JP3134901B2 - Shift control device for continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed change control device for a continuously variable transmission, and more particularly to a speed change control device for a continuously variable transmission capable of improving a starting feeling and power performance when a vehicle starts moving.

[0002]

2. Description of the Related Art In a vehicle, a transmission is interposed between an internal combustion engine and wheels since the characteristics of the internal combustion engine are unsuitable as they are. This transmission changes the driving force and the number of revolutions of the wheels in accordance with the running conditions of the vehicle which vary over a wide range, thereby sufficiently exhibiting the performance of the internal combustion engine.

[0003] As a transmission, the gear ratio is continuously controlled by changing the radius of rotation of a belt wound around a driving pulley and a driven pulley, and a hydraulic clutch is controlled by a clutch pressure set in various control modes. 2. Description of the Related Art There is a continuously variable transmission provided with a transmission control device for controlling an intermittent state.

The various control modes include, for example, a neutral mode (NEU) and a hold mode (HL).
D), a normal start mode (NST) and a special start mode (SST) as start modes,
There is a drive mode (DRV) and the like.

In this transmission control apparatus, a line pressure control valve, a clutch pressure control valve, and a ratio pressure control valve are provided as various pressure control valves in order to control the hydraulic pressure applied to the driving pulley, the driven pulley, and the hydraulic clutch. In addition, a line solenoid valve, a clutch solenoid valve, and a ratio solenoid valve for operating these control valves are provided.

[0006] As such a shift control device, there are those already filed by the applicant of the present invention (Japanese Patent Application Nos. 4-100751 and 4-100757).
issue). The one described in Japanese Patent Application No. Hei 4-100751 raises the primary pressure in a hold mode to a predetermined pressure smaller than the primary pressure in a normal start mode,
This is to improve the starting feeling when shifting to the normal start mode. Also, Japanese Patent Application No. 4-100575
The method described in (1) adjusts the gear ratio in the start mode, shifts the limit line of the engine speed determined when shifting from the start mode to the drive mode to the target engine speed, and starts the drive from the start mode. This is to improve the starting feeling by suppressing the engine speed from rising after shifting to the mode.

Further, in controlling the clutch pressure to the hydraulic clutch, an actual engine torque is generated due to factors such as an engine generated torque, individual differences of the hydraulic clutch, aging, and so on. Feedforward control unit (F / F), which is an operation unit
The engine torque setting map (T
This causes a torque difference between the engine torque (TRQ) and the engine torque (TRQ) obtained by RQCV), so that an appropriate clutch pressure cannot be obtained and the starting feeling deteriorates. To solve this inconvenience, a steady state control unit (S / S) which is a target clutch pressure correction unit different from the feedforward control unit is used.
In S), a correction amount for correcting the target clutch pressure according to the above-described torque difference is calculated and stored, and the target clutch pressure obtained by the feedforward control unit is corrected (corrected) by feedback learning control.

[0008]

However, in the conventional clutch pressure control of the hydraulic clutch, as shown in FIG. 7, the position of the shift lever changes from neutral "N" to drive "D" and the throttle opening (THR) is changed. ) Is increased (indicated by the Z position in FIG. 7), and then the proportional gain (Kn) and the integral gain (Ki) in the steady state control unit.
n) is the same during the start of travel (indicated by R1 and R2 in FIG. 7), the engine speed (NE) decreases (indicated by the arrow W in FIG. 7), so that a start shock may occur. ,
There is a disadvantage that the starting feeling is deteriorated.

In the above-mentioned Japanese Patent Application No. Hei 4-100575, it is a precondition that the engine speed (NE) during starting of the vehicle is controlled to a target engine speed (NESPC) for clutch control. Therefore, in the state shown by the arrow W in FIG. 7, a normal operation of the engine speed cannot be obtained.

Further, the vehicle shifts from the normal start mode (NST) of the start control to the drive mode (DRV),
Since the shift control is set on the assumption that the engine speed (NE) during starting is controlled to the target engine speed (NESPC) for clutch control for a while, the state as indicated by the arrow W in FIG. In this case, there is a disadvantage that a sudden increase in the engine speed (NE) or hunting occurs immediately after the shift from the normal start mode (NST) to the drive mode (DRV).

Furthermore, in the state of the engine speed indicated by the arrow W in FIG. 7, there is a disadvantage that the engine speed becomes extremely low and required power performance cannot be obtained.

FIG. 8 shows the characteristics of the engine torque. As shown in FIG. 8, when the driving force of the wheels is insufficient, the driver increases the throttle opening (THR). The characteristic of the engine torque at the large throttle opening (THR) is the engine speed (NE). ) Increases. In particular, when starting at substantially the full throttle opening (WOT), the engine speed (NE) in the region where the engine torque increases is used for the increase in the engine speed (NE). The lower the rotational speed (NE), the lower the power performance. That is, as shown in FIG. 8, the throttle opening (TH
R) is TR2 at T1 point, and the driving force of the wheels is insufficient. Therefore, even if the driver increases the throttle opening (THR) to substantially the full throttle opening (WOT), the engine speed is not increased. If the number (NE) is controlled to a point T3 lower than the target engine speed (NESPC) of the clutch control at the point T2, the internal combustion engine generates only a torque lower by the torque difference (△ TRQ), and thus the power The performance is inferior.

[0013]

SUMMARY OF THE INVENTION Therefore, in order to eliminate the above-mentioned disadvantages, the present invention continuously controls the gear ratio by changing the radius of rotation of a belt wound around a driving pulley and a driven pulley. In addition, in a transmission control device for a continuously variable transmission that controls the on / off state of a hydraulic clutch by a clutch pressure set in various control modes, a target clutch pressure is calculated by predicting an engine torque according to a throttle opening. A target clutch pressure correction for calculating a correction amount for correcting a target clutch pressure according to the torque difference between the engine torque predicted by the clutch pressure calculation unit and the actual engine torque when the engine torque predicted by the target clutch pressure calculation unit is different from the actual engine torque. And a target clutch pressure correction unit of the control unit, the correction amount in the first half of the start progress of the vehicle Controlled to fence, shift control apparatus for a continuously variable transmission and to control so as to increase the amount of correction in the second half of the starting traveling of the vehicle.

[0014]

According to the structure of the present invention, the target clutch pressure is calculated by predicting the engine torque corresponding to the throttle opening, and when there is a torque difference between the predicted engine torque and the actual engine torque, this torque is calculated. A correction amount for correcting the target clutch pressure is calculated in accordance with the difference, and control is performed such that the correction amount is reduced in the first half of the start of the vehicle, and the correction amount is increased in the second half of the start of the vehicle. Therefore, the clutch pressure is appropriately corrected as the vehicle starts moving, so that the starting feeling can be improved and the required power performance can be secured.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; 1 to 6 show an embodiment of the present invention. In FIG. 6, reference numeral 2 denotes a continuously variable transmission mounted on a vehicle and transmitting the power of an internal combustion engine (not shown) to the wheels. The continuously variable transmission 2 includes a driving pulley (primary pulley) 4, a driven pulley (secondary pulley) 6, and a belt 8 wound around the driving pulley 4 and the driven pulley 6.

The drive pulley 4 has a drive shaft 10 connected to the internal combustion engine, a drive-side fixed pulley piece 12 provided integrally with the drive shaft 10, an axially movable member connected to the drive shaft 10, and And a drive-side movable pulley piece 14 provided non-rotatably. A drive-side belt groove 16 around which the belt 8 is wound is formed between the drive-side fixed pulley piece 12 and the drive-side movable pulley piece 14. On the back side of the drive-side movable pulley portion 14, a drive-side housing 20 that forms a drive-side hydraulic chamber 18 in cooperation with the back surface of the drive-side movable pulley portion 14 is fixed to the drive shaft 10. I have. A drive shaft side oil passage 22 formed at an end portion of the drive shaft 10 is communicated with the drive side hydraulic chamber 18.

An oil pump 24 is provided on the rear side of the driving-side fixed pulley piece 12. The oil pump 24 is supported by a pump housing 26 fixed to the drive shaft 10. This oil pump 2
The oil suction passage 30 is driven by the rotation of the drive shaft 10 and connects the oil in the oil pan 28 to the suction side.
And lubricated from the discharge side to a hydraulic control system or a lubrication system. In the oil pan 28, the oil suction passage 3
An oil strainer 32 is attached to the opening of the oil suction passage 30 to filter the oil to zero.

The driven pulley 6 includes a driven shaft 34 disposed in parallel with the drive shaft 10 and a driven shaft disposed corresponding to the drive-side movable pulley piece 14 and provided integrally with the driven shaft 34. A side fixed pulley portion 36 and a driven side movable pulley portion 38 arranged corresponding to the drive side fixed pulley portion 12 and provided on the driven shaft 34 so as to be axially movable and non-rotatably provided. are doing. Driven side fixed pulley piece 36
A driven-side belt groove 40 around which the belt 8 is wound is formed between the driven-side movable pulley piece 38 and the driven-side movable pulley piece 38. On the back side of the driven side movable pulley portion 38, a driven side housing 44 forming a driven side hydraulic chamber 42 in cooperation with the back side of the driven side movable pulley portion 38 is fixed to the driven shaft 34. I have. The driven-side hydraulic chamber 42 is in communication with a driven-shaft-side oil passage 46 formed at an end portion of the driven shaft 34.

Further, in the driven hydraulic chamber 42, between the back surface of the driven movable pulley 38 and the driven housing 44, the driven movable pulley 38 is pressed toward the driven fixed pulley 36. The spring 48 is contracted.
The spring 48 keeps the gear ratio full low (F / L) and prevents the belt 8 from slipping even when the rotation of the oil pump 24 is low and the line pressure (pump pressure) is low at the time of starting the internal combustion engine or the like. The minimum belt holding force is given.

A hydraulic clutch 50 is provided on the back side of the driven fixed pulley piece 36.

The hydraulic clutch 50 includes a clutch casing 52 fixed at the end of a driven shaft 34 which is a clutch input shaft, and a step 54 of the clutch casing 52.
A pressing piston 56 slidably provided in the driven shaft 34 so as to be axially movable, a clutch hydraulic chamber 58 formed between the clutch casing 52 and the pressing piston 56, and the clutch hydraulic chamber 58 is reduced. A diaphragm spring 60 for urging the pressing piston 56 in the direction, and a direction substantially parallel to the axial direction of the driven shaft 34 so as to move in the axial direction of the driven shaft 34 by the pushing force of the pressing piston 56 and the urging force of the diaphragm spring 60. Clutch casing 5 located
2, a pressure plate 64 slidably provided on the outer peripheral edge 62 of the clutch casing 52, an end plate 66 connected to an end of the outer peripheral edge 62 of the clutch casing 52, and a pressure plate 6.
And a friction plate 70 disposed in a clutch space 68 between the end plate 4 and the end plate 66. A driven shaft clutch oil passage 72 formed at an end of the driven shaft 34 communicates with the clutch hydraulic chamber 58.

The friction plate 70 is connected to a clutch output shaft 74 rotatably provided on the driven shaft 34.

In the hydraulic clutch 50, when the hydraulic pressure acting on the clutch hydraulic chamber 58 is increased, the pressure piston 56 is pushed, and the pressure plate 64 is pushed by the urging force of the diaphragm spring 60. The pressure plate 64 makes the friction plate 70 adhere to the end plate 66,
The connected state of the hydraulic clutch 50, that is, the connected state.
On the other hand, when the clutch pressure applied to the clutch hydraulic chamber 58 is reduced, the urging force of the diaphragm spring 60 causes the pressing piston 56 to move in the contracting direction of the clutch hydraulic chamber 58, and the friction plate 70 to be separated from the end plate 66. The hydraulic clutch 50 is disengaged. Therefore, this hydraulic clutch 50
The clutch is engaged / disengaged depending on the clutch pressure state, and interrupts the driving force to the clutch output shaft 74 side.

The clutch hydraulic chamber 5 of the hydraulic clutch 50
A clutch pressure (PCLU), which is changed according to various control modes (control modes) determined by the control means 134 described later, acts on 8.

The various control modes include, for example, a neutral mode (NEU) and a hold mode (HL).
D), a normal start mode (NST) and a special start mode (SST) as start modes,
There is a drive mode (DRV) and the like.

The neutral mode (NEU) is a case in which the position of the shift lever is determined to be parking "P" or neutral "N" and the hydraulic clutch 50 is completely disengaged, and the clutch pressure to the hydraulic clutch 50 becomes zero. It is a state of.

The hold mode (HLD) is determined based on the position of the shift lever, the engine speed, the vehicle speed, and the depressed state of the accelerator pedal. That is, in the hold mode (HLD), the position of the shift lever is the drive “D”,
The condition of low “L” or reverse “R”, the condition of engine speed (NE) <1000 rpm, and the rotation (vehicle speed) of clutch output shaft 74 of hydraulic clutch 50 (NCO) <
8〓 / h and the accelerator pedal switch 1
The determination is made when 52 is off, that is, when the accelerator pedal (not shown) is not depressed and the driver does not intend to run the vehicle. In the hold mode (HLD), the clutch pressure (PCLU) applied to the clutch hydraulic chamber 58 of the hydraulic clutch 50 will be described later so that the target clutch pressure (CPSP) becomes 4.5 ° / ク リ ー² (creep pressure). Solenoid duty output signal (OPWCL) to the
The feedback control is performed in U). The clutch solenoid duty output signal (OPWCLU) is
4, which controls the operation of the clutch solenoid valve 106 by changing the duty ratio. The hold mode (HLD) is used when the vehicle does not have a driving intention, or when it is desired to decelerate during running to cut off engine torque. The clutch pressure (PCLU) of the hydraulic clutch 50 hardly transmits engine torque, but is maintained at a low value such that the hydraulic clutch 50 is slightly connected.

In the normal start mode (NST), the position of the shift lever, the engine speed (NE) and the vehicle speed (N
CO) and the state of depression of the accelerator pedal.
That is, in the normal start mode (NST), the conditions of the shift lever position of drive “D”, low “L” or reverse “R”, the condition of vehicle speed (NCO) <8 ° / h, the accelerator pedal Accelerator pedal switch 152
Is ON and engine speed (NE) ≧ 1000r
pm is satisfied. In the normal start mode (NST), the clutch pressure (PCLU) according to the engine generated torque (clutch input torque) is applied to the hydraulic clutch 50 when the hydraulic clutch 50 is to be engaged again when the vehicle starts or after the clutch is disconnected. As a result, the clutch pressure (PCLU) is maintained at an appropriate value with a quick response in order to prevent the engine speed (NE) from rising and to start the vehicle smoothly.

The special start mode (SST)
When the position of the shift lever is a drive “D”, a low “L” or a reverse “R”, and the vehicle speed (NCO) ≧ 8 ° / h
Is determined when the condition (2) is satisfied. In the special start mode (SST), the difference between the rotation of the driven shaft 34, which is the clutch input shaft, and the rotation of the clutch output shaft 74 (clutch slip amount) is a constant (φ).
, And the clutch solenoid valve 106 is feedback-controlled by the clutch solenoid duty (OPWCLU) so that the clutch pressure (PCLU) becomes the target clutch pressure (CPSP).

The drive mode (DRV) is determined based on the position of the shift lever, the vehicle speed, and the clutch slip amount.
That is, in the drive mode (DVR), the conditions of the shift lever position of drive "D", low "L" or reverse "R", the condition of vehicle speed (NCO) ≥ 8 / h,
It is determined when the clutch slip amount ≦ 20 rpm is satisfied. In this drive mode (DRV),
In a state where the vehicle shifts to a complete running state and the hydraulic clutch 50 is completely connected (clutch lock-up state), or in a state where the hydraulic clutch 50 is substantially locked up when shifting from the normal start mode (NST). When the vehicle is completely shifted to the running state and the hydraulic clutch 50 is completely engaged, a high clutch pressure (line pressure) having a margin enough to withstand engine torque is applied to the hydraulic clutch 50.
To act on.

The operation of the continuously variable transmission 2 is controlled by a shift control device 76 as shown in FIG. The transmission control device 76 changes the rotation radius of the belt 8 wound around the driving pulley 4 and the driven pulley 6 to change the transmission ratio (R
ATC) is continuously controlled, and the on / off state of the hydraulic clutch 50 is controlled by the clutch pressure (PCLU) set in the various control modes described above.

The transmission control device 76 is provided with a line pressure passage 78 through which oil pumped by the oil pump 24 is supplied to the driven hydraulic chamber 42 to apply a line pressure. One end of the line pressure passage 78 is connected to the oil pump 2.
4 and the other end is connected to the driven shaft side oil passage 46.

One end of a first oil passage 80 is connected in the middle of the line pressure passage 78. On the other end side of the first oil passage 80, a line pressure control valve 82 is provided. The line pressure control valve 82 controls the line pressure in the line pressure passage 78.

One side of the line pressure control valve 82 has a second
One end of the oil passage 84 is connected. This second oil passage 84
A line solenoid valve 86 for controlling the operation of the line pressure control valve 82 is provided on the other end side.

The oil pump 24 and the first oil passage 80
In the middle of the line pressure passage 78 between the connection portions with
One end of the oil passage 88 is connected. This third oil passage 88
On the other end side, a ratio pressure control valve 90 is provided.
One end of a ratio pressure passage 92 is connected to the ratio pressure control valve 90. The other end of the ratio pressure passage 92 is connected to the drive shaft side oil passage 22 of the drive shaft 10.

The ratio pressure control valve 90 is connected to the drive pulley 4
This is for controlling a ratio pressure (primary pressure), which is a hydraulic pressure applied to the drive-side hydraulic chamber 18.

One side of the ratio pressure control valve 90 has a fourth
One end of the oil passage 94 is connected. This fourth oil passage 94
A ratio solenoid valve 96 for controlling the operation of the ratio pressure control valve 90 is provided at the other end of the valve.

One end of a fifth oil passage 98 is connected to the line pressure passage 78 between the connection portion of the first oil passage 80 and the oil passage 46 on the driven shaft side. On the other end side of the fifth oil passage 98, a clutch pressure control valve 100 is provided.

One end of a clutch pressure passage 102 is connected to the clutch pressure control valve 100. The other end of the clutch pressure passage 102 is connected to a driven shaft clutch oil passage 72 on the hydraulic clutch 50 side.

The clutch pressure control valve 100 controls a clutch pressure which is a hydraulic pressure applied to the clutch hydraulic chamber 58.

On one side of the clutch pressure control valve 100,
One end of the sixth oil passage 104 is connected. On the other end side of the sixth oil passage 104, a clutch solenoid valve 106 for controlling the operation of the clutch pressure control valve 100 is provided.

In the middle of the third oil passage 88, the seventh oil passage 10
8 is connected to one end. On the other end side of the seventh oil passage 108, one side of a constant pressure control valve 110 is provided.
The constant pressure control valve 110 is provided with a line pressure (generally 5 to 25 °).
/ 〓 ² ) is controlled to a constant pressure (4-5〓 / 〓 ² ).

The other end of the constant pressure control valve 110 is connected to one end of an eighth oil passage 112. This eighth oil passage 11
The other end of 2 is branched into a ninth oil passage 114 and a tenth oil passage 116. The ninth oil passage 114 is connected to the line pressure control valve 8.
2 is connected to the other side. The tenth oil passage 116 is connected to the line solenoid valve 86.

In the middle of the eighth oil passage 112, one end of an eleventh oil passage 118 is connected. This eleventh
The other end of the oil passage 118 is branched into a twelfth oil passage 120 and a thirteenth oil passage 122. The twelfth oil passage 120 is connected to the other side of the ratio pressure control valve 90. 13th oilway 1
22 is connected to a ratio solenoid valve 96.

Further, one end of a fourteenth oil passage 124 is connected in the middle of the eighth oil passage 112. This 14th
The other end of the oil passage 124 is branched into a fifteenth oil passage 126 and a sixteenth oil passage 128. The fifteenth oil passage 126 is connected to the other side of the clutch pressure control valve 100. The sixteenth oil passage 128 is connected to the clutch solenoid valve 106.

One end of a clutch pressure detecting passage 130 is connected in the middle of the clutch pressure passage 102. At the other end of the clutch pressure detection passage 130, a hydraulic pressure sensor 132 for detecting the clutch pressure of the clutch pressure passage 102 is provided.

The line solenoid valve 86, the ratio solenoid valve 96, and the clutch solenoid valve 10
6 and the oil pressure sensor 132 are connected to a control means (ECM) 134
Has been contacted.

The control means 134 includes a drive shaft rotation sensor 136 for detecting the rotation of the drive shaft 10 as the engine speed (NE) of the internal combustion engine, and the rotation of the driven shaft 34 as the rotation of the clutch input shaft (NCI). A driven shaft rotation sensor 138 to be detected and an output shaft rotation sensor 140 to detect the rotation (NCO) of the clutch output shaft 74 as the vehicle speed are communicated.

The drive shaft rotation sensor 136 detects the rotation of the drive shaft rotation detection gear 142 fixed to the drive shaft 10 on the rear surface of the drive side housing 20 and outputs a signal corresponding to the rotation of the drive shaft 10. 134.

The driven shaft rotation sensor 138 detects the rotation of the driven shaft rotation detecting gear 144 fixed to the driven shaft 34 on the rear side of the driven housing 44 and outputs a signal corresponding to the rotation of the driven shaft 34. 134.

The output shaft rotation sensor 140 has an output shaft rotation detecting gear 146 provided integrally with the clutch output shaft 74.
Rotation of the clutch output shaft 74 (vehicle speed)
(NCO) is output to the control means 134.

The control means 134 includes a shift lever position detection sensor 148 and a throttle opening sensor 150.
, Idle switch 152 and brake switch 15
4, a power mode option switch 156, and an accelerator pedal switch 158.

The shift lever position detecting sensor 148 detects the position of the shift lever, that is, the parking "P", the reverse "R", the neutral "N", the drive "D", and the low "L", respectively, and detects the signal. To the control means 134 to control the line pressure, the ratio pressure, and the clutch pressure required for each shift lever position.

The throttle opening sensor 150 detects the throttle opening (THR) state of a throttle valve (not shown) and outputs a signal corresponding to the throttle opening (THR) to the control means 134. In step 134, the engine torque is predicted from the engine torque setting map (see FIG. 1) previously input to the memory of the program, and the target gear ratio and the target engine speed are determined.

The idle switch 152 is turned on when the internal combustion engine is in an idling operation state.

The brake switch 154 detects whether or not the brake pedal is depressed and outputs a signal to the control means 134 so that the control means 134 can determine a control direction such as disconnecting the hydraulic clutch 50. It is.

Power mode option switch 156
Is used to make the performance of the vehicle sporty or economy, and outputs a signal to the control means 134 so that the control means 134 controls the ratio pressure and the like.

An accelerator pedal switch 158 detects whether or not an accelerator pedal (not shown) is depressed, and outputs a signal to a control means 134, and the control means 134 controls the control direction such as running or starting. Let it be decided.

The program of the control means 134 includes a throttle opening (TH) as shown in FIG. 1 for controlling the clutch pressure applied to the hydraulic clutch 50 when the vehicle starts moving.
R), a feedforward control unit (F / F) FF, which is a target clutch pressure calculation unit that calculates the target clutch pressure (CPSP) by open-loop control by predicting the engine torque (TRQ) according to the input. In the feedforward control unit (F / F) FF, the engine speed (NE) during the start of the vehicle is changed to the target engine speed (NE).
The target clutch pressure (C
PSP) is determined, but the torque difference (ΔT) between the engine torque (TRQ) predicted based on the operating state of the engine 2 or the running state of the vehicle and the actual engine torque is determined.
RQ), the target engine speed (NESPCF) may not be obtained with the target clutch pressure (CPSP). For example, engine speed (NE) <target engine speed (NES) for clutch control after filtering.
In the case of PCF), since the actual engine torque <the predicted engine torque (TRQ), the engine load is reduced by reducing the target clutch pressure (CPSP), thereby reducing the engine speed (NE). Need to be increased. On the other hand, engine speed (NE)>
In the case of the target engine speed (NESPCF) of the clutch control after the filter processing, the actual engine torque>
Since the engine torque (TRQ) is the predicted value, the engine load is increased by increasing the target clutch pressure (CPSP), thereby increasing the engine speed (NE).
Needs to be reduced. For this reason, the engine torque (TR
Q) and the actual engine torque, the torque difference (ΔTRQ)
If there is, the engine speed (NE) and the target engine speed (NESPC) of the clutch control after the filtering process are performed.
F), the feedforward control unit F according to the rotational speed difference corresponding to the torque difference (ΔTRQ).
A steady state control unit (S / S) SS, which is a target clutch pressure correction unit that calculates a correction amount for correcting the target clutch pressure (CPSP) at F, is input to the program of the control unit 134.

The control means 134 controls the engine torque (TR) predicted by the feedforward control section (F / F) FF.
Q) and the actual engine torque, the torque difference (ΔTRQ)
When there is, in the steady state control unit SS, the engine speed (NE) is set to the target engine speed (NESPCF) of the clutch control after the filtering process, that is, the torque difference (ΔTRQ) is eliminated. Next, a correction amount is calculated, and the target clutch pressure (CPSP) is adjusted by feedback learning control based on the correction amount. That is, for example, as shown in FIG. 3, the control unit 134 compares the engine speed (NE) with the target engine speed (NESPCF) of the clutch control after the filter processing. While reducing the engine load by decreasing the pressure (CPSP) and increasing the engine speed (NE),
If NE> NESPCF, the target clutch pressure (CP
By increasing SP), the engine load is increased and the engine speed (NE) is reduced.

As shown in FIG. 1, the control means 134 stores a throttle opening (THR) in a program memory.
An engine torque setting map (TRQCV) for setting the engine torque (TRQ) in accordance with is input.

The steady state control section SS of the control means 134 controls the correction amount to be small in the first half of the start of the vehicle, and increases the correction amount in the second half of the start of the vehicle. That is, the clutch pressure (PCLU) to the hydraulic clutch 50 is controlled.

In other words, the control means 134 controls the clutch pressure (PCLU) applied to the hydraulic clutch 50 in accordance with the first half and the second half of the starting progress of the vehicle. Is changed with respect to the proportional gain (Kn) and the integral gain (Kin).

In this embodiment, for example, a clutch slip amount (CSP) is used as a variable corresponding to the start progress state of the vehicle.

For this reason, the program memory of the control means 134 has a proportional gain setting map (KnCRV) K used in the steady state control section SS.
T (see FIG. 4) and a map for setting the integral gain (KinCR
V) KIN (see FIG. 5) is input.

In the proportional gain setting KI map shown in FIG. 4, the clutch slip amount (C) which is the difference between the rotation of the driven shaft 34 as the clutch input shaft and the rotation of the clutch output shaft 74 is shown.
According to the state SP), the proportional gain (Kn) is constantly increased to the position H1 at a position up to G1 where the clutch slip amount (CSP) as a variable indicating the vehicle start progress is relatively small, and the clutch slip amount (CSP) is increased. ) Is between the position G1 and the position G2, and the proportional gain (K
n) is made proportionally smaller, and above the G2 position, the proportional gain (Kn) is kept constant at the H2 position.

In the integral gain setting map KIN shown in FIG. 5, the integral gain (Kin) is fixedly increased to the position Y1 at a position up to X1 where the clutch slip amount (CSP) as a variable is relatively small. The integral gain (Kin) is reduced in proportion to the slip amount (CSP) from the position X1 to the position X2, and the integral gain (Kin) from the position X2 to the position X2.
At the Y2 position.

That is, in FIGS. 4 and 5, during the start of the vehicle, the smaller the clutch slip amount (CSP), the more the start progresses. Therefore, the proportional gain setting map KN and the integral gain setting map KIN Has a negative gradient, and the smaller the clutch slip amount (CSP), the larger the proportional gain (Kn) and the integral gain (Kin) are set as the correction amounts.

As described above, in order to control the clutch pressure (PCLU) to the hydraulic clutch 50 during the start of the vehicle,
In the steady state control unit SS of the control means 134, the control is performed such that the correction amount is reduced in the first half of the vehicle start progress, and the control is performed such that the correction amount is increased in the second half of the vehicle start progress. For the following reasons.

That is, when the vehicle starts moving, the power of the internal combustion engine is most necessary for the wheels until the vehicle starts moving. After the vehicle starts moving, the vehicle can be started without any problem with relatively low power. On the other hand, the operation of the feedforward control unit FF is changed to the steady state control unit S.
When the engine speed is always larger than the function of S, the coupling of the hydraulic clutch 50 becomes weaker as the engine speed (NE) becomes higher. Therefore, when the power required for the vehicle to start moving cannot be obtained, that is, the power performance is reduced. May be low.

Therefore, in this embodiment, the proportional gain (K) is set while the vehicle is moving forward (shown between R1 and R2 in FIG. 3).
n) and the integral gain (Kin) are changed, and in the first half of the start of the vehicle, the operation of the steady state control unit SS is reduced, and the amount of engagement of the hydraulic clutch 50 is prioritized to transmit a large driving force to the wheels. At the same time, in the latter half of the start of the vehicle, the operation of the steady state control unit SS is increased to increase the clutch pressure so that the engine speed (NE) becomes equal to the target engine speed (NESPCF) of the clutch control after filtering. Adjust the engine speed (N
This is to suppress the fluctuation of E).

Next, the operation of this embodiment will be described with reference to the control block diagram of FIG.

The feedforward control section FF inputs the throttle opening (THR) and predicts the engine torque (TRQ) corresponding to the throttle opening (THR) from the engine torque setting map (TRQCV) (202). ), A gear ratio (RATC) is calculated from the engine torque (TRQ) (204), and the gear ratio (RAT) is calculated.
C) is multiplied by a proportional gain (Kc) in the feedforward control unit FF (206), and a filtering process (208) is performed.

On the other hand, in the steady state control section SS, the target engine speed (NE
SPC) is filtered (210), and a target engine speed (NESPCF) for the clutch control after the filtering is obtained (210).

On the other hand, the clutch input rotation speed (NC
The clutch slip amount (CSP = | NCI-NCO |) is calculated from I) and the clutch output speed (NCO) (21).
2) The proportional gain (Kn) is determined from the proportional gain setting map KN according to the clutch slip amount (CSP) (214). Then, the rotational speed difference between the target engine rotational speed (NESPCF) of the clutch control after the filtering and the actual engine rotational speed (NE) is calculated (216), and the rotational speed difference is determined by the proportional gain setting map KN. The calculated proportional gain (Kn) is multiplied (218), and the value obtained by multiplying the proportional gain (Kn) is multiplied by the phase lead / lag gain (220).

The value obtained by multiplying the phase lead / lag gain is integrated (222). In the integration process (222), the integral gain (Kin) calculated from the integral gain setting map KIN (224) is applied according to the clutch slip amount (CSP).

The value obtained from the phase advance / delay processing (222) is added to the integrated gain value (226), and the value obtained by this calculation is applied to the limiter (228).

Then, the value obtained by the limiter (228), the value of the filter processing of the feedforward control unit FF, and the clutch touch-off pressure (PCE) are calculated (230), and the value obtained by this calculation is calculated. Is the limiter (23
2).

The value obtained by the limiter 232 and the actual clutch pressure (PCLU) are calculated (23).
4) A proportional gain (Kp) is multiplied by the clutch pressure difference obtained by this calculation (236), and a value obtained by multiplying the proportional gain (Kp) is multiplied by a phase lead / lag gain (238).

The value obtained by multiplying the phase lead / lag gain is as follows:
On the other hand, an integral gain (Kis) is applied (24
0).

The value obtained by multiplying the integral gain, the value obtained from the phase advance / delay process (238), and the clutch solenoid value (NPC) are calculated (242), and the clutch solenoid duty (OPWCLU) is calculated. The duty (OPWCLU) is sent to the clutch solenoid valve 106, the clutch solenoid valve 106 is operated and the clutch pressure (PCLU) to the hydraulic clutch 50 is controlled.

FIG. 2 shows the clutch pressure control.
A description will be given based on the flowchart of FIG.

When the program of the control means 134 starts (step 302), it is first determined whether or not the normal start mode (NST) is set (step 304).

In the case of YES at step 304,
A clutch slip amount (CSP) is calculated from the clutch input rotation speed (NCI) and the clutch output rotation speed (NCO) (step 306).

Then, the clutch slip amount (CS
According to P), the proportional gain (Kn) is determined from the proportional gain setting map KN (Step 308), and the integral gain (Kin) is determined from the integral gain setting map KIN (Step 310).

Then, clutch control is performed in the other normal start mode (NST) (step 31).
2), return (step 314).

On the other hand, if NO in step 304, clutch control in another control mode is performed (step 3).
16) Then, return is made in step 314.

As a result, as shown in FIG. 3, during the start and advance of the vehicle (shown between R1 and R2 in FIG. 3), for example, the engine speed (NE) <the target engine speed for clutch control after filtering. (NESPCF)
By reducing the target clutch pressure (CPSP),
The engine load is reduced, thereby increasing the engine speed (NE), while the engine speed (NE)> the target engine speed (NES) of the clutch control after filtering.
In the case of PCF), the engine load is increased by increasing the target clutch pressure (CPSP), and the engine speed (NE) is decreased.

Therefore, as in this embodiment, in the first half of the start of the vehicle, the correction amount is controlled to be small so that the coupling amount of the hydraulic clutch 50 is prioritized, and a large driving force is transmitted to the wheels. In the latter half of the starting movement of the vehicle, control is performed to increase the correction amount so that the engine speed (NE) becomes equal to the target engine speed (NESPCF) of the clutch pressure control after the filtering process. As a result, fluctuations in the engine speed (NE) can be suppressed, the starting feeling can be improved, and required power performance can be ensured.

In this embodiment, the control means 1
It can be dealt with only by changing 34 programs,
It is practically advantageous.

Further, even when the engine speed (NE) is low, required power performance can be ensured. As a result, the required power performance can be improved even when the vehicle is started when the throttle opening is substantially fully opened.

Further, it is possible to reduce the influence on the start due to individual differences of the internal combustion engine and the hydraulic clutch 50 and aging.

Further, the robustness (robustness) of the start control can be increased.

The clutch pressure control in this embodiment is not limited to the continuously variable transmission 2 but can be applied to an automatic transmission and other clutches.

[0095]

As is apparent from the above detailed description, according to the present invention, a target clutch pressure calculating section for predicting an engine torque corresponding to a throttle opening and calculating a target clutch pressure, and the target clutch pressure calculating section When there is a torque difference between the engine torque predicted in step (a) and the actual engine torque, a target clutch pressure correction unit for calculating a correction amount for correcting the target clutch pressure according to the torque difference is provided. The target clutch pressure correction unit of the means controls the correction amount to be small in the first half of the vehicle start progress, and controls to increase the correction amount in the second half of the vehicle start progress. As the start progresses, the clutch pressure is appropriately corrected, the start feeling is improved, and the required power performance can be secured.

Further, this can be dealt with only by changing the program of the control means, and the configuration is simple and inexpensive.

Further, the power performance can be improved even when the vehicle is started at a substantially full throttle opening.

Further, it is possible to reduce the influence of the individual engine and the hydraulic clutch on the starting due to the aging.

Further, the robustness (robustness) of the vehicle start control can be increased.

[Brief description of the drawings]

FIG. 1 is a control block diagram of clutch pressure control.

FIG. 2 is a flowchart of clutch pressure control.

FIG. 3 is a time chart of clutch pressure control.

FIG. 4 is a map for setting a proportional gain.

FIG. 5 is an integration gain setting map.

FIG. 6 is a system configuration diagram of a shift control device of the continuously variable transmission.

FIG. 7 is a time chart of conventional clutch pressure control.

FIG. 8 is a diagram illustrating a relationship among an engine speed, an engine torque, and a throttle opening.

[Explanation of symbols]

 2 Continuously Variable Transmission 4 Drive Pulley 6 Driven Pulley 8 Belt 50 Hydraulic Clutch 76 Shift Control Device 78 Line Pressure Passage 82 Line Pressure Control Valve 86 Line Solenoid Valve 90 Ratio Pressure Control Valve 92 Ratio Pressure Passage 96 Ratio Solenoid Valve 100 Clutch Pressure Control Valve 102 Clutch pressure passage 106 Clutch solenoid valve 134 Control means

Continuation of the front page (56) References JP-A-3-125032 (JP, A) JP-A-3-121351 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 41 / 02-41/06 B60K 41/22 F16D 48/02 F16H 61/00

Claims (1)

(57) [Claims] 1. A speed change ratio is continuously controlled by changing a radius of rotation of a belt wound around a driving pulley and a driven pulley, and an on-off state of a hydraulic clutch is controlled by a clutch pressure set in various control modes. In a speed change control device of a continuously variable transmission to be controlled, a target clutch pressure calculating unit for predicting an engine torque according to a throttle opening and calculating a target clutch pressure, an engine torque predicted by the target clutch pressure calculating unit and an actual A target clutch pressure correction unit for calculating a correction amount for correcting the target clutch pressure according to the torque difference when there is a torque difference with the engine torque.
Control means for controlling the target clutch of the control means.
The pressure correction unit performs the correction amount in the first half of the start progress of the vehicle.
In the second half of the vehicle
And a control for increasing the correction amount .