JP2015232380A - Vehicle drive controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller of a vehicle drive that includes a continuously variable transmission mechanism and a power transmission mechanism in parallel, capable of generating a demanded driving force necessary for subsequent re-acceleration or re-starting even in a case of sudden deceleration or sudden stop.SOLUTION: If a demanded driving force F is lower than a predetermined driving force F1, a downshift control to downshift a continuously variable transmission mechanism 20 or an output torque increase control to increase an output torque from an engine 14 is executed in response to a variation of an accelerator opening Acc. If the demanded driving force F is higher than the predetermined driving force F1, a downshift control to achieve downshift to gear running or the output torque increase control to increase the output torque from the engine 14 is executed. In this way, it is possible to realize the driving force F demanded by a driver by an appropriate control by switching to an optimum control in re-acceleration after sudden deceleration.

Description

  The present invention relates to a control device for a vehicle drive device, and more particularly to control of a vehicle drive device having a transmission that includes a continuously variable transmission mechanism and a transmission mechanism in parallel.

  2. Description of the Related Art A vehicle drive device has been proposed that includes a transmission that has a continuously variable transmission mechanism capable of continuously variable transmission and a transmission mechanism that includes a gear train in parallel. For example, this is the vehicle power transmission device described in Patent Document 1. In Patent Document 1, a torque transmission path by a continuously variable transmission mechanism that continuously changes the transmission ratio and a torque transmission path by a gear train having at least one transmission ratio that cannot be set by the continuously variable transmission mechanism are provided in parallel. A drive device is disclosed. More specifically, a first clutch mechanism that connects at least two rotation elements, that is, an input element, an output element, and a reaction force element, of a forward / reverse switching mechanism composed of three rotation elements capable of differential action, a gear train, and an output A torque transmission path via the gear train is formed by connecting the third clutch mechanism that connects and disconnects the shaft. Further, a torque transmission path via the continuously variable transmission mechanism is formed by connecting a second clutch mechanism that connects and disconnects the secondary shaft of the continuously variable transmission mechanism and the output shaft.

International Publication No. 2013/176208

  In the drive device of Patent Document 1 described above, for example, the gear ratio of the gear train can be set to a gear ratio larger than the maximum gear ratio of the continuously variable transmission mechanism. Here, for example, when the vehicle starts, a large driving force can be generated as the vehicle by connecting the first clutch mechanism and the third clutch mechanism to form a torque transmission path via the gear train. However, if the vehicle is suddenly decelerated or stopped during traveling via the continuously variable transmission mechanism, if the continuously variable transmission mechanism is of the belt type, a belt return failure may occur or torque may be generated via the continuously variable transmission mechanism. Switching control (coast downshift) for switching from continuously variable speed transmission that is transmitted to gear transmission that transmits torque via a gear train occurs, and insufficient driving force occurs during subsequent reacceleration or restart. There was a possibility. Note that the belt return failure that occurs when the continuously variable transmission mechanism is of a belt type is due to insufficient flow of hydraulic oil to the hydraulic actuator that adjusts the groove width of the pulley around which the belt is wound. In addition, the failure of the switching control (coast downshift) for switching from continuously variable speed travel where torque is transmitted via a continuously variable transmission mechanism to gear travel where torque is transmitted via a gear train is This is due to insufficient accuracy of the rotational speed sensor during control execution due to the reduction in vehicle speed.

  The present invention has been made in the background of the above circumstances, and an object of the present invention is to rapidly reduce the speed of a vehicular drive apparatus including a continuously variable transmission mechanism and a transmission mechanism including a gear train in parallel. Another object of the present invention is to provide a control device capable of generating a required driving force required for subsequent reacceleration or re-start even when suddenly stopped.

  In order to achieve the above object, the gist of the first invention is that (a) a continuously variable transmission mechanism and a transmission mechanism constituting at least one gear ratio are provided in parallel, and the gear ratio of the transmission mechanism is: A vehicle drive device that is set to a value larger than the maximum speed ratio of the continuously variable transmission mechanism, a gear running that transmits power to the output shaft via the transmission mechanism, and the continuously variable transmission mechanism; In the control device for a vehicle drive device that selectively switches between continuously variable speed transmission that transmits power to the output shaft, (b) when the vehicle decelerates during traveling in the continuously variable speed travel, the gear If the driver's required driving force at the time of reacceleration is smaller than a predetermined reference value when the switching to traveling is not completed, the continuously variable transmission mechanism according to the amount of change in the accelerator opening Downshift control or drive power source output When any of the torque increase control is selected and the required driving force is output, and (c) when the vehicle decelerates during the continuously variable speed travel, the switching to the gear travel is not completed. When the predicted driving force required by the driver at the time of reacceleration is greater than a predetermined reference value, depending on the amount of change in the accelerator opening and the vehicle speed, the switching control to the gear running, or the One of the output torque increase controls of the driving force source is selected and the requested driving force is output.

  In this way, when re-acceleration after deceleration, if the downshift to gear driving is not completed, there is a possibility that the driving force will be insufficient with respect to the required driving force requested by the driver at the time of subsequent re-acceleration There is. On the other hand, when the required driving force is smaller than the predetermined reference value, the downshift of the continuously variable transmission mechanism or the output torque increase control of the driving force source is executed according to the amount of change in the accelerator opening. By doing so, the required driving force can be realized by appropriate control. Further, when the required driving force is larger than a predetermined reference value, switching control to gear driving or output torque increase control of the driving force source is executed according to the change amount of the accelerator opening and the vehicle speed. Thus, the required driving force can be realized. In this way, in the reacceleration after the rapid deceleration, the driver's required driving force can be realized by appropriate control by switching to the optimal control.

  Preferably, in the control device for a vehicle drive device according to the first aspect of the present invention, the required drive force is smaller than a predetermined reference value, and the change amount of the accelerator opening is preset. If it is less than or equal to the threshold value, the continuously variable transmission mechanism is downshifted. Further, when the required driving force is smaller than a predetermined reference value and the change amount of the accelerator opening is larger than the threshold value, the output torque increase control of the driving force source is executed. Thus, when the change amount of the accelerator opening is smaller than the threshold value, the required driving force can be realized as the gear ratio increases by executing the downshift of the continuously variable transmission mechanism. When the change amount of the accelerator opening is larger than the threshold value, the required driving force can be ensured by executing the output torque increase control of the driving force source.

  Preferably, in the control device for a vehicle drive device according to the first invention, when the required driving force is larger than a predetermined reference value and the change amount of the accelerator opening is equal to or less than a threshold value. When the controllability of the switching control to the gear running is ensured, the output torque increase control of the driving force source is executed, and when the vehicle speed exceeds a predetermined value and the controllability of the switching control is secured, the gear running The switching control to is executed. Further, when the required driving force is larger than a predetermined reference value and the change amount of the accelerator opening is larger than the threshold value, the switching control to the gear traveling is immediately executed. In this way, when the change amount of the accelerator opening is equal to or smaller than the threshold value, the output torque increase control of the driving force source is executed until the controllability of the switching control to the gear traveling is ensured. When the driving force is increased and the control speed of the switching control is secured when the vehicle speed exceeds a predetermined value, the switching control to the gear traveling is executed, so that the required driving force can be secured. Further, when the change amount of the accelerator opening is larger than the threshold value, the required driving force can be secured immediately although the controllability is reduced by executing the switching control to the gear running.

  Preferably, in the control device for a vehicle drive device according to the first invention, between the input shaft to which the output torque of the driving force source is transmitted and the output shaft connected to the drive wheel so as to be able to transmit power, The continuously variable transmission mechanism and the transmission mechanism are provided in parallel, and are inserted on a first power transmission path for transmitting the power transmitted to the input shaft to the output shaft via the transmission mechanism. A first clutch mechanism that selectively connects and disconnects the first power transmission path, and a second power transmission path that transmits the power transmitted to the input shaft to the output shaft via the continuously variable transmission mechanism. And a second clutch mechanism that selectively connects and disconnects the second power transmission path, and the switching control from the continuously variable speed traveling to the gear traveling releases the second clutch mechanism. And a downshift for engaging the first clutch mechanism It is a control (stepped shift control).

  Preferably, in the control device for a vehicle drive device of the first invention, the predetermined reference value corresponds to a driving force output when the continuously variable transmission mechanism is shifted to a maximum gear ratio. . When the required driving force is smaller than the driving force output when the continuously variable transmission mechanism is shifted to the maximum gear ratio, the required driving force can be output without switching to gear traveling. On the other hand, when the required driving force is larger than the driving force output when the continuously variable transmission mechanism is shifted to the maximum gear ratio, it is necessary to switch to gear traveling. Therefore, by setting the predetermined reference value to the driving force that is output when the continuously variable transmission mechanism is shifted to the maximum gear ratio, it is possible to easily determine whether or not it is necessary to switch to gear traveling. .

1 is a skeleton diagram for explaining a schematic configuration of a vehicle drive device to which the present invention is applied, and a functional block for explaining an input / output system of an electronic control device for controlling the vehicle drive device and a main part of a control function. FIG. 2 is an engagement table of engagement elements for each travel pattern in the vehicle drive device of FIG. 1. It is a figure which shows the relationship between the driving force of the vehicle drive device of FIG. 1, driving | running | working resistance, and a vehicle speed. The main part of the control operation of the electronic control unit that controls the vehicle drive device of FIG. 1, that is, the control operation that can ensure the driver's required driving force in the vehicle sudden deceleration or re-acceleration or re-start after sudden stop will be described. It is a flowchart.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a skeleton diagram for explaining a schematic configuration of a vehicle drive device 12 (hereinafter referred to as drive device 12) to which the present invention is preferably applied, and an electronic control device 80 for controlling the drive device 12 is illustrated. FIG. 3 is a functional block diagram for explaining a main part of an output system and a control function by the electronic control unit 80. The driving device 12 includes, for example, an engine 14 that is a driving force source used as a driving force source for traveling, a torque converter 16 as a fluid transmission device, a forward / reverse switching device 18, and a belt type continuously variable transmission mechanism 20 ( Hereinafter, a transmission 23 including a continuously variable transmission mechanism 20) and a gear mechanism 22 (transmission mechanism), an output shaft 25 on which an output gear 24 capable of transmitting power to the drive wheels 70 is formed, and a differential gear 64 are provided. , Including. The transmission 23 includes a gear mechanism 22 and a continuously variable transmission mechanism 20 provided in parallel between a turbine shaft 26 that functions as an input shaft and an output shaft 25. In the drive device 12, power (driving force) output from the engine 14 is input to the turbine shaft 26 (input shaft) via the torque converter 16, and this power is transmitted to the gear mechanism 22 and the continuously variable transmission mechanism 20. Is transmitted to the output shaft 25 via any of the above. In the present embodiment, a power transmission path through which power output from the engine 14 is transmitted from the turbine shaft 26 to the output shaft 25 via the gear mechanism 22 is defined as a first power transmission path, and is output from the engine 14. A power transmission path through which the transmitted power is transmitted to the output shaft 25 via the continuously variable transmission mechanism 20 is defined as a second power transmission path.

  The engine 14 is constituted by an internal combustion engine such as a gasoline engine or a diesel engine. The torque converter 16 is connected to the forward / reverse switching device 18 and the continuously variable transmission mechanism 20 via a pump impeller 16p connected to the crankshaft of the engine 14 and a turbine shaft 26 corresponding to an output side member of the torque converter 16. The turbine impeller 16t and a stator impeller 16s connected to a housing 34, which is a non-rotating member, via a one-way clutch (not shown) are provided to transmit power 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 are integrated. Rotated.

  The forward / reverse switching device 18 includes a forward clutch C1 and a reverse brake B1 and a double pinion planetary gear device 30. A carrier 30c is a turbine shaft 26 of the torque converter 16 and a continuously variable transmission mechanism 20. 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. Further, the sun gear 30s and the carrier 30c are selectively connected via the forward clutch C1, and when the forward clutch C1 is connected, the rotating elements of the planetary gear unit 30 (sun gear 30s, carrier 30c, ring gear 30r). Rotate together. 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 first counter shaft 38 so as not to be relatively rotatable. An idler gear 42 is provided around the same rotational axis as the first counter shaft 38 so as to be rotatable relative to the first counter shaft 38. Further, a meshing clutch D1 is provided between the first counter shaft 38 and the idler gear 42 to selectively connect and disconnect them. The meshing clutch D1 can be engaged with the first gear 48 formed on the first counter shaft 38, the second gear 50 formed on the idler gear 42, and the first gear 48 and the second gear 50 (engagement). And a hub sleeve 61 on which spline teeth are formed, and the hub sleeve 61 is engaged with the first gear 48 and the second gear 50, whereby the first counter The shaft 38 and the idler gear 42 are connected. Further, the meshing clutch D1 further includes a synchromesh mechanism as a synchronization mechanism that synchronizes rotation when the first gear 48 and the second gear 50 are engaged.

  The idler gear 42 is meshed 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 the rotation axis common to the rotation axis of the secondary pulley described later of the continuously variable transmission mechanism 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. Further, on the first power transmission path through which the power of the engine 14 is transmitted from the turbine shaft 26 to the output shaft 25 via the gear mechanism 22, the forward clutch C1, the reverse brake B1, and the meshing clutch D1 are provided. It is inserted.

  The continuously variable transmission mechanism 20 is provided on a power transmission path between a primary shaft 32 connected to the turbine shaft 26 and the output shaft 25, and an effective diameter which is an input side member provided on the primary shaft 32 is variable. A primary pulley 54 (variable pulley 54), a secondary pulley 56 (variable pool 56) having a variable effective diameter which is an output side member, and a transmission belt 58 wound between the pair of variable pulleys 54, 56 Power transmission is performed via a frictional force between the pair of variable pulleys 54 and 56 and the transmission belt 58.

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

  By changing the V groove width of the pair of variable pulleys 54 and 56 and changing the engagement diameter (effective diameter) of the transmission belt 58, the actual transmission ratio (gear ratio) γ (= input shaft rotational speed Nin / output) The shaft rotation speed Nout) is continuously changed. For example, when the V groove width of the primary pulley 54 is reduced, the speed ratio γ is reduced. That is, the continuously variable transmission mechanism 20 is upshifted. Further, when the V groove width of the primary pulley 54 is increased, the speed ratio γ is increased. That is, the continuously variable transmission mechanism 20 is downshifted.

  Further, a belt traveling clutch C2 that selectively connects and disconnects between the secondary pulley 56 and the output shaft 25 of the continuously variable transmission mechanism 20 is inserted, and this belt traveling clutch C2 is engaged. As a result, a second power transmission path in which the power of the engine 14 is transmitted to the output shaft 25 via the turbine shaft 26 and the continuously variable transmission mechanism 20 is formed. When the belt traveling clutch C2 is released, the second power transmission path is interrupted.

  The output gear 24 is meshed with a large-diameter gear 62 that is fixed to the second counter shaft 60. The second counter shaft 60 is provided with a small-diameter gear 68 that meshes with the large-diameter gear 62 and the differential ring gear 66 of the differential gear 64. The differential gear 64 is composed of a differential mechanism, and transmits the driving force input from the differential ring gear 66 to the left and right drive wheels 70L and 70R while appropriately giving a rotational speed difference to the left and right drive wheels 70L and 70R. Since the differential gear 64 is a known technique, a detailed description thereof is omitted.

  Next, the operation of the drive device 12 configured as described above will be described using an engagement table of engagement elements for each traveling pattern shown in FIG. In FIG. 2, C1 corresponds to the operating state of the forward clutch C1, C2 corresponds to the operating state of the belt traveling clutch C2, B1 corresponds to the operating state of the reverse brake B1, and D1 corresponds to the meshing clutch D1. Corresponding to the operating state, “◯” indicates engagement (connection), and “×” indicates release (cutoff). Note that the meshing clutch D1 includes a synchronization mechanism, and the synchronization mechanism operates when the meshing clutch D1 is engaged. Further, the forward clutch C1 is inserted into the first power transmission path to be a first clutch mechanism that selectively connects and disconnects the first power transmission path, and the belt traveling clutch C2 is connected to the second power transmission path. The second clutch mechanism is inserted on the transmission path and selectively connects and disconnects the second power transmission path.

  First, a traveling pattern in which the driving force of the engine 14 is transmitted to the output shaft 25 via the gear mechanism 22, that is, a traveling pattern in which the driving force is transmitted via the first power transmission path will be described. This traveling pattern corresponds to the gear traveling in FIG. 2, and the forward clutch C1 and the meshing clutch D1 are engaged (connected), while the belt traveling clutch C2 and the reverse brake B1 are released (disconnected).

  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 turbine shaft 26. Further, when the meshing clutch D1 is engaged, the counter shaft 38 and the idler gear 42 are connected and rotated integrally. Therefore, when the forward clutch C1 and the meshing clutch D1 are engaged, a first power transmission path is formed, and the driving force of the engine 14 is the torque converter 16, the turbine shaft 26, the forward / reverse switching device 18, the gears. This is transmitted to the output shaft 25 and the output gear 24 via the mechanism 22, the idler gear 42, and the input gear 52. Further, the driving force transmitted to the output gear 24 is transmitted to the left and right drive wheels 70L, 70R via the large diameter gear 62, the small diameter gear 68, and the differential gear 64.

  Next, a traveling pattern in which the power of the engine 14 is transmitted to the output shaft 25 via the continuously variable transmission mechanism 20 will be described. This travel pattern corresponds to the belt travel (high vehicle speed) of FIG. 2, and the belt travel clutch C2 is connected, while the forward clutch C1, the reverse brake B1, and the meshing clutch D1 are disconnected. By connecting the belt traveling clutch C2, the secondary pulley 56 and the output shaft 25 are connected, and the secondary pulley 56, the output shaft 25, and the output gear 24 are integrally rotated. Therefore, when the belt traveling clutch C2 is connected, the second power transmission path is formed, and the power of the engine 14 passes through the torque converter 16, the turbine shaft 26, the primary shaft 32, and the continuously variable transmission mechanism 20. Then, it is transmitted to the output shaft 25 and the output gear 24. Further, the torque transmitted to the output gear 24 is transmitted to the left and right drive wheels 70L and 70R via the large diameter gear 62, the small diameter gear 68, and the differential gear 64. Here, the meshing clutch D1 is released (cut off) during the belt travel in which the torque of the engine 14 is transmitted via the second power transmission path because the gear mechanism 22 and the like are dragged during the belt travel. This is to prevent the gear mechanism 22 and the like from rotating at a high vehicle speed. The belt running corresponds to the continuously variable running of the present invention.

  The gear traveling is selected in the low vehicle speed region. The gear ratio EL (the rotational speed Nin of the turbine shaft 26 / the rotational speed Nout of the output shaft 25) based on the first power transmission path is set to a value larger than the maximum speed ratio γmax of the continuously variable transmission mechanism 20. . Therefore, for example, when the vehicle starts or when traveling at a low vehicle speed, gear traveling is selected. Then, for example, when it is determined that the vehicle travels to the belt traveling because the vehicle speed V increases, the belt traveling is switched. Here, when switching from gear travel to belt travel (high vehicle speed), or from belt travel (high vehicle speed) to gear travel, the belt travel (medium vehicle speed) in FIG.

  For example, when switching from gear running to belt running (high vehicle speed), the belt running clutch C2 and the meshing clutch D1 are engaged from the state in which the forward clutch C1 and the meshing clutch D1 corresponding to the gear running are engaged. Transitions to a state transiently. In other words, a change (stepped transmission) in which the forward clutch C1 is released and the belt traveling clutch C2 is engaged is started. At this time, the power transmission path is switched from the first power transmission path to the second power transmission path, and the drive device 12 is substantially upshifted. Then, after the power transmission path is switched, the meshing clutch D1 is released (cut off) (driven input cut off) in order to prevent unnecessary drag and high rotation of the gear mechanism 22 and the like.

  Further, when switching from belt travel (high vehicle speed) to gear travel, the state is switched 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 gear travel. (Prepared for downshift). 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 further, the change (stepped transmission) in which the forward clutch C1 is engaged and the belt traveling clutch C2 is released. ) Is executed, the power transmission path is switched from the second power transmission path to the first power transmission path. At this time, the driving device 12 is substantially downshifted.

  In the drive device 12 configured as described above, when the vehicle is decelerated during belt travel, the continuously variable transmission mechanism 20 is downshifted with a decrease in the vehicle speed V, and the vehicle speed V is, for example, a predetermined value or less. Then, switching from belt travel to gear travel is executed. Here, consider a case where the vehicle suddenly decelerates or stops suddenly. When the vehicle suddenly decelerates or stops suddenly, a so-called belt return failure may occur in which the downshift is not in time in the continuously variable transmission mechanism 20. Also, when switching from belt travel to gear travel, the switching may not be completed. In this state, when the vehicle is reaccelerated or restarted, the transmission ratio of the transmission 23 does not reach the target transmission ratio, so that the driver's required driving force F cannot be generated. There was a possibility of giving a sense of incongruity. Note that the belt return failure is caused by insufficient hydraulic fluid flow required for downshifting, and the switching to gear driving failure is the detection accuracy of the rotational speed sensor that detects the rotational speed at any time during switching control. The decline is due. On the other hand, the electronic control unit 80 shown in FIG. 1 executes later-described control for generating the driver's required driving force F upon sudden deceleration or re-acceleration or restart after a sudden stop. Hereinafter, the control mode of the electronic control unit 80 will be described.

  Returning to FIG. 1, 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. Various controls of the driving device 12 are executed by performing signal processing according to the stored program. For example, the electronic control unit 80 performs output control of the engine 14, shift control of the continuously variable transmission mechanism 20, belt clamping pressure control, control for appropriately switching the power transmission path of the drive unit 12 to either gear traveling or belt traveling, and the like. It is configured to be divided into an engine control unit, a continuously variable transmission control unit, a driving state switching unit, and the like as necessary.

  In the electronic control unit 80, a signal representing the rotation speed (position) Acr of the crankshaft detected by the engine rotation speed sensor 82 and the rotation speed (engine rotation speed) Ne of the engine 14 is detected by the primary rotation speed sensor 84. A signal representing the rotational speed Nt (primary rotational speed Nt, turbine rotational speed Nt) of the primary pulley 54 and the turbine shaft 26, and the rotational speed Nss (secondary rotational speed Nss) of the secondary pulley 56 detected by the secondary rotational speed sensor 86. Signal, a signal representing the rotational speed No (output shaft rotational speed No) of the output shaft 25 detected by the output shaft rotational speed sensor 88, and the first gear 48 constituting the meshing clutch D1 detected by the pre-synchronized rotational speed sensor 90. Signal indicating the rotation speed Nsf (rotation speed Nsf before synchronization) A signal representing the rotational speed Nsr (post-synchronization rotational speed Nsr) of the second gear 50 constituting the meshing clutch D1 detected by the speed sensor 92, the forward clutch C1 (carrier 30c side) detected by the clutch rotational speed sensor 94 A signal indicating the rotation speed Nc1 (clutch rotation speed Nc1), a signal indicating the accelerator opening degree Acc corresponding to the amount of depression of the accelerator pedal by the driver detected by the accelerator opening degree sensor 96, and the vehicle detected by the acceleration sensor 98 A signal or the like representing the acceleration G is supplied.

  Further, from the electronic control unit 80, an engine output control command signal Se for output control of the engine 14, a hydraulic control command signal Sccv for hydraulic control related to the shift of the continuously variable transmission mechanism 20, and a power transmission path of the drive unit 12 The forward clutch C1 and the reverse brake B1, the belt travel clutch C2, the hydraulic control command signal Sswt, etc. to the forward clutch C1 of the forward / reverse switching device 18 related to the switching are respectively output. Specifically, as the engine output control command signal Se, a throttle signal for controlling the opening / closing of the electronic throttle valve by driving the throttle actuator and an injection signal for controlling the amount of fuel injected from the fuel injection device And an ignition timing signal for controlling the ignition timing of the engine 14 by the ignition device. Further, as the hydraulic control command signal Sccv, a command signal for driving a linear solenoid valve (not shown) that regulates the primary pressure Pin supplied to the primary side actuator 54c and a secondary pressure Pout supplied to the secondary side actuator 56c are regulated. A command signal or the like for driving a linear solenoid valve (not shown) is output to the hydraulic control circuit 100. Further, as the hydraulic control command signal Sswt, command signals for driving the linear solenoid valves that control the hydraulic pressure supplied to the hydraulic actuators of the forward clutch C1, the reverse brake B1, the belt traveling clutch C2, and the meshing clutch D1. Are output to the hydraulic control circuit 100.

Next, the control function of the electronic control unit 80 will be described. The engine output control unit 102 shown in FIG. 1 outputs an engine output control command signal Se such as a throttle signal, an injection signal, and an ignition timing signal to the throttle actuator, the fuel injection device, and the ignition device, respectively, for output control of the engine 14, for example. To do. The engine output control unit 102 sets a target engine torque Te ^* for obtaining a required driving force F (required driving torque) calculated based on, for example, the accelerator opening Acc and the vehicle speed V, and the target engine torque Te ^*. In addition to controlling the opening and closing of the electronic throttle valve by the throttle actuator, the fuel injection amount is controlled by the fuel injection device, and the ignition timing is controlled by the ignition device.

The continuously variable transmission control unit 104 controls the transmission ratio γ of the continuously variable transmission mechanism 20 so that the target transmission ratio γ ^* is calculated based on the accelerator opening Acc, the vehicle speed V, the brake signal Bon, and the like. Specifically, the continuously variable transmission control unit 104 sets the target speed ratio γ ^* of the continuously variable transmission mechanism 20 at which the operating point of the engine 14 is on the optimum fuel consumption line while preventing belt slippage of the continuously variable transmission mechanism 20. In order to achieve this, in other words, the command value of the target primary pressure Pin ^* and the command value of the secondary pressure Pout as the command value of the primary pressure Pin so that the operating point of the engine 14 becomes the target engine speed Ne * on the optimum fuel consumption line. The target secondary pressure Pout ^* is determined, and the target primary pressure Pin ^* and the target secondary pressure Pout ^* are output to the hydraulic control circuit 100. Further, when the vehicle speed V decreases due to the vehicle deceleration operation or the stop operation, the continuously variable transmission control unit 104 executes the downshift control of the continuously variable transmission mechanism 20 according to the decrease in the vehicle speed V.

  The step-variable transmission control unit 106 performs gear travel by the first power transmission path through which the power of the engine 14 is transmitted to the output shaft 25 and the output gear 24 via the gear mechanism 22 and the continuously variable transmission mechanism 20. Then, switching control for selectively switching between belt travel (high vehicle speed) through the second power transmission path through which the power of the engine 14 is transmitted to the output shaft 25 and the output gear 24 based on the travel state of the vehicle is executed.

  For example, when it is determined to switch to belt traveling during traveling by gear traveling, the stepped transmission control unit 106 releases the forward clutch C1 and engages the belt traveling clutch C2, as shown in FIG. Stepped gear shift control (upshift control) is executed. Further, when this stepped shift is completed, the engagement clutch D1 is released. Further, when it is determined that the stepped gear shift control unit 106 switches to the gear traveling during the belt traveling, as shown in FIG. 2, the meshing clutch D1 is engaged and the engagement of the meshing clutch D1 is completed. Then, stepped shift control (downshift control) for releasing the belt traveling clutch C2 and engaging the forward clutch C1 is executed.

Here, when the vehicle suddenly decelerates or stops suddenly, the continuously variable transmission control unit 104 executes the downshift control of the continuously variable transmission mechanism 20, but the flow rate of hydraulic oil necessary for the downshift control is not secured, A so-called belt return failure may occur in which the transmission belt 58 does not move to the winding position corresponding to the target speed ratio γ ^* . In addition, with regard to switching control (stepped shift) for switching from belt travel to gear travel that is executed when the vehicle speed V further decreases, there is a possibility that the shift will not be completed due to a decrease in accuracy of the rotational speed sensor and a short shift time. There is. When the vehicle is re-accelerated or re-started in such a state, there is a possibility that the required driving force is insufficient due to not being shifted to an appropriate gear ratio. In this embodiment, the shortage of driving force is resolved by executing the control described later.

  The gear travel determination unit 108 determines whether or not the gear travel state (gear mode) is set. That is, the gear travel determination unit 108 determines whether or not the switching control to the gear travel has been completed. The gear travel determination unit 108 determines gear travel (switching control completion) based on, for example, the hydraulic pressure supplied to the forward clutch C1 and the meshing clutch D1. When the gear traveling determination unit 108 is denied, for example, the switching control to the gear traveling is not completed at the time of sudden deceleration or sudden stop. The gear shift control is performed by engaging the forward clutch C1 and the stepped gear control for releasing the belt travel clutch C2 so that the gear ratio is greater than the maximum gear ratio γmax of the continuously variable transmission mechanism 20. Since the gear ratio EL is large, downshift control is performed. Hereinafter, the switching control to the gear traveling is referred to as downshift control to the gear traveling.

  When the gear traveling determination unit 108 is negative, the required driving force calculation unit 110 is executed. The required driving force calculation unit 110 calculates the required driving force F of the driver predicted at the time of reacceleration or restart. For example, the required driving force calculation unit 110 calculates the accelerator opening Acc at the time of depression of the accelerator pedal, the amount of change in the accelerator opening Acc (the amount of change per unit time, the rate of change), the gradient Y, the vehicle The driver's required driving force F is calculated predictively based on the factors and the like. For example, even if the accelerator opening Acc at the time of depression of the accelerator pedal is the same, the required driving force F increases as the change amount of the accelerator opening Acc increases. Further, since the required driving force F with respect to the change amount of the accelerator opening degree Acc varies depending on the driver, the learning control of the required driving force F with respect to the change amount of the accelerator opening degree Acc may be executed. The gradient Y is calculated based on the vehicle acceleration G detected by the acceleration sensor 98.

  The driving force securing determination unit 112 determines whether or not a downshift to the gear traveling is unnecessary when the required driving force F calculated by the required driving force calculation unit 110 is generated when the gear traveling determination unit 108 is denied. Determine. FIG. 3 shows the relationship between the driving force and travel resistance and the vehicle speed when the accelerator opening Acc is X%. In FIG. 3, the solid line indicates the driving force in the gear traveling (gear mode), the alternate long and short dash line indicates the belt traveling (belt mode), and the gear ratio of the continuously variable transmission mechanism 20 is the maximum gear ratio γmax. The driving force is shown, the broken line is the belt running (belt mode), the driving force when the transmission gear ratio of the continuously variable transmission mechanism 20 is the predetermined transmission gear ratio γ, and the two-dot chain line is the gradient Y or The running resistance based on vehicle specifications is shown. As shown in FIG. 3, the driving force for gear traveling is larger than the driving force when the gear ratio of the continuously variable transmission mechanism 20 is the maximum gear ratio γmax.

  In a traveling state where the vehicle decelerates and the driving force becomes the current driving force A (point A) shown in FIG. 3, the surplus driving force that can be output at the time of reacceleration is the accelerator opening Acc or throttle opening θth and It is calculated by the difference between the driving force calculated based on the current predetermined gear ratio γ and the current driving force A at the present time. Here, when the required driving force F at the time of reacceleration is predicted to be the driving force at the point B, the driving force F1 when the speed ratio of the continuously variable transmission mechanism 20 indicated by the alternate long and short dash line is shifted to the maximum speed ratio γmax. Therefore, the required driving force F can be output by downshifting the continuously variable transmission mechanism 20. In other words, a downshift to gear running is not necessary. On the other hand, when the required driving force F at the time of reacceleration is predicted to be the driving force at the point C, the gear ratio of the continuously variable transmission mechanism 20 is larger than the driving force F1 when the gear ratio is shifted to the maximum gear ratio γmax. In order to generate the required driving force F, a downshift to gear traveling is required. In other words, it becomes difficult to secure the required driving force F, and a downshift to gear traveling is required.

  The driving force securing determination unit 112 sets a driving force F1 when the continuously variable transmission mechanism 20 indicated by a one-dot chain line is changed to the maximum gear ratio γmax as a reference driving force, and the predicted required driving force F is the driving force F1. If the required driving force F is greater than the driving force F1, it is determined that a downshift to the gear traveling is necessary. For example, when the required driving force F at the time of reacceleration is predicted to be the driving force at point B, the driving force securing determination unit 112 determines that a downshift to gear traveling is unnecessary, and the required driving force F at the time of reacceleration Is predicted to be the driving force at point C, it is determined that a downshift to gear traveling is necessary. The reference driving force F1 corresponds to the predetermined reference value of the present invention.

  The accelerator depression amount determination unit 114 determines whether or not the depression amount of the accelerator pedal, that is, the amount of change in the accelerator opening Acc is greater than a preset threshold value α. Based on the driving force securing determination unit 112, it is determined that a downshift to gear traveling is unnecessary (the predicted required driving force F is smaller than the driving force F1), and the accelerator is opened based on the accelerator depression amount determination unit 114. When it is determined that the change amount of the degree Acc is larger than the threshold value α, the engine output control unit 102 controls the throttle opening degree θth of the electronic throttle valve and executes the output torque increase control, for example, thereby requesting driving force F is realized. Further, when it is determined that the downshift to the gear traveling is unnecessary based on the driving force securing determination unit 112, and the change amount of the accelerator opening Acc is determined to be equal to or less than the threshold value α based on the accelerator depression amount determination unit 114. The continuously variable transmission control unit 104 realizes the required driving force F by executing the downshift control of the continuously variable transmission mechanism 20. The threshold value α is experimentally obtained in advance, and is set to a value at which it is determined that the driver's acceleration request is high. Therefore, when the driver's acceleration request is high, output torque increase control by the engine output control unit 102 is executed, and when the acceleration request is low, downshift control of the continuously variable transmission mechanism 20 is executed. Thus, when the required driving force F is smaller than the driving force F1, either the output torque increase control of the engine 14 or the downshift control of the continuously variable transmission mechanism 20 according to the amount of change in the accelerator opening Acc. Is selectively executed to realize the required driving force F.

  Further, it is determined that a downshift to gear traveling is necessary based on the driving force securing determination unit 112 (the required driving force F is greater than the driving force F1), and the accelerator opening degree is determined based on the accelerator depression amount determination unit 114. When it is determined that the amount of change in Acc is greater than the threshold value α, the stepped shift control unit 106 immediately executes the downshift control to the gear traveling to realize the required driving force F. Therefore, when the driver's acceleration request is high, downshift control to gear traveling is immediately executed. Further, when it is determined that a downshift to gear traveling is necessary based on the driving force securing determination unit 112 and the change amount of the accelerator opening Acc is determined to be equal to or less than the threshold value α based on the accelerator depression amount determination unit 114 Then, the downshift availability determination unit 116 is executed.

  The downshift enable / disable determining unit 116 determines whether controllability is ensured in downshift control to gear traveling. The downshift enable / disable determining unit 116 determines whether the vehicle speed V is greater than a predetermined value V1 set in advance, for example. The predetermined value V1 is a value obtained and stored in advance. For example, the predetermined value V1 is set to such a value that the rotational speed detection accuracy of the clutch rotational speed sensor 94 or the like that detects the clutch rotational speed Nc1 that is referred to at any time during downshift control is good. Has been. In other words, the value is set to a value that enables accurate downshift control to gear running. Accordingly, when the vehicle speed V is higher than the predetermined value V1, it is determined that the controllability of the downshift control is ensured. When the vehicle speed V is less than the predetermined value V1, the controllability of the downshift control is not ensured. It is determined. Even if the controllability of the downshift control is not ensured, the downshift control to the gear traveling can be executed, but the downshift control accuracy is lowered.

  If the vehicle speed V exceeds the predetermined value V1 based on the downshift enable / disable determining unit 116 and it is determined that the controllability of the downshift control to the gear traveling is ensured, the stepped shift control unit 106 performs the gear traveling. The required driving force F is realized by starting the downshift control. On the other hand, when the vehicle speed V is equal to or less than the predetermined value V1 based on the downshift enable / disable determining unit 116 and it is determined that the controllability of the downshift control to the gear traveling is not ensured, the engine output control unit 102 The driving force is increased by controlling the throttle opening θth with the throttle valve and executing the output torque increase control. When the downshift enable / disable determining unit 116 determines that the controllability of the downshift control is ensured during the output torque increase control by the engine output control unit 102, the stepped shift control unit 106 The required driving force F is realized by executing the downshift control. As described above, when the change amount of the accelerator opening Acc is larger than the threshold value α, the controllability is deteriorated in the downshift control to the gear traveling, but the downshift control is immediately executed, so that the driver's The required driving force F that realizes the acceleration request can be realized immediately.

  When the change amount of the accelerator opening Acc is equal to or less than the threshold value α, the driving force is increased by executing the torque increase control by the engine output control unit 102 until the downshift controllability is ensured. On the other hand, when the downshift controllability is ensured, the downshift to the gear traveling is executed, so that the required driving force F can be realized while preventing a shock due to the downshift control. As described above, when the required driving force F is larger than the driving force F1, the downshift control to the gear traveling and the engine 14 are performed in accordance with the change amount of the accelerator opening Acc and the vehicle speed V (downshift controllability). The output torque increase control is selectively executed to realize the required driving force F.

  FIG. 4 is a flow chart for explaining a main part of the control operation of the electronic control unit 80, that is, a control operation that can ensure the driver's required driving force F even in the rapid deceleration of the vehicle or the reacceleration or the restart after the sudden stop. . This flowchart is repeatedly executed with an extremely short cycle time of, for example, about several milliseconds to several tens of milliseconds.

  First, at step S1 (hereinafter, step is omitted), vehicle deceleration or vehicle stop is started based on depression of a brake pedal or the like, and a downshift request to gear traveling is output at S2. In S3 corresponding to the gear traveling determination unit 108, it is determined whether or not the gear traveling is switched, that is, whether or not the downshift control to the gear traveling is completed. When S3 is affirmed, when the accelerator pedal is subsequently depressed and a re-acceleration request or re-start request for the vehicle is output, re-acceleration or re-start of the vehicle is started in S14. When S3 is negative, the required driving force F at the time of reacceleration or re-starting is predictedly calculated at S4 corresponding to the required driving force calculation unit 110.

  In S5 corresponding to the driving force securing determination unit 112, it is determined whether or not a downshift to gear traveling is unnecessary when the required driving force F calculated in S4 is generated. If S5 is negative, that is, if downshifting to gear driving is required, the process proceeds to S6. When S5 is affirmed, that is, when downshifting to gear traveling is unnecessary, the process proceeds to S11.

  In S6 corresponding to the accelerator depression amount determination unit 114, it is determined whether or not the depression amount of the accelerator pedal (change amount of the accelerator opening degree Acc) is larger than a preset threshold value α. When S6 is affirmed, in S10 corresponding to the stepped shift control unit 106, downshift control to gear traveling is immediately executed, and reacceleration or re-start is executed in S14. When S6 is negative, it is determined based on the vehicle speed V whether or not the controllability of the downshift control to the gear traveling is ensured in S7 corresponding to the downshift availability determination unit 116. When S7 is affirmed, downshift control to gear traveling is executed in S8 corresponding to the stepped shift control unit 106, and reacceleration or re-start is executed in S14. When S7 is negative, the output torque of the engine 14 is increased by controlling the throttle opening θth of the electronic throttle valve of the engine 14 in S9 corresponding to the engine output control unit 102. This output torque increase control is executed until the downshift controllability to the gear traveling is ensured. When S7 is affirmed and the downshift controllability is ensured, the downshift control to the gear traveling of S8 is performed. Executed.

  Returning to S5, if S5 is affirmed, that is, if downshifting to gear traveling is not required, the accelerator pedal depression amount (change amount of the accelerator opening Acc) is determined in S11 corresponding to the accelerator depression amount determination unit 114. It is determined whether or not the threshold value is larger than a preset threshold value α. If S11 is negative, that is, if the amount of depression of the accelerator pedal is equal to or less than the threshold value α, the downshift control of the continuously variable transmission mechanism 20 is executed in S13 corresponding to the continuously variable transmission control unit 104. Acceleration or restart is executed. If S11 is affirmed, that is, if the accelerator pedal depression amount exceeds the threshold value α, the throttle opening θth of the electronic throttle valve of the engine 14 is controlled in S12 corresponding to the engine output control unit 102, and in S14 the vehicle Re-acceleration or re-start is executed.

  In S15 corresponding to the stepped shift control unit 106, it is determined whether or not switching to the belt travel (upshift) is requested after reacceleration or restart (whether or not the upshift line is straddled). When S15 is denied, it returns to S4 and the flow below S4 is repeatedly performed. When S15 is affirmed, in S16 corresponding to the stepped shift control unit 106, an upshift to the belt traveling is executed, and the belt traveling is switched.

  As described above, according to the present embodiment, when the required driving force F is smaller than the predetermined driving force F1, depending on the amount of change in the accelerator opening Acc, By selectively executing the output torque increase control of the engine 14, the required driving force F can be realized by appropriate control. Further, when the required driving force F is larger than the predetermined driving force F1, depending on the change amount of the accelerator opening Acc and the vehicle speed V, the downshift control to the gear traveling or the increase of the output torque of the engine 14 is performed. By selectively executing the control, the required driving force F can be realized. Thus, in the reacceleration after the rapid deceleration, the driver's required driving force F can be realized by appropriate control by switching to the optimal control.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, the meshing clutch D1 of the above-described embodiment is not always necessary, and the meshing clutch D1 may be omitted.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

12: Vehicle drive device 14: Engine (drive power source)
20: Belt type continuously variable transmission mechanism (continuously variable transmission mechanism)
22: Gear mechanism (transmission mechanism)
25: Output shaft 80: Electronic control device (control device)

Claims (1)

A vehicular drive comprising a continuously variable transmission mechanism and a transmission mechanism that constitutes at least one gear ratio in parallel, wherein the gear ratio of the transmission mechanism is set to a value larger than the maximum transmission ratio of the continuously variable transmission mechanism In the apparatus, for a vehicle that selectively switches between a gear traveling that transmits power to the output shaft via the transmission mechanism and a continuously variable transmission that transmits power to the output shaft via the continuously variable transmission mechanism. A control device for the drive device,
When the vehicle decelerates during the continuously variable speed travel, if the switching to the gear travel is not completed, the driver's required driving force at the time of reacceleration is less than a predetermined reference value. If small, according to the amount of change in the accelerator opening, select either the downshift control of the continuously variable transmission mechanism or the output torque increase control of the driving force source to output the required driving force,
When the vehicle decelerates during the continuously variable speed travel, if the switching to the gear travel is not completed, the driver's required driving force at the time of reacceleration is less than a predetermined reference value. If it is larger, either the switching control to the gear traveling or the output torque increase control of the driving force source is selected according to the change amount of the accelerator opening and the vehicle speed, and the requested driving force is output. A control device for a vehicle drive device.

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