JPH109379A - Transmission controller for continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a transmission shock at the time of kick-down acceleration and so on, by changing a gear shifting speed according to relationship of magnitude between the present actual driving torque and a target driving torque according to a target transmission gear ratio. SOLUTION: When transmission control means 102 changes a target transmission gear ratio, a target driving torque on the basis of this target transmission gear ratio, and the actual driving torque are respectively calculated, and gear shifting speed changing means 105 varies and controls a gear shifting speed according to relationship of magnitude between the actual and target values of each driving torque. For example, in the case that a driver steps on an accelerator pedal so as to kick-down accelerate, the gear shifting speed is changed to a high level if difference between the target driving torque and the actual driving torque is large and changed to a low level if this difference is small, thereby rapid acceleration can be performed while suppressing a transmission shock due to the fluctuation of an inertia torque. Hereby, the operativity of a vehicle equipped with a continuously variable transmission can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a shift control device for a vehicle having a continuously variable transmission.

[0002]

2. Description of the Related Art In a continuously variable transmission used in a vehicle, a target input shaft speed (a target gear ratio) is determined based on a vehicle speed Vsp and a throttle opening TVO (or an accelerator opening). As a transmission control device for a continuously variable transmission,
Japanese Patent Application Laid-Open No. 1-275944 is known.

[0003] In a continuously variable transmission (CVT), when the target rotational speed greatly changes during kickdown acceleration or the like, a shift shock may occur due to a change in the inertia torque of the drive system. In order to alleviate this, the actual shift speed of the continuously variable transmission is corrected.

[0004]

However, in the above-described conventional shift control device, the above-described shift shock is suppressed by suppressing the actual shift speed and the downshift amount during the downshift. Since the inertia of the system changes depending on the type of vehicle, the above-mentioned conventional shift control device needs to perform fine tuning for each type of vehicle, which requires a large amount of labor and man-hours, and sometimes increases the manufacturing cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to suppress a shift shock during a kick-down acceleration without requiring fine tuning for each vehicle type.

[0006]

According to a first aspect of the present invention, as shown in FIG. 25, a speed change ratio changing means 101 for changing a speed change ratio RTO of a continuously variable transmission 100, and a target speed change according to a driving state of a vehicle. A gear ratio control device for a continuously variable transmission, comprising: a gear ratio control unit that calculates a ratio RTO0 and controls the gear ratio change unit 101 in accordance with the target gear ratio RTO0. Target drive torque calculation means 103 for calculating drive torque RTRQ
A real drive torque calculating means 104 for calculating the current actual drive torque TRQO; and a shift speed changing means 105 for changing the shift speed according to the magnitude relationship between the actual drive torque TRQO and the target drive torque RTRQ.

[0007] In the second invention, a gear ratio changing means 10 for changing the gear ratio of the continuously variable transmission 100 in FIG.
1 and a target gear ratio calculated in accordance with the driving state of the vehicle, and the gear ratio changing means 1 is calculated in accordance with the target gear ratio.
01 in a continuously variable transmission shift control device provided with a shift control means 102 for controlling the target drive ratio 01, a target drive torque calculation means 103 for calculating a target drive torque according to a target gear ratio,
Actual driving torque calculating means 1 for calculating the current actual driving torque
And a shift speed changing means 105 for changing the shift speed when the actual drive torque exceeds a predetermined ratio of the target drive torque.

[0008] In a third aspect of the present invention, in the second aspect of the invention, as shown in FIG.
5 increases the first-order lag time constant when the actual driving torque exceeds a predetermined ratio of the target driving torque.

According to a fourth aspect of the present invention, in the second aspect of the invention, as shown in FIG.
5 includes a threshold changing means 106 for changing the predetermined ratio in accordance with the degree of opening of the accelerator pedal.

[0010]

According to the first invention, when the speed change control means changes the target speed ratio, the target drive torque (output shaft torque of the continuously variable transmission) based on the target speed ratio and the actual actual drive torque are changed. The calculated shift speed changing means can variably control the shift speed according to the magnitude relationship between the actual value of the drive torque and the target value.For example, when the driver depresses the accelerator pedal to perform kickdown acceleration,
When the difference (or ratio) between the target drive torque and the actual drive torque is large, the speed change speed is increased, and when the difference is small, the speed change speed is changed to a small value, whereby rapid acceleration can be performed according to the driver's intention. .

According to a second aspect of the present invention, when the shift control means changes the target gear ratio, a target drive torque (output shaft torque of the continuously variable transmission) based on the target gear ratio and an actual actual drive torque are respectively set. When the actual drive torque exceeds a predetermined ratio of the target drive torque, the shift speed changing means switches the shift speed.For example, when the driver depresses the accelerator pedal to perform kickdown acceleration, the actual drive torque is changed. When the actual drive torque exceeds the predetermined ratio of the target drive torque, the shift speed is set to a small value when the target drive torque is equal to or less than the predetermined ratio. Even when the shift is performed, a quick and smooth shift can be performed while preventing a shift shock due to a change in inertia torque.

According to a third aspect of the present invention, the shift speed changing means increases the first-order time constant when the actual drive torque exceeds a predetermined ratio of the target drive torque. By setting the actual drive torque to be small when the actual drive torque is equal to or less than the predetermined ratio of the target drive torque, while setting the actual drive torque to be large when the actual drive torque exceeds the predetermined ratio of the target drive torque,
Even when the target gear ratio changes significantly, such as during kick-down acceleration, a quick downshift is first performed with a small time constant, and then the downshift is continued gently with a large time constant, thereby reducing the inertia torque. Speed can be changed quickly and smoothly while preventing a shift shock due to fluctuations in the speed.

According to a fourth aspect of the present invention, the speed change speed changing means includes a threshold value changing means for changing the predetermined ratio in accordance with an opening degree of an accelerator pedal. Can be variably controlled in accordance with

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, the continuously variable transmission 10 (CVT in the figure) is set to a predetermined speed ratio according to the driving state of the vehicle by a speed ratio changing means 9 controlled by a speed change controller 2. The continuously variable transmission 10 includes, for example, an input / output disk (not shown) as shown in FIG.
The transmission ratio changing means 9 is driven by a step motor 61, as shown in FIG. 2, while being constituted by a toroidal type continuously variable transmission capable of changing the speed ratio in accordance with the tilt angle of the power roller 18c sandwiched between the power rollers 18c. The case where the control valve 60 is used is shown.

Between the engine 1 and the continuously variable transmission 10,
A torque converter 4 as a fluid transmission means is interposed.

The shift control controller 2 reads the opening TVO (or accelerator pedal opening ACS) of a throttle (not shown) responsive to the driver's operation and the engine speed Ne detected by the crank angle sensor 8. , The input shaft rotation speed N detected by the input shaft rotation sensor 6 of the continuously variable transmission 10
t (that is, the output shaft rotation speed of the torque converter 4) and the output shaft rotation speed No detected by the output shaft rotation sensor 7 are read, and as shown in FIG. Actual target input shaft speed R
REV is obtained, and the step motor 6 of the speed ratio changing means 9 is determined.
1 (see FIG. 2), the control amount A according to the target speed ratio RRTO and the feedback control amount (FB control amount) by PI control.
STP is instructed, and the relationship between the drive amount of the step motor 61 and the gear ratio is set as shown in FIG.

Here, the gear ratio changing means 9 is shown in FIG.
As shown in the figure, the actual gear ratio changes according to the drive of the step motor 61 and the displacement of the trunnion shaft 50a, and the hydraulic actuator 50 that drives the trunnion shaft 50a that supports the power roller 18c of the continuously variable transmission 10 in the axial direction. A step motor 61 drives a spool 63 in response to a command from the transmission control controller 2 to feed a hydraulic oil to the hydraulic actuator 50 while feeding back the hydraulic actuator 50.
The hydraulic pressure is supplied / discharged to the upper and lower oil chambers 50H and 50L of the piston 50P, and the displacement of the trunnion shaft 50a corresponding to the hydraulic pressure is fed back to the sleeve 64 which moves relative to the spool 63 via the copying mechanism 67. , The hydraulic pressure applied to the hydraulic actuator 50 depends on the drive amount of the step motor 61 according to the target speed ratio RRTO,
It is adjusted according to the tilt angle of c, that is, the actual gear ratio RTO, and this gear ratio is uniquely determined according to the driving amount of the step motor 61 as shown in FIG.

As shown in the conceptual diagrams of FIGS. 4 to 6, the speed change controller 2 controls the vehicle speed Vsp and the throttle opening TV.
A shift determining unit that obtains an actual target input shaft rotation speed RREV according to the driving state of the vehicle and the driver's request using O (or accelerator opening, the same applies hereinafter) as a parameter; According to the deviation of the input shaft rotation speed Nt, for example, a feedback control unit by PI control and a shift control unit that drives the step motor 61 (actuator in the figure) according to the target speed ratio RRTO and the feedback control amount are roughly classified. Is done.

Here, an example of the control performed by the shift control controller 2 is shown in the flowcharts of FIGS.
The details will be described below with reference to the conceptual diagrams of FIGS. Each flowchart is executed at predetermined time intervals, for example, 10 minutes.
It is executed every msec.

First, FIG. 7 is a flowchart of a signal measuring section for detecting the operating state of the vehicle. In step S1, the throttle opening TVO and the engine speed Ne are read as the operating state of the engine 1, while the continuously variable transmission 10 is operated. , The input shaft rotation speed Nt and the output shaft rotation speed No are read.

In step S2, each value indicating the driving state of the vehicle is calculated. First, the vehicle speed Vsp is obtained by multiplying the output shaft rotation speed No by the conversion constant A.
From the input shaft speed Nt and the output shaft speed No, the actual speed ratio RT
O, the speed ratio e of the torque converter 4 is calculated from the input shaft speed Nt and the engine speed Ne, respectively.

Next, a flowchart of FIG. 8 shows an outline of the shift control of the continuously variable transmission 10 based on the operating state obtained in steps S1 and S2.

In step S3, as will be described later, a target input shaft rotation speed map value RREV is set in accordance with the driving state of the vehicle.
0, the target gear ratio map value RTO0, the target torque Te0, and the estimated output shaft torque TRQO are respectively calculated, and the actual target input shaft rotation speed RREV with a first order delay is determined from the deviation between the target torque Te0 and the estimated output shaft torque TRQO. In the shift determining unit, the shift determining unit is equivalent to the conceptual diagrams of FIGS. 4 and 5, and the calculation of the first-order delayed actual target input shaft rotational speed RREV is performed by the rotational speed change amount determining unit of FIGS. Is represented as

In step S4, based on the actual target input shaft rotation speed RREV obtained in step S3,
It calculates the control amount ASTP of the step motor 61, and corresponds to the shift control unit in FIG.

As shown in the flow chart of FIG. 9, the shift control unit obtains the control position FSTP of the step motor 61 in accordance with the target gear ratio RRTO in step S5, and in step S6, executes the step by PI (proportional integration) control. The control amount FBSTP of the motor 61 is calculated, and step S7 is performed.
The control amount AST corresponding to the response of the step motor 61
Find P.

The control amount ASTP is commanded to the stepping motor 61 in step S8 in FIG. 10 to drive the speed ratio changing means 9.

First, as shown in FIGS. 11 and 12, the details of the shift determining section shown in step S3 in FIG. 8 are as follows. In step S10, the vehicle speed Vsp and the throttle opening TVO are used as shown in FIG. A target input shaft speed map value RREVO is obtained based on the map, and in step S31, the target input shaft speed map value RREVO is divided by the output shaft speed No to obtain a target speed ratio map value RTO0 (see FIG. 5). Target rotation speed search section).

Next, in step S32, a target engine torque Te0 (engine torque target value) which can be obtained from the target input shaft speed map value RREV0 and the throttle opening TVO based on the map of FIG. (Target torque calculation unit in FIG. 5).

On the other hand, in step S33, the throttle opening TVO and the actual input shaft speed Nt are used to calculate
The actual engine torque Te1 (estimated actual engine torque) is estimated based on the map (1) (actual input torque estimating unit in FIG. 5).

In step S34, a target output shaft torque threshold value RTRQO is calculated from the product of the target engine torque Te0, the target speed ratio map value RTO0, and a predetermined threshold torque ratio Kt (TVO). Here, assuming that the target output shaft torque (target driving torque) is RTRQ, RTRQ
= Te0 × RTO0. The threshold torque ratio Kt is a map set in advance according to the throttle opening TVO, as shown in FIG.

Then, in step S35, step S3
The actual input gear ratio RTO is added to the actual input torque estimated value Te1 obtained in step 3.
Is multiplied to obtain an estimated output shaft torque TRQO (actual driving torque). In step S36, the estimated output shaft torque TRQO
The difference TRQOerr between QO and the target output shaft torque threshold value RTRQO obtained in step S34 is calculated as follows.
The process proceeds to the target rotation speed change amount determination unit in step S37.

TRQOerr = RTRQO-TRQO In the calculation of the output shaft torque threshold value RTRQO and the estimated value TRQO, taking into account the torque amplifying action of the torque converter 4 shown in FIG. ) × RTO RTRQO = Te0 × t (e) × RTO0 × Kt (TV
O).

Here, t (e) is the torque ratio of the torque converter 4 and is determined according to the speed ratio e obtained in step S2 as shown in FIG. However, in this case, even when the speed ratio e is different like e1 and e2 in FIG. 19, the torque ratios t (e1) and t (e2) have substantially the same value, and thus have little effect on TRQO and RTRQO. Here, it is omitted.

In step S37, the rotation speed change amount determining section
It is configured as shown in the block diagram of FIG. 6, in which processing of a subroutine shown in FIG. 12 is performed.

First, in step S40, the actual target input shaft rotation speed RREV obtained in the previous process (one cycle before) is substituted for the previous value RREVold, and in step S41, the target value RTRQ of the output shaft torque and the estimated value are obtained. TRQO difference T
It is determined whether or not RQOerr is greater than 0.

When TRQOerr> 0, since the estimated output shaft torque TRQO is smaller than the threshold value RTRQO, the process proceeds to step S42 to increase the target rotational speed change amount (gear speed), and the first-order lag time constant Kr Small predetermined value K
Substitute 1.

On the other hand, if the estimated output shaft torque TRQO is larger than the threshold value RTRQO, the process proceeds to step S43 to suppress the target rotation speed change amount (shift speed), and the predetermined value K2 is set to a large value for the primary delay time constant Kr. Is assigned. In addition,
These predetermined values are set in a relationship of K1 <K2.

In step S44, based on the target input shaft rotation speed map value RREV0, the previous value actual target input shaft rotation speed RREVold, and the first-order lag time constant Kr, the primary target actual target input shaft rotation with a first-order lag is calculated based on the following equation. Calculate the number RREV.

RREV = (RREV0 + RREVold ×
Kr) / (Kr + 1) Therefore, the relationship between the target input shaft rotation speed map value RREV0 and the actual target input shaft rotation speed RREV is as shown in FIG. 17, and the actual target input shaft rotation speed according to the first-order lag time constant Kr. The number RREV gradually increases toward the map value RREV0.

Next, the details of the shift control section of FIG. 4 and the flowchart of FIG. 9 will be described in detail with reference to the subroutines of FIGS.

First, the shift control amount calculator (step S5 in FIG. 9) and the FB control amount calculator (step S6 in FIG. 9)
This is performed as shown in FIG. 13. In step S50, the target gear ratio RRTO is obtained by dividing the actual target input shaft speed RREV obtained in step S44 by the output shaft speed No. -Determine the control step number FSTP of the step motor 61 based on the step number map.

Next, in step S60 and thereafter, the FB control amount is calculated by the PI control.

First, in step S60, a difference Nerr obtained by subtracting the current input shaft speed Nt from the actual target input shaft speed RREV obtained in step S44 is obtained. In step S61, an integral value of the speed difference Nerr is obtained. Is calculated as Ni.

In step S62, the rotational speed difference Ner
By multiplying r by a predetermined proportional gain kp, a proportional amount FBp of the feedback control amount is calculated. The proportional gain kp is determined from a predetermined map or function according to the actual speed ratio RTO and the vehicle speed Vsp.

In step S63, the above-mentioned step S61 is performed.
Is multiplied by a predetermined integral gain ki to calculate the integral FBi of the feedback control amount. The integral gain ki is determined by the actual speed ratio RTO and the vehicle speed Vsp.
Is determined from a predetermined map or function corresponding to

Thus, in step S64, the proportional component F
From the sum of Bp and the integral FBi, the feedback control amount FB
STP (the number of steps) is obtained.

Next, the step motor control unit shown in step 7 of FIG. 9 executes a subroutine shown in FIG.

First, in step S70, the above step S
The sum of the control step number FSTP obtained in 51 and the feedback control amount FBSTP obtained in step S64 is obtained as the target step number DSRSTP.

In steps S71 to S76, the control amount ASTP is determined from the target step number DSRSTP and the current control amount ASTP according to the response speed of the step motor 61.
When the target control amount DSRSTP is larger than the current control amount ASTP, the control amount ASTP is increased by the control amount DSTP per unit time to the target value DSRSTP.

That is, in FIG. 18, when the control amount of the step motor 61 per unit time is DSTP,
The control amount ASTP actually output to the step motor is increased or decreased by the control amount DSTP per unit time until reaching the target control amount DSRSTP, and the step motor 61 is controlled so that the spool 63 of the control valve 60 has a predetermined speed ratio. Drive.

The control amount ASTP obtained from the flowcharts of FIGS. 7 to 14 is output from the transmission control controller 2 to the step motor 61 in step S9 of the signal output unit in FIG. That is, the continuously variable transmission 10 is set to the target speed ratio RRTO.

[Operation] In this manner, the transmission control controller 2 sets the output shaft torque estimated value TRQO obtained from the target input shaft rotation speed map value RREV0 (target transmission ratio RTO0).
Until the (actual drive torque) achieves the predetermined ratio Kt (TVO) of the target output shaft torque RTRQ, the input shaft rotation speed change speed (shift speed) is set high by a small first-order lag time constant K1 to quickly downshift. After the shift, the change in the inertia torque can be reduced by reducing the rotation speed change speed by the large first-order lag time constant K2, and the shift in the case where the target input shaft rotation speed RREV0 greatly changes during a kick down shift or the like. Shock can be alleviated.

As shown in FIGS. 21 and 22, when the accelerator pedal is depressed from time t0 to perform kickdown acceleration, the target input shaft speed map value RREV0 increases according to the throttle opening TVO and the vehicle speed VSP. And the target engine torque Te corresponding to the map value RREV0.
The target output shaft torque obtained by multiplying the target speed ratio map value RTO0 by 0 also rises as shown in the figure.

At this time t0, the output shaft torque estimated value T
Since RQO is smaller than the target output shaft torque threshold value RTRQO, the first order time constant Kr has a small predetermined value K1.
Is set (step S42), and the actual target input shaft rotation speed RREV increases quickly, so that the gear ratio quickly changes to Lo.
The gear shifts to the w side, and the actual output shaft torque increases according to the driver's request.

From time t1 when the output shaft torque estimated value TRQO exceeds the predetermined ratio Kt of the target output shaft torque, in step S43, a large predetermined value K2 is set as the first-order lag time constant Kr, and the actual target value is set. The change amount of the input shaft rotation speed RREV decreases as compared to before time t1, and the target speed ratio RRTO indicated by the solid line in FIG. 22 and the shift speed toward the Low side of the actual speed ratio RTO indicated by the dotted line also become gentler. After the time t1, the actual target input shaft rotation speed RREV gradually decreases to the map value R.
Therefore, since the actual output shaft torque transmitted to the drive shaft increases smoothly from time t0, it is possible to perform a quick shift while preventing a shift shock as in the conventional example. In addition, it is not necessary to perform fine tuning for each vehicle type, and the manufacturing cost can be reduced.

In the conventional example, since the target input shaft speed directly increases toward the map value, the actual output shaft torque decreases as shown by the dashed line in FIG. , A shift shock occurs because the rate of change in torque is large. On the other hand, in the present invention, although the peak value of the actual output shaft torque at the time t3 is smaller than that of the conventional example, the drop of the torque at the time t2 is eliminated, so that the actual output shaft torque becomes excessive. Speed and smooth kick-down acceleration, improving the operability of vehicles equipped with a continuously variable transmission, and eliminating the need for fine tuning for each model. You can do it.

The threshold value RTRQO for determining the switching of the first-order time constant Kr is determined by the throttle opening TV.
Since it is determined from the predetermined ratio Kt according to O,
When the throttle opening TVO is large, the threshold value RTRQO for switching the time constant Kr is set to a large value to increase the shift speed, and the downshift is quickly performed according to the driver's acceleration request, while the throttle opening TVO is set to a small value. When it is small, the threshold value RTRQO for switching the time constant Kr can be set small, and a smooth gear shift can be performed, and the drivability of the vehicle equipped with the continuously variable transmission can be further improved.

FIGS. 23 and 24 show a second embodiment.
The comparison between the output shaft torque estimated value TRQO and the target output shaft torque threshold value RTRQO is performed by using the torque ratio TRQO between TRQO and RTRQO instead of the difference as in the first embodiment.
err = RTRQO / TRQO, and the other configuration is the same as above.

That is, the calculation of the difference performed in step S36 in FIG. 11 is performed by calculating the torque ratio TRQOerr = RTRQO /
In addition to the TRQO operation, the conditional branch performed in step S41 of FIG. Is replaced by

Therefore, when the torque ratio TRQOerr becomes 1 or less, the time constant Kr of the first-order lag is reduced from K2 to K1, and the amount of change (shift speed) of the actual target input shaft speed RREV is reduced, so that the speed is rapidly increased. After changing the actual target rotational speed RREV (target gear ratio RRTO), the speed is shifted toward the actual target rotational speed RREV at a gentle speed change, and the variation of the inertia torque is not required for each vehicle type without fine tuning. By preventing a shift shock, it is possible to achieve both drivability of a vehicle equipped with a continuously variable transmission and reduction of manufacturing costs.

In the above-described embodiment, the case where the continuously variable transmission 10 is of a toroidal type is shown. However, although not shown, the same applies to the case where a continuously variable transmission such as a belt type is adopted.

The threshold ratio Kt of the target output shaft torque RTRQ may be a predetermined value set in advance.

[0064]

As described above, according to the first aspect, when the shift control means changes the target gear ratio, the target drive torque (the output shaft torque of the continuously variable transmission) based on the target gear ratio.
And the actual actual drive torque are calculated, and the shift speed changing means can variably control the shift speed according to the magnitude relationship between the actual value of the drive torque and the target value.
When the driver depresses the accelerator pedal to accelerate kickdown, the shift speed is increased when the difference (or ratio) between the target drive torque and the actual drive torque is large, and the shift speed is decreased when the difference is small. Thus, rapid acceleration can be performed while suppressing a shift shock due to a change in inertia torque, and the drivability of a vehicle equipped with a continuously variable transmission can be improved.

According to a second aspect of the present invention, when the speed change control means changes the target speed ratio, the target drive torque (output shaft torque of the continuously variable transmission) based on the target speed ratio and the actual actual drive torque are respectively changed. When the actual drive torque exceeds a predetermined ratio of the target drive torque, the shift speed changing means switches the shift speed.For example, when the driver depresses the accelerator pedal to perform kickdown acceleration, the actual drive torque is changed. When the actual drive torque exceeds the predetermined ratio of the target drive torque, the shift speed is set to a small value when the target drive torque is equal to or less than the predetermined ratio. Even when the gearshift is performed, the gearshift can be performed quickly and smoothly while preventing the gearshift shock due to the fluctuation of the inertia torque, and the continuously variable gearshift While improving the drivability of the vehicle equipped with the conventional example in vehicles is no longer necessary subjected to fine tune the like each such as, it is possible to reduce the manufacturing cost.

According to a third aspect of the present invention, the shift speed changing means increases the first-order time constant when the actual drive torque exceeds a predetermined ratio of the target drive torque. By setting the actual drive torque to be small when the actual drive torque is equal to or less than the predetermined ratio of the target drive torque, while setting the actual drive torque to be large when the actual drive torque exceeds the predetermined ratio of the target drive torque,
Even when the target gear ratio changes significantly, such as during kick-down acceleration, in the initial stage of gear shifting, a quick downshift is performed with a small time constant, and then the downshift is continued gently with a large time constant to achieve inertia. The gears can be shifted quickly according to the driver's intention to accelerate while preventing shift shocks due to torque fluctuations, further improving drivability and eliminating the need for fine tuning for each model. Cost reduction can be promoted.

According to a fourth aspect of the present invention, the shift speed changing means includes a threshold value changing means for changing the predetermined ratio in accordance with the opening of the accelerator pedal. Can be variably controlled in accordance with the vehicle speed, and the speed change shock can be suppressed while speedy shifting is performed according to the driver's intention to accelerate, so that the drivability can be further improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a continuously variable transmission and an engine showing an embodiment of the present invention.

FIG. 2 is a conceptual diagram of gear ratio changing means.

FIG. 3 is a graph showing a relationship between a drive amount of a step motor and a gear ratio.

FIG. 4 is a block diagram showing an outline of a shift control.

FIG. 5 is a block diagram showing an outline of a shift determination.

FIG. 6 is a block diagram showing an outline of determination of a rotation speed change amount.

FIG. 7 is a flowchart illustrating an example of control performed by a shift control controller, illustrating a signal measuring unit.

FIG. 8 is a flowchart showing an example of control, and
The outline of the VT control unit is shown.

FIG. 9 is a flowchart showing an example of control, and shows an outline of a shift control unit.

FIG. 10 is a flowchart showing an example of the same control.
3 shows a signal output unit.

FIG. 11 is a flowchart showing details of a shift determining unit performed by the CVT control unit.

FIG. 12 is a flowchart showing details of a target rotation speed change amount determination unit which is also performed by the shift control unit.

FIG. 13 is a flowchart showing details of a shift control amount calculation unit and an FB control amount calculation unit;

FIG. 14 is a flowchart showing details of a step motor control unit.

FIG. 15 is a shift map showing a relationship between the target input shaft rotation speed RREV0 and the vehicle speed Vsp using the throttle opening TVO as a parameter.

FIG. 16 is a torque map showing the relationship between target and actual input shaft rotation speeds RREV0, Nt and target and actual engine torques Te0, Te1, using the throttle opening TVO as a parameter.

FIG. 17 is a graph showing a relationship between an actual target rotation speed RREV and time.

FIG. 18 is a graph showing a relationship between a target step number DSRTP, a control step number ASTP, and time.

FIG. 19 is a map showing a relationship between a speed ratio and a torque ratio of the torque converter.

FIG. 20 shows a threshold torque ratio Kt and a throttle opening TV.
Map showing the relationship of O.

FIG. 21 is a graph showing the operation, showing the relationship between the input shaft rotation speed, the number of control steps, the target output shaft torque and time.

FIG. 22 is a graph showing the operation, showing the relationship between the gear ratio and the actual torque and time.

FIG. 23 is a block diagram illustrating the second embodiment and schematically illustrating a shift determining unit performed by a shift control controller.

FIG. 24 is a block diagram showing an outline of a rotation speed change amount determination unit.

FIG. 25 is a claim correspondence diagram corresponding to any one of the first to fourth inventions.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Transmission control controller 6 Input shaft rotation sensor 7 Output shaft rotation sensor 8 Crank angle sensor 9 Gear ratio changing means 10 Continuously variable transmission 18c Power roller 60 Control valve 61 Step motor 100 Continuously variable transmission 101 Gear ratio changing means 102 Shift control means 103 Target drive torque calculation means 104 Actual drive torque calculation means 105 Shift speed change means 106 Threshold change means

Claims (4)

[Claims] 1. A gear ratio changing means for changing a gear ratio of a continuously variable transmission, a target gear ratio is calculated in accordance with an operation state of a vehicle, and the gear ratio changing means is controlled in accordance with the target gear ratio. A target drive torque calculating means for calculating a target drive torque corresponding to a target gear ratio, and an actual drive torque calculating means for calculating a current actual drive torque. And a shift speed changing means for changing the shift speed in accordance with the magnitude relationship between the actual drive torque and the target drive torque. 2. A gear ratio changing means for changing a gear ratio of a continuously variable transmission, a target gear ratio is calculated in accordance with an operation state of a vehicle, and the gear ratio changing means is controlled in accordance with the target gear ratio. A target drive torque calculating means for calculating a target drive torque corresponding to a target gear ratio, and an actual drive torque calculating means for calculating a current actual drive torque. And a shift speed changing means for changing a shift speed when the actual drive torque exceeds a predetermined ratio of the target drive torque. 3. The continuously variable transmission according to claim 2, wherein the shift speed changing means increases the time constant of the first-order lag when the actual driving torque exceeds a predetermined ratio of the target driving torque. Transmission control device for transmission. 4. The continuously variable transmission according to claim 2, wherein the shift speed changing unit includes a threshold value changing unit that changes the predetermined ratio in accordance with an opening degree of an accelerator pedal. Transmission control device.