JP2010149748A - Driving device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving device of a vehicle for reducing shock upon start-up of an internal combustion engine without impairing acceleration responsiveness suitable for the acceleration request of a driver. <P>SOLUTION: The driving device of a vehicle is configured to, when an internal combustion engine should be started in order to switch an electric traveling mode to an engine traveling mode, determine a shift level at a higher speed side than a shift level to be set after the electric traveling mode is switched to the engine traveling mode when an accelerator opening is equal to or less than a prescribed value Ath and the same shift level as the shift level to be set after the electric traveling mode is switched to the engine traveling mode when the accelerator opening exceeds the prescribed value Ath, respectively as a shift level to be set when the internal combustion engine starts, and to control a transmission mechanism so that the internal combustion engine can be started in the shift level. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle drive apparatus provided with an electric motor.

  As a vehicle drive device, an internal combustion engine is connected to a first motor / generator and an axle via a power split mechanism, a second motor / generator is connected to the axle, and a speed change mechanism is provided in the middle of the axle. Is known (Patent Document 1). This drive device sets the speed change mechanism to the high speed side gear stage when starting the internal combustion engine while the vehicle is stopped. Further, as a similar drive device, there is also known a drive device that starts an internal combustion engine while the vehicle is running by setting a high-speed shift stage when the increase rate of the accelerator opening is equal to or less than a predetermined value (Patent Document 2). ).

JP 2003-127679 A JP 2001-260669 A

  Since these drive devices use a high-speed gear stage when starting the internal combustion engine, the shock at the time of start-up can be reduced, but switching to a low-speed gear stage can be performed after the internal combustion engine is started in response to a driver's acceleration request. In a case where the vehicle is scheduled, it is necessary to switch the gear used at the time of starting to a gear on the low speed side, so that the acceleration response of the vehicle may be deteriorated in response to the driver's acceleration request.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle drive device that can reduce a shock at the start of an internal combustion engine without impairing the acceleration response that meets the driver's acceleration request.

  In the drive device according to the present invention, an internal combustion engine is connected to an electric motor and an output shaft via a power split mechanism, and a power transmission path from the output shaft to a drive wheel of the vehicle has many speeds from the lowest speed stage to the highest speed stage. A speed change mechanism configured to be capable of setting a speed step is provided, and the vehicle is caused to travel using an electric travel mode in which the motor is driven by the electric motor while the internal combustion engine is stopped, and an output of the internal combustion engine. In the vehicle drive device capable of switching between the engine travel mode and determining a gear position to be set by the speed change mechanism in each travel mode based on the vehicle speed of the vehicle and the operation amount of the acceleration operation member, the electric travel mode When the internal combustion engine is to be started in order to switch to the engine travel mode, when the operation amount of the acceleration operation member is a predetermined value or less, after switching to the engine travel mode If the operation amount of the acceleration operating member exceeds the predetermined value, the speed change mechanism should be set after switching to the engine travel mode. The start speed stage determining means for determining the same speed stage as the speed stage to be set by the speed change mechanism when starting the internal combustion engine, and the speed stage determined by the start speed stage determining means Shift control means for controlling the speed change mechanism so that the internal combustion engine is started (Claim 1).

  According to this drive device, when the operation amount of the acceleration operation member reflecting the driver's acceleration request is small, the high-speed side gear position is the same as the gear position based on the operation amount when the operation amount is large. Are used when the internal combustion engine is started. For this reason, when the driver's acceleration request is high, it is not necessary to switch from the gear position used at the start of the internal combustion engine to the gear position used in the engine travel mode, so that the acceleration response of the vehicle is not impaired. On the other hand, when the driver's request for acceleration is low, the internal combustion engine is started using the high-speed gear, so that the shock at the start can be reduced.

  In one aspect of the driving apparatus of the present invention, the start speed stage determining means sets the maximum speed stage when the internal combustion engine is started, on the condition that the vehicle speed of the vehicle is a predetermined value or less. You may determine as a gear stage which should be (Claim 2). In the region where both the acceleration demand and the vehicle speed are low, the sensitivity to the shock at the start is high. According to this aspect, the internal combustion engine can be started at the highest speed stage at which the effect of reducing the shock is most obtained under the condition that the sensitivity to the shock is high.

  In one aspect of the drive device of the present invention, the speed change mechanism includes a plurality of rotating elements that are differentially rotated with each other, and a plurality of engaging means configured as a clutch or a brake that switches a connection relationship between the plurality of rotating elements. The multi-stage gear stage is set by operating each of the plurality of engaging means, and the start-time gear stage determining means is configured so that the transmission mechanism is operated when the internal combustion engine is started. As candidates for the shift speed to be set, there are a plurality of candidates that differ in the number of operations for the plurality of engagement means required when switching from the shift speed at the start of the internal combustion engine to the shift speed after switching to the engine travel mode. If present, among the plurality of candidates, the number of operations is less than the maximum number of times and a gear position on the high speed side than the gear position on the most low speed side is set to the front when the internal combustion engine is started. It may be determined as the shift speed transmission mechanism to be set (claim 3). There may be a plurality of candidates when setting a shift speed higher than the shift speed in the engine travel mode. Even if the number of operations with respect to the engaging means is different among these candidates, if the high speed side gear stage is determined without considering the number of operations, the gear stage after the start of the internal combustion engine is determined. There is a possibility that the acceleration response will deteriorate due to the prolonged time until the shift to the gear position in the engine travel mode. According to this aspect, the gear position on the high speed side is determined as much as possible while avoiding a candidate having the maximum number of operations on the engaging means. Thereby, the shock at the time of start-up can be reduced while suppressing deterioration of acceleration response. For example, if there are three or more gear speed candidates that are less than the maximum number of operations, if the gear speed on the higher speed side than the lowest gear speed is determined among those candidates, the slowest speed is selected from the candidates. Since the shift stage on the side can be avoided, an effect of reducing the shift shock can be obtained while ensuring acceleration response. However, when the number of operations among the plurality of candidates is less than the maximum number of times and the highest speed gear is determined as the gear to be set by the speed change mechanism when the internal combustion engine is started (Claim 4). ), The effect of reducing the shock at the start can be maximized.

  As described above, according to the drive device of the present invention, when the driver's acceleration request is high, there is no need to switch from the shift stage used at the start of the internal combustion engine to the shift stage used in the engine travel mode. Acceleration response is not impaired. On the other hand, when the driver's acceleration request is low, the internal combustion engine is started using the high-speed side gear stage, so that the shock at the start can be reduced.

  FIG. 1 is a diagram schematically showing an overall configuration of a vehicle in which a drive device according to an embodiment of the present invention is incorporated, and FIG. 2 is an explanatory diagram showing a control system of the drive device shown in FIG. . The vehicle 1 is configured as a so-called hybrid vehicle. As is well known, a hybrid vehicle is a vehicle that includes an internal combustion engine as a driving force source for traveling and also includes an electric motor as another driving force source for traveling. The vehicle 1 is configured as an FF layout vehicle in which drive wheels and an internal combustion engine are located at the front of the vehicle.

  The drive device 2 receives the internal combustion engine 3, the first motor / generator 4, the power split mechanism 5 to which the internal combustion engine 3 and the first motor / generator 4 are connected, and the power from the power split mechanism 5. The output shaft 6, the speed change mechanism 7 for changing the rotation of the output shaft 6, the second motor / generator 8, and the power output from the speed change mechanism 7 and the second motor / generator 8 for transmitting to the drive wheels 10. And an output unit 9. That is, in the drive device 2, the internal combustion engine 3 is connected to the first motor / generator 4 and the output shaft 6 through the power split mechanism 5, and the power transmission path from the output shaft 6 to the drive wheels 10 of the vehicle is provided. A transmission mechanism 7 is provided.

  The first motor / generator 4, the power split mechanism 5, and the speed change mechanism 7 are arranged on a common first axis Ax. The second motor / generator 8 is disposed on the second axis Ax2 parallel to the first axis Ax1 so as to overlap the transmission mechanism 7 in the axial direction. That is, the first motor / generator 4 and the second motor / generator 8 are arranged on different axes, and the second motor / generator 8 is disposed on the outer side in the radial direction of the speed change mechanism 7 on the opposite side of the first motor / generator 4. Has been placed. The second motor / generator 8 is arranged on a separate axis from the first motor / generator 4, but does not overlap the first motor / generator 4 in the axial direction.

  The internal combustion engine 3 is configured as a spark ignition type multi-cylinder internal combustion engine, and the power is transmitted to the power split mechanism 5 via the input shaft 15. The input shaft 15 is disposed coaxially with the output shaft 6, and the input shaft 15 and the output shaft 6 rotate about the axis Ax1. A damper (not shown) is interposed between the input shaft 15 and the internal combustion engine 3, and torque fluctuations of the internal combustion engine 3 are absorbed by the damper.

  The first motor / generator 4 and the second motor / generator 8 have the same configuration, and have both a function as an electric motor and a function as a generator. The first motor / generator 4 includes a stator 18 fixed to the case 17 and a rotor 19 arranged coaxially on the inner peripheral side of the stator 18. Similarly, the second motor / generator 8 includes a stator 20 fixed to the case 17 and a rotor 21 disposed coaxially on the inner peripheral side of the stator 20. The first motor / generator 4 corresponds to the electric motor according to the present invention.

  The power split mechanism 5 is configured as a single pinion type planetary gear mechanism having three rotational elements that can rotate differentially with each other, and is coaxial with the sun gear Su1 that is an external gear and the sun gear Su1. A ring gear Ri1, which is an internal gear disposed, and a carrier Cr1 that holds the pinion 25 meshing with the gears Su1, Ri1 so as to rotate and revolve freely. In this embodiment, the input shaft 15 is connected to the carrier Cr1, the first motor / generator 4 is connected to the sun gear Su1, and the output shaft 6 is connected to the ring gear Ri1.

  The speed change mechanism 7 includes a speed change differential mechanism 30 configured as a so-called Ravigneaux type planetary gear mechanism, and two clutches C1 and C2 and two brakes B1 for switching the connection relationship between the rotating elements of the speed change differential mechanism 30. , B2. These two clutches C1 and C2 and the two brakes B1 and B2 correspond to a plurality of engaging means according to the present invention.

  The transmission differential mechanism 30 includes a large-diameter sun gear Su2, a small-diameter small-diameter sun gear Su3 disposed adjacent to the same axis as the large-diameter sun gear Su2, and a ring gear Ri2 disposed concentrically with the large-diameter sun gear Su2. And a carrier Cr2 which is disposed between the sun gears Su2 and Su3 and the ring gear Ri2 and holds the long pinion 31 and the short pinion 32 having different axial lengths so as to rotate and revolve. The long pinion 31 meshes with each of the large-diameter sun gear Su2 and the short pinion 32, and the short pinion 32 meshes with the small-diameter sun gear Su3.

  The first clutch C1 operates between an engagement state for coupling the output shaft 6 and the sun gear Su3 and a release state for releasing the coupling, and the second clutch C2 is an engagement for coupling the output shaft 6 and the carrier Cr2. Operates between a state and a released state that releases its association. The carrier Cr2 is provided with a one-way clutch 35 that allows rotation in only one direction. The first brake B1 operates between an engaged state in which the sun gear Su2 and the case 17 are coupled and a released state in which the coupling is released, and the second brake B2 is in an engaged state in which the carrier Cr2 and the case 17 are coupled. Operates between released states that release the bond. The second brake B <b> 2 is disposed on the outer peripheral side of the speed change operating mechanism 30. For this reason, the dimension of an axial direction can be shortened compared with the case where a brake is arrange | positioned next to the axial direction of the differential mechanism 30 for transmission.

  The speed change mechanism 7 operates the clutches C1 and C2 and the brakes B1 and B2, respectively, so that four stages from the first speed (1st) which is the lowest speed stage to the fourth speed (4th) which is the highest speed stage are performed. Can be set. FIG. 3 shows an operation engagement table in which the shift speeds (1st to 4th) set by the transmission mechanism 7 are associated with the operation states of the clutches C1 and C2 and the brakes B1 and B2. In this figure, “◯” indicates an engaged state, and “−” indicates a released state. FIG. 4 shows an alignment chart of the speed change mechanism 7. As shown in FIG. 3, when the clutches C1 and C2 and the brakes B1 and B2 are operated, four shift stages having different gear ratios are established in stages. The breakdown of the gear ratio of each gear stage is as visually shown in FIG.

  As shown in FIG. 1, the output unit 9 includes a first drive gear 41 to which power output from the speed change mechanism 7 is transmitted, and a second drive gear to which power output from the second motor / generator 8 is transmitted. 42, a counter driven gear 43 in which these drive gears 41 and 42 are meshed in common, and a differential device 44 that transmits power via the counter driven gear 43 to the left and right drive wheels 10. An intermediate gear 45 that is coaxial with the counter driven gear 43 and rotates integrally is interposed between the counter driven gear 43 and the differential device 44, and this intermediate gear 45 is a driven gear provided in the case of the differential device 44. 46 is engaged. The first drive gear 41 is provided so as to rotate integrally with the ring gear Ri 2 of the transmission differential mechanism 30, and the second drive gear 42 rotates integrally with the rotor 21 of the second motor / generator 8.

  As shown in FIG. 2, the control of the drive device 2 is controlled by a control unit 50 configured as a computer. Although not shown, the control unit 50 includes a microprocessor and storage devices such as ROM and RAM necessary for its operation, and peripheral devices such as an input / output interface. The control unit 50 appropriately controls the operating state of the internal combustion engine 3, while maintaining the traveling state of the vehicle 1 properly, the control for the internal combustion engine 3, the control for the speed change mechanism 7, the motor generators 4, 8 operates in accordance with a predetermined control program held therein so that the control on the control unit 8 is linked to each other. Here, control related to the gist of the present invention will be described, and description of control having low relevance to the gist of the present invention will be omitted.

  The control unit 50 uses the electric drive mode in which the vehicle 1 is driven by the first motor / generator 4 and / or the second motor / generator 8 with the internal combustion engine 3 stopped, and the output of the internal combustion engine 3 The drive device 2 is controlled so that the travel mode of the vehicle 1 can be switched between the engine travel mode to travel. In the engine traveling mode, the power of the second motor / generator 8 is normally applied. The switching of the driving mode is performed based on various factors such as the state of charge of a battery (not shown) and the vehicle speed. However, the details of the switching condition are not the gist of the present invention, and thus the description thereof is omitted.

  Control of the gear position set by the transmission mechanism 7 is performed by the control unit 50. As is well known, the control unit 50 determines the gear position to be set by the transmission mechanism 7 in each travel mode based on the vehicle speed of the vehicle 1 and the operation amount of the accelerator pedal 51 as the acceleration operation member. The vehicle speed is detected based on a signal from a vehicle speed sensor 53 input to the control unit 50, and the operation amount of the accelerator pedal 51 is detected based on a signal from an accelerator opening sensor 54 input to the control unit 50.

  When switching from the electric travel mode to the engine travel mode, it is necessary to start the stopped internal combustion engine 3. When the internal combustion engine 3 is started, the first motor / generator 4 is used for cranking, but it is known that the shock at the start is reduced as the gear position at the start is set to a higher speed side. The present embodiment is characterized in that the gear position used at the start of the internal combustion engine 3 is determined according to the degree of the driver's acceleration request. Hereinafter, the shift control at the time of start performed by the control unit 50 will be described with reference to FIGS.

  FIG. 5 is a flowchart showing an example of a control routine of the start time shift control executed by the control unit 50. The program of this routine is held in the storage device of the control unit 50, read out in a timely manner, and repeatedly executed at predetermined intervals.

  In step S1, it is determined whether or not there is a start request for starting the internal combustion engine 3. This start request is issued based on the processing result of start control executed by the control unit 50 in a separate routine. The start request is a request for starting the internal combustion engine 3 as a preparation stage for starting the stopped vehicle 1. In addition, a request for starting the internal combustion engine 3 when switching from the electric travel mode to the engine travel mode is included. If there is a request for starting the internal combustion engine 3, the process proceeds to step S2. If there is no start request, the subsequent processing is skipped and the current routine is terminated.

  In step S2, it is determined whether or not the vehicle 1 is traveling. Whether or not the vehicle is traveling can be determined based on whether or not the drive range is set based on a signal from a shift position sensor (not shown) mounted on the vehicle 1. When the parking range, the neutral range, and the reverse range are set, it can be determined that the vehicle does not correspond to traveling. In addition, information from the vehicle speed sensor 53 may be taken into consideration for this determination. When the vehicle 1 is traveling, it is a start request necessary for switching from the electric travel mode to the engine travel mode. Therefore, the processing proceeds to the processing after step S3 in order to set the gear position at the start in consideration of the vehicle speed and the like. . On the other hand, if the vehicle is not running, the process proceeds to step S7.

  In step S3, the vehicle speed and the accelerator opening as the operation amount of the accelerator pedal 51 are acquired. In order to acquire these physical quantities, the control unit 50 refers to output signals from the vehicle speed sensor 53 and the accelerator opening sensor 54.

  In step S4, the gear stage to be used is determined after switching to the engine travel mode based on the information acquired in step S3. The determination of the shift speed is performed according to a shift map stored in the control unit 50 in advance. The shift map is a well-known map defined by the vehicle speed of the vehicle and the accelerator opening, and a shift line (upshift line, downshift line) is set for each shift stage switching pattern. When the vehicle speed and the accelerator opening in the shift map cross the shift line, it is possible to know the shift speed after switching defined by the shift line.

  In step S <b> 5, the gear position used when starting the internal combustion engine 3 is determined. The determination of the gear position is performed based on the starting speed stage determination map shown in FIG. As shown in FIG. 6, this map is defined by the vehicle speed and the accelerator opening, and the definition plane is divided into three regions, a first region I to a third region III.

  In the first region I, the same shift speed as that for the engine travel mode determined in step S4 is set as the start speed. Since the first region I is a region where the accelerator opening exceeds the first predetermined value Ath1 that is relatively high, it can be said that the driver's acceleration request is high. Therefore, in order to give priority to acceleration response over shock reduction at the time of starting, the engine is started using the gear position planned after switching to the engine running mode as it is. In the second region II and the third region III where the accelerator opening is equal to or less than the first predetermined value Ath1, the driver's acceleration request is not so high and priority is given to reduction of shock over acceleration responsiveness. A gear position on the higher speed side than the gear position planned after the switching is determined as the starting gear position.

  In the second region II, when at least one of the accelerator opening and the vehicle speed is low, that is, the vehicle speed is not more than a predetermined value Vth and the accelerator opening is not more than a first predetermined value Ath1, or the accelerator opening is a first predetermined value. This corresponds to a case where the value is equal to or smaller than a second predetermined value Ath2 smaller than the value Ath1. Under such conditions, the sensitivity to shock at the time of starting increases, so the maximum speed stage (fourth speed) having the highest shock reduction effect is determined as the starting speed stage.

  The third region III corresponds to an intermediate region between the vehicle speed and the accelerator opening. In this case, acceleration responsiveness is not required as in the case of the first region I, but in order to ensure a certain degree of acceleration responsiveness, the engine travel mode is entered after the start of the internal combustion engine so as to shorten the time required for shifting the gear position. Considering the number of times the clutches C1 and C2 and the brakes B1 and B2 have been changed during the transition, in other words, the number of operations of these engaging means, the speed is set as high as possible.

  FIG. 7 is an explanatory diagram showing an example of traveling of the vehicle 1 on the shift map. A line in the figure is a downshift line, and a pair of numbers connected by an arrow disposed at the upper end of the line indicates a downshift switching pattern. Consider a case where the vehicle 1 is switched from the electric travel mode to the engine travel mode as indicated by the arrow F and switched from the fourth speed to the first speed. At this time, when the fourth speed is selected as the starting gear stage, the following operation is required after the internal combustion engine 3 is started and switched to the first speed scheduled for use in the engine travel mode. That is, as is apparent from FIG. 3, after the internal combustion engine 3 is started, in order to switch from the fourth speed to the first speed, (1) the second clutch C2 is operated to the disengaged state. A total of four operations are required to operate 1 brake B1 to the released state, (3) operate the first clutch C1 to the engaged state, and (4) operate the second brake B2 to the engaged state. .

  On the other hand, when the third speed is selected as the start gear, when the internal combustion engine 3 is started and the third speed is switched to the first speed, (1) the second clutch C2 is operated to the released state. (2) A total of two operations of operating the second brake B2 to the engaged state are necessary. Further, when the second speed is selected as the start gear, when the internal combustion engine 3 is started and the second speed is switched to the first speed, (1) the first brake B1 is operated to the released state, (2 ) A total of two operations of operating the second brake to the engaged state are required. When there are a plurality of candidates with different numbers of operations such as clutches as candidates for the gear position used at start-up as in the running example of FIG. 7, the control unit 50 is the candidate with less than the maximum number of operations 4 and the most The third speed on the high speed side is determined as the starting gear position. Thereby, since the number of times of operation of the engaging means after the start is small, it is possible to obtain a shock reduction effect at the start without greatly impairing the acceleration response.

  Returning to FIG. 5, in step S <b> 6, the control unit 50 controls the speed change mechanism 7 so that the starting speed determined in step 5 is set. In step S7, since the vehicle 1 is being started while it is stopped, it is not necessary to consider acceleration responsiveness, so the control unit 50 controls the transmission mechanism 7 so that the fourth speed, which is the highest speed stage, is set.

  In step S8, in order to cause the first motor / generator 4 to function as a starter, the internal combustion engine 3 is cranked while controlling the output of the first motor / generator 4, and a spark plug (not shown) is sparked at a predetermined time. Thus, the start control of the internal combustion engine 3 is executed.

  In step S9, it is determined whether or not the start of the internal combustion engine 3 has been completed, that is, whether or not the complete explosion has been completed. If the start has been completed, the process proceeds to step S10, and if not, the process returns to step S1. In step S10, the control unit 50 controls the speed change mechanism 7 so that the gear set in step S4 is set in preparation for the transition to the travel mode after the start is completed, and then the current routine is finished.

  The control unit 50 functions as a shift control means according to the present invention by executing the control routine of FIG. 5, and functions as a starting speed stage determining means according to the present invention by executing step S5 of the same figure. However, the present invention is not limited to the above embodiment, and can be implemented in various forms within the scope of the gist of the present invention. The above-described differential mechanisms in each form are merely examples, and it is possible to change them to other forms that are mechanically equivalent. The realization of the differential mechanism by a planetary gear mechanism is only an example. For example, all or part of the planetary gear mechanism of each embodiment described above can be replaced with a planetary roller mechanism having a friction wheel (roller) that is not a gear as a rotating element.

  Further, the number of shift stages of the speed change mechanism is not limited, and the present invention is implemented as a drive device including, for example, a 2-speed, 3-speed, or 5-speed speed change mechanism as long as a multi-speed stage can be set. It is also possible. Thus, since the number of shift stages does not matter, the number of operations for a plurality of engagement means is maximized when determining the start shift stage when the number of shift stages increases to 5 or more. There may be three or more candidates for lower speed stages. For example, in a drive device having a seven-speed gear change mechanism, when there are three gear speeds of the fourth speed, the fifth speed, and the sixth speed as candidates, the fastest gear position as in the above embodiment. It is also possible to set the fifth speed, which is the higher speed shift stage than the fourth speed, which is the lowest speed shift stage, as the candidate instead of setting the sixth speed, which is . Even in this case, it is possible to avoid the fourth speed which is the lowest speed among the three candidates, so that it is possible to obtain a shock reduction effect while suppressing deterioration in acceleration response.

  Further, although the two motor / generators 4 and 8 are provided in the driving device of the above embodiment, the second motor / generator 8 that transmits power to the output unit 9 is omitted and the present invention is carried out. It is also possible to do. In addition, the arrangement of the two motor generators 4 and 9 on different axes is merely an example, and the present invention can be implemented in a form in which these are arranged on a common axis.

The figure which showed roughly the whole structure of the vehicle incorporating the drive device which concerns on one form of this invention. Explanatory drawing which showed the control system of the drive device shown in FIG. The figure which showed the action | operation engagement table | surface with which the gear stage which a speed change mechanism sets, and the operation state of a clutch and a brake were matched. The figure which showed the alignment chart of the speed change mechanism. The flowchart which showed an example of the control routine of gear shifting control at the time of starting. The figure which showed an example of the gear stage determination map at the time of starting. Explanatory drawing which showed the traveling example of the vehicle on the transmission map.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Drive apparatus 3 Internal combustion engine 4 1st motor generator (electric motor)
5 Power split mechanism 6 Output shaft 7 Speed change mechanism 10 Drive wheel 50 Control unit (start-up gear position determining means, speed change control means)
51 Accelerator pedal (acceleration operation member)
C1, C2 clutch (engagement means)
B1, B2 Brake (engagement means)

Claims (4)

The internal combustion engine is connected to the electric motor and the output shaft via a power split mechanism, and multiple speed stages from the lowest speed stage to the highest speed stage can be set in the power transmission path from the output shaft to the drive wheels of the vehicle. The speed change mechanism configured as described above is provided, and can be switched between an electric travel mode in which the vehicle is driven by the electric motor while the internal combustion engine is stopped, and an engine travel mode in which the vehicle is driven using the output of the internal combustion engine And a vehicle drive device that determines a gear position to be set by the speed change mechanism in each travel mode based on the vehicle speed of the vehicle and the operation amount of the acceleration operation member.
When the internal combustion engine is to be started in order to switch from the electric travel mode to the engine travel mode, the speed change mechanism is set after switching to the engine travel mode when the operation amount of the acceleration operation member is a predetermined value or less. When the operating amount of the acceleration operating member exceeds the predetermined value, the same speed as that to be set by the speed change mechanism after switching to the engine travel mode is set. Starting speed stage determining means for determining the speed stage as a speed stage to be set by the speed change mechanism when starting the internal combustion engine, and starting the internal combustion engine at the speed stage determined by the starting speed stage determining means. And a shift control means for controlling the shift mechanism to be performed.   The start speed stage determining means determines the highest speed stage as a speed stage to be set by the speed change mechanism when starting the internal combustion engine on the condition that the vehicle speed of the vehicle is a predetermined value or less. The vehicle drive device according to claim 1. The speed change mechanism includes a plurality of rotating elements that differentially rotate with each other, and a plurality of engagement means configured as clutches or brakes that switch a connection relationship between the plurality of rotating elements. The multi-stage gears are set by operating each of the means;
The starting speed stage determining means is a speed stage candidate to be set by the speed change mechanism when starting the internal combustion engine, to a speed stage after switching from the speed stage when starting the internal combustion engine to the engine travel mode. When there are a plurality of candidates having different numbers of operations with respect to the plurality of engaging means required for switching, the number of operations is less than the maximum number among the plurality of candidates, and the speed is higher than the lowest speed gear. The vehicle drive device according to claim 1, wherein the first gear is determined as a gear to be set by the transmission mechanism when the internal combustion engine is started.   The start speed stage determining means sets the speed stage with the smallest number of operations less than the maximum number among the plurality of candidates as the speed stage to be set by the speed change mechanism when starting the internal combustion engine. The vehicle drive device according to claim 3, wherein the vehicle drive device is determined.

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