Technical Field

The present invention relates to a radio controlled motorcycle, particularly of the type with gyroscopic stabilization, used in the field of modeling and hobbies.

Background Art

Motorcycles for modeling and/or hobbies are typically provided with stabilization devices, which enable them to remain in equilibrium on two wheels without falling over.

In particular, the use is known of a flywheel mounted internally in at least one wheel, that makes it possible to maintain the equilibrium of the motorcycle by way of the gyroscopic effect deriving from the rotation of the flywheel proper.

Practically, in the conventional devices the flywheel rotates faster than the wheel in which it is mounted and it keeps its rotation speed substantially unaltered when the wheel slows.

Known flywheel-based stabilization devices are, however, adapted to toy motorcycles, that is to say to motorcycles that travel at low speeds, and are not adapted to remain in equilibrium on uneven surfaces.

Some devices, for example the one disclosed in Italian patent 1377453, can however comprise mechanisms that make it possible for kinetic energy to pass between wheel and flywheel.

More precisely, by way of these mechanisms and in particular by way of clutches of the centrifugal type interposed between the flywheel and the wheel, when the wheel turns at high speeds, i.e. when the gyroscopic effect of the wheel alone is sufficient to keep the motorcycle in equilibrium, the wheel transmits some of its kinetic energy to the flywheel, in which it is thus stored.

When the wheel slows, the rotations of the wheel and of the flywheel are uncoupled and therefore the flywheel can turn freely, thanks to the accumulated energy, keeping the motorcycle in equilibrium thanks to the gyroscopic effect generated by the flywheel.

Flywheel-based stabilization devices that use mechanisms like the one just described, though enabling motor vehicles to travel at high speeds while remaining in equilibrium even on rough ground, suffer the drawback of having no way to control the rotation of the flywheel during the steps of using the motorcycle.

Another drawback consists in that the condition of equilibrium of the motorcycle produced by the gyroscopic effect of the flywheel, when the wheel of the motorcycle is stationary, is a temporary condition. In fact, since the kinetic energy accumulated by the flywheel is exhaustible, once enough time elapses to make the flywheel stop, the motorcycle will fall over.

In order to overcome these drawbacks, in recent years stabilization devices have been devised that use a flywheel accommodated inside a wheel and provided with a dedicated electric motor that is adapted to control its rotation speed independently of the rotation speed of the wheel in which it is accommodated.

More specifically, such conventional stabilization devices, such as for example the one disclosed in EP 2058037 Bl, are provided with a flywheel and an electric motor which are accommodated inside a wheel of the motorcycle.

The flywheel is fitted, so that it can rotate, over the pin of the wheel, which in this case is fixed to the fork that supports the wheel, with the stator of the electric motor integral with the wheel pin and the rotor of the electric motor integral in rotation with the flywheel.

In this way, thanks to the use of a speed governor of the electric motor which can be actuated via radio, the rotation speed of the flywheel can be controlled independently of the wheel.

Notwithstanding the effectiveness of the solution just described, unfortunately the technology used to provide conventional stabilization devices faces miniaturization limits, which make it unsuitable for use in small-scale models, for example of the type with a scaling factor of 1 : 18.

In fact, owing to the reduced dimensioning, the distance between the magnets of the rotor and the stator is reduced to around one tenth of a millimeter and therefore it is necessary for the rotor, integral with the flywheel, to rotate with an axial tolerance with respect to the stator, so as to avoid scraping between the stator and rotor owing to eccentricities between them.

In order to obtain such axial tolerance, the axial distance between the bearings on which the shaft rotates must be at least equal to at least one third of the rotor diameter.

Such distance, together with the thickness of the stator, has the effect of having a swinging fork that is too wide and completely out of scale from the other parts of the motorcycle, making this solution unsuitable for models of small dimensions, for example of the type with a scaling factor of 1 : 18.

Steering a small-scale model radio controlled motorcycle typically is achieved by means of a linear actuator which is integral with the supporting frame of the motorcycle and the movable stem of which is pivoted, eccentrically with respect to the steering head, to the steering plate bearing the columns of the front fork.

In this way, by sliding the movable stem with respect to the actuator, the steering plate is made to rotate with respect to the steering head, as a result steering the front wheel by the desired angle.

In this case too, the technology used faces major limitations in its miniaturization and therefore its use is unsuitable in small-scale motorcycles such as, for example, those with a scaling factor of 1 : 18.

In fact, the encumbrance of the actuator and the eccentricity value necessary for the correct operation of this steering solution make it impossible to provide this solution in motorcycles of small size. Disclosure of the invention

The aim of the present invention is to eliminate the drawbacks and overcome the limitations mentioned above, by providing a radio controlled motorcycle, particularly of the type with gyroscopic stabilization, typically for use in modeling and/or hobbies and at a reduced scale, for example with a scaling factor of 1 : 18, that makes it possible for the motorcycle to travel on two wheels on any type of ground, even on rough ground.

Within this aim, an object of the present invention is to provide a radio controlled motorcycle that can be easily controlled even by pilots who are not expert.

Another object of the present invention is to provide a radio controlled motorcycle that is capable of maintaining the condition of equilibrium on the two wheels without falling over for long intervals of time even when the motorcycle is substantially stationary.

Another object of the present invention is to provide a radio controlled motorcycle that is capable, in the event of falling over, of returning to the condition of equilibrium on the two wheels.

Another object of the present invention is to provide a radio controlled motorcycle that is highly reliable, easy to implement and at low cost.

This aim and these and other objects which will become better apparent hereinafter, are achieved by a radio controlled motorcycle, particularly of the type with gyroscopic stabilization, comprising a supporting frame associated with a front wheel and with a rear wheel, respectively, by means of a steering fork and a swinging fork, a first electric motor being moreover provided associated with one of said wheels for the rotation thereof and a flywheel associated with one of said wheels for the stabilization of the motion of said radio controlled motorcycle, characterized in that it comprises a second electric motor constituted by a stator which is integral with either said steering fork or said swinging fork coaxially with the rotation axis of one of said wheels and a rotor which is integral in rotation with said flywheel, said rotor and said flywheel being integral in rotation with the rotation pin of said wheel with said rotation pin rotatably supported by said steering fork or said swinging fork.

Moreover this aim, and these and other objects which will become better apparent hereinafter, are achieved by a radio controlled motorcycle, particularly of the type with gyroscopic stabilization, comprising a supporting frame associated at least with a front wheel by means of a steering fork at a steering head defined by said supporting frame, characterized in that it comprises a servo-actuator which can be actuated via radio and is associated with said supporting frame behind said front wheel and functionally connected to a steering plate of said steering fork by means of a steering lever that can be oscillated about an oscillation axis that is substantially parallel to the direction of motion of said radio controlled motorcycle.

Brief description of the drawings

Further characteristics and advantages of the present invention will become better apparent from the detailed description of a preferred, but not exclusive, embodiment of a radio controlled motorcycle, particularly of the type with gyroscopic stabilization, which is illustrated by way of non- limiting example in the accompanying drawings, wherein:

Figure 1 is a perspective view of a radio controlled motorcycle, particularly of the type with gyroscopic stabilization, and of a radio controller according to the invention;

Figure 2 is a side elevation view of the radio controlled motorcycle shown in Figure 1 ;

Figure 3 is a sectional view of the rear wheel of the radio controlled motorcycle shown in Figure 2, taken along the line III-III.

Ways of carrying out the invention

With reference to the figures, the radio controlled motorcycle, particularly of the type with gyroscopic stabilization, generally designated by the reference numeral 1, comprises a supporting frame 2 which is associated with a front wheel 3 and with a rear wheel 4, respectively, by means of a steering fork 5 and a swinging fork 6.

Moreover, a first electric motor is provided, preferably of the three- phase type, with rotating case or with brushes, associated with one of the wheels, for example the rear wheel 4 for the rotation thereof, and a flywheel 8 associated with one of the wheels, for example again the rear wheel 4, for the stabilization of the motion of the radio controlled motorcycle 1.

More precisely, the swinging fork 6 is provided by a box-like body which is rotatably supported by the supporting frame 2 in contrast with and by the action of a rear shock absorber 9 which is interposed between the swinging fork 6 and the supporting frame 2.

The first electric motor, which is provided with a first speed governor which can be actuated via radio in order to vary the rotation speed of the wheel with which the first electric motor is associated, i.e. the rear wheel 4, is supported by the supporting frame 2 in proximity to the hingeing thereof with the swinging fork 6 and is kinematically connected to the rim 10 of the rear wheel 4 by way of mechanical transmission elements 11 provided by a cascade of gearwheels 12 which are accommodated so that they can rotate in an arm 13 of the swinging fork 6.

More precisely, the gearwheels 12 are meshing with each other, with the first gearwheel meshing with a pinion that is integral in rotation with the rotor of the first electric motor, and with the last gearwheel meshing with a ring gear 14 that is integral in rotation with the hub 15 of the rear wheel 4.

According to the invention, a second electric motor 16 is provided, preferably of the three-phase type, with rotating case or with brushes, constituted by a stator 17 that is integral with either the steering fork 5 or the swinging fork 6 coaxially with the rotation axis 4a of the corresponding wheel and a rotor 18 that is integral in rotation with the flywheel 8. More precisely, the rotor 18 and the flywheel 8 are integral in rotation with the rotation pin 19 of the wheel, the rotation pin 19 being rotatably supported by the steering fork 5 or by the swinging fork 6.

As already mentioned previously, in this embodiment the flywheel 8 is associated with the rear wheel 4 so as to structurally lighten the front wheel 3 which, as will be better described later, is intended to be responsible for the steering of the radio controlled motorcycle 1.

Structurally, the flywheel 8 comprises a substantially disc-shaped supporting element 20 that is integrally keyed in rotation onto the rotation pin 19 at the center of the supporting element 20 and which defines, at its peripheral region, a substantially ring-shaped flywheel mass 21 in such a way as to be coaxial thereto.

The flywheel 8 thus structured moreover defines a substantially cylindrical indentation that is coaxial to the rotation pin 19 and inside which is partially accommodated, without being in direct contact, the stator 17 that is integral with the swinging fork 6.

The indentation defines a lateral cylindrical surface 21a on which the rotor 18 is fixed.

Advantageously, the second electric motor 16 is provided with a second speed governor which can be actuated via radio independently of the first speed governor in order to vary the rotation speed of the flywheel 8 independently of the rotation speed of the wheel with which the first electric motor is associated, i.e. independently of the rotation speed of the rear wheel 4.

More precisely, such second speed governor is an electronic circuit that, for example by means of a circuit microcontroller, can be configured to vary the rotation speed of the flywheel 8 as a function of the rotation speed of the rear wheel 4.

To this end, a signal inverter can be provided, not shown, in order to generate an acceleration of the flywheel 8 of the opposite sign to the acceleration of the rear wheel 4 by commanding the second speed governor.

Such signal inverter, which can easily be implemented electronically by a person skilled in the art, can be installed in an ordinary radio controller 22 so that it receives the signal for acceleration of the motorcycle input by the user by means of an adapted command lever 23, which as is well known is provided in radio controllers of the known type, and transmits, by means of the antenna 24 of the radio controller, a corresponding radio signal for acceleration of the flywheel 8 of the opposite sign to the signal for acceleration of the radio controlled motorcycle 1 , by using another channel different from the channel of the signal for acceleration.

Alternatively, it is possible to use a conventional programmable radio controller 22 with multiple channels, in which one channel is conveniently programmed to generate a radio signal for acceleration of the flywheel 8 opposite to the signal for acceleration of the radio controlled motorcycle 1.

In another embodiment, if there is sufficient space, the signal inverter can be mounted directly in the radio controlled motorcycle 1 so that it can receive the radio signal for acceleration/deceleration transmitted by the radio controller 22 and generate the corresponding signal for deceleration or acceleration of the flywheel 8, respectively.

As mentioned previously, the front wheel 3 of the radio controlled motorcycle 1 is associated with the supporting frame 2 by means of a steering fork 5 rotatably fixed to the supporting frame 2 at a steering head 25 that is defined by the supporting frame 2.

According to the invention, a servo-actuator 26 is provided which can be actuated via radio, for example by the radio controller 22, and is associated with the supporting frame 2 behind the front wheel 3 and is functionally connected to a steering plate 27 of the steering fork 5 by means of a steering lever 28 that can be oscillated about an oscillation axis 28a which is substantially parallel to the direction of motion of the radio controlled motorcycle 1. More precisely, the steering lever 28 comprises a wire 29 made of harmonic steel and provided with a first end 29a which is associated with the servo-actuator 26 and a second end 29b which is hook-shaped and hooked into a slot 30 defined by the steering plate 26 of the steering fork 5.

Moreover, according to the diameter of the wire 29 a dynamic behavior of the radio controlled motorcycle 1 is achieved: as the diameter increases, the reactivity increases but the stability decreases and vice versa.

Operation of the radio controlled motorcycle 1, particularly of the type with gyroscopic stabilization, according to the invention is the following.

By means of adapted governors 31 carried on the radio controller 22, it is possible to define a mathematical law that links the angular speed of the flywheel 8 with the angular speed of the rear wheel 4.

More precisely, with a first governor 32, the number of revolutions per minute that the flywheel 8 performs with the radio controlled motorcycle 1 stationary is determined. This value can be set from 0 to 100%. Then with a second governor 33, the percentage of revolutions per minute at the top speed of the radio controlled motorcycle 1 , with respect to the initial value set, is set.

For example, if the initial value is set to 80% of the theoretical maximum and the final value to 50% then we obtain a speed of the flywheel 8, at the top speed of the radio controlled motorcycle 1, equal to 50% of 80%, i.e., 40% of the theoretical maximum.

Irrespective of the type of mathematical law between the angular speed of the rear wheel 4 and the angular speed of the flywheel 8, as long as an opposite sign relationship is maintained between the derivatives of the two speeds when the rear wheel 4 turns at a sufficiently high speed to ensure the equilibrium of the radio controlled motorcycle 1 even in the absence of the gyroscopic effect of the flywheel 8, the signal inverter will not send a signal for acceleration or deceleration to the second speed governor, thus deactivating the second electric motor 16.

During acceleration or deceleration, i.e. when the rear wheel 4 has to pass from a zero or low speed to a higher speed and vice versa, the user acts on a command lever 23 of the radio controller 22 in order to send an adapted radio signal to the first electric motor of the radio controlled motorcycle 1.

The signal generated based on the movement of the command lever 23 is acquired by the signal inverter, which determines whether the signal received is for acceleration or deceleration. Consequently, the signal inverter then generates and sends, by means of the antenna 24 and as a function of the mathematical law set previously, a radio signal for deceleration or acceleration, respectively, of the flywheel 8 to the second speed governor.

In this way, with the slowing down of the radio controlled motorcycle 1, the flywheel 8 is put into rotation, until it reaches its maximum angular speed when the rear wheel 4 is substantially stationary.

Vice versa, with the speeding up of the radio controlled motorcycle 1, the flywheel 8 is left idle or is gradually decelerated until it reaches a lower speed.

With regard to the steering of the radio controlled motorcycle 1, by means of a second command lever 34 it is possible to command, via radio, the servo-actuator 26 which, by means of the steering lever 28, makes the steering plate 27 of the steering fork 5 rotate by the desired angle, thus making the radio controlled motorcycle 1 steer.

In practice it has been found that the radio controlled motorcycle, particularly of the type with gyroscopic stabilization, according to the present invention fully achieves the intended aim and objects, in that it makes it possible to ensure a condition of stable equilibrium on even very rough terrain by enabling the maximum control of the speed of the flywheel.

The radio controlled motorcycle, particularly of the type with gyroscopic stabilization, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.

Where the technical features mentioned in any claim are followed by reference numerals and/or signs, those reference numerals and/or signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference numerals and/or signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference numerals and/or signs.