Electric tail door damping device and electric tail door supporting rod system

Abstract

The utility model relates to an electric tail door damping device and an electric tail door supporting rod system. The electric tail gate damping device comprises a hollow shell, a friction plate set, a wave spring and a fastening cover, the friction plate set comprises a fixed friction plate fixed in the shell and a movable friction plate capable of moving relative to the fixed friction plate, the wave spring is positioned between the fastening cover and the friction plate set, and the fastening cover is fixed in the shell so that the wave spring can be compressed. And then the fixed friction plate and the movable friction plate are pressed together. The power tailgate damping device also includes a friction torque compensation member sandwiched between the fastening cover and the wave spring and configured to expand sufficiently to further compress the wave spring when the temperature rises. The electric tail door supporting rod system comprises the electric tail door damping device. According to the electric tail gate damping device, fluctuation of friction force and friction torque caused by temperature change is avoided.

Description

Technical Field

[0001] This utility model relates to the field of vehicles, specifically to vehicle damping devices, such as electric tailgate damping devices for electric tailgate strut systems, which have friction torque compensation functions. This utility model also relates to an electric tailgate strut system including this electric tailgate damping device. Background Technology

[0002] Many vehicles now come equipped with power tailgates, which automatically open and close using a motor. Typically, at the end of the tailgate's travel, or to maintain its open position or prevent pinching, the tailgate's gravitational torque needs to be applied for braking. One method currently used is to apply a back electromotive force through the motor's electronic control unit, but this method consumes a significant amount of energy. Another method utilizes friction to generate resistance for braking, employing a purely mechanical structure that uses friction pads.

[0003] Figure 1A An example of a conventional electric tailgate damping device is shown. The electric tailgate damping device 1 includes a hollow housing 10, a first set of friction plates 20, a second set of friction plates 30, a wave spring 40, and a fastening cover 50. Each set of brake discs includes three friction plates, namely friction plates 21, 22, and 23, and friction plates 31, 32, and 33, which are adjacent to each other. Two of these are fixed friction plates 21, 23, 31, and 33, which are fixed within the housing, and the other is a movable friction plate 22 and 32. The electric tailgate damping device 1 may also include a drive shaft 60 and a driven shaft 70 driven thereto. Each friction plate, wave spring, and fastening cover has a central through-hole for the drive shaft and driven shaft to pass through. The drive shaft 60 has splines on its outer periphery, and the through-holes of the movable friction plates 22 and 32 have corresponding mating keyways for rotation with the drive shaft 60.

[0004] Figure 1B and Figure 1C Perspective views of the electric tailgate damping device 1, seen from the drive shaft side and the fastening cover side, are shown respectively. In the assembled state, the fastening cover 50 is fixed within the housing 10, compressing the wave spring 40 so that the stationary and moving friction plates in each set of friction plates 20 and 30 press against each other. Thus, as the drive shaft 60 drives the moving friction plates 22 and 32 to rotate, dynamic friction is generated between the stationary and moving friction plates, thereby producing braking.

[0005] Figure 2A Another example of an existing electric tailgate damping device is shown. (Compared to...) Figure 1A Similar to the electric tailgate damping device 1 shown, the electric tailgate damping device 1' includes a hollow housing 10', a wave spring 40', a fastening cover 50', a drive shaft 60', and a driven shaft 70'. (Similar to...) Figure 1AUnlike the previous design, the electric tailgate damping device 1' comprises only one set of friction plates 20', which has three friction plates, namely friction plates 21', 22', and 23', adjacent to each other. Two of them are fixed friction plates 21' and 23', which are fixed inside the housing, and the other is a moving friction plate 22'. Similarly, each friction plate, the wave spring, and the fastening cover have a central through opening for the drive shaft and the driven shaft to pass through. The drive shaft 60' has splines on its outer periphery, and the through opening of the moving friction plate 22' has a corresponding keyway for rotation with the drive shaft 60'.

[0006] Figure 2B A cross-sectional view of the electric tailgate damping device 1' is shown. In the assembled state, the fastening cover 50' is fixed inside the housing 10' (e.g., by threaded engagement), compressing the wave spring 40' so that the stationary friction plate and the moving friction plate press against each other. As a result, as the drive shaft 60' drives the moving friction plate 22' to rotate, dynamic friction is generated between the stationary and moving friction plates, thereby producing braking.

[0007] The drawback of the aforementioned purely mechanical electric tailgate damping device is that the coefficient of friction of the friction pads changes with temperature, particularly decreasing as temperature rises. Similarly, the elastic force of the spring also changes with temperature, specifically decreasing as temperature increases. This causes the braking friction force, and consequently the braking torque, to fluctuate with temperature, especially decreasing as temperature rises. This is detrimental to braking and consequently affects the electric tailgate's ability to remain open or its anti-pinch function.

[0008] There is a need to improve the aforementioned shortcomings of existing electric tailgate damping devices.

[0009] CN202410561504.4 discloses a gas spring with temperature compensation function, which has a steel tube assembly. The steel tube assembly contains a temperature compensation component, which includes a sleeve. Inside the sleeve is a temperature-sensitive wax layer that fits against one end of the sleeve and a compensation cavity. A telescopic rod is also provided inside the sleeve, located between the temperature-sensitive wax layer and the compensation cavity, with one end extending out of the sleeve. The temperature-sensitive wax in the temperature compensation component has the characteristic of thermal expansion and contraction, thereby automatically adjusting the extension volume of the telescopic rod to adapt to different temperatures, ultimately maintaining a relatively stable output force value of the gas spring.

[0010] There is currently no improvement solution available for electric tailgate brakes. Summary of the Invention

[0011] The purpose of this invention is to provide an electric tailgate damping device with friction torque compensation function. According to this invention, the electric tailgate damping device includes a hollow housing, a friction plate assembly, a spring, and a fastening cover. The friction plate assembly includes a fixed friction plate fixed within the housing and a movable friction plate movable relative to the fixed friction plate. The spring is positioned between the fastening cover and the friction plate assembly. The fastening cover is fixed within the housing, compressing the spring and thus pressing the fixed and movable friction plates together. The electric tailgate damping device also includes a friction torque compensation component, which is sandwiched between the fastening cover and the spring and is configured to expand sufficiently when the temperature rises to further compress the spring. With this arrangement, under high-temperature conditions, the friction torque compensation component expands and compresses the spring, increasing the spring's elastic force to compensate for the loss of elastic force caused by high temperature, thus keeping the friction force and friction torque within the desired range and avoiding affecting the normal operation of the electric tailgate.

[0012] According to an embodiment, the friction torque compensation member is configured to contract sufficiently to allow the spring to extend when the temperature decreases. This arrangement ensures that, at low temperatures, the friction torque compensation member contracts and the spring extends, reducing the spring's elasticity to counteract the increase in elastic force caused by the low temperature. This keeps the friction force and friction torque within the desired range, preventing excessive braking.

[0013] According to an embodiment, the friction torque compensation member is at least partially housed within the fastening cover. This arrangement allows the friction compensation member to be integrated onto the fastening cover. For example, the friction compensation member is constructed as a ring, with its two ends abutting against a wave spring and the fastening cover, respectively.

[0014] According to an embodiment, the friction torque compensation component includes an elastic cap and a temperature-sensitive synthetic wax. The elastic cap is located on the side that contacts the wave spring, and the synthetic wax is contained within a fastening cap, with the elastic cap providing a seal. Alternatively, the friction compensation component consists of a seal and a temperature-sensitive synthetic wax contained therein, with the side of the seal that contacts the wave spring being elastic. The synthetic wax is capable of thermal expansion and contraction, with an effective operating temperature range of -40 to 100 degrees Celsius. This arrangement allows the synthetic wax to remain solidified into a certain shape and adapt to changes in volume due to temperature variations. Furthermore, the temperature range can be adjusted by selecting the components of the synthetic wax.

[0015] According to an embodiment, the electric tailgate damping device further includes a drive shaft and a driven shaft connected thereto, which extend through the housing, friction plate assembly, wave spring, friction torque compensation component, and fastening cover. For this purpose, the friction plate assembly, wave spring, friction torque compensation component, and fastening cover all have through openings, and the drive shaft has a spline on its outer periphery, with corresponding keyways on the moving friction plates in the openings. In this arrangement, the moving friction plates can rotate with the drive shaft, thereby rubbing against the stationary friction plates to generate frictional force and frictional torque.

[0016] According to an embodiment, the friction plate assembly includes two fixed friction plates and one movable friction plate, with the movable friction plate sandwiched between the fixed friction plates. Preferably, the outer periphery of the fixed friction plates is provided with protrusions, and the inner wall of the housing is provided with corresponding grooves for easy fixing.

[0017] According to one embodiment, the fastening cap is fixed to the housing by a threaded connection. With this arrangement, the compression of the wave spring can be adjusted by screwing on the fastening cap, thereby adjusting the frictional torque and thus the braking tightness.

[0018] This utility model also relates to an electric tailgate strut system, which includes the aforementioned electric tailgate damping device.

[0019] Compared to existing electric tailgate damping devices, the electric tailgate damping device of this invention avoids fluctuations in frictional force and torque caused by temperature changes. Moreover, because it uses temperature-sensitive synthetic wax as the material for thermal expansion and contraction, the electric tailgate damping device increases weight and cost less and is easy to manufacture in various forms. Attached Figure Description

[0020] The embodiments of the present invention will be explained in more detail in the accompanying drawings, in which:

[0021] Figure 1A This is an exploded perspective view of an existing electric tailgate damping device;

[0022] Figure 1B yes Figure 1A A perspective view of the electric tailgate damping device from the fastening cover side;

[0023] Figure 1C yes Figure 1A A perspective view of the electric tailgate damping device from the drive shaft side;

[0024] Figure 2A This is an exploded perspective view of an electric tailgate damping device, another example of the prior art.

[0025] Figure 2B yes Figure 2A A cross-sectional view of the electric tailgate damping device;

[0026] Figure 3 This is an exploded perspective view of the electric tailgate damping device according to an embodiment of the present utility model;

[0027] Figure 4 yes Figure 3 A perspective view of the fastening cover and friction compensation component of the electric tailgate damping device.

[0028] In the accompanying drawings, embodiments of the present invention are shown in a simplified manner for clarity. The drawings are not necessarily shown to scale. Similar reference numerals in the drawings denote similar parts. Detailed Implementation

[0029] Reference Figure 3-4 This invention describes an electric tailgate damping device according to an embodiment of the present invention. Figure 3 This illustration shows an electric tailgate damping device 100 according to an embodiment of the present invention. Figure 2A Similar to the illustrated electric tailgate damping device 1', the electric tailgate damping device 100 includes a hollow housing 110, a friction plate assembly 120, a wave spring 140, a fastening cover 150, a drive shaft, and a driven shaft (not shown) connected to the drive shaft. The friction plate 120 has three friction plates, namely friction plates 121, 122, and 123, which are adjacent to each other. Two of these are fixed friction plates 121 and 123, which are fixed within the housing (e.g., by means of a tab 123a on the outer periphery of the fixed friction plates 121 and 123 engaging with a groove on the inner wall of the housing 110). The other is a movable friction plate 122, which is sandwiched between the fixed friction plates 121 and 123. Similarly, each friction plate, wave spring, and fastening cover has a central through-hole for the drive shaft and driven shaft to pass through. The drive shaft has a spline on its outer periphery, and the through-hole of the movable friction plate 122 has a corresponding keyway for rotation with the drive shaft.

[0030] and Figure 2A Unlike the previous example, the electric tailgate damping device 100 also includes a friction compensation member 180, which is ring-shaped and abuts against a spring 140 and a fastening cap 150 at both ends, being sandwiched between them. In this example, the friction compensation member 180 includes a resilient cap 181 and a temperature-sensitive synthetic wax, wherein the resilient cap is located on the side in contact with the spring, the synthetic wax is contained within the fastening cap, and the resilient cap provides a seal. Alternatively, the friction compensation member may consist of a seal and a temperature-sensitive synthetic wax contained therein, wherein the side of the seal in contact with the spring is resilient, the other sides are hard rubber, and the friction compensation member is contained within the fastening cap. The resilient seal is chosen to keep the synthetic wax solidified into a certain shape and to accommodate the volume changes of the synthetic wax with temperature. The operating temperature range of the synthetic wax is, for example, -40 to 100 degrees Celsius, within which the synthetic wax remains solidified.

[0031] Figure 4 A friction compensation member 180 is shown together with the fastening cover 150, which is partially housed in the fastening cover 150, for example, in a cutout (not shown) provided on the fastening cover 150, so as to partially expose the fastening cover 150. The friction compensation member 180 may also be fully housed in the fastening cover 150 and extend out of the fastening cover 150 when it expands at high temperature to compress the wave spring 140.

[0032] Figure 4It is also shown that the fastening cover 150 includes threads 151 on its outer periphery, and the inner wall of the housing 110 is provided with complementary threads (not shown) to fix the fastening cover 150 to the housing 110 by threaded engagement.

[0033] The foregoing detailed the presently preferred embodiments of this utility model, intended to illustrate the principles of the invention, and the wording and expressions used are illustrative rather than restrictive. Those skilled in the art will understand that various modifications and variations of the above embodiments are possible without departing from the scope of this utility model. Therefore, in some cases, features disclosed in this utility model may be used independently of other features. On the other hand, features disclosed in this utility model may be combined when necessary to provide various combinations.

Claims

1. An electric tailgate damping device comprising a hollow housing, a friction plate set, a wave spring, a fastening cover, wherein, The friction plate set comprises a fixed friction plate fixed in the housing and a movable friction plate capable of moving relative to the fixed friction plate, the wave spring is positioned between the fastening cover and the friction plate set, the fastening cover is fixed in the housing so as to compress the wave spring and in turn press the fixed friction plate and the movable friction plate together, characterized in that the electric tail gate damping device further comprises a friction torque compensation component which is clamped between the fastening cover and the wave spring and is configured to swell enough to further compress the wave spring when the temperature rises.

2. The electrically driven tailgate damping device according to claim 1, characterized in that The friction torque compensation component is also configured to shrink enough to expand the wave spring when the temperature drops.

3. The electrically driven tailgate damping device according to claim 1 or 2, characterized in that The friction torque compensation component is at least partially accommodated in the fastening cover.

4. The electrically driven tailgate damping device according to claim 3, characterized in that The friction torque compensation component is configured in a ring shape with two ends respectively abutting against the wave spring and the fastening cover.

5. The electrically driven tailgate damping device according to claim 1 or 2, characterized in that The friction torque compensation component comprises an elastic cover on the side in contact with the wave spring and a temperature-sensitive synthetic wax accommodated in the fastening cover and encapsulated by the elastic cover, or the friction compensation component is composed of an encapsulation and a temperature-sensitive synthetic wax accommodated therein, the side in contact with the wave spring of the encapsulation being elastic.

6. The electrically driven tailgate damping device according to claim 5, characterized in that The synthetic wax remains solid in the range of -40-100 degrees Celsius.

7. The electrically driven tailgate damping device according to claim 1 or 2, characterized in that The electric tail gate damping device further comprises a driving shaft and a driven shaft in driving connection therewith, the friction plate set, the wave spring, the friction torque compensation component and the fastening cover all have through openings so that the driving shaft and the driven shaft extend through, and the driving shaft is provided with splines on the outer periphery and the movable friction plate is provided with corresponding matching key grooves on the through openings.

8. The electrically driven tailgate damping device according to claim 1 or 2, characterized in that The fastening cover is fixed in the housing by threaded engagement.

9. A power tailgate strut system characterized by, The electric tail gate damping device according to any one of claims 1-8 is also included. The electric tail gate damping device according to any one of claims 1-8 is also included.

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