Drone arm and drone

Abstract

Provided is a drone arm with increased rigidity. The arm, which is attached to a housing of a drone, comprises: a body part to be disposed outside the housing; and a flange disposed on the outside laterally of the body part. The body part and the flange are made of a fiber-reinforced resin including reinforcing fibers and a thermoplastic resin.

Description

Drone arms and drones

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

[0002] A known drone includes a housing in which a battery and other components are disposed, multiple rotors for flying the drone, and an arm for holding the rotors at a position outside the housing and away from the housing. Patent Document 1 describes an example of a drone arm that uses a laminated structure formed by stacking multiple fiber-reinforced resin sheets with woven fibers as the material, and molds the laminated structure into a cylindrical shape. Patent Document 1 also describes that the arm molded from the laminated structure is lightweight and highly rigid.

[0003] JP 2018-118530 A

[0004] As described in Patent Document 1, by using a fiber-reinforced resin as a material, it is possible to reduce the weight of the arm while increasing its rigidity. However, with the recent diversification of drone applications, drones are being required to have higher strength than before. Therefore, there is a demand for each component that constitutes a drone, such as the arm, to have higher rigidity than before.

[0005] The present invention has been made in consideration of the above-mentioned demands, and its object is to provide a drone arm with increased rigidity, and a drone having such a drone arm.

[0006] One aspect of the present invention for solving the above problems relates to drone arms as set forth in the following [1] to [9]. [1] A drone arm attached to a drone housing, the drone arm having a main body portion disposed on the outside of the housing and a flange disposed laterally and externally of the main body portion, the main body portion and the flange being made of a fiber-reinforced resin containing reinforcing fibers and a thermoplastic resin. [2] The drone arm described in [1], the arm having fastening holes for fastening the arm to the housing, the fastening holes being disposed in the flange. [3] The drone arm described in [1] or [2], the main body portion having a root portion fastened to the housing and an extension portion extending outward from the root portion, the flange being disposed in the root portion. [4] The drone arm described in [3], the flange being disposed in the root portion and the extension portion, the overhang width of the flange at the root portion being greater than the overhang width of the flange at the extension portion. [5] The drone arm according to [4], wherein the main body has a tip portion disposed at the tip of the extension portion and to which a separate member is attached, and the tip portion has the flange. [6] The drone arm according to any one of [1] to [5], wherein the flange is integrally molded with the main body. [7] The drone arm according to any one of [1] to [6], wherein a reinforcing rib is provided on the inside of the main body. [8] The drone arm according to any one of [1] to [7], wherein the main body has a rod-like shape with at least one longitudinal surface open. [9] The drone arm according to any one of [1] to [8], wherein the main body and the flange include a unidirectional layer containing carbon fibers oriented in one direction and a thermoplastic resin.

[0007] Another aspect of the present invention for solving the above problems relates to the drones of

[10] to

[11] below.

[10] A drone comprising: the drone arm according to any one of [1] to [9]; and a housing to which the drone arm is fastened.

[11] The drone according to

[10] , wherein the drone arm is fastened to the housing via a hinge and is foldable by bending the hinge.

[0008] According to the present invention, there is provided a drone arm with increased rigidity, and a drone having the drone arm.

[0009] 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 from diagonally above. FIG. 3 is a perspective view showing the appearance of the arm when viewed from diagonally below. FIG. 4 is an exploded perspective view showing how the arm is fastened to a housing. FIG. 5 is a bottom view showing the overall configuration of the arm. FIG. 6 is a perspective view similar to FIG. 3 showing the appearance of the arm when viewed from diagonally below, illustrating the arrangement of ribs. FIG. 7 is a partially enlarged view of one of the portions indicated by dotted lines in FIG. 6. FIG. 8 is a bottom view showing how the holding portion holds the wiring. FIG. 9 is a perspective view showing an exemplary configuration of the extension portion, illustrating the appearance of the periphery of an opening when viewed from diagonally below. FIG. 10 is a bottom view showing the appearance of the periphery of the opening when viewed from below, illustrating how the wiring is being extracted from the opening. FIG. 11 is a side view of the arm, illustrating how the wiring extracted from the opening is connected to a motor. FIG. 12 is a perspective view showing the appearance of the periphery of the opening when viewed from diagonally below, illustrating another exemplary configuration of the extension portion. FIG. 13 is a side view showing the overall configuration of the arm.

[0010] 1 is a schematic diagram showing the appearance of a drone according to an embodiment of the present invention. The drone 100 has a housing 110, a rotor unit 120, and a plurality of arms 130 (four arms in this embodiment).

[0011] The housing 110 has a box-shaped lower body 112 that is open at the top and a box-shaped upper body 114 that is open at the bottom. The lower body 112 and the upper body 114 are arranged with their respective openings facing each other and are fastened to each other with a plurality of fastening screws 116. A battery (not shown) is placed in the space inside the housing 110 (the space between the lower body 112 and the upper body 114) formed by the above fastening. The housing 110 is a monocoque structure whose strength is maintained by its walls, which reduces unnecessary parts and reduces weight.

[0012] In this embodiment, the housing 110 is a hollow box-like member having a substantially square shape in plan view with four curved sides that bulge outward. Mounting portions 118 for attaching the arm 130 are disposed at the four ends of the substantially square shape. The mounting portion 118 is a box-shaped portion that protrudes in the direction in which the arm 130 extends, and an inlet 1182 is formed on the outside of the mounting portion 118 for guiding the wiring 410 from the battery to the arm. The arm 130 is attached to the mounting portion 118 via a hinge 420, and can be folded downward from the housing 110 by bending the hinge 420.

[0013] A rotor unit 120 is disposed at the tip of each of the four arms 130. Each rotor unit 120 has a plurality of rotors 122 (two in this embodiment) and a motor 124 for rotating the rotors 122. The motor 124 is disposed at the tip of the arm 130. A wiring 410 extending from a battery disposed in the housing 110 is connected to the motor 124. The motor 124 rotates the rotor 122 using power supplied via the wiring 410.

[0014] The arm 130 is a rod-shaped member that extends linearly outward from the housing 110. The arm 130 holds the rotor unit 120 at its tip. The arm 130 creates a predetermined distance between the rotor 122 and the housing 110, and between the rotors 122 arranged on each arm 130. This prevents the rotating rotor 122 from colliding with the housing 110 and the rotating rotors 122 from colliding with each other. The arm 130 may have a bent or curved shape. In this embodiment, the arm 130 extends outward from the center of gravity of the housing 110, but it may also extend in a direction at a predetermined angle relative to the outward direction.

[0015] Fig. 2 is a perspective view showing the appearance of arm 130 when viewed from diagonally above. Fig. 3 is a perspective view showing the appearance of arm 130 when viewed from diagonally below. As shown in Figs. 2 and 3 , arm 130 has a main body 210 attached to the outside of housing 110 and a flange 220 arranged on the outside of main body 210. Main body 210 has a semi-cylindrical shape with an open bottom. A flange 220 is arranged at the lower end of the side surface of semi-cylindrical main body 210, extending in the direction of extension of main body 210, toward the side surface of main body 210.

[0016] As shown in Figures 2 and 3, the main body 210 has a base portion 212 for attaching the arm 130 to the housing 110, an extension portion 214 extending outside the base portion, and a tip portion 216 connected to the tip of the extension portion 214 and on which the rotor unit 120 is disposed.

[0017] 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. A base wall 211 is formed on the side of the base portion 212 that contacts the housing 110. An opening 211a is formed in the base wall 211 to introduce wiring from the attachment portion 118 into the inside of the outer shell of the base portion 212.

[0018] The extension portion 214 is a connecting portion that linearly connects the base portion 212 and the tip portion 216, and has a shape that narrows in width toward the tip portion 216. The extension portion 214 also has a shape that increases in height relative to the reference housing 110 from the base portion 212 toward the tip portion 216. The extension portion 214 may have a shape that is bent or flexed midway.

[0019] The tip portion 216 has a holding portion 2161 having a circular shape in a plan view for holding the rotor unit 120, and a connection 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 with respect to the housing 110 and the hinge 420. The holding portion 2161 has a plurality of (four in this embodiment) fastening holes 2161a formed therein for fastening the rotor unit 120. In addition, the connection portion 2162 has an opening 216a formed therein for leading out the wiring 410 from the inside to the outside of the arm 130.

[0020] In this embodiment, a flange 220 is disposed on each of the root portion 212, the extension portion 214, and the tip portion 216.

[0021] In this embodiment, the flange 222 disposed at the base portion 212 has a larger protrusion width toward the outside of the main body portion 210 than the flanges 224 and 226 disposed at the extension portion 214 and the tip portion 216, respectively. The flange 222 disposed at the base portion 212 has fastening holes 222a (shown in FIG. 3) into which fastening screws 222b (shown in FIG. 2) are inserted for attaching the arm 130 to the housing 110 via the hinge 420. The fastening holes 222a are nut members disposed at two locations, one at the front and one at the back of each of the flanges 222 on both sides.

[0022] 2 and 3 has a main body 210 with a top surface and side surfaces, and a flange 220 extending laterally from the lower end thereof, and has a hat-shaped cross section with an open bottom. The flange 220 extending laterally from the main body 210 increases the moment of inertia of the arm 130, thereby increasing its rigidity. However, the shape of the arm 130 is not limited to this, and for example, a flange may be disposed on a cylindrical main body.

[0023] The overhang length of the flange 220 can be set by taking into consideration 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 at the extension portion 214 and the flange 226 disposed at the tip portion 216 can be set to 0% to 10% of 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), preferably greater than 0% to 10%, and more preferably 2% to 6%. Furthermore, the overhang length of the flange 222 disposed at the root portion 212 can be set to 8% to 20% of the width of the root portion 212 (the width in the direction connecting the side surfaces of the root portion 212), preferably 10% to 15%.

[0024] 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 fastening holes 118a on the underside into which fastening screws 118b are inserted. The fastening holes 118a are through-holes formed on the other surface of the mounting portion 118 at two locations, one at the front and one at the back, at positions corresponding to the flanges 222 of the arm 130, respectively.

[0025] The arm 130 is attached to the mounting portion 118 via a pair of foldable hinges 420. Specifically, one end of each hinge 420 is attached to the mounting portion 118 by a fastening screw 118b, and the other end of each hinge 420 is attached to the flange 222 by a fastening screw 222b. This allows the arm 130 to be folded downward relative to the housing 110 when storing the drone 100, for example.

[0026] A ring-shaped protrusion 118c is formed on the upper surface of the mounting portion 118 so as to protrude toward the arm 130. A nut portion 212c is formed on the upper surface of the base portion 212 at a position corresponding to the protrusion 118c. When the arm 130 is extended (when the drone 100 is flown), a mounting screw 118d can be inserted into the protrusion 118c and the nut portion 212c to restrict bending of the arm 130.

[0027] Conventional drones attach the arm to the housing by attaching a cylindrical arm holder to the housing end of the cylindrical arm, which is then attached to a hinge. This attachment method requires post-processing of holes in the cylindrical arm body after molding the cylindrical arm to insert screws for attaching the arm holder. This drilling can reduce the strength of the housing end of the arm. To prevent this reduction in strength due to drilling, it was necessary to adhesively attach the arm holder and other attachment components to the arm. However, adhesives have limitations in their adhesive strength, making it difficult to accommodate larger drones and to improve durability.

[0028] In contrast, in this embodiment, fastening holes 222a are formed in the flange 222, and the arm 130 is attached to the housing 110 through these fastening holes 222a. Therefore, there is no need to drill holes in the main body 210, and drilling holes does not reduce the strength of the arm 130. Furthermore, because the arm 130 can be attached to the housing 110 by fastening using the fastening screws 222b, the fastening strength can be increased and the durability of the fastening portion can also be increased.

[0029] 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 ribs 320 (ribs 322, 324, and 326) extending toward the open surface (bottom surface) inside an outer shell 310 that forms the upper and side surfaces of the main body 210 (root portion 212, extension portion 214, and tip portion 216). In this embodiment, the ribs 320 are reinforcing ribs provided to increase the rigidity of the main body 210 (particularly rigidity against stress in the torsional direction). The shape of the ribs 320 is not particularly limited. In this embodiment, the rib 320 has a shape in which two plate-like ribs 320a and 320b are arranged intersecting each other. Each plate-like rib is arranged obliquely with respect to the extension direction of the arm 130 so as to linearly connect the outer shell 310 that forms one side surface with the outer shell 310 that forms the other side surface, and intersects at the central axis of the arm 130.

[0030] In the extension portion 214, the angles that each plate-like rib 320a and each plate-like rib 320b forms with respect to the extension direction of the arm 130 change along the extension direction of the extension portion 214. Specifically, the angles that the plate-like ribs form with respect to the extension direction of the arm 130 (the more acute angles among the angles they form) are larger on the root portion 212 side where the extension portion 214 is wider. On the other hand, the angles that the plate-like ribs form with respect to the extension direction of the arm 130 (the more acute angles among the angles they form) are smaller on the tip portion 216 side where the extension portion 214 is narrower. In this way, the arm 130 has the ribs 320 densely arranged on the root portion 212 side where higher rigidity is required, and the ribs 320 densely arranged on the tip portion 216 side, thereby reducing the weight of the main body portion 210.

[0031] The height of each plate-like rib (the length from the point of contact between the outer shell 310 that forms the top surface and the plate-like rib to the lower end of the plate-like rib) is not particularly limited, but it is preferable that it be smaller than the height of the outer shell 310 that forms the side surface (the length in a straight line along the plate-like rib from the point of contact between the outer shell 310 that forms the top surface and the plate-like rib to the lower end of the outer shell 310 that forms the side surface).

[0032] As shown in Figures 3 and 5, arm 130 has a main body portion 210 (root portion 212, extension portion 214, and tip portion 216), flange 220 (flanges 222, 224, and 226), and rib 320 (ribs 322, 324, and 326) all molded integrally.

[0033] 5, in this embodiment, the root portion 212, the extension portion 214, and the tip portion 216 all have flanges 220 (flanges 222, 224, and 226), and all of these have ribs 320 (ribs 322, 324, and 326). However, depending on the characteristics of these portions, the flanges 220 and the ribs 320 may be formed only on some of the portions.

[0034] For example, the root portion 212 is a portion used for fastening to the housing 110. The root portion 212 is also a portion that requires rigidity to support the weight of the arm 130 and the rotor unit 120. Therefore, the root portion 212 preferably has a flange 222. The flange 222 of the root portion 212 can be used as a fastening portion and can also increase the rigidity of the root portion 212. Furthermore, using the flange 222 as a fastening portion eliminates the need to drill holes in the main body portion 210, and can also suppress a decrease in the rigidity of the main body portion 210 that would otherwise be caused by drilling holes. On the other hand, if the rigidity can be sufficiently increased by the flange 222, the root portion 212 does not need to have a rib 322 in order to reduce the weight of the arm 130.

[0035] Furthermore, the extension portion 214 is a portion that is required to be resistant to torsional stress that occurs when the drone 100 flies. Therefore, the extension portion 214 preferably has a rib 324. The rib 324 of the extension portion 214 can increase the rigidity of the extension portion 214 and suppress breakage due to torsional stress. On the other hand, the extension portion 214 may or may not have a flange 224 depending on the aerodynamic characteristics.

[0036] Furthermore, the tip portion 216 is a portion that holds the rotor unit 120. The tip portion 216 may or may not have a flange 226 and a rib 326, as long as the tip portion 216 has the strength to hold the rotor unit 120.

[0037] It should be noted that the presence or absence of flanges 220 and ribs 320 described above is merely an example, and it goes without saying that the arrangement of flanges 220 and ribs 320 can be changed depending on the characteristics (for example, rigidity and aerodynamic characteristics) required for each portion of arm 130. For example, flange 222 may not be provided on root portion 212, and flange 224 or flange 226 may be provided on extension portion 214 or tip portion 216. Furthermore, rib 324 may not be provided on extension portion 214, and rib 322 or rib 326 may be provided on root portion 212 or tip portion 216.

[0038] FIG. 6 is a perspective view similar to FIG. 3 , illustrating the arrangement of ribs and showing the appearance of the arm 130 as viewed from diagonally below. FIG. 7 is a partial enlarged view of one of the portions indicated by dotted lines in FIG. 6 . As shown in FIGS. 6 and 7 , in this embodiment, the height of each plate-like rib is not uniform. In other words, each plate-like rib has multiple heights. Specifically, the height of each plate-like rib at its intersection is lower than the height at its contact point with the outer shell 310, which forms the side surface. The low-height portions 328 a of the rib formed at the intersections are formed linearly and continuously along the central axis of the arm 130 inside the outer shell 310 at the root portion 212, the extension portion 214, and the tip portion 216. In this embodiment, these low-height portions 328 a of the rib serve as holding portions for holding wiring.

[0039] 8 is a bottom view showing how the holding portion holds the wiring. Note that FIG. 8 also shows the motor 124.

[0040] The wiring 410 introduced into the inside of the root portion 212 from the opening 211a of the root wall 211 is held in a low portion 328a formed at the intersection of two plate-like ribs in the root portion 212. In this embodiment, the height of the opening 211a is the same as the height of the low portion 328a. Furthermore, the opening 211a is disposed on the central axis of the arm 130 when the arm 130 is viewed from above. Therefore, the wiring 410 introduced into the inside of the root portion 212 is held in the low portion 328a as it is (remains straight) without being bent.

[0041] The wiring 410 held in the low portion 328a is held, without bending (still straight), in the low portion 328a formed at the intersection of the two plate-like ribs in the extension portion 214. The wiring 410 is further held, still straight, in succession in the plurality of low portions 328a formed in succession to the extension portion 214.

[0042] The width of the lower portions of root portion 212 and extension portion 214 (the width in the direction connecting the side surfaces of the outer shells) is constant and matches the width of wiring 410. Therefore, wiring 410 is held by the holding portion (lower portion 328a of rib) with its top surface in contact with the lower portion of the rib and its side surfaces in contact with higher portions 328b on both sides of the lower portion.

[0043] At the connection portion 2162 of the tip portion 216, an opening 216a for taking out the wiring 410 to the outside is formed in the outer shell 310. The wiring 410 is bent at the opening 216a and taken out to the outside of the outer shell 310.

[0044] In the arm 130 of this embodiment having such a configuration, the wiring 410 is fixed to the inside, so when an impact is applied to the drone 100, the wiring 410 is less likely to be displaced or pulled, and the wiring 410 is less likely to be cut as a result of these.

[0045] Furthermore, the arm 130 has a main body 210 that is semi-cylindrical and has an open bottom. Furthermore, portions of the rib 320 are formed with varying heights to serve as wire holders. The arm 130 has a rod-like shape with at least one longitudinal surface open, making it easy to secure the wire 410 (by fitting it into the lower portion 328a) from the open surface (the lower side in this embodiment) after molding the arm 130. This also facilitates the connection of the wire between the battery in the housing 110 and the motor 124 located at the tip 216.

[0046] The configuration of the holding portion is not limited to the above-described embodiment. For example, the lower portion of the rib may be formed along the wiring path of the wiring 410, and may be formed at a position away from the central axis of the arm 130 (for example, along the side surface of the arm 130), or a hole may be drilled in the rib and the wiring 410 may be passed through the hole to hold the wiring.

[0047] Alternatively, a separate holding member for holding the wiring 410 may be disposed inside the arm 130, and the wiring 410 may be held by this holding member. This holding member may be fixed to the outer shell 310, for example, by adhesive or fastening. By using such a holding member, the wiring can be held inside the cylindrical arm. In this case, the holding member may be inserted from the end of the cylindrical arm and fixed in a predetermined position, or an opening may be provided partially on the side of the cylindrical arm and the holding member may be inserted therein.

[0048] In this embodiment, the periphery of opening 216a extends inward of outer shell 310 at the portion where wiring 410 bends to form extension 330. Extension 330 is a cylindrical member formed by a standing wall formed perpendicular to outer shell 310 that forms the top surface.

[0049] Fig. 9 is a perspective view showing an exemplary configuration of the extension portion 330, illustrating the appearance of the periphery of the opening 216a as viewed from diagonally below. Fig. 10 is a bottom view showing the appearance of the periphery of the opening 216a as viewed from below, illustrating how the wiring 410 is taken out from the opening 216a. Fig. 11 is a side view of the arm 130, illustrating how the wiring 410 taken out from the opening 216a is connected to the motor 124.

[0050] 10, wiring 410 extending along the bottom surface of rib 320 inside outer shell 310 is bent along the vertical wall of extension portion 330 on the housing 110 side. The bent wiring 410 then extends upward along the vertical wall and is taken out from opening 216a to the outside of outer shell 310. As shown in FIG. 11, a wiring port for motor 124 is disposed above opening 216a, and the taken-out wiring 410 is connected to motor 124 without being bent.

[0051] The height of the extension portion 330 (the length from the intersection of the outer shell 310 constituting the top surface and the extension portion 330 to the lower end of the extension portion 330) is not particularly limited, but is preferably set to a height corresponding to the height at which the wiring 410 is disposed inside the outer shell 310. In the examples shown in Figures 8 to 10, the height of the extension portion 330 is the same as the height at which the wiring 410 is disposed. This makes it possible to make the angle at which the wiring bends along the extension portion 330 a gentle angle of about 90°, thereby suppressing damage to the wiring due to bending.

[0052] For example, by making the height of opening 211a provided in root wall 211 for receiving wiring 410 the same as the height of extension portion 330 (more specifically, the height at which the wiring is bent in extension portion 330), the height at which wiring 410 is arranged can be made the same as the height of extension portion 330. In addition, in this embodiment, rib 320 has lowered portion 322a formed at the intersection of plate-like rib 320a and plate-like rib 320b, and wiring 410 is fitted into this lowered portion 328a to hold wiring 410 (see FIGS. 6 to 8 ). The height at which the wiring 410 is disposed and the height of the extension portion 330 may be made the same by setting the height at which the holding portion that holds the wiring 410 holds the wiring (the length from the intersection of the outer shell 310 that forms the top surface and the plate-like rib and the portion where the low-height portion 328a holds the wiring) to the same height as the height of the extension portion 330 (more specifically, the height at which the wiring bends in the extension portion 330). Note that the height of the extension portion 330 does not need to be the same as the height of the opening 211a or the height of the low-height portion 328a. For example, when the height of the opening 211a and the height of the low-height portion 328a are different, the height of the extension portion 330 may be set so that the position at which the wiring bends in the extension portion 330 is on the straight line connecting them.

[0053] The cylindrical extension portion 330 has a constant opening width in the length direction (extension direction of extension portion 214) that matches the width of the wiring 410 in the length direction. The extension portion 330 also has a constant opening width in the lateral direction (direction connecting the lateral sides of the outer shell) that matches the width of the wiring 410 in the lateral direction. This allows the wiring 410 to be held in the extension portion 330 so that it contacts the vertical wall of the extension portion 330 in the length direction and the lateral direction. Therefore, when an impact is applied to the drone 100, the wiring 410 is unlikely to be displaced or pulled, and the wiring 410 is unlikely to be cut as a result of these factors.

[0054] Fig. 12 is a perspective view showing the appearance of the periphery of opening 216a as viewed from diagonally below, illustrating another exemplary configuration of extension portion 330. Extension portion 330 shown in Fig. 12 has cutout portion 332 on the housing 110 side, where the height of a portion of the standing wall is reduced. In the example shown in Fig. 12, wiring 410 bends along the standing wall of cutout portion 332.

[0055] The width of the cutout 332 in the lateral direction (the direction connecting the lateral sides of the outer shell) matches the width of the wiring 410 in the lateral direction. Therefore, the wiring 410 is fitted and held in the cutout 332 so that the top surface of the wiring 410 contacts the vertical wall of the cutout 332 and the side surfaces of the wiring 410 contact the tall vertical walls at both ends of the cutout 332.

[0056] 12, the notch 332 holds the wiring 410. Therefore, when an impact is applied to the drone 100, the wiring 410 is less likely to be displaced or pulled, and the wiring 410 is less likely to be cut due to these factors.

[0057] Furthermore, when the extension portion 330 is positioned in contact with the rib 320, as in the extension portion 330 shown in Figure 12, the reinforcing effect of the rib 320 can be improved by the extension portion 330, and the strength of the extension portion 330 can also be improved by the rib 320.

[0058] 9 to 12, the lower end (the tip of the extending portion 330 in the extending direction) of the standing wall (the standing wall of the extending portion 330 on the housing 110 side in FIGS. 9 to 11, and the notched portion 332 in FIG. 12) that contacts the bending wiring 410 is a curved end. This curved end is rounded with a curvature that corresponds to the curvature of the bending of the wiring 410. By making the end curved in this way, it is possible to suppress wear due to friction of the wiring 410 that contacts the extending portion 330.

[0059] The arm 130 of this embodiment having such a configuration allows the wiring 410 to be taken out perpendicularly to the outer shell 310 via the extension portion 330 and the opening 216a. This makes it easy to connect the taken-out wiring to the motor 124.

[0060] Furthermore, the arm has the wiring 410 held and fixed by the extension 330 (and the notch 332). Therefore, when an impact is applied to the drone 100, the wiring 410 is less likely to be displaced or pulled, and the wiring 410 is less likely to be cut as a result of these.

[0061] FIG. 13 is a side view showing the overall configuration of the arm 130. As shown in FIGS. 2 to 6 and 13 , the extension portion 214 has a shape in which the cross-sectional area decreases from the root portion 212 side to the tip portion 216 side (toward the tip of the arm 130). Specifically, the extension portion 214 has a shape in which the width (the width in the direction connecting the side surfaces of the extension portion 214) decreases from the root portion 212 side to the tip portion 216 side. Furthermore, the extension portion 214 has a shape in which the height (the vertical length between the top and bottom surfaces of the extension portion) decreases from the root portion 212 side to the tip portion 216 side. This allows the weight of the arm 130 to be reduced while also increasing the rigidity of the extension portion 214. The extension portion 214 may have a shape in which either the width or the height decreases from the root portion 212 side to the tip portion 216 side.

[0062] 13, the tip portion 216 is positioned higher than the base portion 212. This allows the arm 130 to more reliably prevent the rotating rotor 122 from colliding with the housing 110, and also allows the arm 130 to be shorter, thereby making the drone 100 lighter.

[0063] 13, the angle of the upper end of the arm 130 is different between the extension portion 214 and the tip portion 216. Specifically, the extension portion 214 has an upwardly tilted upper end to raise the position of the tip portion 216. Meanwhile, the tip portion 216 is positioned so that the placement surface 2161b on which the rotor unit 120 is placed, which is the upper end of the holding portion 2161, is parallel to the housing 110 and the hinge 420. This allows the rotor 122 to rotate horizontally relative to the housing 110, stabilizing the flight of the drone 100.

[0064] The arm 130 has a main body 210 (root portion 212, extension portion 214, and tip portion 216), a flange 220 (flanges 222, 224, and 226), and a rib 320, all of which are integrally molded from a fiber-reinforced resin containing a thermoplastic resin and reinforcing fibers. Using a fiber-reinforced resin as the material increases the rigidity while reducing the weight of the arm 130. Using a thermoplastic resin allows the arm 130 to be manufactured by methods such as press molding or injection molding, significantly improving manufacturing efficiency. The thermoplastic resin may be derived from fossil fuels, biomass materials, or a mixture thereof.

[0065] Examples of the thermoplastic resin include polyolefin resins such as polyethylene, polypropylene, polybutene, and poly4-methyl-1-pentene, polyamide resins, polyester resins, polystyrene resins, thermoplastic polyimide resins, polyamideimide resins, polycarbonate resins, polyphenylene ether resins, polyphenylene sulfide resins, polyacetal resins, acrylic resins, polyetherimide resins, polysulfone resins, polyether ketone resins, polyether ether ketone resins, polyarylate resins, polyether nitrile resins, vinyl chloride resins, ABS resins, and fluororesins.

[0066] Of these, polyamide resin and polyolefin resin are preferred because they are less likely to break when struck by flying objects such as pebbles, and can improve the reliability of the arm 130. Furthermore, from the viewpoint of suppressing a decrease in mechanical properties when the arm 130 absorbs water, polyolefin resin is more preferred, and polypropylene resin is even more preferred.

[0067] The thermoplastic resin may be a resin composition containing additives, such as known fillers (inorganic fillers, organic fillers), pigments, dyes, weathering stabilizers, heat stabilizers, antistatic agents, antislip agents, antioxidants, antifungal agents, antibacterial agents, flame retardants, and softeners.

[0068] Examples of the reinforcing fibers include carbon fiber, glass fiber, aramid fiber, alumina fiber, silicon carbide fiber, boron fiber, metal fiber, etc. Among these, carbon fiber and aramid fiber are preferred, and carbon fiber is more preferred, from the viewpoint of low density, lightening the weight of arm 130, and further increasing its specific rigidity.

[0069] From the viewpoint of increasing the rigidity of the arm 130, the fiber-reinforced resin preferably has a unidirectional layer formed from a unidirectional sheet (UD sheet) made of reinforcing fibers (preferably carbon fibers) oriented in one direction and impregnated with a thermoplastic resin. The arm 130 may be a laminate having multiple unidirectional layers in which the reinforcing fibers are oriented in different directions. Alternatively, the arm 130 may be a laminate having a random layer obtained from a random sheet obtained by randomly laying and molding UD sheets cut into chips, in which multiple regions in which the reinforcing fibers are oriented in one direction are arranged and the orientation of the reinforcing fibers varies among the multiple regions. 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.

[0070] The arm 130 can be manufactured by placing a UD sheet or random sheet pre-shaped to the shape of the arm 130 in a mold and hot pressing it. According to the findings of the present inventors, by placing a random sheet on the opposite side of the rib and hot pressing it, the reinforcing fibers of the random sheet can be made to penetrate the rib, and an integrally molded body in which the rib 320 also contains reinforcing fibers can be manufactured.

[0071] [Other Embodiments] It should be noted that the above-described embodiments are merely exemplary embodiments of the present invention, and it goes without saying that the present invention can take on various modified embodiments within the scope of the technical ideas disclosed in this specification.

[0072] In the above embodiment, the arm has an open bottom, but a cover for protecting the wiring may be placed on the open surface of the main body. The cover may be flat or semi-cylindrical, bulging 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.

[0073] In the above embodiment, the main body is semi-cylindrical with a curved surface, but it may be a rod-like shape of any shape, such as a triangular prism, a square prism, a hexagonal prism, a circular cylinder, or an elliptical cylinder. In any of these shapes, at least one of the longitudinal faces may be open. On the other hand, the main body does not have to have an open longitudinal face.

[0074] It will be obvious to those skilled in the art that this specification also discloses the following drone arms and drones. [1] A drone arm comprising: an arm attached to a drone housing, the arm comprising: a main body portion disposed on the outside of the housing and having a tip end to which a separate component is attached; and a holding portion disposed on the main body portion and holding wiring connecting the housing and the separate component. [2] The drone arm described in [1], wherein the main body portion has an outer shell and a reinforcing rib disposed on the inside of the outer shell, and the holding portion is formed in a portion of the reinforcing rib. [3] The drone arm described in [2], wherein the reinforcing rib has multiple heights and has a series of lower-height portions formed thereon, and the holding portion is formed by arranging the lower-height portions of the reinforcing rib along a wiring path. [4] The drone arm described in [3], wherein the reinforcing rib is formed by a plurality of plate-like ribs arranged at an intersection, and the lower-height portions are formed at the intersections of the plate-like ribs. [5] A drone arm according to any one of [2] to [4], wherein the reinforcing rib is integrally molded with the outer shell. [6] A drone arm according to any one of [1] to [5], wherein the main body is rod-shaped with at least one longitudinal surface open. [7] A drone arm according to any one of [1] to [7], wherein the main body is made of a fiber-reinforced resin containing reinforcing fibers and a thermoplastic resin. [8] A drone arm according to any one of [1] to [7], wherein the main body includes a unidirectional layer containing carbon fibers oriented in one direction and a thermoplastic resin. [9] A drone comprising the drone arm according to any one of [1] to [8], a separate member attached to the tip portion, a housing to which the drone arm is attached, and wiring arranged inside the drone arm and held by the holding portion, connecting the housing and the separate member.

[0075] It will be obvious to those skilled in the art that this specification also discloses the following drone arms and drones. [1] An arm attached to a drone housing and having a separate component attached to its tip, the arm having an outer shell having an opening for extracting wiring to the separate component from inside the arm, and an extension portion extending the periphery of the opening into the outer shell, wherein the wiring arranged inside the outer shell is bent at the extension portion and extracted through the opening. [2] The drone arm described in [1], wherein the extension portion has a height corresponding to the height at which the wiring is arranged inside the outer shell. [3] The drone arm described in [1] or [2], wherein the extension portion has a notch portion for holding the bent wiring. [4] The drone arm described in any of [1] to [3], wherein the extension portion has a curved end portion at the tip in the extension direction that corresponds to the bending of the wiring. [5] The drone arm described in any of [1] to [4], wherein the extension portion is integrally molded with the outer shell. [6] A drone arm according to any one of [1] to [5], having a reinforcing rib on the inside of the outer shell, and the extension portion being arranged in contact with the reinforcing rib. [7] A drone arm according to any one of [1] to [6], wherein the outer shell has a rod-like shape with at least one of its longitudinal surfaces being open. [8] A drone arm according to any one of [1] to [7], wherein the outer shell and the extension portion are made of a fiber-reinforced resin containing reinforcing fibers and a thermoplastic resin. [9] A drone arm according to any one of [1] to [8], wherein the outer shell includes a unidirectional layer containing carbon fibers oriented in one direction and a thermoplastic resin.

[10] A drone comprising the drone arm according to any one of [1] to [9], a separate member attached to the tip of the drone arm, a housing to which the drone arm is attached, and wiring arranged inside the outer shell and extending to the outside through the opening, connecting the housing and the separate member.

[0076] In addition, although the above embodiment has been described with respect to an arm that holds a rotor unit at its tip, the arm may hold a component other than a rotor unit at its tip. For example, the arm may hold a robot arm, a camera, a light-emitting component (such as an LED), or the like at its tip.

[0077] This application claims priority from Japanese Patent Application No. 2023-119340, filed July 21, 2023. The entire disclosures of the specification, claims, and drawings of that application as originally filed are incorporated herein by reference.

[0078] The drone arm according to the present invention has high rigidity, which makes it 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.

[0079] 100 drone 110 housing 112 lower body 114 upper body 116 fastening screw 118 mounting portion 118a fastening hole 118b fastening screw 118c protrusion 118d mounting screw 1182 inlet 120 rotor unit 122 rotor 124 motor 130 arm 210 main body 211 root wall 211a opening 212 root portion 212c nut portion 214 extension portion 216 tip portion 216a opening 2161 holding portion 2161a fastening hole 2161b placement surface 2162 connection portion 220, 222, 224, 226 flange 222a fastening hole 222b fastening screw 310 outer shell 320, 322, 324, 326 Ribs 320a, 320b Plate-shaped ribs 328a Low height portion 328b High height portion 330 Extension portion 332 Notch portion 410 Wiring 420 Hinge

Claims

1. An arm for a drone, the arm being attached to a housing of a drone, the arm having a main body portion arranged on the outside of the housing and a flange arranged on the outer side of the main body portion, the main body portion and the flange being made of a fiber-reinforced resin that contains reinforcing fibers and a thermoplastic resin.

2. The arm for a drone as described in claim 1, wherein the arm has a fastening hole for fastening the arm to the housing, the fastening hole being disposed in the flange.

3. A drone arm as described in claim 1 or 2, wherein the main body portion has a base portion fastened to the housing and an extension portion extending outward from the base portion, and the flange is disposed on the base portion.

4. A drone arm as described in claim 3, wherein the flange is arranged at the root portion and the extension portion, and the protruding width of the flange at the root portion is greater than the protruding width of the flange at the extension portion.

5. A drone arm as described in claim 3 or 4, wherein the main body portion has a tip portion arranged at the tip of the extension portion and to which a separate member is attached, and the tip portion has the flange.

6. A drone arm according to any one of claims 1 to 5, wherein the flange is integrally molded with the main body.

7. A drone arm as described in any one of claims 1 to 6, having a reinforcing rib on the inside of the main body.

8. A drone arm as described in any one of claims 1 to 7, wherein the main body is rod-shaped with at least one of its longitudinal faces being open.

9. A drone arm according to any one of claims 1 to 8, wherein the main body and the flange include a unidirectional layer including carbon fibers oriented in one direction and a thermoplastic resin.

10. A drone arm as described in any one of claims 1 to 9, comprising: a separate member attached to the tip of the main body; and a holding portion disposed on the main body and holding wiring connecting the housing and the separate member.

11. A drone arm as described in any one of claims 1 to 10, comprising: a separate member attached to the tip of the main body; an outer shell having an opening for taking out wiring to the separate member from inside the arm; and an extension portion extending the periphery of the opening to the inside of the outer shell; and the wiring arranged on the inside of the outer shell is bent at the extension portion and taken out from the opening.

12. A drone comprising: an arm for a drone according to any one of claims 1 to 11; and a housing to which the arm for a drone is fastened.

13. The drone of claim 12, wherein the drone arm is fastened to the housing via a hinge and is foldable by bending the hinge.

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