JP2000071816A - Controller for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of shifting shock at the time of starting shifting operation. SOLUTION: This controller is provided with an engine 10, a transmission 16 receiving rotation generated by the engine 10 for shifting operation, a shifting determining means 101 which determines whether shifting operation by the transmission 16 is needed or not, and an output reduction means 106 reducing engine torque before starting shifting operation when the shifting operation by the transmission 16 is needed. When the shifting operation by the transmission 16 is needed, the engine torque is reduced before starting shifting operation, therefore, input shaft torque can be reduced. During it, output shaft torque is reduced, thus it is possible to reduce the dropping amount of the output shaft torque at the time of starting shifting operation even if engine torque is large.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission.

[0002]

2. Description of the Related Art Conventionally, in an automatic transmission, a rotation generated by an engine is transmitted to a transmission via a fluid transmission device such as a torque converter, and the transmission performs a shift to perform a shift. The rotation after the transmission is transmitted to the drive wheels. The transmission is provided with a plurality of planetary gear units each including a sun gear, a ring gear, a pinion, and a carrier, and friction engagement elements such as clutches and brakes. By selectively connecting the machine case with a brake or selectively connecting two of the respective elements to each other by a clutch, a predetermined shift speed is achieved, and a gear ratio of the shift speed is achieved. The shift can be performed.

When a shift output is generated by the control device, a predetermined friction engagement element is disengaged. For example, first, the brake is released, and then the clutch is engaged. In a shift in which the one-way clutch is locked or the one-way clutch is locked, when the clutch is engaged during the shift, the output shaft torque generated on the output shaft of the transmission at the end of the shift becomes abnormally large, and Shock occurs.

FIG. 2 is a time chart showing the operation of a conventional control device for an automatic transmission. In the figure, N _C1 is the input rotation speed of the transmission, that is, the rotation speed on the input side of the first clutch disposed between the transmission and the automatic transmission (hereinafter referred to as “clutch input rotation speed”). ETR is a torque reduction signal generated to reduce the engine torque, and T _O is an output shaft torque output from the drive wheels.

[0005] When a shift determination is made at timing t1,
When the time measurement by the timer is started and the time T1 elapses,
A shift output is generated at timing t2. And
The clutch input rotation speed N _C1 is calculated based on the gear ratio and compared with a value before the shift is started to set a value ΔN 1
Is changed, the start of the shift is determined at the timing t3. Further, the clutch input rotation speed N _C1 is set to a set value Δ from a value calculated based on the gear ratio after the shift is completed.
When a value smaller by N2 is reached, the end of the shift is determined at timing t4. Then, with the determination of the end of the shift,
When the torque reduction signal ETR is output and the torque reduction is started, and when the time measurement by another timer is started and the torque reduction time T2 elapses, the output of the torque reduction signal ETR is ended and the torque reduction is ended.

Therefore, at the end of shifting, the output shaft torque T
_O does not become abnormally large, and the occurrence of a shift shock can be prevented.

[0007]

However, the conventional automatic transmission control device prevents the occurrence of a shift shock due to an abnormal increase in the output shaft torque T _O at the end of the shift. However, it is not possible to prevent a shift shock from occurring due to a drop in the output shaft torque T _O at the start of the shift.

That is, as described above, in a shift in which the brake is first released and then the clutch is engaged or the one-way clutch is locked, when the shift is started, the brake is released. Accordingly, the output shaft torque T _O drops. Therefore, a shift shock occurs. In particular, when the engine torque is large, the input shaft torque input to the transmission is large, so that the drop of the output shaft torque T _O at the start of the shift is increased accordingly, and the shift shock is also increased.

The present invention has been made to solve the problems of the conventional control device for an automatic transmission, and to provide a control device for an automatic transmission which can prevent a shift shock from occurring at the start of a shift. Aim.

[0010]

In order to achieve the above object, a control apparatus for an automatic transmission according to the present invention includes an engine, a transmission for receiving a rotation generated by the engine, and performing a shift, and a shift by the transmission. And a power reduction means for reducing engine torque before a shift is started when a shift by the transmission is required.

In another control apparatus for an automatic transmission according to the present invention, the output reduction means may be configured to perform a predetermined torque reduction when a predetermined standby time elapses when a shift is determined. Reduce engine torque based on time and torque reduction level. In still another automatic transmission control device according to the present invention, the torque reduction time and the torque reduction level are set in accordance with the vehicle speed.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a functional block diagram of a control device for an automatic transmission according to an embodiment of the present invention. In the figure, reference numeral 10 denotes an engine, 16 denotes a transmission for performing a shift by receiving rotation generated by the engine 10, 101 denotes a shift determining means for determining whether a shift by the transmission 16 is necessary, and 106 denotes a shift determining means. When the shift by the transmission 16 is necessary, the output reducing means reduces the engine torque before the shift is started.

FIG. 3 is a schematic diagram of the automatic transmission according to the embodiment of the present invention, and FIG. 4 is a diagram illustrating the operation of the automatic transmission according to the embodiment of the present invention. As shown, the rotation generated by the engine 10 is controlled by the output shaft 11.
Is transmitted to a torque converter 12 as a fluid transmission device. The torque converter 12 is connected to the engine 10
Is transmitted to the output shaft 14 via a fluid (hydraulic oil). When the vehicle speed exceeds a set value, the lock-up clutch L / C is engaged, and the rotation can be directly transmitted to the output shaft 14. It has become.

The output shaft 14 is connected to a transmission 16 that performs four forward speeds and one reverse speed. The rotation of the transmission 16 is transmitted to the counter shaft 23 via the counter drive gear 21 and the counter driven gear 22, and the rotation of the counter shaft 23 is
4 and to a differential device 26 via the ring gear 25.

In the differential device 26, the rotation transmitted through the output gear 24 and the ring gear 25 is distributed, and the distributed rotation is transmitted to drive wheels (not shown) via left and right drive shafts 27 and 28. You.
The transmission 16 includes a first planetary gear unit 3.
A first planetary gear unit 32 and a second planetary gear unit 32;
The first clutch C1, the second clutch C2, the third clutch C3, and the fourth clutch C in order to selectively transmit torque between the elements of the planetary gear unit 32 of FIG.
0, a first brake B1, a second brake B2, and one-way clutches F1, F0.

The first planetary gear unit 31
Are the first clutch C1 and the fourth clutch C1
A ring gear R ₁ connected to the output shaft 14 via the clutch C0 and connected to the drive device case 34 via the second brake B2 and the one-way clutch F1 disposed in parallel with each other, and is externally fitted to the output shaft 14 ( A sun gear S ₁ formed on a sun gear shaft 39 rotatably supported, a carrier CR ₁ connected to the counter drive gear 21, and a mesh between the ring gear R ₁ and the sun gear S _1. And pinions P _1A and P _1B rotatably supported by the carrier CR ₁ .

A drum 38 is fixed to the sun gear shaft 39. The drum 38 is connected to the output shaft 14 via the second clutch C2, and has an outer periphery via a first brake B1 for a drive device case. 34. On the other hand, the second planetary gear unit 32 is connected to the first clutch C1 via a third clutch C3 and a one-way clutch F0 disposed in parallel with each other, and
The ring gear R ₂ connected to the output shaft 14 via the first clutch C1, the sun gear S ₂ formed in said sun gear shaft 39, the carrier CR ₁ and linked carrier CR
_2, as well as with brought into meshing between the ring gear R ₂ and the sun gear S _2, consisting of a pinion P ₂ which is rotatably supported by the carrier CR _2.

Next, the operation of the automatic transmission having the above configuration will be described. In FIG. 4, S1 is a first solenoid valve, S2 is a second solenoid valve, S3 is a third solenoid valve, C1 is a first clutch, C2 is a second clutch,
C3 is the third clutch, C0 is the fourth clutch, B1 is the first clutch
Brake, B2 is a second brake, and F1, F0 are one-way clutches (OWC). P is a parking range, R is a reverse driving range, N is an N range,
D is the forward running range, 1ST is the first gear, and 2N
D is the second gear, N ^* is the neutral control state,
3RD indicates a third speed, and 4TH indicates a fourth speed.

○ represents the first solenoid valve S1,
2nd solenoid valve S2 and 3rd solenoid valve S
3 and a second solenoid signal SL _{1 for} opening and closing the second solenoid valve, respectively.
Solenoid signal SL ₂ and the third solenoid signal SL ₃ is a state of ON, the first clutch C1, second clutch C2,
Third clutch C3, fourth clutch C0, first brake B
A state where the first and second brakes B2 are engaged indicates a state where the one-way clutches F1 and F0 are locked. Further, x indicates that the first solenoid signal SL ₁ , the second solenoid signal SL _2, and the third solenoid signal SL ₃ are off, the first clutch C 1, the second clutch C 2, the third clutch C 3, and the fourth clutch C 0. , The first brake B1 and the second brake B2 are released, and the one-way clutches F1, F0 are free.

In addition, ◎ indicates the first release at a predetermined release pressure.
△ is the neutral system to release the brake B1
The state that can be turned on and off at the time of control (○) is the engine
2 shows a state in which it is engaged during braking. In this case, 1
At a high speed, the first clutch C1, the third clutch C3
Are engaged, and the one-way clutches F1, F0 are locked.
In a locked state. The rotation of the output shaft 14 is
Ring gear via the first clutch C1 and the one-way clutch F0.
R _TwoIs transmitted to the one-way clutch F in this state.
1 by ring gear R₁The rotation of is blocked
And the sun gear S_TwoCarrier CR while spinning_TwoTimes
The rotation is greatly reduced, and the reduced rotation is counted.
To the gear drive gear 21.

In the second gear, the first clutch C
1, the third clutch C3 and the first brake B1 are engaged, and the one-way clutch F0 is locked. The rotation of the output shaft 14 is transmitted to the ring gear R ₂ via the first clutch C1 and the one-way clutch F0. However, since the rotation of the sun gear S ₂ is stopped by the first brake B1, the ring gear R ₂ the transmission rotation is slowing the carrier CR _2, the carrier C
Rotation of R ₂ is transmitted to the counter drive gear 21 while idly rotating the ring gear R _1.

Next, at the third speed, the first clutch C
1, the third clutch C3 and the fourth clutch C0 are engaged, the one-way clutch F0 is locked, and the first
The brake B1 is released. The rotation of the output shaft 14, while being transmitted to the ring gear R ₂ via the one-way clutch F0 and the third clutch C3, it is transmitted to the ring gear R ₁ via the fourth clutch C0, first, second
Of the planetary gear units 31 and 32 are directly connected. Therefore, the rotation of the output shaft 14 is transmitted to the counter drive gear 21 as it is.

Further, at the fourth speed, the first clutch C1, the fourth clutch C0, and the first brake B1 are engaged. The rotation of the output shaft 14 is controlled by the fourth clutch C
0 is transmitted to the ring gear R ₁ through, because the first brake B1 is the rotation of the sun gear S ₁ are stopped, a high speed carrier CR ₁ while the rotation of the ring gear R ₁ is idly rotating the ring gear R ₂ in rotated, the rotation of the carrier CR ₁ is transmitted to the counter drive gear 21.

The automatic transmission includes a first clutch C1, a second clutch C2, a third clutch C3,
Clutch C0, first brake B1, and second brake B2
The hydraulic control device 40
Is arranged. Further, the engine 10 can be controlled by an engine control device 43.

The hydraulic control unit 40 and the engine control unit 43 include an automatic transmission control unit (ECU) 41.
And is operated according to the control program of the automatic transmission control device 41. The automatic transmission control device 41 includes a neutral start switch 45, an oil temperature sensor 46, a rotation speed sensor 47, a brake switch 4
8, the engine speed sensor 49, the throttle opening sensor 50, and the vehicle speed sensor 51 are connected respectively.

Then, the neutral start switch
The shift position of a shift lever (not shown)
The oil temperature sensor 4
6, the temperature of the oil in the hydraulic control device 40 is reduced
The input speed N of the clutch_C1Can detect
Can be. Also, the brake switch 48
Whether the brake pedal (not shown) is depressed
The engine speed is detected by the engine speed sensor 49.
Number N _EAnd the engine load by the throttle opening sensor 50.
The throttle opening as shown in FIG.
The vehicle speed as both driving conditions can be detected.

By the way, in the automatic transmission having the above structure, when the 4-3 shift is performed, the first brake B1 is released, the one-way clutch F0 is locked, and the third clutch C3 is engaged. At this time, when the shift is started, the output shaft torque T _O falls with the release of the first brake B1. Thus, the occurrence of a shift shock due to a sharp drop in the output shaft torque T _O is prevented.

Next, the operation of the automatic transmission control device 41 will be described. FIG. 5 is a flowchart showing the operation of the automatic transmission control device according to the embodiment of the present invention.
FIG. 7 is a time chart illustrating the operation of the automatic transmission control device according to the embodiment of the present invention, and FIG. 7 is a diagram illustrating a table of torque reduction conditions according to the embodiment of the present invention.

In this case, the shift determining means 101 (FIG. 1) in the automatic transmission control device 41 (FIG. 3) determines whether the throttle opening detected by the throttle opening sensor 50 and the vehicle speed detected by the vehicle speed sensor 51 Based on the vehicle speed calculated from the output rotation detected by the output rotation sensor (not shown), a gear position corresponding to the throttle opening and the vehicle speed is selected with reference to a vehicle speed line map (not shown), and a shift is required. A shift determination is made to determine whether When the shift determining means 101 determines that a shift is required at timing t11, the first timer (not shown) in the automatic transmission control device 41 starts counting time.

The output reduction means 106 in the automatic transmission control unit 41 refers to the torque reduction condition table shown in FIG. 7 and refers to the vehicle speed range to which the detected vehicle speed belongs (for example, v _i ≤v <v). _{i + 1} ) (i = 1,..., 5), and reads a standby time TA (for example, T _A ). When the standby time TA elapses, a torque reduction level α as a reduction amount corresponding to the vehicle speed range is obtained. (For example,
α _{1 to} α ₅ ) and a torque reduction time TB as a reduction time (for example, T _{B1 to} T _B5 ) and read the torque reduction signal ETR according to the torque reduction level α by the amount of the torque reduction time TB. Send to 43. At the time when the torque reduction signal ETR is output, the automatic transmission control device 4
The measurement of the time by a second timer (not shown) in 1 is started, and when the torque reduction time TB has elapsed, the output of the torque reduction signal ETR is terminated.

The output reduction means 106 reduces the engine torque by performing the torque reduction at the torque reduction level α while the torque reduction signal ETR is being output. Subsequently, the time T11 corresponding to the vehicle speed range (for example,
When T ₁₁₎ has elapsed, the shift output is generated in the timing t12, the shift is started. Then, when the clutch input rotation speed N _C1 changes by a set value ΔN1 as compared with the value before the shift is started, the automatic transmission control device 41
It is determined by the shift start determining means (not shown) that the shift has been started at timing t13. When the clutch input rotational speed N _C1 reaches a value smaller than the value after the shift calculated based on the gear ratio by the set value ΔN 2, a shift not shown in the automatic transmission control device 41 is performed. The end determination means determines that the shift has ended at timing t14.

As described above, when the shift determination is made by the shift determining means 101 at the timing t11, the torque reduction is performed for the torque reduction time TB before the shift is started, and before the shift is determined at the timing t13. , The input shaft torque can be reduced. Accordingly, the output shaft torque T _O is reduced during that time, so that even when the engine torque is large, the output shaft torque T _O is released with the release of the first brake B1 at the start of shifting.
_The amount of _O drop can be reduced. Therefore, it is possible to prevent a shift shock from occurring.

In the present embodiment, the torque reduction is not performed at the timing t14. However, as in the prior art, at the timing t1.
In step 4, torque reduction is performed to prevent the output shaft torque T _O from abnormally increasing at the end of the shift, and to prevent the occurrence of a shift shock at the end of the shift.

Next, the flowchart will be described. Step S1 It is determined whether or not to make a shift determination. If a shift is to be determined, the process proceeds to step S2; otherwise, the process ends. Step S2 The first timer starts measuring time. Step S3: Wait until the waiting time TA elapses. Step S4: The second timer starts measuring time and outputs the torque reduction signal ETR. Step S5: Wait for the torque reduction time TB to elapse. Step S6: End the output of the torque reduction signal ETR.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0036]

As described above in detail, according to the present invention, in the control device for the automatic transmission, the engine,
A transmission that receives a rotation generated by the engine and performs a shift, a shift determination unit that determines whether a shift is required by the transmission, and a shift determining unit that determines whether a shift is required by the transmission. Output reduction means for reducing the engine torque before starting.

In this case, when a shift is required by the transmission, the engine torque is reduced before the shift is started, so that the input shaft torque can be reduced. Therefore, since the output shaft torque is reduced during that time, even when the engine torque is large, the amount by which the output shaft torque drops at the start of shifting can be reduced. As a result, it is possible to prevent a shift shock from occurring.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a control device for an automatic transmission according to an embodiment of the present invention.

FIG. 2 is a time chart showing the operation of a conventional control device for an automatic transmission.

FIG. 3 is a schematic diagram of an automatic transmission according to an embodiment of the present invention.

FIG. 4 is a diagram showing an operation of the automatic transmission according to the embodiment of the present invention.

FIG. 5 is a flowchart showing an operation of the automatic transmission control device according to the embodiment of the present invention.

FIG. 6 is a time chart illustrating an operation of the automatic transmission control device according to the embodiment of the present invention.

FIG. 7 is a diagram showing a table of torque reduction conditions in the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Engine 16 Transmission 101 Speed change determination means 106 Output reduction means TA standby time TB torque reduction time

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tomoji Abe 10 Takane, Fujii-machi, Anjo-shi, Aichi F-term in Aisin AW Co., Ltd. 3D041 AA53 AB01 AC01 AC09 AC15 AC18 AD02 AD04 AD31 AD41 AD51 AE03 AE31 3G093 AA05 BA03 CB08 DA01 DA06 DB05 DB11 DB15 EA02 EB03 FA10 FB02 FB04

Claims (3)

[Claims] 1. An engine, a transmission that receives a rotation generated by the engine, and performs a shift, a shift determination unit that determines whether a shift by the transmission is necessary, and a shift that is performed by the transmission. And a power reduction means for reducing the engine torque before the shift is started. 2. The system according to claim 1, wherein the output reduction unit reduces the engine torque based on a preset torque reduction time and a preset torque reduction level when a preset standby time elapses when a shift determination is made. Item 2. The control device for an automatic transmission according to item 1. 3. The control device for an automatic transmission according to claim 2, wherein the torque reduction time and the torque reduction level are set in accordance with a vehicle speed.