JPH09210189A - Controller for continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine the characteristics between the controlling amount of the hydraulic control valve which controls the hydraulic pressure of the shift control valve in a continuous transmission and the value relating to the displacement of the shift control valve by adding consideration on the variability and degradation of each hydraulic control valves and the aged deterioration to eliminate the dispersion of the characteristics. SOLUTION: The pressure in the oil chamber for shifting pressure control 4a is computed from the pulley ratio and the line pressure when the transfer torque is almost 0, according to which computation, the opening surface ratio Ar used for the second pressure computing means for computing the pressure in the oil chamber for shifting pressure control 4a from the parameter (line pressure) including the opening surface ratio Ar of the flow control valve as the value contributing to the displacement of the flow control valve 7, then based on the relationship between the opening surface ratio Ar as such computed and the control amount of the solenoid valve 8 at this time, the relationships between the opening surface ratio Ar of the flow control valve 7 and the stored control amount of the solenoid valve 8 (characteristics of control amount-opening ratio) will be corrected.

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 provided between a power source such as an engine of a vehicle and a drive shaft, and more particularly to a hydraulic control for changing a gear ratio. Regarding technology.

[0002]

2. Description of the Related Art Conventionally, in a vehicle, a transmission is interposed between an internal combustion engine and driving wheels. Such a transmission changes the driving force transmitted to the driving wheel side in accordance with the traveling conditions of the vehicle that change over a wide range, and allows the internal combustion engine to exhibit its full performance. As a transmission for such a vehicle, a primary pulley as a driving side rotating member that receives a rotational force of a power source, a secondary pulley as a driven side rotating member, and a power transmission between the two pulleys are interposed between the pulleys. A belt as a power transmission member for transmission, and a drive-side contact rotation radius that is the distance from the rotation center of the contact position between the primary pulley and the belt, or a distance from the rotation center of the contact position between the secondary pulley and the belt. 2. Description of the Related Art A continuously variable transmission is known in which any one of the driven-side contact turning radii is changed to change gears.

In such a continuously variable transmission, a hydraulic pressure control oil chamber for changing the speed by changing the supply and discharge of hydraulic oil based on a control signal output from a control device, and the speed change gear. And a contact surface pressure control oil chamber for controlling the contact rotation radius on the side not subjected to speed change control by the pressure control oil chamber so as to apply the contact surface pressure with the belt necessary for torque transmission. The transmission control valve controls the hydraulic pressure to change the transmission ratio.

In this case, the shift control valve is operated by controlling the working hydraulic pressure by an electromagnetic valve as a working hydraulic control valve. In such a configuration, the relationship between the control amount of the solenoid valve and the shift control valve displacement generally changes depending on the environmental conditions of the transmission and the like. In order to deal with this, conventionally, for example, as disclosed in JP-A-64-44348 and JP-A-1-153851, the relationship between the solenoid valve and the speed change control valve, more specifically, the duty neutral. There is a type in which the solenoid valve is driven by switching control of the value according to the oil temperature and the drive frequency.

However, in the case of driving the solenoid valve by switching the duty neutral value according to the oil temperature and the driving frequency as in the above-mentioned conventional technique, the duty neutral value is deviated. The duty neutral value must be controlled within a very small range, and the deviation thereof causes a change in shift speed, which causes discontinuity in shift and a shift shock.

Therefore, in order to solve such a problem, a plurality of drive frequencies and an oil temperature-duty neutral value map for each of these drive frequencies are stored in the control means and driven by the control means. By switching control to any one of the plurality of drive frequencies according to the condition, and switching control to a duty neutral value according to the oil temperature state calculated from the oil temperature-duty neutral value map of this drive frequency. There has been proposed a technique for eliminating the deviation of the duty neutral value when the drive frequency is switched (see Japanese Patent Laid-Open No. 5-118420).

[0007]

However, such prior art does not take into consideration variations with time, such as variations and deterioration of individual solenoid valves. If a characteristic that is related to the value related to the displacement of the control valve is determined, the variation in this characteristic cannot be absorbed, so that the duty neutral value will be displaced, and the shift speed will fluctuate, resulting in discontinuous shift. And a shift shock is still generated.

In view of the above conventional circumstances, the present invention determines the characteristics of the controlled variable of the hydraulic pressure control valve and the value related to the displacement of the shift control valve. It is an object of the present invention to eliminate the variation in the characteristics by setting the hydraulic pressure control valve in consideration of variations over time, such as variations and deterioration of individual operating hydraulic control valves.

[0009]

Therefore, the invention according to claim 1 is, as shown in FIG. 1, a driving side rotating member for receiving a rotational force of a power source and a driven side connected to a driven portion. A rotary member and a power transmission member that is interposed between both rotary members and that transmits power between the two are configured to include a contact surface pressure between one rotary member and the power transmission member as a line pressure, and
By controlling the contact surface pressure between the other rotary member and the power transmission member as the shift pressure adjusted by the line pressure according to the gear ratio, the rotation center of each rotary member to the contact point with the power transmission member is controlled. The configuration is such that the ratio of the radii is changed steplessly to control the speed change steplessly, and a shift pressure control oil chamber, a contact surface pressure control oil chamber, and a shift to the shift pressure control oil chamber. In a continuously variable transmission including a shift control valve for controlling pressure and a working hydraulic control valve for controlling working hydraulic pressure of the shift control valve, a control amount of the working hydraulic control valve and a shift control valve A storage unit that stores a relationship with a value related to displacement, a transmission torque detection unit that detects a transmission torque of the continuously variable transmission, a radius ratio detection unit that detects an actual ratio of the radii, and the line pressure Line pressure detecting means for detecting, and the transmission torque detecting means First hydraulic pressure calculation means for calculating the hydraulic pressure of the shift pressure control oil chamber based on the detection signals output from the radius ratio detection means and the line pressure detection means, and a value related to the displacement of the shift control valve. Based on the calculation result of the second hydraulic pressure calculation means for calculating the hydraulic pressure of the shift pressure control oil chamber from the included parameter and the calculation result of the first hydraulic pressure calculation means,
Displacement related value calculation means for calculating a value related to displacement of the shift control valve used in the second hydraulic pressure calculation means, a value related to displacement of the shift control valve calculated by the displacement related value calculation means, and operation at this time. And a correction unit that corrects the relationship between the control amount of the operating hydraulic control valve and the value related to the displacement of the shift control valve in the storage unit based on the relationship with the control amount of the hydraulic control valve.

In such a configuration, characteristic variations in the control amount of the hydraulic pressure control valve and the values relating to the displacement of the shift control valve due to changes over time such as variations and deterioration of individuals can be absorbed, and the duty neutral value can be reduced. As a result of eliminating the shift, the fluctuation of the shift speed is suppressed and the occurrence of shift shock is suppressed. According to a second aspect of the present invention, the second hydraulic pressure calculating means uses the second hydraulic pressure calculating means as a parameter, as an opening area ratio of the line pressure introducing port and the drain port of the shift control valve as a value related to the displacement of the shift control valve. The hydraulic pressure in the shift pressure control oil chamber is calculated from the line pressure.

According to this structure, the hydraulic pressure in the shift pressure control oil chamber is calculated from the line pressure and the opening area ratio of the line pressure introduction port and the drain port of the shift control valve as values related to the displacement of the shift control valve. Is calculated. According to a third aspect of the present invention, the transmission torque detecting means comprises means for detecting that the transmission torque of the continuously variable transmission is substantially zero.

According to this structure, it is detected that the transmission torque of the continuously variable transmission is substantially zero. According to a fourth aspect of the present invention, the clutch for interposing the means for detecting that the transmission torque of the continuously variable transmission is substantially 0 is released between the continuously variable transmission and the driven portion. The state is configured to be detected as the transmitted torque being substantially zero.

According to this structure, the fact that the transmission torque of the continuously variable transmission is substantially zero can be easily detected from the released state of the clutch interposed between the continuously variable transmission and the driven portion. . According to a fifth aspect of the present invention, the displacement-related value computing means changes the line pressure or the radius ratio state to a plurality of states when the clutch is in the released state, and the first hydraulic pressure computing means in each state. A value related to the displacement of the shift control valve used in the second hydraulic pressure calculation means is calculated based on the calculation result of the above.

According to this structure, the correction (learning) of the value related to the displacement of the shift control valve is performed under a plurality of conditions, and the learning accuracy is improved. According to a sixth aspect of the present invention, a means for detecting that the transmission torque of the continuously variable transmission is substantially 0 is provided as an input / output rotation of a fluid coupling interposed between a drive source and the continuously variable transmission. The transmission torque is detected to be substantially 0 when the speeds are equal.

In such a configuration, it is easy for the transmission torque of the continuously variable transmission to be substantially zero from the state where the input and output rotational speeds of the fluid coupling interposed between the drive source and the continuously variable transmission are equal. Detected by.

[0016]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In FIG. 2 showing a system of a common embodiment of the invention according to claims 1 to 6, a continuously variable transmission (CVT) 3 is provided on the output side of an engine 1 in a vehicle via a torque converter 2 as a fluid coupling.
Is equipped.

The continuously variable transmission 3 has a primary pulley 4 as a drive side rotating member on the engine 1 side as a drive source and a secondary pulley as a driven side rotating member on a drive shaft (differential) side as a driven portion. A pulley 5 and a belt 6 as a power transmission member made of rubber or metal wound around them or a combination thereof are provided, and the shift pressure to the shift pressure control oil chamber 4a on the primary pulley 4 side, By adjusting the line pressure to the contact surface pressure control oil chamber 5a on the secondary pulley 5 side, the ratio of the radius from the rotation center of each rotating member to the contact point of the belt 6 as the power transmission member, that is, the pulley ratio ( By changing the secondary pulley-side belt winding effective diameter / primary pulley-side belt winding effective diameter, the gear ratio can be changed steplessly. However, other CVTs 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 a rotational force of a power source, a driven-side rotating member that is connected to a driven portion, and a rotary member that is interposed between the rotating members. And a power transmission member for transmitting power, and steplessly changes the ratio of the radius from the rotation center of each rotating member to the contact point with the power transmission member to control the speed ratio steplessly. Any continuously variable transmission as described above may be used.

The hydraulic control mechanism controls an oil pump (not shown) directly driven by the engine, a plurality of hydraulic control valves for controlling the line pressure and the shift pressure, an input shaft rotation speed, an accelerator opening degree and a gear ratio. And an input signal system for detection. The oil discharged from the oil pump is sent to the hydraulic control valve, and is used as hydraulic oil for the primary pulley 4 and secondary pulley 5 and lubricating oil for each part.

A flow rate control valve 7 as a shift control valve which is one of hydraulic pressure control valves, a solenoid valve 8 as an operating hydraulic pressure control valve for controlling the operating hydraulic pressure of the flow rate control valve 7,
Is provided. In this case, the amount of depression of the accelerator pedal is determined by determining the groove width of the primary pulley 4 by controlling the inflow / outflow of the line pressure into / from the primary pulley 4 side shift pressure control oil chamber 4a using the engine speed as a signal source. Then, the gear ratio is controlled, and the primary pulley 4
The flow control valve 7 controls the inflow and outflow of the line pressure into and from the shift pressure control oil chamber 4a on the side, and the operating hydraulic pressure of the flow control valve 7 is controlled by the solenoid valve 8.

An underlap valve is applied as the flow control valve 7. That is, the flow control valve 7 includes a slide-free valve body 7A, two springs 7B that normally elastically bias the valve body 7A to a neutral position, and two inlets a,
b, a valve main body 7C provided with one discharge port c and one drain port d, and the neutral value is 2
Both of the inlets a and b are slightly open.

The control unit 10 includes an actual input rotation speed Nin of the continuously variable transmission 3 (a rotation speed N of the engine 3).
Input side rotation sensor 1 that generates a pulse signal in synchronization with the rotation of the input side (primary pulley 4) to detect e)
2, an output side rotation sensor 13 that generates a pulse signal in synchronization with the rotation of the output side (secondary pulley 5) to detect the actual output rotation speed No of the continuously variable transmission 3, the opening degree of the throttle valve of the engine 1 ( Throttle opening) Detection signals are input from a potentiometer-type throttle sensor 14 that generates a voltage signal corresponding to TVO. still,
A vehicle speed sensor can be used as the output side rotation sensor 13.

Here, in the embodiment of the present invention, as described above, the flow rate control valve 7 that controls the shift pressure to the shift pressure control oil chamber 4a and the electromagnetic valve that controls the operating hydraulic pressure of the flow rate control valve 7 are described. The valve 8 and the control means for controlling the solenoid valve 8 are included, and the control means, the storage means, and the first
The respective functions of the hydraulic pressure calculation means, the second hydraulic pressure calculation means, the displacement related value calculation means, and the correction means of the control unit 10
Is equipped with software.

That is, in the embodiment of the present invention, the transmission torque detecting means for detecting the transmission torque of the continuously variable transmission 3 and the pulley ratio detecting means as the radius ratio detecting means for detecting the actual ratio of the radii. , And a line pressure sensor as a line pressure detecting means for detecting the line pressure. In this case, the transmission torque detecting means is composed of means for detecting that the transmission torque of the continuously variable transmission is approximately 0. For example, the engine 1 as the drive source and the continuously variable transmission 3 are provided.
A state in which the input and output rotational speeds of the torque converter 2 as a fluid coupling interposed between and are equal to each other is detected as the transmission torque being substantially zero.

Alternatively, in the case where the torque converter 2 is not provided and a clutch is interposed between the output side (secondary pulley 5) of the continuously variable transmission 3 and the drive shaft side (for example, differential), the clutch is released. Transmission torque is almost 0
To be detected. Further, the pulley ratio detecting means is configured to detect the input rotation speed and the output rotation speed of the continuously variable transmission 3 and calculate the ratio between them.

Then, based on the detection signals output from these detecting means, the hydraulic pressure in the transmission pressure control oil chamber 4a is calculated from the radius ratio and the line pressure when the transmission torque is substantially 0 (first Hydraulic pressure calculation means), based on the calculation result, a parameter (including the opening area ratio of the flow control valve (opening area ratio of the line pressure introduction port a and the drain port d)) as a value related to the displacement of the flow control valve 7 ( In the present embodiment, from the line pressure) to the hydraulic pressure (primary pressure) in the shift pressure control oil chamber 4a.
The opening area ratio used in the second hydraulic pressure calculation means is calculated (displacement related value calculation means).

A method of calculating the hydraulic pressure in the transmission pressure control oil chamber from the line pressure, the pulley ratio, and the transmission torque will be described. Thrust force of primary pulley 4 (pushing force of pulley 4 in the axial direction) Q ₁ , Thrust force of secondary pulley 5 Q
The relationship between ₂ and the effective tension (transmission driving force) Te of the belt 6 is given by the following equation.

Q ₁ tan (α + β) / θ ₁ -Q ₂ tan
(Α + β) / θ ₂ = 1 / 2Te {1-1 / 2 [tanh
(ΛR ₁ θ ₁ ) / (λR ₁ θ ₁ ) + tanh (λR ₂ θ
₂ ) / (λR ₂ θ ₂ )]} However, α Pulley grip angle / 2 β See Fig. 3 θ ₁ , θ ₂ Primary pulley 4, Secondary pulley 5
Belt wrap angle (see FIG. 3) λ constants R ₁ and R ₂ primary pulley 4 and secondary pulley 5
Effective radius of (see FIG. 3) When this equation is modified, Q ₁ = 1/2 × Te {1-1 / 2
(TanhB / B + tanhC / C)} (θ ₁ / A) +
(Θ ₁ / θ ₂ ) × Q ₂ However, A = tan (α + βn) B = λR ₁ θ ₁ C = λR ₂ θ ₂ As described above, the thrust Q of the primary pulley 4 in the steady state is
₁ is determined by the line pressure, torque ratio (pulley ratio), and input torque.

Therefore, when the input torque is 0, that is, when Te in the formula for calculating the thrust Q ₁ of the primary pulley 4 is 0, the thrust Q ₁ of the primary pulley 4 is
Q ₁ = (θ ₁ / θ ₂ ) × Q ₂ , and the thrust Q ₁ of the primary pulley 4 is calculated from the primary pressure P _p , which is the oil pressure in the oil chamber for shift pressure control, and the pressure receiving area A _p of the primary pulley 4. Q ₁ = P _p · A _p , secondary pulley thrust Q ₂ is
From the line pressure P _L , which is the oil pressure in the contact surface pressure control oil chamber, and the pressure receiving area A _{L of the} secondary pulley, Q ₂ = P _L · A _L , so P _p · A _p = (θ ₁ / θ ₂ ) × P _L · A _L , and from this equation, the primary pressure P _p can be determined by the following simple equation.

P _p = P _L · (A _L · Q ₁ ) / (A _p · Q ₂ ) Next, from the opening area ratio Ar of the flow control valve 7 and the line pressure, the primary pressure P _p (shift pressure control oil A method of calculating the hydraulic pressure of the chamber 4a) will be described. Constant primary pressure P _p
When the shift control valve is the flow control valve 7 and this is an underlap valve as in the embodiment, can be obtained as follows from the equation of the flow rate before and after the orifice.

[0031]

[Outside 1]

The primary pressure P _{p in the} steady state is expressed as follows. P _p = (1 + Ar ² ) / Ar ² · P _L The calculation (estimation) of the primary pressure P _p based on the opening area ratio Ar of the flow rate control valve 7 and the line pressure should be performed as shown in the flowchart of FIG. You can That is, in step 1 (abbreviated as S1 in the figure; the same applies hereinafter), it is determined whether or not the flow control valve 7 is in a steady state. That is, it is determined whether the pulley ratio is within the predetermined range.

When it is determined that the pulley ratio is within the predetermined range and it is determined that the pulley ratio is in the steady state, the process proceeds to step 2, and otherwise the process returns. In step 2, the steady determination counter Count 1 is added to st, and in step 3, duty average addition value Dt su
adding the duty Duty to m, in step 4, line pressure average addition value P _L sum in the line pressure P _L
Is added.

In step 5, the steady determination counter
Ta Count st and steady state determination count set value PPC
Compare with, Count If st ≧ PPC, then predetermined
Assuming that the time steady state has continued, proceed to step 6
out If st <PPC, the process returns to step 1.
In step 6, the steady-state determination counter Count st
Is reset to 0, and in step 7, the average duty value
Dtyave is added value Dt for duty averaging sum and
Calculated from the steady-state determination count set value PPC (Dt
sum / PPC).

In step 8, the line pressure average value P _L av
e is calculated from the line pressure average addition value P _L sum and the steady determination count set value PPC (P _L sum / PP
C). In step 9, as shown in FIG. 5, the duty average value Dtyave and the opening area ratio Ar determined in advance by experiments are set.
From the characteristic diagram of, the duty average value Dtyav at that time is
Reference is made to the opening area ratio Ar corresponding to e.

Then, in step 10, the step
Line pressure average value P calculated in _Lave and step
From the opening area ratio Ar referenced in
P_pIs calculated. Here, as shown in FIG. 6, flow rate control
The solenoid pressure PSOL pressing the valve body 7A of the valve 7 is
Reduce the ilot pressure PPI by controlling the duty of the solenoid valve 8.
The solenoid pressure PSOL is determined.
Then, the displacement x of the valve body is determined as follows.

X = (PSOL · A ₁ −PPI · A ₂ ) / 2k However, when the solenoid pressure is 0, x = 0, and the direction in which the valve body 7A is the line pressure supply direction is the positive direction. Then, the opening area ratio Ar, which is a value related to the displacement of the flow rate control valve 7 used in the second hydraulic pressure calculating means, is calculated based on the calculation result of the first hydraulic pressure calculating means.

That is, P _p = P _L · (A _L · Q ₁ ) / (A
_p · Q ₂ ), and P _p = (1 + Ar ² ) / Ar ² · P
_The aperture area ratio Ar is calculated from the equation of _L. Further, the opening area ratio Ar calculated in this way and the solenoid valve 8 at this time
As shown in FIG. 5, the relationship between the control duty of the solenoid valve and the opening area ratio of the flow rate control valve (control duty-opening area ratio characteristic) is corrected based on the relationship between the control duty and the control duty.

As described above, the transmission pressure control oil chamber 4a is calculated from the pulley ratio and the line pressure when the transmission torque is substantially zero.
Is calculated, and based on the calculation result, a parameter including the opening area ratio of the flow control valve as a value related to the displacement of the flow control valve 7 (line pressure in the present embodiment).
The opening area ratio Ar used in the second hydraulic pressure calculating means for calculating the hydraulic pressure of the transmission pressure control oil chamber 4a is calculated from the calculated opening area ratio Ar and the control duty of the solenoid valve 8 at this time. The relationship between the control duty of the solenoid valve 8 and the opening area ratio of the flow rate control valve 7 (control duty-opening area ratio characteristic) is corrected on the basis of the above relationship. Characteristic variations of the control amount of the solenoid valve 8 and the opening area of the flow rate control valve 7 due to deterioration over time and the like can be absorbed, and the deviation of the duty neutral value can be eliminated, and as a result, fluctuations in the shift speed can be suppressed. ,
The occurrence of gear shift shock can be suppressed.

In the case where the torque converter 2 is not provided and a clutch is provided between the output side (secondary pulley 5) of the continuously variable transmission 3 and the drive shaft side (for example, differential),
When the clutch is released, the state of the line pressure or the pulley ratio is changed to a plurality of states, and the flow rate used for the second hydraulic pressure calculation means is based on the calculation result of the first hydraulic pressure calculation means in each state. A configuration related to the displacement of the control valve 7 (for example, the opening area ratio) may be calculated. In this case, the correction (learning) of the value associated with the displacement of the flow control valve 7 is performed under a plurality of conditions. Therefore, learning accuracy can be improved.

[0041]

As described above, according to the first aspect of the present invention, the control amount of the solenoid valve and the value related to the displacement of the shift control valve due to the change over time such as the variation and deterioration of the individual. As a result, it is possible to absorb the characteristic variation and to eliminate the deviation of the duty neutral value. As a result, it is possible to suppress the change of the shift speed and suppress the occurrence of the shift shock.

According to the second aspect of the present invention, the shift pressure control oil is obtained from the line pressure introducing port and the drain port opening area ratio and the line pressure of the shift control valve as values related to the displacement of the shift control valve. The hydraulic pressure of the room can be calculated. According to the invention of claim 3, there is an advantage that it is only necessary to detect that the transmission torque of the continuously variable transmission is substantially zero.

According to the fourth aspect of the present invention, it is easy to confirm that the transmission torque of the continuously variable transmission is approximately 0 from the released state of the clutch interposed between the continuously variable transmission and the driven portion. Can be detected. According to the invention of claim 5, the correction (learning) of the value related to the displacement of the shift control valve is performed under a plurality of conditions, so that the learning accuracy can be improved. .

According to the sixth aspect of the present invention, the fact that the transmission torque of the continuously variable transmission is approximately 0 means that the input / output rotational speed of the fluid coupling interposed between the drive source and the continuously variable transmission is Can be easily detected from the same state.

[Brief description of drawings]

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

FIG. 2 is a system diagram common to the embodiments of the invention according to claims 1 to 6;

FIG. 3 is a schematic view showing an assembled state of a primary pulley, a secondary pulley and a belt.

FIG. 4 is a flowchart illustrating calculation (estimation) of primary pressure.

FIG. 5 is a characteristic diagram of control duty and opening area ratio.

FIG. 6 is a schematic diagram of a flow control valve.

[Explanation of symbols]

 1 Engine 2 Torque Converter 3 Continuously Variable Transmission (CVT) 4 Primary Pulley 4a Speed Change Pressure Control Oil Chamber 5 Secondary Pulley 5a Contact Surface Pressure Control Oil Chamber 6 Belt 7 Flow Control Valve 8 Solenoid Valve 10 Control Unit

Claims (6)

[Claims] 1. A drive-side rotating member that receives a rotating force of a power source, a driven-side rotating member that is connected to a driven portion, and a power-transmitting member that is interposed between the rotating members and that transmits power between the two. The contact surface pressure between the one rotating member and the power transmitting member is controlled as a line pressure, and the contact surface pressure between the other rotating member and the power transmitting member is controlled according to the line ratio according to the gear ratio. The control is performed as a gearshift pressure adjusted in accordance with the above-mentioned method, so that the ratio of the radii from the center of rotation of each rotary member to the contact point with the power transmission member is changed steplessly to control the gear ratio steplessly. A shift pressure control oil chamber, a contact surface pressure control oil chamber, a shift control valve for controlling shift pressure to the shift pressure control oil chamber, and a hydraulic pressure control for controlling the hydraulic pressure of the shift control valve. A valve and control means for controlling the hydraulic pressure control valve. In the continuously variable transmission, a storage unit that stores a relationship between the control amount of the operating hydraulic control valve and a value related to the displacement of the shift control valve; a transmission torque detection unit that detects a transmission torque of the continuously variable transmission; Radius ratio detection means for detecting the actual ratio of the radii, line pressure detection means for detecting the line pressure, and based on detection signals output from the transmission torque detection means, radius ratio detection means and line pressure detection means And a second hydraulic pressure calculation means for calculating the hydraulic pressure of the shift pressure control oil chamber, and a second hydraulic pressure calculation means for calculating the hydraulic pressure of the shift pressure control oil chamber from a parameter including a value related to the displacement of the shift control valve. Hydraulic displacement calculation means, displacement related value calculation means for calculating a value related to the displacement of the shift control valve used in the second hydraulic pressure calculation means based on the calculation result of the first hydraulic pressure calculation means, and displacement related values By calculation means Based on the relation between the calculated value related to the displacement of the shift control valve and the control amount of the working hydraulic control valve at this time, the control amount of the working hydraulic control valve and the displacement of the shift control valve in the storage means are related. A control device for a continuously variable transmission, comprising: a correction unit that corrects a relationship with a value. 2. The second hydraulic pressure calculating means includes a line pressure introducing port and a drain port opening area ratio of the shift control valve as values related to displacement of the shift control valve, and a line pressure as a parameter. 2. The control device for a continuously variable transmission according to claim 1, wherein the hydraulic pressure in the shift pressure control oil chamber is calculated from the above. 3. The control device for a continuously variable transmission according to claim 1, wherein the transmission torque detecting means comprises means for detecting that the transmission torque of the continuously variable transmission is substantially zero. . 4. A means for detecting that the transmission torque of the continuously variable transmission is substantially 0 is a state in which a clutch interposed between the continuously variable transmission and a driven portion is released, The control device for a continuously variable transmission according to claim 1 or 2, wherein the transmission torque is detected as being substantially zero. 5. The displacement-related value calculation means changes the line pressure or radius ratio state to a plurality of states when the clutch is in the released state, and the calculation result of the first hydraulic pressure calculation means in each state. The control device for a continuously variable transmission according to claim 4, wherein a value related to the displacement of the shift control valve used in the second hydraulic pressure calculation means is calculated based on the above. 6. The means for detecting that the transmission torque of the continuously variable transmission is substantially zero has an equal input / output rotational speed of a fluid coupling interposed between the drive source and the continuously variable transmission. The control device for a continuously variable transmission according to claim 1 or 2, wherein the state is detected as the transmission torque being substantially zero.