Device for connecting trailer load and trailer hook ball head

Abstract

The invention discloses a device for connecting a trailer load with a trailer hook ball head, which comprises a base connected to the trailer load; the clamping mechanism is used for clamping the tow hook ball head, the clamping mechanism comprises two clamping components, and at least one clamping component is pivoted to the base; clamping curved surfaces matched with the surface of the tow hook ball head are arranged on the opposite inner walls of the two clamping components, and when the two clamping components are closed, the clamping curved surfaces jointly form an openable space used for receiving the tow hook ball head; a concave avoiding area is arranged in the clamping curved surface, and a gap is formed between the concave avoiding area and the outline of the corresponding tow hook ball head. The tow hook ball head connector has the advantage that the problem that a ball head of an existing tow hook ball head connector is prone to shaking in the dragging process is solved. The transverse swing resistance is remarkably improved, the connection between the connecting ball head and the connector body is more stable, the connecting ball head and the connector body are not prone to shaking in the dragging process, local stress concentration caused by rigid constraint is avoided, and the fracture risk is reduced.

Description

Technical Field

[0001] The present invention relates to a vehicle connection device, and more particularly to a device for connecting a trailer load to a trailer hitch ball head. Background Art

[0002] Some existing devices such as motorhomes, yachts, and trailers need to be towed after being connected to a power vehicle through a ball head connector. A ball head is assembled at the rear of the vehicle, and a connector is provided on the trailer to connect to the ball head. The common structure of the ball head connector is as disclosed in Chinese Patent Publication No. CN221913951U, titled "A Tail Trailer Clamping Ball Connector". A movable clamping ball block and a fixed clamping ball block are provided in the base. Hemispherical inner grooves for clamping and cooperating with the clamping ball are provided on a pair of opposite inner walls of the movable clamping ball block and the fixed clamping ball block. During actual use, when the movable clamping ball block and the fixed clamping ball block clamp the clamping ball, the two hemispherical inner grooves will all closely adhere to the clamping ball, and the acting forces of the movable clamping ball block and the fixed clamping ball block on the clamping ball concentrate towards the equator of the clamping ball, resulting in unstable clamping of the clamping ball and shaking during towing. Summary of the Invention

[0003] The purpose of the present invention is to provide a device for connecting a trailer load to a trailer hitch ball head, which can effectively solve the problem that the ball head is prone to shaking during towing in the existing trailer hitch ball head connector.

[0004] To solve the above technical problems, the present invention is realized through the following technical solutions:

[0005] A device for connecting a trailer load to a trailer hitch ball head, comprising:

[0006] A base, which is connected to the trailer load; and,

[0007] A clamping mechanism for clamping the trailer hitch ball head, the clamping mechanism comprising two clamping members, and at least one clamping member is pivotally connected to the base;

[0008] Clamping surfaces adapted to the surface of the trailer hitch ball head are provided on the opposite inner walls of the two clamping members. When the two clamping members are closed, the clamping surfaces jointly form an openable and closable space for receiving the trailer hitch ball head; a recessed avoidance area is provided in the clamping surface, and a gap is formed between the recessed avoidance area and the corresponding contour of the trailer hitch ball head.

[0009] In the above device for connecting a trailer load to a trailer hitch ball, the cross-section of the recess avoidance area is an arc surface or a rectangular surface. The structure with an arc-shaped cross-section matches the natural curvature of the surface of the trailer hitch ball, reducing the difficulty of numerical control machining, achieving a smooth transition at the contact surface with the trailer hitch ball, reducing the risk of initiation of microcracks, enhancing the fatigue life of the component, and the structure with an arc-shaped cross-section has a significant stress dispersion effect: when it fits the surface of the trailer hitch ball, the arc-shaped cross-section can disperse the local load along the tangent direction, avoiding stress concentration that may cause the clamp block to rupture; while setting the cross-section of the recess avoidance area as a rectangular surface is equivalent to using a straight groove design, which can be quickly formed by conventional milling or wire cutting, reducing the requirements for precision machining.

[0010] In the above device for connecting a trailer load to a trailer hitch ball, the recess avoidance area is an annular avoidance groove, and the avoidance groove is provided with a through hole communicating with the outside. Because the recess avoidance area is an annular avoidance groove with a central opening, it can better avoid the corresponding contour of the trailer hitch ball, having a larger avoidance space, and can also be adapted to trailer hitch balls of different sizes. Moreover, when the closable space is closed, the air between the avoidance groove and the trailer hitch ball can be discharged through the through hole on the avoidance groove, enabling the two clamping members to close smoothly.

[0011] In the above device for connecting a trailer load to a trailer hitch ball, the recess avoidance areas on the two clamping surfaces respectively correspond to the contours at both ends of the diameter of the trailer hitch ball. Since the two ends of the ball diameter do not contact the clamping surfaces, the flexibility of the connection is increased to a certain extent. When the vehicle jolts or steers during driving, the trailer hitch ball can have a small movement space within the range allowed by the recess avoidance area, avoiding excessive stress caused by rigid contact. This flexibility helps buffer the impact force on the ball, reducing damage to the trailer load and the trailer hitch. At the same time, it also enables the connection device to better adapt to different driving conditions and improve the stability of the entire trailer system.

[0012] In the above device for connecting a trailer load to a trailer hitch ball, an avoidance structure is further provided on the clamping surface of the pivotable clamping member, and the avoidance structure is arranged facing the opening of the closable space. When the opening of the closable space is opened, the avoidance structure is configured to prevent interference between the pivotable clamping member and the trailer hitch ball in the disengaged state. The avoidance structure can prevent the pivotable clamping member from abutting against the trailer hitch ball when the movable clamp block is opened, resulting in the trailer hitch ball being stuck and unable to withdraw from the closable space.

[0013] In the above device for connecting a trailer load to a trailer hitch ball, the avoidance structure is a concave cavity that is concave towards the openable and closable space. During the opening process of the pivotable clamping member, even if the trailer hitch ball shakes or deviates to a certain extent, the concave cavity can effectively accommodate the ball, further reducing the risk of interference jamming, ensuring the smooth opening of the moving clamping block, and guaranteeing the safety and reliability during the use of the trailer hitch ball connector.

[0014] In the above device for connecting a trailer load to a trailer hitch ball, a pusher for driving the pivotable clamping member to rotate is provided on the pivotable clamping member. When the trailer hitch ball enters the openable and closable space, the pusher is located directly in front of the trailer hitch ball entering the openable and closable space, and the distance between the pusher and the trailer hitch ball < the distance between the pivotable clamping member in front of the trailer hitch ball entering the openable and closable space and the hitch ball. The pusher plays a role of pre-positioning and buffering. On the one hand, when the trailer hitch ball is inserted into the openable and closable space, it can push the pivotable clamping member to rotate in the clamping direction to achieve pre-positioning, guiding the trailer hitch ball to accurately enter the openable and closable space. On the other hand, when the trailer hitch ball is inserted into the openable and closable space, the trailer hitch ball can consume part of its kinetic energy through the pusher, avoiding direct collision between the trailer hitch ball and the pivotable clamping member and causing damage, improving the convenience and accuracy of installing the trailer hitch ball, and extending the service life of the entire device.

[0015] In the above device for connecting a trailer load to a trailer hitch ball, when the openable and closable space is in a closed state, there is an avoidance gap between the pusher and the trailer hitch ball to prevent the pivotable clamping member from jamming with the trailer hitch ball when the openable and closable space is opened. It avoids the pusher and the trailer hitch ball from abutting against each other when the pivotable clamping member rotates from the closed position to the open position, causing the trailer hitch ball to jam, and ensures that the pivotable clamping member can be smoothly opened to allow the trailer hitch ball to exit the openable and closable space.

[0016] In the above device for connecting a trailer load to a trailer hitch ball, the pusher is detachably fixed to the pivotable clamping member. Since the pusher needs to withstand the impact of the trailer hitch ball during clamping, the detachable structure facilitates timely replacement when the pusher is damaged.

[0017] In the above device for connecting a trailer load to a trailer hitch ball, an elastic driving member is provided inside the base, and the elastic driving member is in contact and cooperation with the pivotable clamping member to drive the two clamping members to rotate away from each other. When unlocking, the elastic driving member can automatically help the pivotable clamping member open the openable and closable space without additional complex operations, improving the convenience and efficiency of the unlocking operation. At the same time, it also enables the pivotable clamping member to remain in a stable open position in the non-working state, facilitating the next use and enhancing the practicality of the device.

[0018] Compared with the prior art, the advantages of the present invention are:

[0019] A recessed avoidance area is provided in the clamping surface, and a gap is formed between the recessed avoidance area and the corresponding tow hook ball head contour, which solves the problem that the tow hook ball head connector is prone to shaking during towing. A clamping surface adapted to the surface of the tow hook ball head is provided on the opposite inner walls of the two clamping components, and an openable space is formed when the two are closed. This design can make the clamping force more evenly distributed on the ball head surface. Compared with the traditional simple clamping method, it can better fit the ball head shape, reduce local stress concentration, and improve the stability of the connection. By setting a recessed avoidance zone in the clamping surface to form a specific contact area and gap area, active regulation of the clamping force distribution can be achieved: the two clamping components are connected to form a mechanical model similar to "two-point clamping", which significantly improves the ability to resist lateral swing, making the connection between the trailer hook ball head and the connector body more stable and less prone to shaking during towing. The gap in the recessed avoidance zone also allows the trailer hook ball head to produce limited micro-deformation under dynamic conditions (such as radial micro-expansion when impacted), avoiding local stress concentration due to rigid constraints and reducing the risk of fracture.

[0020] The existence of a gap between the surface of the trailer hook ball head and the recessed avoidance area allows the clamp to compensate for minor assembly errors through local deformation, avoiding clamping failure caused by hard interference and improving reliability under complex working conditions. If the center axis of the ball head and the axis of the clamp are slightly offset, the traditional structure is prone to interference between the ball head and the clamp and cannot be closed. However, the scheme of setting a recessed avoidance area and forming a gap between the recessed avoidance area and the contour of the trailer hook ball head in the present invention can avoid the risk of "stuck" caused by machining accuracy or installation alignment deviation when the ball head is inserted. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A perspective view of the device for connecting a trailer load to a trailer hook ball head of the present invention when in use;

[0022] Figure 2 A front view of the device for connecting a trailer load to a trailer hook ball head of the present invention in a locked state when in use;

[0023] Figure 3 A front view of the device for connecting a trailer load to a trailer hook ball head of the present invention in an unlocked state when in use;

[0024] Figure 4 for Figure 2 Middle AA section view;

[0025] Figure 5 A perspective view of the device for connecting a trailer load to a trailer hook ball head of the present invention in a locked state;

[0026] Figure 6 For Figure 3 Cross-sectional view B-B in the figure;

[0027] Figure 7 It is a schematic diagram showing the invention's device for connecting a trailer load to a trailer hitch ball moving from a locked state to an unlocked state;

[0028] Figure 8 It is an exploded view of the invention's device for connecting a trailer load to a trailer hitch ball;

[0029] Figure 9 It is a schematic structural diagram of the locking member in the present invention;

[0030] Figure 10 It is a schematic structural diagram when the trailer hitch ball enters the openable and closable space in the present invention;

[0031] Figure 11 It is a schematic structural diagram when the movable clamping block and the fixed clamping block clamp the trailer hitch ball in the present invention;

[0032] Figure 12 It is a perspective view of the movable clamping block in the present invention;

[0033] Figure 13 It is a perspective view of the fixed clamping block in the present invention.

[0034] Reference numerals are:

[0035] Device body 100, base 110, limiting surface 111, movable clamping block 120, clamping curved surface 121, pushing member 123, avoidance gap 1231, abutting surface 124, guiding surface 125, rotating shaft 126, recess avoidance area 127, free end 128, pivot end 129, avoidance structure 1291, fixed clamping block 130, locking member 140, stop member 141, limiting member 142, locking surface 143, guiding surface 144, rotating handle 150, operating handle 151, stop groove 152, elastic driving member 160, adjusting seat 170, adjusting bolt 171, trailer hitch ball 200, handle lock assembly 300, lock tongue 310, vehicle frame 400. Detailed implementation manners

[0036] The device for connecting a trailer load to a trailer hook ball head 200 comprises: a base 110 connected to the trailer load; and a clamping mechanism for clamping the trailer hook ball head 200, the clamping mechanism comprising two clamping members, at least one of which is pivotally connected to the base 110; clamping curved surfaces 121 adapted to the surface of the trailer hook ball head 200 are provided on the opposite inner walls of the two clamping members, and when the two clamping members are closed, the clamping curved surfaces 121 jointly form an openable and closable space for receiving the trailer hook ball head 200; a recessed avoidance area 127 is provided in the clamping curved surface 121, and a gap is formed between the recessed avoidance area 127 and the corresponding trailer hook ball head 200 contour.

[0037] A recessed avoidance area 127 is provided in the clamping curved surface 121, and a gap is formed between the recessed avoidance area 127 and the corresponding tow hook ball head 200 profile, which solves the problem that the tow hook ball head connector is prone to shaking during towing. A clamping curved surface 121 adapted to the surface of the tow hook ball head 200 is provided on the opposite inner walls of the two clamping members, and an openable space is formed when the two are closed. This design can make the clamping force more evenly distributed on the ball head surface. Compared with the traditional simple clamping method, it can better fit the ball head shape, reduce local stress concentration, and improve the stability of the connection. By setting a recessed avoidance area 127 in the clamping surface 121, a specific contact area and a gap area are formed, thereby realizing active regulation of the clamping force distribution: the two clamping components are connected to form a mechanical model similar to "two-point clamping", which significantly improves the ability to resist lateral swing, making the connection between the trailer hook ball head 200 and the connector body more stable and less prone to shaking during towing. The gap in the recessed avoidance area 127 also allows the trailer hook ball head 200 to produce limited micro-deformation under dynamic conditions (such as radial micro-expansion when impacted), thereby avoiding local stress concentration caused by rigid constraints and reducing the risk of fracture.

[0038] The existence of a gap between the surface of the trailer hook ball head 200 and the recessed avoidance area 127 allows the clamping block to compensate for minor assembly errors through local deformation, avoiding clamping failure caused by hard interference and improving reliability under complex working conditions. If the center axis of the ball head and the axis of the clamping block are slightly offset, the traditional structure is prone to interference between the ball head and the clamping block and cannot be closed. However, by adopting the scheme of setting a recessed avoidance area 127 and forming a gap between the recessed avoidance area 127 and the contour of the trailer hook ball head 200 in the present invention, when the ball head is inserted, the gap design of the recessed avoidance area 127 can avoid the risk of "stuck" caused by processing accuracy or installation alignment deviation.

[0039] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0040] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0041] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0042] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or in communication with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] Embodiment 1:

[0044] Refer to Figures 1 to 10 This is Embodiment 1 of the device for connecting a trailer load to a trailer hitch ball of the present invention. The device for connecting a trailer load to a trailer hitch ball includes a device body 100. The device body 100 is fixedly connected to the trailer load. For example, in this embodiment, the trailer load is the frame 400 of the trailer. There are rollers at the bottom of the frame 400 of the trailer, and bicycles or other items can be placed on the frame 400; the trailer hitch ball 200 is fixedly connected to the vehicle. The trailer hitch ball 200 includes a sphere and a connecting rod connected to the sphere. The sphere is fixedly connected to the vehicle through the connecting rod. The device body 100 and the trailer hitch ball 200 are detachably connected for the convenience of users. In order to ensure that the trailer hitch ball 200 can be snapped onto the device body 100, the diameter of the connecting rod is smaller than the diameter of the sphere.

[0045] The device body 100 includes a base 110 and a clamping mechanism disposed within the base 110. The base is connected to the trailer load, and the clamping mechanism is used to clamp the trailer hitch ball 200. The clamping mechanism includes two clamping members, and at least one clamping member is pivotally connected to the base 110 such that the two clamping members form an openable and closable space for receiving the trailer hitch ball 200. That is, only one of the two clamping members in the clamping mechanism can rotate relative to the base, or both can rotate relative to the base. For the sake of more convenient explanation, in this embodiment, the two clamping members are respectively defined as a movable clamping block 120 and a fixed clamping block 130. The movable clamping block 120 is the pivotable clamping member, that is, the movable clamping block 120 can rotate relative to the base 110. Controlling the rotation of the movable clamping block 120 can control the opening and closing of the openable and closable space, while the fixed clamping block 130 is fixedly connected to the base, or the fixed clamping block 130 is substantially immovable and only makes a position fine adjustment when necessary.

[0046] The base 110 mainly functions to protect and accommodate. In this embodiment, the base 110 has a cuboid structure. Clamping surfaces 121 for cooperating with and clamping the trailer hitch ball 200 are provided on the inner walls of the movable clamping block 120 and the fixed clamping block 130 that face each other. For example, the clamping surfaces 121 are set to be hemispherical. In this way, after the movable clamping block 120 and the fixed clamping block 130 are closed, the two clamping surfaces 121 can form a spherical openable and closable space to cooperate with the trailer hitch ball 200, wrap the trailer hitch ball 200, and realize the fixed connection between the device body 100 and the trailer hitch ball 200.

[0047] A locking member 140 is pivotally connected within the base 110 beside the movable clamping block 120. The locking member 140 rotates between a locked position and an unlocked position. When the locking member 140 is in the locked position, the locking member 140 restricts the movement of the movable clamping block 120 and keeps the movable clamping block 120 in the position where the openable and closable space is closed; when the locking member 140 is in the unlocked position, the locking member 140 does not restrict the movement of the movable clamping block 120. In this embodiment, the locking member 140 is taken as an example with a cuboid structure for introduction. The locking member 140 includes a head and a tail. The tail of the locking member 140 is pivotally connected to the base 110 through a coupling, realizing the pivotal connection of the locking member 140 to the base, and the locking member 140 will also rotate around the axis of the coupling; the head of the locking member 140 can abut against the movable clamping block 120, so that the coupling is kept at a certain distance from the movable clamping block 120, enabling the movable clamping block 120 to have a larger swinging distance and leaving enough space to cooperate with the trailer hitch ball 200.

[0048] The head of the locking member 140 is provided with a locking surface 143 having an arc-shaped contour. The central axis of the arc-shaped contour coincides with the pivot axis of the locking member 140. The locking surface 143 abuts against the movable clamping block 120 within the central angle range of the arc-shaped contour. At this time, the acting force direction of the movable clamping block 120 on the locking member 140 points to the rotation center of the locking member 140, that is, the common normal direction at the contact point between the movable clamping block 120 and the locking member 140 points to the rotation center of the locking member 140, so that the moment generated by the acting force of the movable clamping block 120 on the locking member 140 is zero. During the movement of the vehicle, when the movable clamping block 120 is subjected to vibration or other external forces, it cannot push the locking member 140 to deviate from the locked position where it abuts against the movable clamping block 120, ensuring the relative position of the movable clamping block 120 and the fixed clamping block 130 is fixed, avoiding loosening of the connector, and ensuring that the device body 100 can be firmly connected to the trailer hitch ball 200 for a long time, ensuring towing safety.

[0049] In the above embodiment, the locking surface 143 is configured as a partial spherical surface or a partial cylindrical surface, that is, within the rotation plane of the locking member 140, the projection of the locking surface 143 is arc-shaped. A relatively large central angle range can be obtained to adapt to the impact of the clamping member in a larger range, ensuring that the acting forces applied by the movable clamping block 120 on the locking member 140 from multiple angles can point to the pivot axis of the locking member 140. Especially when using a spherical structure, when the trailer hitch ball 200 generates a lateral displacement due to road bumps, the deflection of the clamping member will drive the contact point to slide along the spherical surface, automatically correcting the contact angle through the spherical curvature, avoiding the edge stress concentration problem caused by eccentric loading in the traditional planar locking structure.

[0050] Regarding the connection between the movable clamping block 120 and the base 110, the upper end of the movable clamping block 120 is a pivot end, and the pivot end is rotationally connected to the base 110 through a rotating shaft 126. The lower end of the movable clamping block 120 can be a free end that can rotate relatively. When the free end of the movable clamping block 120 is far from the fixed clamping block 130, the openable space is in an open state, and the trailer hitch ball 200 can conveniently enter or exit the openable space; when the free end of the movable clamping block 120 approaches the fixed clamping block 130, the openable space is in a closed state, and the ball head extending into the openable space can be locked therein to complete the connection of the connector.

[0051] A contact surface 124 is provided at the free end of the movable clamping block 120, that is, the locking surface 143 of the locking member 140 is in contact with the contact surface 124 at the free end of the movable clamping block 120. The contact force generated by the locking member 140 can have a relatively large lever arm with respect to the rotation axis 126 of the movable clamping block 120. In this way, when the locking member 140 is in the locked position, it is more conducive to maintaining the locked state of the movable clamping block 120. The guiding surface 125 is located on the outer wall of the movable clamping block 120 between the rotation axis 126 and the contact surface 124. When the locking member 140 rotates from the unlocked position to the locked position, it smoothly pushes the movable clamping block 120 to rotate and makes the locking member 140 contact with the contact surface 124, completing the locking of the movable clamping block 120.

[0052] On the basis of the above embodiment, for the structure of the movable clamping block 120, in order not to affect the connection relationship between the movable clamping block 120 and the trailer hitch ball 200 when the locking member 140 is in contact with the contact surface 124, the contact surface 124 is generally arranged on the outer wall of the movable clamping block 120 facing away from the fixed clamping block 130. A guiding surface 125 is also provided on this outer wall. The guiding surface 125 is connected to the contact surface 124. The locking member 140 pushes the movable clamping block 120 to rotate towards the fixed clamping block 130 along the guiding surface 125. The cross-section of the guiding surface 125 is arc-shaped, so that when the locking member 140 acts on the guiding surface 125, it can push the movable clamping block 120 to rotate smoothly and avoid jamming. By providing the guiding surface 125, the locking member 140 can also push the movable clamping block 120 to rotate towards the fixed clamping block 130 while rotating from the unlocked position to the locked position. The guiding surface 125 plays an accurate guiding role in the movement of the movable clamping block 120, enabling the movable clamping block 120 to approach the fixed clamping block 130 more accurately and clamp the trailer hitch ball 200.

[0053] A stopper 141 protruding from the tail of the locking member 140 is provided. When the locking member 140 rotates to the locked position, the stopper 141 abuts against the limiting surface 111 of the base 110, preventing the locking member 140 from further rotating. In this embodiment, the stopper 141 is integrally provided with the locking member 140. When the locking member 140 rotates from the unlocked position to the locked position, the positioning of the locking member 140 is achieved by the abutment of the stopper 141 against the limiting surface 111. That is, after the stopper 141 abuts against the limiting surface 111, the locking member 140 can no longer rotate. At this time, the locking member 140 is located at the locked position. By means of the stopper 141, it is ensured that when the locking member 140 is manipulated by rotating the handle 150, the locking member 140 can accurately stop at the locked position, and there will be no problem that the locking member 140 rotates past the locked position and cannot lock the movable clamping block 120. Further, the stopping surface can be the side wall of the base 110, so that there is no need to additionally provide a component to form the stopping surface. The rotation radius R of the stopper 141 is greater than the distance L between the rotation axis of the locking member 140 and the adjacent side wall of the base 110. When the locking member 140 is in the locked position, the stopper 141 abuts against the side wall of the base 110 to ensure that the locking member 140 is accurately located at the locked position.

[0054] In addition to positioning by the abutment of the stopper 141 against the side wall of the base 110, a convex block can be provided on the side wall of the base 110 facing the rotation axis direction of the locking member 140. By the abutment of the convex block against the stopper 141, the stopping of the stopper 141 is achieved. Since the convex block protrudes from the side wall of the base 110, the stopper 141 will apply a force to the convex block along the tangent direction. By designing the position of the stopper 141 when the locking member 140 is in the locked position, the force exerted by the stopper 141 on the convex block can generate only a relatively small component force perpendicular to the side wall of the base 110, thus reducing the amount of deformation of the base 110 caused by the force of the locking member 140, and enabling the locking member 140 to stop more accurately at the locked position.

[0055] Further, a guiding surface 144 is provided between the locking surface 143 and the bottom surface of the locking member 140. The rotation radius of the guiding surface 144 is smaller than that of the locking surface 143, so that when the locking member 140 rotates, it pushes the movable clamping block 120 to generate a one-way displacement. The guiding surface 144 can be an inclined surface or an arc surface, and preferably an arc surface. When the guiding surface 144 contacts the movable clamping block and pushes the movable clamping block 120 to transition from the locking surface 143 to push the movable clamping block 120, it can ensure the smooth rotation of the movable clamping block 120 and reduce the impact. And because the rotation radius of the guiding surface 144 is smaller than that of the locking surface 143, when transitioning from the guiding surface 144 to the contact between the locking surface 143 and the movable clamping block 120, the movable clamping block 120 will not retract, keeping the movable clamping block 120 always rotating towards the fixed clamping block 130 during the clamping process, and reducing the loosening of the trailer hitch ball head 200 when the locking member 140 is in the locked position.

[0056] On the basis of the above embodiments, in order to more conveniently control the switching of the locking member 140 between the locked position and the unlocked position, a rotary handle 150 for driving the movable clamping block 120 to rotate towards the fixed clamping block 130 is rotatably connected to the outside of the base 110. By rotating the rotary handle 150, the movable clamping block 120 can be controlled to rotate towards the fixed clamping block 130, realizing the approach of the movable clamping block 120 and the fixed clamping block 130. The rotary handle 150 controls the rotation of the locking member 140, and then uses the locking member 140 to control the rotation of the movable clamping block 120 towards the fixed clamping block 130. To achieve the rotation of the locking member 140 driven by the rotary handle 150, the coupling shaft of the locking member 140 pivotally connected to the base 110 can be extended, so that one end of the rotary handle 150 and the locking member 140 are fixed on the same coupling shaft, and the other end of the rotary handle 150 is an operating handle 151 for convenient operation.

[0057] Further, as long as the locking member 140 is disengaged from the abutting surface 124, it is in the unlocked position. However, when assembling the device body 100 with the trailer hitch ball 200, the device body 100 is first lifted too high and then lowered to be docked with the trailer hitch ball 200. To facilitate this handling process, the user directly holds the rotary handle 150 and lifts the device body 100. In this embodiment, by restricting the position of the locking member 140 in the unlocked position, the rotary handle 150 is in a better gripping and lifting position. Specifically, along the direction in which the locking member 140 rotates from the locked position to the unlocked position, a 142 is provided on the end surface of the locking member 140 facing the base 110. When 142 abuts against the side wall of the base 110, that is, when the movement stroke of the locking member 140 is restricted by 142, the operating handle 151 is located on the vertical axis passing through the center of gravity of the device body 100. During the operation, the user does not need to deliberately adjust the force direction and strength to overcome the influence brought by the imbalance, and can more easily and accurately lift the device body 100 to be docked with the trailer hitch ball 200, facilitating the user to lift. And when it is necessary to control the movement position of the locking member 140, the rotary handle 150 is rotated to realize the locking and unlocking actions of the locking member 140, improving the operation efficiency. In addition to setting 142 on the locking member 140, 142 can also be set on the side wall of the base 110, which can also achieve the same limiting effect.

[0058] On the basis of the above embodiment, the trailer hitch ball connector further includes a handle lock assembly 300. The handle lock assembly includes a locking tongue 310 rotatably provided on the base 110. The locking tongue 310 includes a stop position and a release position. When the locking tongue 310 is in the stop position, the locking tongue 310 abuts against the rotary handle 150, preventing the rotary handle 150 from driving the locking member 140 to disengage from the locked position and preventing the rotary handle 150 from being accidentally touched to cause the device body 100 and the trailer hitch ball 200 to be unlocked. When the locking tongue 310 is in the release position, the locking tongue 310 moves out of the movement track of the rotary handle 150, allowing the rotary handle 150 to rotate freely. By providing the handle lock assembly 300, it is ensured that the rotary handle 150 will not be accidentally opened during the towing process, improving the safety of the trailer hitch ball connector in the connected state and ensuring the safe progress of the towing operation.

[0059] Further, a stop groove 152 is formed in the rotary handle 150. When the locking tongue 310 is in the stop position, the locking tongue 310 is located in the stop groove 152, and a stop is formed between the locking tongue 310 and the inner side wall of the stop groove 152. In this way, the locking tongue 310 can limit the rotary handle 150 in two directions of rotation, which can not only prevent the rotary handle 150 from accidentally rotating in the connected state and causing the locking claw to deviate from the locking position, but also keep the rotary handle 150 always in the locking position of the locking member 140. The user can also judge whether the locking member 140 is in the locking position by whether the locking tongue 310 can be inserted into the stop groove 152, so that the user can better determine the position of the locking member 140.

[0060] When it is necessary to connect the device body 100 to the trailer hitch ball 200, the movable clamping block 120 will be rotated and swung first, and the distance between the movable clamping block 120 and the fixed clamping block 130 is the largest. Since the device body 100 is lifted and aligned with the trailer hitch ball 200 and then lowered when connecting to the trailer hitch ball 200, after the trailer hitch ball 200 enters between the movable clamping block 120 and the fixed clamping block 130, it will first touch the movable clamping block 120 and drive the movable clamping block 120 to close towards the fixed clamping block 130. During this process, the trailer hitch ball 200 will generate a large impact on the movable clamping block 120, which is likely to cause damage to the movable clamping block 120 and prevent it from rotating and closing with the fixed clamping block 130 normally. Therefore, a pushing member 123 for driving the movable clamping block 120 to rotate is provided on the movable clamping block 120, and the pushing member 123 is located above the trailer hitch ball 200. When the trailer hitch ball 200 enters the clamping surface 121, the trailer hitch ball 200 abuts against the pushing member 123, driving the movable clamping block 120 to rotate and clamp towards the fixed clamping block 130, that is, the pushing member 123 absorbs the impulse of the trailer hitch ball 200, playing a buffering role and also achieving the purpose of driving the movable clamping block 120 and the fixed clamping block 130 to close. When the movable clamping block 120 rotates to the maximum opening angle, the horizontal height of the pushing member 123 relative to the top of the movable clamping block 120 is lower, so as to ensure that the trailer hitch ball 200 first contacts the pushing member 123 after entering the clamping surface 121 and avoid the trailer hitch ball 200 directly hitting the movable clamping block 120.

[0061] In this embodiment, the fixed clamping block 130 can also be pivotally connected to the base through a rotating shaft. However, the fixed clamping block 130 generally does not move when clamping the trailer hitch ball 200. However, due to manufacturing errors or wear after long-term use, after the moving clamping block 120 is abutted by the locking member 140 and is in the locked position, the distance between the moving clamping block 120 and the fixed clamping block 130 may be too large or too small. At this time, fine adjustment of the fixed clamping block 130 is required. Therefore, an adjustment seat 170 is provided on the side wall of the base 110 close to the fixed clamping block 130. An adjustment bolt 171 is threadedly installed on the adjustment seat 170. One end of the adjustment bolt 171 abuts against the outer wall of the fixed clamping block 130. By rotating the adjustment bolt 171 relative to the adjustment seat 170, the distance between the fixed clamping block 130 and the moving clamping block 120 in the locked position is adjusted. The upper part of the fixed clamping block 130 is also rotatably connected to the base 110 through a rotating shaft 126. Generally, one end of the adjustment bolt 171 also abuts against the bottom of the fixed clamping block 130 to obtain a larger adjustment torque. The position of the fixed clamping block 130 can be precisely adjusted by the adjustment bolt 171, so that the trailer hitch connector can adapt to trailer hitch balls 200 of different sizes, improving the versatility and compatibility of the product, meeting diverse usage requirements, allowing users to make flexible adjustments according to actual situations, and enhancing the practicality and applicable range of the connector.

[0062] In order to enable the moving clamping block 120 to automatically separate from the fixed clamping block 130 better and release the trailer hitch ball 200 after the locking member 140 deviates from the locked position, on the basis of the above embodiment, an elastic driving member 160 can be arranged in the base 110. The elastic driving member 160 abuts against the moving clamping block 120 to generate a driving force for driving the moving clamping block 120 to rotate away from the fixed clamping block 130. As Figure 8 , Figure 10 described, the elastic driving member 160 is fixed in the base 110. The elastic driving member 160 has two elastic feet, which respectively abut against the fixed clamping block 130 and the moving clamping block 120. When the moving clamping block 120 rotates towards the fixed clamping block 130, the distance between the two elastic feet becomes smaller, and the elastic driving member 160 is squeezed and stores elastic potential energy; when the locking member 140 is removed, the moving clamping block 120 loses the abutting force of the locking member 140, and the elastic potential energy is released. The elastic driving member 160 can drive the moving clamping block 120 to rotate in a direction away from the fixed clamping block 130, opening the two clamping surfaces 121. In addition to using the elastic driving member 160 with the above structure, a torsion spring can also be directly sleeved on the rotating shaft 126 of the moving clamping block 120 to achieve the above function.

[0063] In use, according to the size of the trailer hitch ball 200 and the error between the movable clamping block 120 and the fixed clamping block 130, the position of the lower end of the fixed clamping block 130 is adjusted by using the adjusting bolt 171. The rotating handle 150 is pulled, driving the locking member 140 to rotate to the unlocking position. At the same time, the operating handle 151 of the rotating handle 150 is directly above the center of gravity of the device body 100. The device body 100 is lifted by using the rotating handle 150. At the same time, the movable clamping block 120 rotates under the drive of the elastic driving member 160, so that the lower end of the movable clamping block 120 and the lower end of the fixed clamping block 130 open to the maximum angle. The device body 100 is aligned with the trailer hitch ball 200, and the device body 100 is lowered so that the trailer hitch ball 200 enters the openable and closable space between the movable clamping block 120 and the fixed clamping block 130. The trailer hitch ball 200 abuts against the pushing member 123, driving the movable clamping block 120 to rotate, so that the movable clamping block 120 and the fixed clamping block 130 close to clamp the trailer hitch ball 200. Then, the rotating handle 150 is pulled downward, and the rotating handle 150 will drive the locking member 140 to rotate from the unlocking position to the locking position. During this process, the locking member 140 moves along the guiding surface 125 of the movable clamping block 120 to the abutting surface 124, keeping the movable clamping block 120 in a locked state. When the stopper 141 connected to the locking member 140 abuts against the side wall of the base 110, the rotating handle 150 cannot continue to rotate, indicating that the locking member 140 is already in the locked position. The lock tongue 310 is screwed out and rotated to the stop position to lock the rotating handle 150, completing the connection between the device body 100 and the trailer hitch ball 200. If unlocking is required, the lock tongue 310 is rotated to the release position, and the rotating handle 150 is pulled to release the locking of the locking member 140 on the movable clamping block 120, allowing the movable clamping block 120 to rotate and open to release the trailer hitch ball 200. When the locking member 140 is in the locked position, it abuts against the abutting surface 124 on the movable clamping block 120, and the tangent of the abutting surface 124 in the rotation direction at this position intersects the rotation axis of the locking member 140, that is, the acting force of the movable clamping block 120 on the locking member 140 passes through the axis of the locking member 140, and the moment generated by the acting force of the movable clamping block 120 on the locking member 140 is zero. The locking member 140 will not deflect due to the impact of the movable clamping block 120, ensuring the relative position of the movable clamping block 120 and the fixed clamping block 130 is fixed, preventing the connector from loosening, ensuring that the device body 100 can be firmly connected to the trailer hitch ball 200 for a long time, and ensuring towing safety.

[0064] In the above embodiments, a pivotable clamping member and a substantially stationary clamping member are mainly taken as examples for introduction. Of course, both clamping members can also be pivotable clamping members. It only needs to mirror the same structure of the pivotable clamping member and its connecting parts in the above embodiments along the joint surface between the two clamping members. In this way, when the openable and closable space needs to be opened, the two clamping members are controlled to rotate in opposite directions to open; when the openable and closable space needs to be closed, the two clamping members are controlled to rotate in the opposite direction of opening to close.

[0065] Example 2

[0066] This embodiment can be improved based on Embodiment 1 or implemented independently. This embodiment is mainly an embodiment for improving the specific structure of the clamping member.

[0067] As Figure 1 shown, the device for connecting the trailer load to the trailer hitch ball includes a device body 100, which is fixedly connected to the trailer load. For example, in this embodiment, the trailer load is the frame 400 of the trailer. The bottom of the frame 400 of the trailer is provided with rollers, and a bicycle or other items can be placed on the frame 400; the trailer hitch ball 200 is fixedly connected to the vehicle. The trailer hitch ball 200 includes a ball and a connecting rod connected to the ball, and the ball is fixedly connected to the vehicle through the connecting rod. The device body 100 and the trailer hitch ball 200 are detachably connected for the convenience of users. In order to ensure that the trailer hitch ball 200 can be clamped to the device body 100, the diameter of the connecting rod is smaller than the diameter of the ball.

[0068] As Figures 11 to 13 shown, the device body 100 includes a base 110 and a clamping mechanism arranged in the base 110. The base is connected to the trailer load, and the clamping mechanism is used to clamp the trailer hitch ball 200. The clamping mechanism includes two clamping members, and at least one clamping member is pivoted to the base 110 so that the two clamping members form an openable and closable space for receiving the trailer hitch ball 200. That is, only one of the two clamping members in the clamping mechanism can rotate relative to the base, or both can rotate relative to the base.

[0069] For more convenient description, in this embodiment, the two clamping members are respectively defined as a movable clamping block 120 and a fixed clamping block 130. The movable clamping block 120 is a pivotable clamping member, that is, the movable clamping block 120 can rotate relative to the base 110. Controlling the rotation of the movable clamping block 120 can control the opening and closing of the openable and closable space, and the fixed clamping block 130 is fixedly connected to the base, or the fixed clamping block 130 hardly moves and only makes a position fine adjustment when necessary.

[0070] The movable clamping block 120 and the fixed clamping block 130 are symmetrically arranged, and clamping curved surfaces 121 adapted to the surface of the trailer hitch ball head 200 are provided on the opposite inner walls. When the movable clamping block 120 and the fixed clamping block 130 are closed, the two clamping curved surfaces 121 close together to form an openable and closable space for clamping the trailer hitch ball head 200. The existing clamping curved surfaces 121 on the movable clamping block 120 and the fixed clamping block 130 are all hemispherical grooves. After the two clamping curved surfaces 121 are closed, a spherical openable and closable space adapted to the trailer hitch ball head 200 is formed. However, this structure will cause the stress to be concentrated in the area with the largest radial dimension of the trailer hitch ball head 200. If the trailer hitch ball head 200 is spherical, the stress will be concentrated on the equator of the trailer hitch ball head 200, that is, the area with the largest radial contour of the trailer hitch ball head 200, resulting in unstable clamping of the ball and shaking during towing.

[0071] Therefore, in this embodiment, a recessed avoidance area 127 is provided in the clamping curved surface 121. A gap is formed between the recessed avoidance area 127 and the contour of the trailer hitch ball head 200, that is, the recessed avoidance area 127 does not contact the trailer hitch ball head 200 after the movable clamping block 120 and the fixed clamping block 130 are closed. The clamping force points generated by the movable clamping block 120 and the fixed clamping block 130 are transferred to the symmetric areas on both sides of the recessed avoidance area 127, forming a mechanical model similar to "two-point clamping", making the clamping of the trailer hitch ball head 200 by the movable clamping block 120 and the fixed clamping block 130 more stable.

[0072] In this embodiment, the recessed avoidance areas 127 on the two clamping curved surfaces 121 respectively correspond to the contours at both ends of the diameter of the trailer hitch ball head. The maximum length of the horizontal connection line from the clamping curved surface on the movable clamping block 120 to the clamping curved surface 121 on the fixed clamping block 130 is less than the diameter of the trailer hitch ball head 200, that is, the recessed avoidance area 127 needs to avoid the equator of the trailer hitch ball head 200 and extend a certain area vertically up and down. Moreover, in this embodiment, the joint surface of the movable clamping block 120 and the fixed clamping block 130 is a vertical surface, and the equatorial plane of the trailer hitch ball head 200 is in a horizontal plane. Corresponding the recessed avoidance areas 127 on the two clamping curved surfaces 121 near the equator of the trailer hitch ball head 200 can also make the acting force of the trailer hitch ball head 200 on the clamping curved surface 121 more evenly distributed to the clamping members, avoiding excessive local stress on the clamping members. The recessed avoidance area 127 accounts for about 20% - 40% of the total area of the clamping curved surface 121. If the recessed avoidance area 127 is too small, it cannot play an effective avoidance role, while if the recessed area is too large, it will affect the clamping effect of the movable clamping block 120 and the fixed clamping block 130 on the trailer hitch ball head 200. Of course, the contours of the trailer hitch ball head 200 corresponding to the two recessed avoidance areas 127 deviating from the equator of the trailer hitch ball head 200 can also achieve the purpose of the present invention.

[0073] Further, as Figure 12 、 Figure 13As shown, the cross-section of the recess avoidance area 127 is an arc surface. The cross-section of the arc surface can avoid stress concentration, and when it fits with the surface of the trailer hitch ball 200, the recess avoidance area 127 with an arc cross-section can disperse the local load along the tangent direction. In addition to the cross-section being an arc, the cross-section can also be made into a rectangular surface, which is equivalent to adopting a straight groove design and can be quickly formed.

[0074] In this embodiment, the recess avoidance area 127 forms an annular avoidance groove, that is, a through hole is opened in the center of the recess avoidance area 127. Through the annular avoidance groove, a trailer hitch ball 200 with a larger diameter can be adapted at the notch of the avoidance groove to avoid the equator of the trailer hitch ball 200, and for a trailer hitch ball 200 with a smaller diameter, it can be avoided through the opening in the center of the avoidance groove, so as to realize the adaptation to trailer hitch balls 200 with different diameters. And the opening of the avoidance hole allows the equator part of the trailer hitch ball 200 to extend out of the moving clamping block 120 or the fixed clamping block 130, which is beneficial to reducing the excessive size of the moving clamping block 120 and the fixed clamping block 130 in the depth direction along the clamping surface 121. Moreover, when the moving clamping block 120 rotates towards the fixed clamping block 130 to close the openable space, the through hole can discharge the air between the trailer hitch ball 200 and the recess avoidance area 127, making the closing of the openable space smoother.

[0075] Based on the above embodiment, as Figure 11 shown, the moving clamping block 120 in this embodiment has a vertical cuboid structure. Its upper left corner is rotationally connected to the base 110 through a rotating shaft 126 to form a pivot end 129, and its lower part is a free end 128. The swing of the free end 128 controls the opening or closing of the openable space. And there is also a pivot end 129 provided on the upper part of the moving clamping block 120. When the free end 128 opens outwards, the upper right corner of the moving clamping block 120 will move downwards, which may abut against the top of the trailer hitch ball 200, causing the trailer hitch ball 200 to be stuck and unable to withdraw from the openable space. Therefore, it is necessary to avoid the occurrence of the above situation. In this embodiment, an avoidance structure 1291 is provided on the clamping surface 121 near the pivot end 129. When the moving clamping block 120 rotates around the rotating shaft 126 from the closed position to the open position, the avoidance structure 1291 is configured to prevent its rotation path from interfering with the trailer hitch ball 200 in the withdrawn state, so as to avoid the moving clamping block 120 being stuck with the trailer hitch ball 200 when the moving clamping block 120 turns to the open position. There is no particular limitation on the specific structure of the avoidance structure 1291, as long as it is ensured that when the moving clamping block 120 opens, the moving clamping block 120 will not interfere with the trailer hitch ball 200. The specific shape and size of the avoidance structure 1291 can be determined according to the size of the moving clamping block 120 and the positional relationship between the upper right corner of the moving clamping block 120 and the rotating shaft 126.

[0076] Further, the avoidance structure 1291 is a concave cavity that is concave towards the openable and closable space. The design of the concave cavity does not additionally increase the size of the movable clamping block 120 and needs to be obtained by cutting on the basis of the original movable clamping block 120. The processing is relatively simple and does not require changing the sizes of other components. Even if the trailer hitch ball head 200 shakes or deflects to a certain extent, the concave cavity can effectively accommodate the ball head to ensure the smooth opening of the movable clamping block 120.

[0077] On the basis of the above embodiments, since the movable clamping block 120 needs to be opened first to allow the trailer hitch ball head 200 to enter the openable and closable space, when the movable clamping block 120 is opened, the upper right corner of the movable clamping block 120 rotates downward and enters the openable and closable space. When the trailer hitch ball head 200 is pushed into the openable and closable space, it will first abut against the inner side of the movable clamping block 120 near the pivot end 129 and push the movable clamping block 120 to rotate. In actual use, the user will lift the device body 100 and move it above the trailer hitch ball head 200 and then put it down. Therefore, when the trailer hitch ball head 200 enters the openable and closable space, a relatively large impact will be generated on the movable clamping block 120, and this impact may cause damage to the movable clamping block 120 or affect the service life of the movable clamping block 120. To solve the above technical problems, a pushing member 123 is provided on the movable clamping block 120. When the trailer hitch ball head 200 is inserted into the openable and closable space, the trailer hitch ball head 200 first contacts the pushing member 123. By the trailer hitch ball head 200 pushing upward against the pushing member 123, the movable clamping block 120 is driven to rotate in the closing direction. When the movable clamping block 120 is in the open position, the pushing member 123 is located directly in front of the trailer hitch ball head 200 entering the openable and closable space. The distance between the pushing member and the trailer hitch ball head 200 < the distance between the movable clamping block 120 directly in front of the trailer hitch ball head 200 entering the openable and closable space and the trailer hitch ball head 200, that is, the pushing member 123 is deeper into the openable and closable space. The pushing member 123 contacts the trailer hitch ball head 200 prior to the movable clamping block 120. As the trailer hitch ball head 200 enters the openable and closable space, the trailer hitch ball head 200 will push against the pushing member 123 to drive the movable clamping block 120 to rotate and gradually close the openable and closable space. Of course, in order to better achieve that the pushing member 123 can drive the movable clamping block 120 to rotate when being pushed by the trailer hitch ball head 200, the pushing member 123 is located at the end of the pivot end 129, so that the force exerted by the trailer hitch ball head 200 on the pushing member 123 has a relatively large moment.

[0078] When the entire movable clamping block 120 is in the closed state, an avoidance gap 1231 is provided between the pushing member 123 and the trailer hitch ball head 200. This is to prevent the pushing member 123 from directly abutting against the trailer hitch ball head 200 and causing the pushing member 123 and the trailer hitch ball head 200 to be stuck when the movable clamping block 120 is opened, affecting the withdrawal of the trailer hitch ball head 200 from the openable and closable space.

[0079] In addition, since the pusher 123 needs to withstand the impact of the trailer hitch ball 200, its own service life is lower than that of the moving clamping block 120. Therefore, in this embodiment, the pusher 123 and the moving clamping block 120 are fixed by a detachable connection method. For example, screws or snap fasteners are used to fix the pusher 123 on the moving clamping block 120, so that the pusher 123 can be conveniently replaced after being damaged.

[0080] In this embodiment, by providing a recessed avoidance area 127 within the clamping surface 121, the problem that the ball head of the existing trailer hitch connector is prone to wobbling during towing is solved. It can better conform to the shape of the ball head, reduce local stress concentration, improve the stability of the connection, significantly enhance the ability to resist lateral swing. The gap of the avoidance area allows the trailer hitch ball 200 to generate limited micro-deformation under dynamic conditions, avoiding local stress concentration caused by rigid constraints and reducing the risk of fracture.

[0081] For other content not described in this embodiment, reference can be made to Embodiment 1.

[0082] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present invention are covered by the patent scope of the present invention.

Claims

1. A device for connecting a trailer load to a trailer hook ball, comprising: a base connected to the trailer load; and, A clamping mechanism for clamping a trailer hook ball head, the clamping mechanism comprising two clamping members, at least one of which is pivotally connected to the base; The invention is characterized in that the inner walls of the two clamping members facing each other are provided with clamping curved surfaces adapted to the surface of the trailer hook ball head, and when the two clamping members are closed, the clamping curved surfaces jointly form an openable and closable space for receiving the trailer hook ball head; A recessed avoidance area is provided in the clamping curved surface, and a gap is formed between the recessed avoidance area and the corresponding trailer hook ball head contour.

2. The device for connecting a trailer load to a trailer hook ball head according to claim 1, characterized in that: The cross section of the recessed avoidance area is an arc-shaped surface or a rectangular surface.

3. The device for connecting a trailer load to a trailer hook ball head according to claim 1, characterized in that: The recessed avoidance area is an annular avoidance groove, and the avoidance groove is provided with a through hole which is the same as the outside.

4. The device for connecting a trailer load to a trailer hook ball head according to claim 1, characterized in that: The concave avoidance areas on the two clamping surfaces correspond to the contours of the two ends of the diameter of the trailer hook ball head respectively.

5. The device for connecting a trailer load to a trailer hook ball head according to claim 1, characterized in that: An avoidance structure is also provided on the clamping curved surface of the pivotable clamping member, and the avoidance structure is arranged opposite to the opening of the openable and closable space. When the opening of the openable and closable space is opened, the avoidance structure is configured to prevent the pivotable clamping member from interfering with the trailer hook ball head in a disengaged state.

6. The device for connecting a trailer load to a trailer ball joint according to claim 5, characterized in that: The avoidance structure is a concave cavity which is concave toward the openable and closable space.

7. The device for connecting a trailer load to a trailer hook ball as claimed in claim 1, characterized in that: A pushing member is provided on the pivotable clamping member for driving the pivotable clamping member to rotate. When the trailer hook ball head enters the openable and closable space, the pushing member is located directly in front of the trailer hook ball head entering the openable and closable space, and the distance between the pushing member and the trailer hook ball head is less than the distance between the pivotable clamping member directly in front of the trailer hook ball head entering the openable and closable space and the trailer hook ball head.

8. The device for connecting a trailer load to a trailer hook ball according to claim 7, characterized in that: When the openable and closable space is in a closed state, an avoidance gap is provided between the pushing member and the trailer hook ball head to prevent the pivotable clamping member and the trailer hook ball head from getting stuck when the openable and closable space is opened.

9. The device for connecting a trailer load to a trailer ball joint according to claim 7, characterized in that: The pushing member is detachably fixed on the pivotable clamping member.

10. The device for connecting a trailer load to a trailer hook ball as claimed in claim 1, characterized in that: An elastic driving member is arranged in the base, and the elastic driving member is in contact with and matched with the pivotable clamping member to drive the two clamping members to rotate in opposite directions.

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