Description

APPARATUS FOR SHIFTING THE CENTER OF GRAVITY OF A VEHICLE HAVING THREE WHEELS OR MORE

Technical Field

[1] The present invention relates to a vehicle having three wheels or more, and more particularly to an apparatus for shifting the center of gravity of a vehicle having three or more wheels by which upon driving, particularly in a curve in the road, the center of gravity of the vehicle is shifted to the left/right side relative to the driving direction so as to secure stability and safe driving. Background Art

[2] In general, a tricar means a vehicle having three wheels, wherein one wheel is mounted behind the driver and two wheels are mounted before the driver (called in general a reversed tricar), or otherwise, two wheels are mounted behind the driver and one wheel is mounted before the driver (called in general a regular tricar).

[3] To secure the stability and safety of the tricar during driving on a linear road and a curve, it should be configured such that the breadth of the car at a position where two wheels are mounted in parallel is made larger than that of a common 4-wheel car, or that like a motorcycle, the center of gravity is momentarily shifted partially or completely in the direction of the centripetal force opposite to the centrifugal force. The former case causes the vehicle to have a large size due to an increase in breadth thereof, and the latter case causes problems of stability and safety thereof upon the momentary shift of the center of gravity. Because of this, development of the tricar has been carried out by excluding the former case but solving the problems of the latter case.

[4] Recently, more particularly, at the 1997 Frankfurt motor show, Mercedes-Benz were noted worldwide for their announcement of a new concept reversed tricar named 'F300 Life-jet'. However, such a reversed tricar had a problem in that power beyond a reasonable need was consumed, and power required for a shift itself of the center of gravity of a car body was also consumed because the tricar was designed so that upon shifting the center of gravity, the car body and all wheels were to be tilted in the direction of the driver's manipulation. In addition, such a tricar still had a problem of shaking upon restoration to a regular position after the shift of the center of gravity, upon stopping, and upon boarding.

[5] Furthermore, at the recent Tokyo motor show, Phiaro, Japan were noted worldwide for their announcement of a regular tricar named 'P67b ETERNITY'. However, in such a regular tricar, as shown in FIG. 14, the center point of the shift circle of the center of

gravity is positioned above the ground, so that upon shifting the center of gravity, side- skidding occurs on a wheel, thereby causing severe wearing of the tire thereof. Such a phenomenon will be weighted particularly upon driving in a curve. In addition, such a tricar is designed so that the center of gravity of the engine, installed on the side of the rear wheels, having the largest weight in the car body is not shifted, so that upon driving in a curve, there will be a greater possibility of incurring an accident as compared to the reversed tricar. Disclosure of Invention Technical Problem

[6] The present invention has been made in view of the above-mentioned problems, and the present invention provides an apparatus for shifting the center of gravity of a vehicle having three wheels or more requiring the shifting of the center of gravity to the left/right relative to the driving direction, capable of minimizing the power need for shifting the center of gravity, upon driving of the vehicle, shifting and restoring the center of gravity more easily, effectively, and precisely, and upon stopping, precisely controlling the left/right movement.

[7] Also, the present invention provides an apparatus for shifting the center of gravity of a vehicle capable of preventing a tire thereof from wearing because the center point of the shift circle of the center of gravity of the vehicle is designed to generally correspond to one point of a virtual line on the ground and securing stability and safety, upon driving a curve in the road as well.

Technical Solution

[8] In accordance with an aspect of the present invention, there is provided an apparatus for shifting the center of gravity of a vehicle having three wheels or more, the apparatus including: [9] a fixed chassis part on which at least one fixed rail part shaped like a circular arc having its origin at one point on a virtual line obtained by projecting a vertical center line of a vehicle body on the ground is included; [10] a movable chassis part in which at least one movable rail part movably assembled in the left/right direction relative to the vertical direction of the vehicle body along the fixed rail part is included; and [11] a control unit for shifting the center of gravity of the vehicle body so as to shift the center of gravity of the vehicle body as needed by controlling a shift of the movable rail part of the movable chassis part relative to the fixed rail part of the fixed chassis part,

[12] wherein the control unit comprises:

[13] a cylindrical rotation body in which a portion of the inside thereof including the

center of rotation is open;

[14] a rotation bar coaxially coupled to the center of rotation of the rotation body to rotate with the rotation body along with the rotation of the rotation body;

[15] a first link member rotatably coupled, at its one end, to the rotation bar included inside the rotation body; and

[16] second link members crossed with each other, each second link member having opposite ends wherein one end is rotatably coupled to the other end of the first link member, and the other end is rotatably coupled to the movable rail part of the movable chassis part.

[17] According to an embodiment of the present invention, the control unit for shifting the center of gravity further includes a ball screw device having a ball screw and a ball nut driven by an electric motor, the cylindrical portion of the rotation body further includes a gear unit integrally or separately, and the ball nut is provided, at a position contacting the gear unit, with a linear gear unit engaged with the gear unit so as to cause the rotating operation of the gear unit. As a modification, the electric motor can be directly connected to the rotation bar.

[18] According to an embodiment of the present invention, the electric motor is controlled by an electronic control unit (ECU).

[19] According to an embodiment of the present invention, at least one rail is formed at either or both of the fixed rail part of the fixed chassis part and the movable rail part of the movable chassis part. Advantageous Effects

[20] As set forth above, according to the apparatus for shifting the center of gravity of a vehicle having three wheels or more requiring the shifting of the center of gravity to the left/right relative to the driving direction, upon driving of the vehicle, the center of gravity is shifted and restored more easily, effectively, and precisely, and upon stopping, the left/right movement is precisely controlled. Further, an apparatus for s hifting the center of gravity of a vehicle according to the present invention can prevent a tire thereof from wearing because the center point of the shift circle of the center of gravity is designed to be one point on a virtual line obtained by projecting the vertical center line of the vehicle body on the ground, and can drive safely without sliding even upon curved driving. Brief Description of the Drawings

[21] The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

[22] FIG. 1 is a perspective view illustrating the main parts of an apparatus for shifting

the center of gravity according to an exemplary embodiment of the present invention;

[23] FIG. 2 is a side-sectional view illustrating a fixed chassis part and a movable chassis part, which are movably assembled with each other by means of a fixed rail part and a movable rail part included in the fixed chassis part and the movable chassis part, respectively;

[24] FIG. 3 is a perspective view illustrating the main parts of a fixed chassis part having a fixed rail part;

[25] FIG. 4 is a perspective view illustrating the main parts of a movable chassis part having a movable rail part;

[26] FIG. 5 is a perspective view illustrating the main parts of a control unit for shifting the center of gravity in an apparatus for shifting the center of gravity according to an exemplary embodiment of the present invention;

[27] FIG. 6 is a view illustrating a control unit for shifting the center of gravity of FIG.

5;

[28] FIG. 7 is a view illustrating a circular arc trace of a movable rail part shaped like a circular arc having its origin at one point on a virtual line obtained by projecting a vertical centerline of a vehicle body on a ground, together with the main parts of the control unit for shifting the center of gravity of FIGS. 5 and 6;

[29] FIG. 8 is a view illustrating a modification of the control unit for shifting the center of gravity of FIGS. 5 to 7;

[30] FIGS. 9 and 10 are views schematically illustrating movement of a movable rail part of a movable chassis part moving by an apparatus for shifting the center of gravity relative to a contacting point of the ground along a circular arc trace, wherein FIG. 9 is a view illustrating linear driving, and FIG. 10 is a view illustrating curved driving;

[31] FIGS. 11 to 13 are views illustrating various vehicles, to which the apparatus for shifting the center of gravity according to the present invention can adapt, wherein FIG. 11 illustrates a reversed tricar, FIG. 12 illustrates a regular tricar, and FIG. 13 illustrates a lozenge-shaped vehicle; and

[32] FIG. 14 is a schematic view illustrating a procedure of shifting the center of gravity in a conventional vehicle having three wheels. Mode for the Invention

[33] Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

[34] FIG. 1 schematically illustrates main parts of an apparatus for shifting the center of gravity according to an exemplary embodiment of the present invention, and FIG. 2 schematically illustrates a fixed chassis part 10a having wheels attached thereto at left/ right sides of the driver and a movable chassis part 10b having a front wheel or a rear

wheel attached thereto, which are movably, especially slidably, assembled with each other by means of a fixed rail part 12a and a movable rail part 12b included in the fixed chassis part 10a and the movable chassis part 10b, respectively. FIG. 3 illustrates a fixed chassis part 10a in which a fixed rail part 12a is included, and FIG. 4 illustrates a movable chassis part 10b in which a movable rail part 12b is included. FIGS. 5 and 6 illustrate a control unit for shifting the center of gravity so as to shift the center of gravity of the vehicle body as needed by controlling the movement of the movable rail part 12b of the movable chassis part 10b relative to the fixed rail part 12a of the fixed chassis part 10a.

[35] Referring to FIGS. 1 to 4, an apparatus 1 for shifting the center of gravity according to an exemplary embodiment of the present invention includes a fixed chassis part 10a with which wheels, on the left/right side of the driver, are directly or indirectly assembled, and a movable chassis part 10b with which either or both of a front wheel and a real wheel are directly or indirectly assembled, so as to move in the left/right direction as chosen by the driver. The fixed chassis part 10a is provided with a fixed rail part 12a shaped like a circular arc having its origin at one point on a virtual line obtained by projecting the vertical center line of the vehicle body on the ground (see FIG. 7). The movable chassis part 10b is provided with a movable rail part 12b assembled movably in the left/right direction relative to the vertical direction of the vehicle body along the fixed rail part 12a. Though not shown, preferably, at least one rail is included in either or both of the fixed rail part 12a of the fixed chassis part 10a and the movable rail part 12b of the movable chassis part 10b.

[36] Referring to FIGS. 5 and 6 together with FIGS. 1 to 4, the apparatus 1 for shifting the center of gravity according to an exemplary embodiment of the present invention includes a control unit for shifting the center of gravity so as to shift the center of gravity of the vehicle body as needed by controlling the movement of the movable rail part 12b of the movable chassis partlOb relative to the fixed rail part 12a of the fixed chassis part 10a in addition to the fixed chassis part 10a and the movable chassis partlOb.

[37] The control unit for shifting the center of gravity includes a rotation body 20, a rotation bar 30 coaxially coupled to the center of rotation of the rotation body 20, a first link member 40 restricted by the rotation of the rotation body 20, and second link members 42 each having opposite ends, one end being coupled to the first link member 40, and the other end being rotatably coupled to the movable rail part 12b of the movable chassis part 10b. The rotation body 20 is open at a portion thereof including the center of rotation. While the embodiment illustrates that the rotation body 20 is shaped like a cylinder, it may take any shape if the shape does not have a bad influence upon the rotation thereof. Preferably, the rotation bar 30 rotates along with the rotation

of the rotation body 20. The first link member 40 is rotatably coupled, at its one end, to the rotation bar 30 included in the inside of the rotation body 20. The second link members are crossed with each other as shown in the drawing.

[38] In addition, the control unit for shifting the center of gravity further includes a ball screw device 60 consisting of a ball screw 62 and a ball nut 64 so as to precisely rotate the rotation body 20. Meanwhile, the cylindrical portion of the rotation body 20 is further integrally provided with a gear unit 22, and the ball nut 64 is provided, at a portion contacting the gear unit 22, with a linear gear unit 66 that is engaged with the gear unit 22 to cause the rotation operation of the gear unit 22. In the present embodiment, while the gear unit 22 is integrally provided to the rotation body 20, it may be separately provided if it can cause the rotation operation of the rotation body 20.

[39] The ball screw device 60 includes a bearing between the ball nut-side 64 inside and the ball screw 62, allowing the precise control of the ball nut 64. By the ball screw device 60, the rotation operation of the rotation body 20 is carried out more precisely. Moreover, the ball screw device 60 restricts the left/right movement of the vehicle when the vehicle is stopped or even driven.

[40] A shuttling motion of the ball nut 64 relative to the ball screw 62 in the ball screw device 60 is carried out by an electric motor M2 or a hydraulic actuator. The electric motor M2or the hydraulic actuator is controlled by an electronic control unit (ECU).

[41] For the prevention of curving and smooth linear movement, an anti-bending roller or rail 70 is disposed under the ball nut 64. Such an anti-bending roller or rail 70 is directly or indirectly fixed to the vehicle body under the ball nut 64.

[42] Referring again to FIGS. 5 to 6, the rotation body 20 rotates in a specified direction

(e.g., an arrow direction in FIG. 6) by the driving of the ball screw device 60 by the electric motor Ml. The rotation body 20 is open at its internal part including the center thereof, so that upon the movement of the rotation body 20 in an arrow direction, the first link member denoted as a reference numeral 40 on the right side of the drawing is pushed by the inner portion of the rotation body 20, thereby lowering. By the pushdown of the first link member 40, the center of the movable rail part 12b of the movable chassis part 10b is shifted in a specified direction (in this case, in the right direction in the drawing) (See FIGS. 7 and 10). That is, the center of the vehicle is shifted in the direction (i.e., centripetal force direction) opposite to the centrifugal force of the vehicle, thereby securing safe driving even upon curved driving. Through the ball screw device 60, the apparatus for shifting the center of gravity according to the present invention can be operated more precisely.

[43] In the exemplary embodiment of the present invention, though the rotation body 20 has been controlled precisely by the ball screw device 60, another driving means,

which the rotation bar 30 is directly provided with, the electric motor M2, as shown in FIG. 8, may be considered by those skilled in the art.

[44] FIG. 7 schematically illustrates a circular arc trace of the movable rail part shaped like a circular arc having its origin at one point on a virtual line obtained by projecting the vertical center line of the vehicle body on the ground, together with the main parts of the control unit for shifting the center of gravity of FIGS. 5 and 6.

[45] FIGS. 9 and 10 schematically illustrate a movement of a movable rail part 12b of a movable chassis part 10b moving by an apparatus 1 for shifting the center of gravity relative to a contacting point of the ground along a circular arc trace, wherein FIG. 9 is a view illustrating linear driving, and FIG. 10 is a view illustrating curved driving. In this way, the apparatus for shifting the center of gravity according to the present invention having its origin of the circular arc trace at one point on a virtual line on the ground can secure the stability and safety in driving or even curved driving because the point of shifting the center of gravity is low. In addition, it is expected to safely drive without side- skidding occurring on a wheel upon driving in a curve, and also prevent a wheel from wearing.

[46] FIGS. 11 to 13 illustrate various vehicles, to which the apparatus for shifting the center of gravity according to the present invention can adapt, wherein FIG. 11 illustrates a reversed tricar, FIG. 12 illustrates a regular tricar, and FIG. 13 illustrates a lozenge-shaped vehicle. These vehicles are common with each other in that the center of gravity should be momentarily shifted by the operation manipulation of the driver in order to secure stability of the vehicle as well as the driver.

[47] Although several exemplary embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.