Japanese Unexamined Patent Application Publication No. 2015-123849 discloses providing a vehicle capable of effectively using both of an electric motor connected to the same wheels as an internal combustion engine, and an electric motor connected different wheels from an internal combustion engine ([0006], Summary).
To this end, Japanese Unexamined Patent Application Publication No. 2015-123849 (Summary) describes a power control device 28 of a vehicle 10 that controls target vehicle power by at least one of first electric motors 16 and 18 and an internal combustion engine 12, in a case where the target vehicle power is forward power and clutch units 38a and 38b (FIG. 1) are engaged. The power control device 28 also controls target vehicle power by at least one of a second electric motor 14 and the internal combustion engine 12, in a case where the target vehicle power is forward power and clutch units 38a and 38b are disengaged.
The first electric motors 16 and 18 (rear-side motors 16 and 18) are connected to clutches 38a and 38b (FIG. 1) that are different from clutches 102, 104 (FIG. 2) of the internal combustion engine 12. The second electric motor 14 (forward-side motor 14) is connected to the same clutch 102 as the internal combustion engine 12 (FIG. 2, [0035] through [0057]).
Japanese Unexamined Patent Application Publication No. 2015-123849 describes switching traveling modes in accordance with position of an accelerator pedal 70 (AP position θap) (FIG. 3). Japanese Unexamined Patent Application Publication No. 2015-123849 illustrates a partial-assist mode (S6 in FIG. 3, and FIGS. 4, 7, and 8) and a full-assist mode (S7 in FIG. 3, and FIGS. 4 through 6) as cases of the first electric motors 16 and 18 or the second electric motor 14 generating traveling drive force in addition to the internal combustion engine 12.
In the partial-assist mode and full-assist mode, the first clutch 102 and second clutch 104 are engaged to supply the drive power Feng of the engine 12 to the front wheels 32a and 32b, and the rear-side motors 16 and 18 or front-side motor 14 are driven to cause the vehicle 10 to travel ([0064], [0066]).
In the partial-assist mode and full-assist mode, the target vehicle torque Tv_tar is satisfied by the engine 12, and the motor 14 or motors 16 and 18 ([0064], [0066]). Disclosure is made to the effect that the target vehicle torque Tv_tar is set based on the position of the accelerator pedal 70 (AP position θap) serving as a target power input unit (claim 1, [0119]).
Thus, in Japanese Unexamined Patent Application Publication No. 2015-123849, traveling modes are switched in accordance with position of an accelerator pedal 70 (AP position θap) (FIG. 3). In the partial-assist mode and full-assist mode, the target vehicle torque Tv_tar based on the position of the accelerator pedal 70 (AP position θap) is satisfied by the engine 12, and the motor 14 or motors 16 and 18 ([0064], [0066]).
Accordingly, it is assumed in Japanese Unexamined Patent Application Publication No. 2015-123849 that the lacking amount of torque of the engine 12 (engine torque) as to the target vehicle torque Tv_tar will be supplemented by the torque of the motor 14 or motors 16 and 18 (motor torque).
However, there may be cases where the engine torque does not reach the target vehicle torque Tv_tar even though the AP position θap is relatively low (i.e., in a case where there is no intent to accelerate by the driver or the intent to accelerate by the driver is weak). In such cases, attempting to constantly supplement lacking engine torque by motor torque may quicken electric power consumption of the battery 20 against the intent of the driver.