Drag surface variable parachute

Abstract

The application discloses a variable-resistance-area parachute, which comprises a small parachute cover 1, an elastic device 2, a follow-up pull rope 3, a large parachute cover 4, a closing rope 5, a guide ring 6, a parachute rope 7 and a protective sleeve 8. The application is a novel parachute structure, which can automatically change the resistance area according to the speed during the deceleration and recovery of a flying vehicle. The parachute has a small resistance area during the high-speed deceleration stage and a large resistance area during the low-speed stable descending stage, so that the opening parachute overload is effectively reduced. Therefore, the load during the deceleration process is reduced.

Description

Technical Field

[0001] This invention relates to the field of aviation parachutes, and more specifically, to a parachute with a variable drag surface. Background Technology

[0002] When an aircraft needs to land after a flight mission or in an emergency, it sometimes deploys pre-assembled parachutes. To ensure a low-speed landing, the parachute needs a certain drag area. At high deployment speeds, the system experiences significant overload after the canopy inflates, potentially damaging the aircraft's structure or internal equipment. However, the parachute's area is a fixed value and cannot be changed.

[0003] Currently, the main method for reducing overload is multi-stage parachute deployment. This involves first using a parachute with a smaller drag area to slow down the vehicle, and then deploying a parachute with a larger drag area for further deceleration or descent once the speed has decreased to a certain range. However, multi-stage parachute deployment has a complex deployment procedure, a high failure rate, and requires a control system, resulting in high costs. Summary of the Invention

[0004] The purpose of this invention is to provide a parachute that automatically changes its drag area according to the speed.

[0005] The technical solution to achieve the purpose of this invention is as follows: a variable drag surface parachute, the parachute canopy includes a large canopy and a small canopy, the small canopy is circular, the large canopy is annular, and the small canopy is installed in the middle of the large canopy; a number of elastic devices are equally distributed on the large and small canopies, one end of the elastic device is fixed near the bottom edge of the small canopy, and the other end is fixed near the small circular bottom edge of the large canopy, the large canopy and the small canopy are connected by the elastic devices;

[0006] Several follow-up pull cords are evenly fixed near the bottom edge of the small umbrella canopy, with the other end of each follow-up pull cord being a loop; several guide loops are evenly fixed at the bottom edge of the large umbrella canopy, with their positions aligned with the follow-up pull cords and the elastic device; at each guide loop, the closing cord is the same length as the bottom edge of the large umbrella canopy, and after being folded and passed through the guide loop, it is looped together with the loop of the follow-up pull cord to form a loop connection.

[0007] Furthermore, the elastic device is fixed to the outside of the canopy, while the follow-up pull cord, guide ring, and closing cord are all fixed to the inside of the canopy. When the small canopy is subjected to air resistance, the elastic device can be stretched, thereby creating an air vent between the large and small canopies.

[0008] Furthermore, the tail of the follow-up pull cord is fixed to the bottom edge of the small umbrella canopy, and the other end is looped around the closing cord and sewn together to form a ring; the follow-up pull cord can move relative to the large umbrella canopy, but cannot move relative to the small umbrella canopy; the closing cord is restricted by the guide ring and moves back and forth at the bottom edge of the umbrella due to the movement of the follow-up pull cord.

[0009] Furthermore, after the follow-up pull cord and the closing cord are secured, a protective sleeve is sewn onto the outside. The paracord is connected to the parasol canopy.

[0010] Compared with the prior art, the present invention has the following significant advantages: (1) The parachute opening procedure is simplified, effectively reducing parachute overload, and only one parachute can complete the deceleration and landing functions that would otherwise require multiple parachute opening stages. (2) Different parachute opening speeds can be achieved by selecting elastic devices with different elastic coefficients for landing and recovery of aircraft. (3) The parachute of the present invention is made of textile material, does not require circuit or pyrotechnic control, has a simple structure, reduces the failure rate, and has a lower cost. Attached Figure Description

[0011] Figure 1 This is a comparison diagram of umbrella canopies.

[0012] Figure 2 This is a schematic diagram of the umbrella canopy structure.

[0013] Figure 3 These are comparison photos of the inside of the umbrella canopy.

[0014] Figure 4 It is a protective sleeve. Detailed Implementation

[0015] The present invention will now be further described with reference to the accompanying drawings.

[0016] Combination Figure 1-4 This invention discloses a parachute that automatically adjusts its drag area according to speed, effectively reducing parachute overload. It includes a small canopy 1, an elastic device 2, a follow-up drawstring 3, a large canopy 4, a closing cord 5, a guide ring 6, parachute lines 7, and a protective sleeve 8.

[0017] The parachute canopy consists of a large canopy and a small canopy. The small canopy is circular, and the large canopy is annular. The area of ​​the small canopy is equal to the area of ​​the gap in the middle of the large canopy. The large and small canopies are connected by an elastic device 2. When the parachute is not in operation, the elastic device is in its natural state, and the large and small canopies fit together seamlessly.

[0018] Inside the canopy, the smaller canopy connects to one end of the follow-up cord at the bottom edge, and the other end of the follow-up cord connects to the closing cord. The length of the closing cord is approximately equal to the length of the bottom edge of the larger canopy. A guide ring is fixed to the bottom edge of the canopy. After the follow-up cord and closing cord are fixed, a protective sleeve is sewn onto the outside to prevent snagging. The parachute cords are sewn directly to the bottom edge of the canopy, connecting the cords to the canopy.

[0019] When the parachute opens at high speed, the canopy is instantly filled with high-speed airflow. The smaller canopy is affected by air resistance, causing the elastic mechanism to extend. The smaller canopy and the larger canopy are displaced relative to each other, and an opening appears.

[0020] When the canopy undergoes relative displacement, the follower cord pulls the closing cord, shortening the actual closing section and creating a closing at the bottom edge of the canopy. At this time, the effective drag area of ​​the parachute is small, resulting in only a small opening overload.

[0021] As the speed decreases, the elastic device extends to a shorter length, the opening gradually decreases, the bottom edge of the parachute gradually widens, and the drag area gradually increases, thus ensuring that the aircraft lands slowly.

[0022] The present invention will be further described below with reference to embodiments.

[0023] This invention is a parachute that automatically changes its drag area according to speed. It has a smaller drag area during the high-speed deceleration phase and a larger drag area during the low-speed steady descent phase, thereby effectively reducing parachute opening overload.

[0024] When an aircraft needs to land after its mission or in an emergency, it must deploy the pre-assembled parachute. During deployment, the aircraft's high speed causes the parachute canopy to fill instantly with high-speed airflow. The smaller canopy 1, due to air resistance, causes the elastic device 2 to extend, resulting in relative displacement between the smaller canopy 1 and the larger canopy 4, creating an air vent. As the smaller canopy 1 shifts relative to the larger canopy 4, a follower cord 7, fixed to it, moves accordingly. Since the other end of the follower cord 7 is attached to the closing cord 5, the moving cord pulls the closing cord 5 upwards along the canopy's diameter, causing it to fold and shorten the actual closing section, resulting in a closing at the bottom edge of the canopy. At this point, the effective drag area of ​​the parachute is small, resulting in only a minor deployment overload.

[0025] As the speed decreases, the air resistance of the small canopy 1 decreases, the air outlet becomes smaller, the extension of the elastic device 2 becomes shorter, the bottom edge of the canopy gradually loosens, and the drag area gradually increases, thereby ensuring that the aircraft lands slowly.

[0026] This invention relates to a novel parachute structure, specifically a parachute that automatically adjusts its drag area according to speed during aircraft deceleration and recovery. It has a smaller drag area during high-speed deceleration and a larger drag area during low-speed descent, effectively reducing deployment overload. This reduces the load generated during deceleration.

Claims

1. A variable drag surface parachute, characterized in that: The parachute canopy includes a large canopy (4) and a small canopy (1). The small canopy (1) is circular, and the large canopy (4) is circular. The small canopy (1) is installed in the middle of the large canopy (4). Several elastic devices (2) are evenly installed on the large and small canopies. One end of the elastic device (2) is fixed near the bottom edge of the small canopy (1), and the other end is fixed near the small circular bottom edge of the large canopy (4). The large canopy (4) and the small canopy (1) are connected by the elastic device (2). Several follower pull ropes (3) are evenly fixed near the bottom edge of the small umbrella canopy (1), and the other end of the follower pull rope (3) is a ring; several guide rings (6) are evenly fixed at the bottom edge of the large umbrella canopy (4), and their positions are on the same straight line as the follower pull rope (3) and the elastic device (2); at each guide ring (6), the closing rope (5) is folded and passes through the guide ring (6) and then loops together with the ring of the follower pull rope (3) to form a loop connection; The elastic device (2) is fixed on the outside of the umbrella canopy, and the follow-up pull rope (3), guide ring (6), and closing rope (5) are all fixed on the inside of the umbrella canopy. When the small umbrella canopy is subjected to air resistance, the elastic device (2) can be stretched, thereby forming an air vent between the large and small umbrella canopies. The tail of the follow-up pull rope (3) is fixed to the bottom edge of the small umbrella canopy (1), and the other end is sewn onto the closing rope (5) to form a ring. The follow-up pull rope (3) can be displaced relative to the large umbrella canopy (4), but cannot be displaced relative to the small umbrella canopy. The closing rope (5) is restricted by the guide ring and moves in a telescopic motion at the bottom edge of the umbrella due to the movement of the follow-up pull rope (3).

2. The variable drag surface parachute according to claim 1, characterized in that: The length of the drawstring (5) is equal to the length of the bottom edge of the large umbrella (4).

3. The variable drag surface parachute according to claim 1, characterized in that: After the follow-up pull rope (3) and the closing rope (5) are fixed, a protective sleeve is sewn on the outside.

4. The variable drag surface parachute according to claim 1, characterized in that: The parachute ropes (7) are connected to the parachute canopy.

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