JPS61129342A - Automatic transmission - Google Patents

Abstract

PURPOSE:To accurately perform the creep operation at a place such as a slope where a load is applied to a vehicle and safely perform the slope start by controlling the feed rate of fuel during the creep operation by way of a control means. CONSTITUTION:The creep operation is enabled when existence or absence of the operation of service and/or parking brakes is defected by a pair of brake sensors 30 and 31 and it neither of these brakes is in operation. In addition, the creep operation is performed almost at a fixed car speed independently of a load applied to a vehicle by controlling the injection rate of fuel during the creep operation using an actuator 20 for fuel control.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an automatic transmission that is capable of automatically changing gear ratios, and in particular selects gears to be used by calculation means according to i speed, accelerator opening, etc. The present invention relates to an automatic transmission that meshes gears selected by a user to achieve a predetermined gear ratio. [Prior Art 1] Conventionally, a transmission has been attached to the engine in order to change the rotational speed of the engine of the personal vehicle III to an appropriate value. This transmission selects the gear to be used in response to the driver's gear change operation, and changes the engine speed to an appropriate value for transmission to the drive wheels. However, with such a conventional transmission, the driver has to operate the gear shift lever depending on the driving condition of the vehicle, etc., which makes driving operations extremely complicated. Automatic transmissions have been proposed to overcome these drawbacks. In this automatic transmission, a calculation means such as a microcomputer selects the gear to be used depending on the I1g speed and the accelerator opening level.
A predetermined gear ratio is automatically obtained by meshing gears selected by an actuator. By equipping an automobile with such an automatic transmission, the driver hardly needs to operate a lever to change gears. When such an automatic transmission is used in conjunction with a hydraulic clutch, the slipping function of the hydraulic clutch can be used to perform a creep operation. In other words, the vehicle can be moved slowly forward or backward. Furthermore, when this automatic transmission is used in combination with a semi-dry type or dry type clutch that does not have a slip function, it is necessary to protect the clutch facing because the clutch does not have a slip function. Therefore, for example, by providing a brake sensor and disengaging the clutch in conjunction with the detection of the operation of the brake applied to the brake sensor, it is possible to provide the function of creep operation without putting a burden on the clutch. By providing such a leap function to the automatic transmission, it is possible to move the vehicle forward or backward slowly on level ground, thereby making it possible to perform safe and accurate TI storage. However, when the load is large, such as when going up a slope, this creep operation is not necessarily carried out smoothly, and for example, the hydraulic clutch slips and the Il! There were some inconveniences such as both cars starting to slowly descend down the slope. Therefore, it has become difficult to start on a slope using the leap function. [Object of the Invention] The present invention has been made in view of the above-mentioned problems, and the present invention has been made in view of the above-mentioned problems. This is necessary because the purpose of the invention is to provide an automatic transmission that can be used.

[Configuration 1 of the Invention] The present invention determines 'af' according to vehicle speed, accelerator opening, etc. A self-help transmission in which a gear to be used is selected by a means and a predetermined gear ratio is achieved by meshing the selected gear by an actuator,
A control means for controlling the fuel supply m is provided, and the entire fuel supply during the creep operation is controlled by the control means III.
The present invention relates to an automatic transmission characterized in that the automatic transmission is controlled so that the creep operation is performed at a substantially constant vehicle speed, and thereby the creep operation can be performed reliably even on slopes, etc. Practical MA Example] The present invention will be described below with reference to an illustrated embodiment. FIG. 1 shows a diesel engine for a truck equipped with an automatic transmission according to one embodiment of the present invention.
Consists of 0. 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 a timer 12.
Moreover, the timing of fuel injection is adjusted by this timer 12. Roughly speaking, the fuel injection line pump 11 is equipped with a mechanical governor 13, and the governor 13 adjusts the amount of fuel to be injected by r14. Flywheel housing 1 is on the back side of engine 1Q.
4 is provided, and a flywheel fixed to the end of the crankshaft is accommodated within this housing 14. A clutch (not shown) 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 this clutch. This transmission 15 has an engine 10
The rotational speed of the propeller is changed to an appropriate value and transmitted to the drive wheels via the propeller shaft 16. The transmission 15 constitutes an automatic transmission, and a shift actuator 17 and a selection actuator 18 are provided above the transmission, respectively. Connecting the clutch installed on the back side of the flywheel and il! 111fO
A clutch actuator 19 is mounted on the outer surface of the casing of the transmission 15. Further, on the front end side of the tower fuel injection pump 11, there is provided an actuator 20 for controlling the fuel supply level by adjusting the position of the control rack.These four actuators 17. 18.19.
20 are adapted to be driven in response to instructions from a microcomputer 21 via respective 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. Roughly speaking, 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 two clutch sensors. 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 distal end side of the clutch actuator 19, and is designed to detect whether the clutch is connected or disconnected. Furthermore, in the automatic transmission according to this embodiment, as shown in FIG. 1, a service brake sensor 30 and a parking brake sensor 31 are connected to the input side of the microcomputer 21 that constitutes the calculating means of this automatic transmission. It has become so. These sensors 30, 31 are adapted to detect whether the service brake and parking brake are in operation, respectively. Such service brake sensor 3oI3 and parking brake sensor 31
By providing this, it is possible to provide a creep operation function to the automatic transmission 15 including a dry or semi-dry type clutch whose connection 6 and disconnection are till lit by the clutch actuator 19. 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 memory of the microcomputer 21, so that when the shift lever 23 of the control box 22 is in the automatic position, the shift operation is automatically performed. It has become. On the other hand, when the shift lever 23 is in the manual position, a manually selected shift operation is carried out via the actuators 17, 18. To give an overview of the operation of automatic gear shifting, the microcomputer 21 detects whether the gear shift lever 23 of the vehicle control box 22 is in the automatic position, and if it is in the automatic position, the accelerator pedal is pressed at regular intervals. The amount of depression or opening of the accelerator 24 and the vehicle speed are read from the accelerator sensor 25 and the vehicle speed sensor 26, respectively. Roughly, 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 specified 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. In addition, during this shift operation, the clutch is switched to the disconnected state by one actuator, and the clutch is brought into the engaged state again in synchronization with the end of the shift operation. Further, in the automatic transmission according to this embodiment, the creep operation is performed at a constant vehicle speed based on a flowchart as shown in FIG. The characteristics of this creep operation are as follows: First, a pair of brake sensors 30 and 31 detect whether or not the service brake and parking brake are in operation, and enable the creep operation when neither of these brakes is in operation. . Therefore, such a brake sensor 3
By providing the clutches o and 31, it is possible to use the clutch with a semi-dry type or dry type clutch. The feature of the second creep operation is that by using the fuel control actuator 20 to inject the fuel m during the creep operation, the creep operation is maintained at a substantially constant vehicle speed regardless of the load applied to the vehicle ( The service brake sensor 30 detects whether the service brake is in operation, and the parking brake sensor 31 detects whether the parking brake is in operation. When the microcomputer 21 reads the detection outputs of the two sensors 30 and 31 and neither of the two types of brakes is in operation, a creep operation is performed as is clear from FIG. When at least one of the brakes is in operation, the creep operation is prevented by prohibiting the start operation.In this way, the creep operation is prevented only when both types of brakes are not in operation. By doing this, burnout of the clutch facing is prevented without adding a large load to the clutch.Accordingly, even when this automatic transmission 15 is used in combination with a semi-dry type or dry type clutch, By enabling the creep operation and moving the vehicle slowly, safe and accurate tFjt insertion, etc. can be performed. Such functionality is particularly useful for large vehicles, trailer trucks, and the like. As is clear from the flowchart shown in FIG. 2, during this creep operation, the microcomputer 21
reads the vehicle speed from the vehicle speed sensor 26, and determines whether this vehicle speed is higher than a predetermined speed, for example, ih'/h, and if it is lower than 1 kl/h, increases the fuel injection port, and When the speed exceeds 1 kll/h, the amount of fuel injected is reduced. This decrease in the fuel injection port is controlled by the microcomputer 21.
This is achieved by a fuel t++ wJ actuator 20 that is operated according to instructions, and this actuator 20 moves the control rack of the fuel injection pump 11 to adjust the fuel injection port. . Therefore, by such an operation, the vehicle speed during the creep operation can be maintained at a substantially constant vehicle speed. Further, by performing the fuel supply amount i+1Itil in combination with the creep operation, the creep operation can be reliably performed when a load is applied to the vehicle such as on a slope. As described above, the automatic transmission according to the present embodiment enables creep operation of the automatic transmission connected to a semi-dry type or dry type clutch, and also enables the creep operation! jJf+! The vehicle speed is maintained at a nearly constant value by controlling the amount of fuel supplied within the vehicle. Therefore, with this configuration, it is possible to stably perform creep operation at a constant vehicle speed on slopes, etc. It is possible to prevent the vehicle from slipping down due to the load applied on a slope as in the past, and it is also possible to start on a slope safely and reliably.In addition, it is also possible to safely and accurately park the vehicle in a garage. This makes it easier to drive, especially large vehicles.

【Effect of the invention】

As described above, the present invention provides the sub-means for controlling the amount of fuel supplied, and controls the amount of fuel supplied during the creep operation by the suppressor means, so that the creep operation is performed at a substantially constant heavy speed. This is what I did. Therefore, with this configuration, it is possible to provide an automatic transmission that can reliably carry out creep operation in places where a load is applied to the vehicle, such as on a slope, and can also safely start on a slope. You will be able to do this.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an automatic transmission according to an embodiment of the present invention, and FIG. 2 is a flow chart showing creep operation of this automatic transmission. In addition, in the symbols used in the drawings, 15...Transmission 17...Shift actuator 18...Select actuator 19...Clutch actuator 20...! FI II+ 121] actuator 21...microcomputer 25...accelerator sensor 26...heavy speed sensor 30...service brake sensor 31...parking brake sensor.

Claims (1)

[Claims] In an automatic transmission in which a calculation means selects a gear to be used according to vehicle speed, accelerator opening, etc., and an actuator engages the selected gear to obtain a predetermined gear ratio, fuel is supplied. An automatic transmission characterized in that the automatic transmission is provided with a control means for controlling the amount of fuel, and the amount of fuel supplied during the creep operation is controlled by the control means so that the creep operation is performed at a substantially constant vehicle speed.