vehicle

Abstract

To provide, while suppressing increase in cost, a vehicle enabling regenerative brake force to function.SOLUTION: A vehicle includes: right and left wheels; a plurality of rotary electric machines for generating drive force or brake force with respect to the right and left wheels independently of others; and a power storage device for exchanging power with the plurality of rotary electric machines. Further, the vehicle includes a control device for executing control in a case that a charge amount of the power storage device is equal to or higher than a threshold, as well as, that the vehicle is in a driving state for charging, wherein the control is to increase a difference between torque distributed to the right and left wheels than in the case of not being in such driving state.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle. [Background technology]

[0002] Patent Document 1 discloses a technique for enabling a regenerative brake to function in a vehicle having an in-wheel motor, even when the battery has no remaining charge capacity, by consuming regenerative power in a shielding member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-112713 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technique disclosed in Patent Document 1 requires the provision of a separate shielding member, which leads to an increase in costs.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a vehicle that is capable of utilizing regenerative braking force while suppressing increases in costs. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the vehicle of the present invention is a vehicle comprising left and right drive wheels, a plurality of rotating electric machines that generate driving force or braking force for the left and right drive wheels independently of each other, and an electric storage device that exchanges power between the plurality of rotating electric machines, and is characterized in that the vehicle is equipped with a control device that performs control to increase the difference in torque distribution to the left and right drive wheels when the charge amount of the electric storage device is equal to or greater than a threshold value and the vehicle is in an operating state in which charging is possible, compared to when the vehicle is not in the operating state. Effect of the Invention

[0007] The vehicle of the present invention can increase the amount of loss in the multiple rotating electric machines by increasing the difference in torque distribution to the left and right drive wheels, and can reduce the amount of regeneration in the multiple rotating electric machines without providing a separate power consumption means, thereby achieving the effect of allowing the regenerative braking force to function while suppressing increases in costs. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a vehicle equipped with an in-wheel motor according to an embodiment. [Diagram 2] FIG. 2 is a flowchart showing an example of torque distribution setting control executed by the ECU. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a vehicle according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiment.

[0010] FIG. 1 is a diagram showing a schematic configuration of a vehicle 1 according to an embodiment.

[0011] As shown in FIG. 1, the vehicle 1 is equipped with a battery 4, an ECU (Electronic Control Unit) 5, an accelerator pedal opening sensor 6, a brake pedal sensor 7, a motor driver 8, a brake actuator 9, two in-wheel motors 10FL, 10FR which are braking / driving force generating mechanisms, temperature detection sensors 11FL, 11FR which detect the motor temperature, which is the temperature of the in-wheel motors 10FL, 10FR, four brake discs 13FL, 13FR, 13RL, 13RR and brake calipers 20FL, 20FR, 20RL, 20RR which constitute the brake mechanism, as well as four wheels 21, namely a left front wheel 21FL, a right front wheel 21FR, a left rear wheel 21RL and a right rear wheel 21RR.

[0012] In addition, when there is no particular distinction between the in-wheel motors 10FL, 10FR, they will be simply referred to as the in-wheel motor 10. In addition, when there is no particular distinction between the temperature detection sensors 11FL, 11FR, they will be simply referred to as the temperature detection sensor 11. In addition, when there is no particular distinction between the brake discs 13FL, 13FR, 13RL, 13RR, they will be simply referred to as the brake discs 13. In addition, when there is no particular distinction between the brake calipers 20FL, 20FR, 20RL, 20RR, they will be simply referred to as the brake calipers 20.

[0013] In-wheel motors 10FL, 10FR are provided inside the left front wheel 21FL and the right front wheel 21FR, which are the left and right driving wheels, respectively. The in-wheel motors 10FL, 10FR are rotating electric machines that generate driving force or braking force (hereinafter referred to as regenerative braking force) for the left front wheel 21FL and the right front wheel 21FR independently of the others. The in-wheel motors 10FL, 10FR are configured by, for example, a brushless motor, and are connected to a battery 4, which is an electricity storage device that exchanges power with the in-wheel motors 10FL, 10FR, via a motor driver 8. It is also possible to provide the in-wheel motor 10 inside each of the four wheels 21. The temperature detection sensors 11FL, 11FR detect the motor temperature, which is the temperature of the in-wheel motors 10FL, 10FR, and output it to the ECU 5.

[0014] Each part of the vehicle 1 is controlled by an ECU 5 serving as a control device. Physically, the ECU 5 is an electronic circuit mainly composed of a well-known microcomputer including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and an interface. The ECU 5 performs calculations using data input to the RAM and data previously stored in the ROM, etc., and outputs the calculation results as command signals. Each function of the ECU 5 is realized by loading a program held in the ROM into the RAM and executing it with the CPU, thereby operating various devices in the vehicle 1 under the control of the CPU, and reading data from the RAM and ROM serving as a recording unit and writing data to the RAM.

[0015] The accelerator pedal opening sensor 6 detects the opening of the accelerator pedal operated by the driver and outputs it to the ECU 5. The brake pedal sensor 7 detects the depression force of the brake pedal operated by the driver and outputs it to the ECU 5. The motor driver 8 is, for example, an inverter, which converts DC power supplied from the battery 4 into AC power and supplies the AC power to the in-wheel motors 10FL, 10FR. This causes the in-wheel motors 10FL, 10FR to be driven and controlled, and drive forces are applied to the left front wheel 21FL and the right front wheel 21FR. Note that the operation of supplying power to the in-wheel motors 10FL, 10FR to generate drive torque is called power running. The in-wheel motors 10FL, 10FR also function as generators, and can regenerate power generated by the rotational energy of the left front wheel 21FL and the right front wheel 21FR to the battery 4 via the motor driver 8. The braking torque generated by the power generation of the in-wheel motors 10FL, 10FR applies a regenerative braking force to the left front wheel 21FL and the right front wheel FR.

[0016] The brake mechanism, which is a friction braking mechanism, is configured by providing a brake disc 13 and a brake caliper 20 on each wheel 21. The brake mechanism can apply a friction braking force to the wheel 21. The brake caliper 20 constituting the brake mechanism is configured, for example, by a disc brake, and is connected to a brake actuator 9. The brake actuator 9 generates a friction braking force from the brake caliper 20 to the brake disc 13 by hydraulic pressure pumped from a master cylinder.

[0017] In the vehicle 1 of this embodiment, when the charge amount of the battery 4 is equal to or greater than a predetermined threshold and the driving state is such that charging is required, the ECU 5 performs torque distribution setting control to increase the difference in torque distribution to the left wheel 21FL and the right wheel 21FL compared to other cases, i.e., at least one of the cases where the charge amount of the battery 4 is less than the threshold or the driving state is such that there is no request for charging.

[0018] Table 1 shows the relationship between the torque distribution to the left and right wheels 21FL and 21FL and the total loss of the in-wheel motors 10FL and 10FR. Table 2 shows the relationship between the torque distribution to the left and right wheels 21FL and 21FL and the total output and regeneration amount of the in-wheel motors 10FL and 10FR.

[0019] [Table 1]

[0020] [Table 2]

[0021] In Tables 1 and 2, No. 1 is a case where the torque distribution between the left and right wheels 21FL and 21FL is equal, and the torque distribution ratio between the left and right wheels 21FL and 21FL is 50:50. In Tables 1 and 2, No. 2 is a case where the torque distribution between the left and right wheels 21FL and 21FL is different, and the torque distribution ratio between the left and right wheels 21FL and 21FL is 70:30. In Tables 1 and 2, No. 3 is a case where the torque distribution between the left and right wheels 21FL and 21FL is different, and the torque distribution ratio between the left and right wheels 21FL and 21FL is 80:20. In addition, if the torque distribution ratio between the left and right wheels 21FL and 21FL is 70:30, for example, if this distribution continues, the vehicle 1 will be more likely to turn right. Therefore, the torque distribution ratio of the left and right wheels 21FL and 21FL may be changed to alternate between 70:30 and 30:70 by inputting currents of opposite phases to the left and right in the in-wheel motors 10FL, 10FR in a sinusoidal or square wave shape.

[0022] Furthermore, the losses (left) and losses (right) in Table 1 are losses of in-wheel motors 10FL, 10FR, and can be calculated by the formula: Loss = Resistance x Current x Current. Furthermore, the motor output (left) and motor output (right) in Table 2 are outputs of in-wheel motors 10FL, 10FR, and can be calculated by the formula: Motor output = Motor rotation speed x Motor torque x (2π / 60).

[0023] In Tables 1 and 2, the motor rotation speed is set to 300 rpm, and the regenerative torque (vehicle braking force) does not change between when the torque distribution to the left wheel 21FL and the right wheel 21FL is equal (No. 1) and when there is a difference (No. 2 and No. 3), only the amount of regeneration (return amount) changes, and when there is a difference in torque distribution, the amount of regeneration (return amount) is less than when the torque distribution is equal.

[0024] In a case where two or more in-wheel motors 10FL, 10FR for driving are provided as in the vehicle 1 according to the embodiment, the amount of current of the in-wheel motors 10FL, 10FR is changed by differentiating the torque distribution between the left wheel 21FL and the right wheel 21FL. This makes it possible to increase the loss due to the relationship between the resistance and the current of the in-wheel motors 10FL, 10FR. As a result, the energy that would normally be returned during regeneration by the in-wheel motors 10FL, 10FR is reduced, and for example, even when the battery 4 is nearly fully charged, the braking force due to regeneration (regenerative braking) can be functioned.

[0025] FIG. 2 is a flowchart showing an example of torque distribution setting control executed by the ECU 5.

[0026] First, in step S1, the ECU 5 determines whether the battery 4 can be charged and the motor temperature is equal to or lower than the allowable value. When the ECU 5 determines that the battery 4 can be charged and that the motor temperature is equal to or lower than the allowable value (Yes in step S1), it determines in step S2 whether to continue regeneration. The determination as to whether to continue regeneration is made based on information such as, for example, road information (decision to continue downhill), destination, accelerator pedal opening, brake pedal depression force (required vehicle braking force), and motor rotation speed. At this time, the ECU 5 acquires information such as the road information (decision to continue downhill) and destination from, for example, a car navigation system mounted on the vehicle 1. When the ECU 5 determines that regeneration is to continue (Yes in step S2), it determines in step S3 whether the battery 4 is close to being fully charged. The determination of whether the battery 4 is close to full charge is made, for example, when the charge amount of the battery 4, in other words, the SOC (State Of Charge) of the battery 4, is equal to or greater than a predetermined threshold, and when it is less than the predetermined threshold, it is determined that the battery 4 is not close to full charge. When the ECU 5 determines that the battery 4 is close to full charge (Yes in step S3), in step S4, the ECU 5 changes the torque distribution between the left front wheel 21FL and the right front wheel 21FR. Then, the ECU 5 ends the series of torque distribution setting controls.

[0027] On the other hand, if the ECU 5 determines in step S2 not to continue regeneration (No in step S2) or determines in step S3 that the battery 4 is not nearly fully charged (No in step S3), then in step S5, the ECU 5 sets the torque distribution to normal, for example, 50:50 between the left front wheel 21FL and the right front wheel 21FR while the vehicle 1 is traveling straight ahead. Then, the ECU 5 ends the series of torque distribution setting controls.

[0028] Furthermore, when the ECU 5 determines in step S1 that the battery 4 can be charged and that the motor temperature is not below the allowable value (No in step S1), in step S6, the ECU 5 ensures braking force by the brake mechanism since regeneration is not possible in the in-wheel motors 10FL, 10FR. Then, the ECU 5 ends a series of torque distribution setting controls.

[0029] In the vehicle 1 according to the embodiment, when the charge amount of the battery 4 is equal to or higher than a predetermined threshold (the battery 4 is close to being fully charged) and the vehicle is in a driving state in which the battery 4 is being charged (the regenerative state is continued), the ECU 5 controls the in-wheel motors 10FL, 10FR to increase the difference in torque distribution between the left front wheel 21FL and the right front wheel 21FR. This allows the vehicle 1 according to the embodiment to increase the amount of loss in the in-wheel motors 10FL, 10FR, and to reduce the amount of regeneration of the in-wheel motors 10FL, 10FR without providing a separate power consumption means for consuming the power (regenerative power) generated by the in-wheel motors 10FL, 10FR through regeneration. Therefore, in the vehicle 1 according to the embodiment, it is possible to function the braking force (regenerative brake) through regeneration while suppressing an increase in cost.

[0030] Furthermore, the vehicle 1 according to the embodiment can be applied not only to vehicles equipped with in-wheel motors, but also to on-board two-motor vehicles that do not have a differential gear and have motors connected independently to the left and right drive wheels. [Explanation of symbols]

[0031] 1 vehicle 4 Battery 5 ECU 6 Accelerator pedal opening sensor 7 Brake pedal sensor 8 Motor Driver 9 Brake Actuator 10, 10FL, 10FR In-wheel motor 11FL, 11FR Temperature detection sensor 13FL, 13FR, 13RL, 13RR brake disc 20FL, 20FR, 20RL, 20RR brake caliper 21 wheels 21FL front left wheel 21FR right front wheel 21RL Left rear wheel 21RR right rear wheel

Claims

[Claim 1] The left and right drive wheels, a plurality of rotating electric machines each generating a driving force or a regenerative braking force for the left and right drive wheels independently of the others; an electricity storage device that exchanges electric power with the plurality of rotating electric machines; A vehicle equipped with The plurality of rotating electric machines are capable of regenerating electric power generated by rotational energy of the left and right drive wheels into the power storage device, The vehicle is characterized by comprising a control device that performs control to increase the difference in torque distribution to the left and right drive wheels when the charge amount of the storage device is equal to or greater than a predetermined threshold value that determines that the charge amount of the storage device is close to full charge and when the vehicle is in an operating state in which the storage device is charged by regeneration, compared to at least one of the cases in which the charge amount of the storage device is less than the threshold value or the vehicle is not in an operating state in which the storage device is charged by regeneration.

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