JPH02111205A - Four-wheel drive electric automobile - Google Patents

Abstract

PURPOSE:To miniaturize and lighten a four-wheel drive electric automobile, to improve its maximum speed of and to lengthen continuous mileage by separately dividing the four wheels with an ultrasonic motor in supplying electric energy from a flexible sheetlike lithium-alkali secondary battery. CONSTITUTION:Each of wheels 1a to 1d is separately driven and controlled by the control of a central controller 500. Each of drive controllers 406a to 406d select an untrasonic motor 201 as well as necessary quantity of drive units 405 from among a plurality of drive units 405 to control steering speed. As to the ultrasonic motor 201, fifteen sets of motor with an output of 400W and 500g in weight to each wheel using piezoelectric elements, e.g., 2mm thick and 30mm in diameter to obtain an output of 24kW. The secondary battery above is shaped into a flexible sheet with a composite anode stuck to a Li cathode on both sides of solid polymer electrolyte and weights 150kg.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a four-wheel drive electric vehicle.

[Prior Art] Conventionally known electric vehicles have their engine drive source replaced by a DC motor, and
A lead acid battery or a fuel cell is generally used as an energy supply source for the DC motor.

[Problem to be solved by the invention] However, the DC motor used as a drive source for an automobile is heavy (one motor weighs more than 100 kg).
Therefore, it is not possible to install multiple DC motors in a single car, and the car usually has a two-wheel drive system in which a single motor drives either the front or rear wheels. Therefore, on rough roads, one wheel would float, resulting in poor drivability. In addition, lead-acid batteries and fuel cells that serve as energy supply sources for DC motors have low energy density, that is, the amount of electricity stored per unit weight of the battery, and the continuous driving distance per charge is short, so attempts are being made to increase this. If large storage batteries were to be installed, this would hinder the ability to reduce the weight of automobiles, and there would also be problems in that it would be difficult to take advantage of passenger space and cargo space.

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a four-wheel drive electric vehicle that is lighter in weight and has improved running performance.

[Means for Solving the Problems] In order to achieve this object, the electric vehicle of the present invention has a compact high-torque, high-torque,
The gist is that ultrasonic motors with high output efficiency are connected. Further, the gist is to use a flexible sheet-shaped alkaline secondary battery, preferably a lithium-based secondary battery, as an energy supply source for the drive source.

[Operations and Effects of the Invention] According to the electric vehicle of the present invention having such a configuration, 4
Since each tire is driven by an independent ultrasonic motor, it is a four-wheel drive system, so by controlling the drive of each tire individually, it can run without trouble even on rough roads, and the driving performance has been significantly improved. Ru. In addition, the ultrasonic motor itself is lightweight, and in addition, heavy objects such as various transmission shafts and differential shafts, which are conventional drive source transmission mechanisms, are no longer required, contributing to the weight reduction of automobiles. Furthermore, if a flexible sheet-shaped lithium secondary battery with high energy density is used as the energy supply source for each ultrasonic motor, it will not only be possible to increase the continuous driving distance and reduce the weight, but also to allow it to be used on the walls or in open spaces of the car body. Since it can be easily installed in any space, it also has the effect of ensuring sufficient passenger space and cargo space.

[Example] An example of the present invention will be described below with reference to the drawings.

First, Figure 1 shows the relationship between the output power and the amount of energy required to run an electric vehicle with a weight of 1000 kg. In the figure, solid lines 1, 2.3 each have a running speed of 3.
2km/h, 65km/h, 100km
/hr, and dashed lines 4 and 5.6 each indicate changes in continuous running distance with one charge. As is clear from this figure, - As an example, the output power and continuous running energy required for a car with an FF of 11,000 kg to travel at 1,100 km/h and 320 kIl are each 2
0kw and 50kwh.

Therefore, in order to satisfy this condition, the present applicant proposes a commercial automatic width having the following configuration. That is, an ultrasonic motor is used as the drive source of the automobile, and this is connected to the axle of each tire. The model structure of this ultrasonic motor is as follows:
An example is shown in FIG. The specifications of this are shown in Table 1 below.

Table 1 Ultrasonic motor specifications (1 Piezoelectric element layer 2 thickness Piezoelectric element diameter 301u11 diameter AC voltage 100v Output power 400w Weight 500g This ultrasonic motor 201 has an output power of 4
00w, but this is the above-mentioned 1100k/h
In order to secure the output power of 20 kW necessary for driving at speed b, one
3 to 15 pieces are linked together. 3 and 4 show the specific configuration thereof, and as shown in the figures, the ultrasonic motors 201 are connected to a drive controller 406 via a drive unit 405 in units of 15, for example.
The transmission gear shaft 40 includes a plurality of output gears 401, 401, 401, .
2a, 402b, and bevel gears 403, 4 fixed to each transmission gear shaft 402a, 402b.
03 is 1 (IN(7) tire 1 no WiIlb), 0
It is meshed with the first umbrella 11L404, 404. In this way, for each ultrasonic motor group, each tire la, lb, lc, ld
Drive controllers 406a, 406b, 406c, and 40 are individually connected to each other and are provided for each motor group.
6d is connected to the central controller 500.

With such a configuration, the central controller 500
to each drive controller 406a.

Each ultrasonic motor 201 is operated via each drive unit 405 according to commands issued to 406b, 406c, and 406d.
is rotationally driven, and the driving force is transmitted to the transmission gear shaft 40.
2 and the axle 101 to each tire la, lb, lc,
ld transmitted. Note that the rotation speed of each tire is controlled by commands from the central controller 500 and each drive controller 406a, 406b, 406c, and 406d.

In FIG. 3, a lithium secondary battery 201 is used as an energy supply source to the motor drive source, which is shown in FIG. 5 and explained as follows:
Li-based solid polymer electrolyte 2 made by mixing C2H & +9L i F3 C503]n material with carbon black
(20~50.) V6O on both sides of thickness, composite anode 4 (50~75 shoulder thickness) and Li cathode 6 (50~75 stores)
It is a flexible sheet-like material in which a Ni current collector 8 is bonded to the surface of the anode 4.

Its use is shown in Table 2 below.

Table 2 Lithium secondary battery specifications Shape (Note) 1.3mX4.0mX3ca+ (flat panel) Weight 150kg Energy density 400wh/kg Total energy 60kwh (Note) Formed by folding the sheet-shaped lithium secondary battery described above What I did.

The total energy possessed by the above lithium secondary battery is 6
The reason for setting it to 0 kwh is based on the following formula 60 assuming that the output efficiency is 80%.
This is because the amount of energy (50kwh) required for the intended travel distance (320km) is almost ensured by kwhX80/100100=48k#50kwh).

Thus, according to the present invention, the specifications of the ultrasonic motor make it possible to obtain the output power of 20 kW required for the running speed of 1100 k/h, and the specifications of the lithium secondary battery ensure the amount of energy of 50 kWh necessary for continuous running 3201. Ru. Therefore, at a running speed of 1001 O1/h, 3
It is also possible to run continuously for 201 am. In addition, the weight of the motor at this time is only about 500g/piece x 50 pieces - 25kg, since the weight of one ultrasonic motor is about 500g, and the lithium secondary battery also weighs about 150kg, so the total weight is 170g/piece. It is lightweight at ~180 kg.

[Brief explanation of drawings]

The drawings relate to one embodiment of the present invention, and FIG. 1 is a diagram showing the relationship between output power and continuous running energy required for a general automobile, and FIG. 2 is a schematic configuration diagram of an ultrasonic motor. , FIGS. 3 and 4 are schematic diagrams of an ultrasonic motor installed in an automobile, and FIG. 5 is a schematic diagram of a lithium secondary battery as an energy source for the motor. In the figure, 1a to 1d are tires, 101 is an axle, 201 is an ultrasonic motor, 301 is a lithium secondary battery, 406 is a drive controller, and 500 is a central controller.

Claims (1)

[Scope of Claims] A four-wheel drive electric vehicle characterized in that ultrasonic motors are connected to the axles of one and four tires as drive sources, respectively. 2. The four-wheel drive electric vehicle according to claim 1, further comprising a flexible sheet-shaped alkaline secondary battery as an energy supply source for each of the ultrasonic motors. 3. The four-wheel drive electric vehicle according to claim 2, wherein the alkaline secondary battery is a lithium-based secondary battery.