US20070105475A1

US20070105475A1 - Radio control helicopter toy

Info

Publication number: US20070105475A1
Application number: US11/542,932
Authority: US
Inventors: Takeo Gotou; Yoshiaki Ohe; Tetsuya Itou
Original assignee: Taiyo Kogyo Co Ltd
Current assignee: Taiyo Kogyo Co Ltd
Priority date: 2005-11-10
Filing date: 2006-10-04
Publication date: 2007-05-10
Also published as: JP4343167B2; JP2007130200A

Abstract

The present invention provides a radio control helicopter toy including a mast mounted projecting to the upper side of an airframe so as to be rotated by a main motor, a rotor mounted on the upper part of the mast via a rotor head with the blade surface of a rotor blade capable of inclining, a blade inclining mechanism having an arm with one end part side thereof mounted rotatably on the airframe side and the other end part side thereof is mounted to be driven to approach to the above-mentioned rotor head side by an actuator, for inclining the blade surface of the above-mentioned rotor by the magnetic force generated between magnets mounted on the end part of the arm and the above-mentioned rotor head or between a magnet and a ferromagnetic material, and a receiver loaded on the above-mentioned airframe for controlling the operation of the above-mentioned main motor and the actuator.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a radio control helicopter toy, the movement control thereof is performed with remote control.
2. Description of the Related Art
Conventionally, for the movement control of a helicopter, movement can be made in front and back, right and left directions by inclining the blade surface of a rotor provided on the aircraft. For inclining the blade surface of such a rotor, in the real helicopter, a mechanism for inclining the blade surface by interlocking a swash plate, rotating together with the rotor, with the blade via a link is adopted. This kind of the rotor blade surface inclining mechanism by a swash plate is adopted also for a movement control for a helicopter toy. For example, a technique related to a radio control helicopter with co-axial rotors, that is upper and lower rotor heads rotating in the opposite directions are provided concentrically, wherein the inclining of the blade rotation surface is controlled by interlocking a blade of the lower rotor head with a swash plate of a blade inclining mechanism provided in a aircraft is disclosed (for example, see Kokai (Jpn unexamined patent application) No. 2004-121798 (p. 3 to 6, FIGS. 1 to 7)).
Since the inside part of the conventional swash plate is connected with the rotor head, which is rotating via a link, a structure allowing the inside part to always rotate together with the rotor head. However, since the outside part is connected with an actuator mounted on the airframe for controlling the inclining of the swash plate with a link, it cannot be rotated. Therefore, a highly sophisticated part such as a ball bearing is required for the inside and the outside of the swash plate, and the structure is also complicated. Moreover, since the all parts from an actuator to the rotor head are connected via links, the structure is extremely complicated as well as the number of parts is large so that the cost may be increased as a whole.

SUMMARY OF THE INVENTION

The present invention has been achieved in view of the above-mentioned circumstances, and an object thereof is to provide a radio control helicopter toy capable of providing a mechanism for the movement control in a simple structure so as to be produced at low cost.
In order to achieve the above-mentioned object, a first aspect of the present invention includes: a mast mounted projecting to the upper side of an airframe so as to be rotated by a main motor loaded on the airframe; a rotor mounted on the upper part of the mast via a rotor head with the blade surface of a rotor blade capable of inclining; a blade inclining mechanism having an arm with one end part side thereof mounted rotatably on the airframe side and the other end part side thereof is mounted to be driven to approach to the above-mentioned rotor head side by an actuator loaded on the above-mentioned airframe, for inclining the blade surface of the above-mentioned rotor by the magnetic force generated between magnets mounted on the end part of the arm and the above-mentioned rotor head or between a magnet and a ferromagnetic material; and a receiver loaded on the above-mentioned airframe for controlling the operation of the above-mentioned main motor and the actuator. Since the rotor blade surface is inclined by the magnetic force, the conventional inclining mechanism by a swash plate can be eliminated so that the mechanism for the movement control can be provided in a simple structure as well as it can be produced at low cost.
In a second aspect of the present invention, the above-mentioned mast has an upper mast and a lower mast to be rotated concentrically in the opposite directions by the above-mentioned main motor; the above-mentioned rotor has an upper rotor mounted on the upper part of the above-mentioned upper mast via an upper rotor head with the blade surface of the upper rotor blade capable of inclining and a lower rotor mounted on the upper part of the above-mentioned lower mast via a lower rotor head with the blade surface of the lower rotor blade capable of inclining; and the above-mentioned blade inclining mechanism is provided on the above-mentioned airframe for inclining the blade surface of the above-mentioned lower rotor. In a helicopter toy having an upper mast and a lower mast to be rotated concentrically in the opposite directions, the movement control mechanism can be provided in a simple structure as well as it can be produced at low cost.
In the third aspect of the present invention, a stabilizer for controlling the flight attitude of the above-mentioned airframe is mounted on the above-mentioned upper mast so as to interlock with the above-mentioned upper rotor head. According to the stabilizer, the attitude of the airframe can be maintained stably.
In the fourth aspect of the present invention, the above-mentioned blade inclining mechanism has the above-mentioned arm to be driven by the actuator provided in for points of the front, back, right and left around the above-mentioned mast. With the masts in the four points, the direction control in the frontward, backward, right and left directions can be enabled.
In the fifth aspect of the present invention, a tail pipe is mounted on the rear side of the above-mentioned airframe and a tail rotor to be driven by a tail motor is mounted on an end part of the tail pipe. With the tail rotor, the airframe turnover can be prevented as well as the airframe can be controlled in the right and left directions.
In the sixth aspect of the present invention, the magnet or the ferromagnetic material mounted on the above-mentioned rotor head of the above-mentioned blade inclining mechanism is formed in a ring-like shape surrounding the rotation center of the above-mentioned mast. Since the magnet or the ferromagnetic material mounted on the rotor head is formed in a ring-like shape, the blade surface inclination of the rotor blade can be controlled certainly.
Since a mast mounted on the upper side of an airframe so as to be rotated by a main motor loaded on the airframe, a rotor mounted on the upper part of the mast via a rotor head with the blade surface of a rotor blade capable of inclining, a blade inclining mechanism having an arm with one end part side thereof mounted rotatably on the airframe side and the other end part side thereof is mounted to be driven to approach to the above-mentioned rotor head side by an actuator loaded on the airframe, for inclining the blade surface of the above-mentioned rotor by the magnetic force generated between magnets mounted on the end part of the arm and the above-mentioned rotor head or between a magnet and a ferromagnetic material, and a receiver loaded on the above-mentioned airframe for controlling the operation of the above-mentioned main motor and the actuator are provided, the rotor blade surface can be inclined by the magnetic force so that the mechanism for the movement control can be provided in a simple structure as well as it can be produced at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view for explaining the entire configuration of a radio control helicopter toy of an embodiment of the present invention.
FIG. 2 is a perspective view for explaining a blade inclining mechanism of a radio control helicopter toy of the embodiment of the present invention.
FIG. 3 is a side view for explaining a blade inclining mechanism of a radio control helicopter toy of the embodiment of the present invention.
FIG. 4 is a perspective view of a blade inclining mechanism part of a radio control helicopter toy of the embodiment of the present invention.
FIG. 5 is a block diagram for explaining the control operation of a radio control helicopter toy of the embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present invention will be explained specifically with reference to an embodiment shown in the figures. FIGS. 1 to 5 are diagrams for explaining a radio control helicopter toy of an embodiment of the present invention. FIG. 1 is a perspective view for explaining the entire configuration of a radio control helicopter toy, FIG. 2 is a perspective view for explaining a blade inclining mechanism of a radio control helicopter toy, FIG. 3 is a side view for explaining a blade inclining mechanism of a radio control helicopter toy, FIG. 4 is a perspective view of a blade inclining mechanism part of a radio control helicopter toy, and FIG. 5 is a block diagram for explaining the control operation of a radio control helicopter toy.
In these figures, the radio control helicopter toy 10 of this embodiment includes an airframe 11, an upper rotor 12 and a lower rotor to be rotated concentrically in the opposite directions, provided in the upper part of the airframe, a stabilizer 14 for stably maintaining the rotating attitude, interlocking with one of the rotors, a driving part 15 loaded on the airframe 11 for rotating the upper rotor 12, the lower rotor 13 and the stabilizer 14, a blade inclining mechanism 16 loaded on the airframe 11 for controlling the moving direction by inclining the blade surface of the lower rotor 13, a tail rotor 17 mounted on the rear side of the airframe 11, a receiver 20 loaded on the airframe 11 for receiving a control signal sent from a transmitter 19 and controlling the operation of the driving part 15, the blade inclining mechanism 16 and the tail rotor 17, a battery 18 loaded in the airframe 11 for supplying the power source to each part, and the like.
The airframe 11 loads the above-mentioned parts, is formed with a plastic material, is formed in an arbitral shape modeled after a helicopter, and is provided with a landing member 21 in the lower part for landing in a stable state.
The upper rotor 12 includes an upper rotor head 25 mounted tiltably on the upper end part side of an upper mast 23 rotatingly driven by the driving part 15, and a pair of upper rotor blades 26, 26 mounted on both end part sides of the upper rotor head 25. The upper rotor head 25 shaped in a substantially rectangular ring-like shape slightly larger than the outer diameter of the upper mast 23 is mounted tiltably on both end parts of a driving shaft 27 provided in a direction orthogonal to the rotation shaft center at the upper end part side of the upper mast 23. The upper rotor blades 26, 26 are mounted on both end part sides of the upper rotor head 25 along the shaft center of the driving shaft 27 for generating the lift up force at the time of being rotatingly driven by the upper mast 23.
The stabilizer 14 includes a stabilizer head 28 mounted on the upper mast 23 on the lower side of the upper rotor 12, a pair of stabilizer shafts 29, 29 mounted on both end faces of the stabilizer head 28, weights 30, 30 each mounted on end part sides of the stabilizer shafts, and a stabilizer link 32 mounted so as to interlock the stabilizer head 28 and the upper rotor head 25. The stabilizer head 28 is formed in a substantially rectangular ring-like shape slightly larger than the outer diameter of the upper mast 23. The stabilizer head 28 is mounted tiltably on both end parts of a shaft 31 penetrating through the upper mast 23 in a direction orthogonal to the rotation shaft center of the upper mast 23 at the lower part side of the upper rotor head 25. The stabilizer 14 is mounted such that the intersection angle the mounting direction of the stabilizer shafts 29, 29 and the mounting direction of the upper rotor blades 26, 26 of the upper rotor 12 is for example an inclination angle of about 30 to 90 degrees. That is, according to the stabilizer 14, in the case the weights 30, 30 and the stabilizer shafts 29, 29 are inclined to a certain direction around the shaft 31 together with the stabilizer head 28, the upper rotor head 25 is interlocked and inclined around the driving shaft 27 via the stabilizer link 32 accompanied by the inclination so that the surfaces of the upper rotor blades are inclined in the same direction.
The lower rotor 13 includes a lower rotor head 33 mounted tiltably on the upper end part side of the lower mast 24 to be rotatingly driven by the driving part 15, and a pair of lower rotor blades 34, 34 mounted on both end part sides of the lower rotor head 33. The lower rotor head 33 with the central part shaped in a substantially rectangular ring-like shape slightly larger than the outer diameter of the lower mast 24 is mounted tiltably on the both end parts of a driving shaft 22 provided in a direction orthogonal to the rotation shaft center at the upper end part side of the lower mast 24. The lower rotor head 33 has mounting parts 35, 35 formed with the both end face sides without having the pair of the lower rotor blades 34, 34 projecting downward. Ferromagnetic materials 49, 49, consisting of small pieces to be attracted by a magnet, are mounted on the lower end parts of the mounting parts 35, 35. As to the inclination angle around the shaft center of the driving shaft 22 of the lower rotor head 33, as it will be explained later in detail, even in the case the ferromagnetic materials 49, 49 are attracted by a magnetic force, they do not come in contact with the blade inclining mechanism 16. The lower rotor blades 34, 34 are mounted on the both end part sides of the lower rotor head 33 along the shaft center direction of the driving shaft 22 so as to generate the lift up force at the time of being rotatingly driven by the lower mast 24.
The upper mast 23 is formed with a slightly thick shaft part on the upper side on which, the upper rotor 12 and the stabilizer 4 are mounted, and with a narrow shaft part on the lower side. The lower mast 24 is formed in a substantially pipe-like shape such that the narrow shaft part on the lower side of the upper rotor 12 is rotatably introduced through the pipe. The upper mast 23 and the lower mast 24 are mounted through from the central upper part to the inside of the airframe 11 so as to be rotated at the same rate in the opposite directions by the driving part 15.
The driving part 15, disposed in the airframe 11 on the lower side of the upper mast 23 and the lower mast 24, includes a main motor 36, a pinion 37, a lower main gear 38 and an upper main gear 39 having the same number of teeth, and an inversion gear pair 40 to be rotated in the opposite directions at the same rate. The main motor 36 is mounted on the airframe 11 with the driving shaft oriented upward, and the pinion 37 is mounted on the driving shaft. The lower main gear 38 is mounted on the lower end part side of the narrow shaft part on the lower side of the upper mast 23, and the upper main gear 39 is mounted on the lower end part side of the lower mast 24. The lower main gear 38 is engaged with the pinion to be rotated by the main motor 36. The lower main gear 38 is engaged with one of the gears of the inversion gear pair 40, and the other gear of the inversion gear pair 40 is engaged with the upper main gear 39. That is, the rotational force by the main motor 36 is transmitted to the lower main gear 38 via the pinion 37, and then is transmitted to the upper main gear 39 via the inversion gear pair 40 from the lower main gear 38 so that the upper mast 23 and the lower mast 24 are rotated in the opposite directions.
The blade inclining mechanism 16, for the movement control by inclining the lower rotor blade 34, 34 surfaces by the magnetic force via the lower rotor head 33 mounted tiltably on the upper end part side of the lower mast 24, includes an actuator 41, a rotation plate 42, a pair of arm supporting parts 43, 43, arms 44, 44, links 45, 46, 47, and magnets 48, 48. The actuator 41 is mounted on the front part side airframe 11 on the lower side of the lower rotor 13 with the driving shaft oriented to the horizontal direction. The rotation plate 42 is mounted on the driving shaft of the actuator 41. The arm supporting parts 43, 43 are mounted on the front and rear parts of the airframe 11 across the lower part side of the lower mast 24 respectively. To each of the arm supporting parts 43, 43, one end parts of the arms 44, 44 formed in a rod-like shape, for example, are mounted rotatably, and the other end part sides are oriented to the lower part side of the upper lower rotor head 33. The magnets 48, 48 are mounted on the other end parts oriented upward of these arms 44, 44, respectively. The rotation plate 42 mounted on the driving shaft of the actuator 41 and one of the arms 44 in front are interlocked with the link 45. The arm 44 in front and the arm 44 in rear are interlocked with the links 46, 47. The blade inclining mechanism is for rotating the rotation plate 42 by the actuator 41, and rotating the arms 44, 44 with the arm supporting parts 43, 43 provided as the supporting points via the links 45, 46, 47. That is, by the drive of the actuator 41, the arm 44 in front is rotated from the slightly inclined neutral position to make the magnet 48 approach to the ferromagnetic material 49 side of the mounting part 35 of the lower rotor head 33. Then, by the magnetic force, the lower rotor head 33 is attracted and rotated so as to incline the surfaces of the lower rotor blades 34, 34 forward. On the other hand, the arm 44 in rear is rotated from the slightly inclined neutral position to make the magnet 48 approach to the ferromagnetic material 49 of the mounting part 35 of the lower rotor head 33. Then, by the magnetic force, the lower rotor head 33 is attracted and rotated so as to incline backward the surfaces of the lower rotor blades 34, 34 backward. In the case the arms 44, 44 are both at the slightly inclined neutral position, it is a position without the function of the magnetic force so as not to rotate the lower rotor head 33. In the case one of the arms 44 is rotated form the neutral position to a position close to the lower part side of the lower rotor head 33, the magnetic force is applied, however, the other arm 44 is further inclined form the neutral position so as to rotate to a position without the function of the magnetic force. Since the lower rotor head 33 is arranged not to be incline to more than a certain angle, either of the magnets 48, 48 approaches to the ferromagnetic materials 49, 49 without contacting thereto and it is rotated with the lower mast.
In this embodiment, since the upper rotor 12 and the lower rotor 13 to be rotated concentrically in the opposite directions are provided, the tail rotor 17 needs not be rotated for preventing turnover of the airframe 11, however, the tail rotor 17 is mounted rotatably on a tail part 50 provided on the end part of the tail pipe 49 elongating horizontally from the rear part of the airframe 11. The tail rotor 17 is arranged to be transmitted the rotational force of the tail motor 51 provided in the rear part of the airframe 11 via the driving shaft provided inside the tail pipe 49, the bevel gear provided in the tail part 50, or the like. By rotating the tail rotor 17 forward or backward by the tail motor 51, the airframe 11 is rotated around the shaft center of the upper mast 23 and the lower mast 24, and thereby the operation control in the right and left direction can be enabled.
The receiver 20 includes an antenna 61, a receiving circuit 62 for receiving a control signal as a radio wave transmitted from the transmitter 19, a control circuit 63 for producing a control signal based on the signal received by the receiving circuit 62, a motor driving circuit 64 for driving the main motor 36 and the tail motor 51 based on the control signal of the control circuit 63, an actuator driving circuit 65 for driving the actuator 41, and the like such that the electric power from the battery 18 can be supplied by a power source switch 66 mounted operatably on the airframe 11, or the like to the receiving circuit 62, the control circuit 63, the motor driving circuit 64 and the actuator driving circuit 65. The transmitter 19 includes a control part 52 having a control lever for the orientation control for elevation, descent, forward or backward movement and the like, a signal producing circuit 53 for producing a control signal according to the operation of the control part 52, a transmitting circuit 54 for transmitting a control signal produced by the signal producing circuit 53 as a radio wave from the antenna 57, and the like such that the electric power is supplied from the battery 55 by the power source switch 56 to the signal producing circuit 53 and the transmitting circuit 54.
The operation of the radio control helicopter toy 10 of the above-mentioned configuration will be explained. First, by switching on the power source switch 66 and placing the airframe 11 at a horizontal portion using the landing member 21, the radio control helicopter toy 10 is prepared for taking off. Next, by switching on the power source switch 56 of the transmitter 19 and operating the control lever of the control part 52, a control signal based on the operation is produced in the signal producing circuit 53 and the control signal is transmitted as a radio wave from the transmitting circuit 54 via the antenna 57. The control signal transmitted from the transmitter 19 is received by the receiving circuit 62 via the antenna 61 of the receiver 20 provided in the airframe 11 of the radio control helicopter toy 10. The control signal from the transmitter 19 received by the receiving circuit 62 is transmitted to the control circuit 63 so as to produce an output signal, and the output signal is outputted to the motor driving circuit 64 so as to produce a motor driving signal in the motor driving circuit 64 so that the main motor 36 or the tail motor 51 starts the rotation based on the motor driving signal. The rotational force of the main motor 36 is transmitted from the pinion 37 to the upper mast 23 via the lower main gear 38, and from the lower main gear 38, the rotation force is also transmitted to the lower mast 24 via the inversion gear pair 40 and the upper main gear 39 so as to rotate the upper rotor 12 and the lower rotor 13 by the same rotational frequency in the opposite directions respectively. Thereby, the upper rotor blades 26, 26 mounted on the upper rotor head 25 of the upper rotor 12 and the lower rotor blades 34, 34 mounted on the lower rotor head 33 of the lower rotor 13 are respectively rotated so as to enable the ascending flight of the airframe 11. At the time, since the upper rotor 12 and the lower rotor 13 are rotated at the same rotational rate in the opposite directions, the respective reaction torques applied to the airframe 11 can be offset with each other so that the airframe 11 can ascend without rotation. Moreover, since the stabilizer 14 mounted on the upper mast 23 is interlocked with the upper rotor 12 via the stabilizer link 32, when the stabilizer shafts 29, 29 are rotated in a horizontal attitude, the stabilizer shafts 29, 29 continue stable operation while maintaining the horizontal attitude due to the centrifugal force of the weights 30, 30. Moreover, in the case the stabilizer shafts 29, 29 are inclined from the horizontal attitude for any reason, the stabilizer shafts 29,29 affects the surfaces of the upper rotor blades 26, 26 to be inclined in the same direction via the stabilizer link 32 so that the function of maintaining the surfaces of the upper rotor blades 26, 26 horizontally is generated automatically by the centrifugal force of the weights 30, 30. Therefore, the stable operation can be enabled while maintaining the attitude of the airframe 11.
Next, the operation of the movement control of the airframe 11 by the blade inclining mechanism 16 after ascending in the air to a predetermined height will be explained. First, when a control signal is transmitted by the forward operation from the transmitter 19, the receiver 20 receives the forward control signal so that the forward signal is transmitted form the actuator driving circuit 65 to the actuator 41. When the actuator 41 receives the forward signal, the rotation plate 42 is driven so as to rotate the arm 44 in front from the neutral position via the link 45 to make the magnet 48 approach to the ferromagnetic material 49 side of the mounting part 35 of the lower rotor head 33. Then, by the magnetic force, the lower rotor head 33 is attracted and rotated so as to incline the surfaces of the lower rotor blades 34, 34 forward. According to the forward inclination of the surfaces of the lower rotor blades 34, 34, the airframe 11 can be moved forward. In the same manner, when a control signal is transmitted by the backward operation from the transmitter 19, the rotation plate 42 is driven so as to rotate the arm 44 from the neutral position via the links 45, 46, 47 to make the magnet 48 approach to the ferromagnetic material 49 side of the mounting part 35 of the lower rotor head 33. Then, by the magnetic force, the lower rotor head 33 is attracted and rotated so as to incline the surfaces of the lower rotor blades 34, 34 backward. According to the backward inclination of the surfaces of the lower rotor blades 34, 34, the airframe 11 can be moved backward. In this embodiment, by rotating forward or backward the tail rotor 17 by the tail motor 51, the airframe 11 is oriented in the right or left direction with respect to the rotation shaft center of the upper mast 23 and the lower mast 24, and thereby, the moving direction can be controlled in the right and left direction.
As heretofore explained, according to the radio control helicopter toy 10 of the embodiment of the present invention, since the surfaces of the lower rotor blades 34, 34 of the lower rotor 13 to be rotated by the lower mast 24 are inclined to the moving direction by attracting using the magnetic force by the blade inclining mechanism 16 mounted on the airframe 11, it can be produced in a simple structure at low cost without the need of a swash plate or a link of a complicated structure as in the conventional configuration.
In the radio control helicopter toy 10 of the above-mentioned embodiment, moving direction can be controlled in forward and backward direction. However, the moving direction can be controlled also in right and left direction by additionally providing a blade inclining mechanism, for inclining the surfaces of the lower rotor blades 34, 34 in the right and left direction utilizing the magnetic force, to the airframe 11. Moreover, although an example of mounting the ferromagnetic materials 49, 49 to the mounting parts 35, 35 of the lower rotor head 33 and mounting the magnets 48, 48 on the end parts of the arms 44, 44 of the blade inclining mechanism 16 has been explained in this embodiment, as long as they are attracted by the magnetic force, either one can be ferromagnetic material and the magnet, or furthermore, both of them can be a magnet. Furthermore, the ferromagnetic material or the magnet to be mounted on the lower side of the lower rotor head 33 may be formed in a ring-like shape instead of a small piece.
Furthermore, although a helicopter toy of a mechanism having the upper rotor 12 and the lower rotor 13 to be rotated concentrically in the opposite directions has been explained in this embodiment, as another embodiment, by mounting a blade inclining mechanism 16, with the same mechanism on one rotor to be driven in one direction by a main motor to an aircraft and applying the resultant mechanism to a radio control helicopter toy of a mechanism rotating the tail rotor 17. Moreover, the tail motor 51 can be mounted to the tail part 50 as well.
The present invention can be utilized for a radio control helicopter toy to have the movement control by the remote control.

Claims

1. A radio control helicopter toy comprising: a mast mounted projecting to the upper side of an airframe so as to be rotated by a main motor loaded on the airframe; a rotor mounted on the upper part of the mast via a rotor head with the blade surface of a rotor blade capable of inclining; a blade inclining mechanism having an arm with one end part side thereof mounted rotatably on the airframe side and the other end part side thereof is mounted to be driven to approach to the rotor head side by an actuator loaded on the airframe, for inclining the blade surface of the rotor by the magnetic force generated between magnets mounted on the end part of the arm and the rotor head or between the a magnet and a ferromagnetic material; and a receiver loaded on the airframe for controlling the operation of the main motor and the actuator.

2. The radio control helicopter toy according to claim 1, wherein the mast has an upper mast and a lower mast to be rotated concentrically in the opposite directions by the main motor; the rotor has an upper rotor mounted on the upper part of the upper mast via an upper rotor head with the blade surface of the upper rotor blade capable of inclining and a lower rotor mounted on the upper part of the lower mast via a lower rotor head with the blade surface of the lower rotor blade capable of inclining; and the blade inclining mechanism is provided on the airframe for inclining the blade surface of the lower rotor.

3. The radio control helicopter toy according to claim 2, wherein a stabilizer for controlling the flight attitude of the airframe is mounted on the upper mast so as to interlock with the upper rotor head.

4. The radio control helicopter toy according to claim 1 or 2, wherein the blade inclining mechanism has the arm to be driven by the actuator provided in four points of the front, back, right and left around the mast.

5. The radio control helicopter toy according to claim 1, wherein a tail pipe is mounted on the rear side of the airframe and a tail rotor to be driven by a tail motor is mounted on an end part of the tail pipe.

6. The radio control helicopter toy according to claim 1, wherein the magnet or the ferromagnetic material mounted on the rotor head of the blade inclining mechanism is formed in a ring-like shape surrounding the rotation center of the mast.