JP2019158032A - Control device of automatic transmission - Google Patents

Abstract

To provide a control device of an automatic transmission which can suppress the generation of an unnecessary gear change.SOLUTION: A control device of an automatic transmission 3 performs a downshift on the basis of requirement torque in the case that a lockup clutch 21 is in an engagement state, and sets a downshift line when a deviation between the requirement torque and actual torque is large to a high-torque side higher than a downshift line in the case that the deviation is small.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device for an automatic transmission.

  In Patent Document 1, when the lockup clutch is in an engaged state and the driving state of the vehicle remains in the NV (Noise, Vibration) deterioration region, the shift map is used when the automatic transmission is at a high gear stage. Has been disclosed, and by downshifting the automatic transmission while keeping the lockup clutch engaged, a technique for suppressing the deterioration of NV while maintaining the fuel efficiency improvement effect due to the engagement of the lockup clutch is disclosed. Yes.

JP 2016-2111686 A

  Here, when the lockup clutch is in an engaged state, in order to avoid traveling in the NV deterioration region, for example, it is conceivable to execute a downshift when the required torque is in the NV deterioration region. However, since there is a delay (torque response delay) until the actual torque follows the required torque, the downshift is actually executed even though there is a margin before the NV deteriorates. There is a risk of shifting.

  The present invention has been made in view of the above, and an object of the present invention is to provide a control device for an automatic transmission that can suppress the occurrence of an unnecessary shift.

  In order to solve the above-described problems and achieve the object, a control device for an automatic transmission according to the present invention is an automatic transmission that performs a downshift based on a required torque when a lockup clutch is engaged. The downshift line when the deviation between the required torque and the actual torque is large is set on the higher torque side than the downshift line when the deviation is small.

  As a result, the automatic transmission control device sets a downshift line that allows a high torque range when the difference between the required torque and the actual torque is large, and increases the torque when the difference between the required torque and the actual torque is small. A downshift line that does not allow a region is set.

  In the automatic transmission control apparatus according to the present invention, when the difference between the required torque and the actual torque is large, a downshift line that allows a high torque range is set, and therefore the timing of the downshift can be delayed in response to the torque request. This can suppress the occurrence of unnecessary shifts. In addition, when the difference between the required torque and the actual torque is small, a downshift line that does not allow the high torque range is set, so that the downshift can be executed before the actual torque becomes the NV deterioration region, and the NV deterioration Can be suppressed.

FIG. 1 is a schematic diagram showing the configuration of a control device for an automatic transmission according to an embodiment of the present invention. FIG. 2 is a flowchart showing a control method by the automatic transmission control device according to the embodiment of the present invention. FIG. 3 is a graph for explaining an NV deterioration region in the control device for an automatic transmission according to the embodiment of the present invention. FIG. 4 is a time chart showing changes in the engine torque, the accelerator opening, and the gear stage when the control method by the control device for the automatic transmission according to the related art is performed. FIG. 5 is a time chart showing changes in the engine torque, the accelerator opening, and the gear stage when the control method by the automatic transmission control device according to the embodiment of the present invention is performed.

  A configuration of a control device for an automatic transmission according to an embodiment of the present invention will be described with reference to FIG. In addition, this invention is not limited to the following embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  The automatic transmission control device according to this embodiment is mounted on a vehicle and includes an engine 1, a torque converter 2, an automatic transmission 3, and a control unit 4.

  The engine 1 is a power device that outputs power by burning fuel. Examples of the engine 1 include an internal combustion engine such as a gasoline engine or a diesel engine. The torque converter 2 is a fluid transmission device disposed between the engine 1 and the automatic transmission 3 and includes a pump impeller, a turbine runner, and a stator (not shown). In addition, the torque converter 2 includes a lockup clutch 21 between the turbine runner and the engine 1. The lockup clutch 21 is configured to be able to directly connect engine rotation and turbine rotation, and is configured to be switched between an engaged state and a released state by a hydraulic control circuit (not shown).

  The automatic transmission 3 changes the rotational speed of a crankshaft (not shown) to a desired rotational speed by forming a desired gear stage.

  The control unit 4 includes an electronic control unit (ECU: Electronic Control Unit) mainly composed of a known microcomputer including interfaces such as a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and an input / output. ).

  The control unit 4 is configured to be able to perform a downshift based on the required torque when the lockup clutch 21 is in an engaged state. That is, when the running is continued in the low-rotation high-torque region (NV deterioration region) while the lock-up control (engagement of the lock-up clutch 21) is being performed, a booming noise (lockup booming noise) is generated. In that case, the control part 4 avoids generation | occurrence | production of the above-mentioned booming noise by raising an engine speed by downshift.

  Further, the control unit 4 is configured to be able to determine whether or not the occurrence of a torque response delay, that is, the difference between the required torque and the actual torque is equal to or greater than a preset specified value. Then, as will be described later, the control unit 4 uses a downshift line when the difference between the required torque and the actual torque is large and a torque response delay occurs. It is configured to be able to be set on the higher torque side than the downshift line when no occurs.

  Hereinafter, a control method by the control device for the automatic transmission 3 according to the present embodiment will be described with reference to FIGS. 2 and 3.

  First, the control unit 4 determines whether or not a torque response delay has occurred, that is, whether or not the difference between the required torque and the actual torque is equal to or greater than a preset specified value (step S1). If it is determined in step S1 that a torque response delay has occurred (Yes in step S1), the control unit 4 performs a downshift determination based on the normal shift line (step S2).

  Specifically, in step S2, as shown in FIG. 3, it is determined whether or not the driving state of the vehicle based on the vehicle speed and the accelerator opening is included in the preset “normal town shift region” of (A). To do. If an affirmative determination is made in step S2, the control unit 4 performs a downshift (step S3) and ends the process. On the other hand, if a negative determination is made in step S2 (No in step S2), the control unit 4 returns to the beginning of step S1 without executing a downshift, and performs the processes after step S1 again.

  Here, when it is determined in step S1 that there is no torque response delay, that is, the deviation between the required torque and the actual torque is less than a preset specified value (No in step S1), the control unit 4 Determines whether it is in the booming sound generation area, that is, in the NV deterioration area (step S4). In step S4, specifically, as shown in FIG. 3, the driving state of the vehicle based on the vehicle speed and the accelerator opening is set in the “Boom sound generation area” of (B) and “Cumbling” of (C). It is determined whether the sound is included in “outside sound generation area”.

  If it is determined in step S4 that the region is within the booming sound generation region (Yes in step S4), the control unit 4 immediately executes downshift (step S3) and ends the process. On the other hand, if it is determined in step S4 that the region is outside the booming sound generation area (Yes in step S4), the control unit 4 returns to the beginning of step S1 without performing a downshift, and performs the processing after step S1. Try again.

  As described above, in the control device for the automatic transmission 3, when the actual torque is output as requested (No in Step S1) and the vehicle is traveling in the booming sound generation region (Yes in Step S4), Downshift is executed (step S3). Further, in the control device of the automatic transmission 3, the downshift line when the difference between the required torque and the actual torque is large and a torque response delay occurs (Yes in step S1 → Yes in step S2 → step S3) Downshift line) when the difference between the required torque and the actual torque is small and there is no torque response delay (No in step S1, Yes in step S4, and downshift line in case of step S3) ) To a higher torque side.

  According to the control device for the automatic transmission 3 as described above, when the difference between the required torque and the actual torque is large, a downshift line that allows a high torque range is set, so the timing of the downshift is set in the torque request. Can be delayed, and the occurrence of unnecessary shifting can be suppressed. In addition, when the difference between the required torque and the actual torque is small, a downshift line that does not allow the high torque range is set, so that the downshift can be executed before the actual torque becomes the NV deterioration region, and the NV deterioration Can be suppressed.

Here, in the control apparatus for an automatic transmission according to the related art, the control is performed along the following flow as shown in FIG.
(1) Engine torque is required when the accelerator is turned on.
(2) Since the actual torque is delayed with respect to the required torque, no booming noise is generated.
(3) Since it is in the booming sound generation area, downshift is executed.
(4) Since the acceleration is higher than expected, the accelerator is returned.
(5) Upshift by returning the accelerator.
(6) Since the driving force is insufficient, the accelerator is stepped on.

  As described above, in the automatic transmission control device according to the related art, there is a case in which the downshift is performed even when the booming noise is not generated.

On the other hand, in the control device for the automatic transmission 3 according to the present embodiment, the control is performed along the following flow, for example, as shown in FIG.
(1) Engine torque is required when the accelerator is turned on.
(2) Since the actual torque is delayed with respect to the required torque, no booming noise is generated.
(3 ′) While the actual torque is delayed with respect to the required torque, the downshift is not determined.
(4 ') Since the vehicle is accelerating when the torque is output as required, the vehicle is outside the booming noise generation region.

  As described above, in the control device for the automatic transmission 3 according to the present embodiment, the downshift is determined in consideration of the response delay of the actual torque with respect to the required torque during vehicle acceleration. Thus, it is possible to perform stable running without generating unnecessary shifts.

  As mentioned above, although the control apparatus for the automatic transmission according to the present invention has been specifically described by the mode for carrying out the invention, the gist of the present invention is not limited to these descriptions, and the scope of the claims It must be interpreted widely based on the description. Needless to say, various changes and modifications based on these descriptions are also included in the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Engine 2 Torque converter 21 Lockup clutch 3 Automatic transmission 4 Control part

Claims (1)

A control device for an automatic transmission that performs a downshift based on a required torque when a lockup clutch is engaged,
A control device for an automatic transmission, wherein a downshift line when the deviation between the required torque and the actual torque is large is set on a higher torque side than a downshift line when the deviation is small.

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