JP2010151326A - Speed change control device of vehicle drive system in continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase responsiveness to a target rotation speed in speed change ratio control by getting the rotation speed of an input rotating element of a continuously variable transmission in a vehicle drive system to follow the target rotation speed. <P>SOLUTION: The speed change control device determines the target rotation speed of the input rotating element based on at least a vehicle speed and either the amount of accelerator pedal depression or the amount of brake pedal depression, and controls the speed change ratio of the continuously variable transmission by the combination of feedback control based on the difference between the target rotation speed of the input rotating element and an actual rotation speed, and feedforward control in accordance with the rate of change of the target rotation speed. The simultaneous pursuit of control hunting suppression when the actual rotation speed approaches the target rotation speed and promptness in changing speed at the start of a speed change, and overshoot suppression at the end of a speed change become possible. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transmission control device for a continuously variable transmission, and more particularly to a transmission control device for a vehicle drive device in which a continuously variable transmission is incorporated between an engine and wheels.

  There is known a continuously variable transmission in which the ratio of the rotational speed of the input rotational element to the rotational speed of the output rotational element is continuously variable, such as a V-belt transmission or a toroidal transmission. It is also known that a vehicle drive device is configured by being incorporated between a vehicle and a wheel. The vehicle is generally operated in such a way that the driver obtains a desired vehicle speed and adjusts the amount of depression of the accelerator pedal and the brake pedal. At this time, the vehicle speed obtained for the amount of depression of the accelerator pedal and the amount of depression of the brake pedal is adjusted. The vehicle's load conditions and the road conditions that change from moment to moment are reflected. Therefore, in order to optimally control the gear ratio of the continuously variable transmission in the vehicle drive unit, the vehicle speed and the depression of the accelerator pedal or brake pedal The optimum gear ratio of the continuously variable transmission is determined in advance as a gear ratio schedule corresponding to the combination of the amounts, and the speed ratio schedule is referred to from the vehicle speed and the accelerator pedal or brake pedal depression amount every moment. The optimum transmission ratio of the continuously variable transmission is obtained, and from this and the vehicle speed, the desired rotational speed of the input rotational element of the continuously variable transmission is calculated as the target rotational speed. It may be controlled gear ratio of the continuously variable transmission so as to match the actual rotational speed of the rolling elements to such a target rotational speed.

When controlling the gear ratio of a continuously variable transmission in a vehicle drive system by paying attention to the rotational speed of its input rotating element as described above, feedback control is normally performed based on the steady target rotational speed, and during acceleration When the engine is in a transient state such as during deceleration, it calculates the transient target rotational speed that predicts the throttle opening after the response delay time of the control system based on the throttle opening and its rate of change, and feeds based on this transient target rotational speed. The following Patent Document 1 describes performing forward control. Further, in Patent Document 2 below, in a speed change control device for a continuously variable transmission having a hydraulic servo mechanism that generates a shift control hydraulic pressure in accordance with an operation amount of an actuator, the feedforward characteristic changes due to individual differences or changes with time. It is described that the feedback operation amount when the deviation is near zero is used as the correction operation amount, and the feedforward operation amount, the feedback operation amount, and the correction operation amount are added to obtain the actuator operation amount. Yes. Further, in Patent Document 3 below, a first speed change mode for controlling the speed change ratio so as to cancel the difference based on the difference between the target rotation speed and the actual rotation speed of the input rotation element, and a predetermined value for the speed change ratio are disclosed. The second speed change mode to be controlled is prepared, and the first speed change mode is selected when the rotation speed of the input rotation element becomes a predetermined speed determined from the characteristics related to the rotation speed of the driving force source. It is described.
JP-A-6-109113 JP 7-4508 A JP 2001-248726 A

  Regarding the transmission gear ratio control in the vehicle drive system, the problem of the response delay of the control system with respect to the change of the throttle opening, the problem of individual differences in the operating characteristics of the control system and the change over time, or the operating status of the control system Although there is room for improvement in the problem of distribution of feedback control and feedforward control, etc., as another problem, the gear ratio that should be the target of speed change control is calculated based on the above various conditions There is a problem of how to make the actual operation of the transmission accurately follow the target gear ratio. This invention makes it a subject to further improve the speed change control apparatus of the vehicle drive device incorporating the continuously variable transmission regarding this point.

  In order to solve the above problems, the present invention provides a vehicle drive in which a continuously variable transmission capable of continuously changing the ratio of the rotational speed of the input rotational element to the rotational speed of the output rotational element is incorporated between the engine and the wheel. The shift control device of the device sequentially obtains the target rotation speed of the input rotation element based on at least the vehicle speed and either the accelerator pedal depression amount or the brake pedal depression amount, and the target rotation speed and the input rotation element The ratio is feedback controlled to bring the actual rotational speed of the input rotational element closer to the target rotational speed based on the difference in actual rotational speed, and the ratio is feedforward controlled based on the rate of change of the target rotational speed, When the rate of change of the target rotational speed increases beyond a predetermined limit value, the ratio of the feedforward control of the ratio based on the rate of change of the target rotational speed is adjusted. A speed change control device characterized by suppressing the above enhancement, or a continuously variable transmission capable of continuously changing the ratio of the rotation speed of the input rotation element to the rotation speed of the output rotation element is an engine and a wheel. The vehicle speed change control device of the vehicle drive device incorporated between the vehicle and the target rotation speed of the input rotation element is obtained based on at least one of the vehicle speed and the accelerator pedal depression amount or the brake pedal depression amount, and the target rotation The ratio is feedback controlled to bring the actual rotational speed of the input rotational element closer to the target rotational speed based on the difference between the speed and the actual rotational speed of the input rotational element, and the ratio based on the rate of change of the target rotational speed. When the deviation between the target rotation speed and the actual rotation speed of the input rotation element is reduced to a predetermined set value or less. It proposes a shift control apparatus characterized by being adapted to reduce the feed-forward control of the ratio based on the target rotational speed change rate.

  In this case, the continuously variable transmission is configured to change the ratio by the hydraulic oil flowing into and out of the hydraulic chamber, and the flow rate of the hydraulic oil that causes the change in the ratio corresponding to the change rate of the target rotational speed. The flow of hydraulic oil into and out of the hydraulic chamber may be controlled by the flow rate.

  Alternatively, in order to solve the above-mentioned problem, the present invention incorporates a continuously variable transmission between the engine and the wheel that can continuously change the ratio of the rotational speed of the input rotational element to the rotational speed of the output rotational element. The vehicle speed change control device of the vehicle drive device sequentially obtains the target rotation speed of the input rotation element based on at least the vehicle speed and either the accelerator pedal depression amount or the brake pedal depression amount, and the target rotation speed and the input The ratio is feedback-controlled to bring the actual rotational speed of the input rotational element closer to the target rotational speed based on the difference between the actual rotational speeds of the rotating elements, and the ratio is feedforward controlled based on the rate of change of the target rotational speed. The continuously variable transmission is configured to change the ratio according to the hydraulic oil entering and exiting the hydraulic chamber, and the change in the target rotational speed. The flow rate of the hydraulic oil that causes the change in the ratio corresponding thereto is obtained, and the flow of hydraulic oil to and from the hydraulic chamber is controlled by the flow rate. The flow rate of the hydraulic oil to and from the hydraulic chamber is predetermined. A further aspect of the present invention is to propose a speed change control device characterized by suppressing further strengthening of the feedforward control of the ratio based on the rate of change of the target rotational speed when the value exceeds a set value. is there.

  The shift control apparatus as described above may be configured to selectively inhibit the feedforward control. In this case, the speed change control device may gradually advance the prohibition of the feedforward control, and may gradually resume the prohibited feedforward control.

  As an example, the continuously variable transmission increases the ratio when hydraulic oil is supplied to the first hydraulic port and discharged from the second hydraulic port, and the hydraulic oil is supplied to the second hydraulic port. The ratio is reduced when hydraulic fluid is supplied and discharged from the first hydraulic port, the first hydraulic port is connected to a hydraulic source, and the second hydraulic port is discharged. Oil switched between a first switching position connected to an oil sump and a second switching position connecting the second hydraulic port to a hydraulic pressure source and connecting the first hydraulic port to an oil sump. The ratio control based on a combination of the feedback control and the feedforward control is configured such that the oil path switching valve is moved to the first switching position based on a difference between the target rotation speed and the actual rotation speed. The first switching rate to switch to and the oil A second switching rate for switching the switching valve to the second switching position, and a third switching rate for switching the oil passage switching valve to the first switching position based on the rate of change of the target rotational speed. And a fourth switching ratio for switching the oil path switching valve to the second switching position, and the oil path switching valve corresponding to the weighted sum of the first switching ratio and the third switching ratio. It is possible to switch to the first switching position and switch the oil passage switching valve to the second switching position in correspondence with the weighted sum of the second switching rate and the fourth switching rate.

  In the shift control apparatus as described above, when the deviation between the target rotational speed of the input rotational element and the actual rotational speed is reduced below a predetermined set value, the ratio based on the rate of change of the target rotational speed is reduced. When the feedforward control is to be reduced, the degree of reduction of the ratio feedforward control is increased as the deviation between the target rotational speed and the actual rotational speed of the input rotational element is reduced. It may be.

  The reduction of the feedforward control of the ratio based on the change rate of the target rotation speed is performed when the change rate of the deviation between the target rotation speed and the actual rotation speed of the input rotation element is equal to or greater than a predetermined positive set value, or When it is less than a predetermined negative set value, it may not be performed. Further, the reduction in the feedforward control of the ratio based on the rate of change of the target rotational speed is such that the rate of change of the deviation between the target rotational speed and the actual rotational speed of the input rotational element is equal to or greater than a predetermined positive set value. And when the change rate of the actual rotation speed of the input rotation element is negative, or the change rate of the deviation between the target rotation speed and the actual rotation speed of the input rotation element is equal to or less than a predetermined negative set value and When the amount of change in the actual rotation speed of the input rotation element is positive, it may not be performed.

  The transmission gear ratio is generally the ratio of the rotational speed of the input rotational element to the rotational speed of the output rotational element. As described above, a continuously variable transmission capable of continuously changing such a gear ratio is an engine and a wheel. In the vehicle speed change control device incorporated in the vehicle, the target rotation speed of the input rotation element is obtained based on at least one of the vehicle speed and the accelerator pedal depression amount or the brake pedal depression amount. The feedback ratio is feedback controlled so that the actual rotational speed of the input rotational element approaches the target rotational speed based on the difference between the actual rotational speed of the input rotational element and the input rotational element, and the transmission ratio is feedforward controlled based on the rate of change of the target rotational speed If this is done, feedback control that causes the actual rotational speed of the input rotational element to follow the target rotational speed is performed according to the rate of change of the target rotational speed. Supplemented by feedforward control, the actual rotational speed of the input rotating element can follow better target rotational speed.

  The continuously variable transmission is configured to change the gear ratio by entering and exiting the hydraulic oil to and from the hydraulic chamber, and obtains the flow rate of the hydraulic oil that causes the corresponding gear ratio change from the change rate of the target rotational speed, Since the flow rate of the hydraulic fluid corresponds to the rate of change of the actual rotational speed of the input rotary element, the rate of change of the target rotational speed is the above. The feedforward control of the ratio based on

  However, when the accelerator pedal or the brake pedal is suddenly depressed greatly, and the target rotational speed calculated based on the accelerator pedal or the brake pedal changes drastically suddenly, this is referred to as the shift control of the transmission by the feedforward control. It may not be preferable to reflect it as it is. Therefore, if control that may selectively prohibit feedforward control is performed, it is reliably avoided that the incorporation of the feedforward control described above impairs the stable running performance of the vehicle in such a case. can do.

  Further, if the feedforward control is selectively prohibited or restarted after the prohibition is gradually advanced, it is possible to avoid a shift shock due to the prohibition or restart of the feedforward control. .

  When the continuously variable transmission is supplied with hydraulic oil to the first hydraulic port and discharged from the second hydraulic port, the transmission ratio is increased, and hydraulic oil is supplied to the second hydraulic port, A first switch configured to reduce the gear ratio when hydraulic fluid is discharged from one hydraulic port, connecting the first hydraulic port to a hydraulic source and connecting the second hydraulic port to a drainage reservoir An oil path switching valve that is switched between a position and a second switching position that connects the second hydraulic port to the hydraulic source and connects the first hydraulic port to the oil sump, and provides feedback control and feed The gear ratio control by the combination of the forward control is based on the difference between the target rotational speed and the actual rotational speed. The first switching ratio for switching the oil path switching valve to the first switching position and the second switching of the oil path switching valve. Calculate the second switching rate to switch to the position and Based on the change rate of the first, the third switching rate for switching the oil passage switching valve to the first switching position and the fourth switching rate for switching the oil passage switching valve to the second switching position are calculated, and the first switching rate is calculated. The oil passage switching valve is switched to the first switching position corresponding to the weighted sum of the second switching rate and the third switching rate, and the oil passage switching valve is switched to the first corresponding to the weighted sum of the second switching rate and the fourth switching rate. If it is switched to the second switching position, the control of the transmission ratio of the continuously variable transmission by the combination of the feedback control and the feedforward control can be accurately executed by the control such as the duty ratio control of the hydraulic pulse. it can.

  Further, in the transmission control apparatus as described above, when the rate of change of the target rotational speed increases beyond a predetermined limit value, the feedforward control of the ratio based on the rate of change of the target rotational speed is further enhanced. Is suppressed, it is possible to prevent a shift shock from occurring when a shift command is issued that causes a large sudden change in the target rotational speed. In particular, if the continuously variable transmission is configured to change the ratio by the hydraulic fluid entering and exiting the hydraulic chamber, the flow rate of the hydraulic fluid corresponds to the rate of change of the actual rotational speed of the input rotary element. It is possible to directly suppress the further strengthening of the feedforward control at the transmission ratio control execution end.

  In the shift control apparatus as described above, when the deviation between the target rotational speed of the input rotational element and the actual rotational speed is reduced below a predetermined set value, the ratio based on the rate of change of the target rotational speed is reduced. If feedforward control is to be reduced, when the deviation between the target rotational speed and the actual rotational speed of the input rotational element is reduced and hunting occurs in the magnitude relationship between the two, correct it each time. It is possible to prevent the hunting from being expanded and the shift control from becoming unstable due to the feedford control being effective.

  In this case, if the degree of reduction in the feedforward control of the ratio is increased as the deviation between the target rotational speed and the actual rotational speed of the input rotational element is reduced, the feedforward control is performed. It is possible to achieve a more advantageous compromise between the advantage of suppressing the hunting by suppressing the hunting and the disadvantage of reducing the follow-up performance of the shift control by suppressing the feedforward control.

  On the other hand, the reduction of the feedforward control of the ratio based on the change rate of the target rotation speed is performed when the change rate of the deviation between the target rotation speed and the actual rotation speed of the input rotation element is equal to or greater than a predetermined positive set value. Or, if the change rate of the deviation between the target rotational speed of the input rotational element and the actual rotational speed is equal to or less than a predetermined negative set value, if it is not performed, then a rapid downshift or upshift is attempted. In this case, it is possible to avoid that it is hindered by the suppression of feedforward control. Further, the reduction in the feedforward control of the ratio based on the rate of change of the target rotational speed is such that the rate of change of the deviation between the target rotational speed and the actual rotational speed of the input rotational element is equal to or greater than a predetermined positive set value. And when the rate of change of the actual rotational speed of the input rotational element is negative, or the rate of change of the deviation between the target rotational speed of the input rotational element and the actual rotational speed is less than a predetermined negative set value, and the input When the amount of change in the actual rotational speed of the rotating element is positive, if it is not performed, it is possible to prevent the change in the gear ratio from overshooting at the end of the downshift or upshift.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows an example of the vehicle drive device provided with a belt-type continuously variable transmission and controlled by the transmission control apparatus by this invention. The flowchart which shows the operation example of the transmission control apparatus of the vehicle drive device shown in FIG. In the vehicle drive apparatus as illustrated in FIG. 1, the change in the primary sheave rotational speed, the shift output duty ratio, and the drive torque in accordance with the change in the accelerator opening as shown in the first stage of the figure. The graph which illustrates the point by which the aspect of this is improved by this invention. The shift control device for a vehicle drive device according to the present invention can be selectively prohibited by feedforward control. At that time, the prohibition is gradually performed, and when the prohibition is canceled and the feedforward control is resumed, the execution is executed. 6 is a flow chart showing one embodiment in the form of its operating process that is made to progress gradually. The shift control device for a vehicle drive device according to the present invention can be selectively prohibited by feedforward control. At that time, the prohibition is gradually performed, and when the prohibition is canceled and the feedforward control is resumed, the execution is executed. 7 is a flow chart showing another embodiment in the form of its operating process that is made to progress gradually. FIG. 4 is a flowchart similar to FIG. 2 showing another embodiment of a shift control device for a vehicle drive device according to the present invention in its operation mode. 7 is a flowchart similar to FIG. 2 and FIG. 6 showing still another embodiment of the shift control device of the vehicle drive device according to the present invention in its operation mode. The graph which illustrates the aspect when the deviation between the target rotational speed of the primary sheave and the actual rotational speed is reduced, and the corresponding feedback duty ratio, feedforward duty ratio, and overall control duty ratio. The same flowchart which shows another one embodiment which changed a part of embodiment shown in FIG. 7 in the operation | movement aspect. The graph which illustrates the change of the related specifications at the time of the shift start by control according to the flowchart shown in FIG. The same flowchart which shows another one embodiment which changed a part of embodiment shown in FIG. 7 in the operation | movement aspect. The graph which illustrates the change of the related specifications at the time of completion | finish of the gear shift by control according to the flowchart shown in FIG.

  FIG. 1 attached herewith is a schematic diagram showing an example of a vehicle drive device that includes a belt-type continuously variable transmission and is controlled by a shift control device according to the present invention. In the figure, 10 is an engine, and its crankshaft 12 drives a pump 16 of a torque converter 14, thereby driving a turbine 18, and driving a torque converter output shaft 22 via a one-way clutch 20, When the direct clutch 24 is engaged, the torque converter is bypassed and the torque converter output shaft 22 is directly driven via the one-way clutch 20. A stator 26 of the torque converter is supported by the housing 30 via a one-way clutch 28. The torque converter output shaft 22 is connected to the rotary frame 32, is connected to the intermediate shaft 36 via the clutch 34, and is also connected to the ring gear 40 of the planetary gear unit 38. The sun gear 42 of the planetary gear device is connected to the intermediate shaft 36. A planetary pinion 46 carried by a carrier 44 is meshed between the ring gear 40 and the sun gear 42 of the planetary gear device. The carrier 44 is supported from the housing 50 so as to rotate concentrically with the intermediate shaft 36 by a brake 48, and at the same time, the carrier 44 is selectively prevented from rotating. The brake 48 is engaged when the vehicle moves backward, and prevents the carrier 44 from rotating and reverses the intermediate shaft 36.

  The fixed primary sheave 52 is fixed to the intermediate shaft 36. Therefore, the intermediate shaft 36 is an input shaft for a continuously variable transmission having the primary sheave 52 as an input rotation element. A movable primary sheave 58 that presents a conical belt engaging surface 56 opposite to the conical belt engaging surface 54 of the fixed primary sheave 52 is movable along the axial direction on the intermediate shaft 36, but by a spline. It is installed in the relationship of transmitting torque. The movable primary sheave 58 is provided with a hydraulic cylinder 60, a piston 62 is engaged with the hydraulic cylinder, and a hydraulic chamber 64 is formed between the piston and the movable primary sheave 58. The piston 62 is fixed on the intermediate shaft 36 and rotates integrally therewith. Therefore, the piston 62 is engaged with the hydraulic cylinder 60 fixed to the movable primary sheave 58 in the hydraulic chamber. While changing the volume of 64 appropriately, it rotates integrally with the movable primary sheave 58. Pressure oil is supplied to the hydraulic chamber 64 from the port 66 through the oil passage 68, or the oil in the hydraulic chamber 64 is discharged from the port 66 through the oil passage 68. The intermediate shaft 36 is rotatably supported by a bearing means (not shown) from a housing (not shown).

  An output shaft 70 is arranged in parallel with the intermediate shaft 36 and is spaced apart from the intermediate shaft 36, and is rotatably supported by a bearing means (not shown) from a housing (not shown). A fixed secondary sheave 72 is fixed to the output shaft 70. A movable-side secondary sheave 78 is movable on the output shaft 70 along its axial direction so as to present a conical belt-engaging surface 76 opposite to the conical belt-engaging surface 74 of the fixed-side secondary sheave 72, but It is installed in the relationship of transmitting torque by spline. The movable secondary sheave 78 is provided with a hydraulic cylinder 80, and a piston 82 is engaged with the hydraulic cylinder, and a hydraulic chamber 84 is formed between the piston and the movable secondary sheave 78. The piston 82 is fixed on the output shaft 70 and rotates integrally therewith. Therefore, the piston 82 is engaged with the hydraulic cylinder 80 fixed to the movable-side secondary sheave 78 in the hydraulic chamber. While changing the volume of 84 as appropriate, it rotates integrally with the movable secondary sheave 78. Pressure oil is supplied to the hydraulic chamber 84 from the port 86 through the oil passage 88, or the oil in the hydraulic chamber 84 is discharged from the port 86 through the oil passage 88.

  A groove having a V-shaped cross section formed by the conical belt engaging surface 54 of the fixed primary sheave 52 and the conical belt engaging surface 56 of the movable primary sheave 58 and the conical belt engaging surface 74 of the fixed secondary sheave 72. And an endless belt 90 is wound around a groove having a V-shaped cross section formed by the conical belt engaging surface 76 of the movable secondary sheave 78. A gear 92 is attached to the output shaft 70, and a gear 94 is engaged with the gear 92. The gear 94 is attached to one end of a shaft 96 rotatably supported by bearing means (not shown), and a gear 98 is provided at the other end of the shaft. The gear 98 meshes with the input gear 102 of the differential device 100, thereby driving the pair of axles 104 and 106.

  The hydraulic oil is supplied to and discharged from the hydraulic chamber 64 of the movable primary sheave 58 and the hydraulic chamber 84 of the movable secondary sheave 78 by connecting the ports 66 and 86 to the pressure oil source 110 such as a hydraulic pump through the hydraulic switching valve 108. This is done by switching to and connecting to the oil reservoir 112. The hydraulic switching valve 108 includes ports 114 and 116 connected to ports 66 and 86, a port 118 connected to the pressure oil source 110, a port 120 connected to the oil reservoir 112, a valve element 122, a valve, Solenoids 124 and 126 that switch the path pattern of element 122. When neither solenoid 124 or 126 is energized, the passage pattern of the valve element is in the state a, and the communication between ports 116 and 118 and the communication between ports 114 and 120 are both disconnected. Yes. When only the solenoid 124 is energized, the passage pattern of the valve element is in the state b, and the ports 116 and 118 are communicated and the ports 114 and 120 are communicated. When only the solenoid 126 is energized, the passage pattern of the valve element is in the state c, and the ports 116 and 120 are communicated, and the ports 114 and 118 are communicated. The gear ratio is kept constant when the passage pattern of the valve element is in the state a, the gear ratio is gradually increased when it is in the state b, and the gear ratio is gradually decreased when it is in the state c.

  The energization of the solenoids 124 and 126 is performed in a pulse manner at a constant cycle, and an electronic type in which a microcomputer is incorporated to determine whether or not a pulse current should be energized to the solenoid 124 or 126 every cycle. This is done by the controller 128. The switching control of the hydraulic switching valve by the pulse current is performed by sorting whether the pulse current should be turned on every cycle, and the number of cycles that are turned on out of a certain number of cycles is the duty ratio. Therefore, it is called duty ratio control. According to such control, if the duty ratio for the solenoid 124 is increased with respect to the duty ratio for the solenoid 126, the speed ratio is increased more quickly according to the increase in the difference, and conversely, the duty ratio for the solenoid 124 is increased. On the other hand, if the duty ratio with respect to the solenoid 126 is increased, the speed ratio is reduced more rapidly as the difference increases.

  In the state shown in the drawing, the hydraulic oil in the hydraulic chamber 64 of the movable primary sheave 58 is largely drained, and the movable primary sheave 58 is far away from the fixed primary sheave 52, and conversely the hydraulic pressure of the movable secondary sheave 78. A large amount of hydraulic oil is supplied to the chamber 84 and the movable secondary sheave 78 is brought closer to the fixed secondary sheave 72, and the gear ratio is almost the maximum value.

  The electronic control device 128 is supplied with various signals I indicating vehicle speed, accelerator pedal depression amount (accelerator opening), brake pedal depression amount (brake hydraulic pressure) and other vehicle driving state information. Based on these information, control calculation is performed according to a control program loaded in advance, and based on the calculation result, the operation of the engine 10, the clutches 24, 34, and 48 is controlled, and the operation of the hydraulic switching valve 108 is controlled, At that time, the control operation according to the present invention is executed.

  FIG. 2 is a flowchart showing one embodiment of a shift control device for a vehicle drive device according to the present invention in its operation mode. Execution determination and determination in each step of the flowchart are performed by the electronic control unit 128. Further, the control according to the flowchart is usually repeatedly performed at a cycle of about several tens to 100 milliseconds.

  When the operation of the vehicle is started by closing an ignition switch (not shown in the figure), first, in step 10, the vehicle speed and the accelerator opening corresponding to the amount of depression of the accelerator pedal or the depression of the brake pedal by the driver. The target primary sheave rotation speed Npt (i) is calculated based on the brake hydraulic pressure corresponding to the amount. Here, (i) represents a value in the i-th period of the periodic control according to the flowchart. (The same applies to i attached to other parameters hereinafter.) When the accelerator pedal is depressed, there is a gear ratio suitable for the driving state as judged from the accelerator opening and the vehicle speed, and the brake pedal. When the engine is depressed, there is a gear ratio that is suitable for the driving state as judged from the brake hydraulic pressure and the vehicle speed, and the primary sheave of the continuously variable transmission that is suitable for the driving state is determined from the value of the gear ratio and the vehicle speed. Is determined as the target value.

  Next, in step 20, a difference ΔNp (i) between the target primary sheave rotation speed Npt (i) and the primary sheave actual rotation speed Np (i) is obtained. Next, at step 30, a duty ratio Dfb (i) for operating the hydraulic switching valve is obtained in order to set ΔNp (i) to zero. The duty ratio Dfb (i) is a duty ratio of feedback control for changing the actual rotational speed of the primary sheave so as to eliminate the deviation based on the deviation from the target rotational speed. The calculation of Dfb (i) based on ΔNp (i) may be performed according to any known feedback technique. For example, Dfb (i) = Kp (ΔNp (i) + KiΣΔNp (i) with Kp and Ki as appropriate coefficients. )).

  Next, at step 40, a difference δNpt (i) between the target primary sheave rotation speed Npt (i) in the current flow and the target primary sheave rotation speed Npt (i-1) in the previous flow is obtained. . This corresponds to the change rate of the target primary sheave rotation speed Npt (i) at the present time (at the time of the i-th flow). Next, at step 50, the target primary sheave rotation speed Npt (i + 1) in the next flow (i + 1st flow) is set to Npt (i) + δNpt based on the change rate of the current target primary sheave rotation speed. Predicted as (i). Next, at step 60, the current gear ratio γ (i) and the gear ratio γ (i + 1) after a predetermined time (here, after one cycle of the flow as the most basic example) Calculated as the ratio of Npt (i) and Npt (i + 1) to the rotational speed Nout (i).

  Next, at step 70, the flow rate Qreq (i) of the control oil required to change the gear ratio from γ (i) to γ (i + 1) is calculated. Qreq (i) corresponds to the rate of change of the target primary sheave rotation speed. Next, at step 80, the duty ratio Dff (i) of the switching operation of the hydraulic switching valve necessary to obtain it is obtained from Qreq (i). The duty ratio Dff (i) is a duty ratio of feedforward control that attempts to match the actual rotational speed of the primary sheave with the changing tendency of the target rotational speed.

  Next, at step 90, Dfb (i) and Dff (i) are added with weighting coefficients α and β to obtain Dr (i). The weighting factors α and β may be appropriately determined based on the operating characteristics of the transmission, and may be set to 0.5, for example. As described above, Dfb (i) is a duty ratio for operating the hydraulic switching valve determined so as to eliminate the difference according to the difference between the target primary sheave rotational speed and the actual primary sheave rotational speed, and this characterizes the degree of feedback control. It is what has. On the other hand, Dff (i) is intended to control the operation of the hydraulic switching valve in advance based on the tendency of the change in the target primary sheave rotation speed, and has the character that determines the degree of feedforward control. is there. In this example, the duty ratio for feedback control and the beauty ratio for feedforward control are additively combined at the ratios of the weighting degrees α and β, respectively, but Dfb (i) and Dff (i ) Various other ideas may be applied. Thus, by combining feedback control aiming at the target value and feedforward control that follows the change trend of the target value with an appropriate relative weight, it is possible to improve the speed of control by feedforward control and to achieve more accurate by feedback control. Control can be converged.

  FIG. 3 shows the primary sheave rotation speed and the shift output when the accelerator pedal is depressed relatively quickly in the vehicle drive apparatus shown in FIG. 1 according to the control according to the present invention described above with reference to FIG. It is a graph which illustrates how the duty ratio of this and the drive torque with respect to a wheel are improved. In the figure, the curve with “target” in the stage of the primary sheave rotation speed is a change with time of the target primary sheave rotation speed calculated with respect to the change of the accelerator opening as shown in the figure. The curve with “conventional” in the stage illustrates the actual rotational speed of the primary sheave in the case of the conventional technique not including the feedforward control based on the rate of change of the target primary sheave rotational speed. The curve marked “present invention” is the target primary sheave rotation compared to the case where the actual rotation speed of the primary sheave is based on the prior art by incorporating the feedforward control based on the change rate of the target primary sheave rotation speed. It indicates that the speed can be approached. Only the feedback control with respect to the deviation of the primary sheave actual rotational speed with respect to the target primary sheave rotational speed causes a delay like the “conventional” curve with respect to the above “target” curve. The duty ratio has a delay as indicated by a broken line as “conventional” in the third row of the figure, and the driving torque for the wheel is correspondingly indicated by a broken line as “conventional” in the fourth row of the figure. However, if the shift output duty ratio is controlled in accordance with the curve shown as “present invention” in the third stage of the figure according to the present invention, the primary sheave rotation speed thereby becomes the second stage of the figure. As described above, the driving torque for the wheel is improved as shown as "present invention" in the fourth row of the figure. .

  FIG. 4 shows that the shift control device for a vehicle drive device according to the present invention can be selectively prohibited by feedforward control, and at that time, the prohibition is gradually performed, and the prohibition is canceled and the feedforward control is resumed. FIG. 4 is a flow chart illustrating one embodiment in the form of its operational process that sometimes causes its execution to proceed gradually.

  First, in step 101, it is determined whether a condition for prohibiting feedforward control (FF control) is satisfied. As a condition for prohibiting feedforward control, a shift in which the target primary sheave rotation speed changes abruptly or a shift command output in which a special shift feedback is performed may be employed, and more specifically, When downshift occurs due to strong depression of the accelerator pedal, when the vehicle does not start at the maximum gear ratio that shifts down more slowly than usual, when the tire slips on a low μ (coefficient of friction) road, or when ABS operates due to sudden deceleration And so on. If the answer is yes, control proceeds to step 102.

  In step 102, the flag F0 indicating the permission / prohibition state of the feedforward control is turned off (prohibited). Next, in step 103, it is determined whether or not the flag F0 has been switched from ON to OFF (ie, feedforward control has been switched from permitted to prohibited). If the answer is yes, control proceeds to step 104 where it is determined whether the feedforward control term needs to be gradually changed. Situations that require gradual change when the feed-forward control term is prohibited may be a sudden downshift, a vehicle start before the gear ratio is not maximized, an ABS operation control end, or the like. If the answer is yes, control proceeds to step 105 where the flag F1 is turned on and the flag F2 is turned off. On the other hand, when the answer is no, the control proceeds to step 106 and both the flags F1 and F2 are turned OFF. In any case, after passing through step 104, control comes to step 105 or 106 because the feedforward control prohibition condition is satisfied from the state where the feedforward control prohibition condition is not satisfied (F0 = ON) (F0). = OFF), the flow is limited to one flow immediately after the transition to the state. After that, the flow proceeds at least once from step 101 to step 107, which will be described later, and then the flow again passes from step 101 to step 103 to step 103. Until then, the answer to step 103 is no, while steps 104 to 106 are bypassed.

  On the other hand, when the answer to step 101 is no, that is, when the feedforward control prohibition condition is not satisfied and the feedforward control may be executed, the control proceeds to step 107 and the flag F0 is turned ON. . Next, at step 108, it is determined whether or not the flag F0 has been switched from OFF to ON (feed forward control has been switched from prohibition to permission). If the answer is yes, control proceeds to step 109 where it is determined whether the feedforward control term needs to be gradually changed. As a situation where a gradual change is required when the prohibition of the feedforward control term is canceled and permitted, tire slip, initial stage of ABS operation control, or the like may be employed. If the answer is yes, control proceeds to step 110 where the flag F1 is turned off and the flag F2 is turned on. When the answer to step 109 is no, the control proceeds to step 106 and both the flags F1 and F2 are turned OFF. Also in this case, control passes through step 109 and then comes to step 110 or 106 because the feedforward control prohibition condition is not satisfied from the state where the feedforward control prohibition condition is satisfied (F0 = OFF). The flow is limited to one flow immediately after the transition to (F0 = ON). After that, the flow proceeds from step 101 to step 102 at least once, and then the flow goes from step 101 to step 108 to step 108 again. Until then, the answer to step 108 is no, while steps 109, 110 and 106 are bypassed.

In step 111, the feedback term Dfb (i) of the duty ratio of the target shift output is calculated. This may be done as described for FIG. Next, at step 112, the feed-forward term Dff (i) of the duty ratio of the target shift output.
Is calculated. This may also be done as described for FIG.

  In step 113, it is determined whether or not the flag F0 is OFF. When the answer is yes, that is, when the feedforward control prohibition condition is newly established and during the subsequent establishment of the same condition, the control proceeds to step 114.

  In step 114, it is determined whether or not the flag F1 is ON. When the establishment of the feedforward control prohibition condition is detected at step 101 and the necessity of gradual change of the feedforward term is confirmed at step 104, and the control reaches this step, the answer is yes. At this time, the control proceeds to step 115 where the value obtained by subtracting the amount of increase by ΔD1 per cycle from the feedforward term Dff (i) of the shift output duty ratio calculated at step 112 for each cycle is transient feedforward. Calculation is performed with the term Dffp (i).

  Control then proceeds to step 116 where it is determined whether Dffp (i) has been reduced to zero. If Dffp (i) gradually decreases in step 115 and the answer becomes yes, the control proceeds to step 117. Until then, the control proceeds to step 118, and in each step 115 in each step 115, the control proceeds to step 118. The calculated Dffp (i) is the value of the feedforward term Dff (i) at that time. When Dffp (i) gradually decreases in step 115 and Dffp (i) is zero or exceeds the negative range, Dffp (i) is set to zero in step 117, and At this time, the flag F1 is switched from ON to OFF.

  When the answer to step 114 is no, that is, when the flag F1 is OFF, when the gradual decrease of Dff (i) is completed as described above, or when Dff (i) is removed. This is when gradual reduction is not necessary from the beginning. At this time, the control proceeds to step 120, and Dff (i) is set to 0 at once regardless of whether or not it is already set to 0.

  When control reaches step 113, if the answer is no, control proceeds to step 121. In step 121, it is determined whether or not the flag F2 is ON. Here, when the flag F2 is ON, it means that the feedforward control is canceled from the state where the feedforward control has been prohibited until then, and that gradual change is necessary to recover the feedforward term. ing. At this time, the control proceeds to step 122, and a calculation is performed in which the transient feedforward term Dffp (i) is incremented by ΔD2 every cycle starting from 0. Control then proceeds to step 123 where it is determined whether Dffp (i) has been increased to Dff (i) calculated at step 112 of the cycle. If Dffp (i) gradually increases in step 122 and the answer is yes, the control proceeds to step 124. Until then, the control proceeds to step 118, and at each step 122 in each cycle, the control proceeds to step 118. The calculated Dffp (i) is the value of the feedforward term Dff (i) at that time. When Dffp (i) gradually increases in step 122 and Dffp (i) reaches Dff (i), Dffp (i) is set to Dff (i) in step 124, and at this time, the flag F2 is switched from ON to OFF.

  When the answer to step 121 is no, that is, when the flag F2 is OFF, when the gradual increase of Dff (i) is completed as described above, or when Dff (i) is recovered. This is when no gradual increase is necessary from the beginning. In either case, control proceeds to step 119 while maintaining Dff (i) calculated in step 112 at this time.

  Thus, in step 119, in accordance with the prohibition or cancellation of the feedforward term Dff (i) as described above, and when there is a gradual change (gradual decrease or gradual increase) in the prohibition or cancellation thereof, the gradual change is made. Based on the above, the shift output duty ratio Dr (i) is calculated by combining the feedback term Dfb (i) and the feedforward term Dff (i). Then, in step 125, the shift control with the duty ratio Dr (i) is executed based on the above control calculation.

  As in the embodiment shown in FIG. 4, FIG. 5 shows that the feed-forward control is selectively prohibited in the shift control device of the vehicle drive device according to the present invention, and at that time, the inhibition is gradually performed. Moreover, when canceling a prohibition and resuming feedforward control, another embodiment in which the execution gradually proceeds is also shown in the form of an operating process. In FIG. 5, steps corresponding to the steps shown in FIG. 4 are indicated by the same step numbers as in FIG.

  In this embodiment, when the feedback term Dfb (i) and the feedforward term Dff (i) of the shift output duty ratio are calculated in steps 111 and 112, respectively, here, in step 201, these are immediately Are combined to calculate the shift output duty ratio Dr (i) in the same manner as in step 119 of FIG.

  Next, by steps 202, 203, and 212 corresponding to steps 113, 114, and 121 in FIG. 4, it is determined whether the control is control for prohibiting feedforward control or control for canceling the prohibition, It is determined whether or not the feed-forward term is gradually changed when switching the control. When the feedforward control is prohibited by gradual change, the control proceeds from step 203 to step 204.

In step 204, it is determined whether or not Dff (i) calculated in step 112 is positive. If the answer is yes, the control proceeds to step 205, and the transient shift output duty ratio Drp (i) is calculated by Dr (i) calculated in step 201.
If the answer is no, the control proceeds to step 206, and the transient speed change output duty ratio Drp (i) is calculated by Dr ( i)
Is increased by ΔD4 per cycle of the flow.

If the control proceeds to step 205, it is determined in step 207 whether Drp (i) has decreased to a value of αDfb (i) or less, and control proceeds to step 206. If so, in step 208, Drp (i) is αDfb (i)
Whether or not the feedforward term βDff (i) in Dr (i) has been completely removed. In either case, if the answer is yes, control proceeds to step 209 where Drp (i)
Is set to αDfb (i), and the flag F1 is turned OFF. Until then, while the answer to step 207 is no, or while the answer to step 208 is no, the control proceeds directly to step 210, and the value of Drp (i) is changed to the gear shift output duty ratio Dr (i). The gear ratio of the machine is set.

  If the answer to step 203 is no, that is, if the flag F1 is OFF, the dripping of Dr (i) is completed as described above, or Dff (i) is removed. This is when gradual reduction is not necessary from the beginning. At this time, the control proceeds to step 211, where Dff (i) is set to 0 at once, regardless of whether Dff (i) has already been set to 0, and Dr (i) is set to αDfb (i).

When control reaches step 202, if the answer is no, control proceeds to step 212. In step 212, it is determined whether or not the flag F2 is ON. Here, when the flag F2 is ON, it means that the feedforward control is canceled from the state where the feedforward control has been prohibited until then, and that gradual change is necessary to recover the feedforward term. ing. At this time, the control proceeds to step 213, and it is determined whether or not Dff (i) calculated in step 112 is positive. If the answer is yes, control proceeds to step 214 where the transient shift output duty ratio Drp (i) is increased by ΔD5 per cycle of the flow, and if the answer is no, control proceeds to step 215. Then, the transient shift output duty ratio Drp (i) is calculated by Dr (i) calculated in step 201.
Is reduced by ΔD6 per cycle of the flow.

If the control proceeds to step 214, whether or not Drp (i) has increased to a value of Dr (i) or higher in step 216, and the control proceeds to step 215. In this case, in step 217, Drp (i) becomes Dr (i).
It is determined whether or not the value has been reduced to a value equal to or less than the value, that is, whether or not the feedforward term βDff (i) in Dr (i) has been completely recovered. In either case, if the answer is yes, control proceeds to step 218 where Drp (i)
Is set to Dr (i), and the flag F2 is turned OFF. Until then, while the answer to step 216 is no, or while the answer to step 217 is no, the control proceeds directly to step 210, and the value of Drp (i) is changed as the shift output duty ratio Dr (i). The gear ratio of the machine is set.

  When the answer to step 212 is no, that is, when the flag F2 is OFF, when Dr (i) is gradually increased as described above, or when Dr (i) is recovered. This is when no gradual increase is necessary from the beginning. In either case, the control is maintained at Dr (i) calculated in step 201 at this time.

  Based on the above control calculation, in step 219, shift control with the duty ratio Dr (i) is executed.

  FIG. 6 is a flowchart similar to FIG. 2 showing another embodiment of the shift control device for a vehicle drive device according to the present invention in its operation mode. In FIG. 6, the same steps as those in the flowchart of FIG. 2 are given the same step numbers as in FIG. 2, and redundant description of these steps will be omitted. In this case, when the feed forward duty ratio Dff (i) is calculated in step 80, the control proceeds to step 81-1, and the control oil flow rate Qreq (i) calculated in step 70 (this is the target primary). It is determined whether the change rate of the sheave rotation speed is a positive value and is equal to or greater than a predetermined limit value Qs1, or is a negative value and equal to or less than the predetermined limit value Qs2. . Qs1 or Qs2 is a value of Qreq (i) that causes a certain sudden change in the target primary sheave rotation speed. If the answer is yes, the control proceeds to step 81-2, and it is determined whether or not the flag F is 1.

  The flag F is reset to 0 at the start of the control, is reset to 0 when the control proceeds to step 81-5 described later, and is 0 when the control first reaches step 81-2. When the control proceeds to step 81-3, the feedforward duty ratio Dff (i-1) in the flow one cycle before is set to the hold value Dffp of the feedforward duty ratio, and the flag F is set to 1. Next, control proceeds to step 81-4, where the shift output duty ratio Dr (i) is calculated using the hold value Dffp instead of Dff (i). Then, even if the temporary control proceeds from step 81-1 to 81-2, the answer to step 81-2 is YES, so control continues by bypassing step 81-3, and the hold value Dffp is used for the temporary time. All shift output duty ratios Dr (i) are continuously calculated.

  Thus, when a shift command that causes a large sudden change in the target rotational speed of the primary sheave is made, it is possible to prevent the shift output duty ratio Dr (i) from changing suddenly and causing a shift shock. In this case, if the continuously variable transmission is configured to change the gear ratio by entering and exiting hydraulic fluid to and from the hydraulic chamber as in the structural example shown in FIG. 1, the feedforward duty ratio is held at the hold value Dffp. This can be done by maintaining the flow rate of the hydraulic oil in and out of the hydraulic chamber at a predetermined set value.

While the request for a large sudden change in the target primary sheave rotation speed Npt (i) continues and thereby the answer to step 81-1 becomes YES, the control to keep the feedforward duty ratio at the hold value Dffp is continued. (i)
Since the answer to step 81-1 is no, the control proceeds to step 81-5, resets the flag F to 0, proceeds to step 90, and Dfb (i) Control in which Dff (i) is combined as usual is performed. Npt (i) from the beginning
When the answer to step 81-1 is no, the control is performed from the beginning according to a route through step 90 from step 81-5.

FIG. 7 is a flow chart similar to FIG. 2 showing still another embodiment of the speed change control device of the vehicle drive device according to the present invention in its operation mode. Also in FIG. 7, the same steps as those in the flowchart of FIG. 2 are denoted by the same step numbers as those in FIG. 2, and redundant description of these steps will be omitted. In this case, when the feedforward duty ratio Dff (i) is calculated in step 80, the control proceeds to step 81-11, and the target rotational speed Npt (i) of the primary sheave calculated in step 20 is Based on the value of the deviation ΔNp (i) between the rotational speeds Np (i), the feed forward duty ratio Dff (i)
A suppression coefficient Kffs (i) is calculated. This coefficient Kffs (i) is negative when the value of the deviation ΔNp (i) is positive and greater than or equal to a predetermined set value, as exemplified by the window graph in FIG. When the value is less than the set value, 1.0, but when the value of the deviation ΔNp (i) is between the positive and negative set values, it is less than 1.0 depending on the degree of decrease in the absolute value. A positive coefficient that decreases to a smaller value. It should be noted that the manner in which Kffs (i) is reduced as the absolute value of ΔNp (i) is reduced may be determined in any suitable non-linear manner other than the linear change manner as illustrated in the figure. In step 80-12, a suppression coefficient Kffs (i) is imposed on the feedforward term βDff (i) in calculating the shift output duty ratio Dr (i).

This is to cope with the possibility that hunting may occur in the magnitude relationship between the target rotational speed of the primary sheave and the actual rotational speed when the deviation decreases. That is, the deviation when the deviation between the target rotational speed of the primary sheave and the actual rotational speed is reduced and the feedback duty ratio, feedforward duty ratio, and overall duty ratio corresponding to the deviation are shown in FIG. As shown in the stage, when the above hunting occurs, the feedback duty ratio Dfb (i) becomes a value corresponding to the deviation between the target rotational speed and the actual rotational speed sequentially as shown in the second stage of the figure. When the feedford control is too effective, the feedford duty ratio Dff (i) changes greatly as shown by the solid line in the third stage of the figure, and as a result, the total control duty ratio Dr (i) is As shown by the solid line in the fourth stage, the change may be considerably large, which may promote hunting and make the shift control unstable. Therefore, this is dealt with and the primary sheave target rotational speed Npt (i) and the actual rotational speed Np as described above.
When the absolute value of the deviation ΔNp (i) of (i) becomes small, the suppression coefficient Kffs (i) as described above is imposed on the feedforward duty ratio Dff (i) calculated in step 80, and Dff ( The value of i) is reduced as indicated by a broken line at the third stage in FIG. 8, and thereby the total control duty ratio Dr (i) is reduced and corrected as indicated by a broken line at the fourth stage in FIG. As a result, as described above, the target rotational speed Npt (i) of the primary sheave and the actual rotational speed Np
When the absolute value of the deviation ΔNp (i) of (i) becomes small, it is possible to prevent the control from becoming unstable due to hunting.

  FIG. 9 is a flowchart similar to FIG. 7 showing, in its operation mode, still another embodiment in which a part of the embodiment shown in FIG. 7 is modified. 9, the same steps as those in the flowcharts of FIGS. 2 and 7 are denoted by the same step numbers as those in FIGS. 2 and 7, and redundant description of these steps is omitted. To do.

  In this case, when the suppression coefficient Kffs (i) for the feedforward duty ratio Dff (i) is calculated in step 80-11, the target rotational speed Npt (i) of the primary sheave is calculated in step 81-21. The rate of change of the deviation ΔNp (i) of the rotational speed Np (i) is calculated as δNp (i) = ΔNp (i) −ΔNp (i−1). Next, at step 81-22, it is determined whether or not δNp (i) is a positive value and not less than a predetermined limit value Rs1, or whether it is a negative value and not more than a predetermined limit value Rs2. Is done. Although not shown in the figure, δNpt (i) calculated in step 40 may be used instead of δNp (i). In that case, in step 81-22, δNpt It may be determined whether (i) is a positive value and not less than a predetermined limit value Rt1, or whether it is a negative value and not more than a predetermined limit value Rt2.

In the embodiment shown in FIG. 7, in steps 81-11 and 81-12, the deviation ΔNp (i) between the target primary sheave rotational speed Npt (i) and the actual primary sheave rotational speed Np (i). When the absolute value of the primary sheave becomes smaller, the suppression coefficient Kffs (i) is calculated to be 1.0 or less, and this is imposed on the feedforward duty ratio Dff (i), whereby the target rotation of the primary sheave is calculated. Speed Npt (i) and actual rotation speed Np (i)
It was attempted to prevent the occurrence of hunting in the control when and are close to each other. However, if the control for suppressing the feedforward control is performed when the absolute value of the deviation ΔNp (i) between the target rotational speed Npt (i) of the primary sheave and the actual rotational speed Np (i) is small as described above, There is a possibility that the progress of the shift is suppressed and the agility of the shift is impaired.

  That is, looking at the graph of FIG. 10 showing the change in the related specifications at the start of the shift as an example of the downshift, the suppression coefficient Kffs (i) is always equal to the feedforward duty ratio Dff (i) calculated in step 80. When the primary sheave target rotational speed is calculated based on the imposed Kffs (i) · Dff (i), ΔNp (i) is small in the vicinity of the time t1 at the beginning of the shift, so that Kffs (i) is a small value. Therefore, the primary sheave target rotation speed changes to a suppressed state as indicated by Npt in FIG. 10, and the actual rotation speed Np is indicated by the broken line Nps in FIG. As such, there is a risk of a large delay in rising.

  Therefore, when the answer to step 81-22 is yes, that is, the rate of change δNp (i) = ΔNp (i) of the deviation ΔNp (i) between the target rotational speed Npt (i) of the primary sheave and the actual rotational speed Np (i). ) −ΔNp (i−1) is a positive value that is greater than or equal to a predetermined limit value Rs1 (during downshift), or a negative value that is less than or equal to the predetermined limit value Rs2 (during an upshift) ), The control proceeds to step 90, and the shift output duty ratio Dr (i) is calculated without using the suppression coefficient Kffs (i) (Kffs is turned OFF at time t1 as shown in FIG. 10). To do. If the answer is no, the control proceeds to step 81-12, and control for correcting Dff (i) with the suppression coefficient Kffs (i) is performed. By incorporating such discrimination control, the rise of the primary sheave actual rotational speed Np (i) at the initial stage of the shift becomes as shown by the solid line Np in FIG. 10, and it is avoided that the rise is delayed as shown by Nps. .

  As described above, the values of the set values Rs1 and Rs2 (the values of Rt1 and Rt2 when δNpt (i) is used instead of δNp (i)) can be set to values of appropriate sizes. For example, as shown in FIG. 10, the answer to step 81-22 is no and the control advances to step 81-12 during the initial stage of shifting, and for a short period of time t0 to t1, and the control proceeds to step 81-12, and the feedforward duty ratio Dff (i) A suppression coefficient Kffs (i) reduced to 1.0 or less is imposed to suppress a sudden change in the primary sheave target rotational speed Npt (i), and after this slight time has passed, the suppression coefficient Kffs is between t1 and t2. By canceling the imposition of (i), the feedforward duty ratio Dff immediately after the start of the shift is prevented from being suppressed as shown by the broken line in FIG. 10, and a quick shift is ensured. The After that, δNp decreases after reaching the apex, becomes Rs1 or less at time t2, and Kffs is imposed on Dff. At this time, the value of Kffs has already risen to 1.0. There is no impact.

  Thus, when the deviation between the target rotational speed of the primary sheave and the actual rotational speed is reduced, the occurrence of hunting in the control is suppressed. On the other hand, at the initial stage of shifting, the target rotational speed Npt of the primary sheave and the actual rotational speed. When the deviation ΔNp of Np increases rapidly (or when the target rotational speed Npt increases rapidly), the shift control is performed using the feedforward duty ratio Dff (i) calculated in step 80 as it is without being suppressed. And the shift can be controlled quickly.

  In the example shown in FIG. 10, Kffs is turned off between time points t3 and t4, and the suppression coefficient Kffs is turned on at time point t4 when the actual rotational speed Np approaches the target rotational speed Npt. The value gradually decreases, and Np is asymptotically matched with Npt. However, depending on the setting of Kffs with respect to ΔNp (window graph in FIG. 9) and the value of Rs2, depending on the difference between the time t4 when the value of δNp becomes Rs2 and the time when Kffs starts to fall below 1.0. Thus, the actual rotational speed Np may overshoot the target rotational speed Npt at the end of shifting. An embodiment for dealing with this is shown in FIG.

  As in the embodiment shown in FIG. 9, FIG. 11 suppresses the occurrence of hunting in the control when the deviation between the target rotational speed of the primary sheave and the actual rotational speed is reduced, and suppresses the above overshoot. FIG. 10 is a flowchart similar to FIG. 9 showing another embodiment that can be performed. Also in FIG. 11, the same steps as those in the flowcharts of FIGS. 2, 7, and 9 are given the same step numbers as in FIGS. Will not be described again.

  In this case, following step 81-21, in step 81-31, δNp (i) is a value equal to or greater than a predetermined positive set value Ru1, and the change rate or moving speed of the actual rotational speed of the primary sheave. Whether or not the control oil flow rate Qreq (i) indicating a negative value (i.e., whether the actual rotational speed of the primary sheave has exceeded the target rotational speed during the downshift) or δNp (i) is a predetermined negative value It is determined whether the value is less than the set value Ru2 and the control oil flow rate Qreq (i) is a positive value (that is, whether the actual rotational speed of the primary sheave has fallen below the target rotational speed during the upshift). The Again, although not shown in the figure, δNpt (i) calculated in step 40 may be used instead of δNp (i). In this case, in step 81-31, Whether δNpt (i) is a value equal to or greater than a predetermined positive set value Rv1 and the control oil flow rate Qreq (i) is a negative value, or δNp (i) is equal to or less than a predetermined negative set value Rv2 And whether the control oil flow rate Qreq (i) is a positive value may be determined. If the answer to step 81-31 is yes, the control proceeds to step 90, and the shift output duty ratio Dr (i) is calculated without using the suppression coefficient Kffs (i). By incorporating such discrimination control, as shown in FIG. 12, the actual rotational speed Np (i) of the primary sheave at the end of the shift (downshift in FIG. 12) is indicated by a broken line in FIG. Thus, overshooting of the target rotational speed Npt (i) is avoided. If the answer to step 81-31 is no, the control proceeds to step 81-12, and control for correcting Dff (i) with the suppression coefficient Kffs (i) is performed.

  In the example of FIG. 12, Kffs is turned on from time t0 to time t4 through time points t1, t2, and t3. However, Kffs at the initial stage of shifting according to the procedure described above with reference to FIGS. It will be apparent that ON / OFF control may be combined.

  After time t3, Kffs decreases as ΔNp decreases. Therefore, between time points t3 and t4, Dff is set to Kffs · Dff and is indicated by a broken line and indicated by a solid line from the state. The amount of Np increase due to feedforward control is reduced. At time t4, the reverse from NO to YES in the above step 81-31 occurs, whereby the feedforward control of Dff acts in a direction to suppress the progress of the shift. Thereafter, at time t5, the answer to step 81-31 is reversed from yes to no, and the control proceeds to step 81-12, and Kffs is imposed for the feedforward control. Thereafter, the shift control ends at time t6 due to the convergence of ΔNp to 0.

  While the present invention has been described in detail with respect to several embodiments thereof, it will be apparent to those skilled in the art that various modifications can be made to these embodiments within the scope of the present invention. . In particular, the control executed after step 80 in the embodiments of FIGS. 6, 7, 9, and 11 may be executed in an appropriate combination. As described above, the embodiment shown in FIGS. 9 and 11 may be combined, and both the shift start time and the shift end time may be controlled as described above. In the combination of the embodiment of FIG. 6 and FIG. 7, after step 80, first, the suppression coefficient Kffs (i) is calculated by executing step 81-11 of FIG. When the control reaches step 81-4, the feedforward term βDffp is multiplied by the suppression coefficient Kffs (i), and when the control reaches step 90 via step 81-5, the feedforward term βDffp is fed forward. The term βDff (i) may be multiplied by the suppression coefficient Kffs (i).

  In the combination of the embodiment of FIG. 6 and FIG. 9, after step 80, step 81-1 to 81-3 or 81-5 of FIG. 6 is executed, and thereafter step 81-11 and subsequent steps of FIG. 9 are executed. To calculate the suppression coefficient Kffs (i) and determine in step 81-22. When the control reaches step 81-12, the feedforward term is Kffs (i) βDffp. When the control reaches step 90, The feedforward term may be set to βDff (i) without using the suppression coefficient Kffs (i).

  Similarly, when the embodiment of FIGS. 6 and 11 is combined, after step 80, steps 81-1 to 81-3 or 81-5 of FIG. 6 are executed, and thereafter steps 81-11 and 81 of FIG. -21 and 81-31 are executed to calculate the suppression coefficient Kffs (i) and determine in step 81-31. When the control reaches step 81-12, the feedforward term is set to Kffs (i) βDffp. When the control reaches step 90, the feedforward term may be set to βDff (i) without using the suppression coefficient Kffs (i).

  In the embodiment shown in FIGS. 7, 9, and 11, the suppression coefficient Kffs (i) is calculated in step 81-11, and is converted to Dff (i) in step 81-12. Although the imposed control calculation is performed, the suppression for the feedforward duty ratio corresponding to the suppression coefficient Kffs (i) corresponds to the primary sheave target rotational speed, the primary sheave movement speed, or the control oil flow rate. You may carry out by the point which imposes a coefficient.

  DESCRIPTION OF SYMBOLS 10 ... Engine, 12 ... Crankshaft, 14 ... Torque converter, 16 ... Pump, 18 ... Turbine, 20 ... One-way clutch, 22 ... Torque converter output shaft, 24 ... Direct coupling clutch, 26 ... Stator, 28 ... One-way clutch, 30 ... Housing, 32 ... rotating frame, 34 ... clutch, 36 ... intermediate shaft, 38 ... planetary gear unit, 40 ... ring gear, 42 ... sun gear, 44 ... carrier, 46 ... planetary pinion pinion, 48 ... brake, 50 ... housing, 52 ... Fixed primary sheave, 54, 56 ... belt engaging surface, 58 ... movable primary sheave, 60 ... hydraulic cylinder, 62 ... piston, 64 ... hydraulic chamber, 66 ... port, 68 ... oil passage, 70 ... output shaft, 72 ... secondary side sheave on fixed side, 74 ... conical belt engaging surface, 76 ... belt engaging surface, 78 ... acceptable Side secondary sheave, 80 ... hydraulic cylinder, 82 ... piston, 84 ... hydraulic chamber, 86 ..., 88 ... oil passage, 90 ... endless belt, 92, 94 ... gear, 96 ... shaft, 98 ... gear, 100 ... differential , 102 ... Input gear, 104, 106 ... Axle, 108 ... Hydraulic switching valve, 110 ... Pressure oil source, 112 ... Oil reservoir, 114, 116, 118, 120 ... Port, 122 ... Valve element, 124, 126 ... Solenoid, 128: Electronic control unit

Claims (16)

  A continuously variable transmission capable of continuously changing the ratio of the rotational speed of the input rotary element to the rotational speed of the output rotary element is used as a speed change control device for a vehicle drive device that is incorporated between the engine and the wheel. A target rotation speed of the input rotation element is obtained based on either the depression amount or the brake pedal depression amount, and the actual rotation speed of the input rotation element is calculated based on the difference between the target rotation speed and the actual rotation speed of the input rotation element. The ratio is feedback-controlled so that the rotation speed approaches the target rotation speed, and the ratio is feedforward controlled based on the change rate of the target rotation speed, and the change rate of the target rotation speed exceeds a predetermined limit value. Further increase in feedforward control of the ratio based on the rate of change of the target rotational speed is suppressed when increasing. Shift control device according to claim.   A continuously variable transmission capable of continuously changing the ratio of the rotational speed of the input rotary element to the rotational speed of the output rotary element is used as a speed change control device for a vehicle drive device that is incorporated between the engine and the wheel. A target rotation speed of the input rotation element is obtained based on either the depression amount or the brake pedal depression amount, and the actual rotation speed of the input rotation element is calculated based on the difference between the target rotation speed and the actual rotation speed of the input rotation element. The ratio is feedback controlled so that the rotational speed approaches the target rotational speed, and the ratio is feedforward controlled based on the rate of change of the target rotational speed. The ratio of the hydraulic oil is configured to change the ratio, and the change rate of the target rotation speed causes the change of the ratio corresponding thereto. The hydraulic fluid is controlled to flow into and out of the hydraulic chamber at the flow rate, and when the flow rate of hydraulic oil to and from the hydraulic chamber increases beyond a predetermined set value, the target rotational speed is increased. A speed change control apparatus characterized by suppressing further enhancement of feedforward control of the ratio based on the rate of change.   A continuously variable transmission capable of continuously changing the ratio of the rotational speed of the input rotary element to the rotational speed of the output rotary element is used as a speed change control device for a vehicle drive device that is incorporated between the engine and the wheel. A target rotation speed of the input rotation element is obtained based on either the depression amount or the brake pedal depression amount, and the actual rotation speed of the input rotation element is calculated based on the difference between the target rotation speed and the actual rotation speed of the input rotation element. The ratio is feedback-controlled so that the rotational speed approaches the target rotational speed, and the ratio is feedforward controlled based on the rate of change of the target rotational speed, and the ratio between the target rotational speed of the input rotational element and the actual rotational speed is controlled. The feedforward control of the ratio based on the rate of change of the target rotational speed is reduced when the deviation is reduced below a predetermined set value. Shift control apparatus characterized by being Tsu.   The continuously variable transmission is configured to change the ratio by entering and exiting hydraulic oil to and from its hydraulic chamber, and obtains the flow rate of hydraulic oil that causes the change in the ratio corresponding to the change rate of the target rotational speed, The shift control apparatus according to claim 1 or 3, wherein the hydraulic oil is controlled to flow in and out of the hydraulic chamber by the flow rate.   The shift control apparatus according to any one of claims 1 to 4, wherein the feedforward control may be selectively prohibited.   6. The shift control apparatus according to claim 5, wherein the prohibition of the feedforward control is gradually advanced.   The speed change control apparatus according to claim 5 or 6, wherein the resumption of the prohibited feedforward control is gradually advanced.   The continuously variable transmission increases the ratio when hydraulic oil is supplied to the first hydraulic port and is discharged from the second hydraulic port, and the hydraulic oil is supplied to the second hydraulic port. The ratio is reduced when hydraulic oil is discharged from the first hydraulic port, the first hydraulic port is connected to a hydraulic source, and the second hydraulic port is connected to a drainage reservoir. An oil path switch that is switched between a first switching position that is connected to the first hydraulic pressure source and a second switching position that connects the second hydraulic pressure port to a hydraulic pressure source and connects the first hydraulic pressure port to an oil sump The ratio control by a combination of the feedback control and the feedforward control has a valve and switches the oil passage switching valve to the first switching position based on a difference between the target rotational speed and the actual rotational speed. First switching rate and the oil passage switching valve A second switching rate for switching to the second switching position, and a third switching rate for switching the oil passage switching valve to the first switching position and the oil based on the rate of change of the target rotational speed. A fourth switching rate for switching the path switching valve to the second switching position is calculated, and the oil path switching valve is set to the first switching rate corresponding to a weighted sum of the first switching rate and the third switching rate. The oil passage switching valve is switched to the second switching position in accordance with a weighted sum of the second switching rate and the fourth switching rate. The shift control device according to any one of 1 to 7.   When the rate of change of the target rotational speed increases beyond a predetermined limit value, further enhancement of feedforward control of the ratio based on the rate of change of the target rotational speed is suppressed. The shift control apparatus according to any one of claims 2 to 8.   When the flow rate of hydraulic oil in and out of the hydraulic chamber increases beyond a predetermined set value, further strengthening of the feedforward control of the ratio based on the rate of change of the target rotational speed is suppressed. The shift control device according to claim 4.   When the deviation between the target rotational speed of the input rotational element and the actual rotational speed is reduced below a predetermined set value, the feedforward control of the ratio based on the rate of change of the target rotational speed is reduced. The shift control apparatus according to any one of claims 1, 2, and 4 to 10.   The degree of reduction of the feedforward control of the ratio is increased as a deviation between a target rotation speed and an actual rotation speed of the input rotation element is reduced. Shift control device.   The reduction of the feedforward control of the ratio based on the change rate of the target rotation speed is not performed when the change rate of the deviation between the target rotation speed and the actual rotation speed of the input rotation element is equal to or greater than a predetermined positive set value. The shift control device according to claim 11 or 12, wherein   The reduction of the feedforward control of the ratio based on the change rate of the target rotation speed is not performed when the change rate of the deviation between the target rotation speed and the actual rotation speed of the input rotation element is equal to or less than a predetermined negative set value. The shift control device according to claim 11 or 12, wherein   The reduction of the feedforward control of the ratio based on the rate of change of the target rotational speed is such that the rate of change of deviation between the target rotational speed and the actual rotational speed of the input rotational element is equal to or greater than a predetermined positive set value and the input The speed change control device according to claim 11 or 12, characterized in that it is not performed when the rate of change of the actual rotational speed of the rotating element is negative. )
The reduction of the feedforward control of the ratio based on the rate of change of the target rotational speed is such that the rate of change of deviation between the target rotational speed and the actual rotational speed of the input rotational element is less than a predetermined negative set value and the input 13. The shift control device according to claim 11, wherein the shift control device is not performed when the amount of change in the actual rotation speed of the rotation element is positive.

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