JP2017187080A - Control apparatus for vehicular power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for suppressing a gear change shock occurring when switching from a travel-on-gear to a travel-on-belt in a vehicle capable of the travel-on-gear and travel-on-belt.SOLUTION: In the case of vehicular travel acceleration being large in switching from a travel-on-gear to a travel-on-belt, selection of longer shift time makes it possible to switch with a small torque variation in an output shaft by reducing a difference in input shaft rotation speeds, that is, a switchover with a small shift shock. In contrast, in the case of a travel acceleration being small, selection of shorter shit time makes it possible to improve certainty of switching from the travel-on-gear to travel-on-belt.SELECTED DRAWING: Figure 8

Description

  The present invention relates to control in switching from a stepped transmission to a continuously variable transmission in a power transmission device including a stepped transmission and a continuously variable transmission.

  A continuously variable transmission and a stepped transmission provided in parallel between an input shaft connected to a drive source and drive wheels, and the power of the drive source is transmitted to the drive wheels via the stepped transmission. A first clutch provided in the first power transmission path, and second power for transmitting the power of the drive source to the drive wheels via the continuously variable transmission at a speed ratio smaller than that of the first power transmission path. In a vehicle power transmission device having a second clutch provided in a transmission path, when switching from the first power transmission path to the second power transmission path, the first clutch is released and the second clutch is engaged. There is known a vehicular power transmission device that performs switching from a stepped transmission to a continuously variable transmission. For example, the control device for a vehicle power transmission device described in Patent Document 1 is this. In such a vehicle, by switching between a stepped transmission and a continuously variable transmission based on a change in the speed of the vehicle, the fuel consumption and power of the vehicle are compared with a vehicle having only a stepped transmission. Performance is improved.

JP2015-105708A

  When a continuously variable transmission is used in the technology of Patent Document 1, a continuously variable transmission ratio is obtained, so that a smooth transmission can be performed in which the rotational speed of the input shaft of the continuously variable transmission does not change with respect to changes in vehicle speed. It becomes. However, when switching from the stepped transmission to the continuously variable transmission by disengagement of the first clutch provided in the stepped transmission and engagement of the second clutch provided in the continuously variable transmission, A large change in the output shaft torque is exhibited along with a change in the rotational speed of the input shaft of the transmission, which may cause a shift shock.

  The present invention has been made against the background of the above circumstances, and its object is to rotate the power input to the transmission that may occur when switching from a stepped transmission to a continuously variable transmission. It is an object of the present invention to provide a technique capable of reducing the shock caused by the fluctuation of the number and capable of reliably ending the shift.

  The subject matter of the first invention is (a) a continuously variable transmission and a stepped transmission provided in parallel between an input shaft connected to a drive source and a drive wheel, and power of the drive source. A first clutch provided on a first power transmission path that transmits the power to the drive wheels via the stepped transmission, and the continuously variable power of the drive source at a speed ratio smaller than that of the first power transmission path. When switching from the first power transmission path to the second power transmission path in a vehicle power transmission device having a second clutch provided in a second power transmission path that transmits to the drive wheels via a transmission, A control device for a vehicle power transmission device for releasing the first clutch and engaging the second clutch, wherein (b) the vehicle is switched from the first power transmission path to the second power transmission path. When acceleration is lower than the specified value Includes a target input shaft rotational speed change rate setting means for setting a target input shaft rotational speed change rate during low acceleration that increases as the vehicle acceleration decreases, and (c) a rate of change in rotational speed of the input shaft during the low acceleration. And a change rate control means for controlling the engagement hydraulic pressure of the second clutch so that the target input shaft rotation speed change rate is obtained.

  The subject matter of the second invention is the control device for the vehicle drive device of the first invention, wherein the target input shaft rotational speed change rate setting means is from the first power transmission path to the second power transmission path. At the time of switching, if the vehicle acceleration is greater than or equal to a predetermined value, set to a predetermined high acceleration target input shaft rotational speed change rate that is set in advance so that the rotational speed change rate of the input shaft becomes gradual, When the vehicle acceleration is greater than or equal to a predetermined value, the rate-of-change control means sets the engagement hydraulic pressure of the second clutch so that the rate of change of the rotational speed of the input shaft becomes the rate of change of the target input shaft rotational speed during high acceleration. It is characterized by controlling.

  A gist of a third aspect of the present invention is that in the control device for a vehicle drive device according to the first aspect or the second aspect, the target input shaft rotational speed change rate setting means is configured to change the vehicle acceleration when the vehicle speed is low. When the target rotational speed change rate is set repeatedly, the low speed target is changed only when the newly set low target rotational speed change rate is larger than the low target rotational speed change rate so far. It is characterized by updating the rotation speed change rate

  A gist of a fourth aspect of the present invention is the vehicle drive device control apparatus according to the first aspect or the second aspect, wherein the rate of change control means is the low acceleration target input shaft rotational speed change rate or the high rate. A feedforward term that generates a control operation amount corresponding to a target input shaft rotational speed change rate during acceleration, a rotational speed change rate of the input shaft, a target input shaft rotational change rate during low acceleration, or the high acceleration The first clutch is released and the second clutch is engaged using a control equation having a feedback term for generating a control operation amount corresponding to the deviation from the target input shaft rotational speed change rate. It is characterized in that change rate control is performed.

  A fifth aspect of the present invention is that a continuously variable transmission and a stepped transmission provided in parallel between an input shaft connected to a drive source and a drive wheel, and the power of the drive source are A first clutch provided in a first power transmission path for transmitting to the drive wheels via a stepped transmission, and the continuously variable transmission at a speed ratio smaller than that of the first power transmission path. In the vehicular power transmission device having a second clutch provided in a second power transmission path for transmitting to the drive wheel via the first clutch, when switching from the first power transmission path to the second power transmission path, the first clutch When the vehicle acceleration is higher than a predetermined value when switching from the first power transmission path to the second power transmission path. If it is low A target engagement time setting means for setting a long time required for engagement of the second clutch, and a mechanism for controlling the engagement hydraulic pressure of the second clutch so as to be a time set by the target engagement time setting means. And a time control means.

  According to the first aspect of the present invention, when the vehicle acceleration is lower than a predetermined value when switching from the first power transmission path to the second power transmission path, the rate-of-change control means has a rate of change in rotation of the input shaft. Since the engagement hydraulic pressure of the second clutch is controlled so that the rate of change of the target input shaft rotation speed during low acceleration increases as the vehicle acceleration decreases, the engagement of the second clutch is completed even when the vehicle is at low acceleration. The change rate control can be terminated.

  According to the second aspect of the present invention, the change rate control means includes the second clutch so that when the vehicle acceleration is high, the rotational speed change rate of the input shaft becomes the target input shaft rotational speed change rate during the high acceleration. Since the change in the input shaft rotation speed change rate during the change rate control is reduced because the engagement hydraulic pressure is controlled, switching from the stepped transmission to the continuously variable transmission with less shift shock can be obtained.

  According to the third invention, the target input shaft rotational speed change rate setting means is set only when the newly set low-speed target rotational speed change rate is larger than the low-speed target rotational speed change rate so far. Since the low-speed target rotational speed change rate is updated, the change rate control is surely terminated even when the vehicle acceleration decreases.

  According to a fourth aspect, the change rate control means generates a control operation amount corresponding to the low acceleration target input shaft rotational speed change rate or the high acceleration target input shaft rotational speed change rate. And a control operation corresponding to the deviation between the feedforward term and the input shaft rotation speed change rate and the low acceleration target input shaft rotation change rate or the high acceleration target input shaft rotation speed change rate. Since the change rate control for releasing the first clutch and engaging the second clutch is executed using a control equation having a feedback term for generating an amount, the control deviation is eliminated and the second clutch is engaged. At the same time, the target input shaft rotational speed change rate during low acceleration or the target input shaft rotational speed change rate during high acceleration is obtained.

  According to the fifth aspect of the present invention, when the vehicle acceleration is higher than a predetermined value when switching from the first power transmission path to the second power transmission path, the time required for engaging the second clutch is made longer than when the vehicle acceleration is low. Since the engagement hydraulic pressure of the second clutch is controlled so as to be set, when the vehicle acceleration is higher than a predetermined value, the stepped transmission with less shift shock is set by setting the time required for engagement of the second clutch to be longer. When the vehicle acceleration is lower than the predetermined value, the time required for engagement of the second clutch is set short, so that even when the vehicle acceleration is reduced, the vehicle can be switched to the continuously variable transmission. The engagement of the second clutch can be completed.

It is a skeleton diagram explaining a power transmission device to which the present invention is applied. It is a figure for demonstrating switching of the running pattern of the power transmission device of FIG. It is a figure explaining the principal part of the control function and various control systems for various control in the vehicle of FIG. FIG. 4 is a diagram for explaining a portion of the hydraulic control circuit of FIG. 3 that controls the hydraulic pressure related to switching of the hydraulic pressure to the torque converter, continuously variable transmission, and clutch. It is the figure which showed an example of the change of the input rotational speed in switching from the stepped transmission to the continuously variable transmission of the power transmission device of FIG. FIG. 2 is a diagram illustrating an example of a change in input rotation speed when the acceleration of a vehicle exceeds a predetermined value and the switching is moderated in switching from a stepped transmission to a continuously variable transmission of the power transmission device of FIG. 1. In the switching from the stepped transmission to the continuously variable transmission of the power transmission device of FIG. 1, the change in the input rotation speed when the vehicle acceleration is equal to or less than a predetermined value and the target value for the change in the input rotation speed is increased. FIG. 7 is a flowchart for explaining a main part of control when changing a target value of a change in input rotational speed based on vehicle acceleration in switching from a stepped transmission to a continuously variable transmission. 7 is a flowchart for explaining a main part of control when changing a time required for shifting based on the acceleration of a vehicle in switching from a stepped transmission to a continuously variable transmission.

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

  FIG. 1 is a skeleton diagram for explaining a schematic configuration of a drive device 12 provided in a vehicle 10 according to an embodiment of the present invention. The drive device 12 includes, for example, an engine 14 used as a driving force source for traveling, a torque converter 16 as a fluid transmission device, a forward / reverse switching device 18, and a belt-type continuously variable transmission 20 (hereinafter referred to as a continuously variable transmission). Machine 20), a gear mechanism 22, and an output shaft 25 on which an output gear 24 capable of transmitting power to the drive wheels 66 is formed. In the drive device 12, torque (driving force) output from the engine 14 is input to the input shaft 26 via the torque converter 16, and this torque is output from the input shaft 26 via the gear mechanism 22 and the like. A first power transmission path that is transmitted to the shaft 25 and a second power transmission path that transmits torque input to the input shaft 26 to the output shaft 25 via the continuously variable transmission 20 are provided in parallel. The power transmission path is switched according to the traveling state of the vehicle 10. In addition, the power from the engine 14 that is output via the output shaft 25 (the torque and the force are synonymous unless otherwise distinguished) is provided on the output shaft 25 and the counter shaft 44 so as not to rotate relative to each other. Further, it is transmitted to the pair of drive wheels 66 through the driven gear 46, the differential ring gear 62 of the differential device 64 meshing with the driven gear 46, and the pair of axles 60.

  The engine 14 is constituted by an internal combustion engine such as a gasoline engine or a diesel engine. The torque converter 16 includes a pump impeller 16p connected to the crankshaft of the engine 14 and a turbine impeller 16t connected to the forward / reverse switching device 18 via an input shaft 26 corresponding to an output side member of the torque converter 16. And power transmission is performed via a fluid. Further, a lockup clutch 28 is provided between the pump impeller 16p and the turbine impeller 16t. When the lockup clutch 28 is completely engaged, the pump impeller 16p and the turbine impeller 16t are integrated. Rotated.

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

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

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

  Further, between the continuously variable transmission 20 and the output shaft 25, a belt traveling clutch C2, that is, a second clutch that selectively connects and disconnects between these, is inserted, and this clutch C2 is engaged. Thus, a second power transmission path is formed in which the torque of the engine 14 is transmitted to the output shaft 25 via the input shaft 26 and the continuously variable transmission 20. Further, when the clutch C2 is released, the second power transmission path is interrupted, and torque is not transmitted from the continuously variable transmission 20 to the output shaft 25.

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

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

  When the V groove width of the pair of variable pulleys 54 and 56 is changed to change the engagement diameter of the transmission belt 58, that is, the effective diameter, the gear ratio γ (= input shaft rotation speed ωin (rpm) / output shaft rotation The speed ωout (rpm)) is continuously changed. Note that ω is used not as an angular velocity (rad / sec) but as a symbol representing a rotational speed (rpm), and the same applies to symbols used thereafter. For example, when the V-groove width of the input pulley 54 is reduced, the speed ratio γ is reduced. That is, the continuously variable transmission 20 is upshifted. Further, when the V-groove width of the input pulley 54 is increased, the speed ratio γ is increased. That is, the continuously variable transmission 20 is downshifted.

  Hereinafter, the operation of the drive device 12 configured as described above will be described using an engagement table of engagement elements for each traveling pattern shown in FIG. In FIG. 2, C1 corresponds to the operating state of the forward clutch C1, C2 corresponds to the operating state of the belt traveling clutch C2, B1 corresponds to the operating state of the reverse brake B1, and D1 corresponds to the meshing clutch D1. Corresponding to the operating state, “◯” indicates engagement, that is, connection, and “x” indicates release, that is, disconnection. Note that the meshing clutch D1 includes a synchronization mechanism S1, and the synchronization mechanism S1 operates when the meshing clutch D1 is engaged.

  First, a traveling pattern in which the torque of the engine 14 is transmitted to the output gear 24 via the gear mechanism 22, that is, a traveling pattern in which the torque is transmitted through the first power transmission path will be described. This traveling pattern corresponds to the gear traveling of FIG. 2, and as shown in FIG. 2, the forward clutch C1 and the meshing clutch D1 are engaged, while the belt traveling clutch C2 and the reverse brake B1 are released.

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

  Next, a traveling pattern in which the torque of the engine 14 is transmitted to the output gear 24 via the continuously variable transmission 20 will be described. This travel pattern corresponds to the belt travel (high vehicle speed) in FIG. 2, and as shown in the belt travel in FIG. 2, the belt travel clutch C2 is connected, while the forward clutch C1, the reverse brake B1, and the meshing The clutch D1 is disconnected. Since the output side pulley 56 and the output shaft 25 are connected by connecting the belt traveling clutch C2, the output side pulley 56, the output shaft 25, and the output gear 24 are integrally rotated. Therefore, when the belt traveling clutch C2 is connected, the second power transmission path is formed, and the torque of the engine 14 is transmitted to the torque converter 16, the input shaft 26, the input side rotating shaft 32, the continuously variable transmission 20, and It is transmitted to the output gear 24 via the output shaft 25. At this time, the meshing clutch D1 is released during the belt travel in which the torque of the engine 14 is transmitted via the second power transmission path, in addition to eliminating dragging of the gear mechanism 22 and the like during the belt travel. This is to prevent the gear mechanism 22 and the like from rotating at a high speed.

  The gear traveling is selected in the low vehicle speed region. The speed ratio γ (input shaft rotational speed ωin / output shaft rotational speed ωout) based on the first power transmission path is set to a value larger than the maximum speed ratio γmax of the continuously variable transmission 20. That is, the speed ratio γ in the first power transmission path is set to a value that is not set in the continuously variable transmission 20. Then, for example, when it is determined that the vehicle travels to the belt running due to an increase in the vehicle speed V, the belt traveling is switched. Here, when switching from gear travel to belt travel (high vehicle speed) or from belt travel (high vehicle speed) to gear travel, the belt travel (medium vehicle speed) in FIG.

  For example, when switching from belt travel (high vehicle speed) to gear travel, the state is switched transiently from the state in which the belt travel clutch C2 is engaged to the state in which the meshing clutch D1 is engaged in preparation for switching to gear travel. . At this time, the rotation is also transmitted to the sun gear 30s of the planetary gear device 30 via the gear mechanism 22. From this state, the forward clutch C1 and the belt traveling clutch C2 are switched, that is, the forward clutch C1 is engaged. In this case, the power transmission path is switched from the second power transmission path to the first power transmission path by executing the disconnection of the belt traveling clutch C2. At this time, the driving device 12 is substantially downshifted.

  Further, when switching from gear traveling to belt traveling (high vehicle speed), the belt traveling clutch C2 and the meshing clutch D1 are engaged from the state in which the forward clutch C1 and the meshing clutch D1 corresponding to the gear traveling are engaged. It is switched to the transition state transiently. That is, the switching of the forward clutch C1 and the belt traveling clutch C2 is started. At this time, the power transmission path is changed from the first power transmission path to the second power transmission path, and the driving device 12 is substantially upshifted. Then, after the power transmission path is switched, the meshing clutch D1 is released to prevent unnecessary drag and high rotation of the gear mechanism 22 and the like.

  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 80 including a control device for the drive device 12, for example. Therefore, FIG. 3 is a diagram showing an input / output system of the electronic control unit 80, and is a functional block diagram for explaining a main part of a control function by the electronic control unit 80. The electronic control unit 80 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like, and the CPU uses a temporary storage function of the RAM according to a program stored in the ROM in advance. Various controls of the vehicle 10 are executed by performing signal processing. For example, the electronic control unit 80 performs output control of the engine 14, shift control of the continuously variable transmission 20, switching control of the driving mode of the drive unit 12, and the like. The electronic control unit 80 is configured separately for engine control, hydraulic control, and the like as necessary.

  The electronic control unit 80 includes values based on detection signals from various sensors provided in the vehicle 10, such as various rotational speed sensors 82, 84, 86, 88, 90, an accelerator opening sensor 92, and the like, for example, engine rotational speed ωeng (rpm ), The input shaft rotation speed ωin (rpm) and the primary pulley rotation speed ωpri (rpm) which are the turbine rotation speed ωt (rpm), the secondary pulley rotation speed ωsec (rpm) which is the rotation speed of the output side rotation shaft 33, and the vehicle speed V. An output shaft rotational speed ωout (rpm), an accelerator opening degree θacc (%), and the like corresponding to (km / h) are supplied. The electronic control unit 80 also outputs an engine output control command signal Se for output control of the engine 14, a hydraulic control command signal Scvt for hydraulic control related to the shift of the continuously variable transmission 20, and the travel mode of the drive device 12. The hydraulic control command signal Sswt for controlling the forward clutch C1, the reverse brake B1, the traveling clutch C2, and the meshing clutch D1 related to the switching, the hydraulic control command signal Slu for controlling the hydraulic pressure of the torque converter 20, etc. , Respectively. For example, as a hydraulic control command signal Sswt, a command for driving each solenoid valve that regulates each hydraulic pressure supplied to each hydraulic actuator of the forward clutch C1, the reverse brake B1, the traveling clutch C2, and the meshing clutch D1. A signal (hydraulic command) is output to the hydraulic control circuit 100. Further, the electronic control unit 80 sequentially calculates the gear ratio γ (= ωin / ωout) of the continuously variable transmission 20 based on, for example, the output shaft rotational speed ωout and the input shaft rotational speed ωin.

  FIG. 4 shows solenoid valves SLU, SLP, SLS, SL1, and SL2, which are linear solenoid valves driven by a hydraulic control command signal (drive current) output from the electronic control unit 80. The solenoid valves SLP and SLS are both normally open solenoid valves. The solenoid valves SLU, SL1, SL2 are all normally closed solenoid valves. The solenoid valves SLU, SLP, SLS each output, for example, a hydraulic pressure using the modulator pressure Pm as a source pressure, and the solenoid valves SL1, SL2 each output, for example, a hydraulic pressure using the line pressure Pl as a source pressure. The torque converter pressure control valve 72 is operated based on the hydraulic pressure Pslu output from the torque converter solenoid valve SLU, thereby adjusting the torque converter pressure Ptc using the second line pressure Pl2 as a source pressure. The primary pressure control valve 68 is operated based on the hydraulic pressure Pslp output from the primary solenoid valve SLP, thereby adjusting the primary pressure Pin using the line pressure Pl as a source pressure. The secondary pressure control valve 70 is operated based on the hydraulic pressure Psls output from the secondary solenoid valve SLS, thereby adjusting the secondary pressure Pout using the line pressure Pl as a source pressure. The hydraulic pressure Pc1 output from the C1 solenoid valve SL1 is supplied to the forward clutch C1. The hydraulic pressure Pc2 output from the C2 solenoid valve SL2 is supplied to the travel clutch C2. Therefore, the hydraulic pressure control in the shift control is performed by these solenoid valves SLU, SLP, SLS, SL1, and SL2.

FIG. 5 shows from the gear traveling in which the torque of the engine 14 is transmitted to the output gear 24 via the forward / reverse switching device 18 and the gear mechanism 22, that is, the traveling in which the torque is transmitted through the first transmission path. An example is shown in which the torque of the engine 14 is switched to the belt travel that is transmitted to the output gear 24 via the step transmission 20. The actual rotation speed ωina (rpm), which is a thick solid line, shows a curve of the change of the input shaft rotation speed ωin, that is, the turbine rotation speed ωt with respect to the elapsed time t (sec). In the 1st synchronization which is a thin solid line, a change with respect to the elapsed time t of the input shaft rotational speed ωin in the gear traveling when the vehicle 10 travels at a substantially constant acceleration is shown by a straight line, and another thin solid line In a certain γmax synchronization, the change with respect to the elapsed time t of the input shaft rotational speed ωin at the maximum speed ratio γmax in the belt traveling when the vehicle 10 travels at a constant acceleration is shown by a straight line. At time t00, the electronic control unit 80 determines, for example, switching from gear travel to belt travel based on the vehicle speed V and the accelerator opening θacc, and controls the forward clutch C1, the travel clutch C2, and the like. Command signal Sswt is output. The time t01 to the time t01 is a so-called torque phase, and the forward clutch C1 engaged in gear traveling is gradually released after the time t00. The traveling acceleration ΔV (m / sec ² ) of the vehicle 10 is substantially constant, and the actual rotational speed ωina shows almost the same change as the 1st synchronization indicated by the thin solid line. For example, the electronic control unit 80 gradually engages the clutch C2 with a control that reduces the actual rotational speed ωina at the time t01 when the inertia phase starts, that is, the differential rotation between the ωmax and the input shaft rotational speed ωin10 on the γmax synchronization at the time t01. To do. In FIG. 5, the vehicle speed V increases from the time point t01 to the time point t1, and therefore, the control of the actual rotational speed ωina is also performed with the input shaft rotational speed ωin on the γmax synchronization that increases based on the vehicle speed V, that is, ωout. Control is performed to reduce the differential rotation. At time t1, the input shaft rotational speed ωin11 is on the γmax synchronization indicated by the thin solid line, which is the maximum gear ratio in belt travel, when the engagement of the travel clutch C2 is completed, and the so-called inertia phase ends. To do. After the time point t1, the actual rotational speed ωina shows a slight difference from the γmax synchronization that is a straight line due to fluctuations in the travel acceleration ΔV of the vehicle 10, but after that, the speed reduction γ continuously continues by the belt running, that is, the continuously variable transmission 20. The actual rotational speed ωina indicates a substantially constant input shaft rotational speed ωin by performing a shift that changes with time.

By the way, in the switching from the gear traveling to the belt traveling in FIG. 5, a large fluctuation of the output shaft torque (not shown) may occur along with the change in the actual rotational speed ωina, which may cause a so-called shift shock. In order to reduce this shift shock, the electronic control unit 80 shown in FIG. 3 is indicated by a chain line in FIG. 6 based on the fact that the traveling acceleration ΔV of the vehicle 10 becomes equal to or greater than the threshold value ΔVc (m / sec ² ). The target rotational speed change rate dωint / dt (hereinafter referred to as Δωint), which is the time change of the target rotational speed ωint, is set, and in the inertia phase, the actual rotational speed change rate dωina / dt (time change of the actual rotational speed ωina) is set. (Hereinafter referred to as Δωina) is controlled to approach the target rotational speed change rate Δωint. The electronic control unit 80 decreases the variation in the input shaft rotational speed ωin by setting the target rotational speed change rate Δωint to a smaller value as the traveling acceleration ΔV of the vehicle 10 is larger, thereby causing the variation in the output shaft torque. Switch from gear running with less shock to belt running. Specifically, the acceleration threshold determination means 110 determines whether or not the travel acceleration ΔV is equal to or greater than a preset threshold ΔVc. If this determination is affirmative, the target value setting means 112, that is, the target input shaft rotational speed change rate setting means, sets a predetermined first target change rate Δωin1, that is, a high value as the target rotational speed change rate Δωint. Sets the target input shaft rotation speed change rate during acceleration. Although the first target change rate Δωin1 is set to a predetermined value, the first target change rate Δωin1 may not be a constant value but may vary depending on the traveling acceleration ΔV. When this determination is denied, that is, when the travel acceleration ΔV is lower than the threshold value ΔVc, the target rotational speed change rate Δωint is increased as the travel acceleration ΔV is smaller than the first target change rate Δωin1. Based on a preset value, that is, a map, a second target change rate Δωin2, that is, a low acceleration target input shaft rotational speed change rate is set. When the first target change rate Δωin1 or the second target change rate Δωin2 is set, the target value update unit 114, that is, the target input shaft rotational speed change rate setting unit, sets the target rotational speed change rate Δωint set in the above determination. That is, it is determined whether or not the first target change rate Δωin1 or the second target change rate Δωin2 is lower than a previously set value, that is, the previous target rotational speed change rate Δωint. If this determination is affirmative, the target value determination update means 114 maintains the previous target rotational speed change rate Δωint as the target rotational speed change rate Δωint, and if this determination is negative, it is newly set. The target rotation speed change rate Δωint, that is, the current target rotation speed change rate Δωint, the first target change rate Δωin1 or the second target change rate Δωint2, is set as the target rotation speed change rate Δωint. The shift control means 116, that is, the change rate control means performs shift control based on FF (feed forward) control and FB (feedback) control, which will be described in detail below. The synchronization determination unit 118 determines whether or not the differential rotation of the traveling clutch C2, that is, the difference between the output shaft rotation speed ωout and the output side rotation speed ωsec that is the rotation speed of the secondary pulley 56 is less than the rotation speed threshold ωinc. To do. If this determination is negative, the determination by the acceleration threshold determination means 110 is repeated. If this determination is affirmative, the target value initializing means 120 returns the value set as the target rotational speed change rate Δωint to the preset initial value, and the control is completed.

  The above-described shift control is performed by switching between the release of the forward clutch C1 and the engagement of the travel clutch C1, and the hydraulic control circuit 100 includes the solenoid valves SLU, SLP, SLS, SL1, By sending hydraulic control command signals such as hydraulic control command signals Scvt and Sswt to SL2, the hydraulic pressure supplied to the forward clutch C1, the traveling clutch C1, the primary pulley 54, and the secondary pulley 56 is controlled. For example, the shift control means 116 reduces the difference between the FF control performed based on the time change of the input shaft rotational speed ωint, that is, the actual rotational speed change rate Δωina, and the target rotational speed change rate Δωina and the target rotational speed Δωint. FB control to be executed is performed. As a specific example, FF control is calculated according to the following equation (1), for example. Further, the FB control is calculated according to the following equation (2), for example, and the FF hydraulic pressure Pc2ff and the FB hydraulic pressure Pc2fb calculated from these equations (1) and (2) are applied to the traveling clutch C2. As shown in the following equation (3), the hydraulic pressure applied to the traveling clutch C2 at the start of the control is further applied. Further, if the differential rotation of the traveling clutch C2, that is, the difference between the output shaft rotational speed ωout and the output side rotational speed ωsec does not fall below the rotational speed threshold ωinc even when the hydraulic pressure to the traveling clutch C2 increases, the acceleration threshold determination The control from the means 110 is repeated. Switching from the gear travel to the belt travel is appropriately performed by controlling the travel clutch C2, that is, using the FF control and the FB control so as to approach the target rotational speed ωint.

  FIG. 6 shows a time chart when the target rotational speed change rate Δωint is changed based on the traveling acceleration ΔV of the vehicle 10 being equal to or greater than the threshold value ΔVc. At t00, the electronic control unit 80 determines switching from gear traveling to belt traveling and outputs a hydraulic control command signal Sswt for starting the release of the forward clutch C1 to the hydraulic control circuit 100. At the time t01, the actual rotational speed ωina reaches ωin0, and the target value setting means 112, that is, the target input shaft rotational speed change rate setting means, sets the target rotational speed change rate Δωint based on the traveling acceleration ΔV. The inertia phase is started by the operation to the engagement of the travel clutch C2. In FIG. 6, the target value setting means 112 sets the target rotational speed change rate Δωint in FIG. 6 to a smaller value compared to FIG. 5 due to the high vehicle running acceleration ΔV. At the time t2, the differential rotation of the traveling clutch C2, that is, the difference between the output shaft rotational speed ωout and the output side rotational speed ωsec, which is the rotational speed of the secondary pulley 56, is so-called synchronization below the rotational speed threshold ωinc, and the traveling clutch C2 Engagement is complete and belt travel is started. Further, the target value initializing means 120 resets the target rotational speed change rate Δωint to the initial set value.

  FIG. 7 shows a time chart in a case where the travel acceleration ΔV of the vehicle 10 changes below the threshold value ΔVc from the start of switching from gear travel to belt travel before the completion of the switch. The travel acceleration ΔV temporarily decreases at time t01 and returns to the travel acceleration ΔV before t01 at time t3. The target value setting means 112 changes the setting of the target rotational speed change rate Δωint according to the change in the travel acceleration ΔV, and the changed target rotational speed change rate Δωint is the input shaft rotational speed ωin0 and the input shaft rotational speed at t4. It is shown by a straight line connecting ωin3 which is ωin with a chain line. When the traveling acceleration ΔV increases at time t3, the target value setting unit 112 sets a new target rotational speed change rate Δωint. The target value update unit 114 compares the current target rotational speed change rate Δωint with the previous target rotational speed change rate Δωint, and the current target change rate Δωint is smaller than the previous target rotational speed change rate Δωint. The target change rate Δωint is not changed. The actual rotational speed ωina approaches the input shaft rotational speed ωin3 determined to be synchronized by the shift control of the traveling clutch C2 started from the time t01. When the input shaft rotational speed ωin3 is reached at the time t4, the traveling speed increases. The engagement of the clutch C2 is reached and the belt travel is started. At the same time, the synchronization determination unit 118 performs the differential rotation of the travel clutch C2, that is, the output side rotational speed ωsec that is the rotational speed of the output shaft rotational speed ωout and the secondary pulley 56. Is less than the rotation speed threshold value ωinc, it is determined that γmax synchronization has been reached. Further, the target value initializing means 120 resets the target rotational speed change rate Δωint to the initial set value.

  FIG. 8 is a flowchart for explaining the main part of the control operation of the electronic control unit 80 that changes the target rotational speed ωint based on the acceleration of the vehicle in switching from gear running to belt running, and is repeatedly executed. In a step (hereinafter, step is omitted) S10 corresponding to the function of the acceleration threshold value 110, it is determined whether or not the traveling acceleration ΔV of the vehicle 10 is equal to or greater than the threshold value ΔVc. If this determination is affirmative, a predetermined first target change rate Δωin1 set in advance is set in S20 corresponding to the target value setting means 112. If this determination is negative, the second target change rate Δωin2 is set as the target rotation speed change rate Δωint in S30 corresponding to the target value setting means 112. In S40 corresponding to the target value update means 114, it is determined whether or not the newly set target rotational speed change rate Δωint is lower than the already set target rotational speed change rate Δωint. If this determination is negative, S60 is performed based on the newly set target rotational speed change rate Δωint. If this determination is affirmative, in S50 corresponding to the target value update means 114, the previous target rotational speed change rate Δωint is set as the target rotational speed change rate Δωint, and the target rotational speed change rate Δωint is set from the previous time. Not going to change. Thereafter, in S60 corresponding to the shift control means 116, shift control is performed. Further, in S70 corresponding to the synchronization determination means 118, whether or not the differential rotation of the traveling clutch C2, that is, the absolute value of the difference between the output side shaft rotational speed ωsec and the output shaft rotational speed ωout falls below the rotational speed difference threshold ωinc. Determined. If this determination is negative, the determination from S10 is repeated. If the determination is affirmative, in S80 corresponding to the target value initializing means 120, a predetermined initial value is set for the target rotational speed change rate Δωint, and the control is completed.

  According to the present embodiment, when the travel acceleration ΔV of the vehicle 10 is lower than the acceleration threshold value ΔVc when switching from the gear travel to the belt travel, the target rotational speed change rate Δωint is set larger as the travel acceleration ΔV is smaller. Therefore, the engagement of the travel clutch C2 is completed even when the travel acceleration ΔV is low.

  Further, when the traveling acceleration ΔV of the vehicle 10 is higher than the acceleration threshold value ΔVc, a preset low change rate is selected as the target rotational speed change rate Δωint, and the hydraulic pressure of the travel clutch C2 is directed toward the target rotational speed change rate Δωint. Be controlled. Therefore, when the traveling acceleration ΔV is high, the target rotational speed change rate Δωint is kept low in the switching from the gear traveling to the belt traveling, thereby enabling the switching from the gear traveling in which the shift shock is suppressed to the belt traveling. .

  Further, when the target rotational speed change rate Δωint is repeatedly set according to the change in the travel acceleration ΔV of the vehicle 10, the newly set target rotational speed change rate Δωint is the target rotational speed change rate Δωint that has been set so far. Only when it is larger, the target rotational speed change rate Δωint is updated. As a result, switching from gear running to belt running is reliably performed.

  Further, when switching from gear running to belt running, the difference between the actual rotational speed change rate Δωina, that is, FF control obtained by multiplying dωina / dt by the FF constant, and the difference between the actual rotational speed change rate Δωina and the target rotational speed change rate Δωint is reduced. By performing the FB control, the engagement with the shock caused by the engagement of the travel clutch C2 being suppressed is possible.

  As described above, the control of the traveling clutch C2 at the time of switching from the gear traveling to the belt traveling is the FB control that reduces the difference between the FF control and the actual rotational speed change rate Δωina and the target rotational speed change rate Δωint. However, the present invention is not limited to this. For example, the control that further incorporates learning control into the FF control and the FB control, in which the engagement of the clutch C2 is appropriately executed and the shock due to the engagement is improved may be used.

  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 vehicle in the flowchart of FIG. 9, the structure of the drive device 12, the hydraulic control circuit 100, and the main part of the control system in the vehicle 10 are the same as those in the first embodiment, and only differences will be described.

  FIG. 9 is a flowchart for explaining the main part of the control operation of the electronic control unit 80 that changes the target rotational speed change rate Δωint based on the vehicle running acceleration ωv when switching from gear running to belt running. Is done. In S110 corresponding to the function of the acceleration threshold determination means 110, it is determined whether or not the traveling acceleration ΔV of the vehicle 10 is equal to or greater than the threshold ΔVA. If this determination is affirmative, in S130 corresponding to the target value setting means 112, that is, the target engagement time setting means, a predetermined first shift control speed SC1 set in advance to the slowest shift speed is set. If this determination is negative, it is determined in S120 corresponding to the target value setting means 110 whether or not the traveling acceleration ΔV of the vehicle 10 is greater than or equal to the threshold value ΔVB. If this determination is affirmative, in S140 corresponding to the target value setting means 112, a predetermined second shift control speed SC2 set in advance to the second lowest shift speed is set. If this determination is negative, the shift control speed SC set in the previous determination is maintained. Next, in S150 corresponding to the target update means 114, it is determined whether or not the set current shift control speed SC is lower than the previously set shift control speed SC. If this determination is the first determination after the reset in S190, that is, the engagement of the travel clutch C2 is once completed and the shift control speed is updated to the initial value of the shift control speed, the previous shift control speed SC is set. As a shift control initial value SCi is used. If this determination is affirmative, the previous shift control speed SC is set to the shift speed SC in S160 corresponding to the target value update means 114. When this determination is negative, the current shift speed SC is set as the shift speed SC, and the shift control is performed based on the set shift control speed SC in the shift control means 116, that is, S170. In S180 corresponding to the synchronization determination means 118, it is determined whether or not the differential rotation of the traveling clutch C2, that is, the absolute value of the difference between the output side shaft rotational speed ωsec and the output shaft rotational speed ωout is less than the rotational speed difference threshold ωinc. Is done. If this determination is negative, the determination from S110 is repeated. If the determination is affirmative, in S190 corresponding to the target value initializing means 120, a predetermined shift speed initial value SCi is set as the shift control speed, and the control is completed.

  According to the present embodiment, when switching from gear running to belt running, when the running acceleration ΔV of the vehicle 10 is high, a longer shift time is selected. The longer the shift time, the higher the input shaft rotational speed ωin, and the smaller the change in the input shaft rotational speed ωin when switching from gear traveling to belt traveling. As a result, switching from the stepped transmission in which the shift shock is suppressed to the continuously variable transmission is obtained. Further, switching with suppressed shock is possible, and for example, even when traveling acceleration ΔV decreases, faster shift control speed SC is selected, and switching from gear traveling to belt traveling is more reliably performed. .

  As described above, the description has been made based on the flowchart of FIG. For example, the traveling acceleration ΔV of the vehicle 10 is compared with the two-stage thresholds ΔωinA and ΔωinB, but the threshold may be three or more.

  In addition, although not illustrated one by one, the present invention can be implemented even if various changes are made without departing from the spirit of the present invention.

10: Vehicle 14: Engine (drive source)
18: Stepped transmission (forward / reverse switching device)
20: Belt type continuously variable transmission (continuously variable transmission)
26: Input shaft 80: Electronic control device (control device)
C1: Forward clutch (first clutch)
C2: Traveling clutch (second clutch)
ΔV: Traveling acceleration (vehicle acceleration)

Claims (1)

A continuously variable transmission and a stepped transmission provided in parallel between an input shaft connected to a drive source and drive wheels, and the power of the drive source is transmitted to the drive wheels via the stepped transmission. A first clutch provided in the first power transmission path, and second power for transmitting the power of the drive source to the drive wheels via the continuously variable transmission at a speed ratio smaller than that of the first power transmission path. In a vehicle power transmission device having a second clutch provided on a transmission path, when switching from the first power transmission path to the second power transmission path, the first clutch is released and the second clutch is engaged. A control device for a vehicle power transmission device to be combined,
When switching from the first power transmission path to the second power transmission path, if the vehicle acceleration is lower than a predetermined value, a target for setting a target input shaft rotational speed change rate during low acceleration that increases as the vehicle acceleration decreases Input shaft rotation speed change rate setting means,
Change rate control means for controlling the engagement hydraulic pressure of the second clutch so that the change rate of the rotation speed of the input shaft becomes the change rate of the target input shaft rotation speed at the time of low acceleration. Control device for transmission device.

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