JPH08178000A - Controller of continuously variable automatic transmission - Google Patents

Abstract

PURPOSE: To quickly complete speed change to a desired change gear ratio at the time of manual speed change in a continuously variable automatic transmission. CONSTITUTION: In a continuously variable automatic transmission provided with a continuously variable speed change gear for transmitting continuously variably the rotation of an engine to a drive shaft, an automatic speed changing means for controlling the change gear ratio of the continuously variable speed change gear to a desired change gear ratio determined according to the running condition, and a manual speed changing means for controlling the ratio to a desired change gear ratio set manually, the increment or decrement (dip) of a pulley ratio larger than that in the automatic speed change is given to a deviation eip between the reach pulley ratio (actual ip) of the continuously variable speed change gear and the actual pulley ratio (actual ip).

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art The output of an engine is transmitted to a drive shaft of a vehicle or the like via a fluid transmission such as a torque converter or a fluid coupling and a continuously variable transmission for continuously changing the output. There is known a continuously variable automatic transmission that is adapted to be transmitted. (For example, as a known document, refer to Japanese Patent Laid-Open No. 61-105353.) In this type of automatic transmission, a target gear ratio is set according to a required load represented by a throttle opening, a vehicle speed, and other operating conditions. In addition to a range for automatic gear shifting (D range), there is a range in which a gear ratio corresponding to a specific low gear, for example, can be selected by a driver's manual operation.

In an automatic transmission having such a manual shift range, for example, if a specific low speed stage is manually specified while running at a small gear ratio corresponding to the top gear in the D range, engine overspeed will result as a result of the shift. As long as there is no problem such as the above, gear shifting is performed to the gear ratio of the low speed stage, and it is possible to operate the vehicle according to the driver's intention other than the predetermined automatic gear shift pattern, and thus a wider driving range The running performance of the vehicle can be exhibited under the conditions.

By the way, according to the conventional automatic transmission as described above, the change speed at the time of changing the gear ratio toward a certain target gear ratio according to the operating state is calculated by changing the actual speed ratio and the target speed ratio (these speed ratios). Correlation value, for example, including the input shaft rotation speed of the continuously variable transmission). However, the speed of change of the gear ratio is set so that the driver does not suddenly feel a large shift shock during an automatic shift such as a downshift or an upshift, so that the manual shift is performed. Even when the gear shift is performed, the gear shift to the gear ratio designated by the driver is performed slowly, which causes a problem that the responsiveness to the driver's intention to shift is not good.

The present invention has been made in view of these problems, and an object thereof is to provide a continuously variable automatic transmission having improved drivability by increasing the speed of change of the gear ratio during manual gear shifting. There is.

[0006]

According to a first aspect of the present invention, there is provided a continuously variable transmission for continuously and variably transmitting engine rotation to a drive shaft, and a target for determining a gear ratio of the continuously variable transmission according to an operating state. In a continuously variable automatic transmission equipped with an automatic transmission means for controlling to a transmission ratio and a manual transmission means for controlling to a manually set target transmission ratio, a change to a target transmission ratio set by the manual transmission means. The speed is set to be higher than the speed of change to the target speed ratio set by the automatic speed changing means.

According to a second aspect of the present invention, in the above first aspect of the invention, the rate of change to the target gear ratio is set to be larger as the difference between the actual gear ratio and the target gear ratio is larger.

According to a third aspect of the present invention, the automatic speed change means and the means speed change means of the first or second aspect of the present invention are changed to a target speed ratio based on a difference between the actual speed ratio and the target speed ratio. It is assumed that each map is provided with.

According to a fourth aspect of the present invention, one of the automatic transmission means and the manual transmission means of the first or second aspect sets the speed of change to the target gear ratio, and the other one corrects the set value. The rate of change shall be set as a value.

[0010]

According to the first aspect of the present invention, when the gear ratio is changed to the gear ratio specified by the driver through the manual gear change means, the gear ratio of the continuously variable transmission is quickly changed to the target gear ratio. Changes to.

According to the second aspect of the present invention, the larger the difference between the actual gear ratio and the target gear ratio, the greater the speed of change of the gear ratio to the target gear ratio. Therefore, the difference in the gear ratio does not increase. Even during the manual shift operation, the speed ratio is promptly controlled to the gear ratio intended by the driver.

According to the third aspect of the present invention, the speed of change to the target gear ratio is given with good response by the map in each of the automatic shift and the manual shift.

In the invention of claim 4, the speed of change to the target gear ratio determined by one of the automatic transmission and the manual transmission is corrected and used by the other, so that the storage device in the manual transmission means or the automatic transmission means is used. The configuration of the included arithmetic device becomes simpler.

[0014]

EXAMPLES Examples of the present invention will be described below.

FIG. 1 shows a vertical sectional structure of a continuously variable automatic transmission to which the present invention can be applied. To explain this, the engine output shaft 10 has a torque converter 1 as a hydraulic transmission device.
Two are connected. A fluid coupling may be used instead of the torque converter 12 as the fluid transmission.

The torque converter 12 is provided with a lockup clutch 11, and by controlling the hydraulic pressures of the converter chamber 12c and the lockup oil chamber 12d reciprocally, a pump impeller 12a on the input side and a turbine runner 12b on the output side are provided. Can be mechanically connected or disconnected.

The output side of the torque converter 12 is the rotary shaft 1
3, the rotary shaft 13 is connected to the forward / reverse switching mechanism 15. The forward / reverse switching mechanism 15 is the planetary gear mechanism 1.
9, a forward clutch 40, a reverse brake 50 and the like. The output side of the planetary gear mechanism 19 has a rotary shaft 13
Is connected to a drive shaft 14 which is coaxially fitted to the outside. A drive pulley 16 of a continuously variable transmission 17 is provided on the drive shaft 14.

The continuously variable transmission 17 is composed of the drive pulley 16, the driven pulley 26, a V belt 24 for transmitting the rotational force of the drive pulley 16 to the driven pulley 26, and the like.

The drive pulley 16 has a fixed conical plate 18 which rotates integrally with the drive shaft 14, and a hydraulic cone which is arranged opposite to the fixed conical plate 18 to form a V-shaped pulley groove and which acts on the drive pulley cylinder chamber 20. The movable conical plate 22 is movable in the axial direction of the drive shaft 14. In this case, the drive pulley cylinder chamber 20 includes the chamber 20a and the chamber 20.
It is composed of two chambers b, and has a larger pressure receiving area than a driven pulley cylinder chamber 32 described later.

The driven pulley 26 is provided on the driven shaft 28. The driven pulley 26 includes a fixed conical plate 30 that rotates integrally with the driven shaft 28, a V-shaped pulley groove that is disposed to face the fixed conical plate 30 to form a V-shaped pulley groove, and a hydraulic pressure that acts on the driven pulley cylinder chamber 32. And a movable conical plate 34 that is movable in the axial direction.

A drive gear 46 is fixed to the driven shaft 28, and the drive gear 46 meshes with an idler gear 48 on an idler shaft 52. The pinion gear 54 provided on the idler shaft 52 meshes with the final gear 44. The final gear 44 drives a propeller shaft or a drive shaft reaching a wheel (not shown) via a differential device 56.

The torque input from the engine output shaft 10 to the continuously variable automatic transmission as described above is converted into the torque converter 1.
2 is transmitted to the forward / reverse switching mechanism 15 via the rotary shaft 13, the forward clutch 40 is engaged, and the reverse brake 50 is released. The rotational force of the rotary shaft 13 is transmitted to the drive shaft 14 of the continuously variable transmission 17 while maintaining the same rotational direction, while the forward clutch 40 is released and the reverse brake 50 is engaged. Due to the action of the gear mechanism 19, the rotational force of the rotary shaft 13 is transmitted to the drive shaft 14 in a state where the rotating direction is reversed.

The rotational force of the drive shaft 14 is the drive pulley 16, V
Belt 24, driven pulley 26, driven shaft 28, drive gear 4
6, the idler gear 48, the idler shaft 52, the pinion gear 54, and the final gear 44 through the differential device 56.
Is transmitted to When both the forward clutch 40 and the reverse brake 50 are released, the power transmission mechanism is in a neutral state.

During the power transmission as described above, the movable conical plate 22 of the drive pulley 16 and the movable conical plate 34 of the driven pulley 26 are moved in the axial direction to change the contact position radius with the V belt 24. The rotation ratio between the drive pulley 16 and the driven pulley 26, that is, the gear ratio (reduction ratio) can be changed. For example, if the width of the V-shaped pulley groove of the drive pulley 16 is increased and the width of the V-shaped pulley groove of the driven pulley 26 is reduced, the V belt 2 on the drive pulley 16 side is reduced.
The contact position radius of No. 4 becomes smaller, and V on the driven pulley 26 side becomes smaller.
Since the V-belt contact position radius of the belt 24 becomes large, a large gear ratio can be obtained. Movable conical plate 2
If 2 and 34 are moved in the opposite direction, the gear ratio becomes smaller, contrary to the above.

Such a drive pulley 16 and a driven pulley 2
The control for changing the width of the V-shaped pulley groove 6 is performed by the drive pulley cylinder chamber 20 (20
a, 20b) or hydraulic control to the driven pulley cylinder chamber 32.

FIG. 2 shows an outline of a control system having a function of performing the basic gear ratio control of the continuously variable automatic transmission including the functions of the manual transmission means and the automatic transmission means of the present invention. Note that, in FIG. 2, the same reference numerals are given to the mechanical parts corresponding to those in FIG.

Hereinafter, this control system will be described focusing on the part related to the present invention. In FIG. 4, 101 is an electronic control unit including a microcomputer and the like, and 102 is a hydraulic control unit including various hydraulic control valves. In this control system, the control means of the continuously variable automatic transmission is mainly these electronic control units. It is configured by 101 and the hydraulic control unit 102.

The electronic control unit 101 performs a central processing unit 101A for performing control arithmetic processing, an input unit 101B for converting various operating state signals from the engine and the vehicle into a processable format and supplying the central processing unit 101A, and Central processing unit 1
The output unit 101C outputs various signals for hydraulic control and the like based on the control signal from 01A.

The input unit 101B has a water temperature signal S1, a throttle opening signal S2, an engine rotation signal S3 and an ABS which are used by a control module 103 for electronically controlling the fuel injection amount and ignition timing of the engine 100.
(Anti-lock brake system) ABS actuation signal S4 from the control device 104, braking signal S5 issued when the vehicle braking device is actuated, selector position signal S6 issued from the inhibitor switch as a signal indicating the operation position of the selector lever 105, drive pulley 16 rotation speed signals S
7, the rotation speed signal S8 of the driven pulley 26, etc. is input,
These signals are supplied to the central processing unit 101A as needed.

The central processing unit 101A includes a shift control unit 10
6, line pressure control unit 107, lockup control unit 108
The step motor drive circuit 109, the line pressure solenoid drive circuit 110, and the lockup solenoid drive circuit 11 which form the output unit 101C by calculating a control signal by using a necessary predetermined signal from the various signals.
By driving 1, the gear ratio of the continuously variable transmission 17, the line pressure, and the lockup clutch 11 are controlled.

More specifically, the shift control unit 106 outputs a control signal to the step motor drive circuit 109 so that the shift is performed according to a predetermined pattern according to the engine load represented by the throttle opening and the vehicle speed. . Based on this control signal, the step motor drive circuit 109 drives the step motor 113 connected to the shift control valve 112 of the hydraulic control unit 102.

That is, the step motor 113 drives the shift control valve 112 so that the target speed ratio corresponding to the signal from the step motor drive circuit 109 is reached, and the drive pulley cylinder chamber 20 and the driven pulley cylinder chamber 32 (see FIG. 1).
Reciprocally increase or decrease the line pressure supplied to the. The displacement of the drive pulley 16, that is, the gear ratio is fed back to the speed change control valve 112 via the link 114, and the step motor 1
When the target gear ratio corresponding to the position of 13 is reached, the hydraulic pressure distribution to the pulley cylinder chambers 20 and 32 becomes constant, and the target gear ratio is stabilized.

On the other hand, when the transmission ratio of the continuously variable transmission 17 is controlled in this way, if the line pressure supplied to the pulleys 16 and 26 is too small, the pulleys 16 and 18 and the V belt 24 will be separated. The frictional force between
On the other hand, if the line pressure is excessive, the frictional force will unnecessarily increase, and in any case, the fuel efficiency and power performance of the vehicle will be adversely affected. Therefore, the line pressure control unit 10 is configured so that proper power transmission can be performed without excess or deficiency according to the gear ratio, the load, and the like.
7 controls the line pressure via the line pressure solenoid drive circuit 110.

That is, the line pressure solenoid drive circuit 1
Reference numeral 10 is a line pressure solenoid 115 of the hydraulic control unit 102.
Is controlled according to a control signal from the drive circuit 110, and the line pressure solenoid 115 responds to this by controlling a hydraulic pressure from a hydraulic pump (not shown) with a modifier (pressure control valve) 116 and a regulator (constant pressure valve). The desired line pressure is adjusted via 117 and supplied to the shift control valve 112 or the pulleys 16 and 26.

Further, the lockup control unit 108 performs hydraulic control so that the lockup clutch 11 is engaged, for example, when the vehicle speed becomes a predetermined value or higher, and released when the vehicle speed becomes a predetermined value or lower. .

That is, the lockup control unit 108
Depending on the vehicle speed, the lockup solenoid 11 of the hydraulic control unit 102 is controlled via the lockup solenoid drive circuit 111.
8 is driven, and thereby the lockup control valve 119 is switch-controlled. In this case, the lockup control valve 119 is
Two systems: a system that supplies the hydraulic pressure from the hydraulic pump as an apply pressure to the converter chamber 12c of the torque converter 12 to connect the lockup clutch 11, and a system that similarly supplies a release pressure to the lockup oil chamber 12d as a release pressure. It is designed to perform reciprocal switching such as. That is, when the lock-up clutch 11 is connected, the apply pressure is supplied to the converter chamber 12c, the lock-up oil chamber 12d is opened, and the lock-up clutch 11 is opened.
When releasing, the release pressure is supplied to the lock-up oil chamber 12d and the converter chamber 12c is opened.

In FIG. 2, reference numeral 120 denotes a manual control valve which is interlocked with the selector lever 105, and is fixedly controlled according to the position of the manual control valve 120 to a specific gear ratio or gear shift pattern designated by the driver. The hydraulic control unit 102 to a state in which the gear ratio is automatically changed to a gear ratio determined by the electronic control unit 101 according to the operating state.
The circuit of is switched.

The above is an example of the continuously variable automatic transmission to which the present invention can be applied. In the present invention, the speed of shifting when continuously shifting such a continuously variable automatic transmission is increased to improve drivability. The purpose is to improve.

This point will be described with reference to the control conceptual diagram relating to the shift control shown in FIG. 3 and the flow chart shown in FIG. 4 while corresponding to the structure of the continuously variable automatic transmission.

In this control, as shown in FIG. 3, it is determined as a result of detecting a predetermined operating condition (usually represented by a load such as a throttle opening and a vehicle speed) by the automatic transmission, or manually. Based on the drive pulley rotation speed Npri and the driven pulley rotation speed Nsecd that should be reached by the driver, the pulley ratio (reaching ip) to be reached is calculated by the transmission means. Next, the change speed (increase / decrease) dip of the pulley ratio is determined based on the deviation eip between the reached ip and the actual pulley ratio (actual ip) corresponding to the actual gear ratio. Then, as the target ip, a value obtained by adding the changing speed dip to the actual ip is output. In the case of gear shifting in the direction of decreasing the pulley ratio, dip has a negative value, so dip is added as a reduction amount with respect to the actual ip. By repeating such control periodically, the actual pulley ratio is brought closer to the target pulley ratio. The N
The secd and the actual ip are detected based on the drive pulley rotation speed signal S7 and the driven pulley rotation speed signal S8 shown in FIG.

However, in determining the dip, it is detected whether the selector lever 105 is in the automatic shift position (D range) or the manual shift position (L range) based on the select position signal S6, and the automatic shift is performed. In the case of the position, the changing speed map M1 is selected, and in the case of the manual shift position, the changing speed map M2 is selected, and the dip is given to the eip with different characteristics. Map M as shown
Compared with 1, the map M2 is set to give a large dip to a smaller eip region. Therefore, the gear ratio is relatively slow during automatic gear shifting and relatively rapidly during manual gear shifting, and the target gear shifting is performed. It will approach the ratio. In each map, dip is set to decrease in a region where eip is small. As a result, when the gear ratio approaches the target value, the speed of change of the gear ratio decreases and the target gear ratio gradually settles. It has become.
Further, in the case of manual shift, a large change in the gear ratio, which is not normally performed in automatic shift control, may be required, but in this control, as the eip increases, d increases as described above.
Since ip is also set to be large, the speed of change of the gear ratio increases as the deviation of the gear ratio increases.
It is possible to quickly complete the shift even when the range of change in the gear ratio accompanying the manual shift is large.

The shift control unit 106 feeds back the position of the drive pulley 16 based on the control signal thus determined, as described above, while feeding back the step motor 1
13 and the shift control valve 112 are driven to control to a target gear ratio. As a result of such control, gear shifting is completed more quickly during manual gear shifting than during automatic gear shifting. When the speed of change of the gear ratio is increased, the shift shock becomes noticeable, but in the case of manual shifting, the shift shock will be generated due to the shift operation of the driver, so even if a shock occurs, there is little discomfort, rather Since the speed change is completed promptly, there is a great effect that good driving performance that matches the driver's feeling is exhibited.

The maps M1 and M2 for giving the speed of change of the gear ratio have been described on the assumption that the maps are stored in a storage device in a table format. It goes without saying that, as long as it has the function of outputting a predetermined changing speed from the parameter corresponding to the deviation of the gear ratio, it may be configured as an arithmetic expression, for example.

Further, the speed of change of the gear ratio is not calculated individually in each of the automatic shift and the manual shift as described above, but basically the dip during the automatic shift is calculated as shown in FIG. 5, for example. However, in the case of manual shift, it is also possible to perform control so as to correct this and increase the changing speed, and in this case, the configuration of the arithmetic unit can be made simpler in terms of storage device capacity and the like. .

[0045]

As described above, according to the first aspect of the invention, the speed of change to the target speed ratio set by the manual speed change means is set to be smaller than the speed of change to the target speed ratio set by the automatic speed change means. Also, when the gear ratio is changed to the gear ratio specified by the driver via the manual gear change mechanism, the gear ratio of the continuously variable transmission is promptly changed to the target gear ratio. Therefore, the drivability can be improved by changing the gear ratio with good response to the driver's operation.

According to the invention of claim 2, in the invention of claim 1, the larger the difference between the actual gear ratio and the target gear ratio, the greater the speed of change of the gear ratio to the target gear ratio. Therefore, even during the manual shift operation in which the difference between the gear ratios before and after the gear shift operation tends to become large, it is possible to quickly shift to the gear ratio intended by the driver.

According to the invention of claim 3, the automatic shifting means and the means shifting means of the invention of claim 1 or 2 are provided.
By providing each map that gives the speed of change to the target speed ratio based on the difference between the actual speed ratio and the target speed ratio, the speed of change to the target speed ratio in each of automatic gear shifting and manual speed shifting. Can be given with good response.

According to the invention of claim 4, one of the automatic speed change means and the manual speed change means of claim 1 or 2 sets the speed of change to the target speed change ratio, and the other one sets the set value. Since the changing speed is set as the correction value of, the configuration of the arithmetic unit including the storage device in the manual transmission unit or the automatic transmission unit becomes simpler.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an embodiment of a continuously variable automatic transmission to which the present invention can be applied.

FIG. 2 is a schematic diagram of a control system of the continuously variable automatic transmission.

FIG. 3 is an explanatory diagram of a shift speed map configuration according to an embodiment of the present invention.

FIG. 4 is a flowchart showing the control contents of the embodiment of the present invention.

FIG. 5 is a flowchart showing the control contents of another embodiment of the present invention.

[Explanation of symbols]

 10 Engine Output Shaft 11 Lockup Clutch 12 Torque Converter 12a Pump Impeller 12b Turbine Runner 12c Converter Chamber 12d Lockup Oil Chamber 13 Rotating Shaft 14 Drive Shaft 15 Forward / Reverse Switching Mechanism 16 Drive Pulley 17 Continuously Variable Transmission 18 Fixed Conical Plate 19 Planetary Gear mechanism 20 Drive pulley cylinder chamber 20c Spring 22 Movable conical plate 24 V belt 26 Driven pulley 28 Driven shaft 30 Fixed conical plate 32 Driven pulley cylinder chamber 32c Spring 34 Movable conical plate 40 Forward clutch 44 Final gear 46 Drive gear 48 Idler gear 50 Reverse brake 52 Idler shaft 54 Pinion gear 56 Differential device 101 Electronic control unit 101A Central processing unit 101B Input unit 101C Output unit 102 Hydraulic control unit 103 Engine controller Roll module 104 ABS control device 105 Selector lever 106 Gear shift control unit 107 Line pressure control unit 108 Lockup control unit 109 Step motor drive circuit 110 Line pressure solenoid drive circuit 111 Lockup solenoid drive circuit 112 Gearshift control valve 113 Step motor 114 Link 115 Line pressure solenoid 116 Modifier 117 Regulator 118 Lockup solenoid 119 Lockup control valve 120 Manual control valve

Claims (4)

[Claims] 1. A continuously variable transmission for continuously and variably transmitting engine rotation to a drive shaft, and an automatic transmission means for controlling a gear ratio of the continuously variable transmission to a target gear ratio determined according to an operating state. In a continuously variable automatic transmission equipped with a manual transmission means for controlling to a manually set target transmission ratio, a change speed to a target transmission ratio set by the manual transmission means is set as a target set by the automatic transmission means. A control device for a continuously variable automatic transmission, characterized in that the speed of change to a gear ratio is set to be larger than that. 2. The continuously variable automatic transmission according to claim 1, wherein the rate of change to the target gear ratio is set to be larger as the difference between the actual gear ratio and the target gear ratio is larger. Control device. 3. The automatic transmission means and the means transmission means are individually provided with maps that give a changing speed to the target speed ratio based on the difference between the actual speed ratio and the target speed ratio. The control device for a continuously variable automatic transmission according to claim 1 or 2. 4. The automatic transmission means and the manual transmission means are configured such that one of them sets a changing speed to a target gear ratio, and the other one sets a changing speed as a correction value of the set value. The control device for a continuously variable automatic transmission according to claim 1 or 2.