JP2007303565A - Shift control device of vehicular continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shift control device restraining a sense of incongruity of a driver during a change in input rotating speed, when requiring acceleration in a shift-up process when decelerating a vehicle, in a vehicular continuously variable transmission changing the gear ratio so that an actual input rotating speed is changed toward a steady rotating speed based on a vehicle state. <P>SOLUTION: When determining that the acceleration is required by an acceleration request determining means 176 in the shift-up process when decelerating the vehicle, since up-shift of the continuously variable transmission 18 is prohibited by an up-shift prohibiting means 170 so as not to reduce an actual input shaft rotating speed N<SB>IN</SB>, when generating an acceleration request such as stepping increasing operation of an accelerator pedal 68 in the middle of the up-shift when decelerating the vehicle, even when a basic target rotating speed N<SB>INBSE</SB>is lower than the actual input shaft rotating speed N<SB>IN</SB>, the sense of incongruity of the driver to a change in the actual input shaft rotating speed N<SB>IN</SB>is restrained by restraining reduction in the actual input shaft rotating speed N<SB>IN</SB>. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transmission control device for a continuously variable transmission for a vehicle that changes a transmission ratio so that an input rotational speed becomes a steady rotational speed based on a vehicle state, and in particular, a change of a transmission ratio in an upshift during vehicle deceleration. It is about.

  In the shift control device of the continuously variable transmission provided in the vehicle, a transient target value in the middle of the shift is set so that the current value gradually approaches the steady target value set based on the running state, It is well known that gear shifting is performed by feedback control, for example, so that the current value becomes this transient target value. The steady target value is set based on, for example, an acceleration request, and is a value that is kept constant when the acceleration request is made constant. This is the basic target value for setting. Further, the transient target value is the final target value for substantially controlling the current value. Further, as a target value at the time of shifting, a target speed ratio is set, a target input rotational speed for setting the target speed ratio is set, or a target input rotational speed is directly set.

  For example, in a shift control mode in which a steady target input rotation speed (hereinafter referred to as a steady rotation speed) is set as a steady target value and the gear ratio is changed, the steady control based on the vehicle state such as the accelerator operation amount is performed. A transient target input rotational speed (hereinafter referred to as transient rotational speed) that gradually approaches the rotational speed is set, and the gear ratio is set so that the actual input rotational speed of the continuously variable transmission becomes the transient rotational speed. Is controlled. Therefore, in the upshift process during vehicle deceleration, the input rotational speed of the continuously variable transmission is gradually decreased with a predetermined change gradient toward the steady rotational speed.

  Further, the change gradient of the input rotational speed of the continuously variable transmission is related to the shift speed, and it is desired that the shift is performed at an appropriate shift speed that does not give the driver a sense of incongruity as much as possible.

  Regarding the execution of an upshift of a continuously variable transmission at an appropriate shift speed, for example, Patent Document 1 discloses a throttle valve in the case of an upshift by a driver's deceleration operation in which the throttle valve opening changes. There has been proposed a shift control device that slows down the shift speed as compared with an upshift that does not depend on the driver's deceleration operation with the opening degree being substantially constant, thereby suppressing the driver from feeling uncomfortable.

Japanese Patent Laid-Open No. 10-47447

  By the way, it is conceivable that an acceleration operation such as an accelerator pedal depression operation is performed during an upshift process during vehicle deceleration by a driver's deceleration operation. In particular, as in Patent Document 1, when the speed of the upshift is relatively slow during vehicle deceleration, the time required for the upshift becomes longer, and the upshift process is faster than when the upshift is performed quickly. This increases the possibility that the driver will perform a reacceleration operation.

  When a driver's re-acceleration request occurs during such an upshift process, the steady target value based on the vehicle state is changed, but this steady target value lowers the actual input rotational speed. In such a case, a transient target value that gradually decreases toward the steady target value is set, and the actual input rotation speed is continuously decreased at a predetermined change gradient. As a result, the upshift is substantially continued, and the input rotational speed continues to decrease despite the depression of the accelerator pedal, resulting in a sense of incongruity with the change in the input rotational speed of the driver. Could occur.

  FIG. 12 is a diagram showing a target input rotation speed set at the time of upshift accompanying accelerator off, and a target input rotation speed that is changed in accordance with the depression of the accelerator pedal during the upshift process.

Before time t _{1 in} FIG. 12, the steady rotational speed, that is, the basic target rotational speed N _INBSE and the transient rotational speed, that is, the final target rotational speed N _IN ^* substantially coincide with each other when the accelerator operation amount is constant, and the actual input rotational speed. Indicates a state in which the basic target rotational speed _NINBSE is substantially matched. In time point t _1, the dashed as reduced stepwise elementary target rotational speed N _INBSE is set for upshifting when the release of the accelerator pedal. Subsequently, at a time point t _{1 to a} time point t ₂ , a final target rotational speed N _IN ^{* that} is gradually decreased with a predetermined gradient toward the basic target rotational speed N _INBSE is set. The upshift is executed under feedback control so as to follow the target rotational speed N _IN ^* . As shown at time t _2, when an acceleration operation is performed such that the accelerator pedal is depressed during the upshift process, a new basic target rotational speed N _INBSE increased stepwise based on the acceleration operation is obtained. Is set. As shown in FIG. 12, when the basic target rotational speed N _INBSE is lower than the final target rotational speed N _IN ^*, that is, the actual input rotational speed, the final target rotational speed N _IN ^* Since it is set so as to be gradually decreased toward the basic target rotational speed N _INBSE , the actual input rotation is achieved despite the fact that the upshift is substantially continued and the accelerator pedal is depressed. The speed continues to decrease toward the basic target rotational speed _NINBSE as indicated by the dashed arrow A. Therefore, there is a possibility that the driver feels uncomfortable with the change in the input rotation speed.

  The present invention has been made against the background of the above circumstances. The purpose of the present invention is to change the gear ratio so that the actual input rotational speed can be changed toward the steady rotational speed based on the vehicle state. In the continuously variable transmission for a vehicle, there is provided a shift control device that suppresses a sense of incongruity with a change in an input rotational speed of a driver when an acceleration request is made in an upshift process during vehicle deceleration.

  The gist of the invention according to claim 1 for achieving such an object is as follows: (a) in a vehicle in which a continuously variable transmission is disposed in a power transmission path between a driving power source and a drive wheel; A shift control device for a continuously variable transmission for a vehicle that changes a gear ratio so that an input rotational speed is gradually decreased toward a steady rotational speed based on a vehicle state when the continuously variable transmission is upshifted during vehicle deceleration. (B) an acceleration request determining means for determining whether or not an acceleration request has occurred in the upshift process during vehicle deceleration, and (c) the acceleration request determining means determines that the acceleration request has been generated. And an upshift prohibiting means for prohibiting an upshift of the continuously variable transmission so that the input rotational speed does not decrease.

  In this way, in the upshift process when the vehicle is decelerating, when it is determined that the acceleration request is determined by the acceleration request determination means, the upshift prohibiting means prevents the input rotational speed from being reduced. Since upshifts are prohibited, when an acceleration request such as an accelerator pedal depressing operation occurs during an upshift during vehicle deceleration, the steady rotational speed based on the vehicle state is lower than the actual input rotational speed. However, the decrease in the input rotation speed is suppressed, and the driver's uncomfortable feeling with respect to the change in the input rotation speed is suppressed.

  According to a second aspect of the present invention, in the shift control device for a continuously variable transmission for a vehicle according to the first aspect, the upshift prohibiting unit fixes the speed ratio of the continuously variable transmission. An upshift is prohibited. In this way, upshifting is reliably prohibited. In addition, reacceleration performance associated with the acceleration request is secured.

  According to a third aspect of the present invention, in the transmission control device for a continuously variable transmission for a vehicle according to the first or second aspect, the acceleration request determining means has an acceleration request amount equal to or greater than a predetermined value, and the acceleration When the change amount of the request amount is equal to or greater than a predetermined value, it is determined that the acceleration request has occurred. By so doing, prohibition of upshifting is appropriately executed at the time of an acceleration request that tends to cause a sense of incongruity with respect to changes in the input rotational speed of the driver.

  According to a fourth aspect of the present invention, in the shift control device for a continuously variable transmission for a vehicle according to any one of the first to third aspects, the upshift prohibiting means is configured such that the steady rotational speed is higher than the input rotational speed. When the value becomes higher, the prohibition of the upshift is terminated. In this way, upshifting is prohibited until the steady rotational speed based on the vehicle state becomes higher than the input rotational speed and the reduction of the input rotational speed is avoided.

  According to a fifth aspect of the present invention, in the shift control device for a continuously variable transmission for a vehicle according to any one of the first to fourth aspects, the upshift prohibiting unit is configured to output the acceleration request by the acceleration request determining unit. When a predetermined time elapses from the time when it is determined that it has occurred, the prohibition of the upshift ends. In this way, the prohibition of upshifting can be surely ended.

  According to a sixth aspect of the present invention, in the shift control device for a continuously variable transmission for a vehicle according to any one of the first to fifth aspects, the upshift prohibiting means includes the upshift when a deceleration request is generated. This will end the prohibition. In this way, upshifting is prohibited until it becomes difficult for the driver to feel uncomfortable with changes in the input rotational speed.

  Here, preferably, the requested acceleration amount is an amount indicating the magnitude of the driver's intention to accelerate, for example, an accelerator operation amount (accelerator opening amount) indicating an accelerator pedal depression amount or an accelerator operation amount thereof. An acceleration operation amount such as a throttle valve opening indicating the opening of the corresponding throttle valve is used. The change amount of the acceleration request amount is an acceleration operation speed such as an accelerator change rate or a throttle valve opening change rate. Further, the fuel injection amount indicating the amount of fuel injected into the chamber or cylinder provided in the intake pipe of the engine corresponding to the accelerator operation amount, the intake air amount sucked through the intake pipe of the engine, etc. are accelerated. It may be used as a required amount.

  Preferably, the continuously variable transmission is a so-called belt in which a transmission belt functioning as a power transmission member is wound around a pair of variable pulleys having a variable effective diameter, and the gear ratio is continuously changed steplessly. Type continuously variable transmission, a pair of cones rotated around a common axis and a plurality of rotatable rollers that intersect with the center of the cone are sandwiched between the pair of cones and the rotation center of the rollers And a so-called traction type continuously variable transmission whose transmission ratio is variable by changing the crossing angle between the shaft and the shaft center.

  Preferably, the mounting position of the continuously variable transmission with respect to the vehicle is such that the axis of the transmission is a horizontal type such as an FF (front engine / front drive) vehicle in which the axis of the transmission is in the width direction of the vehicle. It may be a vertical installation type such as an FR (front engine / rear drive) vehicle in the longitudinal direction of the vehicle.

  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. Further, an electric motor or the like may be used in addition to this 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 lock-up clutch 26 is provided between the pump impeller 14p and the turbine impeller 14t, and is engaged by a switching valve (not shown) in the hydraulic control circuit 100 (see FIGS. 2 and 3). The hydraulic pressure supply to the side oil chamber and the release side oil chamber is switched to engage or release, and the pump impeller 14p and the turbine impeller 14t are integrally rotated by being completely engaged. . The pump impeller 14p is controlled to shift the continuously variable transmission 18, to generate a clamping pressure of the transmission belt 48 (hereinafter referred to as belt clamping pressure), to engage / disengage the lockup clutch 26, or A mechanical oil pump 28 is connected which generates hydraulic pressure for supplying lubricating oil to each part and is rotated by the engine 12.

  The forward / reverse switching device 16 is mainly composed of a double pinion type planetary gear device, the turbine shaft 34 of the torque converter 14 is integrally connected to the sun gear 16s, and the input shaft 36 of the continuously variable transmission 18 is a carrier. The carrier 16c and the sun gear 16s are selectively connected via the forward clutch C1, while the ring gear 16r is selectively fixed to the housing via the reverse brake B1. It has become. 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. Further, when both the forward clutch C1 and the reverse brake B1 are released, the forward / reverse switching device 16 becomes neutral (interrupted state) for interrupting power transmission.

  The continuously variable transmission 18 has an input-side variable pulley (primary sheave) 42 having a variable effective diameter that is an input-side member provided on the input shaft 36, and an effective diameter that is an output-side member provided on the output shaft 44. A variable output side variable pulley (secondary sheave) 46 and a transmission belt 48 wound around the variable pulleys 42 and 46 are provided, and a frictional force between the variable pulleys 42 and 46 and the transmission belt 48 is provided. That is, power transmission is performed via the belt clamping pressure.

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. The movable rotating bodies 42b and 46b provided, and the input-side hydraulic cylinder 42c and the output-side hydraulic cylinder 46c that apply thrust to change the V-groove width between them are configured. By controlling the hydraulic pressure 42c (shift control pressure P _RATIO ) by the hydraulic control circuit 100, the V groove widths of both variable pulleys 42 and 46 are changed, and the engagement diameter (effective diameter) of the transmission belt 48 is changed. The gear ratio γ (= input shaft rotational speed N _IN / output shaft rotational speed N _OUT ) is continuously changed. The hydraulic pressure of the output side hydraulic cylinder 46c (belt clamping pressure, clamping pressure control pressure P _BELT ) is regulated by the hydraulic control circuit 100 so that the transmission belt 48 does not slip.

  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 representing signal, continuously variable transmission 18 within such operating oil that has been detected by the CVT fluid temperature sensor 64 signals representative of the oil temperature T _CVT of (CVT fluid), depressing the accelerator pedal 68 detected by the accelerator operation amount sensor 66 An accelerator operation amount signal indicating the amount of accelerator operation (accelerator opening) Acc, a brake operation signal indicating whether or not the foot brake as a service brake is operated B _ON detected by the foot brake switch 70, and a lever position sensor 72 detected lever position of the shift lever 74 (operation position) operation position signal representative of the P _SH etc. It has been supplied.

The electronic control unit 50 also outputs an engine output control command signal for controlling the output of the engine 12, for example, a throttle signal for driving the throttle actuator 76 for controlling the opening / closing of the electronic throttle valve 30, and an injection from the fuel injection unit 78. An injection signal for controlling the amount of fuel to be burned, 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 shift control command signal for changing the speed ratio γ of the continuously variable transmission 18, for example, a command signal for controlling the shift control pressure P _RATIO , a clamping pressure control command signal for adjusting the belt clamping pressure, for example, clamping pressure A command signal for controlling the control pressure P _BELT , a lock-up control command signal for controlling the engagement, release, and slip amount of the lock-up clutch 26, for example, an unillustrated on-off solenoid valve or lock-up clutch in the hydraulic control circuit 100 26 a command signal for driving a linear solenoid valve for adjusting the torque capacity of such a command signal for driving a linear solenoid valve SLT for controlling the line pressure P _L is output to the hydraulic control circuit 100.

The line pressure P _L, for example in the output oil pressure of the linear solenoid valve SLT that value corresponding to the transmission input torque T _IN is driven in accordance with the command signal output so as to obtain input to the continuously variable transmission 18 Based on a certain control oil pressure P _SLT , the oil pressure generated from a mechanical oil pump 28 that is driven to rotate by the engine 12 is regulated by a relief pressure regulating valve (regulator valve) (not shown) in the oil pressure control circuit 100 as an original pressure. The

  The shift lever 74 is disposed in the vicinity of the driver's seat, for example, and moves to any one of the five lever positions “P”, “R”, “N”, “D”, and “L” (see FIG. 3). It is designed 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).

FIG. 3 shows portions of the hydraulic control circuit 100 relating to the belt clamping pressure control, the transmission gear ratio control of the continuously variable transmission 18, and the engagement hydraulic pressure control of the forward clutch C1 or the reverse brake B1 accompanying the operation of the shift lever 74. FIG. 2 is a main part hydraulic circuit diagram illustrating a pinching pressure control valve 110 that regulates a pinching pressure control pressure P _BELT that is a hydraulic pressure of the output side hydraulic cylinder 46c so that the transmission belt 48 does not slip, and a gear ratio γ continuously. The transmission ratio control valve UP116 and the transmission ratio control valve DN118, the forward clutch C1, and the reverse brake B1 that adjust the transmission control pressure P _RATIO that is the hydraulic pressure of the input side hydraulic cylinder 42c so as to be changed are engaged or released. The manual valve 120 whose oil passage is mechanically switched according to the operation of the shift lever 74 is I have.

In the manual valve 120, the modulator pressure P _M of a constant pressure to the input port 120a pressure regulated by modulator valve (not shown) line pressure P _L as source pressure is supplied, i.e. adjusted to a modulator pressure P _M by the modulator valve Pressurized hydraulic fluid is supplied.

When the shift lever 74 is operated to the "D" position or "L" position, and the reverse brake modulator pressure P _M is supplied to the forward clutch C1 via a forward output port 120f as forward running output pressure The oil passage of the manual valve 120 is switched so that the hydraulic oil in B1 is drained (discharged) to the atmospheric pressure, for example, from the reverse output port 120r through the discharge port EX, and the forward clutch C1 is engaged and reversely moved. The brake B1 is released.

Further, when the shift lever 74 is operated to the "R" position, modulator pressure P _M is the hydraulic fluid in the fed and the forward clutch C1 to the reverse brake B1 via the reverse output port 120r as reverse running output pressure Is switched from the forward output port 120f through the discharge port EX to the atmospheric pressure, for example, so that the oil passage of the manual valve 120 is switched, the reverse brake B1 is engaged, and the forward clutch C1 is released. Be made.

  When the shift lever 74 is operated to the “P” position and the “N” position, the oil path from the input port 120a to the forward output port 120f and the oil path from the input port 120a to the reverse output port 120r are both And the oil passage of the manual valve 120 is switched so that the hydraulic oil in the forward clutch C1 and the reverse brake B1 is drained from the manual valve 120, and both the forward clutch C1 and the reverse brake B1 are released. Be made.

The transmission ratio control valve UP116 is provided so as to be movable in the axial direction, thereby opening and closing the input / output port 116t and the input / output port 116i, and the spool valve element 116a as an input / output port 116t and an input / output port 116i. Spring 116b as an urging means for urging in a direction in which the input / output port communicates, and the spring 116b are accommodated, and a thrust in a direction in which the input / output port 116t and the input / output port 116i communicate with each other is applied to the spool valve element 116a In order to apply an oil chamber 116c that receives a control oil pressure _PS2 that is an output oil pressure of the solenoid valve DS2 that is duty-controlled by the electronic control device 50, and a thrust in a direction that closes the input / output port 116i to the spool valve element 116a. The duty controlled by the electronic control unit 50 And an oil chamber 116d that receives a control oil pressure _PS1 that is an output oil pressure of the renoid valve DS1.

The transmission ratio control valve DN118 is provided so as to be movable in the axial direction, and serves as a spool valve element 118a that opens and closes the input / output port 118t, and an urging unit that urges the spool valve element 118a in the valve closing direction. Oil that accommodates the spring 118b and the control oil pressure _PS1 that is the output oil pressure of the solenoid valve DS1 that is duty-controlled by the electronic control unit 50 to apply the thrust in the valve closing direction to the spool valve element 118a. A chamber 118c and an oil chamber 118d that receives a control hydraulic pressure _PS2 that is an output hydraulic pressure of the solenoid valve DS2 that is duty-controlled by the electronic control unit 50 to apply a thrust force in the valve opening direction to the spool valve element 118a. .

The solenoid valve DS1 supplies hydraulic oil to the input side hydraulic cylinder 42c, increases its hydraulic pressure (shift control pressure P _RATIO ), reduces the V groove width of the input side variable pulley 42, and reduces the speed ratio γ. In order to control to the shift side, the control hydraulic pressure _PS1 is output. Further, the solenoid valve DS2 discharges the hydraulic oil in the input side hydraulic cylinder 42c, _lowers the shift control pressure _PRATIO , increases the V groove width of the input side variable pulley 42, and increases the speed ratio γ, that is, the downshift side. The control hydraulic pressure _PS2 is output in order to perform control.

Specifically, supplied with shift control pressure P _RATIO is controlled continuously control hydraulic pressure P _S1 is the line pressure P _L input to the speed ratio control valve UP116 to be outputted to the input side hydraulic cylinder 42c, the control When the hydraulic pressure _PS2 is output, the hydraulic oil in the input side hydraulic cylinder 42c is continuously discharged from the input / output port 116t through the input / output port 116i and further through the input / output port 118t and from the discharge port 118x, and the shift control pressure P _{RATIO is} continuously maintained. Be controlled.

For example, the final target rotational speed N _IN ^*, which will be described later, as the target input rotational speed of the continuously variable transmission 18 is matched with the actual input shaft rotational speed (hereinafter referred to as the actual input shaft rotational speed) N _IN. In accordance with the rotational speed difference (deviation) ΔN _IN (= N _IN ^* −N _IN ), for example, the transmission of the continuously variable transmission 18 is executed, that is, the shift control is performed by supplying and discharging the hydraulic oil to and from the input side hydraulic cylinder 42c. The pressure P _RATIO is regulated and the speed ratio γ is continuously changed.

The clamping pressure control valve 110 is provided so as to be movable in the axial direction, and thereby a spool valve element 110a that opens and closes the output port 110t, and a spring 110b as an urging means that urges the spool valve element 110a in the valve opening direction. The oil chamber 110c that houses the spring 110b and receives the control hydraulic pressure P _SLT that is the output hydraulic pressure of the linear solenoid valve SLT that is duty-controlled by the electronic control unit 50 to apply a thrust in the valve opening direction to the spool valve element 110a. And a feedback oil chamber 110d for receiving the clamping pressure control pressure P _BELT output for applying a thrust in the valve closing direction to the spool valve element 110a. The control hydraulic pressure P _SLT from the linear solenoid valve SLT is _supplied as a pilot pressure. clamping force control pressure of the line oil pressure P _L continuously regulated pressure control to a And it outputs a _BELT.

For example, the clamping pressure of the output side hydraulic cylinder 46c is obtained so that a necessary hydraulic pressure P _BELT ^* described later, which is the target belt clamping pressure of the output side hydraulic cylinder 46c necessary for applying the belt clamping pressure to the variable pulleys 42, 46, is obtained. The control pressure P _BELT is regulated, and the belt clamping pressure is increased or decreased according to the clamping pressure control pressure P _BELT .

FIG. 4 is a functional block diagram for explaining a main part of the control function by the electronic control unit 50. In FIG. 4, the target driving force calculation means 150 calculates the target driving force F ^* based on the accelerator operation amount Acc as the acceleration request amount. For example, the target driving force calculation means 150 uses the accelerator operation amount Acc as shown in FIG. 5 as a parameter to determine and store the relationship between the vehicle speed V and the target driving force F ^* obtained in advance (map, driving force map). ) Based on the actual vehicle speed V and the accelerator operation amount Acc, the target drive force F ^* (= map (vehicle speed V, accelerator operation amount Acc)) is obtained. The driving force map in FIG. 5 is set such that the target driving force F ^* increases as the vehicle speed V decreases and as the accelerator operation amount Acc increases.

In addition, the target driving force calculation means 150 performs vehicle speed control such as so-called cruise control that automatically controls the vehicle speed V regardless of the accelerator operation amount Acc so as to be a preset speed, that is, the target vehicle speed V ^*. calculates a target driving force F ^* for maintaining the vehicle speed V to the target vehicle speed V ^*.

The target output calculation means 152 calculates the target output P ^* from the vehicle speed V and the target driving force F ^* calculated by the target driving force calculation means 150 according to P ^* = f (F ^* , V) = F ^* × V × 1000/3600 ^. Is calculated. The target output calculation means 152 compensates for the output P ⁻ in the drive wheel 24 that decreases due to an auxiliary load such as an alternator, an air conditioner compressor, a water pump, and a power steering pump, based on the auxiliary load. output P ^- the increase P _E of the corresponding engine output P _E ⁺ was calculated as the accessory load compensation output P _AUX to may calculate the target output P ^* by adding the accessory load compensation output P _AUX .

The basic target rotation speed calculation means 154 calculates a basic target rotation speed N _INBSE that is a steady rotation speed of the continuously variable transmission 18 based on the target output P ^* calculated by the target output calculation means 152. For example, the basic target engine speed calculating means 154 is obtained in advance experimentally to achieve both drivability and fuel consumption in a two-dimensional coordinate composed of the input shaft rotational speed N _IN and the engine torque T _E The input shaft rotational speed N _IN as shown by the broken line in FIG. 6 is operated so that the engine 12 is operated along the stored optimum fuel consumption rate curve (fuel consumption map, relationship) of the engine 12 as shown by the solid line in FIG. the previously obtained with the stored target output P ^* of equal output curve (equal output map, relationship) based on the engine torque T _E basic target rotational speed N _INBSE based from the target output P ^* (= map (target Obtain the output P ^* )). That is, the basic target rotation speed calculation means 154 calculates the basic target rotation speed N _INBSE necessary for satisfying the target output P ^* from the optimum fuel consumption rate curve and the equal output curve.

The final target rotation speed calculation means 156 calculates a final target rotation speed N _IN ^* that is a transient rotation speed of the continuously variable transmission 18 based on the basic target rotation speed N _INBSE calculated by the basic target rotation speed calculation means 154. To do. For example, the final target rotational speed calculation means 156 sets a final target rotational speed N _IN ^* that gradually approaches the basic target rotational speed N _INBSE with a predetermined gradient as shown in FIG. In the transient characteristics as shown in FIG. 7, for example, a predetermined change gradient is uniformly set in advance with respect to the basic target rotation speed N _INBSE so that the shift is executed at a shift speed that does not cause a shift shock or a delayed response. It may be set, or may be changed based on parameters such as accelerator operation amount Acc, change amount of accelerator operation amount (hereinafter referred to as accelerator change amount) ΔAcc, vehicle speed V, and the like. For example, the larger the accelerator change amount ΔAcc is, the faster the rise is set. Alternatively, the final target rotation speed calculation unit 156 may set a final target rotation speed N _IN ^* that is a first-order lag with respect to the basic target rotation speed N _INBSE . A time constant is determined for the final target rotational speed N _IN ^* of the first-order lag so that the shift speed and the suppression of the shift shock are compatible. For example, the time constant may be a preset constant value or may be changed based on parameters such as the accelerator operation amount Acc, the accelerator change amount ΔAcc, the vehicle speed V, or the like from a previously stored relationship. . For example, the larger the accelerator change amount ΔAcc is, the faster the rise is set. Further, the predetermined change gradient and the time constant is, the upper limit value taking into account the fully opened and hydraulic oil temperature or the like of the throttle valve opening theta _TH (upper limit guard value) may be provided.

The target engine torque calculation unit 158 calculates a target engine torque T _E ^* based on the target output P ^* calculated by the target output calculation unit 152. For example, the target engine torque calculation means 158 may set the target output P ^* as shown by the broken line in FIG. 6 so that the engine 12 is operated along the optimum fuel consumption rate curve of the engine 12 as shown by the solid line in FIG. obtaining an equal power curve target engine torque based on the target output ^{P *} from _T ^E * (= map (target output ^P *)) of. That is, the target engine torque calculation means 158 calculates the target engine torque T _E ^* necessary for satisfying the target output P ^* from the optimal fuel consumption rate curve and the equal output curve.

The required throttle opening calculation means 160 calculates the required throttle opening θ _THR based on the target engine torque T _E ^* calculated by the target engine torque calculation means 158. For example, the required throttle opening degree calculation means 160, which is experimentally determined in advance is in memory of the engine rotational speed N _E and the engine torque estimated value T _E0 throttle valve opening theta _TH as shown in FIG. 8 as a parameter relationship calculates the required throttle opening theta _THR so that the engine torque estimation value T _E0 for target engine torque T _E ^* obtained based on the actual engine rotational speed N _E from (engine torque map).

The belt clamping pressure setting means 162 calculates the belt clamping pressure of the transmission belt 48, that is, the necessary hydraulic pressure P _BELT ^* of the output side hydraulic cylinder 46c, based on the required throttle opening θ _THR calculated by the required throttle opening calculation means 160. To do. For example, the belt clamping pressure setting means 162 prevents the belt slip between the gear ratio γ and the required hydraulic pressure P _BELT ^* (corresponding to the belt clamping pressure) with the required throttle opening θ _THR as shown in FIG. 9 as a parameter. The required oil pressure P _BELT ^* is set based on the actual gear ratio γ and the required throttle opening θ _THR from the relationship (squeezing pressure map) obtained and stored experimentally in advance.

The speed change control means 164 determines the difference (deviation) ΔN _IN between the actual input shaft rotational speed N _IN and the final target rotational speed N _IN ^* calculated by the final target rotational speed calculation means 156. The speed ratio γ of the continuously variable transmission 18 is feedback-controlled according to (= N _IN ^* −N _IN ). That is, the input side hydraulic cylinder 42c shift control pressure P _RATIO temper pressure shift control command signal (hydraulic pressure command) is output to S _T to the hydraulic control circuit 100 to continuously change the gear ratio gamma.

The belt clamping pressure control unit 166 regulates the clamping pressure control pressure P _BELT of the output side hydraulic cylinder 46c so that the necessary hydraulic pressure P _BELT ^* set by the belt clamping pressure setting unit 162 is obtained. _B is output to the hydraulic control circuit 100 to increase or decrease the belt clamping pressure.

The hydraulic control circuit 100, together with the pressure regulating the shift control pressure P _RATIO by operating the solenoid valve DS1 and the solenoid valve DS2 so shifting of the continuously variable transmission 18 is executed in accordance with the shift control command signal S _T, the clamping by operating the linear solenoid valve SLT as the belt squeezing pressure is increased or decreased according to the pressure control command signal S _B pressure regulating the squeezing force control pressure P _bELT.

The engine output control means 168 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 168 outputs a throttle signal for opening and closing the electronic throttle valve 30 to the throttle actuator 76 so that the required throttle opening degree θ _THR calculated by the required throttle opening degree calculating means 160 is obtained. The engine torque _TE is controlled by outputting an injection signal to the fuel injection device 78 so that the intake air amount Q _A and the fuel injection amount F (that is, the air-fuel ratio Q _A / F) corresponding to the throttle opening θ _THR are obtained.

Here, when an upshift is performed during deceleration of the vehicle such as when the accelerator is off, the speed is gradually lowered toward the basic target rotational speed N _INBSE that is set to be smaller stepwise than the actual input shaft rotational speed N _IN . Thus, the final target rotation speed N _IN ^* is set, and feedback control is performed so that the actual input shaft rotation speed N _IN follows the final target rotation speed N _IN ^* . As a result, when upshifting during vehicle deceleration, the gear ratio γ is reduced so that the actual input shaft rotational speed N _IN gradually decreases toward the basic target rotational speed N _INBSE .

By the way, when the accelerator pedal 68 is depressed in the upshift process, a basic target rotational speed N _{INBSE that} is increased stepwise based on the accelerator operation amount Acc is newly set, and this basic target rotational speed N _INBSE is set. The final target rotational speed N _IN ^* gradually approaching is set. At this time, if the basic target rotational speed N _INBSE newly set in accordance with the depression of the accelerator pedal 68 is lower than the actual input shaft speed N _IN is lowered toward the base target rotation speed N _INBSE Since the final target rotational speed N _IN ^* is set, the actual input shaft rotational speed N _IN is continuously decreased and the upshift is substantially continued even though the accelerator pedal 68 is depressed. there is a possibility that the sense of discomfort against the actual input shaft change in the rotational speed N _iN of the driver occurs.

Therefore, the upshift prohibiting means 170 is a continuously variable transmission so that the actual input shaft rotational speed _NIN is not reduced when an acceleration request such as a depression operation of the accelerator pedal 68 occurs during the upshift process during vehicle deceleration. 18 upshifts are prohibited.

Specifically, the off-up determining means 172 whether or not the upshift during vehicle deceleration is performed by the shift control means 164, i.e. so that the actual input shaft rotational speed N _IN with decreasing vehicle speed V is lowered Whether or not the vehicle is in a decelerating state, for example, whether or not an off-up flag F _UP indicating that an upshift is being executed in response to the accelerator off being output by the shift control means 164, or a brake It determines the operation signal B _oN is whether it is turned on, or coast flag F _C indicating that the coasting (coasting) is based on such whether oN.

The deceleration travel state continuation determining means 174 determines whether or not the actual input shaft rotational speed N _IN continues to decrease as the vehicle speed V decreases and the deceleration travel state continues, for example, when the off-up flag _FUP is off and the brake It determines the operation signal B _oN is turned off, and the coast flag F _C is based on whether it is within the predetermined time period T _C from when the vehicle state is oFF. The predetermined time T _C is decelerated running state determination off up determination unit 172 is experimentally determined in advance is in memory to determine to continue decelerating state even after a negative is continued This is the continuation judgment value.

The acceleration request determination unit 176 determines whether or not an acceleration request has occurred in the upshift process during vehicle deceleration by the shift control unit 164. For example, the acceleration request determination means 176 has an accelerator operation amount Acc that is greater than or equal to a predetermined operation amount Acc ′ and an accelerator change amount ΔAcc that is greater than or equal to a predetermined change amount ΔAcc ′ (actually, the determination is executed at a predetermined cycle. When the accelerator change rate is equal to or greater than a predetermined change rate, it is determined that an acceleration request has occurred. This predetermined operation amount Acc 'and the predetermined change amount? Acc' is the actual input shaft rotational speed N _IN of the accelerator pedal 68 such that there is a possibility that discomfort may occur with respect to the change of the actual input shaft rotational speed N _IN of the driver decreases This is an acceleration request determination value that is experimentally obtained and stored in advance for determining that the operation is a stepping operation.

When it is determined by the acceleration request determination unit 176 that an acceleration request has been generated, the upshift prohibiting unit 170 does not _{change the} actual input shaft even if the basic target rotational speed N _INBSE is lower than the actual input shaft rotational speed N _IN. as the rotational speed N _iN is not lowered, and outputs the command to prohibit the upshift of the continuously variable transmission 18 to the shift control means 164.

For example, the upshift prohibiting means 170 may change the final target rotation speed N _IN ^* to the fixed target rotation speed N _INRH so that the transmission ratio γ is fixed, that is, the transmission ratio γ is eventually constant. Is output to the final target rotational speed calculation means 156, and the upshift of the continuously variable transmission 18 is surely prohibited. At the same time, the upshift prohibiting means 170 turns on a speed ratio fixing flag _FRH indicating that control for fixing the speed ratio γ is being performed. The final target rotational speed calculating means 156 is in accordance with the transmission ratio fixing command from the upshift prohibiting means 170 and is in the fixed target rotational speed such that the transmission ratio γ is eventually constant instead of the final target rotational speed N _IN ^*. Set N _INRH . Further, the shift control means 164 sets the speed ratio γ of the continuously variable transmission 18 so that the actual input shaft rotation speed N _IN matches the fixed target rotation speed N _INRH set by the final target rotation speed calculation means 156. The feedback control is performed, and the off-up flag _FUP is turned off when the gear ratio fixed flag _FRH is turned on.

  The up prohibition end determination means 178 determines whether or not the vehicle state is such that the upshift prohibition by the upshift prohibition means 170 ends.

For example, up prohibition end determining unit 178, Until the vehicle state basic target rotational speed N _INBSE a decrease in the actual input shaft rotational speed N _IN is higher than the actual input shaft speed N _IN is avoided the up When the basic target rotational speed N _INBSE is higher than the actual input shaft rotational speed N _IN, that is, the fixed target rotational speed N _INRH so that the shift is prohibited, the vehicle state is such that the prohibition of the upshift is finished. judge.

Further, the up prohibition end determination means 178 is configured to execute a predetermined time T _S from when the acceleration request determination means 176 determines that an acceleration request has been generated, so that the prohibition of the upshift is surely ended. It is determined that the vehicle state ends the prohibition of upshifting. This predetermined time T _S is a vehicle state in which it is difficult for the driver to feel uncomfortable with the change in the actual input shaft rotational speed N _IN even when the prohibition of upshifting is finished, for example, the basic target rotational speed N _INBSE and the actual input shaft rotational speed. a prohibition end determination value stored in advance experimentally sought for determining the rotational speed difference between the N _iN is an elapsed time which is a small state, to ensure the inhibition of the upshift It is also a guard timer that has been experimentally determined and stored in advance for termination.

Also, up prohibition end determining unit 178, Until hardly a state which is uncomfortable for the change in the actual input shaft rotational speed N _IN of the driver so that the upshift is prohibited, for example, the accelerator operation amount Acc is predetermined operation When a deceleration request is generated that is smaller than the amount Acc ′ and the absolute amount of the accelerator change amount ΔAcc is equal to or greater than the predetermined change amount ΔAcc ′, it is determined that the vehicle state is such that prohibition of upshifting ends. The predetermined operation amount Acc ′ and the predetermined change amount ΔAcc ′ cause the driver to feel uncomfortable with respect to the change in the actual input shaft rotational speed N _IN even if an upshift is performed such that the actual input shaft rotational speed N _IN decreases. This is a deceleration request determination value that is experimentally obtained and stored in advance to determine that it is difficult to return the accelerator pedal 68.

  When the upshift prohibition means 170 determines that the upshift prohibition determination means 178 is in a vehicle state where the prohibition of upshift ends, the upshift prohibition means 170 of the continuously variable transmission 18 that has been output to the shift control means 164 Release the command prohibiting upshifts.

For example, the upshift prohibiting unit 170 cancels the gear ratio fixing command output to the final target rotational speed calculating unit 156 and ends the prohibition of the upshift of the continuously variable transmission 18. At the same time, the upshift prohibiting means 170 turns off the gear ratio fixed flag _FRH . The final target rotational speed calculation means 156 finishes setting the fixed target rotational speed N _INRH according to the release of the gear ratio fixing command by the upshift prohibiting means 170, and the final target rotational speed based on the basic target rotational speed N _INBSE as usual. to calculate the rotation speed _{N IN} ^*.

Figure 10 is a control operation for suppressing the uncomfortable feeling with respect to the actual input shaft change in the rotational speed N _IN of the driver when the acceleration request in main part i.e. upshift process when the vehicle deceleration control operation of the electronic control unit 50 It is a flowchart to be described, and is repeatedly executed with a predetermined cycle, for example, an extremely 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.

In FIG. 10, first, in step (hereinafter, step is omitted) S1 corresponding to the off-up determination means 172, whether or not an upshift at the time of vehicle deceleration is being performed, that is, actual input along with a decrease in the vehicle speed V. Whether or not the vehicle is in a decelerating traveling state in which the shaft rotational speed N _IN decreases, for example, whether or not the off-up flag F _UP is on, or whether or not the brake operation signal B _ON is on, or Coast flag F _C is determined based on whether such is oN.

If the determination in S1 is negative, in S2 corresponding to the deceleration travel state continuation determination means 174, is the actual input shaft rotational speed _NIN continuously decreased as the vehicle speed V decreases and is the deceleration travel state continuing? whether, for example off-up flag F _uP is turned off, and the brake operation signal B _oN is turned off, and the coast flag F _C is based on whether it is within the predetermined time period T _C from when the vehicle state is oFF Determined. If the determination at S2 is negative, this routine is terminated.

Before time t _{1 in} FIG. 11, in a steady state where the accelerator operation amount is constant, the basic target rotational speed N _INBSE and the final target rotational speed N _IN ^* substantially coincide, and the actual input shaft rotational speed N _IN is the basic target rotational speed. N _INBSE is substantially matched. In time point t _1, is stepwise reduced in accordance with the accelerator pedal as indicated by the broken line basic target rotational speed N _INBSE is set, the off-up flag F _UP is turned on. Subsequently, at time t _{1 to} time t ₂ , a final target rotational speed N _IN ^{* that} is gradually decreased with a predetermined gradient toward the basic target rotational speed N _INBSE is set as shown by a solid line, and the actual input shaft rotation speed N _iN is the final target rotational speed N _iN is feedback controlled so caused to follow the ^* and off upshift is executed.

  If the determination in S1 is affirmed or if the determination in S2 is affirmative, whether or not an acceleration request has occurred in the upshift process during vehicle deceleration is determined in S3 corresponding to the acceleration request determination means 176, for example. The determination is made based on whether or not the accelerator operation amount Acc is equal to or greater than the predetermined operation amount Acc ′ and the accelerator change rate is equal to or greater than the predetermined change rate.

T ₂ point of FIG. 11 shows a state in which the accelerator the accelerator pedal 68 during the off-up shift is depression operation request occurs. And in this t ₂ time, stepwise increases have been new basic target rotational speed N _INBSE based on the accelerating operation is set.

If the determination in S3 is negative, this routine is terminated. If the determination is affirmative, in S4 corresponding to the upshift prohibiting means 170, the transmission ratio γ is fixed, that is, the transmission ratio γ is consequently obtained. _So that the fixed target rotational speed N _INRH is set _instead of the final target rotational speed N _IN ^*, and the _upshift of the continuously variable transmission 18 is prohibited. The transmission ratio fixed flag _FRH is turned on.

In t ₂ time points 11, the fixed gear ratio flag F _RH is turned on with the power-off upshift flag F _UP is turned off, the base target rotation speed N _INBSE as shown in broken line the actual input shaft rotational speed N _IN As a result, the speed ratio γ is made constant instead of the final target rotational speed N _IN ^* so that the actual input shaft rotational speed N _IN does not decrease even if it is lower than (final target rotational speed N _IN ^* ). Such a fixed target rotational speed _NINRH is set, and the upshift of the continuously variable transmission 18 is reliably prohibited. At t ₂ the time to t ₃ time points, so that the actual input shaft speed N _IN coincides with fixed in the target rotational speed N _INRH, gear ratio of the continuously variable transmission 18 gamma is feedback controlled. The t in the _second time point to t ₃ time points, resulting in a gear ratio γ is fixed, without lowering the basic target engine speed N _INBSE the actual input shaft speed N actual input shaft even if lower than the _IN rotational speed N _IN, The actual input shaft rotational speed _NIN is increased as the vehicle speed V increases as the accelerator is depressed.

Subsequently, in S5 corresponding to the up prohibition end determination means 178, it is determined whether or not the vehicle state is such that the upshift prohibition executed in S4 ends. For example, when the basic target rotational speed N _INBSE becomes higher than the actual input shaft rotational speed N _IN, that is, the fixed target rotational speed N _INRH , or when a predetermined time T _{S has} elapsed from when it is determined that an acceleration request has occurred. Or when the deceleration operation request is made such that the accelerator operation amount Acc is smaller than the predetermined operation amount Acc ′ and the absolute amount of the accelerator change amount ΔAcc is greater than or equal to the predetermined change amount ΔAcc ′. The state is determined.

T ₃ time points in FIG. 11 shows a state in which the basic target rotational speed N _INBSE is higher than the actual input shaft rotational speed N _IN when upshift is prohibited.

If the determination in S5 is negative, the process returns to S4, but if the determination is affirmative, in S6 corresponding to the upshift prohibiting means 170, the gear ratio fixing command output in S4 is canceled, and the target being fixed _Instead of setting the rotational speed N _INRH , the final target rotational speed N _IN ^* is calculated based on the basic target rotational speed N _INBSE as usual, and prohibition of upshifting of the continuously variable transmission 18 is finished, and the transmission gear ratio The fixed flag _FRH is turned off.

In _{t 3} time points in FIG. 11, the fixed gear ratio flag with _{F RH} it is turned off, based on the usual basic target rotational speed _{N INBSE} instead set fixed in the target rotational speed _{N INRH} final target rotational speed _{N IN} ^* Is calculated, and prohibition of upshifting of the continuously variable transmission 18 is completed. t ₃ after the time, the actual input shaft speed N _IN is feedback controlled to coincide with the final target rotational speed N _IN ^{*, *} a basic target rotational speed N _INBSE and the final target rotational speed N _IN is substantially coincides This shows a state in which the actual input shaft rotational speed N _IN is substantially matched with the basic target rotational speed N _INBSE . Incidentally, if the time of this t ₃ is, even when the acceleration request is the predetermined time T _S has elapsed since the determined t ₂ time points and caused, similarly, inhibition of the upshift of the continuously variable transmission 18 is terminated .

As described above, according to the present embodiment, when the acceleration request determination means 176 determines that an acceleration request is generated during the upshift process during vehicle deceleration, the actual input shaft rotational speed _NIN is not decreased. Since the upshift of the continuously variable transmission 18 is prohibited by the upshift prohibiting means 170, when an acceleration request such as an operation of increasing the accelerator pedal 68 occurs during the upshift during vehicle deceleration, the basic target rotation speed N _INBSE is even lower than the actual input shaft speed N _iN, discomfort with respect to the change of the actual input shaft rotational speed N _iN of the driver decreases is suppressed in the actual input shaft speed N _iN is suppressed.

  Further, according to the present embodiment, the upshift is prohibited by fixing the speed ratio γ of the continuously variable transmission 18 by the upshift prohibiting means 170, so that the upshift is surely prohibited. In addition, reacceleration performance associated with the acceleration request is secured.

Further, according to the present embodiment, when the accelerator operation amount Acc is not less than the predetermined operation amount Acc ′ and the accelerator change amount ΔAcc is not less than the predetermined change amount ΔAcc ′, an acceleration request is made by the acceleration request determining means 176. since it is determined, the prohibition of upshift is properly executed when the driver of the actual input shaft speed N _iN acceleration request as tends to occur discomfort to changes in.

Further, according to this embodiment, when the basic target rotational speed N _INBSE becomes higher than the actual input shaft rotational speed N _{IN, the} upshift prohibition is ended by the upshift prohibiting means 170, so that the basic target rotational speed is reached. _Upshifting is _{prohibited until} N _INBSE becomes higher than the actual input shaft rotational speed N _IN, that is, the fixed target rotational speed N _INRH, and the vehicle state is such that a decrease in the actual input shaft rotational speed N _IN is avoided.

Further, according to this embodiment, when the acceleration request by the acceleration request determining means 176 has a predetermined time T _S has elapsed from the time it is determined to have occurred, since prohibition of upshift is terminated by an up shift inhibiting means 170, up The shift prohibition is definitely terminated.

Further, according to this embodiment, when a deceleration request that causes an accelerator return operation is generated, the upshift prohibition unit 170 terminates the prohibition of the upshift, so that the actual input shaft rotational speed _NIN of the driver is reduced. Upshifting is prohibited until it becomes difficult to feel uncomfortable with changes.

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

For example, the input shaft rotation speed N _IN and the related basic target rotation speed N _INBSE and final target rotation speed N _IN ^* in the above-described embodiment are replaced with the input shaft rotation speed N _IN and the engine rotation speed N _E and the target, such as the engine rotational speed N _E ^*, or the turbine speed N _T and it may be to the target turbine rotational speed N _T ^* and related associated therewith.

In the above-described embodiment, the basic target rotational speed N _INBSE and the final target rotational speed N _IN ^* are set based on the vehicle state so that the actual input shaft rotational speed N _IN matches the final target rotational speed N _IN ^*. In addition, although the speed change control mode is such that the speed ratio γ of the continuously variable transmission 18 is feedback-controlled, the target speed ratio γ ^* is set based on the vehicle state, and the actual speed ratio γ is set to the target speed ratio γ. ^In a speed change control mode in which the speed ratio γ of the continuously variable transmission 18 is feedback-controlled so as to match the target speed ratio N _IN ^* so as to match the target speed ratio γ ^*. There may be.

In the above-described embodiment, the required throttle opening degree θ _THR for obtaining the target engine torque T _E ^* is calculated by the required throttle opening degree calculation means 160. However, the required throttle opening degree θ _THR is not necessarily required. Other required values for obtaining the target engine torque T _E ^* may be used. For example, a fuel injection amount or an ignition timing for obtaining the target engine torque T _E ^* may be used.

  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, and the torque converter 14 is replaced. In addition, other fluid 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. FIG. 4 is a main part hydraulic circuit diagram showing a part related to belt clamping pressure control of a continuously variable transmission, gear ratio control, and engagement hydraulic control of a forward clutch or a reverse brake accompanying operation of a shift lever in the hydraulic control circuit. 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 relationship (map, driving force map) which was calculated | required experimentally beforehand and memorize | stored beforehand using the accelerator operation amount as a parameter. The optimal fuel consumption rate curve (fuel consumption map, relationship) of the engine that has been experimentally determined and stored in advance so as to achieve both drivability and fuel efficiency within the two-dimensional coordinates composed of the input shaft rotation speed and engine torque. ) And an equal output curve (equal output map, relationship) of the target output obtained and stored in advance based on the input shaft rotation speed and the engine torque. It is a figure which shows an example of the transient characteristic of the final target rotational speed set so that it may approach gradually toward a basic target rotational speed by the final target rotational speed calculation means. It is a figure which shows an example of the relationship (engine torque map) calculated | required experimentally beforehand and memorize | stored by using the throttle valve opening as a parameter as an engine rotational speed and an engine torque estimated value. FIG. 7 is a diagram showing an example of a relationship (clamping pressure map) that is experimentally obtained and stored in advance so that belt slip does not occur between the transmission ratio and the required hydraulic pressure (corresponding to belt clamping pressure) with the required throttle opening as a parameter. is there. FIG. 3 is a flowchart for explaining a main part of the control operation of the electronic control device of FIG. 2, that is, a control operation for suppressing an uncomfortable feeling with respect to a change in the actual input shaft rotational speed when an acceleration request is made in an upshift process during vehicle deceleration. is there. It is a time chart explaining the control action shown in the flowchart of FIG. FIG. 6 is a diagram exemplifying a basic target rotation speed set at the time of an upshift accompanying accelerator off, and a basic target rotation speed that can be changed by re-depressing an accelerator pedal during an upshift process. It is a figure explaining the prior art example in which the final target rotational speed is set based on speed.

Explanation of symbols

12: Engine (power source for running)
18: continuously variable transmission 24: drive wheel 50: electronic control device (shift control device)
170: Upshift prohibition means 176: Acceleration request determination means

Claims (6)

In a vehicle in which a continuously variable transmission is disposed in a power transmission path between a driving power source and driving wheels, when upshifting the continuously variable transmission during vehicle deceleration, the input rotation speed is based on the vehicle state. A shift control device for a continuously variable transmission for a vehicle that changes a gear ratio so as to gradually decrease toward a steady rotational speed,
Acceleration request determination means for determining whether an acceleration request has occurred in the upshift process during vehicle deceleration;
An upshift prohibiting means for prohibiting an upshift of the continuously variable transmission so that the input rotational speed does not decrease when the acceleration request determining means determines that the acceleration request has occurred. A shift control device for a continuously variable transmission for a vehicle.   The shift control device for a continuously variable transmission for a vehicle according to claim 1, wherein the upshift prohibiting means prohibits the upshift by fixing a gear ratio of the continuously variable transmission.   3. The acceleration request determining means determines that the acceleration request has occurred when the acceleration request amount is equal to or greater than a predetermined value and the change amount of the acceleration request amount is equal to or greater than a predetermined value. Shift control device for continuously variable transmission for vehicles.   4. The vehicle continuously variable transmission according to claim 1, wherein the upshift prohibiting unit terminates the prohibition of the upshift when the steady rotational speed is higher than the input rotational speed. 5. Shift control device.   5. The upshift prohibiting unit terminates the prohibition of the upshift when a predetermined time has elapsed from when the acceleration request determining unit determines that the acceleration request is generated. A transmission control device for a continuously variable transmission for a vehicle.   The shift control device for a continuously variable transmission for a vehicle according to any one of claims 1 to 5, wherein the upshift prohibiting means terminates the prohibition of the upshift when a deceleration request is generated.

Images