JP2012224132A - Shift control system of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the sense of incompatibility of the driver according to the gear change operation under deceleration regenerative control.SOLUTION: A shift control system includes: an engine 10; a first transmission mechanism 40 that has a first gear change speed group; a second transmission mechanism 50 that has a second gear change speed group; a first clutch 61 that can connect or disconnect between a crankshaft 11 and an input shaft 42 of the first transmission mechanism 40; a second clutch 62 that can connect or disconnect between a crankshaft 11 and an input shaft 51 of the second transmission mechanism 50; and a motor/generator 20 connected to the second transmission mechanism 50. When downshift of the second gear change speed group is carried out under the deceleration regenerative control, and when the clutch torque to achieve the target deceleration torque is smaller than the cranking torque in the first clutch of the torque alternative gear change speed in the first gear change speed group decided based on the gear change speed before and after the gear shift, the target deceleration torque is generated by outputting the clutch torque at the torque alternative gear change speed according to fluctuation regenerative torque of the motor/generator 20 when switching the gear change speed.

Description

  The present invention relates to a shift control system for a hybrid vehicle including a mechanical power source, an electric power source, and a dual clutch transmission.

  2. Description of the Related Art In recent years, in the field of vehicle transmissions, so-called dual clutch transmissions (DCT: dual clutch transmission) that transmit power from a power source to wheels as driving force without interruption are known. The dual clutch transmission can be broadly divided into a first transmission mechanism composed of an odd number of gears (hereinafter referred to as “odd number”) and an even number of gears (hereinafter referred to as “even number”). A first clutch configured to transmit power from the power source to the first speed change mechanism, or to interrupt transmission of the power, interposed between the second speed change mechanism configured by the power source and the first speed change mechanism; And a second clutch that is interposed between the power source and the second speed change mechanism and transmits power from the power source to the second speed change mechanism or interrupts transmission of the power.

  Here, a mechanical power source such as an engine is used as a power source disposed via the first clutch or the second clutch, and further, the power source is connected to one of the input shafts of the first or second transmission mechanism. A hybrid vehicle provided with an electric power source such as a motor as another power source is known. In this hybrid vehicle, during deceleration, the first and second clutches may be released, the mechanical power source may be stopped, and the electric power source may be regeneratively controlled. In this hybrid vehicle, during the execution of the deceleration regeneration control, for example, a shift request may be made to switch the shift stage between the respective shift stages of the transmission mechanism connected to the electric power source. For example, in Patent Document 1 below, when such a shift request is made during execution of the deceleration regenerative control, the motor regenerative control is stopped (that is, the motor torque is set to 0) to enable a shift. In addition, a technique is disclosed in which a shift is completed without making the driver feel a change in deceleration feeling by compensating for the braking torque that has been reduced accordingly with an engine brake. The following Patent Document 2 discloses a technique for compensating for a decrease in braking torque due to the stop of the regenerative control with a hydraulic brake.

JP 2010-083454 A JP 2009-113535 A

  By the way, when the engine brake is generated when the engine is stopped, the engine speed of the engine increases as the engine brake amount increases. The speed change operation during execution of the deceleration regeneration control is executed by the electronic control unit without the intention of the driver. Therefore, the driver feels uncomfortable when the engine speed increases during the execution of the deceleration regeneration control.

  Therefore, the present invention has an object to provide a shift control system for a hybrid vehicle that can improve the disadvantages of the conventional example and can suppress the driver's uncomfortable feeling associated with the shift operation during the deceleration regeneration control. To do.

  To achieve the above object, the present invention provides a mechanical power source, a first input shaft to which an output shaft of the mechanical power source is coupled, a first output shaft, and the first input shaft and the first output shaft. A first speed change mechanism having a first speed change stage group composed of a plurality of kinds of speed change stages, a second input shaft to which an output shaft of the mechanical power source is connected, a second output shaft, and the second input shaft; And a second output mechanism having a second speed stage group composed of a plurality of types of speed stages, and an output shaft of the mechanical power source and a first input shaft of the first speed change mechanism. A first clutch capable of connecting / disconnecting between the second power transmission mechanism, a second clutch capable of connecting / disconnecting between the output shaft of the mechanical power source and the second input shaft of the second transmission mechanism, and the second transmission mechanism. An electric power source connected to the second input shaft or the second output shaft and capable of powering drive and regenerative drive; The mechanical power source is stopped in a state where the clutch 2 is released and the electric power source is driven to regenerate, and the torque from the driving wheel side during traveling is transmitted to the electric power source, so that power regeneration and target A deceleration regeneration control device that performs deceleration regeneration control capable of decelerating according to deceleration torque, and when switching the gear position in the second gear group during traveling, the electric power source is stopped, A shift control device that switches the shift speed in a stopped state, and when performing a downshift in the second shift speed group during the deceleration regeneration control, the first shift speed determined based on the shift speed before and after the shift If the clutch torque that achieves the target deceleration torque with the first clutch at the torque substitute gear position in the group is smaller than the cranking torque of the mechanical power source, the electric power source at the time of gear shift switching And it outputs a clutch torque of the first clutch at the torque alternative gear stage to match the variations in the regenerative torque is characterized by generating a target deceleration torque.

  Here, the clutch torque that achieves the target deceleration torque in the first clutch at the lowest speed stage in the first speed stage group and the first clutch at the torque alternative speed stage is the cranking torque. If it is equal to or more, the target deceleration torque is set so as not to be larger than the cranking torque until at least the shift of the second gear group is completed. , The regenerative torque of the electric power source that is changed at the time of gear change, and the first clutch at the torque substitute gear that is the lowest speed in the first gear group in accordance with the change. It is desirable to generate the torque with the clutch torque.

  In the shift control system for a hybrid vehicle according to the present invention, when the downshift is performed in the second gear group during the deceleration regenerative control, the fluctuation amount of the regenerative torque is replaced with the clutch torque at the torque substitute gear and output. By doing so, the target deceleration torque is generated. Therefore, in this case, the hybrid vehicle decelerates regardless of the fluctuation of the regenerative torque, so that the driver does not feel uncomfortable. At that time, the maximum clutch torque at the torque substitute gear is smaller than the cranking torque of the mechanical power source, and the replaced clutch torque does not exceed the cranking torque, so the output of the mechanical power source The shaft does not rotate. Therefore, according to this shift control system, when the downshift is performed in the second shift stage group during the deceleration regeneration control, the shift is performed without increasing the rotational speed of the mechanical power source while maintaining the deceleration state. Do not give the driver a sense of incongruity.

FIG. 1 is a diagram illustrating a schematic configuration of a hybrid vehicle to which a shift control system according to the present invention is applied. FIG. 2 is a time chart showing an example of the relationship among the target deceleration torque, the motor torque, and the clutch torque during a downshift during the deceleration regeneration control. FIG. 3 is a time chart showing another example of the relationship among the target deceleration torque, the motor torque, and the clutch torque during a downshift during the deceleration regeneration control. FIG. 4 is a flowchart for explaining a calculation processing operation at the time of downshift during the deceleration regeneration control.

  Embodiments of a shift control system for a hybrid vehicle according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the embodiments.

[Example]
An embodiment of a shift control system for a hybrid vehicle according to the present invention will be described with reference to FIGS.

  FIG. 1 shows an example of a hybrid vehicle to be controlled by the shift control system. Reference numeral 1 in FIG. 1 indicates the hybrid vehicle of this embodiment. In the hybrid vehicle 1, a mechanical power source and an electric power source are provided as power sources, and the power of the power source is transmitted to the drive wheel side through an automatic transmission. As the automatic transmission, when one clutch is in an engaged state, the other clutch is released and the gear shift mechanism of the transmission mechanism related to the other clutch is kept in a synchronized state, A so-called dual clutch transmission is mounted that releases the one clutch and engages the other clutch to transmit the power from the power source to the driving wheels as a driving force without interruption.

  In this hybrid vehicle 1, the operation of the mechanical power source, the electric power source, and the dual clutch transmission is controlled by an electronic control unit (ECU) 100. The shift control system is provided as one of the arithmetic processing functions of the electronic control device 100.

  Initially, the structure of the hybrid vehicle 1 of a present Example is demonstrated using FIG.

  The mechanical power source is an engine 10 such as an internal combustion engine or an external combustion engine that outputs mechanical power (engine torque) from a crankshaft (output shaft) 11. In the hybrid vehicle 1, the engine 10 can be stopped and restarted during traveling. During the stop, the engine 10 is in a so-called fuel cut state, and fuel efficiency is improved. Further, when the engine 10 is restarted, the engine speed is increased to a predetermined speed by a torque transmitted from a dual clutch transmission described later. The torque may be transmitted from the driving wheels WL and WR that are rotating, or may be transmitted from the following motor torque during powering driving of the motor / generator 20. Further, a starter motor (not shown) may be used for restarting the engine 10. The engine speed is obtained from a detection signal of an angle sensor (so-called crank angle sensor) 12 that can detect the rotation angle of the output shaft 11.

  The electric power source is a motor, a generator capable of powering driving, or a motor / generator capable of driving both powering and regeneration. Here, the motor / generator 20 will be described as an example. For example, the motor / generator 20 is configured as a permanent magnet type AC synchronous motor. The motor / generator 20 functions as a motor (electric motor) at the time of power running, converts electric energy supplied via the secondary battery 25 and the inverter 26 into mechanical energy, and mechanical power (motor) from the rotating shaft 21. Torque). On the other hand, at the time of regenerative drive, it functions as a generator (generator) and converts mechanical energy into electric energy when mechanical power (motor torque) is input from the input shaft 51 to the rotary shaft 21, and the inverter 26 is turned on. And stored in the secondary battery 25 as electric power. The motor / generator 20 is provided with a rotation sensor (resolver) 22 that detects the rotation angle position of the rotor, and a detection signal of the rotation sensor 22 is transmitted to the electronic control unit 100.

  The hybrid vehicle 1 is provided with a battery monitoring unit 27 that detects a state of charge (SOC) of the secondary battery 25. The battery monitoring unit 27 transmits a signal related to the detected state of charge of the secondary battery 25 (in other words, a signal related to the remaining capacity amount (SOC amount)) to the electronic control device 100. The electronic control device 100 determines the charge state of the secondary battery 25 based on the signal, and determines whether or not the secondary battery 25 needs to be charged.

  In this hybrid vehicle 1, there is a power transmission device (dual clutch type gear shift comprising a plurality of shift stages) that is interposed between the engine 10 or the motor / generator 20 and the drive wheels WL and WR and enables power transmission therebetween. Machine 30 and final reduction gear 70 with a differential mechanism). This power transmission device transmits, for example, the power of the engine 10 and the motor / generator 20 to the driving wheels WL and WR as a driving force.

  The dual clutch transmission 30 illustrated here has five forward speeds and one reverse speed, and the first speed gear stage 41, the second speed gear stage 52, A third gear stage 43, a fourth gear stage 54, and a fifth gear stage 45 are provided, and a reverse gear stage 49 is provided as a reverse gear stage. The forward gear is configured so that the gear ratio decreases in the order of the first speed gear stage 41, the second speed gear stage 52, the third speed gear stage 43, the fourth speed gear stage 54, and the fifth speed gear stage 45. is doing.

  The dual clutch transmission 30 includes a first speed change mechanism 40 having a first speed stage group consisting of a plurality of kinds of speed stages and a second speed stage group consisting of a plurality of different speed stages. 2 transmission mechanism 50 is provided. In this example, the first transmission mechanism 40 is configured with an odd number of gears (odd number), and the second transmission mechanism 50 is configured with an even number of gears (even number).

  First, the first transmission mechanism 40 will be described in detail. The first speed change mechanism 40 is configured as a parallel shaft gear device including a plurality of gear pairs corresponding to each speed change stage, and an odd first speed gear stage 41, a first speed change stage group, A third gear stage 43 and a fifth gear stage 45 are provided. The first speed change mechanism 40 includes an input shaft (first input shaft) 42 and an output shaft (first output shaft) 44 as parallel shafts arranged in parallel at a predetermined interval.

  The first speed gear stage 41 is constituted by a gear pair of a first speed main gear 41a and a first speed counter gear 41c that are in mesh with each other. The first speed main gear 41a is attached to the input shaft 42 so as to rotate together with the input shaft 42 of the first transmission mechanism 40. On the other hand, the first speed counter gear 41 c is attached to the output shaft 44 so as to be rotatable relative to the output shaft 44 of the first transmission mechanism 40.

  The first speed change mechanism 40 includes an engagement state in which the first speed counter gear 41c and the output shaft 44 can rotate together, and a release state in which the first speed counter gear 41c and the output shaft 44 can rotate relative to each other ( A first speed coupling mechanism 41d is provided for switching between the non-engaged state and the non-engaged state. For example, the first speed coupling mechanism 41d includes a shift engagement sleeve that generates the engagement state, a shift release sleeve that generates the release state, and an engagement state by moving the shift engagement sleeve or the shift release sleeve. Alternatively, an actuator (sleeve operation motor) that switches the release state is provided. The operation of the actuator is controlled by the electronic control unit 100. When the first speed gear stage 41 is selected, the electronic control unit 100 can execute the speed change operation at the first speed gear stage 41 by operating the first speed coupling mechanism 41d to be in the engaged state. If the other gear position is selected, the first speed coupling mechanism 41d is operated to be in a released state (non-engaged state) in order to avoid a speed change operation at the first speed gear stage 41. Let

  The third speed gear stage 43 includes a third speed main gear 43a, a third speed counter gear 43c, and a third speed coupling mechanism 43d similar to the first speed gear stage 41. Similarly to the first speed gear stage 41, the fifth speed gear stage 45 includes a fifth speed main gear 45a, a fifth speed counter gear 45c, and a fifth speed coupling mechanism 45d.

  The reverse gear stage 49 includes a reverse main gear 49a, a reverse intermediate gear 49b, and a reverse counter gear 49c. The reverse main gear 49a and the reverse counter gear 49c are the same as the first speed main gear 41a and the first speed counter gear 41c of the first speed gear stage 41, respectively. The reverse intermediate gear 49b is in mesh with the reverse main gear 49a and the reverse counter gear 49c so that the reverse intermediate gear 49b can rotate integrally with a rotary shaft 49f different from the input shaft 42 and the output shaft 44 of the first transmission mechanism 40. It is attached to the rotating shaft 49f. The reverse gear stage 49 also includes a reverse coupling mechanism 49d that engages or releases the reverse counter gear 49c and the output shaft 44.

  A first clutch 61, which will be described later, is connected to one end of the input shaft 42 of the first transmission mechanism 40. A first drive gear 44 a that rotates integrally with the output shaft 44 is attached to one end of the output shaft 44. The first drive gear 44 a is meshed with the power integrated gear 32 that rotates integrally with the output shaft 31 of the dual clutch transmission 30. Therefore, the first speed change mechanism 40 applies the input torque input from the engine 10 side to the input shaft 42 to the first speed stage group (first speed gear stage 41, third speed gear stage 43 or fifth speed gear stage 45. ) And the reverse gear stage 49, and output it toward the output shaft 31 of the dual clutch transmission 30. Further, the first speed change mechanism 40 can similarly change the input torque input to the output shaft 44 from the drive wheels WL, WR side, and output it to the engine 10 side. Here, the power integrated gear 32 is also meshed with a second drive gear 53 a connected to the output shaft 53 of the second speed change mechanism 50. Therefore, the first transmission mechanism 40 can similarly shift the input torque input to the output shaft 44 from the second transmission mechanism 50 side, and can output it to the engine 10 side.

  Next, the second speed change mechanism 50 will be described in detail. Similar to the first transmission mechanism 40, the second transmission mechanism 50 is configured as a parallel shaft gear device including a plurality of gear pairs corresponding to each gear stage, and the second gear stage group is an even number stage. The second speed gear stage 52 and the fourth speed gear stage 54 are provided. The second speed change mechanism 50 includes an input shaft (second input shaft) 51 and an output shaft (second output shaft) 53 as parallel shafts arranged in parallel at a predetermined interval.

  The second speed gear stage 52 includes a second speed main gear 52a, a second speed counter gear 52c, and a second speed coupling mechanism 52d that are the same as the first speed group. The second speed main gear 52 a rotates integrally with the input shaft 51 of the second transmission mechanism 50. On the other hand, the second speed counter gear 52c rotates integrally with the output shaft 53 in the engaged state by the second speed coupling mechanism 52d, and rotates relative to the output shaft 53 in the released state by the second speed coupling mechanism 52d. I do. Further, the fourth speed gear stage 54 includes a fourth speed main gear 54a, a fourth speed counter gear 54c, and a fourth speed coupling mechanism 54d similar to the second speed gear stage 52.

  A second clutch 62 (described later) is connected to one end of the input shaft 51 of the second speed change mechanism 50, and the rotating shaft 21 of the motor / generator 20 is connected to the other end. A second drive gear 53 a that rotates integrally with the output shaft 53 is attached to one end of the output shaft 53. The second drive gear 53 a is meshed with the power integration gear 32. Accordingly, the second speed change mechanism 50 applies the input torque input to the input shaft 51 from the engine 10 side or the motor / generator 20 side to the second speed stage group (second speed gear stage 52 and fourth speed gear stage 54). The gear can be shifted using any one of the gears and output to the output shaft 31 of the dual clutch transmission 30. Further, the second speed change mechanism 50 similarly changes the input torque input to the output shaft 53 from the drive wheels WL, WR side or the first speed change mechanism 40 side, and transfers it to the engine 10 side or the motor / generator 20 side. Can also be output.

  Further, the dual clutch transmission 30 is interposed between the engine 10 and the first transmission mechanism 40, and is connected between the first clutch 61 and the engine 10 and the second transmission mechanism 50. There is provided a dual clutch mechanism 60 including a second clutch 62 that is interposed between the two and connects and disconnects between them.

  The first clutch 61 engages with the output shaft 11 of the engine 10 and the input shaft 42 of the first speed change mechanism 40, and releases the output shaft 11 and the input shaft 42 from the engaged state (not engaged). A friction clutch device having two engaging portions 61a and 61b configured to be able to switch between a released state (non-engaged state) to be combined. The engaged state here is a state where torque can be transmitted between the output shaft 11 and the input shaft 42, and the released state is between the output shaft 11 and the input shaft 42. This is a state where the torque cannot be transmitted. Therefore, the first clutch 61 can transmit torque between the engine 10 and the first transmission mechanism 40 or can block transmission of the torque. The engagement state includes a semi-engagement state in which the two engagement portions 61a and 61b are in contact with each other and a relative engagement state, and a full engagement state in which the engagement portions 61a and 61b are rotated together. There is.

  The second clutch 62 engages the output shaft 11 of the engine 10 with the input shaft 51 of the second transmission mechanism 50, and releases the output shaft 11 and the input shaft 51 from the engaged state ( This is a friction clutch device having two engaging portions 62a and 62b configured to be able to be switched between a disengaged state (non-engaged state) to be disengaged). The engaged state here is a state where torque can be transmitted between the output shaft 11 and the input shaft 51, and the released state is between the output shaft 11 and the input shaft 51. This is a state where the torque cannot be transmitted. Therefore, the second clutch 62 can transmit torque between the engine 10 and the second speed change mechanism 50, or can block transmission of the torque. The engagement state includes a half-engagement state in which the two engagement portions 62a and 62b are in contact with each other and a relative engagement, and a full engagement state in which the engagement portions 62a and 62b are rotated together. There is.

  The first clutch 61 and the second clutch 62 are controlled by the electronic control unit 100 via the actuators 63 and 64 shown in FIG. The electronic control device 100 controls, for example, only one of the first clutch 61 and the second clutch 62 to the engaged state and the other to the released state when traveling using engine torque. Then, the engine torque is transmitted to either the first transmission mechanism 40 or the second transmission mechanism 50. Further, when traveling with only the motor torque at the time of power running drive, if both the first clutch 61 and the second clutch 62 are controlled to be released and the engine 10 is stopped, a part of the motor power running torque is obtained. So that the engine torque is not transmitted to the first transmission mechanism 40 and the second transmission mechanism 50 when the engine 10 is being driven. Further, during the execution of the deceleration regeneration control, both the first clutch 61 and the second clutch 62 are controlled to be in a released state so that torque from the drive wheels WL and WR is not transmitted to the engine 10, so that the engine brake Is prevented.

  Here, during the execution of the deceleration regeneration control, any one of the speed stages (second speed gear stage 52 or fourth speed gear) belonging to the second speed change mechanism 50 (the speed change mechanism to which the motor / generator 20 is connected). The stage 54) is controlled to be in an engaged state, and torque is regenerated by transmitting torque from the drive wheels WL and WR to the motor / generator 20. While this deceleration regeneration control is being executed, engine braking is not generated, so regeneration as electric power is possible including that amount, but the dual clutch transmission 30 is kept at the current gear stage G (n). As a result, the rotational speed of the motor / generator 20 decreases as the vehicle speed decreases, and the amount of power regeneration decreases. In addition, the hybrid vehicle 1 is originally lowered to a vehicle speed at which the second speed change mechanism 50 travels at a speed stage G (n-2) on the lower speed side than the current speed. In some cases, the current gear stage G (n) is maintained. In this case, when reacceleration is requested by the driver's accelerator operation or the like, the low speed stage shift stage G (n-2) in the same transmission mechanism (second transmission mechanism 50), the first Since re-acceleration starts after shifting to a shift stage G (n-1) or the like at a lower speed stage than the current shift stage G (n) in the transmission mechanism 40, the responsiveness of re-acceleration is lowered. In particular, when a shift to another speed change mechanism (first speed change mechanism 40) to which the motor / generator 20 is not connected is performed, the engine 10 needs to be restarted. Therefore, when the vehicle speed decreases to a predetermined vehicle speed during the execution of the deceleration regeneration control, the gear shifts to the lower gear stage G (n−2) in the second transmission mechanism 50 to which the current gear stage G (n) belongs. It is desirable to make it. Note that “n” indicates the current state and is one of 1, 2, 3, 4, and 5 because it is a dual clutch transmission 30 with five forward speeds.

  However, since the shift in the second transmission mechanism 50 to which the motor / generator 20 is connected needs to stop the regeneration control of the motor / generator 20 during the shift operation, the motor torque during regeneration (regeneration torque) As a result, the driving force is lost and the driver feels uncomfortable that the vehicle accelerates despite being decelerated. Conventionally, in order to suppress the loss of driving force during the shifting operation, it has been considered that the reduction in motor torque during regeneration is compensated by the engine brake. Because it rises, I feel uncomfortable with this.

  Therefore, in this embodiment, when a downshift in the second transmission mechanism 50 to which the motor / generator 20 is connected is requested during the deceleration regeneration control, the shift is performed without causing the driver to feel uncomfortable. To be configured.

  Specifically, the clutch torque Tcl of the first clutch 61 on the first transmission mechanism 40 side that does not have the motor / generator 20 is used, and the gear ratio between the clutch torque Tcl and the gear stage of the first transmission mechanism 40 is calculated. By generating a driving wheel torque on the deceleration side caused by the gear ratio of the final reduction gear 70, etc., it is possible to suppress driving force loss until the shift is completed. At that time, the maximum clutch torque Tclmax is a shift stage where the cranking torque Tcr is smaller than the current shift stage G (n) of the first transmission mechanism 40, and the shift stage {G (N-1), G (n-3), etc.} are connected, and the first clutch 61 is engaged. Here, the cranking torque Tcr is the minimum torque necessary for the output shaft 11 of the stopped engine 10 to start rotating, and can be grasped in advance from the structure of the engine 10 at the time of design. . Here, the torque when the engine 10 starts to rotate is defined as cranking torque Tcr. The maximum clutch torque Tclmax is a clutch torque when the deceleration at the gear stage G (n-2) is realized at the gear stage G (n-1). In other words, here, during the deceleration regeneration control, the engine 10 is not rotated while generating the clutch torque Tcl of the first clutch 61 until at least the shift to the gear stage G (n-2) is completed. This eliminates the uncomfortable feeling of acceleration and increased engine speed.

  The clutch torque Tcl generated by the engagement operation of the first clutch 61 is determined by the target deceleration torque Ts and the motor torque Tmg during regeneration. The target deceleration torque Ts is a target torque by a power source or the like for generating a desired deceleration-side drive wheel torque in the drive wheels WL and WR. For example, during the deceleration regeneration control at the fourth speed gear stage 54, the motor torque Tmg (4) of the motor / generator 20 at that time becomes the target deceleration torque Ts (4). When the driving wheel torque on the deceleration side is generated only by the clutch torque Tcl, the clutch torque Tcl becomes the target deceleration torque Ts.

  The target deceleration torque Ts (n → n−2) is a target value of the deceleration torque for downshifting from the current shift stage G (n) to the shift stage G (n−2), and is the current shift stage. Target deceleration torque Ts (n) {= Tmg (n)} at G (n) and target deceleration torque Ts (n-2) {= Tmg (n-2) at the shift stage G (n-2) after downshift. } Is a value generated between That is, the target deceleration torque Ts (n → n−2) is the time t1 until the motor torque Tmg at the time of regeneration is reduced from Tmg (n) to 0 at the time of the downshift, and the gear stage G (n). Of the deceleration torque during the time t2 required for switching the connection from the gear to the gear stage G (n-2), and the time t3 until the motor torque Tmg at the time of regeneration after the shift is completed is increased from 0 to Tmg (n-2). This is the target value. The times t1 and t3 are determined in advance according to the specifications of the motor / generator 20, and depend on the magnitudes of the motor torques Tmg (n) and Tmg (n-2). On the other hand, the time t2 is determined in advance according to the specifications of the dual clutch transmission 30.

  This target deceleration torque Ts (n → n−2) is mainly the motor torque Tmg (n) during regeneration at the gear stage G (n) and during regeneration at the gear stage G (n−2). Is set based on the motor torque Tmg (n−2) and the time t2. Here, the motor torque Tmg (n) is gradually increased from the motor torque Tmg (n−2). The increase gradient is such that the difference between the motor torques Tmg (n) and Tmg (n−2) is increased over at least the time t2, and the driver does not feel discomfort due to the occurrence of a shock. Set to FIG. 2 shows an example of downshifting from the fourth speed gear stage 54 to the second speed gear stage 52. The maximum clutch torque Tclmax (3) of the third speed gear stage 43 or the first speed gear stage 41 is shown. Or the change of various torques when Tclmax (1) is smaller than the cranking torque Tcr is shown.

  Here, it is conceivable that the maximum clutch torque Tclmax (1) becomes equal to or higher than the cranking torque Tcr even if the speed is changed to the lowest speed stage G (1) in the first transmission mechanism 40. In this case, the target deceleration torque Ts (n → n−2) is greater than the cranking torque Tcr at least until the shift from the gear stage G (n) to the gear stage G (n−2) is completed. Increase so that it does not grow. That is, in this case, at least during that time, the clutch torque Tcl of the first clutch 61 is generated and the engine 10 is not rotated, so that the uncomfortable feeling of acceleration during the deceleration regeneration control and the increase in the engine speed is eliminated. FIG. 3 shows an example of a downshift from the fourth speed gear stage 54 to the second speed gear stage 52, and the maximum clutch torque Tclmax (1) of the first speed gear stage 41 is greater than or equal to the cranking torque Tcr. The change of various torques is shown.

  This will be specifically described below with reference to the flowchart of FIG.

  The electronic control unit 100 determines whether or not the deceleration regeneration control is being performed (step ST1), and if the deceleration regeneration control is not being performed, the arithmetic processing is finished. On the other hand, when the deceleration regeneration control is being performed, the electronic control unit 100 shifts from the current gear stage G (n) to the gear stage based on, for example, vehicle speed information detected by a vehicle speed detection device (vehicle speed sensor, wheel speed sensor, etc.) 81. It is determined whether a downshift to G (n-2) is necessary (step ST2). At this time, when it is determined that the downshift is not necessary, the present arithmetic processing is finished. On the other hand, if it is determined that a downshift is necessary, electronic control unit 100 calculates current regenerative power Pmg (n) by motor / generator 20 (step ST3).

  The regenerative power Pmg (n) is a multiplication value of the rotational speed Nmg (n) of the motor / generator 20 and the motor torque Tmg (n) as shown in the following formula 1. The current detection value of the rotation sensor 22 may be used as the rotation number Nmg (n). For the motor torque Tmg (n), a current detection value by a torque detector (not shown) or a current command value at the time of regenerative control for the motor / generator 20 may be used.

    Pmg (n) = Nmg (n) * Tmg (n) (1)

  The electronic control unit 100 calculates the friction torque Tf (n-2) of the engine 10 when the speed is changed to the gear stage G (n-2) in the current traveling state (step ST4). In this step ST4, the engine speed is obtained based on the gear ratio of the gear stage G (n-2) and the current vehicle speed, and the friction torque Tf (n-2) at this engine speed is calculated. The friction torque Tf (n−2) can be grasped in advance from the structure of the engine 10 at the time of design, and changes according to the engine speed. Therefore, the friction torque Tf (n−2) may be obtained by preparing a map corresponding to the engine speed in advance and comparing the calculated engine speed with the map.

  The electronic control unit 100 calculates the regenerative power Pmg (n-2) by the motor / generator 20 when the speed is changed to the gear stage G (n-2) in the current traveling state (step ST5). In this step ST5, as shown in Equation 2 below, the product of the current rotational speed Nmg (n) of the motor / generator 20 and the friction torque Tf (n-2) in step ST4 is used as the regenerative power Pmg (n-2). ).

    Pmg (n-2) = Nmg (n) * Tf (n-2) (2)

  The electronic control unit 100 is downshifted to the shift stage G (n−1) of the first transmission mechanism 40 to which the motor / generator 20 is not connected, and the first clutch 61 on the first transmission mechanism 40 side is engaged. The maximum clutch torque Tclmax (n-1) when combined is calculated (step ST6). Here, since the downshift is finally performed from the shift speed G (n) to the shift speed G (n-2), the first speed determined based on the shift speeds G (n) and G (n-2) before and after the shift. The maximum clutch torque Tclmax of the shift stage of the first transmission mechanism 40 is obtained. Specifically, the maximum clutch torque Tclmax (n−1) of the gear stage G (n−1) in which the gear ratio between the gear stages G (n) and G (n−2) is set is obtained. As described above, the engaged state of the first clutch 61 and the second clutch 62 includes a half-engaged state and a fully engaged state. The clutch torque Tcl (n−1) increases as the degree of engagement in the half-engaged state increases and becomes maximum in the fully engaged state. Therefore, in this step ST6, the maximum clutch torque Tclmax (n-1) = Pmg (n-2) / Nin (n-1) is obtained. “Nin” is the rotational speed of the input shafts 42 and 51 in the dual clutch transmission 30.

  The electronic control unit 100 determines whether or not the maximum clutch torque Tclmax (n−1) is equal to or higher than the cranking torque Tcr (step ST7).

  If the maximum clutch torque Tclmax (n-1) is smaller than the cranking torque Tcr, the electronic control unit 100 switches the clutch torque generation shift stage (torque replacement) according to the fluctuation of the motor torque Tmg at the time of regeneration. As the shift speed), the shift speed G (n-1) is controlled to be in a connected state (step ST8).

  Then, the electronic control unit 100 calculates a target deceleration torque Ts (n → n−2) (step ST9). In this step ST9, the motor torque Tmg (n) during regeneration at the gear stage G (n), the motor torque Tmg (n-2) during regeneration at the gear stage G (n-2), and the time Based on t2, the target deceleration torque Ts (n → n−2) having an increasing gradient that increases the difference between the motor torques Tmg (n) and Tmg (n−2) over at least the time t2 or more. Ask. Specifically, the difference is increased by multiplying the difference between motor torques Tmg (n) and Tmg (n−2) by multiplying the difference by the time equal to or greater than the sum of the shortest time of time t1 and the shortest time of time t2 and time t3. An increase gradient that does not make the driver feel uncomfortable with a shock is obtained. At this time, if more time than the sum is required, at least one of the times t1 and t2 is set longer than the shortest time. In the hybrid vehicle 1, by outputting the target deceleration torque Ts (n → n−2), the speed change stage without increasing the engine speed without giving a shock while giving the driver a feeling of deceleration. A downshift to G (n-2) can be performed.

  Here, in this step ST9, the shortest time t1 until the motor torque Tmg is reduced from Tmg (n) to 0 and the target deceleration torque Ts when the clutch torque Tcl is changed from 0 to 0. The shortest time for increasing to (n → n−2) is compared. As a result, if the latter shortest time is longer, for example, the gradient of the target deceleration torque Ts (n → n−2) Or the target deceleration torque Ts (n → n−2) may be calculated by replacing the shortest time of the time t1 with the shortest time for increasing the clutch torque Tcl. Further, from the shortest time t3 until the motor torque Tmg is increased from 0 to Tmg (n−2) and the clutch torque Tcl from the target deceleration torque Ts (n → n−2) at the start of the increase of the motor torque Tmg. The shortest time for reducing to 0 is compared. If the latter shortest time is longer, for example, the gradient of the target deceleration torque Ts (n → n−2) is moderated or the shortest time t2 The target deceleration torque Ts (n → n−2) may be calculated by replacing the time with the shortest time for decreasing the clutch torque Tcl.

  Further, in this step ST9, the maximum clutch torque of the gear stage in the connected state (here, the maximum clutch torque Tclmax (n-1) of the gear stage G (n-1)) and the motor torque Tmg (n-2) Compare When the maximum clutch torque Tclmax (n−1) is smaller than the motor torque Tmg (n−2), the target deceleration torque Ts (n → n−2) at the completion of the shift (when the time t2 has elapsed). Is set to increase gradient of the target deceleration torque Ts (n → n−2) until at least the shift is completed so that the maximum clutch torque Tclmax (n−1) does not exceed.

  Furthermore, there may be a case where the motor torque Tmg (n-2) is larger than the cranking torque Tcr. In this case, it is preferable to stop the calculation in step ST9 and calculate the target deceleration torque Ts (n → n−2) in step ST13 described later. That is, in this case, it is desirable to set a target deceleration torque Ts (n → n−2) that does not rotate the engine 10 at least until the shift is completed.

  On the other hand, when it is determined in step ST7 that the maximum clutch torque Tclmax (n-1) is equal to or higher than the cranking torque Tcr, the electronic control unit 100 performs a shift in the first transmission mechanism 40 to which the motor / generator 20 is not connected. The shift stage G (n-3), which is one lower speed stage than the stage G (n-1), is controlled to be in the connected state as a torque substitute shift stage (step ST10).

  The electronic control unit 100 calculates the maximum clutch torque Tclmax (n-3) when the first clutch 61 is engaged in the connected state of the gear stage G (n-3) (step ST11). The maximum clutch torque Tclmax (n-3) is obtained as Pmg (n-2) / Nin (n-3). Then, the electronic control unit 100 determines whether or not the maximum clutch torque Tclmax (n-3) is equal to or higher than the cranking torque Tcr (step ST12).

  If the maximum clutch torque Tclmax (n-3) is smaller than the cranking torque Tcr, the electronic control unit 100 proceeds to step ST9 and calculates the target deceleration torque Ts (n → n-2).

  On the other hand, when the maximum clutch torque Tclmax (n−3) is equal to or higher than the cranking torque Tcr, the electronic control unit 100 performs at least a shift from the gear stage G (n) to the gear stage G (n−2). The target deceleration torque Ts (n → n−2) is calculated until completion, that is, during time t1 + t2 so as not to be larger than the cranking torque Tcr (step ST13). In this step ST13, the target deceleration torque Ts (n → n−) is determined based on the motor torque Tmg (n) during regeneration at the gear stage G (n), the cranking torque Tcr, and the times t1 and t2. Obtain the increasing slope of 2). For example, here, an increasing gradient is set to increase the difference between the motor torque Tmg (n) and the cranking torque Tcr over time t1 + t2. Here, when the target deceleration torque Ts (n → n−2) is increased with its increasing gradient, the motor torque Tmg (n−2) does not reach even when the time becomes the shortest time t3. In this case, the motor torque Tmg (n-2) may be increased with the increasing gradient. On the other hand, when the target deceleration torque Ts (n → n−2) is increased with the increasing gradient, the target deceleration torque Ts (n → n−2) may reach the motor torque Tmg (n−2) before exceeding the shortest time t3. For example, it is preferable that the increasing gradient after the completion of the shift is set more gently than before the shift is completed, and the motor torque Tmg (n−2) is reached at least over the minimum time t3. In the hybrid vehicle 1, by outputting the target deceleration torque Ts (n → n−2), the speed change stage is provided without increasing the engine speed at least until the shift is completed while giving the driver a feeling of deceleration. A downshift to G (n-2) can be performed.

  The electronic control unit 100 outputs the target deceleration torque Ts (n → n−2) obtained in step ST9 or step ST13 when starting the shift from the shift stage G (n) to the shift stage G (n−2). (Step ST14). Here, the motor torque Tmg during regeneration is gradually reduced from Tmg (n) toward zero. At the same time, the clutch torque Tcl is obtained based on the motor torque Tmg and the target deceleration torque Ts (n → n−2) (Equation 3 below) and the first clutch 61 is output so as to output it. Perform joint control. In step ST14, the decrease in the motor torque Tmg is replaced with the clutch torque Tcl, so that the target deceleration torque Ts (n → n−2) is output.

    Tcl = Ts (n → n−2) −Tmg (3)

  The electronic control unit 100 determines whether or not the motor torque Tmg at the time of regeneration has become 0 (step ST15). Here, if the motor torque Tmg has not decreased to 0, the output of the target deceleration torque Ts (n → n−2) in step ST14 is repeated. On the other hand, when the motor torque Tmg becomes 0, the process proceeds to step ST16. That is, the output of the target deceleration torque Ts (n → n−2) in step ST14 continues until the motor torque Tmg becomes zero.

  When the motor torque Tmg becomes 0, the electronic control unit 100 releases the connected gear stage G (n) and puts the gear stage G (n-2) in the connected state (step ST16). In this step ST16, the motor torque Tmg is kept at 0 until only the output of the clutch torque Tcl from when the gear stage G (n) is released until the gear stage G (n-2) is connected. The target deceleration torque Ts (n → n−2) is generated. Accordingly, the electronic control unit 100 controls the engagement of the first clutch 61 in accordance with the target deceleration torque Ts (n → n−2) during that period, and according to the target deceleration torque Ts (n → n−2). The clutch torque Tcl is output. Also during this speed change operation, the target deceleration torque Ts (n → n−2) obtained in step ST9 or step ST13 is output.

  After completion of the shift, the electronic control unit 100 outputs the target deceleration torque Ts (n → n−2) until the motor torque Tmg increases to Tmg (n−2) (step ST17). This target deceleration torque Ts (n → n−2) is also obtained in step ST9 or step ST13. In step ST17, the motor torque Tmg at the time of regeneration is gradually increased from 0 to Tmg (n-2), and the motor torque Tmg and the target deceleration torque Ts (n → n-2) are increased. Based on this, the clutch torque Tcl is obtained (Equation 3), and the engagement of the first clutch 61 is controlled so as to be output. In this step ST17, the clutch torque Tcl obtained by reducing the increase in the motor torque Tmg is output, so that the target deceleration torque Ts (n → n−2) is output.

  The electronic control unit 100 determines whether or not the motor torque Tmg at the time of regeneration has become Tmg (n−2) (step ST18). Here, the output of the target deceleration torque Ts (n → n−2) in step ST17 is repeated until the motor torque Tmg increases to Tmg (n−2).

  As described above, when the target deceleration torque Ts (n → n−2) in step ST9 is output, the motor torque Tmg at the time of regeneration is started to decrease until Tmg (n−2) is output. The motor torque Tmg is replaced with the clutch torque Tcl, and the hybrid vehicle 1 decelerates. Therefore, the driving force is not lost, and the driver does not feel uncomfortable during the downshift during the deceleration regeneration control. At this time, since the clutch torque Tcl does not become larger than the cranking torque Tcr during this time, the engine 10 does not rotate, and the driver does not feel uncomfortable during the downshift during the deceleration regeneration control.

  Similarly, when the target deceleration torque Ts (n → n−2) in step ST13 is output, the period from when the motor torque Tmg during regeneration starts to decrease until Tmg (n−2) is output. The motor torque Tmg is replaced with the clutch torque Tcl, and the hybrid vehicle 1 decelerates. Therefore, the driving force is not lost, and the driver does not feel uncomfortable during the downshift during the deceleration regeneration control. At this time, since the clutch torque Tcl does not become larger than the cranking torque Tcr at least until the completion of the shift, it is possible to downshift to the shift stage G (n−2) without rotating the engine 10. , The driver's discomfort can be suppressed.

  In the present embodiment, the rotating shaft 21 of the motor / generator 20 is directly connected to the input shaft 51 of the second speed change mechanism 50. The motor / generator 20 is connected to the second shaft via a gear group such as a gear pair. You may connect with the input shaft 51 of the transmission mechanism 50. FIG. The motor / generator 20 may be connected to the input shaft 42 of the first transmission mechanism 40, the output shaft 44 of the first transmission mechanism 40, or the output shaft 53 of the second transmission mechanism 50 directly or through a gear group. .

DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 10 Engine 20 Motor / generator 30 Dual clutch transmission 40 First transmission mechanism 50 Second transmission mechanism 60 Dual clutch mechanism 61 First clutch 62 Second clutch 63, 64 Actuator 100 Electronic control unit

Claims (2)

A mechanical power source;
A first shift stage group comprising a first input shaft to which an output shaft of the mechanical power source is coupled, a first output shaft, and a plurality of types of shift stages disposed between the first input shaft and the first output shaft. A first transmission mechanism having
A second shift stage group comprising a second input shaft to which the output shaft of the mechanical power source is coupled, a second output shaft, and a plurality of types of shift stages disposed between the second input shaft and the second output shaft. A second speed change mechanism having
A first clutch capable of connecting and disconnecting between an output shaft of the mechanical power source and a first input shaft of the first transmission mechanism;
A second clutch capable of connecting and disconnecting between the output shaft of the mechanical power source and the second input shaft of the second speed change mechanism;
An electric power source connected to the second input shaft or the second output shaft of the second speed change mechanism and capable of power running drive and regenerative drive;
By stopping the mechanical power source in a state where the first and second clutches are released and regenerating the electric power source, and transmitting the torque from the driving wheel side during traveling to the electric power source, A decelerating regenerative control device that executes decelerating regenerative control capable of decelerating according to power regeneration and target deceleration torque;
A shift control device that stops the electric power source and switches the shift speed in the stopped state when switching the shift speed in the second shift speed group during traveling;
With
When downshifting is performed in the second gear group during deceleration regeneration control, the target is set in the first clutch at the torque substitute gear in the first gear group determined based on the gears before and after the gear shift. If the clutch torque that realizes the deceleration torque is smaller than the cranking torque of the mechanical power source, the first torque change gear in accordance with the fluctuation of the regenerative torque of the electric power source at the time of gear change. A shift control system for a hybrid vehicle that outputs a clutch torque of a clutch to generate a target deceleration torque.   The clutch torque for realizing the target deceleration torque in the first clutch at the lowest speed in the first speed group and the first clutch at the torque alternative is greater than or equal to the cranking torque. In this case, the target deceleration torque is set so as not to be larger than the cranking torque until at least the shift of the second speed group is completed. The regenerative torque of the electric power source that is changed at the time of switching, and the clutch torque of the first clutch at the torque substitution speed that is the lowest speed in the first speed group corresponding to the change, and The shift control system for a hybrid vehicle according to claim 1, wherein

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