Electric folding trailer hitch

Abstract

The application discloses an electric folding trailer hook, which comprises a fixing base, a connecting base relatively rotating on the fixing base, a towing hook relatively rotating on the connecting base, and a rotating driving unit, wherein the rotating driving unit is used for driving the connecting base and the towing hook to rotate and expand or contract along preset first and second axes respectively; the towing hook rotates within a rated rotation range; a compression spring is arranged on a rotating path between the connecting base and the fixing base, and the compression spring provides power assistance for the expanding rotation of the connecting base or resistance for the contracting rotation of the connecting base; when the trailer hook is switched from an expanded state to a contracted state, the towing hook is prior to the connecting base to contract; conversely, when the trailer hook is switched from the contracted state to the expanded state, the connecting base is prior to the towing hook to expand.

Description

Technical Field

[0001] This invention relates to the technical field of vehicle trailer hitches, and in particular to an electric folding trailer hitch. Background Technology

[0002] In the automotive industry, some family cars (such as SUVs and pickup trucks) have the function of towing, which is mainly achieved by connecting the tow hook to the towed object. Traditional tow hooks are mainly divided into fixed type and electric folding type. For the fixed type, the tow hook is usually welded directly or installed on the rear bumper beam, so that the tow hook extends to the rear of the vehicle or is placed under the vehicle. This method is not aesthetically pleasing or affects the vehicle's chassis height. Especially when driving on some uneven road conditions, it can cause the tow hook to scrape and collide with the ground. Electric folding structures (such as patent CN113524993A, a self-locking electric trailer hitch device) use a single-axis, unidirectional rotation to flip the trailer hitch from the horizontal plane to the vertical plane. While this solves the problem of the vehicle chassis height affecting the trailer hitch, the flipped trailer hitch is located under the vehicle chassis, resulting in a compact and limited operating space, making it inconvenient for loading or unloading. Some manufacturers have attempted to use multi-axis, multi-directional drive methods to allow the trailer hitch to unfold or fold in multiple dimensions, but this requires a large number of drive devices, occupies a large space, often requires modification of the chassis structure, and results in high costs and low versatility. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a single-drive, highly versatile, stable and reliable electric folding trailer hitch.

[0004] To achieve the above objectives, the present invention provides an electric folding trailer hitch, comprising a fixed base, a connecting seat that rotates relative to the fixed base, a tow hook that rotates relatively restricted relative to the connecting seat, and a rotation drive unit. The rotation drive unit drives the connecting seat and the tow hook to rotate about a preset first axis and a preset second axis, respectively, to unfold or to retract. The tow hook rotates within a rated rotation range. A compression spring is provided on the rotation path between the connecting seat and the fixed base. This compression spring provides assistance to the unfolding connecting seat or resistance to the retracting connecting seat. Specifically, when the trailer hitch switches from an unfolded state to a retracted state, the tow hook retracts before the connecting seat; conversely, when the trailer hitch switches from a retracted state to an unfolded state, the connecting seat retracts before the tow hook.

[0005] Furthermore, when the trailer hook switches from the extended state to the retracted state, the connecting seat remains stationary relative to the fixed seat during the retraction and rotation of the tow hook until the tow hook rotates to the correct position before retracting and rotating. Conversely, when the trailer hook switches from the retracted state to the extended state, the tow hook remains stationary relative to the connecting seat during the extension and rotation of the connecting seat until the connecting seat rotates to the correct position before extending and rotating.

[0006] Furthermore, it also includes a first drive shaft extending along a first axial direction and a second drive shaft extending along a second axial direction, wherein the first drive shaft rotates through the fixed seat and the connecting seat in sequence, and the second drive shaft rotates through the connecting seat and is connected to the tow hook; the two ends of the first drive shaft are respectively connected to the rotary drive unit and the second drive shaft for transmission.

[0007] Furthermore, the rotary drive unit is fixedly mounted on the fixed base.

[0008] Furthermore, one end of the first drive shaft is provided with a first bevel gear, and the end of the second drive shaft is provided with a second bevel gear that meshes with the first bevel gear for transmission.

[0009] Furthermore, the drive unit is a rotary motor and the output shaft of the rotary motor is provided with a transmission screw, and the other end of the first transmission shaft is fitted with a helical gear that meshes with the transmission screw.

[0010] Furthermore, the first axial direction is arranged perpendicular to the second axial direction.

[0011] Furthermore, the connecting seat is provided with a first limiting part and a second limiting part that respectively cooperate with the tow hook to stop, and the arc-shaped interval between the first limiting part and the second limiting part serves as the rated rotation interval of the tow hook.

[0012] Furthermore, the fixed seat is formed with a third limiting part that can abut against the connecting seat, wherein when the connecting seat is unfolded and rotated into place, the connecting seat abuts against the third limiting part.

[0013] Furthermore, the back of the connecting seat is provided with an arc-shaped groove for accommodating the compression spring, and the front of the fixing seat is formed with a protrusion, wherein the protrusion extends into the arc-shaped groove; the two ends of the compression spring respectively abut against one end face of the arc-shaped groove and the protrusion.

[0014] The present invention adopts the above-mentioned solution, and its beneficial effects are as follows: 1) The connecting seat and the tow hook can be unfolded or folded by a single rotary drive unit. That is, when in use, the connecting seat and the tow hook are unfolded and rotated separately under the drive of the rotary drive unit; conversely, when not in use, the connecting seat and the tow hook are folded and rotated separately under the drive of the rotary drive unit, thereby achieving a folding effect, reducing space occupation and lowering costs; 2) By prioritizing the rotation between the connecting seat and the tow hook, interference with the vehicle chassis space is minimized, making it adaptable to various vehicles and improving versatility. Attached Figure Description

[0015] Figure 1 This is a diagram illustrating the use of a trailer hitch.

[0016] Figure 2 This is a schematic diagram showing the trailer hitch in its deployed state.

[0017] Figure 3 This is a sectional view of the trailer hitch.

[0018] Figure 4 This is a schematic diagram of the mounting bracket.

[0019] Figure 5 This is a schematic diagram of the connecting seats.

[0020] Figure 6 This is a schematic diagram showing the retracted state of the tow hook.

[0021] Figure 7 This is a schematic diagram showing the retracted state of the tow hook and connecting seat.

[0022] Among them, 1-fixed seat, 11-third limiting part, 12-protrusion, 2-connecting seat, 21-first limiting part, 22-second limiting part, 3-towing hook, 4-rotation drive unit, 41-transmission screw, 5-first bevel gear, 6-second bevel gear, 61-stop block, 7-helical gear, 8-compression spring, a-first axial direction, b-second axial direction. Detailed Implementation

[0023] To facilitate understanding of the present invention, a more complete description is given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete.

[0024] See appendix Figure 1-7As shown, in this embodiment, an electric folding trailer hitch includes a fixed base 1, a connecting seat 2, a tow hook 3, and a rotary drive unit 4. The fixed base 1 can be fixed to the vehicle's tilting beam or body by bolts, welding, or other methods. In this embodiment, the connecting seat 2 rotates relative to the fixed base 1, that is, the connecting seat 2 rotates about a first axis a relative to the fixed base 1 to unfold or fold. The tow hook 3 rotates relative to the connecting seat 2, that is, the tow hook 3 rotates about a second axis b relative to the connecting seat 2 to unfold or fold. Specifically, in this embodiment, the first axis a and the second axis b are arranged perpendicularly, wherein the first axis a normally extends horizontally inward and outward, and the second axis b is vertical in the unfolded state and extends horizontally left and right in the folded state.

[0025] In this embodiment, see Appendix Figure 3 As shown, the system also includes a first drive shaft extending along a first axial direction a and a second drive shaft extending along a second axial direction b. The first drive shaft passes sequentially through the fixed seat 1 and the connecting seat 2, allowing the connecting seat 2 to rotate around the first axial direction a. The second drive shaft passes through the connecting seat 2 and connects to the tow hook 3, causing the tow hook 3 and the second drive shaft to rotate synchronously around the first axial direction a. Furthermore, both ends of the first drive shaft are connected to a rotary drive unit 4 and the second drive shaft, respectively. Thus, the rotary drive unit 4 drives the connecting seat 2 and the tow hook 3 to rotate and unfold or retract around the preset first axial direction a and second axial direction b, respectively. Specifically, one end of the first drive shaft is provided with a first bevel gear 5, and the end of the second drive shaft is provided with a second bevel gear 6 that meshes with the first bevel gear 5. The rotary drive unit 4 inputs rotational power to the first drive shaft, which then meshes with the first bevel gear 5 and the second bevel gear 6 to achieve the unfolding or retracting rotation of the connecting seat 2 and the tow hook 3.

[0026] To save space occupied by the tow hook 3 and reduce interference with vehicle chassis components, during the retraction action, the tow hook 3 first retracts and rotates inward around the vertical second axis b (reducing the impact on the space of vehicle chassis components), and then the connecting seat 2 simultaneously drives the hook to retract and rotate upward around the first axis a; conversely, during the unfolding action, the connecting seat 2 firstly drives the hook to unfold and rotate downward around the first axis a, and then the tow hook 3 unfolds and rotates outward around the vertical second axis b (reducing the impact on the space of vehicle chassis components).

[0027] In this embodiment, the tow hook 3 rotates within its rated rotation range. Specifically, the connecting seat 2 is provided with a first limiting part 21 and a second limiting part 22 that respectively cooperate with the tow hook 3 to stop it. The arc-shaped interval between the first limiting part 21 and the second limiting part 22 serves as the rated rotation range of the tow hook 3.

[0028] Furthermore, since the second bevel gear 6 and the tow hook 3 rotate synchronously, a stop 61 is formed on the outer circumferential surface of the second bevel gear 6, which can engage with the first limiting part 21 or the second limiting part 22. This stop 61 moves accordingly within the rated rotation range, thereby enabling the tow hook 3 to rotate within the rated rotation range. For ease of explanation, it is defined here that when the stop 61 abuts against the first limiting part 21, the tow hook 3 correspondingly unfolds outward and rotates to a predetermined position; conversely, when the stop 61 abuts against the second limiting part 22, the tow hook 3 correspondingly retracts and rotates inward to a predetermined position.

[0029] Secondly, when the stop block 61 abuts against the first limiting part 21 or the second limiting part 22, it restricts the tow hook 3 from continuing to unfold or retract, keeping the tow hook 3 and the second bevel gear 6 stationary relative to the connecting seat 2. Then, as the first transmission shaft continues to rotate, the connecting seat 2 is in a movable state relative to the fixed seat 1, and through the transmission cooperation between the first bevel gear 5 and the second bevel gear 6, the tow hook 3, the second bevel gear 6 and the connecting seat 2 simultaneously unfold or retract around the first axis a.

[0030] Furthermore, in this embodiment, a compression spring 8 is provided along the rotation path between the connecting seat 2 and the fixed seat 1. The compression spring 8 provides resistance or assistance to the rotation of the connecting seat 2. Specifically, an arc-shaped groove for accommodating the compression spring 8 is formed on the back of the connecting seat 2, and a protrusion 12 is formed on the front of the fixed seat 1. The protrusion 12 extends into the arc-shaped groove and can move relative to the arc-shaped groove. The two ends of the compression spring 8 abut against one end face of the arc-shaped groove and the protrusion 12, respectively.

[0031] Therefore, see Appendix Figure 2 , 6As shown in Figure 7, when the trailer hook needs to be switched from the extended state to the retracted state, the tow hook 3 and the second bevel gear 6 are in a retractable state (i.e., the stop block 61 does not abut against the second limiting part 22 and the stop block 61 abuts against the first limiting part 21). Most of the rotational power input by the first drive shaft is transmitted to the second bevel gear 6 through the first bevel gear 5, thereby causing the tow hook 3 and the second bevel gear 6 to rotate around the second axis b. A small portion of the rotational power is transmitted to the connecting seat 2 through the friction of the first drive shaft or the friction of the second bevel gear 6, causing the connecting seat 2 to tend to rotate upward relative to the fixed seat 1. This causes the compression spring 8 to contact and compress the arc groove and the protrusion 12, generating a reverse elastic force on the connecting seat 2 as resistance, blocking and restricting the relative rotation of the connecting seat 2 (the connecting seat 2 needs to overcome the resistance to rotate at this time), thus keeping the connecting seat 2 stationary during the rotation of the tow hook 3. Immediately after the tow hook 3 retracts and rotates to its final position (the stop 61 abuts against the second limiting part 22), the tow hook 3 and the second bevel gear 6 are stationary relative to the connecting seat 2. All the rotational power input by the first drive shaft is transmitted to the connecting seat 2 through the second bevel gear 6, which is sufficient to overcome the resistance generated by the compression spring 8, thereby causing the connecting seat 2 to retract and rotate upward relative to the fixed seat 1 (at this time, the connecting seat 2 remains stationary relative to the tow hook 3 and the second bevel gear during the retraction and rotation). After the connecting seat 2 rotates to the predetermined retraction position, the rotation drive unit 4 is turned off so that the tow hook remains in the retracted state.

[0032] Further details can be found in the appendix. Figure 2 , 6 As shown in Figure 7, when the trailer hook needs to switch from the retracted state to the extended state, the compression spring 8 is compressed. At this time, the connecting seat 2 tends to rotate downward relative to the fixed seat 1, causing the compression spring 8 to release and generate a positive elastic force on the connecting seat 2 as an assist. The rotational power transmitted by the first drive shaft is superimposed on the assist, causing the connecting seat 2 to rotate downward preferentially before the tow hook 3 (ensuring that the tow hook 3 remains stationary relative to the connecting seat 2 during its rotation). This causes the connecting seat 2 to rotate downward around the first axis a. Immediately after the connecting seat 2 has rotated downward to its final position (the connecting seat 2 is stationary relative to the fixed seat 1), all the rotational power transmitted by the first drive shaft is transmitted to the tow hook 3 via the second bevel gear 6, causing the tow hook 3 to rotate in retraction relative to the connecting seat 2 around the second axis b until the stop 61 abuts against the first limiting part 21. Then, the rotation drive unit 4 is turned off to keep the trailer hook in the extended state.

[0033] Furthermore, in actual use, due to improper selection or aging of the compression spring 8, the compression spring 8 may provide insufficient resistance or assistance to the connecting seat 2, resulting in the connecting seat 2 or the tow hook 3 being unable to remain stationary. That is, when the trailer hook needs to switch from the extended state to the retracted state, while the tow hook 3 is rotating around the second axis b, the connecting seat 2 may rotate around the first axis a. However, due to the resistance of the compression spring 8, the tow hook 3 completes the retraction rotation before the connecting seat 2. Conversely, when the trailer hook needs to switch from the retracted state to the extended state, while the connecting seat 2 is rotating around the first axis a, the tow hook 3 may rotate around the second axis b. However, due to the assistance of the compression spring 8, the connecting seat 2 completes the extension rotation before the tow hook 3.

[0034] In order to enable the connecting seat 2 to be more accurately unfolded and rotated to the designated unfolding position, the fixed seat 1 of this embodiment is formed with a third limiting part 11 that can abut against the connecting seat 2. When the connecting seat 2 is unfolded and rotated to the position, the connecting seat 2 just abuts against the third limiting part 11, thereby blocking and restricting the connecting seat 2 from continuing to unfold and rotate relative to the fixed seat 1 by the third limiting part 11.

[0035] In this embodiment, the rotary drive unit 4 is a rotary motor. The output shaft of the rotary motor is provided with a transmission screw 41, and the other end of the first transmission shaft is fitted with a helical gear 7 that meshes with the transmission screw 41. Thus, the rotary drive unit 4 transmits rotational power to the first transmission shaft through the transmission screw 41 and the helical gear 7, thereby enabling the trailer hook to better maintain its extended or retracted state, and to be more stable and reliable during rotation.

[0036] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any modifications or variations made by those skilled in the art, without departing from the scope of the present invention, using the disclosed technical content, are equivalent embodiments of the present invention. Therefore, all equivalent changes made based on the concept of the present invention without departing from the scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. An electric folding trailer hitch, characterized in that: The system includes a fixed base (1), a connecting seat (2) that rotates relative to the fixed base (1), a tow hook (3) that rotates relatively restricted relative to the connecting seat (2), and a rotation drive unit (4). The rotation drive unit (4) drives the connecting seat (2) and the tow hook (3) to rotate and unfold or retract around a preset first axis (a) and a second axis (b), respectively. The tow hook (3) rotates within a rated rotation range. A compression spring (8) is provided on the rotation path between the connecting seat (2) and the fixed base (1). The spring (8) provides assistance to the extended rotating connecting seat (2) or resistance to the retracted rotating connecting seat (2), wherein when the trailer hook switches from the extended state to the retracted state, the tow hook (3) retracts and rotates before the connecting seat (2); conversely, when the trailer hook switches from the retracted state to the extended state, the connecting seat (2) retracts and rotates before the tow hook (3); when the trailer hook switches from the extended state to the retracted state, the connecting seat (2) is positioned relative to the fixed seat (1) during the retracted rotation of the tow hook (3). The tow hook (3) remains stationary until it rotates to the correct position before retracting. Conversely, when the tow hook switches from the retracted state to the extended state, the tow hook (3) remains stationary relative to the connecting seat (2) during the extension rotation of the connecting seat (2) until the connecting seat (2) rotates to the correct position before extending. The tow hook (3) also includes a first drive shaft extending along the first axis (a) and a second drive shaft extending along the second axis (b). The first drive shaft rotates through the fixed seat (1) and the connecting seat (2) in sequence, and the second drive shaft rotates through the connecting seat (2) and connects to the tow hook (3). The two ends of the first drive shaft are respectively connected to the rotation drive unit (4) and the second drive shaft. The connecting seat (2) is provided with a first limiting part (21) and a second limiting part (22) that respectively stop with the tow hook (3). The arc-shaped interval between the first limiting part (21) and the second limiting part (22) serves as the rated rotation interval of the tow hook (3). The first axis (a) and the second axis (b) are arranged perpendicularly.

2. The electric folding trailer hitch according to claim 1, characterized in that: The rotary drive unit (4) is fixedly mounted on the fixed base (1).

3. The electric folding trailer hitch according to claim 1, characterized in that: The first drive shaft has a first bevel gear (5) at one end, and the second drive shaft has a second bevel gear (6) at the end that meshes with the first bevel gear (5).

4. The electric folding trailer hitch according to claim 3, characterized in that: The rotary drive unit (4) is a rotary motor and the output shaft of the rotary motor is provided with a transmission screw (41). The other end of the first transmission shaft is fitted with a helical gear (7) that meshes with the transmission screw (41).

5. The electric folding trailer hitch according to claim 1, characterized in that: The fixed seat (1) is formed with a third limiting part (11) that can abut against the connecting seat (2), wherein when the connecting seat (2) is unfolded and rotated into place, the connecting seat (2) abuts against the third limiting part (11).

6. The electric folding trailer hitch according to claim 1, characterized in that: The back of the connecting seat (2) is provided with an arc-shaped groove for accommodating the compression spring (8), and the front of the fixing seat (1) is formed with a protrusion (12), wherein the protrusion (12) extends into the arc-shaped groove; the two ends of the compression spring (8) respectively contact one end face of the arc-shaped groove and the protrusion (12).

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