JP6696658B1 - Unmanned aerial vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fly an unmanned aerial vehicle with one drive source while suppressing the complication of a power transmission mechanism. An engine and a motor that are drive sources, a plurality of horizontal rotors, a power transmission mechanism that transmits the power of the drive source to the plurality of horizontal rotors, and a pitch angle of each of the horizontal rotors are changed. And a pitch changing mechanism, wherein the power transmission mechanism is a parent gear that is a gear member arranged in a direction in which the axis is vertical, and a child gear that is a plurality of gear members connected to the parent gear, And the parent gear and the child gear are arranged such that their axes are non-parallel, the engine and the motor are both capable of driving the parent gear, and the plurality of child gears are different from each other in the horizontal direction. It is solved by an unmanned aerial vehicle characterized by transmitting power to a rotor. [Selection diagram] Figure 4

Description

  The present invention relates to unmanned aerial vehicle technology.

  The following Patent Document 1 discloses a multi-copter that flies with an engine.

JP, 2017-154654, A

  In recent years, application of unmanned aerial vehicles to various business fields has been studied. Small multicopters, which are currently the mainstream of such unmanned aerial vehicles, each rotor has a DC motor and a fixed pitch propeller attached thereto, and a flight controller, which is a control unit, controls each rotor. The attitude control and steering of the airframe are performed by adjusting the rotation speed. Most of the functions of such a multicopter are realized by software, the number of mechanical elements is small, and the flexibility and maintainability of the airframe design are excellent.

  As a matter of course, electric power is required to drive the DC motor. The electric power consumed by the rotor of the multicopter is large, and the one cruising time of a general multicopter is around 20 minutes. In addition, the battery is particularly heavy among the constituent elements of the multicopter, and its size increases in accordance with the storage capacity, so it is not possible to easily adopt a large capacity battery. In addition, it generally takes several hours to charge a battery. Such a property is a problem in putting the multicopter to practical use.

  On the other hand, in order to extend the flight time of the multicopter, if one engine or one large DC motor is rotated at a constant speed to optimize its efficiency and the multicopter is flown, A separate mechanism for transmitting the driving force to each rotor is required, which complicates the body structure.

  In view of such a problem, the problem to be solved by the present invention is to fly an unmanned aerial vehicle with one drive source while suppressing the complication of the power transmission mechanism.

  In order to solve the above problems, the unmanned aerial vehicle of the present invention includes an engine and a motor that are drive sources, a plurality of horizontal rotors, and a power transmission mechanism that transmits the power of the drive source to the plurality of horizontal rotors. A pitch changing mechanism that changes the pitch angle of each of the horizontal rotors, and the power transmission mechanism is connected to the parent gear, which is a parent gear that is a gear member that is arranged in a direction in which the axis is vertical. And a child gear that is a plurality of gear members, the parent gear and the child gear are arranged in a direction in which the axes are non-parallel, the engine and the motor are both capable of driving the parent gear, The gist of the plurality of slave gears is to transmit power to different horizontal rotors.

  With respect to the parent gear arranged so that the axis is vertical, by connecting a plurality of child gears so that the direction of the axis is non-parallel to this, while arranging these child gears on the same horizontal plane, It is possible to convert the power direction of the master gear into a direction suitable for transmission to each horizontal rotor. As a result, the branch structure of power is integrated in the master gear and the slave gear, and the structure of the power transmission mechanism can be simplified as a whole. Further, by using the engine as the drive source, a longer cruising time can be realized as compared with the case where only the motor is used as the drive source. Also, refueling of the engine is completed in a significantly shorter time than charging the battery. This makes continuous operation of unmanned aerial vehicles easier. Further, by making the drive sources redundant, it becomes possible to use a motor to softly land the airframe when the engine fails, for example.

  Further, in the present invention, it is preferable that the master gear and the slave gear are arranged so that their axes are orthogonal to each other. In unmanned aerial vehicles that fly with multiple horizontal rotors, these horizontal rotors are typically located on the same horizontal plane. By making the axis of the slave gear orthogonal to the axis of the master gear, that is, by orienting the axis of the slave gear in the horizontal direction, for example, the rotary shaft is connected to the slave gear and the length of the rotary shaft is adjusted appropriately. By doing so, it becomes possible to transmit power to an arbitrary position in the same horizontal direction.

  Further, in the present invention, it is preferable that the master gear and the slave gear are bevel gears and are directly meshed with each other. This makes it possible to realize branching of power and conversion of power direction by the master gear and the slave gear with a simple structure.

  Further, in the present invention, it is preferable that the master gear rotates all of the plurality of slave gears at the same speed. This makes it possible to drive all the horizontal rotors at the same speed without any special adjustment, which facilitates the attitude control and steering of the airframe by the pitch changing mechanism.

  Further, the unmanned aerial vehicle of the present invention has drive shafts that are a plurality of rotating shafts, one of the slave gears is connected to one end of each drive shaft in the axial direction, and the other end is a bevel gear. An output gear is provided, and a rotor gear that is a bevel gear that meshes with the output gear is provided on a rotor shaft that is a rotation axis of each of the horizontal rotary blades. A first rotor gear that meshes with the output gear and rotates the horizontal rotor to one side; and a second rotor gear that meshes with the output gear with its teeth facing upward and rotates the horizontal rotor to the other side Preferably. An unmanned aerial vehicle that flies with a plurality of horizontal rotors controls the yaw of the airframe by utilizing the anti-torque of the horizontal rotors. Therefore, a horizontal rotor that rotates in the CW direction and a horizontal rotor that rotates in the CCW direction are used. It is common to have the same number. The structure from the parent gear to the output gear is made common to each horizontal rotor, and the direction of rotation of each horizontal rotor is determined by the meshing direction of the rotor gear with respect to the output gear. It is possible to provide both a horizontal rotor rotating in the CW direction and a horizontal rotor rotating in the CCW direction. This makes the structure of the power transmission mechanism simpler. Further, the transmission of power by the rotating shaft is more space efficient than the case where a belt is used, and it is not necessary to consider the dropping of the belt from the pulley and the speed limitation due to centrifugal tension.

  Further, it is preferable that the unmanned aerial vehicle of the present invention includes arms that are a plurality of tubular bodies that extend radially from a center of the body in a plan view, and the drive shaft is disposed inside each of the arms. The drive shaft has a high affinity with the cylindrical arm. For example, compared to a configuration in which the power of the child gear is transmitted to the horizontal rotor by a belt, the diameter of the arm can be kept small, and the drive shaft in the arm can be favorably supported by bearings. Power can be transmitted stably even when adopted.

  Further, in the present invention, the drive shaft and the child gear are connected via a joint member, and the joint member absorbs a predetermined amount of inclination of the drive shaft while rotating the child gear. It is preferably transmissible to the drive shaft. Since the joint member that connects the drive shaft and the slave gear absorbs the inclination of the drive shaft, the engagement between the master gear and the slave gear can be stabilized.

  The unmanned aerial vehicle of the present invention further includes a drive source switching unit that switches a drive source that drives the parent gear between the engine and the motor, and the drive source switching unit is based on a predetermined condition. It is preferable to automatically switch the drive source that drives the parent gear. By automatically switching between the engine and the motor, for example, when the engine fails, the drive source can be switched promptly without the operator's judgment to prevent a crash or enter an area where noise is regulated. It will be possible to automatically stop the engine and fly with a motor when you hit.

  At this time, it is preferable that the drive source switching unit automatically stops the engine and drives the motor when the rotation speed of the parent gear exceeds a predetermined threshold range while the engine is being driven. .. The engine abnormality appears as an abnormality in the rotation speed of the parent gear. The rotation speed of each rotor is determined by the rotation speed of the parent gear. Therefore, by monitoring the rotation of the parent gear, even if an abnormality occurs in the engine, it becomes possible to quickly switch the drive source before the aircraft crashes.

  In addition, it is preferable that the unmanned aerial vehicle of the present invention further includes a battery that is a power source of the motor, and the battery also serves as a power source of other electric / electronic devices mounted on the airframe. By driving the motor with the battery used in other electric / electronic devices, it is possible to make the drive sources redundant while suppressing an increase in the number of parts and the weight of the machine body.

  At this time, it is preferable that the motor be driven by the parent gear to rotate to generate electric power, and the battery be charged by electric power generated by the motor while the engine is being driven. When the engine is used as the main drive source of an unmanned aerial vehicle, the motor is driven by a parent gear to charge the battery, thereby driving the motor even when the battery is shared with other electric / electronic devices. It is possible to secure the electric power of. In addition, it is possible to prevent the remaining battery power from becoming a bottleneck in the cruising time.

  As described above, according to the unmanned aerial vehicle of the present invention, it is possible to fly the power transmission mechanism with one drive source while suppressing the complication of the power transmission mechanism.

It is a perspective view showing appearance of a multi-copter concerning an embodiment. It is the front view which looked at the multicopter of FIG. 1 from the arrow A direction. It is the side view which looked at the multicopter of FIG. 1 from the arrow B direction. FIG. 3 is a partially enlarged perspective view showing a deceleration / branching structure of engine output and motor output. FIG. 3 is a partially enlarged plan view showing a deceleration / branching structure of engine output and motor output. It is a side view sectional view showing the power transmission structure in an arm. It is an exploded perspective view showing the structure of the joint member which connects a child gear and a drive shaft. It is a side view which shows the basic structure of a rotor, and the switching structure of the rotation direction. It is a partial expansion perspective view which shows the structure of a pitch change mechanism. It is a perspective side view showing a support structure of an engine. It is sectional drawing which shows the internal structure of a damper. It is a block diagram which shows the function structure of the multicopter of FIG.

  Embodiments of an unmanned aerial vehicle according to the present invention will be described below with reference to the drawings. The multicopter M described below is an example of an unmanned rotorcraft that flies with multiple horizontal rotors. The "horizontal rotor" referred to in the present invention means a rotor whose axis of rotation extends vertically and whose plane of rotation is a horizontal plane. Even if the rotary shaft or the rotary surface is slightly tilted, the lift is mainly included in the upward component and is included in the “horizontal rotary blade” of the present invention.

  “Upper and lower” in the following description means a direction parallel to the Z axis of the coordinate axes drawn in each drawing, and the Z1 side is “upper” and the Z2 side is “lower”. "Front-back" means a direction parallel to the X-axis of the same coordinate axis, and the X1 side is "front" and the X2 side is "rear". Similarly, “left and right” means a direction parallel to the Y axis of the same coordinate axis, and the Y1 side is “right” and the Y2 side is “left”. In addition, “horizontal” means the XY plane directions indicated by the same coordinate axes.

(Structure overview)
FIG. 1 is a perspective view showing the outer appearance of a multicopter M according to this embodiment. FIG. 2 is a front view of the multicopter M of FIG. 1 viewed from the direction of arrow A. FIG. 3 is a side view of the multicopter M of FIG. 1 viewed from the arrow B direction.

  The multicopter M of the present embodiment is a so-called quadcopter, in which four arms 71 extend from the body frame 10 which is the center of the machine body in an X shape in plan view, and the rotor 50 which is a horizontal rotor is arranged at the tip of each arm 71. Has been done. The multicopter M is equipped with a single engine 30 as a drive source and a DC motor 90 (see FIGS. 4 and 5) (hereinafter, simply referred to as “motor 90”). As will be described in detail later, the multicopter M mainly flies by the engine 30, and its drive source can be switched to the motor 90 as needed. The driving force of the engine 30 is transmitted to each rotor 50 by a power transmission mechanism 40 described later, and the rotors 50 all rotate at the same speed by the driving force of the engine 30.

  The rotor 50 of this embodiment is a variable pitch rotor capable of dynamically changing the pitch angle of the blade 51. The multicopter M includes a pitch changing mechanism 60 that controls the pitch angle of each rotor 50. The multi-copter M of the present embodiment controls the attitude and steering of the airframe by individually adjusting the pitch angle of the rotor 50 by the pitch changing mechanism 60.

  The multicopter M of the present embodiment, by adopting the engine 30 as its drive source, realizes a far longer flight time than the conventional configuration in which the individual rotors 50 are driven by respective DC motors. Further, unlike the battery charging, refueling of the engine 30 is completed in a short time. This also enables continuous flight of the multicopter M. Further, the power transmission mechanism 40 of the engine 30 is simplified by controlling the attitude and steering of the airframe by adjusting the pitch angle instead of the rotational speed of the rotor 50 (synonymous with the rotational speed; the same applies hereinafter).

(Body frame)
The multicopter M is a central portion of the machine body and has a body frame 10 that holds an electric / electronic device such as an engine 30 and a flight controller FC described later. The body frame 10 of the present embodiment is a frame in which flat plate materials made of CFRP (Carbon Fiber Reinforced Plastics) are assembled with fixing members made of aluminum. The body frame 10 of the present embodiment mainly includes a main frame 11, a top plate 12, and an engine frame 13. The structure of each part of the body frame 10 will be described in detail below. However, the body frame 10 of the present embodiment is an example, and if the engine 30 and other necessary devices can be attached, the structure is appropriately selected according to the application. It can be changed.

  The main frame 11 is two plates that are arranged in parallel vertically with their plate surfaces facing up and down. An arm holder 111, which is a pipe clamp for fixing the base end portion of the arm 71, is arranged inside the two plates forming the main frame 11 (hereinafter referred to as “inside the main frame 11”). Two arm holders 111 are prepared for each arm 71 as a set. The base of the arm 71 is fixed to the arm holder 111 and extends horizontally from the main frame 11. Further, the servo holder 14 which is a plate for holding the servo 61 which is the drive source of the pitch changing mechanism 60 is joined to each set of the arm holders 111 of the present embodiment.

  The top plate 12 is a plate that is arranged above the main frame 11 with its plate surface facing up and down. The top plate 12 stands upright on the upper surface of the main frame 11 and is supported by a plurality of columnar plate posts 121. In this embodiment, the fuel tank 31 of the engine 30 is arranged between the top plate 12 and the main frame 11. The use of the top plate 12 is not specified.

  The engine frame 13 is two plates that hold the engine 30. The engine frame 13 is arranged in parallel to the left and right with the plate surface facing left and right, and the upper end thereof is joined to the lower surface of the main frame 11. Between the two plates of the engine frame 13, two reinforcing posts 131 that are columnar reinforcing members are horizontally provided. The rigidity of the engine frame 13 is enhanced by the reinforcement posts 131 limiting the deflection of the engine frame 13.

(arm)
The arm 71 of this embodiment is made of a CFRP pipe material. As described above, the base end of each arm 71 is fixed to the arm holder 111 of the main frame 11, and the rotor 50 is arranged at the tip thereof. A landing stand 72, which is also a CFRP pipe material, is joined to the middle of each arm 71 in the longitudinal direction by a joint member 721. The landing stand 72 extends downward from each arm 71 and supports the body of the multi-copter M during landing.

(Power transmission mechanism)
The power transmission mechanism 40 of the multicopter M will be described below. FIG. 4 is a partially enlarged perspective view showing a deceleration / branching structure of engine output and motor output. FIG. 5 is a partially enlarged plan view showing a deceleration / branching structure of engine output and motor output. FIG. 6 is a cross-sectional side view showing the power transmission structure in the arm 71. FIG. 7 is an exploded perspective view showing the structure of a joint member 46 that couples the child gear 45 and the drive shaft 47.

  The power transmission mechanism 40 is a mechanism that transmits the rotation of the output portion 351 of the engine 30 to each rotor 50, and mainly includes a toothed belt 41, a driven wheel 42, an input gear 43, a parent gear 44, a child gear 45, a drive. It is composed of a shaft 47 and an output gear 49.

  As shown in FIG. 4, the output unit 351 of the engine 30 of the present embodiment is a pulley (driving wheel) that rotates the toothed belt 41. The driven wheel 42, which is the other pulley around which the toothed belt 41 is hung, is a pulley having a larger diameter than the output portion 351. The output unit 351 of the present embodiment rotates in the CCW direction when viewed from the front. Therefore, in the toothed belt 41 of the present embodiment, the Y1 side belt drawn into the output section 351 is the tension side, and the Y2 side belt fed from the output section 351 is the slack side. In this embodiment, the tensioner 411 attached to the engine frame 13 presses the loose side belt to prevent the loose side belt from jumping. The shaft 421 of the driven wheel 42 is rotatably supported by a bearing 113 provided inside the main frame 11. The driven wheel 42 has its upper and lower end portions exposed to the outside through relief holes 112 provided in the upper and lower plates of the main frame 11. When the engine 30 is driven, the rotation of the output portion 351 is transmitted to the driven wheels 42 via the toothed belt 41 and is decelerated.

  As shown in FIG. 5, a master gear 44, which is a bevel gear member, is disposed inside the main frame 11 with a tooth portion 441 facing upward so that the axis is vertical. The master gear 44 is rotatably supported on the lower plate of the main frame 11. The shaft portion 421 of the driven wheel 42 is supported by a total of three bearings 113 in the main frame 11. An input gear 43, which is a bevel gear member that meshes with the tooth portion 441 of the parent gear 44, is attached to the shaft portion 421 of the driven wheel 42. The diameter of the master gear 44 is larger than the diameter of the input gear 43. The rotation of the driven wheel 42 is transmitted from the input gear 43 to the master gear 44 and further reduced by the master gear 44.

  An input gear 93, which is a bevel gear member mounted on the output shaft 91 of the motor 90, meshes with the tooth portion 441 of the master gear 44. The motor 90 is arranged in the main frame 11 with its output shaft 91 extending horizontally. The end face of the motor 90 on the output shaft 91 side is fixed to a motor mount 115 provided in the main frame 11, and the output shaft 91 is supported by a bearing 114 provided in the main frame 11.

  In addition to the input gears 43 and 93, four tooth gears 45, which are four bevel gear members that protrude into the main frame 11 from the openings of the base ends of the arms 71, mesh with the tooth portions 441 of the parent gear 44. ing. The master gear 44 and the slave gear 45 are arranged so that their axes are orthogonal to each other, and these slave gears 45 transmit power to different rotors 50. The child gears 45 of the present embodiment all have the same diameter, and they rotate at the same speed. The diameter of the slave gear 45 is smaller than the diameter of the master gear 44, and the rotation of the master gear 44 is transmitted to the slave gear 45 to be accelerated. The input gear 43 and the child gear 45 of this embodiment have the same diameter, and as a result, they rotate at the same speed. The rotation speed of the slave gear 45 can be flexibly adjusted by appropriately changing the diameters of the driven wheel 42, the input gear 43, the master gear 44, and the slave gear 45.

  As shown in FIG. 6, a drive shaft 47, which is a rotating shaft, is inserted into the arm 71. One end of the drive shaft 47 in the longitudinal direction is connected to the slave gear 45, and the other end is equipped with an output gear 49 that is a bevel gear member. The output gear 49 projects to the outside from the opening on the tip side of the arm 71. The rotation of the child gear 45 is transmitted to the output gear 49 via the drive shaft 47 and causes the output gear 49 to rotate. As a result, the driving force of the engine 30 and the motor 90 is transmitted to each rotor 50.

  In addition, as shown in FIG. 7, the child gear 45 and the drive shaft 47 of the present embodiment are connected via a joint member 46 that absorbs the deviation of the axes thereof. The joint member 46 is a cylindrical fixing member. A shaft portion 452 of the slave gear 45 is fixed to one opening of the joint member 46 with a set screw 461, and an adapter member 471 which is a shaft body screwed to the end portion of the drive shaft 47 is fitted to the other opening. Are combined. The joint member 46 is firmly screwed to the shaft portion 452 of the slave gear 45, while a clearance is provided between the joint member 46 and the adapter member 471 of the drive shaft 47, so that the drive shaft 47 may be slightly inclined. Can be absorbed. The cross section of the adapter member 471 in the lateral direction is formed in a cross shape, and the opening on the side of the joint member 46 is also shaped corresponding to this. By engaging these in the circumferential direction, even if the drive shaft 47 is tilted, the rotation of the slave gear 45 is transmitted to the drive shaft 47. Since the joint member 46 absorbs the inclination of the drive shaft 47 and prevents the inclination from being transmitted to the slave gear 45, the engagement between the master gear 44 and the slave gear 45 is stabilized. In this embodiment, the drive shaft 47 and the output gear 49 are also connected by the same structure using the joint member 46.

  As described above, in the multicopter M of the present embodiment, the slave gear 45 is meshed with the master gear 44 arranged so that the axis is vertical so that the direction of the axis is orthogonal to the axis of the master gear 44. Thus, while arranging the child gears 45 on the same horizontal plane, the power direction of the parent gear 44 is converted to a direction suitable for transmitting power by the drive shaft 47. As a result, the power branch structure is concentrated only on the master gear 44 and the slave gear 45, and the structure of the power transmission mechanism 40 is simplified.

  Further, the drive shaft 47 has high affinity with the cylindrical arm 71. The power transmission by the drive shaft 47 is more space efficient than when a belt or a gear train is used, and it is not necessary to consider the dropping of the belt from the pulley and the speed limitation due to the centrifugal tension of the belt. .. Further, the drive shaft 47 in the arm 71 is supported by the bearing 472, so that power can be stably transmitted even when the long arm 71 is adopted. A belt may be used if the disadvantages of using a belt instead of the drive shaft 47 can be tolerated.

  Further, the meshing angle of the master gear 44 and the slave gear 45 is not limited to the angle at which these axes intersect at right angles, but depending on the positional relationship between the master gear 44 and the rotor 50, the angle at which these axes become non-parallel. Just let it mesh. The shapes of the master gear 44 and the slave gear 45 are not limited to bevel gears, and the axes thereof can be made non-parallel by using, for example, a crown gear, Hypoid (registered trademark), a screw gear, or a worm. Further, the master gear 44 and the slave gear 45 do not always have to be directly meshed with each other, and another gear may be interposed between the master gear 44 and the slave gear 45 if necessary.

  Further, the multicopter M of the present embodiment is a quadcopter including four rotors 50, but it is also possible to make it a hexacopter or an octacopter by increasing the number of the child gears 45.

(Rotor)
FIG. 8 is a side view showing the basic structure of the rotor 50 and the rotation direction switching structure of the rotor 50.

  The rotor 50 of the present embodiment mainly includes a blade 51, a rotor hub 52, a rotor shaft 53, a rotor gear 531 and a rotor base 54.

  As described above, the rotor 50 of this embodiment is a variable pitch propeller, and the pitch angle of the blades 51 can be dynamically changed during flight by a pitch changing mechanism 60 described later. A general multicopter rotor uses a twisted so-called airplane propeller, but the rotor 50 of the present embodiment does not have a twisted down so-called flat blade blade 51 for a helicopter. Has been adopted. The blade 51 of each rotor 50 is connected to the rotor hub 52 via a feathering hinge 67, which will be described later. The rotor hub 52 is fixed to the top of a rotor shaft 53, which is the rotation axis of the rotor 50, and rotates integrally with the rotor shaft 53. A rotor gear 531 that is a bevel gear is attached to the lower end of the rotor shaft 53, and the rotor gear 531 meshes with the output gear 49.

  The rotor base 54 is a bearing member that rotatably supports the rotor shaft 53, and is attached to the tip of the arm 71. The rotor base 54 of this embodiment includes a socket portion 541, a bearing plate 542, and a reinforcing post 543. The socket portion 541 is a cylindrical connection portion that is screwed to the tip of the arm 71. The bearing plate 542 is two plates extending horizontally from the socket portion 541, and these plates are arranged in parallel vertically. The reinforcing post 543 is a columnar reinforcing member and is erected vertically between the bearing plates 542 to limit the deflection of the bearing plates 542.

  The rotor gear 531 of the present embodiment is either the first rotor gear 531a that meshes with the output gear 49 with its teeth facing downward, or the second rotor gear 531b that meshes with the output gear 49 with its teeth facing upward. Is. The first rotor gear 531a and the second rotor gear 531b rotate the rotor shaft 53 in opposite directions. In this embodiment, the first rotor gear 531a and the second rotor gear 531b are selectively used so that the rotation directions of the adjacent rotors 50 are opposite to each other.

  The multicopter M flying with the plurality of rotors 50 controls the yaw of the airframe by utilizing the counter torque of the rotors 50. Therefore, it is desirable to provide the same number of rotors 50 rotating in the CW direction and rotors rotating in the CCW direction. In the multicopter M of this embodiment, the power transmission mechanism 40 is commonly used for each rotor 50, and the rotation direction of each rotor 50 is determined only by the meshing direction of the rotor gear 531 with respect to the output gear 49. It is possible to provide both the rotor 50 that rotates in the CW direction and the rotor 50 that rotates in the CCW direction simply by changing the direction of). This makes the structure of the power transmission mechanism 40 simpler. In addition to this, since the power transmission mechanism 40 is commonly used for each rotor 50, it is possible to drive all the rotors 50 at the same speed without any special adjustment. Attitude control and steering of the airframe are made easier.

(Pitch change mechanism)
FIG. 9 is a partially enlarged perspective view showing the structure of the pitch changing mechanism 60 included in the multicopter M.

  The pitch changing mechanism 60 of the multicopter M mainly includes a servo 61 (see FIGS. 1 and 2), a control rod 62, a pitch lever 63, a slider ring 64, a pitch control plate 65, a pitch link 651, and a feathering hinge 67. It is composed by. The pitch changing mechanism 60 is prepared for each rotor 50.

  The servo 61 is a drive source of the pitch changing mechanism 60. The arrangement angle of the servo horn, which is the output unit of the servo 61, is controlled by the flight controller FC described later.

  The control rod 62 is an elongated rod-shaped link member extending along the arm 71. One end of the control rod 62 is connected to the servo 61, and the other end is connected to the pitch lever link 621. The pitch lever link 621 is a link member that transmits a change in the position of the control rod 62 to the pitch lever 63.

  The pitch lever 63 is a fork-shaped lever and forms a hinge mechanism together with a pedestal portion 631 fixed to the rotor base 54. When the servo 61 moves the control rod 62 back and forth along the arm 71, the pitch lever link 621 swings. The pitch lever 63 pivots up and down in conjunction with the swing of the pitch lever link 621, and lifts the slider ring 64 connected to the slider ring 64 along the rotor shaft 53.

  The slider ring 64 is a cylindrical lifting member. A pair of flanges are formed on the outer peripheral surface of the slider ring 64, and a pair of bosses provided at the free ends of the pitch levers 63 are fitted in the groove 641 which is a portion between these flanges. ing. As a result, the slider ring 64 moves up and down in conjunction with the vertical movement of the pitch lever 63.

  The slider ring 64 is attached to a slider sleeve 66, which is a cylindrical sleeve member that is attached to the rotor shaft 53 and can move up and down along the rotor shaft 53. The slider sleeve 66 is a half-screw member having a flange-shaped head, and is arranged with the head at the bottom and the screw portion at the top. A pitch control plate 65 is screwed onto the threaded portion of the slider sleeve 66, and the slider ring 64 is sandwiched between the head of the slider sleeve 66 and the pitch control plate 65. As a result, the pitch control plate 65 moves up and down integrally with the slider ring 64 (slider sleeve 66).

  The pitch control plate 65 is a connecting member for moving up and down the pitch link 651 which is two link members connected to the pitch control plate 65. The lower end of the pitch link 651 is connected to the pitch control plate 65, and the upper end thereof is connected to the feathering hinge 67. When the pitch control plate 65 moves the pitch link 651 up and down, the arrangement angle of the feathering hinge 67 changes.

  The feathering hinge 67 is a link member fixed to the base end of the blade 51. The feathering hinge 67 rotates in the pitch direction of the blade 51 in association with the elevation of the pitch link 651, and changes the pitch angle of the blade 51.

  As described above, the multicopter M according to the present embodiment performs the power transmission of the engine 30 by controlling the attitude and steering of the airframe by adjusting the pitch angle of each rotor 50 without adjusting the rotation speed of each rotor 50. It is possible to make the mechanism 40 simpler.

(Vibration reduction structure)
FIG. 10 is a perspective side view showing the support structure of the engine 30 by the engine frame 13. FIG. 10 is a view of the multicopter M viewed from the same direction as FIG. Hereinafter, the engine structure and the vibration isolation structure of the multicopter M will be described with reference to FIGS. 2, 4, and 10.

  The engine 30 of this embodiment is a general two-stroke single cylinder engine. As shown in FIGS. 2 and 10, the engine 30 mixes the air that has passed through the air cleaner 321 and the fuel (mixed gasoline) in the fuel tank 31 with the carburetor 32 provided on the right side (Y1 side) of the aircraft, This is combusted in the cylinder 33 to rotate the crankshaft and the output unit 351. Then, exhaust gas is emitted from the muffler 36 provided on the left side (Y2 side) of the engine 30.

  As shown in FIG. 10, the engine 30 according to the present embodiment is a first engine mount 381 and a second engine mount 382 (hereinafter, also referred to as “engine mounts 381 and 382”) that are adapter members for attaching the engine 30 to the engine frame 13. ) I have. The engine mounts 381 and 382 are attached to front and rear ends of the crankcase 34 of the engine 30. The engine mounts 381 and 382 and the engine frame 13 are joined to each other via a damper D1 which is an anti-vibration member using an elastic body, and the engine 30 is not directly fixed to the engine frame 13. That is, the engine 30 of this embodiment does not contact the body frame 10. The damper D1 is also provided at the same position on the back side of the engine mounts 381 and 382 shown in FIG.

  Below the crankcase 34, a cylinder 33 is arranged with its piston direction facing up and down. A spark plug 331 is attached to the lower surface of the cylinder 33. Further, the engine 30 of this embodiment is an air-cooled engine, and the cylinder 33 is cooled by a cooling fan 37. The cooling fan 37 has a case body that defines a flow path of the cooling air, and a fan that is arranged inside the case body. The cooling fan 37 uses the rotation of the crankshaft to rotate the fan inside the case. The case body of the cooling fan 37 does not touch the engine 30, and its connecting portion 371 is screwed to the engine frame 13.

  In front of the crankcase 34, a clutch bell 35, which is an output member whose power transmission is interrupted by a centrifugal clutch, is arranged. A thread groove is formed in the front end portion of the clutch bell 35, and an output portion 351 is screwed therein. The clutch bell 35 and the shaft portion 352 of the output portion 351 are rotatably supported by the bearing portion 15. The bearing portion 15 is joined to the bearing base 151, which is a connecting portion screwed to the engine frame 13, via a damper D2. Further, a recoil starter 341 is arranged behind the crankcase 34.

  FIG. 11 is a sectional view showing the internal structure of the dampers D1 and D2. 11A shows the internal structure of the damper D1, and FIG. 11B shows the internal structure of the damper D2.

  The damper D1 is a vibration isolating member that joins the engine mounts 381 and 382 with the engine frame 13. As shown in FIG. 11A, the damper D1 of the present embodiment mainly includes a cylindrical rubber member 81, a nut member 84 and a bolt 83 that fix the rubber member 81 to the engine frame 13. ..

  The rubber member 81 has a rubber 811 that is a cylindrical elastic body, and a rubber case 812 that is a hard case body that protects the inner and outer circumferences of the rubber 811. The engine mounts 381, 382 are provided with holes corresponding to the outer diameter dimension of the rubber member 81. The rubber member 81 has holes in the engine mounts 381, 382 with its openings facing left (Y-axis direction). It is fitted.

  The nut member 84 has a flange portion 841 having a diameter larger than the inner diameter of the rubber member 81, and a shaft portion 842 having a diameter corresponding to the inner diameter of the rubber member 81. The shaft portion 842 of the member 84 is inserted. The rubber member 81 has its right end surface in contact with the inner surface of the engine frame 13, and its left end surface in contact with the flange portion 841 of the nut member 84. Then, the bolts 83 are screwed into the screw holes of the shaft portion 842 of the nut member 84 from the outside of the engine frame 13, whereby the engine mounts 381 and 382 are fixed to the engine frame 13 via the damper D1. A washer 831 is arranged between the outer surface of the engine frame 13 and the head of the bolt 83 to prevent the head of the bolt 83 from sinking due to the vibration of the engine 30.

  As described above, in the engine 30 of this embodiment, the piston reciprocates up and down. Therefore, the vibration generated by the engine 30 has a large ratio of vertical components. Further, a single-cylinder engine such as the engine 30 generally has larger vibration than a multi-cylinder engine. In the multicopter M of this embodiment, the vertical vibration of the engine 30 is absorbed by the damper D1. As a result, the vibration of the engine 30 transmitted to the engine frame 13 is efficiently reduced. The engine 30 may be replaced with a multi-cylinder engine when the size of the drive source can be increased. By doing so, it becomes possible to further suppress the vibration of the engine 30.

  The damper D2 is a vibration isolating member that joins the bearing portion 15 supporting the shaft portion 352 of the engine output portion 351 and the bearing base 151 fixed to the engine frame 13. As shown in FIG. 11B, the damper D2 of the present embodiment mainly has a cylindrical rubber 86, a rubber case 87 that is a hard case body that protects the upper and lower surfaces of the rubber 86, and a bearing for the rubber 86. It is composed of a bolt 88 fixed to the portion 15.

  The rubber 86 of the damper D2 is arranged with its end surface facing up and down. The rubber case 87 for protecting the upper surface of the rubber 86 has a screw portion 871 extending upward from the center of the upper surface, and the screw portion 871 is screwed into a screw hole of the bearing base 151. The rubber case 87 that protects the lower surface of the rubber 86 has a screw hole 872 in the center thereof, and a bolt 88 is screwed into the screw hole 872 from below the bearing portion 15. Accordingly, the damper D2 is fixed between the bearing base 151 and the bearing portion 15, absorbs the vertical vibration of the bearing portion 15, and reduces the transmission of the vibration to the bearing base 151, that is, the engine frame 13. As described above, in the multicopter M of the present embodiment, the output portion 351 of the engine 30 is supported by the bearing portion 15, and this is separately supported by the damper D2 on the engine frame 13, so that the influence of the vibration of the engine 30 is suppressed. At the same time, the transmission accuracy of the driving force is improved.

Then, in the multicopter M of the present embodiment, the rotation of the output portion 351 of the engine 30 is transmitted to the driven wheels 42 supported by the main frame 11 by the toothed belt 41. The engine 30 of the present embodiment is supported by the dampers D1 and D2 without coming into contact with the body frame 10, so that the vibration of the engine 30 transmitted to the body frame 10 is reduced. On the other hand, since the engine 30 is not firmly fixed, the vibration of the engine 30 itself becomes larger. By transmitting the driving force of the engine 30 to the driven wheels 42 by the toothed belt 41, effects such as absorption of vibration of the engine 30, reliable transmission of power, and noise reduction are realized in a well-balanced manner. There is.

  In the present embodiment, the output portion 351 of the engine 30 and the driven wheel 42 are connected by the toothed belt 41, but the same effect can be obtained by using a chain instead of the toothed belt 41. Further, although the dampers D1 and D2 of the present embodiment have a structure in which the elastic body absorbs the vibration of the engine 30, the damper structure is simplified, but the damper supporting the engine 30 uses the elastic body. The damper is not limited to the one described above, and may be, for example, a damper using gas, oil, or a spring.

(Function configuration)
FIG. 12 is a block diagram showing the functional configuration of the multi-copter M. The function of the multicopter M of this embodiment is to control the flight controller FC that is a control unit, the rotor 50, the engine 30 and the motor 90 that are the drive sources that drive the rotor 50 via the parent gear 44, the pitch changing mechanism 60, the operator ( It comprises a communication device 52 for communicating with the operator terminal 51), a motor 90, a flight controller FC, a pitch changing mechanism 60, and a battery 29 for supplying electric power to electric / electronic devices such as the communication device 52.

  The flight controller FC has a control device 20. The control device 20 has a CPU 21, which is a central processing unit, and a memory 22, which is a storage device such as RAM, ROM, or flash memory.

  The flight controller FC further includes a flight control sensor group S including an IMU 25 (Inertial Measurement Unit), a GPS receiver 26, an atmospheric pressure sensor 27, and an electronic compass 28, which are connected to the control device 20. Has been done.

  The IMU 25 is a sensor that detects the inclination of the multicopter M, and is mainly composed of a triaxial acceleration sensor and a triaxial angular velocity sensor. To be exact, the GPS receiver 26 is a receiver of a navigation satellite system (NSS). The GPS receiver 26 acquires current latitude and longitude values from a Global Navigation Satellite System (GNSS) or a Regional Navigational Satellite System (RNSS). The atmospheric pressure sensor 27 is an altitude sensor that identifies the altitude (elevation) above sea level of the multicopter M from the detected atmospheric pressure altitude. A triaxial geomagnetic sensor is used for the electronic compass 28, and the electronic compass 28 detects the azimuth angle of the nose of the multicopter M.

  With the flight control sensor group S, the flight controller FC can acquire the position information of the aircraft including the longitude and latitude of the aircraft, the altitude, and the azimuth of the nose, in addition to the tilt and rotation of the aircraft. Has been done.

  The flight control sensor group S of the present embodiment is an example, and the sensors forming the flight controller FC are not limited to the combination of the present embodiment. For example, instead of the atmospheric pressure sensor 27, or in addition to the atmospheric pressure sensor 27, it is conceivable to acquire the ground altitude with a laser distance measuring sensor or a stereo camera whose measurement direction is directed downward. Further, in a place where the GPS receiver 26 cannot receive radio waves, it is conceivable that the horizontal movement of the machine body is detected by an optical flow sensor or image recognition. In addition, it is also possible to measure the distance to the surrounding object with a plurality of distance measuring sensors using laser, infrared rays, ultrasonic waves, etc., and specify the spatial position of the multicopter M from the distance.

  The control device 20 has a flight control program FS which is a program for controlling the attitude and basic flight motion of the multicopter M during flight. The flight control program FS adjusts the pitch angle of each rotor 50 by the pitch changing mechanism 60 based on the information acquired from the flight control sensor group S, and flies the multicopter M while correcting the disturbance of the attitude and position of the airframe. Let

  The control device 20 further has an autonomous flight program AP that is a program for causing the multicopter M to fly autonomously. Then, in the memory 22 of the control device 20, the flight plan FP, which is a parameter in which the latitude and longitude of the destination and the waypoint of the multicopter M, the altitude and speed during flight, and the like are designated, is registered. The autonomous flight program AP autonomously causes the multicopter M to fly in accordance with the flight plan FP, with an instruction from the operator terminal 51, a predetermined time, or the like as a start condition.

  As described above, the multi-copter M of this embodiment is an unmanned aerial vehicle having a sophisticated flight control function. However, the unmanned aerial vehicle of the present invention is not limited to the form of the multicopter M, and can fly, for example, an aircraft in which some of the sensors are omitted from the flight control sensor group S, or can be fly only by manual control without an autonomous flight function. An airframe can also be used. Further, although the operator manually operates the servo 39 to operate the air-fuel ratio of the engine 30, it is also possible to automate this.

  Further, the control device 20 has a drive source switching program DS (drive source switching unit) that switches the drive source that drives the parent gear 44 between the engine 30 and the motor 90. As described above, the multicopter M of this embodiment mainly flies by the engine 30. The motor 90 is merely an auxiliary drive source, and temporarily drives the parent gear 44 instead of the engine 30 in a limited situation. The drive source switching program DS can switch the drive source in response to an instruction from the operator terminal 51, and can also automatically switch the drive source based on a predetermined condition.

  For example, the drive source switching program DS automatically stops the engine 30 and drives the motor 90 when an abnormality occurs in the operation of the engine 30. The drive source switching program DS monitors the rotation of the master gear 44 by the encoder 449, and when the rotation number exceeds the threshold value range of the normal value, the drive source is automatically switched to the motor 90, and the multicopter M is operated. Soft land. The abnormality of the engine 30 appears as an abnormality of the rotation speed of the parent gear 44. The rotation speed of each rotor 50 is determined by the rotation speed of the parent gear 44. By monitoring the rotation of the master gear 44, the multi-copter M is capable of quickly switching the drive source before the aircraft crashes even when an abnormality occurs in the engine 30. The encoder 449 may be any rotary encoder that can measure the rotation speed of the master gear 44, and its detection method is not limited. As the encoder 449, for example, a photoelectric sensor, an electromagnetic pickup, an eddy current displacement sensor, or the like can be preferably used.

  Further, the drive source switching program DS monitors the output values of the GPS receiver 26 and the atmospheric pressure sensor 27, and also when the multicopter M passes through an area where noise is regulated, such as an urban area or a low sky area. The drive source is switched to the motor 90. The conditions for the drive source switching program DS to switch the drive sources are arbitrary and can be set appropriately according to the application of the multicopter M and flight requirements. If necessary, a sensor or the like for detecting the condition may be separately mounted. Further, the automatic switching of the driving source by the driving source switching program DS is not an essential function of the multicopter M, and the driving source may be switched only by an instruction from the operator terminal 51.

  As described above, in the multicopter M, the motor 90 and the other electric / electronic device share the battery 29. As a result, it is possible to back up this with the motor 90 when the engine 30 fails while suppressing an increase in the number of parts of the machine and the weight of the machine.

  Further, the motor 90 of the present embodiment generates electric power by being driven and rotated by the master gear 44 while the engine 30 is being driven. Then, the battery 29 is charged by the electric power generated by the motor 90. In the multicopter M, the battery 29 is charged by using the follower of the motor 90 while the engine 30 is being driven, so that the electric power for driving the motor 90 while sharing the battery 29 with other electric / electronic devices can be increased. Secured. Moreover, the remaining amount of the battery 29 does not become a bottleneck of the cruising time.

  Although the embodiment of the present invention has been described above, the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention.

M: Multicopter (unmanned aerial vehicle), 10: Body frame, 11: Main frame, 111: Arm holder, 113: Bearing, 12: Top frame, 13: Engine frame, 14: Servo holder, 15: Bearing section 151: Bearing base , FC: Flight controller, FS: Flight control program, S: Flight control sensor group, DS: Drive source switching program (drive source switching unit), 29: Battery, 30: Engine (drive source), 31: Fuel tank, 351 : Output part, 352: shaft part, 381: first engine mount, 382: second engine mount, 40: power transmission mechanism, 41: toothed belt, 42: driven wheel, 421: shaft part, 43: input gear, 44: parent gear, 441: tooth portion, 449: encoder, 45: child gear, 451: gear portion, 452: coupling portion, 46: joint member, 461: set screw, 47: drive shaft (rotating shaft), 471: Adapter member, 472: Bearing, 49: Output gear, 50: Rotor (horizontal rotor), 51: Blade, 53: Rotor shaft, 531: Rotor gear, 531a: First rotor gear, 531b: Second rotor gear, 60 : Pitch changing mechanism, 61: Servo, 62: Control rod, 621: Pitch lever link, 63: Pitch lever, 64: Slider ring, 65: Pitch control plate, 651: Pitch link, 67: Feathering hinge, 71: Arm , D1, D2: damper, 81: rubber member, 811: rubber (elastic body), 812: rubber case, 83: bolt, 831: washer, 84: nut member, 841: flange portion, 842: shaft portion, 86: Rubber (elastic body), 87: Rubber case, 871: Bolt part, 872: Nut part, 88: Bolt, 90: Motor, 93: Input gear

Claims (10)

An engine and a motor that are drive sources,
Multiple horizontal rotors,
A power transmission mechanism that transmits the power of the drive source to the plurality of horizontal rotors,
A pitch changing mechanism for changing the pitch angle of each horizontal rotor,
The power transmission mechanism is
A parent gear, which is a gear member arranged in a direction in which the axis is vertical,
And a child gear that is a plurality of gear members connected to the parent gear,
The parent gear and the child gear are arranged so that the axes are non-parallel to each other,
Both the engine and the motor can drive the parent gear,
The plurality of child gears transmits power to the different horizontal rotors ,
Further comprising a drive source switching unit that switches a drive source that drives the parent gear between the engine and the motor,
The drive source switching unit automatically stops the engine and drives the motor when the rotation speed of the gear member that constitutes the power transmission mechanism exceeds a predetermined threshold range while the engine is being driven. Characteristic unmanned aerial vehicle.   The unmanned aerial vehicle according to claim 1, wherein the master gear and the slave gear are arranged such that their axes are orthogonal to each other.   The unmanned aerial vehicle according to claim 1 or 2, wherein the master gear and the slave gear are bevel gears and are directly meshed with each other.   The unmanned aerial vehicle according to any one of claims 1 to 3, wherein the master gear rotates all of the plurality of slave gears at the same speed. Having a drive shaft that is a plurality of rotating shafts,
One of the child gears is connected to one end in the axial direction of each drive shaft, and an output gear that is a bevel gear is provided at the other end.
The rotor shaft, which is the rotating shaft of each of the horizontal rotors, is provided with a rotor gear that is a bevel gear that meshes with the output gear,
The rotor gear has a first rotor gear that meshes with the output gear with its teeth facing downward and rotates the horizontal rotor to one side, and a horizontal rotor that meshes with the output gear with its teeth facing upward. The second unmanned aerial vehicle according to any one of claims 1 to 4, further comprising: An arm that is a plurality of cylindrical bodies that extends radially from the center of the machine body in a plan view is provided.
The unmanned aerial vehicle according to claim 5, wherein the drive shaft is disposed inside each of the arms. The drive shaft and the child gear are connected via a joint member,
The unmanned aerial vehicle according to claim 5 or 6, wherein the joint member is capable of transmitting the rotation of the slave gear to the drive shaft while absorbing a predetermined amount of inclination of the drive shaft. The drive source switching unit, according to claim 1, characterized in that the rotational speed of the parent gear during driving of the engine Once exceeds a predetermined threshold value range, automatically the engine is stopped to drive the motor 8. The unmanned aerial vehicle according to any one of claims 7 to 10 . Further comprising a battery that is a power source of the motor,
The unmanned aerial vehicle according to any one of claims 1 to 8 , wherein the battery doubles as a power source for other electric and electronic devices mounted on the airframe. The motor generates power by rotating following the parent gear,
The unmanned aerial vehicle according to claim 9 , wherein the battery is charged by electric power generated by the motor while the engine is being driven.

Images