JPH11208558A - Double-wheel steering gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-wheel structural steering gear by a crank type axle, showing a stable steering performance, and equipped with a remarkable shock-absorbing effect against an impact from the road surface. SOLUTION: A double-wheel steering gear is composed of installing a handle shaft 3 inserted into a head tube 4 of a frame, a bearing 12 attached to a lower end of this handle shaft 3, a crank journal 14 rotatably supported on this bearing 12, two crank arms 16 and 18 attached toward the longitudinal reverse direction with each other from both symmetrical ends of this crank journal 14, and two clamp pins 24 and 26 being projectingly installed each in both ends of these crank arms 16 and 18, and fitted with two wheels 20 and 22, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering device such as a small bicycle or a one-footed scooter for children, and more particularly to a crank having a stable steering performance with a remarkable buffering effect against a road impact. An object of the present invention is to provide a steering device having a two-wheel structure using an axle.

[0002]

A steering device such as a bicycle does not have a steering device having a stable two-wheel structure like a front wheel of an automobile. For example, when a front wheel, which is a one-wheel steering device, rides on a pebble or the like. For example, such a phenomenon that the steering wheel is removed may occur and the vehicle may roll over. Also, slight bumps and bumps on the road are transmitted directly to the steering wheel, causing unpleasant vibration. In particular, children's scooters using small wheels without pneumatic tires cannot cope with slight steps on the road surface, and as a result, stable steering is difficult. However, such a drawback was accepted as fate due to the lightness of one-wheel steering with a simple handle shaft, and no improvement was seen at all.

The inventor of the present invention has worked on the development of a new mechanism that combines the simplicity of operation with a single handle shaft of a conventional bicycle and the stability of two-wheel steering of an automobile or the like. Finally, the two-wheel steering device according to the present invention was completed and provided.

[0004]

The gist of the two-wheel steering device according to the present invention is as follows: a handle shaft inserted through a head tube of a frame; a bearing attached to a lower end of the handle shaft; A crank main shaft rotatably supported, a crank arm attached to the front and rear opposite directions from left and right ends of the crank main shaft, and a crank protruding from ends of the two crank arms to fit wheels. And a pin.

In this configuration, when the handle is operated to turn the handle shaft, the bearing fixed to the lower end of the handle shaft is turned around the center of the bearing.
Accordingly, when the crank main shaft supported by the bearing is turned, the crank arm, the crankpin, and the wheels are also turned. At the same time, the crank arm is rotated in the front-rear and up-down directions about the crank spindle. And at the same time as one crank arm is rotated,
The other crank arm is also rotated. In particular, when a caster angle is provided, both wheels are inclined in the turning direction.

Next, even during traveling, when the center of gravity is at the center of the handle shaft, that is, substantially at the center of the crank main shaft,
The crank main shaft is kept almost horizontal, but when the working position of the center of gravity shifts, the crank main shaft tilts toward the working side of the center of gravity, and at the same time, one crank arm on the working side of the center of gravity rotates upward, and the other crank arm rotates. The crank arm rotates downward. Therefore, the wheels also lean toward the working side of the center of gravity. Similarly, for example, when the handle shaft is turned, the wheels also tilt while changing the direction to the turning side according to the caster angle, and stable steering can be performed.

As described above, in the vehicle equipped with the two-wheel steering device according to the present invention, the steering stability is doubled as compared with the conventional one-wheel steering of a bicycle or a child scooter.

In this two-wheel steering system, when the center of gravity acts substantially at the center of the crankshaft, the crankshaft is positioned substantially horizontally on the left and right, and the crank arm is positioned substantially horizontally on the front and rear sides. When traveling in this state, there is a convex obstacle on the road surface, and if one of the wheels rides on the obstacle, the wheel will be curved upward with the crank arm as a radius around the crank spindle. It turns and rises according to the height of the obstacle. At the same time, the other crank arm and the wheel rotate downward about the crank spindle, and the crank spindle is lifted about the road surface as a fulcrum. At this time, the rising height of the crank main shaft is increased by the amount that the other crank arm and the wheel are rotated downward. Conversely, if one of the wheels falls into the depression, for example, the operation is exactly the opposite of the above-described operation, and the crankshaft descends by the amount of rotation of the other crank arm and the wheel. Therefore, the vertical movement of the crankshaft is halved as compared with the height of the obstacle or the depth of the depression, so that the impact on the main body frame is greatly reduced.

Next, in this two-wheel steering system, the angle between the pair of crank arms attached in the front and rear directions opposite to each other in the rotational direction is asymmetric.

By employing this configuration, when the center of gravity is substantially at the center of the crank main shaft, the crank main shaft is located substantially horizontally, and the pair of crank arms respectively face the front and rear opposite directions about the crank main shaft. Thus, the tip of the crank arm is positioned from substantially horizontal to upward by a predetermined angle difference. Next, when the center of gravity moves and acts on one of the left and right sides of the crank spindle,
At the same time that the crank spindle tilts toward the working side of the center of gravity, the crank arm rotates, and one crank arm rotates upward and the other crank arm rotates downward. At this time, even if one of the crank arms reaches the vertical position where the crank arm is most rotated, the other crank arm does not reach the vertical position by the angle difference between the two crank arms and is located in the inclined state. It will be. As described above, since the two crank arms are not simultaneously positioned vertically, that is, the respective dead points of the pair of crank arms do not overlap with each other, the rotation of the crank arms becomes smooth, and the left and right inclinations are reduced. Restoration to the horizontal will work smoothly.

Further, in the two-wheel steering device, the pair of crank arms mounted in the front and rear opposite directions are configured to freely move within a predetermined angle range around the crank main shaft. is there.

By adopting this configuration, even if the pair of crank arms are reversed in any of the front and rear directions, the distal end of the crank arm is always positioned substantially horizontally from above by a predetermined angle difference. Therefore, the crank main shaft on which the weight of the vehicle body acts is always lower than the position connecting the pair of crankpins, so that the crankshaft is stabilized and the horizontal restoration from the left-right inclination is improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a twin-wheel steering device according to the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the twin-wheel steering device 10 can be configured as a front-wheel steering device of the bicycle 1 as an example. Although the bicycle 1 may be a bicycle having wheels of a normal size, the two-wheel steering device 10 of the present invention is effectively applied to a bicycle having small-diameter wheels configured as an assembling type or a portable type. Is done. The bicycle 1 is configured in the same manner as a normal bicycle except for a twin-wheel steering device 10, and the steering wheel 2 and the two-wheel steering device 10 are turned around the head tube 4.

Here, the configuration and operation of the two-wheel steering device 10 will be described with reference to FIG. The two-wheel steering device 10 includes a crank main shaft 14 and a crank arm 1 attached to the left and right ends of the crank main shaft 14 in opposite directions.
6 and 18, and crank pins 24 and 26 protruding from the left and right outer sides in parallel with the crank main shaft 14 at the ends of the two crank arms 16 and 18. In this twin-wheel steering device 10, wheels 20, 22 having crank pins 24, 26 as rotation axes are attached, and a bearing 12 for rotatably holding a crank main shaft 14 is fixed to the handle shaft 3 shown in FIG. Have been. Therefore, when the crank main shaft 14 is rotated with respect to the bearing 12, the crank arms 16, 18 and the crank pins 24, 26 are rotated about the crank main shaft 14, and when one of the crank arms 16 is rotated, At the same time, the other crank arm 18 is rotated.

As shown in FIGS. 3 and 4, the center of gravity W acting on the two-wheel steering device 10 acts between the two wheels 20 and 22, ie, substantially at the center of the crank main shaft 14, as shown in FIGS. The crank main shaft 14 is located horizontally horizontally, and the crank arms 16 and 18 are located substantially horizontally forward and backward. On the other hand, when the operation position of the center of gravity W moves to the left or right (B), the crank arms 16 and 18 rotate within the angle between the horizontal position and the vertical position in accordance with the movement of the position of the center of gravity, and the crank spindle 14 moves. It will incline to the operation position side of the center of gravity W.

Therefore, when the vehicle travels straight, the wheels 20, 22 are kept substantially vertical, but when the handle shaft is turned, the working position of the center of gravity moves to the turning side, and as shown in FIG. , The crankshaft 14 and the wheels 20, 22 are inclined. As a result, the vehicle can turn stably at a high speed against the centrifugal force, and the steering performance is extremely excellent.

Next, as shown in FIGS. 3 and 5, the center of gravity W
Is acting on the center of the crankshaft 14, there is a convex obstacle 30 on the road surface 28 during traveling, and one wheel 20
When the vehicle rides on the obstacle 30, the wheel 20 rotates upward in an arc shape around the crank shaft 14 with the crank arm 16 as a radius, and rises according to the height of the obstacle 30. At the same time, the other crank arm 18 and the wheel 22
Rotates downward about the crankshaft 14 and the road surface 2
The crank main shaft 14 is lifted with the fulcrum 8 as a fulcrum. At this time, the rising height of the crank main shaft 14 rises by an amount corresponding to the rotation of the crank arm 18.
Conversely, when one of the wheels 20 falls into the depression, for example, the operation described above is completely the reverse of the above-described operation, and the crank main shaft 14 is lowered by an amount corresponding to the rotation of the crank arm 18.

As described above, in any case, if the height of the obstacle 30 or the depth of the depression is within the range of the sum of the lengths of the crank arms 16 and 18, the crank main shaft 14 is kept substantially horizontal. It is. That is, the height h between the wheels 20 and 22 when the crank arms 16 and 18 which have been positioned substantially horizontally rotate and reach the vertical position together is determined by the obstacle 3
When the height H is 0 or less, the crankshaft 14 is inclined.

As is apparent from the above description, the vertical movement of the crankshaft 14 is only half of the vertical movement of the wheels 20, so that the bearing 12 holding the crankshaft 14
The impact of the upper frame and body on the road is greatly reduced.

The wheels 20 and 22 attached to the crank pins 24 and 26 respectively are connected to the crankshaft 14.
Are shifted back and forth by the length of the crank arms 16 and 18. For this reason, when passing through a step substantially parallel to the crankshaft 14, the wheels 20 and 22 do not ride on the step at the same time, but alternately ride on the step, and operate efficiently and smoothly.

As described above, the twin-wheel steering device 10 according to the present embodiment does not require a complicated mechanism including a combination of a spring and a shock absorber, and alleviates an impact only by a simple rotation of a crankshaft. It enables stable steering and exerts a remarkable effect particularly on impact mitigation and turning performance of a steering device using small-diameter wheels, which have been neglected in the past.

Next, in the two-wheel steering device 10 shown in FIG. 2 described above, the crank arms 16 and 18 are fixed so as to face the crank shaft 14 in the front and rear directions, respectively. In practice, the crank arm 1
The front and rear of the crank arms 16 and 18 may be switched according to road surface conditions and the like, as the wheels 6, 18 rotate as appropriate.
When the front and rear of the crank arms 16 and 18 are interchanged, there is a problem in use configuration, and in order to facilitate horizontal restoration, it is preferable to attach a stop device for preventing a dead center. .

As described above, the dual wheel steering device 10 using the crank axle according to the basic embodiment of the present invention and its operation have been described. Next, a practical embodiment will be described.

As shown in FIG. 6, a twin-wheel steering device 32 using a crank-type axle according to this embodiment includes a pair of crank arms 3 attached to the front and rear opposite directions.
The angle between the rotation directions 6 and 38 is asymmetric. That is, the two-wheel steering device 3
Reference numeral 2 denotes a crank main shaft 34 supported by bearings, a pair of crank arms 36 and 38 attached to the left and right ends of the crank main shaft 34 in directions opposite to each other, and an end of the pair of crank arms 36 and 38. Crank pins 2 which are respectively protruded and fitted with wheels 20 and 22
4 and 26 and a pair of crank arms 36 and 3 attached to the front and rear opposite directions.
The direction difference 8 makes a predetermined angle difference X about the crankshaft 34. The predetermined angle difference X formed by the direction difference between the pair of crank arms 36 and 38 about the crankshaft 34 is usually about 20 °, but is not particularly limited to this angle.

In the two-wheel steering device 32 having the above-described structure, when the center of gravity W is substantially at the center of the crank main shaft 34, the crank main shaft 34 is positioned substantially horizontally, and the pair of crank arms 36 and 38 are connected to the crank main shaft 34. With the crank arm 3
6 and 38 are located substantially horizontally upward from the horizontal by a predetermined angle difference (X / 2).

Next, when the center of gravity W moves and acts on one of the right and left sides of the crank main shaft 34, the crank main shaft 34 tilts toward the operating side of the center of gravity W, and at the same time, the crank arms 36 and 38 rotate. And one of the crank arms 36
(38) rotates upward, and the other crank arm 38 (36) rotates downward. At this time, even if one of the crank arms 36 reaches the vertical position where the crank arm 36 is most rotated, the other crank arm 38 does not reach the vertical position by the angle difference X between the two crank arms 36 and 38 without reaching the vertical position. It will be located in the state where it was done. As described above, since the two crank arms 36 and 38 are not simultaneously positioned vertically, that is, since the respective dead points of the pair of crank arms 36 and 38 do not overlap,
The rotation of the crank arms 36 and 38 becomes smooth, and the restoration from the left and right inclination to the horizontal state operates smoothly. Therefore, after turning or crossing a slope, the crank arms 36 and 38 rotate smoothly,
The crank main shaft 34 can return to the horizontal position.

As shown in FIG. 7, in the two-wheel steering device 32, when the wheel 20 reaches an upper dead center position by riding on an obstacle or the like, the vehicle body is caused to act on the crank main shaft 34 in a vertical direction. The own weight (W) acts as a moment on a line (plane) connecting the crankpins 24 and 26. That is, since the crankpin 24 as the center of rotation of the wheel 20, the crankpin 26 and the crankshaft 34 as the center of rotation of the wheel 22 do not overlap on the same vertical plane at the same time, the wheels 20, 22 return to the horizontal direction. Is performed smoothly.

Next, as shown in FIG. 8, a twin-wheel steering device 40 according to still another embodiment has a crank main shaft 42 supported by bearings, and front and rear opposite directions from left and right ends of the crank main shaft 42. And a pair of crank arms 44 and 46
4 and 46 are respectively provided at the ends of the wheels 20 and 2.
2 and a pair of crank arms 44 and 46, which are attached to the front and rear opposite directions, respectively.
As shown by a solid line and an imaginary line with the center as the center, each is configured to move freely within a predetermined angle range.

As a specific example of this twin-wheel steering device,
As shown in FIGS. 9 and 10 (a), the crank main shaft 48 is divided, and the semi-cylindrical portions 54, 54 formed at the divided ends of the divided crank main shafts 50, 52 are engaged in a cylindrical bearing 56. Connect. The semi-cylindrical portion 54 to be engaged
As shown in FIG. 10 (a), the surface 58 of 54 is provided with a gap at an appropriate angle. Therefore, FIG.
As shown in (b) or (c), the crank arms 44, 46
Of the semi-cylindrical portions 54, 54
8 and the surface 58 make contact with each other to form a predetermined angle.

The configuration in which the pair of crank arms 44 and 46 can move freely within a predetermined angle range with respect to the crank main shaft 42 is not limited to the above-described embodiment. For example, various configurations are possible, such as providing a slight play at one or both of the pair of crank arms 44 and 46 attached to both ends of the crank main shaft 48.

Although the embodiments and application examples of the twin-wheel steering device according to the present invention have been described above, the present invention is not limited to the illustrated embodiments. For example, the crank main shaft, the crank arm, and the crank pin related to the two-wheel steering device of the present invention may be integrally formed, or a member made of an appropriate material such as providing a bearing in a bearing portion may be used. Just do it. In addition, the present invention can be carried out in various modified, modified, and modified embodiments based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

[0033]

In the vehicle equipped with the twin wheel steering device according to the present invention, the two wheels can also be inclined according to the caster angle of the handle shaft. As a result, excellent turning performance can be exhibited, and the vehicle can turn with almost the same operation feeling as a conventional two-wheeled vehicle such as a bicycle or a motorcycle. Further, the twin-wheel steering device according to the present invention does not require a complicated mechanism such as a combination of a spring and a shock absorber, only a simple rotation of a crankshaft, reduces impact, enables stable steering, In particular, it has a remarkable effect on the impact mitigation and turning performance of the steering device using the small-diameter wheels which have been neglected in the past. Further, since the present device has no main spring involved in buffering, there is no recoil or resonance phenomenon, and there is an epoch-making effect. In addition, since the two-wheel steering device is a simple device, it is lightweight, has low manufacturing costs, is free from breakdowns, and is a safe device.

[Brief description of the drawings]

FIG. 1 is an explanatory side view of a main part showing an embodiment in which a two-wheel steering device according to the present invention is applied to a bicycle.

FIG. 2 is an explanatory plan view showing a basic configuration of a twin-wheel steering device according to the present invention.

FIG. 3 is an explanatory front view for explaining the operation of the twin-wheel steering device shown in FIG. 2;

FIG. 4 is an explanatory front view for explaining another operation of the twin-wheel steering device shown in FIG. 2;

FIG. 5 is an explanatory side view for explaining the operation of the twin-wheel steering device shown in FIG. 2;

FIG. 6 is an explanatory side view for explaining another embodiment of the twin-wheel steering device according to the present invention.

FIG. 7 is an explanatory side view for explaining another operation of the twin-wheel steering device shown in FIG. 6;

FIG. 8 is an explanatory side view for explaining still another embodiment of the twin-wheel steering device according to the present invention.

FIG. 9 is an explanatory front view illustrating an embodiment of the twin-wheel steering device shown in FIG. 8;

FIGS. 10 (a), (b), and (c) are cross-sectional views of main parts for explaining the operation of the twin-wheel steering device shown in FIG.

[Explanation of symbols]

 1: Bicycle 2: Handle 3: Handle shaft 4: Head tube 10, 32, 40: Two-wheel steering device 12: Bearing 14, 34, 42, 48: Crank main shaft 16, 18, 36, 38, 44, 46: Crank arm 20, 22: wheels 24, 26: crank pins 28: road surface

Claims (3)

[Claims] 1. A handle shaft inserted through a head tube of a frame, a bearing attached to a lower end of the handle shaft, a crank main shaft rotatably supported by the bearing, and a left and right ends of the crank main shaft. A two-wheel steering device comprising: a crank arm mounted in a direction opposite to the front and rear; and crank pins protruding from ends of the two crank arms and fitted with wheels. 2. The two-wheel steering device according to claim 1, wherein the pair of crank arms attached in opposite directions to each other have an asymmetrical angle in a rotational direction with respect to each other. 3. The apparatus according to claim 2, wherein said pair of crank arms attached to the front and rear opposite directions move freely within a predetermined angle range around a crank main shaft. The two-wheel steering device described in the above.