JPS6364834A - Automatic transmission - Google Patents

Abstract

PURPOSE:To effect engine brake on a downward slope to give a safe traveling by providing a means of detecting increase in vehicle speed in a disconnected clutch condition and a means of connecting said clutch even if an accelerator pedal is not stepped in. CONSTITUTION:Four actuators 17-20 are driven via driving means based on the direction of a microcomputer 21. An accelerator sensor 25, a vehicle speed sensor 26, an engine speed sensor 27, a rack sensor 28 and a clutch sensor 29 are connected to the microcomputer 21 and an operation is carried out based on a previously set program, e.g., a speed change operation is automatically carried out when a change lever is in an automatic position. While traveling on a downward slope at a low speed, when a vehicle speed is increased after a clutch 30 is once disconnected, the clutch 30 is automatically connected by the direction of the computer 21 even if an accelerator pedal 24 is not stepped in.

Description

[Detailed description of the invention]

[Field of Industrial Application] The present invention relates to automatic transmissions, and more particularly to an automatic transmission that calculates an appropriate gear position and automatically changes the gear position using an actuator so as to reach the value obtained by this calculation. Regarding transmission. SUMMARY OF THE INVENTION The present invention provides an automatic transmission that automatically changes gears to the appropriate gear position, and when the vehicle speed increases when the clutch is disengaged on a downhill slope, etc., even if the accelerator pedal is not depressed. The clutch is automatically connected to ensure proper engine braking. K. PRIOR ART Automatic transmissions have been proposed to omit the driver's complicated gear shifting operations. In this automatic transmission, a calculation means such as a microcomputer selects the gears to be used depending on the vehicle speed, accelerator opening degree, etc., and an actuator meshes the selected gears to automatically obtain a predetermined gear ratio. This is what I did. By equipping an automobile with such an automatic transmission, the driver hardly needs to operate a lever to change gears.

[Problems to be solved by the invention]

In vehicles equipped with such automatic transmissions, when the accelerator pedal is depressed, the clutch is engaged. In other words, once the clutch was disengaged, the disengaged clutch would not be reconnected unless the accelerator pedal was depressed. Furthermore, when the vehicle speed decreases and the engine speed falls below a predetermined value, the clutch is disengaged to prevent the engine from stalling. Therefore, when decelerating on a downhill slope, the clutch would be disengaged, and the clutch would not be engaged unless the accelerator pedal was depressed. Therefore, there is a problem in that the engine brake cannot be used effectively in such cases. The present invention has been made in view of these problems, and provides an automatic transmission that automatically engages the clutch when the vehicle speed increases when the clutch is disengaged even if the accelerator pedal is not depressed. The purpose is to provide the following. Means for Solving Problem K] As shown in FIG. 1, the present invention calculates an appropriate gear position and automatically changes the gear position using an actuator so that the value obtained by this calculation is obtained. The transmission is equipped with a means for detecting an increase in vehicle speed when the clutch is disengaged, and a means for connecting the clutch even when the accelerator pedal is not depressed. When the number increases, the clutch is connected even if the accelerator pedal is not depressed. [1] Therefore, according to the present invention, if the vehicle speed increases when the clutch is disengaged, such as when going downhill, the clutch is automatically engaged even if the accelerator pedal is not depressed, thereby properly applying engine braking. It becomes possible to take advantage of it. Embodiment] The present invention will be described below with reference to an illustrated embodiment. FIG. 2 shows an automobile engine equipped with an automatic transmission according to an embodiment of the present invention, and this engine is composed of a diesel engine 10 for a truck. The diesel engine 10 is equipped with a fuel injection pump 11, which sequentially supplies fuel to each cylinder of the engine 10. The fuel injection pump 11 is connected to the engine 10 via the timer 12.
Moreover, the timing of fuel injection is adjusted by this timer 12. Furthermore, the fuel injection pump 11 is a governor 13
This governor 13 is used to adjust the fuel injection level. The flywheel housing 1 is located on the back side of the engine 10.
4 is provided, and a flywheel fixed to the end of the crankshaft is accommodated within this housing 14. A clutch 30 is provided on the back side of the flywheel, and a transmission 15 is attached to the back side of the flywheel housing 14 so as to be connected to the clutch 30. This transmission 15 has an engine 1
The rotation speed of 0 is changed to a predetermined value, and the propeller shaft 16
The signal is transmitted to the drive wheels via the The transmission 15 constitutes an automatic transmission, and a shift actuator 17 and a selection actuator 18 are provided above the transmission. Furthermore, a clutch actuator 19 for controlling connection and disconnection of a clutch 3O installed on the back side of the flywheel is connected to a transmission 1.
It is attached on the outer surface of the casing of No. 5. Furthermore, a fuel control actuator 20 is provided on the front end side of the fuel injection pump 11 to adjust the position of the control rack and control the amount of fuel supplied. These 4
The three actuators 17, 18, 19, and 20 are each driven based on instructions from the microcomputer 21 via driving means. The input side of the microcomputer 21 is connected to a control box 22 . This control box 22 is equipped with a gear shift lever 23. Furthermore, this microcomputer 21 is connected to an accelerator sensor 25 that detects the opening degree of the accelerator or the amount of depression of the accelerator pedal 24. Roughly speaking, 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 detects the vehicle speed based on the rotational speed of the output side of the transmission 15. Further, the engine rotation sensor 27 is attached to the front side of the engine 10 and is configured to detect the rotation speed of the engine 10. Moreover, the rack sensor 28 is attached to the tip side of the actuator 20, and the rack sensor 28 is attached to the tip side of the actuator 20.
The position of the control rack No. 1 is detected. Further, the clutch sensor 29 is attached to the tip side of the clutch actuator 19, and the clutch sensor 29
The state of connection and disconnection of 0 is detected. Next, the operation of this automatic transmission configured as described above will be explained. This operation is performed based on a program preset in the microcomputer 21, and when the shift lever 23 of the control box 22 is in the automatic position, the shift operation is automatically performed. There is. On the other hand, when the gear shift lever 23 is in the manual position, the manually selected gear shift operation is performed by the actuator 17.1.
8. To give an overview of the operation of automatic gear shifting, the microcomputer 21 detects whether the gear shift lever 23 of the control box 22 is in the automatic position, and if it is in the automatic position, the accelerator pedal 24 is depressed at regular intervals. m or the accelerator opening degree and vehicle speed are read from the accelerator sensor 25 and vehicle speed sensor 26, respectively. Furthermore, the microcomputer 21 reads the map stored in its memory, and based on this map,
Performs calculations to determine whether automatic gear shifting is possible. If automatic gear shifting is possible, gear shifting is performed to obtain the calculated gear ratio. On the other hand, if it is determined that automatic gear shifting is not possible, gear shifting is not performed. The specific operation of automatic gear shifting is performed by the microcomputer 21.
Based on the command, the shift actuator 17 and the selection actuator 18 are activated via a drive means (not shown).
is operated to select a gear of the transmission 15, thereby achieving meshing of the selected gear of the transmission 15. Therefore, a predetermined gear ratio can be obtained in this way. During this shift operation, the -H clutch 30 is switched to the disconnected state by one actuator, and the clutch 30 is brought into the connected state again in synchronization with the end of the shift operation. When starting a vehicle equipped with such an automatic transmission 15, the accelerator pedal 24 is depressed. accelerator pedal 2
4, the clutch actuator 19 switches the clutch 30 to the connected state. Further, in such a transmission 15,
When the vehicle speed decreases, the engine 10 may stall. Therefore, in order to prevent this engine stall, the third
As shown in the figure, the rotation speed of the engine 10 is measured by the rotation sensor 2.
7, and if this rotation speed falls below a predetermined value, the clutch 30 is activated by the actuator 1.
9 for cutting. and clutch 3
The vehicle speed when 0 is disconnected is read by the vehicle speed sensor 26, and this value is temporarily stored in a register. Next, the microcomputer 21 connects the clutch sensor 29
At the same time, the sensor 29 determines whether the clutch 30 is in the connected state. When the clutch 30 is in the disengaged state, the detection output of the vehicle speed sensor 26 is further read, and the vehicle speed at the time of disengagement of the clutch 30 previously stored in the register is compared with the actual vehicle speed. If it is determined that the vehicle speed is increasing,
Even if the accelerator pedal 24 is not depressed, the microcomputer 21 supplies the υI8 signal to the actuator 19 to switch the clutch 30 to the connected state. Therefore, according to such an automatic transmission, when driving at low speed on a downhill slope, etc., if the clutch 30 is once disengaged to prevent engine stalling and then the vehicle speed increases, the accelerator pedal 24 is depressed. In most cases, the clutch 30 will be automatically connected according to instructions from the microcomputer 21. Therefore, from this,
This allows the vehicle to effectively utilize engine braking, making it possible to drive downhill safely. As described above, the present invention connects the clutch even if the accelerator pedal is not depressed when the vehicle speed increases when the clutch is disengaged, such as when going downhill. Therefore, it becomes possible to use engine braking to drive safely on downhill slopes and the like.

[Brief explanation of the drawing]

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 invention, and FIG. 3 is a flowchart showing clutch switching operation of this automatic transmission. In the symbols used in the drawings, 15... Transmission 17... Shift actuator 18... Select actuator 19... Clutch actuator 21... Microcomputer 24... Accelerator pedal 25... Accelerator Sensor 26...Vehicle speed sensor 27...Two engine rotation sensors...Clutch sensor 30...Clutch.

Claims (1)

[Claims] In a transmission that calculates the appropriate gear position and automatically changes the gear position using an actuator to the value obtained by this calculation, the vehicle speed when the clutch is disengaged A means for detecting an increase in the accelerator pedal and a means for engaging the clutch even if the accelerator pedal is not depressed are provided, so that if the vehicle speed increases when the clutch is disengaged on a downhill slope, etc., the clutch is engaged even if the accelerator pedal is not depressed. An automatic transmission characterized by: