JP2019202593A - Frame assembly - Google Patents

Abstract

To provide a frame assembly which enables reduction of an area of an arm which blocks airflow caused by a propeller while securing rigidity of the arm supporting a motor.SOLUTION: A frame assembly 1 for a rotorcraft according to the invention includes: a top plate 12 and a bottom plate 11 which are parallel to a first plane surface; a side plate which connects the top plate with the bottom plate with the top plate spaced a predetermined distance apart from the bottom plate; and a motor mount supported by two arms integrally molded with the bottom plate.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a frame assembly.

  Unmanned air vehicles with multiple propellers are used in various fields. A motor for rotating the propeller is attached to the tip of the arm. In the multicopter disclosed in Patent Document 1, a rotor unit is provided at the tip of an arm that extends radially from the center of the airframe.

JP 2014-227016 A

  However, when a motor is provided at the tip of the arm, a large stress is applied to the arm due to the rotation of the motor or the air current generated by the propeller. On the other hand, when trying to increase the rigidity of the arm, the arm becomes thick, and the airflow by the propeller is blocked.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a frame assembly that can reduce the area of an arm that blocks airflow by a propeller while ensuring the rigidity of an arm that supports a motor. And

  A main invention of the present invention for solving the above problems is a frame assembly for a rotary wing machine, wherein a top plate and a bottom plate parallel to a first plane, and the top plate and the bottom plate are separated by a predetermined distance. A side plate that is connected to be spaced apart and a motor mount that is supported by two arms formed integrally with the bottom plate are provided.

  Other problems and solutions to be disclosed by the present application will be made clear by the embodiments of the invention and the drawings.

  ADVANTAGE OF THE INVENTION According to this invention, the area of the arm which interrupts | blocks the airflow by a propeller can be reduced, ensuring the rigidity of the arm which supports a motor.

It is a bottom view of the frame assembly 1 which concerns on one Embodiment of this invention. It is a top view of the frame assembly 1 which concerns on one Embodiment of this invention. 1 is a perspective view of a frame assembly 1 according to an embodiment of the present invention.

  The contents of the embodiment of the present invention will be listed and described. An aircraft according to an embodiment of the present invention has the following configuration.

[Item 1]
A frame assembly for a rotorcraft,
A top plate and a bottom plate parallel to the first plane;
A side plate that connects the top plate and the bottom plate with a predetermined distance therebetween; and
A motor mount supported by two arms formed integrally with the bottom plate;
A frame assembly comprising:

[Item 2]
The frame assembly according to claim 1, wherein
The two arms extend in opposite directions from the motor mount;
A frame assembly characterized by the above.

[Item 3]
The frame assembly according to claim 1, wherein
The bottom plate comprises a layer comprising reinforcing fibers;
At least one of the two arms extends in a direction parallel to the reinforcing fiber;
A frame assembly characterized by the above.

[Item 4]
The frame assembly according to claim 1, wherein
At least one of the two arms is curved outward;
A frame assembly characterized by the above.

[Item 5]
The frame assembly according to claim 1, wherein
The area of the motor mount is wider than the area of the bottom surface of the motor mounted on the motor mount;
A frame assembly characterized by the above.

<Details of the embodiment>
Hereinafter, a frame assembly 1 according to an embodiment of the present invention will be described with reference to the drawings. The frame assembly 1 of this embodiment constitutes a frame of the flying object. FIG. 1 is a bottom view of the frame assembly 1 according to this embodiment, and FIG. 2 is a top view of the frame assembly 1 according to this embodiment. FIG. 3 is a perspective view of the frame assembly 1 according to the present embodiment. The vertical direction on the paper surface of FIGS. 1 and 2 is the front-rear direction of the flying object.

  The frame assembly 1 includes a bottom plate 11 and a top plate 12 that is substantially parallel to the bottom plate 11. The bottom plate 11 is a printed board on which a circuit is formed. For example, electronic components such as a flight controller that controls the motor 20 are mounted on the bottom plate 11. In the present embodiment, a control circuit 19 including a flight controller is mounted on the front and rear central portions of the central portion 115 of the bottom plate 11. In the example of FIG. 1, a cover 18 that protects the control circuit 19 is disposed below the portion where the control circuit 19 is mounted. In the bottom plate 11, a copper foil and a circuit pattern are formed on a fiber-reinforced substrate, and an insulating layer (resist) is formed on the surface layer. The substrate is, for example, a glass epoxy substrate (FR4; Flame Retardant Type 4). In the present embodiment, the insulating layer is not provided on the portion where the electronic components are arranged on the bottom plate 11 and soldered, and the copper foil is plated. If necessary, solder plating or gold plating may be performed, or plating may not be performed. In the present embodiment, the top plate 12 is also the same printed board as the bottom plate 11. In the frame assembly 1 of this embodiment, the bottom plate 11 and the top plate 12 are provided with copper foil throughout (except for the part where the circuit is formed). The bending strength of the bottom play 11 and the top plate 12 can be increased using the tension of the copper foil. Further, the heat of the circuit can be diffused by communicating the heat conductive copper foil with the circuit. That is, the copper foil portion of the printed circuit board is generally used for constituting a circuit and a noise shield, but the frame assembly 1 of this embodiment is also used for frame reinforcement and heat dissipation. The bottom plate 11 may be a metal core substrate or a metal base substrate having a metal such as copper as a core.

  The bottom plate 11 includes four motor mounts 111 on which the motor 20 can be mounted. 1 to 3 show a state in which the motor 20 is mounted on the motor mount 111. The motor mount 111 is supported by the arms 112 and 113. The arms 112 and 113 are formed integrally with the bottom plate 11. The arms 112 and 113 are curved outward of the bottom plate 11. Thereby, it is possible to withstand a force from the side surface at the time of a collision in the side surface direction.

  The bottom plate 11 having a plurality of motor mounts 111 is point-symmetric. Thereby, it is possible to make it difficult for the operator to feel the blur of the center of gravity when operating the flying object. Furthermore, the frame assembly 1 is symmetric in the front-rear direction and in the left-right direction. As a result, the symmetry of the control characteristics of the flying object is ensured, and it is possible to reduce the uncomfortable feeling of operation, and it is also possible to easily maintain the level even when the flying object falls. Therefore, when the flying object falls, it is expected to decelerate by air resistance, and damage damage can be reduced.

  The motor mount 111 is formed to be the same as or larger than the bottom surface of the motor 20. Thereby, the motor 20 can be protected at the time of a collision.

  A propeller guard 114 is provided at the front-rear direction end of the bottom plate 11, and a propeller guard 121 is provided at the front-rear direction end of the top plate 12. The propeller guards 114 and 121 protect the rotor 20 (propeller) 21 attached to the motor 20 and the motor 20 when the flying object collides.

  The arm 112 and the arm 113 are arranged on a substantially straight line and extend from the motor mount 111 in a substantially reverse direction. That is, the arm 112 and the arm 113 support the motor mount 111 at a position that is substantially opposed. Since the arm 112 and the arm 113 support the motor mount 111 at a substantially opposite position, the motor mount 111 can be stably supported. Therefore, even when the motor 20 rotates, it can withstand the stress repelling the thrust by the propeller 21. Further, vibration due to the operation of the motor 20 can be suppressed. Therefore, the strength of the frame assembly 1 can be improved, the motor 20 can be stabilized, and consequently the flight of the flying object can be stabilized. Further, the area of the arm that blocks the wake of the propeller can be reduced, and the energy efficiency can be improved. The arm 112 and the arm 113 do not have to be on a straight line, but geometrically, a line connecting the midpoint of the two support points and the action point (the center of the motor 20) is equivalent to the cantilever arm. The closer the two arms 112 and 113 are to a straight line, the shorter the arm length in the case of a cantilever arm, and the more difficult it is to bend. In calculation, the acute angle formed by the arm 112 and the arm 113 is preferably 20 degrees or less.

  The arms 112 and 113 extend in the longitudinal direction of the reinforcing fibers included in the insulating layer of the bottom plate 11. Thereby, the strength of the insulating layer of the bottom plate 11 can be effectively utilized.

  A bridge 119 is provided between the front and rear arms 113 on each of the left and right sides of the bottom plate 11. Thereby, the torsional rigidity of the frame assembly 1 is improved.

  An opening 120 is formed by the arm 112, the motor mount 111, the arm 113, the central portion 115, and the propeller guard 114. By providing the opening 120, the airflow generated when the propeller 21 is rotated can be prevented from being blocked, and the weight of the frame assembly 1 can be reduced.

  The propeller guard 114 of the bottom plate 11 ensures the rigidity to withstand the stress when the frame assembly 1 receives a force from the front or obliquely forward by the tension of the camera guard 117 and the support of the arm 112. Further, the propeller guard 121 of the top plate 12 ensures the rigidity to withstand the stress when the frame assembly 1 receives a force from the front or obliquely forward by the tension of the camera guard 123. Since the propeller guard 121 has a lower rigidity than the propeller guard 114, the outer end 118 of the propeller guard 114 of the bottom plate 11 protrudes outward from the end 124 of the propeller guard 121 of the top plate 12.

  A camera 30 can be mounted in the vicinity of the front end portion on the central portion 115 of the bottom plate 11. A recess 116 is formed at the front end of the bottom plate 11, and a similar recess 122 is formed at the front end of the top plate 12. Camera guards 117 and 123 are provided on the bottom plate 11 and the top plate 12, respectively, so that the camera 30 does not protrude from the frame assembly 1 when the camera 30 is mounted. Thereby, the camera 30 can be protected at the time of a collision. The concave portions 116 and 122 have tapered left and right ends so that the bottom plate 11 does not enter the angle of view of the camera 30.

  Since the camera 30 is mounted on the central portion 115, the deviation of the center of gravity by the camera 30 during the roll operation is suppressed. Therefore, it is possible to bring a stable flight to the flying object. In the present embodiment, it is assumed that the center of gravity of the flying vehicle on which the camera 30 is mounted substantially coincides with the center of gravity of the camera 30. Thereby, when the flying object is flying, it is possible to reduce a sense of incongruity of the image taken in the first person view (FPV) taken by the camera 30.

  Between the bottom plate 11 and the top plate 12, two vertical plates 13 and a plurality of spacers 14 that are substantially perpendicular to the bottom plate 11 and the top plate 12 are arranged, and the bottom plate 11 and the top plate 12 are separated from each other. The The vertical plate 13 can also be the same printed circuit board as the bottom plate 11 and the top plate 12. Spacers 16 are also arranged between the two vertical plates 13. It is assumed that the distance at which the bottom plate 11 and the top plate 12 are separated is equal to or greater than the height at which the propeller 21 is mounted on the motor 20. The vertical plate 13 has a plate shape and can reduce air resistance when the flying object moves up and down.

  The spacer 14 is screwed with the screw 15 and is engaged with each of the bottom plate 11 and the top plate 12 by the screw 15. The spacer 16 is screwed with the screw 17 and is engaged with the vertical plate 13 by the screw 17. The diameters of the screw holes provided in the bottom plate 11, the top plate 12, and the vertical plate 13 are larger than the diameters of the screws 15 and 17. As a result, even when an impact is applied to the frame assembly 1, the screws 15 and 17 can be hardly loaded. Therefore, it is possible to avoid the stress from the highly rigid screws 15 and 17 from being concentrated on the screw hole portions of the bottom plate 11, the top plate 12, and the vertical plate 13, and to prevent breakage.

  The bottom plate 11 is provided with slits at the positions of the front fitting portion 131 and the rear fitting portion 132, and is fitted with the protruding portion of the vertical plate 13. The top plate 12 is also provided with slits at the positions of the front fitting portion 133 and the rear fitting portion 134, and fits with the protruding portion of the vertical plate 13. Thus, the bottom plate 11, the vertical plate 13, and the top plate 12 constitute a box structure. Therefore, the strength of the entire frame assembly 1 can be ensured. On the other hand, the bottom plate 11 and the top plate 12 and the vertical plate 13 form a box structure by fitting, and there is no need to perform processing such as screwing using screws or bonding with an adhesive, screws, etc. Therefore, the frame assembly 1 can be kept lightweight. In addition, a spacer 14 is provided in the vicinity of each fitting portion 131, 132, 133, and 134. When the frame assembly 1 receives an impact and the bottom plate 11 or the top plate 12 bends, the fitting portions 131, 132, 133, and 134 may be disengaged. , 132, 133, and 134, it is expected that the amount of deformation of the fitting portion is reduced, and the fitting can be strengthened.

  The vertical plate 13 and the bottom plate 11 abut on the stress receiving portion 135. The outer edge of the opening 120 includes two arc portions 136 and 137, and the stress receiving portion 135 is provided at a connection portion between the arc portions 136 and 137. The stress receiving portion 135 is configured to receive the stress from the vertical plate 13. The arc portions 136 and 137 have different radii, and the radius of the arc portion 137 near the center of the bottom plate 11 is shorter than the radius of the arc portion 136. Thereby, in the contact part 136, it is possible to increase the area that receives stress from the vertical plate 13, and the strength of the frame assembly 1 can be improved.

  As described above, according to the frame assembly 1 of the present embodiment, the printed circuit board itself for mounting the semiconductor and the like constituting the control circuit constitutes the frame. Therefore, it is not necessary to configure the frame using a material other than the printed circuit board, and the weight of the frame assembly 1 can be extremely reduced. Therefore, the flying object employing the frame assembly 1 can effectively utilize the thrust generated by the propeller 21 and can improve the movement performance of the flying object. In addition, since the frame assembly 1 is lightweight, it is possible to suppress the power consumption of the flying object. Furthermore, by reducing the number of parts, reliability and maintainability can be improved, and manufacturing and assembly costs can be reduced.

  In the frame assembly 1 of the present embodiment, the propeller guard 114 is also integrally provided as a part of the printed board. Therefore, the weight can be reduced as compared with the case where the frame and the printed board are separated. On the other hand, the motor mount 111 is supported by two arms 112 and 113, and the arms 112 and 113 are integrally formed with the printed circuit board. As a result, it is possible to ensure the rigidity to withstand the stress applied to the motor mount 111 and to reduce the areas of the arms 112 and 113 that block the wake of the propeller.

  In the frame assembly 1 of the present embodiment, a control circuit (not shown) is mounted on the bottom plate 11, and the camera 30 is also mounted on the bottom plate 11. Therefore, many parts are arranged below the rotating surface of the propeller 21. In other words, the flying object is designed to have a low center of gravity. It is known that the stability of the flying object is improved by lowering the center of gravity, and blurring during the flying of the flying object can be reduced. Further, the power consumption of the flying object can be suppressed by improving the stability of the flying object.

  Although the present embodiment has been described above, the above embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes equivalents thereof.

  For example, in the present embodiment, the bottom plate 11 and the top plate 12 are substantially parallel to each other, but they may be spaced apart at unequal intervals. Further, the bottom plate 11 and the top plate 12 may be curved instead of being planar.

  In the present embodiment, the bottom plate 11, the top plate 12, and the vertical plate 13 are printed boards. However, at least one of the top plate 12 and the vertical plate 13 may be a different material. For example, at least one of the top plate 12 and the vertical plate 13 can be an epoxy resin plate including glass fibers not provided with a copper foil.

  In the present embodiment, the bottom plate 11, the top plate 12, and the vertical plate 13 are configured such that the copper foil is arranged over the whole except for the portion where the circuit is formed. It is only necessary to provide a copper foil that gives the stress resistance necessary for 113, and there may be a portion where the copper foil is not provided.

  In the present embodiment, four motor mounts 111 are provided on the bottom plate 11. However, the present invention is not limited to this, and an arbitrary number of motor mounts 111 may be provided.

  In the present embodiment, the propeller guard 114 protects the propeller 21 in the front-rear direction, but the propeller 21 can be protected by attaching a separate propeller guard to the side surface (left-right direction). Is possible. The propeller guard 114 is formed integrally with the bottom plate 11 and can disperse the stress on the arm 113. On the other hand, the propeller guard on the side surface is not formed integrally but is a detachable part. Weight reduction as a body can be achieved. In addition, it is possible to easily replace the propeller guard that is highly likely to be damaged during a collision.

  In this embodiment, the arms 112 and 113 both extend in the longitudinal direction of the reinforcing fiber, but only one of them extends in the longitudinal direction of the reinforcing fiber and the other extends in a different direction. It may be.

  In the present embodiment, the center of gravity of the flying object on which the camera 30 is mounted substantially coincides with the center of gravity of the camera 30, but the center of gravity of the camera 30 may be on the center line in the front-rear direction of the bottom plate 11. In this case, it is possible to reduce the FPV discomfort at least during the roll operation of the flying object.

DESCRIPTION OF SYMBOLS 1 Frame assembly 11 Bottom plate 12 Top plate 13 Vertical plate 14 Spacer 20 Motor 21 Propeller 30 Camera 111 Motor mount 112 Arm 113 Arm 114 Propeller guard 115 Central part 116 Recessed part 117 Camera guard 118 Outer end part 119 Bridge 120 Opening part 121 Propeller Guard 122 Recessed portion 123 Camera guard 124 End portion 131 Front side fitting portion 132 Rear side fitting portion 133 Front side fitting portion 134 Back side fitting portion 135 Stress receiving portion

Claims (5)

A frame assembly for a rotorcraft,
A top plate and a bottom plate parallel to the first plane;
A side plate that connects the top plate and the bottom plate with a predetermined distance therebetween; and
A motor mount supported by two arms formed integrally with the bottom plate;
A frame assembly comprising: The frame assembly according to claim 1, wherein
The two arms extend in opposite directions from the motor mount;
A frame assembly characterized by the above. The frame assembly according to claim 1, wherein
The bottom plate comprises a layer comprising reinforcing fibers;
At least one of the two arms extends in a direction parallel to the reinforcing fiber;
A frame assembly characterized by the above. The frame assembly according to claim 1, wherein
At least one of the two arms is curved outward;
A frame assembly characterized by the above. The frame assembly according to claim 1, wherein
The area of the motor mount is wider than the area of the bottom surface of the motor mounted on the motor mount;
A frame assembly characterized by the above.