JPH01193058A - Fuel injection control device - Google Patents

Abstract

PURPOSE:To make it possible to easily perform a crawling control of a vehicle by changing a fuel injection property accompanied with turning of crawling switch and suppressing an increased ratio of an engine speed to step-in quantity of an accelerating pedal. CONSTITUTION:A fuel injection pump A is additionally provided with an electronic governer B with which a control rack is moved, thereby the fuel injection quantity is controlled. Further, a crawling switch C and a means for changing a fuel injection property are additionally provided. Accompanied with turning the crawling switch C, the means D changes the fuel injection property so as to suppress an increased ratio of an engine speed to a step-in quantity of an accelerating pedal. Thus, it is possible to easily perform the crawling control of a vehicle.

Description

[Detailed description of the invention]

FIELD OF INDUSTRIAL APPLICATION 1 The present invention relates to a fuel injection control device for a diesel engine, and more particularly, to a fuel injection control device for a diesel engine, in which an electronic governor is attached to a fuel injection pump, and the amount of fuel injected is controlled by moving a control rack using the electronic governor. The present invention relates to a control device. KSummary of the invention] The present invention changes the fuel injection characteristics so that the engine speed is suppressed when the slow speed running switch is turned on,
This suppresses the number of revolutions of the engine in response to depression of the accelerator pedal, thereby improving the controllability of the vehicle at low speed and running.

[Prior art 1] Generally, a diesel engine is equipped with a fuel injection pump, and by pushing up a plunger with a cam of a camshaft, fuel in a barrel is pressurized, and this fuel is supplied to an injection nozzle through an injection pipe. ing. When pressurized fuel is supplied to the injection nozzle, the nozzle needle rises to open the injection port, so that a spray of fuel is injected into the cylinder. The amount of fuel injected is controlled by an electronic governor installed in the fuel injection pump, and by moving the control rack via this governor, the plunger is rotated within the barrel, and its slanted groove By changing the effective stroke, the fuel injection amount is controlled. [Problems to be Solved by the Invention] However, even in the conventional fuel injection pump having an electronic governor, only a single injection characteristic pattern was stored in the memory of the microcomputer constituting the electronic governor. That is, a map of normal injection characteristics is stored, and by referring to this map, the control rack of the fuel injection pump is moved in accordance with the amount of depression of the accelerator pedal. Therefore, with an engine having such a fuel injection pump, there is a problem in that the engine torque changes drastically with respect to the amount of depression of the accelerator pedal, making it difficult to control the vehicle at a slow speed. The present invention has been made in view of these problems, and an object of the present invention is to provide a fuel injection control device that improves the slow speed controllability of an engine equipped with a fuel injection pump having an electronic governor. It is something to do. Means for Solving Problem K] As shown in FIG. 1, the present invention includes an electronic governor attached to a fuel injection pump, and the amount of fuel injected is controlled by moving a control rack using the electronic governor. The device is provided with a slow speed running switch and a means for changing fuel injection characteristics so that the engine speed is suppressed, and when the slow speed running switch is turned on, the engine speed increases relative to the amount of depression of the accelerator pedal. This allows the ratio to be kept down.

[Effect]

Therefore, according to the present invention, when the slow speed running switch is turned on, the ratio of the engine speed to the accelerator pedal is suppressed, and although the engine torque increases, the speed does not increase and the slow speed control is disabled. becomes easier. K 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 diesel engine 10 is equipped with a fuel injection pump 11,
This pump 11 sequentially supplies fuel to each cylinder of the engine 10. fuel injection pump 1
1 is driven by the engine 10 via a timer 12, and the timing of fuel injection is adjusted by the timer 12. Roughly speaking, the fuel injection pump 11 is equipped with an electronic governor 13, and the governor 13 is adapted to adjust the amount of fuel to be injected. 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. A clutch actuator 19 for controlling connection and disconnection of a clutch 30, which is installed on the rear side of the flywheel, is connected to the transmission 1.
It is attached on the outer surface of the casing of No. 5. Roughly on the rear side of the fuel injection pump 11 is a fuel 1 for controlling the amount of fuel supplied by adjusting the position of a control rack.
An actuator 20 for IiIlIII is provided. The actuator 20 is composed of, for example, a near solenoid, and constitutes the electronic governor 13. And these four actuators 17.18.19.
20 are adapted to be driven based on 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. 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. Further, the microcomputer 21 includes a vehicle speed sensor 26, an engine rotation sensor 27, a rack sensor 28, a clutch sensor 29, a gear position sensor 31, and a slow running switch 3.
2 are connected to each other. 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. Further, the rack sensor 28 is attached to the lower side of the actuator 20, and the rack sensor 28 is attached to the lower side of the actuator 20.
The position of the control rack is detected. Further, the clutch sensor 29 is attached to the tip side of the clutch actuator 19, and the clutch sensor 29 is attached to the tip side of the clutch actuator 19.
It is designed to detect the connection and disconnection status of Further, the gear position sensor 31 is provided on the upper part of the transmission 15, and is adapted to detect the gear position. The slow running switch 32 changes the characteristics of the fuel injection pump 11. It is used for running at very low speeds. 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 shift position, the shift operation is automatically performed. ing. 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.
．． This is done via 18. To give an overview of the automatic gear shifting operation, the microcomputer 21 detects whether the gear shift lever 23 of the control box 22 is in the automatic gear shifting position;
In the case of the automatic shift position, the amount of depression of the accelerator pedal 24 or the opening degree of the accelerator and the vehicle speed are read from the accelerator sensor 25 and the vehicle speed sensor 26, respectively, at regular intervals. Further, the microcomputer 21 reads a map stored in its memory and, based on this map, calculates 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,
Do not perform gear shifting operations. The specific operation of automatic gear shifting is performed by the microcomputer 21.
Based on the command, the shift actuator 17 and the select actuator 18 are activated via an external drive means.
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. Note that during this shift operation, the -H clutch 30 is switched to the disconnected state by the actuator 19, and the clutch 30 is brought into the connected state again in synchronization with the end of the shift operation. Transmission 1 that performs automatic gear shifting in this way
A diesel engine 10 connected to the engine 5 is equipped with a fuel injection pump 11, which pressurizes fuel and sequentially supplies it to the cylinders. This fuel injection pump 11 is equipped with an electronic governor composed of a microcomputer 21 and an actuator 20, and the actuator 20 moves a control rack according to instructions from the microcomputer 21, thereby supplying fuel to be injected at one time. I try to control the amount. When the control rack is moved, the plunger is rotated relative to the barrel of each pump unit, and its slanted grooves are used to change the effective stroke and control the amount of fuel injected. ing. When performing such normal control, the microcomputer 2
The map referenced by 1 is a map as shown in FIG. 3, and this map is stored in the memory of the computer 21. The memory of the microcomputer 21 stores a map of injection characteristics for slow speed running as roughly shown in FIG. As mentioned above, the microcomputer 21
It is connected to the slow running switch 32. As shown in FIG. 6, when the slow running switch 32 is pressed, the fourth
The microcomputer 21 controls the injection amount by the fuel injection pump 11 via the actuator 20 while referring to the map for slow speed running shown in the figure. The injection characteristic shown in FIG. 4 is an all-speed type characteristic, and is composed of a pattern designed to push the rotational speed. Therefore, according to these characteristics, the change in engine speed with respect to the amount of depression of the accelerator pedal will be as shown in Figure 5, and the engine speed will be significantly suppressed compared to when the switch is not pressed. become. Therefore, when this characteristic is selected, the engine 10 generates the torque necessary for running, but its rotational speed is suppressed to a sufficiently low value. Therefore, when the slow speed running switch 32 is turned ON, not only will the engine 10 not be revved up even if the accelerator pedal 24 is fully depressed, but the rotation of the engine 10 can be controlled by subtle adjustment of the accelerator pedal 24. Therefore, slow speed control can be easily performed. This improves slow start performance. In addition, as shown in FIG. 6, when the slow running switch 32 is not pressed, control is performed with reference to the map of normal injection characteristics shown in FIG. 3. Further, the present invention can be used in combination with other slow speed running means, such as controlling the clutch to a half-clutch state. [Effects of the Invention] As described above, according to the present invention, when the slow speed running switch is turned on, the rate of increase in engine speed relative to the amount of depression of the accelerator pedal is suppressed, and as a result, the engine speed is controlled by the accelerator pedal. It becomes possible to delicately control the rotation speed, and it becomes possible to improve slow speed controllability or slow speed starting performance.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the gist of the present invention, FIG. 2 is a block diagram of a diesel engine equipped with a fuel injection control device according to an embodiment of the present invention, FIG. 3 is a graph showing normal injection characteristics, and FIG. FIG. 4 is a graph showing injection characteristics for running at very low speeds, FIG. 5 is a graph showing changes in engine rotational speed with respect to the amount of depression of the accelerator pedal, and FIG. 6 is a flowchart showing operations for running at very slow speeds. In addition, in the symbols used in the drawings, 10...Diesel engine 11...Fuel injection pump 20...Fuel control actuator 21...Microcomputer 27...Engine rotation sensor 32...Low speed running switch be.

Claims (1)

[Claims] In a device in which an electronic governor is attached to a fuel injection pump and the amount of fuel injected is controlled by moving a control rack using the electronic governor, a slow running switch and a fuel injection pump are used to control the amount of fuel injected so that the engine speed can be suppressed. 1. A fuel injection control device, comprising means for changing injection characteristics, so that when the slow speed running switch is turned on, the rate of increase in engine rotational speed relative to the amount of depression of an accelerator pedal is suppressed.