a and the bottom surface 324c and transitions from high to low. The trigger member 600 is biased against the second stepped track 324 by the elastic biasing element 630.

[0129] When the shoulder 620 abuts against the bottom surface 324c, the triggering component 600 does not trigger the stroke sensor 700. As the transmission component 320 rotates, the shoulder 620 is pushed by the slope 324b, which gradually raises the triggering component 600. When the shoulder 620 is guided by the slope 324b to abut against the bottom surface 324c, the triggering component 600 triggers the stroke sensor 700, thereby stopping the pivot drive device 300 and stopping the drive shaft 310 from rotating.

[0130] The top surface 324a and the slope surface 324b of the second stepped track 324 are each constructed as two sections, and the bottom surface 324c is set as one section and connected between the low points of the two slope surfaces 324b. The two slope surfaces 324b guide the shoulder 620 to move to the two top surfaces 324a in two rotational directions, thereby triggering the stroke sensor 700 in the second locked state in the working position and the retracted position of the trailer hook.

[0131] According to the trailer coupling device of the present invention, reference is made to Figure 14 to Figure 32 Its operation process and principle are as follows: likeFigure 14 to Figure 20 As shown, the trailer hitch 200 is in the retracted position and the pivot locking device 400 is in the locked state. Figure 14 The support frame 100 has been removed to facilitate the demonstration of the internal structure of the trailer hook assembly. At this point, the locking element 420 is stopped by one of the locking platforms 412, causing a portion of the locking element 420 to extend out of the guide hole 111 and engage in the outer anti-rotation groove 211. The support 210 cannot rotate relative to the sleeve 110, thus achieving locking of the trailer hook in the retracted position. Furthermore, the drive shaft 310 along... Figure 14 , Figure 15 Rotating the pivot in a clockwise direction allows the pivot locking device 400 to switch from a first locking state to a second locking state.

[0132] At this time, if spindle 311 is in Figure 14 If the spindle 311 rotates clockwise, the main shaft 311, bushing 312, and transmission component 320 will transmit power by sequentially abutting against each other through the protrusions; if the main shaft 311 rotates clockwise... Figure 14 If the spindle 311 rotates counterclockwise, it will be in the first idle stroke relative to the bushing 312.

[0133] At this time, the transmission pin 530 in the clutch mechanism 500 has just moved to the transition track 511b and is supported by the transition track 511b as the movable guide component 520 rotates, and the clutch mechanism 500 has just cut off the power connection between the drive shaft 310 and the support seat 210, or the clutch mechanism 500 is about to cut off the power connection between the drive shaft 310 and the support seat 210.

[0134] At this time, the shoulder 620 of the triggering component 600 is biased against the slope 324b of the second stepped track 324 by the elastic biasing element 630, but the stroke sensor 700 has not yet been triggered.

[0135] Drive shaft 310 along Figure 14 , Figure 15 The clockwise rotation of the drive shaft 310 causes the transmission component 320 to rotate accordingly, and the locking actuator 410 continues to rotate under the torque force transmitted from the locking retainer 430. Until the locking platform 412, locking element 420, and outer anti-rotation groove 211 are completely locked together, the locking actuator 410 can no longer rotate. The torque force of the drive shaft 310 is transmitted to the locking retainer 430 through the transmission component 320, causing the locking retainer 430 to compress and store energy, thus applying a preload torque to the locking actuator 410 to maintain the stop of the locking platform 412 on the locking element 420, thereby placing the pivot locking device 400 in the second locking state.

[0136] In the second locked state, the transmission pin 530 in the clutch mechanism 500 slides onto the low track 511c as the movable guide component 520 rotates, and the clutch mechanism 500 disconnects the power connection between the drive shaft 310 and the support seat 210, and the trailer hook 200 remains in the storage position.

[0137] In the second locked state, the shoulder 620 of the triggering component 600 abuts against the top surface 324a under the pushing and guiding of one of the slopes 324b, and the triggering component 600 triggers the stroke sensor 700.

[0138] In the second locking state, the pivot drive device 300 stops operating, the drive shaft 310 is restricted from rotating under the self-locking force of the self-locking mechanism, and the locking retainer 430 maintains the preload torque applied to the locking actuator 410.

[0139] like Figure 21 to Figure 26 As shown, the trailer hitch 200 is in the retracted position and the pivot locking device 400 is in the just-unlocked state. Figure 21 The support frame 100 has been removed to facilitate the display of the internal structure of the trailer coupling device. Drive shaft 310 along... Figure 14 , Figure 15 Rotate counterclockwise in the middle to make the trailer coupling device move from Figure 14 to Figure 20 The status shown has switched to Figure 21 to Figure 26 The state shown is as follows. In the diagram, the locking element 420 falls back into the guide hole 111, and the support 210 can rotate relative to the sleeve 110, that is, the trailer hook 200 can pivot relative to the support frame 100. At this time, the trailer hook 200 can pivotally switch between the storage position and the working position.

[0140] At this time, if the main shaft 311 along Figure 21 When the main shaft 311 rotates counterclockwise, it enters the first free stroke and rotates relative to the bushing 312. A natural circumferential gap is generated between the bushing 312 and the transmission component 320, preventing them from abutting. As the main shaft 311 rotates further, after completing the first free stroke, the main shaft 311 drives the bushing 312 to rotate relative to the transmission component 320 and enter the second free stroke, until the trailer hook 200 pivots to the storage position and the pivot locking device 400 is about to enter the locking state.

[0141] At this time, the movable guide component 520 in the clutch mechanism 500 rotates under the drive of the drive shaft 310. The transmission pin 530 is guided by the transition track 511 to the guide platform 511a and moves on the guide platform 511a as the movable guide component 520 rotates. One end of the transmission pin 530 abuts against the guide platform 511a, and the other end is driven into the transmission groove 221 of the end cover 220, so that the rotation of the movable guide component 520 drives the trailer hook 200 to rotate from the storage position to the working position through the transmission engagement of the transmission pin 530 and the transmission groove 221.

[0142] At this time, the shoulder 620 of the triggering component 600 is biased against the bottom surface 324c of the second stepped track 324 by the elastic biasing element 630, so that the triggering component 600 is held in a position away from the travel sensor 700.

[0143] like Figure 27 to Figure 32 As shown, the trailer hitch 200 is in the working position and the pivot locking device 400 is in the locked state. Figure 27 The support frame 100 has been removed to facilitate the display of the internal structure of the trailer coupling device. Drive shaft 310 along... Figure 21 , Figure 22 Rotate counterclockwise in the middle to make the trailer coupling device move from Figure 21 to Figure 26 The status shown has switched to Figure 27 to Figure 32 The state shown is as follows. At this time, the locking element 420 is stopped by another locking platform 412, causing a portion of the locking element 420 to extend out of the guide hole 111 and engage in the outer anti-rotation groove 211. The support 210 cannot rotate relative to the sleeve 110, thus achieving locking of the trailer hook in the working position. Furthermore, the drive shaft 310 along... Figure 27 , Figure 28 Further counterclockwise rotation can switch the pivot locking device 400 from the first locking state to the second locking state.

[0144] At this time, if spindle 311 is in Figure 27 If the spindle 311 rotates counterclockwise, the main shaft 311, bushing 312, and transmission component 320 will sequentially abut against each other; if the main shaft 311 rotates counterclockwise... Figure 27 If the spindle 311 rotates clockwise, it will idle relative to the bushing 312 and be in the first idle stroke.

[0145] At this moment, the drive pin 530 in the clutch mechanism 500 has just moved to another transition track 511b and is supported by the transition track 511b as the movable guide component 520 rotates, and the clutch mechanism 500 has just cut off the power connection between the drive shaft 310 and the support seat 210, or the clutch mechanism 500 is about to cut off the power connection between the drive shaft 310 and the support seat 210.

[0146] At this time, the shoulder 620 of the triggering component 600 is biased against the other slope 324b of the second stepped track 324 by the elastic biasing element 630, but the stroke sensor 700 has not yet been triggered.

[0147] Drive shaft 310 along Figure 27 , Figure 28The drive shaft 310 rotates further counterclockwise, causing the transmission component 320 to rotate accordingly. Under the torque force transmitted from the locking retainer 430, the locking actuator 410 continues to rotate. Once the locking platform 412, locking element 420, and outer anti-rotation groove 211 are completely locked together, the locking actuator 410 can no longer rotate. The torque force of the drive shaft 310 is transmitted to the locking retainer 430 through the transmission component 320, causing the locking retainer 430 to compress and store energy, thus applying a preload torque to the locking actuator 410 to maintain the locking platform 412's stop on the locking element 420, thereby placing the pivot locking device 400 in the second locking state.

[0148] In the second locked state, the transmission pin 530 in the clutch mechanism 500 slides onto the low-position rail 511c as the movable guide component 520 rotates, and the clutch mechanism 500 disconnects the power connection between the drive shaft 310 and the support seat 210, and the trailer hook 200 remains in the working position.

[0149] In the second locked state, the shoulder 620 of the triggering component 600 moves under the push and guidance of another slope 324b and abuts against another top surface 324a, triggering the stroke sensor 700.

[0150] In the second locking state, the pivot drive device 300 stops operating, the drive shaft 310 is restricted from rotating under the self-locking force of the self-locking mechanism, and the locking retainer 430 maintains the preload torque applied to the locking actuator 410.

[0151] The trailer hook 200 of the trailer coupling device can be deduced from the above working process and working principle by switching from the locked state to the unlocked state in the working position, then pivoting from the working position to the storage position, and then switching from the unlocked state to the locked state in the storage position. It will not be described in detail here.

[0152] According to the trailer coupling device of the present invention, such as Figure 33 to Figure 36 As shown, there is a gravity balance position between the storage position and the working position of the trailer hook 200. After unlocking, the trailer hook 200 pivots downward to the gravity balance position by its own gravity and synchronizes its rotation speed with the same direction of the drive shaft 310.

[0153] When the trailer hook 200 is unlocked in the storage or working position, the trailer hook 200 has a certain potential energy. The potential energy of the trailer hook 200 is gradually released by the support of the drive shaft 310, so that the trailer hook 200 slowly descends to the gravity balance position. After the trailer hook 200 rotates past the gravity balance position, the drive shaft 310 provides torque to rotate synchronously with the trailer hook 200 to the working or storage position.

[0154] This design of the trailer hitch 200 means that the trailer hitch 200 rotates downwards and then upwards to retract from the working position to the storage position, rather than rotating upwards and then downwards. In this way, the rotation path of the trailer hitch 200 is more conducive to being hidden under the vehicle. The interior of the vehicle does not need to sacrifice space to avoid the rotation path of the trailer hitch 200, and the rotation of the trailer hitch 200 is less likely to collide with items inside the vehicle. At the same time, during the downward pivoting of the trailer hitch 200 to the gravity balance position, the self-weight of the trailer hitch 200 can provide the pivoting force of the trailer hitch 200, which can reduce the output torque of the drive shaft 310.

[0155] like Figure 33 As shown, when the trailer hitch 200 is in the gravity equilibrium position, the main shaft 311 rotates counterclockwise as shown in the figure. The main shaft 311 is about to complete or has just completed its first empty stroke. After the main shaft 311 completes its second empty stroke by rotating counterclockwise as shown in the figure, the trailer hitch 200 is in or near the storage position. Figure 34 As shown, since the spindle 311 is rotating in its idle stroke in the current state, the locking element 420 falls back into the guide hole 111, allowing the support 210 to rotate relative to the sleeve 110. Figure 35 As shown, in the current state, the clutch mechanism 500 establishes a power connection between the drive shaft 310 and the support 210. Figure 36 As shown, in the current state, the trigger component 600 is pushed against the bottom surface 324c by the bias elastic bias element and moved away from the travel sensor 700. The safety pin 610 is located in the inner pin groove 415 and assists in limiting and locking the actuator 410.

[0156] According to the trailer coupling device of the present invention, the locking actuator 410 includes a locking platform 412 and a first groove 414. Since the force on the locking platform 412 is greater than the force on the first groove 414, the structural strength of the material constituting the locking platform 412 must be greater than the structural strength of the material constituting the end wall of the first groove 414. To save costs, the locking actuator 410 can be injection molded using an insert. The insert is a metal frame containing the locking platform 412, with plastic molding wrapping around the side of the metal frame and forming the first groove 414.

[0157] According to the trailer coupling device of the present invention, the transmission member 320 is provided with a transmission protrusion 323 and a second groove 322. Since the force on the transmission protrusion 323 is greater than the force on the end wall of the second groove 322, the structural strength of the material constituting the transmission protrusion 323 needs to be stronger than the structural strength of the material constituting the end wall of the second groove 322. To save costs, the transmission member 320 can be injection molded using an insert. The insert is a metal part including the transmission protrusion 323, and a hollow area is formed on the metal part to avoid the second groove 322. Plastic forms the outer shell of the transmission member 320, which encloses the metal part and forms the second groove 322.

[0158] According to the trailer coupling device of the present invention, the support 210, main shaft 311, bushing 312, transmission component 320, locking actuator 410, and movable guide component 520 are designed to rotate along the same axis of rotation. However, in actual products, due to machining errors, necessary rotational clearances, etc., the rotation axes of the above components will inevitably be offset relative to the designed rotation axis, but the slight offset does not affect the use of the trailer coupling device of the present invention.

[0159] The assembly steps of the trailer coupling device of the present invention are as follows: The first step is to assemble the drive shaft 310; The second step is to install the drive shaft 310 into the locking actuator 410 to form a whole; The third step is to assemble the locking retainer 420 and the transmission component 320 into the above-mentioned whole to form a new assembly; The fourth step is to install the entire assembly into the sleeve 110 of the support frame 100; Fifth step: Install the support frame 100 onto the vehicle beam; Step 6: Install the clutch mechanism 500; Step 7: Insert the locking element 430 into the guide hole 111 of the sleeve 110, and then fit the support seat 210 of the trailer hook 200 onto the sleeve 110. Step 8: Screw the end cap 200 onto the trailer hook 200.

[0160] The end cap 200 is fixed with a nut seat, which has an external thread, and the support seat 210 has an internal thread at one end near the end cap 200.

[0161] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.

Claims

1. A trailer coupling device, characterized in that, include: A support frame for securing to a vehicle body includes a sleeve with guide holes; A trailer hitch includes a support seat having at least one pair of anti-rotation grooves, the support seat being pivotally connected to the outside of the sleeve, allowing the trailer hitch to pivotally switch between a stowed position and a working position relative to the support frame; A pivot drive device, which is disposed within the sleeve, includes a drive shaft and a transmission component that is drively connected to the drive shaft; A pivoting locking device includes a locking actuator, a locking element, and a locking retainer. The locking actuator is pivotally mounted on a drive shaft. The locking actuator has an inner anti-rotation groove and locking platforms disposed on both sides of the inner anti-rotation groove in the circumferential direction. The locking element is disposed in a guide hole and can move along the guide hole. The locking retainer is configured between the locking actuator and the transmission element to transmit torque force and can be compressed and stored by the relative pivoting of the two. The pivot locking device has: In the first locking state, the drive shaft drives the transmission component and the locking actuator to pivot synchronously. The locking element is pushed by the locking actuator and partially enters one of the outer anti-rotation grooves along the guide hole and is stopped by the locking platform to lock the trailer hook in the storage position or the working position. In the second locking state, following the first locking state, the drive shaft drives the transmission component to pivot relative to the locking actuator to compress the locking retainer. In the compressed state, the locking retainer applies a preload torque to the locking actuator to maintain the locking platform's stop on the locking element.

2. The trailer coupling device as described in claim 1, characterized in that, The outer peripheral surface of the locking actuator is partially recessed to form the inner anti-rotation groove. Two locking platforms are formed on the outer peripheral surface that gradually extends radially outward from both sides of the inner anti-rotation groove in a direction away from the inner anti-rotation groove. One of the two locking platforms stops the locking element at the storage position of the trailer hook, and the other stops the locking element at the working position of the trailer hook.

3. The trailer coupling device as described in claim 2, characterized in that, The locking platform is configured as one of the following: a slope, a spiral trajectory surface, or an involute trajectory surface extending circumferentially along the outer peripheral surface of the locking actuator.

4. The trailer coupling device as described in claim 1, characterized in that, Both the locking actuator and the transmission member are constructed in a disc shape and arranged along the drive shaft axially. The disc surface of the locking actuator has a first stop portion distributed in pairs at intervals around the circumference, and the disc surface of the transmission member has a second stop portion distributed in pairs at intervals around the circumference. When the trailer hook is in the retracted position, the drive shaft drives the transmission component to pivot relative to the locking actuator, causing one of the circumferentially misaligned first and second stop portions to compress the locking retainer. When the trailer hook is in the working position, the drive shaft drives the transmission component to pivot relative to the locking actuator, causing another set of circumferentially misaligned first and second stops to compress the locking retainer.

5. The trailer coupling device as described in claim 4, characterized in that, The locking actuator has a first groove on its disc surface, and the two ends of the first groove define a pair of first stop portions. A portion of the locking retainer is housed in the first groove. The transmission member has a second groove on its disc surface, and the two ends of the second groove define a pair of second stop portions. A portion of the locking retainer is housed in the second groove.

6. The trailer coupling device as described in claim 4, characterized in that, The transmission component and the locking retaining component are provided in two sets and are compactly distributed on both sides of the axial direction of the locking actuator. The drive shaft drives the two sets of transmission components to rotate in the same direction.

7. The trailer coupling device as described in claim 1, characterized in that, The locking retainer is one or a combination of a helical spring, a torsion spring, and a rubber spring.

8. The trailer coupling device as described in claim 1, characterized in that, The trailer hook has a gravity balance position between its storage position and its working position. After being unlocked, the trailer hook pivots downward to this gravity balance position by its own weight and synchronizes its rotation speed by means of the same-direction rotation of the drive shaft.

9. The trailer coupling device as described in claim 1, characterized in that, It also includes a clutch mechanism, which is configured as follows: When the trailer hitch is locked in the retracted or working position, disconnect the power connection between the drive shaft and the support. Once the trailer hitch is unlocked in the retracted or working position, a power connection is established between the drive shaft and the support until the trailer hitch is locked again.

10. The trailer coupling device as described in claim 9, characterized in that, The clutch mechanism includes: A fixed guide component is fixed to the support frame, and the fixed guide component is provided with a first stepped track extending circumferentially. A movable guide component is connected to the drive shaft and rotates with the drive shaft; the movable guide component is provided with an axially arranged pin hole. A drive pin passes through a pin hole and can move along the pin hole; The rotation of the movable guide component causes one end of the transmission pin to slide along the first stepped track, while the other end of the transmission pin engages or disengages with the support seat.

11. The trailer coupling device as claimed in claim 1, characterized in that, The drive shaft includes a main shaft and a bushing fitted outside the main shaft. The main shaft has two circumferentially spaced main shaft protrusions, the bushing has two circumferentially spaced bushing protrusions, and the transmission component has two circumferentially spaced transmission protrusions. The two main shaft protrusions and the two bushing protrusions are circumferentially alternating and can rotate relative to each other, the two bushing protrusions and the two transmission protrusions are circumferentially alternating and can rotate relative to each other, and the two main shaft protrusions and the two transmission protrusions are axially misaligned. When the trailer hitch is unlocked in the storage or working position, the main shaft rotates relative to the bushing for a first idle stroke. After the first idle stroke is completed, the main shaft drives the bushing to rotate relative to the transmission component for a second idle stroke.

12. The trailer coupling device as described in claim 11, characterized in that, The pivot drive device further includes a motor drive unit for driving the spindle to rotate in both directions. The motor drive unit is equipped with a self-locking mechanism, which is used to restrict the spindle from being driven to rotate by a load when the motor drive unit is not in operation. In the second locking state, the main shaft protrusion, bushing protrusion, and transmission protrusion abut against each other in sequence, and the compression state of the locking retainer is maintained by the self-locking force of the self-locking mechanism.

13. The trailer coupling device as described in claim 12, characterized in that, The self-locking mechanism is configured as one of the following structures: The self-locking mechanism is a braking element provided on the output shaft of the motor drive unit. When the motor drive unit is not running, the output shaft is restricted from rotation by friction engagement of the braking element. The self-locking mechanism is a worm gear assembly of a motor drive unit. The worm wheel in the worm gear assembly is connected to the main shaft for transmission. The helical teeth of the worm and the teeth of the worm wheel form a one-way friction self-locking mechanism, which allows the worm to drive the worm wheel but the worm wheel cannot drive the worm.

14. The trailer coupling device as described in claim 11, characterized in that, It also includes a stroke sensor and a triggering component, wherein the triggering component is driven by the rotation of a transmission component, and the stroke sensor outputs an electrical signal in response to the action of the triggering component.

15. The trailer coupling device as described in claim 14, characterized in that, The triggering component includes an axially extending safety pin. The inner peripheral wall of the sleeve is provided with an axially extending outer pin groove. The locking actuator is correspondingly provided with an inner pin groove. During the first and second idle strokes, the safety pin is inserted into the outer pin groove and the inner pin groove to limit the locking actuator. When the trailer hook is locked in the storage position or the working position, the safety pin is disengaged from the inner pin groove.

16. The trailer coupling device as described in claim 15, characterized in that, The triggering component includes a radially protruding shoulder, and the transmission component is provided with a circumferentially extending second stepped track. The shoulder is biased on the second stepped track by an elastic biasing element, and the relative sliding of the shoulder on the second stepped track causes the triggering component to generate axial displacement along the outer pin groove.

Images