JP2012166614A - Drive system for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive system for a vehicle that can achieve prompt acceleration by the engine startup control when the vehicle traveling and the engine stops.SOLUTION: This drive system 1 for the vehicle includes: an engine 2; a transmission 4; and a clutch 3 arranged between the engine 2 and the transmission 4. Moreover, the drive system 1 for the vehicle includes: an accelerator opening sensor 724 to obtain the accelerator opening θ; and a control device 7 that performs driving control of the engine 2, the transmission 4, and the clutch 3 based on the output signal of the acceleration request obtaining means. Then the control device 7 changes the gear position of the transmission 4 from the neutral to the ahead stage with the trigger of the acceleration request of the driver having become more than a prescribed threshold value when the vehicle is traveling and the internal combustion engine 2 stops, and the engine 2 starts and the clutch 3 becomes an engaged state.

Description

  The present invention relates to a vehicle drive system, and more particularly to a vehicle drive system capable of realizing rapid acceleration by engine start control while the vehicle is running and the engine is stopped.

  In recent vehicle drive systems, for example, in hybrid vehicles, eco-run control is performed to improve fuel efficiency by stopping the engine while the vehicle is running. Here, when the vehicle is running and the engine is stopped, engine start control (or engine restart control) is performed when a predetermined determination condition is satisfied.

  As a conventional vehicle drive system employing such a configuration, a technique described in Patent Document 1 is known. In the conventional vehicle drive system, the engine speed is changed from the neutral to the forward speed when the engine is started during engine start control while the vehicle is running and the engine is stopped. Acceleration is performed accordingly.

JP 2004-340206 A

  Here, in the engine start control while the vehicle is running and the engine is stopped, it is preferable that rapid acceleration is performed.

  An object of the present invention is to provide a vehicle drive system capable of realizing rapid acceleration by engine start control while the vehicle is running and the engine is stopped.

  To achieve the above object, a vehicle drive system according to the present invention is a vehicle drive system comprising an internal combustion engine, a transmission, and a clutch disposed between the internal combustion engine and the transmission, Acceleration request acquisition means for acquiring an acceleration request of a driver, and a control device for driving and controlling the internal combustion engine, the transmission and the clutch based on an output signal of the acceleration request acquisition means, and the control apparatus When the vehicle is running and the internal combustion engine is stopped, the speed change of the transmission is changed from neutral to a forward speed when the acceleration request exceeds a predetermined threshold, and the internal combustion engine is started. Then, the clutch is engaged.

  In the vehicle drive system according to the present invention, it is preferable that the acceleration request acquisition unit acquires at least one of an accelerator opening and an accelerator speed as the acceleration request.

  In the vehicle drive system according to the present invention, the control device may change the gear position of the transmission when the vehicle is running and the internal combustion engine is stopped, and the acceleration request is equal to or less than a predetermined threshold. It is preferable to set to neutral.

  In the vehicle drive system according to the present invention, when the internal combustion engine is started while the vehicle is running and the internal combustion engine is stopped, the speed change stage of the transmission is previously set before the start of the internal combustion engine, triggered by the driver's acceleration request. To the forward gear. Therefore, quick acceleration can be realized as compared with a configuration in which the gear position of the transmission is changed from the neutral to the forward gear when the start of the internal combustion engine is completed. As a result, it is possible to respond quickly to the driver's acceleration request, and there is an advantage that the drivability of the vehicle is improved.

FIG. 1 is a configuration diagram showing a vehicle drive system according to an embodiment of the present invention. FIG. 2 is a flowchart showing the operation of the vehicle drive system shown in FIG. FIG. 3 is a time chart showing the operation of the vehicle drive system shown in FIG. FIG. 4 is a flowchart showing the operation of a modification of the vehicle drive system shown in FIG. FIG. 5 is a flowchart showing the operation of a modification of the vehicle drive system shown in FIG.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. Further, the constituent elements of this embodiment include those that can be replaced while maintaining the identity of the invention and that are obvious for replacement. In addition, a plurality of modifications described in this embodiment can be arbitrarily combined within a range obvious to those skilled in the art.

[Vehicle drive system]
FIG. 1 is a configuration diagram showing a vehicle drive system according to an embodiment of the present invention. FIG. 1 shows a hybrid vehicle having two power sources of an engine and a motor as an example of a vehicle drive system.

  The vehicle drive system 1 includes an engine 2, a clutch 3, a transmission 4, a reduction differential device 5, a motor 6, and a control device 7 (see FIG. 1). The vehicle drive system 1 includes, for example, a vehicle capable of realizing hybrid travel that switches between engine travel using the engine 2 as a power source and motor travel using the motor 6 as a power source, engine 2 during deceleration travel and free-run travel. It is applied to a vehicle that can realize eco-run traveling that temporarily stops.

  The engine 2 is a first power source, generates drive torque and outputs it from the output shaft 21. The engine 2 is an internal combustion engine or an external combustion engine. For example, in this embodiment, a reciprocating engine using gasoline as fuel is employed.

  The clutch 3 is a mechanical element that can permit and block transmission of driving torque. The clutch 3 includes an input-side rotating unit 31 and an output-side rotating unit 32, and is connected to the output shaft 21 of the engine 2 at the input-side rotating unit 31 and is arranged at the rear stage of the engine 2. The clutch 3 permits torque transmission in the engaged state of the input side rotating unit 31 and the output side rotating unit 32, and interrupts torque transmission in the released state. For example, a friction clutch can be adopted as the clutch 3.

  The transmission 4 is an automatic transmission that can automatically change the gear position (or gear ratio). Further, the transmission 4 has an input shaft 41 and an output shaft 42, and is connected to the output-side rotating portion 32 of the clutch 3 by the input shaft 41 and is arranged at the rear stage of the clutch 3. Further, the transmission 4 can change its gear ratio = (the number of revolutions of the output shaft 42) / (the number of revolutions of the input shaft 41) by switching the gear stage. As the transmission 4, a stepped transmission, a belt type or a toroidal type continuously variable transmission can be adopted. For example, in this embodiment, the transmission 4 has a gear type that can switch between a neutral (N range), four forward stages 43 to 46 (D range), and one reverse stage 47 (R range). The stepped automatic transmission is adopted.

  The deceleration differential 5 is a mechanical element that decelerates the drive torque and distributes it to the left and right wheels (not shown) of the vehicle. The deceleration differential device 5 includes an input shaft 51, a deceleration mechanism 52 that decelerates the drive torque, and a differential mechanism 53 that adjusts the distribution of the drive torque to the left and right wheels of the vehicle. The reduction differential 5 is connected to the output shaft 42 of the transmission 4 by the input shaft 51, and is connected to the wheel axle by the differential mechanism 53.

  The motor 6 is a second power source, generates drive torque and outputs it from the output shaft 61. The motor 6 is connected to the output shaft 42 of the transmission 4 by an output shaft 61. For example, in this embodiment, an AC synchronous motor generator having a motor function and a generator function is employed as the motor 6.

  In this embodiment, the motor 6 is always connected to the output shaft 42 of the transmission 4 (see FIG. 1). However, the configuration is not limited thereto, and the motor 6 and the output shaft 42 of the transmission 4 may be configured to be connected and disconnected via a clutch (not shown). Further, the motor 6 and the input shaft 41 of the transmission 4 may be configured to be connected and disconnected via a clutch (not shown).

  The control device 7 is a device that controls the operation of the vehicle drive system 1, and includes an ECU (Electrical Control Unit) 71 and a sensor unit 72. The ECU 71 outputs a predetermined output signal based on the acquired input signal. The ECU 71 includes an engine control unit 711 that controls driving of the engine 2, a clutch control unit 712 that controls driving of the clutch 3, a transmission control unit 713 that controls driving of the transmission 4, and motor control that controls driving of the motor 6. Unit 714, an engine start control unit 715 that performs engine start control described later, an accelerator speed calculation unit 716 that calculates an accelerator speed (depressing speed of the accelerator pedal) dθ / dt based on the accelerator opening θ, and predetermined information A storage unit 717 for storing (for example, various control programs, control data such as control maps and threshold values). The sensor unit 72 includes a vehicle speed sensor 721 that detects the vehicle speed, an engine speed sensor 722 that detects the rotational speed (engine speed) Ne of the output shaft 21 of the engine 2, and the rotational speed of the input shaft 41 of the transmission 4 ( Input rotational speed) An input rotational speed sensor 723 for detecting Nin, an accelerator opening degree sensor 724 for detecting accelerator opening degree θ, a brake pedal sensor 725 for detecting ON / OFF of depression of a brake pedal, and a battery of the motor 6 And an SOC (state of charge) sensor 726 for detecting a filling state (not shown). In the control device 7, the ECU 71 drives and controls the engine 2, the clutch 3, the transmission 4, and the motor 6 based on the output signal of the sensor unit 72. Thereby, various controls are realized.

  In the vehicle drive system 1, when the vehicle engine is running, the control device 7 drives the engine 2 with the clutch 3 engaged. Then, the engine 2 generates drive torque, and this drive torque is transmitted to the transmission 4 via the clutch 3. Then, this drive torque is shifted by the transmission 4, decelerated by the deceleration differential 5, and distributed to the left and right wheels of the vehicle. Thereby, the vehicle travels using the engine 2 as a power source.

  On the other hand, when the vehicle runs on the motor, the control device 7 opens the clutch 3 and separates the engine 2 from the drive system on the axle side to drive the motor 6. Then, the motor 6 generates a driving torque, and this driving torque is distributed to the left and right wheels of the vehicle via the deceleration differential device 5. As a result, the vehicle travels using the motor 6 as a power source.

  In addition, the vehicle drive system 1 can realize hybrid travel using both engine travel and motor travel. For example, when the vehicle starts or travels at a low speed, the control device 7 stops the engine 2 and drives the motor 6 to drive the motor 6. When the vehicle travels at a medium to high speed, the control device 7 stops the motor 6 and stops the engine. The engine travels by driving 2. Further, switching between engine running and motor running is performed according to the vehicle speed and the state of charge of the battery. Thereby, efficient driving | running | working is implement | achieved and a fuel consumption improves.

  Further, the vehicle drive system 1 can realize eco-run control that temporarily stops the engine 2 while the vehicle is running. For example, when the driving torque is not required, such as when the vehicle is traveling at a reduced speed or during free-running, the control device 7 opens the clutch 3 and stops the engine 2. Thereby, fuel consumption improves. At this time, the motor 6 may be used as a generator for regenerative travel, or the motor 6 may be separated from the drive system and stopped.

[Engine start control while the vehicle is running and the engine is stopped]
FIG. 2 is a flowchart showing the operation of the vehicle drive system shown in FIG. This figure shows a flow of engine start control while the vehicle is running and the engine is stopped.

  Generally, in a hybrid vehicle, engine start control (or engine restart control) may be performed in response to a driver's acceleration request while the vehicle is running and the engine is stopped. At this time, it is preferable that rapid acceleration (or reacceleration) is performed in response to the driver's acceleration request.

  Therefore, in the vehicle drive system 1, the following control is performed in order to realize quick acceleration when the driver requests acceleration while the vehicle is running and the engine is stopped (see FIG. 2).

  In step ST01, it is determined whether the vehicle is running and the engine is stopped. The state in which the vehicle is running and the engine is stopped includes, for example, a state in which the engine 2 and the motor 6 are stopped while the vehicle is running, a state in which the engine 2 is stopped and the motor 6 is generating regenerative power, and the engine 2 Is stopped and the motor 6 is generating a driving force. In this embodiment, the vehicle speed sensor 721 detects the vehicle speed of the vehicle, and the ECU 71 determines whether or not the vehicle is running based on the output signal of the vehicle speed sensor 721. Further, the engine speed sensor 722 detects the engine speed Ne, and the ECU 71 determines whether or not the engine is stopped based on the engine speed Ne. Further, when the engine is stopped, the clutch 3 is in an open state, and torque transmission between the engine 2 and the transmission 4 is interrupted. If an affirmative determination is made in step ST01, the process proceeds to step ST02, and if a negative determination is made, the process ends.

  In step ST02, it is determined whether or not the gear position of the transmission 4 is neutral. For example, in this embodiment, the transmission 4 has a hydraulic cylinder (not shown) that switches the shift speed, and the ECU 71 acquires the hydraulic pressure of the hydraulic cylinder and determines the current shift speed of the transmission 4. . If an affirmative determination is made in step ST02, the process proceeds to step ST03, and if a negative determination is made, the process proceeds to step ST07.

  In step ST03, it is determined whether or not the accelerator opening θ is not less than a predetermined threshold k1 (θ ≧ k1). This determination condition corresponds to the determination condition that the driver's acceleration request (requested torque) is equal to or greater than a predetermined threshold. Further, this determination condition corresponds to a shift start condition for changing a later-described shift stage to a forward stage (step ST04). In this embodiment, the accelerator opening sensor 724 detects the accelerator opening θ, and the ECU 71 compares the accelerator opening θ with a predetermined threshold k1 read from the storage unit 717, thereby Judgment is being made. If an affirmative determination is made in step ST03, the process proceeds to step ST04. If a negative determination is made, the process ends.

  The threshold value k1 is set in advance based on experimental values or the like so that the time when θ ≧ k1 comes before the start time of starting the engine 2 (step ST05) described later. For example, when the start start condition of the engine 2 is defined by the relationship between the accelerator opening degree θ and the predetermined threshold value ke, the threshold value k1 is set smaller than the threshold value ke for starting the engine. Further, the threshold value k1 may be set in relation to the vehicle speed and the vehicle state quantity such as the state of charge of a battery (not shown) of the motor 6.

  Further, as a case where the accelerator opening θ becomes equal to or larger than a predetermined threshold k1 while the vehicle is running and the engine is stopped, for example, when the accelerator is depressed during motor running and switching from motor running to engine running is required, It is assumed that the brake pedal is released and the accelerator pedal is depressed during free-running. These are all the starting conditions for the engine 2.

  In step ST04, the gear position of the transmission 4 is changed from neutral to the forward gear. That is, the start of changing the gear position is performed prior to the start of engine start (step ST05) triggered by the driver's acceleration request (affirmative determination in step ST03). Note that the forward speed of the change destination (target value of the shift control) can be arbitrarily selected. For example, the forward speed of the change destination may be set based on the vehicle speed and the accelerator opening θ, or may be set based on the engine speed Ne after completion of starting of the engine 2 described later (step ST05). . In this embodiment, the ECU 71 sets the forward speed to be changed based on a predetermined control map, and drives the transmission 4 using the set value as a target value to change the speed stage of the transmission 4. is doing. After this step ST04, the process proceeds to step ST05.

  In step ST05, the engine 2 is started (or restarted). The start control of the engine 2 is performed after the change of the gear position is started (step ST04). However, the start start control of the engine 2 may be performed after the shift speed change (step ST04) is completed, or may be performed in parallel with the shift speed change control. In this embodiment, the ECU 71 starts the engine 2 with the clutch 3 opened when the engine 2 starts to start. After this step ST05, the process proceeds to step ST06.

  In step ST06, the clutch 3 is engaged. As a result, the engine 2 is connected to the drive system, and the engine travels using the engine 2 as a power source. At this time, since the gear position of the transmission 4 has been changed to the forward gear in advance (step ST04), rapid acceleration can be realized after the clutch 3 is engaged. After this step ST06, the process is terminated.

  In step ST07, it is determined whether or not the accelerator opening θ is equal to or less than a predetermined threshold k2 (θ ≦ k2). This determination corresponds to determination of whether or not the driver's acceleration request is equal to or less than a predetermined value. In addition, the threshold value k2 can be arbitrarily set, for example, in relation to the vehicle speed and the vehicle state quantity such as the state of charge of the battery (not shown) of the motor 6. In this embodiment, the ECU 71 performs this determination by comparing the accelerator opening θ with a predetermined threshold value k2 stored in the storage unit 717. If an affirmative determination is made in step ST07, the process proceeds to step ST08, and if a negative determination is made, the process ends.

  In step ST08, the gear position of the transmission 4 is changed to neutral. That is, when the vehicle is running and the engine is stopped (affirmative determination in step ST01) and the gear position of the transmission 4 is in a gear position other than neutral (negative determination in step ST02), the accelerator opening θ is predetermined. The gear position of the transmission 4 is changed to neutral on the condition that it is equal to or less than the threshold value k2 (positive determination in step ST07). As a result, the running resistance of the vehicle can be reduced as compared with a configuration (not shown) in which the shift speed is always set to the forward speed.

[Example of engine start control]
FIG. 3 is a time chart showing the operation of the vehicle drive system shown in FIG. FIG. 2 shows an embodiment of the engine start control while the vehicle is running and the engine is stopped as shown in FIG. 2, more specifically, engine start control when the engine 2 is stopped and the motor is running. Example of the present invention is shown. Hereinafter, this embodiment will be described with reference to FIGS.

  At t = 0, the engine 2 is stopped and the motor travel is performed using the motor 6 as a drive source (affirmative determination in step ST01) (see FIG. 2). Further, the gear position of the transmission 4 is neutral (affirmative determination in step ST02) (see FIG. 3A). Further, the accelerator pedal is depressed and the accelerator opening degree θ is constant (see FIG. 3B). Further, the clutch 3 is in the released state, and the clutch torque Tc is Tc = 0 (see FIG. 3C). Further, the ECU 71 controls the motor torque Tm of the motor 6 based on the accelerator opening θ (see FIG. 3D). Further, the engine torque Te is Te = 0 (see FIG. 3 (e)). Further, the engine speed Ne and the input speed Nin of the transmission 4 are Ne = 0 [rpm] and Nin = 0 [rpm] (see FIGS. 3F and 3G).

  At t = t1, the accelerator is further depressed by the driver's acceleration request, and the accelerator opening θ reaches the predetermined threshold k1 (affirmative determination in step ST03) (see FIG. 3B). Then, the ECU 71 drives the transmission 4 to change the gear position of the transmission 4 from neutral to the forward gear (step ST04) (see FIG. 3A). At this time, the ECU 71 sets a target value for the forward speed of the shift destination based on the vehicle speed, the accelerator opening θ, and a predetermined control map, and drives and controls the transmission 4. As a result, the shift speed of the transmission 4 becomes the optimal shift speed (requested shift speed) according to the driver's acceleration request. Further, the input rotational speed Nin of the transmission 4 increases (see FIG. 3 (f)).

  At t = t2, when the change of the gear position of the transmission 4 is completed (see FIG. 3A), the ECU 71 starts the engine 2 (step ST05), and the engine torque Te and the engine speed Ne increase. (See FIGS. 3E and 3F). Therefore, in this embodiment, the ECU 71 starts the engine 2 after the shift stage is changed.

  At t = t3, the ECU 71 starts engaging the clutch 3 (step ST06), and the clutch torque Tc increases (see FIG. 3C). At the same time, the engine speed Ne of the engine 2 and the input speed Nin of the transmission 4 are synchronized (see FIGS. 3 (f) and 3 (g)). Further, the ECU 71 gradually reduces the driving power of the motor 6 to reduce the motor torque Tm (see FIG. 3D).

  At t = t4, the clutch 3 is engaged and the motor 6 stops. Thereby, the motor running is switched to the engine running using the engine 2 as a power source. At this time, since the gear position of the transmission 4 has been changed to the forward gear in advance (step ST04), rapid acceleration can be realized after the clutch 3 is engaged.

[Modification of engine start control]
FIG. 4 is a flowchart showing the operation of a modification of the vehicle drive system shown in FIG. This figure shows a modified example of the engine start control while the vehicle is running and the engine is stopped. Hereinafter, this modification will be described with reference to FIG. In FIG. 4, the same steps as those in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted.

  In the engine start control described in FIG. 2, the engine start control is performed while the vehicle is running and the engine is stopped, on condition that the accelerator opening θ is equal to or greater than a predetermined threshold k1 (affirmative determination in step ST03).

  However, the present invention is not limited to this, and the engine start control may be performed using the accelerator opening θ and the accelerator speed dθ / dt.

  That is, generally, when the driver's acceleration request is moderate, the accelerator opening degree θ increases while the accelerator speed dθ / dt remains substantially constant. On the other hand, when the driver's acceleration request is sudden, the accelerator pedal is suddenly depressed, so that the accelerator speed dθ / dt increases rapidly. Therefore, the acceleration request of the driver can be accurately estimated by using the accelerator speed dθ / dt.

  Therefore, in this modified example, the next step ST09 is provided, and when a negative determination is made in step ST03, the process proceeds to step ST09 (see FIG. 4).

  In step ST09, it is determined whether or not the accelerator speed dθ / dt is equal to or higher than a predetermined threshold k1 ′ (dθ / dt ≧ k1 ′). For example, in this embodiment, the ECU 71 calculates the accelerator speed dθ / dt based on the output signal of the accelerator opening sensor 724, and the accelerator speed dθ / dt and a predetermined threshold value k 1 ′ stored in the storage unit 717. And this determination is made.

  If an affirmative determination is made in step ST09, the process proceeds to step ST04, and if a negative determination is made, the process ends. Therefore, in this modified example, at least one of the determination conditions of θ ≧ k1 and dθ / dt ≧ k1 ′ is satisfied for the accelerator opening θ and the accelerator speed dθ / dt (affirmative determination in step ST03 or step ST09). Affirmative determination), control (step ST04) is performed to change the gear position of the transmission 4 from the neutral to the forward gear.

  FIG. 5 is a time chart showing the operation of the modified example of the vehicle drive system shown in FIG. This figure shows an embodiment of the engine start control described in FIG. Hereinafter, this embodiment will be described with reference to FIGS. 4 and 5. FIG.

  At t = 0, the engine 2 is stopped and the motor travel is performed using the motor 6 as a drive source (affirmative determination in step ST01) (see FIG. 4). Further, the gear position of the transmission 4 is neutral (affirmative determination in step ST02) (see FIG. 5A). Further, the accelerator pedal is depressed and the accelerator opening θ is constant (see FIG. 5B). Further, since the accelerator opening θ is constant, the accelerator speed dθ / dt is dθ / dt = 0 (see FIG. 5B ′). Further, the clutch 3 is in the released state, and the clutch torque Tc is Tc = 0 (see FIG. 5C). Further, the ECU 71 controls the motor torque Tm of the motor 6 based on the accelerator opening θ (see FIG. 5D). Further, the engine torque Te is Te = 0 (see FIG. 5 (e)). Further, the engine speed Ne and the input speed Nin of the transmission 4 are Ne = 0 [rpm] and Nin = 0 [rpm] (see FIGS. 5F and 5G).

  At t = t1, t1 ′, the accelerator opening θ and the accelerator speed dθ / dt rapidly increase as the driver steps on the accelerator suddenly (the driver suddenly requests acceleration) (FIGS. 5B and 5B). ')reference). At this time, when one of the determination conditions of θ ≧ k1 and dθ / dt ≧ k1 ′ is satisfied for the accelerator opening θ and the accelerator speed dθ / dt (positive determination in step ST03 or positive determination in step ST09). The ECU 71 drives the transmission 4 to start changing the gear position of the transmission 4 (step ST04) (see FIG. 5A).

  For example, in this modification, the determination condition for the accelerator speed dθ / dt (dθ / dt ≧ k1 ′) is established before the determination condition for the accelerator opening θ (θ ≧ k1) (t1 ′ <t1). (See FIG. 5 (a)). For this reason, the ECU 71 starts changing the gear position with reference to t = t1 ′ when the determination condition for the accelerator speed dθ / dt is satisfied. At this time, the ECU 71 sets the target value for the forward speed of the shift destination based on the vehicle speed, the accelerator opening θ, the accelerator speed dθ / dt, and a predetermined control map, and drives and controls the transmission 4. . As a result, the shift speed of the transmission 4 is the optimum shift speed (requested shift speed) according to the driver's acceleration request.

  The broken line in FIG. 5B shows the accelerator opening degree θ when the driver gently depresses the accelerator at a constant accelerator speed dθ / dt. Also, the broken lines in FIGS. 5 (a), (f), and (g) indicate changes in the gear position of the transmission 4, the engine speed Ne, and the input speed Nin at this time, respectively. As shown in FIG. 5, it can be seen that as the determination conditions of θ ≧ k1 and dθ / dt ≧ k1 ′ are later established, the start of the engine is delayed and the acceleration is delayed.

  At t = t2 to t4, when the change of the gear position of the transmission 4 (step ST04) is completed, the ECU 71 starts the engine 2 and engages the clutch 3 (step ST05 and step ST06) ( FIG. 4 and FIG. 5). Thereby, the driving mode of the vehicle is switched from motor driving to engine driving. The operations of the engine 2, the clutch 3 and the transmission 4 at this time are the same as those in the embodiment shown in FIG.

  In this modification, as described above, when one of the determination conditions of θ ≧ k1 and dθ / dt ≧ k1 ′ is satisfied for the accelerator opening θ and the accelerator speed dθ / dt (in step ST03). The ECU 71 starts changing the gear position of the transmission 4 (step ST04) (see FIG. 4). However, the present invention is not limited to this, and the ECU 71 may start changing the gear position of the transmission 4 when both determination conditions of θ ≧ k1 and dθ / dt ≧ k1 ′ are satisfied (not shown). This improves the reliability of engine start control.

[effect]
As described above, the vehicle drive system 1 includes the internal combustion engine (engine) 2, the transmission 4, and the clutch 3 disposed between the internal combustion engine 2 and the transmission 4 (see FIG. 1). . The vehicle drive system 1 also obtains acceleration request acquisition means (for example, accelerator position sensor 724, accelerator speed dθ / dt) for acquiring a driver's acceleration request (for example, accelerator position θ, accelerator speed dθ / dt, etc.). An accelerator speed calculation unit 716) for calculating, and a control device 7 for driving and controlling the internal combustion engine 2, the transmission 4 and the clutch 3 based on the output signal of the acceleration request acquisition means. Then, the control device 7 changes the gear position of the transmission 4 when the driver's acceleration request becomes equal to or greater than a predetermined threshold value while the vehicle is running and the internal combustion engine 2 is at rest (affirmative determination in step ST01). At the same time as changing from the neutral to the forward gear (positive determination in step ST03 or positive determination in step ST09 and step ST04), the internal combustion engine 2 is started and the clutch 3 is engaged (step ST05 and step ST06) ( 2 and 4).

  In such a configuration, when the internal combustion engine 2 is started while the vehicle is running and the internal combustion engine 2 is at rest, the speed of the transmission 4 is advanced in advance before the internal combustion engine 2 is started, triggered by the driver's acceleration request. Changed to stage. Therefore, quick acceleration can be realized as compared with a configuration (not shown) in which the shift speed of the transmission is changed from the neutral to the forward speed when the start of the internal combustion engine is completed. As a result, it is possible to respond quickly to the driver's acceleration request, and there is an advantage that the drivability of the vehicle is improved. Note that, as the running state while the vehicle is running and the internal combustion engine 2 is at rest, for example, eco-running during deceleration running or free-running running, motor running using the motor 6 as a drive source, and the motor 6 used as a generator. A driving state such as regenerative driving is assumed.

  In the vehicle drive system 1, the acceleration request acquisition means acquires at least one of the accelerator opening θ and the accelerator speed dθ / dt as a driver acceleration request (see FIG. 1). As a result, the driver's acceleration request can be obtained with high accuracy, and there is an advantage that the control (step ST04) for changing the shift speed to the forward speed is appropriately performed.

  Further, in this vehicle drive system 1, the control device 7 is in a state where the vehicle is running and the internal combustion engine 2 is at rest, and when the driver's acceleration request is equal to or less than a predetermined threshold (accelerator opening θ ≦ k2). The gear position of the transmission is set to neutral (affirmative determination in step ST01, steps ST07 and ST08) (see FIGS. 2 and 4). In such a configuration, the transmission 4 is set to neutral when the vehicle is running and the internal combustion engine 2 is at rest and the acceleration request from the driver is small. Accordingly, there is an advantage that the running resistance of the vehicle can be reduced as compared with a configuration (not shown) in which the transmission gear is always set to the forward gear.

  As described above, the vehicle drive system according to the present invention is useful in that rapid acceleration can be realized by engine start control while the vehicle is running and the engine is stopped.

DESCRIPTION OF SYMBOLS 1 Vehicle drive system, 2 engines (internal combustion engine), 21 output shaft, 3 clutch, 31 input side rotation part, 32 output side rotation part, 4 transmission, 41 input shaft, 42 output shaft, 43-46 advance stage, 47 reverse gear, 5 deceleration differential, 51 input shaft, 52 deceleration mechanism, 53 differential mechanism, 6 motor, 61 output shaft, 7 control device, 71 ECU, 711 engine control unit, 712 clutch control unit, 713 transmission Control unit, 714 motor control unit, 715 engine start control unit, 716 accelerator speed calculation unit, 717 storage unit, 72 sensor unit, 721 vehicle speed sensor, 722 engine speed sensor, 723 input speed sensor, 724 accelerator opening sensor ( Acceleration request acquisition means), 725 brake pedal sensor, 726 SOC sensor

Claims (3)

A vehicle drive system comprising an internal combustion engine, a transmission, and a clutch disposed between the internal combustion engine and the transmission,
An acceleration request acquisition means for acquiring a driver acceleration request;
A control device for drivingly controlling the internal combustion engine, the transmission, and the clutch based on an output signal of the acceleration request acquisition means; and
The control device changes the gear position of the transmission from neutral to a forward gear when the acceleration request becomes a predetermined threshold value or more while the vehicle is running and the internal combustion engine is stopped. A vehicle drive system characterized by starting an internal combustion engine and bringing the clutch into an engaged state.   The vehicle drive system according to claim 1, wherein the acceleration request acquisition unit acquires at least one of an accelerator opening degree and an accelerator speed as the acceleration request.   3. The control device according to claim 1, wherein the control device sets the gear position of the transmission to neutral when the vehicle is running and the internal combustion engine is at rest and the acceleration request is equal to or less than a predetermined threshold. Vehicle drive system.

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