JP2003261039A - Small electric vehicle - Google Patents

Abstract

(57) To provide a small electric vehicle including a steering device having a large steering angle and excellent usability or steering performance. In a steering apparatus, a handle 50 is provided at an upper end.
5 and a steering shaft 501 projecting upward from the tip of the floor 3 and a suspension arm 203 extending outward in the left-right direction.
A front wheel steering knuckle 204 supported on the outer end of the vehicle via a king pin so as to be swingable to the left and right is connected by a tie rod 511 via a tie rod arm 509 and a knuckle arm 510.
09 and knuckle arm 510 are connected to kingpin 208
Are arranged so as to protrude in opposite directions with an axis line connecting the shaft centers between each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-wheeled small-sized electric vehicle, which is used especially for the elderly and people with disabilities.

[0002]

2. Description of the Related Art A small electric vehicle of this type is called, for example, a senior car (R) or the like, and has a very high utility value as a substitute for the elderly and the like. In the basic configuration of such a small electric vehicle, for example, a seat on which an occupant sits is installed in the rear part of a vehicle body, a floor for the occupant to put his / her feet on is provided in front of the seat, and a steering shaft for steering the front wheels is further provided in front of the seat. Is erected. A handle is attached to the upper end of the steering shaft so that an occupant can sit on the seat and operate the handle.

Among conventional small electric vehicles, there is a steering mechanism of a type in which, for example, left and right front wheels are solid and a swing shaft is provided at the center of the vehicle. In this type, a tie rod is first attached from the steering shaft to one knuckle arm, and the tie rod is extended from that to the other knuckle arm.
With this structure, the steering wheel (steering) turning angle can be relatively large, but it cannot be applied to the case where the front wheels are left and right independent suspension type.

Generally, in the case of the left and right independent suspension type, an arm is installed on the central steering shaft, and a tie rod is extended from the arm. In addition, in this structure, the arm length cannot be made long, so that there is a problem that the steering wheel turning angle cannot be made too large.

[0005]

In order to solve the conventional problems, in a steering mechanism which has been known recently, tie rods are arranged above and below an arm of a steering shaft. However, since the tie rods are arranged vertically in this steering mechanism, the degree of freedom in designing the suspension arm and the like is limited.

In view of the above situation, it is an object of the present invention to provide a small electric vehicle which has a steering wheel with a large steering wheel turning angle and is excellent in usability or steering performance.

[0007]

A small-sized electric vehicle according to the present invention has a floor laid on the vehicle body frame below the single seat seat supported on the vehicle body frame.
A pair of left and right front wheels provided in front of the floor as steering wheels that swing left and right by a steering wheel operation, and a pair of left and right rear wheels provided as drive wheels driven by a power unit in a lower rear portion of the single seat. A small-sized electric vehicle having a steering device for steering the pair of left and right front wheels at a front end portion of the vehicle body frame, the steering device rotatably supporting an upper end of the steering device. A steering shaft projecting upward from the front end of the floor, and a front wheel steering knuckle rotatably supported left and right via a king pin at an outer end of a suspension arm extending outward in the left-right direction, The tie rod arm and the knuckle arm are connected by a tie rod via the tie rod arm and the knuckle arm. Beam is characterized by being arranged so as to protrude in opposite directions across the axis connecting the axis cross the kingpin.

Further, the small electric vehicle of the present invention is characterized in that both ends of the tie rod are located in front of and behind an axis connecting the axial centers of the king pins.

Further, in the small-sized electric vehicle of the present invention, the knuckle arm is extended from the front wheel steering knuckle forward, and the tie rod arm is extended rearward from the steering shaft. .

Further, in the small electric vehicle of the present invention, the lower end support portion of the steering shaft is arranged in front of the axis line, and the pivot shaft of the tie rod arm is arranged in rear of the steering shaft, The shaft and the rotating shaft of the tie rod arm are linked by a linking means, and the tie rod arm is arranged below the front part of the floor.

According to the present invention, it is possible to secure a large maximum steering angle, and it is possible to change the turning angle substantially according to the Ackermann theoretical line. As a result, the side slippage of the tire is small even when the vehicle makes a turning motion, a structurally unreasonable load is not applied, and tire wear can be effectively suppressed.

Further, by appropriately setting the positional relationship between the tie rod arm, the knuckle arm and the tie rod,
The maneuverability and stability of the vehicle can be improved, a wide floor can be secured, and the floor can be effectively used. Further, by appropriately setting the reduction ratio of the gear that connects the steering shaft and the tie rod arm, it is possible to improve the steering operability.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a small electric vehicle according to the present invention will be described below with reference to the drawings. 1 to 5 show the overall configuration of the small electric vehicle in this embodiment. This embodiment is an example of a four-wheel small electric vehicle, and in these drawings, a pair of left and right front wheels 1 and rear wheels 2 are supported at the front and rear portions of a frame unit 100 including a body frame. Front wheel 1 is front wheel support mechanism 2
00 and the rear wheel 2 is supported by the rear wheel support mechanism 300. A seat unit 400, which constitutes a single-seat seat for one passenger, is supported near the rear of the frame unit 100. At the lower front of the single-seat seat, there is a floor panel 3 laid on the vehicle body frame and constituting a low-floor footrest floor. At the front of the frame unit 100, there is a steering mechanism 500 that steers the front wheels 1 as steering wheels that swing to the left and right when the steering wheel is operated.

In this example, the rear wheel 2 is configured as a drive wheel, and is driven by a power unit 600 including an electric motor provided at the lower rear portion of the single seat. Further, in the present invention, a battery unit 700 including a secondary battery for supplying electric power to the power unit 600 is arranged below the floor panel 3.

The frame unit 100 is also referred to FIG. 6 to FIG.
The vehicle body frame 101 includes a main frame 103 and a rear frame 104. The main frame 103 further includes a center frame portion 105 and a front frame portion 106 extending in front of the center frame portion 105.

The main frame 103 includes a pair of main frame members 107 arranged on both left and right sides in the front-rear direction. The main frame member 107 is the center frame portion 10.
5 and near the boundary between the front frame portion 106 and
As shown in FIG. The main frame member 107 is preferably formed of a square pipe material, but is not limited to this and may be formed of, for example, a C channel material or a round pipe material. In any case, the main frame member 107 has a constant height (thickness in the vertical direction). In addition, each main frame member 107
A carrying handle 111, which is made of, for example, a round pipe material and projects outwardly, is attached to this.

Further, in this example, the main frame member 10
In FIG. 7, three bridge members 108, 109 and 110 are laterally provided near the boundary between the front end portion, the center frame portion 105 and the front frame portion 106 and the rear end portion, thereby ensuring high rigidity of the main frame 103. There is. As shown in FIG. 7, the bridge members 108 and 109 are curved so as to project downward, and a base member of a front wheel support mechanism described later is arranged on the bridge members 108 and 109. Incidentally, in the actual vehicle, the main frame 103 is appropriately tilted upward as shown in FIG. 7, and at this time, the base member of the front wheel support mechanism is supported substantially horizontally.

Here, as shown in FIG. 9, the steering frame 102 has four pipe members 102a to 102d integrally supported upright inside the front end portion of the front frame portion 106. The steering frame 102 rises vertically from the front frame portion 106 (main frame member 107), but since the main frame 103 tilts forward and upward as described above, the steering frame 102 appropriately tilts toward the single seat. The steering frame 102 is preferably made of a square pipe material.

The rear frames 104 are inclined rearward and upward from the vicinity of the rear end of each main frame member 107, and are connected to each other by a carrying handle 112 at their rear end. A bridge member 1 having a substantially arched or trapezoidal shape is provided in the middle of the rear frame 104 in the front-back direction.
13 is mounted horizontally, and a seat post 114 for supporting the seat unit 400 is attached to the upper portion of the bridge member 113. The rear frame 104 or the bridge member 113 is preferably formed of a square pipe material,
The material is not limited to this, and can be formed of, for example, a C channel material or a round pipe material. At the rear end of the rear frame 104, a bridge member 115 that is curved so as to project downward is installed horizontally.

The front wheel support mechanism 200 rotatably and swingably supports the front wheels 1, but the front frame portion 106
Base member 201 as a supporting portion held below
A suspension arm bracket 202 fixed on the base member 201, and a suspension arm bracket 202 that is swingably supported in the vertical direction, extends outward from the center of the vehicle in the left-right direction, and at the outer end thereof. A suspension arm 203 that rotatably supports the front wheel 1 is included.

Here, mainly by the front wheel support mechanism 200, from a rigid member extending leftward and rightward in front of a battery case, which will be described later, between the facing left and right front wheels 1, and projecting downward from the battery case. Is formed. That is, as shown in FIG. 1 to FIG. 5, FIG. 7, or the like, this projecting structure is such that the base member 201, the suspension arm bracket 202, and the suspension arm 203 that are arranged to project below the front frame portion 106.
By having such a protruding structure on the front side and the lower side of the battery case, it constitutes a barrier or protection means of the battery case having an important function as the power supply device of the vehicle, and effectively protects the delicate power supply device. be able to. Even if the front frame portion 106 has a projecting structure projecting downward as described above, the floor 3 in the actual vehicle is inclined upward as shown in FIG. The ground clearance can be effectively secured.

Referring also to FIG. 9 in the front wheel support mechanism 200, the bridge members 108, 1 of the main frame 103
Two front and rear suspension arm brackets 202 are provided for the left and right suspension arms 203, respectively, on the base member 201 arranged on the 09. Each suspension arm 203 has a bifurcated shape that branches back and forth, and the two branched base ends (inner ends) are pivotally supported vertically by two suspension arm brackets 202. Suspension arm 20
A U-shaped knuckle 204 (front wheel steering knuckle) is pivotally supported at the tip of 3 via a king pin 208 so as to be rotatable left and right. An axle 205 extends horizontally on the knuckle 204, and the front wheel 1 is rotatably supported on the axle 205.

A bracket 207 for mounting a suspension spring 206 is fixed to the outer side of the front frame portion 106, and the suspension spring is provided between the bracket 207 and the suspension arm 203 (the front side of the bifurcated branch). 206 is attached.

The rear wheel support mechanism 300 includes the power unit 6
00 to support the rear wheel 2. In this case, the power unit 600 includes an electric motor and a reduction gear group connected to the output shaft thereof, and the spindle of the final gear is the axle 3 of the rear wheel 2.
01. The front end side of the power unit 600 is pivotally supported via a bracket 302 (see FIGS. 1 to 3, etc.) fixed to the rear end of the main frame member 107.
The rear end side of the power unit 600 is connected to the lower end of the shock absorber 303. The upper end of the shock absorber 303 is pivotally supported via a bracket 304 fixed to the rear end of the rear frame 104. The shock absorber 303 may use a compression coil spring or hydraulic pressure.

In the seat unit 400, a seat cushion frame 401 and a seat back frame 402 formed of a square pipe material or the like are combined and integrated in a substantially L-shape to make the seat cushion frame 401 substantially horizontal and above the seat post 114. Supported by. In this case, the seat unit 400 is supported so as to be rotatable left and right and to be selectively fixed at a plurality of angular positions during the rotation.

An elastic seat cushion 403 is attached to the seat cushion frame 401, and an elastic seat back 404 is attached to the seat back frame 402. An armrest 405 is rotatably supported at an appropriate height position of the seatback frame 402. An occupant seated on the seat unit 400 supported on the seat post 114 as shown in FIG. 3 can put his / her foot on the floor panel 3, and at that time, the foot brake 4 arranged near the front part of the floor panel 3 is pressed. You can step on it.

Here, an example of the structure of the rotation supporting mechanism for the single seat will be described. In FIG. 10, the base bracket 406 is coupled to the lower side of the seat cushion frame 401,
A seat pipe 407 is suspended from the base bracket 406. On the other hand, the seat holder 114 has a pipe holder 4
08 is fitted, and the seat pipe 407 is rotatably fitted in the pipe holder 408. This allows the seat cushion frame 401, and thus the single seat, to rotate left and right. The pipe holder 4
08 may be removable from the seat post 114.

A lever holder 410 having a bearing 409 on its front portion is fixed to the base bracket 406. The rotating shaft 411 is inserted through the bearing 409,
The lever portion 412 is formed by extending 1 to the outside and bending it appropriately as shown in the figure. A claw piece 414 protruding downward from an opening 413 formed in the base bracket 406 is fixed to the rotating shaft 411. Lever part 41
The claw piece 414 can be rotated by the operation of 2. The claw piece 414 has a hole 414a capable of engaging with a tooth of a stopper plate described later. On the other hand, a stopper plate 415 is fixed to the upper end of the pipe holder 408, and a plurality of teeth 4 are formed on the outer peripheral portion of the stopper plate 415 at appropriate angular intervals.
16 are provided. Both sides of each tooth 416 are cut away as a relief so that they can engage the pawl 414.

The seat pipe 407 is attached to the pipe holder 408.
The seat post 11 by inserting the seat
Supported on four. In this case, the single seat can be selectively fixed at a desired angular position by engaging the claw piece 414 with the desired tooth 416 by operating the lever portion 412.

The steering mechanism 500 shown in FIG.
Etc., the steering shaft 5 is provided inside the steering frame 102 via a plurality of holders 502.
01 is rotatably held. Steering shaft 5
01 is an intermediate portion in the longitudinal direction and is a universal joint 50.
The steering handle 505 is bent via the bracket 3 so as to incline toward the single-seat seat side, and the upper end portion thereof supports the steering handle 505 via the bracket 504. Steering wheel 505
Has a deformed U-shape with the front part cut out, and while holding the steering handle 505 in place, the bracket 50
The accelerator lever 506 attached to the No. 4 can be rotated.

A bracket 507 is attached to the inside of the front end of each main frame member 107 of the front frame portion 106, and a boss for rotatably supporting the lower end of the steering shaft 501 is provided on the bracket 507. ing. On the rear side of the steering shaft 501 on the bracket 507, a counter shaft 508 having a gear that meshes with a gear provided at the lower end of the steering shaft 501 is arranged. The tie rod arm 509 is fixed to the counter shaft 508. When the steering shaft 501 is rotated right or left, the tie rod arm 509 rotates right or left via the counter shaft 508.

In each front wheel 1, the knuckle arm 510 fixed to the knuckle 204 and the tie rod arm 509 are connected to each other via a tie rod 511. By rotating the steering handle 505 to the left or right, the front wheel 1 is steered to the right or left via the steering shaft 501, the counter shaft 508, the tie rod arm 509, and the tie rod 511. In this way, the counter shaft 508
By providing the front wheel 1, the front wheels 1 can be steered in the same direction as the turning direction of the steering handle 505. In this case, the steering angle and the steering force can be appropriately set by appropriately selecting the gear ratio between the gear on the steering shaft 501 side and the gear on the counter shaft 508 side.

The power unit 600 is, as described above,
The rear wheel 2 is supported in cooperation with the rear wheel support mechanism 300. A battery unit 700, which will be described later, supplies electric power to the power unit 600, and its electric motor 601 is driven.

In the battery unit 700 of the present invention, as shown in FIG. 8, the floor (or floor panel) is used.
A battery case 701 having a height substantially equal to the height of the frames is housed between the frames arranged along the both side edges in the main region 3 of the battery case 70.
A plurality of secondary batteries 702 are arranged in a row in one unit. In the illustrated example, a plurality of secondary batteries 702 are arranged on the same plane in front and rear two rows.

Here, the floor 3 is located rearward of the front wheels 1 and has a main floor portion 5 having a width substantially equal to the left / right facing distance of the front wheels 1 and a main floor portion narrower than the left / right facing distance of the front wheels 1. The front floor portion 6 extends forward of the main floor portion 5 with a width narrower than the width 5. The main area of the floor 3 is constituted by the main floor portion 5, and the battery case 701 is arranged in this portion.

The center frame portion 105 of the main frame 103 described above extends forward and backward along the left and right edges of the main floor portion 5. Front frame part 106
Are extended in front of the center frame portion 105 at an opposed interval smaller than the left-right opposed interval of the front wheels 1. In this example, the main frame member 1 that constitutes the center frame portion 105
A battery case 701 is arranged between 07.

As shown in FIG. 11, the battery case 701 has a substantially thin box shape and is formed at substantially the same height as the main frame member 107. And this battery case 701
Is the main frame member 107 below the main floor portion 5.
Located between each other. A lithium ion battery is typically used as the dry type secondary battery 702 used in the present invention, but this type of dry type secondary battery is usually packed by combining a large number of cells. In this case, in order to increase the density of a large cell module, so-called bales are often stacked, and as it is, it becomes quite bulky. In this embodiment, as described above, the pair of left and right front wheels 1 is provided, and the main floor portion 5 can be formed in a large area having a width substantially equal to the distance between the front wheels 1 facing left and right. Eight secondary batteries 702 can be arranged. By keeping the width (diameter) of the secondary battery 702 equal to or slightly higher than the height of the main frame member 107, the battery mounting space can be set extremely thin.

As shown in FIG. 12, the bottom of the battery case 701 is provided with a plurality of concave-convex holding portions formed to correspond to the outer shape of the secondary battery 702. In this embodiment, a plurality of half-moon shaped ribs 701a are formed as this holding portion. Since the secondary batteries 702 are arranged on the same plane as described above, it is necessary to fix the secondary battery 702 so as not to move in the battery case 701 due to vibration or the like. By providing the half-moon rib 701a, the secondary battery 702
Are properly fixed so that they do not interfere with each other.

The battery case 701 has flange-shaped mounting portions 701b on both left and right sides, and the mounting portions 701b are mounted on the main frame member 107 by screws and the like. In this case, an insertion hole 701c for the mounting screw is provided.
The front part of the battery case 701, that is, the secondary battery 7 on the front row side
A cell controller (substrate) 703 is arranged on the front side of 02 via a holder 701d.

The cell controller 703 is a secondary battery 70.
It is controlled so that a capacity difference or a potential difference does not occur between two (cells), but it is provided vertically to the bottom of the battery case 701. As described above, the cell controller 703 is vertically provided between the components around the front suspension and the secondary battery 702, so that the space in the front-rear direction can be effectively used. Even if the cell controller 703 is provided vertically, in the actual vehicle, since the floor is inclined upwardly and upwardly, the floor does not project downward, and the minimum ground clearance can be effectively secured.

As shown in FIG. 12 or FIG. 13, a flat plate-shaped cover 704 is provided above the battery case 701. The cover 704 has a shape that matches the upper opening of the battery case 701, and a plurality of claw pieces 704a are vertically provided from the peripheral portion of the lower surface thereof. Claw piece 7 on the battery case 701
A plurality of engaging portions 701e are provided corresponding to 04a, and the cover 704 is fixed by engaging the claw pieces 704a with the engaging portions 701e. The battery case 701 and the cover 7
A gasket is attached to the mating portion 04 so that water, dust, or the like does not enter the battery case 701. A battery or a battery pack is constructed by covering and fixing a cover 704 on a battery case 701 accommodating a secondary battery 702.

Further, as shown in FIG. 13, the floor panel 3 is arranged on the upper side of the battery or the battery pack, that is, on the upper side of the cover 704. The floor panel 3 is mounted on the attachment portion 701b of the battery case 701 via a spacer, and is attached to the main frame member 1 by screws or the like.
It is attached to 07. In this case, the peripheral edge of the floor panel 3 is provided with an insertion hole 3a for its mounting screw, and the mounting portion 701b is also provided with an insertion hole 701f at a position corresponding to the insertion hole 3a.

Under the battery or battery pack, that is, below the battery case 701, a substantially flat plate-shaped underguard 705 is arranged. The under guard 705 covers the lower portion of the battery case 701 with a screw or the like to bridge members 109 and 110 (see FIG. 6 and the like).
Attached to. In this case, insertion holes 705a and 705b for mounting screws are provided at the front edge and the rear edge of the underguard 705, respectively (FIG. 12).

Further, referring to the above-mentioned drawings in the small-sized electric vehicle of the present invention, as shown in FIG. A main controller 7 for electronically controlling the power to be supplied to the motor 601 and a charging device 8 for charging the secondary battery 702 of the battery unit 700 are arranged. The main controller 7 and the charging device 8 are covered with a vehicle body cover (not shown) that is integrally and continuously provided from the floor 3 so as not to be exposed to the outside.

A box-shaped or basket-shaped luggage storage device 9 is mounted in the space between the pair of left and right rear wheels 2 located behind the main controller 7 and the like, and the luggage storage device 9 has an upper portion above the luggage storage device 9. An opening 9a is provided for allowing luggage and the like to be taken in and out. As described above, the single-seat seat is rotatably supported around the seat post 114 at a position close to and above the seat post 114. By appropriately rotating the single-seat seat, a part or all of the opening 9a of the luggage storage device 9 located below the single-seat seat can be covered with the single-seat seat so as to be openable and closable from above.

On the other hand, a switch box (operation panel) 10 is mounted on the upper portion of the steering frame 102 at a position near the front of the steering handle 505. The switch box 10 is supported, for example, via a substantially key-shaped bracket 11 fixed to the upper end of the steering frame 102 as shown in FIG. 7. The switch box 10 is equipped with various switches, for example, a forward / reverse switching knob, a speed setting knob, a battery level indicator and a charging lamp, and further right and left winker switches and horn buttons.

The switch box 10 is appropriately tilted near the front of the steering handle 505 so that the switches necessary for the driving operation can be easily reached and the display contents such as the display lamps can be easily seen. . Therefore, an occupant seated on the single seat can easily and accurately operate the switches of the switch box 10. At that time, the accelerator lever 506 can be appropriately operated as necessary.

In addition, a cord reel case 12 having a cord reel built in at a position close to the lower side of the switch box 10.
Is attached to the steering frame 102. A charging cord biased in the winding direction is wound around the cord reel so as to be able to be drawn out, and the charging cord is connected to the charging device 8. When the secondary battery 702 of the battery unit 700 is charged, the charging cord is unwound from the cord reel case 12, and the charging device 8 is connected to the external power source via the charging cord.

The main key 13 is also attached to the upper portion of the steering frame 102 by using the holder 502, for example. The main key 13 is arranged at a position where an occupant seated on a single seat can easily operate. Main key 1
A box-shaped or basket-shaped luggage storage device 14 is mounted on the steering frame 102 below the steering frame 102, and an opening for allowing luggage and the like to be taken in and out is formed in an upper portion of the luggage storage device 14.

In the above case, each unit is covered with a vehicle body cover made of plastic, synthetic resin, or the like, and is designed so as to obtain a predetermined external appearance design as a whole vehicle. In this case, a leg shield and the like may be mounted around the steering frame 102, and a front fender and a rear fender may be mounted around the front wheel 1 and the rear wheel 2, respectively.

Further, the actual vehicle is equipped with safety or security parts necessary for traveling. This kind of equipment includes headlights, winkers, stoplights, side mirrors, horns, and the like, and is equipped with other parts as necessary.

14 to 17, the steering system according to this embodiment will be further described. As described above in the steering device, the steering handle 505 is provided on the upper end.
And a steering shaft 501 that rotatably supports and that protrudes upward from the front end of the floor 3, and a swing pin to the left and right via a king pin 208 at the outer end of a suspension arm 203 that extends outward in the left-right direction. The knuckle 204 supported so that the tie rod arm 50
9 and knuckle arm 510 through tie rod 51
Connected by 1.

A bracket 507 to be welded to the lower end of the steering frame 102 is provided with a steering shaft mounting boss 512 and a counter shaft mounting boss 513 in the recess as shown in FIG. Boss 51
The lower end of the steering shaft 501 is axially supported by the bearing 2 via a bearing 514 (preferably a resin bush).
The steering shaft 501 is provided above the bearing 514.
A substantially half-moon gear 515 (spur gear) is fixed to the
5 is a substantially half-moon shaped gear 51 fixed to the counter shaft 508.
6 (spur gear) meshes. The counter shaft 508 is supported by a boss 513 via a bearing 517, and in this case, a spacer 518 is inserted between the upper and lower bearings 517.

In the present invention, in particular, as shown in FIG. 15, the tie rod arm 509 and the knuckle arm 510 are arranged so as to project in mutually opposite directions with the axis line connecting the axial centers of the left and right kingpins 208 interposed therebetween. It In this case, attach the knuckle arm 510 to the knuckle 204
Tie rod arm 509
Is extended rearward from the steering shaft 501.

By arranging the tie rod arm 509 and the knuckle arm 510 in this manner, the rod ends 511a and 511b at both ends of the tie rod 511 are arranged.
Are located in front of and behind the axis connecting the axes of the king pins 208.

Further, the lower end support portion (steering shaft mounting boss 512) of the steering shaft 501 is arranged in front of the axis connecting the axial centers of the king pins 208, and the rotary shaft of the tie rod arm 509 (counter shaft 5).
08) is arranged behind the steering shaft 501. Then, the steering shaft 501 and the counter shaft 508 are connected to the gears 515 and 516 serving as linking means.
Will be linked by. In this case, the tie rod arm 509
Is arranged below the front part of the floor 3 (see FIG. 2 or FIG. 9).
Etc.).

In the steering apparatus of the present invention, a steering angle that approaches the so-called Ackermann theory is secured, and smooth and appropriate steering and traveling performance are realized. Here, the Ackermann theory refers to that the axle center lines M1 and M2 of the steered left and right front wheels (F) intersect on the axle extension line M ′ of the rear wheels (R) with reference to FIG. . When the left front wheel is cut at a cutting angle α, and the right front wheel is cut at a cutting angle β, the following equation holds. In the figure, M is a kingpin 20.
An axis line connecting the eight axis centers is shown. cot α = B / L cot β = A + B / L L is the front-rear axle distance (wheel base), and A is the kingpin distance.

For example, as in the illustrated example, the axle center line M _{1 of} the left front wheel (turning angle α) that is inside the turning center of the vehicle and the axle center line M of the right front wheel (turning angle β) that is outside the turning center of the vehicle. ₂ and a straight line M ₁ ′ which is line-symmetric with the axle center line M ₁ with respect to the kingpin center line N parallel to the vehicle center line C.
And The Ackermann theoretical line P can be obtained by changing the inner cutting angle (0 to 90 °) and plotting the intersection of the axle center line M ₂ and the straight line M ₁ ′ for each angle.

FIG. 19 shows that when the front wheels 1 are steered to the left in the steering apparatus of the present invention, the turning angle α of the left front wheel 1 and the turning of the right front wheel 1 are obtained in the same manner as in obtaining the Ackermann theoretical line P described above. The angle β is changed (α = 0 °, 15 °,
30 °, 45 °, 60 ° ,. ． ． And β = 0 °, 15
°, 30 °, 45 °, 60 ° ,. ． ． ), And the corresponding relationship with the Ackermann theoretical line P at this time is shown. In this case, by rotating the tie rod arm 509, the swing angle of the knuckle arm 510 changes, and the intersection of the axle center line M ₂ and the straight line M ₁ ′ on the Ackermann theoretical line P is plotted in the same manner as in the case of cutting. intersection P ₀ for each angle change 15 ° angular α and cutting angle _{β, P 15, P 30,} P 4 5,
P ₆₀ ,. ． ． ． Is a plot of. As can be seen from the figure, the angle almost coincides with the Ackermann theoretical line P up to the cutting angle α = 80 °.

In actual use of the small electric vehicle of the present invention,
The occupant seated on the single seat is the steering wheel 50.
It is possible to drive the vehicle by gripping 5 and pulling the accelerator lever 506 or stepping on the foot brake 4 as necessary. In this case, from the battery unit 700 housed under the floor panel 3 to the power unit 6
00, the electric motor 601 of the power unit 600 drives the rear wheels 2 so that the occupant can smoothly and appropriately drive this small electric vehicle.

By the way, this type of electric vehicle is regulated to have a total length of 1200 mm and a total width of 700 mm or less according to the type approval by the legal regulation. When a four-wheel type vehicle is constructed under this condition, the wheels are arranged at the four corners of the vehicle.
In addition, it is necessary to secure a large steering angle for traveling in a narrow passage or the like. In the present invention, the knuckle arm 510 extends forward from the knuckle 204, and the tie rod arm 509 extends rearward from the steering shaft 501. By arranging the tie rod arm 509 and the knuckle arm 510 in this way, it is possible to set an acute angle between the axis of the tie rod 511 and the axis of the vehicle in the vehicle front-rear direction when going straight (see FIG. 15). A large maximum steering angle can be secured. Then, even if the inside corner of the front wheel 1 becomes about 80 ° (see FIG. 17), the approximate Ackermann theoretical line P
It becomes possible to change the cutting angle according to.

Further, as described above, by setting an acute angle between the axis of the tie rod 511 and the axis of the vehicle front-rear direction during straight traveling, the angle of the knuckle arm 510 and the axis of the vehicle front-rear direction can be set to It can be formed to open inward in the left-right direction. As a result, even if a large clearance is secured between the tip of the knuckle arm 510 and the front wheel 1, the kingpin 208 that swingably supports the knuckle 204 can be brought close to the front wheel 1 and the scrub radius (kingpin offset) can be set small. . By reducing the scrub radius, the maneuverability and stability of the vehicle can be improved.

Further, since the steering shaft 501 protruding upward from the tip of the floor 3 can be arranged in front of the vehicle, the floor 3 can be secured wide and the floor 3 can be effectively used. In this case, the floor 3 can be formed wider by disposing the steering shaft 501 in front of the axis M.

Further, the steering shaft 501 and the tie rod arm 509 are gears 515, which serve as a linking means.
Connected via 516. In that case, steering operability can be improved by appropriately setting the reduction ratios of these gears. For example, for elderly women who have weak arm strength, the reduction ratio can be increased and steering can be performed with a small steering force. Further, in the case of a man, by making the reduction ratio relatively large, the front wheel turning angle can be increased with a small steering wheel turning angle, that is, a quick operation feeling can be obtained.

Although the present invention has been described above with the embodiments, the present invention is not limited to these embodiments, and modifications and the like can be made within the scope of the present invention. For example, by dividing the tie rod arm 509 into two along the center line and allowing the left and right movements separately, it is possible to turn on the spot like a small electric vehicle such as a so-called motor chair. In this case, since it is impossible to make a turn on the spot while continuously operating the steering wheel, a mechanism is provided for temporarily turning the spot and turning the left and right front wheels into a “C” shape. There is a need.

[0066]

As described above, according to the present invention, a large maximum steering angle can be secured in this type of small electric vehicle, and the turning angle can be changed substantially according to the Ackermann theoretical line. As a result, the side slippage of the tire is small even when the vehicle makes a turning motion, a structurally unreasonable load is not applied, and tire wear can be effectively suppressed. In addition, by appropriately setting the positional relationship between the tie rod arm, the knuckle arm, and the tie rod, the maneuverability and stability of the vehicle can be improved, and a wide floor can be secured, so that the floor can be used effectively. You can Furthermore, by appropriately setting the reduction ratio of the gear that connects the steering shaft and the tie rod arm,
It has an advantage that the steering operability can be improved.

[Brief description of drawings]

FIG. 1 is a front perspective view showing a basic configuration in an embodiment of a small electric vehicle of the present invention.

FIG. 2 is a rear perspective view showing the basic configuration of the embodiment of the small electric vehicle of the present invention.

FIG. 3 is a side view showing a basic configuration in the embodiment of the small electric vehicle of the present invention.

FIG. 4 is a plan view showing a basic configuration in the embodiment of the small electric vehicle of the present invention.

FIG. 5 is a front view showing the basic configuration of the embodiment of the small electric vehicle of the present invention.

FIG. 6 is a perspective view showing the periphery of the frame unit and the battery unit in the embodiment of the small electric vehicle of the present invention.

FIG. 7 is a side view showing the periphery of the frame unit in the embodiment of the small electric vehicle of the present invention.

FIG. 8 is a plan view showing the periphery of the frame unit in the embodiment of the small electric vehicle of the present invention.

FIG. 9 is a perspective view showing the periphery of the front wheel support mechanism in the embodiment of the small electric vehicle of the present invention.

FIG. 10 is a perspective view showing the periphery of a single seat seat rotation mechanism in the embodiment of the small electric vehicle of the present invention.

FIG. 11 is a perspective view showing a battery unit in the embodiment of the small electric vehicle of the present invention.

FIG. 12 is an exploded perspective view showing a battery unit in the embodiment of the small electric vehicle of the present invention.

FIG. 13 is a side view showing the battery unit in the embodiment of the small electric vehicle of the present invention.

FIG. 14 is a perspective view showing the periphery of the steering device in the embodiment of the small electric vehicle of the present invention.

FIG. 15 is a plan view showing the periphery of the steering device in the embodiment of the small electric vehicle of the present invention.

16A and 16B are a plan view and a cross-sectional view showing a connecting structure of a steering shaft and a tie rod arm in the embodiment of the small electric vehicle of the present invention.

FIG. 17 is a plan view showing the periphery of the steering device in the embodiment of the small electric vehicle of the present invention.

FIG. 18 is a schematic diagram for explaining an Ackermann theoretical line according to the small electric vehicle of the present invention.

FIG. 19 is a diagram showing a correspondence relationship with an Ackermann theoretical line of the steering device in the embodiment of the small electric vehicle of the present invention.

[Explanation of symbols]

1 front wheel, 2 rear wheels, 3 floor panel, 4 brake pedal, 7 main controller, 8 charging device, 9
Luggage storage device, 10 switch box, 12 cord reel case, 13 main key, 100 frame unit, 101 body frame, 102 steering frame, 103 main frame, 104 rear frame, 105 center frame part, 106 front frame part, 107 main frame Member, 108, 10
9,110 Bridge member, 114 seat post, 2
00 front wheel support mechanism, 201 base member, 202 suspension arm bracket, 203 suspension arm, 204 knuckle, 205 axle, 206
Suspension spring, 207 bracket, 20
8 kingpin, 300 rear wheel support mechanism, 301 axle, 302 bracket, 303 shock absorber, 400 seat unit, 401 seat cushion frame, 402 seat back frame, 403
Seat cushion, 404 seat back, 405
Armrest, 500 steering mechanism, 501 steering shaft, 505 steering handle, 506
Accelerator lever, 507 bracket, 507a clamp part, 508 counter shaft, 509 tie rod arm, 510 knuckle arm, 511 tie rod,
514 Clamping member, 515 bolt, 600 power unit, 601 electric motor, 700 battery unit, 701 battery case, 702 secondary battery, 703
Cell controller, 704 cover, 705 under guard.

Claims (4)

[Claims] 1. A front floor of a floor which is laid on the body frame below the single seat supported on the body frame, and which serves as a steering wheel swinging left and right by a steering wheel operation. A pair of left and right front wheels provided,
As a driving wheel driven by a power unit, it is configured to be able to travel with a pair of left and right rear wheels provided at a lower rear portion of the single seat, and a steering device for steering the pair of left and right front wheels is provided at a front end portion of the body frame. In the steering device, a steering shaft rotatably supporting an upper end of the steering device, the steering shaft protruding upward from a front end of the floor, and a suspension arm extending outward in the left-right direction. A front wheel steering knuckle that is swingably supported to the left and right via a kingpin at the outer end of the tie rod arm and a tie rod via a knuckle arm, and the tie rod arm and the knuckle arm are the axes of the kingpin. They are arranged so that they project in opposite directions with the axis connecting the cores sandwiched. Small electric vehicle according to claim Rukoto. 2. The small electric vehicle according to claim 1, wherein both ends of the tie rod are configured to be located in front of and behind an axis connecting the axial centers of the kingpins. 3. The knuckle arm extends forward from the front wheel steering knuckle, and the tie rod arm extends rearward from the steering shaft. Small electric vehicle. 4. The lower end support portion of the steering shaft is arranged in front of the axis, and the rotating shaft of the tie rod arm is arranged in rear of the steering shaft, so that the steering shaft and the tie rod arm rotate. The small electric vehicle according to any one of claims 1 to 3, wherein the shafts are linked by a linking means, and the tie rod arm is disposed below a front portion of the floor.