Air pressure ejection air cylinder piston of unmanned aerial vehicle and air cylinder

Abstract

The air pressure ejection air cylinder piston of the unmanned aerial vehicle comprises a piston sleeve, the piston sleeve is of a cylindrical structure with one end closed and the other end open, a pull rope shaft is connected to the piston sleeve, and an air bleed hole is formed in the closed end of the piston sleeve; and the piston sleeve is sleeved outside the piston sleeve. The hydraulic cylinder is simple in structure, connection between the pull rope and the piston is facilitated, high-pressure gas in the piston is released through the vent hole formed in the piston sleeve, the internal temperature of the piston and the internal temperature of the cylinder barrel are prevented from being too high, and therefore damage to the pull rope is reduced; and through the arrangement of the vent hole, the stability of the pressure in the launching process is ensured while the gas is released.

Description

Technical Field

[0001] This utility model belongs to the field of pneumatic catapult technology for unmanned aerial vehicles (UAVs), specifically relating to a piston and cylinder for a pneumatic catapult cylinder for UAVs. Background Technology

[0002] Air-pressure catapult launch for drones uses air pressure as the power source for takeoff and is widely used in large drones. Typically, this type of air-pressure catapult uses a launcher, slide rail, trolley, pulleys, and cylinder. The drone is mounted on the trolley, and ropes connect the trolley and the piston in the cylinder. An air supply system supplies air to the cylinder, driving the piston to move at high speed. The ropes then drive the trolley to move at high speed along the slide rail, thus achieving air-pressure catapult launch of the drone. Utility Model Content

[0003] The purpose of this invention is to provide a piston and cylinder for a pneumatic ejection cylinder for unmanned aerial vehicles (UAVs) to meet the requirements for high-speed launch of large UAVs.

[0004] This utility model is achieved through the following technical solution:

[0005] The piston of the pneumatic ejection cylinder for drones includes:

[0006] A piston sleeve, which is a cylindrical structure with one end closed and the other end open, is connected to a pull rope shaft, and a vent hole is provided at the closed end of the piston sleeve.

[0007] The piston sleeve is fitted over the piston barrel.

[0008] In some embodiments, the piston casing includes two semi-circular sleeves.

[0009] In some embodiments, the piston casing is made of ultra-high molecular weight polyethylene material.

[0010] In some embodiments, one end of the piston outer sleeve abuts against the flange of the piston sleeve, and the other end is limited by a cap fixedly connected to the piston sleeve.

[0011] In some embodiments, the vent hole is inclined.

[0012] In some embodiments, the vent hole is tilted at an angle of 20°-30° relative to the axial direction.

[0013] In some embodiments, the piston sleeve is provided with a mounting hole along the radial direction, and the pull rope shaft passes through the mounting hole.

[0014] On the other hand, the present invention also provides a cylinder, including a cylinder barrel and a cylinder piston.

[0015] In some embodiments, the piston outer sleeve and the cylinder inner wall are fitted with a clearance.

[0016] In some embodiments, the inner wall of the cylinder is provided with a wear-resistant layer, which is made of ultra-high molecular weight polyethylene.

[0017] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0018] This utility model has a simple structure, which facilitates the connection between the pull rope and the piston. By setting a vent hole on the piston sleeve, the high-pressure gas inside the piston can be released, avoiding excessively high internal temperature of the piston and cylinder, thereby reducing damage to the pull rope. Furthermore, by setting a vent hole, the pressure stability during the launch process is ensured while releasing the gas.

[0019] The piston sleeve adopts a structure of two semi-circular sleeves. The high-pressure gas on both sides of the semi-circular sleeves makes the semi-circular sleeves self-balanced in the radial direction. The piston sleeve can form a good fit with the cylinder, which can well ensure the stability of the cylinder piston performance. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the cylinder piston structure in an embodiment of the present invention.

[0022] Figure 2 This is a cross-sectional view of the cylinder piston in an embodiment of the present utility model.

[0023] Figure 3 This is a top view of the cylinder piston in an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of a piston structure according to another embodiment of the present invention.

[0025] Figure 5 This is a top view of the semi-circular sleeve of the piston outer casing according to another embodiment of the present invention.

[0026] in:

[0027] 10. Piston sleeve; 11. Vent hole; 12. Mounting hole; 13. Flange; 14. Lower guide rail;

[0028] 20. Piston outer casing; 21. Guide groove;

[0029] 30. Pull rope axle;

[0030] 40. Pressure cap, 41. Through hole, 42. Upper guide rail. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0032] In a pneumatic catapult for drones, the internal energy of high-pressure gas is converted into the mechanical energy required for the drone to take off through a cylinder, enabling the drone to reach the initial velocity required for catapult takeoff. Therefore, the performance of the cylinder has a significant impact on the performance of the pneumatic catapult for drones.

[0033] In some embodiments of this utility model, reference is made to... Figure 1 , Figure 2 and Figure 3 The pneumatic ejection cylinder piston for drones includes:

[0034] Piston sleeve 10 is a cylindrical structure with one end closed and the other end open. A pull rope shaft 30 is connected to the piston sleeve 10, and a vent hole 11 is provided at the closed end of the piston sleeve.

[0035] The piston sleeve 20 is fitted over the piston sleeve 10. The piston sleeve 20 is used to mate with the cylinder barrel to achieve a sealed connection between the piston and the cylinder barrel.

[0036] The piston sleeve 10 is made of 2A12 series aluminum alloy, which has high structural strength and light weight. The piston outer sleeve is fitted onto the piston sleeve, and the pull rope shaft connected to the piston sleeve is used to connect the pull rope.

[0037] A mounting hole 12 matching the pull rope shaft is provided radially along the piston sleeve 10. Both ends of the pull rope shaft 30 pass through the mounting hole 12, fixing the pull rope shaft to the piston sleeve. At this time, the mounting hole is sealed by the externally fitted piston sleeve, which can prevent the pull rope shaft from coming out of the mounting hole.

[0038] The vent hole on the piston sleeve is used to release the high-pressure gas inside the piston sleeve, preventing the internal temperature of the piston sleeve from becoming too high and damaging the draw rope.

[0039] The vent hole 11 on the piston sleeve is inclined, with the inclination angle set at 20°-30° relative to the axial direction, for example, 20°; the diameter of the vent hole is typically set at 0.8-1.0 mm, for example, 0.8 mm. Setting the vent hole 11 as an inclined hole and adjusting its diameter can slow down the gas release rate while releasing gas, ensuring it does not affect the stability of the gas pressure during ejection.

[0040] In some embodiments, the piston outer sleeve 20 is composed of two semi-circular sleeves, which are respectively wrapped around the piston sleeve to form a tight fit and constitute a complete annular cylindrical structure. A through hole is provided radially on the piston sleeve to allow communication between the inside of the piston outer sleeve and the inside of the piston sleeve. This through hole may be a mounting hole on the piston sleeve for installing a pull rope shaft.

[0041] The piston sleeve is designed with a combination of two semi-circular sleeves. Under the action of high-pressure gas, the two sides of the semi-circular sleeves can achieve good balance in the radial direction, so that a uniform gas film is formed between the piston sleeve and the inner wall of the cylinder. The piston sleeve and the cylinder are well fitted, which can well ensure the stability of the piston's motion performance.

[0042] Reference Figure 1 and Figure 2 One end of the piston sleeve 20 abuts against the flange 13 of the piston sleeve, while the other end is limited by a cap 40 fixedly connected to the piston sleeve. By limiting both ends of the piston sleeve, the piston sleeve is connected to the piston sleeve, restricting the relative movement of the piston sleeve and piston sleeve in the axial direction, but not restricting the movement of the piston sleeve in the radial direction. Thus, when the piston sleeve is a semi-circular sleeve, it can restrict the axial movement of the semi-circular sleeve on the piston sleeve, while allowing the semi-circular sleeve to have a degree of freedom in the radial direction.

[0043] The pressure cap 40 is fixedly installed on the piston sleeve 10 with screws. A through hole is provided on the pressure cap 40 for the pull rope to pass through. The pull rope extends into the piston sleeve through the hole and is connected to the pull rope shaft.

[0044] The piston jacket 20 can be made of ultra-high molecular weight polyethylene material, which gives it characteristics such as resistance to high and low temperatures and friction resistance, ensuring the high-speed movement of the piston in the cylinder to meet the launch requirements of the UAV.

[0045] Ultra-high molecular weight polyethylene (UHMWPE) is an unbranched linear polyethylene with a molecular weight of over 1.5 million. Its molecular formula is —(—CH2-CH2—)—n—, and its density is 0.920–0.964 g / cm³. 3With a heat distortion temperature (0.46MPa) of 85℃ and a melting point of 130~136℃, it is a linear thermoplastic engineering material with excellent comprehensive properties.

[0046] In some embodiments, refer to Figure 4 and Figure 5 A lower guide rail 14 is provided on one end face of the outer edge of the piston sleeve 10, and an upper guide rail 42 is provided on one end of the gland 40 near the edge. Guide grooves 21 that mate with the lower and upper guide rails are respectively provided at both ends of the two semi-circular sleeves of the piston outer sleeve 20. The cooperation between the lower and upper guide rails and the guide grooves ensures the stability of the semi-circular sleeves when they float in the radial direction, thereby further ensuring the performance of the cylinder piston and facilitating the installation of the semi-circular sleeves on the piston. Accordingly, the lower and upper guide rails are symmetrically arranged on the piston sleeve and the gland, respectively.

[0047] On the other hand, some embodiments of this utility model provide a cylinder, including a cylinder barrel and a cylinder piston as described in the above embodiments. The cylinder piston is fitted inside the cylinder barrel, and a pull rope extends into the cylinder barrel and is connected to the pull rope shaft of the cylinder piston. High-pressure gas drives the cylinder piston to move at high speed, providing the power for the UAV to launch.

[0048] The piston sleeve and the cylinder inner wall are fitted with a clearance. High-pressure gas is introduced into the cylinder and passes through the gap between the piston sleeve and the cylinder inner wall, forming a gas film between them. At the same time, based on the semi-circular sleeve structure of the piston sleeve, a gas pressure balance is formed on both sides of the semi-circular sleeve. This achieves sealing while ensuring the stability of piston movement and reducing friction between the piston sleeve and the cylinder inner wall.

[0049] A wear-resistant layer is installed on the inner wall of the cylinder, which is also made of ultra-high molecular weight polyethylene material, to improve the cylinder's wear resistance, salt spray and mold resistance, and high and low temperature resistance.

[0050] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", and "outer" used to indicate the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only used to facilitate the description of this utility model and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0051] Furthermore, the use of terms such as "horizontal" or "vertical" in the description of this utility model does not imply that the component is required to be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0052] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0053] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A piston for a pneumatic ejection cylinder of an unmanned aerial vehicle (UAV), characterized in that, include: A piston sleeve, which is a cylindrical structure with one end closed and the other end open, is connected to a pull rope shaft, and a vent hole is provided at the closed end of the piston sleeve. The piston sleeve is fitted over the piston barrel.

2. The UAV pneumatic ejection cylinder piston according to claim 1, characterized in that, The piston casing includes two semi-circular sleeves.

3. The UAV pneumatic ejection cylinder piston according to claim 1 or 2, characterized in that, The piston casing is made of ultra-high molecular weight polyethylene material.

4. The UAV pneumatic ejection cylinder piston according to claim 1 or 2, characterized in that, One end of the piston sleeve abuts against the flange of the piston sleeve, and the other end is limited by a cap that is fixedly connected to the piston sleeve.

5. The UAV pneumatic ejection cylinder piston according to claim 1, characterized in that, The vent hole is set at an angle.

6. The UAV pneumatic ejection cylinder piston according to claim 5, characterized in that, The vent hole has an inclination angle of 20°-30° relative to the axial direction.

7. The UAV pneumatic ejection cylinder piston according to claim 1, characterized in that, The piston sleeve has a mounting hole along the radial direction, and the pull rope shaft passes through the mounting hole.

8. A cylinder, characterized in that, Includes a cylinder barrel and a cylinder piston according to any one of claims 1-7.

9. The cylinder according to claim 8, characterized in that, The piston outer sleeve and the cylinder inner wall are fitted with a clearance.

10. The cylinder according to claim 8 or 9, characterized in that, The inner wall of the cylinder is provided with a wear-resistant layer, which is made of ultra-high molecular weight polyethylene.

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