JP-7856080-B2 - Cooling control system for electric vehicles

JP7856080B2JP 7856080 B2JP7856080 B2JP 7856080B2JP-7856080-B2

Inventors

岩本政隆
奥田弘一
田端淳

Assignees

トヨタ自動車株式会社

Dates

Publication Date: 20260511
Application Date: 20231102

Claims (5)

A cooling control device for an electric vehicle comprising: a first motor that drives a first drive wheel, which is one of the front wheels or the rear wheels; a first electric oil pump that supplies oil to the first motor; a second motor that drives a second drive wheel, which is the other of the front wheels or the rear wheels; a second electric oil pump that supplies the oil to the second motor; a first drive unit that transmits torque from the first motor to the first drive wheel; a second drive unit that transmits torque from the second motor to the second drive wheel; and a mechanical oil pump that is operated by the first drive unit to supply the oil to the first drive unit, wherein the device is switchable between a four-wheel drive driving mode using the first motor and the second motor as the driving force source and a two-wheel drive driving mode using the second motor as the driving force source, The system includes a controller that controls the first electric oil pump and the second electric oil pump, The aforementioned controller, When the two-wheel drive driving mode is selected, a pump selection unit drives only the second electric oil pump among the first electric oil pump and the second electric oil pump, A prediction unit that predicts that the vehicle will be driven in the aforementioned four-wheel drive driving mode, A cooling control device for an electric vehicle, characterized by comprising: a starting control unit that starts operating the first electric oil pump when the prediction unit predicts that the vehicle will be driven in the four-wheel drive driving mode.
A cooling control device for an electric vehicle according to claim 1, The system includes a mode selection unit operated by the driver to select the aforementioned four-wheel drive driving mode, The cooling control device for an electric vehicle is characterized in that the prediction unit predicts whether or not the mode selection unit is operated, and whether or not the vehicle will be driven in four-wheel drive mode.
A cooling control device for an electric vehicle according to claim 1, The aforementioned controller, A cooling control device for an electric vehicle, characterized in that the higher the temperature of the first motor, the greater the amount of oil supplied to the first motor by the first electric oil pump, and the higher the temperature of the second motor, the greater the amount of oil supplied to the second motor by the second electric oil pump.
A cooling control device for an electric vehicle according to claim 1, The aforementioned four-wheel drive driving mode includes multiple driving modes, The aforementioned controller, A cooling control device for an electric vehicle, characterized by controlling the amount of oil supplied to the first motor by the first electric oil pump and the amount of oil supplied to the second motor by the second electric oil pump according to the plurality of driving modes.
A cooling control device for an electric vehicle according to any one of claims 1 to 4, The cooling control device for an electric vehicle is characterized in that the four-wheel drive driving mode includes at least one of the following driving modes: a track mode which enhances turning performance compared to the two-wheel drive driving mode; a drift mode which improves driving precision; a sport mode which enhances acceleration performance or power performance; and a manual range mode which controls the driving torque of the first motor and the second motor based on the driving characteristics corresponding to the driver's shift operation.

Description

This invention relates to a control device for cooling a motor or other component in a vehicle equipped with an electric motor as a driving force source, and more particularly to a cooling control device that uses oil for cooling. Patent Document 1 describes a control device for a four-wheel drive vehicle, comprising a front motor that is the driving force source for a pair of front wheels, and a rear motor that is the driving force source for a pair of rear wheels and has a lower thermal rating or lower cooling performance than the front motor. This control device is configured to maintain the required driving force for the vehicle by increasing the output of the front motor when the operation of the rear motor is limited, and to ensure driving stability by reducing the output of the rear motor when the operation of the front motor is limited, thereby achieving a desired torque distribution ratio between the front and rear wheels. Furthermore, Patent Document 2 describes a hybrid vehicle equipped with an engine and a motor as driving power sources, capable of setting an HV driving mode in which the vehicle is driven by the engine, and an EV driving mode in which the vehicle is driven by the motor with the engine stopped. This hybrid vehicle is also equipped with a mechanical oil pump driven by the engine and an electric oil pump driven by an electric motor in parallel. When the viscosity of the refrigerant discharged by these oil pumps is high, only the oil pump with the higher discharge force is driven; when the viscosity of the refrigerant is low, only the other oil pump is driven. Japanese Patent Publication No. 2001-112114Japanese Patent Publication No. 2014-000848 This is a schematic block diagram showing the drive system of a four-wheel independent drive vehicle in an embodiment of the present invention.This is a skeleton diagram showing an example of a rear-wheel drive unit.This is a skeleton diagram showing an example of a drive unit on the front wheel side.This diagram schematically shows the required drive torque map used in D range.This diagram schematically shows the required drive torque map when the accelerator is open at 50% in D or L range.This figure shows an example of a shift device that allows the user to select a shift range by operating the shift lever.This figure shows an example of a shift device that allows the user to select a shift range by operating paddle switches.This flowchart illustrates an example of control that determines whether or not to switch the shift range.This is a block diagram illustrating the input and output signals of a controller.This is a block diagram showing the functional configuration of the controller.This is a flowchart illustrating an example of control performed in an embodiment of the present invention.This diagram shows an example of a map that determines the oil pump rotation speed for each driving mode. Next, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the embodiments described below are merely examples of how the present invention may be implemented and do not limit the invention. The electric vehicle targeted by this invention is a four-wheeled vehicle consisting of two front wheels and two rear wheels, each equipped with a motor as a driving force source, allowing the front and rear wheels to be driven independently of each other. The front wheels may be connected to the front wheel driving force source via an appropriate differential mechanism, and the rear wheels may be connected to the rear wheel driving force source via another appropriate differential mechanism. Furthermore, the electric vehicle targeted by this invention may be configured to have motors corresponding to each of the four wheels, allowing the driving torque and regenerative braking torque (regenerative torque) of each wheel to be controlled independently of each other. Figure 1 schematically shows an example of a four-wheel independent drive vehicle, configured to allow independent control of the driving torque or regenerative braking torque of the front and rear wheels, as well as to allow independent driving of all four wheels. The electric vehicle shown here (hereinafter simply referred to as "vehicle") Ve comprises left and right front wheels 1r, 1l and left and right rear wheels 2r, 2l. Drive units Pf and Pr are provided as driving force sources, corresponding to the front wheels 1r, 1l and the rear wheels 2r, 2l, respectively. These drive units Pf and Pr are mainly composed of a motor and a gear reduction mechanism (transmission mechanism), respectively. Figure 2 shows a skeleton diagram of an example of the drive unit Pr for the rear wheels 2r and 2l. This drive unit Pr consists of a pair of drive systems that independently control the left and right rear wheels 2r and 2l. Since these drive systems are symmetrically configured, they will be described together without specifically designating them as "