A driving and retracting device for a spatially deployable boom with bistable characteristics

Abstract

The present invention relates to the technical field of new composite material pod rods, and specifically to a driving and folding device for a space-expandable boom with a bistable characteristic, comprising an outer frame of the device, an outer support shaft arranged on the outer frame of the device, and a space-expandable boom wound around the outer support shaft, wherein a driving motor is arranged at the center of the outer frame of the device, a driving gear is arranged on the motor shaft of the driving motor, a group of driven gears are arranged inside the outer frame of the device on the outside of the driving gear, and a group of the driven gears are respectively meshed with the driving gears, and the driven gears are respectively connected to the outer support shaft by keys. The present invention arranges a driving motor and uses gear transmission to realize the transmission of torque to transform multiple pod rods from a curled state to an unfolded state, so that the solar sail support boom can be quickly, smoothly and smoothly unfolded in space.

Description

Technical Field

[0001] The invention relates to the technical field of novel composite material bean pod rods, and in particular to a driving and retracting device of a spatially deployable suspension rod with a bistable characteristic. Background Art

[0002] Solar sail booms made of carbon fiber composite materials are superior to traditional metal booms in various structural parameters such as weight and volume. At present, solar sail booms with pod-shaped cross-sections are more widely used than booms with other cross-sections and are the first candidate for deployable booms. However, there are not many domestic pod-shaped booms, and there are also problems such as low efficiency of traditional preparation processes. At present, my country's aerospace industry is developing rapidly, especially in small aerospace-grade spacecraft. Composite materials have broad application prospects in the field of aerospace. In order to meet the requirements of light weight and small size of small spacecraft, carbon fiber composite materials have become a recognized ideal material for deployable aerospace structures. Common solar sail booms are made of composite materials with carbon fiber epoxy resin as the base. Compared with traditional metal composite materials, they have the advantages of light weight, high specific strength and stiffness. The current preparation method of pod-shaped booms is as follows: Since the cross-sectional shape of the pod-shaped boom is required and designed, different molds are required for cross-sectional shapes of different shapes. The bean pod pole can be divided into two symmetrical shell structures, each of which is cut from carbon fiber prepreg. After cutting, it is laid on the mold surface, and a layer of polytetrafluoroethylene cloth and breathable felt are laid on it. Then another matching mold is pressed on the breathable felt, and the mold is sent into the autoclave for high temperature and high pressure curing. Finally, after cooling to room temperature, half of the bean pod pole can be taken out, and then the two halves of the bean pod pole are glued together through a film to obtain a complete bean pod pole. For this preparation method, when preparing super-long bean pod poles, problems such as weak bonding and complicated process will occur. In order to solve such problems, this paper invents a new preparation method for bean pod poles, which has high practical significance and use value. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a driving and retracting device for a spatially deployable boom with a bistable characteristic, which is rationally designed and integrally formed.

[0004] The technical solution of the present invention is as follows:

[0005] A driving and folding device for a spatially deployable boom with a bistable characteristic comprises an outer frame of the device, an outer support shaft arranged on the outer frame of the device, and a spatially deployable boom wound around the outer support shaft, wherein a driving motor is arranged at the center of the outer frame of the device, a driving gear is arranged on the motor shaft of the driving motor, a group of driven gears are arranged inside the outer frame of the device on the outside of the driving gear, and a group of the driven gears are respectively meshed with the driving gears, and the driven gears are respectively connected to the outer support shaft through keys.

[0006] Furthermore, a fixed shaft is provided on the outer frame of the device, the outer support shaft is a hollow shaft, and the outer support shaft is sleeved on the fixed shaft, and the outer support shaft and the fixed shaft are supported by bearings.

[0007] Furthermore, a guide wheel group is provided on the outer frame of the device at a position corresponding to the driven gear, and the guide wheel group includes a main guide wheel and a secondary guide wheel. A gap is provided between the main guide wheel and the secondary guide wheel for allowing a space for a deployable boom to pass through.

[0008] Furthermore, a locking device is provided on the outer frame of the device, and the locking device includes a locking spring and a locking slide rod. The locking slide rod is arranged between two adjacent driven gears in the circumferential direction. A sliding groove for moving the locking slide rod is provided on the outer frame of the device, and the locking spring is arranged between the locking slide rods in opposite positions.

[0009] Furthermore, the space can unfold the suspension rod into a pod rod.

[0010] Furthermore, the preparation process steps of the bean pod stalks are as follows:

[0011] 1) Cutting carbon fiber prepreg: Cut the prepreg into the set length, width and fiber angle according to the requirements;

[0012] 2) Pre-laying prepreg: lay several layers of prepreg on a flat plate with a release cloth. When laying the prepreg, first wipe the surface of the flat plate with acetone to remove surface dust and impurities. After the acetone evaporates, lay the prepreg on the surface of the flat plate, tear off the film on the surface of the prepreg, and compact it with a heavy object to make each layer of prepreg completely fit together;

[0013] 3) Laying prepreg: tear off the prepreg laid on the flat plate, stick the lower half of the prepreg on the lower mold, place the demoulding cloth on the prepreg and put the inner core on the demoulding cloth, and place the demoulding cloth on the upper surface of the inner core. Finally, stick the upper half of the prepreg tightly on the upper mold, and then cover the upper mold.

[0014] 4) Heat and cure: place the laid prepreg together with the mold into an autoclave, set the autoclave temperature to 150-200°C, and the time to 150-180 minutes.

[0015] 5) Finally, cool to room temperature, pull out the inner core and take out the product.

[0016] Furthermore, in the step 3), in order to compress the upper and lower molds tightly, multiple layers of release cloth may be provided to increase the laying thickness.

[0017] Furthermore, in the step 3), the core adopts a high temperature resistant air-filled inner cavity or a high temperature resistant silica gel body.

[0018] Furthermore, in the step 3), the upper and lower molds are made of carbon fiber reinforced materials.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1) The preparation of the bean pod stem can be completed in one step by providing an inner cavity core, which actually avoids the complexity of the process and the cross-section effect of the integrated molding is better.

[0021] 2) By setting up a driving motor and using gear transmission to realize torque transmission, multiple pod rods are transformed from a curled state to an unfolded state, so that the solar sail support boom can be unfolded quickly, smoothly and smoothly in space. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the outer frame structure of the device of the present invention;

[0024] Figure 3 It is a schematic diagram of the internal structure of the present invention;

[0025] Figure 4 It is a schematic diagram of the structure of the space-expandable boom with bistable characteristics in the expanded state of the present invention;

[0026] Figure 5 It is a schematic diagram of the structure of the space-expandable suspension rod with bistable characteristics in the folded state of the present invention;

[0027] Figure 6 It is a schematic diagram of the mold structure of the present invention;

[0028] In the figure: 1. device outer frame; 101. slide; 2. drive motor; 201. upper part of spatially expandable boom; 202. lower part of spatially expandable boom; 3. locking device; 301. locking spring; 302. locking slide; 4. motor shaft; 5. driving gear; 6. driven gear; 7. guide wheel; 8. spatially expandable boom; 9. main guide wheel; 10. fixed shaft; 11. bearing; 12. external support shaft; 13. key; 14. lower mold; 15. upper mold; 16-inner core. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with the accompanying drawings.

[0030] Example: Figure 1-6 As shown, the spatially expandable suspension rod 8 is a pod-shaped rod, that is, a suspension rod with a pod-shaped cross section.

[0031] The preparation process steps of bean pod stalks are as follows:

[0032] 1) Cutting carbon fiber prepreg: Cut the prepreg into the length, width and fiber angle we need according to our needs. Usually the cutting is done by hand. If conditions permit, you can buy a cutting machine, so that the size and outline of the cut will be more precise and neat.

[0033] 2) Pre-laying prepreg: Since we may need several layers of prepreg, laying them separately on arcs or other irregular surfaces will inevitably cause errors, and a layer of prepreg is very thin and it is easy to tear the fiber cloth during the laying process. So first lay several layers of prepreg on a flat plate with a release cloth. When laying the prepreg, first wipe the surface of the flat plate with acetone to remove surface dust and impurities. After the acetone evaporates, gently lay the prepreg on the surface of the flat plate, tear off the film on the surface of the fiber cloth and compact it with a heavy object to make each layer of prepreg fit completely.

[0034] 3) Laying prepreg: Gently tear off the prepreg laid on the flat plate, stick the lower half of the pod pole on the concave mold of the mold, arrange the demoulding on the prepreg, and place the inflated high-temperature resistant inflatable inner cavity on the demoulding cloth. The role of the inflated inner cavity here is to make its lower surface as the concave mold and the upper surface as the convex mold of the upper mold. At the same time, arrange the demoulding on the upper surface of the air cavity, and finally stick the upper half of the prepreg tightly to the upper mold. Then cover the upper mold. Note that the flange parts of the upper and lower prepregs need to be pressed tightly. If you are not sure, you can lay a thicker demoulding cloth on the flange part to compact it. The inflatable inner cavity here can also be replaced by other materials that are easy to form, high temperature resistant and easy to be pulled out from the mold, such as high temperature resistant silicone. If it can be pulled out smoothly, it is also OK. Note: The mold here is preferably made of carbon fiber reinforced material. First, the structure is light and easy to make extra-long pod poles. Second, the thermal expansion coefficients of metal materials and carbon fiber materials are different. When heated in the furnace, thermal stress will be generated, which will cause the structure to deform and affect the performance.

[0035] 4) Heating and curing: Place the laid prepreg together with the mold into an autoclave. The autoclave temperature is generally set at 180 degrees Celsius for 180 minutes.

[0036] 5) Finally, cool to room temperature: remove the air in the high temperature resistant inflatable inner cavity or remove the high temperature resistant silica gel and take out the pod stem.

[0037] In view of the actual use of the pod pole, in addition to the main deployable pod-shaped support boom, the solar sail spacecraft also needs a driving device to complete the smooth deployment of the solar sail support boom in space through the signal from the ground. Therefore, according to the actual needs of the deployment of the solar sail spacecraft, a driving and retracting device that can freely switch between the two states of the pod pole is designed. The idea of ​​this device is mainly to use a motor drive, and to achieve torque transmission through gear transmission to transform the pod pole from the curled state to the deployed state. The specific structure is as follows:

[0038] A driving and retracting device for a spatially deployable boom with a bistable characteristic comprises an outer frame 1, a slide 101, a driving motor 2, a locking device 3, a locking spring 301, a locking slide bar 302, a motor shaft 4, a driving gear 5, a driven gear 6, a guide wheel 7, a spatially deployable boom 8, a main guide wheel 9, a fixed shaft 10, a bearing 11, an outer support shaft 12 and a key 13;

[0039] An outer support shaft 12 is arranged on the outer frame 1 of the device. The spatially expandable suspension rod 8 has a bistable characteristic and is wound around the outer support shaft 12. A driving motor 2 is provided at the center of the outer frame 1 of the device. A driving gear 5 is provided on the motor shaft 4 of the driving motor 2. Four driven gears 6 are provided on the outside of the driving gear 5 inside the outer frame 1 of the device, and a group of the driven gears 6 are respectively engaged with the driving gear 5 to output one torque as four torques to control the winding and unfolding of the four pod rods 8. The driven gears 6 are respectively connected to the outer support shaft 12 through keys 13. The outer support shaft 12 is mainly used to fix one end of the pod rod and belongs to the contact part. The winding and unfolding are achieved by directly outputting torque.

[0040] In some embodiments, a fixed shaft 10 is provided on the outer frame 1 of the device, and the outer support shaft 12 is a hollow shaft, and the outer support shaft 12 is sleeved on the fixed shaft 10 to play a positioning role. The outer support shaft 12 and the fixed shaft 10 are supported by bearings 11.

[0041] In some embodiments, the guide wheel group is provided on the outer frame 1 of the device at a position corresponding to the driven gear 6, and the guide wheel group includes a main guide wheel 9 and a secondary guide wheel 7, and a gap is provided between the main guide wheel 9 and the secondary guide wheel 7 for the space to allow the deployable suspension rod 8 to pass through. Since there is a transition area between the curled state and the deployed state of the pod rod, the strain energy will change in the transition area. At this time, the main guide wheel 9 and the secondary guide wheel 7 are installed in the transition area, which can limit the deployment direction of the pod rod and guide the pod rod to change from the transition area to the fully deployed state, and at the same time control the distance between the main and secondary guide wheels and the distance from the central rotating axis, so as to convert the excess strain energy generated in the deployment process into the strain energy of the main and secondary guide wheels and consume it, and avoid the abnormal deployment due to excessive strain energy during deployment.

[0042] In some embodiments, a locking device 3 is also provided on the outer frame 1 of the device, and the locking device 3 includes a locking spring 301 and a locking slide bar 302. The locking slide bar 302 is arranged between two adjacent driven gears 6 in the circumferential direction. The outer frame 1 of the device is provided with a slide groove 101 for moving the locking slide bar 302, and the locking spring 301 is arranged between two locking slide bars 302 in opposite positions. Since the pod rods used in space are basically super-long, the curling radius after unfolding is quite different from that before unfolding, and the rolling radius will decrease with the increase of the unfolded part. If the curling radius changes, and no restraining force is applied externally, the self-contact friction force of the pod rod per circle may decrease, so that it cannot be unfolded normally. Therefore, a locking device is added to the driving device, and the tension force restored to the original length by the locking spring 1 is the locking force, which locks the unexpanded part of the pod rod on the support shaft through the locking slide bar 3. When the curling radius of the pod rod changes, the slide bar will change accordingly to achieve the purpose of locking.

Claims

1. A driving and retracting device for a space-expandable boom with bistable characteristics, characterized in that: The invention comprises an outer frame (1) of the device, an outer support shaft (12) arranged on the outer frame (1) of the device, and a space-expandable suspension rod (8) arranged around the outer support shaft (12); a driving motor (2) is arranged at the center of the outer frame (1); a driving gear (5) is arranged on the motor shaft (4) of the driving motor (2); a group of driven gears (6) are arranged inside the outer frame (1) on the outside of the driving gear (5), and the group of driven gears (6) are respectively meshed with the driving gear (5); and the driven gears (6) are respectively connected to the outer support shaft (12) through keys (13); The space-expandable suspension rod (8) is a pod rod; The preparation process steps of the bean pod stalk are as follows: 1) Cutting carbon fiber prepreg: Cut the prepreg into the set length, width and fiber angle according to the requirements; 2) Pre-laying prepreg: lay several layers of prepreg on a flat plate with a release cloth. When laying the prepreg, first wipe the surface of the flat plate with acetone to remove surface dust and impurities. After the acetone evaporates, lay the prepreg on the surface of the flat plate, tear off the film on the surface of the prepreg, and compact it with a heavy object to make each layer of prepreg completely fit together; 3) Laying prepreg: tear off the prepreg laid on the flat plate, stick the lower half of the prepreg on the lower mold, place the demoulding arrangement on the prepreg and put the inner core on the demoulding cloth, and place the demoulding arrangement on the upper surface of the inner core, and finally stick the upper half of the prepreg tightly on the upper mold, and then cover the upper mold; 4) Heat and cure, place the laid prepreg together with the mold into an autoclave, set the autoclave temperature to 150-200°C, and the time to 150-180 minutes; 5) Finally, cool to room temperature, pull out the inner core and take out the product.

2. The driving and retracting device of a space-expandable boom with bistable characteristics according to claim 1, characterized in that: A fixed shaft (10) is provided on the outer frame (1) of the device, the outer support shaft (12) is a hollow shaft, and the outer support shaft (12) is sleeved on the fixed shaft (10), and the outer support shaft (12) and the fixed shaft (10) are supported by a bearing (11).

3. The driving and retracting device of a space-expandable boom with bistable characteristics according to claim 1, characterized in that: A guide wheel group is provided on the outer frame (1) of the device at a position corresponding to the driven gear (6), and the guide wheel group includes a main guide wheel (9) and a secondary guide wheel (7). A gap is provided between the main guide wheel (9) and the secondary guide wheel (7) for allowing a space for a deployable boom (8) to pass through.

4. The driving and retracting device of a space-expandable boom with bistable characteristics according to claim 1, characterized in that: The outer frame (1) of the device is also provided with a locking device (3), the locking device (3) comprising a locking spring (301) and a locking slide bar (302), the locking slide bar (302) being arranged between two adjacent driven gears (6) in the circumferential direction, the outer frame (1) of the device is provided with a slide groove (101) for moving the locking slide bar (302), and the locking spring (301) being arranged between two locking slide bars (302) in opposite positions.

5. The driving and retracting device of a space-expandable boom with bistable characteristics according to claim 1, characterized in that: In the step 3), in order to press the upper and lower molds tightly, multiple layers of release cloth can be provided to increase the laying thickness.

6. The driving and retracting device of a space-expandable boom with bistable characteristics according to claim 1, characterized in that: In the step 3), the inner core is a high temperature resistant air-filled inner cavity or a high temperature resistant silica gel.

7. The driving and retracting device of a space-expandable boom with bistable characteristics according to claim 1, characterized in that: In the step 3), the upper and lower molds are made of carbon fiber reinforced material.

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