JP5114772B2 - Electric vehicle drive device - Google Patents

Description

The present invention relates to a drive device for an electric vehicle in which drive wheels are driven according to the operation of an electric motor.

In recent years, in the field of automobiles, with the improvement in performance of automobile motors and various control devices, research and development of electric vehicles has been actively conducted, paying attention to the excellent fuel efficiency and exhaust gas cleanliness. ing. Here, the electric vehicle is a vehicle in which driving wheels are driven by an electric motor, and is a vehicle including a pure electric vehicle that runs using an electric motor as a drive source instead of an engine.

There are various types of electric vehicles such as hybrid electric vehicles, pure electric vehicles, and fuel cell electric vehicles. Furthermore, the hybrid electric vehicle includes a parallel hybrid electric vehicle and a series hybrid electric vehicle. In the field of passenger cars and commercial vehicles, among other automobiles, many types of cars have already been commercialized in the form of parallel hybrids.

FIGS. 1A, 1B, 1C, and 1D schematically illustrate configuration examples of a parallel hybrid electric vehicle, a series hybrid electric vehicle, a pure electric vehicle, and a fuel cell electric vehicle, respectively.

As shown in FIG. 1A, the parallel hybrid electric vehicle 100 is provided with a power supply system 70 including a generator 50 and an electric motor 60 in parallel with a power transmission mechanism 40 including a transmission 120.

As shown in FIG. 1B, the series hybrid electric vehicle 100 is provided with a power supply system 71 including a generator 50 and an electric motor 60 in series with a power transmission mechanism 41 from the engine 10 to the generator 50. . Unlike the parallel hybrid electric vehicle 100 of FIG. 1A, the series hybrid electric vehicle 100 does not have a mechanical transmission mechanism such as a transmission 120.

As shown in FIG. 1 (c), the pure electric vehicle 100 is configured such that the electric energy stored in the storage battery (battery) 80 is converted into mechanical energy by the electric motor 60, and the drive wheels 1, 2, 3,
4 is transmitted.

As shown in FIG. 1D, in the fuel cell electric vehicle 100, the electric energy generated in the fuel cell 190 is stored in a storage battery (battery) 80, and the electric motor 60 converts the electric energy into mechanical energy. It is transmitted to the drive wheels 1, 2, 3, 4.

Non-Patent Document 1 described below describes an invention relating to a control device for a pure electric vehicle that includes an independent electric motor for each drive wheel and controls each electric motor. In the following, a vehicle in which an independent electric motor is provided for each of the four driving wheels and the four driving wheels are individually driven by the four independent electric motors will be referred to as a “four-wheel independent driving type” type electric vehicle. It will be called a vehicle. In the following description, the output values of the motor and engine are exemplified. However, this is merely a convenience for facilitating understanding of the rough concept, and the energy efficiency is simplified to approximately 100%. explain.
“Toward the current state of electric vehicle control and innovation” Symposium of the IEICE Tokyo Branch, 1998, 9, 18, Yoichi Hori

Among automobiles, there are off-road vehicles for disaster prevention that mainly travel on off-roads (off-road terrain) such as disaster sites. When such an off-road vehicle for disaster prevention is constituted by an electric vehicle, particularly a series hybrid electric vehicle, the required performance and functions are as follows.

1) All-wheel drive (four-wheel drive) Disaster prevention off-road vehicles not only require high-speed driving performance in the same way as ordinary passenger cars, trucks, and buses, but also landslide sites, etc. Therefore, it is required to be able to operate with a large torque even at an extremely low speed. The same applies to a case where the off-road vehicle for disaster prevention is constituted by an electric vehicle, particularly a series hybrid electric vehicle. In order to travel stably on the off-road, it is necessary that the driving force is transmitted from all the wheels to the wheels so that all the wheels are driven as driving wheels. For example, in the case of a four-wheel vehicle having four wheels, it is a four-wheel drive vehicle in which the driving force is transmitted from the electric motor to all four wheels.
Necessary for stable off-road driving.

2) There are many opportunities to drive with the ground contact load of the rear wheels larger than the contact load of the front wheels. Off-road vehicles for disaster prevention often have to climb over steep slopes in forward travel. When going over a steep hill in a forward run, the car body rises forward. At this time, the grounding load of the front wheel and the rear wheel is not uniform, and the grounding load of the rear wheel is larger than the grounding load of the front wheel. For this reason, the output capacity of the electric motor for the rear wheels is required to be larger than the output capacity of the electric motor for the front wheels.

Generally, a load of 60% or more is applied to the rear wheel, and a load of 40% or less is often applied to the front wheel. Assuming that the engine output is 120 kW, for example, on the uphill, for example, a load of 40 kW (40% or less) is applied to the front wheels, and a load of 80 kW (60% or more) is applied to the rear wheels.

3) There are many opportunities for momentary nonuniformity in contact pressure and load between the left and right wheels of the front wheels. Off-road vehicles for disaster prevention often run on uneven road surfaces, such as uphill with uneven surfaces. When traveling forward, momentary non-uniformity occurs in the ground pressure and load between the left and right wheels of the front wheels. As a result, in the worst case, one of the left and right wheels of the front wheel is lifted, and it is necessary to transmit the driving force (driving force for the total of the left and right wheels) necessary to advance the vehicle body to the other wheel. .

4) It is required to secure a large amount of on-board equipment and cabin space, and to ensure a large minimum ground clearance. Off-road vehicles for disaster prevention use a large number of on-board equipment and the number of passengers. It is required to secure a large storage space and cabin space. In addition, since it is necessary to change the optimal device layout according to the use of the vehicle, there is a demand to be able to freely design the layout in the vehicle. In addition, since off-road vehicles for disaster prevention have many opportunities to travel on road surfaces with protrusions and obstacles, the minimum ground clearance must be secured as much as possible.

5) Miniaturization and commonization of electric motors Off-road vehicles for disaster prevention are low-volume, high-mix production vehicles with different specifications for each application, and mass production effects cannot be expected. Therefore, it is desired to reduce the cost of the vehicle by downsizing or sharing a plurality of electric motors mounted on the vehicle.

Despite such requirements and specifications for disaster prevention off-road vehicles, the following problems occur when the disaster-prevention off-road vehicle is configured with a “4-wheel independent drive type” type electric vehicle. .

As mentioned above in 2), when an off-road vehicle for disaster prevention climbs a flat uphill,
If the rear wheel has a ground contact load greater than that of the front wheel, and the engine output is 120 kW, for example, on the uphill, a load of 40 kW (40% or less) is applied to the front wheel, and the rear wheel is applied. A load of 80 kW (60% or more) may be applied. However, on a climbing road that is slippery, the front wheel is less likely to slip because the front wheel's ground contact load is reduced, and if the front wheel slips, the driving force that can be exerted decreases. There must be. In such a situation, if the driving force of the rear wheels is insufficient, climbing may be difficult.

When trying to get over the road surface unevenness with the front wheels, as described above in 3),
If the ground pressure and load on the left and right wheels of the front wheels are momentarily nonuniform, and one of the front wheels lifts up, the driving force required to advance the vehicle to the other wheel (total of left and right wheels) In order to transmit the driving force for one minute), the electric motor of one of the grounded driving wheels is required to have a large output capacity that is twice the average output of the left and right driving wheels. For this reason, for example, with a 120 kW engine and a flat uphill, even if the front wheel electric motor requires only 40 kW of output capacity in total, the front wheel electric motor is With only this electric motor, an output capacity of 40 kW corresponding to the total number of front wheels is required. Thus, there arises a problem that the total output capacity of the electric motor becomes unnecessarily large.

For the rear wheels, there is no such problem because the suspension works and the load imbalance is not as great as the front wheels when the front wheels have overcome the road surface unevenness in advance.

For off-road vehicles for disaster prevention, it is necessary to secure a sufficiently large distance from the floor plate of the vehicle body to the road surface, that is, a minimum ground clearance, in order to run on uneven road surfaces. As shown in FIG. 2 (a), the parts having the largest diameter under the vehicle body floor and having the greatest influence on the ground clearance are shown in FIG.
This is a differential gear case 102 disposed under the floor of the vehicle. Conventionally, there has been no problem simply by designing the vehicle body layout so that the minimum ground clearance can be secured by paying attention to the diameter of the case 102 of the differential gear.

However, when the off-road vehicle for disaster prevention is configured by an electric vehicle, the diameter of the electric motor 60 is larger than the diameter of the differential gear case 102 as shown in FIG.
The arrangement of the electric motor 60 has the most influence on the minimum ground clearance.

For example, the diameter of the electric motor 60 having an output capacity of 40 kW reaches about 1.5 times the diameter of the conventional differential gear case 102. In addition, when the electric motor 60 is disposed under the floor, the upper portion of the electric motor 60 cannot be protruded greatly into the vehicle. This is because, as described above in 4), it is required to secure a large amount of equipment and cabin space. For this reason, the lower part of the electric motor 60 is inevitably positioned at a lower position than the lower part of the differential gear case 102, and there arises a problem that the minimum ground clearance required for off-road driving cannot be secured sufficiently. To do.

The present invention has been made in view of such a situation, and an electric motor mounted when a vehicle having many opportunities to travel on an uphill or an uneven road surface such as an off-road vehicle for disaster prevention is constituted by an electric vehicle. An object of the present invention is to avoid an unnecessary increase in the total output capacity of the motor. In addition, the present invention solves the problem of sufficiently securing the minimum ground clearance required for off-road driving when a vehicle with many opportunities for off-road driving, such as an off-road vehicle for disaster prevention, is configured with an electric vehicle. It is to be an issue.

Therefore, the first invention is
In an electric vehicle drive device in which all wheels are driven as drive wheels according to the operation of the electric motor,
An electric motor for the front drive wheel;
An electric motor for the left rear drive wheel;
An electric motor for the right rear drive wheel;
An electric motor for the front drive wheel and a differential gear interposed between the front drive wheel and transmitting the driving force from the front drive wheel electric motor to the front drive wheel;
The output capacity of each electric motor is such that the total output capacity of the left rear drive wheel electric motor and the right rear drive wheel electric motor is equal to or greater than the output capacity of the front drive wheel electric motor. Is defined.

The second invention is the first invention,
The output capacity of each electric motor is determined so that the front drive wheel electric motor, the left rear drive wheel electric motor, and the right rear drive wheel electric motor have the same or substantially the same output capacity. It is characterized by.

The third invention is the first invention,
At least one of the front drive wheel electric motor, the left rear drive wheel electric motor, and the right rear drive wheel electric motor includes a plurality of electric motors,
The plurality of electric motors are arranged such that the minimum ground clearance of the plurality of electric motors is larger than the minimum ground clearance when a single electric motor having the same output capacity is arranged.

The fourth invention is
In an electric vehicle drive device in which all wheels are driven as drive wheels according to the operation of the electric motor,
Each drive wheel is configured to be driven by a plurality of electric motors,
The plurality of electric motors are arranged such that the minimum ground clearance of the plurality of electric motors is larger than the minimum ground clearance when a single electric motor having the same output capacity is arranged.

In the first invention, as shown in FIG. 3, an electric vehicle 100 is an all-wheel drive vehicle in which all wheels 1, 2, 3, 4 are driven as drive wheels in accordance with the operation of the electric motors 61, 62, 63. Consists of.

The electric motors 61, 62, and 63 include a front drive wheel electric motor 61, a left rear drive wheel electric motor 62, and a right rear drive wheel electric motor 63.

Between the front drive wheel electric motor 61 and the front drive wheels 1 and 2, the front drive wheel electric motor 61 is provided.
A differential gear 102G for transmitting the driving force to the front drive wheels 1 and 2 is interposed.

The total output capacity PrL + PrR of the output capacity PrL of the left rear drive wheel electric motor 62 and the output capacity PrR of the right rear drive wheel electric motor 63 is equal to or greater than the output capacity Pf of the front drive wheel electric motor 61. The output capacity of each electric motor 61, 62, 63 is determined.

In the following, as an example, the engine has a 120 kW engine as described above, and the output capacity of 40 kW is equivalent to the electric motors 61 and 63 corresponding to the rear wheels. Assume an electric vehicle 100 that requires an output capacity of 80 kW.

According to the first aspect of the invention, the differential gear that transmits the driving force from the front drive wheel electric motor 61 to the front drive wheels 1 and 2 between the front drive wheel electric motor 61 and the front drive wheels 1 and 2. 10
Since 2G is provided, when the front wheels 1 and 2 try to get over the road surface unevenness, the ground pressure and load are not instantaneously affected by the left wheel 1 and the right wheel 2 of the front wheels 1 and 2. Evenly, even if the wheel 1 on one side of the front wheels 1 and 2 is lifted, the electric motor 61 for the front drive wheels
To the other wheel 2 via the differential gear 102G, the driving force (driving force for the total of the left and right wheels 1 and 2) 40 kW can be transmitted.

Even if one of the left and right wheels 1 and 2 connected via the differential gear 102G is lifted, a method for preventing idling of the wheel is disclosed in “Traction Control Technology” by “Japanese Examined Patent Publication No. 39-9603”. It has been known for a long time as “tire idling prevention technology”. Further, in order to prevent this slipping, a brake that brakes the left and right tires individually is required, but the structure and control method thereof are well known to those skilled in the art, and are not shown in the present description and will not be described.

For this reason, as in a conventional “four-wheel independent drive type” type electric vehicle, the electric motor of the drive wheel 2 on one side that is grounded is used and the output is as large as twice the average output of the left and right drive wheels 1 and 2. Capacity (40 kW) is not required. Thus, the electric motor 61 for both front wheels is
An output capacity of 40 kW is sufficient. Unlike a conventional “four-wheel independent drive type” type electric vehicle, only an electric motor on one side of the front wheel electric motor does not require an output capacity of 40 kW for the total front wheels. As a result, the problem that the total output capacity of the electric motor becomes unnecessarily large can be avoided.

According to the first aspect of the invention, the front drive wheel electric motor 61, the left rear drive wheel electric motor 62, and the right rear drive wheel electric motor 63 are provided, and the left rear drive wheel electric motor is provided. The total output capacity PrL + P of the output capacity PrL of the motor 62 and the output capacity PrR of the electric motor 63 for the right rear drive wheel.
Each of the electric motors 61, rR is equal to or greater than the output capacity Pf of the front drive wheel electric motor 61.
Since the output capacity of 62 and 63 is determined, when climbing a flat uphill,
When traveling with the ground load of the rear wheels 3 and 4 being larger than the ground load of the front wheels 1 and 2,
The driving force applied from the electric motors 62, 63 to the rear wheels 3, 4 is changed from the electric motor 61 to the front wheels 1,
2 does not fall below the driving force applied. For example, 40 kW (40% or less) for front wheels 1 and 2
The above driving force can be transmitted, and 80 kW (60% or more) can be transmitted to the rear wheels 3 and 4. As a result, it is possible to avoid a situation in which the driving force of the rear wheels 3 and 4 is insufficient and climbing is difficult.

In the second invention, the front drive wheel electric motor 61, the left rear drive wheel electric motor 62, and the right rear drive wheel electric motor 63 have the same or substantially the same output capacity.
The output capacities Pf, PrL, PrR of 1, 62, 63 are determined.

When climbing a steep slope, the driving force of the rear wheels 3 and 4 exceeds 60% of the driving force of the entire vehicle,
That is, for example, it is not rare that a driving force that is 2/3 of the driving force of the entire vehicle is required. According to the present invention, for example, assuming that the engine output is 120 kW, the electric motor 61 having the output capacity Pf corresponding to 1/3 of the entire drive from the electric motor 61 to the front wheels 1 and 2 corresponds to 1/3 of the drive. A force of 40 kW (about 33%) is transmitted, while the rear wheels 3 and 4 are 2/3 of the total.
Is transmitted from each of the electric motors 62 and 63 having an output capacity PrL + PrR equivalent to 2/3 of the driving capacity 80 kW (about 66%). As a result, it is possible to avoid a situation where climbing is difficult due to insufficient driving force of the rear wheels 3 and 4 when climbing a steep slope.

In addition, according to the second invention, the output capacities Pf, PrL,
Since PrR is the same or substantially the same, a plurality of electric motors 61 mounted on the vehicle 100,
It becomes possible to share the part model numbers 62 and 63, and the cost of the vehicle 100 can be reduced.

In the third aspect of the invention, as shown in FIG. 4, FIG. 5 or FIG.
1, at least one of the left rear drive wheel electric motor 62 and the right rear drive wheel electric motor 63 includes a plurality of electric motors 60 </ b> A and 60 </ b> B. Then, as shown in FIG. 2C, the lowest ground height L of the plurality of electric motors 60A and 60B is the lowest ground when the single electric motor 60 having the same output capacity is arranged (FIG. 2B). A plurality of electric motors 60A and 60B are arranged so as to be larger than the height L ′.

That is, the size (for example, diameter) of the electric motors 60 </ b> A and 60 </ b> B is smaller than the size (for example, diameter) of the single electric motor 60. For this reason, the differential gear case 1
The housing 60C including the electric motors 60A and 60B is smaller than 02.

As described above, since the diameter d (FIG. 5) or the thickness t (FIG. 6) of the plurality of electric motors 60A and 60B can be reduced, a housing 60C including the plurality of electric motors 60A and 60B is provided. They can be arranged without projecting greatly on the floor of the vehicle body or protruding from the floor of the vehicle body. For this reason, it is possible to secure a large minimum ground clearance L while securing a large amount of equipment and cabin space.

Moreover, according to the third aspect of the invention, since each electric motor 61, 62, 63 is further divided into a plurality of electric motors 60A, 60B, the output capacities of the individual electric motors 60A, 60B can be further reduced and shared. Can be achieved. That is, for example, each electric motor 61, 62,
If each 63 is divided into two electric motors 60A and 60B, each electric motor 60
The output capacities of A and 60B are the output capacities Pf, PrL of the front drive wheel electric motors 61, 62, 63, respectively.
The output capacity is 20 kW, which is ½ of Pr R (for example, 40 kW), and the individual electric motors can be reduced, and the same standard product can be used. As a result, it becomes possible to reduce the size and share the plurality of electric motors mounted on the electric vehicle 100, and the electric vehicle 1.
The cost of 00 can be greatly reduced.

The fourth invention is not limited to the vehicle 100 having the configuration of the first invention illustrated in FIG. 3 (see FIG. 14A), as illustrated in FIGS. 14B, 14C, and 14D. The present invention can also be applied to general electric vehicles including a conventional “four-wheel independent drive type” type electric vehicle (FIG. 14B). That is, the fourth invention can be applied to the electric vehicle 100 in which all the wheels 1, 2, 3, 4 (or wheels 1 to 6) are driven as drive wheels according to the operation of the electric motors 60A and 60B. .

The vehicle 100 of the fourth aspect of the invention is configured such that each drive wheel 1, 2, 3, 4 (or each drive wheel 1-6) is driven by a plurality of electric motors 60A, 60B.

And similarly to the third invention, the minimum ground height L of the plurality of electric motors 60A, 60B is larger than the minimum ground height L ′ when the single electric motor 60 having the same output capacity is arranged. A plurality of electric motors 60A and 60B are arranged.

According to the fourth invention, not only the vehicle 100 having the configuration of the first invention illustrated in FIG. 3 (FIG. 14).
As shown in FIGS. 14B, 14C, and 14D, an electric vehicle including a conventional “4-wheel independent drive type” type electric vehicle (FIG. 14B). In general, the above-described effects of the third invention can be obtained. In other words, the minimum ground clearance L can be secured while securing a large amount of equipment and cabin space, and a plurality of electric motors mounted on the vehicle 100 can be reduced in size and shared. The cost can be greatly reduced. The fourth invention can be applied not only to multi-axle vehicles such as six wheels, eight wheels, and ten wheels having four or more wheels, but also to an electric trailer including a tire driven by a motor.

BEST MODE FOR CARRYING OUT THE INVENTION

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an electric vehicle driving apparatus according to the present invention will be described with reference to the drawings.

FIG. 3 is a top view showing the positional relationship between the vehicle body 101 and each component of the electric vehicle 100 according to the embodiment. In addition, in an Example, the off-road vehicle for disaster prevention comprised as a series hybrid electric vehicle as the electric vehicle 100 is assumed.

As shown in FIG. 3, an electric vehicle 100 is an all-wheel drive (four-wheel drive) vehicle in which all wheels 1, 2, 3, 4 are driven as drive wheels in accordance with the operation of electric motors 61, 62, 63. It is. The left front drive wheel 1 is provided on the front left side of the vehicle body 101 of the electric vehicle 100, the right front drive wheel 2 is provided on the front right side of the vehicle body 101, and the left rear drive is provided on the rear left side of the vehicle body 101. A ring 3 is provided,
A right rear drive wheel 4 is provided on the rear right side of the vehicle body 101.

The electric motors 61, 62, and 63 include a front drive wheel electric motor 61, a left rear drive wheel electric motor 62, and a right rear drive wheel electric motor 63.

Between the front drive wheel electric motor 61 and the front drive wheels 1 and 2, the front drive wheel electric motor 61 is provided.
A differential gear 102G for transmitting the driving force to the front drive wheels 1 and 2 is interposed. The differential gear 102G includes a differential gear case 10
2 is housed.

The front drive wheel electric motor 61 is housed in a housing 60C. FIG. 4 is a plan view showing the structure of the housing 60C, and FIG. 5 is a perspective view showing the structure of the housing 60C.

The front drive wheel electric motor 61 includes two electric motors 60A and 60B. The rotary shafts 60F of the two electric motors 60A and 60B are coupled by a gear 60D. Gear 60
An output shaft 60E is connected to D. Two electric motors 60A, 60 from the output shaft 60E
An output obtained by combining the outputs of B, that is, an output of the front drive wheel electric motor 61 is taken out. A cooling device or the like for cooling the electric motors 60A and 60B may be incorporated in the housing 60C.

As shown in FIG. 5, the electric motors 60A and 60B are elongated in the direction of the rotation shaft 60F and have a diameter d.
This is a small “horizontal” motor. The “horizontal” electric motor has a small output torque because the moment arm of the rotor is short, but the rotational speed at which the rotor may be disassembled by the centrifugal force of the rotor becomes high and the relatively high maximum speed is increased. It can be set. For this reason, the output characteristics of the “horizontal” electric motor are of the “high rotation speed, low torque” type.

As shown in FIG. 5, the electric motors 60 </ b> A and 60 </ b> B have a rotating shaft 60 </ b> F whose floor surface 105 is a vehicle body.
It arrange | positions so that it may become parallel with respect to.

As shown in FIG. 3, the electric motors 60A and 60B constituting the front drive wheel electric motor 61 are:
It is connected to the input shaft of the speed reducer 103 via the output shaft 60E. The output shaft of the speed reducer 103 is connected to the input shaft to the differential gear 102G. Differential gear 1
The left and right output shafts of 02G are connected to the input shafts of the left and right final gears 107L and 107R, respectively. The output shafts of the final gears 107L and 107R are connected to the left front drive wheel 1 and the right front drive wheel 2, respectively.

In this embodiment, the “horizontal” electric motors 60A and 60B having a small diameter d are connected to the rotary shaft 60F.
Are arranged so as to be parallel to the floor surface 105 of the vehicle body, the electric motors 60A, 6
The size (diameter size) of the housing 60C including 0B can be made smaller than the size (diameter) when the front drive wheel electric motor 61 is configured by a single electric motor 60. Accordingly, the housing 60C including the electric motors 60A and 60B is smaller than the differential gear case 102. For this reason, as shown in FIG. 2C, two electric motors 60 are provided.
The minimum ground height L of the casing 60C including A and 60B is larger than the minimum ground height L ′ when the single electric motor 60 having the same output capacity is arranged (FIG. 2B).

Since the diameter d (FIG. 5) of the two electric motors 60A and 60B can be reduced in this way, the casing 60C including the two electric motors 60A and 60B is protruded greatly on the floor of the vehicle body or from below the floor of the vehicle body. Arrangement can be made without projecting large. For this reason, it is possible to secure a large minimum ground clearance L while securing a large amount of equipment and cabin space.

The electric motors 60A and 60B constituting the front drive wheel electric motor 61 may be “vertical” electric motors.

FIG. 6 is a perspective view showing a structure of a housing 60C when the electric motors 60A and 60B are “vertical” electric motors.

The “vertical” electric motor is flat in the direction of the rotation shaft 60F, has a large diameter d, and instead has a small thickness t. The “vertical” electric motor has a large output torque due to the long moment arm of the rotor, but the maximum rotational speed is often set low to avoid the risk of the rotor being disassembled by the centrifugal force associated with the rotation of the rotor. . For this reason, the output characteristic of the “vertical” electric motor is the “high torque, low rotational speed” type.

As shown in FIG. 6, the electric motors 60 </ b> A and 60 </ b> B are arranged such that the rotation shaft 60 </ b> F is perpendicular to the floor surface 105 of the vehicle body.

Therefore, the output shaft 60E is perpendicular to the floor surface 105 of the vehicle body, unlike the configuration of FIG.

Therefore, an output shaft direction conversion gear 106 that converts the output shaft 60E in a direction parallel to the floor surface 105 of the vehicle body is provided.

The electric motors 60 </ b> A and 60 </ b> B constituting the front drive wheel electric motor 61 are connected to the input shaft of the speed reducer 103 via the output shaft 60 </ b> E and the output shaft direction conversion gear 106. The configuration subsequent to the reduction gear 103 is the same as the configuration of the “horizontal” electric motor.

In this way, the “vertical” electric motors 60A and 60B having a small thickness t are arranged so that the rotation shaft 60F is perpendicular to the floor surface 105 of the vehicle body.
The size (thickness in the thickness direction) of the housing 60C including B may be smaller than the size (thickness) when the front drive wheel electric motor 61 is configured by a single electric motor 60. Can, as well,
The housing 60C including the plurality of electric motors 60A and 60B can be arranged without greatly projecting on the floor of the vehicle body or protruding from the floor of the vehicle body. For this reason, it is possible to secure a large minimum ground clearance L while securing a large amount of equipment and cabin space.

The left rear drive wheel electric motor 62 is housed in the housing 60C. The left rear drive wheel electric motor 62 includes two electric motors 60A and 60B. Such an electric motor 6 for the left rear drive wheel
The relationship between the electric motors 60A and 60B constituting the vehicle 2 and the vehicle body is the same as described with reference to FIG. 5, FIG. 6, and FIG.

The electric motor 62 for the left rear drive wheel is connected to the input shaft of the final gear 104L via the output shaft 60E. The output shaft of the final gear 104L is connected to the left rear drive wheel 3.

Similarly, the right rear drive wheel electric motor 63 is housed in the housing 60C. The right rear drive wheel electric motor 63 includes two electric motors 60A and 60B. The relationship between the electric motors 60A and 60B constituting the electric motor 63 for the right rear drive wheel and the vehicle body is shown in FIGS. 5, 6, and 2 (c).
This is the same as described with reference to FIG.

The electric motor 63 for the right rear drive wheel is connected to the input shaft of the final gear 104R via the output shaft 60E. The output shaft of the final gear 104R is connected to the right rear drive wheel 4.

The total output capacity PrL + PrR of the output capacity PrL of the left rear drive wheel electric motor 62 and the output capacity PrR of the right rear drive wheel electric motor 63 is equal to or greater than the output capacity Pf of the front drive wheel electric motor 61. The output capacity of each electric motor 61, 62, 63 is determined.

In this case, the output capacities Pf, PrL, PrR of the electric motors 61, 62, 63 can be the same or substantially the same.

For example, assuming that the maximum output of the engine 10 is 120 kW, an output capacity (Pf) of 40 kW corresponding to 1/3 thereof is assigned to the electric motor 61 for the front drive wheels, and 2/3 thereof.
80 kW output capacity (PrL + PrR) is assigned to the left rear drive wheel electric motor 62 and the right rear drive wheel electric motor 63. Thus, the output capacity PrL obtained by adding the output capacity PrL of the left rear drive wheel electric motor 62 and the output capacity PrR of the right rear drive wheel electric motor 63 to each other.
+ PrR can be made equal to or larger than the output capacity Pf of the front drive wheel electric motor 61. At this time, the output capacities Pf, PrL, PrR of the electric motors 61, 62, 63 have the same output capacity of 40 kW.

In the present embodiment, each of the electric motors 61, 62, 63 has two electric motors 60A,
The output capacities of the individual electric motors 60A and 60B are set to be the same.

The electric motors 61, 62, 63 are divided into two electric motors 60A, 60B, and the output capacities of the individual electric motors 60A, 60B are changed to the output capacities Pf, PrL,
By setting the output capacity to 20 kW that is ½ of PrR (for example, 40 kW), it becomes possible to reduce the size and share the plurality of electric motors mounted on the electric vehicle 100, and to reduce the cost of the electric vehicle 100. It can be greatly reduced.

FIG. 7 shows a device configuration of the drive control device when the electric vehicle 100 is configured as a series hybrid electric vehicle.

The electric vehicle 100 includes a generator 50, an electric cable 21, a power generation inverter 22, a storage capacitor 23, a drive power system bus 24, in series with a power transmission mechanism 41 from the engine 10 through the speed increaser 20 to the power generator 50. Front wheel drive inverter 25, left rear wheel drive inverter 26, right rear wheel drive inverter 27, electric cables 28, 29, and 30, an electric motor 61 for front drive wheels,
A power supply system 71 including an electric motor 62 for the left rear drive wheel and an electric motor 63 for the right rear drive wheel is provided.

The accelerator pedal 31 is provided in the cab of the electric vehicle 100, and the stepping operation amount Y (mm) changes according to the stepping operation. A signal indicating the depression operation amount Y (mm) of the accelerator pedal 31 is input to the control device 32.

The control device 32 includes an engine controller 33, a power generation inverter 22, a storage capacitor 2
3. Input / output of signals between the front wheel drive inverter 25, the left rear wheel drive inverter 26, and the right front wheel drive inverter 27, and a power generation inverter 22, a storage capacitor 23, a front wheel drive inverter 25, a left rear wheel drive inverter 26, The right front wheel drive inverter 27 is controlled.

The engine controller 33 inputs and outputs signals to and from the control device 32, and the engine 1
Control the number of rotations of zero.
An output shaft of the engine 10 is connected to the speed increaser 20. The output shaft of the speed increaser 20 is connected to the generator 50. The generator 50 is connected to the power generation inverter 22 via the electric cable 21.
Is electrically connected.

The power generation inverter 22, the storage capacitor 23, the front wheel drive inverter 25, the left rear wheel drive inverter 26, and the right front wheel drive inverter 27 are electrically connected by a drive power system bus 24.

The front wheel drive inverter 25 is electrically connected to the front drive wheel electric motor 61 via an electric cable 28, and the left rear wheel drive inverter 26 is electrically connected to the left rear wheel drive electric motor 62 via an electric cable 29. The right rear wheel drive inverter 27 is connected to the electric cable 3
0 is electrically connected to the right rear drive wheel electric motor 63.

The rotational speed of the engine 10 is increased to an optimal rotational speed by the speed increaser 20. The output of the engine 10 is transmitted to the generator 50 via the speed increaser 20.

In the generator 50, the output of the engine 10 is converted into electric power by the power generation action. The generated electric power is supplied from the generator 50 to the power generation inverter 22 via the electric cable 21. The AC power generated by the generator 50 is converted into DC power by the power generation inverter 22. DC power is supplied from the power generation inverter 22 to the drive power system bus 24.

The control device 32 gives a command to the engine controller 33 so that the engine 10 has a rotation speed at which the maximum output can be obtained while the electric vehicle 100 is in steady running. As a result, while the electric vehicle 100 is in steady running, the engine speed is constant regardless of the running load.

The generator 50 rotates at a constant rotation speed, but the output voltage may vary depending on the load current. Therefore, the control device 32 controls the power generation inverter 22 so that the output DC voltage value becomes constant. As a result, a substantially constant DC voltage is supplied from the power generation inverter 22 to the drive power system bus 24.

The storage capacitor 23 includes a high-speed response type high-voltage, large-capacity capacitor.

The voltage value of the drive power system bus 24 is equal to the output voltage value of the storage capacitor 23.
When the output voltage of the storage capacitor 23 falls below a specified value, the control device 32 increases the power generation amount of the generator 50 and returns the output voltage of the storage capacitor 23 to the specified value with respect to the power generation inverter 22. , Command. As a result, the power generation inverter 22 causes the generator 50 to perform a power generation operation to increase the amount of power generation, and return the output voltage of the storage capacitor 23 to the specified value. Conversely, when the output voltage of the storage capacitor 23 rises above a specified value, the control device 32 pauses the power generation amount of the generator 50 with respect to the power generation inverter 22 and sets the output voltage of the storage capacitor 23 to the specified value. To return to. As a result, the power generation inverter 22 stops the power generation operation of the power generator 50 and returns the output voltage of the storage capacitor 23 to the specified value.

Assuming that the output voltage of the storage capacitor 23 continues to rise toward an allowable upper limit voltage,
When the warning value is exceeded, the control device 32 instructs the power generation inverter 22 to electrically actuate the generator 50 to accelerate the engine 10, and at the same time, the engine controller 3
3 so that the engine 10 does not accelerate. As a result, the engine brake is applied to the engine 10 and functions to obstruct the rotation of the generator 50. This avoids overcharging of the storage capacitor 23 and prevents the storage capacitor 23 from being damaged by overvoltage.

FIG. 8 shows the relationship between the horizontal axis as the rotational speed ωx of the output shaft of “virtual transfer” to be described later and the vertical axis as the torque Tx of the output shaft of “virtual transfer”. It is a diagram and shows the curve TL of the characteristic that becomes equal horsepower.

In FIG. 8, TL100 is a torque line indicating a rated torque (100% torque) that can be output for each rotation speed ωx, and TL50 is the rated torque (100%) for each rotation speed ωx.
(Torque) is a torque line showing a torque corresponding to 50%. Similarly, it is assumed that a torque line TLz corresponding to each Z% torque is set in advance.

The control device 32 controls the front wheel drive inverter 25, the left rear wheel drive inverter 26, and the right rear wheel drive inverter 27 so that a torque of Z% proportional to the operation amount Y of the accelerator pedal 31 is generated. Control is performed so that the sum of the torques generated by the front drive wheel electric motor 61, the left rear drive wheel electric motor 62, and the right rear drive wheel electric motor 63 becomes Z%. However, as described above, during steady running of the electric vehicle 100, the accelerator pedal 31 is used.
Even if the stepping operation amount Y changes, the rotation speed of the engine 10 is controlled so that the power demand is properly managed.

Next, a method for controlling the front drive wheel electric motor 61, the left rear drive wheel electric motor 62, and the right rear drive wheel electric motor 63 will be described.

The electric vehicle 100 is not provided with an electric motor, and needs to be accelerated according to the depression operation of the accelerator pedal 31, like a non-electric vehicle in which wheels are driven from an engine via a transmission.

Therefore, in controlling the front drive wheel electric motor 61, the left rear drive wheel electric motor 62, and the right rear drive wheel electric motor 63, the non-electric vehicle 200 shown in FIG. Consider controlling the torque Tx transmitted to the output shaft 203 and the rotational speed ωx of the output shaft of the virtual transfer 203. In the following description, for convenience of explanation, it is assumed that the efficiency of each part of the vehicle is 100% and the gear ratios are all 1.

FIG. 9 shows a configuration example of the non-electric vehicle 200. The non-electric vehicle 200 includes the engine 10
The torque generated by the torque converter 201, transmission (for example, continuously variable transmission)
The vehicle is configured to be transmitted to the transfer 203 via 202 and take out the torque Tx from the transfer 203 and to rotate the output shaft of the transfer 203 at the rotational speed ωx. The output shaft of the transfer 203 is connected to the front drive shaft 204F and the rear drive shaft 204R. The front drive shaft 204F and the rear drive shaft 204R rotate at the same rotational speed ωx. The torque Tx of the output shaft of the transfer 203 is distributed to the front drive shaft 204F and the rear drive shaft 204R as torque Tf and torque Tr (Tx = Tf + Tr).

The torque Tf of the front drive shaft 204F is equal to the front differential gear 205F.
Is transmitted to the front left and right wheels 1 and 2.

Further, the torque Tr of the rear drive shaft 204R is determined by the rear differential gear 2
05R is transmitted to the left and right wheels 3 and 4 via the left and right constant velocity joints 206L and 206R. The torque Tr of the rear drive shaft 204R is determined by the rear differential gear 2
05R distributes torque TrL and torque TrR to the left and right constant velocity joints 206L and 206R, respectively (Tr = TrL + TrR). The left and right constant velocity joints 206L,
206R rotates at the rotational speeds ωrL and ωrR, respectively. The rotational speeds ωrL and ωrR are based on the electric vehicle 10
This corresponds to the rotational speeds of the output shafts 60E of the left rear drive wheel electric motor 62 and the right rear drive wheel electric motor 63 of zero.

Front drive wheel electric motor 61, left rear drive wheel electric motor 62, right rear drive wheel electric motor 6
For example, 3 is controlled as follows.

The rotation speed ωf of the output rotation shaft 60E of the front drive wheel electric motor 61 is assumed to be proportional to the rotation speed ωx of the input shaft 204F of the front differential gear 205F of the non-electric vehicle 200 (control model). The speed control.

The output torque TrL ′ of the output rotating shaft 60E of the left rear drive wheel electric motor 62 is the non-electric vehicle 2
The electric motor 62 is torque controlled on the assumption that it is proportional to the torque TrL of the left constant velocity joint 206L of 00 (control model).

The output torque TrR ′ of the output rotating shaft 60E of the electric motor 63 for the right rear drive wheel is the non-electric vehicle 2
The electric motor 63 is torque controlled assuming that it is proportional to the torque TrR of the right constant velocity joint 206R of 00 (control model).

    As described above, the following relationship is established in the non-electric vehicle 200 of the control model.

Tx = Tf + Tr (1)
Tr = TrL + TrR (2)
TrL = TrR (3)
Further, in the electric vehicle 100 of the embodiment, there is no differential gear on the rear wheel side,
In the non-electric vehicle 200 of the control model, a differential gear 205R exists on the rear wheel side. Assuming that the efficiency of the rear differential gear 205R is 100% and the gear ratio is 1, the rotational speed ωx of the input shaft (rear drive shaft 204R) of the rear differential gear 205R and the output shaft (left and right constant velocity joints 206L). , 206R) at the rotational speeds ωrL, ωr
The following relationship is established with R.

ωx = (ωrL + ωrR) / 2 (4)
Hereinafter, the control processing procedure will be described with reference to the flowchart shown in FIG. Below,
It is assumed that each component of the non-electric vehicle 200 (control model) is treated as “virtual” and the electric vehicle 100 is controlled.

In FIG. 10, step 301 reads the initial value, and steps 302 and 303
Calculation processing of command value of torque Tx on output shaft of “virtual transfer”, step 3
04 to 306 are rotation speed control processing of the rotation speed ωf of the output rotation shaft 60E of the front drive wheel electric motor 61, and steps 307 to 309 are output torque TrL of the output rotation shaft 60E of the left rear drive wheel electric motor 62. 'And the output torque T of the output rotating shaft 60E of the right rear drive wheel electric motor 63
This corresponds to rR ′ torque control processing.

(Read initial value)
In the initial state, since electric vehicle 100 is stopped, rotation speed ωx of the output shaft of virtual transfer 203 is 0 (step 301). After such an initial state, steps 301 to 301 are performed.
Each time the control loop consisting of 309 makes a round, the current virtual transfer 20 is calculated.
3 is obtained (step 309).

(Calculation processing of command value of torque Tx on output shaft of “virtual transfer”)
Next, the depression operation amount Y of the accelerator pedal 31 is measured and input to the control device 32 (step 302).

Next, by using the torque diagram shown in FIG.
Is selected, and an output torque value Tx corresponding to the current output shaft rotational speed ωx of the virtual transfer 203 is calculated on the torque line TLz (step 303).

(Rotation speed control processing of the rotation speed ωf of the output rotation shaft 60E of the front drive wheel electric motor 61)
Next, the control device 32 rotates the output rotation shaft 60E of the front drive wheel electric motor 61 at the target rotation speed ωf corresponding to the current output shaft rotation speed ωx of the virtual transfer 203.
The front wheel drive inverter 25 is controlled. The output shaft rotational speed ω of the current virtual transfer 203
Conversion from x to the rotational speed ωf of the output rotating shaft 60E of the front drive wheel electric motor 61 is performed in consideration of the gear ratio of each part (step 304).

Next, the torque of the output rotating shaft 60E of the front drive wheel electric motor 61 is measured (step 305). In addition, when the estimated value of the motor torque is used for calculation of control inside the inverter that drives each electric motor, this estimated torque value can be used as the measured torque value.

Next, the measured torque value of the output rotation shaft 60E of the front drive wheel electric motor 61 is converted into a virtual torque Tf of the front drive shaft 204F. Conversion from the torque of the output rotating shaft 60E of the front drive wheel electric motor 61 to the virtual torque Tf of the front drive shaft 204F is performed in consideration of the gear ratio of each part (step 306).

(Torque control processing of the output torque TrL ′ of the output rotation shaft 60E of the left rear drive wheel electric motor 62 and the output torque TrR ′ of the output rotation shaft 60E of the right rear drive wheel electric motor 63)
Next, the control device 32 determines the current virtual transfer 2 calculated in step 303.
Based on the output torque value Tx corresponding to the output shaft rotational speed ωx of 03 and the torque Tf of the virtual front drive shaft 204F calculated in step 306, the above equation (1) (Tx =
From Tf + Tr), the torque Tr (= Tx−Tf) of the virtual rear drive shaft 204R
Ask for. Here, from the above equation (2) (Tr = TrL + TrR) and (3) equation (TrL = TrR),
Since TrL = Tr = Tr / 2, the torque TrL and torque TrR to be applied to the left and right constant velocity joints 206L and 206R are obtained using the torque Tr obtained as described above. Next, the control device 32 drives the left rear wheel so that the output rotation shaft 60E of the left rear drive wheel electric motor 62 rotates at the target torque TrL ′ corresponding to the current torque TrL of the left constant velocity joint 206L. The inverter 26 is controlled. Similarly, the current right constant velocity joint 206R
The right rear wheel drive inverter 27 is controlled so that the output rotation shaft 60E of the right rear drive wheel electric motor 63 rotates at a target torque TrR ′ corresponding to the torque TrR. Conversion from the torque TrL to the torque TrL ′ and the conversion from the torque TrR to the torque TrR ′ are performed in consideration of the gear ratio of each part. However, in this embodiment, regenerative braking is not applied to the rear wheels 3 and 4. For this reason, it is limited to TrL = Tr = Tr / 2 ≧ 0. When TrL = Tr = Tr / 2 <0, the left rear wheel drive inverter 26 and the right rear wheel drive inverter 27 are instructed to make the torques TrL ′ and TrR ′ zero (step 307).

Next, each output shaft 60E of the electric motor 62 for the left rear driving wheel and the electric motor 63 for the right rear driving wheel.
Are measured (step 308).

Next, based on the above equation (4) (ωx = (ωrL + ωrR) / 2), the rotational speeds ωrL and ωrR measured as described above are used for the current output shaft rotational speed ω of the virtual transfer 203.
x is calculated (step 309).

By the way, when the brake pedal is stepped on to brake the electric vehicle 100 and the brake is applied, the speed of the rear wheels 3 and 4 decreases, and the output shaft rotational speed ωx of the virtual transfer 203
The update value of decreases gradually. At this time, if the accelerator pedal 31 is not depressed, no driving torque or braking torque is generated in the rear wheels 3 and 4. In addition, since the front wheels 1 and 2 are controlled so as to obtain a speed ωf that is smaller than that in the previous control loop according to the updated and reduced rotational speed ωx, the electric vehicle 100 is decelerated sequentially. Go. However, depending on the state of motion of the electric vehicle 100, for example, when the vehicle is making a steady circular turn, the average rotational speed of the front wheels 1 and 2 may exceed the average rotational speed of the rear wheels 3 and 4. At this moment, the front wheel drive inverter 25 applies regenerative braking to forcibly decelerate the front drive wheel electric motor 61. Thereby, the kinetic energy of the electric vehicle 100 is converted into electric power,
As the voltage value of the drive power system bus 24 increases, power is stored in the storage capacitor 23. Such regenerative braking does not always occur when the brake is applied, but occurs accidentally depending on the situation. In addition, the amount of energy generated by regenerative braking is small and instantaneous. Therefore, the storage capacitor 23 has a high-speed response type high voltage,
As long as a large-capacity capacitor is used, no major problem occurs.

As described above, the front drive wheel electric motor 61 can be composed of the two electric motors 60A and 60B. Therefore, a configuration example in the case of controlling the rotational speed of the front drive wheel electric motor 61 composed of the two electric motors 60A and 60B will be described with reference to FIGS.

As shown in FIG. 11, one electric motor 60A is a master, and the other electric motor 60B.
The apparatus is configured such that master-slave control is performed with the slave as the slave.

That is, corresponding to each of the electric motors 60A and 60B, the front wheel drive inverter 25A,
25B is provided. A rotational speed command corresponding to the target rotational speed ωf is given to the plus (+) input side of the front wheel drive inverter 25A and the subtractor 34. On the other hand, the minus (−) of the subtractor 34.
On the input side, a value obtained by multiplying the estimated torque value of the front wheel drive inverter 25B by a coefficient K is added.

The output of the differentiator 34 is input to the front wheel drive inverter 25B as a speed command value. Thereby, when the load of the electric motor 60B becomes heavy, the speed command value input to the front wheel drive inverter 25B is compensated and the load is reduced.

FIG. 12 shows the relationship between the rotational speed and torque output of the electric motor 60A on the master side and the electric motor 60B on the slave side. The characteristics of the electric motor 60A on the master side are indicated by LNA, and the characteristics of the electric motor 60B on the slave side are indicated by LNB.

Since the rotation shafts 60F of the master-side electric motor 60A and the slave-side electric motor 60B are coupled by the gear 60D, they rotate at the same rotation speed, but the load (torque output) of the master-side electric motor 60A. Until the upper limit value is reached, the slave-side electric motor 60
Compared to B, the electric motor 60A on the master side bears a larger load (torque output). Also,
When the load (torque output) increases after the electric motor 60A on the master side reaches the upper limit value,
The load increase will be borne by the slave-side electric motor 60B (torque output) until the slave-side electric motor 60B reaches the upper limit. In this way
The rotational speed of the front drive wheel electric motor 61 including the two electric motors 60A and 60B can be easily controlled.

The left rear drive wheel electric motor 62 and the right rear drive wheel electric motor 63 can be constituted by two electric motors 60A and 60B, respectively. Therefore, FIG. 13 is used for a configuration example when torque control is performed on the left rear drive wheel electric motor 62 including two electric motors 60A and 60B and the right rear drive wheel electric motor 63 including two electric motors 60A and 60B. I will explain. Hereinafter, the left rear drive wheel electric motor 62 will be described as an example. Right rear drive wheel electric motor 63
The same can be configured.

As shown in FIG. 13, left rear wheel drive inverters 26A and 26B are provided corresponding to electric motors 60A and 60B, respectively.

A torque command corresponding to a torque TrL ′ / 2 that is ½ of the target torque TrL ′ is given to each of the left rear wheel drive inverters 26A and 26B. In this way, the two electric motors 60A,
Torque control of the left rear drive wheel electric motor 62 comprising 60B can be easily performed. Similarly, the torque control can be easily performed on the right rear drive wheel electric motor 63 including the two electric motors 60A and 60B.

As described above, in this embodiment, between the front drive wheel electric motor 61 and the front drive wheels 1 and 2,
A differential gear 102G that transmits a driving force from the front drive wheel electric motor 61 to the front drive wheels 1 and 2 is provided. For this reason, when trying to get over the road surface unevenness with the front wheels 1 and 2, the ground pressure and load are instantaneously nonuniform between the left wheel 1 and the right wheel 2 of the front wheels 1 and 2. Even if one of the wheels 1 is lifted, a differential (not shown) brake for traction control (or anti-slipping) described above is provided and operated, so that the differential from the electric motor 61 for the front drive wheels. A driving force (driving force corresponding to the total of the left and right wheels 1 and 2) 40 kW required to advance the vehicle body to the other wheel 2 can be transmitted via the gear 102G. For this reason, the conventional “4-wheel independent drive type”
As in the type of electric vehicle, only the electric motor of the drive wheel 2 on one side that is grounded does not require a large output capacity (40 kW) that is twice the average output of the left and right drive wheels 1 and 2. As described above, it is sufficient for the electric motor 61 to have an output capacity of 40 kW for both front wheels. As in the conventional “four-wheel independent drive type” type electric vehicle, the front wheel electric motor has only one side of the electric motor and does not require an output capacity of 40 kW for the total front wheel. As a result, the problem that the total output capacity of the electric motor becomes unnecessarily large can be avoided.

In this embodiment, the front drive wheel electric motor 61 and the left rear drive wheel electric motor 62 are also provided.
And an electric motor 63 for the right rear driving wheel, and an output capacity P of the electric motor 62 for the left rear driving wheel.
The total output capacity PrL + PrR of rL and the output capacity PrR of the right rear drive wheel electric motor 63 is:
Each of the electric motors 61, 62, so that the output capacity Pf of the front drive wheel electric motor 61 is greater than or equal to the output capacity Pf.
The output capacity of 63 is determined. For this reason, when climbing a flat uphill,
When traveling with the ground load of the rear wheels 3 and 4 being larger than the ground load of the front wheels 1 and 2,
The driving force applied from the electric motors 62, 63 to the rear wheels 3, 4 is changed from the electric motor 61 to the front wheels 1,
2 does not fall below the driving force applied. For example, 40 kW (40% or less) for front wheels 1 and 2
The above driving force can be transmitted, and 80 kW (60% or more) can be transmitted to the rear wheels 3 and 4. As a result, it is possible to avoid a situation in which the driving force of the rear wheels 3 and 4 is insufficient and climbing is difficult.

In this embodiment, the front drive wheel electric motor 61, the left rear drive wheel electric motor 62,
The output capacities Pf, PrL, and PrR of the electric motors 61, 62, and 63 are determined so that the right rear drive wheel electric motor 63 has the same or substantially the same output capacity (for example, 40 kW).

When climbing a steep slope, the driving force of the rear wheels 3 and 4 exceeds 60% of the driving force of the entire vehicle,
That is, it is not rare that a driving force that is 2/3 of the driving force of the entire vehicle is required. According to the present embodiment, for example, if the output of the engine is 120 kW, it corresponds to 1/3 of the whole from the electric motor 61 having the output capacity Pf corresponding to 1/3 of the whole to the front wheels 1 and 2. While the driving force of 40 kW (about 33%) is transmitted, the rear wheels 3 and 4 have the output capacity PrL + PrR corresponding to 2/3 of the entire electric motors 62 and 63 to 2/3 of the total. A driving force of 80 kW (about 66%) is transmitted. As a result, it is possible to avoid a situation where climbing is difficult due to insufficient driving force of the rear wheels 3 and 4 when climbing a steep slope.

Moreover, according to this embodiment, the output capacities Pf, PrL, P of the electric motors 61, 62, 63 are obtained.
Since rR is the same or substantially the same, a plurality of electric motors 61 mounted on the electric vehicle 100,
62 and 63 can be shared, and the cost of the electric vehicle 100 can be reduced.

In this embodiment, as shown in FIG. 4 or 5 or 6, at least one of the front drive wheel electric motor 61, the left rear drive wheel electric motor 62, and the right rear drive wheel electric motor 63 is used. One is composed of two electric motors 60A and 60B. And FIG. 2 (c)
As shown in FIG. 2, the minimum ground height L of the two electric motors 60A and 60B is larger than the minimum ground height L ′ when the single electric motor 60 having the same output capacity is disposed (FIG. 2B). like,
A plurality of electric motors 60A and 60B are arranged.

That is, the electric motors 60A and 60B (for example, the diameter) are smaller than the size (for example, the diameter) of the single electric motor 60. As a result, the differential gear case 10
The housing 60C including the electric motors 60A and 60B is smaller than 2.

As described above, since the size in the diameter d (FIG. 5) direction or the thickness t (FIG. 6) direction of the housing 60C including the plurality of electric motors 60A and 60B can be reduced, the plurality of electric motors. The casing 60C including 60A and 60B can be arranged without greatly projecting on the floor of the vehicle body or protruding from the floor of the vehicle body. For this reason, it is possible to secure a large minimum ground clearance L while securing a large amount of equipment and cabin space.

FIG. 14A shows an embodiment in which the electric motors 61, 62, 63 of the electric vehicle 100 having the configuration shown in FIG. 3 are further divided into two electric motors 60A, 60B, respectively.

According to the present embodiment, each of the electric motors 61, 62, 63 further includes two electric motors 60A, 6
Since it is divided into 0B, the output capacities of the individual electric motors 60A and 60B can be further reduced and can be shared.

Each of the electric motors 61, 62, 63 is further replaced with three or more electric motors 60A, 60B,.
It is also possible to divide into two.

Each electric motor 61, 62, 63 is divided into two electric motors 60A, 60B, and the output capacity of each electric motor 60A, 60B is changed to each electric motor 61, 62,
63 output capacity Pf, PrL, PrR (for example, 40 kW) 1/2 output capacity (20 kW)
Implementation is also possible. Thereby, while each electric motor 60A, 60B becomes small, the same standard product can be used. As a result, a plurality of electric motors mounted on the electric vehicle 100 can be reduced in size and shared, and the cost of the electric vehicle 100 can be significantly reduced.

Further, in this embodiment, as shown in FIG. 14A, each of the electric motors 61, 62, 63 of the electric vehicle 100 having the configuration shown in FIG. 3 is further divided into two electric motors 60A, 60B. However, as illustrated in FIGS. 14B, 14C, and 14D, the electric vehicle including the conventional “4-wheel independent drive type” type electric vehicle (FIG. 14B) is generally used. By applying, each electric motor can be divided into a plurality (for example, two).

14 (b), 14 (c), and 14 (d) show an all-wheel drive electric vehicle 100 in which all wheels are driven by an electric motor as drive wheels, as in FIG. 14 (a). .

FIG. 14 (b) shows four electric motors 61, 62 in which four drive wheels 1, 2, 3, 4 are independent.
The electric vehicle 100 of the “4-wheel independent drive type” type that is individually driven by the electric motors 63 and 64, and each electric motor 61, 62, 63, and 64 has two electric motors 60A and 60A, respectively.
It is divided into B. As described in FIGS. 2B and 2C, two electric motors 60A,
A plurality of electric motors 60A and 60B are arranged so that the minimum ground height L of 60B is larger than the minimum ground height L ′ when a single electric motor 60 having the same output capacity is arranged. .

FIG. 14C shows the differential gears 102Gf, 102 on the front side and the rear side of the vehicle body.
Gr is provided, and the output of the electric motor 61 is transmitted to the front drive wheels 1 and 2 via the differential gear 102Gf to drive the front drive wheels 1 and 2, and the output of the electric motor 62 is transmitted via the differential gear 102Gr. Are transmitted to the rear drive wheels 3 and 4 to be transmitted to the rear drive wheels 3 and 4.
In which the electric motors 61 and 62 are divided into two electric motors 60A and 60B, respectively. 2B and 2C, the two electric motors 60A and 60B have the lowest ground clearance L when the single electric motor 60 having the same output capacity is disposed. A plurality of electric motors 6 so as to be larger than the ground height L ′.
0A and 60B are arranged.

FIG. 14D shows an electric vehicle 100 configured as a connected vehicle including a tractor 100F and a trailer 100R. The tractor 100F includes a differential gear 102Gf, 1
02Gr is provided, and the output of the electric motor 61 is transmitted to the front drive wheels 1 and 2 via the differential gear 102Gf to drive the front drive wheels 1 and 2, and the output of the electric motor 62 is transmitted via the differential gear 102Gr. Then, the rear drive wheels 3 and 4 are driven by being transmitted to the rear drive wheels 3 and 4. On the other hand, the drive wheels 5 and 6 of the trailer 100R are individually driven by two independent electric motors 63 and 64. Each electric motor 61, 62, 63 is respectively
It is divided into two electric motors 60A and 60B. 2B and 2C, the two electric motors 60A and 60B have the lowest ground clearance L when the single electric motor 60 having the same output capacity is disposed. A plurality of electric motors 60A and 60B are arranged so as to be larger than the ground height L ′. Also, the left and right wheels 5, 6 of the trailer 100R
A differential gear may be provided between the two and the input shaft may be driven by one electric motor or an electric motor divided into two.

Therefore, the electric vehicle 100 illustrated in FIG. 14B, FIG. 14C, and FIG.
As with the electric vehicle 100 having the configuration illustrated in FIG. 5, the minimum ground clearance L can be ensured while ensuring a large amount of equipment and cabin space, and a plurality of electric motors mounted on the vehicle 100 can be downsized. Sharing can be achieved, and the effect that the cost of the vehicle 100 can be greatly reduced is obtained.

In each of the above embodiments, the description has been made on the assumption that the electric vehicle 100 is a series hybrid electric vehicle. However, the present invention is illustrated in FIGS. 1A, 1C, and 1D, respectively. The present invention can be similarly applied to such parallel hybrid electric vehicles, pure electric vehicles, and fuel cell electric vehicles.

FIGS. 1A, 1B, 1C, and 1D are diagrams schematically illustrating configuration examples of a parallel hybrid electric vehicle, a series hybrid electric vehicle, a pure electric vehicle, and a fuel cell electric vehicle, respectively. . FIGS. 2A, 2B, and 2C are diagrams for explaining the case of the differential gear disposed under the floor of the vehicle body and the size of the electric motor, respectively. FIG. 3 is a configuration diagram of the electric vehicle according to the embodiment. FIG. 4 is a plan view showing the structure of a housing incorporating two electric motors. FIG. 5 is a perspective view showing the structure of a housing incorporating two electric motors. FIG. 6 is a perspective view showing the structure of a housing incorporating two electric motors. FIG. 7 is a configuration diagram of a drive control device for an electric vehicle according to the embodiment. FIG. 8 is a torque diagram showing a characteristic curve for equal horsepower. FIG. 9 is a diagram showing a non-electric vehicle as a control model. FIG. 10 is a flowchart illustrating a control processing procedure. FIG. 11 is a diagram showing a configuration example in the case of controlling the rotational speed of two electric motors. FIG. 12 is a graph showing the characteristics of two electric motors. FIG. 13 is a diagram showing a configuration example when torque control is performed on two electric motors. FIGS. 14A, 14 </ b> B, 14 </ b> C, and 14 </ b> D are diagrams illustrating an electric vehicle having a configuration in which each drive wheel is driven by two electric motors.

Explanation of symbols

1, 2, 3, 4 Drive wheel, 100 electric vehicle, 102G differential gear, 1
0 engine, 61, 62, 63 electric motor, 32 control device

Claims (2)

In an electric vehicle drive device in which all wheels are driven as drive wheels according to the operation of the electric motor,
An electric motor for the front drive wheel, the electric motor for the front drive wheel driven by the energy generated in the engine, storage battery or fuel cell ;
An electric motor for the left rear drive wheel, the electric motor for the left rear drive wheel driven by the energy generated in the engine or the storage battery or the fuel cell without going through the electric motor of the front drive wheel;
An electric motor for the right rear drive wheel, the electric motor for the right rear drive wheel driven by the energy generated in the engine, the storage battery or the fuel cell without going through the electric motor of the front drive wheel;
An electric motor for the front drive wheel and a differential gear interposed between the front drive wheel and transmitting the driving force from the front drive wheel electric motor to the front drive wheel are provided,
The output capacity of each electric motor is determined so that the front drive wheel electric motor, the left rear drive wheel electric motor, and the right rear drive wheel electric motor have the same or substantially the same output capacity.
The output capacity of each electric motor is such that the total output capacity of the left rear drive wheel electric motor and the right rear drive wheel electric motor is equal to or greater than the output capacity of the front drive wheel electric motor. A drive device for an electric vehicle, characterized in that At least one of the front drive wheel electric motor, the left rear drive wheel electric motor, and the right rear drive wheel electric motor includes a plurality of electric motors,
The plurality of electric motors are arranged such that the minimum ground clearance of the plurality of electric motors is larger than the minimum ground clearance when a single electric motor having the same output capacity is arranged. The drive device of the described electric vehicle.

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