JP2017036783A - Power transmission control device - Google Patents

Abstract

An object of the present invention is to appropriately control the rotational speed of a pulley of a continuously variable transmission mechanism when a second engagement device is in a slip state or a release state. When a second clutch C2 is in a disengaged state, a priority is set in the first target speed ratio γtgt1 and the third target speed ratio γtgt3 on condition that the second target speed ratio γtgt2 is satisfied. Any one of the high target gear ratios is selected, and the gear ratio γcvt of the continuously variable transmission 24 is controlled based on the selected target gear ratio γtgt, so that the second clutch C2 is in the released state. Sometimes, the target speed ratio γcvttgt of the continuously variable transmission 24 is set according to the traveling state of the vehicle, and the optimum speed ratio γcvt according to the traveling state can be realized. Therefore, when the second clutch C2 is in the released state, the secondary pulley rotational speed Nsec can be appropriately controlled. [Selection] Figure 4

Description

  The present invention relates to a control device for a power transmission device including a belt-type continuously variable transmission mechanism and a transmission mechanism in which a gear stage is formed, provided in parallel in a power transmission path between a driving force source and driving wheels. It is.

  A belt-type continuously variable transmission mechanism and gear stage are formed in parallel in the power transmission path between the input rotating member that transmits the power of the driving force source and the output rotating member that outputs the power to the driving wheels. A power transmission device having a transmission mechanism is well known. For example, the transmission described in Patent Document 1 is that. In Patent Document 1, a stepped transmission unit and a continuously variable transmission unit provided in parallel to a power transmission path between an input shaft and an output shaft, and a power transmission path via the stepped transmission unit are connected and disconnected. In a transmission including a first clutch mechanism and a second clutch mechanism that connects and disconnects a power transmission path via a continuously variable transmission, engaging the first clutch mechanism and releasing the second clutch mechanism The vehicle is started using a power transmission path through a stepped transmission unit that has a larger transmission ratio than the power transmission path through the step transmission unit. When the vehicle speed increases after the start, the first clutch mechanism is released. It is disclosed that traveling is performed using a power transmission path via a continuously variable transmission by engaging a second clutch mechanism.

JP 2014-126181 A

  By the way, in the transmission of Patent Document 1, the engine (also agrees with the input shaft) and the continuously variable transmission (especially the primary pulley) are directly connected, and the continuously variable transmission (especially the secondary pulley) and the drive wheels (including the output shaft). (Agree) is connected via a second clutch mechanism. For this reason, when the second clutch mechanism is released, the pulley of the continuously variable transmission is rotated along with the rotation of the engine. At this time, if the gear ratio of the continuously variable transmission is on the speed increasing side (high gear ratio side), the secondary pulley may overspeed even if the engine speed does not exceed the predetermined overspeed. There is. On the other hand, in the case of a power transmission device in which the secondary pulley and the output rotation member are directly connected and the input rotation member and the primary pulley are connected via the second engagement device, the continuously variable transmission mechanism is driven. When the gear ratio of the continuously variable transmission portion is on the speed increasing side (high gear ratio side), the primary pulley is rotated at a low speed and the second engaging device is rotated at a differential rotational speed (= The rotational speed of the input rotating member—the rotational speed of the primary pulley) increases, and the amount of heat generated when the second engagement device is engaged may increase.

  The present invention has been made against the background of the above circumstances. The object of the present invention is to rotate the pulley of the continuously variable transmission mechanism when the second engagement device is in the slip state or the release state. An object of the present invention is to provide a control device for a power transmission device capable of appropriately controlling the speed.

  The subject matter of the first invention is (a) provided in parallel to a power transmission path between an input rotating member to which power of a driving force source is transmitted and an output rotating member for outputting the power to driving wheels. In addition, a continuously variable transmission mechanism in which a transmission element is wound between a primary pulley and a secondary pulley, a transmission mechanism in which a gear stage is formed, and the power of the driving force source to the driving wheels via the transmission mechanism A first engagement device for connecting / disconnecting a first power transmission path for transmission, and a power transmission path between the secondary pulley and the output rotating member; A second engagement device for connecting and disconnecting a second power transmission path for transmitting power to the drive wheel, and a speed ratio formed by the first power transmission path can be formed by the second power transmission path. Dynamics with a gear ratio on the low side of the low gear ratio A control device of a force transmission device, wherein (b) an operation state determination unit that determines whether or not the second engagement device is in a slip state or a release state; and (c) the operation state determination unit When it is determined that the second engagement device is in the slip state or the release state, the gear ratio of the continuously variable transmission mechanism is determined based on the gear ratio at which the rotation speed of the secondary pulley becomes a predetermined upper limit rotation speed. And a transmission control unit that controls the transmission ratio to the low side.

  According to a second aspect of the present invention, in the control device for a power transmission device according to the first aspect of the invention, the shift control unit controls the transmission ratio of the continuously variable transmission mechanism to be 1 or more. .

  According to a third aspect of the present invention, in the control device for a power transmission device according to the first aspect of the present invention, the first target gear ratio for reducing the load in the continuously variable transmission mechanism and the over-rotation of the secondary pulley are prevented. Target shift ratios for calculating a second target speed ratio to be calculated and a third target speed ratio based on a running state in a state where the second engagement device is engaged and the second power transmission path is formed. Select one of the first target gear ratio and the third target gear ratio, which has a higher priority, on condition that the ratio calculation unit and the second target gear ratio are satisfied And a target speed ratio selecting unit that controls the speed ratio of the continuously variable transmission mechanism based on the selected target speed ratio.

  The gist of the fourth invention is that (a) a power transmission path between the input rotating member to which the power of the driving force source is transmitted and the output rotating member for outputting the power to the driving wheel is provided in parallel. A continuously variable transmission mechanism in which a transmission element is wound between a primary pulley and a secondary pulley, a transmission mechanism in which a gear stage is formed, and driving the power of the driving force source via the transmission mechanism The first driving device for connecting and disconnecting the first power transmission path for transmitting to the wheel, and the driving force via the continuously variable transmission mechanism provided in the power transmission path between the primary pulley and the input rotating member. And a second engagement device for connecting and disconnecting a second power transmission path for transmitting the power of the power source to the drive wheel, and a speed ratio formed by the first power transmission path is formed by the second power transmission path With the lower gear ratio than the lowest possible gear ratio (B) an operation state determination unit that determines whether or not the second engagement device is in a slip state or a release state; and (c) the operation state determination unit. If it is determined that the second engagement device is in the slip state or the release state, the gear ratio of the continuously variable transmission mechanism is the gear ratio at which the rotation speed of the primary pulley is a predetermined lower limit rotation speed. And a gear shift control unit that controls the gear ratio to the lower side.

  According to a fifth aspect of the invention, in the control device for a power transmission device according to the fourth aspect of the invention, the shift control unit controls the transmission ratio of the continuously variable transmission mechanism to be 1 or more. .

  According to a sixth aspect of the present invention, there is provided the control device for a power transmission device according to the fourth aspect, wherein the first target gear ratio for reducing the load in the continuously variable transmission mechanism and the second engagement device are related. A second target speed change ratio that suppresses the amount of heat generated by the friction material at the time, and a third state based on a running state in which the second power transmission path is formed by engaging the second engagement device. The target speed ratio calculation unit for calculating the target speed ratio and the first target speed ratio and the third target speed ratio on the condition that the second target speed ratio is satisfied. A target speed ratio selection unit that selects any one of the target speed ratios having a high value, and the speed change control unit controls the speed ratio of the continuously variable transmission mechanism based on the selected target speed ratio. There is.

  According to the first aspect of the invention, when the second engagement device is in the slip state or the release state, the rotation speed of the secondary pulley is lower than the gear ratio at which the rotation speed becomes the predetermined upper limit rotation speed. Since the speed ratio of the continuously variable transmission mechanism is controlled so that the speed ratio becomes the same, the secondary pulley is prevented from over-rotating. Therefore, when the second engagement device is in the slip state or the release state, the rotational speed of the pulley of the continuously variable transmission mechanism can be appropriately controlled.

  According to the second aspect of the present invention, the rotation speed of the secondary pulley is lower than the rotation speed of the primary pulley by controlling the gear ratio of the continuously variable transmission mechanism to be 1 or more. When the output rotation member and the secondary pulley are connected via the second engagement device, the secondary pulley is prevented from over-rotating even if the engine rotation speed increases.

  In addition, according to the third aspect of the invention, it is possible to realize an optimum gear ratio according to the traveling state by setting the target gear ratio according to the traveling state of the vehicle.

  According to the fourth aspect of the invention, when the second engagement device is in a slip state or a release state, the primary pulley has a rotation speed lower than a gear ratio at which the rotation speed of the primary pulley becomes a predetermined lower limit rotation speed. Since the speed ratio of the continuously variable transmission mechanism is controlled so that the speed ratio becomes the same, the primary pulley is prevented from rotating at a low speed, and the differential rotation speed of the second engagement device is prevented from increasing. Therefore, when the second engagement device is in the slip state or the release state, the rotational speed of the pulley of the continuously variable transmission mechanism can be appropriately controlled.

  According to the fifth aspect of the present invention, the rotation speed of the primary pulley is higher than the rotation speed of the secondary pulley by controlling the gear ratio of the continuously variable transmission mechanism to be 1 or more. When the input rotation member and the primary pulley are connected via the second engagement device, the rotation speed of the primary pulley is unlikely to be low, so that the differential rotation speed of the second engagement device is prevented from increasing. Is done.

  In addition, according to the sixth aspect of the invention, it is possible to realize an optimum gear ratio according to the traveling state by setting the target gear ratio according to the traveling state of the vehicle.

It is a figure explaining the schematic structure of the vehicle to which the present invention is applied. It is a figure for demonstrating the switching of the driving modes of a power transmission device. It is a figure explaining the principal part of the control function and various control systems for various control in vehicles. It is a flowchart explaining the control action for controlling the secondary pulley rotational speed appropriately when the principal part of the control action of the electronic control unit, that is, the second clutch is in the released state.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of a vehicle 10 to which the present invention is applied. In FIG. 1, a vehicle 10 is provided in an engine 12 such as a gasoline engine or a diesel engine that functions as a driving power source for traveling, a driving wheel 14, and a power transmission path between the engine 12 and the driving wheel 14. And a power transmission device 16. The power transmission device 16 is connected to a known torque converter 20 as a fluid transmission device connected to the engine 12, an input shaft 22 connected to the torque converter 20, and an input shaft 22 in a housing 18 as a non-rotating member. A known belt-type continuously variable transmission 24 serving as a continuously variable transmission, a forward / reverse switching device 26 connected to the input shaft 22, and a continuously variable transmission connected to the input shaft 22 via the forward / reverse switching device 26. A gear transmission mechanism 28 serving as a gear transmission provided in parallel with the transmission 24, an output shaft 30, which is a common output rotation member of the continuously variable transmission 24 and the gear transmission mechanism 28, a counter shaft 32, an output shaft 30, and a counter A reduction gear device 34 composed of a pair of gears which are provided on the shaft 32 so as not to rotate relative to each other and meshed with each other, and a gear 36 provided on the counter shaft 32 so as not to rotate relatively. Differential gear 38, and a axle 40 or the like of the pair coupled to a differential gear 38. In the power transmission device 16 configured as described above, the power of the engine 12 (the torque and the force are synonymous unless otherwise specified) is transmitted from the torque converter 20, the continuously variable transmission 24 (or the forward / reverse switching device 26 and the gear transmission mechanism). 28), the reduction gear device 34, the differential gear 38, the axle 40 and the like are sequentially transmitted to the pair of drive wheels 14.

  As described above, the power transmission device 16 transmits the power of the engine 12 to the engine 12 (here, the input shaft 22 which is an input rotating member to which the power of the engine 12 is transmitted) and the driving wheel 14 (here, the driving wheel 14 is transmitted). A gear transmission mechanism 28 and a continuously variable transmission 24 are provided in parallel with the power transmission path PT between the output shaft 30 as an output rotating member and the output. Therefore, the power transmission device 16 transmits the power of the engine 12 from the input shaft 22 to the drive wheels 14 (here, the output shaft 30 also agrees) via the gear transmission mechanism 28, and the engine 12 A plurality of power transmission paths including a second power transmission path PT2 that transmits power from the input shaft 22 to the drive wheels 14 (here, the output shaft 30 also agrees) via the continuously variable transmission 24, the input shaft 22 and the output shaft 30 in parallel. The power transmission device 16 is switched between the first power transmission path PT1 and the second power transmission path PT2 in accordance with the traveling state of the vehicle 10. Therefore, the power transmission device 16 includes a plurality of engagement devices that selectively switch the power transmission path for transmitting the power of the engine 12 to the drive wheels 14 between the first power transmission path PT1 and the second power transmission path PT2. I have. This engagement device is a first clutch as a first engagement device that connects and disconnects the first power transmission path PT1 (in other words, a first engagement device that is engaged to form the first power transmission path PT1). C1 and the first brake B1 as a second engagement device that connects and disconnects the second power transmission path PT2 (in other words, a second engagement device that forms the second power transmission path PT2 by being engaged). A second clutch C2. The first clutch C1, the first brake B1, and the second clutch C2 correspond to a connection / disconnection device, and all of them are known hydraulic wet friction engagement devices (frictions) that are frictionally engaged by a hydraulic actuator. Clutch). Further, each of the first clutch C1 and the first brake B1 is one of the elements constituting the forward / reverse switching device 26, as will be described later.

  The torque converter 20 is interposed in a power transmission path between the engine 12 and the input shaft 22, and is provided around the input shaft 22 and coaxially with the input shaft 22. The torque converter 20 includes a pump impeller 20p connected to the engine 12 and a turbine impeller 20t connected to the input shaft 22, and transmits the power of the engine 12 to the input shaft 22. The torque converter 20 includes a known lock-up clutch Clu that can be directly connected between the pump impeller 20p and the turbine impeller 20t, that is, between the input / output rotating members of the torque converter 20. The power transmission device 16 includes a mechanical oil pump 42 connected to the pump impeller 20p. The oil pump 42 is rotationally driven by the engine 12 to control shift of the continuously variable transmission 24, operate the plurality of engaging devices, supply lubricating oil to each part of the power transmission device 16, and the like. To generate (discharge) hydraulic pressure.

  The forward / reverse switching device 26 is provided coaxially with the input shaft 22 around the input shaft 22 in the first power transmission path PT1, and includes a double pinion planetary gear device 26p, a first clutch C1, and a first clutch C1. One brake B1 is provided. The planetary gear device 26p is a differential mechanism having three rotating elements: a carrier 26c as an input element, a sun gear 26s as an output element, and a ring gear 26r as a reaction force element. The carrier 26c is integrally connected to the input shaft 22, the ring gear 26r is selectively connected to the housing 18 via the first brake B1, and the sun gear 26s is coaxial with the input shaft 22 around the input shaft 22. It is connected to a small-diameter gear 44 provided so as to be relatively rotatable. The carrier 26c and the sun gear 26s are selectively connected via the first clutch C1. Therefore, the first clutch C1 is an engagement device that selectively connects two of the three rotating elements, and the first brake B1 selectively connects the reaction element to the housing 18. It is an engaging device to do.

  The gear transmission mechanism 28 includes a small-diameter gear 44 and a large-diameter gear 48 that is provided around the gear mechanism counter shaft 46 so as not to rotate relative to the gear mechanism counter shaft 46 and meshes with the small-diameter gear 44. ing. The gear transmission mechanism 28 includes an idler gear 50 provided around the gear mechanism counter shaft 46 so as to be relatively rotatable coaxially with the gear mechanism counter shaft 46, and the output shaft 30 with respect to the output shaft 30. An output gear 52 that is provided on the coaxial center so as not to rotate relative to the idler gear 50 is provided. The output gear 52 has a larger diameter than the idler gear 50. Therefore, the gear transmission mechanism 28 has a single gear ratio (gear stage, gear stage) as a predetermined speed ratio (gear stage, gear stage) in the power transmission path PT between the input shaft 22 and the output shaft 30. It is a transmission mechanism to be formed. The gear transmission mechanism 28 further includes a meshing clutch D1 that is provided between the large-diameter gear 48 and the idler gear 50 around the gear mechanism counter shaft 46, and selectively connects and disconnects between these gears. The meshing clutch D1 is disposed in a power transmission path between the forward / reverse switching device 26 (here, the first clutch C1 also agrees) and the output shaft 30 (in other words, the output shaft 30 than the first clutch C1). Provided on the side), a third engagement device that connects and disconnects the first power transmission path PT1 (in other words, a third engagement device that is engaged with the first clutch C1 to form the first power transmission path PT1). ) And is included in the plurality of engagement devices.

  Specifically, the meshing clutch D1 includes a clutch hub 54 provided around the gear mechanism counter shaft 46 so as not to rotate relative to the gear mechanism counter shaft 46, an idler gear 50, and a clutch hub 54. A clutch gear 56 disposed between and fixed to the idler gear 50 is spline-fitted to the clutch hub 54 so that the gear mechanism counter shaft 46 cannot rotate relative to the shaft center and is parallel to the shaft center. And a cylindrical sleeve 58 provided so as to be relatively movable in various directions. The sleeve 58 that is always rotated integrally with the clutch hub 54 is moved to the clutch gear 56 side and meshed with the clutch gear 56, whereby the idler gear 50 and the gear mechanism counter shaft 46 are connected. Further, the meshing clutch D1 includes a known synchromesh mechanism S1 as a synchronizing mechanism that synchronizes rotation when the sleeve 58 and the clutch gear 56 are engaged. In the meshing clutch D1 configured as described above, the fork shaft 60 is operated by the hydraulic actuator 62, whereby the sleeve 58 is connected to the shaft of the gear mechanism counter shaft 46 via the shift fork 64 fixed to the fork shaft 60. It is slid in a direction parallel to the center, and the engaged state and the released state are switched.

  The first power transmission path PT1 is formed by engaging the meshing clutch D1 and the first clutch C1 (or the first brake B1) provided closer to the input shaft 22 than the meshing clutch D1. . A forward power transmission path is formed by the engagement of the first clutch C1, and a reverse power transmission path is formed by the engagement of the first brake B1. In the power transmission device 16, when the first power transmission path PT <b> 1 is formed, the power transmission state in which the power of the engine 12 can be transmitted from the input shaft 22 to the output shaft 30 via the gear transmission mechanism 28 is set. The On the other hand, the first power transmission path PT1 is in a neutral state (power transmission) that interrupts power transmission when at least the first clutch C1 and the first brake B1 are both released or at least the meshing clutch D1 is released. It is said that it is in a cut-off state.

  The continuously variable transmission 24 includes a primary pulley 66 having a variable effective diameter provided on the input shaft 22, a secondary pulley 70 having a variable effective diameter provided on a rotary shaft 68 coaxial with the output shaft 30, and each of these. A transmission belt 72 serving as a transmission element wound between the pulleys 66 and 70 is provided, and power is transmitted through a frictional force (belt clamping pressure) between the pulleys 66 and 70 and the transmission belt 72. This is a belt type continuously variable transmission mechanism. In the primary pulley 66, a hydraulic pressure control circuit 80 (see FIG. 3) in which the hydraulic pressure supplied to the primary pulley 66 (that is, the primary pressure Pin supplied to the primary hydraulic cylinder 66c) is driven by the electronic control unit 90 (see FIG. 3). Thus, the primary thrust Win (= primary pressure Pin × pressure receiving area) for changing the V groove width between the sheaves 66a and 66b is applied. In the secondary pulley 70, the hydraulic pressure supplied to the secondary pulley 70 (that is, the secondary pressure Pout supplied to the secondary hydraulic cylinder 70c) is regulated by the hydraulic control circuit 80, so that the sheaves 70a and 70b are separated. Secondary thrust Wout (= secondary pressure Pout × pressure receiving area) for changing the V groove width is applied. In the continuously variable transmission 24, the primary thrust Win (primary pressure Pin) and the secondary thrust Wout (secondary pressure Pout) are controlled, so that the V-groove widths of the pulleys 66 and 70 change and the transmission belt 72 is engaged. The diameter (effective diameter) is changed, the gear ratio γcvt (= primary pulley rotational speed Npri / secondary pulley rotational speed Nsec) is changed, and the pulleys 66 and 70 and the transmission belt are prevented from slipping. The frictional force with 72 is controlled.

  The output shaft 30 is disposed around the rotation shaft 68 so as to be rotatable relative to the rotation shaft 68 coaxially. The second clutch C2 is provided on the drive wheel 14 (here, the output shaft 30 also agrees) side with respect to the continuously variable transmission 24 (that is, provided in the power transmission path between the secondary pulley 70 and the output shaft 30). The power transmission path between the secondary pulley 70 (rotating shaft 68) and the output shaft 30 is selectively connected or disconnected. The second power transmission path PT2 is formed by engaging the second clutch C2. In the power transmission device 16, when the second power transmission path PT <b> 2 is formed, a power transmission possible state in which the power of the engine 12 can be transmitted from the input shaft 22 to the output shaft 30 via the continuously variable transmission 24. Is done. On the other hand, the second power transmission path PT2 is set to the neutral state when the second clutch C2 is released.

  The operation of the power transmission device 16 will be described below. FIG. 2 is a diagram for explaining the switching of the travel mode using the engagement table of the engagement device for each travel pattern (travel mode) of the power transmission device 16 switched by the electronic control unit 90. In FIG. 2, C1 corresponds to the operating state of the first clutch C1, C2 corresponds to the operating state of the second clutch C2, B1 corresponds to the operating state of the first brake B1, and D1 corresponds to the meshing clutch D1. Corresponding to the operating state, “◯” indicates engagement (connection), and “×” indicates release (cutoff).

  In FIG. 2, a travel mode in which the power of the engine 12 is transmitted to the output shaft 30 via the gear transmission mechanism 28 (that is, via the first power transmission path PT1) (that is, the first power transmission via the gear transmission mechanism 28). In the gear travel mode, which is a travel mode that travels using the path PT1, the first clutch C1 and the meshing clutch D1 are engaged, and the second clutch C2 and the first brake B1 are released. In this gear travel mode, forward travel is possible. In the gear travel mode in which the first brake B1 and the meshing clutch D1 are engaged and the second clutch C2 and the first clutch C1 are released, reverse travel is possible.

  Further, a travel mode in which the power of the engine 12 is transmitted to the output shaft 30 via the continuously variable transmission 24 (that is, via the second power transmission path PT2) (that is, the second power transmission via the continuously variable transmission 24). In a CVT travel mode (also referred to as a belt travel mode) that is a travel mode that travels using the route PT2, the second clutch C2 is engaged and the first clutch C1 and the first brake B1 are released. In this CVT travel mode, forward travel is possible. Among the CVT traveling modes, the meshing clutch D1 is engaged in the CVT traveling (medium vehicle speed) mode, while the meshing clutch D1 is released in the CVT traveling (high vehicle speed) mode. The meshing clutch D1 is released in the CVT traveling mode (high vehicle speed) mode, for example, the dragging of the gear transmission mechanism 28 and the like during traveling in the CVT traveling mode is eliminated, and the gear transmission mechanism 28 and the planetary gear are operated at a high vehicle speed. This is to prevent the constituent member (for example, pinion gear) of the gear device 26p from rotating at a high speed. The meshing clutch D1 functions as a driven input cutoff clutch that blocks input from the drive wheel 14 side.

  The gear travel mode is selected, for example, in a low vehicle speed region including when the vehicle is stopped. In the power transmission device 16, the speed ratio γ gear formed in the first power transmission path PT1 (that is, the speed ratio EL formed by the gear transmission mechanism 28) is the maximum speed ratio (that can be formed in the second power transmission path PT2 ( In other words, it is set to a value larger than the lowest vehicle speed side speed ratio (gamma) max γmax that can be formed by the continuously variable transmission 24 (that is, the low side gear ratio). That is, in the continuously variable transmission 24 (second power transmission path PT2), the speed ratio γcvt on the higher vehicle speed side (high side) than the speed ratio γgear (speed ratio EL) formed in the first power transmission path PT1 is It is formed. For example, the gear ratio EL corresponds to the first speed gear ratio γ1 which is the gear ratio γ of the first speed gear stage in the power transmission device 16, and the lowest gear ratio γmax of the continuously variable transmission 24 is equal to that in the power transmission device 16. This corresponds to the second speed gear ratio γ2 that is the speed ratio γ of the second speed gear. Therefore, the gear travel mode and the CVT travel mode are switched, for example, according to a shift line for switching between a first speed shift stage and a second speed shift stage in a shift map of a known stepped transmission. Further, in the CVT travel mode, for example, a known method is used to perform a shift in which the speed ratio γcvt is changed based on the travel state such as the accelerator opening θacc and the vehicle speed V.

  In switching from the gear travel mode to the CVT travel (high vehicle speed) mode or from the CVT travel (high vehicle speed) mode to the gear travel mode, as shown in FIG. 2, the CVT travel (medium vehicle speed) mode is passed. For example, in switching from the gear travel mode to the CVT travel (high vehicle speed) mode, a shift (for example, a clutch-to-clutch shift (hereinafter referred to as CtoC shift) that disengages the first clutch C1 and engages the second clutch C2 is performed. In this case, the shift is executed to switch to the CVT running (medium vehicle speed) mode, and then the meshing clutch D1 is released to cut off the driven input. Further, for example, in switching from the CVT travel (high vehicle speed) mode to the gear travel mode, the meshing clutch D1 is engaged as preparation for switching to the gear travel mode (that is, preparation for downshift) and the CVT travel (medium vehicle speed) mode is set. After that, a downshift is executed at a shift (for example, a CtoC shift) in which the second clutch C2 is released and the clutch is switched so as to engage the first clutch C1.

  FIG. 3 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. 3, the vehicle 10 includes an electronic control device 90 including a control device for the power transmission device 16, for example. Therefore, FIG. 3 is a diagram showing an input / output system of the electronic control unit 90, and is a functional block diagram for explaining a main part of a control function by the electronic control unit 90. The electronic control unit 90 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and follows 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 90 executes output control of the engine 12, shift control of the continuously variable transmission 24, switching control of the driving mode of the power transmission device 16, and the like. The electronic control unit 90 is configured separately for engine control, hydraulic control, and the like as necessary.

  The electronic control unit 90 has various actual values (for example, engine rotational speed Ne, input) based on detection signals from various sensors (for example, various rotational speed sensors 100, 102, 104, 106, accelerator opening sensor 108, etc.) provided in the vehicle 10. A primary pulley rotation speed Npri that is the shaft rotation speed Nin, a secondary pulley rotation speed Nsec that is the rotation speed of the rotation shaft 68, an output shaft rotation speed Nout corresponding to the vehicle speed V, an accelerator opening degree θacc, and the like are respectively supplied. The electronic control unit 90 also outputs an engine output control command signal Se for output control of the engine 12, a hydraulic control command signal Sccv for hydraulic control related to the shift of the continuously variable transmission 24, and a travel mode of the power transmission device 16. The hydraulic control command signal Sswt and the like for controlling the first clutch C1, the first brake B1, the second clutch C2, and the meshing clutch D1 are output. For example, as a hydraulic control command signal Sswt, for driving each solenoid valve that regulates each hydraulic pressure supplied to each hydraulic actuator of the first clutch C1, the first brake B1, the second clutch C2, and the meshing clutch D1. A command signal (hydraulic command) is output to the hydraulic control circuit 80.

  The electronic control unit 90 includes an engine output control unit, that is, an engine output control unit 92, a transmission control unit, that is, a transmission control unit 94, and a target transmission ratio calculation unit, that is, a target transmission ratio calculation unit 96.

  The engine output control unit 92 is requested, for example, by applying the accelerator opening θacc and the vehicle speed V to a relationship (for example, a driving force map) that has been obtained and stored experimentally or design in advance (that is, predetermined). A driving force Fdem is calculated, a target engine torque Tetgt from which the required driving force Fdem is obtained is set, and an engine output control command signal Se for controlling the output of the engine 12 so as to obtain the target engine torque Tetgt is set to a throttle actuator, Output to a fuel injection device or ignition device.

  The shift control unit 94 outputs a command to the hydraulic control circuit 80 to engage the engagement clutch D1 by the hydraulic actuator 62 in preparation for the gear traveling mode while the vehicle is stopped. Thereafter, when the shift lever is switched to the forward travel operation position D (or the reverse travel operation position R), the transmission control unit 94 issues a command to engage the first clutch C1 (or the first brake B1). Output to 80.

  Further, the shift control unit 94 executes switching control for switching between the gear travel mode and the CVT travel mode. Specifically, the shift control unit 94, for example, the gear ratio EL in the gear travel mode (that is, the first speed gear stage in the power transmission device 16) and the lowest gear ratio γmax in the CVT travel mode (that is, the first gear ratio in the power transmission device 16). By applying the vehicle speed V and the accelerator opening θacc to the upshift line and the downshift line having a predetermined hysteresis for switching to the (second speed gear stage), it is determined to switch the speed ratio γ, and based on the determination result Switch the driving mode.

  The shift control unit 94 releases the first clutch C1 and engages the second clutch C2 when switching from the gear travel mode to the CVT travel (medium vehicle speed) mode by determining an upshift during traveling in the gear travel mode. A command to perform CtoC shift is output to the hydraulic control circuit 80. Thereby, the power transmission path PT in the power transmission device 16 is switched from the first power transmission path PT1 to the second power transmission path PT2. When switching from the CVT travel (medium vehicle speed) mode to the CVT travel (high vehicle speed) mode, the shift control unit 94 outputs a command to the hydraulic control circuit 80 to release the meshing clutch D1 by the hydraulic actuator 62. Further, when switching from the CVT travel (high vehicle speed) mode to the CVT travel (medium vehicle speed) mode, the shift control unit 94 outputs a command to the hydraulic control circuit 80 to engage the engagement clutch D1 by the hydraulic actuator 62. . When the shift control unit 94 determines a downshift during the travel in the CVT travel (medium vehicle speed) mode and switches to the gear travel mode, the shift control unit 94 releases the second clutch C2 and engages the first clutch C1. A command to be executed is output to the hydraulic control circuit 80. As a result, the power transmission path PT in the power transmission device 16 is switched from the second power transmission path PT2 to the first power transmission path PT1. In the switching control for switching between the gear travel mode and the CVT travel mode, the first power transmission path PT1 and the second power transmission are simply performed by passing the torque by the CtoC shift through the state of the CVT travel (medium vehicle speed) mode. Since the path PT2 is switched, the switching shock is suppressed.

  The target gear ratio calculation unit 96 applies the accelerator opening θacc and the vehicle speed V to, for example, a predetermined relationship (for example, a CVT shift map) in the CVT travel mode, thereby achieving a target that is a target value of the input shaft rotational speed Nin. The input shaft rotational speed Nintgt is calculated. The target speed ratio calculation unit 96 calculates a target speed ratio γcvttgt (= Nintgt / Nsec) that is a target value of the speed ratio γcvt of the continuously variable transmission 24 based on the target input shaft rotational speed Nintgt. The CVT shift map is determined in advance so that, for example, a target speed ratio γcvttgt of the continuously variable transmission 24 for operating the engine 12 on a predetermined optimal line (for example, an engine optimal fuel consumption line) is calculated. .

  The transmission control unit 94 controls the transmission ratio γcvt of the continuously variable transmission 24 based on the target transmission ratio γcvttgt of the continuously variable transmission 24 calculated by the target transmission ratio calculation unit 96 in the CVT travel mode (that is, the continuously variable transmission). (Shift control of the transmission 24 is performed). Specifically, the shift control unit 94 determines the hydraulic pressure commands (hydraulic control command signal Scvt) for the primary pressure Pin and the secondary pressure Pout for achieving the target gear ratio γcvttgt, and these hydraulic pressure commands are transmitted to the hydraulic control circuit. Output to 80 to execute CVT shift.

  By the way, in the power transmission device 16, the engine 12 (the input shaft 22 is also agreed) and the continuously variable transmission 24 (particularly the primary pulley 66) are directly connected (that is, connected without a clutch), and the continuously variable transmission 24 is connected. (Especially the secondary pulley 70) and the drive wheel 14 (the output shaft 30 also agrees) are connected via the second clutch C2. Therefore, when the second clutch C2 is disengaged, the pulleys 66 and 70 of the continuously variable transmission 24 are engine regardless of the rotation of the drive wheels 14 (that is, not restricted by the rotation of the drive wheels 14). It is driven by 12 rotations. Then, when the speed ratio γcvt of the continuously variable transmission 24 is on the speed increasing side (high gear ratio side), the secondary pulley 70 is overrotated even if the engine speed Ne does not exceed the predetermined overspeed. There is a possibility.

  Therefore, when the second clutch C2 is in the disengaged state, the shift control unit 94 makes the secondary pulley rotational speed Nsec fall within a predetermined range (that is, the secondary pulley rotational speed Nsec has a predetermined upper limit rotational speed). The speed ratio γcvt of the continuously variable transmission 24 is controlled so as not to exceed. That is, when the second clutch C2 is in the disengaged state, the speed change control unit 94 sets the speed change ratio γcvt of the continuously variable transmission 24 to be greater than the speed change ratio at which the secondary pulley rotational speed Nsec is a predetermined upper limit rotational speed. Control to the low gear ratio. The predetermined upper limit rotational speed is a secondary over-rotation upper limit rotational speed Nsecolim that is determined in advance as the secondary pulley 70 will be over-rotated when the secondary pulley rotational speed Nsec exceeds the rotational speed.

  Here, even if the second clutch C2 is released (that is, the second power transmission path PT2 is in the neutral state) and power transmission via the second power transmission path PT2 is interrupted, the input shaft 22 Since the primary pulley 66 is connected, a difference in the transmission gear ratio γcvt of the continuously variable transmission 24 may affect the power transmission device 16. Further, the second clutch differential rotation speed ΔNc2 (= Nsec−Nout), which is the differential rotation speed of the second clutch C2 that is engaged when forming the second power transmission path PT2, is obtained when the second clutch C2 is engaged. It is desirable that the difference be within a predetermined differential rotation ΔNc2lim for suppressing the heat generation amount of the friction material. It is also conceivable to previously control the speed ratio γcvt of the continuously variable transmission 24 assuming the time of power transmission via the second power transmission path PT2 from the time when the second clutch C2 is released. Thus, there are various demands for the transmission ratio γcvt of the continuously variable transmission 24 when the second clutch C2 is in the released state. In this embodiment, when the second clutch C2 is in the released state, from the viewpoint of hardware protection, it is an optimal stepless considering various requirements with the highest priority given to suppressing over-rotation of the secondary pulley 70. A transmission ratio γcvt of the transmission 24 is set.

  More specifically, the electronic control unit 90 further includes an operation state determination unit, that is, an operation state determination unit 98, and a target speed ratio selection unit, that is, a target speed ratio selection unit 99.

  The operating state determination unit 98 determines whether or not the second clutch C2 is in a released state, for example, based on whether or not a hydraulic pressure command value for a solenoid valve for engaging the second clutch C2 is output. judge.

  When the operation state determination unit 98 determines that the second clutch C2 is not disengaged (that is, the target speed ratio calculation unit 96 is the second because the second clutch C2 is engaged). As described above, when the power transmission path PT2 is formed, the target input shaft rotational speed Nintgt is calculated based on the CVT shift map, and the target input shaft rotational speed Nintgt and the secondary pulley rotational speed Nsec are calculated. Based on this, the target gear ratio γcvttgt (= Nintgt / Nsec) of the continuously variable transmission 24 in the CVT travel mode is calculated.

  When the operation state determination unit 98 determines that the second clutch C2 is not released, the transmission control unit 94 determines the continuously variable transmission 24 in the CVT travel mode calculated by the target gear ratio calculation unit 96. The speed ratio γcvt of the continuously variable transmission 24 is controlled based on the target speed ratio γcvttgt.

  On the other hand, when the operation state determination unit 98 determines that the second clutch C2 is in the released state, the target gear ratio calculation unit 96 reduces the load on the continuously variable transmission 24. A gear ratio (hereinafter referred to as a first target speed ratio γtgt1), a second target speed ratio (hereinafter referred to as a second target speed ratio γtgt2) that regulates the secondary pulley rotational speed Nsec, and a second clutch C2 are engaged. Then, a third target speed ratio (hereinafter referred to as a third target speed ratio γtgt3) based on the traveling state in a state where the second power transmission path PT2 is formed is calculated.

  The first target speed ratio γtgt1 is a target speed ratio for realizing the requirement 1 for controlling the speed ratio γcvt of the continuously variable transmission 24 itself. Therefore, the first target gear ratio γtgt1 is the target value that is the gear ratio γcvt itself that changes the load in the continuously variable transmission 24.

  The first target speed ratio γtgt1 is, for example, a speed ratio for reducing the burden on the hardware of the continuously variable transmission 24 (hereinafter referred to as the first target speed ratio γtgt1-1). The first target gear ratio γtgt1-1 is, for example, a gear ratio at which a load is small for a ring connecting elements constituting the transmission belt 72, and is a value near the gear ratio 1 or the gear ratio 1.

  The first target speed ratio γtgt1 is, for example, a speed ratio that can reduce loss in the continuously variable transmission 24 (hereinafter referred to as a first target speed ratio γtgt1-2). The loss in the continuously variable transmission 24 is, for example, a friction loss (drag loss) of the continuously variable transmission 24 or an inertia loss of the continuously variable transmission 24. In general, the friction loss is minimized at an intermediate gear ratio (for example, gear ratio 1), and simply increases toward the highest gear ratio γmin or the lowest gear ratio γmax. On the other hand, since the angular acceleration of the secondary pulley 70 is generally increased toward the highest gear ratio γmin, the inertia loss of the secondary pulley 70 increases on the highest gear ratio γmin side, and simply decreases toward the lowest gear ratio γmax side. Get smaller. That is, as the highest gear ratio γmin side increases, the equivalent inertia on the input side of the continuously variable transmission 24 increases (that is, the equivalent inertia on the input side of the secondary pulley 70 depending on the gear ratio increases), thereby accelerating the vehicle. Sometimes the inertia loss on the input side due to rotational fluctuation increases. On the other hand, in order to reduce the booming noise and vibration, it is advantageous that the equivalent inertia is large. Therefore, the first target speed ratio γtgt1-2 may be determined in advance as a speed ratio that minimizes the loss in the continuously variable transmission 24, or in a low engine speed range or a low vehicle speed range, a noise or vibration may occur. It is also possible to use a gear ratio that prioritizes reducing the gear ratio, and a gear ratio that prioritizes reducing loss in the high engine speed range and the high vehicle speed range.

  The second target speed ratio γtgt2 is a target speed ratio for realizing the requirement 2 for controlling the secondary pulley rotational speed Nsec that is changed in accordance with the change of the speed ratio γcvt. Therefore, the second target gear ratio γtgt2 is calculated based on the target secondary pulley rotational speed Nsectgt that is a target value of the secondary pulley rotational speed Nsec that regulates the secondary pulley rotational speed Nsec, and the input shaft rotational speed Nin. The speed ratio γtgt (= Nin / Nsectgt).

  The second target speed ratio γtgt2 is a speed ratio for preventing the secondary pulley 70 from over-rotating, for example, and is the limit speed ratio at which the secondary pulley 70 does not over-rotate (hereinafter referred to as the second target speed ratio γtgt2-1). This is the lower gear ratio range. Therefore, the target secondary pulley rotational speed Nsectgt at this time is the secondary over-rotation upper limit rotational speed Nsecolim. The target gear ratio calculation unit 96 calculates the second target gear ratio γtgt2-1 (= Nin / Nsecolim) based on the secondary overspeed upper limit rotational speed Nsecolim and the input shaft rotational speed Nin.

  The second target speed ratio γtgt2 is a speed ratio for suppressing the amount of heat generated by the friction material when the second clutch C2 is engaged, for example, and the second clutch differential rotation speed ΔNc2 (= Nsec−Nout) is This is the speed ratio range on the low side of the limit speed ratio (hereinafter referred to as the second target speed ratio γtgt2-2) that does not exceed the predetermined differential rotation ΔNc2lim. Therefore, the target secondary pulley rotational speed Nsectgt at this time is the secondary differential rotation upper limit rotational speed Nsecdlim (= Nout + ΔNc2lim) obtained by adding the predetermined differential rotation ΔNc2lim to the output shaft rotational speed Nout. The target gear ratio calculation unit 96 calculates the second target gear ratio γtgt2-2 (= Nin / Nsecdlim) based on the secondary differential rotation upper limit rotation speed Nsecdlim and the input shaft rotation speed Nin. The predetermined differential rotation ΔNc2lim is an upper limit value of the predetermined differential rotation ΔNc2 for suppressing the heat generation amount of the friction material when the second clutch C2 is engaged, as described above. Or a value that decreases as the engine torque Te increases.

  The third target gear ratio γtgt3 is a gear ratio γcvt after engagement of the second clutch C2 assuming power transmission via the continuously variable transmission 24 (that is, power transmission via the second power transmission path PT2). This is the target gear ratio for realizing the requirement 3 to be controlled in advance. Therefore, the third target speed ratio γtgt3 is calculated based on the target input shaft rotational speed Nintgt and the output shaft rotational speed Nout in consideration of the travel state after engagement of the second clutch C2. = Nintgt / Nout). Since the third target speed ratio γtgt3 is the speed ratio γcvt after the second clutch C2 is engaged, the third target speed ratio γtgt3 is calculated using the output shaft rotational speed Nout instead of the secondary pulley rotational speed Nsec.

  The third target speed ratio γtgt3 is a speed ratio in consideration of, for example, fuel consumption and drivability after engagement of the second clutch C2 (hereinafter referred to as a third target speed ratio γtgt3-1). Therefore, the target input shaft rotational speed Nintgt at this time is the target input shaft rotational speed Nintgt calculated based on the CVT shift map. The target speed ratio calculation unit 96 calculates a third target speed ratio γtgt3-1 (= Nintgt / Nout) based on the target input shaft rotational speed Nintgt and the output shaft rotational speed Nout.

  The third target speed ratio γtgt3 is a speed ratio for preventing, for example, engine stall after the engagement of the second clutch C2 or securing a brake negative pressure, and the engine 12 falls below the idling rotational speed. This is a gear ratio range on the low side with respect to a limit gear ratio (hereinafter referred to as a third target gear ratio γtgt3-2). Therefore, the target input shaft rotational speed Nintgt at this time is the input shaft lower limit rotational speed Ninllim corresponding to the idling rotational speed of the engine 12. The target speed ratio calculation unit 96 calculates a third target speed ratio γtgt3-2 (= Ninllim / Nout) based on the input shaft lower limit rotational speed Ninllim and the output shaft rotational speed Nout.

  The third target speed ratio γtgt3 is a speed ratio for suppressing, for example, a rise in the rotation of the engine 12 after engagement of the second clutch C2 at a high oil temperature, and the engine 12 does not overspeed at a high oil temperature. The speed ratio range is higher than the limit speed ratio (hereinafter referred to as a third target speed ratio γtgt3-3). Therefore, the target input shaft rotational speed Nintgt at this time is the input shaft upper limit rotational speed Nilnim corresponding to the engine upper limit rotational speed at a predetermined high oil temperature. The target gear ratio calculation unit 96 calculates a third target gear ratio γtgt3-3 (= Ninulim / Nout) based on the input shaft upper limit rotational speed Ninulim and the output shaft rotational speed Nout.

  The target speed ratio selection unit 99 is based on a predetermined arbitration method, and is calculated from the first target speed ratio γtgt1, the second target speed ratio γtgt2, and the third target speed ratio γtgt3 calculated by the target speed ratio calculation unit 96. Any one of the target gear ratios γtgt is selected. The predetermined arbitration method selects the target speed ratio γtgt having the highest priority. However, when the target speed ratio γtgt that defines the speed ratio range is selected, priority is given to satisfying the speed ratio range. The target gear ratio γtgt having the next highest degree is selected.

  Specifically, the target speed ratio γtgt having the highest priority is the second target speed ratio γtgt2. Of the second target speed ratio γtgt2, the second target speed ratio γtgt2 (a speed ratio range on the lower side than the second target speed ratio γtgt2-1) for suppressing over-rotation of the secondary pulley 70 is Higher priority than the second target gear ratio γtgt2 (the gear ratio range on the lower side than the second target gear ratio γtgt2-2) for suppressing the heat generation amount of the friction material when the second clutch C2 is engaged. Has been. Since both are the target speed ratio γtgt that defines the low speed ratio range, either the second target speed ratio γtgt2-1 or the second target speed ratio γtgt2-2 is set to the low side second target speed ratio. γtgt2 is selected.

  In the vehicle speed range close to the vehicle speed V at which the CtoC shift (upshift) for switching from the gear travel mode to the CVT travel (medium vehicle speed) mode is determined, the third target speed ratio γtgt3 is next to the second target speed ratio γtgt2. The target speed ratio γtgt is high in priority. On the other hand, in the vehicle speed range away from the vehicle speed V at which the upshift is determined, the first target speed ratio γtgt1 is set to the target speed ratio γtgt having the second highest priority after the second target speed ratio γtgt2.

  When the third target speed ratio γtgt3 has the second highest priority after the second target speed ratio γtgt2, the third target speed ratio for preventing engine stall and ensuring brake negative pressure is within the range satisfying the second target speed ratio γtgt2. γtgt3 (transmission ratio range lower than the third target transmission ratio γtgt3-2) and a third target transmission ratio γtgt3 (third target transmission ratio γtgt3-3 for suppressing the increase in rotation of the engine 12 at a high oil temperature. The third target speed ratio γtgt3-1 is selected in consideration of fuel consumption and drivability within a range that satisfies the speed range defined so far.

  On the other hand, when the first target speed ratio γtgt1 has the second highest priority after the second target speed ratio γtgt2, the burden on the hardware of the continuously variable transmission 24 is reduced within a range that satisfies the second target speed ratio γtgt2. Therefore, the first target speed ratio γtgt1-1 or the first target speed ratio γtgt1-2 that can reduce the loss in the continuously variable transmission 24 is selected. As the first target speed ratio γtgt1-1 and the first target speed ratio γtgt1-2, the higher priority is selected, or the range that satisfies the second target speed ratio γtgt2 is selected. In the first target speed ratio γtgt1-1 and the first target speed ratio γtgt1-2, for example, the priority is switched according to the engine speed Ne or the vehicle speed V.

  The target gear ratio selection unit 99 determines any one of the selected target gear ratios γtgt as the post-arbitration target gear ratio γtgtmed, and sets the target gear ratio γtgtmed after the arbitration when the second clutch C2 is in the released state. The target speed ratio γcvttgt of the continuously variable transmission 24 is set.

  If the operation state determination unit 98 determines that the second clutch C2 is in the disengaged state, the speed change control unit 94 selects any one of the target speed ratios γtgt (selected by the target speed ratio selection unit 99. That is, the speed ratio γcvt of the continuously variable transmission 24 is controlled based on the target speed ratio γcvttgt) of the continuously variable transmission 24 set by the target speed ratio selecting unit 99.

  FIG. 4 is a flowchart for explaining a control operation for appropriately controlling the secondary pulley rotation speed Nsec when the main control operation of the electronic control unit 90, that is, when the second clutch C2 is in the disengaged state. Executed.

  In FIG. 4, first, in step (hereinafter, step is omitted) S10 corresponding to the function of the operating state determination unit 98, it is determined whether or not the second clutch C2 is in a released state. If the determination in S10 is affirmative, in S20 corresponding to the function of the target gear ratio calculation unit 96, the target gear ratio γtgt is calculated for each classification of request 1-3. Specifically, in S21, the target speed ratio for reducing the load in the continuously variable transmission 24 is set as the first target speed ratio γtgt1 for realizing the requirement 1 for controlling the speed ratio γcvt of the continuously variable transmission 24 itself. γtgt is calculated. Next, in S22, the target secondary that regulates the secondary pulley rotational speed Nsec is set as the second target speed ratio γtgt2 for realizing the request 2 for controlling the secondary pulley rotational speed Nsec that is changed in accordance with the change of the speed ratio γcvt. A target gear ratio γtgt (= Nin / Nsectgt) is calculated based on the pulley rotational speed Nsectgt and the input shaft rotational speed Nin. Next, in S23, as a third target speed change ratio γtgt3 for realizing the request 3 for controlling in advance to the speed change ratio γcvt after the engagement of the second clutch C2 assuming power transmission via the continuously variable transmission 24. The target gear ratio γtgt (= Nintgt / Nout) is calculated based on the target input shaft rotational speed Nintgt and the output shaft rotational speed Nout in consideration of the travel state after engagement of the second clutch C2. Next, in S30 corresponding to the function of the target gear ratio selection unit 99, the first target gear ratio γtgt1, the second target gear ratio γtgt2, and the third target gear ratio γtgt3 calculated in S20 are determined according to predetermined arbitration. Arbitration is performed according to the priority based on the method, and any one target gear ratio γtgt is determined as the post-arbitration target gear ratio γtgtmed. Next, in S40 corresponding to the function of the target speed ratio selection unit 99, the post-arbitration target speed ratio γtgtmed determined in S30 is set to the target speed ratio γcvttgt of the continuously variable transmission 24. On the other hand, if the determination in S10 is negative, a target input shaft rotational speed Nintgt is calculated based on the CVT shift map in S50 corresponding to the function of the target gear ratio calculation unit 96, and this target input shaft rotational speed Nintgt. And the secondary pulley rotational speed Nsec, the target gear ratio γcvttgt (= Nintgt / Nsec) of the continuously variable transmission 24 in the CVT traveling mode is calculated. Subsequent to S40 or S50, in S60 corresponding to the function of the shift control unit 94, the continuously variable transmission 24 is controlled to be shifted based on the target speed ratio γcvttgt of the continuously variable transmission 24.

  As described above, according to this embodiment, when the second clutch C2 is in the disengaged state, the gear ratio on the lower side than the gear ratio at which the secondary pulley rotational speed Nsec becomes the predetermined upper limit rotational speed. Since the gear ratio γcvt of the continuously variable transmission 24 is controlled so that the secondary pulley 70 is over-rotated. Therefore, when the second clutch C2 is in the released state, the secondary pulley rotational speed Nsec can be appropriately controlled.

  Further, according to the present embodiment, when the second clutch C2 is in the released state, the target transmission ratio γcvttgt of the continuously variable transmission 24 is set according to the traveling state of the vehicle, so that the traveling state is achieved. The optimum gear ratio γcvt can be realized.

  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, in the above-described embodiment, the control operation when the second clutch C2 is in the released state has been described. Even when the second clutch C <b> 2 is in the slip state, the pulleys 66 and 70 of the continuously variable transmission 24 can be rotated with the rotation of the engine 12 regardless of the rotation of the drive wheels 14. Therefore, even when the second clutch C2 is in the slip state, the same problem as when the second clutch C2 is in the released state may occur. Therefore, when the second clutch C2 is in the slip state, the speed change control unit 94 sets the speed ratio γcvt of the continuously variable transmission 24 to be greater than the speed ratio at which the secondary pulley rotational speed Nsec is a predetermined upper limit rotational speed. You may control to the low gear ratio. In this way, it is possible to appropriately control the secondary pulley rotational speed Nsec so that the secondary pulley 70 is prevented from over-rotating when the second clutch C2 is in the slip state. Further, when the second clutch C2 is in the slip state, the optimum speed ratio γcvt according to the traveling state is set by setting the target speed ratio γcvttgt of the continuously variable transmission 24 according to the traveling state of the vehicle. Can be realized. Thus, the present invention can also be applied when the second clutch C2 is in the slip state. In this case, the operating state determination unit 98 determines whether or not the second clutch C2 is in a slip state based on, for example, a hydraulic pressure command value for a solenoid valve for engaging the second clutch C2. Further, in S10 in the flowchart of FIG. 4, it is determined whether or not the second clutch C2 is in the slip state.

  In the above-described embodiment, the vehicle state in which the second clutch C2 is in the released state is not only the state in which the first power transmission path PT1 is formed, but also with the second power transmission path PT2. This includes a state where the first power transmission path PT1 is in the neutral state. As long as at least the second power transmission path PT2 is in the neutral state, such as when the vehicle is in the gear travel mode or when the vehicle is stopped, and when the power transmission device 16 is in the neutral state, the present invention Can be applied.

  In the above-described embodiment, the second clutch C2 is provided in the power transmission path between the secondary pulley 70 and the output shaft 30, but this is not a limitation. The second clutch C <b> 2 may be provided in a power transmission path between the primary pulley 66 and the input shaft 22. Even in this case, the second power transmission path PT2 is formed by the engagement of the second clutch C2, while the neutral state is established by releasing the second clutch C2.

  In the case where the second clutch C2 is provided between the primary pulley 66 and the input shaft 22, the shift control unit 94, when the second clutch C2 is in the released state, the primary pulley rotational speed Npri (in this case) Controls the gear ratio γcvt of the continuously variable transmission 24 so that the primary pulley rotation speed Npri detected by a rotation sensor different from the rotation sensor for detecting the input shaft rotation speed Nin falls within a predetermined range. That is, when the second clutch C2 is in the disengaged state, the speed change control unit 94 sets the speed change ratio γcvt of the continuously variable transmission 24 to be higher than the speed change ratio at which the primary pulley rotation speed Npri is a predetermined lower limit rotation speed. Control to the low gear ratio. When the second clutch C2 is provided between the primary pulley 66 and the input shaft 22, when the second clutch C2 is released, the pulleys 66 and 70 of the continuously variable transmission 24 are rotated by the drive wheels 14. Be taken around. The vehicle speed V during traveling in the gear traveling mode and the lowest speed ratio γmax of the continuously variable transmission 24 are higher than the speed ratio γgear formed in the first power transmission path PT1. In consideration of this, the possibility that the primary pulley 66 will over-rotate is low. On the other hand, as the gear ratio γcvt of the continuously variable transmission 24 is on the high gear ratio side, the primary pulley rotational speed Npri is lowered, so that the second clutch differential rotational speed ΔNc2 (= Nin−Npri) is increased. Therefore, the above-described primary pulley rotation speed Npri being in a predetermined range means that the primary pulley rotation speed Npri does not fall below a predetermined lower limit rotation speed. The predetermined lower limit rotation speed is a primary differential rotation lower limit rotation speed Npridlim (= Nin−ΔNc2lim) obtained by subtracting a predetermined differential rotation ΔNc2lim from the input shaft rotation speed Nin. In this way, when the second clutch C2 is in the disengaged state, the continuously variable transmission is performed so that the primary pulley rotational speed Npri is a lower speed ratio than the speed ratio at which the predetermined lower limit rotational speed is achieved. Since the gear ratio γcvt of the machine 24 is controlled, the primary pulley 66 is suppressed from rotating at a low speed and the second clutch differential rotation speed ΔNc2 (= Nin−Npri) is suppressed from increasing. Therefore, the primary pulley rotation speed Npri can be appropriately controlled when the second clutch C2 is in the released state.

  When the second clutch C2 is provided between the primary pulley 66 and the input shaft 22, the target speed ratio calculation unit 96 calculates a second target speed ratio γtgt2 that regulates the primary pulley rotation speed Npri. The second target speed ratio γtgt2 is a target speed ratio for realizing the requirement 2 for controlling the primary pulley rotational speed Npri that is changed in accordance with the change of the speed ratio γcvt. Therefore, the second target speed change ratio γtgt2 is a target primary pulley rotation speed Npritgt that is a target value of the primary pulley rotation speed Npri that regulates the primary pulley rotation speed Npri, and a secondary pulley rotation speed Nsec (here, output shaft rotation speed Nout). Is also a target gear ratio γtgt (= Npritgt / Nsec). The second target speed ratio γtgt2 is a speed ratio for suppressing, for example, the amount of heat generated by the friction material when the second clutch C2 is engaged, and the second clutch differential rotation speed ΔNc2 (= Nin−Npri) is a predetermined value. The speed ratio range is on the low side with respect to the limit speed ratio that does not exceed the differential rotation ΔNc2lim (hereinafter referred to as the second target speed ratio γtgt2-1). Therefore, the target primary pulley rotation speed Npritgt at this time is the primary differential rotation lower limit rotation speed Npridlim. The target gear ratio calculation unit 96 calculates the second target gear ratio γtgt2-1 (= Npridlim / Nsec) based on the primary differential rotation lower limit rotation speed Npridlim and the secondary pulley rotation speed Nsec. In addition, the target speed ratio calculation unit 96 calculates the first target speed ratio γtgt1 and the third target speed ratio γtgt3, respectively, as in the above-described embodiment.

  When the second clutch C2 is provided between the primary pulley 66 and the input shaft 22, the target gear ratio γtgt having the highest priority is determined by the engagement of the second clutch C2 in the predetermined arbitration method by the target gear ratio selection unit 99. This is a second target speed ratio γtgt2 (a speed ratio range on the low side with respect to the second target speed ratio γtgt2-1) for suppressing the heat generation amount of the friction material at the time. Accordingly, the target speed ratio selection unit 99 has a priority among the first target speed ratio γtgt1 and the third target speed ratio γtgt3 on condition that the second target speed ratio γtgt2 is satisfied, as in the above-described embodiment. One of the higher target gear ratios is selected. In this way, when the second clutch C2 is in the released state, the target speed ratio γcvttgt of the continuously variable transmission 24 is set according to the traveling state of the vehicle, so that the optimum according to the traveling state is set. A gear ratio γcvt can be realized.

  As described above, even when the second clutch C2 is provided between the primary pulley 66 and the input shaft 22, the present invention can be applied. In addition to the case where the second clutch C2 is in the released state, the present invention can be applied even when the second clutch C2 is in the slip state.

  In the above-described embodiment, the shift control unit 94 is configured so that the rotational speeds of the pulleys 66 and 70 of the continuously variable transmission 24 fall within a predetermined range when the second clutch C2 is in the released state. The gear ratio γcvt of the continuously variable transmission 24 was controlled. When the second clutch C2 is provided between the secondary pulley 70 and the output shaft 30, the target gear ratio γtgt is set to a lower gear ratio range than the limit gear ratio at which the secondary pulley 70 does not overspeed. Thus, the gear ratio γcvt of the continuously variable transmission 24 is controlled so that the secondary pulley rotational speed Nsec falls within a predetermined range. When the second clutch C2 is provided between the primary pulley 66 and the input shaft 22, the target gear ratio γtgt is greater than the limit gear ratio at which the second clutch differential rotation speed ΔNc2 does not exceed the predetermined differential rotation ΔNc2lim. By setting the low gear ratio range, the gear ratio γcvt of the continuously variable transmission 24 is controlled so that the primary pulley rotational speed Npri falls within a predetermined range. For this reason, the shift control unit 94 controls the speed ratio γcvt of the continuously variable transmission 24 to be a low-side speed ratio of 1 or more, so that the rotational speeds of the pulleys 66 and 70 of the continuously variable transmission 24 are increased. The speed ratio γcvt of the continuously variable transmission 24 may be controlled so as to fall within a predetermined range. In this way, since the secondary pulley rotational speed Nsec is lower than the primary pulley rotational speed Npri, when the output shaft 30 and the secondary pulley 70 are connected via the second clutch C2, the engine Even if the rotational speed Ne increases, the secondary pulley 70 is prevented from over-rotating. Alternatively, since the primary pulley rotational speed Npri is higher than the secondary pulley rotational speed Nsec, the primary pulley rotational speed Npri is obtained when the input shaft 22 and the primary pulley 66 are connected via the second clutch C2. Is less likely to decrease, the second clutch differential rotation speed ΔNc2 is suppressed from increasing.

  In the above-described embodiment, the first target speed ratio γtgt1, the second target speed ratio γtgt2, and the third target speed ratio γtgt3 are calculated, and the target speed ratio γtgt is selected based on a predetermined arbitration method. It is not restricted to this aspect. Based on a predetermined arbitration method, a target gear ratio γtgt necessary for setting the post-arbitration target gear ratio γtgtmed is selected from the first target gear ratio γtgt1, the second target gear ratio γtgt2, and the third target gear ratio γtgt3. Only the selected target speed ratio γtgt may be calculated.

  In the above-described embodiment, the operation state determination unit 98 determines whether or not the second clutch C2 is in the released state based on the hydraulic pressure command value, but is not limited to this mode. For example, the operation state determination unit 98 may determine whether or not the second clutch C2 is in a released state based on whether or not the second clutch differential rotation speed ΔNc2 exceeds a predetermined rotation difference. Further, a hydraulic switch or a hydraulic sensor for detecting the hydraulic pressure input to the second clutch C2 is provided, and the operating state determination unit 98 only engages the second clutch C2 with the hydraulic pressure detected by the hydraulic switch or the hydraulic sensor. It may be determined whether or not the second clutch C2 is in a disengaged state based on whether or not the hydraulic pressure is not the same. The same applies when determining whether or not the second clutch C2 is in the slip state.

  Further, in the above-described embodiment, the gear transmission mechanism 28 is a transmission mechanism in which one gear stage having a lower gear ratio than the lowest gear ratio γmax of the continuously variable transmission 24 is formed. Not limited to. For example, the gear transmission mechanism 28 may be a transmission mechanism in which a plurality of gear stages having different gear ratios are formed. That is, the gear transmission mechanism 28 may be a stepped transmission that is shifted to two or more stages. Further, the gear transmission mechanism 28 may be a transmission mechanism that forms a gear ratio higher than the highest gear ratio γmin of the continuously variable transmission 24 and a gear ratio lower than the lowest gear ratio γmax. .

  In the above-described embodiment, the traveling mode of the power transmission device 16 is switched using a predetermined shift map, but the present invention is not limited to this. For example, the driving request amount (for example, required torque) of the driver is calculated on the basis of the vehicle speed V and the accelerator opening degree θacc, and the speed change ratio that can satisfy the required torque is set, so that the driving mode of the power transmission device 16 is set. May be switched.

  In the above-described embodiment, the engine 12 is exemplified as the driving force source. However, the present invention is not limited to this. For example, the driving force source may employ another prime mover such as an electric motor alone or in combination with the engine 12. Further, the power of the engine 12 is transmitted to the input shaft 22 via the torque converter 20, but the present invention is not limited to this. For example, instead of the torque converter 20, another fluid transmission device such as a fluid coupling (fluid coupling) having no torque amplification action may be used. Alternatively, this fluid transmission device is not necessarily provided. Further, the meshing clutch D1 is provided with the synchromesh mechanism S1, but the synchromesh mechanism S1 is not necessarily provided. The continuously variable transmission 24 includes the transmission belt 72 wound between the pulleys 66 and 70 as a transmission element, but is not limited thereto. Instead of the transmission belt 72, a transmission chain may be used as the transmission element. In this case, the continuously variable transmission 24 is a chain-type continuously variable transmission mechanism, but in a broad sense, the concept of a belt-type continuously variable transmission mechanism may include a chain-type continuously variable transmission mechanism.

  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: Engine (power source)
14: Drive wheel 16: Power transmission device 22: Input shaft (input rotation member)
24: continuously variable transmission (continuously variable transmission mechanism)
28: Gear transmission mechanism (transmission mechanism)
30: Output shaft (output rotating member)
66: Primary pulley 70: Secondary pulley 72: Transmission belt (transmission element)
90: Electronic control device (control device)
94: Transmission control unit 96: Target transmission ratio calculation unit 98: Operating state determination unit 99: Target transmission ratio selection unit B1: First brake (first engagement device)
C1: First clutch (first engagement device)
C2: Second clutch (second engagement device)
PT: power transmission path PT1: first power transmission path PT2: second power transmission path

The subject matter of the first invention is (a) provided in parallel to a power transmission path between an input rotating member to which power of a driving force source is transmitted and an output rotating member for outputting the power to driving wheels. In addition, a continuously variable transmission mechanism in which a transmission element is wound between a primary pulley and a secondary pulley, a transmission mechanism in which a gear stage is formed, and the power of the driving force source to the driving wheels via the transmission mechanism A first engagement device for connecting / disconnecting a first power transmission path for transmission, and a power transmission path between the secondary pulley and the output rotating member; A second engagement device for connecting and disconnecting a second power transmission path for transmitting power to the drive wheel, and a speed ratio formed by the first power transmission path can be formed by the second power transmission path. Dynamics with a gear ratio on the low side of the low gear ratio A control device of a force transmission device, wherein (b) an operation state determination unit for determining whether or not the second engagement device is in a slip state or a release state; and (c) in the continuously variable transmission mechanism In a state where the second power transmission path is formed by engaging the first target gear ratio for reducing the load, the second target gear ratio for restricting the rotation of the secondary pulley, and the second engagement device. A target speed ratio calculating unit that calculates a third target speed ratio based on each of the travel states; and (d) satisfying a speed ratio range that is lower than the second target speed ratio. A target speed ratio selecting unit that selects any one of the first target speed ratio and the third target speed ratio that has a higher priority, and (e) the second state by the operating state determination unit. If the engagement device is determined to be a slip state or released state, the And based on the-option is desired transmission ratio the continuously variable transmission mechanism of the gear ratio control Gosuru shift control unit is to contain.

According to a third aspect of the present invention, in the control device for a power transmission device according to the first aspect of the invention, the speed ratio range on the low side of the second target speed ratio prevents the secondary pulley from over-rotating. It is a gear ratio .

The gist of the fourth invention is that (a) a power transmission path between the input rotating member to which the power of the driving force source is transmitted and the output rotating member for outputting the power to the driving wheel is provided in parallel. A continuously variable transmission mechanism in which a transmission element is wound between a primary pulley and a secondary pulley, a transmission mechanism in which a gear stage is formed, and driving the power of the driving force source via the transmission mechanism The first driving device for connecting and disconnecting the first power transmission path for transmitting to the wheel, and the driving force via the continuously variable transmission mechanism provided in the power transmission path between the primary pulley and the input rotating member. And a second engagement device for connecting and disconnecting a second power transmission path for transmitting the power of the power source to the drive wheel, and a speed ratio formed by the first power transmission path is formed by the second power transmission path With the lower gear ratio than the lowest possible gear ratio (B) an operation state determination unit that determines whether or not the second engagement device is in a slip state or a release state; and (c) the continuously variable transmission mechanism. A state in which the second power transmission path is formed by engaging the first target speed ratio for reducing the load at the second position, the second target speed ratio for restricting the rotation of the primary pulley, and the second engagement device. A target speed ratio calculating unit for calculating a third target speed ratio based on the running state at (d), and (d) satisfying a speed ratio range on a lower side than the second target speed ratio, A target speed ratio selection unit that selects any one of the first target speed ratio and the third target speed ratio that has a higher priority, and (e) the operation state determination unit determines the first speed ratio . When it is determined that the two-engagement device is in the slip state or the release state A control Gosuru shift control unit the gear ratio of the continuously variable transmission mechanism on the basis of the selected target gear ratio is to contain.

According to a sixth aspect of the present invention, there is provided the control device for a power transmission device according to the fourth aspect of the present invention, wherein the lower speed ratio range than the second target speed ratio is within the engagement of the second engagement device. This is the gear ratio that suppresses the heat generation amount of the friction material at the time .

According to the first aspect of the invention, when the second engagement device is in the slip state or the release state, it is provided that the gear ratio range on the lower side than the second target gear ratio is satisfied. Any one of the first target speed ratio and the third target speed ratio having a higher priority is selected, and the continuously variable transmission mechanism is selected based on the selected target speed ratio. Since the gear ratio is controlled, when the second engagement device is in the slip state or the released state, the target gear ratio is set according to the traveling state of the vehicle, and the optimum gear ratio according to the traveling state is set. Can be realized. Therefore, when the second engagement device is in the slip state or the release state, the rotational speed of the pulley of the continuously variable transmission mechanism can be appropriately controlled.

According to the third aspect of the invention, since the speed ratio range on the lower side than the second target speed ratio is a speed ratio that prevents the secondary pulley from over-rotating, the secondary pulley is over-rotated. It is suppressed.

According to the fourth aspect of the invention, when the second engagement device is in a slipping state or a releasing state, the second gearing device satisfies the condition that the lower gear ratio range than the second target gear ratio is satisfied. Any one of the first target speed ratio and the third target speed ratio having a higher priority is selected, and the continuously variable transmission mechanism is selected based on the selected target speed ratio. Since the gear ratio is controlled, when the second engagement device is in the slip state or the released state, the target gear ratio is set according to the traveling state of the vehicle, and the optimum gear ratio according to the traveling state is set. Can be realized. Therefore, when the second engagement device is in the slip state or the release state, the rotational speed of the pulley of the continuously variable transmission mechanism can be appropriately controlled.

According to the sixth aspect of the present invention, the speed ratio range that is lower than the second target speed ratio is a speed ratio that suppresses the heat generation amount of the friction material when the second engagement device is engaged. Thus, the primary pulley is prevented from rotating at a low speed, and the differential rotation speed of the second engagement device is suppressed from increasing.

The continuously variable transmission 24 includes a primary pulley 66 having a variable effective diameter provided on the input shaft 22, a secondary pulley 70 having a variable effective diameter provided on a rotary shaft 68 coaxial with the output shaft 30, and each of these. and a transmission belt 72 of a wound about transmission element between the pulleys 66 and 70, power transmission line through a frictional force (belt clamping force) between the pulleys 66, 70 and the transmission belt 72 This is a belt type continuously variable transmission mechanism. In the primary pulley 66, a hydraulic pressure control circuit 80 (see FIG. 3) in which the hydraulic pressure supplied to the primary pulley 66 (that is, the primary pressure Pin supplied to the primary hydraulic cylinder 66c) is driven by the electronic control unit 90 (see FIG. 3). Thus, the primary thrust Win (= primary pressure Pin × pressure receiving area) for changing the V groove width between the sheaves 66a and 66b is applied. In the secondary pulley 70, the hydraulic pressure supplied to the secondary pulley 70 (that is, the secondary pressure Pout supplied to the secondary hydraulic cylinder 70c) is regulated by the hydraulic control circuit 80, so that the sheaves 70a and 70b are separated. Secondary thrust Wout (= secondary pressure Pout × pressure receiving area) for changing the V groove width is applied. In the continuously variable transmission 24, the primary thrust Win (primary pressure Pin) and the secondary thrust Wout (secondary pressure Pout) are controlled, so that the V-groove widths of the pulleys 66 and 70 change and the transmission belt 72 is engaged. The diameter (effective diameter) is changed, the gear ratio γcvt (= primary pulley rotational speed Npri / secondary pulley rotational speed Nsec) is changed, and the pulleys 66 and 70 and the transmission belt are prevented from slipping. The frictional force with 72 is controlled.

As described above, according to the present embodiment, when the second clutch C2 is in the released state , the first target speed ratio γtgt1 and the third target speed are satisfied on the condition that the second target speed ratio γtgt2 is satisfied. Any one of the target gear ratios with high priority is selected from the gear ratio γtgt3, and the gear ratio γcvt of the continuously variable transmission 24 is controlled based on the selected target gear ratio γtgt. When C2 is in the released state, the target speed ratio γcvttgt of the continuously variable transmission 24 is set according to the traveling state of the vehicle, and the optimum speed ratio γcvt according to the traveling state can be realized. Therefore, when the second clutch C2 is in the released state, the secondary pulley rotational speed Nsec can be appropriately controlled.

Further, according to the present embodiment, the speed ratio range lower than the second target speed ratio γtgt2-1 is a speed ratio for preventing the secondary pulley 70 from over-rotating, so the secondary pulley 70 is over-rotated. Is suppressed.

Claims (6)

A transmission element is provided between the primary pulley and the secondary pulley provided in parallel in the power transmission path between the input rotating member to which the power of the driving force source is transmitted and the output rotating member that outputs the power to the driving wheel. A transmission mechanism in which a continuously variable transmission mechanism and a gear stage are formed, and a first engagement that connects and disconnects a first power transmission path that transmits the power of the driving force source to the driving wheels via the transmission mechanism. A second power transmission path for transmitting the power of the driving force source to the driving wheels via the continuously variable transmission mechanism provided in a power transmission path between the secondary pulley and the output rotating member. A power transmission mechanism including a second engagement device connected and disconnected, wherein a speed ratio formed in the first power transmission path is a lower speed ratio than a lowest speed ratio that can be formed in the second power transmission path. A control device of the device,
An operation state determination unit that determines whether or not the second engagement device is in a slip state or a release state;
When the operation state determination unit determines that the second engagement device is in the slip state or the release state, the gear ratio of the continuously variable transmission mechanism is set to a predetermined upper limit rotation speed. And a speed change control unit that controls the speed change ratio to be lower than the speed change ratio.   The power transmission control device according to claim 1, wherein the transmission control unit controls the transmission ratio of the continuously variable transmission mechanism to be 1 or more. A first target speed ratio for reducing the load in the continuously variable transmission mechanism, a second target speed ratio for preventing the secondary pulley from over-rotating, and the second engagement device are engaged to engage the second power. A target speed ratio calculating unit that calculates a third target speed ratio based on a traveling state in a state where the transmission path is formed;
Target speed ratio selection for selecting any one of the first target speed ratio and the third target speed ratio having a higher priority on condition that the second target speed ratio is satisfied And further comprising
2. The control device for a power transmission device according to claim 1, wherein the transmission control unit controls a transmission ratio of the continuously variable transmission mechanism based on the selected target transmission ratio. A transmission element is provided between the primary pulley and the secondary pulley provided in parallel in the power transmission path between the input rotating member to which the power of the driving force source is transmitted and the output rotating member that outputs the power to the driving wheel. A transmission mechanism in which a continuously variable transmission mechanism and a gear stage are formed, and a first engagement that connects and disconnects a first power transmission path that transmits the power of the driving force source to the driving wheels via the transmission mechanism. A second power transmission path for transmitting the power of the driving force source to the drive wheels via the continuously variable transmission mechanism provided in a power transmission path between the primary pulley and the input rotating member. A power transmission mechanism including a second engagement device connected and disconnected, wherein a speed ratio formed in the first power transmission path is a lower speed ratio than a lowest speed ratio that can be formed in the second power transmission path. A control device of the device,
An operation state determination unit that determines whether or not the second engagement device is in a slip state or a release state;
When the operation state determination unit determines that the second engagement device is in the slip state or the release state, the speed ratio of the continuously variable transmission mechanism is set to a predetermined lower limit rotation speed of the primary pulley. And a speed change control unit that controls the speed change ratio to be lower than the speed change ratio.   5. The control device for a power transmission device according to claim 4, wherein the shift control unit controls the transmission ratio of the continuously variable transmission mechanism to be 1 or more. A first target gear ratio that reduces a load in the continuously variable transmission mechanism, a second target gear ratio that suppresses a heat generation amount of the friction material when the second engagement device is engaged, and the second member. A target speed ratio calculating unit that calculates a third target speed ratio based on a traveling state in a state in which the second power transmission path is formed by engaging a combined device;
Target speed ratio selection for selecting any one of the first target speed ratio and the third target speed ratio having a higher priority on condition that the second target speed ratio is satisfied And further comprising
5. The control device for a power transmission device according to claim 4, wherein the transmission control unit controls a transmission ratio of the continuously variable transmission mechanism based on the selected target transmission ratio.

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