JP2016196940A - Control method for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method for an automatic transmission, for enabling continuous smooth travel on a curve.SOLUTION: An ECU 11 gives a command to a TCM (Transmission Control Machine) 12 for prohibiting shifting operation of an ATM 1 to shift up to a target shift stage when detecting that the opening of an accelerator is being reduced from a signal from an accelerator opening sensor 15, calculates an increment d in the steering angle of a vehicle within a preset time t from a signal from a steering angle sensor 20, and gives a command to the TCM 12 for cancelling the prohibition of the shifting operation to shift up to the target shift stage when the increment d in the steering angle is smaller than a preset threshold value D.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for controlling an automatic transmission, and more particularly to a method for controlling an automatic transmission that can continue running smoothly on a curve.

  In general, when driving a vehicle, before entering the curve, the driver returns the accelerator that was previously depressed, then turns the steering to the angle necessary to turn the curve, and then depresses the accelerator again. Tend. The same applies to intersections and branch roads.

  On the other hand, in recent vehicles, it is common to mount an automatic transmission (AMT) that outputs the rotational power input from the internal combustion engine at a predetermined speed ratio that is automatically increased or decreased. It has become. In this AMT, the target shift speed is determined based on preset map data indicating the relationship between the vehicle speed, the accelerator opening, and the gear speed (see, for example, Patent Document 1).

  In a vehicle equipped with an AMT, when a driving operation on a curve as described above is performed, a shift operation is normally performed to shift up when the accelerator is returned, so that sufficient acceleration can be obtained when the accelerator is depressed again. There is no change or a shifting operation is performed to shift down, which may impair drivability.

JP 2014-163462 A

  An object of the present invention is to provide a control method for an automatic transmission capable of smoothly running on a curve.

  A control method for an automatic transmission according to the present invention that achieves the above object is a control method for an automatic transmission that automatically performs a shift operation to shift to a target shift stage determined from a vehicle speed of a vehicle and an accelerator opening. When the accelerator opening is decreasing, the shift operation for shifting up to the target shift stage is prohibited, the increment of the steering angle of the vehicle within a preset time is calculated, and the increment of the steering angle is When it is less than a preset threshold value, the prohibition of the shift operation for shifting up to the target shift stage is canceled.

  According to the control method of the automatic transmission of the present invention, before the driver enters the curve, after the accelerator that has been stepped on is returned once, the steering is operated, and then the driving operation is performed such that the accelerator is depressed again. However, since the shifting operation for shifting up is not performed, it is possible to continue traveling smoothly on the curve.

It is a block diagram of the automatic transmission which implements the control method of the automatic transmission which consists of embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of an automatic transmission.

  The automatic transmission (AMT) 1 includes an input shaft 4 connected to a crankshaft 3 of a diesel engine 2 mounted on a vehicle, an output shaft 5 extending coaxially with the input shaft 4, and the input shaft 4 and the output shaft. 5 has a countershaft 6 arranged in parallel with the gearbox 7. Further, an input side main gear 8 is attached to the input shaft 4, a plurality of output side main gears 9 are attached to the output shaft 5, and a plurality of sub gears 10 are attached to the auxiliary shaft 6. The input main gear 8 of the input shaft 4 meshes with one of the sub gears 10 of the sub shaft 6, and the other sub gear 10 of the sub shaft 6 and the output main gear 9 of the output shaft 5 mesh with each other. The rotation of the input shaft 4 is transmitted to the output shaft 5 via the auxiliary shaft 6. A gear ratio which is a ratio of the rotational speed of the input shaft 4 and the rotational speed of the output shaft 5 is determined by the gear ratio of the input side main gear 8, the sub gear 10 and the output side main gear 9.

  Shifting of the shift speed in the AMT 1 is performed by a shift and selection drive device 13 controlled by a shift speed control device 12 (TCM) connected to the ECU 11. The TCM 12 determines a target gear position with reference to map data based on vehicle speed and accelerator position information provided from the vehicle speed sensor 14 and the accelerator position sensor 15 connected to the ECU 11 through a signal line (indicated by a one-dot chain line). Then, the shift and selection drive device 13 is operated so as to shift to the target shift stage. The shift and selection drive device 13 shifts the shift shaft 17 through a link mechanism 16 or the like connected to a built-in electric actuator, thereby selecting a shift fork for rearranging the output side main gear 9 and shifting to the target shift stage. Shifting up or down is performed.

  Further, at the crankshaft side end portion of the input shaft 4, a torque converter 18 to which rotational power is transmitted from the rear end of the crankshaft 3, and a wet multi-plate clutch 19 for connecting and disconnecting the rotational power at the time of a shifting operation in the AMT1 are provided. Are in order.

  Furthermore, a steering angle sensor 20 that detects the steering angle of the steering is connected to the ECU 11 through a signal line.

  Such an automatic transmission control method in the AMT 1 will be described below as a function of the ECU 11.

  First, when the ECU 11 detects from the signal from the accelerator opening sensor 15 that the accelerator opening is decreasing, the ECU 11 instructs the TCM 12 to prohibit a shift operation to shift up to the target gear. Here, “when the accelerator opening is decreasing” refers to a state in which the accelerator pedal is returning to a direction in which the opening becomes zero as the driver relaxes the depression force of the accelerator pedal. Next, from the signal from the steering angle sensor 20, an increment d of the steering angle within a preset time t is calculated. The preset time t is a value in the range of 0.3 to 1.0 seconds, preferably 0.5 seconds.

  When the calculated steering angle increment d is less than the preset threshold value D, the ECU 11 instructs the TCM 12 to cancel the prohibition of the shift operation to shift up to the target shift stage.

  By performing such control, the driver can shift up even if the driver depresses the accelerator before returning to the vehicle before returning to the curve, and then operates the steering and then depresses the accelerator again. Since the shifting operation is not performed, the vehicle can continue to travel smoothly on the curve.

  In addition, this invention is applied not only when a vehicle drive | works a curve but when changing the advancing direction in an intersection or a branch road.

1 AMT
2 Diesel engine 4 Input shaft 5 Output shaft 11 ECU
12 TCM
14 Vehicle speed sensor 15 Accelerator opening sensor 20 Steering angle sensor

Claims (2)

A control method for an automatic transmission that automatically performs a shift operation to shift to a target shift stage determined from the vehicle speed of the vehicle and the accelerator opening,
When the opening degree of the accelerator is decreasing, the shift operation for shifting up to the target shift stage is prohibited,
Calculating an increment of the steering angle of the vehicle within a preset time;
A method for controlling an automatic transmission, wherein when the increment of the steering angle is less than a preset threshold value, the prohibition of a shift operation for shifting up to the target shift stage is canceled.   2. The method of controlling an automatic transmission according to claim 1, wherein the preset time is a value in a range of 0.3 to 1.0 seconds.

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