JPH0574744B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic transmission device capable of changing the shift point at which the transmission is shifted to a high speed gear or a low speed gear.

〔overview〕

In an automatic transmission device that can downshift by pressing down on the accelerator pedal, when the accelerator pedal is pressed down, the shift point is changed to the higher side of the vehicle speed until the amount of depression of the accelerator pedal returns to a predetermined value or less. By controlling the engine in a kick-down mode where the engine has a large driving force, acceleration or deceleration is performed in accordance with the driver's will.

[Conventional technology]

When the shift lever is placed in the drive range, a typical automatic transmission automatically increases or decreases gears depending on the vehicle speed and the amount of accelerator pedal depression.

FIG. 3 is a diagram showing an example of an automatic shift line that changes depending on the vehicle speed and the amount of depression of the accelerator pedal. The thick solid line indicates an upshift line where the transmission is switched from a low gear to a high gear, and the broken line indicates a downshift line where the transmission is switched from a high gear to a low gear. That is, the speed of the vehicle at which the automatic gear shift is performed varies depending on the amount of depression of the accelerator pedal. For example, the greater the amount of depression of the accelerator pedal, the greater the vehicle speed at which the gear shift is performed. Furthermore, if the vehicle speed decreases even when the accelerator pedal is depressed, the downshift is performed at a shift point where the vehicle speed is faster as the amount of depression of the accelerator pedal is greater.

In such conventional automatic transmissions, upshifts or downshifts are not performed when the automatic shift line as shown in FIG. 3 is not reached.

However, when overtaking, for example, it is necessary to forcibly downshift even if the downshift automatic shift line has not been reached, and increase the engine rotational speed relative to the vehicle speed to increase the engine's driving force. Further, there are cases where a greater engine braking effect is required by downshifting.

In such a case, a so-called kickdown operation is performed to intentionally downshift. A kick-down operation is an operation in which when the accelerator pedal is depressed to a predetermined opening degree or more in a short period of time, the downshift shift point is passed and the gear is shifted to a lower gear (FIGS. 3a and 3b). In this way,
Cars equipped with automatic transmissions can now be operated in the same way as cars with manual transmissions.

[Problem that the invention seeks to solve]

In such conventional automatic transmissions, when the accelerator pedal is slightly released after a kick-down operation, the upshift line is immediately passed and the gear is shifted to a high gear again.
In other words, if the upshift line is passed (Fig. 3c) while accelerating with a large driving force due to a kick-down operation, the transmission gear will be switched to a high gear before sufficient acceleration can be achieved, and the driving force will decrease. Sometimes I end up doing it. For example, when driving while following the vehicle in front of you on a climbing board, if you sense that the vehicle in front of you has slowed down a little and release the accelerator pedal a little, the kickdown mode will be canceled immediately. Alternatively, when deceleration by engine braking is intended and the accelerator pedal is released (Fig. 3 d), the upshift line is similarly immediately passed and an upshift is performed, and the expected engine braking effect is not sufficient. Sometimes you can't get it.

Further, the same problem occurs not only when the accelerator pedal is pressed down, but also when the situation corresponds to the situation when the accelerator pedal is turned down. In other words, when the change in vehicle speed associated with the depression of the accelerator pedal is small and the vehicle exceeds the downshift line, or when the vehicle is running on a long uphill slope, the downshift occurs in an area where the amount of depression of the accelerator pedal is large. Even if you want to maintain this downshift state even when you cross the shift line, if you release the accelerator pedal a little, the upshift will occur immediately.

The present invention is intended to improve upon such conventional problems, and an object of the present invention is to provide an automatic transmission that can maintain a state of high driving force through downshifting even if the depression of the accelerator pedal is slightly changed.

[Means for solving problems]

In the present invention, when the amount of depression of the accelerator pedal exceeds a shift point at which the gear is shifted to a low speed gear and the amount of depression exceeds a first predetermined value, when the kickdown mode is entered, the amount of depression of the accelerator pedal is changed to that point. The present invention is characterized in that it includes means for maintaining the kickdown mode and performing automatic gear change control until it returns to a second predetermined value or less.

The first predetermined value is generally the amount of depression of the accelerator pedal that instructs the kickdown mode, and the second predetermined value is set to 0 to 40% from the release point of the amount of depression of the accelerator pedal. is preferred.

[Effect]

In the present invention, when the amount of depression of the accelerator pedal exceeds a shift point at which the gear is shifted to a low speed gear, and the amount of depression exceeds a first predetermined value, control is performed in the kickdown mode. After that, the kick-down mode is maintained even if the accelerator pedal changes slightly, and the kick-down mode is canceled only when the amount of depression of the accelerator pedal becomes less than a second predetermined value. The mode is controlled to return to automatic shifting using the upshift line and downshift line.

In other words, in the kickdown mode, until the accelerator pedal returns to the second predetermined value or less,
It is possible to move the low gear region toward a higher vehicle speed than normal and maintain a high driving force state for a long time.

The second predetermined value of the accelerator pedal depression amount for canceling the kick-down mode is preferably set to the lowest possible value in consideration of ease of driving. 0~ from the release value of the accelerator pedal
The 40% range is a range in which the engine will not rev up due to the characteristics of the governor, and if the accelerator pedal returns within this range, it is determined that the driver does not intend to accelerate.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In FIG. 1, the microprocessor 1 is connected via an input/output control device 2 to a stroke sensor 4 that detects the amount of depression of an accelerator pedal 3 as an electrical signal, as related to the present invention.
A rotation speed detection sensor 7 that detects the rotation speed of a propeller shaft 6 connected to the output shaft of a transmission 5 as a vehicle speed detection means, and a solenoid valve 1 that drives and controls an actuator 9 that connects and disconnects a clutch 8.
0 is connected. Furthermore, a position sensor 11 that detects the gear position of the transmission 5, a rotation speed sensor 13 that detects the rotation speed of the engine 12, and an injection pump 1 that is linked to the accelerator pedal 3.
4 etc. are also connected. A mechanism for switching gears of the transmission 5 is omitted in the drawing.

Normally, the microprocessor 1 inputs the amount of depression of the accelerator pedal 3 detected by the stroke sensor 4 and the rotation speed information of the propeller shaft 6 detected by the rotation speed detection sensor 7 when the clutch 8 is connected or disconnected. The connection state of the clutch 8 is controlled so that the rotational speed changes gradually.

FIG. 2 is a diagram showing an example of an automatic shift line for explaining an embodiment of the present invention. In FIG. 2, the horizontal axis is the vehicle speed, and the vertical axis is the amount of depression of the accelerator pedal, and in particular, only the automatic shift line between 2nd speed and 3rd speed is shown. The thick solid line shows an upshift line where the transmission gear is changed from 2nd speed to 3rd speed, and the broken line shows a downshift line where the transmission gear is changed from 3rd speed to 2nd speed.

Here, when the gear is in the 3rd gear range (point A) and the accelerator pedal is suddenly depressed to the 2nd gear range (point B) beyond the downshift line, that is, when a kickdown operation is performed, the A downshift to second gear is performed.

A feature of the present invention is that when the amount of depression of the accelerator pedal exceeds the shift point at which the gear is shifted to a low speed gear, and the amount of depression exceeds a predetermined value, the upshift line and the downshift line are respectively changed to a dashed line. A steady mode in which the original automatic shift line (solid line and dashed line) returns only when the accelerator pedal returns to a predetermined depression amount or less. It is in the place where it returns to.

That is, when the kickdown mode is set, both the upshift line and the downshift line are shifted to the side where the vehicle speed is faster. While the amount of depression of the accelerator pedal exceeds a predetermined value, the second speed region moves to the high vehicle speed side, and the state in which the driving force is greater than at a normal shift point can be maintained for a longer period of time.

The second predetermined value of the accelerator pedal depression amount at which this kick-down mode is canceled is the normal depression play of the accelerator pedal, as well as a substantial It is set to a value equivalent to the stepping play, or a value slightly higher than it. In FIG. 2, the predetermined value is illustrated as approximately 40%, but this predetermined value can be set to any value greater than or equal to 0%. Practically speaking, it is desirable to set it between 0% and 40%. This is because the range of 0 to 40% from the opening value of the accelerator pedal is the range in which the engine does not overshoot due to the governor characteristics of the injection pump, and in gasoline engines that are controlled by a throttle valve, the vehicle required performance,
Alternatively, the range can be arbitrarily selected depending on the vehicle based on the vehicle weight, ease of driving, etc. If the predetermined value is approximately 0%, the normal mode will be restored when the accelerator pedal is completely released.

An example of the operation of the apparatus according to the embodiment of the present invention will be described below.

When a downshift is performed at point A, where the transmission gear is in 3rd gear, and a downshift is performed to 2nd gear at point B, the vehicle speed increases by maintaining the amount of depression of the accelerator pedal at the downshift position. For example, conventionally, the upshift to 3rd gear was immediately crossed over the upshift line. In the automatic transmission of the present invention, at this time, the upshift line and the downshift line are changed to the one-dot chain line and the two-dot chain line automatic shift line, respectively, and the automatic transmission becomes the kickdown mode. In this state, the gear ratio becomes large and the driving force becomes large. With the control device of the present invention, this state can be maintained even if the accelerator pedal is slightly changed (Fig. 2e). Similarly,
When the vehicle speed decreases after upshifting,
In particular, even if you do not perform a kickdown operation,
A downshift to second gear is performed earlier than a normal downshift (FIG. 2 f), and the kickdown mode is also established.

In addition, when applying engine braking due to a kick-down operation, even if the accelerator pedal is pressed down immediately (Fig. 2g), the upshift line will not be (dot-dash line) without exceeding
The engine brake can be operated effectively.

This kickdown mode is canceled only when the amount of depression of the accelerator pedal becomes less than a second predetermined value, and the automatic shift line returns to upshift or downshift operation in the normal mode.

The invention can also be implemented if special means are provided for detecting that a kickdown operation has taken place. As this means, for example, the amount of depression of the accelerator pedal 3 and the vehicle speed are input, and the microprocessor determines that a kick-down operation has been performed when the change in vehicle speed is small relative to the depression of the accelerator pedal 3 exceeding a predetermined level. 1 is program-controlled so that it makes a judgment. Alternatively, a case where the accelerator pedal is depressed to a level exceeding a first predetermined value (for example, 80%) and which exceeds the downshift line can simply be considered to be a kickdown operation.

〔Effect of the invention〕

As explained above, the present invention allows the kick-down mode to be canceled even if the accelerator pedal is slightly changed while driving with a large gear ratio and a large engine driving force. It never gets put away. Especially when overtaking, the driver can accelerate or decelerate as desired. It is also effective when using engine braking in kickdown mode.

That is, there is an excellent effect in that acceleration and deceleration operations can be performed faithfully according to the driver's intention by operating the accelerator pedal.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is an automatic transmission diagram for explaining an embodiment of the present invention. Figure 3 is a normal automatic transmission diagram. DESCRIPTION OF SYMBOLS 1... Microprocessor, 2... Input/output control device, 3... Accelerator pedal, 4... Stroke sensor, 5... Transmission, 6... Propeller shaft, 7... Rotation speed detection sensor, 8... Clutch, 9... Actuator, 10... Solenoid valve, 11...Position sensor, 12
...Engine, 13...Rotational speed sensor, 14...Injection pump.

Claims (1)

[Scope of Claims] 1. A mechanical clutch provided on the power transmission shaft of the engine; A transmission provided between the mechanical clutch and the axle; and a control means that takes in the amount of depression and program-controls the selection of the transmission gear and the engagement/disengagement of the clutch based on a shift map consisting of information on shift points that change depending on the vehicle speed and the amount of depression of the accelerator pedal. In the transmission, the control means controls the accelerator pedal when the amount of depression of the accelerator pedal exceeds a shift point at which the gear is shifted to a low speed gear, and the amount of depression exceeds a first predetermined value at which a kickdown mode is activated. Until the pedal depression amount returns to below the second predetermined value, the normal shift map changes to a kick-down mode shift map in which the above shift point and the shift point for shifting to a high gear are changed to the high side of the vehicle speed. An automatic transmission device characterized in that it includes means for controlling automatic transmission by changing the transmission speed. 2. The automatic transmission device according to claim 1, wherein the second predetermined value is set to a value between 0 and 40% from the release point of the amount of depression of the accelerator pedal.