JP6398859B2 - Control device for driving device - Google Patents

Description

  The present invention relates to a control device for a drive device including an engine, a first motor generator, and a second motor generator.

  International Publication No. 2013/114594 (Patent Document 1) discloses an engine, a first motor generator, a second motor generator, a transmission, a carrier connected to the engine via a transmission, and a first motor generator. A hybrid vehicle is disclosed that includes a sun gear connected to a planetary gear unit (differential mechanism) having a second gear and a ring gear connected to a drive wheel.

International Publication No. 2013/114594 JP 2012-166737 A

  In the hybrid vehicle disclosed in Patent Document 1, the temperature of oil (ATF: Automatic Transmission Fluid) in a drive unit including a transmission and a differential mechanism during motor traveling with the engine stopped and traveling using the second motor generator If the pressure decreases, the viscosity of the oil increases and the loss of the rotating member in the driving device increases, so there is a concern that the power transmission efficiency of the driving device will decrease.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to suppress a reduction in power transmission efficiency of the drive device during motor travel.

  The control device according to the present invention is a control device for a drive device. The drive device is connected to the engine through the engine, the first motor generator, the second motor generator, a power cutoff unit that can be switched between a power transmission state and a power cutoff state, and the power cutoff unit. And a differential section having a second rotating element connected to the first motor generator, and a third rotating element connected to the second motor generator and the driving wheel. When the temperature of the oil inside the drive device is lower than the first temperature during the motor traveling that stops the engine and travels using the second motor generator, the control device maintains the engine in the stopped state and sets the power shut-off unit. A first engine stop mode for controlling the transmission unit and the first motor generator is selected so that the first motor generator is rotated while the power is cut off.

  According to such a configuration, the first engine stop mode is selected when the temperature of the oil in the drive device drops below the first temperature during motor running. Accordingly, while maintaining the engine in the stopped state and the power shut-off portion in the power shut-off state, heat generation due to oil agitation loss is promoted by rotation of the first motor generator, and the temperature of the oil can be easily increased. . Thereby, since the increase in the viscosity of the oil due to a decrease in the temperature of the oil is suppressed, it is possible to suppress a decrease in the power transmission efficiency of the drive device.

  Preferably, when the control device selects the first engine stop mode, the rotation direction of the first motor generator does not exceed the upper limit rotation speed corresponding to each rotation element of the differential unit. And determine the rotation speed.

  According to such a configuration, even when the first motor generator is rotated in the first engine stop mode, the rotation of each rotation element of the drive device is prevented, and thus the durability of the drive device is deteriorated. This can be suppressed.

  Preferably, the differential unit is a planetary gear device including a sun gear, a ring gear, a pinion gear disposed between the sun gear and the ring gear, and a carrier that supports the pinion gear so as to be capable of rotating and revolving. The first rotating element is a carrier, the second rotating element is a sun gear, and the third rotating element is a ring gear. When the first engine stop mode is selected, the control device determines the rotation direction of the first motor generator based on the rotation state of the ring gear so that the rotation speed of the pinion gear does not exceed the upper limit rotation speed.

  According to such a configuration, even when the first motor generator is rotated in the first engine stop mode, over-rotation of the pinion gear of the drive device is prevented.

  Preferably, when the first engine stop mode is selected, the control device determines the rotation speed of the first motor generator according to the absolute value of the vehicle speed.

  According to such a configuration, when the first motor generator is rotated in the first engine stop mode, the rotation speed of the first motor generator is changed according to the absolute value of the vehicle speed (the loudness of the traveling sound). be able to. For example, as the absolute value of the vehicle speed is higher, the traveling sound is larger and the operation sound of the first motor generator is relatively smaller and difficult for the user to hear. Therefore, the higher the vehicle speed, the higher the rotational speed of the first motor generator. Can be set. As a result, the temperature of the oil can be raised at an early stage by increasing the rotational speed of the first motor generator within a range that does not deteriorate drivability.

  Preferably, when the temperature of the oil exceeds a second temperature higher than the first temperature while the motor is running, the control device maintains the engine in a stopped state and sets the power cut-off portion in the power cut-off state, A second engine stop mode for controlling the first motor generator so as to be stopped is selected.

  According to such a configuration, when the temperature of the oil in the drive device exceeds the second temperature during motor running, the second engine stop mode is selected. Accordingly, while maintaining the engine in the stopped state and the power cut-off portion in the power cut-off state, the first motor generator is brought into the stopped state to suppress generation of heat due to oil agitation loss and make it difficult to raise the oil temperature. be able to. As a result, the second motor generator can be properly cooled with oil, and a decrease in the output (vehicle driving force) of the second motor generator can be suppressed. Further, since a decrease in the viscosity of the oil due to an increase in the temperature of the oil is suppressed, it is possible to prevent the oil film from being cut and sufficiently lubricate the rotating member in the driving device.

It is a figure which shows the whole structure of a vehicle. It is the block diagram which showed the structure of the control apparatus. FIG. 6 is a collinear diagram (part 1) when traveling forward during hybrid traveling. FIG. 6 is a nomographic chart (part 2) when traveling forward during hybrid traveling. FIG. 6 is a nomographic chart during selection of an engine stop mode A. FIG. 6 is a nomographic chart during selection of an engine stop mode B. It is a flowchart which shows the process sequence of a control apparatus. It is a figure which shows change of MG1 rotation speed etc. in the case of switching from engine stop mode B to engine stop mode A during motor run.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Overall configuration of hybrid vehicle]
FIG. 1 is a diagram showing an overall configuration of a vehicle 1 according to the present embodiment. The vehicle 1 includes a drive device and a control device 100 that controls the drive device. The driving device includes an engine 10, a first motor generator (hereinafter referred to as “first MG”) 20, a second motor generator (hereinafter referred to as “second MG”) 30, a transmission 40, a differential device 50, and a counter. A shaft 70, a differential gear 80, and a drive wheel 90 are included.

  Vehicle 1 is an FF (front engine / front drive) type hybrid vehicle that can travel using the power of at least one of engine 10 and second MG 30. The driving method of the vehicle 1 is not limited to the FF method, and may be an FR (front engine / rear drive) method.

  The engine 10 is, for example, an internal combustion engine such as a gasoline engine or a diesel engine. First MG 20 and second MG 30 are, for example, permanent magnet type three-phase (U-phase, V-phase, W-phase) AC rotating electrical machines including a rotor in which permanent magnets are embedded.

  The rotation shaft 21 of the first MG 20 is disposed coaxially with the crankshaft of the engine 10. The rotation shaft 31 of the second MG 30 is arranged in parallel with the rotation shaft 21 of the first MG 20. Counter shaft 70 is arranged in parallel with rotating shaft 21 of first MG 20 and rotating shaft 31 of second MG 30.

  First MG 20 and second MG 30 are driven by inverters 25 and 35, respectively. Inverter 25 converts direct-current power from a vehicle battery (not shown) into three-phase alternating-current power and supplies it to first MG 20. Similarly, inverter 35 converts DC power from a vehicle-mounted driving battery (not shown) into three-phase AC power and supplies it to second MG 30. The second MG 30 is also driven by the electric power generated by the first MG 20.

  The transmission 40 is provided between the engine 10 and the differential device 50, changes the rotation of the engine 10, and outputs it to the differential device 50. The transmission 40 includes a single pinion planetary gear mechanism including a sun gear S1, a pinion gear P1, a ring gear R1, and a carrier CA1, a clutch C1, and a brake B1.

  The carrier CA1 is an input element to which the rotation of the engine 10 is input. The ring gear R <b> 1 is an output element that outputs the rotation after shifting of the engine 10 to the differential device 50. The pinion gear P1 is disposed between the sun gear S1 and the ring gear R1, and meshes with the sun gear S1 and the ring gear R1, respectively. Pinion gear P1 is supported by carrier CA1 so as to be capable of rotating and revolving.

  The rotational speed of the sun gear S1, the rotational speed of the carrier CA1 (that is, the rotational speed of the engine 10), and the rotational speed of the ring gear R1 are as follows. Once determined, the remaining rotational speed is also determined.

  The clutch C1 is a hydraulic friction engagement element capable of connecting the sun gear S1 and the carrier CA1. When the clutch C1 is engaged, the sun gear S1 and the carrier CA1 are connected. When the clutch C1 is released, the sun gear S1 and the carrier CA1 are disconnected.

  The brake B1 is a hydraulic friction engagement element that can restrict (lock) the rotation of the sun gear S1. When the brake B1 is engaged, the sun gear S1 is fixed to the gear case (vehicle body), so that the rotation of the sun gear S1 is restricted. When the brake B1 is released, the sun gear S1 is disconnected from the gear case (vehicle body), so that the sun gear S1 is allowed to rotate.

  When either one of the clutch C1 and the brake B1 is engaged and the other is disengaged, the transmission 40 transmits power between the carrier CA1 as an input element and the ring gear R1 as an output element (power) Transmission state). On the other hand, when the clutch C1 is disengaged and the brake B1 is disengaged, the transmission 40 is in a neutral state (power cut-off state) in which power is not transmitted between the carrier CA1 as an input element and the ring gear R1 as an output element. It becomes.

  When the transmission 40 is in a power transmission state, the transmission ratio (the ratio between the rotational speed of the carrier CA1 as an input element and the rotational speed of the ring gear R1 as an output element, specifically, the rotation of the carrier CA1) Speed / rotation speed of the ring gear R1) is switched according to a combination of engagement and release of the clutch C1 and the brake B1. When the clutch C1 is engaged and the brake B1 is released, a low gear stage Lo having a gear ratio of 1.0 (directly connected state) is formed. When the clutch C1 is released and the brake B1 is engaged, a high gear stage Hi is formed in which the gear ratio becomes a value smaller than 1.0 (for example, 0.7, so-called overdrive state).

  The differential device 50 is a single pinion type planetary gear device including a sun gear S2, a pinion gear P2, a ring gear R2, and a carrier CA2. The carrier CA2 of the differential device 50 is connected to a ring gear R1 that is an output element of the transmission 40, and rotates integrally with the ring gear R1.

  Pinion gear P2 is arranged between sun gear S2 and ring gear R2, and meshes with sun gear S2 and ring gear R2, respectively. Pinion gear P2 is supported by carrier CA2 so as to be capable of rotating and revolving.

  Sun gear S2 is coupled to rotating shaft 21 of first MG 20. A counter drive gear 51 is connected to the ring gear R2. The counter drive gear 51 is an output gear of the differential device 50 that rotates integrally with the ring gear R2.

  As described later, the rotational speed of the sun gear S2 (that is, the rotational speed of the first MG 20), the rotational speed of the carrier CA2, and the rotational speed of the ring gear R2 are connected in a straight line on the nomograph (that is, any two rotations). If the speed is determined, the remaining rotational speed is also determined). Therefore, by adjusting the rotation speed of the first MG 20, the ratio between the rotation speed of the carrier CA2 and the ring gear R2 can be switched steplessly.

  The counter shaft 70 is provided with a driven gear 71 and a drive gear 72. The driven gear 71 meshes with the counter drive gear 51 of the differential device 50. The power of the engine 10 and the first MG 20 is transmitted to the counter shaft 70 via the counter drive gear 51 of the differential device 50.

  The transmission device 40 and the differential device 50 are connected in series on the power transmission path from the engine 10 to the counter shaft 70. Therefore, the rotation of the engine 10 is transmitted to the counter shaft 70 after being shifted by the transmission 40 and the differential 50.

  The driven gear 71 also meshes with the reduction gear 32 connected to the rotation shaft 31 of the second MG 30. That is, the power of the second MG 30 is transmitted to the counter shaft 70 via the reduction gear 32.

  The drive gear 72 meshes with the diff ring gear 81 of the differential gear 80. The differential gear 80 is connected to the left and right drive wheels 90 via left and right drive shafts 82, respectively. That is, the rotation of the counter shaft 70 is transmitted to the left and right drive shafts 82 via the differential gear 80.

  The vehicle 1 is configured to supply hydraulic oil of the transmission 40 (hereinafter also referred to as “ATF” (Automatic Transmission Fluid)) to the transmission 40, and includes an electric oil pump (hereinafter also referred to as “EOP”) 61, mechanical oil. A pump (hereinafter also referred to as “MOP”) 62 and a hydraulic circuit 63 are provided.

  The EOP 61 and the MOP 62 suck in ATF stored in an oil pan (not shown) and supply the ATF to the hydraulic circuit 63. The EOP 61 is driven by a motor provided inside. The MOP 62 is connected to the ring gear R1 of the transmission 40 and is driven by the power transmitted from the ring gear R1.

  The hydraulic circuit 63 adjusts the ATF hydraulic pressure supplied from at least one of the EOP 61 and the MOP 62 to a constant hydraulic pressure (line pressure), and the hydraulic pressure supplied to the clutch C1 of the transmission 40 using the line pressure as a source pressure. (Hereinafter also referred to as “C1 hydraulic pressure”) and a solenoid valve that regulates the hydraulic pressure supplied to the brake B1 (hereinafter also referred to as “B1 hydraulic pressure”).

  The ATF not only functions as hydraulic fluid for the transmission 40 but also serves as a rotating member (rotary shaft, gear, bearing, etc.) inside the drive device (transmission 40, differential device 50, first MG20, second MG30, etc.). Is also supplied and functions as a lubricating oil. Further, the ATF functions as a cooling oil for the first MG 20 and the second MG 30. The ATF is returned to the oil pan again after being circulated in the drive unit.

[Configuration of control device]
FIG. 2 is a block diagram showing the configuration of the control device 100 in FIG. Control device 100 includes an HVECU (Electric Control Unit) 150, MGECU 160, and engine ECU 170. Each of HVECU 150, MGECU 160, and engine ECU 170 is an electronic control unit including a computer. Note that the number of ECUs is not limited to three, and may be integrated into one ECU as a whole, or may be divided into two or four or more numbers.

  The MGECU 160 controls the first MG 20 and the second MG 30. For example, the MGECU 160 controls the output torque of the first MG 20 by adjusting the current value supplied to the first MG 20, and controls the output torque of the second MG 30 by adjusting the current value supplied to the second MG 30. .

  The engine ECU 170 controls the engine 10. The engine ECU 170 performs, for example, control of the opening degree of the electronic throttle valve of the engine 10, engine ignition control by outputting an ignition signal, fuel injection control to the engine 10, and the like. The engine ECU 170 controls the output torque of the engine 10 by electronic throttle valve opening control, injection control, ignition control, and the like.

  The HVECU 150 performs integrated control of the entire vehicle. A vehicle speed sensor, an accelerator opening sensor, an output shaft rotational speed sensor, an MG1 rotational speed sensor, an MG2 rotational speed sensor, a battery sensor, an oil temperature sensor, and the like are connected to the HVECU 150. By these sensors, the HVECU 150 causes the vehicle speed, the accelerator opening, the output shaft rotational speed (the rotational speed of the counter shaft 70), the first MG rotational speed, the second MG rotational speed, the SOC (State Of Charge) of the driving battery, and the ATF. The temperature (hereinafter simply referred to as “oil temperature” or “ATF temperature”) is acquired. The oil temperature sensor is provided, for example, inside the hydraulic circuit 63.

  The HVECU 150 calculates a required driving force, a required driving torque, and the like for the vehicle based on the acquired information. The HVECU 150 is based on the calculated required value, the torque of the first MG 20 (hereinafter also referred to as “first MG torque Tm1”), the torque of the second MG 30 (hereinafter also referred to as “second MG torque Tm2”), and the engine 10. The output torque (hereinafter also referred to as “engine torque Te”) is determined. HVECU 150 outputs a command value for first MG torque Tm1 and a command value for second MG torque Tm2 to MGECU 160. Further, HVECU 150 outputs a command value for engine torque Te to engine ECU 170.

  The HVECU 150 controls the clutch C1 and the brake B1 of the transmission 40 according to a travel mode described later. HVECU 150 outputs C1 oil pressure command value PbC1 and B1 oil pressure command value PbB1 to the solenoid valve of hydraulic circuit 63 in FIG.

[Running mode of vehicle 1]
The control device 100 causes the vehicle 1 to travel in either travel mode of hybrid travel or motor travel. The hybrid travel is a travel mode in which the vehicle 1 travels with the power of the engine 10 and the second MG 30. The motor travel is a travel mode in which the engine 10 is stopped and the vehicle 1 is traveled by the power of the second MG 30.

<Hybrid driving>
FIG. 3 is a collinear diagram when the vehicle travels forward with the gear position of the transmission 40 set to the low gear stage Lo during hybrid travel. FIG. 4 is a collinear diagram when traveling forward with the gear position of the transmission 40 set to the high gear stage Hi during hybrid traveling.

  3 and 4, “S1”, “CA1”, and “R1” indicate the sun gear S1, the carrier CA1, and the ring gear R1 of the transmission 40, respectively, and “S2”, “CA2”, and “R2” indicate the differential devices, respectively. 50 sun gear S2, carrier CA2, and ring gear R2 are shown. The same applies to FIGS. 5 and 6 described later.

  With reference to FIG. 3, the control state in the case of traveling forward at the low gear stage Lo during hybrid traveling will be described. When the low gear stage Lo is formed, the clutch C1 is engaged and the brake B1 is released. Therefore, the rotation elements S1, CA1, R1 of the transmission 40 rotate as a unit. Therefore, the torque output from the ring gear R1 (hereinafter referred to as “transmission portion output torque Tr1”) has the same magnitude (Te = Tr1) as the engine torque Te.

  The rotation of the engine 10 transmitted to the carrier CA2 of the differential device 50 is steplessly changed by the rotational speed of the sun gear S2 (rotational speed of the first MG 20) and transmitted to the ring gear R2 of the differential device 50. The engine torque Te transmitted to the ring gear R2 (hereinafter referred to as “engine transmission torque Tec”) is transmitted from the counter drive gear 51 to the counter shaft 70 and acts as a driving force for the vehicle 1.

  The second MG torque Tm2 is transmitted from the reduction gear 32 to the counter shaft 70 and acts as a driving force for the vehicle 1. Therefore, in the hybrid travel, the vehicle 1 travels using the engine transmission torque Tec and the second MG torque Tm2.

  Next, with reference to FIG. 4, the control state in the case of traveling forward at the high gear stage Hi during hybrid traveling will be described. When the high gear stage Hi is formed, the clutch C1 is released and the brake B1 is engaged. Therefore, the rotation of the sun gear S1 is restricted. As a result, the rotation of the engine 10 input to the carrier CA1 of the transmission 40 is increased, and an overdrive state is established in which the ring gear R1 of the transmission 40 is transmitted to the carrier CA2 of the differential device 50. Therefore, the transmission output torque Tr1 is smaller than the engine torque Te (Te> Tr1).

  During hybrid traveling, the control device 100 forms the high gear stage Hi in the high speed range where the vehicle speed exceeds the threshold vehicle speed (see FIG. 4 above), and the low gear stage Lo in the medium / low speed range where the vehicle speed is less than the threshold vehicle speed. (See FIG. 3 described above).

<Motor running>
While the motor is running (when the engine is stopped), one of the engine stop mode A and the engine stop mode B is selected. The engine stop mode A is a mode for controlling the first MG torque Tm1 so that the first MG 20 is stopped while maintaining the engine 10 in the stopped state. The engine stop mode B is a mode in which the first MG torque Tm1 is controlled so that the first MG 20 is rotated while the engine 10 is maintained in a stopped state.

  Regardless of which one of the engine stop mode A and the engine stop mode B is selected, the transmission 40 is controlled to the neutral state (the state in which the clutch C1 is released and the brake B1 is released). Thereby, power transmission between the engine 10 and the carrier CA2 of the differential device 50 is interrupted. As a result, while maintaining the engine 10 in the stopped state, the rotational speed of the carrier CA2 of the differential device 50 is set to the first MG rotational speed (rotational speed of the sun gear S2 of the differential device 50) and the vehicle speed (ring gear of the differential device 50). It can be arbitrarily changed according to the rotational speed of R2.

  In the present embodiment, the device provided between the engine 10 and the differential device 50 is the transmission device 40 capable of switching the gear ratio, but is provided between the engine 10 and the differential device 50. The device only needs to be able to switch between the power transmission state and the power cut-off state, and is not necessarily limited to being capable of switching the gear ratio. For example, a clutch may be used instead of the transmission 40.

  FIG. 5 is an alignment chart during the selection of the engine stop mode A. While engine stop mode A is selected, control device 100 places transmission 40 in a neutral state (power cut-off state), stops engine 10 and causes vehicle 1 to travel using second MG torque Tm2. In the example shown in FIG. 5, the case where the second MG torque Tm2 is applied in the forward direction to travel forward (the ring gear R2 is rotated in the forward direction) is shown.

  Further, during the selection of engine stop mode A, control device 100 feedback-controls first MG torque Tm1 so that first MG 20 is stopped (that is, MG1 rotational speed is zero). Therefore, the carrier CA1 of the transmission 40 and the sun gear S2 of the differential device 50 are maintained in a stopped state, and the ring gear R1 of the transmission 40 and the carrier CA2 of the differential device 50 rotate in conjunction with the vehicle speed (second MG rotation speed). To do.

  FIG. 6 is an alignment chart during the selection of the engine stop mode B. “P2” shown in FIG. 6 indicates the pinion gear P2 of the differential device 50. Even during the selection of engine stop mode B, control device 100 places transmission 40 in a neutral state to stop engine 10 and causes vehicle 1 to travel using second MG torque Tm2. In the example shown in FIG. 6, the case where the second MG torque Tm2 is applied in the forward direction and the vehicle travels forward (the ring gear R2 is rotated in the forward direction) is shown.

  Further, during the selection of engine stop mode B, control device 100, as shown in FIG. 6, controls first MG torque Tm1 so that first MG 20 is in a rotating state (that is, the absolute value of MG1 rotational speed is greater than 0). To control.

  In FIG. 6, the solid line indicates the case where the first MG torque Tm1 is applied in the positive direction and the first MG 20 is rotated in the positive direction, and the alternate long and short dashed lines indicate that the first MG torque Tm1 is applied in the negative direction. The case where 1MG20 is rotated to a negative direction is shown. As shown in FIG. 6, when the first MG 20 is rotated in the negative direction during forward travel, the magnitude (absolute value) of the rotational speed of the pinion gear P2 increases as the magnitude (absolute value) of the first MG 20 increases. growing. On the other hand, when the first MG 20 is rotated in the positive direction during forward travel, the magnitude of the rotational speed of the pinion gear P2 is smaller than that when the first MG 20 is rotated in the negative direction.

[Mode selection during motor running]
When the vehicle 1 having the above-described configuration performs motor traveling, it is possible to select either the engine stop mode A or the engine stop mode B as described above. However, when drag loss due to ATF stirring (hereinafter simply referred to as “stirring loss”) is different between the engine stop mode A and the engine stop mode B, the amount of heat generated due to the stirring loss is different. If the engine stop mode B is not properly selected, there is a concern that the ATF temperature will not be an appropriate temperature and the ATF will not function properly.

  Therefore, when a simulation for comparing the agitation loss in the engine stop mode A and the engine stop mode B was performed, a result that the agitation loss in the engine stop mode A was smaller than that in the engine stop mode B was obtained. From this simulation result, when the engine stop mode A is selected, compared with the case where the engine stop mode B is selected, the first MG 20 is in a stopped state, so that the ATF is stirred less and the amount of heat generated due to the stirring loss. It is thought that there are few. On the contrary, when the engine stop mode B is selected, the ATF is actively stirred when the first MG 20 is in a rotating state as compared with the case where the engine stop mode A is selected, and the amount of heat generated due to the stirring loss. It is thought that there are many.

  Based on the above simulation results, when the engine stop mode A is selected in a state where the ATF temperature is low, the ATF temperature is difficult to rise because the amount of heat generated due to the stirring loss is small. For this reason, there is a concern that the state where the ATF temperature is low and the viscosity of the ATF is high lasts for a long time, and the power transmission efficiency of the drive device is lowered.

  Further, when the engine stop mode B is selected in a state where the ATF temperature is high, the amount of heat generated due to the stirring loss is large, so that the ATF temperature is difficult to decrease. Therefore, a state where the ATF temperature is high and the viscosity of the ATF is low continues for a long time. As a result, the second MG 30 cannot be sufficiently cooled, and the output (vehicle driving force) of the second MG 30 may be reduced, or the oil film may be cut off in the rotating member in the driving device, resulting in insufficient lubrication. Is done.

  In view of the above problems, the control device 100 according to the present embodiment selects the engine stop mode B when the ATF temperature is lower than the low temperature threshold value Tlow while the motor is running. Thereby, compared with the case where the engine stop mode A is selected, heat generation is promoted and the ATF temperature is likely to rise. As a result, the power transmission efficiency of the drive device can be improved early.

  Further, when the ATF temperature exceeds the high temperature threshold Thi (Thi> Tlow) during motor running, the engine stop mode A is selected. Thereby, compared with the case where the engine stop mode B is selected, the generation of heat is suppressed and the ATF temperature is hardly increased. As a result, the second MG 30 can be appropriately cooled by the ATF, and a decrease in the output (vehicle driving force) of the second MG 30 can be suppressed. Further, sufficient lubrication can be performed by preventing the oil film from being cut off in the rotating member in the driving device.

  FIG. 7 is a flowchart showing a processing procedure performed by the control device 100 while the motor is running. This flowchart is repeatedly executed at a predetermined cycle while the motor is running (when the engine is stopped).

  In step (hereinafter, step is abbreviated as “S”) 11, control device 100 determines whether or not the oil temperature (ATF temperature) exceeds high temperature threshold value Thi. The high temperature threshold value Thi is set in advance from the viewpoint of whether or not the ATF temperature is high (ATF viscosity is low) to such an extent that cooling and lubrication by the ATF cannot be performed properly.

  When oil temperature (ATF temperature) exceeds high temperature threshold Thi (YES in S11), control device 100 selects engine stop mode A in S12. Thereby, as mentioned above, generation | occurrence | production of a heat | fever is suppressed and an ATF temperature rise is suppressed.

  If the oil temperature does not exceed high temperature threshold Thi (NO in S11), control device 100 determines in S13 whether the oil temperature is lower than low temperature threshold Tlow. The low temperature threshold value Tlow is set in advance from the viewpoint of whether or not the ATF temperature is low (the viscosity of ATF is high) to such an extent that the power transmission efficiency of the drive device is lower than the target efficiency.

  When the oil temperature is lower than low temperature threshold value Tlow (YES in S13), control device 100 selects engine stop mode B in S14 to S16. Thereby, as described above, generation of heat is promoted, and an increase in the ATF temperature can be promoted.

  When the engine stop mode B is selected and the first MG 20 is rotated, the rotation speed of each rotation element in the drive device exceeds the corresponding upper limit rotation speed depending on the rotation direction and rotation speed of the first MG 20. Therefore, there is a concern that the durability of the drive device is deteriorated, or that the operating sound of the first MG 20 is relatively larger than the traveling sound and the drivability is deteriorated.

  Therefore, in the present embodiment, when the engine stop mode B is selected, the rotational direction and the magnitude (absolute value) of the first MG 20 are determined from the viewpoint of ensuring the durability of the drive device and preventing noise.

  Specifically, control device 100 determines the rotation direction of first MG 20 in S14 according to the vehicle speed. When the vehicle speed is high during forward travel, there is a concern that if the first MG 20 is rotated in the negative direction, the rotation speed of the pinion gear P2 increases and an over-rotation state occurs (see the dashed line in FIG. 6). Therefore, when the vehicle speed is equal to or higher than a predetermined value (the predetermined value is a positive value), control device 100 determines the rotation direction of first MG 20 as the “positive direction” (see the solid line in FIG. 6). Conversely, when the vehicle speed is less than the predetermined value (during reverse travel or during forward travel at a low speed), control device 100 determines the rotation direction of first MG 20 as the “negative direction”. Thereby, over-rotation of the pinion gear P2 can be prevented and deterioration of the durability of the differential device 50 can be suppressed. The above-described method for determining the rotation direction of the first MG 20 is merely an example, and the rotation direction of the first MG 20 may be determined by another determination method.

  In the present embodiment, the case where the rotation direction of the first MG 20 is determined from the viewpoint of preventing over-rotation of the pinion gear P2 in S14 of FIG. 7 will be described as an example. However, in S14 of FIG. The rotational direction and rotational speed of the first MG 20 may be determined so that the rotational speeds of the rotary elements 40 and the differential device 50) do not exceed the corresponding upper limit rotational speed.

  Further, in S15, control device 100 determines the magnitude (absolute value) of the rotational speed of first MG 20 in accordance with the magnitude (absolute value) of the vehicle speed. For example, when the vehicle speed exceeds a predetermined speed, the traveling sound is large and the operating sound of the first MG 20 is relatively small and is difficult for the user to hear. Therefore, the control device 100 determines the rotational speed of the first MG 20. A relatively high rotational speed N1 is optimal for increasing the oil temperature. On the other hand, when the vehicle speed is less than the predetermined speed, the traveling sound is small and the operation sound of the first MG 20 is relatively loud and is easily heard by the user. Therefore, the control device 100 determines the magnitude of the rotation speed of the first MG 20. Is a rotational speed N2 lower than the rotational speed N1. As a result, the oil temperature can be raised at an early stage by increasing the rotation speed of the first MG 20 within a range that does not deteriorate drivability. The rotational speed of the first MG 20 may be set to a higher value as the absolute value of the vehicle speed is larger.

  In S16, control device 100 feedback-controls first MG torque Tm1 so that the rotation direction and rotation speed of first MG 20 are the rotation direction and rotation speed determined in S14 and S15.

  When the oil temperature is included between high temperature threshold value Thi and low temperature threshold value Tlow (NO in both S11 and S13), control device 100 ends the process. In this case, the currently selected engine stop mode (either engine stop mode B or engine stop mode A) is maintained as it is.

  FIG. 8 is a diagram exemplarily showing changes in the MG1 rotation speed and the like when the engine stop mode B is switched to the engine stop mode A during motor travel. FIG. 8 shows a case where the MG2 rotational speed is a positive value (that is, when traveling forward).

  Prior to time t1, the engine stop mode B is selected, and in the example shown in FIG. 8, the MG1 rotation speed is controlled to the negative rotation state.

  When it is determined that the oil temperature has reached the high temperature threshold value Thi at time t1, switching to the engine stop mode A is started at subsequent time t2. Specifically, the MG1 torque is increased so that the MG1 rotation speed becomes zero. At this time, the MG2 torque is also increased in order to handle the reaction force of the MG1 torque.

  When the MG1 rotation speed reaches 0 at time t3, the switching to the engine stop mode A is completed, and the MG1 rotation speed is maintained at 0 after time t3. By switching to the engine stop mode A, generation of heat due to stirring loss is suppressed, and the oil temperature falls below the high temperature threshold value Thi. Therefore, the ATF can be properly cooled and lubricated.

  As described above, control device 100 according to the present embodiment selects engine stop mode B when the ATF temperature is lower than low temperature threshold value Tlow during motor travel. As a result, heat generation due to stirring loss is promoted, and the ATF temperature easily rises. As a result, the power transmission efficiency of the drive device can be improved early.

  Further, when the ATF temperature exceeds the high temperature threshold value Thi (Thi> Tlow) while the motor is running, the control device 100 selects the engine stop mode A. As a result, heat generation due to stirring loss is suppressed and the ATF temperature is unlikely to rise. As a result, it is possible to achieve a state where cooling and lubrication by ATF can be performed appropriately.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 Vehicle, 10 Engine, 21, 31 Rotating shaft, 25, 35 Inverter, 30 2nd MG, 32 Reduction gear, 40 Transmission, 50 Differential device, 51 Counter drive gear, 63 Hydraulic circuit, 70 Counter shaft, 71 Driven gear, 72 drive gear, 80 differential gear, 81 differential gear, 82 drive shaft, 90 drive wheel, 100 controller, B1 brake, C1 clutch, CA1, CA2 carrier, P1, P2 pinion gear, R1, R2 ring gear, S1, S2 sun gear.

Claims (4)

A control device for the drive device,
The driving device includes:
Engine,
A first motor generator;
A second motor generator;
A power cutoff unit that can be switched between a power transmission state and a power cutoff state;
A first rotating element connected to the engine via the power shut-off unit; a second rotating element connected to the first motor generator; and a third rotating element connected to the second motor generator and drive wheels. Having a differential part,
The control device includes:
When the temperature of the oil inside the drive device is a low temperature lower than the first temperature during motor traveling that stops the engine and travels using the second motor generator, the engine is maintained in the stopped state and the power the blocking unit selects the first engine stop mode for controlling the pre-Symbol first motor generator to the rotating state of the first motor generator while said power transmission interrupted state,
When the temperature of the oil is higher than the first temperature while the motor is running, the first motor generator is stopped while the engine is stopped and the power shut-off unit is in the power shut-off state. A control device for a drive device that selects a second engine stop mode for controlling the first motor generator as described above .   When selecting the first engine stop mode, the control device rotates the first motor generator so that the rotation speed of each rotation element of the differential section does not exceed the corresponding upper limit rotation speed. The control device of the driving device according to claim 1, wherein the control device determines a direction and a rotational speed. The differential unit is a planetary gear device including a sun gear, a ring gear, a pinion gear disposed between the sun gear and the ring gear, and a carrier that supports the pinion gear so as to rotate and revolve.
The first rotating element is the carrier;
The second rotating element is the sun gear;
The third rotating element is the ring gear;
When the control device selects the first engine stop mode, the rotation direction of the first motor generator is based on the rotation state of the ring gear so that the rotation speed of the pinion gear does not exceed the upper limit rotation speed. The controller of the drive device according to claim 1, wherein:   The said control apparatus controls the drive device in any one of Claims 1-3 which determines the rotational speed of the said 1st motor generator according to the absolute value of a vehicle speed, when selecting the said 1st engine stop mode. apparatus.

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