Composite propeller mounting shaft of unmanned aerial vehicle and preparation process of composite propeller mounting shaft

Abstract

The invention provides an unmanned aerial vehicle composite material propeller mounting shaft and a preparation technology thereof in the technical field of composite material shaft parts, the unmanned aerial vehicle composite material propeller mounting shaft comprises a composite material hollow shaft and a connector insert, the whole composite material hollow shaft is of a hollow shaft structure and comprises a composite material hollow shaft outer layer and a composite material hollow shaft inner layer, and the inner layer is shorter than the outer layer; the composite material hollow shaft is of a stepped shaft structure and is made of a composite material. The whole connector insert is of a hollow structure and comprises a first connecting part and a second connecting part, the first connecting part is of a hollow shaft structure, the second connecting part is of a hollow circular truncated cone structure, bolt holes are distributed in the side face of the second connecting part, and the connector insert is made of metal materials. According to the manufacturing method, the composite propeller mounting shaft is manufactured through the technological method of mold embedding, prepreg tape winding and mold pressing integrated forming, the machining time is saved, close fit between the composite hollow shaft and the metal insert is achieved, and the bonding strength of a metal-composite interface is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material shaft parts, and in particular to a composite material propeller mounting shaft for an unmanned aerial vehicle and a preparation process thereof. Background Art

[0002] Carbon fiber composite materials have excellent mechanical properties, such as high specific strength, specific stiffness, specific energy absorption, etc. Compared with traditional metal lightweight materials, they have better lightweight effects while achieving the same performance. They also have the advantage of one-piece molding of parts and have broad application prospects in the aerospace field.

[0003] The propeller mounting shaft is an important shaft-type load-bearing component in the UAV body structure. It requires high axial load-bearing capacity while ensuring lightweight effect, which is difficult to achieve with ordinary forming processes. The fiber winding process is a relatively mature composite material preparation process, which is suitable for the preparation of shaft parts. However, shaft parts often need to be connected to the connectors before installation, which will cause matching errors and additional connection processes. Summary of the invention

[0004] In view of the defects in the prior art, the purpose of the present invention is to provide a UAV composite propeller mounting shaft and a preparation process thereof.

[0005] According to the present invention, a composite propeller mounting shaft for a drone comprises a composite hollow shaft and a joint insert, wherein the joint insert is embedded in the composite hollow shaft, the composite hollow shaft comprises a composite hollow shaft outer layer and a composite hollow shaft inner layer, and the joint insert comprises a first connecting portion and a second connecting portion;

[0006] The length of the inner layer of the composite hollow shaft is set to be shorter than the length of the outer layer of the composite hollow shaft, the outer layer of the composite hollow shaft and the inner layer of the composite hollow shaft form a stepped shaft structure, and the stepped shaft structure is cooperatively connected with the first connecting portion;

[0007] The thickness of the first connection portion is set to be consistent with the thickness of the inner layer of the composite hollow shaft, and the length of the first connection portion end after being connected to the inner layer of the composite hollow shaft is set to be consistent with the length of the outer layer of the composite hollow shaft.

[0008] In some embodiments, two sides of the first connecting portion are embedded in one end of the composite hollow shaft.

[0009] In some embodiments, the stepped shaft structure is disposed at one end of the composite hollow shaft, two sides of the first connecting portion are correspondingly engaged with the stepped shaft structure, and two sides of the first connecting portion are also integrally connected to the second connecting portion.

[0010] In some implementations, the joint insert has a hollow structure.

[0011] In some embodiments, the first connecting portion adopts a cylindrical hollow shaft structure.

[0012] In some embodiments, the second connecting portion adopts a hollow truncated cone structure, and a plurality of conical bolt holes are provided on the side of the second connecting portion for connection.

[0013] In some embodiments, the composite hollow shaft is prepared by composite winding process and molding process, and the winding angle is 20 degrees, which can be adjusted according to actual installation and load requirements;

[0014] In some embodiments, the composite material is a thermosetting carbon fiber unidirectional prepreg tape;

[0015] In some embodiments, the joint insert is made of aluminum alloy;

[0016] In order to ensure a reliable connection between the joint insert and the composite hollow shaft, the present invention also provides a metal insert embedded part mold, composite prepreg winding, and a preparation process for manufacturing a propeller installation shaft by hot molding. The preparation process steps include:

[0017] Step S1, pre-inserting the joint insert onto the inner core mold of the cylinder;

[0018] Step S2, winding a composite material unidirectional prepreg tape back and forth between one end of the cylindrical inner core mold and the end of the first connecting portion of the joint insert to form the inner layer of the hollow shaft;

[0019] Winding the composite material unidirectional prepreg tape back and forth between one end of the cylindrical inner core mold and the end of the second connecting portion of the joint insert to form the outer layer of the hollow shaft;

[0020] Step S3, closing the mold, and the joint insert and the composite hollow shaft are integrally molded;

[0021] Step S4, demoulding, core pulling, and obtaining the finished product.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The composite propeller mounting shaft of the unmanned aerial vehicle of the present invention is prepared by a process method of pre-embedded in a mold-prepreg winding-molding integrated molding, and its structure includes a composite hollow shaft and a joint insert, the joint insert is embedded in the composite hollow shaft, the composite hollow shaft includes a composite hollow shaft outer layer and a composite hollow shaft inner layer, and the joint insert includes a first connecting portion and a second connecting portion;

[0024] The length of the inner layer of the composite hollow shaft is shorter than the length of the outer layer of the composite hollow shaft, the outer layer of the composite hollow shaft and the inner layer of the composite hollow shaft form a stepped shaft structure, and the stepped shaft structure is cooperatively connected with the first connecting portion;

[0025] The thickness of the first connection portion is consistent with the thickness of the inner layer of the composite hollow shaft, and the length of the end of the first connection portion after being connected to the inner layer of the composite hollow shaft is consistent with the length of the outer layer of the composite hollow shaft;

[0026] The above structural design not only ensures the close fit between the composite hollow shaft and the metal insert, avoiding the interchangeability caused by part manufacturing errors and assembly, but also effectively enhances the interface strength between the metal and the composite material, avoiding the influence of insufficient strength caused by secondary bonding.

[0027] At the same time, due to the advantages of pre-embedded parts and one-piece molding, the later assembly and connection steps are omitted, greatly saving time costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0029] Figure 1 This is a schematic diagram of the overall structure of the composite propeller mounting shaft of the UAV of the present invention;

[0030] Figure 2 A cross-sectional view of a composite propeller installation shaft for a UAV of the present invention;

[0031] Figure 3 It is a side view of the composite propeller mounting shaft of the UAV of the present invention.

[0032] Reference numerals:

[0033] Composite hollow shaft 1 Joint insert 2

[0034] Composite hollow shaft outer layer 11 first connecting portion 21

[0035] Composite hollow shaft inner layer 12 Second connecting portion 22

[0036] Step shaft structure 13 bolt holes 221 DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0038] Example 1

[0039] like Figure 1-2 As shown, the composite propeller mounting shaft of the unmanned aerial vehicle of the present invention comprises a composite hollow shaft 1 and a joint insert 2, the joint insert 2 is embedded in the composite hollow shaft 1, the composite hollow shaft 1 comprises a composite hollow shaft outer layer 11 and a composite hollow shaft inner layer 12, and the joint insert 2 comprises a first connecting portion 21 and a second connecting portion 22. The length of the composite hollow shaft inner layer 12 is set to be shorter than the length of the composite hollow shaft outer layer 11, the composite hollow shaft outer layer 11 and the composite hollow shaft inner layer 12 form a stepped shaft structure, and the stepped shaft structure is connected with the first connecting portion 21. The thickness of the first connecting portion 21 is set to be consistent with the thickness of the composite hollow shaft inner layer 12, and the length of the end of the first connecting portion 21 after being connected to the composite hollow shaft inner layer 12 is set to be consistent with the length of the composite hollow shaft outer layer 11.

[0040] The first connection part 21 is embedded at one end of the composite hollow shaft 1. The stepped shaft structure 13 is arranged at one end of the composite hollow shaft 1, and the first connection part 21 is correspondingly embedded with the stepped shaft structure 13 on both sides, and the first connection part 21 is also integrally connected to the second connection part 22 on both sides. The joint insert 2 adopts a hollow structure. The first connection part 21 adopts a cylindrical hollow shaft structure. The second connection part 22 adopts a hollow truncated cone structure, and 8 conical bolt holes 221 are arranged on the side of the second connection part 22 for connection.

[0041] Specifically, in this embodiment, the composite hollow shaft 1 is prepared by a composite winding process and a molding process, and the winding angle is 20 degrees, which can be adjusted according to actual installation and load-bearing requirements.

[0042] Specifically, in this embodiment, the composite material is a thermosetting carbon fiber unidirectional prepreg tape.

[0043] Specifically, in this embodiment, the joint insert 2 is made of aluminum alloy.

[0044] Example 2

[0045] A preparation process for the composite propeller mounting shaft of the unmanned aerial vehicle applied to Example 1 comprises the following steps:

[0046] Step S1, pre-insert the joint insert 2 into one end of the cylindrical core mold and fix the position;

[0047] Step S2, winding the composite material unidirectional prepreg tape back and forth between one end of the inner core mold of the cylinder and the end of the first connecting portion 21 to form the composite hollow shaft inner layer 12, at which time the thickness of the composite hollow shaft inner layer 12 is consistent with the thickness of the first connecting portion 21 and the ends are completely fitted;

[0048] Then continue to wind back and forth between the same end of the cylindrical inner core mold and the end face of the second connecting part 22 to form the outer layer 11 of the composite hollow shaft. At this time, the outer layer 11 of the composite hollow shaft is completely in contact with the side face of the first connecting part 21 and the end face of the second connecting part 22. At this time, the wound composite hollow shaft 1 automatically forms a two-layer stepped shaft structure, with the inner and outer layers tightly combined, and the prepreg tape winding angle is 20 degrees;

[0049] Step S3, closing the mold, and integrally molding the joint insert 2 and the composite hollow shaft 1;

[0050] Step S4, demoulding, core pulling, and obtaining the finished product.

[0051] How it works

[0052] The present invention adopts lightweight and high-strength carbon fiber composite materials to replace traditional metal materials through its composite hollow shaft 1, and ensures a tight and reliable connection between the metal-composite material interface by pre-embedded integrally formed joint inserts 2 embedded in the composite hollow shaft 1.

[0053] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0054] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A composite propeller mounting shaft for a drone, characterized in that: The invention comprises a composite hollow shaft (1) and a joint insert (2), wherein the joint insert (2) is connected to the composite hollow shaft (1), the composite hollow shaft (1) comprises a composite hollow shaft outer layer (11) and a composite hollow shaft inner layer (12), and the joint insert (2) comprises a first connecting portion (21) and a second connecting portion (22); The length of the composite hollow shaft inner layer (12) is shorter than the length of the composite hollow shaft outer layer (11), the composite hollow shaft outer layer (11) and the composite hollow shaft inner layer (12) form a stepped shaft structure (13), and the stepped shaft structure (13) is cooperatively connected to the first connecting portion (21); The thickness of the first connecting portion (21) is consistent with the thickness of the inner layer (12) of the composite hollow shaft, and the length of the end of the first connecting portion (21) after being connected to the inner layer (12) of the composite hollow shaft is consistent with the length of the outer layer (11) of the composite hollow shaft.

2. The composite propeller mounting shaft for unmanned aerial vehicle according to claim 1, characterized in that: Both sides of the first connecting portion (21) are embedded in one end of the composite hollow shaft (1).

3. The composite propeller mounting shaft for unmanned aerial vehicle according to claim 2, characterized in that: The stepped shaft structure (13) is arranged at one end of the composite hollow shaft (1), the two sides of the first connecting portion (21) are correspondingly engaged with the stepped shaft structure (13), and the two sides of the first connecting portion (21) are also integrally connected to the second connecting portion (22).

4. The composite propeller mounting shaft for unmanned aerial vehicle according to claim 1, characterized in that: The joint insert (2) is made of metal.

5. The composite propeller mounting shaft for unmanned aerial vehicle according to claim 1, characterized in that: The joint insert (2) adopts a hollow structure.

6. The composite propeller mounting shaft for a drone according to claim 5, characterized in that: The first connecting portion (21) adopts a cylindrical hollow shaft structure.

7. The composite propeller mounting shaft for a drone according to claim 6, characterized in that: The second connecting portion (22) adopts a hollow truncated cone structure, and a plurality of bolt holes (221) are arranged on the side surface of the second connecting portion (22), and the plurality of bolt holes (221) are conical bolt holes.

8. A process for preparing a composite propeller mounting shaft for a drone according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step S1, pre-inserting the joint insert (2) into one end of the cylindrical inner core mold and fixing the position; Step S2, winding a composite material unidirectional prepreg tape back and forth between one end of the cylindrical inner core mold and the end of the first connecting portion (21) of the joint insert (2) to form the inner layer (12) of the hollow shaft; Winding the composite material unidirectional prepreg tape back and forth between one end of the cylindrical inner core mold and the end of the second connecting portion (22) of the joint insert (2) to form the outer layer (11) of the hollow shaft; Step S3, closing the mold, and the joint insert (2) and the composite hollow shaft (1) are integrally molded; Step S4, demoulding, core pulling, and obtaining the finished product.

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