JP2001099286A - Speed change control device for continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speed change control device for a continuously variable transmission to prevent the occurrence of the influence of a clutch slide by a method wherein inertia torque determined by the output rotation change of a transmission is exerted on the parts of a transmission. SOLUTION: This device comprises a change gear ratio deviation calculating means to calculate a change gear ratio deviation between a change gear ratio at a current point of time and an arrival change gear ratio after change gear operation during manual mode gear shifting, a speed change time constant setting means to set a speed change time constant necessary to calculate a transient target speed change ratio from a steady arrival change gear ratio according to the magnitude of a calculated change gear ratio deviation; and a speed change time constant correcting means to apply correction, for delaying a speed change speed, on a speed change time constant set by the speed change time constant setting means, when it is decided that it is a continuous speed change operation period where a first speed change operation is performed through manual speed change operation and thereafter, second speed change operation is effected before a real speed change ratio reaches an arrival speed change ratio available after speed change.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a shift control device for a continuously variable transmission having a manual mode function in which a fixed gear ratio can be selected manually from a plurality of shift stages manually.

[0002]

2. Description of the Related Art Conventionally, as a shift control device of a continuously variable transmission having a manual mode function, for example, Japanese Unexamined Patent Publication No.
The thing described in 264415 is known.

This publication describes a shift control device of a continuously variable transmission having a manual mode function in which a fixed speed ratio can be selected manually from a plurality of shift speeds manually.

Japanese Patent Application Laid-Open No. 5-126239 discloses that in a shift control device for a continuously variable transmission, when a target value changes stepwise due to sudden depression of an accelerator, sudden release of the accelerator, or the like.
A shift control device that calculates a transient control target value from a steady control target value and improves shift transient response characteristics is described.

Therefore, at the time of a shift operation in the manual mode, shift control is performed using a shift time constant corresponding to a shift ratio deviation which is a difference between the current shift ratio and a steady target shift ratio after the shift operation. Can be presumed.

[0006]

However, in the conventional shift control in the manual mode, when the shift in the manual mode is continuously operated, the shift time constant is changed in each one-step shift. Since the switching is not performed with the constant, there is a problem that the amount of change in the target speed ratio per unit time increases, in other words, the speed change speed increases.

That is, in the shift in the normal manual mode, as shown in FIG. 9, for example, when performing 4 → 3 shift, a shift time constant is set based on the speed ratio deviation a,
A transient target gear ratio is calculated. Thereafter, when a 3 → 2 shift is performed, a shift time constant is set based on the shift ratio deviation b, and a transient target shift ratio is calculated. That is, if the shift time constant is constant, the time t until the steady target gear ratio (attained gear ratio) is reached is the same.

However, if the 3 → 2 shift operation is performed in the manual mode after the 4 → 3 shift operation and before the actual speed ratio reaches the speed ratio corresponding to the 3rd speed, FIG.
As shown in FIG. 0, the speed ratio deviation c (> b) from the time when the 3 → 2 speed change operation is performed to the attained speed ratio corresponding to the second speed becomes a large deviation. Is set so as to reach the speed change, so that the change in the gear ratio per unit time increases, in other words, the gear speed increases.

As a result, the inertia torque (inertia torque) accompanying the gear shift may affect components such as the clutch and the torque converter, and may cause slippage of the clutch.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. In the continuous shift operation in the manual mode, the shift speed is reduced by correcting the shift time constant to thereby reduce an inertia torque determined by a change in output rotation of the transmission. It is an object of the present invention to provide a shift control device for a continuously variable transmission that prevents the influence of clutch slippage or the like caused by acting on each component of the transmission.

[0011]

According to the first aspect of the present invention, in addition to the stepless smooth shifting, a manual mode function that allows a user to manually select a fixed speed ratio from a plurality of shift speeds is provided. A shift control device for a continuously variable transmission provided with: a manual mode determining means for determining whether or not a shift is being performed in a manual mode; Transmission ratio deviation calculating means for calculating the transmission ratio deviation, and a transmission time constant required for calculating a transient target transmission ratio from a steady attained transmission ratio according to the magnitude of the calculated transmission ratio deviation. Shifting time constant setting means,
Continuous shift operation determining means for determining whether or not a continuous shift operation in which a first shift operation is performed by a manual shift operation, and thereafter, a second shift operation is performed before the actual gear ratio reaches the attained gear ratio after shifting. And a shift time constant correction means for correcting the shift time constant set by the shift time constant setting means to reduce the shift speed when it is determined that a continuous shift operation is being performed. And

According to a second aspect of the present invention, in the shift control device for a continuously variable transmission according to the first aspect, the continuous shift operation time determining means includes a current speed ratio and an attained speed change after the speed change operation. If the absolute value of the gear ratio deviation, which is the absolute value of the difference with the ratio, is greater than a threshold value set to a value larger than the gear ratio deviation in each single-speed gearshift, it is determined that a continuous gearshift operation has been performed. Means for performing

According to a third aspect of the present invention, in the transmission control apparatus for a continuously variable transmission according to the second aspect, the time constant correcting means is provided with a speed ratio calculated by a continuous speed change operation determining means. The shift time constant is corrected by variably setting such that the larger the inertia-equivalent variable calculated from the deviation absolute value and the transmission output speed at that time is, the slower the shift speed is.

[0014]

According to the first aspect of the present invention, in the manual mode determining means,
It is determined whether or not the shift is in a manual mode in which a fixed gear ratio is manually selected from among a plurality of shift speeds.
A gear ratio deviation between the current gear ratio and the attained gear ratio after the gear change operation is calculated, and the shift time constant setting means transitions from the steady attained gear ratio to a transient state according to the magnitude of the calculated gear ratio deviation. A shift time constant required for calculating the target gear ratio is set, and the first gear shift operation is performed by a manual gear shift operation in the continuous gear shift operation determining means, and thereafter, the actual gear ratio becomes the ultimate gear ratio after the gear shift. It is determined whether or not the second shift operation is performed before the shift is performed. If the shift time constant correction unit determines that the continuous shift operation is being performed, the shift time constant set by the shift time constant setting unit is determined. A correction for slowing down the shift speed is added to the constant.

That is, if the speed change time constant is set based on the speed ratio deviation before and after the speed change irrespective of the presence or absence of the continuous speed change operation, the speed ratio deviation becomes larger during the continuous speed change operation than during the normal speed change operation, For example, when the shift time constant is set so as to end the shift in the same shift time, the shift speed is higher during a continuous shift operation than during a normal shift operation.

On the other hand, when the continuous shift operation determining means determines that a continuous shift operation is being performed, the shift time constant correcting means sets the shift speed to the shift time constant set by the shift time constant setting means. Since the correction for slowing down is added, it is possible to prevent the speed change speed from increasing even when the continuous speed change operation is performed.

[0017] Therefore, by reducing the shift speed by correcting the shift time constant during the continuous shift operation in the manual mode, the clutch slip due to the inertia torque determined by the change in the output rotation of the transmission acting on each part of the transmission. And the like can be prevented.

According to a second aspect of the present invention, in the continuous gear shifting operation determining means, the gear ratio deviation absolute value which is the absolute value of the difference between the current gear ratio and the attained gear ratio after the gear shifting operation. When the value is larger than a threshold value set to a value larger than the speed ratio deviation at the time of each one-speed shift, it is determined that a continuous shift operation is being performed.

That is, in the continuous gear shifting operation, after the first gear shifting operation, before the actual gear ratio reaches the attained gear ratio after gear shifting, the second gear shifting operation is performed.
Since the speed change operation is performed, the speed ratio deviation between the current speed ratio and the attained speed ratio after the speed change operation has a larger value than the speed ratio deviation at the time of each one-step speed change.

Therefore, it is possible to accurately judge the time of the continuous shift operation while using an easy judgment method using the speed ratio deviation, which is the setting information of the shift time constant, as the judgment criterion.

According to a third aspect of the present invention, in the shift time constant correcting means, the speed ratio deviation absolute value calculated by the continuous shift operation time determining means, and the transmission output speed at that time. As the inertia-equivalent variable calculated by is larger, the shift time constant is corrected by a variable setting that makes the shift speed slower.

That is, since the inertia torque is determined by the change in the output rotation of the transmission, it is possible to estimate the magnitude of the inertia torque from a variable corresponding to the absolute value of the gear ratio deviation and the inertia calculated from the transmission output rotation speed (vehicle speed). it can.

Therefore, by taking in the element of the number of revolutions capable of estimating the magnitude of the inertia torque and correcting the shift time constant, each component of the transmission can be operated at the time of the continuous shift operation regardless of the driving condition or the driving condition. Optimal shift time constant correction can be performed to keep the magnitude of the inertia torque acting constant.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A shift control device for a continuously variable transmission according to the present invention will be described in detail with reference to the drawings.

[Construction of Transmission Unit of Continuously Variable Transmission and Transmission Control Apparatus] FIGS. 1 and 2 show a toroidal type continuously variable transmission equipped with a transmission control apparatus of a continuously variable transmission according to the present invention. 2 is a longitudinal sectional side view showing a transmission unit of the toroidal type continuously variable transmission, and FIG. 2 is a diagram showing a shift control device of the toroidal type continuously variable transmission.

First, a transmission unit which is a main part of a toroidal type continuously variable transmission will be described with reference to FIG. This transmission unit includes an input shaft 20 to which rotation from an engine (not shown) is transmitted. As shown in FIG. 1, the input shaft 20 has an end remote from the engine via a bearing 22 in a transmission case 21. And a central portion is rotatably supported in a middle wall 23 of the transmission case 21 via a bearing 24 and a hollow output shaft 25.

The input shaft 20 has an input cone disk 1
And the output cone disk 2 is supported on the hollow output shaft 25, and the input and output cone disks 1 and 2 are coaxially arranged such that the toroidal curved surfaces 1a and 2a face each other.

A pair of power rollers 3, 3 disposed on both sides of the input shaft 20 with the input shaft 20 interposed therebetween are interposed between the opposed toroidal curved surfaces 1a, 2a of the input / output cone disks 1, 2, and these power rollers The following configuration is adopted in order to pinch 3, 3 between the input and output cone disks 1, 2.

That is, a loading nut 26 is screwed into an end of the input shaft 20 on the bearing 22 side, and a cam disk 27 which is prevented from slipping off by the loading nut 26 and is rotationally engaged on the input shaft 20; Loading cam 2 between the toroidal surface 1a and the end surface far from the toroidal surface 1a
The rotation from the input shaft 20 to the cam disk 27 is transmitted to the input cone disk 1 via the loading cam 28.

Here, the rotation of the input cone disk 1 is transmitted to the output cone disk 2 via the rotation of the two power rollers 3, 3, and during this transmission, the loading cam 28 generates a thrust proportional to the transmission torque. The power rollers 3 are narrowed between the input and output cone disks 1 and 2 to enable the power transmission.

The output cone disk 2 has an output shaft 25
The output gear 29 is fitted on the output shaft 25 so as to rotate integrally therewith.

The output shaft 25 is further rotatably supported in an end cover 31 of the transmission case 21 via a radial / thrust bearing 30, and the output shaft 25 receives an input through a separate radial / thrust bearing 32 in the end cover 31. The shaft 20 is rotatably supported. Here, the radial and thrust bearings 30 and 32 are butted so as not to approach each other at the start of the spacer 33, and the axis of the corresponding output gear 29 and the input shaft 20 are set so as not to be displaceable relative to each other. Make contact in the direction.

With the above configuration, the thrust acting between the input and output cone disks 1 and 2 by the loading cam 28 becomes an internal force that sandwiches the spacer 33 and does not act on the transmission case 21.

As shown in FIG. 2, the power rollers 3 are rotatably supported by trunnions 41, 41. The trunnions 41, 41 have spherical joints 42 at their upper ends.
Thus, the lower end is rotatably and swingably connected to both ends of the lower link 45 by the spherical joint 44.

The upper link 43 and the lower link 45 are supported at the center by spherical joints 46 and 47 on the transmission case 21 so as to be swingable in the vertical direction.
41 can be moved up and down in synchronization with each other in opposite directions.

Thus, both trunnions 41, 41 are
A shift control device that shifts by vertically moving in synchronization with each other will be described with reference to FIG.

Each of the trunnions 41, 41 is provided with a piston 6, 6 for individually moving the trunnions 41 in a vertical direction.
1, 52 and lower chambers 53, 54 are defined. To control the strokes of the pistons 6 and 6 in opposite directions, a speed change control valve 5 is provided.

Here, the speed change control valve 5 has a spool-type inner valve element 5a and a sleeve-type outer valve element 5b slidably fitted to each other, and slides the outer valve element 5b to a valve case 5c. It is configured to be movably fitted.

The speed change control valve 5 has an input port 5d connected to a pressure source 55, one communication port 5e connected to the piston chambers 51 and 54, and the other communication port 5f connected to pistons 52 and 53, respectively. I do.

Then, the inner valve body 5a cooperates with the cam surface of the precess cam 7 fixed to the lower end of the one trunnion 41 via a bell crank type shift lever 8, and the outer valve body 5a
b to the step motor 4 as a speed change actuator,
Drive and engage in a rack and pinion type.

The operation command of the shift control valve 5 is given by the step motor 4 responding to the actuator driving position command Asstep (step position command) as a stroke to the outer valve body 5b via a rack and pinion.

With this operation command, the outer valve body 5 of the shift control valve 5
b is relative to the inner valve body 5a from a neutral position, for example,
When the shift control valve 5 is opened by being displaced to the position shown in FIG. 2, the fluid pressure (line pressure PL) from the pressure source 55 is supplied to the chambers 52 and 53, while the other chambers 51 and 54 are drained. When the outer valve 5b of the transmission control valve 5 is displaced in the opposite direction from the neutral position with respect to the inner valve 5a and the transmission control valve 5 is opened, the fluid pressure from the pressure source 55 flows into the chambers 51 and 54. While being supplied, the other chambers 52 and 53 are drained, and the two trunnions 41 and 41 are displaced in the corresponding vertical directions in the figure via the pistons 6 and 6 by fluid pressure in opposite directions.

[0043] Thus both the power rollers 3 and 3, the rotation axis _{O 2} of the rotary shaft axis _{O 1} is output cone discs 1 and 2
Offset from the illustrated position (offset amount y)
Is the result in, at swing component force from the power rollers 3,3 are output cone discs 1 and 2 by nuclear offset, tilt about the oscillation axis O ₃ orthogonal to the rotation axis O ₁ of the self ( With the tilt angle φ), continuously variable transmission can be performed.

During such a gear shift, one trunnion 41
The precess cam 7 coupled to the lower end of the transmission gear 8 mechanically transmits the above-described vertical movement (offset amount y) and tilt angle φ of the trunnion 41 and the power roller 3 to the inner valve body 5 a of the transmission control valve 5 via the transmission link 8. Is fed back as indicated by x.

When the gear ratio command value corresponding to the actuator drive position command Asstep to the step motor 4 is achieved by the stepless speed change, the mechanical feedback through the precess cam 7 is applied to the speed change control valve 5. and the inner valve body 5a of, is returned to a relatively initial neutral position with respect to the outer valve member 5b, at the same time, both the power rollers 3,3, rotates the rotation axis O ₁ of input and output cone discs 1 and 2 Axis 0 ₂
By returning to the illustrated position intersecting with the above, it is possible to maintain the state of attainment of the speed ratio command value.

Since the purpose of control is to make the power roller tilt angle φ a value corresponding to the gear ratio command value, the precess cam 7 basically has to feed back only the power roller tilt angle φ. However, the reason why the power roller offset amount y is also fed back here is to provide a damping effect for preventing the shift control from becoming oscillating, thereby avoiding the hunting phenomenon of the shift control.

The actuator drive position command Asstep to the step motor 4 is set by the controller 61.

For this purpose, as shown in FIG. 2, a signal from a throttle opening sensor 62 for detecting an engine throttle opening TVO, a signal from a vehicle speed sensor 63 for detecting a vehicle speed VSP, and an input cone disk 1 are provided to the controller 61 as shown in FIG.
From the input rotation sensor 64 for detecting the rotation speed Ni (or the engine rotation speed Ne), a signal from the output rotation sensor 65 for detecting the rotation speed No of the output cone disk 2, and the transmission operating oil temperature TMP. signal from sly oil temperature sensor 66, the detecting the line pressure P _L from the hydraulic source 55 (normally detects from the internal signal of the controller 61 from controlling the line pressure P _L by the controller 61) the line pressure sensor 67 , A signal from the engine rotation sensor 68 for detecting the engine rotation speed Ne, a signal about range information from the inhibitor switch 60, UP / D
A signal for UP / DOWN information from the OWN switch 69, a selection mode signal from the mode selection switch 70, a torque down permission signal from the engine control device 310, and an A from the anti-skid control device (ABS) 320.
BS control signal, traction control device (TC
S) TCS control signal from 330 and constant-speed traveling device 34
An ASCD cruise signal from 0 is input.

The controller 61 sets an actuator drive position command Astep (shift command value) to the step motor 4 by the following calculation based on the above various input information.

[Configuration of Controller] In the present embodiment, the controller 61 is configured as shown in FIG.

The shift map selecting section 71 is provided with the sensor 6 shown in FIG.
The shift map is selected in accordance with various conditions such as the oil temperature TMP detected in 6 and whether or not the exhaust gas purifying catalyst is being activated.

The case where the shift map selected in this way is, for example, as shown in FIG. 4 will be described.
From the throttle opening TVO and the vehicle speed VSP detected at 63, respectively, based on the shift map corresponding to the shift diagram in the same figure, the reached input speed to be the steady target input speed in the current operating state Search for and find Ni ^* .

[0053] attained gear ratio calculation unit 73, by dividing the arrival input rotation speed Ni ^* by the transmission output rotational speed No detected by the sensor 65 of FIG. 2, a constant corresponding to the arrival input rotation speed Ni ^* A target speed ratio i ^* , which is a target speed ratio, is determined.

The shift time constant calculating section 74 calculates the selected range (normal forward travel range D, forward sports travel range Ds),
Vehicle speed VSP, throttle opening TVO, engine speed N
e, an accelerator pedal operation speed, a signal relating to the amount of torque reduction from a torque-down control device (not shown), a torque-down permission signal, an anti-skid control signal, a traction control signal, a constant speed traveling signal, and a target gear ratio Ratio0 described later. The first speed change time constant Tg1 and the second speed change time constant Tg2 of the speed change control are set in accordance with various conditions such as a speed ratio deviation RtoERR with respect to the target speed ratio i.
A deviation Eip between ^* and the target gear ratio Ratio0 is calculated.

Here, the first speed change time constant Tg set to correspond to the secondary delay system of the toroidal type continuously variable transmission.
The first and second shift time constants Tg2 are used to determine the shift speed by setting the shift responsiveness to the attained speed ratio i ^* . The target speed ratio calculation unit 75 calculates the attained speed ratio i ^* by the first speed change. The target speed ratio Ratio0 and the intermediate speed ratio Ratio00 at each transitional time and time for realizing with the speed response determined by the time constant Tg1 and the second speed time constant Tg2 are calculated, and only the target speed ratio Ratio0 is output.

The input torque calculator 76 calculates the transmission input torque Ti by a known method. First, the engine output torque is calculated from the throttle opening TVO and the engine speed Ne, and then the input / output speed of the torque converter is calculated. The torque ratio t of the torque converter is determined from the speed ratio which is the (Ne, Ni) ratio, and finally, the transmission input torque Ti is calculated by multiplying the engine output torque by the torque ratio t.

The torque shift compensating speed ratio calculating section 77 eliminates the torque shift (incorrect speed ratio) peculiar to the toroidal-type continuously variable transmission from the transient target speed ratio Ratio0 and the transmission input torque Ti. Is calculated.

Here, a supplementary explanation of the torque shift of the toroidal type continuously variable transmission will be given. During transmission of the toroidal type continuously variable transmission, the power rollers 3, 3 are transmitted as described above.
Is compressed between the input and output cone disks 1 and 2, the trunnion 41 is deformed. As a result, the position of the precess cam 7 at the lower end of the trunnion changes, and the mechanical feedback system including the precess cam 7 and the speed change link 8 A change in the path length is caused, thereby causing the torque shift.

Therefore, the torque shift of the toroidal type continuously variable transmission differs depending on the target speed ratio Ratio0 and the transmission input torque Ti, and the torque shift compensation speed ratio calculation unit 77 calculates the torque shift compensation speed ratio from these two-dimensional maps. TSrto is obtained by search.

The actual transmission ratio calculating section 78 calculates the transmission output rotation speed N obtained by detecting the transmission input rotation speed Ni by the sensor 65 in FIG.
By dividing by o, the actual gear ratio Ratio is calculated. The gear ratio deviation calculator 79 calculates the target gear ratio Rat.
The actual gear ratio Ratio is subtracted from io0, and the gear ratio deviation RtoERR (= Ratio0-Ra) between the two.
tio).

The first feedback (FB) gain calculating section 80 is provided with a well-known PID corresponding to the speed ratio deviation RtoERR.
It is used when calculating a gear ratio feedback correction amount by control (P is proportional control, I is integral control, and D is differential control).
First proportional control feedback gain fbpDAT to be set according to transmission input rotation speed Ni and vehicle speed VSP
A1, feedback gain fbiDATA for integral control
1, and feedback gain fbdDAT for differential control
A1 is obtained.

The first feedback gain fbp
DATA1, fbiDATA1, fbdDATA1 are
A two-dimensional map of the transmission input rotation speed Ni and the vehicle speed VSP is determined in advance, and the map is obtained from the transmission input rotation speed Ni and the vehicle speed VSP based on the map.

[0063] The second feedback (FB) gain calculation unit 81, among the feedback gain used when calculating the speed ratio feedback correction amount by the PID control, set in accordance with the transmission hydraulic oil temperature TMP and the line pressure P _L Feedback gain fbp for second proportional control to be performed
DATA2, feedback gain fbiD for integral control
ATA2 and differential control feedback gain fbd
DATA2 is obtained respectively.

These second feedback gains fbp
DATA2, fbiDATA2, fbdDATA2 are
A two-dimensional map of the hydraulic oil temperature TMP and the line pressure P _L is determined in advance, and the map is obtained from the hydraulic oil temperature TMP and the line pressure P _L based on this map.

The feedback gain calculating section 83 multiplies the first feedback gain and the second feedback gain by the corresponding feedback gains and multiplies the corresponding feedback gains by a corresponding feedback gain fbpDATA (= fbpDATA).
1 × fbpDATA2), feedback gain fbiDATA for integration control (= fbiDATA1 × fbiDA)
TA2) and feedback gain fbd for differential control
DATA (= fbdDATA1 × fbdDATA2) is obtained.

The PID control section 84 uses the feedback gain obtained as described above to determine the speed ratio deviation RtoE.
To calculate the gear ratio feedback correction amount FBrto by the PID control according to the RR, the gear ratio feedback correction amount by the proportional control is calculated as RtoERR × fbpD.
ATA, then the speed ratio feedback correction amount by integral control is obtained by ∫RtoERR × fbiDATA, the speed ratio feedback correction amount by differential control is obtained by (d / dt) RtoERR × fbdDATA, and finally the sum of these three values Is the gear ratio feedback correction amount FBrto (= RtoERR × f) by the PID control.
bpDATA + @ RtoERR × fbiDATA + (d /
dt) RtoERR × fbdDATA).

The target gear ratio corrector 85 calculates the target gear ratio Ra
tio0 is corrected by the torque shift compensation speed ratio TSrto and the speed ratio feedback correction amount FBrto, and the corrected target speed ratio DsrRTO (= Ratio0 + TSrt)
o + FBrto). The target step number (actuator target drive position) calculation unit 86 obtains a target step number (actuator target drive position) DsrSTP of the step motor (actuator) 4 for realizing the corrected target gear ratio DsrRTO by searching a map.

Step motor drive position command calculation section 87
If the step motor 4 cannot be displaced to the target step number DsrSTP during one control cycle even at the limit drive speed of the step motor 4 set by the step motor drive speed setting unit 88 based on the transmission working oil temperature TMP or the like, If the achievable limit position achievable at the limit drive speed of the motor 4 is set as a drive position command Astep to the step motor 4, and the step motor 4 can be displaced to the target step number DsrSTP in one control cycle, It is assumed that the target step number DsrSTP is directly used as the drive position command Asstep for the step motor 4.

Therefore, the drive position command Asstep can always be regarded as the actual drive position of the step motor 4.

The step motor 4 is driven by a drive position command Ast.
The outer valve body 5b of the transmission control valve 5 is displaced in the direction and position corresponding to ep through the rack and pinion, and the toroidal-type continuously variable transmission can be shifted in a predetermined manner as described above. it can.

By this shift, the drive position command Astep
When the gear ratio command value corresponding to
The mechanical feedback via 7 is the internal valve of the shift control valve 5
Do the body 5a, the initial neutral position relatively to the outer segment 5b
And at the same time, both power rollers 3, 3 rotate
Axis 0₁Is the rotation axis 0 of the input and output cone disks 1 and 2. ₂
By returning to the illustrated position intersecting with
The achievement state can be maintained.

In the present embodiment, a step motor follow-up determination section 89 is additionally provided.

This step motor follow-up determination section 89
Means that the stepper motor 4 has the corrected target gear ratio DsrRTO
It is determined below whether or not it is possible to follow the target step number (actuator target drive position) DsrSTP corresponding to.

That is, the judgment unit 89 firstly calculates the step number deviation (actuator driving position deviation) △ STP between the target step number (actuator target driving position) DsrSTP and the driving position command Asstep which can be regarded as the actual driving position. Ask.

The determination unit 89 determines whether the stepping motor 4 has reached the limit driving speed of the stepping motor 4 already set by the stepping motor driving speed setting unit 88 as described above.
Is the lower limit of the step number deviation (actuator drive position deviation) that cannot be eliminated in one control cycle _{ step number deviation from STP _LIM (actuator drive position deviation)} ST
When P is small (△ STP <△ STP _LIM ), the step motor 4 sets the target number of steps (actuator target drive position) DsrS corresponding to the corrected target speed ratio DsrRTO.
It is determined that the TP can be followed, and conversely, △ STP ≧ △ ST
When P _LIM, it is determined that the step motor 4 cannot follow the target step number (actuator target drive position) DsrSTP.

If the determination unit 89 determines that the step motor 4 can follow the target step number (actuator target drive position) DsrSTP corresponding to the corrected target gear ratio DsrRTO, the PID control unit 84 has already explained. The calculation of the gear ratio feedback correction amount FBrto by the same PID control is continued.

In this way, the step motor 4 is driven to the target step number (actuator target drive position) DsrST
If it is determined that P cannot be followed, the gear ratio feedback correction amount by the integral control ∫RtoERR × fbiD
The PID control unit 84 is instructed to hold ATA at the value at the time of the determination.

Further, in the present embodiment, in the step motor drive position command calculation section 87, when the step motor 4 cannot be displaced to the target step number DsrSTP during one control cycle even at the limit drive speed of the step motor 4, 4 is set as a drive position command Astep to the step motor 4, and the drive position command Astep is set as an actual drive position of the step motor 4 by the determination unit 89 to follow the step motor. The actual drive position of the step motor 4 required for performing such a follow-up determination is detected by the drive position command Astep from the speed change control device to the step motor 4, as described above. Inexpensive for the following determination without depending on the actual measurement of the actual driving position of the step motor 4 It can be carried out.

In the present embodiment, the step motor follow-up determination section 89 determines the step number deviation (actuator drive) between the target step number (actuator target drive position) DsrSTP and the actual drive position (drive position command) Asstep. When the position deviation △ STF is smaller than the reference deviation 判定 STP _LIM determined according to the limit driving speed of the step motor 4 (△ STP <△ STP
_LIM ), and the stepper motor 4 outputs the corrected target gear ratio Dsr.
It is determined that the target step number (actuator target drive position) DsrSTP corresponding to the RTO can be followed, and when △ STP ≧ △ STP _LIM , the step motor 4 sets the target step number (actuator target drive position) D
The oil temperature TM is determined to be incapable of following srSTP.
The determination that the stepping motor 4 can follow can be reliably performed regardless of the limit driving speed of the stepping motor 4 that varies in various ways such as P.

[Overall Shift Control] When the controller 61 in FIG. 2 is constituted by a microcomputer, the shift control described with reference to FIG. 3 is executed by the programs in FIG. 5 and FIG.

FIG. 5 shows the entire shift control, and this routine is executed, for example, every 10 ms. First, in step 91, the shift time constant calculation unit 74 (FIG. 3)
Vehicle speed VS detected by vehicle speed sensor 63 (FIG. 2)
P, the engine speed Ne detected by the engine speed sensor 68 (FIG. 2), the transmission input speed Ni detected by the input speed sensor 64 (FIG. 2), and the throttle opening sensor 62 (FIG. 2) It reads the throttle opening TVO, range information (automatic shift (D) range, sports running (S) range, etc.) from the inhibitor switch 60 (FIG. 2).

Next, at step 92, the reached input speed calculating section 72 (FIG. 3) calculates the actual speed ratio Ratio by dividing the input speed Ni by the transmission output speed No. Next, at step 93, the reached input rotational speed Ni is calculated from the throttle opening TVO and the vehicle speed VSP based on the shift map as shown in FIG.
Search for ^* and ask.

Next, in step 94 as the attained speed ratio setting means, the attained speed ratio calculating section 73 (FIG. 3)
The attained speed ratio i ^* is calculated by dividing the attained input speed Ni ^* by the transmission output speed No. Next, in step 95 as the deviation calculating means, the shift time constant calculating unit 74 (FIG. 3) uses the target speed ratio Ratio0 calculated in the previous routine from the attained speed ratio i ^* (this is calculated in a later step 99). ) Is subtracted to obtain the deviation E
Calculate ip.

Next, at step 96, it is determined whether or not there is a stepped shift by mode switching and manual shift (hereinafter referred to as "switch shift"). Specifically, in response to a selection mode signal from the mode selection switch 70 (FIG. 2), the presence or absence of switching between the power mode and the snow mode is detected, and a manual range signal is output from the inhibitor switch 60 (FIG. 2). UP / DO while detecting
It is determined whether a signal for UP / DOWN information has been detected from the WN switch 69 (FIG. 2). Next, in step 97 and step 98 as mode setting means and step 99 as target gear ratio setting means, the shift time constant calculation unit 74 (FIG. 3) sets the time constant calculation mode to the first
And the second speed change time constants Tg1 and Tg2 and the target speed ratio R
ratio0 and the intermediate speed ratio Ratio00 are calculated.

Thereafter, in step 100, the torque shift compensation speed ratio calculating section 77 (FIG. 3) outputs the target speed ratio R
A torque shift compensation speed ratio TSrto is calculated from a map relating to atio0 and the transmission input torque Ti. Next, in step 101, the PID control unit 84 (FIG. 3) calculates the gear ratio feedback correction amount FBrto by PID control. Next, in step 102, the target gear ratio correction unit 85 (FIG. 3) outputs the target gear ratio R
The corrected target speed ratio DsrRTO is calculated by adding the torque shift compensation speed ratio TSrto and the speed ratio feedback correction amount FBrto to atio0. Next, at step 103, a drive position command Asstep to the step motor 4 (FIG. 2) is calculated, and this routine ends.

[Shift Time Constant Setting Process in Manual Mode] FIG. 6 is a flowchart showing the shift time constant setting process in the manual mode in the shift control program. This process is executed by the shift time constant calculation unit 74 (FIG. 3).

First, in step 104, it is determined whether or not a manual mode is selected in which a fixed gear ratio is manually selected from the six gears based on whether a manual range signal is output from the inhibitor switch 60 (FIG. 2). If YES, the process proceeds to step 105 (corresponding to a manual mode determining means). Although not shown, when the select lever is tilted to the left from the D range of the H-type shift gate, the mode is switched to the manual mode (the inhibitor switch 60 is activated). When it is moved backward (-side), the downshift is performed (the UP / DOWN switch 69 is operated), and the shift operation can be performed while the accelerator is depressed, so that the speed change can be performed quickly and easily.

In step 105, the target gear ratio Ratio0 calculated in the previous routine is subtracted from the attained gear ratio i ^* at the next gear position by manual operation to obtain a deviation Eip.
Is calculated, and the routine proceeds to step 106 (speed ratio deviation calculating means).

Here, the ultimate speed ratio i ^* is expressed by UP / DOW
The next shift speed is obtained from the UP / DOWN information from the N switch 69, and the reached input rotational speed Ni ^* is searched and obtained based on the vehicle speed VSP and the shift line corresponding to the next shift speed in the shift map shown in FIG. Is calculated by dividing the attained input rotation speed Ni ^* by the transmission output rotation speed No. Further, the target speed ratio Ratio0 is such that the attained speed ratio i ^* at the speed before the speed change is realized with the speed response determined by the first speed time constant Tg1 and the second speed time constant Tg2 which are already set. Is calculated.

In step 106, a first shift time constant Tg1 and a second shift time constant Tg2 for determining the shift speed in the shift control are set according to the deviation Eip calculated in step 105, and the routine proceeds to step 107 (shift (Corresponds to constant setting means).

The first shift time constant Tg1 and the second shift time constant Tg2 are such that a shift response in which the time t required for one-step shift by manual operation is a fixed time determined by the type of shift and the like can be obtained. Is set according to the magnitude of the deviation Eip.

In step 107, the absolute deviation value | Eip |
Is greater than or equal to a threshold value A which is larger than the shift deviation at the time of each one-step shift. If YES, the process proceeds to steps 108 to 110, and if NO, the process proceeds to step 106. The obtained first shift time constant Tg1 and second shift time constant Tg2 are directly used as shift time constants (corresponding to continuous shifting operation time determining means).

In step 108, the absolute deviation value | Eip |
And the output rotation speed No of the transmission at that time (or the vehicle speed VS
P) to obtain a correction coefficient K0.

In step 109, the first shift time constant Tg
The first shift time constant correction value Tg1 'is calculated by multiplying 1 by the correction coefficient K0, and the second shift time constant correction value Tg2' is calculated by multiplying the second shift time constant Tg2 by the correction coefficient K0.

In step 110, the first shift time constant correction value Tg1 'is set as the first shift time constant Tg1, and the second shift time constant correction value Tg2' is set as the second shift time constant Tg2.

Steps 108 to 110 correspond to the shift time constant correcting means.

Therefore, for example, in the shift in the manual mode, after the 4 → 3 shift operation (first shift operation), the 3 → 2 shift operation (second shift operation) before the actual speed ratio reaches the speed ratio corresponding to the third speed. When the two-shift operation is performed (see FIG. 7), the flow proceeds to step 104 → step 105 → step 106 → step 107 → step 108 → step 109 → step 110 in the flowchart of FIG. A first shift time constant correction value Tg1 'obtained by multiplying Tg1 by the correction coefficient K0 is set as a first shift time constant Tg1,
From the shift time constants Tg1 and Tg2 obtained in step 106, a second shift time constant correction value Tg2 ′ obtained by multiplying the second shift time constant Tg2 by the correction coefficient K0 is set as the second shift time constant Tg2. A correction to a large value, that is, a correction to reduce the speed change speed is added.

That is, as shown in FIG. 8, in the conventional case, the time required to reach the final M2 speed was faster at time t from the 3 → 2 speed change operation. In this case, the time T (> t) has elapsed since the 3 → 2 shift operation, and the shift speed is reduced.

As a result, when the shift speed is reduced by correcting the shift time constants Tg1 and Tg2 during the continuous shift operation in the manual mode, the inertia torque determined by the change in the output rotation of the transmission acts on each component of the transmission. Therefore, it is possible to prevent the influence of clutch slippage and the like.

In the determination at the time of the continuous gear shifting operation in step 107, the deviation absolute value | Eip |, which is the absolute value of the difference between the current target gear ratio Ratio0 and the attained gear ratio i ^* after the gear shifting operation, is 1 When it is larger than the threshold value A which is a value larger than the shift deviation at the time of the step shift, it is determined that a continuous shift operation is being performed, so that the shift time constant Tg1,
It is possible to accurately judge the time of the continuous shift operation while being an easy judgment method using the deviation Eip, which is the setting information of Tg2, as a judgment criterion.

Steps 108 to 110
In the shift time constant correction process, the shift time constant becomes larger as the deviation absolute value | Eip | calculated in step 105 and the correction coefficient K0 of the inertia-equivalent variable calculated from the output rotation speed No of the transmission at that time are larger. The shift time constant Tg1 and Tg2 are variably set by increasing the values of Tg1 and Tg2 so that the shift time constant is corrected to reduce the shift speed. , It is possible to perform the optimal shift time constant correction for keeping the magnitude of the inertia torque acting on each component of the transmission constant during the continuous shift operation regardless of the driving condition or the driving condition.

[0102] The present invention is not limited to the above embodiment, and many modifications and variations are possible.

For example, in the above-described embodiment, a case has been described in which the transmission control device of the continuously variable transmission according to the present invention is applied to a toroidal type continuously variable transmission. It can also be applied to transmissions.

Further, in the above-described embodiment, an example has been described in which the speed ratio deviation is obtained from the difference between the current target speed ratio and the attained speed ratio after shifting, but instead of the current target speed ratio,
The actual gear ratio at the present time may be used.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a toroidal type continuously variable transmission including a shift control device for a continuously variable transmission according to the present invention.

FIG. 2 is a vertical sectional front view showing the toroidal-type continuously variable transmission shown in FIG. 1 together with a shift control system thereof.

FIG. 3 is a functional block diagram of a shift control executed by a controller of FIG. 2;

FIG. 4 is a shift diagram illustrating a shift pattern of the continuously variable transmission.

FIG. 5 is a flowchart showing the entire shift control program of the shift control device for the continuously variable transmission according to the present invention.

FIG. 6 is a flowchart showing a shift time constant setting process in a manual mode in a shift control program.

FIG. 7 is a diagram showing a shift map used in a manual mode.

FIG. 8 shows 4 → by the shifting time constant setting method in the embodiment.
5 is a time chart showing a target speed ratio characteristic and an attained speed ratio characteristic when a 3 → 2 continuous speed change operation is performed.

FIG. 9 is a time chart showing a target gear ratio characteristic and an attained gear ratio characteristic when a gear shift operation of 3 → 2 is performed after reaching a gear ratio of the third speed after a gear shift operation of 4 → 3.

FIG. 10 shows 4 → 3 → 2 by a conventional shifting time constant setting method.
4 is a time chart showing a target speed ratio characteristic and an attained speed ratio characteristic when the continuous speed change operation is performed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input cone disc 2 Output cone disc 3 Power roller 4 Step motor 5 Shift control valve 6 Piston 7 Precess cam 8 Shift link 20 Input shaft 28 Loading cam 41 Trunnion 43 Upper link 45 Lower link 60 Inhibitor switch 61 Controller 62 Throttle opening sensor 63 Vehicle speed sensor 64 input rotation sensor 65 output rotation sensor 66 oil temperature sensor 67 line pressure sensor 68 engine rotation sensor 69 UP / DOWN switch 70 mode selection switch 71 shift map selection unit 72 reaching input rotation speed calculation unit 73 reaching gear ratio calculation unit 74 Shift time constant calculation unit 75 Target gear ratio calculation unit 310 Engine control switch 320 Anti-skid control device 330 Traction control device 340 Constant-speed traveling device

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Tetsu Takizawa 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Nissan Motor Co., Ltd. 72) Inventor Shigeki Shimanaka 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Inside Nissan Motor Co., Ltd. (72) Inventor Hiroyasu Tanaka 2 Takaracho, Kanagawa-ku, Yokohama City, Kanagawa Prefecture Nissan Motor Co., Ltd. F-term (reference) in Nissan Motor Co., Ltd. 2 Takara-cho, Kanagawa-ku, Yokohama-shi, Kanagawa 3J052 AA04 AA09 CA22 DB01 FB31 GC43 GC72 HA13 KA01 LA01

Claims (3)

[Claims] 1. A shift control device for a continuously variable transmission having a manual mode function in which a fixed speed ratio can be selected manually from a plurality of speed stages manually in addition to a smooth speed change by a stepless step. Manual mode determining means for determining whether or not a gear shift is being performed; and gear ratio deviation calculating means for calculating a gear ratio deviation between the current gear ratio and the attained gear ratio after the gear shifting operation during manual mode gear shifting. Shift time constant setting means for setting a shift time constant necessary for calculating a transient target gear ratio from a steady attained gear ratio in accordance with the magnitude of the gear ratio deviation; Is performed, and then the continuous gear shift operation is performed to determine whether or not the second gear shift operation is performed before the actual gear ratio reaches the attained gear ratio after the gear shift. And a shift time constant correcting means for correcting the shift time constant set by the shift time constant setting means to slow down the shift speed when it is determined that the shift time is a continuous shift operation. A shift control device for a continuously variable transmission. 2. The shift control device for a continuously variable transmission according to claim 1, wherein said continuous shift operation time determining means determines an absolute value of a difference between a current speed ratio and an attained speed ratio after the speed change operation. When the absolute value of the ratio deviation is larger than a threshold value set to a value larger than the speed ratio deviation at the time of each one-step shift, a means for judging a continuous shift operation is provided. Transmission control device for a step transmission. 3. The shift control device for a continuously variable transmission according to claim 2, wherein the shift time constant correcting means includes a speed ratio deviation absolute value calculated by a continuous shift operation time determining means and a transmission at that time. A shift control device for a continuously variable transmission, characterized in that the shift time constant is corrected by a variable setting that reduces the shift speed as the inertia-equivalent variable calculated from the output rotation speed increases.