JP3243782U - Drone arms and drones - Google Patents

Abstract

[Problem] To provide a drone arm with increased rigidity. [Solution] An arm attached to a casing of a drone, the arm having a main body disposed on the outside of the casing, and a flange disposed on the lateral outside of the main body, the main body and an arm for a drone, wherein the flange is made of fiber-reinforced resin containing reinforcing fibers and thermoplastic resin. [Selection diagram] Figure 2

Description

The present invention relates to a drone arm and a drone.

Drones are known that have a casing in which batteries and the like are placed, multiple rotors for flying the drone, and an arm for holding the rotors outside the casing and at a position away from the casing. . Patent Document 1 discloses that the arm of such a drone is made of a laminated structure in which a plurality of fiber-reinforced resin sheets in which fibers are woven are laminated, and the laminated structure is formed into a cylindrical shape. An example using a body is described. Patent Document 1 describes that an arm obtained by molding the above-mentioned laminated structure is lightweight and has high rigidity.

Japanese Patent Application Publication No. 2018-118530

As described in Patent Document 1, by using fiber-reinforced resin as the material, the arm can be made lighter and also have higher rigidity. By the way, with the diversification of uses for drones in recent years, there is a growing need for drones to have higher strength than before. For this reason, there is a demand for increased rigidity of each component of the drone, such as the arm, compared to the past.

The present invention has been made in view of the above requirements, and an object thereof is to provide a drone arm with increased rigidity and a drone having the drone arm.

One aspect of the present invention for solving the above problems relates to the following drone arms [1] to [9].
[1] An arm that can be attached to the housing of a drone,
a main body disposed outside the casing;
a flange disposed on the outer side of the main body;
Arm for drone.
[2] The arm has a fastening hole for fastening the arm to the casing,
the fastening hole is arranged in the flange,
The drone arm according to [1].
[3] The main body portion has a root portion fastened to the casing, and an extending portion extending outside the root portion,
the flange is located at the root portion;
The drone arm according to [1] or [2].
[4] The flange is arranged at the root portion and the extension portion,
The overhanging width of the flange at the root portion is larger than the overhanging width of the flange at the extending portion.
The drone arm according to [3].
[5] The main body portion has a distal end portion disposed at the distal end of the extension portion to which another member is attached;
the tip portion has the flange;
The drone arm according to [4].
[6] The flange is integrally molded with the main body,
The drone arm according to any one of [1] to [5].
[7] Having reinforcing ribs on the inside of the main body,
The drone arm according to any one of [1] to [5].
[8] The reinforcing rib is integrally molded with the main body,
The drone arm according to [7].
[9] The main body has a rod-like shape with at least one open surface along the longitudinal direction.
The drone arm according to any one of [1] to [8].

Other aspects of the present invention for solving the above problems relate to the following drones [10] to [11].
[10] The drone arm according to any one of [1] to [9],
A casing to which the drone arm is fastened.
[11] The drone arm is fastened to the casing via a hinge,
foldable by bending the hinge;
The drone according to [10].

According to the present invention, a drone arm with increased rigidity and a drone having the drone arm are provided.

FIG. 1 is a schematic diagram showing the appearance of a drone according to an embodiment of the present invention. FIG. 2 is a perspective view showing the appearance of the arm when viewed diagonally from above. FIG. 3 is a perspective view showing the appearance of the arm when viewed diagonally from below. FIG. 4 is an exploded perspective view showing how the arm is fastened to the housing. FIG. 5 is a bottom view showing the overall configuration of the arm.

[First embodiment]
FIG. 1 is a schematic diagram showing the appearance of a drone according to an embodiment of the present invention. The drone 100 includes a housing 110, a rotor unit 120, and a plurality of (four in this embodiment) arms 130.

The housing 110 has a box-shaped lower body 112 with an open top surface and a box-shaped upper body 114 with an open bottom surface. The lower body 112 and the upper body 114 are arranged with their opening surfaces facing each other, and are fastened to each other by a plurality of fastening screws 116. A battery (not shown) is arranged in the space inside the casing 110 (the space between the lower body 112 and the upper body 114) formed by the above-described fastening. The casing 110 is a monocoque structure that maintains strength through its walls, thereby reducing unnecessary parts and reducing weight.

In this embodiment, the housing 110 is a hollow box-shaped member that has a substantially square plan view with four curved sides that bulge outward. Attachment portions 118 for attaching the arm 130 are arranged at the four ends of the substantially square shape. The attachment portion 118 is a box-shaped portion that protrudes in the direction in which the arm 130 extends, and an introduction port 1182 for guiding the wiring 410 from the battery to the arm is formed on the outside thereof. The arm 130 is attached to the attachment part 118 via a hinge 420, and can be folded down below the housing 110 by bending the hinge 420.

The rotor unit 120 is arranged at the tip of each of the four arms 130. Each rotor unit 120 includes a plurality of rotors 122 (two in this embodiment) and a motor 124 for rotating the rotors 122. The motor 124 is arranged at the tip of the arm 130. Further, wiring 410 from a battery arranged in the housing 110 is connected to the motor 124. Motor 124 rotates rotor 122 using electric power supplied via wiring 410.

The arm 130 is a rod-shaped member that extends linearly outward from the housing 110. Arm 130 holds rotor unit 120 at its tip. The arms 130 create a predetermined distance between the rotor 122 and the housing 110 and between the rotors 122 disposed on each arm 130. Thereby, the arm 130 prevents the rotating rotor 122 from colliding with the housing 110 and the rotating rotors 122 from colliding with each other. Note that the arm 130 may have a bent or bent shape in the middle. Further, in the present embodiment, the arm 130 extends in a direction outward from the center of gravity of the housing 110, but may extend in a direction having a predetermined angle with respect to the above-mentioned outward direction.

FIG. 2 is a perspective view showing the appearance of the arm 130 when viewed diagonally from above. FIG. 3 is a perspective view showing the appearance of the arm 130 when viewed diagonally from below. As shown in FIGS. 2 and 3, the arm 130 includes a main body 210 attached to the outside of the housing 110 and a flange 220 disposed outside the main body 210. The main body portion 210 has a semi-cylindrical shape with an open bottom surface. A flange 220 extending toward the side surface of the main body section 210 is disposed at the lower end of the side surface of the semi-cylindrical main body section 210 along the extending direction of the main body section 210.

As shown in FIGS. 2 and 3, the main body part 210 includes a root part 212 for attaching the arm 130 to the housing 110, an extension part 214 extending outside the root part, and a connection to the tip of the extension part 214. The rotor unit 120 has a distal end portion 216 in which the rotor unit 120 is disposed.

The base portion 212 is a portion for attaching the arm 130 to the housing 110. In this embodiment, the base portion 212 is fastened to the hinge 420 by inserting a fastening screw 222b into a fastening hole 222a formed in the flange 222, and is attached to the housing 110 via the hinge. Note that a root wall 211 is formed on the side of the root portion 212 that is in contact with the housing 110. An opening 211a is formed in the root wall 211 for introducing the wiring from the mounting portion 118 into the outer shell of the root portion 212.

The extending portion 214 is a connecting portion that linearly connects the root portion 212 and the tip portion 216, and has a shape in which the width becomes narrower toward the tip portion 216. Further, the extending portion 214 has a shape in which the height relative to the reference casing 110 increases from the base portion 212 toward the tip portion 216. Note that the extending portion 214 may have a bent or bent shape in the middle.

The tip portion 216 includes a holding portion 2161 having a circular plan view for holding the rotor unit 120 and a connecting portion 2162 for connecting to the extension portion 214. The tip portion 216 has a shape such that the circular surface of the holding portion 2161 is horizontal to the housing 110 and the hinge 420. A plurality of (four in this embodiment) fastening holes 2161a for fastening the rotor unit 120 are formed in the holding portion 2161. Furthermore, an opening 216a is formed in the connecting portion 2162 for taking out the wiring 410 from the inside of the arm 130 to the outside.

In this embodiment, flanges 220 are located at each of the root portion 212, the extension portion 214, and the tip portion 216.

In this embodiment, the flange 222 disposed on the base portion 212 extends outward from the main body portion 210 to a greater extent than the flanges 224 and 226 disposed on the extension portion 214 and the tip portion 216, respectively. The flange 222 disposed on the base portion 212 has a fastening hole 222a (shown in FIG. 3) into which a fastening screw 222b (shown in FIG. 2) for attaching the arm 130 to the housing 110 via the hinge 420 is inserted. has. The fastening holes 222a are nut members arranged at two locations on the front and rear of each of the flanges 222 on both sides.

The arm 130 shown in FIGS. 2 and 3 has a main body 210 having a top surface and side surfaces, and a flange 220 extending laterally from a lower end thereof, and has a hat-shaped cross section with an open lower surface. The moment of inertia of the arm 130 is increased by the flange 220 extending laterally with respect to the main body portion 210, thereby increasing the rigidity. However, the shape of the arm 130 is not limited to this shape, and for example, a flange may be arranged on the cylindrical main body.

The overhang length of the flange 220 can be set in consideration of the balance between the effect of improving rigidity and the change in aerodynamic force caused by the flange 220. For example, the overhang length of the flange 224 disposed on the extension portion 214 and the flange 226 disposed on the distal end portion 216 is the width of the main body portion 210 at each location (the width in the direction connecting the side surfaces of the main body portion 210). It can be set to 0% or more and 10% or less, preferably greater than 0% and 10% or less, and more preferably 2% or more and 6% or less. Further, the overhang length of the flange 222 disposed on the root portion 212 can be 8% or more and 20% or less of the width of the root portion 212 (the width in the direction connecting the side surfaces of the root portion 212). , preferably 10% or more and 15% or less.

FIG. 4 is an exploded perspective view showing how the arm 130 is fastened to the housing 110. The mounting portion 118 of the housing 110 has a fastening hole 118a on the lower surface side into which a fastening screw 118b is inserted. The fastening holes 118a are through holes formed on the other side of the attachment portion 118 at two locations, front and rear, at positions corresponding to the flanges 222 of the arm 130, respectively.

The arm 130 is attached to the attachment portion 118 via a pair of hinges 420, both of which are bendable. Specifically, one end of each hinge 420 is attached to the mounting portion 118 using the fastening screw 118b, and the other end of each hinge 420 is attached to the flange 222 using the fastening screw 222b. Thereby, the arm 130 can be folded downward with respect to the housing 110 when the drone 100 is stored.

Note that, on the upper surface side of the attachment portion 118, a ring-shaped protrusion portion 118c is formed to protrude toward the arm 130 side. A nut portion 212c is formed on the upper surface of the root portion 212 at a position corresponding to the protruding portion 118c. When extending the arm 130 (when flying the drone 100), the bending of the arm 130 can be restricted by inserting the mounting screw 118d into the protruding portion 118c and the nut portion 212c.

In conventional drones, a cylindrical arm holder is attached to cover the end of the cylindrical arm on the housing side, and this arm holder is attached to a hinge to attach the arm to the housing. In this installation method, in order to insert the screw for attaching the arm holder, it is necessary to form a cylindrical arm and then drill a hole for insertion in a part of the cylindrical arm body in post-processing. be. This drilling may reduce the strength of the end of the arm on the casing side. In order to suppress the decrease in strength due to drilling, it was necessary to attach mounting parts such as arm holders to the arm with adhesive, but there is a limit to the adhesive strength of adhesive, and it is not possible to increase the size of drones. There have been problems in that it has not been possible to deal with this problem or to improve durability.

In contrast, in this embodiment, a fastening hole 222a is formed in the flange 222, and the arm 130 is attached to the housing 110 through the fastening hole 222a. Therefore, there is no need to make holes in the main body portion 210, and the strength of the arm 130 does not decrease due to the holes. Further, since the arm 130 can be attached to the housing 110 by fastening using the fastening screw 222b, the fastening strength can be increased, and the durability of the fastening portion can also be increased.

FIG. 5 is a bottom view showing the overall configuration of the arm 130. As shown in FIGS. 3 and 5, the arm 130 has an open surface (a lower surface) inside an outer shell 310 that constitutes the upper surface and side surfaces of the main body portion 210 (root portion 212, extension portion 214, and tip portion 216). ) side (ribs 322, ribs 324, and ribs 326). In this embodiment, the ribs 320 are reinforcing ribs provided to increase the rigidity of the main body portion 210 (particularly the rigidity against stress in the torsional direction). The shape of the rib 320 is not particularly limited. In this embodiment, the rib 320 has a shape in which two plate-shaped ribs 320a and 320b are arranged to intersect with each other. Each plate-like rib is arranged diagonally with respect to the extending direction of the arm 130 so as to linearly connect an outer shell 310 forming one side surface and an outer shell 310 forming the other side surface. , intersect at the central axis of arm 130.

In the extending portion 214 , the angles formed by the plate-like ribs 320 a and 320 b with respect to the extending direction of the arm 130 change along the extending direction of the extending portion 214 . Specifically, on the side of the base portion 212 where the width of the extending portion 214 is wider, the angle that the plate-shaped ribs make with respect to the extending direction of the arm 130 (among the angles made by these, the angle that is an acute angle) is made larger. ing. On the other hand, on the side of the distal end 216 where the width of the extending portion 214 is narrower, the angle that the plate-like ribs make with respect to the extending direction of the arm 130 (among the angles made by these, the angle that is an acute angle) is made smaller. . In this way, the arm 130 has the ribs 320 densely arranged on the base portion 212 side where higher rigidity is required, while the ribs 320 are densely arranged on the tip portion 216 side to reduce the weight of the main body portion 210. ing.

The height of each plate-shaped rib (the length from the contact point of the plate-shaped rib with the outer shell 310 forming the top surface to the lower end of the plate-shaped rib) is not particularly limited, but the outer shell 310 forming the side surface (the length on a straight line along the plate-like rib from the point of contact between the outer shell 310 forming the top surface and the plate-like rib to the lower end of the outer shell 310 forming the side surface) is preferred.

As shown in FIGS. 3 and 5, the arm 130 includes a body portion 210 (root portion 212, extension portion 214, and tip portion 216), a flange 220 (flange 222, flange 224, and flange 226), and a rib 320 (rib 322). , ribs 324 and ribs 326) are all integrally molded.

As shown in FIG. 5, in this embodiment, the root portion 212, the extension portion 214, and the tip portion 216 all have flanges 220 (flange 222, flange 224, and flange 226), and all of these have ribs 320 ( ribs 322, 324, and 326). However, depending on the characteristics of these parts, the flange 220 and the rib 320 may be formed only in any part.

For example, the base portion 212 is a portion used for fastening to the housing 110. Further, the base portion 212 is also a portion that requires rigidity to support the weight of the arm 130 and the rotor unit 120. Therefore, it is preferable that the root portion 212 has a flange 222. The flange 222 that the root portion 212 has can be used as a fastening portion and can also increase the rigidity of the root portion 212. Further, by using the flange 222 as a fastening portion, it is not necessary to drill holes in the main body portion 210, and a decrease in the rigidity of the main body portion 210 due to drilling can also be suppressed. On the other hand, if the stiffness is sufficiently increased by the flange 222, the root portion 212 may not have the rib 322 in order to reduce the weight of the arm 130.

Furthermore, the extending portion 214 is a portion that is required to be resistant to stress in the torsional direction that occurs when the drone 100 is flying. Therefore, it is preferable that the extending portion 214 has ribs 324. The ribs 324 of the extending portion 214 can increase the rigidity of the extending portion 214 and suppress destruction due to stress in the torsional direction. On the other hand, depending on the aerodynamic characteristics, the extending portion 214 may have the flange 224 or may not have the flange 224.

Further, the tip portion 216 is a portion that holds the rotor unit 120. The tip portion 216 may have the flange 226 and the rib 326, or may not have the flange 226 and the rib 326, as long as the strength for holding the rotor unit 120 is obtained.

Note that the presence or absence of the flange 220 and rib 320 described above is merely an example, and the arrangement of the flange 220 and rib 320 can be changed depending on the characteristics (for example, rigidity and aerodynamic characteristics) required for each part of the arm 130. Needless to say. For example, the proximal portion 212 may not be provided with the flange 222, but the extension portion 214 or the tip portion 216 may be provided with the flange 224 or the flange 226. Further, the rib 324 may not be provided on the extending portion 214, but the rib 322 or the rib 326 may be provided on the root portion 212 or the tip portion 216.

In the arm 130 of this embodiment having such a configuration, the main body portion 210 has a semi-cylindrical shape with an open bottom surface. Furthermore, portions having different heights are formed in part of the rib 320 to serve as a holding portion for the wiring. The arm 130, which has a rod-like shape with at least one open surface along the longitudinal direction, is formed by molding the arm 130 and then molding the arm 130 from the open side (lower side in this embodiment). The wiring 410 can be easily arranged. This also makes it possible to easily connect the wiring between the battery in the casing 110 and the motor 124 disposed at the tip 216.

In the arm 130, the main body portion 210 (root portion 212, extension portion 214, and tip portion 216), the flange 220 (flange 222, flange 224, and flange 226), and the rib 320 are all made of fibers containing thermoplastic resin and reinforcing fibers. It is integrally molded from reinforced resin. By using fiber-reinforced resin as the material, the arm 130 can be made lighter while increasing its rigidity. By making the arm 130 made of thermoplastic resin, the arm 130 can be manufactured by a method such as press molding or injection molding, and manufacturing efficiency is greatly improved. Note that the thermoplastic resin may be derived from fossil fuels, may be derived from biomass raw materials, or may be a mixture thereof.

Examples of the thermoplastic resins include polyolefin resins including polyethylene, polypropylene, polybutene, and poly4-methyl-1-pentene, polyamide resins, polyester resins, polystyrene resins, thermoplastic polyimide resins, polyamide-imide resins, and polycarbonate resins. , polyphenylene ether resin, polyphenylene sulfide resin, polyacetal resin, acrylic resin, polyetherimide resin, polysulfone resin, polyether ketone resin, polyether ether ketone resin, polyarylate resin, polyether nitrile resin, vinyl chloride resin, ABS This includes resins and fluororesins.

Among these, polyamide resins and polyolefin resins are preferred because they are less likely to be damaged even if a flying object such as a pebble collides with them, and the reliability of the arm 130 can be increased. Moreover, from the viewpoint of suppressing deterioration of mechanical properties when the arm 130 absorbs water, polyolefin resin is more preferable, and polypropylene resin is even more preferable.

The thermoplastic resin may be a resin composition containing additives. Examples of additives include known fillers (inorganic fillers, organic fillers), pigments, dyes, weather-resistant stabilizers, heat-resistant stabilizers, antistatic agents, anti-slip agents, antioxidants, anti-mold agents, These include antibacterial agents, flame retardants, and softeners.

Examples of the reinforcing fibers include carbon fibers, glass fibers, aramid fibers, alumina fibers, silicon carbide fibers, boron fibers, and metal fibers. Among these, carbon fibers and aramid fibers are preferable, and carbon fibers are more preferable, from the viewpoint of having low density, reducing the weight of the arm 130, and further increasing its specific rigidity.

From the viewpoint of increasing the rigidity of the arm 130, the fiber-reinforced resin is formed from a unidirectional sheet (UD sheet) in which reinforcing fibers (preferably carbon fibers) oriented in one direction are impregnated with a thermoplastic resin. It is preferred to have a unidirectional layer. The arm 130 may be a laminate having a plurality of unidirectional layers in which reinforcing fibers are oriented in different directions. In addition, the arm 130 has a plurality of regions in which reinforcing fibers are oriented in one direction, which are obtained from a random sheet obtained by randomly laying and molding UD sheets cut into chips, and each region has a plurality of regions. It may be a laminate having random layers in which reinforcing fibers are oriented differently. The arm 130 is preferably a laminate having two types of unidirectional layers: an oriented layer in which all of the reinforcing fibers in the layer are oriented in one direction, and a random layer.

The arm 130 can be manufactured by arranging a UD sheet or random sheet, which has been previously shaped into the shape of the arm 130, in a mold and hot pressing the sheet. According to the findings of the present inventors, by placing a random sheet on the opposite side of the ribs and hot pressing, the reinforcing fibers of the random sheet can be penetrated into the ribs, and the ribs 320 can also be formed into an integral mold that includes reinforcing fibers. It is also possible to manufacture bodies.

[Other embodiments]
The embodiments described above are merely exemplary embodiments of the present invention, and the present invention may be modified in various ways within the scope of the technical idea disclosed in this specification. Needless to say.

Further, in the above embodiment, the arm has an open bottom surface, but a cover for protecting the wiring may be placed on the open surface of the main body. The cover may have a flat plate shape or a semi-cylindrical shape that bulges downward. The cover may be attached by forming an opening in the flange and inserting a fastening screw into the opening, or by using an adhesive.

Further, in the above embodiment, the main body part is semi-cylindrical with a curved surface, but it may be any rod shape such as a triangular prism, a quadrangular prism, a hexagonal prism, a cylinder, an elliptical cylinder, etc. In any of these shapes, at least one of the surfaces along the longitudinal direction may be open. On the other hand, the main body portion does not have to have an open surface along the longitudinal direction.

Further, in the above embodiment, an arm that holds a rotor unit at its tip has been described, but the arm may hold another member other than the rotor unit at its tip. For example, the arm may hold a robot arm, a camera, a light emitting member (such as an LED), etc. at its tip.

The drone arm according to the present invention has high rigidity. Therefore, it is easy to increase the size of the drone and improve its durability. Furthermore, since the drone arm according to the present invention is made of thermoplastic resin, it is easy to mass-produce.

100 Drone 110 Housing 112 Lower body 114 Upper body 116 Fastening screw 118 Mounting part 118a Fastening hole 118b Fastening screw 118c Projection part 118d Mounting screw 1182 Inlet 120 Rotor unit 122 Rotor 124 Motor 130 Arm 210 Main body part 211 Root wall 211a Opening 212 Root part 212c Nut part 214 Extension part 216 Tip part 216a Opening 2161 Holding part 2161a Fastening hole 2161b Arrangement surface 2162 Connection part 220, 222, 224, 226 Flange 222a Fastening hole 222b Fastening screw 310 Outer shell 320, 322, 324, 326 Rib 320a, 320b plate-shaped rib 410 wiring 420 hinge

Claims (11)

An arm that is attached to the housing of a drone,
a main body disposed outside the casing;
a flange disposed on the outer side of the main body;
Arm for drone. The arm has a fastening hole for fastening the arm to the housing,
the fastening hole is arranged in the flange,
The arm for a drone according to claim 1. The main body portion has a root portion fastened to the casing, and an extension portion extending outside the root portion,
the flange is located at the root portion;
The arm for a drone according to claim 1. the flange is disposed at the root portion and the extension portion;
The overhanging width of the flange at the base portion is larger than the overhanging width of the flange at the extending portion.
The arm for a drone according to claim 3. The main body portion has a distal end portion disposed at the distal end of the extension portion to which another member is attached,
the tip portion has the flange;
The arm for a drone according to claim 4. The flange is integrally molded with the main body.
The arm for a drone according to claim 1. A reinforcing rib is provided inside the main body.
The arm for a drone according to claim 1. The reinforcing rib is integrally molded with the main body.
The arm for a drone according to claim 7. The main body has a rod-like shape with at least one open surface along the longitudinal direction.
The arm for a drone according to claim 1. A drone arm according to any one of claims 1 to 9,
A casing to which the drone arm is fastened. The drone arm is fastened to the housing via a hinge,
foldable by bending the hinge;
The drone according to claim 10.

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