JPH04103467A - Electric automobile - Google Patents

Abstract

PURPOSE:To cancel the limitation in direction of turn of each wheel to greatly enhance the movility performance of a four-wheel automobile, in which each wheel independently driven by a motor is rotatable around a king pin shaft, by making larger than substantially 180 deg. or so the angular range through which each wheel is rotated around a king pin shaft. CONSTITUTION:A through hole 4a is vertically passed through in a support device 4 fixed to a side surface of a frame 3. A king pin shaft 5, having wheels 2 at its low end portion, is passed through the mentioned through hole via a bearing 4b and is mounted there. Integrally fixed to the lower end portion of the king pin shaft 5 there is a base plate 7 which concurrently serves as a frame for a drive motor 6 and which supports a wheel shaft 15. The drive motor 6 is made an outer-rotor type induction prime mover disposed between the wheel shaft 15 and a rotor frame 26. And a worm wheel 14 is secured to an upper end of the king pin shaft 5. With this worm wheel is meshed a worm 13 driven by a geared motor 12. By driving this geared motor 12, the wheel 2 is made rotatable around the king pin shaft 5 in all directions including the back-and-forth direction and a sideward direction perpendicular to this direction.

Description

[Detailed description of the invention] (Industrial application field) This invention uses a motor to steer the wheels.

It also relates to driving electric vehicles, particularly to improving the driving performance at low speeds.

(Prior Art) In order to improve the driving performance of automobiles, 4WS' (four-wheel steering) has recently been proposed as a new technology.

On the other hand, an electric vehicle has been proposed in which wheels are driven using a motor, and the motor is used to turn and displace the wheels to steer the vehicle.

By employing the 4WS technology in such an electric vehicle, it is easy to use electrical control technology, so it can be expected that the driving performance of the vehicle will be significantly improved.

However, in such conventional electric vehicles, the turning range of the wheels is relatively small.

(Problem to be solved by the invention) In other words, in conventional electric vehicles of this type, it is not possible to expect a significant improvement in the driving performance of the vehicle even if electrical control technology is used. ing.

This invention was made based on this background, and aims to significantly improve the driving performance of this type of electric vehicle, and provides a vehicle that directly leads to improved driving performance through the use of electrical control technology. The purpose is to

(Means for Solving the Problems) For this purpose, the present invention provides a drive motor that independently drives each wheel of a four-wheeled vehicle around its respective axle, and also connects these wheels to their respective king pin axles. In an electric vehicle configured to be able to turn around the kingpin axis, and in which the wheels are independently driven to turn around the kingpin axis by a steering motor installed for each wheel, the turning angle range of each wheel around the kingpin axis is is approximately 180 degrees or more, and this turning angle range includes a direction in which each wheel is aligned with the longitudinal direction of the electric vehicle, and a direction in which each wheel is perpendicular to the longitudinal direction of the electric vehicle.

(Function) According to the present invention, each wheel can be oriented in all directions around its respective kingpin axis within a turning angle range that includes the front-rear direction of the vehicle and the sides at right angles thereto. Restrictions are removed.

Since the direction of each of these wheels can be easily and comprehensively controlled using electrical control technology, the driving performance of this type of electric vehicle can be greatly improved.

(Example) The present invention will be explained below with reference to an embodiment shown in the drawings.

The electric vehicle 1 of this embodiment is a four-wheeled vehicle, and is of a four-wheel steering type in which each wheel is configured to be able to turn around its own kingpin axis 5, and includes a steering device for each wheel, The respective drive and suspension devices are constructed in the same way as shown in FIG. 2 (see FIG. 3).

In FIG. 2, 2 is a wheel and 3 is a frame.

A support device 4 is fixed to the side surface of the frame 3, and this support device 4 has a through hole 4a penetrating in the vertical direction, and bearings 4b are installed at the upper and lower ends of the through hole 4a.

The axle 2 is held at the lower end of the through hole 4a of the support device 4. A king pin shaft 5 is inserted through the shaft.

The upper part of the king pin shaft 5 is integrally provided with a flange portion 5a.
The lower end of the king pin shaft 5 also serves as a frame for a drive motor 6, which will be described later.

The axle 15 is supported horizontally. A base plate 7 is fixed together by welding or the like.

A coil spring 4d is interposed between the washer 4c mounted on the upper side of the flange portion 5a and the lower end surface of the upper bearing 4b fixed to the support device 4, and this king pin shaft 5 is attached to the support device 4. It is movable up and down with respect to it, and is supported rotatably in the circumferential direction.

A boss portion and a boss hole are formed in the center of the base plate 7 fixed to the lower end of the king pin shaft 5,
The stator winding of the drive motor 6 is fixed on the outer peripheral surface of the boss portion, and by rotatably mounting the axle 15 in the boss hole, the wheel 2 is supported, and the rotor frame 2
A drive motor 6 consisting of an outer rotor type induction motor is constructed between the drive motor 6 and the drive motor 6 .

This axle 15 is formed integrally with a rotor frame 26 fixed to the wheel rim 11, and extends inside the vehicle through the base plate 7. Brake disc unit 6 at the end
is fixed.

Then, facing the edge of this brake disc 16,
A brake caliper 17 is disposed so as to be supported by the base plate 7, and braking is performed by appropriately operating the brake caliper 17 using a lever. In addition, in FIG. 2, 18 indicates a tire.

In this drive motor 6, the rotor is located on the outer circumferential side and rotates, so the rotor frame 26 on the outer circumference can be installed with a simple structure such as connecting it to the wheel rim 11 using bolts or the like. It can be used as the drive motor 6 of the wheel 2, and in this embodiment, power is supplied to the drive motor 6 from a joint part 19 installed at the top of the kingpin shaft 5 through the inside of the kingpin shaft 5. It is done.

Since the drive motor 6 is configured to supply electric power as shown in item 2, it is not necessary to install a power transmission structure to apply a driving force to the wheels 2.

Therefore, it is possible to configure the steering device by widely utilizing the space on either side of the wheels 2, and the turning angle (steering angle) of each wheel 2 can be set much larger than conventionally.

A worm wheel 14 is fixed on the king pin shaft 5 on the upper side of the support member 4, and a worm 13 driven by a guard motor 12 is disposed near the worm wheel 14 and meshed with the worm 13.

This geared motor 12 corresponds to the steering motor in the present invention, and by driving the geared motor 12, the kingpin shaft 5. Steering is performed by turning the wheels 2 via the base plate 7 and the axle 15.

The worm boiler 14 is attached to a spline portion 5b formed on the kingpin shaft 5, and the worm boiler 14 remains engaged with the worm 13 even when the kingpin shaft 5 moves up and down as the wheel 2 moves up and down. It remains stationary in position and is always ready for power transmission.

In this embodiment, since the drive motor 6 is arranged inside the wheels 2 as described above, the turning angle range of each wheel is set to a large range as shown in FIG.

That is, FIG. 1 is an enlarged plan view of the right front wheel 2a of the electric vehicle 1 shown in FIG. 3, where arrow F indicates the front of the electric vehicle 1, and arrow S indicates the side of the vehicle body. show.

In the case of normal straight forward running, the wheels 2a
As shown by the solid line, is positioned facing in the direction coincident with the arrow F (hereinafter referred to as the straight position).

When the electric vehicle 1 turns, the wheels 2a are turned around the kingpin shaft 5, but in this embodiment, the wheels 2a are turned by 90 degrees on both sides in the front and rear directions from the straight-ahead position. In this embodiment, the turning angle range is 180 degrees in total, and within this range, the wheels 2a can stop turning at any desired position.

At the end position of this turning angle range, the first
As shown by Wl and W2 in the figure, the wheels 2a are in a position facing toward the side of the vehicle body as shown by arrow S.

Note that during the turning angle range, the straight ahead position and the W1
Or, if either one of W2 is included, the wheel 2a can be oriented all around the kingpin shaft 5.

Four wheels 2a, 2b configured in this way.

It has 2c and 2d. The drive device of the electric vehicle 1 is constructed as shown in FIG.

That is, the right front wheel 2a, the left front wheel 2b, the right rear wheel 2c, and the left rear wheel 2d are provided with drive motors 6a, 6b, 8c, and 8d similar to those described above, and geared motors 12a, 12b, 12c, and steering motors as steering motors, respectively. 1
2d are installed independently, and these motors are comprehensively controlled as a whole by an electric control device shown in a block diagram in FIG.

That is, the drive motors 6a, 6b, 6c.

6d and guard motor units 2a, 12b, 12c
, 12d are driven by current supplied from a battery (not shown), but they are controlled by signals from the controller 21 and driven independently of each other (FIG. 4).

The controller 21 includes a computer 31 and four motor controllers 32a for drive motors.

32 b, 32 c, 32 d, and four motor controllers 33 a, 33 for guard motors.
Lever from 33b, 33c, 33d The output signals from these motor controllers 32a, 33a, etc. control the corresponding drive motor 6a, etc., guard motor 12a, etc., respectively.

The computer 31 also includes information on each wheel 2a, 2b, 2c.
, wheel rotation sensors 22a, 22b installed every 2d,
22c and 22d, a steering signal from the steering sensor 23 on the steering wheel, an acceleration command signal detected by the accelerator sensor 24 installed on the accelerator pedal, and a brake sensor 25 installed on the brake pedal. A brake signal is input.

These signals are stored in the ROM in the computer 31.
It is calculated according to a program stored in a storage medium such as (Read Only Memory), and compared with the stored driving data of the electric vehicle 1, and the required output is sent to all the motor controllers 32a, 33a,
etc., each drive motor 6a, 8
b, 6c, 6d and guard motor 12a, 1
2 b, 12 c, and 12 d are placed in an appropriate rotational state, and the direction (turning angle displacement amount) and rotational speed of each wheel 2 a, 2 b, 2 c, and 2 d are controlled.

The electric vehicle of this embodiment is capable of various movements shown in Fig. 5, and the control table shown in Fig. 6 is created based on the need to perform these movements appropriately.
This control table is stored in the ROM in the computer 31, and an appropriate operation mode is selected based on a signal from a command means such as a steering wheel.

If the driver selects, for example, the driving mode in which the pivot center P is the center of the vehicle body shown in A-1 in FIG. 5, the computer 31 selects the driving mode shown in FIG. The signals written in column A-1 are read out, and these signals are sent to the motor controllers 32a, 32b, 32 for the drive motors of the respective wheels 2a, 2b, 2c, and 2d.
c, 32d and a motor controller 33a for the guard motor.

Output to 33b, 33c, and 33d.

In the control table shown in FIG. 6, the turning direction is based on the target position of the wheels in the turning direction when the electric vehicle 1 is arranged with the front (arrow F) facing upward in the figure as shown in FIG. The driving direction indicates the direction in which the wheel is moving, and the "+" mark means that the wheel is fixed in a straight line.

Of the outputs in column A-1 of Fig. 6, depending on the turning direction,
Each guard motor 12a, 12b, l2
c.

12cl is driven and each wheel 2a, 2b, 2c
, 2d are given a required turning angle displacement, and are arranged in a direction surrounding the pivot center as shown in A-1 in FIG.

Thereafter, the respective drive motors of the wheels 2a, 2b, 2c, and 2d are driven according to the driving direction shown in FIG. 6, and the driving of these wheels causes the pivot rotation shown by the arrow in A-1 in FIG. An action is taken.

Note that the arrows in FIG. 5 indicate the direction of movement of the electric vehicle 1, and these movements other than A-1 will not be described in detail, but the control shown in FIG. This can be done by operating the guard motor and drive motor of each wheel according to the table, and in FIG. 6, the "+" indicates that the wheels are fixed in the straight-ahead state.

(Effects of the Invention) As explained above, according to the present invention, each wheel can be oriented in all directions around its respective kingpin axis within a turning angle range that includes the longitudinal direction of the automobile and the sides perpendicular to this direction. This eliminates restrictions on wheel orientation.

Since the direction of each of these wheels can be easily and comprehensively controlled using electrical control technology, the motion performance of this type of electric vehicle can be greatly improved.

[Brief explanation of drawings]

The drawings relate to an embodiment of the present invention, and FIG. 1 is an explanatory diagram of the turning range of the wheels, FIG. 2 is an explanatory diagram of the structure as viewed from the ■-] arrow in FIG. 3, and FIG. 3 is an explanatory diagram of the arrangement of the wheels of an electric vehicle. 4 is a control block diagram of the electric vehicle, FIG. 5 is an explanatory diagram of the motion mode of the electric vehicle, and FIG. 6 is a control table diagram. Front, electric vehicle, 2a, 2b, 2c, 2d; Wheels, kingpin shaft, 6a, 6b, 6c, 6d; Drive motor, 2° 12 a. 2b. 2c 2d Geared motor (steering motor), 5; Axle.

Claims (1)

[Scope of Claims] Drive motors that independently drive each wheel of a four-wheeled vehicle around their respective axles are provided, and these wheels are configured to be able to rotate around their respective kingpin axes, and these wheels are In an electric vehicle in which each wheel is independently driven to turn around a kingpin axis by a steering motor installed in each wheel, the turning angle range of each wheel around the kingpin axis is approximately 180 degrees or more, and the turning angle range is within this turning angle range. An electric vehicle characterized in that each wheel has a direction that corresponds to the longitudinal direction of the electric vehicle, and a direction in which each wheel is perpendicular to the longitudinal direction of the electric vehicle.