JP3389827B2 - Transmission control device for continuously variable transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for a continuously variable transmission, and more particularly to an improvement in a shift control device having a manual shift mode. 2. Description of the Related Art Continuously variable transmissions used in vehicles include:
Conventionally, belt-type and toroidal-type transmissions have been considered. In these continuously variable transmission transmission control devices, an automatic transmission mode (D) that determines a target transmission ratio in accordance with a vehicle speed and a throttle opening (accelerator opening). Range driving mode)
As with the manual transmission, there is known one provided with a manual transmission mode (M range running mode) for setting a predetermined target gear ratio. In this method, the target speed ratio of the continuously variable transmission is set in steps according to the shift position of the shift lever, so that the driver can select a desired speed ratio regardless of the vehicle speed and the throttle opening. is there. [0003] In the operation in such a manual shift mode, a step in the vehicle acceleration occurs due to a difference in the gear ratio at the time of upshifting or downshifting, and when the driver recognizes that the shift has been performed due to the step. At the same time, a sporty run can be enjoyed by obtaining a feeling of an acceleration step corresponding to the shift operation of the user. [0004] Incidentally, in the continuously variable transmission having the manual shift mode as described above, what is the gear ratio when the automatic shift mode is switched to the manual shift mode? There is a problem of setting. For example, FIG. 5 shows an example of setting a target gear ratio in the manual gear change mode in relation to a vehicle speed and a rotation speed of a primary pulley (a rotation speed on an input shaft side of a continuously variable transmission). In this figure, if it is assumed that a select operation from the D range to the M range, that is, a switch from the automatic shift mode to the manual shift mode is performed at a point T which is halfway between the target speed ratios of the second speed and the third speed, at this time, T Since the point does not ride on any of the set target gear ratios in the manual gear shift mode, conventionally, the gear ratio is moved to the nearest gear ratio, in this case, the second speed. However, if the gear ratio is forcibly moved in this manner, the driving force expected by the driver may not always be obtained depending on the gear ratio after the movement, so that the driver may be in a transient state. , Which requires an accelerator operation. In addition, if the gear ratio at the time of switching to the manual gear shift mode happens to match the gear ratio of any of the gears, it is not necessary to adjust the driving force by the accelerator operation. Unnecessary will occur, which will also give the driver a sense of discomfort. On the other hand, for example, Japanese Patent Laid-Open No. 6-6636
Japanese Patent Publication No. 9 discloses a device in which the speed ratio at the time of switching to the manual speed change mode is maintained.
According to such control, for example, if the mode is switched to the manual shift mode at the point T in FIG. 5, the gear ratio at the point T is maintained until the driver further performs an operation of changing the gear position. However, the problem due to the forcible movement of the gear ratio as described above does not occur. However, on the other hand, if a shift down to the second speed or a shift up to the third speed is performed next from the state where the gear ratio is maintained at the point T, the gear ratio from the point T in any direction is determined. Is small, the acceleration step after the gear shift is also small, which gives the driver the feeling that the driver does not accelerate or decelerate as expected despite the gear shifting operation. The present invention has been made in view of such problems, and solves the problems by setting the target gear ratio of each gear based on the gear ratio immediately after switching to the manual gear mode. It is intended to be. As shown in FIG. 6, the present invention relates to an automatic transmission control means A for setting a target transmission ratio of a continuously variable transmission according to a driving state of a vehicle, Manual transmission control means C for setting the target gear ratio of the continuously variable transmission to one of a plurality of gear positions based on a signal from manual transmission command means B operated by a user, and the automatic transmission control means A
And a shift mode switching means D for selectively switching between a manual shift control means C and a manual shift control means C. The manual shift control means C is shifted from the automatic shift control means A by the shift mode switching means D. When the gear position is set, the actual gear ratio at that time is set as the target gear ratio.
The target gear ratio of at least an adjacent gear is determined within a range of a gear ratio that is predetermined based on the gear ratio immediately after the switching. In the present invention, the manual shift control means C
Is the target of the gear position adjacent to the gear position set immediately after switching.
Provided with a plurality of speed ratios, based on the driver's selection operation
Shift width selection to set any of multiple target gear ratios
Means. The plurality of types of target gear ratios can be set, for example, as follows. The first, the target speed ratio gear set after switching straight, the target speed ratio of adjacent gear stages, which is set to a small Claus side of the acceleration level difference due to the shift, the second, the switching The target gear ratio of the adjacent gear position is set to the wide side where the acceleration step accompanying the gear shift is large with respect to the target gear ratio of the gear position set immediately after. The target gear ratio of the adjacent gear is set near the middle between the wide limit corresponding to the maximum allowable amount of acceleration difference due to gear shifting and the close limit corresponding to the minimum required amount. Things. According to the present invention, when the control shifts from the automatic shift to the manual shift with the shift mode switching, the actual gear ratio at that time is set as the target gear ratio and the gear stage is set. That is, since the actual gear ratio immediately after the mode switching is maintained as one gear, the necessity of the accelerator operation due to the forced gear ratio movement does not occur, and the driver does not have to operate the gear. Does not give a sense of discomfort. Further, since the target gear ratio of at least the adjacent gear is determined within a predetermined gear ratio range based on the actual gear ratio immediately after the switching, the manual gear ratio control is performed at any actual gear ratio. Even if the gear is changed, a certain gear ratio width, that is, an acceleration step is always ensured in the gears before and after the gear at that time, and therefore the driver's expectation for the subsequent upshift or downshift operation is ensured. Alternatively, the acceleration / deceleration feeling as expected is obtained. If the gear ratio of the manual gear change control means C has the above-mentioned first characteristic, the target gear ratio of the gear next to the target gear ratio set immediately after switching to the manual gear shift control is closer to the close side. Is set to The close side is a speed ratio width at which the acceleration step difference felt when the driver performs a shift up or down operation is relatively small, and is a speed ratio setting corresponding to a so-called close ratio in a manual transmission. Therefore, in this case, although the feeling of the acceleration step is small, the amount of change in the engine rotation speed with respect to the shift operation is small, and the decrease in torque accompanying the shift-up especially during acceleration can be reduced, so that excellent acceleration performance can be obtained. On the other hand, when the gear ratio of the manual gear shift control means has the second characteristic, the target gear ratio of the gear position adjacent to the target gear ratio set immediately after the shift to the manual gear shift control is set. The ratio is set to the wide side. The wide side is a speed ratio width at which the acceleration step felt when the driver performs an upshift or downshift operation is relatively large,
This is a gear ratio setting corresponding to a wide ratio in a manual transmission. In this case, since the torque difference at the time of the shift operation is correspondingly large, the feeling of the acceleration step is increased, but the number of set shift steps within the shiftable range as the continuously variable transmission is naturally reduced, which covers each shift step. This means that the vehicle speed range is widened, and the frequency of shift operations is generally low. When the gear ratio of the manual transmission control means C has the third characteristic, the characteristic is intermediate between the first characteristic and the second characteristic. According to the present invention, a plurality of types of target change ratio setting change widths are provided, and a shift width selecting means for selectively switching to any one of the characteristics by a driver's operation is provided.
Since, Introduction Bei serves a plurality of characteristics to a wide ratio from Claus ratio as illustrated above, it is possible select one of them in the driver's preference. Next, an embodiment of the present invention will be described. FIG. 1 shows a longitudinal sectional structure of a continuously variable automatic transmission to which the present invention can be applied. Describing this, a torque converter 12 as a fluid transmission is connected to the engine output shaft 10. As a hydraulic transmission,
In some cases, a fluid coupling is used instead of the torque converter 12. The torque converter 12 has a lock-up clutch 11, and reciprocally controls the oil pressures of the converter chamber 12c and the lock-up oil chamber 12d, so that the input side pump impeller 12a and the output side turbine runner 12b are connected to each other. Can be mechanically connected or disconnected. The output side of the torque converter 12 is a rotary shaft 1
3 and the rotating shaft 13 is connected to a forward / reverse switching mechanism 15. The forward / reverse switching mechanism 15 includes 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 is the rotating shaft 13
The drive shaft 14 is coaxially fitted to the outside of the drive shaft 14. The drive shaft 14 is provided with a primary pulley 16 of a belt-type continuously variable transmission 17. The continuously variable transmission 17 includes the primary pulley 16, the secondary pulley 26, and the primary pulley 16.
Belt 2 that transmits the rotational force of the belt to the secondary pulley 26
4 and so on. The primary pulley 16 is provided with a fixed conical plate 18 that rotates integrally with the drive shaft 14, and is disposed opposite to the fixed conical plate 18 to form a V-shaped pulley groove and hydraulic pressure acting on the primary pulley cylinder chamber 20. Drive shaft 1
4 comprises a movable conical plate 22 movable in the axial direction. In this case, the primary pulley cylinder chamber 20 is composed of two chambers, a chamber 20a and a chamber 20b, and has a larger pressure receiving area than a secondary pulley cylinder chamber 32 described later. The secondary pulley 26 is provided on a driven shaft 28. The secondary pulley 26 has a driven shaft 28
A fixed conical plate 30 that rotates integrally with the fixed conical plate 30, is formed to face the fixed conical plate 30 to form a V-shaped pulley groove, and is movable in the axial direction of the driven shaft 28 by hydraulic pressure acting on the secondary pulley cylinder chamber 32. It comprises a movable conical plate 34. 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. A pinion gear 54 provided on the idler shaft 52 is engaged with the final gear 44. The final gear 44 drives a propeller shaft or a drive shaft to wheels (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 applied to the torque converter 1
When the forward clutch 40 is engaged and the reverse brake 50 is released, the planetary gear mechanism 19 that is integrally rotated is transmitted to the forward / reverse switching mechanism 15 via the rotation shaft 2 and the rotary shaft 13. 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 planetary gear is engaged when 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 rotational direction is reversed. The rotational force of the drive shaft 14 is
6, V belt 24, secondary pulley 26, driven shaft 2
8, drive gear 46, idler gear 48, idler shaft 5
2, transmitted to the differential 56 via the pinion gear 54 and the final gear 44. When both the forward clutch 40 and the reverse brake 50 are released, the power transmission mechanism is in a neutral state. At the time of power transmission as described above, the movable conical plate 22 of the primary pulley 16 and the secondary pulley 2
6 by moving the movable conical plate 34 in the axial direction.
By changing the radius of the contact position between the primary pulley 16 and the secondary pulley 26, the rotation ratio, that is, the gear ratio (also referred to as a pulley ratio) can be changed. For example, if the width of the V-shaped pulley groove of the primary pulley 16 is increased and the width of the V-shaped pulley groove of the secondary pulley 26 is reduced, the radius of the contact position of the V belt 24 on the primary pulley 16 side is reduced, and Since the radius of the contact position of the V-belt 24 on the pulley 26 side with the V-belt becomes large, a large gear ratio can be obtained. If the movable conical plates 22 and 34 are moved in the opposite directions, the gear ratio becomes smaller, contrary to the above. The control for changing the widths of the V-shaped pulley grooves of the primary pulley 16 and the secondary pulley 26 is performed by controlling the primary pulley cylinder chamber 20 (20a, 20b) or the secondary pulley cylinder via a control system described below. This is performed by hydraulic control of the chamber 32. FIG. 2 shows a control having the function of performing the basic gear ratio control of the above-described continuously variable automatic transmission, including the functions of the automatic transmission control means, the manual transmission control means, and the transmission mode switching means of the present invention. The outline of the system is shown. In FIG. 2, the same reference numerals are given to the mechanical parts corresponding to those in FIG. Hereinafter, the control system will be described focusing on parts related to the present invention. In the figure, reference numeral 101 denotes an electronic control unit comprising a microcomputer or the like, and 102 denotes a hydraulic control unit comprising various hydraulic control valves or the like. In this control system, the control means of the continuously variable automatic transmission mainly includes these electronic control units 101 And a hydraulic control unit 102. The electronic control unit 101 includes a central processing unit 101A that performs control arithmetic processing, an input unit 101B that converts various operating state signals from the engine and the vehicle into a processable format and supplies the processed processing signals to 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 a control signal from the control unit 01A. The input unit 101B includes a water temperature signal S1, a throttle opening signal S2, an engine rotation signal S3, an ABS signal 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 control device 104, braking signal S5 issued when the braking device of the vehicle is actuated, selector position signal S6 issued from the inhibitor switch as a signal indicating the operating position of selector lever 105, primary pulley 16 and the rotation speed signal S8 of the secondary pulley 26, etc., are input to the central processing unit 10 as necessary.
1A. The central processing unit 101A includes a transmission control unit 10
6. Line pressure control unit 107, lock-up control unit 108
A control signal is calculated using necessary predetermined signals from the various signals, and a step motor drive circuit 109, a line pressure solenoid drive circuit 110, and a lock-up solenoid drive circuit 11 constituting the output unit 101C are formed.
By driving the transmission 1, the transmission ratio, the line pressure, and the lock-up clutch 11 of the continuously variable transmission 17 are controlled. More specifically, the shift control unit 106 controls the step motor drive circuit 109 to perform a shift according to a predetermined pattern according to an engine load (TVO) represented by a throttle opening, a vehicle speed, and the like. Output a signal. 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 as to attain the target speed ratio corresponding to the signal from the step motor drive circuit 109, and the primary pulley cylinder chamber 20 and the secondary pulley cylinder chamber 32
(See FIG. 1). The shift of the primary pulley 16, that is, the gear ratio, is fed back to the gear change control valve 112 via a link 114, and when the gear ratio reaches a target gear ratio corresponding to the position of the step motor 113, the hydraulic pressure to each of the pulley cylinder chambers 20, 32 is increased. The distribution is stabilized and the target gear ratio is stabilized. On the other hand, the line pressure solenoid drive circuit 110
Controls the position of the line pressure solenoid 115 of the hydraulic control unit 102 in accordance with a control signal from the drive circuit 110. In response to this, the line pressure solenoid 115 changes the hydraulic pressure from a hydraulic pump (not shown) to a modifier ( The transmission control valve 11 is adjusted to a target appropriate line pressure via a pressure control valve 116 and a regulator 117 (constant pressure valve).
2 to each pulley 16, 26. The lock-up control unit 108 controls the hydraulic pressure so as to connect the lock-up clutch 11 when the vehicle speed becomes equal to or higher than a predetermined value, and release the lock-up clutch 11 when the vehicle speed becomes equal to or lower than the predetermined value. . In FIG. 2, reference numeral 120 denotes a manual control valve which is linked to the selector lever 105 corresponding to a manual shift commanding means. According to the position of the manual control valve 120, a specific speed ratio or shift pattern designated by the driver is set. The hydraulic control unit 10 is in a controlled state (manual shift mode) or in a state in which the electronic control unit 101 automatically shifts to a gear ratio determined according to the operating state (automatic shift mode).
The second circuit is switched. The above is an example of the continuously variable transmission to which the present invention can be applied. In the present invention, the target speed ratio of the speed when such a continuously variable transmission is used in the manual transmission mode is set. The gist of the present invention is to provide a good shift operation feeling by adjusting. Next, this point will be described with reference to FIG. 3 showing shift characteristics and a control flowchart for realizing the shift characteristics. In the following description, the control state by the automatic shift control means of the present invention is called an automatic shift mode, and the control state by the manual shift control means is called a manual shift mode. In FIG. 3, T ₀ indicates an operating point at the time of switching from the automatic shift mode to the manual shift mode, and L ₀ indicates a running characteristic line based on the speed ratio at T ₀ . L ₁ and L ₂ Wazorezo Re CVT low gear limit line shows a top gear limit line, that is, between these limit line becomes the transmission region. A, C, B
Shows Claus side running characteristic lines are set with reference to the gear ratio of the L _0, respectively, wide side travel characteristic line, the intermediate travel characteristic line. Which of the characteristics A, C, and B is obtained depends on the driver's selection. At the beginning when the mode is switched to the manual shift mode,
The actual gear ratio at T ₀ point corresponding to the operating point at that time is set as a target gear ratio of one gear stage. Therefore, as long as the driver does not operate the shift-up or shift down the gear ratio is controlled to a value in the T0 point, it is fixed to the running characteristic along the L ₀ line. Since movement of the force transmission ratio from the T ₀ point is not performed, the drive torque with the switching from the automatic shift mode to the manual shift mode does not occur a problem that was the accelerator operation is required to change. [0043] When the driver while driving in the L ₀ line makes a shift-up or shift-down operation, to the characteristic line that has been selected by the driver at that time among A~C the characteristic line (gear ratio) The target gear ratio is set so as to shift, and the actual gear ratio also changes. Since each of the characteristic lines A to C is set to have a certain speed ratio width with respect to the initial characteristic line L ₀ , a torque change or an acceleration step is surely generated by a shift-up or shift-down operation. , Giving the driver a response to the shift operation. [0044] However, when the operating point of the switching from the automatic shift mode to the manual shift mode is close to L ₁ is a low gear limit line as indicated by T ₁ point of FIG. 3, the shift down from the operating point since L ₁ is the limit, control for increasing the transmission ratio width more than that is not performed. Further, when the operating point similarly mode switching is close to L ₂ is a top gear limit line as indicated by T ₂ are the upshifting direction is set gear ratio width exceeding L ₂ is performed Absent. Note that the mode switching of the thus in very close operating point to L ₁ or L ₂ may be moved forcibly gear ratio to L ₁ or L _2. FIG. 4 shows an example of a method for realizing the above-described shift characteristics. In this control, first, in step (indicated by the symbol S, the same applies hereinafter) 1, the above-described selector lever 105 is provided. , It is determined whether the driver has selected the manual shift mode or the automatic shift mode. When the manual shift mode is not selected, the control is performed in the automatic shift mode. In this case, the speed ratio of the vehicle is automatically determined from the start to the maximum speed. On the other hand, when the manual shift mode is selected, the next gear position command position (in this case, any of a plurality of shift positions determined according to the position of the manual shift valve 120), the vehicle speed, The current pulley ratio ip and the like are detected or read, and the current pulley ratio i
p is set as the target gear ratio ip 'of the current gear stage. (S2). Next, it is determined which of A, B, and C is selected as the gear ratio width by the driver (S3), and based on the result of this determination, the target of each gear position is determined by the characteristic of the corresponding gear ratio width. The gear ratio ip 'is set (S4, S5, S
6). After the target gear ratio ip 'is determined in this way, the target gear ratio ip' selected by the driver's shift operation is compared with the current pulley ratio ip (S7).
If p = ip ', the actual gear ratio is the same as the target value, so ip' is output to the gear ratio control unit as it is to maintain the gear ratio (S8 to S10). On the other hand, ip @ i
In the case of p ', since the target value ip' does not match the current pulley ratio ip immediately after the up-down shift is performed in the manual shift mode, either the up-shift or the down-shift is performed for the current ip at that time. The gear ratios of the adjacent gears are set and output as the target gear ratio ip 'in accordance with the selected direction (S9 to S10). By repeating such control, the gear ratio in the manual gear shift mode as shown in FIG. 3 is set at each gear position. The speed change control unit 106 drives the step motor 113 and the speed change control valve 112 while feeding back the position of the primary pulley 16 based on the target speed ratio ip ′ determined in this manner, as described above. The gear ratio control is performed so that the ratio becomes the target value. In addition to the three types of characteristics A to C shown in the above-described embodiment, one of the choices of the shift characteristics by the driver is the gear ratio when the shift to the manual shift mode is performed as in the conventional case. Regardless of the above, a characteristic that only the fixed target gear ratios of a plurality of stages can be selected may be included.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of an example of a continuously variable automatic transmission to which the present invention can be applied. FIG. 2 is a control system diagram of the continuously variable automatic transmission shown in FIG. FIG. 3 is a shift characteristic diagram according to the embodiment of the present invention. FIG. 4 is a flowchart showing control contents of the embodiment. FIG. 5 is a shift characteristic diagram of a conventional manual shift mode. FIG. 6 is a diagram corresponding to claims of the present invention. DESCRIPTION OF SYMBOLS A automatic shift control means B manual shift command means C manual shift control means D shift mode switching means 10 engine output shaft 11 lock-up clutch 12 torque converter 12a pump impeller 12b turbine runner 12c converter chamber 12d lock-up oil chamber Reference Signs List 13 rotating shaft 14 drive shaft 15 forward / reverse switching mechanism 16 primary pulley 17 continuously variable transmission 18 fixed conical plate 19 planetary gear mechanism 20 primary pulley cylinder chamber 20c spring 22 movable conical plate 24 V belt 26 secondary pulley 28 driven shaft 30 fixed cone Plate 32 secondary pulley cylinder chamber 32c spring 34 movable cone 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 Control unit 101A Central processing unit 101B Input unit 101C Output unit 102 Hydraulic control unit 103 Engine control module 104 ABS control unit 105 Selector lever 106 Shift control unit 107 Line pressure control unit 108 Lockup control unit 109 Step motor drive circuit 110 Line pressure solenoid Drive circuit 111 Lock-up solenoid drive circuit 112 Shift control valve 113 Step motor 114 Link 115 Line pressure solenoid 116 Modifier 117 Regulator 118 Lock-up solenoid 119 Lock-up control valve 120 Manual control valve

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Claims (1)

(57) [Claim 1] Automatic shift control means for setting a target gear ratio of a continuously variable transmission in accordance with a driving state of a vehicle, and manual shift command means operated by a driver. A manual transmission control unit that sets a target transmission ratio of the continuously variable transmission to one of a plurality of transmission speeds based on a signal; and selectively controlling the automatic transmission control unit and the manual transmission control unit by a driver's operation. Shift mode switching means for switching, wherein the manual shift control means sets a gear position at which the actual gear ratio at that time is the target gear ratio when control is shifted from the automatic shift control means by the shift mode switching means. And a target gear ratio of at least an adjacent gear is determined within a range of a predetermined gear ratio based on the gear ratio immediately after the switching, and the target gear ratio adjacent to the gear set immediately after the switching is determined. It includes a plurality of types of target gear ratio of the gear stage to the shift control device for a continuously variable transmission that includes a shift width selecting means for setting any of the driver's operation of selecting the basis of the plurality of target gear ratio.