An opening device and method for using a parachute compartment drag parachute compartment door

Abstract

This invention discloses an opening device and method for using a drag parachute compartment door. The opening device includes: a door, a drive mechanism, and a latch mechanism. The door is installed at the opening of the drag parachute placement slot to close the opening. The drive mechanism is mounted on the front wall panel of the drag parachute placement slot via its internal bracket. The latch mechanism is installed through the door along the flight direction, and one end of the latch mechanism is associated with the drive mechanism, so that the drive mechanism controls the latch mechanism to open and close the door. The latch mechanism includes: a front lock seat and a rear lock, which are correspondingly installed on the inner sides of the front and rear wall panels of the drag parachute placement slot. The invention comprises a locking pin assembly that runs along the flight path through the hatch. The front locking pin of the assembly passes through the front side plate of the inner box-shaped component of the hatch and inserts into the front locking seat. The rear locking pin passes through the rear side plate of the inner box-shaped component of the hatch and inserts into the rear locking seat. Both the front and rear locking pins are hinged to a central crank via a hinged connecting rod. A compression spring is fitted onto the front locking pin. One end of the spring is fixed to a designated axial position on the front locking pin, and the other end is fixed to a designated position on the hatch via a support. The spring provides a clamping force to the front and rear locking pins, pushing the front locking pin into the front locking seat and the rear locking pin into the rear locking seat, thus locking the hatch when closed. This invention solves the problems of existing drag chute hatch opening devices, which are mostly hydraulic or pneumatic, resulting in complex structures, large space requirements, and low reliability.

Description

Technical Field

[0001] This invention relates to, but is not limited to, the field of aircraft structural design technology, specifically to an opening device and method for using a lower parachute compartment drag parachute door. Background Technology

[0002] The drag chute in the lower tail section is an aerodynamic deceleration device installed in the drag chute placement slot at the bottom of the aircraft's tail. During landing, the pilot presses the chute deployment button, activating the drag chute compartment door opening mechanism. The door opens, and the drag chute is deployed under its own weight, immediately inflating to generate significant drag. This assists the wheel brakes in slowing the aircraft, reducing the landing roll distance, and extending the lifespan of the wheels and their braking system. The drag chute can also be deployed to abort takeoff in case of a failed takeoff, ensuring flight safety.

[0003] Currently, most existing drag chute door opening devices, both domestically and internationally, are hydraulic or pneumatic, which suffer from problems such as complex structure, large space occupation, and low reliability. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned technical problems. This invention provides an opening device and method for a drag parachute cabin door, which solves the problems that existing drag parachute cabin door opening devices are mostly hydraulic or pneumatic, and have complex structures, large space occupation, and low reliability.

[0005] The technical solution of the present invention: In a first aspect, the present invention provides an opening device for a drag parachute compartment door, wherein a drag parachute placement slot 1 embedded in the fuselage is provided at the door opening position of the aircraft body for placing the drag parachute; the opening device for the drag parachute compartment door includes: a door 2, a drive mechanism 3, and a door bolt mechanism 4.

[0006] The hatch 2 is installed at the opening of the drag parachute placement slot 1 to close the opening of the drag parachute placement slot 1. The drive mechanism 3 is installed on the front wall of the drag parachute placement slot 1 through its internal bracket 10. The door bolt mechanism 4 is installed inside the hatch 2 along the flight direction, and one end of the door bolt mechanism 4 is associated with the drive mechanism 3 so that the door can be opened and closed by controlling the door bolt mechanism 4 through the drive mechanism 3.

[0007] The door bolt mechanism 4 includes: a front lock seat 14 and a rear lock seat 27 correspondingly installed on the inner sides of the front and rear walls of the drag umbrella placement slot 1; a locking pin assembly that passes through the cabin door 2 along the flight direction; the front locking pin 19 in the locking pin assembly passes through the front side plate of the inner box-shaped part of the cabin door 2 and is inserted into the front lock seat 14; the rear locking pin 25 in the locking pin assembly passes through the rear side plate of the inner box-shaped part of the cabin door 2 and is inserted into the rear lock seat 27; the front locking pin 19 and the rear locking pin 25 are respectively hinged to the intermediate crank 23 by a hinged connecting rod; and the front locking pin 19 is fitted with a compression spring 17; one end of the compression spring 17 is fixedly connected to a designated position in the axial direction of the front locking pin 19, and the other end is fixed to a designated position in the cabin door 2 by a support; the compression spring 17 provides a clamping force to the front locking pin 19 and the rear locking pin 25 to push the front locking pin 19 into the front lock seat 14 and the rear locking pin 25 into the rear lock seat 27, thereby achieving the locked state when the cabin door 2 is closed.

[0008] Optionally, the opening device for the lower parachute compartment drag parachute compartment door as described above,

[0009] The hatch 2 is installed at the opening of the drag umbrella placement slot 1 via a hinge, and the hatch includes an inner box-shaped component, an outer skin, and a partition disposed between the inner box-shaped component and the outer skin. The inner box-shaped component is formed by pressing an aluminum alloy plate; the plate bending partition arranged between the inner box-shaped component and the outer skin serves as a reinforcement.

[0010] Optionally, the door bolt mechanism 4 of the lower parachute compartment drag parachute compartment door opening device described above includes: a front lock seat 14, a front lock pin support 15, a retaining ring 16, a compression spring 17, a limiting support 18, a front lock pin 19, a front connecting rod 20, a crank 23, a rear connecting rod 24, a rear lock pin 25, a rear lock pin support 26, and a rear lock seat 27 arranged sequentially from front to rear along the flight direction.

[0011] Among them, the front locking seat 14 and the rear locking seat 27 are respectively fixedly installed on the inner side of the front and rear wall panels of the drag umbrella placement slot 1, the front locking pin support 15 and the rear locking pin support 26 are respectively fixedly installed on the front and rear ends of the inner box-shaped part in the hatch 2, the front end of the front locking pin 19 passes through the through hole of the front locking pin support 15 and moves along the heading in the through holes of the front locking pin support 15 and the front locking seat 14, and the rear locking seat 27 passes through the through hole of the rear locking pin support 26 and moves along the heading in the through holes of the rear locking pin support 26 and the rear locking seat 27.

[0012] The front locking pin 19 is hinged to the front connecting rod 20, the front connecting rod 20 is hinged to the crank 23, the crank 23 is hinged to the rear connecting rod 24, and the rear connecting rod 24 is hinged to the rear locking pin 25, and rotates around the hinge axis.

[0013] The retaining ring 16 is fixedly sleeved on the front locking pin 19 near the front locking pin support 15. The limiting support 18 is sleeved on the outside of the front locking pin 19 through its support hole and fixedly installed on the inner side of the outer skin of the hatch 2 through its base. The compression spring 17 is sleeved on the front locking pin 19 and located between the retaining ring 16 and the limiting support 18. It is used to provide a clamping force to the front locking pin 19 and the rear locking pin 25 to push the front locking pin 19 into the front locking seat 14 and the rear locking pin 25 into the rear locking seat 27, so as to realize the locked state when the hatch 2 is closed.

[0014] Optionally, in the opening device of the lower parachute compartment resistance parachute compartment door as described above, the door bolt mechanism 4 further includes: upper crank support 21 and lower crank support 22.

[0015] The crank 23 includes a crank portion and a shaft portion that extends vertically through the center of the crank portion. One end of the shaft portion is a cylindrical pin for inserting into the center hole of the upper crank support 21. The hexagonal head at the other end of the shaft portion passes through the through hole of the lower crank support 22 and is flush with the outer skin of the hatch 2. The hatch 2 can be manually opened or closed by using a tool to screw the hexagonal head of the shaft portion.

[0016] Optionally, in the opening device of the lower parachute compartment drag parachute compartment door as described above, the drive mechanism 3 includes: a bracket 10, a rocker arm 11, a round head bolt 13, a push rod 12, a stop 8 configured with an L-shaped structure, a top rod 9, a torsion spring 7, and an explosion actuator 6.

[0017] The bracket 10 includes a mounting seat for mounting on the front wall of the resistance umbrella placement slot 1, and a support plate vertically mounted on the mounting seat, with the end of the support plate fixedly mounted on the explosion actuator 6.

[0018] One end of the rocker arm 11 and the corner of the stop 8 are respectively hinged to the support plate of the bracket 10 via a flat-head shaft. The other end of the rocker arm 11 is hinged to a push rod 12 facing the end face of the front locking pin 19 in the bolt mechanism 4 via a flat-head shaft. A retaining plate is provided on the end of the rocker arm 11 facing the explosive actuator 6. A round-head bolt 13 for directly bearing the impact load is installed on the outside of the retaining plate. The piston rod 28 of the explosive actuator 6 is opposite to the end face of the round-head bolt 13. One end of the push rod 9 is hinged to one end of the stop 8 via a flat-head shaft. The flat end of the other end of the push rod 9 passes through the bracket 10. An L-shaped buckle structure that cooperates with the retaining plate is provided on the other end of the stop 8. The torsion spring 7 is installed on the flat-head shaft that rotates around the support plate of the stop 8.

[0019] The drive mechanism 3 is used to generate gas pressure by energizing the electric explosion tube in the explosion actuator 6 during landing and parachute deployment. This gas pressure creates an impact force on the piston rod 28 in the explosion actuator 6, impacting the round-headed bolt 13 mounted on the rocker arm 11. Under the impact force, the rocker arm 11 rotates and drives the push rod 12 to move. This pushes the front locking pin 19 to overcome the clamping force of the compression spring 17 and move it into the hatch 2, thus opening the hatch 2. The latch structure on the stop 8 engages with the latch plate on the rocker arm 11, maintaining the open position of the hatch 2. Before closing the drag parachute hatch, the drive mechanism 3 is used to press the top rod 9 hinged to the stop 8, causing the rocker arm 11 and the push rod 12 connected to the rocker arm 11 to return to their pre-impact position.

[0020] Optionally, in the opening device of the lower parachute compartment drag parachute compartment door as described above, the opening device specifically includes: two compartment doors 2 installed on the left and right along the flight direction, the opening position of the drag parachute placement slot 1 is closed by the two compartment doors 2, and in the closed state, the right compartment door is supported on the inside of the left compartment door by a straight profile, and the straight profile is riveted together with the inner and outer skin of the right compartment door along the edge of the right compartment door.

[0021] The bolt mechanism 4 is installed inside the left hatch 2 along the flight direction. After the left hatch is opened by the drive mechanism 3 and the bolt mechanism 4, the right hatch is opened by gravity.

[0022] Optionally, the opening device for the lower parachute compartment drag parachute compartment door as described above further includes: a support mechanism 5;

[0023] One end of the support mechanism 5 is installed on the rear wall of the drag umbrella placement slot 1, and the other end is installed on the hatch 2, with each hatch equipped with a set of support mechanisms 5.

[0024] Optionally, in the opening device of the lower parachute compartment resistance parachute compartment door as described above, each set of support mechanism 5 includes: a support 33, a telescopic pull rod 29, a spring 30, a triangular rocker arm 31, and a connecting rod 32.

[0025] One end of the telescopic rod 29 and the first end of the triangular rocker arm 31 are respectively mounted on the rear wall of the drag umbrella placement slot 1 through a hinged support 33. The other end of the telescopic rod 29 is hinged to the second end of the triangular rocker arm 31, and the third end of the triangular rocker arm 31 is hinged to one end of the connecting rod 32. The other end of the connecting rod 32 is mounted on the inner wall of the hatch 2 through a hinged support 33. A spring 30 is connected between the two ends of the telescopic rod 29.

[0026] Each set of support mechanisms 5 is used to support the hatch 2 in the open position through the support structure formed by the telescopic rod 29, the triangular rocker arm 31, the connecting rod 32 and the support 33 when the hatch 2 is lowered, so as to prevent the hatch from being damaged by left and right swinging.

[0027] Optionally, in the opening device of the lower parachute compartment drag parachute compartment door as described above, the telescopic rod 29 includes: a sleeve 35, a core rod 36, a first rod joint 34, and a second rod joint 37.

[0028] One end of the sleeve 35 is embedded in the first tie rod joint 34, the other end of the sleeve is sleeved outside one end of the core rod 36, and the other end of the core rod 36 is embedded in the second tie rod joint 37.

[0029] Secondly, embodiments of the present invention also provide a method for using an opening device for a lower parachute compartment drag parachute door, comprising: opening or closing the drag parachute compartment door using the opening device for the lower parachute compartment drag parachute door as described in any of the preceding claims, including:

[0030] During flight, the front locking pin 19 and the rear locking pin 25 are inserted into the front locking seat 14 and the rear locking seat 27 respectively under the spring force of the compression spring 17, so as to reliably close the cabin door.

[0031] When the aircraft lands and deploys the parachute, the pilot presses the parachute deployment button. The electric explosion tube in the explosion actuator 6 of the drive mechanism 3 is energized and explodes, generating gas pressure. This pressure is converted into an impact force through the piston rod 28 in the explosion actuator 6. The impact force strikes the round head bolt 13 mounted on the rocker arm 11. The rocker arm 11 rotates under the impact force, causing the push rod 12 to move forward and push the front locking pin 19. This drives the door bolt mechanism 4 to open the drag parachute compartment door. The stop 8 rotates under the action of the torsion spring 7 to lock the rocker arm 11, preventing the rocker arm 11 from returning to its position before the impact.

[0032] During the opening of the hatch, the push rod 12 on the drive mechanism 3 impacts the front end of the front locking pin 19, causing the front locking pin 19 to move backward. The front end of the front locking pin 19 disengages from the front locking seat 14 and retracts into the hatch 2. At the same time, under the drive of the front connecting rod 20, the crank 23 rotates around the upper crank support 21 and the lower crank support 22, thereby causing the rear locking pin 25 to move forward under the drive of the rear connecting rod 24, disengage from the rear locking seat 27 and retract into the hatch. The door bolt mechanism 4 opens along with the hatch 2 around the hinge on the drag umbrella placement slot 1.

[0033] When the hatch 2 is opened, under the spring force of the spring 30, the triangular rocker arm 31 rotates, causing the connecting rod 32 to be lowered along with the hatch 2, and "locking" the drag umbrella hatch in the open position;

[0034] Before closing the drag parachute compartment door, press the top rod 9 hinged to the stop 8 to return the rocker arm 11 and the push rod 12 connected to the rocker arm 11 to the position before the impact.

[0035] When closing the drag parachute hatch, manually push the connecting rod 32 until it passes the "dead point" and then push the triangular rocker arm 31 to rotate, compressing the spring 30. Then, use a universal socket wrench 38 to hold the hexagonal head on the crank 23 shaft and rotate the socket wrench handle to retract the front and rear locking pins into the hatch under the action of the connecting rod, thus closing the drag parachute hatch.

[0036] The beneficial effects of the present invention: The embodiments of the present invention provide an opening device and a method for using a lower parachute compartment drag parachute compartment door, which have the following beneficial effects:

[0037] 1) The drag chute door opening device has a simple structure, reliable operation, stable performance, convenient installation and maintenance, mature materials and manufacturing processes, and good interchangeability; 2) The door bolt mechanism is installed inside the door on the left side of the drag chute placement slot, without occupying the internal space of the drag chute placement slot; 3) The drive mechanism prevents the rocker arm from returning to the pre-impact position through a stop, ensuring that the drag chute door can be reliably opened when the aircraft lands and deploys the parachute; 4) A compression spring is installed on the locking pin of the door bolt mechanism. The compression spring plays a role in locking, buffering, and limiting. The locking pin is inserted into the lock seat under the spring force of the compression spring, realizing the reliable closing of the door; the compression spring plays a buffering role against the explosive impact force generated by the electric fuel explosive tube, avoiding impact damage to the door and door bolt mechanism; the compression spring is embedded between the retaining ring and the limiting support to limit the locking pin and prevent it from coming out of the support; 5) When the drag chute door is lowered, the support mechanism supports the door in the open position, which can prevent the door from being damaged by left and right swinging; 6) No special tools are required. The door can be closed and opened using a general socket wrench. Attached Figure Description

[0038] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0039] Figure 1 A schematic diagram of the composition and assembly structure of the drag parachute cabin door opening device;

[0040] Figure 2 A schematic diagram of the drive mechanism and door bolt mechanism in the closed and open states of the hatch; Figure 2 Figure a shows the hatch closed, and figure b shows the hatch open.

[0041] Figure 3 A schematic diagram of the support mechanism in the closed and open states of the hatch; Figure 3 Figure a shows the hatch closed, and figure b shows the hatch open.

[0042] Figure 4 This is a schematic diagram of the crank mechanism;

[0043] Figure 5This is a schematic diagram of a telescopic tie rod structure;

[0044] Figure 6 A schematic diagram showing the state of the crank during the cabin door closing process;

[0045] Figure 7 The diagram shows the hatch closed.

[0046] Explanation of markings in the diagram:

[0047] 1. Drag parachute placement slot; 2. Hatch door; 3. Drive mechanism; 4. Door bolt mechanism; 5. Support mechanism; 6. Explosion actuator; 7. Torsion spring; 8. Stop; 9. Push rod; 10. Bracket; 11. Rocker arm; 12. Push rod; 13. Round head bolt; 14. Front lock seat; 15. Front lock pin support; 16. Retaining ring; 17. Compression spring; 18. Limiting support; 19. Front lock pin; 20. Connecting... 21. Upper crank support, 22. Lower crank support, 23. Crank, 24. Connecting rod, 25. Rear locking pin, 26. Rear locking pin support, 27. Rear locking seat, 28. Piston rod, 29. Telescopic pull rod, 30. Spring, 31. Triangular rocker arm, 32. Connecting rod, 33. Support, 34. Pull rod joint, 35. Sleeve, 36. Core rod, 37. Pull rod joint, 38. Sleeve plate. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0049] As explained in the background section, existing drag chute door opening devices are mostly hydraulic or pneumatic, which have problems such as complex structure, large space occupation, and low reliability.

[0050] Low reliability can lead to malfunctions such as accidental parachute opening and failure to open the door, affecting the completion of flight missions. In severe cases, it may even cause runway overrun, resulting in injury to personnel and equipment. Therefore, it is necessary to design a simple, reliable, stable, and easy-to-maintain lower parachute compartment drag chute door opening device to meet the requirements of current high-intensity and high-difficulty flight missions.

[0051] To address the aforementioned problems and design requirements, this invention provides an opening device and method for the drag parachute compartment door of a lower parachute compartment. This opening device ensures that the drag parachute compartment door can be reliably closed during flight to prevent accidental parachute deployment, while also meeting the requirement for rapid opening of the drag parachute compartment door during parachute deployment.

[0052] The present invention provides the following specific embodiments, which can be combined with each other. For the same or similar concepts or processes, they may not be described again in some embodiments.

[0053] Figure 1 This is a schematic diagram illustrating the composition and assembly structure of an opening device for a lower parachute compartment drag parachute door, provided as an embodiment of the present invention. (See attached diagram.) Figure 1 As shown, the opening device for the lower parachute cabin drag parachute cabin door provided in this embodiment of the invention comprises: cabin door 2, drive mechanism 3, door bolt mechanism 4, and support mechanism 5.

[0054] The hatch 2 is installed at the lower part of the drag parachute placement slot 1 via a hinge (the hatch 2 overlaps left and right along the heading; after the left hatch 2 falls, the right hatch falls accordingly). The drive mechanism 3 is installed on the front wall of the drag parachute placement slot 1 via a bracket 10. The door bolt mechanism 4 is installed inside the left hatch 2 of the drag parachute placement slot 1. One end of the support mechanism 5 is connected to the rear wall of the drag parachute placement slot 1, and the other end is connected to the rear of the hatch.

[0055] Two hatches 2 are hinged to the opening of the drag chute placement slot 1. The opening of the drag chute placement slot 1 is closed by the two hatches 2. When closed, the right hatch is supported on the left hatch by a straight profile, which is riveted to the inner and outer skins of the right hatch along its edge. Each hatch consists of an inner box-shaped component, a bulkhead, and an outer skin. The inner box-shaped component is made of pressed aluminum alloy sheet. A bent bulkhead is arranged between the inner box-shaped component and the outer skin for reinforcement.

[0056] The drive mechanism 3 is mounted on the front wall of the resistance umbrella placement slot 1 via the bracket 10, as follows: Figure 2 As shown, the drive mechanism 3 mainly consists of a bracket 10, a rocker arm 11, a round-head bolt 13, a push rod 12, a stop 8, a top rod 9, a torsion spring 7, and an explosive actuator 6. The drive mechanism provides power for the operation of the bolt mechanism 4. The rocker arm 11 and the stop 8 are mounted on the bracket 10 via a flat-head shaft. The top rod 9 is mounted on one end of the stop 8 via a flat-head shaft. The push rod 12 is mounted on the rocker arm 11 via a flat-head shaft. The rocker arm 11, the stop 8, the top rod 9, and the push rod 12 can all rotate around the flat-head shaft. The round-head bolt 13, which directly bears the impact load, is mounted on the rocker arm 11. The torsion spring 7 is mounted on the shaft on which the stop 8 rotates around the bracket 10.

[0057] The door bolt mechanism 4 is installed inside the left hatch 2 of the drag chute placement slot 1, such as... Figure 2As shown, the door bolt mechanism 4 mainly consists of a front lock seat 14, a front lock pin support 15, a front lock pin 19, a retaining ring 16, a compression spring 17, a limiting support 18, a front connecting rod 20, a crank 23, an upper crank support 21, a lower crank support 22, a rear connecting rod 24, a rear lock pin 25, a rear lock pin support 26, and a rear lock seat 27. The door bolt mechanism 4 is used for opening and closing the hatch. The front lock seat 14 and the rear lock seat 27 are respectively fixed to the inner sides of the front and rear bulkheads of the drag chute placement slot 1. The front lock pin support 15 and the rear lock pin support 26 are respectively fixed to the front and rear ends of the inner box-shaped part in the left hatch. The front lock pin 19 and the rear lock pin 25 can move along the course within the through holes of the front lock pin support 15 and the rear lock pin support 26, respectively. The front locking pin 19 is hinged to the front connecting rod 20, the front connecting rod 20 to the crank 23, the crank 23 to the rear connecting rod 24, and the rear connecting rod 24 to the rear locking pin 25, respectively, via hinge shafts and can rotate around these hinge shafts. The crank 23 (e.g., Figure 4 (As shown) The shaft on the crank is fitted into the holes on the upper crank support 21 and the lower crank support 22. The compression spring 17 is mounted on the front locking pin 19 via the retaining ring 16 and the limiting support 18. The compression spring functions as a locking, buffering, and limiting mechanism. Under the spring force of the compression spring 17, the front and rear locking pins are inserted into the front and rear locking seats, achieving reliable closure of the hatch. Marking lines are drawn on the outer skin of the left hatch and the hexagonal head of the crank 23 shaft, as shown. Figure 7 As shown, its function is to check whether the hatch can be reliably closed by observing the relative position of the marking line on the hexagonal head and the marking line on the skin.

[0058] One end of the support mechanism 5 is installed on the rear wall panel of the placement slot 1, and the other end is installed on the hatch 2. Each of the two hatches has one set of support mechanisms 5 installed. Figure 3 As shown, the support mechanism mainly consists of a support 33 and a telescopic tie rod 29 (such as...). Figure 5 As shown, it consists of a sleeve 35, a core rod 36, a pull rod joint 34 and 37, a spring 30, a triangular rocker arm 31, a connecting rod 32, etc. Its function is to support the door in the open position when the drag parachute door is lowered, so as to prevent the door from being damaged due to left and right swinging.

[0059] Based on the opening device for the lower parachute compartment drag parachute door provided in the above embodiments of the present invention, the present invention also provides a method for using the opening device for the lower parachute compartment drag parachute door, including the following steps:

[0060] During flight, the front locking pin 19 and the rear locking pin 25 are inserted into the front locking seat 14 and the rear locking seat 27 respectively under the spring force of the compression spring 17, thus reliably closing the cabin door. When the aircraft lands and deploys the parachute, the pilot presses the parachute deployment button, energizing the electric flare tube in the explosion actuator 6 to generate gas pressure. This pressure is converted into an impact force through the piston rod 28 in the explosion actuator 6, impacting the round-headed bolt 13 mounted on the rocker arm 11. Under the impact force, the rocker arm 11 rotates, causing the push rod 12 to move forward, pushing the front locking pin 19 and driving the door bolt mechanism 4 to open the drag chute cabin door. The stop 8 rotates under the action of the torsion spring 7 to lock the rocker arm 11, preventing the rocker arm 11 from returning to its pre-impact position.

[0061] When the hatch is opened, the push rod 12 on the drive mechanism 3 strikes the front end of the front locking pin 19, causing the front locking pin 19 to move backward. The front end of the front locking pin 19 disengages from the front lock seat 14 and retracts into the hatch 2. Simultaneously, driven by the front connecting rod 20, the crank 23 rotates around the upper crank support 21 and the lower crank support 22, causing the rear locking pin 25 to move forward under the drive of the rear connecting rod 24, disengaging from the rear lock seat 27 and retracting into the hatch. The door bolt mechanism 4 opens along with the hatch 2, rotating around the hinge on the drag parachute placement slot 1. When the hatch 2 is opened, under the spring force of the spring 30, the triangular rocker arm 31 rotates, causing the connecting rod 32 to be in the lowered state along with the hatch 2, thus "locking" the drag parachute hatch in the open position.

[0062] Before closing the drag chute door, press the push rod 9 hinged to the stop 8 to return the rocker arm 11 and the push rod 12 connected to the rocker arm 11 to their pre-impact positions. When closing the drag chute door, gently push the connecting rod 32 through its "dead point" to rotate the triangular rocker arm 31, compressing the spring 30. Simultaneously, use a universal socket wrench 38 to engage the hexagonal head on the crank 23 shaft and rotate the socket wrench handle. Figure 6 As shown, the front and rear locking pins retract into the hatch under the action of the connecting rod, closing the drag chute hatch. Loosening the socket wrench allows the front and rear locking pins to be inserted into the front and rear locking seats under the spring force of the compression spring 17, thus achieving reliable closure of the hatch.

[0063] This invention provides an opening device and method for using a lower parachute compartment drag parachute compartment door, which has the following beneficial effects:

[0064] 1) The drag chute door opening device has a simple structure, reliable operation, stable performance, convenient installation and maintenance, mature materials and manufacturing processes, and good interchangeability; 2) The door bolt mechanism is installed inside the door on the left side of the drag chute placement slot, without occupying the internal space of the drag chute placement slot; 3) The drive mechanism prevents the rocker arm from returning to the pre-impact position through a stop, ensuring that the drag chute door can be reliably opened when the aircraft lands and deploys the parachute; 4) A compression spring is installed on the locking pin of the door bolt mechanism. The compression spring plays a role in locking, buffering, and limiting. The locking pin is inserted into the lock seat under the spring force of the compression spring, realizing the reliable closing of the door; the compression spring plays a buffering role against the explosive impact force generated by the electric fuel explosive tube, avoiding impact damage to the door and door bolt mechanism; the compression spring is embedded between the retaining ring and the limiting support to limit the locking pin and prevent it from coming out of the support; 5) When the drag chute door is lowered, the support mechanism supports the door in the open position, which can prevent the door from being damaged by left and right swinging; 6) No special tools are required. The door can be closed and opened using a general socket wrench.

[0065] While the embodiments disclosed in this invention are as described above, they are merely illustrative of the embodiments to facilitate understanding of the invention and are not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. An opening device for a lower parachute compartment drag parachute compartment door, characterized in that, The aircraft fuselage has a drag chute placement slot (1) embedded in the fuselage at the hatch opening position for placing the drag chute; the opening device of the drag chute hatch of the lower parachute compartment includes: hatch (2), drive mechanism (3), and door bolt mechanism (4). The hatch (2) is installed at the opening of the parachute placement slot (1) to close the opening of the parachute placement slot (1). The drive mechanism (3) is installed on the front wall of the parachute placement slot (1) through its internal bracket (10). The door bolt mechanism (4) is installed inside the hatch (2) along the flight direction, and one end of the door bolt mechanism (4) is associated with the drive mechanism (3) so that the door can be opened and closed by controlling the door bolt mechanism (4) through the drive mechanism (3). The door bolt mechanism (4) includes: a front lock seat (14) and a rear lock seat (27) correspondingly installed on the inner sides of the front and rear bulkheads of the drag chute placement slot (1); a locking pin assembly that passes through the cabin door (2) along the flight direction; the front locking pin (19) in the locking pin assembly passes through the front side plate of the inner box-shaped part of the cabin door (2) and is inserted into the front lock seat (14); the rear locking pin (25) in the locking pin assembly passes through the rear side plate of the inner box-shaped part of the cabin door (2) and is inserted into the rear lock seat (27); the front locking pin (19) and the rear locking pin (25) are respectively connected by a hinge. The connecting rod is hinged to the intermediate crank (23), and the front locking pin (19) is fitted with a compression spring (17). One end of the compression spring (17) is fixedly connected to a designated position in the axial direction of the front locking pin (19), and the other end is fixed to a designated position on the hatch (2) by a support. The compression spring (17) provides a clamping force to the front locking pin (19) and the rear locking pin (25) to push the front locking pin (19) into the front locking seat (14) and the rear locking pin (25) into the rear locking seat (27), thereby achieving the locked state when the hatch (2) is closed.

2. The opening device for the lower parachute compartment drag parachute compartment door according to claim 1, characterized in that, The hatch (2) is installed at the opening of the drag umbrella placement slot (1) by a hinge, and the hatch includes an inner box-shaped part, an outer skin, and a partition between the inner box-shaped part and the outer skin. The inner box-shaped part is formed by pressing an aluminum alloy plate. The plate bending partition arranged between the inner box-shaped part and the outer skin plays a reinforcing role.

3. The opening device for the lower parachute compartment drag parachute compartment door according to claim 2, characterized in that, The bolt mechanism (4) includes: a front lock seat (14), a front lock pin support (15), a retaining ring (16), a compression spring (17), a limit support (18), a front lock pin (19), a front connecting rod 20, a crank (23), a rear connecting rod (24), a rear lock pin (25), a rear lock pin support (26), and a rear lock seat (27) arranged sequentially from front to back along the flight direction. Among them, the front lock seat (14) and the rear lock seat (27) are respectively fixedly installed on the inner side of the front and rear wall panels of the drag umbrella placement slot (1), the front lock pin support (15) and the rear lock pin support (26) are respectively fixedly installed on the front and rear ends of the inner box-shaped part in the cabin door (2), the front end of the front lock pin (19) passes through the through hole of the front lock pin support (15) and moves along the heading in the through holes of the front lock pin support (15) and the front lock seat (14), and the rear lock seat (27) passes through the through hole of the rear lock pin support (26) and moves along the heading in the through holes of the rear lock pin support (26) and the rear lock seat (27). The front locking pin (19) is hinged to the front connecting rod 20, the front connecting rod 20 is hinged to the crank (23), the crank (23) is hinged to the rear connecting rod (24), and the rear connecting rod (24) is hinged to the rear locking pin (25) respectively, and rotates around the hinge axis. The retaining ring (16) is fixedly sleeved on the front locking pin (19) near the front locking pin support (15). The limiting support (18) is sleeved on the outside of the front locking pin (19) through its support hole and fixedly installed on the inner side of the outer skin of the hatch (2) through its base. The compression spring (17) is sleeved on the front locking pin (19) and located between the retaining ring (16) and the limiting support (18). It is used to provide clamping force to the front locking pin (19) and the rear locking pin (25) to push the front locking pin (19) into the front locking seat (14) and push the rear locking pin (25) into the rear locking seat (27) to realize the locked state when the hatch (2) is closed.

4. The opening device for the lower parachute compartment drag parachute compartment door according to claim 3, characterized in that, The bolt mechanism (4) further includes: upper crank support (21) and lower crank support (22). The crank (23) includes a crank section and a shaft section that extends vertically through the center of the crank section. One end of the shaft section is a cylindrical pin, which is used to insert into the center hole of the upper crank support (21). The hexagonal head at the other end of the shaft section passes through the through hole of the lower crank support (22) and is flush with the outer skin of the hatch (2). The hatch (2) can be manually opened or closed by using a tool to screw the hexagonal head of the shaft section.

5. The opening device for the lower parachute compartment drag parachute compartment door according to claim 3, characterized in that, The drive mechanism (3) includes: bracket (10), rocker arm (11), round head bolt (13), push rod (12), stop (8) configured as L-shaped structure, top rod (9), torsion spring (7), and explosion actuator (6); The bracket (10) includes a mounting seat for mounting on the front wall of the resistance umbrella placement slot (1) and a support plate vertically mounted on the mounting seat, with the end of the support plate fixedly mounted on the explosion actuator (6). One end of the rocker arm (11) and the corner of the stop (8) are respectively hinged to the support plate of the bracket (10) by a flat-head shaft. The other end of the rocker arm (11) is hinged to a push rod (12) facing the end face of the front locking pin (19) in the bolt mechanism (4). A card plate is provided on the end of the rocker arm (11) facing the explosive actuator (6). A round head bolt (13) for directly bearing the impact load is installed on the outside of the card plate. The piston rod (28) of the explosive actuator (6) is opposite to the end face of the round head bolt (13). One end of the push rod (9) is hinged to one side of the stop (8) by a flat-head shaft. The flat end of the other end of the push rod (9) passes through the bracket (10). An L-shaped buckle structure that cooperates with the card plate is provided on the other side of the stop (8). The torsion spring (7) is installed on the flat-head shaft that rotates around the support plate of the stop (8). The drive mechanism (3) is used to generate gas pressure by energizing the electric explosion tube in the explosion actuator (6) during landing and parachute deployment, forming an impact force on the piston rod (28) in the explosion actuator (6), impacting the round head bolt (13) installed on the rocker arm (11), causing the rocker arm (11) to rotate under the impact force and drive the push rod (12) to move, pushing the front locking pin (19) to overcome the clamping force of the compression spring (17) and move into the cabin door (2), realizing the opening of the cabin door (2), and the buckle structure on the stop (8) is locked on the plate of the rocker arm (11) to keep the cabin door (2) in the open position; it is also used to press the top rod (9) hinged on the stop (8) before closing the drag parachute cabin door, so that the rocker arm (11) and the push rod (12) connected to the rocker arm (11) return to the position before impact by pressing the top rod (9) hinged on the stop (8).

6. The opening device for the lower parachute compartment drag parachute compartment door according to any one of claims 1 to 5, wherein the opening device specifically includes: Two hatches (2) are installed on the left and right sides along the heading. The opening of the drag parachute placement slot (1) is closed by the two hatches (2). When the hatches are closed, the right hatch is supported on the inside of the left hatch by a straight profile. The straight profile is riveted to the inner and outer skin of the hatch along the edge of the right hatch. The door bolt mechanism (4) is installed in the left cabin door (2) along the flight direction. After the left cabin door is opened by the drive mechanism (3) and the door bolt mechanism (4), the right cabin door is opened by gravity.

7. The opening device for the lower parachute compartment drag parachute compartment door according to claim 6, characterized in that, Also includes: Supporting structure (5); One end of the support mechanism (5) is installed on the rear wall of the drag umbrella placement slot (1), and the other end is installed on the hatch (2), and each hatch is equipped with a set of support mechanisms (5).

8. The opening device for the lower parachute compartment drag parachute compartment door according to claim 7, characterized in that, Each support mechanism (5) includes: a support (33), a telescopic rod (29), a spring (30), a triangular rocker arm (31), and a connecting rod (32); One end of the telescopic rod (29) and the first end of the triangular rocker arm (31) are respectively mounted on the rear wall of the drag umbrella placement slot (1) through a hinged support (33). The other end of the telescopic rod (29) is hinged to the second end of the triangular rocker arm (31), and the third end of the triangular rocker arm (31) is hinged to one end of the connecting rod (32). The other end of the connecting rod (32) is mounted on the inner wall of the hatch (2) through a hinged support (33). A spring (30) is connected between the two ends of the telescopic rod (29). Each set of support mechanisms (5) is used to support the hatch (2) in the open position through the support structure formed by the telescopic rod (29), the triangular rocker arm (31), the connecting rod (32) and the support (33) when the hatch (2) is lowered, so as to prevent the hatch from being damaged by left and right swinging.

9. The opening device for the lower parachute compartment drag parachute compartment door according to claim 8, characterized in that, The telescopic rod (29) includes: a sleeve (35), a core rod (36), a first rod connector (34), and a second rod connector (37). One end of the sleeve (35) is embedded in the first tie rod joint (34), the other end of the sleeve is sleeved outside one end of the core rod (36), and the other end of the core rod (36) is embedded in the second tie rod joint (37).

10. A method of using an opening device for a lower parachute compartment drag parachute compartment door, characterized in that, The method of using the opening device of the lower parachute compartment drag parachute compartment door as described in any one of claims 1 to 9 to open or close the drag parachute compartment door includes: During flight, the front locking pin (19) and the rear locking pin (25) are inserted into the front locking seat (14) and the rear locking seat (27) respectively under the spring force of the compression spring (17) to achieve reliable closing of the cabin door; When the aircraft lands and deploys the parachute, the pilot presses the parachute deployment button. The electric explosion tube in the explosion actuator (6) of the drive mechanism (3) is energized and explodes, generating gas pressure. This pressure is converted into an impact force through the piston rod (28) in the explosion actuator (6). The impact force strikes the round head bolt (13) mounted on the rocker arm (11). Under the action of the impact force, the rocker arm (11) rotates, driving the push rod (12) to move forward and push the front locking pin (19). This drives the door bolt mechanism (4) to open the drag parachute compartment door. The stop (8) rotates under the action of the torsion spring (7) to lock the rocker arm (11) and prevent the rocker arm (11) from returning to the position before the impact. During the opening of the hatch, the push rod (12) on the drive mechanism (3) impacts the front end of the front locking pin (19), the front locking pin (19) moves backward, and the front end of the front locking pin (19) disengages from the front lock seat (14) and retracts into the hatch (2). At the same time, under the drive of the front connecting rod 20, the crank (23) rotates around the upper crank support (21) and the lower crank support (22), thereby causing the rear locking pin (25) to move forward under the drive of the rear connecting rod (24), disengage from the rear lock seat (27) and retract into the hatch. The door bolt mechanism (4) opens along with the hatch (2) around the hinge on the drag umbrella placement slot (1). When the hatch (2) is opened, under the action of the spring force of the spring (30), the triangular rocker arm (31) rotates, so that the connecting rod (32) is in the lowered state along with the hatch (2), and the drag umbrella hatch is "locked" in the open position; Before closing the drag parachute door, press the push rod (9) hinged to the stop (8) to return the rocker arm (11) and the push rod (12) connected to the rocker arm (11) to the position before the impact; When closing the drag parachute hatch, manually push the connecting rod (32) to pass the "dead point" and then push the triangular rocker arm (31) to rotate, compressing the spring (30). Use a universal socket wrench (38) to hold the hexagonal head on the crank (23) shaft and rotate the socket wrench handle to retract the front and rear locking pins into the hatch under the action of the connecting rod, thus closing the drag parachute hatch.

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