JPH05141515A - Controller of continuously variable transmission for vehicle - Google Patents

Abstract

PURPOSE:To prevent a belt from slipping by calculating a safety ratio based on the effective tension of a CVT belt and secondary side hydraulic pressure, determining a limit operation quantity by which a safety ratio during speed change becomes a specified value or more based on the calculated value and operation quantity and the change rate of primary hydraulic pressure, and correcting line pressure. CONSTITUTION:A continuously variable transmission controls the supply and discharge of hydraulic fluid to and from the hydraulic servo mechanisms provided in movable pulley members 8 and 14 of a primary and secondary pulleys 4 and 10 respectively and takes out speed change output from an output shaft. In this case, in a control section 82, line pressure is controlled so as to be objective line pressure based on the driving state, and the speed change ratio is controlled to the objective speed change ratio. In addition, the minimum belt holding force value is operated based on the torque transmitted and the actual belt tension of actual diameter ratio, and the second belt holding value is operated based on the line pressure, and the first holding value is operated based on these holding force values and speed change ratio. In the next step, operation quantity for speed changing is limited so that the ratio of the second holding force value during speed change to the first holding force value may become a specified value or more, and line pressure is corrected based on the limit information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission (hereinafter referred to as "CVT") used as a power transmission device for vehicles.
The present invention relates to the control device.

[0002]

2. Description of the Related Art In a vehicle, a transmission is interposed between an internal combustion engine and driving wheels. The transmission system changes the driving force of the drive wheels and the traveling speed in accordance with the traveling condition of the vehicle, which varies over a wide range, so that the performance of the internal combustion engine is fully exhibited. BACKGROUND ARTOne type of speed change device is a continuously variable transmission, which is a pulley having a fixed pulley part fixed to a rotary shaft and a movable pulley part mounted on the rotary shaft so as to be able to come in contact with and separate from the fixed pulley part. By increasing or decreasing the groove width of the groove formed between the two pulley pieces, the radius of rotation of the belt wound around the pulley is reduced to transmit power and change the belt ratio (gear ratio). .. This continuously variable transmission is disclosed, for example, in JP-A-57-186656 and JP-A-59-4324.
No. 9, JP-A-59-77159, JP-A-61.
It is disclosed in Japanese Patent Publication No. 233256.

[0003]

The gear ratio of the belt-type continuously variable transmission is feedback-controlled so that the actual engine speed matches the target engine speed determined by the operating condition of the vehicle, and also follows the target value. Each control gain is determined to satisfy the above requirement, but the operation amount becomes too large due to a temporary sudden increase in deviation due to sudden acceleration or deceleration, and belt slip occurs if the tracking limit of the continuously variable transmission is exceeded. There were challenges. Further, in order to prevent the transitional belt slip, constantly applying an excessive belt holding force causes deterioration of the belt life and fuel consumption.

The present invention has been made to solve the above problems, and can prevent the deterioration of the belt life due to the belt slip and the excessive gripping force, and at the same time, the speed change without impairing the followability. An object of the present invention is to obtain a control device for a continuously variable transmission for a vehicle that can be controlled.

[0005]

The belt slip is caused by the relationship between the belt clamping force and the belt tension generated by the pressure supplied to the movable pulley piece, and is generally found in the equilibrium state where the gear ratio is almost constant. It can be shown by the following formula. When the primary side (engine side) is driven and the secondary side (wheel shaft side) is driven, the clamping force F ₁ on the input shaft side = primary side is

[0006]

[Equation 1]

The clamping force F ₂ on the output shaft side = secondary side is

[0008]

[Equation 2]

Where A = exp (μφ / sin β) T _eff : Effective belt tension = M ₁ / R ₁ M ₁ : Primary torque α ₁ , α ₂ : Belt contact angle β: Sheave half top Angle R ₁ : Primary-side belt radius μ: Coefficient of friction between pulley and belt φ: Angle at which belt tension at the contact point between pulley and belt changes from maximum to minimum

If φ ≦ α ₁ or α ₂ , belt slip does not occur, and conversely, if φ> α ₁ or α ₂ , belt slip occurs. The first term in each of the equations (1) and (2) is the minimum belt holding force for preventing belt slip, and the value in {} is considered to be a safety factor for it. On the other hand, the gear ratio R _C = R ₂ / R ₁ (R ₂ = belt radius on the secondary side) is determined by the ratio of each clamping force (each axial thrust) F ₁ and F ₂ (that is, the safety factor ratio) and the safety factor. Depends on. An example showing this relationship is shown in FIG. That is, FIG. 2 shows the primary and secondary side safety factors S
The relationship between F ₁ and SF ₂ and the gear ratio R _C is shown.

Normally, in a continuously variable transmission, the second clamping force F ₂ is secured by the line pressure controlled so that belt slip does not occur, and the primary side hydraulic pressure, that is, the first hydraulic pressure, is adjusted so as to reach the target engine speed. 1 The grip ratio F ₁ is adjusted to control the gear ratio.

FIG. 3 shows a hydraulic circuit diagram related to gear shifting.
The relational expression in this figure is as follows. Ignoring the centrifugal hydraulic pressure, each clamping force is F ₁ = P ₁ · S ₁ (3) F ₂ = P ₂ · S ₂ (4) Also, the flow rate Q ₁ of the first oil passage 30 to the second hydraulic chamber 24 The flow rate Q ₂ is

[0013]

[Equation 3]

[0014]

[Equation 4]

From the control valve and the line resistance at the time of downshift,

[0016]

[Equation 5]

[0017]

[Equation 6]

Where x ₁ , x ₂ are the axial positions P ₁ , P _{2 of the} primary and secondary movable pulley part pieces 8, 14: pressures S ₁ , of the first and second hydraulic chambers 22, 24, S ₂ : Pressure receiving areas of the primary and secondary side movable pulley part pieces 8 and 14, V ₁ , V ₂ : Volumes of the first and second hydraulic chambers 22 and 24 B: Volume elastic coefficients of hydraulic oil L ₁ and L ₂ : Equivalent pipe lengths A ₁ and A _{2 of} the first and line oil passages 30 and 32: Equivalent cross-sectional area of the first and line oil passages 30 and 32 ρ, ν: Density and kinematic viscosity of hydraulic fluid Aa, Ca: 1 The opening area and the flow coefficient of the port a of the secondary hydraulic control valve 34, and the opening area Aa is a function of the duty (= actual neutral value) in the equilibrium state and the duty difference,
When the duty is an actual neutral value, it is zero, and when the difference becomes large, the opening area Aa also becomes large. P _l : Line hydraulic pressure.

The pulley moving speed dx / dt is the sandwiching force F ₁ , F that deviates from the equilibrium condition expressions (1) and (2).
_It is considered to be proportional to the difference between ₂ (equations (3) and (4)).
Therefore, under a certain condition, dP ₁ / dt≈0 from the relations of the expressions (1) to (8). FIG. 4 shows an example of the step response of the downshift in the actual machine of the primary hydraulic pressure P _{1 with} respect to the duty which is the operation amount. In the shift control, dx / dt = 0 is reached when a new equilibrium point is reached or a positional limit is reached.
When the new equilibrium point is reached, the primary hydraulic pressure P ₁ is (1),
The value is such that the first clamping force F ₁ determined by the equation (3) is obtained. When the positional limit is reached, the primary hydraulic pressure P ₁ becomes zero, but the clamping force is secured by the reaction force from the stopper.

The higher the speed of change of the gear ratio is required, the more
That is, the larger the actual neutral value-duty, the lower the transient primary hydraulic pressure P ₁ (while the pulley is moving), and belt slip occurs when the minimum belt clamping force of the equation (1) is not secured. Therefore, in order to prevent the occurrence of belt slip, the duty of the operation amount is limited so that the primary hydraulic pressure P ₁ during the downshift becomes equal to or higher than the value that can secure the minimum belt clamping force of the formula (1). ..

Therefore, the control device for a continuously variable transmission for a vehicle according to the present invention includes first calculating means for calculating the minimum belt clamping force value from the effective belt tension of the ratio of the transmission torque and the effective diameter of the pulley, and the minimum calculating means. Third computing means for computing the first clamping force value in the equilibrium state from the belt clamping force value, the second clamping force value by the second computing means, and the gear ratio, and the change of the first clamping force with respect to the operation amount of the shift control means. Of the determining means for determining the relationship between the ratios, the fourth calculating means for calculating the second clamping force value during shifting from this relationship and the output of the third calculating means, and the fourth calculating means for the output of the first calculating means. Limiting means for limiting the operation amount of the shift control means so that the output ratio becomes a predetermined value or more, and line pressure correction means for correcting the line pressure according to the operation amount limitation information of the shift control means are provided. ..

[0022]

In the present invention, the primary safety factor in the equilibrium state obtained from the relationship between the secondary hydraulic pressure = the secondary hydraulic pressure determined by the line hydraulic pressure and the input torque and the gear ratio, and the actual neutral value-duty obtained in advance. And the relationship between the primary hydraulic damping factor, that is, the primary safety factor, the primary safety factor in the transient state = the equilibrium safety factor x the primary safety factor's damping factor. Restricts the operation amount of the shift control means to a duty that does not fall below a predetermined value. When it is determined that the deviation becomes large as a result of the operation amount restriction, the line pressure is corrected in order to ease the operation amount restriction.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a control device for a belt type continuously variable transmission according to this embodiment, and 2 denotes a belt type continuously variable transmission.
2A is a belt, 4 is a primary side pulley, 6 is a primary side fixed pulley section piece, 8 is a primary side movable pulley section piece, 10 is a secondary side pulley, 12 is a secondary side fixed pulley section piece, and 14 is It is a secondary movable pulley piece. As described above, the primary pulley 4 has the fixed pulley part 6 fixed to the rotating shaft 16 and the movable pulley part 8 mounted on the rotating shaft 16 so as to be movable in the axial direction but non-rotatable. However, the secondary pulley 10 has the same structure.

The primary side movable pulley section piece 8 and the secondary side movable pulley section piece 14 are respectively provided with first and second housings 18 and 2.
0 is mounted, and first and second hydraulic chambers 22 and 24 are formed. In the second hydraulic chamber 24, a biasing means 26 including a spring or the like for biasing the second housing 20 in the expanding direction is provided. The rotary shaft 16 is provided with a hydraulic pump 28, and the working oil that has recirculated into the oil tank 94 is sucked through the strainer 96 and pressure-fed to the line oil passage 32. Line oilway 32
Communicates with the second hydraulic chamber 24, and the first three-way solenoid valve 4
2 communicates with the primary-side hydraulic control valve 34 controlled by the second hydraulic passage 40 via the second hydraulic passage 40.
0 to communicate with the first hydraulic chamber 22.

The line oil passage 32 is connected to the third three-way solenoid valve 5
8 communicates with the clutch oil passage 64 via the clutch pressure control valve 52 controlled by the fourth oil passage 56. An oil pressure sensor 68 is provided in the clutch oil passage 64 via a sixth oil passage 66 for detecting the oil pressure. The line pressure P _l is
The line pressure control valve 44 controlled by the second three-way solenoid valve 50 through the fifth oil passage 48 regulates the pressure (for example, 6 to 2).
5 kg / cm ² ). The line pressure control valve 44 is the seventh oil passage 46.
Through the line oil passage 32. The hydraulic pressure in the third oil passage 60 is maintained at a constant control pressure (for example, 4.2 kg / cm ² ) by the pressure regulating valve 38 for reducing the line pressure, and the control valves 34, 44,
52 and three-way solenoid valves 42, 50, 58.

For measuring the rotational speed of the continuously variable transmission,
A primary side rotation detection gear 70 and a primary side rotation speed detector 72 are provided outside the first housing 18, and the second housing 20
A secondary side rotation detection gear 74 and a secondary side rotation speed detector 76 are provided on the outside of the. In this embodiment, the primary side rotation speed N ₁
Is equal to the engine speed Ne, and the gear ratio Rc = N ₁
Calculated as / N ₂ . A transmission gear 78 is provided on the output side of the hydraulic start clutch 62, and the transmission gear 78 is connected to the forward / reverse switching device, the reduction gear, the differential gear, the drive shaft, and the tire. A clutch output rotation speed detector 80 is provided for measuring the rotation speed of the transmission gear 78 to obtain the clutch output rotation speed N ₃ . N ₃ corresponds to the vehicle speed. Also, (N ₂ −
N ₃ ) is the clutch slip rotation speed.

Further, information such as a throttle opening of a carburetor, an engine speed, a vehicle speed, vehicle operating states such as switch signals, and hydraulic pressure and oil temperature (not shown) are input to the control unit 82. The control unit 82 outputs the duty to the three-way solenoid valves 42, 50 and 58 to control the line pressure, the clutch and the shift.

FIG. 5 shows the structure of the control unit 82.
The flow of control will be described using. First, in the clutch control, the throttle opening θ detected by the throttle opening sensor 113 and the clutch output rotation speed detector 8
Clutch output speed N ₃ detected by 0 = vehicle speed V,
Primary-side rotation speed N ₁ detected by the primary-side rotation speed detector 72 = engine rotation speed Ne, secondary-side rotation speed detector 7
The secondary side rotation speed N ₂ detected by 6 = the clutch input rotation speed and the other vehicle operating state 114 are input, and the target clutch pressure determination means 104 determines the target clutch pressure. On the other hand, the oil pressure Pc of the starting clutch 62 is detected by the oil pressure sensor 6
The target clutch pressure and the hydraulic pressure Pc are detected by the subtractor 111.
To the clutch pressure control calculation means 109.
The clutch pressure control calculation means 109 outputs a duty Dc which is an operation amount, and this output is output to the hydraulic circuit 11.
5, the hydraulic pressure of the starting clutch 62 is controlled to the target clutch pressure.

Next, in the control of the line pressure, the gear ratio calculating means 102 is operated by the primary side rotation speed N ₁ and the secondary side rotation speed N.
₂ is input, and the gear ratio Rc = N ₁ / N ₂ is calculated.
Further, CVT input torque calculation means 103 is input to the throttle opening θ and the engine speed Ne = N _1, and calculates the primary torque M _1. The target line pressure determining means 105 receives the gear ratio Rc and the primary side torque M ₁ and receives the target line pressure P.
_{Determine lsp1} . The line pressure correction means 112 is a deviation EIR between the output of the target engine speed determination means 101 and the output Ne of the primary side rotation speed detector 72 and the duty limit value D.
_The line correction value P _lad after inputting _max and duty Dr
The calculated, this line correction value P _lad is input to the target line pressure determining means 105, a target line pressure P _lsp are added to the target line pressure P _LSP1. Line pressure control calculation means 10
8 inputs the target line pressure P _1sp and the hydraulic pressure Pc, and inputs the duty D ₁ which is the operation amount to the hydraulic circuit 115.

FIG. 6 is a flow chart showing the operation of the line pressure correction means 112. In step 401, the deviation EI
It is determined whether R is 200 rpm or more or less, and if it is less than or equal to 100 rpm in step 402, 10
If it is 0 rpm or more, dEIR / dt is performed in step 403.
That is, it is determined whether the change direction of EIR is positive or negative. If it is positive, the routine proceeds to step 404, where it is judged whether or not the duty Dr is being limited (Dr = D _max ), and if it is being limited, at step 405 a predetermined increment ΔP _lad is added to the previous correction amount P _lad. This is the correction amount. If the EIR is 100 rpm or less or dEIR / dt is negative, then in step 407, the predetermined reduction amount ΔP _lad is subtracted from the previous correction amount P _lad to obtain the current correction amount.

Next, in the shift control, the target engine speed determining means 101 determines the target engine speed N _esp from the throttle opening θ and the vehicle speed V, and the target engine speed N _esp and the engine speed Ne are determined. The difference EIR is input to the subtractor 110, and the deviation EIR is input to the shift control calculating means 106. The shift control calculating means 106 outputs the duty Dr, which is an operation amount, and the CVT 11 is output via the hydraulic circuit 115.
7 is gear shift controlled. Reference numeral 116 is an engine, and 118 is a drive device.

The duty output Dr from the shift control calculating means 106 is limited by the duty limit value D _max determined by the limit value determining means 107. FIG. 7 shows a detailed configuration of the shift control calculation means 106. The output of the integrator 201 having the integral gain K _I is subtracted by the subtracter 2 by the proportional-integral control.
The actual neutral value D is subtracted from the nominal neutral value Dnn in 04.
get n. On the other hand, the output of the proportional calculator 202 of the proportional gain K _P is limited by the limit value D _max of the limiter 203, and the subtracter 205 subtracts the output of the limiter 203 from the actual neutral value Dn and outputs it as the duty Dr. ..

FIG. 9 shows a flowchart of the operation of the limit value determining means 107. In step 301, R ₁ is calculated from the relationship map MAP1 of the gear ratio Rc and the radius R ₁ . In step 302, it is determined whether or not the clutch is directly connected. If the clutch is in the direct connected state, in step 303 the primary side torque M ₁ = T _E
If it is not in the direct connection state, in step 304 the product of clutch pressure Pc and clutch gain Kc (torque / pressure) = secondary torque divided by Rc, primary conversion torque Pc · Kc / R
The smaller of c and T _{E is} the primary torque M ₁ .

In step 305, the effective tension T _eff = M
₁ / R ₁ is calculated, and in step 306, the minimum line pressure P
_lmin = T _eff · cos β / S ₂ · _2μ , and step 3
At 07, the secondary side safety factor SF ₂ = P _lsp / P _lmin is calculated. Step 308 determines the sign of the T _E, calculates the relation map MAP3 than primary safety factor SF ₁ indicated by the broken line in FIG. 2 in step 309 if the negative case i.e. secondary drive, is T _E If it is positive or zero, that is, if it is the primary side drive, the routine proceeds to step 310, where the relationship MAP shown by the solid line in FIG.
The primary safety factor SF ₁ is calculated from 2. In step 311, the duty limit value D _max is calculated from the steady state safety factor SF ₁ and MAP4 shown in FIG. 8 so that the transient state safety factor does not fall below 1. FIG. 8 shows SF ₁ as the reciprocal of the primary hydraulic damping rate which is almost constant in FIG.
And D _max .

Embodiment 2 In the above embodiment, the engine 116 and the CVT 11 are used.
7, the connection order of the starting clutch 62, the engine 1
The same applies to the connection order of 16, the start clutch 62, and the CVT 117. Although the starting clutch 62 is described as a wet hydraulic clutch, it may be an electromagnetic clutch or a fluid clutch. In step 304 of FIG. 9, the clutch torque can be estimated from the current value of the electromagnetic clutch, for example. Further, in the case of a fluid clutch, it is possible from the capacity coefficient and the input rotation speed given as a function of the speed ratio, for example. Further, the determination as to whether the primary side of the CVT 117 is the driving side or the driven side in step 308 of FIG. 9 can be made by the sign of the difference between the input rotation speed and the output rotation speed of the clutch, for example. Further, the primary side safety factor in the transient state is set to 1 or more, but it may be set to a value larger than 1 in order to make it more reliable.

[0036]

As described above, according to the present invention, the CVT
The steady-state safety factor is calculated from the effective tension of the belt, the secondary hydraulic pressure, and the gear ratio. By limiting the operation amount during the shift control by obtaining the limit operation amount that is equal to or more than the predetermined value, it is possible to reliably prevent the CVT belt slip caused by the decrease in the primary side hydraulic pressure due to the excessive operation amount. Further, since the line pressure correcting means for correcting the line pressure only when necessary is provided, it is possible to avoid the reduction of the shift control performance due to the operation amount limitation without increasing the loss due to the high line pressure. Moreover, since everything is electronically controlled, the cost can be reduced and a highly accurate product can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus according to the present invention.

FIG. 2 is a relationship diagram between a primary and secondary safety factor and a gear ratio of a continuously variable transmission for a vehicle.

FIG. 3 is a detailed hydraulic circuit diagram related to gear shifting by the device of the present invention.

FIG. 4 is a step response diagram of the primary hydraulic pressure of the device of the present invention.

FIG. 5 is a configuration diagram of a control unit of the device of the present invention.

FIG. 6 is a flowchart showing the operation of the line pressure correction means according to the present invention.

FIG. 7 is a block diagram of a shift control calculation means according to the present invention.

FIG. 8 is a relationship diagram between a primary side safety factor and a duty limit value of a continuously variable transmission for a vehicle.

FIG. 9 is a flowchart showing the operation of the limit value determining means according to the present invention.

[Explanation of symbols]

 2 Belt type continuously variable transmission 2A Belt 4 Primary pulley 6,12 Fixed pulley piece 8,14 Movable pulley piece 10 Secondary pulley 32 Line oil passage 34,44,52 Control valve 68 Hydraulic sensor 72,76 , 80 rotational speed detector 82 control unit 101 target engine speed means 102 gear ratio calculation means 103 CVT input torque calculation means 104 target clutch pressure determination means 105 target line pressure determination means 106 shift control calculation means 107 limit value determination means 108 lines Pressure control calculation means 109 Clutch pressure control calculation means 112 Line pressure correction means 113 Throttle opening sensor 115 Hydraulic circuit 116 Engine 117 CVT

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 3, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

The higher the speed of change of the gear ratio is required, the more
That is, the larger the actual neutral value-duty, the lower the transient primary hydraulic pressure P ₁ (while the pulley is moving), and belt slip occurs when the minimum belt clamping force of the equation (1) is not secured. Therefore, in order to prevent the occurrence of belt slip, so that the primary hydraulic P ₁ in the downshift (1) or a value which can ensure the minimum belt clamping force type, and child limits the duty of the operation amount There is drivability
We must avoid the deterioration.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

Next, in the control of the line pressure, the gear ratio calculating means 102 is operated by the primary side rotation speed N ₁ and the secondary side rotation speed N.
₂ is input, and the gear ratio Rc = N ₁ / N ₂ is calculated.
Further, CVT input torque calculation means 103 is input to the throttle opening θ and the engine speed Ne = N _1, and calculates the primary torque M _1. The target line pressure determining means 105 receives the gear ratio Rc and the primary side torque M ₁ and receives the target line pressure P.
_{Determine lsp1} . The line pressure correction means 112 is a deviation EIR between the output of the target engine speed determination means 101 and the output Ne of the primary side rotation speed detector 72 and the duty limit value D.
_The line correction value P _lad after inputting _max and duty Dr
The calculated, this line correction value P _lad is input to the target line pressure determining means 105, a target line pressure P _lsp are added to the target line pressure P _LSP1. Line pressure control calculation means 10
A target line pressure P _1sp and a hydraulic pressure Pc are input to the hydraulic circuit 8, and a duty D ₁ which is an operation amount is output to the hydraulic circuit 115 . Was
However, the state where Pc is not equal to the line pressure (clutch
In the (connected state), a predetermined duty corresponding to the target line pressure
Is output.

[Procedure 3]

[Document name to be corrected] Drawing

[Correction target item name] Figure 9

[Correction method] Change

[Correction content]

[Figure 9]

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area F16H 59:54 8207-3J

Claims (1)

[Claims] 1. A primary pulley and a secondary pulley having a fixed pulley portion, a movable pulley portion, and a hydraulic servo provided on the movable pulley portion, the effective diameter of which is continuously variable, and between these pulleys. A second clamping force of the drive belt is provided by providing a tensioned drive belt and supplying a line pressure, which regulates the hydraulic pressure generated by the hydraulic pressure source, to the hydraulic servo of either the primary side pulley or the secondary side pulley. And the line pressure is selectively supplied to the other hydraulic servo of each pulley to generate the shift hydraulic pressure to generate the first clamping force of the drive belt and to move the movable pulley piece in the axial direction. In a control device for a continuously variable transmission for a vehicle, which controls the gear ratio by moving the line speed to a line pressure control means for controlling to a target line pressure determined from information of a driving state detecting means, and a target gear shift determined from the above information. Ratio or A shift control means for controlling to a target engine speed, a first calculating means for calculating a minimum belt clamping force value from an effective belt tension of a ratio of a transmission torque and the effective diameter, and a second clamping force value from the line pressure. Operation of the shift control means, a second calculation means for calculating the first clamping force value in an equilibrium state in which the gear ratio is substantially constant based on the outputs of the first and second calculation means and the gear ratio. First to quantity
Determining means for determining the relationship of the changing rate of the clamping force, fourth calculating means for calculating the second clamping force value during shifting from the above relationship and the output of the third calculating means, and fourth for the output of the first calculating means.
A limiting means for limiting the operation amount of the shift control means so that the ratio of the output of the computing means becomes a predetermined value or more, and a line pressure correction means for correcting the line pressure according to the operation amount limitation information of the shift control means. A control device for a continuously variable transmission for a vehicle, comprising: