Hybrid vehicle control device

Abstract

To provide a hybrid-vehicular control apparatus suppressing the occurrence of a torque shock.SOLUTION: A hybrid-vehicular control apparatus, capable of shifting from a first travel mode with one of an engine and a motor as a traveling drive power source to a second travel mode with the other of the engine and motor as the traveling drive power source, includes: a load torque calculation part for calculating load torque on a torque converter and a transmission; a share ratio calculation part for calculating, in a case where torque on the one becomes equal to or less than the load torque due to a shift from the first travel mode to the second travel mode requested, a share ratio in a manner to gradually decrease the share ratio of the one of the load torque and gradually increase the share ratio of the other by the decrease in the share ratio of the one so as to decrease the share ratio of the one down to zero; a clutch control part for controlling, in the case of the torque of the one becoming equal to or less than the load torque, the clutch into an engagement state; and a torque control part for controlling torque of the engine and torque of the motor in accordance with the share ratio of the one and the share ratio of the other in the engagement state.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] A hybrid vehicle can shift from one driving mode in which the engine is used as a driving source for running to the other driving mode in which the motor is used as a driving source for running (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-176934 A Summary of the Invention [Problem to be solved by the invention]

[0004] Some hybrid vehicles have a motor, clutch, torque converter, and transmission in this order on the power transmission path from the engine to the wheels. In such hybrid vehicles, for example, in a driving mode in which the vehicle runs on the engine, the engine needs to output torque at least equal to the load torque of the torque converter and the transmission. If the engine torque is less than the load torque, the engine rotation will gradually decrease and the rotation speed cannot be maintained. Similarly, in a driving mode in which the vehicle runs on the motor, the motor needs to output torque equal to the load torque.

[0005] Here, even when transitioning from a driving mode in which the vehicle runs on one of the engine and the motor to a driving mode in which the vehicle runs on the other, it is necessary to transfer the load torque from one of the engine and the motor to the other while maintaining the total torque of the engine and the motor at the load torque amount while keeping the clutch engaged. If torque is not transferred smoothly from one of the engine and the motor to the other during such a transition period of the driving mode, the total torque of the engine and the motor may deviate from the load torque, causing a torque shock.

[0006] SUMMARY OF THE PRESENT EMBODIMENTS The present invention has an object to provide a control device for a hybrid vehicle that suppresses the occurrence of torque shock. [Means for solving the problem]

[0007] The above object is to provide the following in order along the power transmission path from the engine to the wheels: Clutch, motor, This can be achieved by a control device for a hybrid vehicle that is provided with a torque converter and a transmission and is capable of shifting from a first driving mode in which one of the engine and the motor is a driving force source for driving to a second driving mode in which the other of the engine and the motor is a driving force source for driving. The control device for a hybrid vehicle includes: a load torque calculation unit that calculates a load torque of the torque converter and the transmission; and a share rate calculation unit that, when a request for shifting from the first driving mode to the second driving mode is made and the torque of the one of the engine and the motor becomes equal to or less than the load torque, calculates a share rate of the one of the engine and the other of the motor so as to gradually reduce a share rate of the load torque of the one of the engine and the other of the motor while gradually increasing a share rate of the load torque of the other of the engine and the motor by an amount equivalent to the decrease in the share rate of the one of the engine and the other of the motor so as to decrease the share rate of the one of the engine and the other of the motor to zero. A clutch control unit that controls the clutch to an engaged state when the shift request is made and the torque of the one of the engine and the motor becomes equal to or less than the load torque.

[0008] The one may be the engine and the other may be the motor, and the clutch control unit may control the clutch to a released state when the torque of the motor becomes equal to or greater than the load torque.

[0009] The one may be the motor and the other may be the engine, and the clutch control unit may control the clutch from the released state to the engaged state when there is a request to transition from the first driving mode to the second driving mode and the torque of the one becomes equal to or less than the load torque.

[0010] The sharing rate calculation unit may calculate a rate at which the one sharing rate decreases to be constant, and may calculate a rate at which the other sharing rate increases to be constant.

[0011] The load torque calculation unit may calculate the load torque based on a temperature of lubricant supplied to at least one of the motor, the clutch, and the transmission.

[0012] The load torque calculation unit may calculate the load torque based on a rotation speed input to the torque converter. Effect of the Invention

[0013] According to the present invention, it is possible to provide a control device for a hybrid vehicle that suppresses the occurrence of torque shock. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram of a hybrid vehicle. [Diagram 2] FIG. 2 is a timing chart showing an example of the transition from the HV driving mode to the EV driving mode. [Diagram 3] FIG. 3 is a flowchart showing an example of transition control from the HV driving mode to the EV driving mode executed by the ECU. [Figure 4] FIG. 4 is an example of a map showing the T / M load torque according to the oil temperature. [Diagram 5] FIG. 5 is a timing chart showing an example of the transition from the EV driving mode to the HV driving mode. [Figure 6] FIG. 6 is a flowchart showing an example of a transition control from the EV driving mode to the HV driving mode executed by the ECU. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] [General configuration of hybrid vehicle] FIG. 1 is a schematic diagram of a hybrid vehicle. The hybrid vehicle is equipped with an engine 10 and a motor 15 as driving sources for traveling. The engine 10 is, for example, a gasoline engine, but may be a diesel engine. The engine 10 is provided with a starter 24 for cranking and starting the engine 10. A transmission unit 11 is provided on a power transmission path from the engine 10 to wheels 13. The transmission unit 11 and the left and right wheels 13 are drivingly connected via a differential 12.

[0016] The transmission unit 11 is provided with a K0 clutch 14 and a motor 15. In the transmission unit 11, the motor 15 is installed so as to be located on a power transmission path from the engine 10 to the wheels 13. The K0 clutch 14 is provided between the engine 10 and the motor 15 on the power transmission path. The K0 clutch 14 is engaged when supplied with hydraulic pressure, connecting the power transmission between the engine 10 and the motor 15. The K0 clutch 14 is released when the hydraulic pressure supply is stopped, disconnecting the power transmission between the engine 10 and the motor 15.

[0017] The motor 15 is connected to the vehicle battery 16 via an inverter 17. The motor 15 functions as a motor that generates driving force for the vehicle in response to power supplied from the vehicle battery 16, and also functions as a generator that generates power to charge the vehicle battery 16 in response to power transmission from the engine 10 and the wheels 13. The power exchanged between the motor 15 and the vehicle battery 16 is adjusted by the inverter 17.

[0018] The transmission unit 11 is provided with a torque converter 18, which is a fluid coupling having a torque amplifying function, and a stepped automatic transmission 19 that switches the gear ratio in multiple stages by switching the gear stage. In the transmission unit 11, the automatic transmission 19 is provided between the motor 15 and the wheels 13 on the power transmission path. The motor 15 and the automatic transmission 19 are connected via the torque converter 18. The torque converter 18 is provided with a lock-up clutch 20 that is supplied with hydraulic pressure and enters an engaged state to directly connect the motor 15 and the automatic transmission 19.

[0019] The transmission unit 11 is further provided with an oil pump 21 and a hydraulic control mechanism 22. The hydraulic pressure generated by the oil pump 21 is supplied to the K0 clutch 14, the torque converter 18, the automatic transmission 19, and the lock-up clutch 20 via the hydraulic control mechanism 22. The hydraulic control mechanism 22 is provided with hydraulic circuits for each of the K0 clutch 14, the torque converter 18, the automatic transmission 19, and the lock-up clutch 20, and various hydraulic control valves for controlling the operating hydraulic pressures thereof.

[0020] The hybrid vehicle is provided with an ECU (Electronic Control Unit) 23 as a control device for the vehicle. The ECU 23 is an electronic control unit including a calculation processing circuit that performs various calculation processes related to vehicle driving control, and a memory that stores control programs and data. The ECU 23 is an example of a control device for a hybrid vehicle, and functionally realizes a load torque calculation unit, a share calculation unit, a clutch control unit, and a torque control unit, which will be described in detail later.

[0021] The ECU 23 controls the operation of the engine 10 and the motor 15. For example, the ECU 23 controls the torque of the engine 10 by controlling the throttle opening, ignition timing, and fuel injection amount of the engine 10. The ECU 23 also controls the inverter 17 to adjust the amount of power exchanged between the motor 15 and the vehicle battery 16, thereby controlling the torque of the motor 15. Furthermore, the ECU 23 controls the operation of the K0 clutch 14, the lock-up clutch 20, and the automatic transmission 19 through the control of the hydraulic control mechanism 22. The ECU 23 receives detection signals from a crank angle sensor 25 that detects the rotation speed of the crankshaft of the engine 10, a motor rotation speed sensor 26 that detects the rotation speed of the output shaft of the motor 15, an oil temperature sensor 27 that detects the temperature of the lubricating oil (hereinafter referred to as the oil temperature) of the automatic transmission 19, and other sensors, such as an accelerator pedal opening degree, which is the amount of depression of the accelerator pedal by the driver.

[0022] The ECU 23 drives the hybrid vehicle in either the EV driving mode or the HV driving mode. In the EV driving mode, the ECU 23 releases the K0 clutch 14 and uses the motor 15 as the driving power source for driving. In the HV driving mode, the ECU 23 engages the K0 clutch 14 and uses at least the engine 10 as the driving power source for driving. In the HV driving mode, the motor 15 can be operated in power running mode to drive the vehicle using the engine 10 and the motor 15 as the driving power source for driving, and the engine 10 can be operated in regenerative mode to generate electricity while the engine 10 is used as the driving power source for driving.

[0023] The driving mode is switched based on the vehicle's required driving force calculated from the vehicle speed and accelerator pedal depression, and the state of charge of the vehicle battery 16. For example, when the required driving force is relatively small and the remaining charge of the vehicle battery 16 is relatively high, the EV driving mode in which the engine 10 is stopped is selected to improve fuel efficiency. When the required driving force is relatively large or the remaining charge of the vehicle battery 16 is relatively low, the HV driving mode in which at least the engine 10 is driven is selected.

[0024] [Transition from HV driving mode to EV driving mode] The transition from the HV driving mode to the EV driving mode will be described. FIG. 2 is a timing chart showing an example of the transition from the HV driving mode to the EV driving mode. FIG. 2 shows the transition of the torque [N·m] of each of the engine 10 and the motor 15, and the transition of the share of the motor 15 in the T / M load torque. In FIG. 2, the torque of the engine 10 is shown by a solid line, the torque of the motor 15 is shown by a dotted line, and the total torque of the engine 10 and the motor 15 during the transition period is shown by a dashed line. The T / M load torque is the torque of the torque converter 18 and the automatic transmission 19 that become a rotation resistance against the torque of the engine 10 and the motor 15. The share of the motor 15 is shown as a minimum value of "0" and a maximum value of "1". In the example of FIG. 2, a case will be described in which the hybrid vehicle is running in the HV driving mode with only the engine 10 as the driving source for running. The HV driving mode, in which only the engine 10 is used as the driving source for driving, corresponds to one of the first driving mode and the second driving mode, and the EV driving mode, in which only the motor 15 is used as the driving source for driving, corresponds to the other of the first driving mode and the second driving mode.

[0025] When the vehicle is traveling in the HV driving mode by the engine 10, the torque of the engine 10 starts to decrease from time t0, and when the torque of the engine 10 decreases to the T / M load torque at time t1, the vehicle transitions from the HV driving mode to the EV driving mode. Specifically, while the total torque of the engine 10 and the motor 15 maintains the T / M load torque, the motor 15's share of the T / M load torque is gradually increased from "0", and the engine 10's share of the T / M load torque is gradually decreased by the amount of the increase in the motor 15's share. This causes the torque of the engine 10 to decrease by the amount of the increase in the motor 15 torque. When the torque of the engine 10 decreases to zero at time t2 and the torque of the motor 15 increases to the T / M load torque, the K0 clutch 14 is released and the engine 10 is disconnected from the power transmission path to the wheels 13, completing the transition to the EV driving mode.

[0026] In this way, during the transition period of the travel mode from time t1 to t2, the torque of each of the engine 10 and the motor 15 is controlled so that the torque ratio of the motor 15 gradually increases and the torque ratio of the engine 10 gradually decreases while maintaining the total torque of the engine 10 and the motor 15 at the T / M load torque. By maintaining the total torque of the engine 10 and the motor 15 at the T / M load torque, the rotation speeds of the engine 10 and the motor 15 can be maintained.

[0027] Here, for example, if during the transition period of the above-mentioned driving modes, the torque of the engine 10 is controlled to be momentarily reduced and the torque of the motor 15 is controlled to be momentarily increased at the same time, if the timing of the increase and decrease of both torques is misaligned, the total torque of the engine 10 and the motor 15 may momentarily increase or decrease more than the T / M load torque, causing a risk of torque shock. In this embodiment, as will be described in detail later, by gradually changing the share of the engine 10 and the motor 15 with respect to the T / M load torque, it is possible to suppress the occurrence of a torque shock while maintaining the total torque of the engine 10 and the motor 15 at the T / M load torque.

[0028] During the transition period of the driving mode from time t1 to t2, it is preferable that the rate at which the sharing rate of the engine 10 decreases, in other words, the rate at which the sharing rate of the motor 15 increases, is constant. This is because it makes it easy to control the torques of the engine 10 and the motor 15 in accordance with the sharing rates.

[0029] FIG. 3 is a flowchart showing an example of a transition control from the HV driving mode to the EV driving mode executed by the ECU 23. This control is repeatedly executed while the ignition of the hybrid vehicle is on. First, the ECU 23 calculates the T / M load torque (step S1). The T / M load torque is a value obtained in advance by an experiment, and varies depending on the oil temperature and the input rotation speed to the torque converter 18. FIG. 4 is an example of a map showing the T / M load torque depending on the oil temperature. In FIG. 4, the horizontal axis indicates the oil temperature [°C], and the vertical axis indicates the T / M load torque [N·m]. FIG. 4 also shows an example of a case where the input rotation speed to the torque converter 18 is a high rotation speed and a low rotation speed. The input rotation speed to the torque converter 18 corresponds to the rotation speed of the engine 10 and the rotation speed of the motor 15 when the K0 clutch 14 is engaged, and corresponds to the rotation speed of the motor 15 when the K0 clutch 14 is released. The ECU 23 obtains the oil temperature and the rotation speed of the motor 15 from the oil temperature sensor 27 and the motor rotation speed sensor 26, respectively, and calculates the T / M load torque by referring to the map shown in FIG.

[0030] As shown in FIG. 4, whether the input rotation speed to the torque converter 18 is a high rotation speed or a low rotation speed, the lower the oil temperature is below temperature α, the greater the T / M load torque. This is because when the oil temperature is lower than temperature α, the viscosity of the lubricating oil increases and the friction torque of the automatic transmission 19 also increases. When the oil temperature is lower than temperature (-β), the T / M load torque becomes constant. This is because when the oil temperature is lower than temperature (-β), the viscosity of the lubricating oil becomes approximately constant and the friction torque of the automatic transmission 19 also becomes approximately constant. In addition, the faster the input rotation speed to the torque converter 18, the smaller the T / M load torque. This is because the higher the rotation speeds of the engine 10 and the motor 15, the greater the friction torque of the torque converter 18 and the automatic transmission 19, and the greater the T / M load torque. Note that FIG. 4 only shows two examples of the rotation speeds of the engine 10 and the motor 15, one where the rotation speed is high and the other where the rotation speed is low. However, in reality, the T / M load torque is specified for each rotation speed of the engine 10 and the motor 15, and the T / M load torque is specified so that the higher the rotation speed of the engine 10 and the motor 15, the greater the T / M load torque.

[0031] Next, the ECU 23 determines whether or not there is a request to switch from the HV driving mode to the EV driving mode (step S2). For example, as described above, when the remaining charge of the vehicle battery 16 is relatively high and the required driving force is relatively low, a request to switch from the HV driving mode to the EV driving mode is made. If the result in step S2 is No, this control ends.

[0032] If the answer is Yes in step S2, the ECU 23 determines whether the torque of the engine 10 is equal to or lower than the T / M load torque (step S3). The torque of the engine 10 may be regarded as a target engine torque set in response to the driving operation by the driver, or may be calculated from the engine speed, the intake air amount, and the ignition timing, or may be calculated or estimated by other methods. If the answer is No in step S3, this control ends.

[0033] If the result of step S3 is Yes, the ECU 23 maintains the K0 clutch 14 in an engaged state (step S4). This allows the transfer of torque equivalent to the T / M load torque from the engine 10 to the motor 15, which will be described later. Step S4 is an example of a process executed by the clutch control unit.

[0034] Next, the ECU 23 calculates the sharing rate of the torque of the engine 10 and the torque of the motor 15 with respect to the T / M load torque (step S5). This sharing rate is calculated so that the sum of the sharing rate of the engine 10 and the sharing rate of the motor 15 is always "1", and the sharing rate of the engine 10 decreases and the sharing rate of the motor 15 increases over time. The process of step S5 is an example of a process executed by a sharing rate calculation unit.

[0035] Next, the ECU 23 calculates the target engine torque and the target motor torque in consideration of the sharing ratios of the engine 10 and the motor 15 (step S6). Specifically, the ECU 23 calculates the target engine torque by multiplying the T / M load torque by the sharing ratio of the engine 10. The ECU 23 also calculates the target motor torque by multiplying the T / M load torque by the sharing ratio of the motor 15.

[0036] Next, the ECU 23 controls the engine 10 and the motor 15 so that the torques of the engine 10 and the motor 15 become the calculated target engine torque and target motor torque (step S7). Specifically, the ECU 23 can adjust the fuel injection amount and the intake air amount by controlling the opening period of the fuel injection valve of the engine 10 and the opening degree of the throttle valve, thereby controlling the torque of the engine 10. The ECU 23 can also control the torque of the motor 15 by adjusting the power supplied from the vehicle battery 16 to the motor 15 by controlling the inverter 17. Steps S6 and S7 are an example of processing executed by the torque control unit.

[0037] Next, the ECU 23 determines whether the torque of the motor 15 is equal to or greater than the T / M load torque (step S8). If the result in step S8 is No, this control ends. Note that in step S8, it may be determined whether the sharing rate of the engine 10 has become "0" or whether the sharing rate of the motor has become "1".

[0038] If the answer is Yes in step S8, the ECU 23 reduces the hydraulic pressure supplied to the K0 clutch 14 from the hydraulic control mechanism 22 to release the K0 clutch 14 (step S9). This separates the engine 10 from the power transmission path, completing the transition to the EV driving mode by the motor 15. Step S9 is an example of a process executed by the clutch control unit.

[0039] As described above, during the transition period from the HV driving mode to the EV driving mode, the total torque of the engine 10 and the motor 15 can be maintained at the T / M load torque, while the torque equivalent to the T / M load torque can be smoothly transferred from the engine 10 to the motor 15. This makes it possible to suppress the occurrence of torque shock during the transition period from the HV driving mode to the EV driving mode.

[0040] [Transition from EV driving mode to HV driving mode] The transition from the EV driving mode to the HV driving mode will be described. FIG 5 is a timing chart showing an example of the transition from the EV driving mode to the HV driving mode. FIG 5 corresponds to FIG 2.

[0041] At time t10, the torque of the motor 15 decreases from a state in which the vehicle is traveling by the motor 15 in the EV traveling mode, and when the torque of the motor 15 decreases to the T / M load torque at time t11, a transition from the EV traveling mode to the HV traveling mode is performed. Specifically, the K0 clutch 14 is engaged, and while the total torque of the engine 10 and the motor 15 maintains the T / M load torque, the motor 15's share of the T / M load torque is gradually decreased from "1", and the engine 10's share of the T / M load torque is gradually increased by the amount by which the motor 15's share rate has decreased. This increases the torque of the engine 10 by the amount by which the motor 15 torque has decreased. When the torque of the engine 10 increases to the T / M load torque and the motor 15 torque decreases to zero at time t12, the transition to the HV traveling mode is completed. In this way, even during the transition period from EV mode to HV mode from time t11 to t12, the torque of each of the engine 10 and the motor 15 is controlled so that the total torque of the engine 10 and the motor 15 maintains the T / M load torque while the share of the motor 15 gradually decreases, thereby suppressing the occurrence of torque shock. When there is a request to transition from the EV driving mode to the HV driving mode, the engine 10 may be started in advance by the starter 24 before time t11, or, if the starter 24 is not provided, the K0 clutch 14 may be engaged immediately before time t11 to motor the engine 10 by the motor 15, and combustion in the engine 10 may begin, and then sharing of the T / M load torque by the engine 10 and the motor 15 may begin.

[0042] 6 is a flowchart showing an example of a transition control from the EV driving mode to the HV driving mode executed by the ECU 23. This control is repeatedly executed while the ignition of the hybrid vehicle is on. First, the ECU 23 calculates the T / M load torque (step S11). The process of step S11 is the same as the process of step S1 described above.

[0043] Next, the ECU 23 determines whether or not there is a request to switch from the EV driving mode to the HV driving mode (step S12). For example, as described above, when the remaining charge of the in-vehicle battery 16 is relatively low, a request to switch from the EV driving mode to the HV driving mode is made. If the result in step S12 is No, this control ends.

[0044] If the answer is Yes in step S12, the ECU 23 determines whether the torque of the motor 15 is equal to or less than the T / M load torque (step S13). The torque of the motor 15 may be determined to be a target motor torque set in response to driving operations by the driver, for example, or the torque of the motor 15 may be calculated based on the power supplied from the inverter 17 to the motor 15, or the torque of the motor 15 may be calculated or estimated by other methods. If the answer is No in step S13, this control ends.

[0045] If the result of step S13 is Yes, the ECU 23 increases the hydraulic pressure supplied to the K0 clutch 14 from the hydraulic control mechanism 22 to engage the K0 clutch 14 (step S14). Step S14 is an example of a process executed by the clutch control unit.

[0046] Next, the ECU 23 calculates the sharing rate of the torque of the engine 10 and the torque of the motor 15 with respect to the T / M load torque (step S15). This sharing rate is calculated so that the sharing rate of the engine 10 increases and the sharing rate of the motor 15 decreases over time. The process of step S15 is an example of a process executed by a sharing rate calculation unit.

[0047] Next, the ECU 23 calculates the target engine torque and the target motor torque in consideration of the sharing ratios of the engine 10 and the motor 15 (step S16). Step S16 is the same process as step S6 described above.

[0048] Next, the ECU 23 controls the engine 10 and the motor 15 so that the torques of the engine 10 and the motor 15 become the calculated target engine torque and target motor torque, respectively (step S17). Step S17 is the same process as step S7 described above. Steps S16 and S17 are examples of processes executed by the torque control unit.

[0049] As a result, the torque of the engine 10 becomes the T / M load torque, and the transition to the HV driving mode is completed. After the HV driving mode is completed, the motor 15 may be operated in power running or regenerative running.

[0050] As described above, during the transition period from the EV driving mode to the HV driving mode, the total torque of the engine 10 and the motor 15 can be maintained at the T / M load torque, while the torque equivalent to the T / M load torque can be smoothly transferred from the engine 10 to the motor 15. This makes it possible to suppress the occurrence of torque shock during the transition period from the EV driving mode to the HV driving mode.

[0051] In the above embodiment, the T / M load torque is calculated based on the temperature of the lubricant in the automatic transmission 19, but it is sufficient to use the temperature of the lubricant in at least one of the motor 15, the K0 clutch 14, and the automatic transmission 19. This is because the temperatures of these lubricants can be considered to be approximately the same temperature.

[0052] It is also conceivable to use the temperature of the engine 10 cooling water instead of the temperature of the lubricating oil, and to specify that the T / M load torque increases as the temperature of the cooling water decreases. However, there is a time lag between when the engine 10 starts and the temperature of the cooling water starts to rise, and when the temperature of the lubricating oil in the automatic transmission 19 and the like starts to rise due to the heat of the engine 10 and the like. For this reason, even if the temperature of the cooling water becomes relatively high, the temperature of the lubricating oil may still remain low and the friction torque of the automatic transmission 19 may be large. For this reason, using the temperature of the lubricating oil makes it possible to accurately calculate the T / M load torque corresponding to the magnitude of the friction torque of the automatic transmission 19, and to control the torque of the engine 10 and the motor 15 without excess or deficiency.

[0053] In this embodiment, a case where a hybrid vehicle is controlled by a single ECU 23 has been illustrated, but this is not limited to the above, and the above-mentioned control may be performed by multiple ECUs, such as an engine ECU that controls the engine 10, a motor ECU that controls the motor 15, and a clutch ECU that controls the K0 clutch 14.

[0054] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0055] 10 Engine 13 wheels 14 K0 clutch 15 Motor 18 Torque converter 19 Automatic transmission 23 ECU (internal combustion engine control unit) 25 Crank angle sensor 26 Motor rotation speed sensor 27 Oil temperature sensor

Claims

1. A control device for a hybrid vehicle, which has a clutch, a motor, a torque converter, and a transmission provided in this order on a power transmission path from an engine to wheels, and which is capable of shifting from a first driving mode in which one of the engine and the motor is used as a driving force source for driving to a second driving mode in which the other of the engine and the motor is used as a driving force source for driving, a load torque calculation unit that calculates a load torque of the torque converter and the transmission; a sharing rate calculation unit that, when there is a request to transition from the first traveling mode to the second traveling mode and the one torque becomes equal to or less than the load torque, gradually reduces the one share rate of the load torque while gradually increasing the other share rate of the load torque by an amount equivalent to the reduction in the one share rate, and calculates the one share rate and the other share rate so that the one share rate is reduced to zero; a clutch control unit that controls the clutch to an engaged state when the transition request is received and the torque of the one of the two is equal to or less than the load torque; a torque control unit that controls, in the engaged state, the torque of the engine and the torque of the motor in accordance with the sharing rate of one of the two and the sharing rate of the other of the two.

2. The one of the two is the engine, the other is the motor, 2. The control device for a hybrid vehicle according to claim 1, wherein the clutch control unit controls the clutch to a released state when the torque of the motor becomes equal to or greater than the load torque.

3. The one of the two is the motor, the other is the engine, 2. The control device for a hybrid vehicle according to claim 1, wherein the clutch control unit controls the clutch from a released state to the engaged state when there is a request to transition from the first driving mode to the second driving mode and the torque of one of the two becomes equal to or less than the load torque.

4. 4. The control device for a hybrid vehicle according to claim 1, wherein the share calculation unit calculates a rate at which the one share is decreased to be constant, and calculates a rate at which the other share is increased to be constant.

5. 5. The control device for a hybrid vehicle according to claim 1, wherein the load torque calculation unit calculates the load torque based on a temperature of lubricating oil supplied to at least one of the motor, the clutch, and the transmission.

6. 6. The control device for a hybrid vehicle according to claim 1, wherein the load torque calculation unit calculates the load torque based on a rotation speed input to the torque converter.

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