JPH10184875A - Transmission control device for continuously variable transmission - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To quickly shift gears while suppressing shift shock during downshifting. SOLUTION: First target gear ratio setting means 100 for setting a target gear ratio of the continuously variable transmission according to a driving state of a vehicle;
Second target gear ratio setting means 101 for setting a target gear ratio of the continuously variable transmission 10 within a predetermined gear range based on a signal from gear change command means 95 operated by the driver.
A speed change mode switching means 102 for selectively switching between the first target speed ratio setting means 100 and the second target speed ratio setting means 101; and a speed ratio of the continuously variable transmission 10 based on an output of the speed mode switching means 102. Deceleration intention detection means 10 for detecting the driver's intention to decelerate when the actuator 103 for driving the change means, the vehicle acceleration detection means 104, and the shift mode switching means 102 are switched to the deceleration side.
5, and a shift speed changing means 106 for changing the shift speed based on the acceleration when the intention of deceleration is detected.

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 A continuously variable transmission used in a vehicle has a vehicle speed VSP and a throttle opening TVO (or an accelerator opening AC).
Based on S), the target input shaft speed (target gear ratio) is determined to perform gear shifting, and the automatic gear shift range (D range) used for normal traveling and the gear ratio are maintained on the Low side that is equal to or greater than a predetermined value. A vehicle equipped with a sports range (Ds range) and the like is conventionally known, and when a driver downshifts from the D range to the Ds range in order to apply engine braking, the shift speed is increased to increase the speed. For example, Japanese Patent Application Laid-Open No. 63-68427 discloses a method of reducing the speed.

[0003]

However, in the above-mentioned conventional shift control device, the maximum value of the shift speed is constantly increased by downshifting from the D range to the Ds range, so that the engine brake can be quickly operated. However, depending on the driving condition, there is a case where a shift shock due to the inertia torque of the driving system occurs, and the driving performance is reduced.

Accordingly, the present invention has been made in view of the above problems, and provides a shift control device for a continuously variable transmission capable of shifting quickly while suppressing shift shock during downshifting. The purpose is to:

[0005]

According to a first aspect of the present invention, as shown in FIG. 24, a first target gear ratio setting means 100 for setting a target gear ratio of a continuously variable transmission 10 according to a driving state of a vehicle.
And setting the target gear ratio of the continuously variable transmission 10 to one of a preset shift range or a plurality of preset shift speeds based on a signal from a shift command means operated by the driver. Target gear ratio setting means 101; and gear mode switching means 1 for selectively switching between the first target gear ratio setting means 100 and the second target gear ratio setting means 101.
02 and an actuator 103 for driving the speed ratio changing means 110 of the continuously variable transmission 10 based on the output of the speed change mode switching means 102. Acceleration detection means 1
04, when the shift mode switching means 102 is switched from the first target gear ratio setting means 100 to the deceleration side of the second target gear ratio setting means 101, a deceleration intention detecting means 105 for detecting a driver's intention to decelerate. And a shift speed changing unit 106 that changes the shift speed based on the detected acceleration when the deceleration intention detection unit 105 detects the driver's intention to decelerate.

In a second aspect based on the first aspect, the speed change speed changing means changes a time constant of a first-order lag for setting an actual target speed ratio by a preset map or filter in accordance with the acceleration. I do.

In a third aspect based on the first aspect, the shift speed changing means changes a drive speed of the actuator in accordance with an acceleration.

In a fourth aspect based on the first aspect, the speed change speed changing means changes the speed change speed on the deceleration side more slowly than on the acceleration side.

According to a fifth aspect of the present invention, in the first aspect, the shift speed changing means includes a braking shift speed switching means for switching a shift speed in accordance with an operation state of the vehicle braking means.

In a sixth aspect based on the first aspect, the deceleration intention detecting means operates when the accelerator pedal is released in addition to the operation of the shift mode switching means for downshifting. The intention of the driver to decelerate.

[0011]

According to the first aspect of the present invention, the first target gear ratio setting means comprises, for example, a D range for automatically changing the gear ratio according to the vehicle speed, the load, etc. The speed ratio setting means is constituted by, for example, a sports range or the like for maintaining a high engine speed, and the driver switches from the first target speed ratio setting means to the second speed ratio setting means, thereby decelerating by a downshift. In such a deceleration, by changing the shift speed according to the acceleration of the vehicle, for example, by changing the shift speed to increase according to an increase in the absolute value of the vehicle acceleration, Since the shift can be performed at a speed in accordance with the driver's intention to decelerate, a shift shock that gives the driver an uncomfortable feeling by preventing a shift shock as in the conventional example described above is provided, and a continuously variable transmission is provided. car It is possible to improve the drivability.

According to a second aspect of the present invention, the control of the shift speed is performed by:
The time constant of the first-order lag that sets the actual target gear ratio is changed by a filter or a map, so that gear speed control can be performed with high accuracy, and in particular, suppression of gear shift shock during downshifts due to the inertia torque of the drive system. This makes it possible to perform the shift operation in a finely detailed manner, and to achieve both high-precision shift shifting operation according to the acceleration of the vehicle and prevention of shift shock during downshifting.

According to a third aspect of the present invention, the control of the shift speed is performed by:
Since the drive speed of the actuator is changed in accordance with the acceleration of the vehicle, the control can be simplified and smooth shifting operation can be performed, so that the drivability of the vehicle having the continuously variable transmission can be improved. is there.

According to the fourth aspect of the present invention, the speed change speed on the deceleration side is changed more slowly than on the acceleration side. The side becomes relatively insensitive, so that the shift speed can be set large within a range that does not give the driver or passenger a discomfort such as a shift shock,
On the deceleration side, the skid of the drive wheels due to excessive deceleration is prevented to ensure vehicle stability.

Further, the fifth aspect of the present invention is provided with a shifting speed changeover device during braking which changes the shifting speed in accordance with the operating condition of the braking device of the vehicle, so that, for example, a downshift from the D range to the Ds range is performed, When the braking is started, it is possible to switch to a larger shift speed, and it is possible to quickly apply the engine brake according to the driver's intention to decelerate, thereby improving the drivability of a vehicle equipped with a continuously variable transmission. It is possible to further improve.

According to a sixth aspect of the present invention, in addition to the operation of the shift mode switching means to the downshift side, the driver's intention to decelerate is detected when the accelerator pedal is released. It is possible to more accurately detect and control the speed change during deceleration according to the driver's intention.

[0017]

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

FIG. 1 shows an example in which the present invention is applied to a continuously variable transmission 1 that employs a double-cavity toroidal type continuously variable transmission 10 as a continuously variable transmission, and shows a torque converter 12 and a forward / reverse switching device. The driving force of the engine is input to the toroidal-type continuously variable transmission 10 through 40, and in the continuously variable transmission 1, the step motor 61 responsive to the command value of the shift control controller 2 is operated by the hydraulic control device 4. The speed ratio of the toroidal type continuously variable transmission 10 is controlled.

The toroidal-type continuously variable transmission 10 is a double-cavity type having a half-toroidal first toroidal transmission section 18 and a second toroidal transmission section 20 and having two sets of input / output disks. As shown in FIG. 2, the power roller 18c sandwiched between the input disk and the output disk of the toroidal transmission unit 18 is supported by an offset rotary shaft 50b.
The trunnion shaft 50a, which is driven up and down in the figure and is rotatable around the axis, is driven in the axial direction by a hydraulic cylinder 50. Although the power roller 18c of the first toroidal transmission unit 18 has been described with reference to FIG. 2, the power roller of the second toroidal transmission unit 20 has the same configuration.

The transmission ratio is continuously changed by changing the inclination angle (displacement around the axis of the trunnion shaft 50a) of the power roller 18c according to the vertical displacement of the trunnion shaft 50a.

The shift control controller 2 reads the throttle opening TVO (or accelerator pedal opening ACS) and the engine speed Ne from the engine control controller 3 in response to the driver's operation of an accelerator pedal (not shown). The input shaft rotation speed Nt detected by the input shaft rotation sensor 6 of the continuously variable transmission 10, the output shaft rotation speed No detected by the output shaft rotation sensor 7, and the shift lever 5 as shift command means and shift mode switching means. The shift position Pos set by the driver from the inhibitor switch 51 and the signal BRK (ON during braking, OFF during non-braking) from the brake switch 52 corresponding to the operation of the brake pedal are read from the inhibitor switch 51, respectively, as shown in FIG. , The target gear ratio (target input shaft speed) in advance using the throttle opening TVO as a parameter An actual target input shaft rotation speed RREV according to the operation state is determined from the set shift map, and the target speed ratio RTO and PI control are performed to a step motor 61 (see FIGS. 1 and 2) as an actuator for driving the speed ratio changing means. Control amount AST corresponding to the feedback control amount by
P, and the relationship between the drive amount of the step motor 61 (the number of steps FSTP) and the gear ratio (the target gear ratio RRTO) is set as shown in FIG.

The shift lever 5 has a sports range (hereinafter, Ds range) for maintaining a high gear ratio according to the driver's intention, in addition to an automatic transmission range (hereinafter, D range) used for normal running. FIG. 13
As shown in the shift map of FIG. 13B, the gear ratio is set relatively higher than the shift range in the D range shown in FIG. The shift control is performed with the restriction being made to be on the Low side as compared with the case of performing the shift control.

As shown in FIG. 2, the transmission ratio changing means includes a hydraulic cylinder 50 for axially driving a trunnion shaft 50a supporting the power roller 18c of the toroidal type continuously variable transmission 10, and a stepping motor. A control valve 60 that supplies pressure oil to the hydraulic cylinder 50 while feeding back the actual gear ratio in accordance with the driving of the motor 61 and the displacement of the trunnion shaft 50a is mainly configured. The spool 63 is driven in accordance with the command of the hydraulic cylinder 50 to supply and discharge the hydraulic pressure to the oil chambers 50H and 50L above and below the piston 50P of the hydraulic cylinder 50.

On the other hand, the trunnion shaft 50 corresponding to the hydraulic pressure
a in the axial direction and the displacement around the axis (= power roller 18)
(tilting angle of c) is fed back to the sleeve 64 which moves relative to the spool 63 via a copying mechanism 67 including a link, and the oil pressure to the hydraulic cylinder 50 is changed according to the target speed ratio RTO. The drive amount of the step motor 61 and the tilt angle of the power roller 18c, that is, the actual speed ratio RTO, are adjusted in accordance with the drive amount of the step motor 61, as shown in FIG. Determined uniquely.

As shown in the conceptual control diagrams of FIGS. 3 and 4, the speed change controller 2 controls the vehicle speed VSP, the throttle opening TVO, and the shift position P from the inhibitor switch 51.
a shift determining unit that obtains an actual target input shaft rotation speed RREV according to the driving state of the vehicle and a driver's request, using the signal os and the signal BRK from the brake switch 52 as parameters;
Actual target input shaft speed RREV and actual input shaft speed Nt
For example, a feedback control unit based on PI control and a shift control unit that drives the step motor 61 in accordance with the target gear ratio RRTO and the feedback control amount are roughly classified according to the deviation of the control.

As shown in FIG. 4, the speed change determination unit determines the target input shaft rotation speed map value RR based on the vehicle speed VSP, the throttle opening TVO, and the shift position Pos, as shown in FIG.
Find EV0.

On the other hand, the vehicle speed VSP is obtained by differentiating the vehicle acceleration dVSP after flattening the vehicle speed VSP by a filter F1 constituted by a Butterworth filter or the like.
Further, the vehicle acceleration dVSP is similarly flattened by the filter F2.

Then, the target rotational speed change amount determining section calculates the vehicle acceleration d by adding the target input shaft rotational speed map value RREV0.
VSP, taking into account the state of the brake switch signal BRK,
As will be described later, an actual target rotational speed RREV with a first-order delay is obtained.

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 control conceptual diagrams of FIGS. Each flowchart is executed at predetermined time intervals, for example, 1
This is executed every 0 msec.

First, FIG. 5 is a flowchart of a signal measurement process for detecting a driving state of a vehicle and an operation state of a driver.
In step S1, while reading the throttle opening TVO and the engine speed Ne from the engine controller 3 as the operating state of the engine, while reading the input shaft speed Nt and the output shaft speed No from the continuously variable transmission 10,
To detect the driver's driving intention, the shift position Pos from the inhibitor switch 51 and the brake switch 5
2 is 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 speed No by the conversion constant A.
The actual gear ratio RTO is calculated from the ratio between the input shaft speed Nt and the output shaft speed No.

Further, at step S3, the vehicle speed VS
P is filtered and a differential operation is performed to calculate a vehicle acceleration dVSP. The process of step S3 is performed by the filter F1 of the shift determination unit shown in FIG.
This corresponds to the process of F2.

Next, the flowchart of FIG. 6 shows an outline of the shift control performed based on the operating state obtained in steps S1 to S3.

In step S4, as will be described later, a target input shaft rotation speed map value RREV is set according to the driving state of the vehicle.
0, vehicle acceleration dVSP and brake switch signal BRK
This is a shift determining unit that determines the actual target input shaft rotation speed RREV with a first-order delay. This shift determining unit corresponds to the shift determining unit in FIG. 3 and is equivalent to the control conceptual diagram in FIG.

Then, in step S5, based on the actual target input shaft speed RREV obtained in step S4,
It calculates the control amount ASTP of the step motor 61, and corresponds to the shift control unit in FIG.

The shift control unit determines the control position FSTP of the step motor 61 according to the target speed ratio RRTO in step S6 as shown in the flowchart of FIG.
In step S7, a feedback control amount FBSTP of the step motor 61 by PI (proportional integration) control is calculated,
In step S8, a control amount ASTP corresponding to the response characteristic of the step motor 61 is obtained.

Then, the control amount ASTP obtained in step S8 is applied to the step motor 6 in step S9 in FIG.
1 to drive the gear ratio changing means.

Next, the details of step S4 in FIG. 6 and the shift determining section shown in the control conceptual diagrams of FIGS. 3 and 4 will be described with reference to FIG.
This will be described in detail based on the flowchart of FIG.

First, in step S10, the shift position Pos from the inhibitor switch 51 is set to the value shown in FIG.
It is determined whether the D range of FIG. 13A has been switched to the Ds range of FIG. 13B. If the D range has been switched, the process proceeds to step S11. If the D range remains, the process proceeds to step S12. move on.

In step S11, the target input rotational speed map value RREV is obtained from the vehicle speed VSP and the throttle opening TVO within the shift range of the Ds range indicated by the solid line in FIG.
Find 0. On the other hand, in step S12, the target input rotation speed map value RR is obtained from the vehicle speed VSP and the throttle opening TVO within the shift range of the D range shown by the solid line in FIG.
Find EV0.

Step S13 shows the rotation speed change amount determining section in FIG. 4, and steps S20 to S25 in FIG.
It is composed of a subroutine.

First, in step S20, the actual target input shaft rotation speed RREV during the previous control is stored in the previous value RREVold.
It is determined whether a deceleration request has been made by downshifting to the s range. If the downshift has been performed from the D range to the Ds range, the process proceeds to step S21; otherwise, the process proceeds to step S24.

Next, in step S22, the intention of the driver to decelerate due to the release of the accelerator pedal is determined based on whether or not the throttle opening TVO = 0, and if the throttle opening TVO = 0, the process proceeds to step S23. On the other hand, if not, the process proceeds to step S24.

In step S23, a first order time constant K for bringing the actual target input shaft rotation speed RREV closer to the map value RREV0 from the previous value RREVold in step S20.
r is the vehicle acceleration dVSP obtained in step S3.
And the brake switch signal B read in step S1
Based on the RK, a calculation is made from the map of FIG. The map in FIG. 15 is set in advance according to the characteristics of the vehicle.

Kr = Kdr (dVSP, BRK) Therefore, as shown by the broken line in FIG.
The first-order lag constant Kr is changed so as to have a shift speed (a change amount of RREV) according to the VSP and the brake switch signal BRK.

On the other hand, in step S24 where the throttle opening TVO ≧ 0, a preset fixed value K1 is set to the first-order lag time constant Kr so that Kr = K1.
6, the speed change operation is performed with a constant time constant Kr.

Then, in step S25, step S
From the primary delay time constant Kr set in step S23 or S24, the target input shaft speed map value RREV0, and the previous value actual target input shaft speed RREVold, the actual target input shaft speed with the first delay based on the following equation. Calculate RREV.

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

In this way, when the actual target input shaft speed RREV is obtained from the primary delay time constant Kr and the shift determining section is completed, the shift control section shown in step S5 of FIG.
That is, the processing of steps S6 to S8 in FIG. 7 is performed.

The shift control amount calculating section in step S6 and the feedback control amount calculating section in step S7 comprise a subroutine of steps S30 to S36 in FIG. 11. Steps S30 and S31 are executed by the shift control amount calculating section. Subsequent steps S32 to S36 show the feedback control amount calculation unit.

First, at step S30, the target speed ratio R is calculated from the ratio of the actual target input shaft speed RREV of the temporary delay obtained by the above equation (1) to the output shaft speed No of the continuously variable transmission 10.
End for RTO.

Next, in step S31, the control step number FSTP, which is the drive amount of the step motor 61, is calculated from the map shown in FIG. 14 from the actual target gear ratio RRTO obtained in step S30. In addition, the map of FIG.
This is preset in accordance with the characteristics of the step motor 61 and the like.

In the subsequent feedback control amount calculation, first, in step S32, the actual target input shaft rotation speed RR
The difference Nerr between the EV and the input shaft rotation speed Nt is obtained, and in step S33, the integral value of the rotation speed difference Nerr is calculated as Ni.

In step S34, a proportional component FBp of the feedback control amount is calculated by multiplying the rotational speed difference Nerr by a predetermined proportional gain kp. Note that the proportional gain k
p is determined from a predetermined map or function (not shown) according to the actual speed ratio RTO and the vehicle speed VSP.

In step S35, the above-mentioned step S33 is executed.
Is multiplied by a predetermined integral gain ki to calculate the integral FBi of the feedback control amount. Note that the integral gain ki is determined by the actual speed ratio RTO and the vehicle speed VS.
It is determined from a predetermined map or function (not shown) corresponding to P.

Thus, in step S36, 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 section shown in step S8 of FIG. 7 is configured as a subroutine shown in FIG.

First, in step S40, the number of control steps FSTP obtained in step S31 of the shift control unit is determined.
And step S36 of the feedback control amount calculation unit
Is obtained as the target step number DSRSTP.

In steps S42 to S47, the control amount AS is determined according to the response speed of the step motor 61 from the target step number DSRSTP and the current control amount ASTP.
When the calculation of TP is performed and the target control amount DSRSTP is larger than the current control amount ASTP, the control amount ASTP is increased by a preset control amount DSTP to the target value DSRSTP. Note that DSTP indicates the number of steps per unit time, and is set in advance according to the speed characteristics of the step motor 61.

That is, in FIG. 17, the control amount ASTP actually output to the step motor 61 is equal to the target control amount D.
The step motor 61 is driven so that the spool 63 of the control valve 60 has a predetermined speed ratio by increasing or decreasing the predetermined control amount DSTP until SRSTP is reached.

The control amount ASTP obtained from the flowcharts of FIGS. 5 to 12 is output from the transmission control controller 2 to the step motor 61 in step S9 of the signal output unit in FIG. By inclining at a speed corresponding to the constant Kr, the continuously variable transmission 10 is set to the actual target gear ratio RRTO.

For example, when the vehicle is driven on a mountain road or the like by the continuously variable transmission 1 as described above, the driver's driving operation is performed in a normal traveling mode in order to decelerate on a downhill or at the entrance of a curve. When the downshift from the D range to the Ds range where the engine speed Ne is kept high at the same time as releasing the accelerator pedal to decelerate by the engine brake, or in addition to these driving operations, depress the brake pedal. There is a case where braking is further performed to perform more rapid deceleration.

Therefore, the first-order lag constant Kr for determining the actual target input shaft rotation speed RREV is calculated by using the above-described steps S21 to S2.
As shown in FIG. 15, when the downshift from the D range to the Ds range is performed and the throttle opening TVO = 0, the vehicle acceleration dVS is reduced as shown in the map of FIG.
The map is changed according to the state of P and the brake switch signal BRK, and a map with a small time constant Kdr is provided so that the shift speed increases during the braking when the brake switch signal BRK is ON. O
In the case of FF, a large map of the time constant Kdr gives
While controlling the shift speed, the actual target input shaft rotation speed RRE is increased during braking by increasing the shift speed by a map with a small time constant Kdr so that the engine brake can be quickly applied.
Set V.

The map of FIG. 15 shows the vehicle acceleration dVS
The time constant Kdr of the first-order lag is set to decrease as P increases, and the brake switch signal BRK is further set.
Is ON (= during braking), the time delay Kdr of the first-order lag is preset so as to be smaller, and the actual target input shaft rotation speed R is reduced with the decrease of the time constant Kdr of the first-order lag.
The amount of change in REV = shift speed increases as shown by the broken line in FIG.

Here, the time constant Kdr set in the map of FIG. 15 decreases to the lowest value between 0 G and a predetermined vehicle acceleration dVSP in accordance with the increase in the absolute value of the vehicle acceleration dVSP. Maintain the lowest value.

This map is set so that the time constant Kdr is smaller when the brake switch signal BRK is ON than when the brake switch signal BRK is OFF.
2. The accelerator pedal is released as in S23 (TVO
= 0) In the case of braking (BRK = ON), the minimum value is set for each acceleration.

Further, the amount of change in the time constant Kdr on the deceleration side (dVSP <0G) is set to change more slowly than the amount of change in the time constant Kdr on the acceleration side (dVSP> 0G). When the absolute value of? Increases, the change in the speed change speed on the deceleration side is set to be gentler than that on the acceleration side.

This is because the human perceived acceleration is very sensitive on the deceleration side, but relatively insensitive on the acceleration side, so that the driver or the passenger may feel uncomfortable, such as a shift shock. The shift speed can be set to a large value in a range that is not within the range, and skid of the drive wheels due to excessive deceleration can be prevented on the deceleration side to ensure vehicle stability.

As described above, when the downshift from the D range to the Ds range is performed and the accelerator pedal is released, the speed is changed (the first-order lag time constant Kr) according to the vehicle acceleration dVSP. When the shift position Pos is downshifted from the D range to the Ds range and the accelerator pedal is released, the shift speed is increased from a normal value (Kr = K1) according to the driver's intention to decelerate, and the shift speed is rapidly increased. While performing the downshift, as shown in FIG. 15, the time constant Kdr based on the human perceived acceleration or the like is used.
By setting, it is possible to rapidly reduce the speed while suppressing the shift shock as in the conventional example, and it is possible to improve the drivability of the vehicle including the continuously variable transmission.

Further, since the map of the time constant Kdr for determining the shift speed is switched in accordance with the operation state of the braking device, the deceleration at the time when the accelerator pedal is released and the deceleration at the time of deceleration are described.
The shift speed can be switched during deceleration with the brake pedal depressed, and the downshift is performed at the shift speed according to the driver's intention, so that the driver does not feel uncomfortable and equipped with a continuously variable transmission. This makes it possible to further improve the drivability of the vehicle.

Further, the speed change speed is set to the first-order time constant Kdr.
The shift speed can be controlled with high accuracy, and in particular, it is possible to finely suppress the shift shock at the time of a downshift due to the inertia torque of the drive system. It is possible to achieve both the prevention and the quick shift operation according to the acceleration dVSP with high accuracy.

In the above embodiment, an example in which the time constant Kdr of the first-order lag is changed by the map shown in FIG. 15 is shown. However, although not shown, the same operation and effect can be obtained by using a band-pass filter or the like. Obtainable.

FIGS. 18 and 19 show the second embodiment.
By changing the control speed DSTP of the step motor 61 instead of changing the time constant Kr of the first embodiment,
This is for changing the speed change speed.

FIG. 18 is one in which steps S41A to S41C are inserted between steps S40 and S42 in the flowchart of FIG. 12 of the first embodiment.

In this step S41A, it is determined whether or not the driver has downshifted from the D range to the Ds range by operating the shift lever 5, and if the downshift to the Ds range has been performed, the flow proceeds to step S41B. And the speed control amount D of the step motor 61 according to the acceleration dVSP.
If STP is set, otherwise, the process proceeds to step S41C, where a preset fixed value K2 is set to the speed control amount DSTP.

In step S41B, step S3
Based on the vehicle acceleration dVSP obtained in step S1 and the brake switch signal BRK read in step S1, the control amount (the number of steps) per unit time of the step motor 61 is calculated.
That is, the speed control amount DSTP is calculated from the map of FIG. FIG. 19 is set in advance according to the characteristics of the step motor 61 and the vehicle.

DSTP = Kds (dVSP, BRK) The map of FIG. 19 shows the time constant Kd of the first embodiment.
r and a map of the vehicle acceleration dVSP, which are set in the same manner as the map of the vehicle acceleration dVSP and the brake switch signal BR.
The speed control amount DSTP is changed according to the state of K, and set to a shift speed according to the operation of the driver.

The map of FIG. 19 shows the vehicle acceleration dVS
The speed control amount DSTP is set so as to increase as P increases. When the brake switch signal BRK is ON (= during braking), the speed control amount DSTP is set in advance so as to further increase. As the DSTP increases, the change amount of the actual target input shaft rotation speed RREV = the shift speed increases. The maximum value of the speed control amount DSTP is set according to the response speed of the step motor 61.

Here, the speed control amount DSTP set in the map of FIG. 19 is set to 0 according to the increase of the absolute value of the vehicle acceleration dVSP, similarly to the time constant Kdr of the first embodiment.
After increasing to a maximum value between G and a predetermined vehicle acceleration dVSP, this maximum value is maintained. Further, this map shows that when the brake switch signal BRK is ON,
The speed control amount DSTP is set to be larger than when OFF, and the change amount of the speed control amount DSTP on the deceleration side (dVSP <0G) is set on the acceleration side (dVSP> 0).
G) The speed control amount is set to change more gently than the change amount of the DSTP, and the shift speed is set to a large value and excessive deceleration is performed within a range that does not give a driver or a passenger a discomfort such as a shift shock. This prevents the skid of the drive wheels from occurring, thereby ensuring vehicle stability.

In this manner, when the downshift from the D range to the Ds range is performed, the speed control amount DSTP is changed according to the vehicle acceleration dVSP, so that the shift speed is reduced from the normal value according to the driver's intention to decelerate. As shown in FIG. 19, the speed control amount DSTP is set on the basis of the sensible acceleration of the human body while performing the downshift quickly so as to prevent the shift shock as in the conventional example and smoothly reduce the speed. Further, since the speed control amount DSTP can be smoothly increased and decreased as shown in FIG. 17, the control contents can be simplified and a smooth shift operation can be performed, so that the continuously variable transmission can be operated. The drivability of the equipped vehicle can be improved.

FIGS. 20 to 23 show a third embodiment, in which a manual mode is provided in place of the sports range Ds of the first embodiment.

FIG. 20 shows the shift lever 5 and the shift gate 5A.
In addition to a shift position such as a range, a manual mode changeover switch 13 (shift mode changeover means), an up switch 8 and a down switch 9 are added. Each time the shift lever 5 passes through the central manual mode changeover switch 13, , D range to manual mode or vice versa. In manual mode,
When the up switch 8 or the down switch 9 is turned on by operating the shift lever 5, the gear SP is sequentially switched between the first gear and the sixth gear based on the shift map of FIG. At each gear position, a predetermined maximum rotation speed Ne is set.
Up to lim, the gear ratio i (n) is fixed regardless of the throttle opening TVO or the like.

In the case where such a manual mode is provided, the shift determining unit is controlled by the flowcharts shown in FIGS. 22 and 23 instead of the flowcharts shown in FIGS. 9 and 10 of the first embodiment. .

First, the flowchart of FIG. 22 is different from the flowchart of FIG. 9 in that steps S10 and S11 are changed to S10A and S11A, respectively, and step S14 is added between them. This is the same as the embodiment.

In step S10A, the shift position Pos
Is switched from the D range to the manual mode, and if it is switched to the manual mode,
Proceeding to step S14, the gear SP is determined in accordance with the state of the up switch 8 or the down switch 9, and in step S11A, the target input rotational speed map value is calculated from the gear ratio i (SP) corresponding to the gear SP. RREV0
Is calculated.

The flowchart of FIG. 23 corresponds to step S21 of the flowchart of FIG. 10 of the first embodiment.
Is replaced by step S21 ′, and the downshift determination is made by the manual mode
The determination is made based on N, and the other controls are performed in the same manner as in the first embodiment.

Also in this case, similarly to the first embodiment,
When the shift position Pos is changed to the manual mode, a downshift is performed in which the down switch 9 is turned on, and the accelerator pedal is released, the vehicle acceleration dVSP becomes negative.

According to the map shown in FIG. 15, the primary delay constant Kdr decreases in accordance with the magnitude of the absolute value of the vehicle acceleration dVSP. Since the reduction of the first-order lag constant Kdr on the deceleration side is set smaller than that on the acceleration side while shifting, the downshift can be performed smoothly and quickly by suppressing the shift shock as in the conventional example.

In the above embodiment, the case where the toroidal type is employed as the continuously variable transmission has been described.
Although not shown, the same operation and effect as described above can be obtained when the V-belt type is adopted.

The calculation of the feedback control amount in steps S32 to S36 is based on the actual target value RR of the input shaft speed.
Although the calculation was performed based on the difference Nerr between the EV and the current value Nt, although not shown, the same may be performed based on the difference between the actual gear ratio and the target gear ratio, the difference between the target value of the tilt angle of the power roller 18c, and the like. Function and effect can be obtained.

Further, the vehicle acceleration dVSP is changed to the vehicle speed VSP.
Was obtained by performing a filtering process, but may be detected by an acceleration sensor or the like.

Also, the case of the sports range (Ds range) has been described as an automatic transmission range in which the engine speed (input shaft speed) is maintained at or above a predetermined value. Similar functions and effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of a continuously variable transmission according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram of gear ratio changing means of the toroidal continuously variable transmission.

FIG. 3 is a block diagram showing an outline of a shift control.

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

FIG. 5 is a flowchart illustrating an example of control performed by a shift control controller, illustrating a signal measurement process.

FIG. 6 is a flowchart showing an example of the control, wherein C
The outline of the VT control process will be described.

FIG. 7 is a flowchart showing an example of control, and shows an outline of a shift control unit.

FIG. 8 is a flowchart showing an example of control, showing signal output processing.

FIG. 9 is a flowchart illustrating details of a shift determination unit similarly performed in CVT control processing.

FIG. 10 is a flowchart showing details of a target rotational speed change amount determining unit which also constitutes a shift determining unit.

FIG. 11 is a flowchart showing details of a shift control amount calculation unit and an FB control calculation unit which are also performed by the shift control unit.

FIG. 12 is a flowchart showing details of a step motor control unit.

FIG. 13 is a shift map showing the relationship between the target input shaft rotation speed RREV0 and the vehicle speed VSP using the throttle opening TVO as a parameter, wherein (A) shows the D range and (B) shows the Ds range.

FIG. 14 is a map showing a relationship between an actual target gear ratio RRTO and a control position FSTP of a step motor.

FIG. 15 is a map showing a relationship between a vehicle acceleration dVSP and a target rotational speed first-order lag time constant Kdr.

FIG. 16 is a graph showing a relationship between a time constant Kr, an actual target rotation speed RREV, and a target rotation speed map value RREV0 as time passes.

FIG. 17 is a graph showing a relationship between a target step number DSRSTP and an actual output step number ASTP.

FIG. 18 is a flowchart of the step motor control unit according to the second embodiment.

FIG. 19 is a map showing a relationship between a vehicle acceleration dVSP and a speed control amount Kds of a step motor.

FIG. 20 is a schematic view of a shift gate having a manual mode according to the third embodiment.

FIG. 21 is a shift map in the manual mode,
The vehicle speed VSP and the target input shaft rotation speed are shown using the shift speed SP as a parameter.

FIG. 22 is a flowchart showing details of a shift determination unit.

FIG. 23 is a flowchart showing details of a target rotational speed change amount determining unit constituting the shift determining unit.

FIG. 24 is a diagram corresponding to claims corresponding to the first to sixth inventions.

[Explanation of symbols]

 Reference Signs List 1 continuously variable transmission 2 shift control controller 5 shift lever 6 input shaft rotation sensor 7 output shaft rotation sensor 8 up switch 9 down switch 10 continuously variable transmission 13 manual mode switch 18c power roller 51 inhibitor switch 52 brake switch 60 control valve 61 Step motor 100 First target gear ratio setting means 101 Second target gear ratio setting means 102 Gear mode switching means 103 Actuator 104 Acceleration detecting means 105 Deceleration intention detecting means 106 Gear speed changing means 107 Gear command means 110 Gear ratio changing means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F16H 59:54 63:06

Claims (6)

[Claims] A first target gear ratio setting means for setting a target gear ratio of the continuously variable transmission in accordance with a driving state of the vehicle; and a continuously variable transmission based on a signal from a gear shift command means operated by a driver. Second target gear ratio setting means for setting a target gear ratio of the transmission to a predetermined gear range or one of a plurality of predetermined gear positions; a first target gear ratio setting means and a second target gear ratio A shift control device for a continuously variable transmission, comprising: a shift mode switching unit that selectively switches between setting units; and an actuator that drives a speed ratio changing unit of the continuously variable transmission based on an output of the shift mode switching unit. An acceleration detecting means for detecting an acceleration of the vehicle; and a driver's intention to decelerate when the shift mode switching means is switched from the first target gear ratio setting means to the deceleration side of the second target gear ratio setting means. A deceleration intention detecting unit that outputs the deceleration intention, and a shift speed changing unit that changes the shift speed based on the detected acceleration when the deceleration intention detection unit detects a driver's intention to decelerate. Transmission control device for continuously variable transmission. 2. The apparatus according to claim 1, wherein the shift speed changing means changes a time constant of a first-order lag for setting an actual target gear ratio by a preset map or a filter in accordance with the acceleration of the vehicle. Transmission control device for a continuously variable transmission. 3. The shift control device for a continuously variable transmission according to claim 1, wherein the shift speed changing means changes a drive speed of the actuator in accordance with an acceleration. 4. The shift control device for a continuously variable transmission according to claim 1, wherein the shift speed changing means changes the shift speed on the deceleration side more gradually than on the acceleration side. 5. The continuously variable transmission according to claim 1, wherein the shift speed changing unit includes a brake shift speed switching unit that switches a shift speed in accordance with an operation state of a vehicle braking unit. Transmission control device. 6. The deceleration intention detecting means detects a driver's intention to decelerate when an accelerator pedal is released, in addition to the operation of the shift mode switching means for downshifting. Item 3. The shift control device for a continuously variable transmission according to Item 1.