JP2001304387A - Controller for vehicular continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller for a vehicular continuously variable transmission having no slipping of a power transmission member, even if the vehicle detecting atmospheric pressure, when a vehicle traveling state is with in a prescribed traveling area. SOLUTION: An intake air capacity correcting means 84 limits an intake air capacity Q to a value corresponding to a level ground atmospheric pressure, in an area where an atmospheric pressure PA detected by an atmospheric pressure detecting means 90 is lower than the level ground atmospheric pressure expected in level ground traveling. It makes correction according to the atmospheric pressure PA detected by the atmospheric pressure detecting means 90, in an area where the atmospheric pressure PA detected by the atmospheric pressure detecting means 90 is higher than the level ground atmospheric pressure expected in level ground traveling. When the atmospheric pressure PA, detected by the atmospheric pressure detecting means 90, is lower than the level ground atmospheric pressure, the intake air capacity Q is limited to the value corresponding to this level ground atmospheric pressure, namely one atmospheric pressure. Thus, in traveling from highland to level ground, the calculated value of an engine output torque TE does will become lower than the actual engine output torque, thereby slipping of a transmission belt 48 is prevented from occurring.

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 for a vehicle, and more particularly to a control device for a continuously variable transmission for a vehicle, in which a calculated value of an engine output torque becomes smaller than an actual value due to a detection delay by an atmospheric pressure detecting device. The present invention relates to a technique for preventing slippage of a power transmission member by preventing slippage.

[0002]

2. Description of the Related Art A continuously variable transmission that transmits power to a power transmission path between an engine and drive wheels via friction of a power transmission member interposed between an input side rotating body and an output side rotating body. A vehicle provided with is known. The continuously variable transmission includes, for example, an input-side variable pulley and an output-side variable pulley whose effective diameters are variable, a transmission belt wound around the input-side variable pulley and the output-side variable pulley, And an input-side actuator and an output-side actuator for changing the V-groove width of the output-side variable pulley. Power is transmitted through a frictional force between the transmission belt and the variable pulley, and the vehicle is driven in a driving state. The gear ratio and belt clamping pressure are controlled accordingly.

[0003] The belt clamping force corresponds to the pressing force of the transmission belt against the inner wall surface of the V-groove of the variable pulley, that is, the frictional force between the transmission belt and the variable pulley. While the durability (life) of the belt-type continuously variable transmission decreases due to the wear of the sliding portion, if the belt clamping pressure is higher than necessary, the power loss increases and the fuel efficiency and the like decrease. For this reason, control is performed in accordance with the input torque from the engine, that is, the transmission torque, the speed ratio of the belt-type continuously variable transmission, and the like, so that the transmission belt slips as little as possible within a range in which the transmission belt does not slip. Further, since the output torque of the engine corresponding to the input torque from the engine changes in accordance with changes in the atmospheric pressure and the intake air temperature of the engine, the accuracy of the calculated value is increased when calculating the engine output torque. For this purpose, correction is made using an atmospheric pressure correction coefficient or a suction temperature correction coefficient. For example, the control device for a continuously variable transmission described in Japanese Patent Application Laid-Open No. 2-38755 predicts a decrease in engine output torque when the atmospheric pressure is lower than a predetermined value, and predicts the decrease in engine output torque in order to improve responsiveness. The target value of the speed ratio control is corrected in accordance with the decrease of the engine output torque.

[0004]

By the way, in order to detect the above-mentioned atmospheric pressure, a vehicle provided with an atmospheric pressure detecting means for detecting by taking in the atmospheric pressure when the vehicle running state is within a predetermined area. is there. For example, a negative pressure sensor that detects a negative pressure in the intake pipe is used to detect the intake air amount together with the engine rotation speed. This is the case where the pressure detected by the negative pressure sensor is taken in as atmospheric pressure and detected sequentially when the vehicle is within the predetermined traveling region. However, in a vehicle equipped with an atmospheric pressure detecting means for taking in and detecting the pressure of the atmosphere when the vehicle running state is within a predetermined running area as described above, the atmospheric pressure may not be detected depending on the vehicle running state. There are periods that cannot be done. For example, during traveling from a high altitude to a low altitude, the throttle valve opening rarely exceeds a predetermined value, and it is difficult to newly detect and update the atmospheric pressure. Therefore, the contact pressure control of the power transmission member of the continuously variable transmission is performed. May be lower than the actual atmospheric pressure. In such a case, the calculated value of the engine output torque is smaller than the actual engine output torque, so that the pressing force of the power transmission member is too small to cause slippage, and the durability (lifetime) ) Could be reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle in which the atmospheric pressure is detected when the vehicle travels within a predetermined travel area. Another object of the present invention is to provide a control device for a continuously variable transmission for a vehicle in which a power transmission member does not slip.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide a power transmission path from an engine to a driving wheel, wherein a power transmission path is provided between an input side rotating body and an output side rotating body. In the continuously variable transmission in which the gear ratio is changed steplessly by changing the contact position of the power transmission member interposed between the input side rotating body and the output side rotating body, the vehicle traveling state is predetermined. Atmospheric pressure detecting means for detecting the pressure of the atmosphere when it is within the traveling region, and intake air amount correcting means for correcting the amount of intake air taken into the engine based on the atmospheric pressure detected by the atmospheric pressure detecting means. An engine output torque calculating means for calculating an engine output torque based on the intake air amount corrected by the intake air amount correcting means; and an engine output torque calculation A contact pressure control unit that adjusts a contact pressure of the power transmission member based on the engine output torque calculated by the step, wherein the intake air amount correction unit includes: In an area where the atmospheric pressure detected by the atmospheric pressure detecting means is lower than the level pressure assumed for flatland traveling, the value is limited to a value corresponding to the level pressure. In an area higher than the atmospheric pressure assumed during traveling, the correction is performed in accordance with the atmospheric pressure detected by the atmospheric pressure detecting means.

[0007]

According to this configuration, the intake air amount correcting means reduces the intake air amount in the region where the atmospheric pressure detected by the atmospheric pressure detecting means is lower than the level pressure assumed for flatland traveling. Although it is limited to a value corresponding to the atmospheric pressure, in an area in which the atmospheric pressure detected by the atmospheric pressure detecting means is higher than a flat ground pressure assumed in flatland traveling, according to the atmospheric pressure detected by the atmospheric pressure detecting means. When the atmospheric pressure detected by the atmospheric pressure detecting means is lower than the level pressure, the intake air amount is limited to a value corresponding to the level pressure. Therefore, the amount of intake air is not corrected to a value corresponding to a pressure lower than the pressure of the flat ground when traveling from high altitude to a flat ground, so that the calculated value of the engine output torque is smaller than the actual engine output torque. Because
Slippage due to an excessively low pressing force of the power transmission member is suitably prevented. In addition, the durability (life) of the power transmission member is prevented from being reduced due to wear.

[0008]

In another embodiment of the present invention, preferably, the atmospheric pressure correction coefficient does not change in a region where the atmospheric pressure is lower than the flat-land pressure, but the atmospheric pressure correction coefficient changes in a region where the atmospheric pressure is high. An atmospheric pressure correction coefficient calculating means for calculating an atmospheric pressure correction coefficient based on the atmospheric pressure detected by the atmospheric pressure detecting means, wherein the intake air amount correcting means comprises an atmospheric pressure correction coefficient calculating means for calculating the atmospheric pressure correction coefficient; The intake air amount is corrected based on the atmospheric pressure correction coefficient. With this configuration, during traveling from high altitude, which is an area in which the atmospheric pressure detected by the atmospheric pressure detecting means is lower than the flat-land pressure to a flat ground, the atmospheric-pressure correction coefficient is fixed to a value corresponding to the flat-land pressure. However, in an area where the atmospheric pressure detected by the atmospheric pressure detecting means is higher than the flat-land pressure, the atmospheric pressure correction coefficient is changed according to the atmospheric pressure detected by the atmospheric pressure detecting means. In the region where the atmospheric pressure is lower than the pressure of the flat ground, the slip of the power transmission member is prevented in the contact pressure control of the power transmission member of the continuously variable transmission, while the atmospheric pressure rises due to the fluctuation of the atmospheric pressure during traveling on flat ground. In this case, the calculated value of the engine output torque is changed according to the atmospheric pressure, so that the pressing force of the power transmission member of the continuously variable transmission becomes a necessary and sufficient value,
Durability is increased.

[0009]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a skeleton view of a power transmission device 10 including a vehicle belt-type continuously variable transmission 18 to which a control device according to one embodiment of the present invention is applied. The power transmission device 10 is suitably used, for example, in a laterally mounted FF (front engine / front drive) driven vehicle, and includes an engine 12 as an internal combustion engine used as a power source for traveling. The output of the engine 12 is supplied from a torque converter 14 to a forward / reverse switching device 16 and a belt-type continuously variable transmission (C).
VT) 18, and transmitted to the differential gear device 22 via the reduction gear 20, and distributed to the left and right drive wheels 24 </ b> L and 24 </ b> R. The belt-type continuously variable transmission 18 is provided on a power transmission path from the engine 12 to the left and right drive wheels 24L and 24R.

The torque converter 14 includes a pump impeller 14p connected to the crankshaft of the engine 12, a turbine impeller 14t connected to the forward / reverse switching device 16 via a turbine shaft 34, and a one-way clutch. A fixed impeller 14s rotatably supported by a non-rotating member is provided to transmit power via a fluid. Also, the pump impeller 14p and the turbine impeller 14p
During the time t, a lock-up clutch 2 for connecting them together and rotating them together
6 are provided.

The forward / reverse switching device 16 is composed of a double pinion type planetary gear device. The turbine shaft 34 of the torque converter 14 is connected to the sun gear 16s, and the input shaft 36 of the continuously variable transmission 18 is connected to the carrier 16c. It is connected to. When the clutch 38 disposed between the carrier 16c and the sun gear 16s is engaged, the forward / reverse switching device 16 is rotated integrally, and the turbine shaft 34 is directly connected to the input shaft 36, and the drive in the forward direction is performed. Power is drive wheel 24
R, 24L. When the brake 40 disposed between the ring gear 16r and the housing is engaged and the clutch 38 is released, the input shaft 36 is rotated in the reverse direction with respect to the turbine shaft 34, and the drive in the reverse direction is performed. The force is transmitted to the drive wheels 24R, 24L.

The continuously variable transmission 18 includes an input-side variable pulley 42 provided on the input shaft 36 having a variable effective diameter and an output-side variable pulley 46 provided on the output shaft 44 having a variable effective diameter.
And a transmission belt 48 wound around the V-grooves of the variable pulleys 42 and 46. The transmission belt 48 and the V of the variable pulleys 42 and 46 function as power transmission members.
Power transmission is performed via frictional force between the groove and the inner wall surface. The variable pulleys 42 and 46 include an input hydraulic cylinder 42c and an output hydraulic cylinder 46c for changing the width of each V-groove, that is, the diameter of the transmission belt 48.
The hydraulic pressure of the second hydraulic cylinder 42c is changed by the shift control valve 50 (FIG. 3).
), The two variable pulleys 4
The width of the V-grooves 2 and 46 changes to change the hanging diameter (effective diameter) of the transmission belt 48, and the speed ratio γ (= input side rotation speed N
_IN / output side rotation speed N _OUT ) is continuously changed.

The hydraulic pressure P _B in the hydraulic cylinder 46c of the output side variable pulley 46 corresponds to the squeezing pressure of the variable pulley 46 against the transmission belt 48 and the tension of the transmission belt 48, respectively. Since it is closely related to the tension, that is, the pressing force of the transmission belt 48 against the inner wall surfaces of the V-grooves of both the variable pulleys 42 and 46, it can also be called a belt tension control pressure, a belt clamping pressure control pressure, and a belt pressing force control pressure. In order to prevent the transmission belt 48 from slipping, the clamping pressure control valve 60 in the hydraulic control circuit 52 is
The pressure is regulated.

FIG. 2 is a diagram showing an example of the hydraulic control circuit 52. The hydraulic oil recirculated to the oil tank 56 is pumped by a hydraulic pump 54 driven by the engine 12 and is regulated by a line pressure regulating valve (not shown), and then supplied to the linear solenoid valve 58 and the clamping pressure control valve 60 as a base pressure. Supplied. When the exciting current from the electronic control unit 66 (see FIG. 3) is continuously controlled, the linear solenoid valve 58 is changed from the hydraulic pressure of the hydraulic oil supplied from the hydraulic pump 54 to a size corresponding to the exciting current. Control pressure P
_S is generated and supplied to the clamping pressure control valve 60. Clamping pressure control valve 60, the control pressure P _S to generate a hydraulic pressure P _B that is raised in accordance with increases and supplies the hydraulic cylinder 46c of the output side variable pulley 46. Its oil pressure P _B increases the frictional force between the accompanied in its raised and the belt clamping pressure or variable pulleys 42, 46 and the transmission belt 48.

[0016] The linear solenoid valve 58, while the oil chamber 58a of the control pressure P _S which is output therefrom at ON cutback valve 62 is supplied is provided, the cut-back valve 62 OFF times, to the oil chamber 58a the control pressure is interrupted supply of P _S being adapted oil chamber 58a is opened to the atmosphere, so that oN times characteristic of the control pressure P _S than when OFF cutback valve 62 is switched to the low-pressure side It has become. When the lock-up clutch 26 of the torque converter 14 is turned on (engaged), the cutback valve 62 is turned on by supplying a signal pressure P _ON from a solenoid valve (not shown).

The electronic control unit 66 shown in FIG.
Inhaled into the intake pipe 67 such as the intake manifold 2
Intake air temperature T_AAir temperature sensor 6 for detecting
8 the intake air temperature T_AIn the intake pipe 67
Negative pressure and atmospheric pressure P_AProvided on the intake pipe 67 to detect
Atmospheric pressure P from the detected negative pressure sensor 69_ASignal that represents
Accelerator pedal connected to throttle valve via cable
Of opening 70_ACCAccelerator operation amount sensor 7 for detecting
Accelerator opening θ from 1_ACC(Throttle valve opening θ_TH)
, The rotation speed N of the engine 12_ETo detect
The rotation speed N from the engine rotation speed sensor 72_EA sign of
No., vehicle speed V (specifically, rotation speed N of output shaft 44)_OUT)
Speed sensor (output side rotation speed sensor) 74
Signal representing the vehicle speed V, the input shaft rotation speed N of the input shaft 36.
_INInput shaft rotation from the input side rotational speed sensor 76 that detects
Rolling speed N_IN, The operating oil temperature of the power transmission device 10
T _OILOil temperature T from oil temperature sensor 78 that detects
_OIL, The hydraulic cylinder of the output side variable pulley 46
Internal pressure P of 46c_BThat is, the actual belt clamping pressure control pressure P
_BOil pressure P from the pressure sensor 80 which detects the_BRepresents
Signals are respectively supplied.

The electronic control unit 66 includes a CPU, an RO,
M, RAM, so-called I / O interface
RAM including a microcomputer
Using the temporary storage function of
By performing signal processing in accordance with the
The shift control and the clamping pressure control of the transmission 18 are performed.
Specifically, in the shift control, for example,
From the memorized relation (map), the actual output power required by the driver
Accelerator operation amount, that is, accelerator opening θ
_{AC C}(%) And vehicle speed V (output side rotation speed N_OUTTo
Response) to the target rotation speed N from the map._IN ^TCalculate
And the actual input-side rotation speed N_INIs the target rotation speed N_IN
^TAnd the hydraulic series of the input-side variable pulley 42
Feedback control of the oil pressure of the cylinder 42c. FIG. 4 above
Is the engine at its optimum power and fuel economy.
In order to operate along the appropriate curve
And that γ_{ma x}Is the maximum gear ratio, γ_minIs the minimum shift
Ratio.

In the belt squeezing pressure control, the electronic control unit 66 determines in advance a necessary and sufficient necessary oil pressure (a target oil pressure corresponding to an ideal belt squeezing pressure) as shown in FIG. From the basic equation showing the relationship (map), that is, the equation (1), based on the accelerator operation amount θ _ACC and the actual gear ratio γ corresponding to the actual input torque T _IN or the transmission torque of the belt type continuously variable transmission 18. The belt clamping pressure control pressure (target value) P _B ′ is calculated, and the clamping pressure control valve 60 in the hydraulic control circuit 52 is adjusted so as to obtain the belt clamping pressure control pressure (target value) P _B ′. Formula
In (1), μ is the friction coefficient of the transmission belt 48, R is the belt hanging diameter of the input-side variable pulley 42, A is the pulley area, α is a safety factor in consideration of a control error and the like, and is a value larger than 1.0. It is. The required hydraulic pressure, that is, the belt clamping pressure corresponds to the magnitude of the frictional force of the transmission belt 48. Note that instead of the accelerator opening θ _ACC , the engine 12
The engine load values such as the throttle valve opening θ _TH , the fuel injection amount, and the intake air amount can also be used.

(Equation 1) P _B ′ = (T _IN / μ · RA) × α (1)

Further, the electronic control unit 66 determines the engine speed based on the actual intake air amount Q and the engine rotational speed N _E from a well-known relationship [T _E = f (Q, N _E )] stored in advance. calculating the output torque T _E ie estimated torque of 12 to calculate the input torque T _iN is multiplied by the torque amplification factor of the torque converter 14. For example, when the lock-up clutch 26 is engaged, the torque amplification factor is 1, so the output torque is reduced by the belt-type continuously variable transmission 18.
_Is determined as the input torque T _IN . Also, when calculating the estimated torque or input torque T _IN of such an engine 12, corrects the intake air quantity Q based on the temperature T _A and the atmospheric pressure P _A of the actual intake air to increase the calculation accuracy. For example, to determine the intake air temperature correction coefficient k _TA and the atmospheric pressure correction coefficient k _PA, their intake air temperature correction coefficient k _TA and the intake air amount Q after the correction by multiplying the atmospheric pressure correction coefficient k _PA '(= Q × k _TA × k _PA ) is calculated. The intake air temperature correction coefficient k _TA and the atmospheric pressure correction coefficient k _PA are for correcting thermal expansion or volume change due to atmospheric pressure in order to make the intake air amount correspond to the mass, and the intake air temperature correction coefficient k _{PA TA} is, for example, normal temperature (2
5 ° C.), the value becomes smaller as the temperature becomes higher, and becomes larger as the temperature becomes lower. Further, for example, the atmospheric pressure correction coefficient k _PA is, for example,
Atmospheric pressure, that is, 1 atm (= 1.01325 × 10 ⁵ P)
In the case of a), the value is 1 and the value is limited so that the value does not become smaller than 1 even when the pressure becomes lower or higher than the value. The value becomes 1 as the pressure becomes higher or lower.

FIG. 6 is a functional block diagram for explaining the main part of the control function of the electronic control unit 66, that is, the belt clamping force control. In FIG. 6, the intake air amount calculating means 82
Is the amount of intake air Q (cm ³ / mi
n) is calculated, for example, from a well-known calculation formula (2) in a four-stroke engine, by a pressure (negative pressure) P _IN detected by a negative pressure sensor 69 provided in the intake pipe 67.
And sequentially calculated based on the engine rotational speed N _E and the number of cylinders N _C and the cylinder volume V _C of the engine 12.

(Equation 2) Q = P _IN × V _C × N _C × N _E / 2 (2)

The intake air amount correcting means 84 is provided to
Quantity Q, intake air temperature correction coefficient k_TA, And atmospheric pressure correction
Number k_PAIntake air amount Q ′ (= Q × k)_TA
× k _PA) Is calculated sequentially. Engine output torque calculation means
86 is a well-known relation [T_E= F
(Q ', N_E)] And the corrected intake air amount Q ′ and
And engine speed N_EOutput of engine 12 based on
Torque T_EThat is, the estimated torque is calculated.

The belt clamping pressure control means 88, together determine the input torque T _IN based on the torque amplification rate of the engine output torque calculating unit 86 the engine output torque T _E and the torque converter 14 calculated by, for example, predetermined From the basic equation showing the relationship (map), that is, equation (1), based on the actual input torque T _IN and the actual speed ratio γ of the belt-type continuously variable transmission 18, the belt clamping pressure control pressure (target value) P _B 'Is calculated, and the belt clamping pressure control pressure (target value) P _B ' and the actual belt clamping pressure control pressure P _B
Are successively adjusted by the squeezing pressure control valve 60 in the hydraulic control circuit 52 in such a manner as to match. The engine output torque _TE is determined based on the corrected intake air amount Q ′, and the corrected intake air amount Q ′ is corrected based on the atmospheric pressure correction coefficient k _PA. The control means 88
It means that by changing the clamping pressure of the transmission belt 48 (contact pressure) according to the pressure P _A in the atmosphere.

The atmospheric pressure detecting means 90 detects the atmospheric pressure by using the negative pressure sensor 69 when the traveling state of the vehicle is within a predetermined traveling region such that the inside of the intake pipe 67 becomes the atmospheric pressure. For example to determine the atmospheric update the throttle valve opening theta _TH '(atmospheric updated accelerator opening theta _ACC') based on the actual engine rotational speed N _E from the relationship shown in FIG 7,
In a vehicle running state where the actual throttle valve opening θ _TH (accelerator opening θ _ACC ) exceeds the atmospheric pressure updating throttle valve opening θ _TH '(atmospheric pressure updating accelerator opening θ _ACC '),
The pressure P _IN is detected by the negative pressure sensor 69 atmospheric pressure P _A
To be stored. For example, if the engine speed _NE is 10
If the throttle valve opening θ _TH is in the running range of 20% or more at 00 rpm, for example, the engine speed _NE
Is 2000 rpm, the throttle valve opening θ _TH is 4
It becomes 0% or more travel area is to employ to and update the pressure detected by the negative pressure sensor 69 as the atmospheric pressure P _A. According to the atmospheric pressure detecting means 90, for example, the throttle valve opening θ _TH
If there is a lot of coasting near the idle, the atmospheric pressure P _A
Detection and update are delayed, so that a value lower than the actual atmospheric pressure tends to be output.

The atmospheric pressure correction coefficient calculating means 92 based on the atmospheric pressure P _A to a predetermined stored relationship detected by the atmospheric pressure detecting means 90, the intake air amount correcting means 84
Sequentially calculates the atmospheric pressure correction coefficient k _PA used in. The relationship used in this calculation is, for example, as shown in FIG.
The atmospheric pressure correction coefficient k _PA becomes, for example, “1” when the atmospheric pressure is the atmospheric pressure that is assumed in flatland traveling, that is, when the atmospheric pressure is 1 atm (= 1.1325 × 10 ⁵ Pa). In a region where the air pressure becomes lower or higher, the value corresponding to the flat land pressure is limited (maintained) to "1", and as the pressure becomes higher or lower, the value corresponding to the air pressure becomes higher than the value "1". It is what becomes. Thus, in the lower highlands running than the atmospheric pressure P _A is 1 atm, the value of the atmospheric pressure correction coefficient k _PA is set to "1", the engine output torque calculating unit 86
Is a value that the engine output torque T _E corresponding to 1 atm calculated in, so the size of the belt squeezing force corresponding to that one atmosphere is used.

FIGS. 9 and 10 show the electronic control unit 6.
FIG. 9 is a flowchart for explaining a main part of the control operation of FIG. 6, wherein FIG. 9 shows an atmospheric pressure detecting routine corresponding to the atmospheric pressure detecting means 90, and FIG. 10 shows a belt clamping pressure control routine.

Referring to FIG. 9, in step SA1, the actual pressure P _IN in the intake pipe 67 supplied from the negative pressure sensor 69 is read, and in SA2, the actual engine rotational speed N _E. And the throttle valve opening θ _TH are read. Then, SA
In 3, the atmospheric pressure update the throttle valve opening is determined reference value whether it is possible to the atmospheric pressure detected by the negative pressure sensor 69 based on the actual engine rotational speed N _E, for example, from pre-stored relationship shown in FIG. 7 θ _TH 'is determined. And S
In A4, it is determined whether or not the actual throttle valve opening θ _TH exceeds the above-mentioned atmospheric pressure updating throttle valve opening θ _TH '. If the determination at SA4 is affirmative, SA5
, The actual pressure P _IN in the intake pipe 67 becomes the atmospheric pressure P _A
After that, SA1 and subsequent steps are repeatedly executed. However, while the determination in SA4 is denied due to running at a low throttle opening such as coasting, SA5
Since but not executed, the atmospheric pressure P _A is not updated.

[0030] In Figure 10, after being well-known signal input processing performed for inputting the signal in SB1, the atmospheric pressure P _A obtained by the atmospheric pressure detection routine is read in SB2. In SB3 corresponding to the atmospheric pressure correction coefficient calculating means 92, for example, as shown in FIG.
The value of the atmospheric pressure correction coefficient k _PA based on the atmospheric pressure P _A is calculated from the pre-stored relationship shown in FIG. The value of the atmospheric pressure correction coefficient k _PA is than flat pressure envisioned (1 atm) in the flat road surface when the atmospheric pressure P _A high is a value larger than "1", the atmospheric pressure P _A When the pressure is lower than the flat ground pressure (1 atm), the value is restricted to a value lower than “1” and is kept at “1”. Relationship shown in FIG. 8 is preferably stored in a data map form showing the relationship between the atmospheric pressure P _A and the atmospheric pressure correction coefficient k _PA numerically logarithm.

Next, at SB4 corresponding to the value of the intake air amount correction means 84, the intake air amount Q is corrected based on the atmospheric pressure correction coefficient k _PA calculated at SB3, and the corrected intake air amount Q '(= Q × k _TA × k _PA ) is obtained. Subsequently, the engine output torque calculating means 86
In SB5 corresponding to the engine 1 based on the previously stored known relationship _{[T E = f (Q ',} N E) ] intake air amount Q after the correction from the' and the engine speed N _E
The second output torque _TE is calculated. Then, in SB6 corresponding to the belt clamping pressure control unit 88, the actual input torque T _IN based on the engine output torque T _E obtained from the intake air quantity Q 'and the engine rotational speed N _E of the corrected is determined And, for example, from a basic formula showing a predetermined relationship (map), that is, formula (1),
The belt clamping pressure control pressure (target value) P _B ′ is calculated based on the actual input torque T _{IN of the} belt type continuously variable transmission 18 and the actual gear ratio γ, and the belt clamping pressure control pressure (target value) P The clamping pressure control valve 60 in the hydraulic control circuit 52 is operated to regulate the pressure so that _B ′ and the actual belt clamping pressure control pressure P _B match.

As described above, according to the present embodiment, the intake air amount correcting means 84 (SB4) uses the atmospheric pressure detecting means 90.
Atmospheric pressure P _A detected by (SA1 to SA5) is in the region lower than the level ground pressure contemplated by flat road surface to limit to a value corresponding to the intake air quantity Q to the flat pressure, but its atmospheric pressure detecting means Atmospheric pressure P detected by 90
Since the region higher than the level ground pressure _{of A} is assumed on level ground traveling is corrected according to the atmospheric pressure P _A detected by the atmospheric pressure detecting means 90, the air detected by the atmospheric pressure detection means 90 when the pressure P _a of falls below level ground pressure, intake air amount Q is limited to a value corresponding to the flat pressure i.e. 1 atm. Therefore, since the intake air quantity Q during travel leading to flat is prevented from being corrected to a value corresponding to a pressure lower than the plain pressure from high altitude, than the calculated value of the actual engine output torque of the engine output torque T _E Is not reduced to a small value, so that the pressing force of the power transmission belt (power transmission member) 48 becomes too small and the occurrence of slippage is suitably prevented. Also,
It is also possible to prevent the durability (life) from being reduced due to the wear of the transmission belt 48.

Further, according to this embodiment, in the region lower than the atmospheric pressure P _A is flat pressure but the atmospheric pressure correction coefficient k _PA unchanged, in a high region is prestored a change in atmospheric pressure correction coefficient k _PA From the relationship (FIG. 8), the atmospheric pressure correction coefficient k based on the atmospheric pressure P _A detected by the atmospheric pressure detecting means 90.
_An atmospheric pressure correction coefficient calculating means 92 (SB3) for calculating _PA is provided, and the intake air amount correcting means 84 (SB4) is based on the atmospheric pressure correction coefficient k _PA calculated by the atmospheric pressure correction coefficient calculating means 92. This is for correcting the intake air amount Q. Therefore, when the vehicle travels from a high altitude, which is an area where the atmospheric pressure P _A detected by the atmospheric pressure detecting means 90 is lower than the pressure on the flat ground to a flat ground, the atmospheric pressure correction coefficient k _PA
Although but is fixed to the value "1" corresponding to the level ground pressure, the atmospheric pressure P in the region higher than the atmospheric pressure P _A is flat pressure detected by the atmospheric pressure detecting means 90 detected by the atmospheric pressure detecting means 90 _{Since the} atmospheric pressure correction coefficient k _PA is increased in accordance with the increase of _{A, in} the region where the atmospheric pressure P _A detected by the atmospheric pressure detecting means 90 is lower than the flat-land pressure, the transmission belt 48 of the continuously variable transmission 18 is controlled. the one that slippage of the transmission belt 48 in the clamping pressure control (control contact pressure) is prevented, in flat road surface, when the atmospheric pressure rises by pressure variations, the calculated value of the engine output torque T _E is the atmospheric pressure P _By being changed according to _A , the continuously variable transmission 1
8, the pressing force of the transmission belt 48 becomes a necessary and sufficient value, and the durability is enhanced.

While one embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments.

For example, in the above embodiment, a pair of variable pulleys 42, 4 around which a transmission belt 48 is wound
Although the so-called belt-type continuously variable transmission 18 having the gear 6 is used, the present invention can be applied to other continuously variable transmissions such as a toroidal-type continuously variable transmission. In short, the gear ratio is steplessly changed by changing the contact position of the power transmission member interposed between the input side rotating body and the output side rotating body with respect to the input side rotating body and the output side rotating body. What is necessary is just a continuously variable transmission.

In the belt type continuously variable transmission 18 of the above-described embodiment, the clamping force of the transmission belt 48 is controlled by the hydraulic cylinder 46c, but may be controlled by another actuator such as an electric motor. .

Further, the atmospheric pressure correction coefficient calculating means 92 in the illustrated example, according to the relationship shown in FIG. 8, the atmospheric pressure P _A is flat pressure detected by the atmospheric pressure detecting means 90 (1 atm)
At lower space but its atmospheric pressure P _A becomes a value corresponding to the flat pressure had calculated atmospheric pressure correction coefficient k _PA is higher than flat pressure (1 atm) region increases with the atmospheric pressure P _A, the large calculating the atmospheric pressure correction coefficient k _PA based a predetermined stored linear function indicating a relationship in which the pressure correction coefficient k _PA increases with the atmospheric pressure P _a the atmospheric pressure P _a, than the atmospheric pressure P _a is flat pressure If it is low, the atmospheric pressure correction coefficient k
_{The PA} may be limited to a value corresponding to the barometric pressure.

Although the embodiment of the present invention has been described in detail with reference to the drawings, this is merely an embodiment,
The present invention can be implemented in various modified and improved aspects based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of a vehicle drive device to which a control device according to an embodiment of the present invention is applied.

FIG. 2 is a hydraulic control circuit diagram for controlling a continuously variable transmission in the vehicle drive device of FIG.

FIG. 3 is a diagram simply illustrating an electrical configuration of a control device according to the embodiment of FIG. 1;

FIG. 4 is a diagram showing a relationship stored in advance used for determining a target rotation speed in a gear ratio control executed by the electronic control device of FIG. 3;

5 is a diagram showing a required oil pressure for setting a clamping pressure of a transmission belt to a necessary and sufficient value in a belt clamping pressure control executed by the electronic control device of FIG. 3;

6 is a functional block diagram illustrating a main part of a control function of the electronic control device of FIG. 3;

FIG. 7 is a diagram showing a relationship used for obtaining an atmospheric pressure update throttle valve opening degree in the atmospheric pressure detecting means of FIG. 6;

FIG. 8 is a diagram showing a relationship used for obtaining an atmospheric pressure correction coefficient in an atmospheric pressure correction coefficient calculating means of FIG. 6;

9 is a flowchart illustrating a main part of a control operation of the electronic control device of FIG. 3, and is a diagram illustrating an atmospheric pressure detection routine.

FIG. 10 is a flowchart illustrating a main part of a control operation of the electronic control device of FIG. 3, and is a diagram illustrating a belt clamping pressure control routine.

[Explanation of symbols]

 12: Engine (motor) 18: Belt-type continuously variable transmission (continuously variable transmission) 24L, 24R: Drive wheels 48: Transmission belt (power transmission member) 69: Negative pressure sensor 82: Intake air amount calculation means 84: Intake Air amount correction means 86: Engine output torque calculation means 88: Belt clamping pressure control means (contact pressure control means) 90: Atmospheric pressure detection means 92: Atmospheric pressure correction coefficient calculation means

Claims (3)

[Claims] 1. A power transmission member provided in a power transmission path from an engine to a driving wheel and interposed between an input-side rotator and an output-side rotator, for contacting the input-side rotator and the output-side rotator. In a continuously variable transmission in which the gear ratio is steplessly changed by changing the position, an atmospheric pressure detecting means for detecting atmospheric pressure when the vehicle running state is within a predetermined running area; and Intake air amount correction means for correcting the amount of intake air to be taken in based on the atmospheric pressure detected by the atmospheric pressure detection means; and an engine for the engine based on the intake air amount corrected by the intake air amount correction means. An engine output torque calculating means for calculating an output torque, and adjusting a contact pressure of the power transmission member based on the engine output torque calculated by the engine output torque calculating means. A contact pressure control means for controlling the continuously variable transmission for a vehicle, the control means comprising: In a lower region, the pressure is limited to a value corresponding to the level pressure, but in a region where the atmospheric pressure detected by the atmospheric pressure detecting means is higher than a level pressure assumed in flatland traveling, the atmospheric pressure detecting means A control device for a continuously variable transmission for a vehicle, wherein a correction is made in accordance with a detected atmospheric pressure. 2. The atmospheric pressure correction coefficient does not change in a region where the atmospheric pressure is lower than the flat-land pressure, but the atmospheric pressure correction coefficient changes in a high region. An atmospheric pressure correction coefficient calculating means for calculating an atmospheric pressure correction coefficient based on the atmospheric pressure; wherein the intake air amount correcting means calculates the atmospheric pressure correction coefficient based on the atmospheric pressure correction coefficient calculated by the atmospheric pressure correction coefficient calculating means. 2. The control device for a continuously variable transmission for a vehicle according to claim 1, wherein the controller corrects the amount. 3. The continuously variable transmission transmits power by being wound around a pair of input-side variable pulleys and output-side variable pulleys whose effective diameters are variable, and wound around the input-side variable pulleys and the output-side variable pulleys. The belt-type continuously variable transmission according to claim 1 or 2, comprising a transmission belt, and an input hydraulic cylinder and an output hydraulic cylinder that change the V-groove width of the input variable pulley and the output variable pulley. Control device for continuously variable transmission for vehicles.