Model car steering mechanism

Abstract

To provide a steering mechanism of a model car, which increase steering control accuracy.SOLUTION: In a steering mechanism of a model car, a servomotor for steering, which is positioned between a steering wheel and an arm part extended toward the steering wheel from a vehicle body side and which rotatively drives the steering wheel by an output shaft parallel to a steering rotation shaft of the steering wheel, is provided as the servomotor for steering, which is used to rotatively drive the steering wheel of the model car in a steering angle direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a steering mechanism for a model car. In structure Regarding. [Background technology]

[0002] Some model cars are provided with a steering mechanism for steering and driving steering wheels such as the left and right front wheels (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-29669 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, as disclosed in Patent Document 1, conventional steering mechanisms for model cars have a steering servomotor mounted on the vehicle body (chassis), and so the rotational driving force of the steering servomotor is transmitted to the steering wheel side via a steering link mechanism. Specifically, this is a link mechanism that converts the rotational motion of the steering servomotor into translational motion in the left-right direction.

[0005] However, in the above-described link mechanism, a considerable amount of connection play occurs, and this connection play leads to a decrease in steering control accuracy. Furthermore, because the above-mentioned link mechanism converts the rotational motion of the motor into translational motion in the left-right direction to drive the steered wheels, the amount of change in the rotational angle of the steered wheels relative to a change in the rotational angle of the motor output shaft varies depending on the steering angle, which is also a factor that leads to a decrease in steering control accuracy.

[0006] The present invention has been made in view of the above circumstances, and has as its object to improve the steering control accuracy of the steering mechanism of a model car. [Means for solving the problem]

[0007] The steering mechanism of the model car according to the present invention comprises: A steering mechanism for a model car having a steering wheel and an arm portion extending from a vehicle body side toward the steering wheel, The steering wheel is rotated by an output shaft that is positioned between the arm portion and the steering wheel and is parallel to the steering rotation axis of the steering wheel. In the direction of the steering angle It is equipped with a steering servo motor that drives the rotation. As described above, the steering servo motor positioned between the arm portion and the steering wheel is configured to rotate the steering wheel using an output shaft parallel to the steering rotation axis, thereby making it possible to eliminate the steering link mechanism that was previously required when the steering servo motor was located on the vehicle body side, and to synchronize the rotation angle of the steering servo motor with the rotation angle of the steering wheel. [Effects of the Invention]

[0009] According to the present invention, the steering control accuracy of the steering mechanism of the model car can be improved. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a block diagram for explaining an outline of the electrical configuration of a radio control system according to an embodiment of the present invention; [Figure 2] FIG. 10 is a diagram showing an example of the configuration of a steering mechanism using a link mechanism. [Figure 3] 5 is an explanatory diagram of the steering angle dependency of the amount of change in the rotation angle of the steered wheels. FIG. [Figure 4] 1 is a perspective view of the exterior of a model car according to an embodiment, mainly showing the steering mechanism and its surroundings in the model car; [Figure 5] 1 is an explanatory diagram of an external configuration of a steering servo motor according to an embodiment; [Figure 6] FIG. 2 is a diagram showing the state in the vicinity of the left steering wheel when traveling straight. [Figure 7] FIG. 10 is a diagram showing the state in the vicinity of the left steered wheel when steering to the right. [Figure 8] 3 is an explanatory diagram of an input damping mechanism provided in the model car of the embodiment. FIG. [Figure 9] FIG. 10 is an explanatory diagram of an input damping mechanism provided in the model car of the embodiment. [Figure 10] FIG. 10 is an explanatory diagram of a steering mechanism as a first alternative example. [Figure 11] FIG. 10 is an explanatory diagram of a second alternative steering mechanism. [Figure 12] FIG. 10 is an explanatory diagram of a third alternative steering mechanism. [Figure 13] FIG. 10 is an explanatory diagram of an example of a connection position displacement mechanism for adjusting the caster angle. [Figure 14] FIG. 10 is an explanatory diagram of another example of a connection position displacement mechanism for adjusting the caster angle. [Figure 15] FIG. 4 is an explanatory diagram of an example of a connection position displacement mechanism for adjusting a camber angle. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in the following order. <1. Overview of the radio control system configuration> <2. Steering mechanism as an embodiment> <3. Input attenuation mechanism> <4. Another example of a steering mechanism> (4-1. First Alternative Example) (4-2. Second and third alternative examples) <5. Angle adjustment mechanism> <6. Variations> <7. Summary of embodiments>

[0012] <1. Overview of the radio control system configuration> FIG. 1 is a block diagram for explaining the outline of the electrical configuration of a radio control system 100 according to an embodiment. The radio control system 100 includes at least a model car 1 as a controlled object, and a transmitter 2 that functions as a controller for controlling the model car 1 wirelessly.

[0013] Although not shown in the figures, in this example the model car 1 is configured as a four-wheeled vehicle with a pair of wheels, one at the front and one at the back, for a total of four wheels, with the pair of left and right wheels serving as front wheels being provided as steering wheels W for turning the model car 1, and the pair of left and right wheels serving as rear wheels being provided as drive wheels for running the model car 1. In the following, the left steering wheel W will be referred to as "steering wheel WL" and the right steering wheel W will be referred to as "steering wheel WR".

[0014] The model car 1 is provided with at least a receiver 10 that receives a control signal from the transmitter 2, a running servomotor 14 as a servomotor for accelerating, decelerating, and steering, and a steering servomotor 15. In the model automobile 1 of this example, the steering servo motors 15 include a steering servo motor 15 (hereinafter referred to as "steering servo motor 15L") for driving the left steering wheel WL to rotate in the steering angle direction, and a steering servo motor 15 (hereinafter referred to as "steering servo motor 15R") for driving the right steering wheel WR to rotate in the steering angle direction. The running servo motor 14 is a servo motor for adjusting the carburetor of an engine (not shown) mounted on the model automobile 1. In this example, the model automobile 1 is an engine vehicle, and the rear wheels are driven by the engine as a drive source. By controlling the rotation of this running servo motor 14, it is possible to control the acceleration (accelerator) and deceleration (brake) of the model automobile 1. It is also possible to configure the model car 1 so that the wheels are driven by a motor as a drive source. In this case, an ESC (speed controller) is provided to control the motor for running.

[0015] The receiver 10 in the model car 1 will be described in detail later.

[0016] The transmitter 2 modulates a control signal for wirelessly controlling the model car 1 and transmits it as radio waves. As shown in the figure, the transmitter 2 includes an interface unit 20, an encoder 25, a transmitting unit 26, and an antenna 27.

[0017] The interface unit 20 performs interface operations for the user, such as accepting operation inputs from the user as a pilot and presenting various information to the user. The interface unit 20 is provided with two operation levers 21, two trim switches 22, a display unit 23, and a setting operation unit 24.

[0018] The operating levers 21 include an operating lever 21X for controlling the steering of the model automobile 1 and an operating lever 21Y for controlling acceleration and deceleration. In the example of Figure 1, the direction of the steering wheel W can be controlled by operating the steering control lever 21X in the direction indicated by the arrow X (horizontal on the paper), and the acceleration and deceleration of the model car 1 can be controlled by operating the other control lever 21Y in the direction indicated by the arrow Y (vertical on the paper). The steering and acceleration / deceleration controls are not limited to the lever-shaped controls shown as examples, and controls in other shapes, such as wheel-shaped controls, can also be used.

[0019] In this example, the steering servo motors 15 of the model automobile 1 are provided for the left and right steering wheels W, respectively, as described above, and therefore, in response to the operation of the operating lever 21X, a signal for driving the left steering servo motor 15L and a signal for driving the right steering servo motor 15R are generated separately. In this example, the operating lever 21X is configured to change the resistance value of a variable resistor in accordance with the amount of operation (displacement) and output a control signal for each of the steering servo motors 15L and 15R. The operating lever 21Y is also configured to output a control signal for the traveling servomotor 14 by changing the resistance value of a variable resistor in accordance with the amount of operation.

[0020] By the operation levers 21X and 21Y as described above, the transmitter 2 generates control signals for a total of three channels, one for the steering servomotor 15L, one for the steering servomotor 15R, and one for the traveling servomotor 14. In the figure, the control signals of these channels generated based on the operation of the control lever 21X and the control lever 21Y are shown as signals CH1, CH2, and CH3. Here, the signal CH1 is the control signal for the traveling servomotor 14, and the signals CH2 and CH3 are the control signals for the steering servomotors 15L and 15R, respectively. As shown, these signals CH1, CH2, and CH3 are input to an encoder 25.

[0021] The above channel assignment is merely an example for the purpose of explanation, and the combination of channels and signals can be changed as appropriate, for example, CH1 can be used for steering signals (left and right) and CH2 can be used for driving signals.

[0022] The interface unit 20 is also provided with a trim switch 22 for adjusting the resistance value of the variable resistor (value of the control signal of the servo motor) relative to the neutral position when the control lever 21 is not being operated. In this example, this trim switch 22 is provided for each of the control levers 21X and 21Y (see 22X and 22Y in the figure). The resistance value of the variable resistor for the neutral position can also be configured to be set by operation via the setting operation unit 24, which will be described later.

[0023] Furthermore, the interface unit 20 is provided with a display unit 23 configured, for example, by an LCD (Liquid Crystal Display) or an organic EL (Electro-Luminescence) display. The user can use various controls provided in a setting operation unit 24 to configure various settings related to the operation of the model automobile 1 through a setting screen displayed on the display unit 23. For example, the maximum turning angle of the steering wheel W can be set as a steering-related setting. Settings here also include whether or not to perform control to change the toe angles of the steering wheels WL and WR (control to improve straight-line stability) in response to brake or accelerator operation using the control lever 21Y. In this case, toe angle adjustment is achieved by superimposing a toe angle adjustment signal on the control signal for the steering servo motors 15L and 15R.

[0024] In the transmitter 2, the encoder 25 performs, for example, pulse width conversion on the signals CH1, CH2, CH3 of each channel input from the interface unit 20, and also time-division multiplexes and outputs these signals CH1, CH2, CH3 at a predetermined frame period. The time-division multiplexed signals CH1, CH2, and CH3 are input to the transmitter 26, which then performs AM modulation (amplitude modulation) or FM modulation (frequency modulation FM) on the time-division multiplexed signals CH1, CH2, and CH3, and transmits the modulated signals as control signals via radio waves from the antenna 27.

[0025] In the model car 1, the receiver 10 has an antenna 11, a receiving unit 12, and a decoder 13. The receiver 10 receives and demodulates the control signal transmitted by the transmitter 2 via the antenna 11 and outputs the demodulated received signal to the decoder 13 .

[0026] The decoder 13 separates the operation signal received by the receiver 10 into signals CH1, CH2, and CH3 for each channel, and outputs the separated signals CH1, CH2, and CH3 to the corresponding servo motors among the traveling servo motor 14 and the steering servo motors 15L and 15R. Specifically, in this example, the signal CH1 is output to the traveling servo motor 14, the signal CH2 to the steering servo motor 15L, and the signal CH3 to the steering servo motor 15R. As a result, the steering servomotors 15L and 15R are each driven and controlled in response to the operation of the control lever 21X, and the steering of the model automobile 1 is realized in response to the operation of the control lever 21X. Furthermore, the running servo motor 14 is driven and controlled in response to the operation of the control lever 21Y, and the model car 1 is accelerated or decelerated in response to the operation of the control lever 21Y.

[0027] <2. Steering mechanism as an embodiment> Here, with regard to the steering mechanism of the model car 1, it is conceivable to adopt a configuration in which the steering servo motor 15 is provided on the vehicle body (chassis) side, and the rotational driving force from the steering servo motor 15 is transmitted to the steering wheel side via a steering link mechanism, as in the aforementioned Patent Document 1. FIG. 2 illustrates the configuration disclosed in FIG. 6 of Patent Document 1 as an example of a steering mechanism using such a link mechanism. As can be understood by referring to FIG. 2, the link mechanism converts the rotational driving force of the steering servo motor 15 into translational motion in the left and right direction, thereby driving the left and right steering wheels W to rotate in the steering angle direction.

[0028] However, in the above-described link mechanism, a considerable amount of connection play occurs, and this connection play leads to a decrease in steering control accuracy. Furthermore, because the above-mentioned link mechanism converts the rotational motion of the steering servo motor 15 into translational motion in the left-right direction to drive the steering wheels W, the amount of change in the rotational angle of the steering wheels W relative to a change in the rotational angle of the output shaft of the steering servo motor 15 changes depending on the steering angle, which is also a factor that leads to a decrease in steering control accuracy.

[0029] FIG. 3 is an explanatory diagram of the steering angle dependency of the amount of change in the rotation angle of the steered wheels W. As can be seen from Figure 3, when the above-mentioned link mechanism is used, the amount of change in the rotation angle of the steered wheels W relative to the change in the rotation angle of the output shaft of the steering servo motor 15 is relatively large in the region where the steering angle is small, whereas the amount of change in the rotation angle of the steered wheels W relative to the change in the rotation angle of the output shaft of the steering servo motor 15 is relatively small in the region where the steering angle is large, and the amount of change in the rotation angle of the steered wheels W varies depending on the steering angle.

[0030] Therefore, in view of the above-mentioned problems, in this embodiment, the steering mechanism of the model car 1 is configured such that a steering servo motor 15 is placed between the steering wheel W and an arm portion from the vehicle body side, that is, a so-called in-wheel servo configuration is adopted.

[0031] The steering mechanism 50 provided in the model car 1 according to the embodiment will be described with reference to FIGS. Figure 4 is an external perspective view of the model automobile 1, mainly showing the area around the steering mechanism 50 in the model automobile 1, Figure 5 is an explanatory diagram of the external configuration of the steering servo motor 15, and Figures 6 and 7 are diagrams showing the area around the left steering wheel WL when traveling straight and when steering to the right, respectively. In FIG. 4, the wiring for the steering servomotor 15, the receiver 10, and the traveling servomotor 14 are omitted from the illustration. 5A and 5B are respectively a top view and a side view of the steering servo motor 15. Furthermore, in Fig. 6, Fig. 6A and Fig. 6B are respectively a top view and a rear view (viewed from the rear of the vehicle) of the vicinity of the left steered wheel WL.

[0032] The steering mechanism 50 is disposed near the front end of the chassis 1a of the model car 1 (see FIG. 4). In this example, the steering mechanism 50 has a symmetrical configuration, and each of the left and right sides has at least an upper arm 51, a lower arm 52, a steering servo motor 15, a wheel hub portion 53, and a steering wheel W. In the following description, when distinguishing between the left and right components of the steering mechanism 50, the left component will have the suffix "L" added to the end of its reference number, and the right component will have the suffix "R" added to the end of its reference number.

[0033] Here, in FIG. 4, shock absorbers 61 (61L and 61R) and shock towers 62 are shown as components related to the suspension of the model automobile 1, but these components will be explained again later.

[0034] Upper arm 51 and lower arm 52 function as arm sections for supporting steered wheel W from the chassis 1a side, and are arranged spaced apart in the vertical direction. Upper arm 51 and lower arm 52 have their bases attached to the chassis 1a side so as to extend toward the outside of the vehicle body, and the portions near their tips (the portions farthest from the chassis 1a side) are formed as tip section 51a and tip section 52a, respectively.

[0035] In this example, a steering servo motor 15 is arranged between the tip 51a of the upper arm 51 and the tip 52a of the lower arm 52, and the steering wheel W is connected to the steering servo motor 15 via the wheel hub portion 53.

[0036] The steering servo motor 15 has a main body 15a and an output shaft 15b (see FIG. 5). The output shaft 15b is an output shaft for the rotational driving force generated by the motor, and the main body 15a is a portion that rotatably holds the output shaft 15b. As shown in the figure, the main body 15a has a substantially rectangular parallelepiped shape in this example, and the output shaft 15b protrudes upward from the top surface of the main body 15a. The directions here are based on the directions when attached to the model car 1.

[0037] The lateral side surfaces of the main body 15a are formed with connected portions 151 for connecting the wheel hub portion 53. In this example, the connected portions 151 are formed on both the left and right sides of the main body 15a so that the steering servo motor 15 can be used on both the left and right sides. There are various possible connection configurations for the wheel hub portion 53 to the connected portion 151, and the present invention is not limited to a specific configuration. For example, the wheel hub portion 53 may be connected with one or more screws. In this case, the connected portion 151 is formed as one or more screw holes. It is desirable that the connected portion 151 be formed with a positioning portion for determining the connection position of the wheel hub portion 53 .

[0038] A connection part 15c is attached to the tip of the output shaft 15b for connection to the upper arm 51. The connection part 15c has a plate-like part 152 arranged parallel to a plane perpendicular to the output shaft 15b, and a pole part 153 extending from the end of the plate-like part 152 in a direction parallel to the output shaft 15b (upward in this example). The plate-like portion 152 has a substantially rectangular shape when viewed from above, and the tip of the output shaft 15b is connected to the center portion in the longitudinal direction. The pole part 153 is located at one of both ends in the longitudinal direction of the plate-like part 152. The portion of the pole part 153 near its tip is formed as a tip part 153a.

[0039] Furthermore, a pillow ball 154 is formed on the lower surface of the main body 15a. The pillow ball 154 is formed to protrude downward from the lower surface of the main body 15a, and the tip end portion in the protruding direction (i.e., the lower end portion) is formed in a substantially spherical shape.

[0040] 6 and 7, a specific connection between the upper arm 51 and the lower arm 52 and the steering servo motor 15 will be described. In the following explanation, the configuration of the left side of the steering mechanism 50 will be described as a representative, but the configuration of the right side will not be described with reference to the drawings because it is the same as the left side except that it is symmetrical to the left side. 6 and 7 also show a wheel rotation axis Ar. The wheel rotation axis Ar refers to the axis of rotation about which the wheel rotates as the model automobile 1 travels. In other words, the wheel rotation axis Ar is an axis passing through the radial center of the wheel.

[0041] First, in this example, the main body 15a of the steering servo motor 15L and the plate-like portion 152 at the connection portion 15c are oriented in a direction substantially parallel to the front-rear direction when traveling straight as shown in Fig. 6. Specifically, when traveling straight, the left and right side surfaces of the main body 15a and the longitudinal direction of the plate-like portion 152 are both substantially parallel to the front-rear direction. In this example, when traveling straight, the orientation of the plate-like portion 152 is such that the pole portion 153 is positioned on the rear end side as shown in the figure.

[0042] In this example, the tip 153a of the pole part 153 at the connection part 15c is connected to the tip 51a of the upper arm 51L so as to prevent rotation of the pole part 153. As a result, the output shaft 15b of the steering servo motor 15L, which is connected to the pole part 153 via the plate-shaped part 152, is supported from the upper arm 51L side so as not to be able to rotate.

[0043] 6B, a ball bearing 154 provided on the lower surface of the main body 15a of the steering servo motor 15L is connected to the tip end 52a of the lower arm 52L. Specifically, a recess D is formed in the tip end 52a of the lower arm 52L to fit the spherical portion of the ball bearing 154 so that it can slide freely in a direction along the spherical surface, and the ball bearing 154 is connected to the lower arm 52L via this recess D. As a result, the main body 15a of the steering servomotor 15L is supported from the lower arm 52L side so as to be freely rotatable about an axis parallel to the steering rotation axis (axis parallel to the output shaft 15b).

[0044] Here, when a drive signal is given to the steering servo motor 15L, it generates a drive force that rotates the output shaft 15b, but since the output shaft 15b is non-rotatably supported by the upper arm 51L and the main body 15a is rotatably supported by the lower arm 52L as described above, in response to the generation of such a rotational drive force, the main body 15a rotates about an axis parallel to the steering rotation axis, as exemplified by the state during right steering in Fig. 7. Then, in response to such rotation of the main body 15a, the steered wheel WL connected to the side of the main body 15a via the wheel hub 53 also rotates about an axis parallel to the steering rotation axis.

[0045] As can be seen from FIGS. 6 and 7, the steering rotation axis in the steering mechanism 50 of this example is the axis indicated by "As" in FIG. 7A, that is, the rotation center axis of the output shaft 15b. Hereinafter, the steering rotation shaft will be denoted by the symbol "As".

[0046] In the above configuration, the ball connector 154 formed on the main body 15a is connected to the lower arm 52, and the pole portion 153 of the connecting portion 15c is connected to the upper arm 51. However, in order to realize a configuration in which the steering wheel W rotates in conjunction with the rotation of the main body 15a as described above, it is also possible to connect the ball connector 154 to the upper arm 51 and the pole portion 153 to the lower arm 52. In this case, a recess D for fitting the ball connector 154 is formed in the tip 51a of the upper arm 51, and the tip 153a is connected to the tip 52a of the lower arm 52 so as to prevent the pole portion 153 from rotating. In other words, inversely to the above configuration, the output shaft 15b is held non-rotatably from the lower arm 52 side, and the main body 15a is supported from the upper arm 51 side so as to be rotatable about an axis parallel to the steering rotation axis As. As can be understood from this point, in order to realize the operation of rotating the steered wheels W in conjunction with the rotation of the main body 15a, the steering mechanism 50 only needs to be configured as follows: That is, the output shaft 15b is supported non-rotatably from either the upper arm 51 or the lower arm 52, the main body 15a is supported from the other arm of either the upper arm 51 or the lower arm 52 so as to be rotatable about an axis parallel to the steering rotation axis As, and the wheel hub 53 is connected to the main body 15a.

[0047] Here, in this specification, the term "connection" is a concept that includes not only direct connection between certain members, but also connection via other members. Therefore, in this example, the wheel hub portion 53 is directly connected to the main body portion 15a, but it is also possible to configure the wheel hub portion 53 to be connected to the main body portion 15a via another member.

[0048] As can be understood from the explanations of Figures 4 to 7, the steering mechanism 50 of this embodiment is configured such that the steering servo motor 15 positioned between the arm portions, namely the upper arm 51 and the lower arm 52, and the steering wheel W rotates the steering wheel W using the output shaft 15b (in this example, coaxial with the steering rotation axis As) parallel to the steering rotation axis As. By adopting this configuration, it is possible to eliminate the steering link mechanism that was previously required when the steering servo motor was placed on the vehicle body side, and it is also possible to synchronize the rotation angle of the steering servo motor with the rotation angle of the steering wheels. By eliminating the need for a steering link mechanism, it is possible to suppress a decrease in steering control accuracy due to connection play in the link mechanism. Also, by eliminating the need for a link mechanism, it is possible to prevent the rotation angle of the steered wheels from changing depending on the steering angle. Therefore, in these respects, it is possible to improve steering control accuracy.

[0049] <3. Input attenuation mechanism> In this embodiment, in response to the configuration in which the steering servo motor 15 is arranged between the arm portion and the steering wheel W, the configuration of the input damping mechanism for damping the input from the road surface via the steering wheel W has been devised. The input damping mechanism provided in the model car 1 of the embodiment will be described with reference to FIGS.

[0050] 8A is a front view (viewed from the front side of the vehicle) of the vicinity of the left side portion of the steering mechanism 50. Note that the wheel hub portion 53L and the steered wheel WL are not shown. The model automobile 1 of this embodiment is provided with a shock absorber 61L and a shock tower 62 as a component for input attenuation. The shock absorber 61L is configured to have a cylinder portion filled with a buffer material such as a liquid inside and a spring wound around the outer periphery of the cylinder portion, and is configured to be able to absorb impacts applied to the spring by the drag force generated by the liquid or gas inside the cylinder portion. The shock tower 62 is a member for connecting the left and right shock absorbers 61 to the chassis 1a side.

[0051] First, as a premise, in the steering mechanism 50 of the embodiment, the vehicle body side end 51b (the aforementioned base portion), i.e., the end opposite to the tip end 51a, of the upper arm 51L is connected to the chassis 1a so as to enable the upper arm 51L to swing up and down around the vehicle body side end 51b as a fulcrum. Also, the tip end 51a of the upper arm 51L is connected to the tip end 153a of the pole portion 153 so as to enable the upper arm 51L to swing up and down around the tip end 51a as a fulcrum. In other words, the upper arm 51L is connected to the output shaft 15b.

[0052] 8B is a perspective view for explaining an example of a connection configuration between the tip 51a of the upper arm 51L and the tip 153a of the pole part 153. As shown in the figure, the tip 153a is formed with a substantially cylindrical hook part 160 that protrudes toward the front of the model automobile 1, and the tip 51a of the upper arm 51L is formed with a substantially circular hole H into which the hook part 160 is inserted. In this case, the tip 51a is clamped to the pole part 153 side by a clamping member such as a nut 161, with the hook part 160 inserted into the hole H. For example, with such a configuration, the upper arm 51L is connected to the tip 153a of the pole part 153 so as to be able to swing up and down with the tip 51a as a fulcrum.

[0053] The lower arm 52L has a vehicle body side end 52b, i.e., an end opposite to the tip end 52a, connected to the chassis 1a so as to enable the lower arm 52L to swing up and down around the vehicle body side end 52b as a fulcrum. The tip end 52a of the lower arm 52L is connected to a pillow ball 154 so as to enable the lower arm 52L to swing up and down around the tip end 52a as a fulcrum. In other words, the tip end 52a is connected to the main body 15a of the steering servomotor 15L. As mentioned above, the lower arm 52L is slidably fitted with the spherical portion of the pillow ball 154 in the recess D, and therefore the lower arm 52L is connected to the main body 15a of the steering servo motor 15L so as to be able to swing up and down with the tip end 52a as the fulcrum.

[0054] With the above-described configuration, the shock absorber 61L has a lower end 61a connected to the lower arm 52L so as to be able to swing up and down about the vehicle body side end 52b of the lower arm 52L as a fulcrum, and to be able to swing up and down about the tip end 52a of the lower arm 52L as a fulcrum. In other words, the lower end 61a of the shock absorber 61L is connected to the lower arm 52 so as to be able to swing up and down about the connection portion between the lower end 61a and the lower arm 52L as a fulcrum. The upper end 61b of the shock absorber 61L is connected to the shock tower 62 (that is, connected to the vehicle body side) without the upper arm 51L interposed therebetween.

[0055] The suspension structure described above is a so-called double wishbone type suspension structure. The double wishbone system uses a parallel link, so the camber angle does not change even if the steering wheel W moves up and down due to unevenness in the road surface. Figure 9 is an explanatory diagram showing the steering and input damping mechanism when the steered wheel WL passes over a bump (Figure 9A) and a depression (Figure 9B) on the road surface, as viewed from the front, similar to Figure 8A. Figures 9A and 9B show that the camber angle of the steered wheel WL does not change in response to road surface irregularities.

[0056] Furthermore, according to the double wishbone suspension structure described above, the upper end 61b of the shock absorber 61 is not connected to the upper arm 51L, so even if a configuration is adopted in which the steering servo motor 15 is inserted between the upper arm 51 and the lower arm 52, the input attenuation action from the road surface is not hindered.

[0057] As described above, it is also possible to employ a configuration in which the tip 51 a of the upper arm 51L is connected to the main body 15a via the pillow ball 154, and the tip 52 a of the lower arm 52L is connected to the output shaft 15b. In that case, in order to realize the double wishbone suspension structure described above, it is sufficient that the tip 51 a of the upper arm 51L is connected to the main body 15a so as to enable the upper arm 51L to swing in the up and down direction around the tip 51 a as a fulcrum, and it is sufficient that the tip 52 a of the lower arm 52L is connected to the output shaft 15b so as to enable the lower arm 52L to swing in the up and down direction around the tip 52 a as a fulcrum.

[0058] Regarding the input attenuation mechanism, the configuration on the right side is the same as the configuration on the left side described above except that it is symmetrical, so a description using illustrations will be omitted.

[0059] <4. Another example of a steering mechanism> (4-1. First Alternative Example) In the above, the output shaft 15b and the upper arm 51 are connected to each other via the connecting portion 15c. However, as shown in the first alternative example in FIG. 10, the tip of the output shaft 15b may be directly connected to the tip 51a of the upper arm 51. In the following description, parts that are similar to parts that have already been described will be given the same reference numerals and description thereof will be omitted.

[0060] 10, in this case, the tip of output shaft 15b is connected to tip 51a of upper arm 51 so as to disable rotation of output shaft 15b. As a result, a configuration is realized in which main body 15a and steered wheels W move in conjunction with each other in response to steering, similar to the case where the configuration described in FIG. 6 etc. is adopted.

[0061] (4-2. Second and third alternative examples) In the explanation so far, as an example of a steering mechanism 50 in which a steering servo motor 15 is disposed between an arm portion and the steering wheel W, a configuration has been given in which the main body portion 15a of the steering servo motor 15 and the steering wheel W move in conjunction with each other in response to steering, but it is not essential to adopt such a configuration in which the main body portion 15a and the steering wheel W move in conjunction with each other in response to steering. For example, as in the second variant shown in FIG. 11 and the third variant shown in FIG. 12, a configuration can be adopted in which the member (rotating member 155, connected member) to which the wheel hub portion 53L is connected is rotationally driven by the rotational driving force of the output shaft 15b, thereby rotating the steered wheel WL in the steering angle direction. 11 and 12, the main body 15a of the steering servo motor 15L is non-rotatably connected to the arm. Specifically, in the example of Fig. 11, the main body 15a is formed with a substantially cylindrical support portion 15d that protrudes downward from the underside, and the tip (lower end) of the support portion 15d is connected to the tip 52a of the lower arm 52L so as to disable the rotation of the main body 15a. Also, the upper end of the main body 15a is connected to the tip 51a of the upper arm 51 so as to disable the rotation of the main body 15a. On the other hand, in the example of FIG. 12, the main body portion 15a is fixed to the lower arm 52L at a position closer to the base than the tip end portion 52a so as not to be able to rotate.

[0062] In the example of FIG. 11, wheel hub portion 53L is connected to rotating member 155. As shown in the figure, rotating member 155 has a substantially U-shaped cross section in rear view, and an upper surface portion 155a is connected to the tip end of output shaft 15b so as to rotate in conjunction with output shaft 15b around the rotation center axis of output shaft 15b. Although not shown in the figure, a substantially circular hole is formed in lower surface portion 155c of rotating member 155, and support portion 15d is inserted into this hole. At this time, the hole and support portion 15d are connected via, for example, a ball bearing or the like so as not to interfere with the rotation of rotating member 155. As shown in the figure, the wheel hub portion 53L is connected to the outer surface of the side surface portion 155b of the rotating member 155.

[0063] 11, when the steering servo motor 15L is driven, the output shaft 15b rotates, and the rotating member 155 rotates in conjunction with the rotation of the output shaft 15b, thereby rotating the steered wheels WL in the steering angle direction. In this case, the steering rotation axis As is coaxial with the rotation center axis of the output shaft 15b.

[0064] In the configuration shown in FIG. 12, gears 165 and 166 transmit the rotational driving force of output shaft 15b to transmission shaft 167, to which wheel hub 53L is connected, and a connected member 168, which is coaxial with transmission shaft 167 and rotates in conjunction with transmission shaft 167, drives steered wheels WL to rotate in the steering direction. The upper end of transmission shaft 167 is connected to tip 51a of upper arm 51L so as to rotate transmission shaft 167, and the lower end is connected to tip 52a of lower arm 52L so as to rotate transmission shaft 167. Power is transmitted to transmission shaft 167 from gear 165 connected to output shaft 15b via gear 166 connected to transmission shaft 167. The connected member 168 is disposed coaxially with transmission shaft 167, and the wheel hub 53L is connected to its side.

[0065] In the configuration shown in Figure 12, the steering wheel WL is driven to rotate in the steering angle direction around a steering rotation axis As that is parallel to the rotation center axis R of the transmission shaft 167, which does not coincide with the rotation center axis R of the transmission shaft 167, shown as "R" in the figure.

[0066] As can be seen from the second and third alternative examples, it is not essential to adopt a configuration in which the main body 15b of the steering servomotor 15 and the steering wheel WL rotate in conjunction with each other. Furthermore, the output shaft 15b is not limited to being coaxial with the steering rotation axis As, but may be at least parallel to the steering rotation axis As, as in the third alternative example.

[0067] <5. Angle adjustment mechanism> The steering servo motor 15 can be provided with a connection position displacement mechanism that allows the connection position with the arm portion side to be freely displaced, thereby making it possible to adjust the caster angle and camber angle. 13 and 14 are explanatory diagrams of the connection position displacement mechanism 156 and the connection position displacement mechanism 156A for adjusting the caster angle. FIG. 13 shows that the caster angle can be adjusted by changing the position of the pillow ball 154 in the front-rear direction, that is, the position of the connection part with the lower arm 52 in the front-rear direction. In this case, the connection position displacement mechanism 156 is configured as a mechanism that can adjust the position of the pillow ball 154 in the front-rear direction. Specifically, for example, holes for positioning and detachably fixing the pillow ball 154 can be formed at a plurality of positions spaced apart in the front-rear direction on the underside of the main body 15a, and the holes formed at these plurality of positions can serve as the connection position displacement mechanism 156. Alternatively, the connection position displacement mechanism 156 can be configured as a mechanism that holds the pillow ball 154 so that it can slide in the front-rear direction.

[0068] FIG. 14 shows that the caster angle can be adjusted by changing the position of the tip 153a of the pole part 153 in the front-rear direction, that is, the position of the connection part with the upper arm 51 in the front-rear direction. The position of the tip 153a in the fore-and-aft direction can be changed by adjusting the mounting angle of the connection part 15c relative to the output shaft 15b of the steering servo motor 15 when the output shaft 15b is in a neutral state (rotation angle in a non-driven state). Therefore, in this case, the connection position displacement mechanism 156A may be configured as a mechanism that allows adjustment of this attachment angle.

[0069] Fig. 15 is an explanatory diagram of the connection position displacement mechanism 156B for adjusting the camber angle. Specifically, Fig. 15 shows that the camber angle can be adjusted by changing the connection position of the tip end 51a of the upper arm 51 relative to the tip end 153a of the pole part 153 in the left-right direction. Therefore, the connection position displacement mechanism 156B is configured as a mechanism that can adjust the connection position of the tip 153a of the pole portion 153 with the tip 52a of the upper arm 51 in the left-right direction. Specifically, for example, hook portions 160 (see FIG. 8B) for engaging the tip 52a can be formed at multiple positions spaced apart in the left-right direction on the front surface of the tip 153a, and the hook portions 160 formed at these multiple positions can serve as the connection position displacement mechanism 156B. Alternatively, the connection position displacement mechanism 156B can be configured as a mechanism that holds the hook portions 160 so that they can slide in the left-right direction.

[0070] <6. Variations> The present invention is not limited to the specific examples described above, but can be configured in a variety of modified forms. For example, although the above example shows the steering mechanism 50 having a bilaterally symmetrical configuration, the steering mechanism according to the present invention may include an asymmetrical configuration in at least a portion of the left and right sides.

[0071] Furthermore, although the above example shows the application of the present invention to the model automobile 1 as a four-wheeled vehicle, the present invention can be suitably applied to a model automobile having one or more steering wheels and two or more wheels.

[0072] <7. Summary of embodiments> As described above, the steering mechanism (50) of the model automobile as an embodiment is equipped with a steering servo motor (15) for driving the steering wheel (W) of the model automobile (1) to rotate in the steering angle direction, the steering servo motor being positioned between the steering wheel and an arm portion (upper arm 51, lower arm 52) extending from the vehicle body side toward the steering wheel, and the steering servo motor driving the steering wheel to rotate by an output shaft (15b) parallel to the steering rotation axis (As) of the steering wheel. As described above, the steering servo motor positioned between the arm portion and the steering wheel is configured to rotate the steering wheel using an output shaft parallel to the steering rotation axis, thereby making it possible to eliminate the steering link mechanism that was previously required when the steering servo motor was located on the vehicle body side, and to synchronize the rotation angle of the steering servo motor with the rotation angle of the steering wheel. By eliminating the need for a steering link mechanism, it is possible to suppress a decrease in steering control accuracy due to connection play in the link mechanism. Also, by eliminating the need for a link mechanism, it is possible to prevent the rotation angle of the steered wheels from changing depending on the steering angle. Therefore, in these respects, it is possible to improve steering control accuracy. Furthermore, since the link mechanism is no longer necessary, the steering wheel can be rotated 180 degrees. Furthermore, the above configuration eliminates the need for a link mechanism and allows the left and right steered wheels to be steered independently, which allows the Ackermann ratio to be adjusted electrically by adjusting the rotation angle of the steering servo motor (i.e., adjustment can be made while the vehicle is running). Here, the Ackermann ratio refers to the difference in the turning angle between the left and right steering wheels. If the turning angles of the left and right steering wheels were the same for a certain amount of steering, the left and right steering wheels would describe circles of the same radius. In this case, there is a difference equivalent to the width of the vehicle between the center of the arc described by the outside steering wheel and the center of the arc described by the inside steering wheel, so at some point the trajectory of the outside steering wheel and the trajectory of the inside steering wheel will intersect, causing the trajectory of the outside steering wheel to turn more inward than the trajectory of the inside steering wheel. As can be seen from this, if the turning angles of the left and right steering wheels were the same, it would be difficult to turn a model car smoothly. Therefore, the Ackermann ratio is adjusted to adjust the turning angle of the left and right steering wheels to achieve the desired steering characteristics of the model car, such as making the model car turn smoothly. Furthermore, the steering mechanism of the above-described embodiment allows the rotation angles of the left and right steered wheels to be adjusted independently, compared to a steering mechanism that rotates the left and right steered wheels using the output of a single servo motor, such as the configuration shown in Figure 6 of Patent Document 1. Furthermore, being able to adjust the rotation angles of the left and right steered wheels independently makes it possible to electrically adjust the toe angle even while the vehicle is traveling.

[0073] In addition, in the steering mechanism of the model car as an embodiment, the output shaft of the steering servo motor is positioned coaxially with the steering rotation shaft (see FIGS. 6, 7, 10, and 11). This makes it possible to transmit the rotational driving force generated by the steering servo motor to the steered wheels without going through a gear such as that illustrated in FIG. Therefore, when the steering wheel is rotated by the steering servo motor located between the arm and the steering wheel, the number of components in the steering mechanism can be reduced and the size and weight of the steering mechanism can be reduced.Furthermore, by reducing the weight of the steering mechanism, the weight of the model car can be reduced.

[0074] Furthermore, in the steering mechanism of the model car as an embodiment, the steering servo motor has a main body portion (15a) that rotatably holds the output shaft, and the arm portion is provided with a first arm portion and a second arm portion that are spaced apart in the vertical direction, the output shaft is supported non-rotatably from either the first arm portion or the second arm portion side, the main body portion is supported from the other arm portion of the first arm portion or the second arm portion side so that it can rotate freely around an axis parallel to the steering rotation axis, and a wheel hub portion that rotatably holds the steering wheel is connected to the main body portion (see Figures 6, 7, and 10). As described above, the output shaft is supported non-rotatably from either the upper or lower arm, and the main body is supported from the other arm so as to be rotatable about an axis parallel to the steering rotation axis, so that in this steering servo motor, the main body rotates about an axis parallel to the steering rotation axis in response to steering. And, because the wheel hub is connected to the main body, the steered wheels rotate in conjunction with the rotation of the main body. As described above, by configuring the steering wheel to rotate in conjunction with the rotation of the main body, in this case, it is not necessary to connect a transmission mechanism (for example, rotating member 155 in FIG. 11 or transmission shaft 167 and connected member 168 in FIG. 12) to the output shaft for transmitting the rotational force of the output shaft to the steering wheel, and this makes it possible to reduce the number of components of the steering mechanism and make it smaller and lighter. Furthermore, by reducing the weight of the steering mechanism, it is possible to reduce the weight of the model car.

[0075] Furthermore, in the steering mechanism of the model car as an embodiment, a shock absorber (61) is provided on the car body to attenuate input from the road surface via the steering wheel, and the steering servo motor has a main body that rotatably holds the output shaft, and the arm section is provided with an upper arm section and a lower arm section that are separated in the vertical direction, and one end of the upper arm section is connected to the car body side so as to enable the upper arm section to swing in the vertical direction with the one end as a fulcrum, and the other end is connected to the output shaft, the main body section, so as to enable the upper arm section to swing in the vertical direction with the other end as a fulcrum. The lower arm portion has one end connected to the vehicle body so as to enable the lower arm portion to swing up and down around the one end as a fulcrum, and the other end connected to the other of the output shaft or the main body so as to enable the lower arm portion to swing up and down around the other end as a fulcrum, and the shock absorber has a lower end connected to the lower arm portion so as to enable the lower arm portion to swing up and down around the one end of the lower arm portion as a fulcrum, and an upper end connected to the vehicle body without via the upper arm portion (see Figures 8 and 9). In other words, a so-called double wishbone suspension structure is adopted. The double wishbone system uses a parallel link, which prevents the camber angle from changing even if the steering wheel moves up and down due to unevenness in the road surface. Furthermore, since the upper end of the shock absorber is not connected to the upper arm portion, even if a steering servo motor is inserted between the upper arm portion and the lower arm portion, the input attenuation action from the road surface is not hindered.

[0076] In the steering mechanism of the model car according to the embodiment, the steering servo motor has a connection position displacement mechanism (156, 156A, 156B) that allows the connection position with the arm portion to be freely displaced. The steering servo motor is positioned between the arm and the steering wheel, and the connection position with the arm can be freely displaced, allowing adjustment of the caster angle and camber angle.

[0077] The steering servo motor (same as 15) as an embodiment is a steering servo motor for driving the steering wheel of a model car to rotate in the steering angle direction, and is positioned between the steering wheel and an arm portion extending from the vehicle body side toward the steering wheel, and drives the steering wheel to rotate by an output shaft parallel to the steering rotation axis of the steering wheel. Such a steering servo motor also provides the same effect as the steering mechanism of the above embodiment. Therefore, the steering control accuracy of the steering mechanism of the model car can be improved.

[0078] In addition, the steering servo motor according to the embodiment has a main body portion that holds the output shaft rotatably, and the main body portion is formed with a connected portion (same as 151) for connecting a wheel hub portion that holds the steering wheel rotatably. This makes it possible to rotate the steering wheel in conjunction with the rotation of the main body, in cases where the main body is configured to rotate around an axis parallel to the steering rotation axis in response to steering. Therefore, the steered wheels can be appropriately turned in the steering angle direction.

[0079] Furthermore, the steering servomotor according to the embodiment has a connection position displacement mechanism that allows the connection position with the arm portion side to be freely displaced. The steering servo motor is positioned between the arm and the steering wheel, and the connection position with the arm can be freely displaced, allowing adjustment of the caster angle and camber angle. [Explanation of symbols]

[0080] 1 model car 1a chassis 2 Transmitters 10 Receivers 11,27 Antenna 15(15L, 15R) Steering servo motor 20 Interface section 21(21X,21Y) Operating lever 23 Display section 24 Setting operation section W(WL,WR) Steering wheels 50 Steering mechanism 51(51L,51R) Upper arm 52(52L,52R) Lower arm 51a,52a Tip 51b, 52b Vehicle body side end 53 (53L, 53R) Wheel hub 61 (61L, 61R) shock absorber 62 Shock Tower 61a Lower end 61b Upper end 15a Main body 15b Output shaft 15c Connection 15d Support part 151 Connected part 152 Plate-shaped part 153 Pole section 153a Tip 154 Pillow Ball D recess 155 Rotating member 155a Top part 155b Side part 155c Bottom part 156, 156A, 156B Connection position displacement mechanism 160 Hook part 161 Nut H hole 165,166 gears 167 Transmission shaft 168 Connected parts

Claims

1. A steering mechanism for a model car having left and right steering wheels and a pair of arms extending from a vehicle body toward the respective steering wheels, a steering servo motor positioned on each of the left and right sides between the arm portion and the steering wheel, the servo motor rotating the steering wheel in the steering angle direction by an output shaft parallel to the steering rotation shaft of the steering wheel; the steering servomotor has a main body that rotatably holds the output shaft, The arm portion includes a first arm portion and a second arm portion spaced apart in the vertical direction, the output shaft is supported non-rotatably from one of the first arm portion and the second arm portion, the main body is supported from the other arm side of either the first arm or the second arm so as to be freely rotatable about an axis parallel to the steering rotation axis, A wheel hub portion that rotatably holds the steering wheel is connected to the main body portion. Steering mechanism of a model car.

2. The steering servo motor has an output shaft positioned coaxially with the steering rotation shaft.

2. A steering mechanism for a model car according to claim 1.

3. a shock absorber for attenuating an input from a road surface via the steering wheel; the steering servomotor has a main body that rotatably holds the output shaft, The arm portion includes an upper arm portion and a lower arm portion that are spaced apart in the vertical direction, The upper arm portion one end of the upper arm portion is connected to the vehicle body so as to allow the upper arm portion to swing up and down around the one end as a fulcrum; the other end portion is connected to either the output shaft or the main body portion so as to enable the upper arm portion to swing in the up and down direction around the other end portion as a fulcrum portion, The lower arm portion one end of the lower arm portion is connected to the vehicle body so as to allow the lower arm portion to swing up and down around the one end as a fulcrum; the other end of the lower arm is connected to the other of the output shaft and the main body so as to enable the lower arm to swing in the up and down direction around the other end as a fulcrum, The shock absorber is a lower end portion is connected to the lower arm portion so as to be able to swing up and down about the one end portion of the lower arm portion as a fulcrum portion and to swing up and down about the other end portion as a fulcrum portion; The upper end is connected to the vehicle body side without passing through the upper arm portion.

3. A steering mechanism for a model car according to claim 1 or 2.

4. The steering servo motor has a connection position displacement mechanism that allows the connection position with the arm portion to be freely displaced.

4. A steering mechanism for a model car according to claim 1.

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