JPH0659794B2 - Automatic transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission, and in particular to calculating a proper gear position and automatically adjusting the gear position by an actuator so as to obtain a value obtained by this calculation. Regarding the automatic transmission that has been changed.

[Outline of Invention]

The present invention relates to an automatic transmission that automatically shifts gears to an appropriate gear position, and when downshifting is performed when the accelerator pedal is depressed from a substantially idle position, the amount of fuel supplied to the engine is reduced. Is delayed so that a shock is prevented from being generated when the clutch is disengaged due to downshifting.

[Conventional technology]

Automatic transmissions have been proposed in order to avoid frequent driver shifting operations. This automatic transmission selects a gear used by a computing unit such as a microcomputer according to a vehicle speed, an accelerator opening degree, etc., and meshes the gear selected by an actuator to automatically obtain a predetermined gear ratio. It was done.
By equipping an automobile with such an automatic transmission, the lever operation for the driver to shift gears becomes almost unnecessary.

[Problems to be solved by the invention]

When shifting is performed by such an automatic transmission, the microcomputer performs the shifting operation while reading the depression amount of the accelerator pedal and the vehicle speed and referring to the map. When shifting is performed, the clutch is temporarily disengaged prior to this. Therefore, when the accelerator pedal depresses from the almost idle position as shown in FIG. 5 and the operation line crosses the downshift line of the map, the downshift is performed. At this time, the accelerator pedal is depressed, so that the engine torque is rapidly increasing. Therefore, if the clutch is disengaged for downshifting in such a state,
The drive system causes torsional vibration, which causes a great shock to the vehicle.

The present invention has been made in view of such a problem, and occurs when the clutch is disengaged prior to the downshift when the downshift is performed by depressing the accelerator pedal from substantially the idle position. It is an object of the present invention to provide an automatic transmission that prevents a large shock.

[Means for solving problems]

According to the present invention, as shown in FIG. 1, in a transmission in which an appropriate gear position is calculated and the gear position is automatically changed by an actuator so as to obtain a value obtained by this calculation A shift map that is stored and has a step-like shift-down line in relation to the accelerator opening with respect to the vehicle speed, and that shifts down when the shift-down line is crossed, and when the accelerator pedal is depressed Means to determine whether or not the accelerator pedal is depressed from almost the idle position, Means to determine whether or not the shift down line of the shift map is exceeded when the accelerator pedal is depressed, and Shift when the accelerator pedal is depressed from the almost idle position A means for delaying the increase in fuel supply to the engine in the event of a down. Is relates automatic transmissions equipped.

[Action]

When the accelerator pedal is depressed and the depression is from the idle position, and the operation line associated with this accelerator pedal depression exceeds the shift down line in the shift map, the amount of fuel supplied to the engine Is delayed. Therefore, no torque fluctuation occurs during this delay period. Therefore, even if the clutch is disengaged during this period, the drive system does not generate torsional vibration, and a great shock is prevented from being generated in the vehicle.

〔Example〕

The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 2 shows an engine of an automobile equipped with an automatic transmission according to an embodiment of the present invention, which is composed of a diesel engine 10 for a truck. The diesel engine 10 is equipped with a fuel injection pump 11, and the engine 11 is driven by the pump 11.
Fuel is sequentially supplied to each of the cylinders.
The fuel injection pump 11 is connected to the engine 10 via the timer 12.
The timer 12 adjusts the fuel injection timing. Further, the fuel injection pump 11 is provided with a mechanical governor 13, and the governor 13 adjusts the fuel injection amount.

The flywheel housing 1 is on the rear side of the engine 10.
4 is provided, and a flywheel fixed to the end of the crankshaft is housed in the housing 14. A clutch 30 is provided on the rear side of the flywheel, and a transmission 15 is mounted on the rear side of the flywheel housing 14 so as to be connected to the clutch 30. This transmission 15 is the engine 1
Change the rotation speed of 0 to a predetermined value, and
It is adapted to be transmitted to the drive wheels via.

The transmission 15 constitutes an automatic transmission, and a shift actuator 17 and a select actuator 18 are provided on the upper portion thereof. Further, the clutch actuator 19 for controlling connection and disconnection of the clutch 30 mounted on the rear side of the flywheel is provided by the transmission 1
5 is mounted on the outer surface of the casing. Further, on the front end side of the fuel injection pump 11, there is provided a fuel control actuator 20 for adjusting the position of the control rack to control the fuel supply amount. These 4
The two actuators 17, 18, 19, and 20 are driven based on instructions from the microcomputer 21 via driving means.

The input side of the microcomputer 21 is connected to the control box 22. The control box 22 has a speed change lever 23. Further, the microcomputer 21 is connected to an accelerator sensor 25 that detects the accelerator opening or the depression amount of the accelerator pedal 24. Further, the microcomputer 21 is connected to a vehicle speed sensor 26, an engine rotation sensor 27, a rack sensor 28, and a clutch sensor 29, respectively.

The vehicle speed sensor 26 is provided on the side surface of the transmission 15, and the vehicle speed is detected by the number of rotations on the output side of the transmission 15. The engine rotation sensor 27 is attached to the front side of the engine 10 and detects the rotation speed of the engine 10. The rack sensor 28 is attached to the tip end side of the actuator 20, and the fuel injection pump 1
The position of the control rack No. 1 is detected. The clutch sensor 29 is attached to the tip end side of the clutch actuator 19, and the clutch 3
It is designed to detect 0 connection and disconnection states.

Next, the operation of the automatic transmission having the above structure will be described. This operation is performed based on a program preset in the microcomputer 21, and when the position of the speed change lever 23 of the control box 22 is the automatic position, the speed change operation is automatically performed. There is. On the other hand, when the shift lever 23 is at the manual position, the manually selected shift operation is performed by the actuators 17, 1
8 is performed.

The outline of the automatic shift operation will be described. The microcomputer 21 detects whether or not the position of the shift lever 23 of the control box 22 is the automatic position. The amount or the accelerator opening and the vehicle speed are read from the accelerator sensor 25 and the vehicle speed sensor 26, respectively. Further, the microcomputer 21 reads the map stored in the memory, and based on this map,
Calculates whether automatic gear shifting is possible. If automatic gear shifting is possible, the gear shifting operation is performed so as to obtain the calculated gear ratio. On the other hand, when it is determined that the automatic shift is impossible, the shift operation is not performed.

The specific operation of automatic shifting is performed by the microcomputer 21.
On the basis of the command from the above, via a drive means (not shown), the shift actuator 17 and the select actuator 18
Is operated so that the gears of the transmission 15 are selected, so that the meshing of the selected gears of the transmission 15 is achieved. Therefore, a predetermined gear ratio can be obtained in this way. During this gear shifting operation, the actuator 19 switches the clutch 30 to the disengaged state, and the clutch 30 is brought into the engaged state again in synchronization with the end of the gear shifting operation.

In a transmission that automatically shifts in this way, it is possible to prevent a shock from occurring due to a sudden change in the torque of the drive system, especially when a downshift is performed by depressing the accelerator pedal 24 from an almost idle position. Therefore, in such a downshift, the increase in the amount of fuel supplied to the engine 10 is delayed.

That is, as shown in FIG. 3, the microcomputer 21 reads the amount of depression of the accelerator pedal 24 by the accelerator sensor 25 and determines whether or not the accelerator pedal 24 is depressed from the idle position. When the vehicle is stepped on from the idle position, the shift map as shown in FIG. 5 is further read from the memory and it is determined whether or not the operation line crosses the downshift line. As a result, it is determined whether or not the accelerator pedal 24 is depressed substantially from the idle position to downshift. When the accelerator pedal 24 is not depressed substantially from the idle position or when the operation line does not cross the downshift line, normal fuel is supplied as indicated by the chain line in FIG. In response to the depression, the microcomputer 21 moves the control rack of the fuel injection pump 11 by the actuator 20 to increase the amount of fuel.

On the other hand, when the accelerator pedal 24 is depressed from the almost idle position and the operation line at this time exceeds the downshift line as shown in FIG. 5, the control rack of the fuel injection pump 11 is moved to the increasing side. Delay moving. That is, the microcomputer 21 counts the time and delays the increase of the fuel for a fixed time, for example, 0.1 seconds. Then, as shown by the solid line in FIG. 4, the microcomputer 21 moves the control rack of the fuel injection pump 11 to the increasing side by the actuator 20 only after a certain period of time elapses, as shown in FIG. In addition, the clutch 30 for downshifting is disengaged at about the same time as the start of the movement of the control rack. Therefore, the drive system does not undergo large torque fluctuations before downshifting.

As described above, according to the automatic transmission according to the present embodiment, when the accelerator pedal is depressed from the almost idle position to perform the downshift, the amount of fuel supplied from the fuel injection pump 11 is increased by the microcomputer 21.
Therefore, the drive system does not generate a large torque fluctuation until the clutch 30 is disengaged for downshifting. Therefore, in this state, even if the clutch 30 is disengaged, the drive does not generate torsional vibration, which prevents the vehicle from generating a large shock. Therefore, the downshift operation as described above can be performed smoothly.

〔The invention's effect〕

As described above, the present invention delays the increase in the fuel supply amount to the engine when the downshift is performed when the accelerator pedal is depressed from the almost idle position. Therefore, according to the present invention, when downshifting is performed by depressing the accelerator pedal substantially from the idle position, it is possible to prevent a great shock from occurring due to the disengagement of the clutch for downshifting, and this downshifting is performed. It will be carried out smoothly.

[Brief description of drawings]

FIG. 1 is a block diagram showing the gist of the present invention, FIG. 2 is a block diagram showing an automatic transmission according to an embodiment of the present invention, and FIG. 3 is a flow chart showing a shift-down operation of the automatic transmission. FIG. 4 is a graph showing the same, and FIG. 5 is a graph showing a shift-down operation linked to the depression of the accelerator pedal. In the drawings, reference numerals 10 ... Diesel engine 11 ... Fuel injection pump 15 ... Transmission 17 ... Shift actuator 18 ... Select actuator 19 ... Clutch actuator 20 ... Fuel control actuator 21 ... Microcomputer 24 ... Accelerator pedal 25 ... Accelerator sensor 26 ... Vehicle speed sensor 30 ... Clutch.

Claims (1)

[Claims] 1. A transmission in which an appropriate gear position is calculated, and the gear position is automatically changed by an actuator so as to obtain a value obtained by the calculation, and the transmission is stored in a storage means and a vehicle speed is set. In relation to the accelerator opening, there is a step-down shift down line, and a shift map that allows downshifting when the shift down line is crossed, and when the accelerator pedal is stepped on, the pedal is pushed almost from the idle position. A means for determining whether or not, when the accelerator pedal is depressed, it is determined whether or not the shift down line of the shift map is crossed, and when the accelerator pedal is depressed from almost the idle position, the shift down is performed. Means for delaying an increase in the amount of fuel supplied to the engine; Lance mission.