JPH03103661A - Shift control device for automatic transmission - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a shift control device for an automatic transmission in which gear changes are performed using vehicle speed as one of the requirements for determining a shift.

Prior art A conventional automatic transmission is, for example, Japanese Patent Application Laid-Open No. 6262047.
There is a system disclosed in the above publication, in which a plurality of frictional elements such as clutches and brakes are incorporated into a gear train consisting of a plurality of planetary gear sets, and by appropriately engaging and releasing the frictional elements, a plurality of speed changes can be performed. You can now get dan.

Incidentally, the engagement and disengagement of the friction elements are performed by line pressure supplied from a hydraulic control valve, and in the automatic transmission disclosed in the above-mentioned publication, the switching combination of two shift valves is used. Line pressure is supplied and stopped to the friction element.

Further, the switching of the shift valve is performed according to a shift schedule predetermined based on the vehicle speed and throttle opening.

Problems to be Solved by the Invention However, in such a conventional shift control device for an automatic transmission, the shift point is determined based on the above-mentioned shift schedule, and the shift is performed when a certain vehicle speed and a certain throttle opening are reached. By outputting a switching signal to the valve and switching the shift valve, line pressure is supplied to the friction element to be engaged at the target gear position, and the target gear shift is performed only when the engagement of the friction element is completed. You can now get dan.

Therefore, there is a slight time lag between when the shift time is determined based on the shift schedule and when the friction elements are completely engaged, and this time lag is approximately constant.

However, even if the vehicle is in a rapid acceleration/deceleration state or a slow acceleration/deceleration state, the time point at which the gear shift is determined remains constant.
The time point at which the shift is finally completed varies depending on the time lag until the engagement of the friction elements is completed.

That is, FIG. 1l is a characteristic diagram showing the shift timing in an accelerated state, in which A1 shows the characteristic during sudden acceleration, and A shows the characteristic during slow acceleration, and in both cases, the vehicle speed is constant. If a shift is determined based on the characteristic A., the vehicle speed will be V after the predetermined time t when the friction element is completely engaged in the case of slow acceleration with the characteristic A. In the case of sudden acceleration, the actual gear shift will be performed after the predetermined time t at a vehicle speed of V, which is larger.

,, For this reason, during sudden acceleration, the vehicle speed at the time the shift is completed becomes high, and the engine speed increases accordingly, resulting in a large shock at the time the engagement is completed.

Furthermore, Fig. 12 is a characteristic diagram showing the shift timing in a decelerating state, in which B indicates the characteristic during sudden deceleration and B indicates the characteristic during slow deceleration. Even in this case, the vehicle speed v0' Assuming that a shift is determined at , in the case of slow deceleration of characteristic B, the engagement is completed at vehicle speed vI' after a predetermined time t', but in the case of sudden deceleration of characteristic B1, the engagement is completed at vehicle speed Vt' at predetermined time t'. V+'
>V*'), the conclusion is completed.

Therefore, during sudden deceleration in this case, the vehicle speed at the time the gear shift is completed will be too low, which may cause the engine to stall when the engagement is completed, or if the torque converter is equipped with a lock-up device, the lock-up control may be disabled. There was a problem that delays occurred.

In view of such conventional problems, the present invention provides a shift system for an automatic transmission that can always set a constant vehicle speed at the time of completion of the shift by correcting the time point at which the shift is determined according to the acceleration/deceleration state of the vehicle. The purpose is to provide a control device.

Means for Solving the Problems In order to achieve the object, the shift control device for an automatic transmission according to the present invention, as shown in FIG. In the transmission, acceleration/deceleration detection means a for detecting acceleration/deceleration of the vehicle
and a correction means b for correcting the time point at which the shift is determined according to the acceleration/deceleration of the vehicle.

Effects With the above-described configuration, in the shift control device for an automatic transmission of the present invention, the correcting means b corrects the timing at which the shift of the automatic transmission is determined in accordance with the acceleration/deceleration of the vehicle, so that sudden acceleration/deceleration is prevented. In this case, by making the shift decision earlier,
The vehicle speed at which the shift is finally completed can always be set constant.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

That is, FIG. 2 shows an embodiment of the speed change control device for an automatic transmission according to the present invention, where 10 is an engine, 11 is an automatic transmission, and the output rotation of the engine 10 is controlled by the automatic transmission 11. It is output to drive wheels (not shown) through the motor.

By the way, the gear train of the automatic transmission l1 is configured as shown in FIG. 3, for example, and includes a first planetary gear set PC. and a second planetary gear set PGt.

The first and second planetary gears PG, PC, are configured as simple planetary gears, and the first and second sun gears S. ，
S, the first and second pinion gears P,,P, and the lth,
2nd ring gear R. ,R. and the first and second binion carriers PC. Pct.

In addition, the first and second planetary gear sets PG+. As shown in the figure, the gear train composed of PGz has a reverse clutch R/C connecting the input shaft I/S and the first sun gear S, and a reverse clutch R/C connecting the input shaft I/S and the first pinion carrier PC. High clutch II/
C, first binion carrier PCI and second ring gear R,
Forward clutch F/C, which connects the forward clutch F/C, and band brake B, which fixes the first sun gear SI to the casing C/S side.
/B, first pinion carrier PC, casing C/S
A low and reverse brake L&R/B fixed to the side is provided.

Further, a forward one-way clutch F/O・C is provided between the forward clutch F/C and the second ring gear R.
is provided, and a row one-way clutch L/0 is provided between the first pinion carrier PC and the casing C/S.
C is provided, and the first binion carrier PC. and the second ring gear R, an overrun clutch 0.
R/C is placed.

Furthermore, 10 revolutions of the engine are input to the input shaft 1/S in FIG. 3 through the torque converter T/C.

By the way, in the automatic transmission l1, each friction element (R/C, H/C, F/C, B
/B, L&R/B) are engaged and released at the ρ line pressure as the working fluid pressure supplied from the one-pressure control valve l2, so that various gears can be obtained.

Table 1: In the same table, the ○ mark indicates a fastened state, and the blank mark indicates a released state.

Further, the forward one-way clutch F/O-C is connected to the first pinion carrier PC. The second ring gear R is free when rotating in the forward direction and locked when rotating in the reverse direction, and the row one-way clutch L/
OC is free when the first pinion carrier PC1 rotates in the forward direction, and is locked when it rotates in the reverse direction.

Furthermore, although the above-mentioned overrun clutch 0・R/C is not shown in Table 1, the overrun clutch 0・R/C
By engaging the accelerator opening at 1/16 or less in a low gear such as 3rd gear or lower, the function of the forward one-way clutch F/O・C is eliminated and the engine brake is activated. There is.

FIG. 4 shows a schematic configuration of the hydraulic pressure control valve 12, which includes a pressure regulator valve 20, a pressure modifier valve 22, a line pressure solenoid 24, a pilot valve 26, and a torque converter regulator valve 2. 8. Lockup control valve 30. shuttle valve 32,
Lockup solenoid 34, manual valve 36, first shift valve 38, second shift valve 40, first shift solenoid 42. 2nd shift solenoid 44, forward clutch control valve 46.3-2 timing valve 48.4
-2 relay valve 50.4-2 sequence valve 52, ■range pressure reducing valve 54, shuttle valve 56, overrun clutch control valve 58, third shift solenoid 60, overrun clutch pressure reducing valve 62, 2nd speed servo briny pressure akicomulator 64, A third speed servo release pressure accumulator 66, a fourth speed servo release pressure accumulator 68, an accumulator control valve 70, etc. are provided.

Each component of the hydraulic pressure control valve 12 has the relationship shown in the figure, and the reverse clutch R/C
, high clutch H/C, forward club fP/C
, Flake Band B/B. Low-ant reverse brake L&R/B, overrun clutch 0/R/C
is connected to each friction element and the oil bomb O/P, and the switching combination of the first shift valve 38 and the second shift valve 40 supplies and stops hydraulic pressure to each friction element, and also supplies hydraulic pressure to each friction element. Pressure control of the line pressure as the fastening pressure is performed.

The detailed configuration and functions of each component of the hydraulic pressure control circuit are the same as those described in Japanese Patent Application Laid-Open No. 62-62047, and detailed explanation thereof will be omitted.

Incidentally, the above bunt brake B/B is a band servo B/S.
The band servo B/S is operated by a 2nd speed servo brining pressure chamber 2S/A, a 3rd speed servo release pressure chamber 3
Composed of S/R and 4th speed servo brining pressure chamber 4S/A, bunt brake B/B is engaged by supplying hydraulic pressure to 2nd speed servo brining pressure chamber 2S/A, and in this state, 3rd speed servo release pressure chamber The bunt brake B/B is released when hydraulic pressure is supplied to 3S/R, and in this state, the bunt brake B/B is engaged when hydraulic pressure is supplied to the 4th speed servo briny pressure chamber 48/A. The structure is such that

By the way, switching of the first and second shift valves 38.40 is performed by turning on the first and second shift solenoids 42.44,
When turned OFF, pilot pressure is supplied to the first and second shift valves 38 and 40 to take the right half position (upper position) in the figure, and when turned OFF, the pilot pressure is drained and the first and second shift valves 38 and 40 are shifted to the upper position. The second shift valves 38 and 40 are in the lower position where the left half of the figure is located.

Then, the first and second shift valves 38, 40 are shifted to the next second shift valve 38, 40.
As shown in the table, ON and OFF switching is performed according to each gear stage.

Table 2 The switching signals for the first and second shift valves 38 and 40 are as follows:
For example, as shown in FIG. 5, a shift schedule is used in which the horizontal axis is the vehicle speed and the vertical axis is the throttle opening, and these vehicle speed and throttle opening are determined as the shift determination requirements.

The above shift schedule is based on the A/T control unit.
} It is input in advance to the gear change judgment means l4 built in the vehicle speed sensor 15 and the throttle sensor 16.
The time to shift is determined by applying each signal input from the transmission to the shift schedule.

Further, in the hydraulic pressure control valve l2, the discharge pressure of the oil pump O/P driven by the engine is regulated as a line pressure according to the driving conditions by the pressure regulator valve 20, and the line pressure is applied to each of the friction elements. Supplied as hydraulic pressure.

Here, in this embodiment, the above A/T control unit 1
3, acceleration/deceleration detection means l7 which calculates the acceleration/deceleration of the vehicle by introducing the vehicle speed signal from the vehicle speed sensor 15; and the shift determination means l4 according to the acceleration/deceleration detected by the acceleration/deceleration detection means 17. A correction means 18 is provided for correcting the shift timing determined by the above.

That is, the correction means 18 corrects so that as the vehicle acceleration increases, the shift determination time point is shifted to the low speed side, and as the vehicle deceleration increases, the shift determination time point is shifted to the high speed side.

With the above configuration, the operation of the speed change control device of this embodiment can be controlled in the sixth manner.
The process will be explained below according to the flowchart shown in the figure.

Note that the above flowchart is executed for a predetermined short time (for example, lo
It is assumed that the processing is performed every (msec).

That is, in the above flowchart, first, in step I, the vehicle speed data detected last time by the vehicle speed sensor 15 is set as vX, and in step ■, the vehicle speed data detected this time is set as ■1, and in the next step ■, r
V. -V. Set J as AV.

Then, in the next step (2), a correction value (2) corresponding to the above IV is determined from the correction map shown in FIG. In the next step (2), rVY-VoJ is calculated as the vehicle speed V set for making a shift judgment, and this V set and the throttle opening signal from the throttle sensor l6 read in the next step (2) are calculated. Based on this, in step (2), a shift determination time point is searched from the corrected shift schedule.

Then, in the next step ■, as a result of searching with the corrected shift schedule, it is determined whether or not a shift has occurred, and in the case of rYEsJ, the process proceeds to step ■, where a shift signal is output from the shift determination means 14 to the hydraulic pressure control valve l2. and shift control, while rNO in step IX.
If it is determined to be J, the current gear position is maintained without performing shift control.

Therefore, in the shift control device of this embodiment, since the shift point is corrected according to the acceleration/deceleration of the vehicle, for example,
As shown in the figure, the shift line a of A-knob shift indicated by a solid line is shifted to the side where the vehicle speed decreases as the throttle opening increases,
In addition, the downshift shift line b shown by a broken line is shifted to the side where the throttle opening is decreased and the vehicle speed is increased, and a corrected shift schedule is given by each shift line shifted in this way.

FIG. 9 is a characteristic diagram showing the shift timing in the acceleration state performed in this embodiment, in which A1 is the characteristic during sudden acceleration, A,
indicates the characteristic during slow acceleration, the slope of characteristic A, is an acceleration state that requires correction at the time of shifting, and the slope of characteristic A, is an acceleration state that does not require correction at the time of shifting. shall be taken as a thing.

Therefore, in the case of slow acceleration with characteristic A, the vehicle speed is V as set in the shift schedule shown in FIG. 5, as in the conventional case. After a predetermined time t when the friction element is completely engaged, the shift is completed at the vehicle speed v1.

On the other hand, characteristic A. In the case of sudden acceleration, the shift judgment point is corrected, so please refer to (■) above. Shifting is determined based on the lower vehicle speed Vr,
After the predetermined time t, the gear shift is completed at the same vehicle speed (2) as in the case of the above-mentioned slow acceleration.

For this reason, the shift is always completed at a constant vehicle speed v1, whether it is a sudden acceleration or a slow acceleration.
The gears are always changed at a constant timing relative to the engine rotation.

In addition, Fig. 10 is a characteristic diagram showing the shift timing in a deceleration state. In the figure, B1 is the characteristic during sudden deceleration that requires correction in the shift judgment, and B is the characteristic during slow deceleration that does not require correction in the shift judgment. In this case, the vehicle speed ■ is the time point at which the speed change is determined during slow deceleration of characteristic B. 'Vehicle speed higher than ■r
′ is the time to judge the speed change during sudden deceleration of characteristic B, so
In the case of either sudden or slow deceleration, after a predetermined time t', the friction element is engaged at the same vehicle speed V% and the shift is completed, so that a constant shift timing is obtained as in the case of acceleration. be able to.

Effects of the Invention As explained above, in the shift control device for an automatic transmission of the present invention, the time point at which the shift is determined is corrected in accordance with the acceleration/deceleration of the vehicle speed, which is one of the requirements for determining the shift.
In the case of sudden acceleration/deceleration, by making the shift decision earlier, the vehicle speed at which the shift is finally completed can be always set constant.

Therefore, even when changing gears during sudden acceleration, it is possible to prevent the engine from over-rotating and reduce shift shock, and even during sudden deceleration, the engine speed is constantly reduced when changing gears. It is possible to prevent this from occurring and to appropriately perform lock-up control of the torque converter.

Further, it is possible to perform correction in real time even when shifting is performed on a slope, etc., and various excellent effects such as being able to suppress occurrence of shift shock on a slope are produced.

[Brief explanation of drawings]

Fig. 1 is a schematic block diagram showing the concept of the present invention, Fig. 2 is a schematic block diagram showing an embodiment of the present invention, and Fig. 3 is a schematic diagram showing an embodiment of the gear train of an automatic transmission used in the present invention. 4 is a schematic configuration diagram showing an embodiment of the hydraulic control valve of the automatic transmission used in the present invention, and FIG. 5 is an implementation of the shift schedule of the automatic transmission used in the present invention. An explanatory diagram showing an example, FIG. 6 is a flowchart showing an example of processing executed when controlling the present invention, and FIG. 7 shows correction values at the time of shifting used when executing the flowchart in FIG. 6. A data map, FIG. 8 is an explanatory diagram schematically showing a shift schedule when corrected by the present invention, and FIG. 9 is a characteristic diagram showing an example of shift timing in an acceleration state performed by the present invention. FIG. 10 is a characteristic diagram showing an example of the shift timing in a deceleration state performed in the present invention, FIG. 11 is a characteristic diagram showing the shift timing in an acceleration state performed in a conventional automatic transmission, and FIG. FIG. 2 is a characteristic diagram showing shift timing in a deceleration state performed in a conventional automatic transmission. 10...Engine, l1...Automatic transmission, l2...
- Hydraulic pressure control valve, 13... A/T control unit, 14... Speed change judgment means, 15... Vehicle speed sensor, 16... Throttle sensor, 17... Acceleration/deceleration detection means, 18. ...Correction means. Figure 2 Figure 1 Figure 3 Section O To-L whole body Figure 6 Figure 7 O Deceleration 11 + 11 Acceleration ΔV value Figure 8 "Vs. 1 electric Figure 9 Figure 10 Time Time

Claims (1)

[Claims] (1) In an automatic transmission in which multiple gear changes are performed using vehicle speed as one of the requirements for determining a gear shift, there is an acceleration/deceleration detection means that detects the acceleration/deceleration of the vehicle, and a time point at which the gear shift is determined is corrected according to the acceleration/deceleration of the vehicle. What is claimed is: 1. A shift control device for an automatic transmission, characterized in that it is provided with a correction means for: