Maintenance method for arms of industrial unmanned aerial vehicle
By dimensional compensation and local reinforcement of the damage areas of the industrial drone arm, the problem of difficult arm fracture is solved, and the maintenance effect of low-cost and low-energy consumption is achieved, which is in line with the sustainable development of the low-altitude economy.
Patent Information
- Application Number
- CN202510761246.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-09
- Publication Date
- 2025-07-22
AI Technical Summary
The industrial drone arm consists of carbon fiber composite support rods and rotor end connection sleeves, which are difficult to repair when broken, and the replacement structure is high and does not conform to the sustainable development of the low-altitude economy.
By compensating the damage area with dimensions, combining the patch and reinforcement sheet laying, the internal shape is partially strengthened, the structural repair of the machine arm is completed, including circumcision of the damage area, laying the reinforcement sheet prepreg and patch prepreg, embedded in the snap position of the rotor end connection sleeve and encapsulating and curing.
The repair of traditional arm fracture damage has been achieved, solid waste caused by part replacement is avoided, material and energy consumption is reduced, and maintenance costs and carbon emissions are significantly reduced.
Smart Images
Figure CN120348476A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of low-altitude aircraft maintenance, and particularly relates to a maintenance method for the arm of an industrial unmanned aerial vehicle (UAV). Background Art
[0002] With the booming development of the low-altitude economy, industrial UAVs are designed and manufactured for specific industrial applications and are increasingly widely used in the commercial field, covering multiple fields such as surveying and mapping, security, inspection, emergency response, and agricultural and forestry plant protection. However, during use, various damage problems will inevitably occur to UAVs.
[0003] For some vulnerable components such as propellers and batteries, operators usually carry spare parts to replace them on-site. Domestic industrial UAV manufacturers generally provide users with a certain number of spare parts and simple replacement guides to ensure that users can restore the basic flight ability of UAVs in a short time.
[0004] However, as the main structure of UAVs, the arm is composed of a carbon fiber composite rod and a rotor end connection sleeve. When the arm structure connecting the UAV and the rotor is fractured due to a serious collision or crash accident, it is difficult to repair, and the replacement structure comes with high costs.
[0005] In view of the above problems, the present invention provides a new maintenance method applicable to the maintenance process when the arm of an industrial UAV is fractured, which replaces the high replacement cost through structural maintenance and is in line with the sustainable development of the low-altitude economy. Summary of the Invention
[0006] Aiming at the deficiencies of the prior art, the present invention proposes a maintenance method for the arm of an industrial UAV, which is particularly applicable to the damage maintenance of fractures occurring at the connection between the carbon fiber composite rod with an arm length greater than 400 mm and the rotor end connection sleeve. By performing dimensional compensation on the damaged area, increasing the bonding area between the repair structure and the body structure by overlapping patches, and locally strengthening the inner surface, the maintenance process for the difficult-to-repair fractures occurring in the arms of traditional UAVs is completed without affecting the aerodynamic profile of the structure.
[0007] A maintenance method for the arm of an industrial UAV specifically includes the following steps:
[0008] Step 1: After performing a circumferential cut along the root of the fractured damage area of the carbon fiber composite rod, process the carbon fiber composite rod layer by layer from the outer surface of the rod and set it aside for later use;
[0009] Step 2: Lay up the reinforcing patch prepreg on the outer surface of the repair mandrel. After embedding the repair mandrel with a length exceeding the original length of the carbon fiber composite rod into the rod, lay up the patch prepreg in sequence in the processing area of the carbon fiber composite rod in Step 1 to complete the dimensional compensation, and obtain a carbon fiber composite rod with restored structural characteristics;
[0010] Step 3: After embedding the carbon fiber composite rod obtained in Step 2 into the rotor head connecting sleeve, fix it at the buckle position inside the rotor head connecting sleeve, and complete the repair of the UAV arm after encapsulation and curing together with the repair mandrel.
[0011] Wherein:
[0012] In the said Step 1, the circumcision position is based on the lowest point of the fracture of the fracture damage area and extends along the length direction by no less than 12.7 mm.
[0013] In the said Step 1, the processing conditions of the carbon fiber composite are as follows: Let the length of the rod be L. Based on the inner surface of the carbon fiber composite rod, arrange n layers of plies from the inside to the outside, and record the interval between ply Ply(x - 1) and ply Ply(x) along the length direction of the rod as D, D=(k×25.4)mm, and satisfy (n - 1)D<0.5L;
[0014] Wherein, 2≤x≤n, and both x and n are integers; k is an integer multiple of 1 / 2, k≥0.
[0015] In the said Step 2, the repair mandrel consists of two modules, an outer module and an inner module. After combination, the profile characteristics are consistent with the inner surface of the UAV arm rod and the rotor head connecting sleeve, and are combined and disassembled through the parting surface design. A release cloth is laid on the outer surface of the repair mandrel or a release agent is coated.
[0016] The said outer module is die aluminum or die steel, and the inner module is a silicone rubber core or a vacuum cylinder bag. After the inner module expands or is inflated, it is ensured that it fits tightly with the outer module of the repair mandrel.
[0017] In the said Step 2, the fit clearance between the outer module of the repair mandrel and the inner surface of the rod is 0.3 mm to 0.5 mm, and the fit clearance of the parting surface of the outer module of the repair mandrel is 0 mm to 0.2 mm.
[0018] In the said Step 2, the resin system of the reinforcing patch prepreg is the same as that of the carbon fiber composite rod, and the curing temperature does not exceed the glass transition temperature of the carbon fiber composite rod.
[0019] In Step 2, the preferred number of layers of the reinforcement ply pre-preg is 2 layers, and the laying method is to lay along the same axis of symmetry. Denote the dimension of the reinforcement ply pre-preg layer QPly(1) adjacent to the repair mandrel in the length direction of the strut as J, and denote the distance between the circumferential cutting position of the carbon fiber composite strut and the inner opening position of the rotor head connection sleeve of the UAV arm as d. The dimension of the reinforcement ply pre-preg layer QPly(2) on the layer above the reinforcement ply pre-preg layer QPly(1) is J - 50.8 mm, and it satisfies (J - 50.8) > (n - 1)D + d + 25.4.
[0020] In Step 2, the resin system of the patch pre-preg is the same as that of the carbon fiber composite strut, and the curing temperature ≤ the glass transition temperature of the carbon fiber composite strut. Before laying, a pre-compaction and / or pre-bagging process is adopted to ensure that the assembly gap between the carbon fiber composite strut after laying the patch and the rotor head connection sleeve is 0.1 mm to 0.15 mm.
[0021] In Step 2, denote the embedding length of the strut between the inner opening position of the rotor head connection sleeve of the UAV arm and the buckle position of the rotor head connection sleeve of the UAV arm as y. The length of the patch pre-preg is: RPly(1) = d + y, RPly(2) = d + y + D,..., RPly(n - 1) = d + y + (n - 2)D, RPly(n) = d + y + (n - 1)D.
[0022] In Step 2, preferably, a structural adhesive is coated between the reinforcement ply pre-preg and the inner surface of the carbon fiber composite strut, and between the patch pre-preg and the outer surface of the carbon fiber composite strut.
[0023] In Step 3, before embedding the carbon fiber composite strut into the rotor head connection sleeve of the UAV arm, it is necessary to remove the carbon fiber composite strut embedded in it after fracture; if both the rotor head connection sleeve of the UAV arm and the strut are fractured, directly replace the rotor head connection sleeve.
[0024] In Step 3, during the curing repair of the UAV arm, through the vacuum bag pressing and the expansion effect of the silicone rubber core or the vacuum cylinder bag in the repair mandrel, the quality of the outer surface and the inner surface of the arm is ensured simultaneously.
[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0026] 1. The present invention can solve the technical problem that traditional arm fractures cannot be repaired and can only be scrapped, and avoid the generation of solid waste caused by part replacement through structural repair.
[0027] 2. The present invention only operates locally on the structurally damaged area, and the usage amounts of the reinforcing patch prepreg and the repair patch prepreg during the repair process are much smaller than those during the structure manufacturing process, with obvious material cost advantages.
[0028] 3. The present invention adopts vacuum bag pressing in cooperation with the expansion and pressurization of the repair mandrel, and only needs to be heated by low-energy consumption equipment such as a hot patching instrument. The energy consumption involved in the repair process is much smaller than that during the structure manufacturing process, with significant manufacturing cost advantages.
[0029] 4. By replacing the damaged parts of the drone arm after fracture damage with replacement parts, the present invention has a relatively low comprehensive structure cost and a short manufacturing cycle. At the same time, the carbon emissions generated during the repair process are much smaller than those during the raw material manufacturing and curing processes. Brief Description of the Drawings
[0030] Figure 1 In Embodiment 1 of the present invention, a schematic diagram of the structural characteristics and repair method of a drone arm;
[0031] Among them: (a) is the front view of the drone arm, (b) is the side view of the drone arm, (c) is the cross-sectional view of the drone arm, (d) is the cross-sectional view of the fracture form of the drone arm, (e) is the cross-sectional view after the damage of the drone arm is removed, and (f) is the schematic diagram of the patch and reinforcing patch layup in the repair method;
[0032] In the figure: 1 - drone arm, 2 - rotor end connection sleeve after fracture, 3 - rotor end connection sleeve after composite material removal, 4 - carbon fiber composite rod after fracture, 5 - carbon fiber composite rod after damage removal, 6 - circumcision position, 7 - inner opening position of the rotor end connection sleeve, 8 - outer opening position of the rotor end connection sleeve, 9 - buckle position of the rotor end connection sleeve, 10 - ply Ply(1) of the rod after damage removal, 11 - ply Ply(2) of the rod after damage removal, 12 - ply Ply(3) of the rod after damage removal, 13 - ply Ply(4) of the rod after damage removal, 14 - reinforcing patch prepreg QPly(2), 15 - reinforcing patch prepreg QPly(1), 16 - repair patch prepreg RPly(1), 17 - repair patch prepreg RPly(2), 18 - repair patch prepreg RPly(3), 19 - repair patch prepreg RPly(4). Detailed Embodiments
[0033] The content disclosed by the present invention, including the changes in the fracture damage parts at the connection between the rod and the rotor end connection sleeve in the drone arm, the cross-sectional shape (circular, elliptical, rectangular) of the drone arm, the size compensation method of the drone arm rod, the layup design of the reinforcing patch prepreg and the repair patch prepreg, and the cross-sectional shape and separation surface design concept of the drone arm repair mandrel, etc., should all be regarded as the protection scope of the present invention.
[0034] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to these embodiments.
[0035] In the embodiment of the present invention, the resin system of the reinforcing patch prepreg is the same as that of the carbon fiber composite strut, and the curing temperature ≤ the glass transition temperature of the carbon fiber composite strut.
[0036] In the embodiment of the present invention, the resin system of the selected patch prepreg is the same as that of the carbon fiber composite strut, and the curing temperature ≤ the glass transition temperature of the carbon fiber composite strut. Before laying, a pre-compaction and / or pre-bagging process is adopted.
[0037] Embodiment 1
[0038] Taking the fracture at the connection sleeve between the carbon fiber composite strut and the rotor end of an industrial UAV arm 1 as an example, the length, outer diameter and wall thickness of the carbon fiber composite strut are 800 mm, 50 mm and 1 mm respectively. The length between the outer position 8 and the buckle position 9 of the rotor end connection sleeve is 76.5 mm, and the width between the inner position 7 and the outer position 8 of the rotor end connection sleeve is 13.5 mm.
[0039] Taking the inner position 7 of the rotor end connection sleeve as the reference, the fracture (the root of the damaged area) occurs at 43.2 mm along the length direction from the inner position 7 of the rotor end connection sleeve.
[0040] A repair method for an industrial UAV arm. The structural characteristics and schematic diagram of the repair method of the industrial UAV arm are as Figure 1 shown, and specifically includes the following steps:
[0041] Step 1: Circumferentially cut the fracture at 56 mm along the length direction from the inner position 7 of the end connection sleeve, and then sequentially remove the ply areas Ply(2), Ply(3) and Ply(4) arranged from the inside to the outside of the strut along the axial direction of the strut, with lengths of 12.7 mm, 25.4 mm and 38.1 mm respectively.
[0042] Step 2: First, prepare a repair core mold: The length of the repair core mold is 900 mm ± 5 mm, which consists of two modules, an outer module and an inner module. The outer module is made of mold aluminum, and the inner module is a vacuum tube bag. After the inner module is inflated, it is ensured that it fits tightly with the outer module of the repair core mold; the surface characteristics of the combined outer module and inner module of the repair core mold are consistent with the strut and the end connection sleeve of the inner surface of the UAV arm. The fitting gap between the outer module and the inner surface of the strut is 0.4 mm ± 0.1 mm, and it can be combined and disassembled through the split surface design. The fitting gap of the split surface is 0.1 mm ± 0.1 mm. The outer surface of the repair core mold is coated with a release agent.
[0043] Lay two layers of reinforcing patch prepregs on the outer surface of the repair mandrel in sequence. The reinforcing patch prepregs QPly(1) 15 and QPly(2) 14 are laid with the same axis of symmetry. The reinforcing patch prepreg QPly(1) 15 is 50.8 mm longer than the reinforcing patch prepreg QPly(2) 14. The length of the reinforcing patch prepreg QPly(2) 14 is 150 mm. One end is based on the inner opening position 7 of the rotor head connection sleeve, and the other end is preferably 25.4 mm beyond the contour line of the strut ply Ply(4) 13 after damage removal. Insert the repair mandrel into the inside of the carbon fiber composite strut. Lay the repair patch prepregs RPly(1) 16, RPly(2) 17, RPly(3) 18, and RPly(4) 19 on the repair mandrel in sequence at the circumferential cutting position of the carbon fiber composite strut. The lengths of the repair patch prepregs are: RPly(1) 132.5 mm, RPly(2) 145.2 mm, RPly(3) 157.9 mm, and RPly(4) 170.6 mm. The assembly clearance between the carbon fiber composite strut after laying the repair patches and the rotor head connection sleeve is 0.1 mm to 0.15 mm, and a carbon fiber composite strut with restored structural characteristics is obtained.
[0044] Among them, a structural adhesive is coated between the reinforcing patch prepreg and the inner surface of the carbon fiber composite strut, and between the repair patch prepreg and the outer surface of the carbon fiber composite strut.
[0045] Step 3: Remove the carbon fiber composite strut that has broken and is embedded in the rotor head connection sleeve. Subsequently, insert the repair mandrel with the reinforcing patch prepregs and repair patch prepregs laid on its surface, together with the carbon fiber composite strut obtained in Step 2, into the rotor head connection sleeve from which the broken part of the strut has been removed, fix it at the buckle position inside the rotor head connection sleeve, ensure the quality of the outer surface of the arm through the vacuum bag after encapsulation and curing, and ensure the quality of the inner surface of the arm through the expansion of the flexible core in the repair mandrel, thus completing the repair of the drone arm.
[0046] After the repair of the drone arm in this embodiment, the dimensional accuracy is less than ±0.5 mm; the step difference in the repair area of the carbon fiber composite strut in the arm is less than ±0.05 mm.
Claims
1. A maintenance method for the arm of an industrial drone, characterized in that, Specifically, it includes the following steps: Step 1: After circumferentially cutting along the root of the fracture damage area of the carbon fiber composite strut, process the carbon fiber composite strut layer by layer from the outer surface of the strut and set it aside for later use; Step 2: Lay the reinforcing patch prepreg on the outer surface of the repair mandrel. After embedding the repair mandrel with a length exceeding the original length of the carbon fiber composite strut into the strut, lay the patch prepreg in sequence in the processing area of the carbon fiber composite strut in Step 1 to complete size compensation, and obtain a carbon fiber composite strut with restored structural characteristics; Step 3: After embedding the carbon fiber composite strut obtained in Step 2 into the rotor head connection sleeve, fix it at the buckle position inside the rotor head connection sleeve, and complete the repair of the UAV arm after encapsulation and curing together with the repair mandrel.
2. The repair method of an industrial drone arm according to claim 1, characterized in that, In Step 1, the circumferential cutting position is based on the lowest point of the fracture of the fracture damage area and extends along the length direction by no less than 12.7 mm.
3. A maintenance method for an industrial drone arm according to claim 1, characterized in that, In Step 1, the processing conditions of the carbon fiber composite material are as follows: Let the length of the strut be L. Based on the inner surface of the carbon fiber composite strut, arrange n layers of plies from the inside to the outside, and record the interval between ply Ply(x - 1) and ply Ply(x) along the length direction of the strut as D, D=(k×25.4)mm, and satisfy (n - 1)D<0.5L; Among them, 2≤x≤n, and both x and n are integers; k is an integer multiple of 1 / 2, and k≥0.
4. The maintenance method of an industrial drone arm according to claim 1, characterized in that, In Step 2, the repair mandrel consists of two modules, an outer module and an inner module. After combination, the surface characteristics are consistent with the inner surface of the UAV arm strut and the rotor head connection sleeve. It is combined and disassembled through the parting surface design. A release cloth is laid on the outer surface of the repair mandrel or a release agent is coated; The outer module is die aluminum or die steel, and the inner module is a silicone rubber core or a vacuum tube bag. After the inner module expands or is inflated, it ensures a tight fit with the outer module of the repair mandrel.
5. A maintenance method for an arm of an industrial drone according to claim 1, characterized in that, In Step 2, the fit clearance between the outer module of the repair mandrel and the inner surface of the UAV arm strut is 0.3 mm - 0.5 mm, and the fit clearance of the parting surface of the outer module of the repair mandrel is 0 mm - 0.2 mm.
6. The repair method of an industrial drone arm according to claim 3, wherein In Step 2, the resin system of the reinforcing patch prepreg is the same as that of the carbon fiber composite strut, and the curing temperature does not exceed the glass transition temperature of the carbon fiber composite strut; The number of layers of the reinforcing patch prepreg is preferably 2 layers, and its laying method is to lay along the same axis of symmetry. Record the dimension of the reinforcing patch prepreg ply QPly(1) adjacent to the repair mandrel along the length direction of the strut as J, and record the distance between the circumferential cutting position of the carbon fiber composite strut and the inner mouth position of the rotor head connection sleeve of the UAV arm as d. The dimension of the reinforcing patch prepreg ply QPly(2) on the layer above the reinforcing patch prepreg ply QPly(1) is J - 50.8 mm, and satisfy (J - 50.8)>(n - 1)D + d + 25.
4.
7. A maintenance method for an arm of an industrial drone according to claim 1, characterized in that, In the step 2, the resin system of the patch prepreg is the same as that of the carbon fiber composite strut, the curing temperature is not higher than the glass transition temperature of the carbon fiber composite strut, and pre-compaction and / or pre-bagging processes are adopted before laying to ensure that the assembly clearance between the carbon fiber composite strut after laying the patch and the rotor head connecting sleeve is 0.1 mm to 0.15 mm.
8. A maintenance method for an industrial drone arm according to claim 6, characterized in that, In the step 2, the embedding length of the strut between the inner opening position and the buckle position of the rotor head connecting sleeve of the drone arm is denoted as y, and the length of the patch prepreg is: RPly(1) = d + y, RPly(2) = d + y + D,..., RPly(n - 1) = d + y + (n - 2)D, RPly(n) = d + y + (n - 1)D.
9. A maintenance method for an arm of an industrial drone according to claim 1, characterized in that In the step 2, preferably, a structural adhesive is coated between the reinforcement patch prepreg and the inner surface of the carbon fiber composite strut, and between the patch prepreg and the outer surface of the carbon fiber composite strut.
10. The maintenance method of an industrial drone arm according to claim 1, characterized in that, In the step 3, before the carbon fiber composite strut is inserted into the rotor head connecting sleeve of the drone arm, it is necessary to remove the carbon fiber composite strut embedded in it after fracture; if the rotor head connecting sleeve of the drone arm and the strut are fractured simultaneously, the rotor head connecting sleeve is directly replaced; During the curing repair of the drone arm, the quality of the outer and inner surfaces of the arm is ensured synchronously through the vacuum bag pressing and the expansion effect of the silicone rubber core or the vacuum cylinder bag in the repair mandrel.