JP2006325367A - Cooling apparatus for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling apparatus for a vehicle that can reduce the drive loss of an oil pump by reducing a discharging oil quantity of the oil pump. <P>SOLUTION: The cooling apparatus for the vehicle cools a motor generator MG by using the oil of a transmission TM that reduces the rotation of the motor generator MG and transmits it. The apparatus also comprises the cooling circuit 12 of the motor generator MG, the lubrication cooling circuit 14 of the transmission TM, and the bypass circuit 15 that reaches the lubrication cooling circuit 14 from the cooling circuit 12. An oil passage switch valve 6 connects the cooling circuit 12 and the lubrication cooling circuit 14 via the bypass circuit 15 in series, and switches the cooling circuit 12 and the lubrication cooling circuit 14 so as to connect them in parallel. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicular cooling device, and more particularly, to a vehicular cooling device that cools an electric motor and a power transmission device suitable for use in a hybrid vehicle.

  Among conventional hybrid vehicles, in a hybrid vehicle in which the same wheels are driven by an engine and an electric motor, the electric motor is arranged in the engine room. Since the engine room is relatively hot, a liquid cooling method is used as a cooling method for the electric motor.

  Here, as a liquid cooling system for an electric motor, for example, as described in Japanese Patent Laid-Open No. 8-98464, there is known a method for cooling an electric motor using lubricating oil of a transmission which is a power transmission means. . In the one described in Japanese Patent Laid-Open No. 8-98464, a discharge circuit that supplies oil discharged from an oil pump further includes a lubricating circuit that supplies lubricating oil to the power transmission means, and a cooling circuit that supplies cooling oil to the electric motor. Are connected in parallel, and a lubrication circuit and a cooling circuit are connected via a valve. Then, by adjusting the pressure of the valve, the amount of lubricating oil in the power transmission means is kept constant, and only the amount of cooling oil in the motor is increased with the increase in the amount of oil discharged from the oil pump. By eliminating this, the motor is efficiently cooled while reducing the drive loss of the oil pump.

JP-A-8-98464

  However, in the one described in Japanese Patent Application Laid-Open No. 8-98464, a lubricating circuit that supplies lubricating oil to the power transmission means and a cooling circuit that supplies cooling oil to the electric motor are connected in parallel. Since the flow rate is always the sum of the amount of lubricating oil that lubricates the power transmission means and the amount of cooling oil that cools the motor, a large amount of oil is required to be discharged from the oil pump, and the oil pump that discharges this large amount of oil There is a problem that the driving force becomes a driving loss of the oil pump.

  An object of the present invention is to provide a vehicular cooling device capable of reducing the oil pump discharge oil amount and reducing the drive loss of the oil pump.

(1) In order to achieve the above object, the present invention provides a vehicular cooling device that cools the electric motor by using oil of a power transmission device that decelerates and transmits the rotation of the electric motor. A cooling circuit of the power transmission device, a lubricating cooling circuit of the power transmission device, and a bypass circuit extending from the cooling circuit to the lubricating cooling circuit.
With this configuration, the amount of oil discharged from the oil pump can be reduced, and the drive loss of the oil pump can be reduced.

  (2) In the above (1), preferably, the cooling circuit and the lubrication cooling circuit are selectively disconnected in the middle of the circuit from the cooling circuit to the lubrication cooling circuit, and the cooling circuit and the oil pan are cooled. An oil passage changeover valve for connecting a drain circuit for draining is provided.

  (3) In the above (1), preferably, the oil passage switching valve disconnects the cooling circuit and the lubrication cooling circuit when the oil temperature after cooling is extremely low, connects at a normal temperature, and disconnects at a high temperature. It is a thing.

(4) Moreover, in order to achieve the said objective, this invention is a cooling device for vehicles which cools the said electric motor using the oil of the power transmission device which decelerates and transmits rotation of an electric motor, When the cooling circuit of the motor, the lubrication cooling circuit of the power transmission device, and the oil temperature after cooling are lower than a first predetermined temperature, the power transmission device is cooled with oil that has cooled the motor. A flow path switching valve for switching the flow path so that the cooling circuit and the lubrication cooling circuit are connected in parallel when the cooling circuit and the lubrication cooling circuit are connected in series and are higher than the second predetermined temperature; It is intended to provide.
With this configuration, the amount of oil discharged from the oil pump can be reduced, and the drive loss of the oil pump can be reduced.

  (5) In the above (4), preferably, when the oil temperature after cooling is lower than a second predetermined temperature lower than the first predetermined temperature, the flow path switching valve is connected to the cooling circuit. The flow path is switched so as to be connected in parallel with the lubrication cooling circuit.

(6) Furthermore, in order to achieve the above-mentioned object, the present invention uses an electric motor, a power transmission device that transmits the rotation of the motor at a reduced speed, and oil for the power transmission device. When the oil temperature after cooling is lower than a first predetermined temperature, a cooling circuit for the electric motor is configured to cool the power transmission device with oil that has cooled the electric motor. A lubrication cooling circuit of the power transmission device is connected in series, and when the temperature is higher than the second predetermined temperature, a flow path switching valve that switches the flow path so as to connect the cooling circuit and the lubrication cooling circuit in parallel. It is intended to provide.
With this configuration, the amount of oil discharged from the oil pump can be reduced, and the drive loss of the oil pump can be reduced.

  According to the present invention, the amount of oil discharged from the oil pump can be reduced, and the drive loss of the oil pump can be reduced.

Hereinafter, the configuration and operation of the vehicle cooling device according to the embodiment of the present invention will be described with reference to FIGS.
First, the configuration of the hybrid vehicle including the vehicle cooling device according to the present embodiment will be described with reference to FIG.
FIG. 1 is a system block diagram showing a configuration of a hybrid vehicle including a vehicle cooling device according to an embodiment of the present invention.

  The hybrid vehicle of this embodiment is configured to drive the front wheels WH-F by an engine EN that is an internal combustion engine and a motor / generator MG. The rear wheels WH-R may be driven by the engine EN and the motor / generator MG.

  A transmission TM as a power transmission means is mechanically connected to the front wheel axle DS-F of the front wheel WH-F via a differential (not shown). An engine EN and a motor / generator MG are mechanically connected to the transmission TM via an output control mechanism (not shown). The output control mechanism (not shown) is a mechanism that controls composition and distribution of rotation outputs. The AC side of the inverter INV is electrically connected to the stator winding of the motor / generator MG. The inverter INV is a power conversion device that converts DC power into three-phase AC power, and controls driving of the motor / generator MG. A battery BA is electrically connected to the DC side of the inverter INV. The inverter INV includes a conversion circuit unit for the motor / generator MG and a drive control unit for driving the conversion circuit unit.

  The transmission TM and the motor / generator MG, which are power transmission means, are cooled by the vehicle cooling device CA. A detailed configuration of the vehicle cooling device CA will be described later with reference to FIG.

  When the hybrid vehicle starts up and travels at a low speed (a travel region in which the operating efficiency (fuel consumption) of the engine EN decreases), the front wheels WH-F are driven by the motor / generator MG. DC power is supplied from the battery BA to the inverter INV. The supplied DC power is converted into three-phase AC power by the inverter INV. The three-phase AC power thus obtained is supplied to the stator winding of the motor / generator MG. As a result, the motor / generator MG is driven as an electric motor and generates a rotational output. This rotational output is input to the transmission TM via an output control mechanism (not shown). The input rotation output is shifted by the transmission TM and input to a differential (not shown). The input rotation output is distributed to the left and right by a differential (not shown) and transmitted to the front wheel axle DS-F on one of the front wheels WH-F and the front wheel axle DS-F on the other of the front wheels WH-F. Thereby, the front wheel axle DS-F is rotationally driven. Then, the front wheels WH-F are rotationally driven by the rotational driving of the front wheel axle DS-F.

  During normal traveling of the hybrid vehicle (when traveling on a dry road surface, where the driving efficiency (fuel efficiency) of the engine EN is good), the front wheels WH-F are driven by the engine EN. For this reason, the rotational output of the engine EN is input to the transmission TM via an output control mechanism (not shown). The input rotation output is shifted by the transmission TM. The shifted rotational output is transmitted to the front wheel axle DS-F via a differential (not shown). Thereby, the front wheel WH-F is rotationally driven. Further, when it is necessary to charge the battery BA by detecting the state of charge of the battery BA, the rotational output of the engine EN is distributed to the motor / generator MG via an output control mechanism (not shown). MG is driven to rotate. As a result, the motor / generator MG operates as a generator. By this operation, three-phase AC power is generated in the stator winding of the motor / generator MG. The generated three-phase AC power is converted into predetermined DC power by the inverter INV. The DC power obtained by this conversion is supplied to the battery BA. Thereby, the battery BA is charged.

  During acceleration of the hybrid vehicle, the front wheels WH-F are driven by the engine EN and the motor / generator MG. The rotational outputs of the engine EN and the motor / generator are input to the transmission TM via an output control mechanism (not shown). The input rotation output is shifted by the transmission TM. The shifted rotational output is transmitted to the front wheel axle DS-F via a differential (not shown). Thereby, the front wheel WH-F is rotationally driven.

  During regeneration of the hybrid vehicle (when depressing the brake, depressing the accelerator, or decelerating the accelerator), the rotation output of the front wheel WH-F is converted to the front wheel axle DS-F, differential unit (Not shown), transmitted to the motor / generator MG via the transmission TM and an output control mechanism (not shown), and the motor generator MG is driven to rotate. Thereby, the motor / generator MG operates as a generator. By this operation, three-phase AC power is generated in the stator winding of the motor / generator MG. The generated three-phase AC power is converted into predetermined DC power by the inverter INV. The DC power obtained by this conversion is supplied to the battery BA. Thereby, the battery BA is charged.

Next, the configuration of the vehicle cooling device according to the present embodiment will be described with reference to FIG.
FIG. 2 is a block diagram showing the configuration of the vehicle cooling device according to the embodiment of the present invention.

  The vehicle cooling device CA cools the motor / generator MG and lubricates and cools the transmission TM, which is a power transmission device that decelerates and transmits the output torque of the motor / generator MG to drive wheels (not shown).

  The vehicle cooling device CA includes an oil pan 7, an oil pump 8, an oil pump drive device 3, a radiator 9, a thermostat valve 10, a flow rate control valve 5, an oil path switching valve 6, and an electronic control unit 30. With. The oil pan 7 cools the motor / generator MG and collects oil that has been subjected to lubrication cooling of the transmission TM that is a power transmission device. The oil pump 8 cools oil accumulated in the oil pan 7 from the oil pan 7 to the motor / generator MG, the oil pump drive device 3, and the transmission TM, which is a power transmission device, via the discharge circuit 11, and the cooling oil. And circulate as lubricating oil. The oil pump 8 is driven by an oil pump driving device 3 such as a motor. The circulating oil is cooled by the radiator 9. The thermostat valve 10 switches the oil path according to the temperature of the oil discharged from the oil pump 8, and bypasses the radiator 9 that cools the oil when the oil temperature is low, and the radiator 9 when the temperature is high. And switch the oil path to cool the oil. The flow rate control valve 5 supplies oil whose temperature is controlled by a thermostat valve 10 and a radiator 9, a cooling circuit 12 for cooling the motor / generator MG and the oil pump drive device 3, and a transmission TM which is a power transmission device. The amount of oil is distributed to the lubrication cooling circuit 14 for lubrication cooling. The oil passage switching valve 6 is connected to a cooling drain circuit 13 that drains oil that has cooled the motor / generator MG and the oil pump driving device 3 to the oil pan 7 or is connected to a lubricating cooling circuit 14 of the transmission TM that is a power transmission device. Whether to connect to the bypass circuit 15 to be connected is switched.

  The flow control valve 5 and the oil passage switching valve 6 are controlled by the electronic control unit 30. The electronic control unit 30 is configured as a microprocessor centered on a CPU 32, and includes a ROM 34 that stores a processing program, a RAM 36 that temporarily stores data, and an input / output port (not shown). The electronic control unit 30 includes a coil temperature from the temperature sensor 20 attached to the coil portion of the motor / generator MG, a coil temperature from the temperature sensor 21 of the oil pump driving device 3, and a transmission TM that is a power transmission device. The oil temperature from the temperature sensor 19 attached to the oil pan 7 and the vehicle speed from the rotation sensor 22 attached to the output shaft of the transmission TM as a power transmission device are input via the input port. . The electronic control unit 30 also outputs a drive signal to the duty solenoid that forms the flow control valve 5 and the ON-OFF solenoid that constitutes the oil passage switching valve 6 via the output port.

Next, the operation of the cooling circuit of the motor / generator MG and the oil pump driving device 3 by the vehicle cooling device according to the present embodiment and the lubrication cooling circuit of the transmission TM as a power transmission device will be described with reference to FIG.
FIG. 3 is a flow chart showing the operation of the motor / generator and oil pump drive device cooling circuit and the power transmission device lubrication cooling circuit of the transmission according to the embodiment of the present invention.

  The process shown in FIG. 3 shows an example of a cooling lubricating oil passage / oil amount control routine executed by the electronic control unit 30. This routine is repeatedly executed every predetermined time.

  First, in step S101, the electronic control unit 30 reads various signals. The signals to be read are 1) oil temperature (To), 2) coil temperature of motor / generator MG (Tm), 3) temperature of oil pump drive device 3 (Top), 4) vehicle speed (Vsp), and 5) motor. The command torque (TQm) to the generator MG, 6) The command rotation speed (Nop) of the oil pump drive device 3. The oil temperature (To) is an output signal of the temperature sensor 19 disposed in the oil of the oil pan 7. The coil portion temperature (Tm) of the motor / generator MG is an output signal of the temperature sensor 20 disposed in the coil portion of the motor / generator MG. The temperature (Top) of the oil pump drive device 3 is an output signal of the temperature sensor 21 disposed in the coil portion of the oil pump drive device 3 (for example, an electric motor). The vehicle speed (Vsp) is an output signal of the rotation sensor 22 disposed on the output shaft of the transmission TM that is a power transmission device. The instruction torque (TQm) to the motor / generator MG is a required torque to the motor / generator MG obtained from information such as an accelerator opening degree that is a driving operation of the driver and a vehicle speed that is a driving state of the vehicle.

  Next, in step S102, the electronic control unit 30 performs oil path switching valve control based on the signal read in step S101.

Here, the content of the oil passage switching valve control by the vehicle cooling device according to the present embodiment will be described with reference to FIG.
FIG. 4 is an explanatory diagram showing the contents of the oil passage switching valve control by the vehicle cooling device according to the embodiment of the present invention.

  The oil passage switching valve 6 is a three-port electromagnetic switching valve constituted by, for example, an ON-OFF solenoid. When the ON-OFF solenoid is OFF, the oil path switching valve 6 bypasses the cooling circuit 12 of the motor / generator MG and the oil pump drive device 3 and the lubrication cooling circuit 14 of the transmission TM as a power transmission device. And the cooling circuit 12 and the drain circuit 13 of the oil pump driving device 3 are disconnected. That is, the cooling circuit 12 of the motor / generator MG and the lubrication cooling circuit 14 of the transmission TM, which is a power transmission device, are connected in series by the bypass circuit 15.

  When the ON-OFF solenoid is ON, the oil passage switching valve 6 connects the motor / generator MG and the cooling circuit 12 of the oil pump driving device 3 to the drain circuit 13 to the oil pan 7 and transmits power. The lubrication cooling circuit 14 of the transmission TM as the device is disconnected. That is, the cooling circuit 12 of the motor / generator MG and the lubrication cooling circuit 14 of the transmission TM as a power transmission device are connected in parallel.

  In the table shown in FIG. 4, the oil temperature (To) is an output signal of the temperature sensor 19 disposed in the oil of the oil pan 7. The temperature (Th) is the higher one of the coil part temperature (Tm) of the motor / generator MG and the temperature (Top) of the oil pump drive device 3. Moreover, it has setting value T1, T2, T3. The set value T1 is used to determine whether the cooling lubricating oil has a low temperature with a high viscosity or a high temperature with a low viscosity, and is set to 0 ° C., for example. The set value T2 is the operating temperature of the thermostat valve 10, and is 80 ° C., for example. The set value T3 is used to determine whether the coil portion temperature (Tm) of the motor / generator MG and the temperature (Top) of the oil pump drive device 3 are high. For example, the set value T3 is set to 150 ° C. ing.

  As shown in FIG. 4, when the oil temperature (To) of the oil pan 7 is lower than the set value T1, the ON / OFF solenoid of the oil passage switching valve 6 is turned ON to drive the motor / generator MG and the oil pump. The cooling circuit 12 of the device 3 and the drain circuit 13 to the oil pan 7 are connected, and the lubrication cooling circuit 14 of the transmission TM that is a power transmission device is disconnected.

  Further, when the oil temperature (To) of the oil pan 7 is higher than the set value T1 and lower than the set value T2, the ON-OFF solenoid of the oil path switching valve 6 is turned OFF, and the motor / generator MG and the oil pump are turned off. The cooling circuit 12 of the drive device 3 and the lubrication cooling circuit 14 of the transmission TM, which is a power transmission device, are connected by a bypass circuit 15 and the cooling circuit 12 and the drain circuit 13 of the oil pump drive device 3 are disconnected.

  Further, the oil temperature (To) of the oil pan 7 is higher than the set value T2, and the higher temperature Th obtained by comparing the coil temperature of the motor / generator MG and the coil temperature of the oil pump drive device 3 is higher than the set value T3. Is higher, the ON / OFF solenoid of the oil passage switching valve 6 is turned ON to connect the motor / generator MG and the cooling circuit 12 of the oil pump drive device 3 to the drain circuit 13 to the oil pan 7, The lubrication cooling circuit 14 of the transmission TM, which is a power transmission device, is disconnected.

  On the other hand, the oil temperature (To) of the oil pan 7 is higher than the set value T2, and the higher temperature Th obtained by comparing the coil temperature of the motor / generator MG and the coil temperature of the oil pump drive device 3 is higher than the set value T3. Is lower, the ON / OFF solenoid of the oil passage switching valve 6 is turned off, the cooling circuit 12 of the motor / generator MG and the oil pump drive device 3, and the lubrication cooling circuit 14 of the transmission TM which is a power transmission device, Are connected by a bypass circuit 15 and the cooling circuit 12 and the drain circuit 13 of the oil pump drive device 3 are disconnected.

  Next, in step S103 of FIG. 3, the electronic control unit 30 determines whether or not the oil temperature (To) of the oil pan 7 is lower than the set value T1, and if it is lower, the process proceeds to step S104, otherwise. In this case, the process proceeds to step S105, and a cooling oil amount (Q1) for cooling the motor / generator MG and the oil pump driving device 3 and a lubricating cooling oil amount (Q2) for the transmission TM as a power transmission device are obtained.

  In step S103, when it is determined that the oil temperature is lower than the set value T1 (for example, 0 ° C.), in step S104, both Q1 and Q2 are set to the maximum flow rate. This is because when the oil is at a low temperature, the viscosity increases rapidly, so that the pressure loss in the oil passage increases and the oil does not flow easily. Accordingly, the maximum flow rate is supplied to prevent oil clogging in the oil passage.

  On the other hand, if it is determined in step S103 that the oil temperature is higher than a set value T1 (for example, 0 ° C.), Q1 and Q2 are calculated in S105.

Here, using FIG. 5 and FIG. 6, the cooling oil amount (Q1) for cooling the motor / generator MG and the oil pump drive device 3 in the vehicular cooling device according to the present embodiment, and the transmission TM which is a power transmission device. A method of calculating the amount of lubricating cooling oil (Q2) will be described.
FIG. 5 is an explanatory diagram of a calculation method of the cooling oil amount (Q1) and the lubricating cooling oil amount (Q2) in the vehicle cooling device according to the embodiment of the present invention. FIG. 6 is an explanatory diagram of arithmetic expressions for the cooling oil amount (Q1) and the lubricating cooling oil amount (Q2) in the vehicle cooling device according to the embodiment of the present invention.

  As shown in FIG. 5, the amount of cooling oil (Q1) for cooling the motor / generator MG and the oil pump drive device 3 from the operating state of the oil passage switching valve 6 obtained in step S102, and the shift that is the power transmission device The amount of lubricating cooling oil (Q2) of the machine TM is obtained.

  In other words, when the oil passage switching valve 6 is OFF, the cooling oil amount Q1 is equal to the cooling required oil amount Q11 of the motor / generator MG and the oil pump driving device 3 and the lubricating cooling required oil amount of the transmission TM which is a power transmission device. Let Q21 be the larger flow rate and Q2 be 0. A method of calculating the required cooling oil amount Q11 and the required lubricating cooling oil amount Q21 will be described later with reference to FIG.

  This is because the oil passage switching valve 6 connects the motor / generator MG and the cooling circuit 12 of the oil pump drive device 3 and the lubrication cooling circuit 14 of the transmission TM, which is a power transmission device, in series by a bypass circuit 15. Therefore, the larger amount of oil required by both circuits is selected, and the drive of the oil pump drive device 3 is minimized. That is, if the temperature of the cooling oil after cooling the electric motor is not high, it can be used as the lubricating oil for the power transmission means, and if the cooling oil after cooling the electric motor is used as the lubricating oil for the power transmission means, The amount of oil discharged from the oil pump can be reduced as compared with the case where the circuit is configured in parallel so as to separately supply the lubricating oil to the transmission means and the cooling oil to the electric motor. As a result, unnecessary oil discharge amount of the oil pump is eliminated, and it is possible to efficiently lubricate the power transmission device and cool the electric motor while reducing drive loss of the oil pump.

  On the other hand, when the oil passage switching valve 6 is ON, the cooling oil amount Q1 = the required cooling oil amount Q11 and the lubricating cooling oil amount Q2 = the lubricating cooling required oil amount Q21. At this time, the oil passage switching valve 6 causes the motor / generator MG and the cooling circuit 12 of the oil pump drive device 3 and the lubrication cooling circuit 14 of the transmission TM, which is a power transmission device, to flow in parallel. .

  Next, a calculation method of the required oil amount Q11 for the motor / generator MG and the oil pump driving device 3 and the required lubricating oil amount Q21 for the transmission TM that is a power transmission device will be described with reference to FIG. The required oil amount Q11 for cooling the motor / generator MG and the oil pump drive device 3 is calculated by multiplying the sum of coefficients k determined by the following parameters by the basic flow rate using the oil temperature as a parameter. The basic flow rate is set so that the flow rate increases when the oil temperature is high. When the oil temperature increases, the difference between the coil temperature of the motor / generator MG and the oil temperature decreases and the cooling capacity decreases. Increases the flow rate and secures cooling capacity. The coefficient k is 1) the coil temperature (Tm) of the motor / generator MG, 2) the command torque (TQm) to the motor / generator MG, 3) the temperature (Top) of the oil pump driving device 3, and 4) the oil pump driving device. It is set based on the four parameters of the indicated rotation speed (Nop) of 3.

  When the coil temperature Tm of the motor / generator MG and the temperature Top of the oil pump driving device 3 are high, the coefficient k is set to be large in order to increase the cooling capacity. Further, when the instruction torque TQm to the motor / generator MG is large, it can be predicted that the coil temperature of the motor / generator MG will increase, so the coefficient k is set large. Furthermore, when the command rotational speed Nop of the oil pump drive device 3 is large, it can be predicted that the temperature rise of the oil pump drive device 3 will increase, so the coefficient k is set large.

  The oil quantity Q21 required for lubrication and cooling of the transmission TM as a power transmission device is calculated by multiplying the sum of the coefficient k determined by the following parameters by the basic flow rate using the oil temperature as a parameter. The basic flow rate is set to be a large flow rate when the oil temperature is high. This is because the viscosity of the oil decreases as the oil temperature increases and the oil film in the lubrication part tends to break. Therefore, the flow rate is set larger as the temperature increases. The coefficients are set with 1) vehicle speed (Vsp) and 2) command torque (TQm) to the motor / generator MG as parameters. The coefficient k increases because the rotational speed of the transmission TM, which is a power transmission device, is high when the vehicle speed is high, and because the input torque to the power transmission device is large when the indicated torque of the motor / generator MG is large. Is set to

  As described above, based on the required cooling oil amount Q11 and the required lubricating cooling oil amount Q21, as shown in FIG. 5, the cooling oil amount Q1 is determined from the operating state of the oil passage switching valve 6 determined in step S102. , Determine the lubricating cooling oil amount Q2.

  Next, in step S106 of FIG. 3, the electronic control unit 30 calculates an instruction Duty to the flow control valve 5, and supplies the cooling oil amount Q1 to the motor / generator MG and the transmission TM which is a power transmission device. Control distribution of lubricating cooling oil amount Q2. As the flow control valve 5, for example, a 3-port electromagnetic switching valve constituted by a Duty solenoid is used. When the duty solenoid is not energized, that is, when On-Duty = 0%, the discharge circuit 11 is connected to the cooling circuit 12 and disconnected from the lubrication cooling circuit 14. Conversely, when the duty solenoid is energized, that is, when On-Duty = 100%, the discharge circuit 11 is linked to the lubrication cooling circuit 14 and is disconnected from the cooling circuit 12. The distribution ratio of the cooling oil amount Q1 of the motor / generator MG to the duty value in the flow control valve 5 and the lubricating cooling oil amount Q2 of the transmission TM as a power transmission device is On-Duty = 25%. Q1: Lubricating cooling oil amount Q2 = 75: 25, On-Duty = 50%, cooling oil amount Q1: Lubricating cooling oil amount Q2 = 50: 50, On-Duty = 75%, cooling oil amount Q1: The distribution ratio between the cooling oil amount Q1 and the lubricating cooling oil amount Q2 can be linearly changed according to On-Duty, such as the lubricating cooling oil amount Q2 = 25: 75. The instruction On-duty to the flow control valve 5 is 0% when (Q2 / (Q1 + Q2)) is 0 using the cooling oil amount Q1 and the lubricating cooling oil amount Q2 calculated in step S104 or step S105. When (Q2 / (Q1 + Q2)) is 0.5, it is determined to be 50%, and when (Q2 / (Q1 + Q2)) is 1, it is determined to be 100%.

Next, in step S <b> 107 of FIG. 3, the electronic control unit 30 controls the oil pump drive device 3 by calculating the rotational speed N of the oil pump drive device 3 by the following equation (1).

N = (Q1 + Q2) / (ηv · V) (1)

Here, N: oil pump rotational speed, ηv: oil pump volumetric efficiency, and V: oil pump displacement volume.

Next, the operation state of the vehicle cooling device according to the present embodiment will be described with reference to FIGS.
FIGS. 7-10 is an oil circuit diagram which shows the operating state of the vehicle cooling device by one Embodiment of this invention. 7 to 10, a thick solid line indicates that oil is flowing. The same reference numerals as those in FIG. 2 denote the same parts.

  First, FIG. 7 shows cooling in the case where the oil temperature is lower than the set value T1 (for example, 0 ° C.), that is, when To read in step S101 in FIG. 3 is lower than the set value T1 (for example, 0 ° C.). The oil flow of the device is shown. From the condition of step S103 in FIG. 3, Q1 = Q2 = QMAX (maximum flow rate) is calculated in step S104, and the oil pump drive device 3 is controlled by the electronic control unit 30 so that the discharge flow rate of the oil pump 8 becomes Q1 + Q2. Is done. And since oil temperature is low, the thermostat valve 10 comprises an oil path so that the radiator 9 may be bypassed. Since the flow rate control valve 5 is Q1 = Q2, Duty = 50% in step S106 in FIG. 3 and the cooling circuit 12 for cooling the motor / generator MG and the oil pump drive unit 3 and the transmission TM which is a power transmission device. The oil amount is distributed to the lubricating cooling circuit 14. The oil path switching valve 5 is turned ON in step S102 of FIG. 3 as shown in FIG.

  That is, the oil that has cooled the motor / generator MG and the oil pump drive device 3 is drained to the oil pan 7. Oil that has been lubricated and cooled for the transmission TM that is a power transmission device is also drained to the oil pan 7. As described above, when the oil temperature is low, the viscosity of the oil is large and the pressure loss is large, so that the oil is difficult to flow. Therefore, the pressure loss of the oil passage from the oil pump 8 to the oil pan 7 is not increased by paralleling the cooling circuit 12 of the motor / generator MG and the oil pump drive device 3 and the lubrication cooling circuit 14 of the transmission TM as a power transmission device. The oil passage configuration is as follows. Further, by maximizing the discharge amount of the m oil pump 3, clogging due to high oil viscosity in the circuit is prevented.

  Second, FIG. 8 shows the flow of oil in the cooling device when the oil temperature To is equal to or greater than a set value T1 (for example, 0 ° C.) and less than a set value T2 (the thermostat valve 10 operating temperature: for example, 80 ° C.). The oil pump driving device 3 is controlled so that the discharge amount of the oil pump 8 becomes Q1, and the oil temperature is lower than a set value T2 (thermostat valve 10 operating temperature: for example, 80 ° C.). The road bypasses the radiator 9. Since the flow rate control valve 5 is Q2 = 0, On-Duty = 0%, the discharge circuit 11 is connected to the cooling circuit 12, and the lubrication cooling circuit 14 is disconnected. As shown in FIG. 4, the oil passage switching valve 6 is turned off, and the cooling circuit 12 and the lubrication cooling circuit 14 are connected in series, and the motor / generator MG and the oil pump driving device 3 are cooled and heated oil is transmitted to the power transmission device. To the transmission TM.

  As a result, the oil agitation resistance decreases as the oil viscosity decreases. Further, the temperature of each part of the transmission TM that is the power transmission device rises rapidly, so that the friction of the sliding portion of the power transmission device is reduced.

  Third, FIG. 9 shows cooling when the oil temperature To is equal to or higher than the set value 2 (thermostat valve 10 operating temperature: for example, 80 ° C.) and the motor / generator MG coil temperature is lower than the set value T 3 (for example, 150 ° C.). The oil flow of the device is shown. Since the temperature of the oil becomes equal to or higher than the operating temperature of the thermostat valve 10, the oil discharged from the oil pump 8 is cooled by the radiator 9 by the operation of the thermostat valve 10. The oil passages of the other cooling devices are the same as in the second case. At this time, the power transmission device is used as one means for cooling the oil by cooling the motor / generator MG and the oil pump driving device 3 as lubricating cooling oil to the transmission TM which is the power transmission device. The mass of a certain transmission TM can be used.

  Fourth, FIG. 10 shows the oil of the cooling device when the oil temperature To is equal to or higher than a set value T2 (thermostat valve 10 operating temperature: for example, 80 ° C.) and the motor / generator MG coil temperature is equal to or higher than the set value (for example, 300 ° C.). Shows the flow. Since the motor / generator MG coil temperature is high, the temperature of the oil after cooling the motor / generator MG becomes high. If this high-temperature oil is used as a lubricating cooling oil for the transmission TM as a power transmission device, the oil film of the sliding portion may be cut off, leading to damage. Therefore, the cooling circuit 12 and the lubricating cooling circuit 14 are controlled by the flow control valve 5. Distribute the oil amount. Further, the oil passage switching valve 6 is turned ON, and the cooling circuit 12 is connected to the drain circuit 13 to the oil pan 7 so as to be in parallel with the lubrication cooling circuit 14.

  Thereby, since the transmission TM which is a power transmission device is not lubricated with high-temperature oil, the oil film of the sliding portion can be prevented from being cut, and as a result, the durability of the transmission TM which is the power transmission device can be improved.

  As described above, according to this embodiment, the bypass circuit from the motor cooling circuit to the lubrication cooling circuit of the power transmission device is provided, and the cooling oil after cooling is cooled when the temperature of the cooling oil after cooling the motor is not high. By supplying oil to the lubricating circuit of the power transmission device, the oil pump discharge flow rate can be reduced, and the oil pump driving load can be reduced. Thereby, the driving loss of the vehicle is reduced, and as a result, the fuel efficiency of the vehicle can be improved.

  In addition, when the oil temperature is extremely low, the cooling circuit of the electric motor and the drain circuit are connected and disconnected from the lubrication cooling circuit of the power transmission device, so that the oil can be circulated even in a situation where the oil viscosity is high. In addition, when the electric current flows, that is, when the driving torque is generated, the electric motor generates heat immediately and absorbs the heat with the cooling oil, so that the oil temperature can be raised quickly. Thereby, it is possible to reduce losses such as friction of the sliding portion of the power transmission device and oil agitation resistance.

  In addition, when the oil temperature is high, the motor cooling circuit and the drain circuit are connected and disconnected from the lubrication cooling circuit of the power transmission device, so that it is possible to prevent the power transmission device from being lubricated with high temperature oil. A failure of the power transmission device due to cutting or the like can be avoided.

Next, the configuration and operation of a vehicle cooling device according to another embodiment of the present invention will be described with reference to FIGS.
FIG. 11 is a block diagram showing a configuration of a vehicle cooling device according to another embodiment of the present invention. FIG. 12 is a flowchart showing the operation of the cooling circuit and the lubrication cooling circuit by the vehicle cooling device according to another embodiment of the present invention. FIG. 13 is an explanatory diagram showing the contents of the oil passage switching valve control by the vehicle cooling device according to another embodiment of the present invention. FIG. 14 is an explanatory diagram of arithmetic expressions for the cooling oil amount (Q1) and the lubricating cooling oil amount (Q2) in the vehicle cooling device according to another embodiment of the present invention.

  The configuration of the hybrid vehicle including the vehicle cooling device according to the present embodiment is the same as that shown in FIG. However, instead of the motor / generator MG shown in FIG. 1, an electric motor 25 and a generator 23 are connected to the cooling circuit 12 as shown in FIG. 11. Moreover, the temperature sensor 26 attached to the coil part of the electric motor 25 and detecting the coil temperature and the temperature sensor 24 attached to the coil part of the generator 23 and detecting the coil temperature are provided.

  In the present embodiment, the flow control valve 6 is oiled in two systems: 1) cooling of the electric motor 25, generator 23, and oil pump peristaltic device 3, and 2) lubrication cooling of the transmission TM that is a power transmission device. Apportion. Then, the oil path switching valve 6 includes a motor 25, a generator 23, and a cooling circuit 12 for the oil pump drive device 3, a lubrication cooling circuit 14 for the transmission TM that is a power transmission device, and a drain circuit 13 for the oil pan 7. Connect to one and disconnect from the other.

  Next, the operation of the motor, the generator, the oil pump drive device cooling circuit, and the transmission lubrication cooling circuit, which is the power transmission device, of the vehicle cooling device according to the present embodiment will be described with reference to FIG. The same reference numerals as those in FIG. 3 indicate the same processing contents. The process shown in FIG. 12 shows an example of a cooling lubricating oil passage / oil amount control routine executed by the electronic control unit 30A. This routine is repeatedly executed every predetermined time.

  First, in step S101A, the electronic control unit 30 reads various signals. The signals to be read are 1) oil temperature (To) read in step S101 of FIG. 3, 2) coil portion temperature (Tm) of electric motor 25, 3) temperature of oil pump drive device 3 (Top), 4) vehicle speed ( Vsp), 5) Instructed torque (TQm) to the electric motor 25, 6) In addition to the instructed rotational speed (Nop) of the oil pump driving device 3, 7) Generator temperature (Tg), and 8) Temperature of the generator 25 It is an expected increase value (TQg).

  Next, in step S102A, the electronic control unit 30 performs oil path switching valve control based on the signal read in step S101.

Here, the content of the oil passage switching valve control by the vehicle cooling device according to the present embodiment will be described with reference to FIG.
The oil passage switching valve 6 is a three-port electromagnetic switching valve constituted by, for example, an ON-OFF solenoid. When the ON-OFF solenoid is OFF, the oil passage switching valve 6 bypasses the motor 25, the generator 23, the cooling circuit 12 of the oil pump drive device 3, and the lubrication cooling circuit 14 of the transmission TM that is a power transmission device. While being connected by the circuit 15, the cooling circuit 12 and the drain circuit 13 of the oil pump driving device 3 are disconnected. That is, the cooling circuit 12 of the electric motor 25 and the lubrication cooling circuit 14 of the transmission TM that is a power transmission device are connected in series by the bypass circuit 15.

  When the ON-OFF solenoid is ON, the oil passage switching valve 6 connects the electric motor 25 generator 23, the cooling circuit 12 of the oil pump driving device 3, and the drain circuit 13 to the oil pan 7, and power The lubrication cooling circuit 14 of the transmission TM that is the transmission device is disconnected. That is, the cooling circuit 12 of the electric motor 25 and the lubrication cooling circuit 14 of the transmission TM that is a power transmission device are connected in parallel.

  In the table shown in FIG. 13, the horizontal axis is the same as in FIG. The temperature Th ′ on the vertical axis is the highest temperature as a result of comparing the coil temperature Tm of the electric motor 25, the coil temperature Tg of the generator 23, and the coil temperature Top of the oil pump driving device 3. Other than that, the ON / OFF switching conditions of the ON-OFF solenoid of the oil passage switching valve 6 for each set temperature T1, T2, T3 are the same.

  Steps S103 and S104 are the same as steps S103 and S104 in FIG.

  On the other hand, if it is determined in step S103 that the oil temperature is higher than the set value T1 (for example, 0 ° C.), Q1 and Q2 are calculated in S105A.

  Here, referring to FIG. 14, the cooling oil amount (Q1) for cooling the electric motor 25, the generator 23, and the oil pump driving device 3 in the vehicle cooling device according to the present embodiment, and the transmission TM that is the power transmission device. A method of calculating the lubricating cooling oil amount (Q2) will be described.

  As shown in FIG. 5, from the operating state of the oil passage switching valve 6 obtained in step S102, the cooling oil amount (Q1) for cooling the electric motor 25, the generator 23, and the oil pump drive device 3, and the power transmission device The amount of lubricating cooling oil (Q2) of the transmission TM is calculated.

  That is, when the oil passage switching valve 6 is OFF, the cooling oil amount Q1 is required to lubricate and cool the electric motor 25, the generator 23, the oil amount Q11 required for the oil pump drive device 3, and the transmission TM that is the power transmission device. The flow rate is the larger of the oil amount Q21, and Q2 is 0. A method of calculating the required cooling oil amount Q11 and the required lubricating cooling oil amount Q21 will be described later with reference to FIG.

  On the other hand, when the oil passage switching valve 6 is ON, the cooling oil amount Q1 = the required cooling oil amount Q11 and the lubricating cooling oil amount Q2 = the lubricating cooling required oil amount Q21. At this time, since the motor 25, the generator 23, the cooling circuit 12 of the oil pump driving device 3 and the lubrication cooling circuit 14 of the transmission TM which is a power transmission device are arranged in parallel by the oil path switching valve 6, the required flow rate is set respectively. Shed.

  Next, a calculation method of the required oil amount Q11 for cooling the electric motor 25, the generator 23, and the oil pump driving device 3 and the required lubricating oil amount Q21 for the transmission TM that is a power transmission device will be described with reference to FIG. . The required oil amount Q11 for cooling the electric motor 25, the generator 23, and the oil pump drive device 3 is calculated by multiplying the sum of the coefficients k determined by the following parameters by the basic flow rate using the oil temperature as a parameter. The basic flow rate is set so that the flow rate increases when the oil temperature is high. When the oil temperature increases, the difference between the coil temperature of the motor 25 and the oil temperature decreases and the cooling capacity decreases. The flow rate is increased to ensure the cooling capacity. The coefficient k is 1) the coil temperature (Tm) of the electric motor 25, 2) the instruction torque (TQm) to the electric motor 25, 3) the temperature (Top) of the oil pump driving device 3, and 4) the oil pump described in FIG. In addition to the instructed rotational speed (Nop) of the driving device 3, it is set on the basis of six parameters of 5) generator temperature (Tg) and 6) predicted temperature rise value (TQg) of the generator 25.

  When the coil temperature Tm of the electric motor 25 and the temperature Top of the oil pump drive device 3 are high, the coefficient k is set to be large in order to increase the cooling capacity. Further, when the instruction torque TQm to the electric motor 25 is large, it can be predicted that the increase in the coil temperature of the electric motor 25 will be large, so the coefficient k is set large. Furthermore, when the command rotational speed Nop of the oil pump drive device 3 is large, it can be predicted that the temperature rise of the oil pump drive device 3 will increase, so the coefficient k is set large.

  The oil quantity Q21 required for lubrication and cooling of the transmission TM as a power transmission device is calculated by multiplying the sum of the coefficient k determined by the following parameters by the basic flow rate using the oil temperature as a parameter. The basic flow rate is set to be a large flow rate when the oil temperature is high. This is because the viscosity of the oil decreases as the oil temperature increases and the oil film in the lubrication part tends to break. Therefore, the flow rate is set larger as the temperature increases. The coefficient is set with 1) vehicle speed (Vsp) and 2) instruction torque (TQm) to the electric motor 25 as parameters. When the vehicle speed is high, the rotational speed of the transmission TM as a power transmission device is fast, and when the instruction torque of the electric motor 25 is large, the input torque to the power transmission device is large, so that the coefficient k is increased. Is set.

  Based on the required cooling oil amount Q11 and the required lubrication cooling oil amount Q21 as described above, as shown in FIG. 5, the cooling oil amount is determined from the operating state of the oil passage switching valve 6 determined in step S102A. Q1 and lubricating oil quantity Q2 are obtained.

  Steps S106 and S107 are the same as steps S106 and S107 in FIG.

  As described above, according to this embodiment, the bypass circuit from the motor cooling circuit to the lubrication cooling circuit of the power transmission device is provided, and the cooling oil after cooling is cooled when the temperature of the cooling oil after cooling the motor is not high. By supplying oil to the lubricating circuit of the power transmission device, the oil pump discharge flow rate can be reduced, and the oil pump driving load can be reduced. Thereby, the driving loss of the vehicle is reduced, and as a result, the fuel efficiency of the vehicle can be improved.

  In addition, when the oil temperature is extremely low, the cooling circuit of the electric motor and the drain circuit are connected and disconnected from the lubrication cooling circuit of the power transmission device, so that the oil can be circulated even in a situation where the oil viscosity is high. In addition, when the electric current flows, that is, when the driving torque is generated, the electric motor generates heat immediately and absorbs the heat with the cooling oil, so that the oil temperature can be raised quickly. Thereby, it is possible to reduce losses such as friction of the sliding portion of the power transmission device and oil agitation resistance.

In addition, when the oil temperature is high, the motor cooling circuit and the drain circuit are connected and disconnected from the lubrication cooling circuit of the power transmission device, so that it is possible to prevent the power transmission device from being lubricated with high temperature oil. A failure of the power transmission device due to cutting or the like can be avoided.

1 is a system block diagram illustrating a configuration of a hybrid vehicle including a vehicle cooling device according to an embodiment of the present invention. It is a block diagram which shows the structure of the cooling device for vehicles by one Embodiment of this invention. It is a flowchart which shows the operation | movement of the lubrication cooling circuit of the transmission which is the cooling circuit of the motor generator by the vehicle cooling device by one Embodiment of this invention, and an oil pump drive device, and a power transmission device. It is explanatory drawing which shows the content of the oil path switching valve control by the vehicle cooling device by one Embodiment of this invention. It is explanatory drawing of the calculation method of the cooling oil amount (Q1) and the lubrication cooling oil amount (Q2) in the vehicle cooling device by one Embodiment of this invention. It is explanatory drawing of the arithmetic expression of the cooling oil amount (Q1) and the lubrication cooling oil amount (Q2) in the vehicle cooling device by one Embodiment of this invention. It is an oil circuit diagram which shows the operating state of the cooling device for vehicles by one Embodiment of this invention. It is an oil circuit diagram which shows the operating state of the cooling device for vehicles by one Embodiment of this invention. It is an oil circuit diagram which shows the operating state of the cooling device for vehicles by one Embodiment of this invention. It is an oil circuit diagram which shows the operating state of the cooling device for vehicles by one Embodiment of this invention. It is a block diagram which shows the structure of the cooling device for vehicles by other embodiment of this invention. It is a flowchart which shows operation | movement of the cooling circuit and lubrication cooling circuit by the vehicle cooling device by other embodiment of this invention. It is explanatory drawing which shows the content of the oil path switching valve control by the vehicle cooling device by other embodiment of this invention. It is explanatory drawing of the arithmetic expression of the cooling oil amount (Q1) and the lubrication cooling oil amount (Q2) in the vehicle cooling device by other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 ... Oil pump drive device 5 ... Flow control valve 6 ... Oil path switching valve 7 ... Oil pan 8 ... Oil pump 11 ... Discharge circuit 12 ... Cooling circuit 13 ... Cooling oil drain circuit 14 ... Lubrication cooling circuit 15 ... Bypass circuit 30 ... Electronic control unit 19, 20, 21, 24, 26 ... temperature sensor 22 ... rotation sensor 23 ... generator 25 ... motor MG ... motor generator TM ... power transmission device

Claims (6)

A vehicular cooling device that cools the electric motor by using oil of a power transmission device that decelerates and transmits the rotation of the electric motor,
A cooling circuit for the electric motor;
A lubricating cooling circuit of the power transmission device;
A vehicular cooling device comprising a bypass circuit from the cooling circuit to the lubrication cooling circuit. The vehicle cooling device according to claim 1,
In the middle of the circuit from the cooling circuit to the lubrication cooling circuit, the cooling circuit and the lubrication cooling circuit are selectively disconnected, and an oil passage switching valve that connects the cooling circuit and a drain circuit for draining cooling oil to the oil pan A vehicle cooling device characterized by comprising: The vehicle cooling device according to claim 1,
The oil passage switching valve disconnects the cooling circuit and the lubrication cooling circuit when the oil temperature after cooling is extremely low, connects when the oil temperature is normal temperature, and disconnects when the oil temperature is high. A vehicular cooling device that cools the electric motor by using oil of a power transmission device that decelerates and transmits the rotation of the electric motor,
A cooling circuit for the electric motor;
A lubricating cooling circuit of the power transmission device;
When the oil temperature after cooling is lower than the first predetermined temperature, the cooling circuit and the lubrication cooling circuit are connected in series so as to cool the power transmission device with oil that has cooled the electric motor, and the second A vehicular cooling device comprising a flow path switching valve that switches a flow path so as to connect the cooling circuit and the lubrication cooling circuit in parallel when the temperature is higher than a predetermined temperature. The vehicle cooling device according to claim 4,
When the oil temperature after cooling is lower than a second predetermined temperature that is lower than the first predetermined temperature, the flow path switching valve flows so as to connect the cooling circuit and the lubrication cooling circuit in parallel. A vehicle cooling device characterized by switching a road. An electric motor, a power transmission device that decelerates and transmits the rotation of the electric motor, and a vehicle cooling device that cools the electric motor using oil of the power transmission device,
When the oil temperature after cooling is lower than the first predetermined temperature, the motor cooling circuit and the lubrication cooling circuit of the power transmission device are connected in series so that the power transmission device is cooled by the oil that has cooled the motor. A vehicle cooling system comprising: a flow path switching valve for switching a flow path so as to connect the cooling circuit and the lubrication cooling circuit in parallel when connected and higher than the second predetermined temperature apparatus.

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