JP2022059886A - Hybrid vehicle - Google Patents

Abstract

To enable an instantaneous response to a power regeneration when shifting to a decelerating operation.SOLUTION: A hybrid vehicle includes: an engine 12 for transmitting drive force to a first drive shaft 28; a motor 13 for transmitting drive force to a second drive shaft 18; a clutch 14 disposed between the motor 13 and the second drive shaft 18; temperature information obtainment means 15 for obtaining information of a temperature of the motor 13; clutch control means 51 for disengaging the clutch 14 when a temperature of the motor 13 reaches or exceeds a given temperature and engaging the clutch 14 when a vehicle 10 is decelerating; and motor control means 53 for controlling the motor 13. Further, the motor control means 53 executes power travel control for driving the motor 13 while the clutch 14 is disengaged, and controls regeneration of the motor 13 when the clutch 14 is switched to an engaged state with a vehicle 10 decelerating.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hybrid vehicle.

In a vehicle that travels by the driving force of an electric motor (motor) such as a hybrid vehicle, a clutch is placed between the electric motor and the wheels, and by connecting the clutch, the rotational force of the electric motor is transmitted to the wheels to transfer the vehicle. At the same time as driving, depending on the operating condition, the rotational force of the wheels is transmitted to the motor to recover the regenerative energy. When the vehicle speed reaches the maximum rotation speed of the motor or the temperature of the motor reaches a predetermined upper limit temperature, the clutch is disengaged to prevent an excessive load from acting on the motor. There is.

Further, for example, in Patent Documents 1 and 2, when it is necessary to connect a clutch between an electric motor and a wheel for electric power regeneration after the vehicle starts decelerating, the clutch is sandwiched prior to the connection. Disclosed is a technique for controlling the output of an electric motor so that the rotation speeds on both sides are close to each other, and reducing the shock by connecting a clutch when the difference between the rotation speeds becomes a predetermined value or less.

Japanese Unexamined Patent Publication No. 2006-50767 Japanese Unexamined Patent Publication No. 2008-126869

When a vehicle in the clutch disengaged state shifts to deceleration operation, there is a demand to start regeneration of electric power as soon as possible and effectively utilize the regenerative energy during deceleration. However, in Patent Documents 1 and 2, the rotation speed of the shaft of the motor is increased after the vehicle shifts to the deceleration operation so that the difference between the rotation speed on the motor side and the rotation speed on the wheel side becomes a predetermined value or less. It is controlled to. Therefore, there is a problem that regeneration cannot be started until the difference in rotation speed becomes equal to or less than a predetermined value. Therefore, the energy of deceleration is wasted until the start of regeneration. When shifting to deceleration operation, it is required to start regeneration of electric power as soon as possible.

Therefore, an object of the present invention is to be able to immediately cope with the regeneration of electric power when shifting to the deceleration operation.

In order to solve the above problems, the present invention relates to an engine that transmits a driving force to a first drive shaft, an electric motor that transmits a driving force to a second drive shaft, and between the electric motor and the second drive shaft. The clutch arranged in, the temperature information acquisition means for acquiring the temperature information of the motor, and the clutch are disengaged when the temperature of the motor exceeds a predetermined value, and the clutch is disengaged when the vehicle is decelerated. The clutch control means for connecting to the motor and the motor control means for controlling the motor are provided. The motor control means controls the power running to drive the motor while the clutch is disengaged, and the clutch is in a decelerated state of the vehicle. Adopted a hybrid vehicle that performs regeneration control by the motor when the is switched to the connected state.

Here, from the steady mode in which the electric motor is driven at a predetermined rotation speed or less or rotated in an idling state in the first temperature range including the predetermined value while the clutch is disengaged, and from the lower limit of the first temperature range. In the second temperature range set to a low temperature range, it is possible to adopt a configuration including a vehicle speed tracking mode in which the electric motor is driven and rotated at a rotation speed corresponding to the vehicle speed of the vehicle.

At this time, the motor control means adopts a configuration that controls to shift to the steady mode when an acceleration equal to or higher than a predetermined acceleration is detected during the vehicle speed tracking mode or when a predetermined accelerator opening is detected. Can be done.

In each of these embodiments, a battery for supplying electric power to the electric motor is provided, and the electric motor control means may adopt a configuration in which the steady mode is selected when the remaining capacity of the electric power of the battery is less than the predetermined remaining capacity. can.

The cooling means for cooling the electric motor is provided, and the cooling means is provided with a first cooling passage for refrigerant flow provided in a member on the rotating side of the electric motor, and the refrigerant is provided in the first cooling passage during power running control. By supplying the above member, it is possible to adopt a configuration in which the cooling effect of the member on the rotating side is higher than that when the member is not rotating.

According to the present invention, it becomes possible to immediately cope with the regeneration of electric power when shifting to the deceleration operation.

It is a schematic diagram which shows an example of the hybrid vehicle which concerns on this invention. It is a graph which shows the temperature of a motor and the control of a clutch. It is a graph which shows the control of this invention. It is a graph which shows the control of this invention. It is a graph which shows the control of this invention. It is a graph which shows the control of this invention. It is a graph which shows the control of this invention. It is a graph which shows the control of this invention. It is a flowchart which shows the control of this invention. It is a schematic diagram which shows the cooling means of an electric motor. It is a figure which shows the control of this invention. It is a figure which shows the control of this invention. It is a flowchart which shows the control of this invention.

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a hybrid vehicle 10 (hereinafter, simply referred to as a vehicle 10) equipped with a vehicle control device according to an embodiment of the present invention. In the vehicle 10, the front wheels (front wheels) 11a are driven by the driving force of the engine 12, and the rear wheels (rear wheels) 11b can be driven by the assisting force of the electric motor 13 (hereinafter referred to as the main motor 13). It is a four-wheel drive mild hybrid vehicle. The vehicle control device mounted on the vehicle 10 is for efficiently recovering the regenerative energy by the main motor 13, and includes the main motor 13, the clutch 14 (hereinafter referred to as the main clutch 14), and the main motor 13. The main components are the temperature information acquisition means 15, the vehicle speed sensor 16, the electronic control unit 50, and the like for acquiring the temperature information of the above. In this embodiment, the temperature sensor 15 is adopted as the temperature information acquisition means 15, but a temperature information acquisition means, a temperature information estimation means, and the like having other forms other than the sensor may be adopted.

The main motor 13 is attached to the rear wheel side axle 18 so as to transmit the driving force to the second drive shaft (hereinafter referred to as the rear wheel side axle) 18 leading to the rear wheel 11b. The main motor 13 applies a rotational force to the rear wheels 11b during power running to assist the driving force of the engine 12. This assist force is transmitted to the rear wheel side axle 18 via the main clutch 14 and the rear wheel side differential 19. Further, the main motor 13 recovers regenerative energy (hereinafter referred to as regenerative power) from the rotational force of the rear wheels 11b during braking. Since the main motor 13 is directly connected to the rear wheel side axle 18 via a gear having a small transmission loss, high regenerative efficiency can be obtained.

The main clutch 14 is arranged between the motor 13 and the rear wheel side axle 18. The main clutch 14 has a connection state in which rotational force can be transmitted between the main motor 13 and the rear wheel 11b via the rear wheel side differential 19 and the rear wheel side axle 18, and a cutoff state in which this transmission is cut off. It has a function to switch between. The main clutch 14 is normally connected. The rear wheel side differential 19 has a function of distributing the drive assist force from the main motor 13 to the left and right rear wheels 11b in response to the rotational resistance of the left and right rear wheels 11b.

When the main clutch 14 is connected, the drive assist force is transmitted from the main motor 13 to the rear wheels 11b during power running, and the rotational force of the rear wheels 11b is transmitted to the main motor 13 during braking. Regenerative power is recovered. This regenerative power is charged in the battery 20 mounted on the vehicle 10. When the main clutch 14 is disengaged, the main motor 13 and the rear wheels 11b are disconnected, so that the regenerative power cannot be recovered by the main motor 13 during braking.

The battery 20 is provided with a charge amount sensor 21 that detects the charge amount. Information on the remaining capacity (remaining charge amount) of the battery 20 detected by the charge amount sensor 21 is sent to the electronic control unit 50.

The temperature sensor 15 is attached to the casing 13c or the like of the main motor 13, and the temperature of the casing 13c or the stator 13b immediately inside the casing 13c is adopted as a representative value of the temperature of the main motor 13. However, as the temperature sensor 15, it is also possible to acquire another temperature as a representative value of the temperature of the main motor 13, such as the temperature of the lubricating oil flowing in the vicinity of another part of the main motor 13, for example, the temperature of the main motor 13. can. The temperature information of the main motor 13 detected by the temperature sensor 15 is sent to the electronic control unit 50.

The vehicle speed sensor 16 is provided on an axle or the like and has a function of detecting the speed of the vehicle 10. The vehicle speed information detected by the vehicle speed sensor 16 is also sent to the electronic control unit 50. The position of the vehicle speed sensor 16 shown in FIG. 1 is an example, and the mounting position thereof can be changed as appropriate.

The driving force of the engine 12 is a first drive shaft (hereinafter referred to as a front wheel side axle) that leads to the front wheel 11a via a torque converter 24, a continuously variable transmission 25, an auxiliary clutch 26, and a front wheel side differential 27. It is transmitted to (referred to as) 28. The torque converter 24 has a function of transmitting the driving force of the engine 12 to the continuously variable transmission 25. The auxiliary clutch 26 has a function of switching between a connected state in which the driving force can be transmitted between the engine 12 and the front wheel 11a and a disconnected state in which the transmission is cut off. The front wheel side differential 27 has a function of distributing the driving force from the engine 12 to the left and right front wheels 11a in response to the rotational resistance of the left and right front wheels 11a.

Further, the engine 12 is provided with an auxiliary motor (hereinafter referred to as an auxiliary motor) 29. The sub-motor 29 is connected to the crankshaft 31 of the engine 12 by a belt 30, and is mainly used for starting the engine 12. Also, by connecting the sub-clutch 26, regenerative power is recovered during braking. It is also possible. The auxiliary motor 29 is normally rotated by the crankshaft 31 while the engine 12 is operating.

The main motor 13 is a prime mover in which a coil is provided on one of a fixed-side member and a rotating-side member, and a permanent magnet is provided on the other, and an output shaft provided on the rotating-side member rotates about an axis by a driving force. It exerts the function of. Further, when the rotation from the axle side is input to the output shaft, the regenerated electric power is generated, and the function of the generator for charging the regenerated electric power to the battery 20 is exhibited. By regenerating the electric power in the main motor 13 in addition to the auxiliary motor 29 attached to the engine 12, the deceleration energy can be recovered to the maximum as the regenerative electric power.

The vehicle 10 is provided with a brake pedal 22 and an accelerator pedal 32 operated by the driver. The brake pedal 22 is provided with a brake sensor 23 that detects the depression force of the brake pedal 22 by the driver. Further, the accelerator pedal 32 is provided with an accelerator position sensor 33 that detects the amount of depression of the accelerator pedal 32 by the driver. The brake information detected by the brake sensor 23 and the accelerator information detected by the accelerator position sensor 33 are sent to the electronic control unit 50.

The electronic control unit 50 includes a clutch control means 51 that controls the connection and disconnection of the main clutch 14 and the sub-clutch 26, a cooling control means 52 that controls the cooling means 40, and an electric motor control that controls the main motor 13 and the sub-motor 29. The means 53, the engine 12, and other control means 54 for controlling the vehicle 10 in general are provided.

Regarding the main clutch 14, the clutch control means 51 switches the main clutch 14 from the connected state to the disengaged state when the temperature of the main motor 13 becomes equal to or higher than a preset threshold value (first temperature threshold value). Further, when the temperature of the main motor 13 falls below a preset threshold value (second temperature threshold value), the main clutch 14 is switched from the disengaged state to the connected state. The first temperature threshold value and the second temperature threshold value may be set uniformly regardless of the operating conditions, but they can also be set so as to change according to the vehicle speed at that time. Further, if the hunting in which the main clutch 14 repeatedly turns on and off can be avoided in a short time, the first temperature threshold value and the second temperature threshold value can be set to the same temperature. FIG. 2 shows control of engagement / disengagement of the main clutch 14 based on the first temperature threshold value and the second temperature threshold value. The section X in the figure is a period during which the main clutch 14 is disengaged based on the temperature of the main motor 13. Further, when the vehicle 10 is in the decelerated state, the clutch control means 51 puts the main clutch 14 in the connected state in order to acquire the regenerative power. It should be noted that the regeneration of electric power can also be performed by the auxiliary motor 29.

The electric motor control means 53 controls the outputs of the main motor 13 and the sub motor 29 in cooperation with the operations of the main clutch 14 and the sub clutch 26 by the clutch control means 51. Further, when the electric power is regenerated, the acquired regenerative electric power is supplied to the battery 20 to be charged. The cooling control means 52 adjusts the cooling performance of the main motor 13 by the cooling means 40 between the first state in which the cooling performance is exhibited and the second state in which the cooling performance is lower than the first state. When the auxiliary motor 29 is provided with the cooling means 40, the cooling control means 52 can also adjust the cooling performance of the auxiliary motor 29. Further, the motor control means 53 performs power running control for driving the main motor 13 not only while the main clutch 14 is connected but also while the main clutch 14 is disengaged, and the main clutch 14 is connected in the decelerated state of the vehicle 10. When the state is switched, the regeneration control is performed by the main motor 13.

In the first temperature range including a predetermined value (corresponding to the above-mentioned first temperature threshold in the embodiment) while the main clutch 14 is disengaged, the main motor 13 is driven at a predetermined rotation speed or less, or in an idling state. A steady mode of rotation and a vehicle speed tracking mode in which the main motor 13 is driven and rotated at a rotation speed corresponding to the vehicle speed of the vehicle 10 in a second temperature range set to a temperature range lower than the lower limit of the first temperature range. It is equipped with. The above-mentioned power running control corresponds to the case where the main motor 13 is driven at the minimum necessary rotation speed in the steady mode and the case where the main motor 13 is driven at the rotation speed corresponding to the vehicle speed in the vehicle speed follow-up mode. The drive of the main motor 13 in the steady mode is a drive corresponding to a small rotation speed that does not raise the temperature of the main motor 13, and is a drive corresponding to a rotation speed smaller than the rotation speed according to the vehicle speed. When the motor control means 53 detects acceleration equal to or higher than a predetermined acceleration during the vehicle speed follow-up mode, the motor control means 53 controls to cancel the vehicle speed follow-up mode and shift to the steady mode. Further, the motor control means 53 controls to select the steady mode when the remaining capacity of the electric power of the battery 20 is less than the predetermined remaining capacity. The acceleration may be detected by an acceleration sensor included in the vehicle 10, or may be calculated by the electronic control unit 50 based on information such as the accelerator opening degree.

(Vehicle speed tracking control)
An example of the vehicle speed tracking control of the present invention will be described with reference to FIGS. 3 to 9.

3 to 5 show a first control example of vehicle speed tracking control. As shown on the left side in FIG. 4, when the vehicle speed increases due to the driver's acceleration request, the temperature of the main motor 13 also increases accordingly. When the temperature of the main motor 13 (“the temperature of the electric motor” in the figure) becomes equal to or higher than the first temperature threshold value a, the main clutch 14 is switched to the disengaged state. As shown in FIG. 2, the first temperature threshold value a is a temperature at which the main clutch 14 is switched from the connected state to the disconnected state when the temperature of the main motor 13 becomes higher than that. Here, the drive of the main motor 13 is stopped, and the subsequent rotation speed (“rotation speed of the electric motor” in the figure) changes at the rotation speed of idling due to inertia (“idle rotation speed” in the figure). This state is called steady mode. The drive of the main motor 13 is stopped, and the temperature of the main motor 13 drops.

Here, as shown in FIG. 3, the first temperature threshold a (for example, a = 120 ° C.), the second temperature threshold b (for example, b = 110 ° C.), and the third temperature threshold c (for example, for example) are in descending order of temperature. c = 105 ° C.) and a fourth temperature threshold d (for example, d = 100 ° C.) are defined. The temperature range A is above the first temperature threshold a, and the temperature is above the second temperature threshold b and below the first temperature threshold a. Region B, the temperature region C is defined as the third temperature threshold c or more and less than the second temperature threshold b, and the temperature region D is defined as the fourth temperature threshold d or more and less than the third temperature threshold c. That is, the temperature range B is set to a temperature range lower than the lower limit of the temperature range A, the temperature range C is set to a temperature range lower than the lower limit of the temperature range B, and the temperature range D is lower than the lower limit of the temperature range C. It is set to a temperature range, and the temperature range E is set to a temperature range lower than the lower limit of the temperature range D.

FIG. 4 shows the control when the vehicle speed tracking control is not performed. In the section of the steady mode indicated by reference numeral X in FIG. 4, when the shaft 13a of the main motor 13 slips while the shaft 13a of the main motor 13 is in the disengaged state, the temperature of the main motor 13 drops below the second temperature threshold value b. The temperature of the motor 13 enters the temperature range C (see FIG. 3 for the temperature range C). When the temperature of the main motor 13 falls below the second temperature threshold value b, the main clutch 14 is switched from the disengaged state to the connected state. As shown in FIG. 2, the second temperature threshold value b is a temperature at which the main clutch 14 is switched from the disengaged state to the connected state when the temperature of the main motor 13 falls below it. Here, the main clutch 14 remains in the disengaged state, and the main motor 13 starts to be driven. The rotation speed of the main motor 13 is controlled so as to be maintained at the rotation speed corresponding to the vehicle speed. This is hereinafter referred to as vehicle speed tracking control, and corresponds to a section of the vehicle speed tracking mode indicated by reference numeral Y in FIG. The vehicle speed tracking control is the rotation speed on both sides of the main clutch 14 in the clutch disengaged state so that the recovery of the regenerative power can be started immediately by using the main motor 13 when the vehicle in the clutch disengaged state shifts to deceleration operation. Is a control that brings the two closer to each other. If the difference between the rotation speeds on both sides of the main clutch 14 is less than a predetermined rotation speed, the vehicle can shift to the regenerative operation without receiving a large shock when the main clutch 14 is connected. Further, by performing vehicle speed tracking control, the main clutch 14 can be immediately connected when the vehicle 10 shifts to the deceleration state, so that the time until the start of electric power regeneration is shortened and the regenerative energy is made efficient. Will be able to be collected.

However, if the main motor 13 is continuously driven at a constant rotation speed or higher in the clutch disengaged state by the vehicle speed tracking control, there is a concern that the power consumption will increase and the remaining power capacity of the battery 20 will decrease. Therefore, after shifting to the vehicle speed tracking control, the vehicle speed tracking control is canceled in the driving situation where the acceleration is likely to continue without decelerating thereafter.

FIG. 5 shows the control when the vehicle speed tracking control is performed. In FIG. 5, after the vehicle speed tracking control is started, when the accelerator opening degree of 20% or more acquired by the accelerator position sensor 33 continues for a predetermined time (section indicated by reference numeral V in FIG. 5) or more. It is set to cancel the vehicle speed tracking control. This is because when the accelerator opening degree of 20% or more continues for a predetermined time or more, it can be determined that the acceleration is continued thereafter. The predetermined predetermined time is 5 seconds in this embodiment, but this can be another numerical value such as 10 seconds. Further, the vehicle speed tracking control may be canceled when the accelerator opening degree of 20% or more is detected regardless of the duration. After that, when the vehicle 10 shifts to the deceleration state, the main clutch 14 is engaged, the regeneration of electric power is started, and the series of control is completed. The threshold value of the accelerator opening to be released from the vehicle speed tracking control is not limited to the above 20%, and other values such as 15% or 25% may be adopted. Further, regardless of the accelerator opening degree, the vehicle speed tracking control may be canceled when the acceleration of the accelerating vehicle 10 becomes equal to or higher than a predetermined acceleration.

6 and 7 show a second control example of vehicle speed tracking control. Hereinafter, the differences from the first control example of the vehicle speed tracking control will be mainly described. FIG. 6 shows the control when the vehicle speed tracking control is not performed, and FIG. 7 shows the control when the vehicle speed tracking control is performed. In FIG. 6, the steering wheel steering angle acquired by the steering angle sensor 34 (see FIG. 1) provided on the steering wheel operated by the driver is constant at the neutral position (0 °) corresponding to the straight-ahead state.

In FIG. 7, after the steering wheel steering angle becomes 60 ° or more with respect to the neutral position after the vehicle speed tracking control is started, the steering wheel returns to the neutral state again and a predetermined predetermined time (section indicated by reference numeral W in FIG. 7). ) When the above continues, the vehicle speed tracking control is set to be canceled. When the steering angle becomes 60 ° and then returns to the neutral state and continues for a predetermined time or longer, for example, turn left or right inside the intersection to finish passing, or pass through a curve. This is because it can be determined that acceleration will start after that. The predetermined predetermined time is 10 seconds in this embodiment, but this can be another numerical value such as 15 seconds. After that, when the vehicle 10 shifts to the deceleration state, the main clutch 14 is engaged, the regeneration of electric power is started, and the series of control is completed. Here, the threshold value of the steering wheel steering angle to be released from the vehicle speed tracking control is not limited to the above 60 °, and other numerical values such as 50 ° and 70 ° may be adopted. Further, the neutral state is not limited to 0 °, and may have a width such as 0 ° to 5 °. The steering angle of the steering wheel is shown as an absolute value (positive value) with respect to the left and right steering directions.

FIG. 8 shows a third control example of vehicle speed tracking control. Hereinafter, similarly, the differences between the first control example and the second control example of the vehicle speed tracking control will be mainly described. In FIG. 8, the vehicle speed tracking upper limit rotation speed is the maximum rotation speed at which the main motor 13 can be rotated in the clutch disengaged state in the vehicle speed tracking control. Vehicle speed tracking control is not performed at a rotation speed that exceeds the vehicle speed tracking upper limit rotation speed. The vehicle speed tracking upper limit rotation speed is usually set to the maximum rotation speed allowed for the main motor 13.

In FIG. 8, the vehicle speed tracking control is canceled when the rotation speed of the main motor 13 exceeds the vehicle speed tracking upper limit rotation speed and then continues for a predetermined time (section indicated by reference numeral Z in FIG. 8) or longer. It is set to do. This is because if the rotation speed of the main motor 13 becomes equal to or higher than the vehicle speed tracking upper limit rotation speed and then the state continues for a predetermined time or longer, it can be determined that the vehicle continues to travel at a high vehicle speed. The predetermined predetermined time is 5 seconds in this embodiment, but this can be another numerical value such as 10 seconds. After that, when the vehicle 10 shifts to the deceleration state, the main clutch 14 is engaged, the regeneration of electric power is started, and the series of control is completed.

A flowchart of this control is shown in FIG. Control is started in step S1. In the previous stage, information on the temperature of the main motor 13 (hereinafter referred to as an electric motor in the flowchart) is acquired, and after it is determined that the temperature of the electric motor is equal to or higher than the first temperature threshold value a, the main clutch 14 is disengaged, and then the main clutch 14 is disengaged. It is assumed that the vehicle speed tracking mode is entered after the steady mode. In step S2, the vehicle speed tracking mode is entered (vehicle speed tracking mode ON), and in step S3, information on the accelerator opening is acquired. Here, if it is determined that "accelerator opening ≥ 20%" continues for 5 seconds or more, the process proceeds to step S5, and the vehicle speed tracking mode is canceled (vehicle speed tracking mode OFF). Then, the process proceeds to step S6 to end the control. If it is determined in step S4 that the accelerator opening degree is less than 20% or "accelerator opening degree ≥ 20%" does not continue for 5 seconds or more, the process proceeds to step S7.

In step S7, the information on the rotation speed of the electric motor is acquired, and in the subsequent step S8, it is determined whether or not the state of "rotational speed of the electric motor <rotational speed corresponding to the vehicle speed" continues for 5 seconds or more. If it continues for 5 seconds or more, the process proceeds to step S9, and the vehicle speed tracking mode is canceled (vehicle speed tracking mode OFF). Then, the process proceeds to step S10 to end the control. If it is determined in step S8 that the continuation is not continued for 5 seconds or more, the process proceeds to step S11.

In step S11, information on the steering wheel steering angle is acquired, and in the following step S12, it is determined whether or not the vehicle has returned to the neutral position from the state of "steering wheel steering angle ≥ 60 °" after the vehicle speed tracking mode is started. If there is such a history, the process proceeds to step S13, and the vehicle speed tracking mode is canceled (vehicle speed tracking mode OFF). Then, in step S14, it is determined whether or not the release state of the vehicle speed tracking mode continues for 10 seconds. If the release state of the vehicle speed tracking mode continues for 10 seconds, the process proceeds to step S15, the vehicle speed tracking mode is set (vehicle speed tracking mode ON), and the control ends in step S16. If it is determined in step S14 that the release state of the vehicle speed tracking mode has not continued for 10 seconds or more, the process proceeds to step S17 and the control is terminated.

By the way, as shown in FIG. 10, the configuration of the main motor 13 of this embodiment includes a shaft 13a as an output shaft inserted in the casing 13c, and a rotor 13d and a rotor 13d that rotate around the shaft together with the shaft 13a. It is provided with a stator 13b or the like provided on the outer periphery. The shaft 13a and the rotor 13d are members on the rotating side, and the casing 13c and the stator 13b are members on the fixed side.

The main motor 13 is provided with cooling means 40. The cooling means 40 has a function of suppressing the temperature rise or lowering the temperature by cooling each part of the main motor 13. As shown in FIGS. 1 and 10, the cooling means 40 has a cooling passage 42 through which a cooling medium (hereinafter referred to as a refrigerant) is passed in order to cool each member constituting the main motor 13. Generally, a fluid, particularly a liquid such as water or oil, is used as the refrigerant. Refrigerant is supplied to the cooling passage 42 by the pump 41. The pump 41 is driven by electric power from the battery 20.

The cooling passage 42 includes a first cooling passage 42a provided on a member on the rotating side composed of a rotor 13d, a shaft 13a, and the like, a casing 13c, a stator 13b, and the like between the pump 41 that sends out the refrigerant and the main motor 13. It has two systems of a second cooling passage 42b provided in the member on the fixed side to be configured. Further, the cooling path 42 has a return path 42c between the main motor 13 and the pump 41. The first cooling passage 42a has an axial passage 42d that opens at the shaft end of the shaft 13a and extends in the axial direction inside the shaft, and a radial passage that branches from the axial passage 42d and opens to the peripheral surface of the shaft 13a. It has a radial passage 42e and the like. Further, the first cooling passage 42a may have an appropriate passage for a refrigerant on the rotor 13d side as appropriate. The refrigerant cools the shaft 13a through the axial passage 42d and the radial passage 42e, and is discharged in the outer diameter direction from the opening on the peripheral surface of the shaft 13a to cool the rotor 13d. Therefore, if the output shaft of the main motor 13 is rotated, the refrigerant is widely dispersed and the entire main motor 13 can be efficiently cooled. The second cooling passage 42b leads into the casing 13c through the through hole 42f provided in the casing 13c at the upper part of the stator 13b. Therefore, the refrigerant flows down from the upper part of the stator 13b into the casing 13c to mainly cool the stator 13b.

Since the refrigerant supply adjusting means 43 is provided at the branch point between the first cooling passage 42a and the second cooling passage 42b, the ratio of the refrigerant supplied to the first cooling passage 42a and the second cooling passage 42b is adjusted. can do. For example, the ratio of the flow rates of the refrigerant supplied to the first cooling passage 42a and the second cooling passage 42b can be set to an arbitrary value such as 0: 100, 25:75, 50:50, 75:25, 100: 0. Can be set. In this embodiment, a three-way valve is adopted as the refrigerant supply adjusting means 43, but the first cooling passage 42a on the downstream side of the branch point and the second cooling passage 42b on the downstream side of the branch point are respectively used. A flow rate adjusting valve capable of adjusting the opening degree of the valve body may be provided.

Although the details are not shown, the auxiliary motor 29 can have the same configuration as the main motor 13, and the cooling means also has a configuration for circulating the refrigerant in the cooling path as in the main motor 13. Can be done.

In the above-mentioned vehicle speed follow-up control, the refrigerant is supplied to the first cooling passage 42a of the cooling means 40 during power running control, so that the main motor 13 is mainly from the shaft 13a and the rotor 13d, which are members on the rotation side. Refrigerant is easily distributed throughout the motor 13. Therefore, it can be expected that the cooling effect is enhanced as compared with the case where the shaft 13a is not rotated, except when the power running is controlled. Further, even in the steady mode, as long as the shaft 13a is rotated, it can be expected that the area where the refrigerant is scattered due to the rotation of the shaft 13a or the like is expanded.

(Cooling control)
Next, an example of the cooling control of the present invention will be described with reference to FIGS. 3 and 11 to 13. This cooling control can be performed in addition to the vehicle speed tracking control described above, or can be performed independently of the vehicle speed tracking control.

As shown on the left side in FIG. 3, when the vehicle speed increases due to the driver's acceleration request, the temperature of the main motor 13 also increases accordingly. When the temperature of the main motor 13 (“the temperature of the electric motor” in the figure) becomes equal to or higher than the first temperature threshold value a, the main clutch 14 is switched to the disengaged state. As shown in FIG. 2, the first temperature threshold value a is a temperature at which the main clutch 14 is switched from the connected state to the disconnected state when the temperature of the main motor 13 becomes higher than that. Here, the drive of the main motor 13 is stopped, and the subsequent rotation speed (“rotation speed of the electric motor” in the figure) changes at the rotation speed of idling due to inertia (“idle rotation speed” in the figure). The drive of the main motor 13 is stopped, and the temperature of the main motor 13 drops. The first temperature threshold a, the second temperature threshold b, the third temperature threshold c, the fourth temperature threshold d, and the temperature range A, the temperature range B, the temperature range C, the temperature range D, and the temperature range E are described above. It's a street.

Here, when the main clutch 14 is disengaged, cooling by the cooling means 40 starts under the cooling condition 1. The cooling condition 1 is a cooling method in the temperature ranges A and B (see also FIG. 3 for the temperature ranges A and B) shown at the top of the chart (map) of FIG. Under the cooling condition 1, since the first cooling path discharge flag 1 is set, cooling by the first cooling path 42a is used in addition to the second cooling path 42b, and the cooling performance is enhanced. Since the shaft 13a of the main motor 13 is idling, the refrigerant is scattered over a wide range, and efficient cooling is possible.

Here, the state in which the refrigerant is supplied to both the first cooling passage 42a and the second cooling passage 42b is defined as the first state of the cooling performance. In the embodiment, this first state is positioned as the state having the highest cooling performance. However, the cooling performance increases or decreases depending on the ratio of the flow rates of the refrigerant supplied to the first cooling passage 42a and the second cooling passage 42b, but the ratio of the most efficient cooling performance is mainly determined. It depends on the type and specifications of the motor 13 and the configuration of the cooling means 40. Further, the refrigerant supply adjusting means 43 which can adjust the ratio of the flow rate of the refrigerant supplied to the first cooling passage 42a and the second cooling passage 42b only to 100: 0, 50:50, 0: 100 is adopted. In some cases. Therefore, here, the case where the refrigerant is supplied to at least both the first cooling passage 42a and the second cooling passage 42b is defined as the first state having the highest cooling performance. The first state is not limited to the state in which the cooling performance is the highest among the performances of the cooling means 40.

When the temperature of the main motor 13 drops below the second temperature threshold b while the shaft 13a of the main motor 13 idles, the temperature of the main motor 13 enters the temperature range C. When the temperature of the main motor 13 falls below the second temperature threshold value b, the main clutch 14 is switched from the disengaged state to the connected state. As shown in FIG. 2, the second temperature threshold value b is a temperature at which the temperature of the main motor 13 is lower than that of the main clutch 14 and the main clutch 14 is switched from the disconnected state to the connected state. Here, the main clutch 14 remains in the disengaged state, and the main motor 13 starts to be driven. The rotation speed of the main motor 13 is controlled so as to be maintained at the rotation speed corresponding to the vehicle speed, and the vehicle speed follow-up control is performed. Under the vehicle speed tracking control, the cooling by the cooling means 40 shifts to the cooling condition 2. The cooling condition 2 is a cooling method in the temperature range C shown in the second stage of FIG. Under the cooling condition 2, the first cooling path discharge flag 1 and the electric motor rotation flag 1 are set, and the second cooling path discharge flag is 0. Therefore, cooling is performed only by the first cooling path 42a, and the main motor 13 is used. The shaft 13a is rotated by a driving force at a rotation speed that follows the vehicle speed. The cooling condition 2 uses only the first cooling passage 42a out of the two cooling passages 42, and the cooling performance is limited as compared with the first state using both the first cooling passage 42a and the second cooling passage 42b. It is a cooling restricted state.

When the vehicle speed tracking control is performed, the main motor 13 rotates by the driving force, so that the temperature of the main motor 13 tends to rise. However, due to the cooling of the above cooling condition 2, the temperature of the main motor 13 becomes the first. Since the temperature is maintained lower than the temperature threshold a, it is possible to prepare for the regeneration of electric power when shifting to the deceleration operation. As shown at the right end in FIG. 3, when the deceleration operation is started, the clutch is engaged and the power regeneration is started. Cooling to the main motor 13 by the cooling means 40 can be stopped until the temperature of the main motor 13 exceeds the third temperature threshold value c.

That is, in this control, as shown in FIG. 11, in the clutch disengaged state, the cooling means 40 cools, for example, in the first temperature range (corresponding to temperature ranges A and B) including a predetermined value equal to or higher than the second temperature threshold b. Condition 1 is adopted, and the refrigerant is supplied to both the first cooling passage 42a and the second cooling passage 42b to rotate the main motor 13. At this time, although the rotation of the main motor 13 is idling in the embodiment, it may be rotated by driving. Further, in the second temperature range (corresponding to the temperature range C) set to a temperature lower than the lower limit of the first temperature range (corresponding to the temperature ranges A and B), the cooling condition 2 is adopted and the first cooling path 42a is adopted. The second cooling passage 42b is cut off to stop the supply of the refrigerant, and the main motor 13 is rotated. At this time, in the embodiment, the rotation of the main motor 13 is the rotation by driving, but this may be rotated by idling. Further, in the third temperature range (corresponding to the temperature range D) set to a temperature range lower than the lower limit of the second temperature range (corresponding to the temperature range C), the cooling condition 3 is adopted, and the first cooling passage 42a and the second cooling path 42a and the second. Refrigerant is supplied to both of the cooling passages 42b to stop the rotation of the main motor 13. Further, in the fourth temperature range (corresponding to the temperature range E) set to a temperature range lower than the lower limit of the third temperature range (corresponding to the temperature range D), the cooling condition 4 is adopted to shut off the first cooling path 42a. The supply of the refrigerant is stopped and the refrigerant is supplied to the second cooling passage 42b to stop the rotation of the main motor 13.

The cooling conditions 2, 3 and 4 are all cooling limited states in which the cooling performance is more limited than the cooling condition 1 which is the maximum cooling performance. Further, the state in which the pump 41 is stopped, all the supply of the refrigerant is stopped, and the rotation of the main motor 13 is stopped is the minimum state of the cooling performance by the cooling means 40. That is, in this control, the cooling control means 52 sets the cooling performance to a cooling limited state in which the cooling performance is restricted more than the first state while the main clutch 14 is disengaged, and the cooling limited state is set as the temperature of the main motor 13 is higher. By controlling it so that it is close to one state, it is possible to immediately respond to the regeneration of electric power at the time of transition to the deceleration state.

As another control example, for example, the cooling control means 52 adopts a method of controlling the cooling performance by the cooling means 40 so that the higher the remaining capacity of the electric power of the battery 20 is, the closer the cooling limit state is to the first state. be able to.

FIG. 12 shows three charts (maps) based on the remaining power capacity of the battery 20. The upper row is a cooling map for high remaining capacity with high remaining power, the lower row is a cooling map for low remaining capacity with low remaining power, and the middle row is cooling for medium remaining capacity in between. Each map is shown. When the remaining capacity is high, for example, the remaining capacity of electric power can be defined as the first predetermined capacity p or more, and when the remaining capacity is low, for example, the remaining capacity of electric power can be defined as less than the second predetermined capacity r (p> r). .. At this time, when the remaining capacity is medium, it can be defined that the remaining capacity of electric power is equal to or more than the predetermined capacity r and less than the predetermined capacity p. The first predetermined capacity p can be, for example, 75% of the full charge capacity, and the second predetermined capacity r can be, for example, 25% of the full charge capacity. Here, the cooling map at the time of the remaining capacity is the same as that shown in FIG. 5, which is an example of control not based on the remaining capacity of the electric power of the battery 20.

Comparing the three maps in FIG. 12, regarding the utilization of the first cooling passage 42a, when the residual capacity is high, the refrigerant is supplied to the first cooling passage 42a under all the cooling conditions 1 to 4. When the remaining capacity is medium, the refrigerant is supplied to the first cooling passage 42a only under the cooling conditions 1 to 3, and when the remaining capacity is low, the refrigerant is supplied to the first cooling passage 42a only under the cooling conditions 1 and 2. As the remaining capacity of the amount of electricity decreases, the operating conditions for utilizing the first cooling passage 42a are reduced. This is intended to preserve the electric power remaining in the battery 20 by limiting the utilization opportunity of the first cooling passage 42a as the remaining electric power capacity is small.

Comparing the three maps in FIG. 12, regarding the utilization of the second cooling passage 42b, the refrigerant is not supplied to the second cooling passage 42b only under the cooling condition 3 when the remaining capacity is high. When the remaining capacity is set, the refrigerant is not supplied to the second cooling passage 42b only under the cooling condition 2, and when the remaining capacity is low, the refrigerant is not supplied to the second cooling passage 42b only under the cooling conditions 1 and 4. That is, as the remaining capacity of the electric power becomes smaller, the operating conditions for utilizing the second cooling passage 42b are reduced, and the purpose is to preserve the electric power remaining in the battery 20. However, in the case of high residual capacity, in the comparison between the cooling condition 3 and the cooling condition 4, the rotation of the main motor 13 is prioritized over the utilization of the second cooling passage 42b under the cooling condition 3 targeting a higher temperature range. In the cooling condition 4, which targets a temperature range lower than the cooling condition 3, the utilization of the second cooling passage 42b is adopted instead of the rotation of the main motor 13. Further, in the comparison between the cooling condition 2 and the cooling condition 3 at the time of the medium remaining capacity, the rotation of the main motor 13 is prioritized over the utilization of the second cooling passage 42b under the cooling condition 2 targeting a higher temperature range. In the cooling condition 3, which targets a temperature range lower than the cooling condition 2, the utilization of the second cooling passage 42b is adopted instead of the rotation of the main motor 13. Further, in the comparison between the cooling condition 1 and the cooling condition 2 at the time of low residual capacity, the rotation of the main motor 13 is prioritized over the utilization of the second cooling passage 42b under the cooling condition 1 targeting a higher temperature range. In the cooling condition 2, which targets a temperature range lower than the cooling condition 1, the utilization of the second cooling passage 42b is adopted instead of the rotation of the main motor 13. Further, under the cooling condition 4, the utilization of the second cooling passage 42b is stopped. In the embodiment, three cooling maps are set according to the remaining capacity of the battery 20, but the number of the cooling maps can be freely set. For example, two cooling maps may be set according to the remaining capacity of the battery 20, or four or more cooling maps may be set.

In the control according to each of the above aspects, the electric motor control means 53 adds a control that increases the rotation speed of the main motor 13 as the temperature of the main motor 13 increases while the main clutch 14 is disengaged. Can be done. By adding a control to increase the rotation speed of the main motor 13 as the temperature of the main motor 13 is higher, the higher the temperature of the main motor 13 is, the wider the scattering range of the refrigerant is and the higher the temperature of the main motor 13 is. The cooling performance can be improved as time goes by.

The flowchart of this cooling control is shown in FIG. Control is started in step S101, and information on the temperature of the main motor 13 (hereinafter referred to as an electric motor in the flowchart) is acquired in step S102. In step S103, if the temperature of the electric motor is equal to or higher than the first temperature threshold value a, the main clutch 14 (hereinafter referred to as a clutch in the flowchart) is disengaged. If the temperature of the electric motor is less than the first temperature threshold value a, the process returns to the previous step and the process is repeated. The clutch is disengaged in step S104, and the temperature of the motor is acquired again in step S105. If the disengagement of the clutch is not continued in step S106, the process returns to step S102 and the process is repeated. If the clutch is continuously disengaged in step S106, the temperature of the motor is determined in step S107. Here, if the temperature of the motor is equal to or higher than the second temperature threshold value b, the process proceeds to step S108 to acquire information on the remaining capacity of the battery. In a subsequent step S109, a cooling map is selected according to the remaining capacity of the battery. In step S110, in the selected cooling map, the cooling of the motor is started under the cooling condition corresponding to the temperature of the motor (in this case, the cooling condition 1 is applicable). After that, the process returns to step S105 and the process is repeated. On the other hand, if the temperature of the electric motor is less than the second temperature threshold value b in step S107, the process proceeds to step S121.

In step S121, the temperature of the motor is determined again. Here, if the temperature of the motor is equal to or higher than the third temperature threshold value, the process proceeds to step S122 to acquire information on the remaining capacity of the battery. In the following step S123, the cooling map is selected according to the remaining capacity of the battery 20. In step S124, in the selected cooling map, the cooling of the electric motor is started under the cooling condition corresponding to the temperature of the electric motor (in this case, the cooling condition 2 is applicable). After that, in step S125, it is determined whether or not the operating state at that time is deceleration running. The deceleration state can be determined, for example, by the speed information from the vehicle speed sensor 16, or it is estimated that the electronic control unit 50 is in the deceleration state based on the operation amount of the brake pedal 22 and the accelerator pedal 32. It is also possible. If the operating state is not decelerated, the process returns to step S121 and the process is repeated. If the operating state is decelerated traveling, the process proceeds to step S126 and the clutch is engaged. Regeneration of electric power starts by connecting the clutch, and the control process ends in step S127. On the other hand, if the temperature of the electric motor is less than the third temperature threshold value c in step S121, the process proceeds to step S131.

In step S131, the temperature of the motor is determined again. Here, if the temperature of the electric motor is equal to or higher than the fourth temperature threshold value d, the process proceeds to step S132 to acquire information on the remaining capacity of the battery 20. In the following step S133, the cooling map is selected according to the remaining capacity of the battery. In step S134, in the selected cooling map, the cooling of the motor is started under the cooling condition corresponding to the temperature of the motor (in this case, the cooling condition 3 is applicable). After that, in step S135, it is determined whether or not the operating state at that time is deceleration running. If the operating state is not decelerated traveling, the process returns to step S131 and the process is repeated. If the operating state is decelerated traveling, the process proceeds to step S136 and the clutch is engaged. Regeneration of electric power starts by connecting the clutch, and the control process ends in step S137. On the other hand, if the temperature of the motor is less than the fourth temperature threshold d in step S131, the process proceeds to step S142.

In step S142, information on the remaining capacity of the battery is acquired. In the following step S143, the cooling map is selected according to the remaining capacity of the battery 20. In step S144, in the selected cooling map, cooling of the motor is started under the cooling condition corresponding to the temperature of the motor (in this case, the cooling condition 4 is applicable). After that, in step S145, it is determined whether or not the operating state at that time is deceleration running. If the operating state is not decelerated running, the process returns to the previous stage and the process of step S145 is repeated. If the operating state is decelerated traveling, the process proceeds to step S146 and the clutch is engaged. Regeneration of electric power starts by connecting the clutch, and the control process ends in step S147.

In the above embodiment, the cooling passages 42 to which the refrigerant is supplied are set as two systems, and the cooling performance of the cooling means 40 is made variable by switching the cooling passages 42 of the two systems. For example, the cooling performance of the cooling means 40 may be made variable by increasing or decreasing the output of the pump 41 that sends out the refrigerant regardless of the number of systems of the cooling passage 42.

By adding this cooling control in the vehicle speed tracking control described above, for example, the temperature of the electric motor is equal to or higher than the third temperature threshold value c (for example, c = 105 ° C.) and the second temperature threshold value b (for example, b =). In the case of the temperature range C of 110 ° C.) or lower, efficient cooling is performed through the rotating first cooling passage 42a to reduce the temperature at an early stage. Further, when the vehicle speed is, for example, 60 km / h or more, a large recovery amount of deceleration energy can be expected by the regenerative power. Therefore, in such a temperature range C and in an operating state where a large regenerative power can be expected when the vehicle speed shifts to a deceleration state in a high vehicle speed range above a certain level, the rotation speed of the motor is adjusted to the axle according to the vehicle speed. The regenerative operation can be started quickly by idling at a rotation speed that is equal to or close to the rotation speed of the above, and by engaging the clutch immediately when the deceleration state is entered. In general, maintaining the vehicle speed tracking mode in the high vehicle speed range has a problem that the power consumption is large, but if the steady mode is maintained, the power consumption is relatively small, so that it is efficient through the rotating first cooling path 42a. Cooling can accelerate the temperature drop. That is, since the rotation speed of the shaft 13a required only for rotating the discharge direction of the refrigerant in the steady mode does not have to be so large, the cooling of the electric motor is continued even when the remaining capacity of the electric power of the battery 20 is small. can.

The configurations, control maps, control flow flowcharts, etc. of the hybrid vehicle 10 and its control device described in the above embodiments are merely examples for explaining the present invention, and the regeneration of power by the main motor 13 is merely an example. As long as the problem of the present invention of starting, that is, starting the recovery of deceleration energy as soon as possible can be solved, the above-mentioned components, control map, control flow and the like can be appropriately modified. Further, in the above, the present invention has been described based on the vehicle 10 in which the axle direct connection type main motor 13 is provided only on the rear wheel 11b side, but the axle is different from the side where the main motor 13 is provided with the engine 12. For example, the vehicle 10 in which the main motor 13 is provided on both the front wheel 11a side and the rear wheel 11b side, and the vehicle 10 in which the main motor 13 is provided only on the front wheel 11a side. The invention can be applied.

10 Hybrid vehicle (vehicle)
11a Front wheel (wheel)
11b Rear wheel (wheel)
12 Engine 13 Motor (main motor)
14 Clutch (main clutch)
15 Temperature information acquisition means (temperature sensor)
16 Vehicle speed sensor 18 Rear wheel side axle (second drive shaft)
19 Rear wheel side differential 20 Battery 21 Charge sensor 22 Brake pedal 23 Brake sensor 24 Torque converter 25 Continuously variable transmission 26 Sub-clutch 27 Front wheel side differential 28 Front wheel side axle (first drive shaft)
29 Sub-motor (sub-motor)
30 Belt 31 Crankshaft 32 Accelerator pedal 33 Accelerator position sensor 40 Cooling means 41 Pump 42 Cooling path 42a First cooling path 42b Second cooling path 42c Return path 43 Refrigerant supply adjusting means 50 Electronic control unit 51 Clutch control means 52 Cooling control means 53 Electric motor control means 54 Control means

Claims (5)

An engine that transmits driving force to the first drive shaft,
An electric motor that transmits the driving force to the second drive shaft,
A clutch arranged between the motor and the second drive shaft,
A temperature information acquisition means for acquiring temperature information of the motor, and
A clutch control means that disengages the clutch when the temperature of the motor exceeds a predetermined value and engages the clutch when the vehicle decelerates.
The motor control means for controlling the motor and the motor control means
Equipped with
The electric motor control means is a hybrid vehicle that performs power running control for driving the electric motor while the clutch is disengaged, and performs regenerative control by the electric motor when the clutch is switched to the connected state in the deceleration state of the vehicle. A steady mode in which the motor is driven at a predetermined rotation speed or less or rotated in an idling state in a first temperature range including the predetermined value while the clutch is disengaged.
In the second temperature range set to a temperature range lower than the lower limit of the first temperature range, a vehicle speed follow-up mode in which the motor is driven and rotated at a rotation speed corresponding to the vehicle speed of the vehicle, and a vehicle speed follow-up mode.
The hybrid vehicle of claim 1. The hybrid vehicle according to claim 2, wherein the motor control means controls to shift to the steady mode when an acceleration equal to or higher than a predetermined acceleration is detected during the vehicle speed tracking mode or when a predetermined accelerator opening degree is detected. It is equipped with a battery that supplies electric power to the motor.
The hybrid vehicle according to claim 2 or 3, wherein the motor control means selects the steady mode when the remaining capacity of the electric power of the battery is less than a predetermined remaining capacity. A cooling means for cooling the motor is provided.
The cooling means includes a first cooling path for refrigerant flow provided in a member on the rotating side of the motor, and the refrigerant is supplied to the first cooling path during power running control, whereby the rotating side. The hybrid vehicle according to any one of claims 1 to 4, wherein the cooling effect of the member is higher than that when the member is non-rotating.

Images