JPH03125068A - Gear controller for automatic transmission - Google Patents

Abstract

PURPOSE:To reduce shock during double reciprocal gear change by temporarily raising the gear change liquid pressure of an preceding upshift-side transmission with the start of downshift gear change during double reciprocal gear change. CONSTITUTION:When a main transmission (a) and an auxiliary transmission (b) are synchronized and then double reciprocal gear change, that when one is upshifted the other is downshifted, is detected by a detecting means (c) from running conditions, a gear change priority deciding means (d) conducts upshift- side gear change in priority and starts downshift-side gear change on the way of its gear change. Then, when a detecting means (e) detects the start of the downshift-side gear change, an upshift-side gear change liquid pressure control means (f) temporarily raises upshift-side gear change liquid pressure with the start of the downshift-side gear change. Torque pull-in due to downshift-side gear change start is thus offset by torque increase of an upshift-side transmission to restrain 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.
As disclosed in the publication, a main transmission (first transmission) and a sub-transmission (second transmission) are arranged in series, and the final transmission ratio is determined by the product of the transmission ratios of the sub-transmission. There are some things that have come to be done.

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 changeover between the main transmission and the auxiliary transmission is normally performed by switching friction elements such as hydraulically operated clutches and brakes, but a unique engagement shock is generated when the friction elements are switched. .

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 shifts the upshift side of the main transmission and the auxiliary transmission first during the double changeover, and eliminates the problem that occurs during the downshift that is changed later. To provide a shift control device for an automatic transmission which can significantly suppress shift sizic by temporarily increasing the torque of an upshift side transmission to reduce torque pull.

Means for Solving the Problems In order to achieve the above object, one configuration of the present invention is as follows.
As shown in the figure, a main transmission a having a transmission function of at least two or more stages and a sub-transmission a having a transmission function of at least two or more stages are arranged in series. Machine a.

In an automatic transmission in which the final gear ratio is determined by the product of the respective gear ratios by shifting at least one of the gear ratios of the main transmission a and the sub-transmission are synchronized and one upshifts,
a double changeover detection means C for detecting a double changeover in which the other side is downshifted; and when a double changeover is detected, an upshift side shift is executed prior to a downshift side shift. , a shift order determining means d for causing the downshift side shift to be performed in the middle of the upshift side shift; a downshift shift start detecting means e for detecting the start of the downshift side shift; and an upshift side shift hydraulic pressure control means f for temporarily increasing the upshift side shift hydraulic pressure.

Another configuration of the present invention is that, as shown in FIG. 2, a main transmission a having a transmission function of at least two or more stages and an auxiliary transmission A having a transmission function of at least two or more stages are arranged in series. , these main and sub-shifts 1131 based on driving conditions.
In an automatic transmission in which the final gear ratio is determined by the product of the respective gear ratios by shifting at least one of the gear ratios of the main transmission a and the sub-transmission a double changeover detection means C that detects a double changeover in which one side is upshifted and the other is downshifted in synchronization; a shift order determining means d for causing the downshift side shifting to be executed prior to the upshift side shifting, and a downshift gear ratio for detecting a change in the gear ratio of the downshift side transmission; a detection means g, which increases the shift hydraulic pressure on the upshift side with the start of the gear ratio change on the downshift side, and increases the shift hydraulic pressure on the upshift side with the end of the gear ratio change on the downshift side; The upshift side shift hydraulic pressure control means for returning to the original state is provided.

With the above-described structure, in the automatic transmission shift control device of the present invention shown in FIG. The downshift is performed prior to the upshift and is performed during the upshift, and in this way, the downshift, which is to be changed later, is started. This pull-in torque is generated by temporarily increasing the shift hydraulic pressure on the upshift side via the upshift side shift hydraulic pressure control means f. This is offset by the increased torque of the transmission on the shift side.

Therefore, the shock at the time of double gear shifting is significantly reduced on the downshift side, resulting in a significant reduction in shift shock as a whole.

In addition, in the shift control device for an automatic transmission shown in FIG. 2 of the present invention, the downshift gear ratio detection means g can detect a substantial shift of the transmission on the downshift side, and By reliably matching the shift hydraulic pressure increase with the shift on the downshift side, the pull-in torque on the downshift side can be reliably removed, and the reduction in shift shock can be further improved.

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

That is, FIG. 3 shows an embodiment of the 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 at two constant speeds.

The gear trains of the main transmission 12 and the sub-transmission 14 are configured as shown in FIG. 4, and the main transmission 12 includes a first planetary gear set PGr and a second planetary gear set PC, and 14 is the 3rd il! Equipped with star gear set PG3.

Above 1. Second. 3rd planetary gear set PC,, PC,, PG
.

are respectively configured as simple planetary gears, with the first, second, and so on being configured as simple planetary gears.
The third sun gear S, , S, , S3 and the first sun gear. 2nd and 3rd pinion gears P, , P, , P, 1st and 2nd gears. The third ring gears R, , R, , R, and the first and second ring gears. The third binion carrier is composed of PCr, PCr, and PCs.

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

Further, a forward one-way clutch F10/C is connected between the forward clutch P/C and the second ring gear R2.
is provided, and a row one-way clutch L10 is provided between the first pinion carrier PCI and the casing C/S.
-C is provided, and an overrun clutch O-C is provided between the first pinion carrier PC8 and the second ring gear R6 in parallel with the forward one-way clutch F10-C.
R/C is placed.

In addition, in the sub-transmission 14, the gear train composed of the third planetary gear set PGs includes a direct clutch D/C connecting the third pinion carrier PC3 and the third sun gear S3, and a third sun gear as shown in the figure. Keishin S3,
A reduction brake R-D/B is provided which is fixed to the engine C/S.

Furthermore, the t between the third sun gear S and the casing C/S is
Reduction one-way clutch R-Dlo- for ifl
C is placed.

The second pinion carrier PC, which is the output member of the main transmission 12, and the third ring gear R3, which is the 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, as shown in Table 2 below, each friction element (R/C, If/C, F/C, B/B.

L&R/B) are engaged and released by shift hydraulic pressure (line pressure) supplied from a control valve (not shown), so that various shift stages can be obtained.

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

Further, the forward one-way clutch F10.C is locked 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, and is locked when the second ring gear R2 rotates in the reverse direction. The clutch L10-C is free when the first pinion carrier PC+ rotates in the forward direction, and is locked when the first pinion carrier PC+ 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 0-R
For /C, the accelerator opening is 1/16 on the low gear side below 3rd gear.
By being engaged as follows, the function of the forward one-way clutch F10.C is eliminated 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, the input rotation is outputted in a constant velocity (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 Ss rotates in the normal direction, and is locked when the third sun gear Ss rotates in the reverse direction.

In the automatic transmission IO, the final transmission ratio output from the output shaft O/S is determined by the product of the transmission ratio of the main transmission 12 and the transmission ratio of the auxiliary transmission 14. The number of gears obtained by the transmission IO 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 l2 is switched to four forward gears. , sub-transmission 14
Since the gears are switched to two gears, a total of eight forward gears can be shifted as shown in Table 3 below.

Table 3 Main transmission controller 30 built into A/T control unit 28 (1st, 2nd shift solenoid 22.
24 control) and sub-transmission controller 32 (for control of the third
It is turned ON and OFF by a control signal output from a shift solenoid 26 (for controlling the shift solenoid 26).

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.

(Left below) 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. The second and third shifters and the lenses 22, 24, and 26 are shown in Table 4. By the way, the main transmission controller 30 and the sub-transmission controller 32 are connected to the first and second shifters. Commands for ON and OFF signals to be output to the second and third shift lenses 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 inputted to the shift control controller 34, and the gear is changed based on a shift schedule set in advance from these throttle openings and vehicle speed. Judgment is about to be made.

Further, the main transmission 12 is provided with a line pressure solenoid 40 for controlling line pressure.
is operated by a control signal output from the main transmission shift hydraulic pressure controller 42 as an upshift side shift hydraulic pressure control means, thereby controlling the shift hydraulic pressure for engaging the friction element.

Incidentally, the line pressure control of the main transmission 12 is performed using a brake 9. provided in a control valve in response to a signal pressure generated from a line pressure solenoid, as disclosed in, for example, Japanese Patent Application Laid-Open No. 62-62047. .

The discharge pressure of the oil pump is regulated by a jar regulator valve, and the regulated line pressure is supplied to the friction element as shift hydraulic pressure.

Here, in this embodiment, a delay circuit 50 is provided between the shift control controller 34 and the auxiliary transmission shift controller 32 as a shift order determining means, and the shift control controller 34 is connected to the automatic transmission 10. When the main transmission 12 and the sub-transmission 14 are shifted in synchronization, one of them is upshifted and the other is downshifted. provided.

The above-mentioned double changeover transmission refers to a transmission in which the main transmission 12 and the sub-transmission 14 are synchronized to upshift one and downshift the other, for example, as shown in Table 3 above. This includes shifting from second gear to third gear, shifting from fourth gear to fifth gear, and shifting from sixth gear to seventh gear, etc. in the sequential step-by-step gear shifting, and the main transmission 12 In this embodiment, the main transmission 12 is upshifted and the auxiliary transmission 14 is downshifted. Let's take an example.

When the double shift change is detected, the double shift change detection means 52 outputs an activation signal to the delay circuit 50, and the shift control controller 34 outputs an activation signal to the sub-transmission shift hydraulic pressure controller. The speed change command signal outputted to 42 is delayed by a predetermined period of time.

Further, after a predetermined time, a downshift on the side of the auxiliary transmission 14 is started by the shift command signal output from the delay circuit 50, but the downshift is performed by introducing the shift command signal output from the delay circuit 50. A downshift shift start detection means 54 is provided for detecting the start of the downshift, and upon the start of the downshift, the downshift shift start detection means 54 outputs a jerk signal to the main transmission shift hydraulic pressure controller 42 for a predetermined period of time; The shift hydraulic pressure on the main transmission 12 side is temporarily increased.

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 1, and the vehicle speed is read in step (2). A shift schedule is searched from the driving conditions based on these throttle opening and vehicle speed, and the gear is shifted in step (3). If r NO OJ, the process returns to step I, and if rYESJ, the process proceeds to step 2, where it is determined whether or not it is a double shift.

Then, if rNOl is determined in step 2, proceed to step 2, and execute the gear shift determined in step 2, and if rYESJ, proceed to step 2, and send a shift signal to the main transmission 12. is output to start upshifting.

Incidentally, the start of the shift on the upshift side is performed by outputting an actuation signal from the double shift shift detection means 52 to the delay circuit 50 in FIG. 3, and delaying the shift on the sub-transmission 14 side. be exposed.

In the next step (2), the system waits until the delay time (t5ee) set by the delay circuit 50 has elapsed, and when the delay time has elapsed, the process proceeds to step (2) to shift to the downshift side, that is, the sub-shift. Shifting on the machine 14 side is started.

In the next step (2), it is determined whether a predetermined time has elapsed since the start of the downshift, and until the predetermined time has elapsed, the shift hydraulic pressure on the upshift side is increased by a predetermined amount in step After the time has elapsed, the process proceeds to step M, where the upshift hydraulic pressure is reduced to the original hydraulic pressure value.

As described above, in this embodiment, when a double shift is detected, an upshift is first performed by the main transmission 12, and then a downshift is performed by the auxiliary transmission 14 after a predetermined period of time.

Therefore, the total output torque of the automatic transmission IO is a in Figure 6.
As shown in the characteristics, first an upshift causes an output fluctuation, and then a downshift causes an output fluctuation B as shown by the broken line due to the pull-in torque of the inertia phase.
is about to occur.

However, in this embodiment, as shown in the characteristic shown in FIG. Since the shift hydraulic pressure increases (portion C), considering only the output torque of the main transmission 12, after the above output fluctuation occurs as shown in characteristic C in the figure, the discharge portion of torque increases. is generated.

Therefore, since the torque discharge portion is set to be generated simultaneously with the output fluctuation B on the downshift side, the output fluctuation B and the torque discharge portion cancel each other out, and the solid line of the a characteristic As shown, the output variation B is eliminated and the variation portion is significantly reduced.

Therefore, the shock generated during double gear shifting is
Only the fluctuation portion A is generated approximately on the main transmission 12 side,
Since this is substantially the same as in the case of normal single-shift shifting, it is possible to achieve a significant reduction in shift shock.

FIG. 7 shows another embodiment of the present invention, in which the same components as in the above embodiment are denoted by the same reference numerals and redundant explanations will be omitted.

That is, in the shift control device for the automatic transmission of this embodiment, the A/T control unit 28 is provided with an auxiliary transmission gear ratio calculation circuit 60 as downshift shift start detection means, and the auxiliary transmission gear ratio calculation circuit 60 is provided as a downshift shift start detection means. The gear ratio of the sub-transmission 14 detected by the circuit 60 is output to the main transmission shift hydraulic pressure controller 42, and the gear ratio is substantially changed in the main transmission shift hydraulic pressure controller 42. By this, the shift hydraulic pressure on the main transmission 12 side is increased, and when the gear ratio change is stopped, the shift hydraulic pressure is reduced to the hydraulic pressure value before the gear ratio change. There is.

By the way, the sub-transmission gear ratio calculation circuit 60 receives a detection signal from an intermediate shaft rotation sensor 62 that detects the rotation speed of the intermediate shaft M/S that connects the main transmission 12 and the sub-transmission 14, and a sub-transmission gear ratio calculation circuit 60. A detection signal from the vehicle speed sensor 38 that detects the 0/S rotation of the output shaft of the transmission 14 is input, and the gear ratio of the sub-transmission 14 is calculated from the rotation difference between these two sensors 62 and 38. There is.

Therefore, in this embodiment, control is performed using the flowchart shown in FIG. 8, and this flowchart will be explained below.

Note that this flowchart is processed at regular short intervals in the same way as shown in FIG. 5 above, and the same processing parts as in the flowchart in FIG. .

That is, in the flowchart of FIG. 8, from step 1 to step (2), the same processing as in FIG. is read, and from these two rotational speeds, the gear ratio on the downshift side is calculated in step (2).

Then, in the next step W, it is determined whether or not the gear ratio change on the downshift side has been completed, and until the gear ratio change is completed, that is, in the case of rNOJ, the process proceeds to step X, and the shift on the upshift side is performed. While the hydraulic pressure is increased by a predetermined amount, when the gear ratio change is completed, the process proceeds to step °C and the shift hydraulic pressure on the upshift side is decreased to the original state.

As described above, in this embodiment, the shift hydraulic pressure on the upshift side is increased due to the gear ratio change on the side of the auxiliary transmission 14 that is downshifted, but the gear ratio change on the downshift side has the characteristic d in FIG. The period during which the gear ratio is changing is the period during which the inertia phase occurs, and a fluctuation portion I3 due to the pulling torque is generated as shown in the characteristic a in the figure.

Therefore, since the gear ratio change period on the downshift side is the period during which the fluctuation portion B occurs, as in this embodiment, by increasing the shift hydraulic pressure on the upshift side during the gear ratio change period, C Since it is possible to reliably match the protruding part of the torque on the upshift side shown in the characteristics with the above-mentioned fluctuation part B, the fluctuation part B can be deleted more effectively, and the reduction in shift shock is greatly improved. will be done.

By the way, in each of the embodiments described above, the main transmission 1
The 2nd side is upshifted and the sub-shift I! The explanation has been given using an example of a double changeover shift in which the 14 side is downshifted, but in contrast to this, a double changeover shift in which the 2nd side is downshifted and the auxiliary transmission 14th side is upshifted. The present invention can be applied even in this case, in which case the auxiliary transmission 14 to be upshifted is shifted in advance, and the main transmission 12 to be downshifted is shifted after a predetermined period of time. .

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.

Effects of the Invention As explained above, in the shift control device for an I-dynamic transmission according to the present invention, a main transmission having a shift function with a shift function of "at least 2 film thicknesses" in claim 1, and at least 2 stages. In an automatic transmission in which a sub-transmission having the above-mentioned shift functions is arranged in series, the main transmission and the sub-transmission are synchronized so that one is upshifted and the other is downshifted. When a gear shift is performed, the upshift side gear change is performed before the downshift side gear change, and the downshift side gear change is performed in the middle of the upshift, and at the same time as the downshift is started. Since the shift hydraulic pressure on the upshift side is temporarily increased, the pull-in torque generated at the start of a downshift can be offset by the increased torque due to the increase in the shift hydraulic pressure on the upshift side. Therefore, it is possible to significantly reduce shock during double gear shifting.

Further, in claim 2 of the present invention, a change in the gear ratio of the transmission on the downshift side is detected, and with the start of the gear ratio change, the transmission hydraulic pressure on the upshift side is increased, and the shift hydraulic pressure on the upshift side is increased. Since the shift fluid pressure on the upshift side is returned to its original state upon completion of the shift, the increase in shift fluid pressure on the upshift side can be reliably matched to the shift period on the downshift side.
Each of these has the excellent effect of being able to reliably eliminate the pull-in torque on the downshift side and further reduce shift shock.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram showing one concept of the present invention, FIG. 2 is a schematic block diagram showing another concept of the present invention, FIG. 3 is a schematic block diagram showing one embodiment of the present invention, and FIG. Figure 5 is a schematic configuration diagram showing a gear train of an automatic transmission to which the present invention is applied.
The figure is a flowchart showing an example of processing of a program executed in one embodiment of the present invention, FIG. 6 is a time chart of each control element obtained when controlling the present invention, and FIG. FIG. 8 is a schematic configuration diagram showing an embodiment. FIG. 8 is a flowchart showing an example of processing of a program executed in another embodiment of the present invention. 10... automatic transmission, 12... main transmission, 14...
- Stiffness iMm, 28... A/T control unit, 34... Shift control controller, 42... Main transmission shift hydraulic pressure controller (upshift side shift hydraulic pressure control means), 50... Delay- Circuit (speed change order determining means)
, 52...Double shift shift detection means, 54...Downshift shift start detection means, 60...Sub-transmission gear ratio calculation circuit (downshift shift start detection means). Fig. 1 Fig. 2 Fig. 5 Fig. 6 Output torque of the entire automatic transmission Upshift side hydraulic pressure Downshift side gear ratio 542-

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 the other side is upshifted and the other is downshifted; a shift order determining means for causing the downshift side shift to be performed in the middle of the upshift side shift; a downshift shift start detection means for detecting the start of the downshift side shift; 1. A shift control device for an automatic transmission, comprising: upshift side shift hydraulic pressure control means for temporarily increasing shift hydraulic pressure on the upshift side. (2) 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 the other side is upshifted and the other is downshifted; a gear change order determining means for causing the downshift side gear change to be performed during the upshift side gear change; a downshift gear ratio detection means for detecting a gear ratio change of the downshift side transmission; Upshift side shift hydraulic pressure control that increases the upshift side shift hydraulic pressure with the start of a ratio change, and returns the upshift side shift hydraulic pressure to the original level with the end of the downshift side gear ratio change. 1. A speed change control device for an automatic transmission, comprising: means.