pneumatic struts, tailgate system and vehicle

Abstract

This application relates to the field of vehicle tailgate technology, specifically to a pneumatic strut, a tailgate system, and a vehicle. The pneumatic strut includes: a cylinder, hollow inside, comprising alternating grooved sections and sealing sections along the length of the cylinder, the radial dimension of the grooved sections being larger than that of the sealing sections; and a piston assembly, slidably disposed within the cylinder, dividing the cylinder into a first chamber and a second chamber. The piston assembly includes a piston rod, a piston ring, a first seal, a valve core assembly, and a second seal. One end of the piston rod extends out of the cylinder, and the other end is connected to the piston ring. The piston ring has a receiving cavity and an opening communicating with the receiving cavity. The valve core assembly is telescopically disposed within the receiving cavity and connected to the piston rod. The first seal is sleeved on the outer periphery of the piston ring, and the second seal is located between the valve core assembly and the opening. When the vehicle is parked on a slope or in a tilted position, the tailgate can be limited without automatically closing, exhibiting high reliability.

Description

Technical Field

[0001] This application relates to the field of vehicle tailgate technology, specifically to a pneumatic strut, tailgate system, and vehicle. Background Technology

[0002] The tailgate of a vehicle generally refers to the opening door of the trunk, including two types: flip-up and side-opening. Side-opening tailgates are common in off-road vehicles with a spare tire mounted on the tailgate. A gas spring is installed between the tailgate and the vehicle body to limit its movement. The gas spring in this technology generally consists of a cylinder and a piston rod. The cylinder stores compressed gas that drives the piston rod. This type of gas spring can only remain at its maximum compression and maximum extension positions, and cannot remain in the middle position. Especially when parking on a slope or in a tilted position, the tailgate may suddenly close due to wind or other forces after opening. If someone is standing between the tailgate and the rear door of the vehicle, it could cause injury. Summary of the Invention

[0003] The purpose of this application is to provide a pneumatic strut, a tailgate system, and a vehicle, which, when the vehicle is parked on a slope or in a tilted position, can limit the tailgate opening to the limit position and prevent the tailgate from closing automatically.

[0004] In a first aspect, embodiments of this application provide a pneumatic strut, comprising: a cylinder, hollow inside, including grooved sections and sealing sections alternately arranged along the length of the cylinder, the radial dimension of the grooved sections being larger than the radial dimension of the sealing sections; and a piston assembly, slidably disposed within the cylinder, dividing the cylinder into a first cavity and a second cavity, the piston assembly including a piston rod, a piston ring, a first seal, a valve core assembly, and a second seal, one end of the piston rod extending out of the cylinder, the other end of the piston rod connected to the piston ring, the piston ring having a receiving cavity and an opening communicating with the receiving cavity, and a valve core assembly... The valve core assembly is telescopically disposed in the receiving cavity and connected to the piston rod. The first seal is sleeved on the outer periphery of the piston ring, and the second seal is located between the valve core assembly and the opening. When the piston assembly moves in the grooved section, a gap is formed between the first seal and the inner wall of the grooved section, and the pressure in the first cavity is equal to the pressure in the second cavity. When the piston assembly moves in the sealing section, the first seal is sealed to the inner wall of the sealing section, and the pressure difference formed between the first cavity and the second cavity compresses the valve core assembly at the opening and disengages from the second seal, so that the pneumatic strut generates friction.

[0005] Furthermore, the piston ring includes a fixed part and a moving part arranged sequentially along its own length. A first sealing member is sleeved on the outer periphery of the fixed part, the piston rod extends into the fixed part, and the moving part has a receiving cavity with an opening located on the side of the moving part away from the fixed part.

[0006] Furthermore, the valve core assembly includes a bushing, a valve core, and an elastic element. The valve core is located in the receiving cavity of the moving part. One end of the bushing is connected to the piston rod, and the other end of the bushing extends into the valve core. The elastic element is located between the valve core and the bushing, and the second seal is located between the opening and the valve core.

[0007] Furthermore, the length of the grooved section is greater than the length of the sealing section, and the length of the sealing section is greater than the length of the piston ring.

[0008] Furthermore, the number of grooved sections and the number of sealing sections are both two.

[0009] Furthermore, a dust cover is provided on the end of the cylinder corresponding to the end of the piston rod that extends out.

[0010] Furthermore, a first ball socket is provided at the end of the piston rod extending out of the cylinder, and a second ball socket is provided at the end of the cylinder away from the first ball socket. The first ball socket and the second ball socket are respectively connected to the ball head pin or the ball head pin of the bracket.

[0011] Furthermore, the frictional force generated by the pneumatic strut is 300N~700N.

[0012] Secondly, this application also provides a tailgate limiting system, including: a vehicle body; a tailgate assembly, including a side-opening tailgate; a pneumatic strut as described above, disposed between the vehicle body and the tailgate assembly, and located at the bottom of the side-opening tailgate, with one end of the piston rod of the pneumatic strut extending out of the cylinder connected to the tailgate assembly, and the other end of the cylinder of the pneumatic strut away from the piston rod connected to the vehicle body; and a limiter, disposed between the vehicle body and the tailgate assembly, and located at the middle of the height direction of the side-opening tailgate.

[0013] Furthermore, the limiter includes a base, a main arm, a limiting component, and a bracket. The base is pivotally connected to the side-opening tailgate, the bracket is connected to the vehicle body, the main arm is connected to the base, one end of the limiting component is connected to the vehicle body, and the other end can slide along the length of the main arm. The main arm is provided with grooves spaced apart along its own length. When the side-opening tailgate drives the main arm to open to a preset opening angle, the limiting component is located in the groove, and the piston assembly of the pneumatic strut is located in the sealing section of the cylinder.

[0014] Furthermore, there are two sealing sections and two corresponding grooves. When the limiting member is located in one of the grooves, the first opening angle of the side-opening tailgate is 40°~50°; when the limiting member is located in the other groove, the second opening angle of the side-opening tailgate is 80°~90°.

[0015] Furthermore, the tolerance between the first and second opening angles of the side-opening rear door is ±2°.

[0016] Furthermore, the frictional force generated when the limiting element of the limiter is located in the groove is 30N~60N.

[0017] Thirdly, embodiments of this application also provide a vehicle including the tailgate limiting system as described above.

[0018] The pneumatic strut, tailgate system, and vehicle provided in this application embodiment utilize a piston assembly and seals connected to a piston rod within the cylinder of the pneumatic strut. The piston assembly includes a retractable valve core assembly, providing both auxiliary force for opening the tailgate and frictional force, unaffected by temperature. Alternating grooved sections and sealing sections are arranged along the length of the cylinder. When the piston assembly moves in the grooved section, it provides only auxiliary force for opening; when it moves in the sealing section, it provides only frictional force. The sealing section corresponds to a groove on a limiter, ensuring that when the limiter is within the groove, the frictional force provided by the pneumatic strut and the frictional force of the limiter are superimposed. Therefore, when the vehicle is parked on a slope or in a tilted position, the tailgate is limited when opened to the limit position, preventing it from automatically closing. This design is simple, low-cost, and has a short development cycle. Attached Figure Description

[0019] Figure 1 This document shows a schematic diagram of the structure of the pneumatic strut provided in an embodiment of this application;

[0020] Figure 2 Show Figure 1 Schematic diagram of the internal structure of a medium-pressure strut;

[0021] Figure 3 Show Figure 2 Enlarged schematic diagram of the piston assembly;

[0022] Figure 4 This illustration shows a structural schematic diagram of the rear tailgate system provided in an embodiment of this application;

[0023] Figure 5 Show Figure 4 A partial structural diagram of the rear tailgate system;

[0024] Figure 6 Show Figure 5 Schematic diagram of the middle limit switch;

[0025] Figure 7 Show Figure 5 A schematic diagram showing the structural relationship between the middle limit switch and the pneumatic strut.

[0026] in,

[0027] 1. Pneumatic strut; 11. Cylinder; C1. First cavity; C2. Second cavity;

[0028] 111. Grooved section; 112. Sealing section; 12. Piston assembly; 121. Piston rod; 122. Piston ring; 122a. Fixed part; 122b. Moving part; 123. First seal; 124. Valve core assembly; 124a. Bushing; 124b. Valve core; 124c. Elastic element; 125. Second seal; O. Receiving cavity; K. Opening;

[0029] 13. Dust cover; 14. First ball socket; 15. Second ball socket; 16. Ball head pin;

[0030] 2. Body; 3. Tailgate assembly; 31. Side-opening tailgate;

[0031] 4. Limiter; 41. Base; 42. Main arm; 421. Groove; 43. Bracket. Detailed Implementation

[0032] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0033] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0034] like Figures 1 to 3 As shown in the figure, this application provides a pneumatic strut 1, including a cylinder 11 and a piston assembly 12.

[0035] The cylinder 11 is hollow inside and includes a grooved section 111 and a sealing section 112 arranged alternately along the length of the cylinder 11. The radial dimension of the grooved section 111 is larger than the radial dimension of the sealing section 112. Optionally, the cylinder 11 is cylindrical or approximately cylindrical. The radial dimension of the sealing section 112 is the same as the radial dimension of the cylinder 11 body. The grooved section 111 is formed by grooved sections at both ends of the cylinder 11 body using a grooving device, so that the radial dimension of the grooved section 111 is larger than the radial dimension of the sealing section 112. Specifically, the grooved section 111 protrudes along one radial side of the cylinder 11 body.

[0036] Piston assembly 12 is slidably disposed within cylinder 11, dividing cylinder 11 into a first cavity C1 and a second cavity C2. Piston assembly 12 includes piston rod 121, piston ring 122, first seal 123, valve core assembly 124, and second seal 125. One end of piston rod 121 extends out of cylinder 11, and the other end of piston rod 121 is connected to piston ring 122. Piston ring 122 has a receiving cavity O and an opening K communicating with the receiving cavity O. Valve core assembly 124 is telescopically disposed in receiving cavity O and connected to piston rod 121. First seal 123 is sleeved on the outer periphery of piston ring 122, and second seal 125 is located between valve core assembly 124 and opening K.

[0037] When the piston assembly 12 moves in the grooved section 111, a gap is formed between the first seal 123 and the inner wall of the grooved section 111, and the pressure in the first cavity C1 is equal to the pressure in the second cavity C2. When the piston assembly 12 moves in the sealing section 112, the first seal 123 is sealed to the inner wall of the sealing section 112, and the pressure difference formed between the first cavity C1 and the second cavity C2 compresses the valve core assembly 124 at the opening K and disengages from the second seal 125, so that the pneumatic strut 1 generates friction.

[0038] In this embodiment, the pneumatic strut 1 can be disposed between the vehicle body 2 and the tailgate assembly 3. The grooved section 111 is used for the flow of air pressure at both ends of the piston assembly 12 during the opening process of the pneumatic strut 1. Specifically, when the piston assembly 12 moves in the grooved section 111, a gap is formed between the first seal 123 and the inner wall of the grooved section 111, allowing the gas in the cylinder 11 to flow freely. At this time, the pressure in the first chamber C1 is equal to the pressure in the second chamber C2, and the pneumatic strut 1 does not provide frictional force, but is used to provide an auxiliary force for opening the tailgate assembly 3.

[0039] When the piston assembly 12 moves in the sealing section 112, there is no gap between the first seal 123 and the inner wall of the sealing section 112, thus achieving a seal. The pressure in the first cavity C1 increases, and the pressure in the second cavity C2 decreases, creating a pressure difference between them. This pressure difference compresses the valve core assembly 124 at the opening K and causes it to detach from the second seal 125, resulting in internal seal failure. Gas passes through the valve core assembly 124, and this pressure difference creates friction on the pneumatic strut 1.

[0040] In related technologies, the tailgate can only be opened to its maximum size at a time. When the distance between the rear of the vehicle and the tailgate is less than the distance corresponding to the maximum opening angle, the tailgate may collide with obstacles behind it. Furthermore, gas springs are greatly affected by temperature. At temperatures as low as -30°C, when parking on a slope (≥10°) or a side-sloping surface (≥10°), the force of the gas spring decreases, posing a risk of automatic closure and injury. In contrast, the friction force provided in this application is unaffected by temperature, resulting in higher limiting reliability.

[0041] The pneumatic strut 1 provided in this application embodiment, by setting a piston assembly 12 and a seal connected to a piston rod 121 inside a cylinder 11, and the piston assembly 12 including a retractable valve core assembly 124, can not only provide an auxiliary force for opening the tailgate, but also provide frictional force and is unaffected by temperature; at the same time, alternating grooved sections 111 and sealing sections 112 are arranged in the length direction of the cylinder 11. When the piston assembly 12 moves in the grooved section 111, it only provides an opening auxiliary force, and when it moves in the sealing section 112, it only provides frictional force. Thus, when the vehicle is parked on a slope or in a tilted state, the tailgate can be stopped when it is opened to the limit position and the tailgate will not close automatically. Moreover, the structure is simple, the cost is low, and the development cycle is short.

[0042] In some embodiments, the piston ring 122 includes a fixed portion 122a and a moving portion 122b arranged sequentially along its own length direction. A first sealing member 123 is sleeved on the outer periphery of the fixed portion 122a. The piston rod 121 extends into the fixed portion 122a. The moving portion 122b has a receiving cavity O and an opening K is provided on the side of the moving portion 122b away from the fixed portion 122a.

[0043] The fixing part 122a maintains a preset gap with the grooved section 111 of the cylinder 11 through the first seal 123, which is used to provide auxiliary force for opening the tailgate assembly 3. The fixing part 122a is sealed with the sealing section 112 of the cylinder 11 through the first seal 123, and a pressure difference is generated between the first cavity C1 and the second cavity C2. At this time, the valve core assembly 124 in the moving part 122b is compressed by the gas entering from the opening K side, causing the second seal 125 to disengage from the valve core assembly 124, the seal fails, and the pneumatic strut 1 generates friction. Therefore, when the vehicle is parked on a slope or in a tilted state, the tailgate can be limited when it is opened to the limit position and the tailgate will not close automatically.

[0044] Furthermore, the valve core assembly 124 includes a bushing 124a, a valve core 124b, and an elastic member 124c. The valve core 124b is located in the receiving cavity O of the moving part 122b. One end of the bushing 124a is connected to the piston rod 121, and the other end of the bushing 124a extends into the valve core 124b. The elastic member 124c is located between the valve core 124b and the bushing 124a. The second seal 125 is located between the opening K and the valve core 124b.

[0045] Optionally, the elastic element 124c is a compressible spring. When the valve core assembly 124 is compressed by the gas entering from the opening K side, the elastic element 124c pushes the valve core 124b to move relative to the bushing 124a, causing the seal between the second seal 125 and the valve core 124b to fail and air to enter, thereby causing the pneumatic strut 1 to generate friction.

[0046] Furthermore, the length of the grooved section 111 is greater than the length of the sealing section 112, and the length of the sealing section 112 is greater than the length of the piston ring 122. The length of the grooved section 111 is related to the stroke of the tailgate, and the length of the sealing section 112 is greater than the length of the piston ring 122. This ensures that the piston assembly 12 can generate sufficient friction when the sealing section 112 is in operation, preventing the pneumatic strut 1 from losing friction due to shaking and movement, and further improving the reliability of the limit.

[0047] Furthermore, the number of grooved sections 111 and the number of sealing sections 112 are both two. For example... Figure 1 As shown, one sealing section 112 is located in the middle of the cylinder 11, corresponding to one limiting position of the tailgate, and the other sealing section 112 is located at the end of the cylinder 11, corresponding to another limiting position of the tailgate.

[0048] Furthermore, a dust cover 13 is provided at the end of the cylinder 11 corresponding to the protruding end of the piston rod 121. Since the piston rod 121 moves repeatedly along the axial direction and is in a non-sealed state, the dust cover 13 can prevent dust and other impurities from entering the cylinder 11 from the protruding end of the cylinder 11 corresponding to the piston rod 121 and affecting the movement performance of the pneumatic strut 1.

[0049] Furthermore, a first ball joint 14 is provided at the end of the piston rod 121 extending out of the cylinder 11, and a second ball joint 15 is provided at the end of the cylinder 11 away from the first ball joint 14. The first ball joint 14 and the second ball joint 15 are respectively connected to the ball joint pin 16 or the ball joint pin 16 of the bracket 43. The ball joint pin 16 or the ball joint pin 16 of the bracket 43 can be provided on one side of the vehicle body 2 and one side of the tailgate assembly 3 to improve the smoothness of the movement of opening the tailgate assembly 3.

[0050] Furthermore, the maximum outer diameter of the pneumatic strut 1 is 18mm, which is 45mm larger than the maximum outer diameter of the stepless limit rod in the related technology. This saves space in the trunk and effectively reduces the threshold height of the tailgate assembly 3, making it easier to load and unload luggage.

[0051] Furthermore, the frictional force generated by the pneumatic strut 1 is 300N~700N. This frictional force can be adjusted according to the specific product to adapt to different limit requirements.

[0052] like Figure 4 and Figure 5 As shown, this application embodiment also provides a tailgate limiting system, including: vehicle body 2, tailgate assembly 3, pneumatic strut 1 as described above, and limiter 4.

[0053] The tailgate assembly 3 includes a side-opening tailgate 31. A pneumatic strut 1 is located between the vehicle body 2 and the tailgate assembly 3, and at the bottom of the side-opening tailgate 31. The piston rod 121 of the pneumatic strut 1 extends out of the cylinder 11 and is connected to the tailgate assembly 3. The cylinder 11 of the pneumatic strut 1, away from the piston rod 121, is connected to the vehicle body 2. A limiter 4 is located between the vehicle body 2 and the tailgate assembly 3, and at the middle of the side-opening tailgate 31 in the height direction.

[0054] In this embodiment, the limiter 4 passes through the through hole opened on the tailgate assembly 3 and is connected to the vehicle body 2 and the tailgate assembly 3 respectively by bolts. It is used to adjust the limiting position of the opening angle of the side-opening tailgate 31. The pneumatic strut 1 is used to provide friction for the side-opening tailgate 31 at the limiting position to prevent the side-opening tailgate 31 from closing automatically due to external force.

[0055] like Figure 6 and Figure 7 As shown, the limiter 4 includes a base 41, a main arm 42, a limiting member (not shown in the figure), and a bracket 43. The base 41 is pivotally connected to the side-opening tailgate 31, the bracket 43 is connected to the vehicle body 2, the main arm 42 is connected to the base 41, one end of the limiting member is connected to the vehicle body, and the other end is slidable along the length of the main arm 42. The main arm 42 is provided with grooves 421 spaced apart along its own length. When the side-opening tailgate 31 drives the main arm 42 to open to a preset opening angle, the limiting member is located in the groove 421, and the piston assembly 12 of the pneumatic strut 1 is located in the sealing section 112 of the cylinder 11.

[0056] Since the groove 421 corresponds to the sealing section 112, the friction force generated by the limiter 4 will be superimposed with the friction force generated by the pneumatic strut 1 to reach the maximum limit force value, thereby increasing the limit friction force. When parking on a slope (≥10°) or a side-sloping road surface (≥10°), the maximum friction limit force value of the pneumatic strut 1 and the limiter 4 can generate a sufficiently large torque to ensure reliable limit and is not affected by temperature, thereby reducing the risk of injury caused by the automatic closing of the tailgate assembly 3.

[0057] Furthermore, such as Figure 7 As shown, there are two sealing sections 112 and two corresponding grooves 421. When the limiting member is located in one of the grooves 421, the first opening angle of the side-opening tailgate 31 is 40°~50°; when the limiting member is located in the other groove 421, the second opening angle of the side-opening tailgate 31 is 80°~90°. In one example, the first opening angle is 44° and the second opening angle is 88°. There can be more sealing sections 112, and correspondingly more grooves 421, which correspond one-to-one, forming multiple limiting positions and generating limiting friction at each position.

[0058] Furthermore, the tolerance between the first opening angle and the second opening angle of the side-opening tailgate 31 is ±2°. This setting can improve the accuracy of the opening angle of the side-opening tailgate 31.

[0059] Furthermore, the frictional force generated when the limiting member of the limiter 4 is located within the groove 421 is 30N~60N. Thus, when the side-opening tailgate 31 reaches the limit position of the opening angle, the frictional force generated by the limiter 4 and the frictional force generated by the pneumatic strut 1 are superimposed to achieve a maximum limiting force value of 330N~760N.

[0060] Additionally, this application embodiment also provides a vehicle including the aforementioned tailgate limiting system. This vehicle can be an off-road vehicle, such as a multi-purpose vehicle (MPV) or a sport utility vehicle (SUV). MPVs evolved from station wagons, combining the spaciousness of a station wagon, the comfort of a sedan, and the functionality of a van. They are generally two-box structures, seating 6-7 people, offering better comfort and more interior space. Unlike off-road vehicles that can be used on rough terrain, they are popular as suburban multi-purpose vehicles. SUVs, combining the space and functionality of a station wagon with the off-road capabilities of a truck, offer better traction on rough and uneven roads, resulting in a more enjoyable driving experience.

[0061] The pneumatic strut 1, tailgate system, and vehicle provided in this application embodiment utilize a piston assembly 12 and a seal connected to a piston rod 121 within a cylinder 11. The piston assembly 12 includes a retractable valve core assembly 124, which provides both an auxiliary force for opening the tailgate and a frictional force unaffected by temperature. Furthermore, alternating grooved sections 111 and sealing sections 112 are provided along the length of the cylinder 11. When the piston assembly 12 moves along the grooved section 111, it provides only an auxiliary force for opening, while moving along the sealing section 112, it provides only a frictional force. Therefore, when the vehicle is parked on a slope or in a tilted position, the tailgate can be stopped at the limit position without automatically closing. This design is simple, low-cost, and has a short development cycle.

[0062] It should be noted that the terms "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," etc., mentioned in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0063] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A pneumatic strut, characterized in that, include: A cylinder barrel, hollow internally configured, includes grooved sections and sealing sections alternately arranged along the length of the cylinder barrel, wherein the radial dimension of the grooved sections is larger than the radial dimension of the sealing sections; and A piston assembly is slidably disposed within a cylinder, dividing the cylinder into a first chamber and a second chamber. The piston assembly includes a piston rod, a piston ring, a first seal, a valve core assembly, and a second seal. One end of the piston rod extends out of the cylinder, and the other end of the piston rod is connected to the piston ring. The piston ring has a receiving cavity and an opening communicating with the receiving cavity. The valve core assembly is telescopically disposed in the receiving cavity and connected to the piston rod. The first seal is sleeved on the outer periphery of the piston ring, and the second seal is located between the valve core assembly and the opening. When the piston assembly moves in the grooved section, a gap is formed between the first seal and the inner wall of the grooved section, and the pressure in the first cavity is equal to the pressure in the second cavity. When the piston assembly moves in the sealing section, the first seal is sealed to the inner wall of the sealing section, and the pressure difference between the first cavity and the second cavity compresses the valve core assembly at the opening and disengages from the second seal, so that the pneumatic strut generates friction.

2. The pneumatic strut according to claim 1, characterized in that, The piston ring includes a fixed part and a moving part arranged sequentially along its own length. The first sealing member is sleeved on the outer periphery of the fixed part. The piston rod extends into the fixed part. The moving part has the receiving cavity. The opening is located on the side of the moving part away from the fixed part.

3. The pneumatic strut according to claim 2, characterized in that, The valve core assembly includes a bushing, a valve core, and an elastic element. The valve core is located within the receiving cavity of the moving part. One end of the bushing is connected to the piston rod, and the other end of the bushing extends into the valve core. The elastic element is located between the valve core and the bushing, and the second sealing element is located between the opening and the valve core.

4. The pneumatic strut according to claim 1, characterized in that, The length of the grooved section is greater than the length of the sealing section, and the length of the sealing section is greater than the length of the piston ring.

5. The pneumatic strut according to claim 1, characterized in that, The number of grooved sections and the number of sealing sections are both two.

6. The pneumatic strut according to claim 1, characterized in that, The cylinder is provided with a dust cover at the end corresponding to the extended end of the piston rod.

7. The pneumatic strut according to claim 1, characterized in that, The piston rod extending out of the cylinder is provided with a first ball socket, and the cylinder is provided with a second ball socket at the end away from the first ball socket. The first ball socket and the second ball socket are respectively connected to the ball head pin or the ball head pin of the bracket.

8. The pneumatic strut according to claim 1, characterized in that, The frictional force generated by the pneumatic strut is 300N~700N.

9. A tailgate limiting system, characterized in that, include: Body; Rear door assembly, including side-opening rear door; The pneumatic strut as described in any one of claims 1 to 8 is disposed between the vehicle body and the tailgate assembly, and located at the bottom of the side-opening tailgate; one end of the piston rod of the pneumatic strut extending out of the cylinder is connected to the tailgate assembly, and the end of the cylinder of the pneumatic strut away from the piston rod is connected to the vehicle body; and A limiter is disposed between the vehicle body and the tailgate assembly, and is located at the middle of the side-opening tailgate in the height direction.

10. The tailgate limiting system according to claim 9, characterized in that, The limiter includes a base, a main arm, a limiting member, and a bracket. The base is pivotally connected to the side-opening tailgate, the bracket is connected to the vehicle body, the main arm is connected to the base, one end of the limiting member is connected to the vehicle body, and the other end is slidable along the length of the main arm. The main arm is provided with grooves spaced apart along its own length. When the side-opening tailgate drives the main arm to open to a preset opening angle, the limiting member is located in the groove, and the piston assembly of the pneumatic strut is located in the sealing section of the cylinder.

11. The tailgate limiting system according to claim 10, characterized in that, There are two sealing sections and two corresponding grooves. When the limiting member is located in one of the grooves, the first opening angle of the side-opening back door is 40°~50°; when the limiting member is located in the other groove, the second opening angle of the side-opening back door is 80°~90°.

12. The tailgate limiting system according to claim 11, characterized in that, The tolerance between the first opening angle and the second opening angle of the side-opening back door is ±2°.

13. The tailgate limiting system according to claim 10, characterized in that, The frictional force generated when the limiting element of the limiter is located in the groove is 30N~60N.

14. A vehicle, characterized in that, Includes the rear door limiting system as described in any one of claims 9 to 13.

Images