JP2011220478A - Warming-up control device of vehicle driving system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively promote warming-up of a transmission, in a vehicle driving system for exchanging heat between a lubricant (ATF) of the transmission and an AC motor.SOLUTION: Transmission early warming-up control is performed for promoting warming-up of the transmission 13 by raising the temperature of the ATF by increasing a calorific value of the AC motor 12 by increasing reactive power that does not contribute to torque generation of the AC motor 12 when warming up the transmission 13. In this transmission early warming-up control, the caloric value of the AC motor 12 can be increased without generating torque when stopping rotation of the AC motor 12 (when command torque=0), and the calorific value of the AC motor 12 can be increased while maintaining the torque in the command torque when driving the rotation of the AC motor 12. Thus, the ATF temperature can be early raised by reliably increasing the calorific value of the AC motor 12 without being influenced by an operation state of a vehicle (the command torque of the motor).

Description

  The present invention relates to a warm-up control device for a vehicle drive system that includes a motor and a transmission and performs heat exchange between the lubricating oil of the transmission and the motor.

Before the completion of warm-up of a transmission such as an automatic transmission mounted on a vehicle, the viscosity of the lubricating oil (hydraulic fluid) of the transmission increases and the friction loss of the transmission increases. descend.
Therefore, for example, as described in Patent Document 1 (Japanese Patent Laid-Open No. 2002-70997), high-temperature lubricating oil (hydraulic oil) warmed during vehicle operation is placed in the heat storage tank when the vehicle is stopped. There is a storage system in which high-temperature lubricating oil in a heat storage tank is released at the start of vehicle operation so as to accelerate the warm-up of the transmission.

  Further, as described in Patent Document 2 (Japanese Patent Laid-Open No. 2009-35053), a motor is mounted as a power source for a vehicle, and a lubricating oil (hydraulic oil) for a transmission is also used as a cooling oil for the motor. In the system, when the transmission temperature is lower than a predetermined value, the motor drive range is expanded to increase the amount of heat generated by the motor, thereby increasing the temperature of the lubricating oil and promoting the warm-up of the transmission. There is what I did.

JP 2002-70997 A JP 2009-35053 A

  However, the technique disclosed in Patent Document 1 has a drawback in that it is not possible to satisfy the demand for cost reduction and space saving of the drive system because it is necessary to provide a heat storage tank for storing high-temperature lubricating oil.

  Moreover, although the command torque of a motor changes with the driving | running states of a vehicle, since the technique of the said patent document 2 is a technique which expands the drive area of a motor and increases the emitted-heat amount of a motor, for example, rotation stop of a motor When the command torque of the motor is small (when the command torque = 0) or when the motor power consumption is low, the amount of heat generated by the motor cannot be increased sufficiently, and the warm-up of the transmission cannot be promoted. There are drawbacks.

  Therefore, the problem to be solved by the present invention is that it is possible to promote the warm-up of the transmission without being influenced by the driving state of the vehicle (command torque of the motor), and demands for cost reduction and space saving. An object of the present invention is to provide a warm-up control device for a vehicle drive system that can be satisfied.

  In order to solve the above-mentioned problem, the invention according to claim 1 is directed to a warm-up control device for a vehicle drive system that includes a motor and a transmission and performs heat exchange between the lubricating oil of the transmission and the motor. When the transmission is warmed up, the reactive power that does not contribute to the torque generation of the motor is increased to increase the amount of heat generated by the motor, thereby increasing the temperature of the lubricating oil and promoting the warming up of the transmission. The warm-up control means for executing the warm-up control is provided.

  In the transmission early warm-up control according to the present invention, the reactive power that does not contribute to the torque generation of the motor can be increased to increase the amount of heat generated by the motor. Therefore, when the motor stops rotating (when the command torque = 0) Can increase the heat generation amount of the motor while maintaining the motor in a rotation stop state without generating torque, and increase the heat generation amount of the motor while maintaining the torque at the command torque during the rotation of the motor. be able to. As a result, it is possible to increase the heat generation amount of the motor and increase the temperature of the lubricating oil early without being influenced by the driving state of the vehicle (command torque of the motor), and not depending on the driving state of the vehicle. In addition, the warm-up of the transmission can be promoted. Moreover, since the motor torque can be maintained at the command torque, it is possible to promote the warm-up of the transmission without adversely affecting the operation of the vehicle. In addition, since it is not necessary to provide a heat storage tank or the like for storing high-temperature lubricating oil, it is possible to satisfy the demand for cost reduction and space saving of the drive system.

By the way, when the temperature of the motor is high, if the transmission early warm-up control is executed to increase the heat generation amount of the motor, the motor may be overheated.
Therefore, as described in claim 2, motor temperature determination means for detecting or estimating the temperature of the motor is provided, and when the motor temperature detected or estimated by the motor temperature determination means is higher than a predetermined value, the transmission is quickly warmed up. Control may be prohibited. In this way, it is possible to prevent the motor from being overheated.

  In addition, when the electric power that can be supplied from the battery mounted on the vehicle is small, if the reactive power of the motor is increased by executing the transmission early warm-up control, the motor and auxiliary equipment (for example, an electric oil pump, electric water) The driving power of the pump, electric air conditioner, headlight, etc.) may be insufficient.

  Therefore, as in claim 3, when the suppliable power of the battery mounted on the vehicle is smaller than a predetermined value, the transmission early warm-up control may be prohibited. In this way, it is possible to ensure the driving power of the motor and the auxiliary machines. In this case, the predetermined value may be a fixed value set in advance, or may be changed according to the required power of the motor or auxiliary equipment.

  Further, as in claim 4, when the outside air temperature is higher than a predetermined value, the transmission early warm-up control may be prohibited. That is, when the outside air temperature is higher than a predetermined value (for example, the target temperature of the lubricating oil), it is determined that it is not necessary to execute the transmission early warm-up control because the lubricating oil and the transmission are already warmed to some extent by the outside air. Thus, by prohibiting the transmission early warm-up control, it is possible to avoid executing the transmission early warm-up control more than necessary, and to reduce power consumption.

  Further, as in claim 5, when the travel distance to the destination set by the navigation system mounted on the vehicle is shorter than a predetermined value, the transmission early warm-up control may be prohibited. That is, when the travel distance to the destination is shorter than the predetermined value, the vehicle is likely to stop early, so it is determined that there is no need to execute the transmission early warm-up control. By prohibiting the control, it is possible to avoid performing the transmission early warm-up control more than necessary, and to reduce power consumption.

  Further, according to the sixth aspect of the invention, during the transmission early warm-up control, the reactive power increase amount is changed according to at least one of the temperature of the lubricating oil, the temperature of the motor, and the power that can be supplied from the battery. You may do it. In this way, the amount of heat generated by the motor can be changed by changing the amount of increase in the reactive power according to the temperature of the lubricating oil, the temperature of the motor, the power that can be supplied from the battery, and the like. The amount of heat generated by the motor can be appropriately controlled according to the temperature of the battery, the power that can be supplied from the battery, and the like.

FIG. 1 is a diagram showing a schematic configuration of a hybrid vehicle drive system in an embodiment of the present invention. FIG. 2 is a diagram illustrating transmission early warm-up control. FIG. 3 is a flowchart for explaining the flow of processing of the early warm-up control prohibition determination routine. FIG. 4 is a flowchart for explaining the flow of processing of the early warm-up control routine. FIG. 5 is a time chart for explaining an execution example of the transmission early warm-up control.

Hereinafter, an embodiment embodying a mode for carrying out the present invention will be described.
First, the overall configuration of the hybrid vehicle drive system will be described with reference to FIG.
An engine 11 that is an internal combustion engine and an AC motor 12 are mounted as power sources for the vehicle. The power of the output shaft (crankshaft) of the engine 11 is transmitted to a hydraulically driven transmission 13 via a clutch 17 and an AC motor 12 described later, and the power of the output shaft of the transmission 13 is transmitted to the differential gear mechanism 14 and the axle. 15 is transmitted to the wheel 16 via 15 or the like. The transmission 13 may be, for example, a torque converter, a transmission mechanism, and the like, and may be a stepped transmission that switches a gear step among a plurality of gear steps, or a CVT that changes continuously (nothing). A step transmission).

  In addition, the rotary shaft of the AC motor 12 is connected between the engine 11 and the transmission 13 in the power transmission path for transmitting the power of the engine 11 to the wheels 16 so that the power can be transmitted. 12 is provided with a hydraulically driven clutch 17 for interrupting power transmission. The AC motor 12 is, for example, a three-phase permanent magnet type synchronous motor in which a permanent magnet is incorporated. An inverter 18 that drives the AC motor 12 is connected to a battery 19, and the AC motor 12 is connected via the inverter 18. Electric power is exchanged with the battery 19.

  Lubricating oil (hereinafter referred to as “ATF”) of the transmission 13 is used as hydraulic oil for operating the transmission 13 and the clutch 17, and ATF pumped by the electric oil pump 20 is passed through the hydraulic control circuit 21. And supplied to the transmission 13 and the clutch 17. Further, a heat exchanger (not shown) for exchanging heat between the ATF and the AC motor 12 is connected to the ATF circulation circuit through which the ATF circulates, and the ATF is heated by the heat of the AC motor 12 (the AC motor is driven by the ATF) 12 can be cooled).

  The ATF temperature is detected by the ATF temperature sensor 22, the temperature of the AC motor 12 is detected by the motor temperature sensor 23 (motor temperature determination means), and the outside air temperature sensor 24 detects the outside air temperature. The accelerator sensor 25 detects the accelerator opening (the amount of operation of the accelerator pedal), and the shift switch 26 detects the operation position of the shift lever. Further, the brake operation is detected by the brake switch 27, and the vehicle speed is detected by the vehicle speed sensor 28.

  The hybrid ECU 29 is a computer that comprehensively controls the entire hybrid vehicle, and detects the driving state of the vehicle by reading the output signals of the various sensors and switches described above. The hybrid ECU 29 includes an engine ECU 30 that controls the operation of the engine 11, an MG-ECU 31 that controls the inverter 18 to control the operation of the AC motor 12, and a hydraulic control circuit 21 that controls the transmission 13 and the clutch 17. Control signals and data signals are transmitted to and received from the transmission ECU 32 that controls the operation, and the ECUs 11 to 32 control the engine 11, the AC motor 12, the transmission 13, and the clutch 17 according to the driving state of the vehicle.

  The hybrid ECU 29 (or MG-ECU 31) functions as warm-up control means in the claims by executing each routine for early warm-up control in FIGS. When the engine warms up, the reactive power that does not contribute to the torque generation of the AC motor 12 is increased to increase the amount of heat generated by the AC motor 12, thereby increasing the ATF temperature and promoting the warm-up of the transmission 13. Perform warm-up control.

  Specifically, for example, as shown in FIG. 2, in the dq coordinate system set as the rotation coordinates of the rotor of the AC motor 12, during normal control (when transmission early warm-up control is not executed), The current vector is controlled along a maximum torque / current curve (a curve representing a current that generates torque most efficiently) so as to realize the command torque of AC motor 12. With respect to the current vector during normal control, the current vector is changed along a constant torque curve (curve representing a current that generates the same torque) for realizing the command torque of the AC motor 12 during transmission early warm-up control. Thus, the current vector is corrected so as to increase the reactive current (d-axis current) that does not contribute to the torque generation of the AC motor 12. As a result, reactive power that does not contribute to torque generation of AC motor 12 (that is, power that is converted into thermal energy) can be increased, and the amount of heat generated by AC motor 12 can be increased accordingly.

In this transmission early warm-up control, the reactive power that does not contribute to the torque generation of the AC motor 12 can be increased to increase the amount of heat generated by the AC motor 12. Therefore, when the rotation of the AC motor 12 is stopped (command torque = 0). ), The amount of heat generated by the AC motor 12 can be increased while maintaining the AC motor 12 in a rotation stopped state without generating torque, and the torque is maintained at the command torque while the AC motor 12 is rotationally driven. As a result, the amount of heat generated by the AC motor 12 can be increased.
Hereinafter, the processing contents of each routine for early warm-up control of FIGS. 3 and 4 executed by the hybrid ECU 29 (or MG-ECU 31) will be described.

[Early warm-up control prohibition judgment routine]
The early warm-up control prohibition determination routine shown in FIG. 3 is executed immediately after the hybrid ECU 29 is powered on (immediately after the drive system is activated). When this routine is started, first, at step 101, it is determined whether or not the travel distance to the destination set by the navigation system (not shown) is greater than or equal to a predetermined value L. Here, the predetermined value L is set to a lower limit value (for example, 3 km) of the travel distance that is considered better to execute the transmission early warm-up control.

  If it is determined in step 101 that the travel distance to the destination is shorter than the predetermined value L, it is not necessary to execute the transmission early warm-up control because the vehicle is likely to stop early. In step 103, the prohibition flag is set to “ON”, which means that the transmission early warm-up control is prohibited.

  On the other hand, if it is determined in step 101 that the travel distance to the destination is greater than or equal to the predetermined value L, the process proceeds to step 102 to determine whether or not the outside air temperature is equal to or less than the predetermined value T1. Here, the predetermined value T1 is set to the upper limit value of the outside air temperature (for example, the target temperature of ATF) for which it is considered better to execute the transmission early warm-up control.

  If it is determined in this step 102 that the outside air temperature is higher than the predetermined value T1, the ATF and the transmission 13 are already warmed to some extent by the outside air, so there is no need to execute the transmission early warm-up control. In step 103, the prohibition flag is set to “ON”, which means that the transmission early warm-up control is prohibited.

  On the other hand, if it is determined in step 101 that the travel distance to the destination is equal to or greater than the predetermined value L, and if it is determined in step 102 that the outside air temperature is equal to or less than the predetermined value T1, It is determined that it is not necessary to prohibit the early machine warm-up control, the process proceeds to step 104, and the prohibition flag is set to “OFF”.

[Early warm-up control routine]
The early warm-up control routine shown in FIG. 4 is repeatedly executed at a predetermined cycle while the hybrid ECU 29 is powered on. When this routine is started, first, at step 201, it is determined whether or not the prohibition flag is OFF. If it is determined in step 201 that the prohibition flag is ON, the process proceeds to step 208, the early warm-up control flag is set to “OFF”, and then the process proceeds to step 209, where the target increase in reactive power is set. Set to “0” to prohibit transmission early warm-up control.

  On the other hand, if it is determined in step 201 that the prohibition flag is OFF, the process proceeds to step 202, in which whether or not the ATF temperature (ATF temperature) detected by the ATF temperature sensor 22 is equal to or less than a predetermined value T2. Determine. Here, the predetermined value T2 is set to the upper limit value of the ATF temperature (for example, the target temperature of the ATF) for which it is considered better to execute the transmission early warm-up control.

  If it is determined in step 202 that the ATF temperature is equal to or lower than the predetermined value T2, the process proceeds to step 203, and the motor temperature (temperature of the AC motor 12) detected by the motor temperature sensor 23 is equal to or lower than the predetermined value T3. It is determined whether or not. Here, the predetermined value T3 is set to a temperature (for example, an allowable upper limit value of the motor temperature) slightly lower than the temperature at which the AC motor 12 is overheated.

  If it is determined in step 203 that the motor temperature is equal to or lower than the predetermined value T3, the process proceeds to step 204, where it is determined whether or not the battery power (the power that can be supplied from the battery 19) is equal to or higher than the predetermined value P. . Here, the predetermined value P ensures drive power for the AC motor 12 and auxiliary equipment (for example, the electric oil pump 20, the electric water pump, the electric air conditioner, the headlight, etc.) during the execution of the transmission early warm-up control. Set to the battery power required to In this case, the predetermined value P may be a fixed value set in advance, but the predetermined value P may be changed according to the required power of the AC motor 12 or the auxiliary machinery. Further, the battery power (power that can be supplied from the battery 19) is calculated based on, for example, battery voltage, remaining battery capacity, battery temperature, and the like.

  If all of the above steps 202 to 204 are determined as “Yes”, that is, it is determined in step 202 that the ATF temperature is equal to or lower than the predetermined value T2, and in step 203, the motor temperature is equal to or lower than the predetermined value T3. If it is determined in step 204 that the battery power is greater than or equal to the predetermined value P, the process proceeds to step 205 and the early warm-up control flag is set to “ON”.

  Thereafter, the process proceeds to step 206, and a target increase amount of reactive power corresponding to the ATF temperature, motor temperature, and battery power is calculated by a map or a mathematical expression. In this case, the reactive power target increase map or formula is set so that, for example, the target increase decreases as the ATF temperature or the motor temperature increases, and the target increase decreases as the battery power decreases. ing. Thereby, the target increase amount of the reactive power is changed according to the ATF temperature, the motor temperature, and the battery power, and the heat generation amount of the AC motor 12 is changed.

  Thereafter, the process proceeds to step 207, where the current vector of the AC motor 12 is corrected (the reactive current is increased) so that the reactive power is increased by the target increase amount with respect to the current vector during normal control. Thereby, the reactive power that does not contribute to the torque generation of the AC motor 12 is increased and the amount of heat generated by the AC motor 12 is increased, thereby increasing the temperature of the ATF and promoting the warm-up of the transmission 13. Execute control.

  On the other hand, if it is determined as “No” in any of the above steps 202 to 204, that is, if it is determined in step 202 that the ATF temperature is higher than the predetermined value T2, or in step 203 described above. If it is determined that the motor temperature is higher than the predetermined value T3, or if it is determined in step 204 that the battery power is lower than the predetermined value P, the process proceeds to step 208 and the early warm-up control flag is set to “ After setting to “OFF”, the routine proceeds to step 209, where the target increase amount of the reactive power is set to “0” and the transmission early warm-up control is prohibited.

  In the present embodiment described above, the ATF temperature is raised by increasing the amount of heat generated by the AC motor 12 by increasing the reactive power that does not contribute to the torque generation of the AC motor 12 when the transmission 13 is warmed up. Transmission early warm-up control that promotes warm-up of the transmission 13 is executed. In this transmission early warm-up control, the reactive power that does not contribute to the torque generation of the AC motor 12 can be increased to increase the amount of heat generated by the AC motor 12. Therefore, when the rotation of the AC motor 12 is stopped (command torque = 0). ), The amount of heat generated by the AC motor 12 can be increased while maintaining the AC motor 12 in a rotation stopped state without generating torque, and the torque is maintained at the command torque while the AC motor 12 is rotationally driven. As a result, the amount of heat generated by the AC motor 12 can be increased. As a result, as shown in FIG. 5, it is possible to reliably increase the heat generation amount of the AC motor 12 without being influenced by the driving state of the vehicle (motor command torque) and to raise the ATF temperature earlier than before. Thus, warm-up of the transmission 13 can be promoted without being influenced by the driving state of the vehicle. Moreover, since the torque of the AC motor 12 can be maintained at the command torque, the warm-up of the transmission 13 can be promoted without adversely affecting the operation of the vehicle. In addition, since it is not necessary to provide a heat storage tank or the like for storing high-temperature ATF, it is possible to satisfy the demand for cost reduction and space saving of the drive system.

  In this embodiment, when it is determined that the motor temperature (the temperature of the AC motor 12) is higher than the predetermined value T3, the transmission early warm-up control is prohibited, so that the AC motor 12 is in an overheated state. In addition, when it is determined that the battery power (power that can be supplied from the battery 19) is smaller than the predetermined value P, the transmission early warm-up control is prohibited. Therefore, it is possible to ensure the driving power of the AC motor 12 and the auxiliary machines.

  Further, in this embodiment, when it is determined that the outside air temperature is higher than the predetermined value T1, the ATF and the transmission 13 are already warmed to some extent by the outside air, so it is necessary to execute the transmission early warm-up control. If it is determined that there is no transmission, the transmission early warm-up control is prohibited, and it is determined that the travel distance to the destination is shorter than the predetermined value L, the vehicle is likely to stop early, Since it was determined that there was no need to execute transmission early warm-up control, transmission early warm-up control was prohibited. Electric power can be reduced.

  Further, in the present embodiment, during the transmission early warm-up control, the target increase amount of the reactive power is changed according to the ATF temperature, the motor temperature, and the battery power so as to change the heat generation amount of the AC motor 12. Thus, the amount of heat generated by AC motor 12 can be controlled appropriately according to the ATF temperature, the motor temperature, and the battery power.

  In the above embodiment, the reactive power target increase amount is changed according to the ATF temperature, the motor temperature, and the battery power. However, the present invention is not limited to this. Of the ATF temperature, the motor temperature, and the battery power, You may make it change the target increase amount of reactive power according to two or one. Alternatively, the target increase amount of reactive power may be a fixed value set in advance.

  In the above embodiment, the motor temperature sensor 23 detects the motor temperature (the temperature of the AC motor 12). However, the present invention is not limited to this. For example, the driving current, the driving voltage, the driving time of the AC motor 12, The motor temperature may be estimated based on the outside air temperature, the vehicle speed, or the like.

  Furthermore, in the above embodiment, the ATF temperature sensor 22 detects the ATF temperature (ATF temperature). However, the present invention is not limited to this. For example, the drive current, drive voltage, drive time, and outside air temperature of the AC motor 12 are used. The ATF temperature may be estimated based on the vehicle speed or the like.

  In the above embodiment, the present invention is applied to a hybrid vehicle in which the AC motor 12 is disposed between the engine 11 and the transmission 13 in the power transmission path for transmitting the power of the engine 11 to the wheels 16. For example, the present invention may be applied to a hybrid vehicle in which the AC motor 12 is disposed between the transmission 13 and the wheel 16 in the power transmission path for transmitting the power of the engine 11 to the wheel 16, or Is a hybrid vehicle of a type in which an engine, a first AC motor, and a wheel drive shaft are connected via a power split mechanism (for example, a planetary gear mechanism) and a second AC motor and a wheel drive shaft are connected. The present invention may be applied. In this case, the power split mechanism corresponds to a transmission.

  Further, the present invention is not limited to a hybrid vehicle using both the engine and the motor as a power source, and may be a vehicle equipped with a motor and a transmission, such as an electric vehicle using only a motor as a power source. For example, the present invention can be applied to various vehicles.

  DESCRIPTION OF SYMBOLS 11 ... Engine (internal combustion engine), 12 ... AC motor, 13 ... Transmission, 17 ... Clutch, 18 ... Inverter, 19 ... Battery, 22 ... ATF temperature sensor, 23 ... Motor temperature sensor (motor temperature determination means), 24 ... Outside air temperature sensor, 29 ... hybrid ECU (warm-up control means), 30 ... engine ECU, 31 ... MG-ECU, 32 ... transmission ECU

Claims (6)

In a warm-up control device for a vehicle drive system that includes a motor and a transmission and performs heat exchange between the lubricating oil of the transmission and the motor.
When the transmission is warmed up, the reactive power that does not contribute to the torque generation of the motor is increased to increase the heat generation amount of the motor, thereby increasing the temperature of the lubricating oil and promoting the warming up of the transmission. A warm-up control device for a vehicle drive system, comprising warm-up control means for executing transmission early warm-up control. Motor temperature determining means for detecting or estimating the temperature of the motor;
The warm-up control means includes means for prohibiting the transmission early warm-up control when the motor temperature detected or estimated by the motor temperature determination means is higher than a predetermined value. The warm-up control device for the vehicle drive system described.   The said warm-up control means has a means for prohibiting the said transmission early warm-up control, when the electric power which can be supplied of the battery mounted in the vehicle is smaller than predetermined value. Warm-up control device for vehicle drive system.   The vehicle drive system according to any one of claims 1 to 3, wherein the warm-up control means includes means for prohibiting the transmission early warm-up control when the outside air temperature is higher than a predetermined value. Warm-up control device.   The warm-up control means includes means for prohibiting the transmission early warm-up control when a travel distance to a destination set by a navigation system mounted on a vehicle is shorter than a predetermined value. The warm-up control device for a vehicle drive system according to any one of claims 1 to 4.   The warm-up control means, during the transmission early warm-up control, increases the reactive power increase amount according to at least one of the lubricant temperature, the motor temperature, and the battery suppliable power. The warm-up control device for a vehicle drive system according to any one of claims 1 to 5, further comprising means for changing.

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