An integrally formed carbon fiber composite power arm and flying car

Abstract

The application discloses an integrally-formed carbon fiber composite power arm and a flying car, wherein the power arm is a symmetrical structure along the length direction, and comprises: a middle part located at the middle of the power arm; a main body mounting part located at the side of the middle part, which is a mounting position of the power arm and the main body of the flying car; a transition part located at the side of the main body mounting part; and a motor mounting part located at the side of the main body mounting part, which is a mounting position of the motor. The power arm is integrally formed by fusing multiple layers of pre-impregnated materials with customized fiber angles according to the stress direction. Different layer numbers are adopted in different regions of the power arm, and first additional reinforcing parts are additionally arranged on the upper and lower sides of the different regions of the power arm, and second additional reinforcing parts are additionally arranged on the whole motor mounting part. Through the variable-thickness and equal-rigidity layer design and cross-section design, the power arm can reduce the weight and improve the bending and torsional mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of aircraft technology, specifically to a one-piece molded carbon fiber composite power arm and a flying car. Background Technology

[0002] The most obvious difference between flying cars and ordinary cars is that flying cars have the ability to fly. In recent years, with the rise of the concept of urban air mobility, electric vertical take-off and landing aircraft that only have the ability to fly and are used to solve urban traffic congestion are also called flying cars. The concept of flying cars has been expanded to include vehicles with amphibious capabilities or used for urban air mobility.

[0003] Aircraft typically include flying cars, drones, etc., and their functions are constantly being optimized and enriched as aircraft continue to develop. The power arm, or fuselage arm, is a major component of an aircraft, used to transfer the lift from the rotor to the fuselage, and it needs to withstand various mechanical loads. However, the mechanical performance of existing aircraft arms is poor, exhibiting defects such as easy deformation and poor fatigue resistance, requiring further improvement. For example, Chinese patent CN114193990A discloses a fuselage arm and a flying car. This fuselage arm includes a support beam, ribs, and a fairing skin. The support beam encloses a receiving space for mounting the rotor; the ribs are installed in the receiving space, with both ends connected to the support beam; the fairing skin covers the ribs and wraps around the support beam, forming a closed cavity around the outer perimeter of the support beam. By wrapping the fairing skin around the support beam and forming a closed cavity around its outer perimeter, the bending and torsional resistance of the support beam can be improved, giving the fuselage arm excellent mechanical performance.

[0004] It is evident that although the aforementioned patent documents provide solutions to improve the mechanical performance of the boom, the boom still uses a split aluminum alloy structure. This is similar to the aluminum alloy or steel structure used in traditional power booms, which suffers from high density leading to excessive overall mass, making it difficult to meet the high thrust-to-weight ratio requirements of flying cars. Furthermore, it has low stiffness and insufficient bending and torsional resistance, resulting in large bending deformation under extreme conditions, leading to rotor attitude deviation, reduced aerodynamic efficiency, and even resonance failure.

[0005] To address the aforementioned technical problems, this invention proposes an integrally molded carbon fiber composite power arm and a flying car, which solves the problems of existing flying car power arms being heavy, low stiffness, difficult to maintain, and expensive to process, achieving the design goals of lightweight, high stiffness, easy maintenance, and low processing cost. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an integrally molded carbon fiber composite power arm and flying car, solving the problems of traditional power arms that mostly use aluminum alloy or steel structures, which have high density and result in excessive overall mass, making it difficult to meet the high thrust-to-weight ratio requirements of flying cars. In addition, they have low stiffness and insufficient bending and torsional resistance, leading to large bending deformation under extreme conditions, which can cause rotor attitude deviation, aerodynamic efficiency reduction, and even resonance failure.

[0007] Specifically, the technical problem to be solved by the present invention is to address the shortcomings of the prior art. The first aspect of the present invention provides an integrally molded carbon fiber composite power arm, wherein the power arm has a symmetrical structure along its length, and the power arm includes: The middle section is located in the exact center of the power arm; The main mounting section is located on the side of the middle section. This area is where the power arm and the main body of the flying car are mounted. The transition section is located on the side of the main body mounting section; The motor mounting section is located on the side of the main body mounting section, and this area is the mounting location for the motor; The power arm integrates multiple layers of prepreg material with customized fiber angles based on the direction of force by integral molding; Different numbers of layers are used in different areas of the power arm, and a first additional reinforcing part is added to the upper and lower sides of different areas of the power arm, and a second additional reinforcing part is added to the motor mounting part as a whole.

[0008] Preferably, the number of layers in the intermediate portion is a base value, and the value is the minimum. The number of plies in the transition section is less than the number of plies in the main mounting section, and the number of plies in the transition section gradually decreases from the side closer to the main mounting section to the side farther away from the main mounting section until it reaches the base value. The number of layers in the motor mounting section is a base value.

[0009] Preferably, the number of plies in the first additional reinforcement portion within the corresponding region is one or more times the number of plies in the unreinforced portion within the same region.

[0010] Preferably, the number of plies in the second additional reinforcement portion is one or more times greater than the number of plies in the non-additionally reinforced portion.

[0011] Preferably, the power arm has an elliptical hollow cross-section.

[0012] Preferably, the motor mounting part is a vertically placed U-shaped structure; The motor is bolted to both ends of the U-shaped structure; The ESC is installed in the cavity portion of the U-shaped structure; The propeller is connected to the motor and is at a certain angle to the power arm; The cable is placed inside the U-shaped structure and electrically encapsulated through end caps.

[0013] Preferably, the material of the layup is T700 epoxy resin carbon woven fabric, which is laid alternately at a certain angle, with a single layer thickness of 0.2mm.

[0014] Preferably, the power arm is a variable thickness constant stiffness arm design.

[0015] A second aspect of the invention provides a flying car, including a vehicle body and a power arm as described above, the power arm being connected to the vehicle body.

[0016] Compared with the prior art, the positive effects of the present invention are: (1) The one-piece molded carbon fiber composite power arm of the present invention adopts a layup scheme dominated by carbon fiber fabric at a certain angle, which can significantly improve shear resistance and torsional stiffness compared with the unidirectional tape layup dominated by 0° in the prior art.

[0017] (2) The one-piece molded carbon fiber composite power arm of the present invention: adopts an elliptical cross section to replace the traditional Π-shaped support beam, which improves the moment of inertia of the cross section and has better bending resistance than the rectangular closed cavity structure.

[0018] (3) The integrally molded carbon fiber composite power arm of the present invention: different numbers of lay-up are used in different areas of the power arm, and a first additional reinforcement is added on the upper and lower sides of different areas of the power arm, and a second additional reinforcement is added on the motor mounting part as a whole. That is, by the gradient change of the number of lay-up, especially in the motor mounting area, the number of lay-up of the second additional reinforcement is increased to more than one or more times the number of lay-up of the non-additionally reinforced part. Compared with the traditional homogeneous thickness design, the local impact resistance is higher.

[0019] (4) The one-piece molded carbon fiber composite power arm of the present invention: the motor mounting part is a horizontally placed U-shaped structure. The U-shaped structure forms a receiving space, which can integrate the motor and ESC cable. Compared with the traditional external cable + fairing design, the drag coefficient is lowered and the maintenance and disassembly time is shortened. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the power arm and the installation of its various components in this invention.

[0021] Figure 2 This is a schematic diagram of an elliptical cross-section shown in the sectional view of the power arm in this invention.

[0022] Figure 3This is a schematic diagram of the layup area for the variable thickness constant stiffness arm design in this invention.

[0023] Figure 4 This is an isometric view of the propeller power arm in this invention.

[0024] The labels in the attached diagram are: 1-power arm, 2-motor, 3-electro-speed controller, 4-propeller, 5-end cap. Detailed Implementation

[0025] The following is combined Figures 1-4 The present invention will be further described with reference to specific embodiments.

[0026] See Figures 1-4 The present invention provides a one-piece molded carbon fiber composite power arm 1, wherein the power arm 1 has a symmetrical structure along its length direction, and the power arm 1 includes: The middle part is located in the exact center of the power arm 1; The main body mounting section is located on the side of the middle section. This area is the mounting location of the power arm 1 and the main body of the flying car. The transition section is located on the side of the main body mounting section; The motor mounting section is located on the side of the main body mounting section, and this area is the mounting location for the motor 2; The power arm 1 integrates multiple layers of prepreg material with customized fiber angles according to the direction of force into a whole through integral molding technology; Different numbers of layers are used in different areas of the power arm 1, and a first additional reinforcing part is added to the upper and lower sides of different areas of the power arm 1, and a second additional reinforcing part is added to the motor mounting part as a whole. The number of layers in the middle section is the base value, and the value is the minimum; The number of plies in the transition section is less than the number of plies in the main mounting section, and the number of plies in the transition section gradually decreases from the side closer to the main mounting section to the side farther away from the main mounting section until it reaches the base value. The number of layers in the motor mounting section is a basic value; The number of plies in the first additional reinforcement portion within the corresponding area is one or more times the number of plies in the unreinforced portion within the same area.

[0027] The number of plies in the second additional reinforcement portion is one or more times greater than the number of plies in the non-additionally reinforced portion; The power arm 1 has an elliptical hollow cross section.

[0028] The motor mounting section is a vertically placed U-shaped structure; Motor 2 is bolted to both ends of the U-shaped structure; ESC 3 is installed in the cavity portion of the U-shaped structure; The propeller 4 is connected to the motor 2 and is at a certain angle to the power arm 1; The cable is placed inside the U-shaped structure and electrically encapsulated through the end cap 5; The material used for the layup is T700 epoxy resin carbon woven fabric, which is laid alternately at a certain angle, with a single layer thickness of 0.2mm.

[0029] The power arm 1 is a variable thickness constant stiffness arm design.

[0030] Example

[0031] like Figures 2-3 As shown, the power arm integrates multiple layers of prepreg with customized fiber angles based on the direction of force using a one-piece molding technology. The layup thickness is designed and localized reinforcements are implemented according to different force requirements, achieving a power arm design with variable thickness and constant stiffness. For example... Figure 3 As shown, the power arm has an elliptical hollow cross-section design, which not only enhances its bending and torsional resistance, but also allows the motor 2 and the ESC 3 to be fixed to the power arm 1 by bolts. The cable is placed inside the hollow power arm 1 and electrically encapsulated through the end cover 5.

[0032] like Figure 1 As shown, the propeller power arm includes: power arm 1, motor 2, ESC 3, propeller 4, and end cap 5.

[0033] The interconnections or relative positions of the components in this embodiment are as follows: Motors 2 are bolted to the upper and lower ends of the power arm, with a total of four motors. ESCs 3 are installed on the left and right sides of the power arm 1, two on each side, for a total of four. Four propellers are connected to the motors 2 and are angled relative to the power arm 1. End caps 5 are installed on both sides of the power arm 1, with a total of two end caps, used to enclose the internal cables.

[0034] like Figure 3 The power arm 1 shown achieves variable thickness and constant stiffness arm design and local reinforcement through a ply-layout design. The scheme in this embodiment is as follows: Power arm 1 has a symmetrical structure, and the ply-layout method is also symmetrical. Regions A and B of power arm 1 and regions H and I are the mounting parts of power arm 1 and the main body of the flying car. The ply-layout material is T700 epoxy resin carbon fiber woven fabric, laid alternately at a certain angle, with a single layer thickness of 0.2mm. According to the stress characteristics of the power arm 1 structure, different numbers of ply-layouts are used in different regions of power arm 1, with additional reinforcement at the upper and lower sides of power arm 1 and the motor mounting location. Specifically, the number of ply-layouts on the upper and lower sides of power arm 1 is twice the number of ply-layouts in the unreinforced areas, and the motor mounting location is reinforced with an additional 10 ply-layouts.

[0035] The specific number of ply layers in each region is shown in Table 1 below:

[0036] As can be seen, the one-piece molded carbon fiber composite power arm, variable thickness constant stiffness arm design, elliptical arm cross-section design, and rotor angle used in this invention have the following characteristics: 1. The layup scheme dominated by carbon fiber fabric at a certain angle can significantly improve shear resistance and torsional stiffness compared with the traditional unidirectional tape layup dominated by 0°. 2. By replacing the Π-shaped support beam in the traditional scheme with an elliptical cross section, the moment of inertia of the cross section is increased, and the bending performance is better than that of the rectangular closed cavity structure; 3. By varying the number of layers, the number of layers in the motor mounting area is increased to 17, resulting in higher local impact resistance compared to the homogeneous thickness design in traditional schemes; 4. The housing integrates the motor and ESC cable, which, compared to the traditional external cable + fairing design, results in a lower drag coefficient and shortens maintenance and disassembly time.

[0037] In summary, this invention designs an integrally molded carbon fiber composite power arm. Through variable thickness and constant stiffness design, elliptical arm cross-section design, and ply layup design, it not only ensures the power arm's torsional and bending resistance during operation but also reduces its weight.

[0038] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0039] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems or apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.

[0040] The above description only illustrates the preferred technical solution of the present invention. Any modifications that may be made by those skilled in the art to certain parts thereof all reflect the principles of the present invention and should be within the technical scope of the present invention.

Claims

1. A one-piece molded carbon fiber composite power arm, wherein the power arm has a symmetrical structure along its length, and the power arm comprises: The middle section is located in the exact center of the power arm; The main mounting section is located on the side of the middle section. This area is where the power arm and the main body of the flying car are mounted. The transition section is located on the side of the main body mounting section; The motor mounting section is located on the side of the main body mounting section, and this area is the mounting location for the motor; The power arm integrates multiple layers of prepreg material with customized fiber angles based on the direction of force by integral molding; The feature is that different numbers of layers are used in different areas of the power arm, and a first additional reinforcing part is added to the upper and lower sides of different areas of the power arm, and a second additional reinforcing part is added to the motor mounting part as a whole; The number of layers in the intermediate section is the base value and is the smallest; the number of layers in the transition section is less than the number of layers in the main mounting section, and the number of layers in the transition section gradually decreases from the side closer to the main mounting section to the side farther away from the main mounting section until it reaches the base value; the number of layers in the motor mounting section is the base value.

2. The integrally molded carbon fiber composite power arm as described in claim 1, characterized in that, The number of plies in the first additional reinforcement portion within the corresponding area is one or more times the number of plies in the unreinforced portion within the same area.

3. The integrally molded carbon fiber composite power arm as described in claim 1, characterized in that, The number of plies in the second additional reinforcement portion is one or more times greater than the number of plies in the non-additionally reinforced portion.

4. A one-piece molded carbon fiber composite power arm as described in claim 2 or 3, characterized in that, The power arm has an elliptical hollow cross-section.

5. A one-piece molded carbon fiber composite power arm as described in claim 2 or 3, characterized in that, The motor mounting section is a vertically placed U-shaped structure; the motor is bolted to the upper and lower ends of the U-shaped structure; the ESC is installed in the cavity of the U-shaped structure; the propeller is connected to the motor and forms a certain angle with the power arm; the cable is placed inside the U-shaped structure and electrically encapsulated by end caps.

6. A one-piece molded carbon fiber composite power arm as described in claim 2 or 3, characterized in that, The material used for the layup is T700 epoxy resin carbon woven fabric, which is laid alternately at a certain angle, with a single layer thickness of 0.2mm.

7. The integrally molded carbon fiber composite power arm as described in claim 1, characterized in that, The power arm is a variable thickness constant stiffness arm design.

8. A flying car, characterized in that, It includes a vehicle body and a power arm as described in any one of claims 1 to 7, wherein the power arm is connected to the vehicle body.

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