Vehicle control device

Abstract

To prevent a rotation speed of a crank shaft from getting out of a specified range.SOLUTION: A vehicle control device can execute a first driving process for rotating a crank shaft while making a restricting device restrict the rotation of a rotary shaft of a first motor generator to zero, under the condition that a specified requirement for requiring driving of an oil pump is satisfied during an EV mode. The vehicle control device can execute a second driving process for rotating the crank shaft so that a rotation speed of the crank shaft is in a specified range, while making the first motor generator apply torque to the crank shaft, under the condition that the specified requirement for requiring driving of the oil pump is satisfied during the EV mode. The vehicle control device executes the first driving process when it is predicted that the rotation speed of the crank shaft is in the specified range on the assumption that the first driving process is executed, and executes the second driving process when it is predicted that the rotation speed of the crank shaft is out of the specified range on the assumption that the first driving process is executed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a vehicle control device. [Background technology]

[0002] The vehicle of Patent Document 1 includes an internal combustion engine, a first motor generator, a second motor generator, and a planetary gear mechanism. The planetary gear mechanism includes a sun gear, a ring gear, a plurality of pinion gears, and a carrier. The sun gear is rotatable on its axis. The ring gear is rotatable coaxially with the sun gear. The pinion gear meshes with both the sun gear and the ring gear. The pinion gear is revolved around the sun gear. The carrier is rotatable coaxially with the sun gear in accordance with the revolution of the pinion gear. The crankshaft of the internal combustion engine is connected to the carrier. The rotating shaft of the first motor generator is connected to the sun gear. The rotating shaft of the second motor generator is connected to the ring gear.

[0003] Furthermore, the vehicle of Patent Document 1 is equipped with an oil pump and a brake device. The oil pump is a so-called mechanical oil pump that discharges oil based on the rotation of the crankshaft of the internal combustion engine. The brake device is capable of restricting the rotation of the rotary shaft of the first motor generator.

[0004] The vehicle control device of Patent Document 1 controls the vehicle's driving mode to one of an EV mode in which the second motor generator is driven while the internal combustion engine is stopped to drive the vehicle, and a non-EV mode in which the internal combustion engine is driven to drive the vehicle. The vehicle control device of Patent Document 1 also executes a pump drive process to drive the oil pump when a condition that requires the oil pump to be driven is satisfied during the EV mode. In this pump drive process, the crankshaft is rotated by restricting the rotation speed of the rotating shaft of the first motor generator to zero by a brake device. As a result, the oil pump is driven. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-189102 A Summary of the Invention [Problem to be solved by the invention]

[0006] In a vehicle such as that of Patent Document 1, when the pump drive process is executed, the rotation speed of the crankshaft of the internal combustion engine is determined according to the rotation speed of the rotary shaft of the second motor generator. The rotation speed of the rotary shaft of the second motor generator is determined by the speed of the vehicle, etc. In other words, the rotation speed of the crankshaft during the pump drive process is determined by the speed of the vehicle, etc. Therefore, the rotation speed of the crankshaft during the pump drive process does not necessarily fall within a preferable range. [Means for solving the problem]

[0007] A vehicle control device for solving the above problem is applied to a vehicle including an internal combustion engine, a first motor generator, a second motor generator, a planetary gear mechanism capable of distributing the torque of the internal combustion engine, the torque of the first motor generator, and the torque of the second motor generator among others, an oil pump that discharges oil based on the rotation of a crankshaft of the internal combustion engine, and a regulating device that regulates the rotation of a rotating shaft of the first motor generator, wherein the planetary gear mechanism has a sun gear that rotates on its own axis, a ring gear that rotates coaxially with the sun gear, a plurality of pinion gears that are meshed with both the sun gear and the ring gear and revolve around the sun gear, and a carrier that rotates coaxially with the sun gear in accordance with the revolution of the pinion gears, the carrier is connected to the crankshaft, the sun gear is connected to the rotating shaft of the first motor generator, and the ring gear is connected to the rotating shaft of the second motor generator, and the vehicle travel mode is changed by driving the second motor generator while stopping the internal combustion engine. a control device that can control the driving mode of the vehicle to either an EV mode in which the vehicle is driven by an EV engine or a non-EV mode in which the internal combustion engine is driven to drive the vehicle, and that is capable of executing a first drive process in which, on condition that specified requirements requiring the drive of the oil pump are satisfied during the EV mode, the crankshaft is rotated while regulating the rotation of the rotating shaft of the first motor generator to zero by the regulating device, with fuel combustion in the internal combustion engine being stopped; and a second drive process in which, on condition that the specified requirements are satisfied during the EV mode, the crankshaft is rotated so that the rotation speed of the crankshaft is within a predetermined specified range while applying torque from the first motor generator to the crankshaft, with fuel combustion in the internal combustion engine being stopped, and that executes the first drive process if it is expected that the rotation speed will be within the specified range when it is assumed that the first drive process has been executed, and executes the second drive process if it is expected that the rotation speed will be outside the specified range when it is assumed that the first drive process has been executed.

[0008] According to the above configuration, the rotation speed of the crankshaft falls within the specified range regardless of whether the first drive process or the second drive process is executed, and therefore, it is possible to prevent the rotation speed of the crankshaft from becoming an undesirable rotation speed outside the specified range as a result of the execution of each drive process.

[0009] Furthermore, according to the above configuration, when the rotation speed of the crankshaft is within a specified range even if the rotation speed of the rotating shaft of the first motor generator is restricted to zero, the first drive process is executed, and therefore the second drive process that requires the supply of electric power to the first motor generator is not executed excessively frequently. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic configuration diagram of a vehicle. [Diagram 2] 4 is a flowchart showing pump control. [Diagram 3] FIG. 4 is a collinear diagram showing a state of a vehicle when the vehicle speed is low. [Figure 4] FIG. 4 is a collinear diagram showing a state of a vehicle when the vehicle speed is high. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <Vehicle mechanical configuration> An embodiment of the present invention will now be described with reference to Figures 1 to 4. First, the mechanical configuration of a vehicle 100 to which a control device 90 of the present invention is applied will be described.

[0012] As shown in FIG. 1, a vehicle 100 includes an internal combustion engine 10, a power split mechanism 40, a reduction mechanism 50, a first motor generator 61, and a second motor generator 62. The internal combustion engine 10 has a crankshaft 11 as an output shaft. The crankshaft 11 is connected to a power split mechanism 40. The power split mechanism 40 is a planetary gear mechanism having a sun gear 41, a carrier 42, a plurality of pinion gears 43, a ring gear 44, and a ring gear shaft 45.

[0013] The sun gear 41, which is an external gear, and the ring gear 44, which is an internal gear, are positioned on the same axis. The sun gear 41 can rotate on its axis. The ring gear 44 can rotate on its axis. The sun gear 41 is connected to the ring gear 44 via a plurality of pinion gears 43. That is, the pinion gear 43 meshes with both the sun gear 41 and the ring gear 44. The carrier 42 supports the pinion gear 43 in a rotatable state. The carrier 42 also supports the pinion gear 43 so that it can revolve. That is, the pinion gear 43 revolves around the sun gear 41. The carrier 42 also rotates coaxially with the sun gear 41 in accordance with the revolution of the pinion gear 43. The carrier 42 is connected to the crankshaft 11. The sun gear 41 is connected to a rotating shaft 61A of the first motor generator 61. The ring gear 44 is connected to a ring gear shaft 45.

[0014] In this embodiment, the power split mechanism 40 is a planetary gear mechanism capable of distributing the torque of the internal combustion engine 10, the torque of the first motor generator 61, and the torque of the second motor generator 62 among each other.

[0015] When the torque of the internal combustion engine 10 is input to the carrier 42, the torque of the internal combustion engine 10 is distributed to the sun gear 41 side and the ring gear 44 side. Then, when the torque of the internal combustion engine 10 transmitted via the sun gear 41 is input to the rotating shaft 61A of the first motor generator 61, the first motor generator 61 functions as a generator.

[0016] On the other hand, when the first motor generator 61 is caused to function as an electric motor, the torque of the first motor generator 61 is input to the sun gear 41. Then, the torque of the first motor generator 61 input to the sun gear 41 is distributed to the carrier 42 side and the ring gear 44 side. Then, when the torque of the first motor generator 61 transmitted via the carrier 42 is input to the crankshaft 11 of the internal combustion engine 10, the crankshaft 11 of the internal combustion engine 10 rotates. That is, the first motor generator 61 is capable of rotating the crankshaft 11 by transmitting the torque of the first motor generator 61 to the crankshaft 11.

[0017] As shown in Fig. 1, the vehicle 100 includes a transmission mechanism 66, a differential 67, and a plurality of drive wheels 68. The transmission mechanism 66 is connected to the ring gear shaft 45. The transmission mechanism 66 includes, for example, a reduction gear mechanism and an automatic transmission. The transmission mechanism 66 is connected to the drive wheels 68 via the differential 67. The differential 67 allows a difference in rotational speed to occur between the left and right drive wheels 68.

[0018] The ring gear shaft 45 is connected to the reduction mechanism 50. The reduction mechanism 50 is a planetary gear mechanism having a sun gear 51, a carrier 52, a plurality of pinion gears 53, a ring gear 54, and a case 55. The sun gear 51, which is an external gear, and the ring gear 54, which is an internal gear, are positioned coaxially. The sun gear 51 is connected to the ring gear 54 via a plurality of pinion gears 53. The carrier 52 supports the pinion gear 53 in a state in which the pinion gear 53 can rotate. The carrier 52 is fixed to a case 55 of the reduction mechanism 50. That is, the carrier 52 cannot rotate. Therefore, the pinion gear 53 is in a state in which it cannot revolve due to the carrier 52. The ring gear 54 is connected to the ring gear shaft 45. The sun gear 51 is connected to a rotating shaft 62A of the second motor generator 62. In other words, the ring gear 44 of the power split mechanism 40 is connected to the rotating shaft 62A of the second motor generator 62 via the ring gear shaft 45 and the reduction mechanism 50.

[0019] The second motor generator 62 functions as a generator when decelerating the vehicle 100, thereby making it possible to generate a regenerative braking force in the vehicle 100 according to the amount of power generated by the second motor generator 62.

[0020] On the other hand, when the second motor generator 62 is caused to function as an electric motor, the torque of the second motor generator 62 is input to the drive wheels 68 via the reduction mechanism 50, the ring gear shaft 45, the transmission mechanism 66, and the differential 67. Then, the drive wheels 68 are rotated by the torque of the second motor generator 62.

[0021] As shown in Fig. 1, vehicle 100 is equipped with oil pump 77 as a mechanism for supplying oil. Oil pump 77 is connected to crankshaft 11. Oil pump 77 is driven by the rotation of crankshaft 11. Therefore, oil pump 77 is a so-called mechanical oil pump that discharges oil based on the rotation of crankshaft 11. Oil pump 77 supplies oil to various parts of internal combustion engine 10 via a supply passage (not shown).

[0022] As shown in FIG. 1, the vehicle 100 includes a brake device 65. The brake device 65 is located near the rotating shaft 61A of the first motor generator 61. The brake device 65 can regulate the rotation of the rotating shaft 61A of the first motor generator 61. For example, in an engaged state in which the brake device 65 contacts the rotating shaft 61A, the brake device 65 regulates the rotation of the rotating shaft 61A. On the other hand, in a released state in which the brake device 65 is separated from the rotating shaft 61A, the brake device 65 does not regulate the rotation of the rotating shaft 61A. The brake device 65 is an example of a regulating device.

[0023] <Vehicle Electrical Configuration> Next, the electrical configuration of the vehicle 100 will be described. 1, the vehicle 100 includes a first inverter 71, a second inverter 72, and a battery 73 as devices for transferring electric power. The first inverter 71 adjusts the amount of electric power transferred between the first motor generator 61 and the battery 73. The second inverter 72 adjusts the amount of electric power transferred between the second motor generator 62 and the battery 73.

[0024] As shown in FIG. 1, the vehicle 100 is equipped with a crank angle sensor 81, an accelerator opening sensor 82, a vehicle speed sensor 83, a first rotation angle sensor 84, a second rotation angle sensor 85, a current sensor 86, a voltage sensor 87, and a temperature sensor 88.

[0025] The crank angle sensor 81 is located near the crankshaft 11. The crank angle sensor 81 detects a crank angle SC, which is the angular position of the crankshaft 11. The accelerator opening sensor 82 detects an accelerator opening ACC, which is the amount of operation of an accelerator pedal (not shown) operated by a driver. The vehicle speed sensor 83 detects a vehicle speed SP, which is the speed of the vehicle 100. The first rotation angle sensor 84 is located near the rotating shaft 61A of the first motor generator 61. The first rotation angle sensor 84 detects a first rotation angle SM1, which is the angular position of the rotating shaft 61A of the first motor generator 61. The second rotation angle sensor 85 is located near the rotating shaft 62A of the second motor generator 62. The second rotation angle sensor 85 detects a second rotation angle SM2, which is the angular position of the rotating shaft 62A of the second motor generator 62. The current sensor 86 detects a current IB, which is a current input to and output from the battery 73. The voltage sensor 87 detects the voltage VB, which is the voltage between the terminals of the battery 73. The temperature sensor 88 detects the battery temperature TB, which is the temperature of the battery 73.

[0026] The vehicle 100 is equipped with a control device 90. The control device 90 obtains a signal indicating a crank angle SC from a crank angle sensor 81. The control device 90 obtains a signal indicating an accelerator opening ACC from an accelerator opening sensor 82. The control device 90 obtains a signal indicating a vehicle speed SP from a vehicle speed sensor 83. The control device 90 obtains a signal indicating a first rotation angle SM1 from a first rotation angle sensor 84. The control device 90 obtains a signal indicating a second rotation angle SM2 from a second rotation angle sensor 85. The control device 90 obtains a signal indicating a current IB from a current sensor 86. The control device 90 obtains a signal indicating a voltage VB from a voltage sensor 87. The control device 90 obtains a signal indicating a battery temperature TB from a temperature sensor 88.

[0027] The control device 90 calculates the engine rotation speed NE, which is the rotation speed of the crankshaft 11, based on the crank angle SC. The control device 90 calculates the first rotation speed NM1, which is the rotation speed of the rotating shaft 61A of the first motor generator 61, based on the first rotation angle SM1. The control device 90 calculates the second rotation speed NM2, which is the rotation speed of the rotating shaft 62A of the second motor generator 62, based on the second rotation angle SM2.

[0028] The control device 90 calculates the charging rate SOC of the battery 73 based on the current IB, the voltage VB, and the battery temperature TB. Specifically, the control device 90 calculates the charging rate SOC based on the following formula.

[0029] Equation (1): Charging rate SOC [%] = remaining capacity of battery 73 [Ah] / fully charged capacity of battery 73 [Ah] × 100 [%] In the above formula (1), the full charge capacity is calculated based on, for example, the voltage VB and the battery temperature TB of the battery 73. Also, the remaining capacity is calculated based on, for example, the voltage VB and the current IB of the battery 73.

[0030] The control device 90 performs charging control of the battery 73. Through this charging control, the charging rate SOC of the battery 73 is controlled to be in a range between an upper limit SOCH and a lower limit SOCL. An example of the upper limit SOCH is 60 to 80%, and an example of the lower limit SOCL is 20 to 30%.

[0031] The control device 90 also calculates a vehicle required output, which is a required value of an output necessary for the vehicle 100 to run, based on the accelerator opening ACC and the vehicle speed SP. The control device 90 determines the torque distribution of the internal combustion engine 10, the first motor generator 61, and the second motor generator 62, based on the vehicle required output. The control device 90 controls the output of the internal combustion engine 10 and the power running and regeneration of the first motor generator 61 and the second motor generator 62, based on the torque distribution of the internal combustion engine 10, the first motor generator 61, and the second motor generator 62.

[0032] The control device 90 executes various controls such as adjustment of the intake air amount, adjustment of the fuel injection amount, and adjustment of the ignition timing in the internal combustion engine 10 by outputting a control signal to the internal combustion engine 10. Furthermore, the control device 90 outputs a control signal to the first inverter 71 when controlling the first motor generator 61. The control device 90 controls the first motor generator 61 by adjusting the amount of electric power exchanged between the first motor generator 61 and the battery 73 via the first inverter 71. Furthermore, the control device 90 outputs a control signal to the second inverter 72 when controlling the second motor generator 62. The control device 90 controls the second motor generator 62 by adjusting the amount of electric power exchanged between the second motor generator 62 and the battery 73 via the second inverter 72.

[0033] When the vehicle 100 travels, the control device 90 selects either the EV mode or the HV mode as the travel mode of the vehicle 100. Here, the EV mode is a travel mode in which the vehicle 100 travels by driving one or more motor generators selected from the first motor generator 61 and the second motor generator 62 while stopping the internal combustion engine 10. Therefore, in the EV mode, the vehicle 100 travels by the driving force of the first motor generator 61 and the driving force of the second motor generator 62. Also, the HV mode is a travel mode of the vehicle 100 in which the internal combustion engine 10 is driven in addition to the first motor generator 61 and the second motor generator 62. Therefore, in the HV mode, the vehicle 100 travels by the driving force of the internal combustion engine 10 in addition to the driving force of the first motor generator 61 and the second motor generator 62. In this embodiment, the HV mode is an example of a non-EV mode.

[0034] The control device 90 selects the EV mode, for example, when the charging rate SOC of the battery 73 has a sufficient margin and the above-mentioned required vehicle output is small. Examples of a small required vehicle output include when the vehicle 100 starts moving and when the vehicle 100 is running under a light load with low acceleration. On the other hand, the control device 90 selects the HV mode, for example, when the charging rate SOC of the battery 73 does not have a sufficient margin.

[0035] The vehicle 100 is equipped with a car navigation system 95. The car navigation system 95 is a device that guides the vehicle 100 to a predetermined destination. The car navigation system 95 stores map information in advance. The car navigation system 95 can acquire the current location of the vehicle 100 from a GPS (not shown) or the like. The car navigation system 95 calculates information about the route from the current location of the vehicle 100 to the destination and topographical information on the route based on the map information, the current location of the vehicle 100, and the destination set by the driver or the like. The car navigation system 95 can communicate with the control device 90.

[0036] The control device 90 and the car navigation system 95 may be configured as a circuit including one or more processors that execute various processes according to a computer program (software). The control device 90 and the car navigation system 95 may also be configured as a circuit including one or more dedicated hardware circuits, such as an application specific integrated circuit (ASIC), that execute at least a part of the various processes, or a combination thereof. The processor includes a CPU and memories such as a RAM and a ROM. The memory stores program codes or instructions that are configured to cause the CPU to execute processes. The memory, i.e., the computer-readable medium, includes any medium that can be accessed by a general-purpose or dedicated computer.

[0037] <Pump control> Next, a description will be given of the pump control performed by the control device 90. The control device 90 selects the EV mode as the driving mode of the vehicle 100 and executes the pump control whenever the vehicle 100 is in a situation where acceleration is not required. One example of such a situation is when the vehicle 100 is traveling downhill and the driver takes his / her foot off the accelerator pedal.

[0038] As shown in FIG. 2, when the control device 90 starts pump control, the control device 90 proceeds to the process of step S11. In step S11, the control device 90 judges whether or not the drive of the oil pump 77 is requested. For example, the control device 90 judges that the drive of the oil pump 77 is requested when the length of the period during which the oil pump 77 is not driven is equal to or longer than a predetermined period. Also, for example, the control device 90 judges that the drive of the oil pump 77 is requested when the distance traveled by the vehicle 100 in a state in which the oil pump 77 is not driven is equal to or longer than a predetermined distance. In step S11, when the control device 90 judges that the drive of the oil pump 77 is not requested (S11: NO), the control device 90 performs the process of step S11 again. On the other hand, in step S11, when the control device 90 judges that the drive of the oil pump 77 is requested (S11: YES), the control device 90 proceeds to the process of step S21. In other words, the control device 90 proceeds to the process from step S21 onwards on the condition that the prescribed requirements for requiring the oil pump 77 to be driven during the EV mode are satisfied.

[0039] In step S21, the control device 90 judges whether or not the situation is favorable for obtaining regenerative energy. For example, the control device 90 judges whether or not the situation is favorable for obtaining regenerative energy as follows. First, the control device 90 acquires information on the route from the current position of the vehicle 100 to the destination and topographical information on the route from the car navigation system 95. Next, the control device 90 acquires the length of the downhill slope from the current position of the vehicle 100 to a point a certain distance away, the gradient of the downhill slope, and the like, based on the information acquired from the car navigation system 95. Then, the control device 90 judges whether or not the situation is favorable for obtaining regenerative energy based on the length of the downhill slope, the gradient of the downhill slope, and the like. For example, the control device 90 judges that the situation is favorable for obtaining regenerative energy when the length of the downhill slope is equal to or greater than a predetermined distance. Also, for example, the control device 90 judges that the situation is favorable for obtaining regenerative energy when the gradient of the downhill slope is equal to or greater than a predetermined gradient. In step S21, when the control device 90 judges that the situation is favorable for obtaining regenerative energy (S21: YES), the control device 90 advances the process to step S41. On the other hand, in step S21, when the control device 90 determines that the situation is not conducive to obtaining regenerative energy (S21: NO), the control device 90 advances the process to step S31.

[0040] In step S31, the control device 90 judges whether the charging rate SOC of the battery 73 is equal to or lower than a predetermined charging specified value A. Here, the charging specified value A is a value higher than the charging rate lower limit SOCL and lower than the charging rate upper limit SOCH. An example of the charging specified value A is about 50%. In step S31, if the control device 90 judges that the charging rate SOC of the battery 73 is higher than the charging specified value A (S31: NO), the process proceeds to step S41. On the other hand, in step S31, if the control device 90 judges that the charging rate SOC of the battery 73 is equal to or lower than the charging specified value A (S31: YES), the process proceeds to step S64. In other words, if the battery 73 is in a state where it can be charged, the control device 90 proceeds to step S64.

[0041] In step S64, the control device 90 executes engine drive processing. Specifically, the control device 90 selects the HV mode as the driving mode of the vehicle 100. Then, the control device 90 drives the internal combustion engine 10 to drive the vehicle 100. That is, the internal combustion engine 10 is driven to rotate the crankshaft 11. As a result, the oil pump 77 is driven. At this time, when the torque of the internal combustion engine 10 is input to the rotating shaft 61A of the first motor generator 61 via the power split mechanism 40, the first motor generator 61 functions as a generator. Then, at the time when the processing of step S64 is executed, the battery 73 is in a state where it can be charged. Therefore, even if the internal combustion engine 10 is driven, the battery 73 will not be overcharged or the like.

[0042] On the other hand, as described above, in step S21, if the control device 90 determines that the situation is favorable for obtaining regenerative energy (S21: YES), the process proceeds to step S41. In addition, in step S31, if the control device 90 determines that the charging rate SOC of the battery 73 is higher than the charging specified value A (S31: NO), the process proceeds to step S41.

[0043] In step S41, the control device 90 calculates a tentative engine speed NEX, which is the rotation speed of the crankshaft 11 on the assumption that a locking process has been executed in step S63, which will be described later. For example, the control device 90 calculates the tentative engine speed NEX to be a higher value as the second rotation speed NM2 at the time of the process in step S41 is higher.

[0044] Specifically, as shown in Figs. 3 and 4, in the vehicle 100 of this embodiment, the rotation speed of the sun gear 41, the rotation speed of the carrier 42, and the rotation speed of the ring gear 44 are related to each other. Therefore, the first rotation speed NM1, which is the rotation speed of the rotating shaft 61A of the first motor generator 61, the engine rotation speed NE of the internal combustion engine 10, and the second rotation speed NM2, which is the rotation speed of the rotating shaft 62A of the second motor generator 62, are also related to each other. In addition, on the alignment charts shown in Figs. 3 and 4, the rotation speeds are in a relationship such that a straight line can be drawn between the rotation speeds. Therefore, in a state in which the locking process is executed, that is, when the first rotation speed NM1 is assumed to be zero, the tentative engine rotation speed NEX is in a positive proportional relationship with the second rotation speed NM2. In addition, in the alignment charts of Figs. 3 and 4, the S axis indicates the rotation speed of the sun gear 41 and the first rotation speed NM1. In addition, the C axis indicates the rotation speed of the carrier 42 and the engine rotation speed NE. Furthermore, the R-axis is an axis that indicates a value proportional to the rotation speed of the ring gear 44 and the second rotation speed NM2. As shown in Fig. 2, after the process of step S41, the control device 90 advances the process to step S42.

[0045] As shown in FIG. 2, in step S42, the control device 90 calculates a supply oil amount BX, which is an amount of oil that can be supplied from the oil pump 77 when it is assumed that a locking process is performed in step S63, which will be described later. Specifically, first, the control device 90 acquires information about the route from the current position of the vehicle 100 to the destination and topographical information on the route from the car navigation system 95. Next, the control device 90 calculates a predicted value of the period from the current time until the vehicle speed SP becomes zero based on the vehicle speed SP, the deceleration that is the amount of decrease in the vehicle speed SP per unit time, and the topographical information acquired from the car navigation system 95. Furthermore, the control device 90 calculates a predicted value of the number of rotations of the crankshaft 11 from the current time until the vehicle speed SP becomes zero based on the predicted period until the vehicle speed SP becomes zero and the tentative engine rotation speed NEX. Then, the control device 90 calculates the supply oil amount BX to be a larger value as the predicted value of the number of rotations of the crankshaft 11 becomes larger. After that, the control device 90 advances the process to step S51.

[0046] In step S51, the control device 90 judges whether the supply oil amount BX is smaller than a predetermined oil specified value B. Here, the oil specified value B is determined, for example, as follows. First, in a situation where the processing in step S11 results in a positive judgment, the minimum amount of oil to be supplied from the oil pump 77 to each part of the internal combustion engine 10 is obtained by experiment or the like. Then, a value that is a certain amount larger than the minimum oil amount is determined as the oil specified value B. In step S51, if the control device 90 judges that the supply oil amount BX is smaller than the oil specified value B (S51: YES), the control device 90 advances the processing to step S61. On the other hand, in step S51, if the control device 90 judges that the supply oil amount BX is equal to or larger than the oil specified value B (S51: NO), the control device 90 advances the processing to step S52.

[0047] In step S52, the control device 90 judges whether the tentative engine speed NEX is lower than a first threshold value NEA that is determined in advance. Here, an example of the first threshold value NEA is about 1000 rpm. The first threshold value NEA is determined, for example, as follows. First, when the engine speed NE is relatively low, the engine speed NE is likely to fluctuate. Then, due to such fluctuations in the engine speed NE, gears of the transmission mechanism 66 and the like may separate and contact again, causing abnormal noise to be generated from the transmission mechanism 66 and the like. Therefore, an upper limit value of the engine speed NE at which abnormal noise is generated from the transmission mechanism 66 and the like is obtained by experiment or the like. Then, a value that is higher by a certain value than the obtained upper limit value of the engine speed NE is determined as the first threshold value NEA. In step S52, when the control device 90 judges that the tentative engine speed NEX is lower than the first threshold value NEA (S52: YES), the control device 90 advances the process to step S61.

[0048] In step S61, the control device 90 executes a process of increasing the engine rotation speed NE by the first motor generator 61. Specifically, the control device 90 applies a positive torque from the first motor generator 61 to the crankshaft 11, thereby rotating the crankshaft 11 so that the engine rotation speed NE becomes equal to or higher than the first threshold value NEA. In this embodiment, the control device 90 controls the engine rotation speed NE to be higher than the first threshold value NEA by a certain rotation speed. The control device 90 controls the engine rotation speed NE to be equal to or higher than the first threshold value NEA and equal to or lower than a second threshold value NEB, which will be described later. The positive torque is a torque applied to the crankshaft 11 so that the engine rotation speed NE becomes higher. When the process of step S61 is executed, the engine rotation speed NE becomes a positive value, but fuel is not burned in the cylinders of the internal combustion engine 10. In other words, since the combustion of fuel in the internal combustion engine 10 is stopped, the crankshaft 11 of the internal combustion engine 10 is in an idling state. Thereafter, the control device 90 ends the current pump control.

[0049] On the other hand, in step S52, when the control device 90 determines that the tentative engine rotation speed NEX is equal to or higher than the first threshold value NEA (S52: NO), the control device 90 advances the process to step S53. In step S53, the control device 90 judges whether the tentative engine speed NEX is higher than a second threshold value NEB that is determined in advance. Here, the second threshold value NEB is a value higher than the first threshold value NEA. An example of the second threshold value NEB is about 4000 rpm. The second threshold value NEB is determined, for example, as follows. First, when the engine speed NE is relatively high, noise caused by the movement of the pistons of the internal combustion engine 10 is likely to occur. The noise caused by the movement of the pistons of the internal combustion engine 10 tends to become louder as the engine speed NE is higher. Therefore, a permissible value of the loudness of the noise caused by the movement of the pistons of the internal combustion engine 10 is determined. In addition, a value of the engine speed NE that corresponds to the permissible value of the loudness of the noise is obtained by an experiment or the like. Then, a value that is a certain value lower than the obtained value of the engine speed NE is determined as the second threshold value NEB. In step S53, when the control device 90 judges that the tentative engine speed NEX is higher than the second threshold value NEB (S53: YES), the control device 90 advances the process to step S62.

[0050] In step S62, the control device 90 executes a process of decreasing the engine rotation speed NE by the first motor generator 61. Specifically, the control device 90 applies a negative torque from the first motor generator 61 to the crankshaft 11, thereby rotating the crankshaft 11 so that the engine rotation speed NE becomes equal to or lower than the second threshold value NEB. In this embodiment, the control device 90 controls the engine rotation speed NE to be lower than the second threshold value NEB by a certain rotation speed. The control device 90 controls the engine rotation speed NE to be equal to or higher than the first threshold value NEA and equal to or lower than the second threshold value NEB. The negative torque is a torque applied to the crankshaft 11 so as to reduce the engine rotation speed NE. In addition, in a state where step S62 is executed, the combustion of fuel in the internal combustion engine 10 is stopped, so that the crankshaft 11 of the internal combustion engine 10 is in an idling state. Thereafter, the control device 90 ends the current pump control.

[0051] On the other hand, in step S53, when the control device 90 determines that the tentative engine speed NEX is equal to or lower than the second threshold value NEB (S53: NO), the control device 90 advances the process to step S63. In other words, when the tentative engine speed NEX is expected to be within a range of equal to or higher than the first threshold value NEA and equal to or lower than the second threshold value NEB, the control device 90 advances the process to step S63.

[0052] In step S63, the control device 90 executes a lock process for the first motor generator 61. Specifically, the control device 90 outputs a control signal to the brake device 65. The control device 90 then restricts the rotation of the rotating shaft 61A of the first motor generator 61 by the brake device 65, thereby setting the first rotation speed NM1 to zero. Then, the crankshaft 11 rotates at a rotation speed determined according to the rotation speed of the sun gear 41 and the rotation speed of the ring gear 44. At this time, since the rotation speed of the sun gear 41 becomes zero, the crankshaft 11 rotates according to the second rotation speed NM2 proportional to the rotation speed of the ring gear 44. Note that, in the state where step S63 is executed, the combustion of fuel in the internal combustion engine 10 is stopped, and therefore the crankshaft 11 of the internal combustion engine 10 is in an idling state. After that, the control device 90 ends the current pump control.

[0053] In this embodiment, the range equal to or greater than the first threshold value NEA and equal to or less than the second threshold value NEB is an example of a specified range. That is, the control device 90 executes the process of step S63 when the tentative engine speed NEX is expected to be within the specified range. Therefore, the process of step S63 corresponds to a first drive process. Moreover, the control device 90 executes the process of step S61 or the process of step S62 when the tentative engine speed NEX is expected to be outside the specified range. Therefore, the processes of steps S61 and S62 correspond to a second drive process.

[0054] <Action of this embodiment> During the EV mode of the vehicle 100, the internal combustion engine 10 stops, and therefore the oil pump 77, which is driven by the internal combustion engine 10, also stops. Therefore, oil is not supplied from the oil pump 77 to each part of the internal combustion engine 10. Therefore, the control device 90 executes pump control to drive the oil pump 77 and supply oil to each part of the internal combustion engine 10.

[0055] Here, it is assumed that the lock process of step S63 is executed in the pump control. Then, the first rotation speed NM1 becomes zero by restricting the rotation of the rotating shaft 61A of the first motor generator 61 by the brake device 65. Therefore, for example, as shown by the two-dot chain line in FIG. 3, the rotation speed of the sun gear 41 connected to the rotating shaft 61A of the first motor generator 61 also becomes zero. Then, the carrier 42 and the crankshaft 11 rotate at a rotation speed determined according to the rotation speed of the sun gear 41 and the rotation speed of the ring gear 44. At this time, since the rotation speed of the sun gear 41 becomes zero, the crankshaft 11 rotates at the engine rotation speed NE according to the second rotation speed NM2 proportional to the rotation speed of the ring gear 44. Then, the oil pump 77 discharges oil based on the rotation of the crankshaft 11.

[0056] <Effects of this embodiment> (1) The control device 90 executes the process of step S61 or the process of step S62 when the tentative engine speed NEX is expected to fall outside the specified range, which is equal to or higher than the first threshold value NEA and equal to or lower than the second threshold value NEB. On the other hand, the control device 90 executes the process of step S63 when the tentative engine speed NEX is expected to fall within the specified range. As a result, regardless of whether the process of steps S61 to S63 is executed, the engine speed NE falls within the specified range. Therefore, by executing the processes of steps S61 to S63, it is possible to prevent the engine speed NE from becoming an undesirable speed outside the specified range.

[0057] Specifically, in the vehicle 100, the second rotation speed NM2 is determined by the vehicle speed SP. Therefore, the engine speed NE during the locking process of step S63 in the pump control is determined by the vehicle speed SP. More specifically, the engine speed NE during the locking process of step S63 becomes higher as the vehicle speed SP becomes higher. Here, for example, when the locking process of step S63 in the pump control is executed, the vehicle speed SP is assumed to be a relatively low value. Then, for example, as shown by the two-dot chain line in FIG. 3, the second rotation speed NM2 also becomes a relatively low value according to the vehicle speed SP. Then, the engine speed NE according to the second rotation speed NM2 becomes a relatively low value. And, when the engine speed NE is lower than the first threshold value NEA, the engine speed NE is likely to fluctuate. As a result, the gears of the transmission mechanism 66 and the like may separate or contact each other again due to the fluctuation of the engine speed NE, which may cause abnormal noise from the transmission mechanism 66 and the like.

[0058] In this regard, in the present embodiment, when the control device 90 determines that the tentative engine speed NEX is lower than the first threshold value NEA, the control device 90 executes a process of increasing the engine speed NE by the first motor generator 61 in step S61. Then, a positive torque is applied from the first motor generator 61 to the crankshaft 11. Specifically, for example, as shown by a solid straight line in FIG. 3, the positive torque from the first motor generator 61 causes the rotation speed of the sun gear 41 to become higher than zero. Then, the rotation speed of the carrier 42, which is determined according to the rotation speed of the sun gear 41 and the rotation speed of the ring gear 44, becomes higher. As a result, the rotation speed of the crankshaft 11 connected to the carrier 42, i.e., the engine speed NE, becomes equal to or higher than the first threshold value NEA. This makes it possible to suppress the generation of abnormal noise from the transmission mechanism 66 and the like, which is caused by the engine speed NE becoming lower than the first threshold value NEA.

[0059] Also, for example, when the locking process of step S63 in the pump control is executed, the vehicle speed SP is assumed to be a relatively high value. Then, as shown by the two-dot chain line in Fig. 4, the second rotation speed NM2 also becomes a relatively high value according to the vehicle speed SP. Then, the engine speed NE according to the second rotation speed NM2 becomes a relatively high value. If the engine speed NE is higher than the second threshold value NEB, the volume of the sound caused by the movement of the piston of the internal combustion engine 10 may become excessively large.

[0060] In this regard, in the present embodiment, when the control device 90 determines that the tentative engine speed NEX is higher than the second threshold value NEB, the control device 90 executes a process of decreasing the engine speed NE by the first motor generator 61 in step S62. Then, a negative torque is applied to the crankshaft 11 from the first motor generator 61. Specifically, for example, as shown by a solid straight line in FIG. 4, the negative torque from the first motor generator 61 causes the rotation speed of the sun gear 41 to become lower than zero. Then, the rotation speed of the carrier 42, which is determined according to the rotation speed of the sun gear 41 and the rotation speed of the ring gear 44, becomes lower. As a result, the rotation speed of the crankshaft 11 connected to the carrier 42, i.e., the engine speed NE, becomes equal to or lower than the second threshold value NEB. This makes it possible to suppress the sound associated with the movement of the pistons of the internal combustion engine 10 from becoming excessively large due to the engine speed NE becoming higher than the second threshold value NEB.

[0061] (2) As described above, the control device 90 executes the process of step S63 when the tentative engine speed NEX is expected to be within a specified range. Therefore, the process of step S61 and the process of step S62, which require the transfer of electric power to the first motor generator 61, are not executed excessively frequently. This makes it possible to suppress, for example, deterioration of the first motor generator 61 caused by an increase in the frequency of the transfer of electric power to the first motor generator 61.

[0062] (3) When the control device 90 determines that the tentative engine speed NEX is higher than the second threshold value NEB, the control device 90 executes a process of lowering the engine speed NE by the first motor generator 61 in step S62. At this time, the first motor generator 61 applies a negative torque to the crankshaft 11, that is, the first motor generator 61 functions as a generator. This makes it possible to store the electric power generated by the first motor generator 61 in the battery 73 while controlling the engine speed NE to be equal to or lower than the second threshold value NEB by the first motor generator 61.

[0063] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0064] In the above embodiment, the pump control process may be changed. For example, the control device 90 may execute the process of step S41 after making a positive determination in the process of step S11 without executing the process of step S21. First, since the power of the battery 73 is used in the EV mode, it can be expected that the charging rate SOC of the battery 73 is secured to a certain degree when the pump control is being executed. Therefore, even if the increase process in step S61 is executed regardless of the determination result of step S21, it is possible to apply a positive torque to the crankshaft 11 from the first motor generator 61, that is, to cause the first motor generator 61 to function as an electric motor. In other words, the process of step S21 may be omitted in the pump control.

[0065] For example, the calculation process of the supply oil amount BX in step S42 may be changed. As a specific example, the control device 90 may calculate the supply oil amount BX based only on the vehicle speed SP and the deceleration, which is the amount of decrease in the vehicle speed SP per unit time.

[0066] For example, the control device 90 may execute the process of step S52 after the process of step S41. Even in this case, it is possible to at least prevent the engine speed NE from falling outside the specified range. That is, in the pump control, the processes of steps S42 and S51 may be omitted.

[0067] In the above embodiment, the specified range may be changed. For example, the value of the first threshold value NEA can be changed. As a specific example, the engine rotation speed NE at which abnormal noise is generated from the transmission mechanism 66 can change depending on the structure of the transmission mechanism 66. Thus, the value of the first threshold value NEA may be changed in accordance with the structure of the transmission mechanism 66.

[0068] For example, the conditions for determining the first threshold value NEA may be changed. As a specific example, in addition to abnormal noise generated from the transmission mechanism 66, etc., a low engine speed NE may be undesirable from the viewpoint of ensuring a minimum amount of oil supplied from the oil pump 77. In this case, the lower limit of the engine speed NE that is acceptable may be set as the first threshold value NEA. Also, the first threshold value NEA may be determined taking other technical factors into consideration.

[0069] For example, the first threshold value NEA does not need to be set. As a specific example, if a low engine speed NE is acceptable, there is no need to set the first threshold value NEA. In this case, the specified range is a range equal to or less than the second threshold value NEB. In this case, the control device 90 may execute the process of step S53 after making a negative determination in step S51.

[0070] For example, the value of the second threshold value NEB can be changed. As a specific example, the engine speed NE corresponding to the allowable value of the loudness of the sound caused by the movement of the pistons of the internal combustion engine 10 may change depending on the structure of the internal combustion engine 10. Therefore, the value of the second threshold value NEB may be changed depending on the structure of the internal combustion engine 10.

[0071] For example, the conditions for determining the second threshold value NEB may be changed. As a specific example, in addition to the noise caused by the movement of the pistons of the internal combustion engine 10, for example, a high engine speed NE may be undesirable from the viewpoint of setting an upper limit of the amount of oil supplied from the oil pump 77. In this case, the upper limit that is permissible for the engine speed NE may be set as the second threshold value NEB. Also, the second threshold value NEB may be set in consideration of other technical factors.

[0072] For example, the second threshold value NEB does not need to be set. As a specific example, if a high engine speed NE is acceptable, there is no need to set the second threshold value NEB. In this case, the specified range is a range equal to or greater than the first threshold value NEA. In this case, the control device 90 may execute the process of step S63 after making a negative determination in step S52.

[0073] In the above embodiment, the configuration of the vehicle 100 may be changed. For example, the ring gear 44 of the power split mechanism 40 may be directly connected to the rotating shaft 62A of the second motor generator 62 without passing through the ring gear shaft 45 and the reduction mechanism 50. [Explanation of symbols]

[0074] NE: Engine speed NEA…First threshold NEB: Second threshold NEX: Provisional engine speed 10. Internal combustion engine 11…Crankshaft 40...Power split mechanism 41…Sun Gear 42…Career 43…Pinion gear 44…Ring gear 45…Ring gear shaft 50…Reduction mechanism 61…First motor generator 61A…Rotary shaft 62…Second motor generator 62A…Rotary shaft 65...Brake device 66...Transmission mechanism 67…Differential 68...Drive wheel 77…Oil pump 90...Control device 95…Car navigation system 100…Vehicle

Claims

[Claim 1] An internal combustion engine; A first motor generator; A second motor generator; a planetary gear mechanism capable of distributing a torque of the internal combustion engine, a torque of the first motor generator, and a torque of the second motor generator among each other; an oil pump that discharges oil based on rotation of a crankshaft of the internal combustion engine; a restricting device that restricts rotation of a rotary shaft of the first motor generator; Equipped with the planetary gear mechanism includes a sun gear that rotates, a ring gear that rotates coaxially with the sun gear, a plurality of pinion gears that mesh with both the sun gear and the ring gear and revolve around the sun gear, and a carrier that rotates coaxially with the sun gear in accordance with the revolution of the pinion gears, The carrier is connected to the crankshaft, the sun gear is connected to a rotating shaft of the first motor-generator, and the ring gear is connected to a rotating shaft of the second motor-generator. Applied to vehicles, a control device capable of controlling a driving mode of the vehicle to either an EV mode in which the vehicle is driven by driving the second motor generator while stopping the internal combustion engine, or a non-EV mode in which the vehicle is driven by driving the internal combustion engine, a first drive process for rotating the crankshaft while regulating the rotation of the rotary shaft of the first motor generator to zero by the regulating device in a state in which fuel combustion in the internal combustion engine is stopped, on condition that a prescribed requirement requiring the drive of the oil pump during the EV mode is satisfied; a second drive process for rotating the crankshaft such that a rotation speed of the crankshaft is within a predetermined specified range while applying a torque to the crankshaft from the first motor generator in a state in which fuel combustion in the internal combustion engine is stopped, on condition that the specified requirement is satisfied during the EV mode; When it is expected that the rotation speed will be within the specified range when the first drive process is executed, the first drive process is executed, and when it is expected that the rotation speed will be outside the specified range when the first drive process is executed, the second drive process is executed. Vehicle control device.

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