JP2926786B2 - Transmission control device for automatic transmission - Google Patents

Description

The present invention relates to an automatic transmission mounted on a vehicle, and more particularly to an automatic transmission mounted on a vehicle.
The present invention relates to a shift control device for an automatic transmission configured by arranging a main transmission and a subtransmission each having a plurality of gears in series.

2. Description of the Related Art A conventional automatic transmission for a vehicle includes a main transmission (first transmission) and an auxiliary transmission (second transmission) arranged in series as disclosed in Japanese Patent Application Laid-Open No. 62-83541. In some cases, the final transmission ratio is determined by the product of the transmission ratios of both transmissions.

Therefore, in such an automatic transmission, the number of gears obtained by multiplying the number of gears of the main transmission by the number of gears of the sub-transmission is obtained.
For example, the main transmission has three forward speeds and the subtransmission has two speeds (Lo, Hi
In the case of (switching), as shown in Table 1 below, a total of six forward gears can be obtained, and a multi-speed automatic transmission can be achieved.

SUMMARY OF THE INVENTION However, such a conventional shift control device for an automatic transmission, when the overall shift speed is shifted from the second speed to the third speed and from the fourth speed to the fifth speed, Upshifting of the transmission and downshifting of the auxiliary transmission are performed in synchronization.

That is, the gear changeover between the main transmission and the subtransmission is normally performed by switching a friction element such as a hydraulically operated clutch or a brake. When the friction element is switched, a specific engagement shock is generated. .

For this reason, when the main transmission and the sub-transmission are shifted in synchronization with each other, the engagement shock in each transmission occurs twice consecutively, and the frequency of the transmission shock increases, or In the case where two engagement shocks are generated at the same time, a large shift shock is generated at a time, and there is a problem that the ride comfort of the vehicle is significantly deteriorated.

In view of such a conventional problem, the present invention is generated during a downshift, in which the upshift side of the main transmission and the subtransmission is shifted in advance during a double shift shift, and the shift is performed later. It is an object of the present invention to provide a shift control device for an automatic transmission in which the pull-in of the torque is temporarily reduced by increasing the torque of the upshift-side transmission, thereby significantly reducing shift shock.

Means for Solving the Problems In order to achieve the above object, one configuration of the present invention is, as shown in FIG. 1, a main transmission a having at least two or more gears, and a main transmission a having at least two or more gears. A sub-transmission b having a function is arranged in series, and at least one of the main and sub-transmissions a and b is shifted based on running conditions, so that the final transmission ratio is determined by the product of the respective transmission ratios. In the determined automatic transmission, the main transmission a and the auxiliary transmission b are synchronously shifted up on one side and down-shifted on the other side in synchronization with the traveling condition.
Double shift detection means c for detecting double shifts c
A shift order determining means d for executing, upon detection of a double shift, a shift on the upshift side prior to a shift on the downshift side and performing the shift on the downshift side during a shift on the upshift side; A downshift-shift start detecting means e for detecting the start of a downshift-side shift; and an upshift-side shift-hydraulic-pressure control means for temporarily increasing the upshift-side shift fluid pressure with the start of the downshift-side shift. and f.

In another configuration of the present invention, as shown in FIG. 2, a main transmission a having at least two-stage shift function and an auxiliary transmission b having at least two-stage shift function are arranged in series. And the main and auxiliary transmissions a and b based on the driving conditions.
In an automatic transmission in which at least one of the transmissions is shifted so that the final transmission ratio is determined by the product of the respective transmission ratios, the main transmission a and the auxiliary transmission b Are synchronized, one is upshifted and the other is downshifted 2
Double shift detection means c for detecting double shifts c
A shift order determining means d for executing, upon detection of a double shift, a shift on the upshift side prior to a shift on the downshift side and performing the shift on the downshift side during a shift on the upshift side; A downshift gear ratio detecting means g for detecting a gear ratio change of the downshift side transmission; and increasing the upshift side shift hydraulic pressure with the start of the downshift side gear ratio change; And the upshift-side transmission hydraulic pressure control means h for returning the upshift-side transmission hydraulic pressure to the original value in response to the end of the gear ratio change.

Operation With the above-described configuration, in the shift control device for an automatic transmission shown in FIG. 1 of the present invention, when a double changeover is performed, the shift on the upshift side is reduced via the shift order determining means d. The downshift is performed prior to the shift, and the downshift is performed in the middle of the upshift. The pull-in torque is generated by temporarily increasing the upshift-side shift hydraulic pressure via the upshift-side shift hydraulic pressure control means f. This is offset by the increase in the torque of the shift-side transmission.

For this reason, the shock at the time of the double shift is greatly reduced on the downshift side, and the shift shock is significantly reduced as a whole.

Further, in the shift control device for an automatic transmission shown in FIG. 2 of the present invention, the downshift gear ratio detecting means g can detect the substantial shift of the downshift-side transmission, and By ensuring that the shift hydraulic pressure rise coincides with the shift on the downshift side, the pull-in torque on the downshift side can be reliably eliminated, and the reduction in shift shock can be further improved.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

That is, FIG. 3 shows an embodiment of a shift control device for an automatic transmission according to the present invention. The automatic transmission 10 shown in FIG. 3 includes a main transmission 12 in which four forward gear shifts are performed, and a reduction gear. ,
It is constituted by arranging in series a subtransmission 14 in which two-stage switching at a constant speed is performed.

The main gear train of the transmission 12 and the sub transmission 14 is configured as shown in FIG. 4, the main transmission 12 includes a first planetary gear set PG ₁ and the second planetary gear set PG _2, and the auxiliary transmission machine 14 includes a third planetary gear set PG _3.

The first, second, and third planetary gear sets PG ₁ , PG ₂ , PG ₃ are each configured as a simple planetary gear, and the first, second, and third sun gears are provided.
S ₁ , S ₂ , S ₃ , first, second, third pinion gears P ₁ , P ₂ , P ₃ ,
The first and second ring gears R ₁ , R ₂ and R ₃ and the first, second and third pinion carriers PC ₁ , PC ₂ and PC ₃ are provided.

In the main transmission 12, the first and second planetary gear sets PG ₁ , PG ₁
The gear train composed of _2, connects the input shaft I / S as illustrated reverse clutch R / C to connect the first sun gear S _1, the input shaft I / S and the first pinion carrier PC ₁ the high clutch H / C, the forward clutch F / C which connects the first pinion carrier PC ₁ and the second ring gear R _2, the band brake B / B to the first sun gear S ₁ is fixed to the casing C / S side, the 1 pinion carrier P
The low and reverse brake L & R / B is provided for fixing the C ₁ to the casing C / S side.

Further, the forward clutch F / C and the second ring gear R
₂ , a forward one-way clutch F / OC is provided, and a first pinion carrier PC ₁ and a casing C
/ S is provided between the first pinion carrier PC ₁ and the second ring gear R.
₂ , an overrun clutch O / R / C is arranged in parallel with the forward one-way clutch F / O / C.

In addition, the gear train composed of the auxiliary transmission 14 in the third planetary gear set PG _3, direct clutch D / C which connects the third pinion carrier PC ₃ as shown and the third sun gear S _3, the 3 sun gear S ₃ is the reduction brake R · D / B for fixing the casing C / S is provided.

Furthermore, reduction one-way clutch R · D / O · C between the third sun gear S ₃ and casing C / S is arranged.

The second pinion carrier PC _{2 serving as} an output member of the main transmission 12 and the third ring gear R _{3 serving as} an input member of the auxiliary transmission 14 are connected via an intermediate shaft M / S. I have.

In FIG. 3, the torque of the engine E is input to the input shaft I / S via a torque converter T / C.

Incidentally, in the main transmission 12, as shown in Table 2 below, each friction element (R / C, H / C, F / C, B / B, L & R / B) is supplied from a control valve (not shown). Shifting hydraulic pressure (line pressure)
By engaging and disengaging the gears, various speeds can be obtained.

In the table, a circle indicates a fastened state, and a blank indicates a released state.

In addition, the forward one-way clutch F / O ・ C
The second ring gear R to the first pinion carrier PC _1
2 is free when rotating in the forward direction, locked when rotating in the reverse direction, and the low one-way clutch L / O
C is unlocked, upon rotation in the reverse direction during rotation of the first forward direction of the pinion carrier PC _1.

By the way, the overrun clutch O / R / C is the first
Although not shown in the table, the overrun clutch OR
C is engaged at lower speeds of 3rd speed and lower with an accelerator opening of 1/16 or less, losing the function of the forward one-way clutch F / O · C, and allowing the engine brake to operate. ing.

On the other hand, in the subtransmission 14, the input rotation is output at a constant speed (Hi) state by engaging the direct clutch D / C, and the deceleration (Lo) state is output by releasing the direct clutch D / C. It is output.

In addition, the above reduction one-way clutch R / D / O
· C is adapted to be locked at the time of free and will, reverse at the time of the forward rotation of the third sun gear S _3.

In the automatic transmission 10, the final speed ratio output from the output shaft O / S is determined by the product of the speed ratio of the main transmission 12 and the speed ratio of the auxiliary transmission 14. The number of gears obtained by the transmission 10 depends on the main transmission 12
In this embodiment, the main transmission 12 is switched to four forward speeds and the sub transmission 14 is switched to two speeds. As shown in Table 3, a total of eight forward gears can be achieved.

The control valve has a first transmission for switching the main transmission 12.
A shift solenoid 22 and a second shift solenoid 24;
A third shift solenoid 26 for switching the sub-transmission 14 is provided, and the first, second, and third shift solenoids 22, 24, 26
Main transmission controller 30 built in T control unit 28 (for controlling first and second shift solenoids 22 and 24)
And the auxiliary transmission controller 32 (third shift solenoid
ON / OFF drive is performed by a control signal output from the control circuit 26).

Therefore, the first, second, and third shift solenoids 22, 24, 26
Are turned on and off, the first, second, and third shift valves (not shown) built in the control valve are switched, and the friction elements are engaged and released, and the next As shown in Table 4, each shift speed can be obtained.

By the way, the ON / OFF signal commands output from the main transmission controller 30 and the sub transmission controller 32 to the first, second, and third shift solenoids 22, 24, 26 are output from the transmission control controller 34. It has become so.

The shift control controller 34 includes a throttle sensor
Throttle opening signal detected by 36 and vehicle speed sensor 38
The shift speed is determined based on a preset shift schedule based on the throttle opening and the vehicle speed.

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

The line pressure control of the main transmission 12 is described in, for example,
As disclosed in JP-A-62-62047, the discharge pressure of an oil pump is regulated by a pressure regulator valve provided in a control valve in accordance with a signal pressure generated from a line pressure solenoid, The regulated line pressure is supplied to the friction element as a shifting 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 includes the automatic transmission 10. When shifting, the main transmission 12 and the auxiliary transmission 14 are synchronized, and a double shift detection means 52 for detecting a double shift in which one is upshifted and the other is downshifted is provided. Can be

Note that the double shift shift is a shift in which the main transmission 12 and the subtransmission 14 are synchronously upshifted and one shifted down, for example, as shown in Table 3 above. The shifts following the rank stages correspond to a shift from the second speed to the third speed, a shift from the fourth speed to the fifth speed, a shift from the sixth speed to the seventh speed, and the like. The side of the transmission is up-shifted and the side of the sub-transmission 14 is down-shifted. Let's take an example.

And, when the above-mentioned double change is detected,
The double change-shift detecting means 52 outputs the delay circuit 50
And a shift command signal output from the shift control controller 34 to the auxiliary transmission shifting hydraulic pressure controller 42 is delayed by a predetermined time.

A downshift on the side of the sub-transmission 14 is started by a shift command signal output from the delay circuit 50 after a predetermined time, but the shift command signal output from the delay circuit 50 is introduced to start the downshift. A downshift start detection means 54 for detecting the shift is provided, and when the downshift starts, an operation signal is output from the downshift start detection means 54 to the main transmission transmission hydraulic pressure controller 42 for a predetermined time, and the main transmission The transmission fluid pressure on the 12 side is temporarily increased.

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

That is, the above-described flowchart is performed for a predetermined short time (for example, 10
msec). First, the throttle opening is read in step I, the vehicle speed is read in step II, and a shift schedule is searched from the running conditions based on the throttle opening and the vehicle speed. Is determined, and if “NO”, the process returns to step I again, and if “YES”, step IV
Then, it is determined whether or not a double shift is performed.

If “NO” is determined in step IV, the process proceeds to step V to execute the shift determined in step III, and if “YES”, the process proceeds to step VI, where the speed change signal is transmitted to the main transmission 12. Is output to start shifting on the upshift side.

The start of the upshift side shift is performed by outputting an operation signal from the double changeover shift detecting means 52 to the delay circuit 50 in FIG. 3 to delay the shift on the auxiliary transmission 14 side. .

Then, in the next step VII, the process stands by until the delay time (t sec) set by the delay circuit 50 has elapsed. When the delay time has elapsed, the process proceeds to step VIII, where the downshift side, that is, the auxiliary transmission The shift on the 14 side is started.

In the next step IX, it is determined whether or not a predetermined time has elapsed since the start of the downshift. Until the predetermined time has elapsed, the shift hydraulic pressure on the upshift side is increased by a predetermined amount in step X, and After a lapse of time, the routine proceeds to step XI, in which the upshift-side shifting hydraulic pressure is reduced to the original hydraulic pressure value.

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

Accordingly, the output torque of the entire automatic transmission 10 is a
As shown in the characteristics, first, an output fluctuation A is generated by an upshift, and then, when a downshift is performed, an output fluctuation B indicated by a broken line is generated by a pull-in torque of an inertia phase.
Is about to be generated.

However, in the present embodiment, as shown by the b characteristic in FIG.
The shift hydraulic pressure on the upshift side (main transmission 12 side) is temporarily increased (part C) with the start of the downshift shift (the predetermined time set in step IX). When only the output torque on the 12th side is considered, a torque discharge portion D is generated after the output fluctuation A is generated as shown by the characteristic c in FIG.

For this reason, since the torque discharge portion D is set so as to be generated simultaneously with the output fluctuation B on the downshift side, the output fluctuation B and the torque discharge portion D cancel each other out, and are indicated by the solid line in the a characteristic. As shown, the output fluctuation B is deleted, and the fluctuation portion is significantly reduced.

Therefore, the shock generated at the time of the double shift is substantially only the fluctuation portion A generated on the main transmission 12 side, which is substantially the same as the case of the normal single shift, so that the shift shock is generated. Can be achieved.

FIG. 7 shows another embodiment of the present invention, in which the same components as those in the above embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

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

By the way, the auxiliary transmission gear ratio calculation circuit 60 includes a detection signal from an intermediate shaft rotation sensor 62 that detects the rotational speed of the intermediate shaft M / S connecting the main transmission 12 and the auxiliary transmission 14, A detection signal from the vehicle speed sensor 38 that detects the output shaft O / S rotation of the transmission 14 is input, and the gear ratio of the auxiliary transmission 14 is calculated from the rotation difference between the two sensors 62 and 38. I have.

Accordingly, in this embodiment, control is performed according to the flowchart shown in FIG. 8, and the flowchart will be described below.

Note that this flowchart is processed every fixed short time similarly to the one shown in FIG. 5, and the same parts as those in the flowchart of FIG. .

That is, in the flowchart of FIG. 8, the same processing as in FIG. 5 is performed from step I to step VIII, and the next step XII is the intermediate shaft rotation sensor 62 and the vehicle speed sensor 38.
, The input and output rotations of the subtransmission 14 are read, and the gear ratio on the downshift side is calculated in step XIII from these two rotation speeds.

Then, in the next step XIV, it is determined whether or not the change of the gear ratio on the downshift side has been completed. Until the change of the gear ratio is completed, that is, if “NO”, the step XIV is executed.
Then, while increasing the upshift-side shifting hydraulic pressure by a predetermined amount, if the gear ratio change is completed, the process proceeds to step XI to decrease the upshifting-side shifting hydraulic pressure to the original state.

As described above, in this embodiment, the transmission hydraulic pressure on the upshift side is increased by the gear ratio change on the side of the sub-transmission 14 that is downshifted. However, the change in the gear ratio on the downshift side is the d characteristic in FIG. The change in the gear ratio is a period during which the inertia phase occurs, and a fluctuation portion B due to the pull-in torque is generated as shown by the characteristic a in FIG.

Accordingly, the downshift-side gear ratio change period is a period during which the fluctuation portion B occurs. Therefore, by increasing the upshift-side shift hydraulic pressure during the gear ratio change period as in the present embodiment, c in FIG. Since the protruding portion D of the torque on the upshift side shown in the characteristics and the above-mentioned fluctuating part B can be surely matched, the fluctuating part B can be deleted more effectively, and the reduction of shift shock is greatly improved. Will be done.

By the way, in each of the embodiments described above, the main transmission
The above description has been made with reference to an example of a double shift shift in which the side of the transmission 12 is upshifted and the side of the subtransmission 14 is downshifted. The present invention can also be applied to the case of a double shift shift in which a shift is performed, in which case the sub-transmission 14 to be upshifted is shifted in advance and the main shift is shifted down after a predetermined time. The machine 12 is shifted.

Further, in this embodiment, the main transmission 12 is provided with four forward gears and the auxiliary transmission 14 is switched between two gears. However, the present invention is not limited to this. Machine 14
The present invention can be applied as long as it has two or more shift speeds and the double changeover is executed.

Effect of the Invention As described above, in the shift control device for an automatic transmission according to the present invention, the main transmission having at least two or more shift functions and the at least two or more shift functions are provided in claim 1. In the automatic transmission in which the sub-transmission and the sub-transmission are arranged in series, when the main transmission and the sub-transmission are synchronized to perform a double changeover in which one is upshifted and the other is downshifted, The shift on the upshift side is performed prior to the shift on the downshift side, the shift on the downshift side is performed during the shift in the upshift, and the shift on the upshift side is performed with the start of the shift in the downshift. Since the hydraulic pressure is increased temporarily, the pull-in torque generated by the start of the downshift shift can be offset by the increase in torque due to the increase in the shift hydraulic pressure on the upshift side. Therefore, the shock at the time of the double shift can be greatly reduced.

According to a second aspect of the present invention, a change in the gear ratio of the transmission on the downshift side is detected, and when the change in the gear ratio is started, the transmission hydraulic pressure on the upshift side is increased. Since the upshift-side shifting hydraulic pressure is returned to the original value at the end, the upshift-side shifting hydraulic pressure rise can be reliably matched with the downshift-side shifting period, and the downshift-side pull-in torque can be reduced. There are various excellent effects that the deletion can be reliably performed and the shift shock can be further reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one concept of the present invention, FIG. 2 is a schematic diagram showing another concept of the present invention, FIG. 3 is a schematic diagram showing one embodiment of the present invention, FIG. FIG. 5 is a schematic configuration diagram showing a gear train of an automatic transmission to which the present invention is applied.
FIG. 6 is a flowchart showing one processing example 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, and FIG. 8 is a flowchart showing one processing example of a program executed in another embodiment of the present invention. 10 ... automatic transmission, 12 ... main transmission, 14 ... auxiliary transmission,
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 (shift order determining means), 52 ... Double shift change detection means, 54... Downshift start detection means, 60... Sub-transmission gear ratio calculation circuit (downshift start detection means).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (2)

(57) [Claims] 1. A main transmission having at least two-stage shifting functions and a sub-transmission having at least two-stage shifting functions are arranged in series.
An automatic transmission in which at least one of the sub-transmissions is shifted so that the final transmission ratio is determined by the product of the respective transmission ratios. A double shift-shift detecting means for detecting a double shift-shift in which one is up-shifted and the other is down-shifted in synchronism with the first shift-down shift; Shift order determining means for executing the shift operation prior to the shift operation, and performing the downshift operation in the middle of the upshift operation, downshift operation start detecting means for detecting the start of the downshift operation, and A shift control system for an automatic transmission, comprising: an upshift-side shift hydraulic pressure control means for temporarily increasing an upshift-side shift hydraulic pressure in response to a shift-side shift start. Control device. 2. A main transmission having at least two or more gears and a sub-transmission having at least two or more gears are arranged in series.
An automatic transmission in which at least one of the sub-transmissions is shifted so that the final transmission ratio is determined by the product of the respective transmission ratios. A double shift-shift detecting means for detecting a double shift-shift in which one is up-shifted and the other is down-shifted in synchronism with the first shift-down shift; Shift order determining means for executing the downshift side shift in the middle of the upshift side shift, and downshift gear ratio detecting means for detecting a change in the gear ratio of the downshift side transmission. The upshift-side hydraulic pressure is increased with the start of the downshift-side gear ratio change, and the upshift-side gear ratio is changed with the end of the downshift-side gear ratio change. A shift control device for an automatic transmission, comprising: an upshift-side shift hydraulic pressure control unit that restores a fast hydraulic pressure.