JP2014094596A - Gear shift controller for hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear shift controller capable of improvement of responsibility of gear change on kickdown.SOLUTION: A gear shift controller for hybrid vehicles 1 comprises a dual clutch type change gear 10, a first MG3 connected to a first input axis 13 of the change gear 10 in a power transmittable way, and a second MG4 connected to a second input axis 14 of the change gear 10 in a power transmittable way. When the vehicle 1 runs with an internal combustion engine 2, the gear shift controller estimates a required driving force for the vehicle 1. Then, when the estimated driving force is greater than a second determination value, the gear shift controller shifts the gear train on the side not related to the running of the vehicle 1 to a shift stage three stages lower than the present, and, when the estimated driving force is equal to or smaller than the second determination value, the gear shift controller shifts to a sift stage one stage lower than the present. When the shift stage shifted is different from a target shift stage to be practically shifted to, the change gear 10 is shifted to the target shift state while assisting the drive of a driving wheel 6 by the first MG3 or the second MG4.

Description

  The present invention relates to a shift control device applied to a hybrid vehicle that includes a dual clutch type transmission and that has electric motors connected to two input shafts of the transmission.

  A dual clutch is provided with gear trains between the first input shaft and the output system and between the second input shaft and the output system, and selectively connects one of the two input shafts to the internal combustion engine. A type of transmission is known. Moreover, a hybrid vehicle in which such a dual clutch transmission is mounted and a motor is connected to each input shaft is known (see Patent Document 1). In the vehicle of Patent Document 1, when traveling with an electric motor provided on one input shaft, a friction clutch interposed between the other input shaft and the internal combustion engine is released, or the other input shaft and output shaft are disengaged. All the hub sleeves of the gear train provided between and are made neutral. When traveling with an internal combustion engine, the internal combustion engine is connected to one input shaft and the power of the internal combustion engine is output to the output shaft via the gear train of the one input shaft. In preparation for gear shifting, the gear is connected to the output shaft at a gear position on the low speed side or the high speed side of the current gear speed. However, when one motor is driven by the internal combustion engine to generate power, all the hub sleeves on the input shaft on the other motor side are neutralized and the other motor is disconnected. In addition, there is Patent Document 2 as a prior art document related to the present invention.

JP 2003-079005 A JP 2011-230741 A

  When the accelerator pedal is greatly depressed and a large driving force is required for the vehicle, control for switching the shift speed from the current shift speed to the low speed shift speed, so-called kick down is performed. At this time, the low-speed side gear stage to be changed varies depending on the driving force required for the vehicle. For this reason, when the current shift speed is 4th speed or higher, there is a case where the speed is switched to the shift speed on the third low speed side. In the device of Patent Document 1, an input shaft that is not involved in traveling of a vehicle is connected to an output shaft at a gear position on the lower speed side. For this reason, when it is necessary to switch the transmission to a gear position on the third low speed side by kickdown, it takes time for the gear shift, and the response may be delayed.

  Therefore, an object of the present invention is to provide a shift control device for a hybrid vehicle that can improve the response of a shift at the time of kickdown.

  The transmission control device of the present invention includes an internal combustion engine, a first input shaft connected to the internal combustion engine via a first clutch, and an input including a second input shaft connected to the internal combustion engine via a second clutch. A system, an output system connected to the drive wheels so as to be able to transmit power, a portion interposed between the first input shaft and the output system, and the rest between the second input shaft and the output system. And a plurality of gear trains having different gear ratios, and the first input shaft by any one of the gear trains interposed between the first input shaft and the output system, By selectively establishing power transmission to and from the output system, the gear ratio between them can be switched, and switching to a neutral state that interrupts power transmission between the first input shaft and the output system A possible first transmission mechanism, the second input shaft and the output A gear ratio between them is switched by selectively establishing power transmission between the second input shaft and the output system by any one of the gear trains interposed between them. Power transmission between the input system and the output system, and a second speed change mechanism capable of switching to a neutral state that interrupts power transmission between the second input shaft and the output system. And a gear train corresponding to an odd number of the plurality of gears is interposed between the first input shaft and the output system. A dual-clutch transmission in which a gear train corresponding to even stages is interposed between the second input shaft and the output system, and a first electric motor connected to the first input shaft so as to be able to transmit power, Connected to the second input shaft so that power can be transmitted. A second electric motor, and the transmission has a gear stage corresponding to each of the gear speeds as the plurality of gear speeds and has a gear train corresponding to each of the gear speeds. Either one of the first input shaft and the second input shaft is connected to the internal combustion engine so that power can be transmitted, and power transmission between the other input shaft and the internal combustion engine is interrupted. As described above, in the shift control apparatus applied to the hybrid vehicle in which the first clutch and the second clutch are controlled, the transmission is shifted to a shift speed of 4th speed or more, and the vehicle is the internal combustion engine. Required driving force estimation means for estimating the magnitude of the driving force expected to be required for the vehicle when traveling at the vehicle, and estimation that is the driving force estimated by the required driving force estimation means The required driving force is preset If the estimated shift speed is larger than the predetermined gear position determination value, the gear ratio of the gear train used for power transmission between the internal combustion engine and the output system when the estimated required driving force is estimated is three times greater. Of the first transmission mechanism and the second transmission mechanism, the other input shaft and the output system so that power transmission between the other input shaft and the output system is established by the gear train on the lower speed side. One transmission mechanism that controls power transmission between the internal combustion engine and the output when the estimated required driving force is estimated when the estimated required driving force is less than or equal to the shift speed determination value. The one gear shift is such that power transmission between the other input shaft and the output system is established by a gear train that is one step lower than the gear ratio of the gear train used for power transmission to the system. Pre-shift control means for controlling the mechanism, and the vehicle When traveling with the internal combustion engine and power transmission between the other input shaft and the output system is established by the first-stage low-speed gear train or the third-stage low-speed gear train, Corresponds to the gear train used for power transmission between the other input shaft and the output system when a predetermined gear shift condition for switching the transmission from the current gear to another target gear is established. When the shift speed to be changed and the target shift speed are different, the assist drive for driving the drive wheels by the first electric motor or the second electric motor is performed so that the speed of the vehicle does not fluctuate, and the assist drive Shift means for controlling the first speed change mechanism or the second speed change mechanism so that the speed change stage of the transmission becomes the target speed change.

  In the speed change control device of the present invention, when the vehicle is driven by the internal combustion engine and the transmission is shifted to a gear stage of 4th speed or higher, the estimated required driving force is estimated, and the estimated required driving force is When the estimated speed is greater than the shift speed determination value, the gear position on the lower speed side is used to connect the other input shaft to the output system. The power transmission of is established. Therefore, kickdown can be executed only by switching the states of the first clutch and the second clutch. In addition, since the gear train is changed for power transmission between the other input shaft and the output system according to the estimated required driving force, it is a case where the gear train is switched to the gear train on the third low speed side by kickdown. However, response delay can be suppressed. Accordingly, it is possible to improve the responsiveness of the shift at the time of kick down.

  Further, in the present invention, even if the shift speed changed according to the estimated required driving force and the target shift speed are different, the drive wheels are driven by the first electric motor or the second electric motor, and the speed change of the transmission is performed in the meantime. Since the speed is set to the target speed, the transmission can be shifted to an appropriate speed while suppressing fluctuations in the vehicle speed.

  In one form of the speed change control device of the present invention, the pre-shift control means, when the estimated required driving force is equal to or smaller than the neutral judgment value set to a value smaller than the gear speed judgment value, The mechanism may be controlled to the neutral state (Claim 2). According to this aspect, when the estimated required driving force is equal to or less than the neutral determination value, one transmission mechanism is set to the neutral state, so that the other input shaft can be disconnected from the internal combustion engine and the output system. In this case, the rotation of the electric motor connected to the other input shaft can be prevented, so that the power of the internal combustion engine can be prevented from being wasted. In addition, by preventing the motor from being rotated in this way, it is possible to prevent the occurrence of power loss and prevent wasteful consumption of battery power. Therefore, the fuel consumption of the internal combustion engine can be improved.

  As described above, in the shift control device of the present invention, when the vehicle is running on the internal combustion engine and the transmission is shifted to a shift speed of 4th speed or higher, the gear train of the current shift speed is set. In addition, power transmission between the other input shaft and the output system is established with a gear train on the lower speed side or a gear train on the lower speed side of the third stage. Therefore, kickdown can be executed only by switching the states of the first clutch and the second clutch. Further, since the gear train is changed for power transmission between the other input shaft and the output system in accordance with the estimated required driving force, occurrence of a response delay can be suppressed. Accordingly, it is possible to improve the responsiveness of the shift at the time of kick down.

1 is a diagram schematically showing a vehicle in which a shift control device according to one embodiment of the present invention is incorporated. The figure which shows an example of a shift map. The figure which shows an example of the correspondence of the control method of each sleeve of the 1st determination value and the 2nd determination value, and the input shaft of a sub side. The flowchart which shows the pre shift control routine which a vehicle control apparatus performs. The flowchart which shows the kickdown control routine which a vehicle control apparatus performs. The flowchart following FIG.

  FIG. 1 schematically shows a vehicle in which a shift control device according to one embodiment of the present invention is incorporated. The vehicle 1 includes an internal combustion engine (hereinafter sometimes referred to as an engine) 2 as a driving power source, and a first motor / generator (hereinafter also referred to as first MG) 3 as a first electric motor. And a second motor / generator (hereinafter also referred to as second MG) 4 as a second electric motor. That is, the vehicle 1 is configured as a hybrid vehicle. The engine 2 is a known spark ignition internal combustion engine having a plurality of cylinders. The first MG 3 and the second MG 4 are well-known ones that are mounted on a hybrid vehicle and function as an electric motor and a generator. Therefore, the detailed description regarding these is abbreviate | omitted.

  The vehicle 1 is equipped with a transmission 10 capable of shifting to a plurality of shift speeds (first to fifth and reverse). The transmission 10 is configured as a dual clutch transmission. The transmission 10 includes an input system 11 and an output system 12. The input system 11 includes a first input shaft 13 and a second input shaft 14. The first input shaft 13 is connected to the engine 2 via the first clutch 15. The second input shaft 14 is connected to the engine 2 via the second clutch 16. The first clutch 15 and the second clutch 16 are known friction clutches that can be switched between an engaged state in which power is transmitted between the engine 2 and the input shafts 13 and 14 and a released state in which the power transmission is interrupted. is there.

  The output system 12 includes a first output shaft 17, a second output shaft 18, and a drive shaft 19. As shown in this figure, a first output gear 20 is provided on the first output shaft 17. A second output gear 21 is provided on the second output shaft 18. A drive gear 22 is provided on the drive shaft 19. The first output gear 20 and the second output gear 21 mesh with the driven gear 22, respectively. The drive shaft 19 is connected to the differential mechanism 5 so that power can be transmitted. The differential mechanism 5 is a well-known mechanism that distributes input power to the left and right drive wheels 6.

  Between the input system 11 and the output system 12, the first to fifth gear trains G1 to G5 and the reverse gear train GR are interposed. As shown in this figure, the first gear train G1, the third gear train G3, and the fifth gear train G5 are interposed between the first input shaft 13 and the first output shaft 17. The second gear train G2, the fourth gear train G4, and the reverse gear train GR are interposed between the second input shaft 14 and the second output shaft 18.

  The first gear train G1 includes a first drive gear 23 and a first driven gear 24 that mesh with each other, and the second gear train G2 includes a second drive gear 25 and a second driven gear 26 that mesh with each other. The third gear train G3 includes a third drive gear 27 and a third driven gear 28 that mesh with each other, and the fourth gear train G4 includes a fourth drive gear 29 and a fourth driven gear 30 that mesh with each other. The fifth gear train G5 includes a fifth drive gear 31 and a fifth driven gear 32 that mesh with each other. The first to fifth gear trains G1 to G5 are provided so that the drive gear and the driven gear are always engaged. Different gear ratios are set for the respective gear trains G1 to G5. The gear ratio is smaller in the order of the first gear train G1, the second gear train G2, the third gear train G3, the fourth gear train G4, and the fifth gear train G5. Therefore, the first gear train G1 is the first gear, the second gear train G2 is the second gear, the third gear train G3 is the third gear, the fourth gear train G4 is the fourth gear, and the fifth gear train G5 is the fifth gear. Correspond to each. The reverse gear train GR includes a reverse drive gear 33, an intermediate gear 34, and a reverse driven gear 35.

  The first drive gear 23, the third drive gear 27, and the fifth drive gear 31 are fixed to the first input shaft 13 so as to rotate integrally with the first input shaft 13. On the other hand, the first driven gear 24, the third driven gear 28, and the fifth driven gear 32 are supported by the first output shaft 17 so as to be rotatable relative to the first output shaft 17. The second drive gear 25, the fourth drive gear 29, and the reverse drive gear 33 are fixed to the second input shaft 14 so as to rotate integrally with the second input shaft 14. On the other hand, the second driven gear 26, the fourth driven gear 30, and the reverse driven gear 35 are supported on the second output shaft 18 so as to be rotatable relative to the second output shaft 18. The intermediate gear 34 is rotatably supported by a case (not shown) of the transmission 10. As shown in this figure, the intermediate gear 34 meshes with each of the reverse drive gear 33 and the reverse drive gear 35.

  The first output shaft 17 is provided with a first sleeve 36, a third sleeve 38, and a fifth sleeve 40. These sleeves 36, 38, and 40 are supported by the first output shaft 17 so as to rotate integrally with the first output shaft 17 and to be movable in the axial direction. The first sleeve 36 is provided to be switchable between an engagement position where the first output shaft 17 and the first driven gear 24 are engaged with each other so that the first driven gear 24 is rotated integrally and a release position where the engagement is released. ing. The third sleeve 38 is provided so as to be switchable between an engagement position where the first output shaft 17 and the third driven gear 28 are engaged with each other and an engagement position where the engagement is released, and a release position where the engagement is released. ing. The fifth sleeve 40 is provided so as to be switchable between an engagement position where the first output shaft 17 and the fifth driven gear 32 rotate together, and a release position where the engagement is released. ing. Hereinafter, the case where the first sleeve 36, the third sleeve 38, and the fifth sleeve 40 are all switched to the release position may be referred to as a neutral state. By controlling the power transmission between the first output shaft 17 and the driven gears 24, 28, and 32 in this way, the first sleeve 36, the third sleeve 38, and the fifth sleeve 40 are moved to the first speed change of the present invention. Acts as a mechanism. When the first sleeve 36 is switched to the engaged position, the third sleeve 38 is switched to the engaged position, or the fifth sleeve 40 is switched to the engaged position. Corresponds to the state.

  The second output shaft 18 is provided with a second sleeve 37, a fourth sleeve 39, and a reverse sleeve 41. These sleeves 37, 39, 41 are supported by the second output shaft 18 so as to rotate integrally with the second output shaft 18 and to be movable in the axial direction. The second sleeve 37 is provided so as to be switchable between an engagement position where the second output shaft 18 and the second driven gear 26 are engaged with each other and an engagement position where the engagement is released, and a release position where the engagement is released. ing. The fourth sleeve 39 is provided so as to be switchable between an engaging position where the second output shaft 18 and the fourth driven gear 30 are engaged with the fourth driven gear 30 and a release position where the engagement is released. ing. The reverse sleeve 41 is provided so as to be switchable between an engagement position where the second output shaft 18 and the reverse drive gear 35 are engaged with each other and an engagement position where the reverse drive gear 35 is released, and a release position where the engagement is released. Hereinafter, the case where the second sleeve 37, the fourth sleeve 39, and the reverse sleeve 41 are all switched to the release position may be referred to as a neutral state. In this way, by controlling the power transmission between the second output shaft 18 and each driven gear 26, 30, 35, the second sleeve 37, the fourth sleeve 39, and the reverse sleeve 41 become the second speed change mechanism of the present invention. Function as. When the second sleeve 37 is switched to the engagement position, the fourth sleeve 39 is switched to the engagement position, or the reverse sleeve 41 is switched to the engagement position. It corresponds to.

  Although not shown, the output shafts 17 and 18 each have a synchro mechanism that synchronizes rotation when the sleeves 36 to 41 and the driven gears 24, 26, 28, 30, 32, and 35 are engaged with each other. It is provided for each driven gear. For these synchro mechanisms, a synchro mechanism that synchronizes rotation by friction engagement, for example, a known key-type synchromesh mechanism may be used. Therefore, detailed description of the synchro mechanism is omitted.

  A first driven gear 42 is provided on the first input shaft 13. A first drive gear 43 that meshes with the first driven gear 42 is provided on the output shaft 3 a of the first MG 3. As a result, the first MG 3 is connected to the first input shaft 13 so that power can be transmitted. The transmission ratio between the first drive gear 43 and the first driven gear 42 is set so that the rotation of the first MG 3 is decelerated and transmitted to the first input shaft 13. The second input shaft 14 is provided with a second driven gear 44. A second drive gear 45 that meshes with the second driven gear 44 is provided on the output shaft 4 a of the second MG 4. As a result, the second MG 4 is connected to the second input shaft 14 so that power can be transmitted. The gear ratio between the second drive gear 45 and the second driven gear 44 is set so that the second MG 4 and the second input shaft 14 rotate at substantially the same rotational speed. Thus, the transmission ratio between the first drive gear 43 and the first driven gear 42 and the transmission ratio between the second drive gear 45 and the second driven gear 44 are set to be different from each other. .

  Operations of the first clutch 15, the second clutch 16, and the sleeves 36 to 41 are controlled by the vehicle control device 50. The operations of the engine 2, the first MG3, and the second MG4 are also controlled by the vehicle control device 50. The vehicle control device 50 is configured as a computer unit including a microprocessor and peripheral devices such as RAM and ROM necessary for its operation. The vehicle control device 50 holds various control programs for causing the vehicle 1 to travel appropriately. The vehicle control device 50 executes control of the control objects such as the engine 2 and the MGs 3 and 4 by executing these programs. Various sensors for acquiring information relating to the vehicle 1 are connected to the vehicle control device 50. For example, a vehicle speed sensor 51, an accelerator opening sensor 52, an acceleration sensor 53, and the like are connected to the vehicle control device 50. The vehicle speed sensor 51 outputs a signal corresponding to the speed (vehicle speed) of the vehicle 1. The accelerator opening sensor 52 outputs a signal corresponding to the depression amount of the accelerator pedal, that is, the accelerator opening. The acceleration sensor 53 outputs a signal corresponding to the longitudinal acceleration of the vehicle 1. The vehicle control device 50 is also connected with a shift lever (not shown). In addition to this, various sensors, switches, and the like are connected to the vehicle control device 50, but these are not shown.

  The vehicle control device 50 switches the travel mode of the vehicle 1 based on the vehicle speed or the like. As the travel mode, an EV travel mode in which the drive wheels 6 are driven by the first MG 3 or the second MG 4 and an engine travel mode in which the drive wheels 6 are mainly driven by the engine 2 are set. The vehicle control device 50 switches the travel mode to the EV travel mode when the vehicle speed is less than the predetermined determination speed. In the EV travel mode, both the first clutch 15 and the second clutch 16 are switched to the released state, and the engine 2 is disconnected. On the other hand, when the vehicle speed is equal to or higher than the determination speed, or when the capacity of a battery (not shown) connected to the MGs 3 and 4 is equal to or lower than the determination value, the travel mode is switched to the engine travel mode. In the engine travel mode, of the first clutch 15 and the second clutch 16, the clutch on the input shaft side having the gear stage used for travel of the vehicle 1 is switched to the fully engaged state, and the other clutch is switched to the released state.

  Further, the vehicle control device 50 switches the gear position of the transmission 10 based on the vehicle speed and the accelerator opening. In the ROM of the vehicle control device 50, a shift diagram showing the relationship between the vehicle and the accelerator opening and the gear position is stored as a map. FIG. 2 shows an example of a shift diagram. The vehicle control device 50 sets a gear position according to the current traveling state of the vehicle 1 based on this shift diagram. Then, the operations of the sleeves 36 to 41 are controlled so that the transmission 10 is switched to the set gear position. At this time, each sleeve on the one input shaft side involved in power transmission is controlled so as to be in the set gear position. On the other hand, each sleeve on the other input shaft side that is not involved in power transmission is appropriately controlled according to the travel mode and travel state of the vehicle 1. Hereinafter, one input shaft used for traveling of the vehicle 1 is referred to as a main-side input shaft, and the other input shaft not used for traveling of the vehicle 1 is referred to as a sub-side input shaft. is there. The main side input shaft clutch, MG, gear train, and each sleeve are called the main side clutch, main side MG, main side gear train, and main side sleeve, respectively, and the sub side input shaft clutch. , MG, gear train, and each sleeve may be referred to as a sub-side clutch, sub-side MG, sub-side gear train, and sub-side sleeve, respectively.

  In addition, the vehicle control device 50 shifts the shift speed from the current shift speed to the low speed shift speed when a large driving force is required for the vehicle 1 due to a large depression of the accelerator pedal. Perform control, ie kick down. At this time, to which of the low speed side gears the speed is changed depends on the amount of change in the accelerator opening, that is, the required driving force to the vehicle 1. For example, as shown in FIG. 2, when the accelerator opening is changed from the opening A1 to the opening A2 when the current shift speed is the fifth speed, the transmission 10 shifts to the fourth speed on the lower speed side. Is done. When the accelerator opening is changed from the opening A1 to the opening A3, the second speed on the second low speed side is changed to the third speed on the second speed, and when the accelerator opening is changed from the opening A1 to the opening A4, the second speed on the third speed side. The speed is changed.

  Therefore, the vehicle control device 50 is expected to be required for the vehicle 1 when the travel mode of the vehicle 1 is the engine travel mode and the transmission 10 is shifted to the fourth speed or higher. The force is estimated, and each sleeve on the sub side is controlled in accordance with the estimated driving force (hereinafter also referred to as an estimated required driving force). At this time, the vehicle control device 50 compares the estimated required driving force with the first determination value and the second determination value, and controls the sleeve on the input shaft side that is not involved in power transmission based on the comparison result. Note that a value larger than the first determination value is set as the second determination value. FIG. 3 shows an example of a correspondence relationship between each determination value and the control method of each sleeve on the sub side. As shown in this figure, when the estimated required driving force is equal to or smaller than the first determination value, the sub-side sleeves are switched to the neutral state, that is, all the release positions. On the other hand, when the estimated required driving force is greater than the first determination value and less than or equal to the second determination value, the shift speed of the sub-side input shaft is set to a shift speed that is one speed lower than the current shift speed. Each sleeve is controlled. Specifically, for example, when the current shift speed is 5th gear, each sleeve is controlled to be 4th gear. When the estimated required driving force is larger than the second determination value, each sleeve is controlled so that the gear position of the sub-side input shaft is the gear position that is three speeds lower than the current gear speed. . Specifically, for example, when the current shift speed is 5th gear, each sleeve is controlled to be 2nd gear. Note that the first determination value and the second determination value shown in FIG. 3 may have hysteresis. In this case, it is possible to prevent so-called hunting in which the shift stage of the sub-side input shaft is frequently changed.

  FIG. 4 shows a pre-shift control routine executed by the vehicle control device 50 to control the sub-side sleeves in this way. This control routine is repeatedly executed at a predetermined cycle when the travel mode of the vehicle 1 is the engine travel mode and the current shift speed is the fourth speed or higher.

  In this control routine, the vehicle control device 50 first acquires the state of the vehicle 1 in step S11. As the state of the vehicle 1, for example, the vehicle speed, the accelerator opening, the current gear position, the acceleration in the front-rear direction, and the like are acquired. When a navigation device is mounted on the vehicle 1, the state of the road on which the vehicle 1 is currently traveling, such as a corner or an uphill, is acquired from the navigation device.

  In subsequent step S <b> 12, the vehicle control device 50 estimates the magnitude of the driving force (estimated required driving force) that is expected to be required for the vehicle 1. The magnitude of the estimated required drive amount can be estimated based on, for example, the traveling state of the vehicle 1 or the state of the road on which the vehicle 1 is traveling. For example, when the vehicle 1 is traveling on an uphill, it can be expected that a large driving force is required for the vehicle 1. It is considered that the estimated required driving force increases as the slope of the uphill increases. Therefore, the relationship between the slope of the uphill and the estimated required driving force is obtained in advance by experiments and numerical calculations, and stored in the ROM of the vehicle control device 50 as a map. Then, the magnitude of the estimated required driving force may be estimated based on this map. The slope of the uphill may be acquired from the navigation device or acquired based on the acceleration in the front-rear direction of the vehicle 1. Further, for example, when a sudden deceleration is detected by the acceleration sensor 53 or the like, it can be estimated that the driver is driving in a sport. In this case, it is expected that a large driving force is required for the vehicle 1 after a sudden deceleration is detected. The estimated required driving force at that time is expected to increase as the amount of change in the vehicle speed or the amount of depression of the brake pedal during sudden deceleration increases. Therefore, the relationship between the amount of change in the vehicle speed during deceleration, the amount of depression of the brake pedal, and the estimated required driving force is obtained in advance by experiment, numerical calculation, etc., and stored in the ROM of the vehicle control device 50 as a map. Based on this, the estimated required driving force may be estimated.

  In the next step S13, the vehicle control device 50 determines whether or not the estimated required driving force is equal to or less than the first determination value. As shown in FIG. 3, the first determination value is set as a reference for determining whether the sub-side sleeves are controlled to the neutral state or the low-speed side gear. An appropriate value may be set for the first determination value so that the sub-side input shaft is not connected wastefully so that power is transmitted to the output system 12.

  When it is determined that the estimated required driving force is equal to or less than the first determination value, the process proceeds to step S14, and the vehicle control device 50 executes neutral control. In this neutral control, each sub-side sleeve is controlled to a neutral state. Thereafter, the current control routine is terminated.

  On the other hand, if it is determined that the estimated required driving force is greater than the first determination value, the process proceeds to step S15, and the vehicle control device 50 determines whether the estimated required driving force is equal to or less than the second determination value. The second determination value is set as a reference for determining whether the sub-side sleeves are controlled to the first gear position or the third gear position. The second determination value may be set to an appropriate value according to the driving force that can be transmitted to the driving wheel 6 at each shift stage.

  When it is determined that the estimated required driving force is equal to or less than the second determination value, the process proceeds to step S16, and the vehicle control device 50 executes the one-step low speed side preshift control. In this one-stage low-speed pre-shift control, each sub-side sleeve is controlled so that the sub-side input shaft and the output system 12 are connected to the current gear stage by a gear train of the first-stage low-speed gear stage. . For example, when the current gear position is 5th gear, the second gear 37 and the reverse sleeve 41 are switched to the release position and the fourth sleeve 39 is moved so that the gear position of the second input shaft 14 is 4th gear. The second sleeve 37, the fourth sleeve 39, and the reverse sleeve 41 are controlled so as to switch to the engagement position. Further, when the current gear position is 4th gear, the first sleeve 36 and the fifth sleeve 40 are switched to the release position and the third sleeve 38 so that the gear position of the first input shaft 13 is 3rd gear. The first sleeve 36, the third sleeve 38, and the fifth sleeve 40 are controlled such that the first sleeve 36, the third sleeve 38, and the fifth sleeve 40 are switched to the engaged position. Thereafter, the current control routine is terminated.

  On the other hand, if it is determined that the estimated required driving force is greater than the second determination value, the process proceeds to step S17, and the vehicle control device 50 executes the three-stage low speed side preshift control. In this three-stage low-speed side pre-shift control, the sub-side sleeves are connected so that the sub-side input shaft and the output system 12 are connected to the current gear stage by the gear train of the three-stage low speed side gear stage. Control. For example, when the current shift speed is 5th, the shift speed of the second input shaft 14 is changed to 2nd, that is, the fourth sleeve 39 and the reverse sleeve 41 are switched to the release position and the second sleeve 37 is The second sleeve 37, the fourth sleeve 39, and the reverse sleeve 41 are controlled so as to switch to the engagement position. Further, when the current gear position is the fourth speed, the first sleeve 13 and the fifth sleeve 40 are switched to the release position and the first sleeve 36 so that the gear position of the first input shaft 13 is the first speed. The first sleeve 36, the third sleeve 38, and the fifth sleeve 40 are controlled such that the first sleeve 36, the third sleeve 38, and the fifth sleeve 40 are switched to the engaged position. Thereafter, the current control routine is terminated.

  5 and 6 show a kick-down control routine executed by the vehicle control device 50 to perform kick-down when the accelerator pedal is actually depressed greatly. This control routine is performed when the vehicle 1 is traveling in the engine travel mode and the sub-side gear is set to the one-speed low speed or the three-speed low speed according to the pre-shift control routine described above. It is repeatedly executed at a predetermined cycle. In this control routine, the same processes as those in the control routine of FIG.

  In this control routine, the vehicle control device 50 first acquires the state of the vehicle 1 in step S11. In the next step S12, the vehicle control device 50 determines whether or not the vehicle 1 has been requested to kick down. This determination may be made based on the amount of change in the accelerator opening and the shift diagram in FIG. Note that the case where the kick down is requested corresponds to the case where the predetermined speed change condition of the present invention is satisfied. If it is determined that kickdown is not requested, the current control routine is terminated.

  On the other hand, if it is determined that the kick-down is requested, the process proceeds to step S22, and the vehicle control device 50 acquires a gear position (hereinafter, referred to as a target gear position) that should be changed after the kick-down is completed. . The target shift speed may be acquired based on the change amount of the accelerator opening and the shift diagram. In the next step S23, the vehicle control device 50 determines whether or not the sub-side gear stage (hereinafter also referred to as a pre-shift gear stage) switched in the pre-shift control routine matches the target gear stage.

  When it is determined that the pre-shift gear position and the target gear position match, the process proceeds to step S24, and the vehicle control device 50 executes normal kick-down control. In this normal kickdown control, the first clutch 15 and the second clutch 16 are controlled so that the input shaft connected to the engine 2 so as to be able to transmit power is switched. As a result, the main-side input shaft and the sub-side input shaft are interchanged. More specifically, when the first clutch 15 has been engaged and the second clutch 16 has been released, the first clutch 15 is switched to the released state by the normal kick-down control. The second clutch 16 is switched to the engaged state. Thereafter, the current control routine is terminated.

  On the other hand, if it is determined that the pre-shift gear stage is different from the target gear position, the process proceeds to step S25, and the vehicle control device 50 determines whether or not the target gear position is the gear position of the main-side input shaft. More specifically, for example, when the current shift speed is the fifth speed, the target shift speed is determined to be the shift speed of the main-side input shaft when the target shift speed is the third speed or the first speed. When it is determined that the target shift speed is the shift speed of the input shaft on the main side, the process proceeds to step S26, and the vehicle control device 50 executes shift preparation control by the sub-side MG. In this gear shift preparation control, the sub-side MG is caused to function as an electric motor. Then, the main clutch is switched to the disengaged state while assisting the driving of the driving wheels 6 with the sub MG so that the vehicle speed does not fluctuate. The driving of the driving wheel 6 by the sub-MG corresponds to the assist driving of the present invention. When the main clutch is released and the engine 2 is disconnected from the output system 12, the drive wheels 6 are driven by the sub MG. Specifically, for example, when the current shift speed is 5th, the first clutch 15 is switched to the disengaged state while assisting the drive of the drive wheels 6 by the second MG 4. When the engine 2 is disconnected from the output system 12, the drive wheels 6 are driven only by the second MG 4.

  In the next step S27, the vehicle control device 50 executes shift speed switching control. In this shift speed change control, each sleeve on the main side is controlled so that the shift speed of the input shaft on the main side becomes the target shift speed. In subsequent step S28, the vehicle control device 50 executes engine speed adjustment control. In this control, the rotational speed of the engine 2 is adjusted so that the rotational speed of the input shaft on the main side after being shifted to the target gear stage is substantially the same as the rotational speed of the engine 2.

  In the next step S29, the vehicle control device 50 executes main-side clutch engagement control. In this control, the main clutch is switched to the engaged state. At this time, the assist of the drive wheels 6 performed by the sub-MG is terminated. Thereafter, the current control routine is terminated.

  On the other hand, when it is determined in step S25 that the target shift speed is the shift speed of the sub-side input shaft, the process proceeds to step S30 in FIG. 6, and the vehicle control device 50 executes shift preparation control by the main MG. In this shift preparation control, the main MG is caused to function as an electric motor. Then, the main side clutch is switched to the disengaged state while assisting driving of the drive wheels 6 by the main side MG so that the vehicle speed does not fluctuate. The driving of the driving wheels 6 by the main side MG also corresponds to the assist driving of the present invention. When the main-side clutch is released and the engine 2 is disconnected from the output system 12, the drive wheels 6 are driven by the main-side MG. More specifically, for example, when the current shift speed is the fifth speed, the first clutch 15 is switched to the disengaged state while assisting the drive of the drive wheels 6 by the first MG 3. When the engine 2 is disconnected from the output system 12, the drive wheels 6 are driven only by the first MG 3.

  In the next step S31, the vehicle control device 50 executes shift speed switching control. In the shift speed switching control, each sub-side sleeve is controlled so that the shift speed of the input shaft on the sub-side becomes the target shift speed. In subsequent step S32, the vehicle control device 50 executes engine speed adjustment control. In this control, the rotational speed of the engine 2 is adjusted so that the rotational speed of the input shaft on the sub-side after being shifted to the target gear stage is substantially the same as the rotational speed of the engine 2.

  In the next step S33, the vehicle control device 50 executes sub-side clutch engagement control. In this control, the sub clutch is switched to the engaged state. At this time, the assist of the drive wheels 6 performed by the MG on the main side is terminated. Thereafter, the current control routine is terminated.

  As described above, according to the present invention, the driving force expected to be required for the vehicle 1 when the vehicle is traveling in the engine traveling mode and the transmission 10 is shifted to the fourth speed or higher. In accordance with the estimated required driving force, the shift stage of the sub-side input shaft is switched to a one-speed low-speed shift stage or a three-speed low-speed shift stage. Therefore, when the accelerator pedal is greatly depressed, the kickdown can be executed only by switching the states of the first clutch 15 and the second clutch 16. Further, since the shift stage of the sub-side input shaft to be switched is changed according to the estimated required driving force, it is possible to suppress the occurrence of a response delay even when switching to the three-stage low-speed shift stage by kickdown. Accordingly, it is possible to improve the responsiveness of the shift at the time of kick down.

  When the estimated required driving force is equal to or less than the first determination value, the shift stage of the sub-side input shaft is set to the neutral state, so that the sub-side input shaft can be disconnected from the engine 2 and the output system 12. In this case, since the MG connected to the sub-side input shaft can be prevented from being rotated, the power of the engine 2 can be prevented from being wasted. In addition, by preventing the MG from being rotated in this way, it is possible to prevent the occurrence of power loss and prevent wasteful consumption of battery power. Therefore, the fuel consumption of the engine 2 can be improved.

  Furthermore, in the present invention, even if the target gear position for kickdown is different from the preshift gear position, the drive wheels 6 are driven by the MG on the main side or the MG on the sub side, and the transmission 10 is set to the target gear position during that time. Shift. Therefore, the transmission 10 can be shifted to an appropriate shift stage while suppressing fluctuations in the vehicle speed.

  In the embodiment described above, the second determination value corresponds to the gear position determination value of the present invention, and the first determination value corresponds to the neutral determination value of the present invention. Further, by executing step S12 in FIG. 4, the vehicle control device 50 functions as the required driving force estimation means of the present invention, and by executing steps S17 to S17 in FIG. 4, the vehicle control device 50 performs the preshift of the present invention. It functions as a control means. And the vehicle control apparatus 50 functions as a transmission means of this invention by performing the control routine of FIG.5 and FIG.6.

  The present invention is not limited to the above-described form and can be implemented in various forms. For example, in the above-described embodiment, the input shaft and the motor / generator are connected via a gear so that power can be transmitted, but the output shaft of the motor / generator may be directly connected to the input shaft. The hybrid vehicle to which the present invention is applied is not limited to a hybrid vehicle equipped with a forward five-speed transmission. The present invention may be applied to various hybrid vehicles equipped with a transmission having a shift speed of four or more forward speeds.

DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 2 Internal combustion engine 3 1st motor generator (1st electric motor)
4 Second motor / generator (second motor)
6 drive wheel 10 transmission 11 input system 12 output system 13 first input shaft 14 second input shaft 15 first clutch 16 second clutch 36 first sleeve (first transmission mechanism)
37 Second sleeve (second transmission mechanism)
38 Third sleeve (first speed change mechanism)
39 Fourth sleeve (second transmission mechanism)
40 Fifth sleeve (first transmission mechanism)
41 Reverse sleeve (second speed change mechanism)
50 Vehicle control device (required driving force estimation means, pre-shift control means, transmission means)
G1-G5, GR Gear train

Claims (2)

An internal combustion engine;
An input system including a first input shaft connected to the internal combustion engine via a first clutch and a second input shaft connected to the internal combustion engine via a second clutch, and a drive wheel connected to be able to transmit power. A plurality of output systems, a part of which is interposed between the first input shaft and the output system, and the rest is interposed between the second input shaft and the output system, and the gear ratios are different from each other. Power transmission between the first input shaft and the output system by any one of the gear trains and a gear train interposed between the first input shaft and the output system. A first speed change mechanism capable of switching a gear ratio between them and switching to a neutral state that cuts off power transmission between the first input shaft and the output system, and the second input. Of the gear train interposed between the shaft and the output system A gear ratio between the second input shaft and the output system can be switched by selectively establishing power transmission between the second input shaft and the output system by one gear train, and the second input shaft and the output system. A second speed change mechanism capable of switching to a neutral state that interrupts power transmission between the input system and the output system, and switching a gear train used for power transmission between the input system and the output system. And a gear train corresponding to an odd number of the plurality of gears is interposed between the first input shaft and the output system, and a gear train corresponding to an even number is the second gear. A dual clutch type transmission interposed between the input shaft and the output system;
A first electric motor connected to the first input shaft to transmit power;
A second electric motor connected to the second input shaft so as to be capable of transmitting power,
The transmission has a gear stage corresponding to each of the gear stages, and has a gear stage of four or more speeds as the plurality of gear stages.
When traveling with the internal combustion engine, one of the first input shaft and the second input shaft is connected to the internal combustion engine so that power can be transmitted, and the other input shaft and the internal combustion engine are connected. A transmission control device applied to a hybrid vehicle in which the first clutch and the second clutch are controlled such that power transmission between the first clutch and the second clutch is controlled;
The magnitude of the driving force expected to be required for the vehicle when the transmission is shifted to a gear stage of 4th speed or more and the vehicle is running on the internal combustion engine. A required driving force estimating means for estimating;
When the estimated required driving force, which is the driving force estimated by the required driving force estimating means, is greater than a predetermined shift speed determination value set in advance, the internal combustion engine and the output when the estimated required driving force is estimated The first transmission is established so that power transmission between the other input shaft and the output system is established by a gear train that is three speeds lower than the gear ratio of the gear train that is used for power transmission to the system. When one of the transmission mechanism and the second transmission mechanism that controls power transmission between the other input shaft and the output system is controlled, and the estimated required driving force is less than or equal to the shift stage determination value Includes the other input by a gear train that is one speed lower than the gear ratio of the gear train that is used for power transmission between the internal combustion engine and the output system when the estimated required driving force is estimated. Power transmission between the shaft and the output system A pre-shift control means for controlling the one of the speed change mechanism so that,
When the vehicle is driven by the internal combustion engine and power transmission between the other input shaft and the output system is established by the one-stage low-speed gear train or the three-stage low-speed gear train. In addition, a gear that is used for power transmission between the other input shaft and the output system that satisfies a predetermined speed change condition for switching the transmission from the current speed to another target speed. When the shift speed corresponding to the row and the target shift speed are different, an assist drive for driving the drive wheels with the first electric motor or the second electric motor is performed so that the speed of the vehicle does not fluctuate. A speed change control device comprising: a speed change means for controlling the first speed change mechanism or the second speed change mechanism so that the speed change stage of the transmission becomes the target speed change stage during execution of the assist drive.   The pre-shift control unit controls the one transmission mechanism to the neutral state when the estimated required driving force is equal to or less than a neutral determination value set to a value smaller than the shift speed determination value. The shift control device described in 1.

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