Background of the Present Invention
Field of Invention
[0001] The present invention relates to a linkage device for a model helicopter, and more
particularly to a linkage device for a remote control model helicopter with coaxial
and counter rotating double-propeller.
Description of Related Arts
[0002] The conventional remote control model helicopter with coaxial and counter rotating
double-propeller mainly comprises a landing gear, a body, a receiver controlling device,
a motor power transmitting device, a rotor lifting device, a flybar device and a forward
and backward device.
[0003] The forward and backward device of a conventional four-channel model helicopter is
embodied as an operating unit of a forward and backward servo steering engine in a
servo steering engine controlling system which is realized by a manner that the servo
steering engine drives a servo steering engine joystick; that the servo steering engine
joystick further drives a swashplate to tilt; and that the swashplate further drives
a rotor head via a rotor connecting rod to force a rotating plane of a lower rotor
to tilt forwardly or backwardly. However, the forward and backward device thereof
has a disadvantage that, when the rotating plane of the lower rotor tilts forwardly
and the helicopter flies forwardly, under the action of a centrifugal force of the
flybar, the upper rotor would produce an opposite equal force tilting backwardly to
counteract with the force driving the helicopter to fly forwardly; and vice versa.
Thus this type of helicopter has relatively weak forces of flying forwardly and backwardly
and is vulnerable to airflows; a strong wind may stop the helicopter.
[0004] The forward and backward device of a conventional three-channel model helicopter
is embodied as a tail motor operating system which is realized by a manner that a
tail motor rotates positively and reversely to drive a screw propeller to rotate positively
and reversely, so as to generate forces to lower or raise a head thereof. The conventional
three-channel model helicopter also has the problem of the weak forces of flying forward
and backward. Because the tail motor is related with power matching, an appearance
and a center of gravity, a volume, a size and a weight thereof are strictly limited,
and thus the tail motor has a small power and provides very small motive forces; moreover,
under the action of the centrifugal forces of the flybar, the rotating plane of the
upper rotor tilts opposite to a tilting direction of the body and a force of the tilting
adequately counteracts with the force lowering or raising the head thereof generated
by the positive and negative rotations of the tail motor, so that the body thereof
is unable to effectively generate torque to lower or raise the head; and thus the
conventional three-channel helicopter is unable to fly in outdoor winds.
Summary of the Present Invention
[0005] An object of the present invention is to provide a linkage device for a remote control
model helicopter with coaxial and counter rotating double-propeller having a good
resistance to winds, so as to satisfy requirement for the model helicopter to fly
fast against winds outdoors.
[0006] In order to accomplish the above objects, the linkage device of the present invention
adopts following technical solutions. The linkage device comprises a servo steering
engine operating system, a tail motor operating system and a receiver controlling
device. The servo steering engine operating system comprises a forward and backward
servo steering engine operating unit and a leftward and rightward servo steering engine
operating unit. The receiver controlling device is connected to both the servo steering
engine operating system and the tail motor operating system and able to control the
forward and backward servo steering engine operating unit and the tail motor operating
system to link simultaneously.
[0007] The receiver controlling device is for controlling the forward and backward servo
steering engine operating unit and the tail motor operating system to link simultaneously
to control the forward and backward servo steering engine operating unit and the tail
motor operating system to act simultaneously when the model helicopter flies forwardly
and backwardly.
[0008] The forward and backward servo steering engine operating unit comprises a forward
and backward servo steering engine, a servo steering engine joystick, a swashplate,
a rotor head connecting rod, a rotor head and rotors. The forward and backward servo
steering engine is installed on a body of the model helicopter; a first end of the
servo steering engine joystick is installed on the forward and backward servo steering
engine and a second end thereof is connected to the swashplate; a first end of the
rotor end connecting rod is installed on the swashplate and a second end thereof is
installed on the rotor head; the rotors are installed on the rotor head. The tail
motor operating system comprises a tail motor frame, a tail motor, a screw propeller
and tail motor fasteners. The tail motor frame is fixed on a back of the body; the
tail motor is fixed on the tail motor frame via the tail motor fasteners; and the
screw propeller is fixed on the tail motor.
[0009] The tail motor operating system further comprises a tail motor manual switch connected
to the receiver controlling device.
[0010] The receiver controlling device comprises a radio frequency (RF) signal circuit,
a micro controller unit (MCU) and a motor driving circuit, wherein the MCU is connected
to the servo steering engine operating system; the motor driving circuit is connected
to the tail motor operating system; after receiving a controlling instruction, the
RF signal circuit is processed by the MCU and then sends controlling signals into
the servo steering engine operating system and the motor driving circuit.
[0011] The present invention combines a conventional three-channel model helicopter with
a conventional four-channel model helicopter via the receiver controlling device,
and controls a lower rotor to tilt via the forward and backward servo steering engine
operating unit of the servo steering engine operating system to counteract with reaction
forces of an upper rotor; meanwhile, the tail motor operating system receives an instruction
of the receiver controlling device that the tail motor drives the screw propeller
to rotate positively or reversely to generate an upward force or a downward force
without restrictions which acts on the body of the helicopter to form and keep a relatively
big angle tilting forwardly or backwardly, when rotating planes of the upper rotor
and the lower rotor also form and keep an identically big angle, in such a manner
that the upper rotor and the lower rotor rotate to generate a relatively big force
pushing forwardly or backwardly to provide a relatively strong forwardly or backwardly
driving force for the helicopter to reach effects of a strong resistance to winds
and a fast flying speed, so as to satisfy needs of flying against the winds outdoors.
[0012] These and other objectives, features, and advantages of the present invention will
become apparent from the following detailed description, the accompanying drawings,
and the appended claims.
Brief Description of the Drawings
[0013]
Fig. 1 is a perspective view of a linkage device for a remote control model helicopter
with coaxial and counter rotating double-propeller according to a preferred embodiment
of the present invention.
Fig. 2 is a block diagram of circuit principles of a receiver controlling device of
Fig. 1.
Fig. 3 is a sketch view of installing the linkage device according to the preferred
embodiment of the present invention.
[0014] In the drawings: 1-forward and backward servo steering engine; 2-tail motor; 3-screw
propeller; 4-receiver controlling device; 5-tail motor manual switch; 6-RF signal
circuit; 7-MCU; 8-motor driving circuit; 9-servo steering engine joystick; 10-swashplate;
11-rotor head connecting rod; 12-rotor head; 13-rotor; 14-tail motor frame; 15-tail
motor fastener; 16-leftward and rightward servo steering engine.
Detailed Description of the Preferred Embodiment
[0015] Referring to Fig. 1 of the drawings, according to a preferred embodiment of the present
invention, a linkage device for a remote control model helicopter with coaxial and
counter rotating double-propeller comprises a servo steering engine operating system
(only a forward and backward servo steering engine 1 and a leftward and rightward
servo steering engine 16 showed), a tail motor operating system (only a tail motor
2 and a screw propeller 3 showed) and a receiver controlling device 4. The receiver
controlling device 4 is respectively connected to the forward and backward servo steering
engine 1, the leftward and rightward servo steering engine 16 and the tail motor 2
via electric wires and able to control the forward and backward servo steering engine
1 and the tail motor 2 to link simultaneously to control the forward and backward
servo steering engine operating unit and the tail motor operating system to act simultaneously
when the helicopter flies forwardly and backwardly. The screw propeller 3 is installed
on the tail motor 2. A tail motor manual switch 5 is installed on the electric wires
connecting the tail motor 2 and the receiver controlling device 4 to control whether
the tail motor operating system accepts and executes acting instructions from the
receiver controlling device 4.
[0016] Fig. 2 shows circuit principles of the receiver controlling device 4 which comprises
a RF signal circuit 6, an MCU 7 and a motor driving circuit 8, wherein the MCU 7 is
connected to the forward and backward servo steering engine 1 and the leftward and
rightward servo steering engine 16; and the motor driving circuit 8 is connected to
the tail motor 2. After receiving a first controlling instruction of flying forwardly
or backwardly, the RF signal circuit 6 is processed by the MCU 7 and sends two groups
of controlling signals into the forward and backward servo steering engine 1 and the
motor driving circuit 8; a first group comprises pulse position modulation (PPM) signals
for controlling the forward and backward servo steering engine 1 to act according
to the first controlling instruction of flying forwardly or backwardly; a second group
comprises pulse width modulation (PWM) signals for synchronously controlling the motor
driving circuit 8 to drive the tail motor 2 to act according to the first controlling
instruction of flying forwardly or backwardly. Thereby it is realized that the forward
and backward servo steering engine 1 and the tail motor 2 are linked simultaneously,
so as to accomplish a purpose of improving performance in resisting winds. When the
model helicopter flies indoors or without winds, the tail motor manual switch 5 can
be turned off, when a signal route to reach the tail motor 2 is cut off and the tail
motor 2 is idle, so as to satisfy needs of flying without winds. After receiving a
second controlling instruction of flying leftwardly or rightwardly, the RF signal
circuit 6 is processed by the MCU 7 and sends the first group of PPM signals into
the leftward and rightward servo steering engine 16 to control the leftward and rightward
servo steering engine 16 to act according to the second controlling instruction of
flying leftwardly or rightwardly.
[0017] Fig. 3 shows an installing structure of the linkage device of the present invention.
The servo steering engine operating system is installed on an upper part of a body,
comprising the forward and backward servo steering engine operating unit and the leftward
and rightward servo steering engine operating unit which is provided at backside and
not showed, wherein the forward and backward servo steering engine operating unit
comprises the forward and backward servo steering engine 1, a servo steering engine
joystick 9, a swashplate 10, a rotor head connecting rod 11, a rotor head 12 and rotors
13. The forward and backward servo steering engine 1 is installed on the body; a first
end of the servo steering engine joystick 9 is installed on the forward and backward
servo steering engine 1 and a second end thereof is installed on the swashplate 10;
a first end of the rotor end connecting rod 11 is installed on the swashplate 10 and
a second end thereof is installed on the rotor head 12; the rotors 13 are installed
on the rotor head 12. The tail motor operating system, provided on a tail part of
the body, comprises a tail motor frame 14, a tail motor 2, a screw propeller 3 and
tail motor fasteners 15. The tail motor frame 14 is fixed on a back part of the body;
the tail motor 2 is fixed on the tail motor frame 14 via the tail motor fasteners
15; and the screw propeller 3 is fixed on the tail motor 2. The receiver controlling
device 4 is provided in a front part of the body.
[0018] After receiving a synchronous controlling instruction of flying forwardly or backwardly,
the receiver controlling device 4 sends synchronous action signals into the forward
and backward servo steering engine 1 and the tail motor 2, and then the forward and
backward servo steering engine operating unit and the tail motor operating system
act simultaneously. A specific process is as follows. The forward and backward servo
steering engine 1 drives the servo steering engine joystick 9; the servo steering
engine joystick 9 drives the swashplate 10 to tilt; and the swashplate 10 drives the
rotor head 12 via a rotor head connecting rod 11 to force a rotating plane of a lower
rotor 13 to tilt forwardly or backwardly. When the rotating plane of the lower rotor
13 tilts forwardly according to instructions, the tail motor 2 drives the screw propeller
3 to positively rotate synchronously to generate a downward force to lift the tail
part of the helicopter and lower the head of the helicopter and instantly the helicopter
gains force components tilting forwardly to fly forwardly; when the rotating plane
of the lower rotor 13 tilts backwardly according to instructions, the tail motor 2
drives the screw propeller 3 to reversely rotate synchronously to generate an upward
force to press the tail part of the helicopter downwardly and lift the head and instantly
the helicopter gains force components tilting backwardly to fly backwardly. Thereby,
even flying in a windy weather, the helicopter is protected from airflows. The tail
motor manual switch 5 can be turned on and off according to practical needs to control
whether the tail motor 2 is synchronously linked with the forward and backward servo
steering engine 1. When the tail motor manual switch 5 is turned off, the forward
and backward servo steering engine 1 drives the rotating plane of the lower rotor
13 to tilt forwardly or backwardly under instructions, but the tail motor 2 is idle,
so as to suit for flying indoors or without winds. Similarly, a tail motor circuit
can be turned off via wireless instructions to realize flying without winds when the
tail motor operating system and the forward and backward servo steering engine operating
unit are unable to link simultaneously, i.e., the tail motor operating system is idle
and the forward and backward servo steering engine operating unit acts.
[0019] After receiving the synchronous controlling instruction of flying leftwardly or righwardly,
the receiver controlling device 4 sends action signals to the leftward and rightward
servo steering engine 16 and instantly the leftward and rightward servo steering engine
operating unit acts to force the helicopter to fly leftwardly or rightwardly.
[0020] In order to prove superior performance of the linkage device of the present invention,
a testing and comparison experiment about resistance to winds is held between identical
helicopter types of each conventional model helicopter with coaxial and counter rotating
double-propeller on the market and a model helicopter with coaxial and counter rotating
double-propeller using the linkage device of the present invention. Table 1 shows
results thereof.
Table 1
| 350 helicopter types |
test frequency |
flying tests of model helicopters against winds of each scale |
conclusion |
| scale 0 |
scale 1 |
scale 2 |
scale 3 |
scale 4 |
| status of the flight speed |
status of the flight speed |
status of the flight speed |
status of the flight speed |
status of the flight speed |
| 350 two-channel helicopter |
5 |
3 m/s stable & controllable |
0 m/s going with winds & losing control |
0 m/s going with winds & losing control |
0 m/s unable to take off |
0 m/s unable to take off |
suitable for flying indoors |
| 350 three-channel helicopter |
5 |
6m/s stable & controllable |
4 m/s stable & controllable |
2 m/s bumpy & hardly controllable |
0 m/s going with winds & losing control |
0 m/s unable to take off |
suitable for flying indoors or in outdoor breeze |
| 350 four-channel helicopter |
5 |
7 m/s stable & controllable |
5 m/s stable & controllable |
3 m/s bumpy & controllable |
0 m/s going with winds & losing control |
0 m/s unable to take off |
suitable for flying indoors or in outdoor breeze |
| 330 helicopter using the present invention |
5 |
14 m/s stable & controllable |
12 m/s stable & controllable |
10 m/s stable & controllable |
8 m/s stable & controllable |
5 m/s bumpy & controllable |
suitable for flying indoors or in outdoor winds below scale 4 |
[0021] The results show that, in a condition of no winds, the model helicopter using the
linkage device of the present invention flies faster than the conventional model helicopter;
in a condition of winds below scale 4, the model helicopter using the linkage device
of the present invention flies faster than the conventional model helicopter and has
better stability and controllability than the conventional model helicopter, especially
in relatively strong winds of scale 3 to scale 4, the conventional model helicopter
totally lose control while the model helicopter using the linkage device is still
able to fly against winds.
[0022] One skilled in the art will understand that the embodiment of the present invention
as shown in the drawings and described above is exemplary only and not intended to
be limiting.
[0023] It will thus be seen that the objects of the present invention have been fully and
effectively accomplished. Its embodiments have been shown and described for the purposes
of illustrating the functional and structural principles of the present invention
and is subject to change without departure from such principles. Therefore, this invention
includes all modifications encompassed within the spirit and scope of the following
claims.
1. A linkage device for a remote control model helicopter with coaxial and counter rotating
double-propeller, characterized in that said linkage device comprises a servo steering engine operating system, a tail motor
operating system and a receiver controlling device, wherein said servo steering engine
operating system comprises a forward and backward servo steering engine operating
unit and a leftward and rightward servo steering engine operating unit; said receiver
controlling device is connected to both said servo steering engine operating system
and said tail motor operating system and for controlling said forward and backward
servo steering engine operating unit and said tail motor operating system to link
simultaneously.
2. The linkage device, as recited in claim 1, characterized in that said receiver controlling device is for controlling said forward and backward servo
steering engine operating unit and said tail motor operating system to link simultaneously
to control said forward and backward servo steering engine operating unit and said
tail motor operating system to act simultaneously when the model helicopter flies
forwardly or backwardly.
3. The linkage device, as recited in claim 1, characterized in that said forward and backward servo steering engine operating unit comprises a forward
and backward servo steering engine, a servo steering engine joystick, a swashplate,
a rotor head connecting rod, a rotor head and rotors, wherein said forward and backward
servo steering engine is installed on a body of the model helicopter; a first end
of said servo steering engine joystick is installed on said forward and backward servo
steering engine and a second end thereof is installed on said swashplate; a first
end of said rotor head connecting rod is installed on said swashplate and a second
end thereof is installed on said rotor head said rotors are installed on said rotor
head; and said tail motor operating system comprises a tail motor frame, a tail motor,
a screw propeller and tail motor fasteners, wherein said tail motor frame is fixed
on a back part of the body; said tail motor is fixed on said tail motor frame via
said tail motor fasteners; and said screw propeller is fixed on said tail motor.
4. The linkage device, as recited in claim 3, characterized in that said tail motor controlling system further comprises a tail motor manual switch connected
to said receiver controlling device.
5. The linkage device, as recited in any claim from 1 to 4, characterized in that said receiver controlling device comprises a RF signal circuit, an MCU and a motor
driving circuit, wherein said MCU is connected to said servo steering engine operating
system; said motor driving circuit is connected to said tail motor operating system;
after receiving a controlling instruction, said RF signal circuit is processed by
said MCU and sends controlling signals into said servo steering engine operating system
and said motor driving circuit.