JP2008101716A - Control device for vehicle continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a vehicle continuously variable transmission capable of suppressing belt slip when learning of control amount of a working fluid feed/discharge adjusting device is incomplete. <P>SOLUTION: When learning of a gear shift control command signal S<SB>T</SB>by a learning control means 160 is incomplete, a nipping force control command signal S<SB>B</SB>is corrected by a secondary pressure control amount correction means 168 such that secondary pressure Pout is increased by correction oil pressure α compared with the case at the time of completion of learning of the gear shift control command signal S<SB>T</SB>. Thus, even if the same state as closing control state is brought about and the secondary pressure Pout is temporarily declined when the learning of the gear shift control command signal S<SB>T</SB>is incomplete, slip of a driving belt 48 can be suppressed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device for a continuously variable transmission for a vehicle having a primary pulley and a secondary pulley and a belt wound around both pulleys, and in particular, adjusts the amount of hydraulic oil supplied to and discharged from a primary hydraulic cylinder. This is related to the control when learning of the control amount of the hydraulic oil supply / discharge adjustment device is not completed.

  A primary pulley and a secondary pulley, a belt wound around both pulleys, a primary hydraulic cylinder for changing the groove width of the primary pulley, a secondary hydraulic cylinder for changing the groove width of the secondary pulley, A vehicle having a hydraulic oil supply / discharge adjustment device for adjusting the amount of hydraulic oil supplied to and discharged from the primary side hydraulic cylinder, and a secondary pressure adjustment device for adjusting the hydraulic pressure (secondary pressure) in the secondary side hydraulic cylinder. In the continuously variable transmission control device, the hydraulic oil supply / discharge adjustment device is controlled so that the actual value becomes a preset target value to perform the shift, and the secondary pressure is adjusted so that the belt does not slip. It is well known to control the device.

  For example, the control device for a continuously variable transmission described in Patent Document 1 is this. In Patent Document 1, an upshift and a downshift flow rate adjustment valve (flow rate control valve) is provided in an oil passage for supplying and discharging hydraulic oil to and from the primary hydraulic cylinder for controlling the transmission ratio. The flow rate control valve is operated according to the control pressure supplied from the control pressure adjusting valve (solenoid valve) corresponding to each flow rate control valve, and the amount of hydraulic oil supplied to and discharged from the primary hydraulic cylinder is adjusted. More specifically, when controlling the gear ratio, the target input shaft rotational speed of the continuously variable transmission is set based on the vehicle state such as the accelerator opening and the vehicle speed, and the actual input shaft rotational speed is set to the target input shaft rotational speed. The drive duty ratio of the solenoid valve for achieving the speed is obtained, and the flow rate control valve is operated by adjusting the control pressure supplied to each flow rate control valve based on the drive duty ratio, so that the primary side hydraulic pressure The hydraulic oil is supplied to and discharged from the cylinder. The one set of flow control valve and solenoid valve correspond to the hydraulic oil supply / discharge adjustment device, and the drive duty ratio corresponds to the control amount of the hydraulic oil supply / discharge adjustment device.

  Here, the control amount of the hydraulic oil supply / discharge adjustment device and the hydraulic oil amount supplied to the primary hydraulic cylinder (flow rate) due to variations in components of the hydraulic oil supply / discharge adjustment device, changes over time, etc. There may be variations in the relationship (flow characteristics). Then, the flow rate with respect to the control amount of the hydraulic oil supply / discharge adjustment device does not become a predetermined standard flow rate, and there is a possibility that the response delay of the shift and the overshoot of the actual value may occur and drivability is impaired.

  Therefore, regarding the problem due to such variation, the above-mentioned Patent Document 1 describes the characteristic of the equivalent throttle diameter (corresponding to the hydraulic oil amount) of the flow control valve with respect to the drive duty ratio (the control amount of the hydraulic oil supply / discharge adjustment device). It has been proposed that the drive duty ratio is corrected by learning control so as to have a predetermined relationship to suppress a decrease in drivability.

  Further, in Patent Document 1, for example, so-called confinement control for controlling the hydraulic oil supply / discharge adjustment device to limit (stop) hydraulic oil supply / discharge to the primary hydraulic cylinder when the vehicle is stopped is performed. A control operation for maintaining (holding or controlling) the speed ratio of the continuously variable transmission in a predetermined state is described.

  However, in the closing control described in the above-mentioned Patent Document 1, since a check valve that makes the differential pressure constant is provided between the line oil passage and the primary hydraulic cylinder, the high accelerator opening degree Then, the hydraulic pressure to the primary side hydraulic cylinder becomes excessively high and the gear ratio tends to change to the speed increasing side, and the necessary torque cannot be obtained when starting the vehicle. Therefore, Patent Document 2 discloses a continuously variable transmission for a vehicle having a pressure reducing valve corresponding to a hydraulic pressure ratio adjusting device having a predetermined relationship between a hydraulic pressure (primary pressure) in a primary hydraulic cylinder and a secondary pressure. In the control device of the machine, when starting from the vehicle stop state, the maximum speed ratio (minimum speed side speed ratio) is established by executing the closing control using the pressure reducing valve, and the speed ratio is increased (upshift) It has been proposed to realize a good start performance.

JP 2004-125209 A JP 2005-42799 A

  By the way, in the control device having a pressure reducing valve as proposed in Patent Document 2, when learning of the control amount of the hydraulic oil supply / discharge adjustment device is not completed, the control amount and the operation supplied / discharged to / from the primary hydraulic cylinder Even if there is a variation in the flow rate characteristic with the oil amount, shift hunting does not occur during steady running when the actual value approaches the target value and the amount of hydraulic oil supplied to and discharged from the primary hydraulic cylinder decreases toward zero As described above, the control amount of the hydraulic oil supply / discharge adjustment device during the steady running is a value that makes the predetermined hydraulic pressure act on the primary hydraulic cylinder by the pressure reducing valve, that is, a value that is equivalent to the closed control state It is conceivable to set to

  However, when the control amount learning of the hydraulic oil supply / discharge adjustment device is not completed, if the state is equivalent to the closed control state, the primary pressure decreases and a sudden shift occurs, that is, the sudden reduction to the maximum gear ratio side. Shift occurs, that is, the groove width of the primary pulley is rapidly expanded and the groove width of the secondary pulley is rapidly narrowed, and the volume in the secondary hydraulic cylinder increases rapidly. Until the hydraulic oil is supplied to the secondary hydraulic cylinder, there is a possibility that the secondary pressure temporarily decreases and the belt slips.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to suppress belt slipping when learning of the control amount of the hydraulic oil supply / discharge adjustment device is incomplete. An object of the present invention is to provide a control device for a continuously variable transmission for a vehicle.

  To achieve this object, the gist of the invention according to claim 1 is that (a) a primary pulley, a secondary pulley, and both pulleys are wound around a power transmission path between a driving power source and a drive wheel. And a continuously variable transmission having a primary hydraulic cylinder for changing the groove width of the primary pulley and a secondary hydraulic cylinder for changing the groove width of the secondary pulley. A hydraulic oil supply / discharge adjustment device for adjusting the amount of hydraulic oil supplied to and discharged from the primary hydraulic cylinder, and a secondary pressure adjustment device for adjusting the hydraulic pressure in the secondary hydraulic cylinder, , Hydraulic ratio adjustment for setting a ratio between the hydraulic pressure in the primary hydraulic cylinder and the hydraulic pressure in the secondary hydraulic cylinder to a predetermined relationship And the secondary pressure regulating device so as to control the hydraulic oil supply / discharge adjustment device so that the actual value becomes a preset target value to perform a shift, and to prevent the belt from slipping. (B) the control amount is set so that the characteristic of the hydraulic oil amount with respect to the control amount of the hydraulic oil supply / discharge adjustment device has a predetermined relationship. Learning control means for learning, and (c) when learning of the control amount of the hydraulic oil supply / discharge adjustment device by the learning control means is incomplete, when the learning of the oil pressure in the secondary hydraulic cylinder is completed And a secondary pressure control amount correcting means for correcting the control amount of the secondary pressure regulating device so as to increase by a predetermined value compared to the value.

  In this way, when the learning by the learning control means that learns the control amount so that the characteristic of the hydraulic oil amount with respect to the control amount of the hydraulic oil supply / discharge adjustment device has a predetermined relationship, Since the control amount of the secondary pressure regulating device is corrected by the secondary pressure control amount correction means so that the hydraulic pressure in the secondary hydraulic cylinder increases by a predetermined value compared to the value when the learning is completed, the hydraulic oil supply / discharge Even if learning of the control amount of the adjusting device is incomplete, even if the hydraulic pressure in the secondary side hydraulic cylinder is temporarily lowered by the hydraulic pressure ratio adjusting device and the hydraulic pressure in the secondary side hydraulic cylinder is temporarily reduced, the belt It is possible to suppress the occurrence of slippage.

  The invention according to claim 2 is the control device for a continuously variable transmission for vehicle according to claim 1, wherein the secondary pressure control amount correction means is a control amount of the hydraulic oil supply / discharge adjustment device. The control amount of the secondary pressure regulating device is corrected based on the above. In this way, the hydraulic pressure in the secondary hydraulic cylinder can be increased only when it is assumed that the state is equivalent to the closed control state based on the magnitude of the control amount of the hydraulic oil supply / discharge adjustment device. Therefore, it is possible to prevent the hydraulic pressure in the secondary hydraulic cylinder from being increased more than necessary. This reduces the burden on the belt.

  Here, preferably, in the continuously variable transmission, the normal shift control in a vehicle state in which the rotation speed of the rotating member exceeds the predetermined vehicle speed, for example, the rotation speed of the rotation member can be detected by a rotation speed sensor, for example, according to a predetermined shift condition. The target gear ratio is obtained, and the amount of hydraulic oil supplied to and discharged from the primary hydraulic cylinder using the hydraulic oil supply / discharge adjusting device is determined so that the actual gear ratio (hereinafter referred to as the actual gear ratio) becomes the target gear ratio. It is executed by feedback control that adjusts and changes the groove width of the primary pulley, or obtains the target rotational speed on the input side (drive source side) according to the vehicle speed, output rotational speed (drive wheel side rotational speed), etc. Adjust the amount of hydraulic oil supplied to and discharged from the primary hydraulic cylinder using the hydraulic oil supply / discharge adjustment device so that the input rotation speed becomes the target rotation speed, and adjust the groove width of the primary pulley. Etc. or it is executed by the feedback control for further, can employ various aspects.

  The above-mentioned predetermined speed change conditions are set by a map or an arithmetic expression using, for example, driving conditions such as a driver output request amount (acceleration request amount) such as an accelerator operation amount and a vehicle speed (corresponding to an output rotation speed) as parameters. Is done.

  The shift control in the vehicle state when the feedback control is difficult, such as when traveling at an extremely low vehicle speed below a predetermined vehicle speed, is performed by, for example, supplying / discharging the hydraulic oil to / from the primary hydraulic cylinder by the hydraulic oil supply / discharge adjustment device. Without using the hydraulic pressure adjusting device, the hydraulic oil is applied to the primary hydraulic cylinder while applying the predetermined hydraulic pressure to the primary hydraulic cylinder so that the transmission gear ratio of the continuously variable transmission is a predetermined gear ratio. As a confined state, the control is executed by the closing control in which the ratio between the hydraulic pressure in the primary hydraulic cylinder and the hydraulic pressure in the secondary hydraulic cylinder is set in a predetermined relationship. More specifically, the hydraulic pressure ratio adjusting device is configured such that the hydraulic pressure of the secondary hydraulic cylinder is introduced as a pilot pressure to output a predetermined hydraulic pressure, and the predetermined hydraulic pressure is applied to the primary hydraulic cylinder. Thus, a predetermined gear ratio, for example, a maximum gear ratio (minimum speed side gear ratio) is configured to be a predetermined thrust ratio.

  Preferably, an engine that is an internal combustion engine such as a gasoline engine or a diesel engine is widely used as the driving power source. Furthermore, an electric motor or the like may be used in addition to the engine as an auxiliary driving power source. Alternatively, only an electric motor may be used as a driving power source.

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

  FIG. 1 is a skeleton diagram illustrating the configuration of a vehicle drive device 10 to which the present invention is applied. This vehicle drive device 10 is a horizontal automatic transmission, which is suitably employed in an FF (front engine / front drive) type vehicle, and includes an engine 12 as a driving power source. The output of the engine 12 composed of an internal combustion engine is the crankshaft of the engine 12, the torque converter 14 as a fluid transmission device, the forward / reverse switching device 16, the belt type continuously variable transmission (CVT) 18, the reduction gear. It is transmitted to the differential gear device 22 via the device 20 and distributed to the left and right drive wheels 24L, 24R.

  The torque converter 14 includes a pump impeller 14p connected to the crankshaft of the engine 12 and a turbine impeller 14t connected to the forward / reverse switching device 16 via a turbine shaft 34 corresponding to an output side member of the torque converter 14. And power transmission is performed via a fluid. A lockup clutch 26 is provided between the pump impeller 14p and the turbine impeller 14t, and a lockup (not shown) in a hydraulic control circuit 100 (see FIGS. 2 and 3) as a hydraulic circuit is provided. The hydraulic pressure supply to the engagement side oil chamber and the release side oil chamber is switched by a control valve (L / C control valve), etc., so that it is engaged or released. The impeller 14p and the turbine impeller 14t are integrally rotated. The pump impeller 14p has a hydraulic pressure for controlling the transmission of the continuously variable transmission 18, generating a belt clamping pressure, controlling the engagement release of the lockup clutch 26, or supplying lubricating oil to each part. Is coupled to a mechanical oil pump 28 that is generated by being driven to rotate by the engine 12.

  The forward / reverse switching device 16 is composed mainly of a forward clutch C1, a reverse brake B1, and a double pinion type planetary gear device 16p, and the turbine shaft 34 of the torque converter 14 is integrally connected to the sun gear 16s. The input shaft 36 of the continuously variable transmission 18 is integrally connected to the carrier 16c, while the carrier 16c and the sun gear 16s are selectively connected via the forward clutch C1, and the ring gear 16r is connected to the reverse brake B1. And is fixed to the housing selectively. The forward clutch C1 and the reverse brake B1 correspond to an intermittent device, both of which are hydraulic friction engagement devices that are frictionally engaged by a hydraulic cylinder.

  When the forward clutch C1 is engaged and the reverse brake B1 is released, the forward / reverse switching device 16 is brought into an integral rotation state, whereby the turbine shaft 34 is directly connected to the input shaft 36, and the forward power The transmission path is established (achieved), and the driving force in the forward direction is transmitted to the continuously variable transmission 18 side. When the reverse brake B1 is engaged and the forward clutch C1 is released, the forward / reverse switching device 16 establishes (achieves) the reverse power transmission path, and the input shaft 36 is connected to the turbine shaft 34. On the other hand, it is rotated in the opposite direction, and the driving force in the reverse direction is transmitted to the continuously variable transmission 18 side. When both the forward clutch C1 and the reverse brake B1 are released, the forward / reverse switching device 16 enters a neutral state (power transmission cut-off state) in which power transmission is cut off.

  The continuously variable transmission 18 has a variable effective diameter, which is an input side member provided on the input shaft 36, and a driving side pulley (primary pulley) 42 having a variable effective diameter, and an output side member, which is provided on the output shaft 44. Driven pulley (secondary pulley) 46 and a transmission belt 48 wound around these variable pulleys 42, 46, and through frictional force between the variable pulleys 42, 46 and the transmission belt 48. Power transmission.

The variable pulleys 42 and 46 are fixed rotation bodies 42 a and 46 a fixed to the input shaft 36 and the output shaft 44, respectively, and are not rotatable relative to the input shaft 36 and the output shaft 44 and are movable in the axial direction. Driven hydraulic cylinders (primary hydraulic cylinders) 42c and driven hydraulic cylinders (secondary side) as hydraulic actuators that apply thrust for changing the V-groove width between the movable rotors 42b and 46b provided Hydraulic cylinder) 46c, and the hydraulic fluid supply / discharge flow rate to the primary hydraulic cylinder 42c is controlled by the hydraulic control circuit 100, so that the V groove widths of both variable pulleys 42, 46 change. Thus, the engagement diameter (effective diameter) of the transmission belt 48 is changed, and the transmission gear ratio γ (= input shaft rotational speed N _IN / output shaft rotation) The rolling speed N _OUT ) is continuously changed. Further, the secondary pressure (belt clamping pressure) Pout, which is the hydraulic pressure of the secondary hydraulic cylinder 46c, is regulated by the hydraulic control circuit 100, whereby the belt clamping pressure is controlled so that the transmission belt 48 does not slip. . As a result of such control, a primary pressure (shift pressure) Pin that is the hydraulic pressure of the primary hydraulic cylinder 42c is generated.

  FIG. 2 is a block diagram for explaining a main part of a control system provided in the vehicle for controlling the vehicle drive device 10 of FIG. The electronic control unit 50 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and follows a program stored in the ROM in advance. By performing signal processing, output control of the engine 12, shift control of the continuously variable transmission 18, belt clamping pressure control, torque capacity control of the lockup clutch 26, and the like are executed. This is divided into control and hydraulic control for the continuously variable transmission 18 and the lockup clutch 26.

The electronic control unit 50, representing the crankshaft rotation speed corresponding to the engine rotational speed crankshaft detected by the sensor 52 rotation angle (position) A _{CR (°)} and the rotational speed of the engine 12 (engine rotational speed) N _E Signal, a signal representing the rotational speed (turbine rotational speed) _NT of the turbine shaft 34 detected by the turbine rotational speed sensor 54, and an input that is the input rotational speed of the continuously variable transmission 18 detected by the input shaft rotational speed sensor 56. rotational speed (input shaft rotational speed) signal representing the N _iN of the shaft 36, a vehicle speed sensor (output shaft rotation speed sensor) 58 by the rotational speed (output of the output shaft 44 is the output rotational speed of the continuously variable transmission 18 detected axis rotation speed) N _OUT ie vehicle speed signal representing a vehicle speed V corresponding to the output shaft speed N _OUT, en detected by the throttle sensor 60 Intake pipe 32 throttle valve opening signal representing the throttle valve opening theta _TH of the electronic throttle valve 30 provided in (see FIG. 1) of the emission 12, the cooling water temperature T _W of the engine 12 detected by a coolant temperature sensor 62 signals representative signal representative of the oil temperature T _CVT of a hydraulic circuit of the continuously variable such as transmission 18 detected by the CVT oil temperature sensor 64, the accelerator opening is an operation amount of the accelerator pedal 68 detected by the accelerator opening sensor 66 an accelerator opening signal representative of the acc, brake operation signal indicating whether B _ON operation of the foot brake is a service brake, which is detected by a foot brake switch 70, a lever position (operation of the shift lever 74 detected by a lever position sensor 72 Position) An operation position signal representing _PSH is supplied.

Further, the electronic control device 50 receives an engine output control command signal S _E for controlling the output of the engine 12, for example, a throttle signal for driving a throttle actuator 76 for controlling the opening / closing of the electronic throttle valve 30, and a fuel injection device 78. An injection signal for controlling the amount of fuel injected from the engine, an ignition timing signal for controlling the ignition timing of the engine 12 by the ignition device 80, and the like are output. Further, a command for driving the solenoid valve DS1 and the solenoid valve DS2 for controlling the flow of hydraulic fluid to the shift control command signal S _T for example the primary hydraulic cylinder 42c for changing the speed ratio γ of the continuously variable transmission 18 signal, a command signal for driving a linear solenoid valve SLS that pressure regulating the squeezing force control command signal S _B for example secondary pressure Pout for aligning clamping pressure of the transmission belt 48, the linear solenoid valve controls line pressure P _L SLT A command signal or the like for driving is output to the hydraulic control circuit 100.

  The shift lever 74 is, for example, one of five lever positions “P”, “R”, “N”, “D”, and “L” that are arranged in the vicinity of the driver's seat and sequentially positioned. To be manually operated.

  The “P” position (range) releases the power transmission path of the vehicle drive device 10, that is, a neutral state (neutral state) where the power transmission of the vehicle drive device 10 is interrupted, and is mechanically output by the mechanical parking mechanism. The parking position (position) for preventing (locking) the rotation of 44, the “R” position is the reverse traveling position (position) for reversely rotating the output shaft 44, and the “N” position. Is a neutral position (position) for setting the neutral state in which the power transmission of the vehicle drive device 10 is interrupted, and the “D” position establishes an automatic transmission mode within a transmission range that allows the transmission of the continuously variable transmission 18. This is a forward travel position (position) that allows automatic shift control to be executed, and the “L” position is operated by a strong engine brake. An engine brake position (position). Thus, the “P” position and the “N” position are non-traveling positions that are selected when the vehicle is not traveling, and the “R” position, the “D” position, and the “L” position are when the vehicle is traveling. This is the selected driving position.

FIG. 3 is a hydraulic circuit diagram showing a main part of the hydraulic control circuit 100 related to belt clamping pressure control and speed ratio control of the continuously variable transmission 18. In FIG. 3, the hydraulic control circuit 100 includes a clamping pressure control valve 110 that regulates the secondary pressure Pout so that the transmission belt 48 does not slip, and the primary hydraulic cylinder 42 c so that the speed ratio γ can be continuously changed. The speed ratio control valve UP114 and the speed ratio control valve DN116 as speed change control valves for controlling the flow rate of the hydraulic oil are primary when the hydraulic oil supply / discharge operation is not performed by the speed ratio control valve UP114 and the speed ratio control valve DN116. thrust ratio control valve 118 as the hydraulic ratio pressure regulator to a predetermined relationship to the ratio between the primary pressure Pin and the secondary pressure Pout by acting thrust ratio control oil pressure P _tau as predetermined hydraulic pressure on the side hydraulic cylinder 42c Etc. Although not shown in the drawings, a manual valve or the like that mechanically switches the oil path according to the operation of the shift lever 74 is provided so that the forward clutch C1 and the reverse brake B1 are engaged or released.

The line pressure P _L as source pressure working oil pressure output from the mechanical oil pump 28 that is driven to rotate (see FIG. 1) (generated) by the engine 12, for example, a relief-type primary regulator valve (line pressure The pressure adjusting valve) is adjusted to a value corresponding to the engine load or the like based on the control oil pressure P _SLT which is the output oil pressure of the linear solenoid valve SLT. Modulator pressure P _M, the control hydraulic pressure P _SLT and with a linear solenoid valve and serves as a hydraulic pressure output at the original pressure of the control oil pressure P _SLS is the SLS, normally closed solenoid valve that is duty controlled by the electronic control unit 50 DS1 be comprised with the output hydraulic pressure at which the original pressure of the control oil pressure P _DS1 and the output hydraulic pressure at a control pressure P _DS2 normally closed type solenoid valve DS2, a constant pressure by a modulator valve 120 to line pressure P _L as source pressure The pressure is adjusted.

The speed ratio control valve UP114 upshift to close the suppliable and output port 114k of the line pressure P _L by being movable in the axial direction from the input port 114i to the primary pulley 42 via the output port 114j A spool valve element 114a which is positioned at a position where the input pulley 114a is closed and the primary pulley 42 is communicated with the input / output port 114k via the input / output port 114j. A spring 114b as an urging means that urges toward the side, and an oil chamber 114c that accommodates the spring 114b and receives the control oil pressure _PDS2 to _apply a thrust toward the original position to the spool valve element 114a, Heading up spool position 114a upshift position And an oil chamber 114d that receives the control oil pressure _{P DS1} to impart a force.

Further, the transmission ratio control valve DN116 is provided so as to be movable in the axial direction, so that the input / output port 116j communicates with the discharge port EX and the input / output port 116j is disconnected from the input / output port 116k. A spool valve element 116a in which the output port 116j is communicated with the input / output port 116k and the input / output port 116j is positioned at the original position where the output port 116j is disconnected from the discharge port EX, and the spool valve element 116a is moved toward the original position. A spring 116b as an urging means for urging, an oil chamber 116c that accommodates the spring 116b and receives the control hydraulic pressure _PDS1 for applying a thrust toward the original position to the spool valve element 116a, and the spool valve element 116a Control hydraulic pressure to apply thrust toward the downshift position And an oil chamber 116d for receiving _PDS2 .

In the transmission ratio control valve UP114 and the transmission ratio control valve DN116 thus configured, in the closed state in which the spool valve element 114a is held in the original position in accordance with the urging force of the spring 114b as shown in the left half of the center line, The input port 114i and the input / output port 114j are blocked, and the input / output port 114j and the input / output port 114k are communicated with each other, so that the hydraulic oil in the primary pulley 42 (primary hydraulic cylinder 42c) flows to the input / output port 116j. Is acceptable. In the closed state in which the spool valve element 116a is held in the original position in accordance with the urging force of the spring 116b as shown in the right half of the center line, the input / output port 116j and the discharge port EX are blocked and the input / output port 116j. output port 116k are communicated aligned to each, the thrust ratio control oil pressure P _tau from the thrust ratio control valve 118 is allowed to flow to the input-output port 114k and. Accordingly, the thrust ratio control oil pressure P _tau from the thrust ratio control valve 118 to the primary hydraulic cylinder 42c is caused to act.

Further, when the control oil pressure _PDS1 is supplied to the oil chamber 114d, the spool valve element 114a is increased against the urging force of the spring 114b by a thrust according to the control oil pressure _PDS1 as shown in the right half of the center line. is moved to the shift position side, the line pressure _{P L} is supplied to the control oil pressure _{P DS1} to the corresponding flow rate at the input port 114i primary hydraulic cylinder 42c via the input-output port 114j from output port 114k is shut off Accordingly, the flow of the hydraulic oil to the speed ratio control valve DN116 side is prevented. As a result, the primary pressure Pin is increased, the V groove width of the primary pulley 42 is narrowed, and the speed ratio γ is reduced, that is, the continuously variable transmission 18 is upshifted.

When the control oil pressure _PDS2 is supplied to the oil chamber 116d, the spool valve element 116a is lowered against the urging force of the spring 116b by the thrust according to the control oil pressure _PDS2 , as shown in the left half of the center line. The hydraulic oil in the primary hydraulic cylinder 42c is moved to the shift position side and discharged from the discharge port EX from the input / output port 114j through the input / output port 114k and the input / output port 116j at a flow rate corresponding to the control hydraulic pressure _PDS2. together, the thrust ratio control oil pressure P from the thrust ratio control valve 118 and the output port 116j and the input-output port 116k is cut off _τ is prevented to be distributed to the output port 114k. As a result, the primary pressure Pin is reduced, the V groove width of the primary pulley 42 is increased, and the transmission gear ratio γ is increased, that is, the continuously variable transmission 18 is downshifted.

Thus, the transmission ratio control valve UP114 and the transmission ratio control valve DN116, and the solenoid valve DS1 and the solenoid valve DS2 that output the control hydraulic pressure for operating these transmission control valves perform the speed change of the continuously variable transmission 18. Functions as a hydraulic oil supply / discharge adjustment device that adjusts the amount of hydraulic oil supplied to and discharged from the primary hydraulic cylinder 42c, and a gear ratio that becomes the primary pressure of the primary pressure Pin when the control hydraulic pressure _PDS1 is output. is inputted line pressure P _L is supplied to the primary hydraulic cylinder 42c is increased primary pressure Pin continuously upshift control valve uP 114, the control pressure P _DS2 is output on the primary side hydraulic cylinder 42c The hydraulic oil is discharged from the discharge port EX, and the primary pressure Pin is lowered. It is continuously down shift.

For example, as shown in FIG. 4, it is actually determined from a previously stored relationship (shift map) between the vehicle speed V and the target input shaft rotational speed N _IN ^* that is the target input rotational speed of the continuously variable transmission 18 using the accelerator opening Acc as a parameter. The target input shaft rotational speed N _IN ^* set based on the vehicle state indicated by the vehicle speed V and the accelerator opening Acc matches the actual input shaft rotational speed (hereinafter referred to as the actual input shaft rotational speed) N _IN. by being feedback-controlled to the a controlled variable of the hydraulic fluid supply and discharge adjusting device shift control command signal S _{T (i.e.} DS1 transmission Duty and DS2 transmission Duty is the control amount of the solenoid valve DS1 and the solenoid valve DS2) Is adjusted to change the speed of the continuously variable transmission 18, that is, the supply flow rate or discharge flow rate of the hydraulic oil to the primary hydraulic cylinder 42c is adjusted. By adjusting the width, the V groove widths of both variable pulleys 42 and 46 are changed, and the speed ratio γ is continuously changed.

The shift map in FIG. 4 corresponds to the shift conditions, and the target input shaft rotational speed N _IN ^* is set such that the larger the vehicle speed V is and the larger the accelerator opening Acc is, the larger the gear ratio γ is. Further, since the vehicle speed V corresponds to the output shaft rotation speed _{N OUT,} which is the target value of the input shaft rotational speed _{N IN} target input shaft rotational speed _{N IN} ^* is the target speed ratio ^{_{γ * (= N IN * /}} N OUT) And is determined within the range of the minimum speed ratio γmin and the maximum speed ratio γmax of the continuously variable transmission 18.

Further, the control hydraulic pressure _PDS1 is supplied to the oil chamber 116c of the transmission ratio control valve DN116, and regardless of the control hydraulic pressure _PDS2 , the transmission ratio control valve DN116 is closed to limit the downshift, while the control hydraulic pressure _{PDS2 changes} the speed. The oil ratio is supplied to the oil chamber 114c of the ratio control valve UP114, and regardless of the control oil pressure _PDS1 , the transmission ratio control valve UP114 is closed to prohibit the upshift. That is, the control when the hydraulic _{P DS1} and the control pressure _{P DS2} are not supplied together but of course, also, the speed change ratio control valve UP114 and speed ratio control valve when the control oil pressure _{P DS1} and the control pressure _{P DS2} is supplied together Each of the DNs 116 is in a closed state held in its original position. As a result, one of the solenoid valves DS1 and DS2 does not function due to a failure in the electrical system, and a sudden upshift occurs even when the control hydraulic pressure _PDS1 or the control hydraulic pressure _PDS2 continues to be output at the maximum pressure. It is possible to prevent a downshift or a belt slip due to the sudden shift.

The clamping force control valve 110, via an output port 110t to line pressure P _L by opening and closing an input port 110i from the input port 110i output side variable pulley 46 and the thrust ratio control by being movable in the axial direction valve 118 The spool valve element 110a that enables the belt clamping pressure Pd to be supplied, the spring 110b as an urging means that urges the spool valve element 110a in the valve opening direction, and the spring 110b is accommodated in the spool valve element 110a. An oil chamber 110c that receives the control hydraulic pressure _PSLS to give thrust in the valve opening direction, and feedback that receives belt clamping pressure Pd output from the output port 110t to give thrust in the valve closing direction to the spool valve element 110a. The thrust in the valve closing direction is applied to the oil chamber 110d and the spool valve element 110a. And an oil chamber 110e that accepts modulator pressure P _M in order to impart.

In the clamping pressure control valve 110 thus configured, by the transmission belt 48 is line pressure P _L is continuously regulated pressure control control oil pressure P _SLS so as not slip as a pilot pressure, an output port 110t To output the secondary pressure Pout.

Thus, the clamping pressure control valve 110 and the linear solenoid valve SLS that outputs the control hydraulic pressure P _SLS for operating the clamping pressure control valve 110 function as a secondary pressure regulating device for regulating the secondary pressure Pout. be one that, the control oil pressure P _SLS When is output secondary pressure Pout source pressure to become clamping force control is input to the valve 110 the line pressure P _L of is supplied to the secondary side hydraulic cylinder 46c, the control oil pressure P _SLS Accordingly, as the control hydraulic pressure P _SLS increases, the secondary pressure Pout is increased and the belt clamping pressure is increased.

For example the corresponding accelerator opening Acc in the transmission torque, as shown in FIG. 5 (or the throttle valve opening theta _TH, the input torque T _IN, etc. to the continuously variable transmission 18) corresponding to the speed ratio γ and the belt clamping pressure as a parameter Based on the vehicle state indicated by the actual gear ratio γ and the accelerator opening Acc from the relationship (belt clamping pressure map) that has been experimentally obtained and stored in advance so as not to cause belt slip with the required secondary pressure Pout ^*. determining (calculating) have been required secondary pressure Pout ^* is obtained as slippage of the transmission belt 48 does not occur, the secondary pressure adjusting device clamping pressure control command signal S _B is regulated by the secondary pressure Pout is a control amount of And the frictional force (belt clamping pressure) between the variable pulleys 42 and 46 and the transmission belt 48 is increased or decreased according to the secondary pressure Pout.

The thrust ratio control valve 118, a thrust ratio control oil pressure P the line pressure _{P L} by opening and closing an input port 118i by being movable in the axial direction from the input port 118i via an output port 118t to the speed ratio control valve DN116 a spool valve element 118a that can supply _τ , a spring 118b as an urging means that urges the spool valve element 118a in the valve opening direction, and the spring 118b is accommodated in the valve opening direction in the valve opening direction. an oil chamber 118c that accepts secondary pressure Pout to apply thrust, the feedback oil chamber receiving a thrust ratio control oil pressure P _tau output from the output port 118t to apply a thrust force in the valve closing direction to the spool valve element 118a 118d And.

In the thrust ratio control valve 118 configured as described above, the pressure receiving area of the secondary pressure Pout in the oil chamber 118c a, the pressure receiving area of the thrust ratio control oil pressure P _tau in the feedback oil chamber 118d b, the biasing force of the spring 118b F _{Assuming S} , the following equation (1) results in an equilibrium state. Therefore, the thrust ratio control oil pressure P _tau, represented by the following formula (2), a linear function of the secondary pressure Pout.
_Pτ × b = Pout × a + F _S (1)
_Pτ = Pout × (a / b) + F _S / b (2)

Then, the control oil pressure _P or _DS1 and the control pressure _{P DS2} is not supplied together, or the predetermined pressure or more control pressure _{P DS1} and the predetermined pressure or more control pressure _{P DS2} is both supplied, the speed ratio control valve UP114 and the speed ratio control when the valve DN116 has both been a closed state is held in the original position, consistent since the thrust ratio control oil pressure P _tau is supplied to the primary hydraulic cylinder 42c, the primary pressure Pin and the thrust ratio control oil pressure P _tau Be made. That is, the thrust ratio control oil pressure P _tau i.e. primary pressure Pin maintain the relationship shown in predetermined Formula the ratio between the primary pressure Pin and the secondary pressure Pout by the thrust ratio control valve 118 (2) is output.

For example, because of the accuracy of the input shaft rotation speed sensor 56 and the vehicle speed sensor 58, the detection accuracy of the input shaft rotation speed _NIN and the vehicle speed V is inferior in a low vehicle speed state below a predetermined vehicle speed V ′. Instead of feedback control of the gear ratio γ at the time of starting, for example, so-called closing control is performed in which both the control hydraulic pressure P _DS1 and the control hydraulic pressure P _DS2 are not supplied and both the gear ratio control valve UP114 and the gear ratio control valve DN116 are closed. Execute. As a result, the primary pressure Pin determined by the secondary pressure Pout is supplied to the primary hydraulic cylinder 42c so that the ratio between the primary pressure Pin and the secondary pressure Pout is set in a predetermined relationship during low vehicle speed traveling or starting, and the vehicle The belt slip of the transmission belt 48 from the stop to the extremely low vehicle speed is prevented, and at this time, for example, the thrust ratio τ corresponding to the maximum gear ratio γmax (= secondary hydraulic cylinder thrust W _OUT / primary hydraulic cylinder thrust W _IN ; _{W OUT} is secondary pressure Pout × pressure receiving area Sout of the secondary-side hydraulic cylinder _{46c, W iN} is the primary pressure Pin × primary hydraulic cylinder 42c of the pressure receiving area Sin) from possible large thrust ratio τ of as the equation (2) If (a / b) or F _S / b in the first term on the right-hand side is set, the maximum gear ratio γmax or Good start is performed at a gear ratio γmax ′ in the vicinity of. The predetermined vehicle speed V ′ is a lower limit vehicle speed at which a predetermined feedback control can be executed as a vehicle speed V at which the rotational speed of the predetermined rotating member, for example, the input shaft rotational speed _NIN cannot be detected. For example, it is set to about 2 km / h.

FIG. 6 shows a relationship that is obtained and stored in advance between the speed ratio γ and the thrust ratio τ using the vehicle speed V as a parameter. FIG. 10 is a diagram illustrating an example when / b) and F _S / b are set. The parameter of the vehicle speed V shown by the one-dot chain line in FIG. 6 is a thrust ratio τ calculated in consideration of the centrifugal hydraulic pressure in the primary side hydraulic cylinder 42c and the secondary side hydraulic cylinder 46c, and the intersections with the solid lines (V0, V20, V50). To obtain a transmission gear ratio γ as a predetermined transmission gear ratio that can be held during the closing control. For example, as shown in FIG. 6, in the continuously variable transmission 18 according to this embodiment, the maximum speed ratio γmax can be maintained as a predetermined speed ratio when the vehicle speed V is 0 km / h, that is, the closing control is performed while the vehicle is stopped. .

FIG. 7 is a functional block diagram for explaining the main part of the control function by the electronic control unit 50. In FIG. 7, the target input rotation setting means 150 is configured to change the input shaft rotation speed N _IN based on the vehicle state indicated by the actual vehicle speed V and the accelerator opening Acc from a shift map stored in advance as shown in FIG. The target input shaft rotational speed N _IN ^* is sequentially set in advance.

The shift control means 152 has an actual input shaft rotational speed N _IN (hereinafter referred to as an actual input shaft rotational speed N _IN ) that matches the target input shaft rotational speed N _IN ^* preset by the target input rotational setting means 150. Thus, for example, based on the rotational deviation ΔN _IN (= N _IN ^* −N _IN ) between the actual input shaft rotational speed N _IN and the target input shaft rotational speed N _IN ^* , the continuously variable transmission 18 is shifted by feedback control. To do. That is, the shift control unit 152 controls the flow rate of the hydraulic oil to the primary hydraulic cylinder 42c based on the rotation deviation ΔN _IN to change the V groove width of both the variable pulleys 42 and 46 ( It determines the hydraulic pressure command) S _T, continuously changing the speed ratio γ and outputs the shift control command signal S _T to the hydraulic control circuit 100.

The belt clamping pressure setting means 154 calculates a necessary secondary pressure (belt clamping pressure) based on the accelerator opening Acc and the actual gear ratio γ from a belt clamping pressure map that is experimentally obtained and stored in advance as shown in FIG. ) Set Pout ^* . That is, the belt clamping pressure setting means 154 sets the secondary pressure Pout of the output side hydraulic cylinder 46c for obtaining the necessary secondary pressure Pout ^* . The actual speed ratio γ (= N _IN / N _OUT ) is calculated by the electronic control unit 50 based on the detected actual input shaft rotational speed N _IN and output shaft rotational speed N _OUT .

Belt clamping pressure control means 156, the hydraulic said belt clamping pressure setting means 154 by the set required secondary pressure Pout ^* is squeezing force control command signal S _B for pressurizing the secondary pressure Pout of the secondary-side hydraulic cylinder 46c tone so as to obtain Output to the control circuit 100 to increase or decrease the belt clamping pressure.

The hydraulic control circuit 100, the supply of hydraulic fluid to actuate the solenoid valve DS1 and the solenoid valve DS2 so shifting of the continuously variable transmission 18 is executed to the primary hydraulic cylinder 42c in accordance with the shift control command signal S _T · to control the emissions, by operating the linear solenoid valve SLS so the belt clamping force is increased or decreased pressure of the secondary pressure Pout tone in accordance with the above clamping force control command signal S _B.

Further, in addition to the above-described function, the speed change control means 152 does not perform feedback control of the speed ratio γ as normal speed change control on condition that the vehicle speed V is equal to or lower than the predetermined vehicle speed V ′, and controls the thrust ratio control. The valve 118 performs the closing control for maintaining the ratio between the primary pressure Pin and the secondary pressure Pout in a predetermined relationship. That is, by closing the transmission ratio control valve UP114 and the transmission ratio control valve DN116, the thrust ratio control hydraulic pressure _Pτ is supplied to the primary side hydraulic cylinder 42c to change the transmission ratio γ of the continuously variable transmission 18 to a predetermined speed. A shift command (closed control command) signal S _T ′ for shifting control for low vehicle speed as a ratio is output to the hydraulic control circuit 100 to establish a predetermined gear ratio, for example, the maximum gear ratio γmax.

The hydraulic control circuit 100 does not operate both the solenoid valve DS1 and the solenoid valve DS2 so that the transmission ratio control valve UP114 and the transmission ratio control valve DN116 are closed in accordance with the closing control command signal S _T ′, or the solenoid together actuate the valve DS1 and the solenoid valve DS2, supplies the thrust ratio control oil pressure P _tau from the thrust ratio control valve 118 to the primary hydraulic cylinder 42c.

The engine output control means 158 outputs an engine output control command signal S _E , for example, a throttle signal, an injection signal, an ignition timing signal, etc., to the throttle actuator 76, the fuel injection device 78, and the ignition device 80, respectively, for output control of the engine 12. To do. For example, the engine output control means 158 controls the engine torque T _E and outputs a throttle signal for opening and closing the electronic throttle valve 30 such that the throttle opening theta _TH corresponding to the accelerator opening Acc to the throttle actuator 76.

Here, due to variations in components of the hydraulic fluid supply and discharge adjusting device, such as the speed change ratio control valve UP114 and solenoid valves DS1, hydraulic oil supplied and drained in the shift control command signal S _T and the primary hydraulic cylinder 42c There may be variations in the relationship (shift flow rate characteristics) with the amount (hereinafter referred to as shift flow rate Q). In other words, it deviates from the speed change flow rate characteristic of the standard characteristics of the actual gear flow Q _A relative shift control command signal S _T (i.e. actual gear flow characteristics) is stored preliminarily obtained experimentally, the actual transmission rate Q _a may not become a standard transmission rate Q _S in the shift control command signal S _T at that time as determined from the standard speed change flow characteristics. Then, there is a possibility that the drivability is impaired overshoot response delay and the actual input shaft rotational speed N _IN of the shift occurs.

FIG. 8 is a diagram illustrating an example of a shift flow rate characteristic of the DS1 shift Duty and the shift flow rate Q during upshifting. In FIG. 8, a solid line S is a predetermined standard shift characteristic, and each broken line A and B is an actual shift flow characteristic that is deviated from the standard shift flow characteristic. For example, when outputting the D _S1S as DS1 transmission Duty, actual gear flow characteristics of the actual transmission rate if consistent with standard gear shift characteristic (solid line S) is a standard speed change flow rate Q _S, If the actual shift flow rate characteristic is the solid line A, the actual shift flow rate becomes the shift flow rate Q _A and a deviation ΔQ (= Q _S −Q _A ) occurs. In other viewpoint, if the actual speed change rate characteristic is the solid line A as DS1 shift Duty in order to obtain a standard transmission rate Q _S, in place of the D _S1S, for correcting the DS1 transmission Duty to the D _S1S shift Duty correction amount Dadj (positive value) is required to output the D _S1A applied. Similarly, if the actual shift flow rate characteristic is the solid line B, in order to obtain the standard shift flow rate Q _S , the DS1 shift Duty is changed to _{DS1S instead} of _DS1S, and the shift duty correction amount Dadj (negative value) is replaced with DS1S. ) To which _DS1B is added needs to be output.

Therefore, the learning control means 160, in order to suppress a decrease in drivability, actual gear flow characteristic learning the shift control command signal S _T such that the standard speed change flow characteristics.

For example, the learning control means 160, the actual transmission rate Q and the transmission rate calculating unit 162 for calculating the _A, actual gear flow Q _A and the standard speed change rate Q shifting flow rate difference calculating means for calculating a difference ΔQ between _S and a 164 learns the transmission Duty correction amount Dadj for correcting the shift control command signal S _T based on the deviation Delta] Q. That is, the learning control means 160 learns the shift control command signal S _T as a result by learning the shifting Duty correction amount Dadj.

More specifically, the shift flow rate Q is the flow rate of hydraulic oil per unit time supplied to and discharged from the primary side hydraulic cylinder 42c, and moves in the axial direction per unit time and the pressure receiving area Sin of the primary side hydraulic cylinder 42c. The movement amount ΔX of the movable rotating body 42b (that is, the moving speed dX of the movable rotating body 42b) is multiplied. Accordingly, the shift flow rate calculation means 162 calculates the actual shift flow rate Q _A according to the following equation (3). The moving speed dX of the movable rotating body 42b is a changing speed of the absolute position X of the movable rotating body 42b corresponding to the actual speed ratio γ on a one-to-one basis. The absolute position X is obtained based on the actual gear ratio γ from the relationship (absolute position map) obtained experimentally in advance and stored with X, and the moving speed dX is calculated based on the absolute position X.
Q _A = Sin × dX (3)

The speed change rate deviation calculating section 164 calculates the standard transmission rate Q _S at the shift control command signal S _T based on the shift control command signal S _T that is actually output from the transmission rate characteristics of said standard, Based on the standard shift flow rate Q _S and the actual shift flow rate Q _A calculated by the shift flow rate calculation means 162, a deviation ΔQ (= Q _S −Q _A ) is calculated. And this deviation (DELTA) Q is memorize | stored in RAM of the electronic controller 50, for example being updated at any time. In this way, the deviation ΔQ is learned.

The learning control means 160 determines from the relationship (correction amount map) between the deviation ΔQ and the shift duty correction amount Dadj, which is experimentally obtained and stored in advance so that the shift duty correction amount Dadj increases as the deviation ΔQ increases. The shift duty correction amount Dadj is calculated (learned) based on the deviation ΔQ calculated by the shift flow rate deviation calculating means 164. Then, the learning control means 160, the shift control means 152 by correcting the shift control command signal S _T by adding the shift Duty correction amount Dadj to the shift control command signal S _T which is determined based on the rotational deviation .DELTA.N _IN ( learn. The shift control means 152 outputs a shift control command signal S _T which is corrected by the learning control unit 160 to the hydraulic control circuit 100.

Incidentally, in this embodiment, wherein the learning control means 160 when the learning completion of the shift control command signal S _T by, while in the shift control command signal S _T is determined to be shifting flow rate Q based on the rotation deviation .DELTA.N _IN, during learning incomplete shift control command signal S _T, due to variations in components of the hydraulic fluid supply and discharge adjustment device at the time of rotation deviation .DELTA.N _iN is small becomes in constant gradually decreases towards zero the speed rate Q travel since the shift hunting phenomenon by the variation of the transmission rate characteristics may occur, so as not to be shift hunting occurs when there is variation in the speed change flow characteristics, the shift control command signal S _T at the time of steady running, Do you value the thrust ratio control oil pressure P _tau is a state which is allowed to act on the primary hydraulic cylinder 42c from the thrust ratio control valve 118 Is set to a value equivalent to the closed control state.

That is, the shift control unit 152 does not output the closing control command signal S _T ′ but does not output the closing control command signal S _T ′ when learning of the shift control command signal S _T by the learning control unit 160 is not completed, but the shift control command signal S for feedback control. Although of outputting a _T, as the shift control command signal S _T, for the thrust ratio control oil pressure P _tau is allowed to act on the primary hydraulic cylinder 42c, for example, an original without the speed ratio control valve UP114 upshift position side The DS1 shift duty for outputting the control hydraulic pressure _{PDS1 in the} vicinity of the position or the original position side is output.

FIG. 9 is a diagram illustrating an example of a change characteristic of the primary pressure Pin with respect to the DS1 shift duty. 9, the primary pressure Pin and DS1 transmission Duty is a state similar to the control state confinement if D ₁ or less will be the thrust ratio control oil pressure P _tau. Referred to as Duty confinement this _{D 1} less DS1 transmission Duty. Further, the primary pressure Pin DS1 transmission Duty is to source pressure is the line pressure P _L is the speed change ratio control valve UP114 is upshift position side exceeds D ₁ is supplied to the primary hydraulic cylinder 42c, DS1 transmission Duty is primary pressure Pin with the increased beyond the D ₁ increases.

However, when an equivalent state learning and narrowing control state closed when incomplete shift control command signal S _T by the learning control unit 160 as described above, abrupt downshifting to maximum speed ratio γmax side is generated That is, since the V-groove width of the primary pulley 42 is rapidly expanded and the V-groove width of the secondary pulley 46 is rapidly narrowed, the volume in the secondary hydraulic cylinder 46c is rapidly increased. Until the hydraulic oil corresponding to the minute is supplied to the secondary hydraulic cylinder 46c, the secondary pressure Pout may temporarily decrease and the transmission belt 48 may slip.

Therefore, in this embodiment, when the learning of the shift control command signal S _T by the learning control unit 160 is not completed, clamping so as to increase the predetermined value than the value when the secondary pressure Pout is completed learning by correcting the pressure control command signal S _B, to suppress the slippage of the transmission belt 48 that occurs when a state similar control state confinement.

Specifically, learning incomplete determination unit 166, the learning of the shift control command signal S _T by the learning control unit 160 determines whether or not incomplete. For example, learning incomplete determination unit 166, learning of the transmission flow rate difference calculating means 164 shift control command signal by the learning control means 160 when the learning number of the deviation ΔQ does not exceed the predetermined number of times by S _T is in unfinished while it determined that determines the number of times of learning of the deviation ΔQ by the shift rate deviation calculation unit 164 in the case where a predetermined number of times or more complete learning of the shift control command signal S _T by the learning control means 160.

Secondary pressure control amount correction means 168, when said by learning incomplete determination unit 166 learning shift control command signal S _T by the learning control means 160 is judged to be not completed, the shift control command signal S _T secondary pressure Pout as compared to when learning completion corrects the clamping pressure control command signal S _B to increase the predetermined value. For example, the secondary pressure control amount correction means 168 changes the squeezing force control command signal S _B as secondary pressure Pout increases correction oil pressure α min as a predetermined value as compared to when learning the completion of the shift control command signal S _T A command is output to the belt clamping pressure control means 156. Alternatively, the secondary pressure control amount correction means 168 outputs a command to increase the correction hydraulic α min the shift control command signal S required secondary pressure compared to when learning the completion of the _T Pout ^* to the belt clamping pressure setting means 154.

The belt clamping pressure control unit 156 according to the instruction by the secondary pressure control amount correction means 168, clamping force control command signal secondary pressure Pout is increased correction oil pressure α min compared to when learning the completion of the shift control command signal S _T and outputs the S _B, i.e. to change the belt clamping required secondary pressure set by the pressure setting means 154 Pout ^* is squeezing force control command signal S _B obtained as secondary pressure Pout is increased correction oil pressure α min. Alternatively, the belt clamping pressure setting means 154 according to the instruction by the secondary pressure control amount correction means 168, increasing correction oil pressure α min the required secondary pressure Pout ^* compared to when learning the completion of the shift control command signal S _T, i.e. For example, the required secondary pressure Pout ^* set based on the accelerator opening Acc and the actual gear ratio γ from the belt clamping pressure map shown in FIG. 5 is increased by the correction hydraulic pressure α.

The correction hydraulic pressure α is preliminarily assumed when the secondary pressure Pout temporarily decreases due to a state equivalent to the closed control state during a shift by feedback control executed by the learning control unit 160, for example. The hydraulic pressure is set to be equal to or higher than the maximum reduced hydraulic pressure of the secondary pressure Pout obtained experimentally. Thus, temporarily secondary pressure Pout in learning incomplete shift control command signal S _T is even decreased, secondary pressure Pout of learning completion time and least as shift control command signal S _T is ensured.

Further, at the time of learning incomplete shift control command signal S _T by the learning control unit 160, increasing correction oil pressure α partial secondary pressure Pout uniformly, increasing the burden on the transmission belt 48 is increased secondary pressure Pout more than necessary because of the potential, the secondary pressure control amount correction means 168, in order to load the drive belt 48 is reduced, closed by the shift control command signal S _T based on the magnitude of the shift control command signal S _T only when it is assumed to be a write control state equivalent conditions, the secondary pressure Pout may perform the correction of the clamping pressure control command signal S _B as increased correction oil pressure α min. In other words, the secondary pressure control amount correction means 168, when it is assumed that not be a state similar control state confinement is shift control command signal S _T does not perform the correction of the clamping pressure control command signal S _B You may do it.

Variation of the time which is assumed to be closed narrowing control state and not be a state equivalent to the shift control command signal S _T and, when learning of the shift control command signal S _T is not completed transmission rate characteristics For example, it is necessary to consider that the DS1 shift Duty is equal to or greater than a predetermined DS1 shift Duty that has been experimentally obtained and stored in advance. Is output.

Furthermore, the secondary pressure control amount correction means 168, when said by learning incomplete determination unit 166 learning shift control command signal S _T by the learning control means 160 is judged to be complete, the clamping pressure control command signal S _B do not execute the correction, or to reduce the burden of the transmission belt 48 as a zero terminated to i.e. the correction oil pressure α to correct the clamping force control command signal S _B.

Figure 10 is a flowchart illustrating a control operation for suppressing the slippage of the transmission belt 48 when the learning of the main portion, that the shift control command signal S _T of the control operation of the electronic control device 50 has not been completed, for example, It is repeatedly executed with a very short cycle time of about several milliseconds to several tens of milliseconds. FIG. 11 is a time chart for explaining the control operation shown in the flowchart of FIG.

10, first, the learning steps corresponding to the non-completion determination means 166 (hereinafter, omitting step) in S1, the learning of the shift control command signal S _T is equal to or incomplete is determined. For example, while the number of learning times of the deviation ΔQ is determined to be the determination of the S1 is affirmative and in the case does not exceed the predetermined number of times learning of the shift control command signal S _T is not completed, the number of times of learning of the deviation ΔQ There is the case where a predetermined number of times or more is determined that learning of the shift control command signal S _T has been completed the determination in S1 is negative.

T ₀ time to t ₂ time points 11 show that the learning of the shift control command signal S _T is the learning flag is determined to be incomplete turned OFF. From time t _{0 to} time t ₂ , the rotation between the actual input shaft rotational speed N _IN and the target input shaft rotational speed N _IN ^* is performed so that shift hunting does not occur during steady running even if there is a variation in the shift flow rate characteristics. deviation .DELTA.N _iN is the Duty confinement DS1 transmission Duty (solid line) during the steady running became a predetermined or less (t ₁ after the time). Thus, when ^* required secondary pressure Pout as shown in broken lines ^(target pressure) is set, the secondary from time point t _1, which is a state similar to the control state confinement pressure Pout (actual pressure) is temporarily It will decline. Incidentally, the two-dot chain line in DS1 transmission Duty shows a DS1 transmission Duty output when learning the completion of the shift control command signal S _T.

Squeezing as if the determination in S1 is affirmative, the at secondary pressure control amount correction means 168 S2 corresponding to the secondary pressure Pout increases correction oil pressure α min compared to when learning the completion of the shift control command signal S _T pressure control command signal S _B is corrected. For example, the command to change the clamping pressure control command signal S _B to add the correction oil pressure α to the secondary pressure Pout is output. Then, the not-shown step corresponding to the belt clamping pressure control means 156, in accordance with the instruction, clamping pressure control command signal S _B is output for adding the correction oil pressure α to the secondary pressure Pout, the secondary pressure Pout is corrected hydraulic α min Will be increased.

Note that S2 is not executed uniformly when the determination of S1 is affirmed, but because the burden on the transmission belt 48 is reduced, the shift control that is assumed to be equivalent to the closed control state. It may be executed only when the command signal _ST is output. In other words, this S2 is may be prohibited executed when that is supposed to not be a state similar control state confinement is shift control command signal S _T.

T ₀ time to t ₂ time points 11, clamping pressure control command signal S _B is output for adding the correction oil pressure α to the secondary pressure Pout, shows that the secondary pressure Pout is increased correction oil pressure α min . Therefore, from time point t ₁ secondary pressure Pout (actual pressure) is also temporarily lowered, the secondary pressure Pout of learning completion time and least as shift control command signal S _T is ensured.

Burden of the transmission belt 48 is reduced the routine or is terminated, or squeezing force control command signal S correction That correction oil pressure α is terminated and _B is made zero by the case the determination in S1 is negative .

T ₂ after the time of FIG. 11 shows that the learning flag is determined that learning of the shift control command signal S _T has been completed is turned ON. The t in the _two time points after the correction of the clamping pressure control command signal S _B for adding a correction oil pressure α to the secondary pressure Pout is then terminated correction oil pressure α is set to zero.

As described above, according to this embodiment, the learning when the learning of the control unit 160 the shift control command signal S _T is not completed, compared to the secondary pressure Pout in the correction at the time of learning the completion of the shift control command signal S _T since the secondary pressure control amount correction means 168 to increase the hydraulic α worth squeezing force control command signal S _B is corrected, the shift control command signal S _T learning equivalent to the control state confinement when an uncompleted Even if the secondary pressure Pout is temporarily reduced due to the state, the transmission belt 48 can be prevented from slipping.

Further, according to this embodiment, the secondary pressure control amount correction means 168 is assumed to be a state similar control state confinement by the shift control command signal S _T based on the magnitude of the shift control command signal S _T only Rutoki, those secondary pressure Pout to perform the correction of the clamping pressure control command signal S _B as increased correction oil pressure α min, transmission is prevented from secondary pressure Pout increases unnecessarily belt 48 The burden of is reduced.

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

For example, in the above-described embodiment, the continuously variable transmission 18 is shift-controlled based on the rotational deviation ΔN _IN (= N _IN ^* −N _IN ) between the actual input shaft rotational speed N _IN and the target input shaft rotational speed N _IN ^*. but was, on the basis of the deviation between the target value and the actual value of such speed ratio γ and the sheave position corresponding to the one-to-one with the input shaft rotational speed N _iN may perform the shift control of the continuously variable transmission 18. This sheave position represents the absolute position of the movable rotating body 42b from the reference position in the direction parallel to the axis, with the position of the movable rotating body 42b when the speed ratio γ is 1, for example, being the reference position, that is, the sheave position is zero. Is.

Further, the input shaft rotational speed N _IN and the related target input shaft rotational speed N _IN ^* in the above-described embodiment are replaced with the input rotational speed N _{IN and the} like, and the engine rotational speed _NE and the related target. The engine rotational speed N _E ^* or the like, or the turbine rotational speed _NT or a target turbine rotational speed _NT ^* related thereto may be used. Accordingly, a rotational speed sensor such as the input shaft rotational speed sensor 56 may be appropriately provided in accordance with the rotational speed that needs to be controlled.

  In the above-described embodiment, the torque converter 14 provided with the lock-up clutch 26 is used as the fluid transmission device. However, the lock-up clutch 26 is not necessarily provided. In addition, other fluid type power transmission devices such as a fluid coupling (fluid coupling) having no torque amplification function may be used.

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

1 is a skeleton diagram illustrating a vehicle drive device to which the present invention is applied. It is a block diagram explaining the principal part of the control system provided in the vehicle in order to control the vehicle drive device etc. of FIG. It is a hydraulic circuit diagram which shows the principal part regarding the belt clamping pressure control and speed ratio control of a continuously variable transmission among hydraulic control circuits. It is a figure which shows an example of the shift map used when calculating | requiring a target input rotational speed in the shift control of a continuously variable transmission. It is a figure which shows an example of the belt clamping pressure map which calculates | requires required secondary pressure according to gear ratio etc. in clamping pressure control of a continuously variable transmission. This is a relationship obtained and stored in advance between the gear ratio and the thrust ratio with the vehicle speed as a parameter. It is a functional block diagram explaining the principal part of the control function of the electronic control apparatus of FIG. It is a figure which shows an example of the shift flow rate characteristic of DS1 shift Duty at the time of upshift, and a shift flow rate, A solid line is a predetermined standard shift characteristic, and each broken line is the actual which the deviation generate | occur | produced from the standard shift flow characteristic This is a variable speed flow rate characteristic. It is a figure which shows an example of the change characteristic of the primary pressure with respect to DS1 transmission Duty. 3 is a flowchart for explaining a control operation for suppressing slippage of the transmission belt when learning of a shift control command signal is incomplete, that is, a main part of the control operation of the electronic control device of FIG. It is a time chart explaining the control action shown in the flowchart of FIG.

Explanation of symbols

12: Engine (power source for running)
18: continuously variable transmission 24: drive wheel 42: primary pulley 42c: primary hydraulic cylinder 46: secondary pulley 46c: secondary hydraulic cylinder 48: transmission belt (belt)
50: Electronic control device (control device)
110: Nipping pressure control valve (secondary pressure regulator)
114: Gear ratio control valve UP (hydraulic oil supply / discharge adjustment device)
116: Transmission ratio control valve DN (hydraulic oil supply / discharge adjustment device)
118: Thrust ratio control valve (hydraulic pressure regulator)
160: Learning control means 168: Secondary pressure control amount correction means DS1, DS2: Solenoid valve (hydraulic oil supply / discharge adjustment device)
SLS: Linear solenoid valve (secondary pressure regulator)

Claims (2)

A primary side hydraulic pressure for changing the groove width of the primary pulley, having a primary pulley, a secondary pulley, and a belt wound around both pulleys in a power transmission path between the driving power source and the drive wheel In a vehicle provided with a continuously variable transmission having a cylinder and a secondary hydraulic cylinder for changing the groove width of the secondary pulley, the amount of hydraulic oil supplied to and discharged from the primary hydraulic cylinder is adjusted. The hydraulic oil supply / discharge adjustment device, the secondary pressure regulating device for regulating the hydraulic pressure in the secondary hydraulic cylinder, and the ratio between the hydraulic pressure in the primary hydraulic cylinder and the hydraulic pressure in the secondary hydraulic cylinder are set in advance. A hydraulic pressure ratio adjusting device for establishing a predetermined relationship, and adjusting the hydraulic oil supply and discharge so that the actual value becomes a preset target value. It performs transmission device control to said a control device for a vehicle continuously variable transmission that controls the secondary pressure adjusting apparatus as slippage of the belt does not occur,
Learning control means for learning the control amount such that the characteristic of the hydraulic oil amount with respect to the control amount of the hydraulic oil supply / discharge adjustment device has a predetermined relationship;
When learning of the control amount of the hydraulic oil supply / discharge adjustment device by the learning control means is incomplete, the oil pressure in the secondary hydraulic cylinder is increased by a predetermined value compared to the value when the learning is completed. And a secondary pressure control amount correcting means for correcting the control amount of the secondary pressure regulating device.   2. The continuously variable vehicle for a vehicle according to claim 1, wherein the secondary pressure control amount correcting means corrects the control amount of the secondary pressure regulating device based on a control amount of the hydraulic oil supply / discharge adjusting device. Transmission control device.

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