Drone arms and drones

Abstract

To provide a drone arm and drone that have a small number of parts and can generate high thrust. [Solution] The arm 1 is positioned where airflow is delivered by the rotation of the propeller and extends outward from the housing. The arm body 10 for securing a predetermined distance, the connecting part 20 for connecting to the housing, and the fixing part 30 for fixing the motor are integrally formed from carbon fiber reinforced thermoplastic. The cross-section of the arm body 10 in a direction perpendicular to the longitudinal direction has a length perpendicular to the rotation plane of the propeller that is greater than the width in the parallel direction, and the width of the upper and lower parts of the cross-section is smaller than the width of the central part of the cross-section.

Description

Technical Field

[0001] The present invention relates to an arm for a drone and a drone.

Background Art

[0002] A drone has a housing in which a flight control device and a battery are arranged, and a motor and a propeller for exerting thrust (for example, Patent Document 1). For example, in a drone with a large maximum takeoff weight, such as a drone for agricultural chemical spraying, a propeller with a large diameter is adopted to ensure thrust. And, in order to prevent interference between the housing and the propeller, the motor for rotating the propeller is arranged at the tip of an arm extending outward from the housing. Conventionally, such an arm is generally formed of carbon fiber reinforced plastics (CFRP) from the viewpoints of weight and strength.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-mentioned arm, for example, as shown in FIGS. 15 to 17, a connecting member for connection to the housing 110 of the drone 100 is required, and a fixing member (motor mount) for fixing the motor is also required. Therefore, in addition to the weight of the CFRP pipe, the weights of the connecting member and the fixing member are also added. Further, the number of parts increases and the manufacturing process becomes complicated.

[0005] The present invention attempts to solve such problems, and an object thereof is to provide an arm for a drone and a drone with a small number of parts and capable of obtaining a large thrust. [Means for solving the problem]

[0006] The first invention relates to a drone arm for a drone that obtains thrust by the rotation of a propeller, for connecting a housing that houses the drone's control device and battery to a motor for rotating the propeller at a predetermined distance, wherein the arm is positioned where airflow is delivered by the rotation of the propeller and extends outward from the housing, and the arm body for securing the predetermined distance, the connecting part for connecting to the housing, and the fixing part for fixing the motor are integrally formed from carbon fiber reinforced thermoplastic, wherein the cross-section of the arm body in a direction perpendicular to the longitudinal direction is such that the length in the direction perpendicular to the rotation plane of the propeller is greater than the width in the direction parallel, and the width of the upper and lower parts of the cross-section is smaller than the width of the central part of the cross-section.

[0007] According to the configuration of the first invention, the arm is integrally formed from carbon fiber reinforced thermoplastic plastic, comprising an arm body, a connecting part for connecting to the housing, and a fixing part for fixing the motor. The arm body made of carbon fiber reinforced thermoplastic plastic has greater mechanical strength than that made of aluminum pipe, and since the arm body, connecting part, and fixing part are integrally formed, there is no need for a connecting part or fixing part as a separate component from the arm body. As a result, the number of parts is reduced and the manufacturing process is simplified. Furthermore, the inventors of the present invention have found that the cross-sectional shape of the arm body allows for efficient utilization of the thrust generated by the rotation of the propeller. Specifically, while the cross-section of an aluminum pipe is substantially circular, in the configuration of the first invention, the cross-section of the arm body has a length perpendicular to the rotation plane of the propeller that is greater than the width in the parallel direction, and the widths of the upper and lower parts of the cross-section are smaller than the width of the central part of the cross-section. Due to this cross-sectional shape of the arm body, the airflow generated by the rotation of the propeller flows downward without generating a force that reduces thrust.

[0008] The second invention is a drone arm in which, in the configuration of the first invention, the upper and lower parts of the cross-section are formed in a convex shape toward the outside.

[0009] According to the configuration of the second invention, since the upper and lower parts of the cross-section of the arm body are formed in a convex shape toward the outside, when the airflow generated by the rotation of the propeller hits the upper part of the arm body, it flows smoothly downward, and the airflow flowing along the surface of the arm body smoothly separates from the lower part of the arm body.

[0010] The third invention is the drone arm according to claim 1, wherein, in the configuration of the first invention, the cross-section is elliptical in shape.

[0011] The fourth invention is the drone arm according to claim 2 or 3, wherein, in the configuration of the second or third invention, the central portion is formed closer to the upper portion than to the lower portion.

[0012] The inventors of the present invention have found that the reduction in thrust is smaller when the cross-section of the arm body has a length perpendicular to the propeller's rotation plane that is greater than the width in the parallel direction, the widths of the upper and lower parts of the cross-section are smaller than the width of the central part of the cross-section, and the central part, which is larger in the width direction, is closer to the upper part than the lower part. In this regard, according to the configuration of the fourth invention, the reduction in thrust can be further reduced because the enlarged central part of the cross-section of the arm body is closer to the upper part.

[0013] The fifth invention is a drone arm in which, in the configuration of the first invention, the arm body is formed to be hollow, and linear projections are formed on the inner circumferential surface of the arm body to maintain the shape of the cross-section of the arm body.

[0014] According to the configuration of the fifth invention, the linear projections formed on the inner circumferential surface of the arm body can maintain the cross-sectional shape of the arm body. [Effects of the Invention]

[0015] According to the present invention, the number of parts is small and a large thrust can be obtained.

Brief Description of the Drawings

[0016] [Figure 1] It is a schematic perspective view of the upper part constituting the drone arm according to an embodiment of the present invention, viewed from the rear. [Figure 2] It is a schematic perspective view of the upper part constituting the drone arm, viewed from the front. [Figure 3] It is a schematic plan view of the upper part constituting the drone arm. [Figure 4] It is a schematic bottom view of the upper part constituting the drone arm. [Figure 5] It is a schematic side view of the upper part constituting the drone arm. [Figure 6] It is a schematic front view of the upper part constituting the drone arm. [Figure 7] It is a schematic rear view of the upper part constituting the drone arm. [Figure 8] It is a partial enlarged view of the upper part constituting the drone arm. [Figure 9] It is a partial enlarged view of the upper part constituting the drone arm. [Figure 10] It is a partial enlarged view of the upper part constituting the drone arm. [Figure 11] It is a partial enlarged view of the upper part constituting the drone arm. [Figure 12] It is a schematic view showing the connection between the upper part and the lower part of the drone arm. [Figure 13] It is a diagram showing a comparison between the drone arm according to an embodiment of the present invention and a conventional drone arm. [Figure 14] It is a diagram showing the result of an airflow test. [Figure 15] It is a diagram showing a conventional drone and a drone arm. [Figure 16] It is a diagram showing a conventional drone arm. [Figure 17] This is a diagram showing a conventional drone arm. [Modes for carrying out the invention]

[0017] The embodiments for carrying out the present invention will be described in detail below. In the following description, the same reference numerals will be used for similar components, and their descriptions will be omitted or simplified. Furthermore, descriptions of components that can be appropriately implemented by those skilled in the art will be omitted, and only the basic components of the present invention will be described.

[0018] Arm 1 (see Figures 12 and 13) is constructed by connecting the upper arm 1A and the lower arm 1B.

[0019] In the drone 100, arm 1 extends outward from the housing 110 and is positioned to receive airflow from the rotation of the propeller 120, similar to the conventional arm 130 (see Figure 15).

[0020] The upper arm 1A will be described below with reference to Figures 1 to 5. Since the upper arm 1A and the lower arm 1B have the same shape, the description of the lower arm 1B will be omitted.

[0021] Arm 1A has an arm body portion 10, a connecting portion 20, and a fixing portion 30. The arm body portion 10, the connecting portion 20, and the fixing portion 30 are integrally formed from carbon fiber reinforced thermoplastic.

[0022] The arm body 10 ensures a predetermined distance between the housing 110 and the motor that rotates the propeller 120. This prevents the propeller 120 from interfering with the housing 110. The arm body 10 is hollow, and linear protrusions are formed on the inner circumferential surface of the arm body 10 to maintain the cross-sectional shape of the arm body 10.

[0023] The connection part 20 is configured to connect the arm 1 to the housing 110. The fixing part 30 is configured to fix the motor.

[0024] As shown in Figure 13(b), in the cross-section of the arm body 10 in a direction perpendicular to the longitudinal direction, the length L1 perpendicular to the rotation plane of the propeller is greater than the width W1 in the parallel direction, and the widths of the upper and lower parts of the cross-section are smaller than the width of the central part of the cross-section.

[0025] As shown in Figure 13(b), the upper and lower parts of the cross-section of the arm body 10 are formed in a convex shape toward the outside. Specifically, the cross-section is elliptical.

[0026] As shown in Figure 14(a), the conventional CFRP arm 130 has a circular cross-section, and when airflow strikes it from the direction of arrow X1, a low-pressure area is created behind the arm 130, reducing thrust. In contrast, as shown in Figure 14(b), the arm body 10 in this embodiment has a cross-section where the length L1 perpendicular to the propeller's rotation plane is greater than the width W1 in the parallel direction, and the widths of the upper and lower parts of the cross-section are smaller than the width of the central part of the cross-section. When airflow strikes the arm body 10 from the direction of arrow X1, no low-pressure area is created behind the arm body 10, and thrust is not reduced.

[0027] Unlike this embodiment, the widest central portion of the arm body 10 may be formed closer to the upper portion than to the lower portion. This shape prevents the formation of a region with even lower air pressure behind the arm body 10, further reducing the reduction in thrust.

[0028] It should be noted that the present invention is not limited to the embodiments described above, and any modifications, improvements, etc., that can achieve the objectives of the present invention are included in the present invention. [Explanation of Symbols]

[0029] 1. Arm for drone 1A Upper part of the drone arm 1B Lower part of the drone arm 10. Arm body 20 Connection part 30 Fixing part

Claims

1. In a drone that obtains thrust by the rotation of a propeller, a drone arm for connecting a housing that houses the drone's control device and battery to a motor for rotating the propeller while ensuring a predetermined distance between them, The aforementioned arm is It is positioned in a location where airflow is delivered by the rotation of the aforementioned propeller, The arm extends outward from the housing and is integrally formed from carbon fiber reinforced thermoplastic, with an arm body portion for securing the predetermined distance, a connecting portion for connecting to the housing, and a fixing portion for fixing the motor. The cross-section of the arm body in a direction perpendicular to the longitudinal direction is such that the length perpendicular to the rotation plane of the propeller is greater than the width in the parallel direction. The widths of the upper and lower parts of the cross-section are smaller than the width of the central part of the cross-section. Drone arm.

2. The upper and lower parts of the cross-section are formed in a convex shape toward the outside. The drone arm according to claim 1.

3. The drone arm according to claim 1, wherein the cross-section is elliptical.

4. The drone arm according to claim 2 or 3, wherein the central portion is formed closer to the upper portion than the lower portion.

5. The arm for a drone according to claim 1, wherein the arm body is formed to be hollow, and linear projections are formed on the inner circumferential surface of the arm body to maintain the shape of the cross-section of the arm body.

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