JP2019152300A - Control device of automatic transmission - Google Patents

Abstract

A control device for an automatic transmission that can reduce a driver's discomfort in a linear upshift after switching a power transmission path. A first power transmission path for transmitting engine power to wheels via a continuously variable transmission and a second power transmission path for transmitting engine power to wheels via a gear device are provided in parallel, A control device for an automatic transmission in which a first power transmission path and a second power transmission path are used alternatively. The switching control to one power transmission path is performed, and the predetermined rotation speed during the linear shift control is the rotation speed for determining a linear upshift when the first power transmission path is selected. [Selection] Figure 3

Description

  The present invention relates to a control device for an automatic transmission.

  Patent Document 1 discloses a control device for an automatic transmission. When switching from gear travel to belt travel is performed, when the vehicle travel acceleration is large, a longer shift time is selected, whereby the input shaft rotation speed is controlled. It is disclosed that the difference can be reduced and the torque fluctuation of the output shaft is small, that is, switching with a small shift shock is possible.

JP 2017-187080 A

  However, in the automatic transmission as described above, when executing a linear upshift in which the engine speed is increased together with the vehicle speed and an upshift is performed in order to suppress a feeling of stagnation near the upper limit speed, If the upshift point in the belt running is different from the upshift point in the subsequent belt running, the driver feels uncomfortable.

  The present invention has been made in view of the above problems, and an object thereof is to provide a control device for an automatic transmission that can reduce a driver's uncomfortable feeling in a linear upshift after switching a power transmission path. It is to be.

  In order to solve the above-described problems and achieve the object, a control device for an automatic transmission according to the present invention includes a first power transmission path for transmitting engine power to wheels via a continuously variable transmission, and the engine. Of the automatic transmission in which the first power transmission path and the second power transmission path are alternatively used, and a second power transmission path for transmitting the power of the motor to the wheels via the gear device in parallel. The apparatus performs switching control from the second power transmission path to the first power transmission path on condition that the input rotational speed is a predetermined rotational speed, and the predetermined rotational speed during the linear shift control is The linear upshift determination rotational speed at the time of selecting the first power transmission path is used.

  Further, in the above, when an accelerator change occurs during the switching control from the second power transmission path to the first power transmission path, the initial target input rotational speed after switching to the first power transmission path is determined by the accelerator. It is characterized by correcting the amount corresponding to the change.

  According to this, it is possible to suppress an early occurrence of a linear upshift after switching to the first power transmission path due to an accelerator change during the switching control from the second power transmission path to the first power transmission path. .

  The control apparatus for an automatic transmission according to the present invention aligns the input rotational speed at the switching point from the second power transmission path to the first power transmission path and the input rotational speed at the subsequent linear upshift point. Thus, it is possible to ensure the continuity of the linear shift control and to reduce the driver's uncomfortable feeling during the linear upshift after switching the power transmission path.

FIG. 1 is a skeleton diagram showing a schematic configuration of a drive device provided in a vehicle according to an embodiment. FIG. 2 is a diagram for explaining the main functions of the control function and the control system for various controls in the vehicle. FIG. 3 is a graph showing an example of the relationship between the input shaft rotational speed and the output shaft rotational speed in the linear shift control. FIG. 4 is a graph showing a comparative example of the relationship between the input shaft rotation speed and the output shaft rotation speed in the linear shift control. FIG. 5 is a graph showing an example of the relationship between the input shaft rotational speed and the output shaft rotational speed when a change in the accelerator opening occurs during switching control from the gear travel mode to the belt travel mode. FIG. 6 is a flowchart illustrating an example of control performed by the electronic control device according to the embodiment.

  Hereinafter, an embodiment of a control device for an automatic transmission according to the present invention will be described. In addition, this invention is not limited by this embodiment.

  FIG. 1 is a skeleton diagram illustrating a schematic configuration of a vehicle 10 including an automatic transmission 12 according to the embodiment. The vehicle 10 according to the embodiment includes an engine 14, an automatic transmission 12, a differential device 64, a pair of wheels 66, and the like.

  The engine 14 is constituted by an internal combustion engine such as a gasoline engine or a diesel engine. The automatic transmission 12 includes a torque converter 16 as a fluid transmission device, a forward / reverse switching device 18, a belt-type continuously variable transmission 20, a gear mechanism 22, and an output gear 24 capable of transmitting power to wheels 66. The output shaft 25 is formed. In the automatic transmission 12, torque (driving force) output from the engine 14 is input to the input shaft 26 via the torque converter 16, and torque input to the input shaft 26 passes through the continuously variable transmission 20. In parallel, a first power transmission path that is transmitted to the output shaft 25 and a second power transmission path that transmits torque from the input shaft 26 to the output shaft 25 via the gear mechanism 22 and the like are provided. The power transmission path is configured to be switched according to the traveling state of the vehicle 10.

  In addition, the power from the engine 14 output via the output shaft 25 (the torque and the force are synonymous unless otherwise distinguished) is provided in the output shaft 25 and the counter shaft 44 so as not to be relatively rotatable and meshes with the drive gear 45. And the driven gear 46, the differential gear 64 of the differential device 64 that meshes with the driven gear 46, and the pair of axles 60.

  The torque converter 16 includes a pump impeller 16p connected to the crankshaft of the engine 14 and a turbine impeller 16t connected to the forward / reverse switching device 18 via an input shaft 26 corresponding to an output side member of the torque converter 16. And power transmission is performed via a fluid. Further, a lockup clutch 28 is provided between the pump impeller 16p and the turbine impeller 16t. When the lockup clutch 28 is completely engaged, the pump impeller 16p and the turbine impeller 16t rotate integrally. Be made.

  The forward / reverse switching device 18 is mainly composed of a forward clutch C1 and a reverse brake B1 that are first clutches, and a double pinion type planetary gear device 30, and a carrier 30c is connected to an input shaft 26 of the torque converter 16 and The ring gear 30r is selectively connected to the housing 34 as a non-rotating member via the reverse brake B1 and the sun gear 30s is connected to the small-diameter gear 36. Has been. Further, the sun gear 30s and the carrier 30c are selectively coupled via the forward clutch C1. The forward clutch C1 and the reverse brake B1 correspond to a connection / disconnection device, both of which are hydraulic friction engagement devices that are frictionally engaged by a hydraulic actuator.

  Further, the sun gear 30 s of the planetary gear device 30 is connected to a small diameter gear 36 that constitutes the gear mechanism 22. The gear mechanism 22 includes the small-diameter gear 36 and a large-diameter gear 40 that is provided on the counter shaft 38 so as not to be relatively rotatable. An idler gear 42 is provided around the same rotational axis as the counter shaft 38 so as to be rotatable relative to the counter shaft 38. A meshing clutch D1 is provided between the counter shaft 38 and the idler gear 42 to selectively connect and disconnect them. The meshing clutch D1 can be fitted (engageable) with the first gear 48 formed on the counter shaft 38, the second gear 50 formed on the idler gear 42, and the first gear 48 and the second gear 50. And a hub sleeve (not shown) on which spline teeth (not shown) are formed, and the hub sleeve is engaged with the first gear 48 and the second gear 50. The counter shaft 38 and the idler gear 42 are connected. The meshing clutch D1 further includes a synchronization mechanism S1 as a synchronization mechanism that synchronizes the rotation when the first gear 48 and the second gear 50 are fitted.

  The idler gear 42 meshes with an input gear 52 having a larger diameter than the idler gear 42. The input gear 52 is provided so as not to rotate relative to the output shaft 25 disposed on a rotation axis common to a rotation axis of an output-side pulley 56 described later of the continuously variable transmission 20. The output shaft 25 is disposed so as to be rotatable around the rotation axis, and the input gear 52 and the output gear 24 are provided so as not to be relatively rotatable. Thus, the forward clutch C1, the reverse brake B1, and the meshing clutch D1 are placed on the second power transmission path through which the torque of the engine 14 is transmitted from the input shaft 26 to the output shaft 25 via the gear mechanism 22. Is inserted. Note that the meshing clutch D1 includes a synchronization mechanism S1, and the synchronization mechanism S1 operates when the meshing clutch D1 is engaged.

  Further, between the continuously variable transmission 20 and the output shaft 25, a belt traveling clutch C2, which is a second clutch that selectively connects and disconnects between the two, is interposed. By being engaged, a first power transmission path through which the torque of the engine 14 is transmitted to the output shaft 25 via the input shaft 26 and the continuously variable transmission 20 is formed. Further, when the belt traveling clutch C2 is released, the first power transmission path is interrupted, and torque is not transmitted from the continuously variable transmission 20 to the output shaft 25.

  The continuously variable transmission 20 is provided on a power transmission path between the input side rotating shaft 32 and the output shaft 25 connected to the input shaft 26, and the effective diameter provided on the input side rotating shaft 32 is variable. An input-side pulley 54 that is a pulley, an output-side pulley 56 that is a variable pulley having a variable effective diameter provided on an output-side rotating shaft 33 parallel to the input-side rotating shaft 32, and the input-side pulley 54 and the output-side pulley 56. A transmission belt 58 wound around the transmission belt 58 is provided, and power is transmitted through a frictional force between the input side pulley 54 and the output side pulley 56 and the transmission belt 58.

  The input-side pulley 54 includes a fixed sheave 54a fixed to the input-side rotating shaft 32, a movable sheave 54b provided so as not to rotate relative to the input-side rotating shaft 32 and to be movable in the axial direction, and And a primary hydraulic actuator 54c that generates a thrust for moving the movable sheave 54b to change the V-groove width therebetween. The output-side pulley 56 includes a fixed sheave 56a fixed to the output-side rotating shaft 33, and a movable sheave 56b provided so as not to rotate relative to the output-side rotating shaft 33 and to move in the axial direction. And an output-side hydraulic actuator 56c that generates thrust for moving the movable sheave 56b to change the width of the V-groove therebetween.

  By changing the V groove width of the input pulley 54 and the output pulley 56 and changing the engagement diameter of the transmission belt 58, that is, the effective diameter, the speed ratio γ is continuously changed. For example, when the V-groove width of the input pulley 54 is reduced, the speed ratio γ is reduced. That is, the continuously variable transmission 20 is upshifted. Further, when the V-groove width of the input pulley 54 is increased, the speed ratio γ is increased. That is, the continuously variable transmission 20 is downshifted.

  Hereinafter, the operation of the automatic transmission 12 configured as described above will be described using the engagement state of the engagement element in each traveling pattern.

  First, a description will be given of a belt traveling mode that is a traveling pattern in which the torque of the engine 14 is transmitted to the output gear 24 via the continuously variable transmission 20, that is, a traveling pattern in which the torque is transmitted through the first power transmission path. . In this belt travel mode, the belt travel clutch C2 is connected, while the forward clutch C1, the reverse brake B1, and the meshing clutch D1 are disconnected. Since the output side pulley 56 and the output shaft 25 are connected by connecting the belt traveling clutch C <b> 2, the output side pulley 56, the output shaft 25, and the output gear 24 are integrally rotated. Therefore, when the belt traveling clutch C2 is connected, a first power transmission path is formed, and the torque of the engine 14 is changed to the torque converter 16, the input shaft 26, the input side rotating shaft 32, the continuously variable transmission 20, and It is transmitted to the output gear 24 via the output shaft 25.

  Next, a description will be given of a gear traveling mode that is a traveling pattern in which the torque of the engine 14 is transmitted to the output gear 24 via the gear mechanism 22, that is, a traveling pattern in which the torque is transmitted through the second power transmission path. In this gear travel mode, the forward clutch C1 and the meshing clutch D1 are engaged, while the belt travel clutch C2 and the reverse brake B1 are released.

  Engaging the forward clutch C1 causes the planetary gear device 30 constituting the forward / reverse switching device 18 to rotate integrally, so that the small diameter gear 36 is rotated at the same rotational speed as the input shaft 26. The forward / reverse switching device 18 can be regarded as a stepped transmission capable of switching between forward and backward travel. Further, the small-diameter gear 36 is meshed with the large-diameter gear 40 provided on the counter shaft 38, so that the counter shaft 38 is similarly rotated. Further, when the meshing clutch D1 is engaged, the counter shaft 38 and the idler gear 42 are connected. When the idler gear 42 is meshed with the input gear 52, the counter gear 38 is provided integrally with the input gear 52. The output shaft 25 and the output gear 24 are rotated. Thus, when the forward clutch C1 and the meshing clutch D1 inserted in the second power transmission path are engaged, the torque of the engine 14 is changed to the torque converter 16, the input shaft 26, the forward / reverse switching device 18, It is transmitted to the output shaft 25 and the output gear 24 via the gear mechanism 22 and the idler gear 42.

  The gear travel mode is selected in the low vehicle speed region. The speed ratio γ based on the second power transmission path is set to a value larger than the maximum speed ratio γmax of the continuously variable transmission 20. That is, the speed ratio γ in the second power transmission path is set to a value that is not set in the continuously variable transmission 20. For example, when it is determined that the vehicle travel mode is changed from the gear travel mode to the belt travel mode due to an increase in the vehicle speed V, the belt travel mode is switched.

  When switching from the gear travel mode to the belt travel mode, the state is changed from the state where the forward clutch C1 and the meshing clutch D1 corresponding to the gear travel mode are engaged to the state where the belt travel clutch C2 and the meshing clutch D1 are engaged. It can be switched transiently. That is, the switching of the forward clutch C1 and the belt traveling clutch C2 is started. At this time, the power transmission path is changed from the second power transmission path to the first power transmission path, and the automatic transmission 12 is substantially upshifted. Then, after the power transmission path is switched, the meshing clutch D1 is released in order to prevent unnecessary drag and high rotation of the gear mechanism 22 and the like.

  When the belt travel mode is switched to the gear travel mode, the state is switched transiently from the state in which the belt travel clutch C2 is engaged to the state in which the meshing clutch D1 is engaged in preparation for switching to the gear travel mode. At this time, the rotation is also transmitted to the sun gear 30s of the planetary gear device 30 via the gear mechanism 22, and from this state, the forward clutch C1 and the belt travel clutch C2 are switched, that is, the forward clutch C1 is engaged. And the disconnection of the belt traveling clutch C2 is executed, whereby the power transmission path is switched from the first power transmission path to the second power transmission path. At this time, the automatic transmission 12 is substantially downshifted.

  FIG. 2 is a diagram for explaining the main functions of the control function and the control system for various controls in the vehicle 10. In FIG. 2, the vehicle 10 includes an electronic control device 80 including a control device for the automatic transmission 12, for example. The electronic control unit 80 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like, and the CPU uses a temporary storage function of the RAM according to a program stored in the ROM in advance. Various controls of the vehicle 10 are executed by performing signal processing. For example, the electronic control unit 80 executes output control of the engine 14, shift control of the continuously variable transmission 20, control for switching the traveling mode of the automatic transmission 12, and the like.

  The electronic control unit 80 includes values based on detection signals from various sensors provided in the vehicle 10, such as various rotational speed sensors 82, 84, 86, 88, 90, an accelerator opening sensor 92, and the like, such as engine rotational speed Ne, turbine rotational speed. The input shaft rotational speed Nin which is the number Nt, the primary pulley rotational speed Npri, the secondary pulley rotational speed Nsec which is the rotational speed of the output side rotational shaft 33, the output shaft rotational speed Nout corresponding to the vehicle speed V, the accelerator opening Acc, etc. Are supplied respectively. Further, the electronic control unit 80 receives an engine output control command signal Se for output control of the engine 14, a hydraulic control command signal Scvt for hydraulic control related to the shift of the continuously variable transmission 20, and a travel mode of the automatic transmission 12. The hydraulic control command signal Sswt for controlling the forward clutch C1, the reverse brake B1, the belt traveling clutch C2, and the meshing clutch D1 related to the switching of the torque, and the hydraulic control command signal for controlling the hydraulic pressure of the torque converter 16 Slu and the like are respectively output. For example, as the hydraulic control command signal Sswt, each solenoid valve that regulates each hydraulic pressure supplied to each hydraulic actuator of the forward clutch C1, the reverse brake B1, the belt traveling clutch C2, and the meshing clutch D1 is driven. Command signal (hydraulic command) is output to the hydraulic control circuit 100. Further, the electronic control unit 80 sequentially calculates the speed ratio γ (= Nin / Nout) of the continuously variable transmission 20 based on, for example, the output shaft speed Nout and the input shaft speed Nin.

  Here, in the vehicle 10 according to the embodiment, on the condition that the input shaft rotational speed Nin is a predetermined rotational speed, switching control from the second power transmission path to the first power transmission path, that is, from the gear traveling mode, is performed. Switch control to the belt running mode is executed. The predetermined rotational speed during the linear shift control is the linear upshift determination rotational speed when the first power transmission path (belt travel mode) is selected.

  Specifically, as shown in FIG. 3, the input shaft speed Nin at the switching point from the gear travel mode to the belt travel mode, in other words, the switching determination speed from the gear travel mode to the belt travel mode, The input shaft rotational speed Nin at the linear upshift point after switching from the mode to the belt travel mode, in other words, the same as the linear upshift determination rotational speed in the belt travel mode.

  When the vehicle 10 is accelerated in the gear travel mode and the input shaft rotational speed Nin reaches the linear upshift determination rotational speed (point A in FIG. 3), the gear travel mode is switched to the belt travel mode. Note that the initial linear target rotational speed (input shaft rotational speed Nin at point C in FIG. 3) at the time of transition to the belt running mode is lower than the linear upshift determination rotational speed, and is the maximum speed ratio γmax of the continuously variable transmission 20. This is the linear target rotational speed calculated from the upper input shaft rotational speed Nin. When the vehicle 10 is accelerated in the belt travel mode and the input shaft rotational speed Nin reaches the linear upshift determination rotational speed (point B in FIG. 3), V of the input side pulley 54 of the continuously variable transmission 20 is reached. The groove width is narrowed by a predetermined amount, and the continuously variable transmission 20 is upshifted. The initial linear target rotational speed (input shaft rotational speed Nin at point D in FIG. 3) after the upshift of the continuously variable transmission 20 is the linear target rotational speed.

  In the vehicle 10 according to the embodiment, as described above, by aligning the switching determination rotational speed from the gear traveling mode to the belt traveling mode during the linear shift control with the linear upshift determining rotational speed in the belt traveling mode, The continuity of the linear shift control can be ensured, and the driver's uncomfortable feeling can be reduced as compared with the case where switching from the gear travel mode to the belt travel mode is performed using the basic shift line as shown in FIG. Further, the driving force can be ensured by using the gear running mode up to high rotation.

  It should be noted that if a change in the accelerator opening Acc occurs during switching control from the second power transmission path to the first power transmission path, that is, during switching control from the gear travel mode to the belt travel mode, the first You may make it correct | amend the initial target rotational speed after switching to a power transmission path | route (belt drive mode) by the part corresponding to the change of accelerator opening Acc.

  For example, as shown in FIG. 5, the accelerator opening Acc at the start of switching control from the gear travel mode to the belt travel mode (point a in FIG. 5) and the transition to the belt travel mode (point b in FIG. 5). The target input shaft rotational speed at the start of the switching control (point a ′ in FIG. 5) is corrected by an amount corresponding to the change in the accelerator opening Acc from the accelerator opening Acc of FIG. The target input shaft speed at the point b ′) in FIG. Then, the initial linear target rotational speed at the time of transition from the gear traveling mode to the belt traveling mode (point C in FIG. 5) is corrected by the amount of change G of the target input shaft rotational speed, and after correction (point C ′ in FIG. 5). ) Is calculated.

  Thereby, it is possible to suppress the occurrence of an early linear upshift after switching to the belt travel mode due to a change in the accelerator opening Acc during the switch from the gear travel mode to the belt travel mode.

  FIG. 6 is a flowchart illustrating an example of control performed by the electronic control device 80 according to the embodiment.

  First, the electronic control unit 80 determines whether it is linear shift control (step S1). If it is linear shift control (Yes in step S1), the electronic control unit 80 determines whether the system state is the belt running mode (step S2). When the system state is the belt running mode (Yes in Step S2), the linear target rotational speed is set (Step S3), and the target input shaft rotational speed is set (Step S6). On the other hand, when the system state is not the belt running mode (No in Step S2), the electronic control unit 80 sets the linear upshift determination rotational speed (Step S4) and sets the target input shaft rotational speed (Step S6). . If it is not linear shift control at step S1 (No at step S1), the electronic control unit 80 sets a basic shift line (step S5) and sets a target input shaft speed (step S6).

  Next, the electronic control unit 80 determines whether the system state is the gear travel mode (step S7). When the system state is the gear travel mode (Yes in Step S7), the electronic control unit 80 calculates the switching determination rotational speed from the gear travel mode to the belt travel mode (Step S8). Then, the electronic control unit 80 determines whether the relationship of “target input shaft rotational speed <switching determination rotational speed from the gear travel mode to the belt travel mode” is satisfied (step S9). When the relationship of “target input shaft rotational speed <rotational speed for determining switching from gear travel mode to belt travel mode” is satisfied (Yes in step S9), the electronic control unit 80 becomes “system state = belt travel mode”. In addition, the gear travel mode is switched to the belt travel mode (step S10), and the series of controls is terminated. On the other hand, when the relationship of “target input shaft rotational speed <rotational speed for switching from gear travel mode to belt travel mode” is not satisfied (No in step S9), the electronic control unit 80 ends the series of controls as it is.

  In step S7, when the system state is not the gear travel mode (No in step S7), the electronic control unit 80 calculates the switching determination rotational speed from the belt travel mode to the gear travel mode (step S11). Then, the electronic control unit 80 determines whether the relationship “target input shaft rotational speed ≧ switching rotational speed from the belt travel mode to the gear travel mode” is satisfied (step S12). When the relationship “target input shaft rotational speed ≧ switching rotational speed from belt travel mode to gear travel mode” is satisfied (Yes in step S12), the electronic control unit 80 is set to “system state = gear travel mode”. Then, the belt travel mode is switched to the gear travel mode (step S13), and the series of controls is terminated. On the other hand, if the relationship “target input shaft rotational speed ≧ switching rotational speed from belt travel mode to gear travel mode” is not satisfied (No in step S12), the electronic control unit 80 ends the series of controls as it is.

DESCRIPTION OF SYMBOLS 10 Vehicle 12 Automatic transmission 14 Engine 18 Forward / reverse switching device 20 Continuously variable transmission 66 Wheel 80 Electronic control unit

Claims (2)

A first power transmission path for transmitting engine power to the wheels via a continuously variable transmission and a second power transmission path for transmitting engine power to the wheels via a gear device are provided in parallel.
A control device for an automatic transmission in which the first power transmission path and the second power transmission path are alternatively used,
Switch control from the second power transmission path to the first power transmission path is performed on the condition that the input rotational speed is a predetermined rotational speed,
The control apparatus for an automatic transmission, wherein the predetermined rotation speed during linear shift control is a linear upshift determination rotation speed when the first power transmission path is selected.   When an accelerator change occurs during the switching control from the second power transmission path to the first power transmission path, the initial target rotational speed after switching to the first power transmission path is corrected by an amount corresponding to the accelerator change. The control device for an automatic transmission according to claim 1.

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