JPH09112675A - Control device of continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the driving characteristics at shifting by setting a target value by a target inertia torque setting means, determining the final target value while the set target value is limited within the upper limitation set by an upper limit setting value, and controlling the shift speed with the inertial torque generated at shifting to the final target value. SOLUTION: A target value of inertia torque generated at shifting is set according to the driving conditions by a target inertia torque setting means. An upper limit setting means sets the upper limit for the taget value in such a way that it is related to the rotating speed of the driven side rotary member. From the set target value, the final target value is determined using a target value limiting means whereby the upper limit set by the upper limit setting means is confined within the specified extent. A shiftspeed control means controls the shift speed with the inertia torque generated at shifting so that the final target value is obtained. This improves the driving characteristics at the time of shifting to enable suppression of the requisite capacity of an oil pump.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a continuously variable transmission, and more particularly to a technique for avoiding slippage of a power transmission member during a gear shift transition.

[0002]

2. Description of the Related Art Conventionally, a continuously variable transmission is wound between a driving pulley (primary pulley) and a driven pulley (secondary pulley) whose effective diameters can be continuously changed, and these two pulleys. A driving belt, and while changing the effective diameter of the driven pulley based on the line pressure, the line pressure is used as the source pressure, and the source pressure is reduced based on the hydraulic pressure (primary pressure) adjusted by the shift control valve. 2. Description of the Related Art There is known a pulley type continuously variable transmission configured to change a gear ratio steplessly by changing an effective diameter of a drive pulley.

Here, the line pressure is generally set so as to satisfy the following requirements. The belt should not slip. (→ Higher line pressure is better.) The durability of each part is not impaired due to excessive belt pressing force, and rotational friction does not become excessive. (→ Lower line pressure is better.) Do not cause fuel consumption deterioration due to oil pump loss.
(→ The line pressure should be low.) Furthermore, in order to prevent the belt from slipping during a gear shift transition such as a downshift, a configuration in which the line pressure is temporarily increased during a gear shift transition is disclosed, for example, in Japanese Examined Patent Publication No. 63-661. It is disclosed in Japanese Patent Publication No. 5-50615.

[0004]

By the way, at the time of downshifting, as shown in FIG. 22, the decrease in the primary pressure obtained by reducing the line pressure tends to increase as the shift speed increases. Therefore, in order to avoid the slippage of the belt even when the shift speed is high, it is necessary to supply a sufficiently high line pressure and to prevent the primary pressure from being lowered enough to cause the slippage of the belt. Occurs. However, in order to supply a sufficiently high line pressure, it is necessary to increase the capacity of the oil pump, which adversely affects the size and cost of the transmission and further the fuel consumption. To do.

In FIG. 22, TVO is the throttle valve opening degree, N _E is the engine speed, Base-ratio is the steady gear ratio, Next-ratio is the target gear ratio during the transition, and Cur-ratio is the actual gear ratio. The gear ratio, To is the output shaft torque of the transmission, VSP is the vehicle speed, PL is the line pressure, and Pp is the primary pressure. For example, in the case of the configuration proposed by the applicant of the present invention to control the shift speed so as to obtain the target inertia torque during the shift (see Japanese Patent Application No. 6-29843), the required line pressure during downshift (belt slippage) The minimum pressure that does not cause
It was experimentally confirmed that the tendency shown in FIG. 9 is obtained. That is, it is necessary to increase the line pressure during downshift as the vehicle speed becomes lower at the same target inertia torque and as the target inertia torque becomes higher at the same vehicle speed.

The inertia torque T _I of the engine is determined by the following equation, assuming that the engine inertia I _E is dominant. Where i is the gear ratio, ω _E is the angular velocity of the engine, N
_E is the engine speed (transmission input shaft speed), and No is the transmission output shaft speed. T _I = I _E · dω _E / dt · i (t) ω _E = 2π / 60 · N _E N _E = i (t) · No ∴T _I = _IE · di / dt · i (t) · No ∵No≈const From the above theoretical formula, if the inertia torque T _I is the same, it is predicted that the smaller the output shaft speed No, the higher the gear shift speed and the greater the decrease in the line pressure.

Therefore, in order to secure the required line pressure even when the vehicle speed is low, it is necessary to increase the capacity of the oil pump as described above. If the capacity is insufficient, the speed is low and the target inertia torque is large. At times, there was the problem of causing the belt to slip. The present invention has been made in view of the above problems, and in a continuously variable transmission, by controlling the shift speed so as to obtain a target inertia torque, the drivability at the time of shifting is improved, while the capacity of the oil pump is changed. It is an object of the present invention to prevent slipping of a power transmission member (for example, a belt) at the time of a gear shift transient while suppressing the above.

[0008]

Therefore, a control device for a continuously variable transmission according to a first aspect of the present invention includes a drive-side rotating member that receives the rotational force of a power source, a driven-side rotating member, and a space between them. A power transmission member that is interposed and transmits power between the two;
A drive-side contact rotation radius that is a distance from a rotation center of a contact position between the drive-side rotation member and the power transmission member, and a rotation center of a contact position between the driven-side rotation member and the power transmission member. And the driven-side contact turning radius, which is the distance from, are continuously changed, so that the gear ratio between the driving-side rotating member and the driven-side rotating member can be set steplessly. A control device for a continuously variable transmission,
It is configured as shown in FIG.

In FIG. 1, the target inertia torque setting means sets the target value of the inertia torque generated at the time of shifting according to the operating conditions. Also, the upper limit value setting means,
The upper limit of the target value is set in correlation with the rotation speed of the driven side rotating member. Then, the target value limiting means limits the target value set by the target inertia torque setting means to within the upper limit value set by the upper limit value setting means to set a final target value.

Here, the shift speed control means controls the shift speed so that the inertia torque generated during the shift reaches the final target value. With such a configuration, the gear shift speed is controlled so that the inertia torque generated during gear shift reaches the target value, but the gear shift speed is set in correlation with the rotation speed of the driven side rotating member (corresponding to the vehicle speed in the case of a vehicle). By limiting the target value within the upper limit value, it is possible to avoid shifting at a shift speed that requires a line pressure higher than a predetermined value to avoid slippage of the power transmission member.

According to a second aspect of the present invention, the target inertia torque setting means sets the throttle valve opening of the engine combined with the continuously variable transmission as an operating condition, and the target value of the inertia torque based on the throttle valve opening. Is set. According to such a configuration, the target inertia torque is set based on the throttle opening operated by the driver (for example, the opening change rate or the absolute value of the opening), and the target reflecting the driver's intention to accelerate or the like is reflected. The value can be set.

According to the third aspect of the present invention, the upper limit setting means sets the upper limit of the target value of the inertia torque to be smaller as the rotational speed of the driven side rotating member is lower. According to such a configuration, even when the target inertia torque is the same, the target inertia torque is limited to a smaller value as the rotational speed of the driven-side rotating member is lower, so that the target inertia torque is generated. The target inertia torque is restricted to a lower value on the low speed side where a high speed change speed is set, thereby limiting the speed change speed and avoiding a line pressure higher than a predetermined level being required.

According to the fourth aspect of the invention, the target value limiting means limits the target value of the inertia torque only during downshift. According to such a configuration,
The target inertia torque can be limited only when a drop in the hydraulic pressure applied to the drive-side rotating member occurs, and the target inertia torque can be prevented from being unnecessarily limited.

According to the fifth aspect of the present invention, during the shift transition,
The smaller the value correlated to the rotation speed of the driven-side rotating member and the larger the target value of the inertia torque, the transient for increasing control of the line pressure for pressing the driven-side rotating member to the power transmission member. The time line pressure control means is provided. With such a configuration, the line pressure required to avoid slippage of the power transmission member increases as the value that correlates with the rotation speed of the driven-side rotating member decreases and the inertia torque increases. ,
It is possible to set the line pressure that matches such characteristics,
Sliding of the power transmission member can be avoided by proper line pressure. Here, since the target inertia torque used for setting the line pressure is limited based on the upper limit value, a state in which a line pressure higher than a predetermined value is required is avoided in advance. Can be suppressed. That is, the maximum required line pressure can be suppressed by limiting the target inertia torque, and the suppressed required line pressure can be accurately controlled by controlling the line pressure according to the target inertia torque.

According to a sixth aspect of the present invention, the driving-side rotating member is a pulley whose effective winding radius can be changed, and the driven-side rotating member is a pulley whose effective winding radius can be changed. The transmission member is a wound conductive medium that is wound around them. With this configuration, continuously changing the effective diameters of the two pulleys results in continuously variable transmission, and it is possible to prevent slipping of the winding conductive medium such as a belt during the transition of the speed change that changes the effective diameters. Avoid by limiting the torque.

[0016]

Embodiments of the present invention will be described below. FIG. 2 is a system configuration diagram. In FIG. 2, a continuously variable transmission 3 is mounted on the output side of the engine 1 via a long travel damper (spring type damper for absorbing rotation fluctuation) 2. The starting clutch 15 to be described later
The long travel damper 2 can be omitted in a system in which the engine is installed between the engine 1 and the continuously variable transmission 3 or a system in which a torque converter is installed.

The continuously variable transmission 3 includes a primary pulley 4 on the engine 1 side and a secondary pulley 5 on the drive shaft (differential) side.
And a belt 6 made of rubber or metal, or a combination thereof, wound between them, and a primary pulley side actuator 4a (shift control hydraulic chamber)
Shift pressure to the secondary pulley actuator 5
By adjusting the line pressure to a (tension control hydraulic chamber), the pulley ratio (secondary pulley side belt winding effective diameter / primary pulley side belt winding effective diameter) is changed to change the gear ratio steplessly. Is something that can be done.

However, other continuously variable transmissions such as a known toroidal type can also be used. That is, the continuously variable transmission 3 includes a drive-side rotating member that receives the rotational force of the power source, a driven-side rotating member, and a power transmission member that is interposed between the driving-side rotating member and the driving-side rotating member. And a drive-side contact turning radius that is the distance from the center of rotation of the contact position with the power transmission member,
A driven-side contact turning radius that is a distance from a rotation center of a contact position between the driven-side rotating member and the power transmission member,
It suffices if it is a continuously variable transmission in which the gear ratio between the driving-side rotating member and the driven-side rotating member can be set steplessly by making relative changes in steplessly.

In the system shown in FIG. 2, the primary pulley 4 corresponds to the driving side rotating member, the secondary pulley 5 corresponds to the driven side rotating member, and the belt 6 serves as the power transmission member and the winding transmission medium. Equivalent to. The pressing hydraulic pressure for pressing the drive-side rotating member against the power transmission member corresponds to the shift pressure, and the pressing hydraulic pressure for pressing the driven-side rotation member against the power transmission member corresponds to the line pressure. .

The shift pressure and the line pressure are obtained by opening / closing the hydraulic pressure in each hydraulic path (for example, a broken line portion) arranged inside the hydraulic circuit 8 connected to the oil pump 7 by opening / closing the solenoid valves 9 and 10 having a relief function. And the like are adjusted via a flow rate control valve for controlling the shift pressure and line pressure provided in the hydraulic path, and the drive control of the solenoid valves 9 and 10 and the flow rate control valve is controlled by the controller 11. It

In other words, the controller 11 controls the gear ratio to the target gear ratio via the solenoid valve 9 and the flow rate control valve so that the gear ratio required according to the traveling conditions and the like can be achieved. Further, the solenoid valve 10 controls the line pressure via the pressure control valve. Further, a starting clutch 15 is interposed between the output side (secondary pulley 5) of the continuously variable transmission 3 and the drive shaft side (for example, differential), and the clutch pressure to the starting clutch 15 is the solenoid valve 16. The solenoid valve 16 is also controlled by the controller 11.

In order to control the gear ratio and the line pressure, the controller 11 controls the input side (primary pulley 4) of the continuously variable transmission 3 in order to detect the actual input rotational speed Nin (the rotational speed N _{E of the} engine 1). Input side rotation sensor 12 that generates a pulse signal in synchronization with rotation, output that generates a pulse signal in synchronization with rotation of the output side (secondary pulley 5) to detect the actual output rotation speed No of the continuously variable transmission 3. Detection signals are respectively inputted from the side rotation sensor 13, the potentiometer type throttle sensor 14 which generates a voltage signal corresponding to the opening (throttle opening) TVO of the throttle valve of the engine 1. An engine rotation sensor can be used as the input side rotation sensor 12, and a vehicle speed sensor can be used as the output side rotation sensor 13.

FIG. 3 is a flowchart of a shift control routine executed by the controller 11. It should be noted that this routine is executed every unit time. In step 1 (denoted as S1 in the figure. The same applies hereinafter), the final target steady-state gear ratio (final target gear ratio, map gear ratio) Base i is determined based on the vehicle speed VSP and the throttle opening TVO. The Base i is read from the actual VSP and TVO by referring to the defined map.

In step 2, the transmission output shaft speed N
The output side rotation sensor 13 detects o. Step 3
Then, the current gear ratio i is detected. The gear ratio i can be obtained as a ratio (N _E / N _O ) between the engine speed (input shaft speed of the transmission) N _E and the output shaft speed No of the transmission.

In step 4, the target inertia torque TTINR is calculated according to the operating condition. The target inertia torque is a target value of the inertia torque generated at the time of shifting, and this portion corresponds to the target inertia torque setting means. The target inertia torque TTINR is calculated, for example, as shown in the flowchart of FIG.

In step 431, the change rate ΔTVO (the absolute value of the change amount per unit time) of the throttle valve opening is calculated. In step 432, the target inertia torque TTINR is set from the change rate ΔTVO with reference to the map as shown in FIG. Here, the larger the rate of change ΔTVO, the larger the target inertia torque TTINR is set, and the larger the TTINR is set during upshifting compared to during downshifting.

Further, as shown in the flow chart of FIG. 6, the target inertia torque TTINR may be set from the throttle valve opening TVO.
In 1, a larger target inertia torque TTINR is set as the throttle valve opening TVO is larger.
The target inertia torque TTINR is set by setting the throttle valve opening TVO and the throttle valve opening change rate Δ.
In addition to TVO, a method of setting from gear ratio, horsepower, driving force, engine load, etc. may be used.

As described above, the target inertia torque T
When TINR is set, in the next step 5, a process of limiting the target inertia torque TTINR within a predetermined upper limit value is performed. This part corresponds to the upper limit setting means and the target value limiting means. The processing content of step 5 is
This is shown in the flowchart of FIG. In the flowchart of FIG. 7, first, at step 531, it is determined whether or not a downshift is being performed.

Then, during the downshift,
Proceed to step 532, and target inertia torque TTINR
The upper limit value TTILMT of is set with reference to a map as shown in FIG. 8 (upper limit value setting means). The map shown in FIG. 8 is a value that is proportional to the vehicle speed VSP (output shaft speed No of the transmission, and is a secondary pulley (driven pulley).
Upper limit value TT according to the rotation speed of 5)
ILMT is stored in advance, and the lower the vehicle speed VSP, the smaller the upper limit value TTILMT is set.

At the next step 533, the target inertia torque TTINR set at step 4 is compared with the upper limit value TTILMT set at step 532.
Then, the target inertia torque T set in step 4
If the TINR exceeds the upper limit value TTILMT, the routine proceeds to step 534, where the upper limit value TTIMT is set in the target inertia torque TTINR to set the upper limit value TTIMT.
The target inertia torque TTINR exceeding LMT is prevented from being set as a final value (target value limiting means).

In step 5, the target inertia torque TTI
When the limitation based on the upper limit value TTILMT of NR is performed, the following
In step 6, the current gear ratio i, the output shaft rotation of the transmission
Number N _O, And the target inertia torque TTINR
Then, the increase / decrease SV that determines the shift speed is set according to the following equation.
Set. SV = TTINR / (I_E× i × N_O) Where I_EIs a constant equivalent to the engine inertia.

The above step 6 corresponds to the shift speed control means. In step 7, the current set speed ratio (target speed ratio) Nexti is compared with the final target steady-state speed ratio (final target speed ratio) Basei to determine the magnitude relationship. When Nexti> Basei, it is an upshift request (gear ratio reduction request), and the routine proceeds to step 8.

In step 8, the set gear ratio (target gear ratio) Nexti is decreased by the increase / decrease SV from the current value (Nexti = Nexti-SV). When Nexti <Basei,
It is a downshift request (gear ratio increase request), and the routine proceeds to step 9. In step 9, the set gear ratio (target gear ratio)
Nexti is increased by the above-mentioned increase / decrease SV with respect to the current value (Next
i = Nexti + SV).

In this way, the set gear ratio (target gear ratio)
When Nexti is set, the process proceeds to step 10. Step 10
Then, feedback control is performed so that the set gear ratio (target gear ratio) Nexti is obtained. That is, the ratio of the engine speed N _E to the output shaft speed N _O of the transmission (N _E /
The gear ratio is feedback-controlled so that the current gear ratio i detected as N _O ) becomes the set gear ratio Nexti.

By setting the shift speed so that the target inertia torque is obtained as described above, it is possible to avoid the occurrence of a feeling of deceleration (hehe) during downshifting. Further, as a result of the shift speed control as described above, when the vehicle speed is low (see FIG. 9), in which a larger line pressure is required to avoid the occurrence of slippage of the belt, the upper limit value TTILMT is set to a smaller value. Since the target inertia torque TTINR is set and limited, the required line pressure at low vehicle speed can be suppressed, and thus the required capacity of the oil pump can be suppressed.

By the way, the controller 11 in the present embodiment achieves the control of the shift pressure and the line pressure when the above-mentioned shift control is performed by executing the flowchart shown in FIG. In FIG. 10, in the block (1) (simply described as (1) in the figure. The same applies hereinafter), the primary pulley side actuator 4a is used.
(Minimum shift pressure (Pp
min) is calculated. That is, the required minimum pressure (Ppmin) of the shift pressure that can achieve the target gear ratio without the belt 6 slipping is calculated.

Specifically, this is achieved by executing the flowchart of FIG. First, in step 11, in order to obtain an actual gear ratio (a gear ratio instructed from the controller 11 and the like) and a necessary minimum pressure (Ppmin) of the gear shift pressure commensurate with the engine torque, first, each gear ratio for the gear ratio = 1. The required minimum primary pressure (shift pressure) ratio (θ ₁ / θ)
It is determined by referring to a map or the like (see FIG. 12) set based on the relationship between the engine torque (or the input torque to the continuously variable transmission 3) and the required minimum primary pressure.

In the controller 11, the gear ratio is set based on the actual VSP and TVO by referring to a map that defines the gear ratio based on the vehicle speed VSP and the throttle opening TVO. ing. Further, the gear ratio can be set so that the vehicle speed intended by the driver can be obtained while maintaining the desired engine operating state. In such a case, the engine operating state with good fuel economy and exhaust performance can be maintained, which is advantageous in fuel economy and exhaust performance.

Then, in step 12, the primary minimum pressure (Ppmin) is obtained according to the following equation. Primary minimum pressure (Ppmin) = engine torque × θ × magnification + offset amount The offset amount is a margin. In block (2), the minimum line pressure (Plmin) of the line pressure supplied to the secondary pulley side actuator 5a (tension control hydraulic chamber) is calculated. That is, the minimum required pressure (Plmin) for preventing the belt 6 from slipping on the secondary pulley 5 side is calculated.

Specifically, this is achieved by executing the flowchart of FIG. First, in step 21, in order to obtain the required minimum line pressure (Plmin) corresponding to the actual gear ratio and the engine torque, the ratio of the minimum required line pressure of each gear ratio to the gear ratio = 1 (θ ₁ / θ ) Is obtained by referring to a map or the like (see FIG. 14) set based on the relationship between the engine torque TQ _ENG (or the input torque to the continuously variable transmission 3) and the required minimum line pressure. .

In step 22, the minimum line pressure (Plmin)
Is calculated according to the following formula. Line minimum pressure (Plmin) = engine torque x θ x magnification +
Offset Amount The offset amount is a margin. In the block (3), the movable wall 5 of the secondary pulley side actuator 5a
Calculate the required thrust (FS) of A.

That is, a desired gear ratio (secondary pulley side effective diameter / primary pulley effective diameter = primary pulley rotation speed / secondary pulley rotation speed, torque ratio) can be obtained without causing slippage of the belt 6 on the primary pulley side. In order to achieve this, the thrust (pressing force) required of the movable wall 5A of the secondary pulley side actuator 5a is obtained.

The primary pulley side actuator 4
If the thrust force (in other words, hydraulic pressure) of either a or the secondary pulley side actuator 5a is determined, the other thrust force can be theoretically determined from the relationship between the belt tension, the engine torque, and the torque ratio. it can. Therefore, here, the thrust force FP on the primary pulley side 4a can be determined from the primary minimum pressure (Ppmin) set by the solenoid valve 9 and the like and the area of the primary pulley side movable wall 4A to obtain a desired gear ratio. So based on this
In block (3), the required secondary thrust (FS) is calculated.

After that, based on the required secondary thrust (FS) in the block (4), the secondary pulley side required for achieving the desired gear ratio without causing the belt 6 to slip on the primary pulley side. It is designed to calculate the required pressure. Specifically, the required secondary thrust (FS) of the block (3) is obtained by executing the flowchart of FIG.

In step 31, the required secondary thrust (FS) is calculated based on the following equation. Required secondary thrust (FS) = minimum primary pressure (Ppmi
n) x area of the primary pulley side movable wall 4A x coefficient 0-
Engine torque × coefficient 1 Incidentally, coefficient 0 and coefficient 1 are coefficients determined by the gear ratio.

In block (4), the gear ratio required line pressure (Plratio) is calculated based on the required secondary thrust (FS) obtained in block (3). In particular,
The gear ratio required line pressure (Plratio) is obtained by executing the flowchart of FIG. In step 41,
The gear ratio required line pressure (Plratio) is calculated based on the following equation.

Gear ratio required line pressure (Plratio) = [required secondary thrust (FS) -secondary pulley spring constant x
Shrink length] / Area of movable wall 5A The secondary pulley spring constant is a constant of a spring (not shown) for pushing back the movable wall 5A in which the secondary pulley-side actuator 5a is installed against the line pressure. is there.

In block (5), the basic line pressure (Pl b
ase) is calculated. That is, the line pressure (Plpr
s; this will be described later) is the supply line pressure (basic line pressure) and the secondary pulley side actuator 5a.
The oil trapped inside is determined based on the secondary centrifugal hydraulic pressure that pushes the movable wall 5A in the moving direction by the centrifugal force, the secondary pulley spring force, the transient line pressure for preventing the slip of the belt 6 during the shift transient, and the like. As a basis for obtaining the final line pressure, first,
Calculate the basic line pressure (Pl base).

Specifically, the flowchart of FIG. 17 is executed. First, at step 51, the line minimum pressure (Plmin) for preventing the belt 6 from slipping is compared with the gear ratio required line pressure (Plratio) for achieving a desired gear ratio. If the line minimum pressure (Plmin) ≧ the gear ratio required line pressure (Plratio), the routine proceeds to step 52. on the other hand,
Line minimum pressure (Plmin) <Gear ratio required line pressure (Plrati
If o), go to step 53.

In step 52, the basic line pressure (Pl base) = line minimum pressure (Plmin) is set and the flow is finished in order to prioritize prevention of slippage of the belt 6. In step 53, since there is a margin for slipping of the belt 6, the basic line pressure (Pl base) = the gear ratio required line minimum pressure (Plratio)
), The present flow ends.

In block (6), the secondary centrifugal hydraulic pressure (Pscen) is calculated. Specifically, the flowchart of FIG. 18 is executed. In step 61, the secondary centrifugal hydraulic pressure (Pscen) is calculated according to the following equation. Secondary centrifugal oil pressure (Pscen) = (secondary pulley rotation speed) ² × coefficient In block (7), a transient line pressure (Pl add) for preventing slippage of the belt 6 during a gear shift transient is obtained.

Specifically, the flowchart of FIG. 19 is executed. In step 71, it is determined whether or not it is a downshift. The downshift determination can be made, for example, by comparing the final target gear ratio Basei with the gear ratio i (at the start of the routine). If it is the downshift, the routine proceeds to step 72, where the basic required line pressure Pl add φ during transition is stored in advance according to the target inertia torque TTINR and the vehicle speed VSP from the map (see FIG. 9) corresponding to the target inertia torque. TTINR and vehicle speed V
The basic required line pressure Pl add φ at the time of transition corresponding to SP and SP is obtained by searching.

Here, the target inertia torque TTINR
Is larger, and the vehicle speed VSP (value correlating with the rotational speed of the driven side rotating member) is lower, the basic required line pressure Pl add φ during the transition is set larger. In the next step 73, the correction coefficient for the basic required line pressure Pl add φ is set based on the gear ratio width (see FIG. 20).

The gear ratio width is the deviation between the target gear ratio in the steady state and the current gear ratio, and the correction coefficient is set to a smaller value of 1 or less as the gear ratio width is smaller. And is set to 1 when the gear ratio width is equal to or greater than a predetermined value. In step 74, the basic required line pressure is
Multiply Pl add φ by the correction coefficient obtained in step 73,
Set the final transient line pressure Pl add.

On the other hand, if it is determined at step 71 that it is not a downshift, the routine proceeds to step 75, where it is determined whether or not it is within a predetermined time after the end of the downshift, and if it is within the predetermined time, the routine proceeds to step 72. Then, continuously set the line pressure for transient. When the predetermined time or more has elapsed, the routine proceeds to step 76, where the transient line pressure is used.
It is determined whether Pl add is 0, and when it is not 0,
At step 77, the transient line pressure Pl add is set to the predetermined value DE.
Decrease only CPLADD. Therefore, even after the downshift is completed, the transient line pressure Pl add is set within the predetermined time in the same manner as during the shift transient, and after the predetermined time elapses, the transient line pressure Pl add gradually becomes 0. Change to decrease.

In block (8), the final output line pressure (Plprs) is calculated. That is, the basic line pressure (Pl base) determined in block (5), the secondary centrifugal hydraulic pressure (Pscen) determined in block (6), and the transient line pressure (Pl add) determined in block (7) Seek based on. Specifically, the flowchart of FIG. 21 is executed.

In step 81, the basic output line pressure (Plprs φ) is calculated according to the following equation. Basic output line pressure (Plprs φ) = Basic line pressure (Pl bas
e) -Secondary centrifugal hydraulic pressure (Pscen) In step 82, the basic output line pressure (Plprs φ)
And the transient line pressure Pl add are compared.

When the basic output line pressure (Plprs φ) is larger, the routine proceeds to step 83, where Plprs φ is set to the output line pressure (Plprs), and the transient line pressure Pladd is larger. In this case, the process proceeds to step 84 and Pl add is set to the output line pressure (Plprs). The steps 82 to 84 correspond to the transient line pressure control means.

When the output line pressure (Plprs) thus obtained is controlled via the flow control valve or the like incorporated in the hydraulic circuit 8, the output line pressure (Plprs)
The flow rate can be adjusted by adjusting the pressure acting on the valve body of the flow rate control valve through the solenoid valve 9 or the like or by switching the hydraulic path and adjusting the opening degree.

As described above, the target inertia torque TT
The target inertia torque TT after limiting INR
By controlling the line pressure during a gear shift transition according to the INR, the actual line pressure can be accurately controlled to the suppressed required line pressure.

[0061]

As described above, according to the first aspect of the present invention, the target value of the inertia torque at the time of shifting is limited to the upper limit value that is correlated with the rotation speed of the driven side rotating member. When the vehicle speed is low, the target inertia torque is limited to suppress the shift speed, and it is possible to reliably avoid the shift at the shift speed that requires the line pressure higher than a predetermined value to avoid the slip of the power transmission member such as the belt. Therefore, there is an effect that the required capacity of the oil pump can be suppressed.

According to the second aspect of the present invention, the target inertia torque is set on the basis of the throttle opening, so that the target value can be set in consideration of the driver's intention of acceleration and the like. There is an effect that can be set. According to the third aspect of the present invention, the target inertia torque is limited to a smaller value as the rotational speed of the driven-side rotating member is lower, and at a low speed side where a relatively high line pressure is required to suppress belt slippage. The effect is that the demand for line pressure can be suppressed.

According to the fourth aspect of the present invention, the target inertia torque is limited only when the hydraulic pressure applied to the drive side rotating member is reduced, so that it is possible to prevent the target inertia torque from being unnecessarily limited. effective. According to the invention of claim 5, the maximum required line pressure can be suppressed by limiting the target inertia torque, and by controlling the line pressure according to the target inertia torque, the suppressed required line pressure can be accurately controlled. effective.

According to the sixth aspect of the present invention, in a continuously variable transmission in which continuously variable transmission is performed by continuously changing the effective diameters of two pulleys, a belt is provided during a gear shift transition while suppressing the capacity of the oil pump. There is an effect that it is possible to avoid slipping of the wound conductive medium such as.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of the invention according to claim 1.

FIG. 2 is a system configuration diagram in the embodiment.

FIG. 3 is a flowchart showing shift control.

FIG. 4 is a flowchart showing setting of a target inertia torque.

FIG. 5 is a diagram showing a correlation between a change rate ΔTVO of a throttle valve opening and a target inertia torque.

FIG. 6 is a flowchart showing setting of a target inertia torque.

FIG. 7 is a flowchart showing target inertia torque limit control.

FIG. 8 is a diagram showing a correlation between an upper limit value TTILMT of a target inertia torque and a vehicle speed VSP.

FIG. 9 is a diagram showing a correlation between a vehicle speed VSP, a target inertia torque, and a required line pressure.

FIG. 10 is a flowchart showing line pressure setting control in the embodiment.

FIG. 11 is a flowchart illustrating a block (1) of line pressure setting control.

FIG. 12 is a diagram showing a setting characteristic of primary pressure.

FIG. 13 is a flowchart illustrating a block (2) of line pressure setting control.

FIG. 14 is a diagram showing setting characteristics of the minimum line pressure.

FIG. 15 is a flowchart illustrating a block (3) of line pressure setting control.

FIG. 16 is a flowchart illustrating a block (4) of line pressure setting control.

FIG. 17 is a flowchart illustrating a block (5) of line pressure setting control.

FIG. 18 is a flowchart illustrating a block (6) of line pressure setting control.

FIG. 19 is a flowchart illustrating a block (7) of line pressure setting control.

FIG. 20 is a diagram showing the correction characteristic of the line pressure for transient state due to the shift width.

FIG. 21 is a flowchart illustrating a block (8) of line pressure setting control.

FIG. 22 is a time chart showing how the primary pressure is reduced during a downshift.

[Explanation of symbols]

 1 engine 3 continuously variable transmission 4 primary pulley 4a primary pulley side actuator 5 secondary pulley 5a secondary pulley side actuator 6 belt 7 oil pump 8 hydraulic circuit 9 solenoid valve 10 solenoid valve 11 controller 12 input side rotation sensor 13 output side rotation sensor 14 Throttle sensor

Claims (6)

[Claims] 1. A drive-side rotating member that receives a rotating force of a power source, a driven-side rotating member, and a power transmitting member that is interposed between the driving-side rotating member and the driven-side rotating member to transmit power between the two. A drive-side contact rotation radius that is the distance from the center of rotation of the contact position between the rotating member and the power transmission member, and a distance from the center of rotation of the contact position between the driven-side rotation member and the power transmission member. Control of a continuously variable transmission capable of continuously setting the gear ratio between the driving-side rotating member and the driven-side rotating member by continuously changing the driving-side contact turning radius and the driving-side contact turning radius. In the device, target inertia torque setting means for setting a target value of inertia torque generated during gear shifting according to operating conditions, and an upper limit for setting the upper limit value of the target value in correlation with the rotation speed of the driven side rotating member. With value setting means Target value limiting means for setting a final target value by limiting the target value set by the target inertia torque setting means to within the upper limit value set by the upper limit value setting means, and inertia torque generated during gear shifting. A control device for a continuously variable transmission, comprising: a shift speed control means for controlling a shift speed so that the final target value becomes. 2. The target inertia torque setting means sets a throttle valve opening of an engine combined with a continuously variable transmission as an operating condition, and sets a target value of the inertia torque based on the throttle valve opening. The control device for a continuously variable transmission according to claim 1. 3. The upper limit value setting means sets the upper limit value of the target value of the inertia torque to be smaller as the rotational speed of the driven side rotating member is lower. A control device for the continuously variable transmission described. 4. The control device for a continuously variable transmission according to claim 1, wherein the target value limiting means limits the target value of the inertia torque only during downshifting. . 5. The shift of the driven side rotating member to the power transmission member is made smaller as the value correlated with the rotational speed of the driven side rotating member becomes smaller and the target value of the inertia torque becomes larger at the time of a gear shift transition. The control device for a continuously variable transmission according to any one of claims 1 to 4, further comprising: transient line pressure control means for increasing and controlling the line pressure to be pressed. 6. The drive-side rotating member is a pulley whose effective winding radius can be changed, the driven-side rotating member is a pulley whose effective winding radius can be changed, and the power transmission member is The control device for a continuously variable transmission according to any one of claims 1 to 5, wherein the control device is a wound conductive medium that is wound around.