JPH03125066A - Controller for automatic transmission - Google Patents

Abstract

PURPOSE:To reduce shock due to double reciprocal gear change by lowering gear change liquid pressure of an upshift-side transmission which is located on the way of gear change in double reciprocal gear change immediately after gear change completion of a downshift-side transmission. CONSTITUTION:When a main transmission (a) and an auxiliary transmission (b) is synchronized and then double reciprocal gear change, that when one is upshifted the other is downshifted, is detected by a double reciprocal gear change detecting means (c), a gear change priority deciding means (d) gives the gear change of an upshift-side transmission priority to the gear change of a downshift-side transmission and conducts downshift-side gear change on the way of its gear change. When a detecting means (e) detects the completion of the downshift-side gear change, a control means (f) lowers gear change liquid pressure of the upshift-side transmission immediately after gear change completion of the downshift-side transmission. It is thus possible to absorb the protruded portion of inertia phase torque and reduce the occurrence of gear change shock.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an automatic transmission mounted on a vehicle, and more particularly, to an automatic transmission equipped with a main transmission and a sub-transmission, each of which has a plurality of gears, arranged in series. The present invention relates to a shift control device for an automatic transmission.

Conventional technology Conventional automatic transmissions for vehicles include Japanese Patent Application Laid-Open No. 62-83541.
Main transmission as disclosed in the issue! There is one in which a (first transmission) and an auxiliary transmission (second transmission) are arranged in series, and the final transmission ratio is determined by the product of the transmission ratios of the auxiliary transmission.

Therefore, in such an automatic transmission, the number of gear stages of the main transmission multiplied by the number of gear stages of the auxiliary transmission is the sum of the number of gear stages, for example, the main transmission has 3 forward stages and the auxiliary transmission has 2 stages. (Lo, H
i switching), a total of six forward gears can be obtained as shown in Table 1 below, and a multi-stage automatic transmission can be achieved.

Table 1 Problems to be Solved by the Invention However, in the conventional shift control device for an automatic transmission, the entire gear stage is changed from second gear to third gear and fourth gear.
When the gear is shifted from 1st to 5th speed, the upshift of the main transmission and the downshift of the auxiliary transmission are performed in synchronization.

That is, the gear change between the main transmission and the auxiliary transmission is normally performed by switching friction elements such as hydraulically operated clutches and brakes, but when the friction elements are switched, a peculiar engagement occurs. be done.

Therefore, when the main transmission and the sub-transmission are shifted in synchronization, the engagement shock in each transmission is repeated two times in a row.
If the two engagement shocks occur at the same time, a large shift shock will be generated at once, which will significantly deteriorate the ride comfort of the vehicle. There was a problem.

Therefore, in view of such conventional problems, the present invention absorbs the shift shock on the downshift side, which is accompanied by a large increase in torque, during the shift process on the upshift side.
It is an object of the present invention to provide a shift control device for an automatic transmission which is designed to significantly reduce shift shock.

Means for Solving the Problems In order to achieve the above objects, the present invention provides a main transmission a having at least two or more gear shifting functions, as shown in FIG.
and an auxiliary transmission having a transmission function of at least two or more gears are arranged in series, and based on the driving conditions, the main and auxiliary transmissions a and b (one of which is shifted,
In an automatic transmission in which the final gear ratio is determined by the product of the respective gear ratios, from the above driving conditions, the main transmission a and the sub-transmission A are synchronized so that one upshifts and the other a double changeover detection means C for detecting a double changeover in which the double changeover is downshifted; A shift order determining means d for causing the downshift side shift to be performed during the upshift side shift; a downshift shift completion detecting means e for detecting the completion of the downshift side shift; and a downshift shift completion detecting means e immediately after the downshift side shift chamber r. It is constituted by providing an upshift side shift hydraulic pressure control means f for reducing the shift hydraulic pressure on the upshift side.

Effect With the above-described configuration, in the shift control device for an automatic transmission of the present invention, when a double shift is performed, the upshift side shift is performed before the downshift side shift,
In addition, a shift on the downshift side is performed during the upshift, and immediately after the shift on the downshift side is completed, the shift hydraulic pressure on the upshift side that is in the middle of the shift is reduced. In the part where the torque on the upshift side decreases due to the drop in the shift fluid pressure, the inertia phase torque generated immediately after the downshift side is reduced, thereby alleviating the torque step on the downshift side and reducing shock. .

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

That is, FIG. 2 shows an embodiment of a shift control device for an automatic transmission according to the present invention. It is constructed by arranging in series a sub-transmission 14 that performs two-stage switching of one constant speed.

The gear trains of the main transmission 12 and the auxiliary transmission 14 are configured as shown in FIG. 3, and the main transmission 12 includes a first planetary gear set PC and a second planetary gear set PC, The machine 14 is equipped with a third planetary gear set PGs.

Above 1. Second. Third planetary gear set PC, PG, P
G.

are respectively configured as simple planetary gears, with the first, second, and so on being configured as simple planetary gears.
The third sangia S,,S,,S,and the first. The second and third pinion gears P I, P tr Ps, and the first and second pinion gears. The third ring gears R, , R, , R, and the first and second ring gears.
It is composed of third binion carriers PC, , PC, , PC3.

Further, in the main transmission 12, the first. 2nd planetary gear set PG
,, PG, the gear train includes a reverse clutch R/C connecting the input shaft I/S and the first sun gear S, the input shaft I/S and the first pinion carrier PC9, as shown in the figure. high clutch H/C, first pinion carrier PC1 and second
Forward clutch F/C connecting with ring gear R2
A band brake B/B that fixes the first sun gear S to the casing C/S side, and a low and reverse brake L&R/B that fixes the first binion carrier Pct to the casing C/S side are provided.

Further, a forward one-way clutch P10・C is connected between the forward clutch F/C and the second ring gear R2.
is provided, and a row one-way clutch L10 is provided between the first pinion carrier PC1 and the casing C/S.
-C is provided between the first pinion carrier PC and the second ring gear R in parallel with the forward one-way clutch P10.C.
R/C is placed.

Further, in the sub-transmission 14, the gear train composed of the third planetary gear set PC includes a third pinion carrier PC3 and a third sun gear S, as shown in the figure.

A direct clutch 1-inch D/C that connects the casing C/S, and a duction brake R-D/B that fixes the third sun gear S3 to the casing C/S are provided.

Furthermore, a reduction one-way clutch R-Dlo.C is disposed between the third sun gear S3 and the casing C/S.

The second pinion carrier PC7, which serves as an output member of the main transmission 12, and the third ring gear R3, which serves as an input member of the auxiliary transmission 14, are connected via an intermediate shaft M/S. .

Further, the rotational force of the engine E is inputted to the input shaft 1/S in FIG. 3 through the torque converter T/C.

By the way, in the main transmission 12, each friction element (R/C, II/C, P/C, B/B.

! , &R/B) are engaged and released by shift hydraulic pressure (line pressure) supplied from an unillustrated funnel valve, so that various shift stages can be obtained.

(Margins below) Table 2: In the same table, the ○ mark indicates the engaged state, and the blank mark indicates the released state.

Further, the forward one-way clutch F10-C is free when the second ring gear R2 rotates in the forward direction with respect to the first pinion carrier PC, and is locked when the second ring gear R2 rotates in the reverse direction.
0.C is free when the first pinion carrier PC3 rotates in the forward direction, and is locked when it rotates in the reverse direction.

By the way, the above-mentioned overrun clutch 0・R/C is the first
Although not shown in the table, the overrun clutch O-R
/C is when the accelerator opening is 1716 on the low gear side below 3rd gear.
By engaging as follows, the function of the forward one-way clutch F10.C is nullified and the engine brake is operated.

On the other hand, in the sub-transmission 14, the direct clutch D/C
When the direct clutch D/C is engaged, manual rotation is outputted in a constant speed (Hi) state, and when the direct clutch D/C is released, it is outputted in a decelerated (Lo) state.

In addition, the above reduction one-way clutch R-Dlo
・C becomes free when the third sun gear S3 rotates in the forward direction, and is locked when the third sun gear S3 rotates in the reverse direction.

- In the automatic transmission 10, the final gear ratio outputted from the output shaft O/S is determined by the product of the gear ratio of the main transmission 12 and the gear ratio of the auxiliary gear a14. The number of gears obtained by the automatic transmission 10 is determined by the combination of the number of gears of the main transmission 12 and the sub-transmission 14, and in this embodiment, the main transmission 2 is set to 4 forward gears. As a result, the sub-transmission 14 is shifted to two gears, so that a total of eight forward gears can be shifted as shown in Table 3 below.

Table 3 The above control valve has the first valve for switching the main transmission 12.
Shift solenoid 22 and second shift solenoid 24
and a third shift solenoid 26 for switching the sub-transmission 14. 2nd and 3rd shift solenoid 2
2, 24, and 26 are built into the ^/T control unit 28, and are the main transmission controller 30 (for controlling the first and second shift solenoids 22, 24) and the sub-transmission controller 32 (for controlling the third shift gear/id 26). It is designed to be turned ON and OFF by a control signal output from a control device.

Therefore, the above 1. Second. third shift solenoid 22,
24 and 26 are turned ON and OFF, the first valve (not shown) built in the control valve is activated. Second.
The third shift valve is switched to engage and release each of the friction elements described above, so that each gear stage is obtained as shown in Table 4 below.

(Margins below) Table 4 By the way, from the main transmission controller 30 and the auxiliary transmission controller 32, the first. Commands for ON and OFF signals to be output to the second and third shift solenoids 22, 24, and 26 are output from the shift control controller 34.

A throttle opening signal detected by a throttle sensor 36 and a vehicle speed signal detected by a vehicle speed sensor 38 are manually inputted to the speed change control controller 34, and the speed is changed based on a preset shift schedule based on these throttle opening degrees and vehicle speed. Judgment is about to be made.

In addition, 1, the E fertilizer transmission 12 is provided with a line pressure solenoid 40 for controlling line pressure, and the line pressure solenoid 4
0 is operated by a control signal output from a main transmission transmission hydraulic pressure controller 42 serving as an upshift side transmission hydraulic pressure control means, thereby controlling the transmission hydraulic pressure for engaging the friction element. .

Note that the line pressure control of the main transmission 12 is performed by controlling the pressure provided in the control valve according to the signal pressure generated from the line pressure solenoid, as disclosed in, for example, Japanese Unexamined Patent Publication No. 62-620/17. The discharge pressure of the oil pump is regulated by a regulator valve, and the regulated line pressure is supplied to the friction element as shift hydraulic pressure.

Here, in this embodiment, the A/T control unit 28 is provided with an auxiliary transmission gear ratio calculation circuit 50, and the auxiliary transmission 14 is adjusted based on the gear ratio calculated by the auxiliary transmission gear ratio calculation circuit 50. A downshift completion trigger generation circuit 52 is provided to detect the time point at which the shift is completed, and the sub-transmission gear ratio calculation circuit 50 and the downshift completion trigger generation circuit 52 constitute a downshift completion detection means 54. The signal generated by the completion trigger generation circuit 52 is output to the main transmission shift hydraulic pressure controller 42.

The sub-transmission gear ratio calculation means 50 receives a detection signal from an intermediate shaft rotation sensor 56 that detects the rotation speed of the intermediate shaft M/S connecting the main transmission 12 and the sub-transmission 14, and a detection signal from the sub-transmission The vehicle speed sensor 38 detects the 0/S rotation of the output shaft of 14.
A detection signal is input from the sensor 56, 38.
The gear ratio of the auxiliary transmission 14 is calculated from the rotational difference.

The speed change controller 34 also includes an automatic transmission 1.
0 is shifted, the main transmission 12 and the sub-transmission 1
A double changeover detection means 58 is provided for detecting a double changeover in which one side is upshifted and the other is downshifted in synchronization with 4, and when the double changeover is detected, A signal is outputted from the double shift change detection means 58 to the main transmission shift hydraulic pressure controller 42 and the downshift completion trigger generation circuit 52.

Note that the above-mentioned double changeover transmission refers to a shift in which the main transmission 12 and the auxiliary transmission 14 synchronize, upshifting the main transmission 12 side and downshifting the auxiliary transmission 14 side.
For example, in the sequential step-by-step shifting as shown in Table 3 above, shifting from 2nd gear to 3rd gear, shifting from 4th gear to 5th gear, and shifting from 6th gear to 7th gear is This applies.

Furthermore, a delay circuit 60 is provided between the shift control controller 34 and the sub-transmission shift controller 32 as a shift order determining means, and when a double shift is detected, the delay circuit 60 Changing speed detection means 56
An activation signal is output from the delay circuit 60 to the delay circuit 60.

Therefore, when the delay circuit 60 is activated, if a shift signal is simultaneously output from the shift control controller 34 to the main transmission shift controller 30 and the auxiliary transmission shift controller 32, the delay circuit 60 is activated. The signal input to the sub-transmission shift controller 32 is delayed.

The functions of the shift control device for the automatic transmission according to the present embodiment having the above configuration will be described below with reference to the flowchart shown in FIG.

That is, the above flowchart is executed for a predetermined short time (for example, 10
First, the throttle opening is read in Step I, and the vehicle speed V is read in Step ■, and a shift schedule is searched from the driving conditions of these throttle opening and vehicle speed.
It is determined whether or not it is heavy shifting.

Then, if it is determined that r N Oj in the above step ■, the process returns to the above step I, and if "YES", the process proceeds to step ■, where the upshift side transmission (in this embodiment, the main transmission 12) is changed. After starting the gear shift, proceeding to step (2) and activating the delay circuit 60 to allow a predetermined period of time to pass, the downshift side transmission (
In this embodiment, the sub-transmission 14) starts shifting.

Next, in step (2), the rotational speeds of the vehicle speed sensor 38 and intermediate shaft rotation sensor 56 are read, respectively, and based on these two rotational speeds, the gear ratio of the downshift side transmission is calculated in step (2).

Then, in step IK, it is determined from the calculated gear ratio of the downshift side transmission whether or not the downshift of the auxiliary transmission 14 has been completed, and if rNOJ, the process returns to step (2) above, and if rYES, step Proceed to X and lower the shift fluid pressure of the upshift side transmission,
End this flow once.

That is, as an example of the mode of the double changeover shift controlled in this embodiment, let us take the case where the entire gear stage shown in Table 3 above is upshifted from 2nd speed to 3rd speed. In this case, the main transmission 12 is upshifted from 1st speed to 2nd speed, and the auxiliary transmission 14 is downshifted from T to Lo, but the 2nd speed setting of the main transmission 12 is As shown in Table 2, this is performed by newly engaging the band brake B/B, and the downshift of the auxiliary transmission 14 is performed by releasing the direct clutch D/C as described above.

Therefore, in this embodiment, as shown in FIG. 5, after the engagement pressure A of the band brake B/H starts to rise (A, p), the engagement pressure B of the direct clutch D/C is lowered all at once.
The direct clutch D/C is released quickly, that is, the downshift of the auxiliary transmission 14 is performed quickly, and at this time, the engagement pressure A of the band brake B/H is conventionally in the process of rising as shown by the broken line in the figure. It is in.

In this embodiment, at the time when the direct clutch D/C is released and the downshift of the auxiliary transmission 14 is completed (B down), the engagement pressure A of the band brake B/H is reduced.

In other words, in this embodiment, the engagement pressure A on the main transmission 12 side is reduced at the same time as the downshift of the auxiliary transmission 14 is completed, so that the slipping portion of the band brake B/H increases, and the sixth As shown by the broken line in the output torque characteristic T in the figure, the protruding portion P of the output torque conventionally generated by the inertia phase torque when direct clutch D/C is engaged can be substantially eliminated.

Therefore, with the above output torque characteristic T, the band brake B/
With the start of fastening H, only the descending portion Q of the output torque that is generated before the protruding portion P is generated, so that the frequency of occurrence of shock can be reduced, and the descending portion Q of the output torque is not protruding. Since the degree of shock experienced is significantly reduced compared to the portion P, the shift shock felt by the occupants is significantly reduced, and the ride comfort of the vehicle is greatly improved.

In this embodiment, an example has been described in which the entire gear stage is upshifted from second speed to third speed as a double changeover. It goes without saying that the present invention can be applied even in the case of heavy shifting.

Further, in this embodiment, the main transmission 12 has four forward gears, and the sub-transmission 14 has two gears, but the present invention is not limited to this. The present invention can be applied to the machines 14 as long as they each have two or more gear stages and are capable of performing double gear shifting.

As described in detail, the automatic transmission shift control device of the present invention includes a main transmission having a shift function of at least two or more stages, and a sub-transmission having a shift function of at least two or more stages. When the main transmission and the sub-transmission are synchronized and one is upshifted and the other is downshifted, a double changeover is performed.
The upshift side gear change is performed before the downshift side gear change, and the downshift side gear change is performed during the upshift side, and immediately after the downshift side gear change is completed, the upshift side gear change is performed in the middle of the downshift side gear change. Since the shift hydraulic pressure on the shift side is lowered, the slipping portion on the upshift side due to the drop in the hydraulic pressure on the shift side can absorb the protruding portion of the inertia phase torque generated immediately after the shift on the downshift side. can.

Therefore, it is possible to significantly reduce the degree of shock caused by double shifting, thereby greatly reducing the shift shock while significantly increasing the number of shift modes and increasing the number of shift selections suitable for driving conditions. This has the excellent effect of allowing smoother operation.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the concept of the present invention, FIG. 2 is a schematic diagram showing an embodiment of the present invention, and FIG. 3 is a schematic diagram showing a gear train of an automatic transmission to which the present invention is applied. , FIG. 4 is a flowchart showing an example of the processing of a program executed in the present invention, FIG. 5 is a shift hydraulic pressure characteristic diagram when double shifting occurs in the present invention, and FIG. FIG. 3 is a diagram of the obtained output torque characteristics. 10... automatic transmission, 12... main transmission, 14...
・Sub-shift 8! , 28... A/T control unit, 34... Shift control controller, 42... Main transmission shift hydraulic pressure controller (upshift side shift hydraulic pressure control means), 54... Downshift completion detection means , 58・
. . . double changeover shift detection means, 60 . . . delay circuit (shift order determining means). Figure 5 Figure 1 Figure 6 Time

Claims (1)

[Claims] (1) A main transmission having a transmission function of at least two or more stages and a sub-transmission having a transmission function of at least two or more stages are arranged in series, and at least one of the main transmission and the sub-transmission is switched based on driving conditions. In an automatic transmission in which the final gear ratio is determined by the product of the respective gear ratios when the gears are changed, based on the above driving conditions, the main transmission and the auxiliary transmission are synchronized and one of them is A double changeover detection means detects a double changeover in which one is upshifted and the other is downshifted; a shift order determination means for causing the downshift side shift to be performed during the upshift side shift; a downshift shift completion detection means for detecting the completion of the downshift side shift; and immediately after the downshift side shift is completed. upshift side shift hydraulic pressure control means for reducing shift hydraulic pressure on the upshift side;
A speed change control device for an automatic transmission, characterized in that it is provided with: