JPS61123726A - Fuel injection quantity controlling method of engine - Google Patents

Abstract

PURPOSE:To aim at improvements in engine performance ever so better, by detecting the gear-shifting step of a transmission, while constolling a fuel injection quantity so as to accord with an engine torque characteristic corresponding to the allowable torque of the transmission in that gear-shifting step. CONSTITUTION:Each output of engine speed and other various sensors is fed to a control unit 10, while output of a hear-shifting step sensor 12 detecting gear-shifting steps of a transmission connected to an engine is also fed to the control unit. And, with the control unit 10, an optimum fuel injection quantity, namely, an optimum rack position is set according to each output signal, and the rack position setting signal is outputted to an actuator drive circuit 13. With this signal outputting, an actuator 3 is driven, regulating a position of a control rack varying the furl injection quantity of a fuel injection pump. That is to say, the fuel injection quantity is controlled so as to accord with an engine torque characteristic corresponding to allowable torque of the transmission in a certain gear-shifting step.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for controlling the fuel injection amount of an automobile engine.

<Conventional technology> In transformers installed in automobiles, the permissible torque is generally not uniform for each gear stage, and gears with a large number of teeth are meshed with gears with a large number of teeth due to factors such as gear surface pressure. The permissible torque of the trans tension in low speed gears is limited to a smaller value than in high gear gears.

Particularly, in a transmission that has a large number of lζ gears, such as a transmission installed in a large vehicle such as a truck, there is a large difference in allowable torque between low and high gears.

On the other hand, although the torque generated by the engine can be output independently of the transmission, if the generated torque exceeds the permissible torque of the transmission, there is a risk of damaging the transmission. Conventionally, this problem has been dealt with by keeping the fuel injection amount low in advance so that the torque generated by the engine does not exceed the allowable torque of the transmission.

<Problems to be Solved by the Invention> In other words, in the past, the engine fuel was controlled so that the generated torque of the engine did not exceed the smallest allowable torque among the allowable torques at each gear stage of the transmission, that is, the allowable torque at the low gear stage. The amount of injection is suppressed. Therefore, when the high-speed gear of the transmission is selected, even though the transmission has a margin of allowable torque and the engine has the ability to output even higher torque, the engine cannot use its high output range. The problem was that it was not possible to take full advantage of its performance.

For this reason, for example, when the vehicle is climbing, the necessary high torque cannot be obtained in the high speed gear, so the vehicle must travel in the low gear, resulting in complicated gear shift operations and deterioration of fuel efficiency.

Means for Solving the Problems> The present invention solves the above-mentioned conventional problems, and provides an engine fuel injection amount control method that allows the transformer to fully exhibit engine performance depending on the gear position of the transmission. is intended to provide.

The structure of the engine fuel injection amount control method according to the present invention to achieve this object is to detect the gear position of a transmission connected to the engine and to adjust the engine torque commensurate with the allowable torque of the transmission at the gear position. It is characterized by controlling the fuel injection amount so as to achieve the characteristics.

Therefore, depending on the transmission change yN stage IC,
For example, in a low speed gear, the maximum output torque of the engine is suppressed, while in a high speed gear, the permissible torque of the transmission increases, so that the maximum output torque of the engine is increased.

Embodiment> An embodiment of the present invention will be explained below with reference to the drawings. This implementation series is applied to a fuel injection system that uses an electronic governor.

The electronic governor has a control device equipped with a microcomputer, and the function of this control device is to set the position of the control rack in the fuel injection device and adjust the fuel injection amount to achieve the optimum state under the given conditions. Figure 3 shows a schematic configuration diagram of the control rack and surrounding parts, and Figure 4 shows a control block diagram of the electronic governor.

In the diagram 11g3, 1 is the fuel injection pump, 2 is the control rack, and control rack 2 is the pump 1.
It is a component of the fuel increase/decrease mechanism in the figure, and the injection amount of the pump 1 changes depending on the movement position in the left-right direction in the drawing. An actuator 3 sets the position of the rack 2, and is composed of a linear solenoid 4 and a plunger 5, and the plunger 5 is connected to the rack 2. Further, a rack position sensor 7 is connected to the rack 2 via a link 6. 8 is a pump camshaft, and 9 is its rotation speed sensor.

On the other hand, in FIG. 4, 10 is an electronic governor control device using a CPU, and the control device 10 includes an engine rotation speed sensor, a vehicle speed sensor, a brake switch, a clutch switch, a fuel temperature sensor, an intake pressure sensor, an intake air Outputs from various sensors 11 such as a temperature sensor, water temperature sensor, and accelerator pedal position sensor are supplied.

Furthermore, the control device 10 is connected to a transmission gear position sensor 12 that detects the transmission gear position of the transmission connected to the engine.
output is supplied.

Then, the control device 10 determines the optimal fuel injection amount, that is, the optimal rack position, according to the various senna signals and the gear stage senna signal, and outputs a rack position setting signal to the actuator drive circuit 13. The actuator drive circuit 13 drives the aforementioned actuator 3 according to the rack position setting signal, and at this time, the actuator drive circuit 13, the actuator 3, and the rack position sensor 7 constitute a servo control system.

That is, as shown in FIG. 1 which shows the fuel injection amount characteristic (q characteristic) when the accelerator pedal is depressed to the maximum according to this embodiment, when the low speed gear of the transmission is selected, the control device 10 As shown by the solid line in Figure 1, while suppressing the maximum fuel injection amount and determining the optimal rank position,
When the high speed gear is selected, the control device 10 sets the optimum rack position R so that the maximum fuel injection amount is larger than that in the low speed gear, as shown by the chain line in FIG. 1, so that higher torque is output. It is designed to determine the FIG. 2 shows the torque characteristics, and by doing so, higher torque characteristics can be obtained in the high speed gear (dashed line) than in the low speed gear (solid line). In FIG. 2, the broken line represents a constant fuel consumption curve, and good fuel consumption can be obtained in the low engine speed and high torque region.

Therefore, high torque can be obtained at high speed, so
For example, the number of times when the vehicle can be driven in a high speed gear is increased, such as when the vehicle is climbing, which not only simplifies the gear shift operation by reducing the number of downshift operations, but also improves fuel efficiency.

In the above embodiment, the torque characteristics of the engine are controlled in two cases, high speed gear and low gear gear, but in the present invention, the control may be performed in more cases.

<Effects of the Invention> As described above in detail with reference to one embodiment, according to the present invention, the gear position of the transmission connected to the engine i is detected and the gear position is adjusted to match the permissible torque of the transmission at the gear position. Since the fuel injection amount is controlled to match the torque characteristics of the engine, it is possible to fully demonstrate the performance of the engine in response to the transmission speed change Rζ, and the number of gear shift operations is reduced.
This improves maneuverability and fuel efficiency.

[Brief explanation of drawings]

The drawings are an embodiment of the present invention, the power and force, Figure 1 is a graph showing fuel injection amount characteristics, and Figure 2 is a graph showing fuel injection amount characteristics. Graph showing other torque characteristics, Figure 3 (schematic configuration diagram of the control rack and surrounding parts, Figure 4 is a control block diagram of the electronic governor. In the figure, 1 is the fuel injection pump, 2 is the control 3 is an actuator, 10 is a control device, 12 is a gear position sensor, and 13 is an actuator drive circuit.

Claims (1)

[Claims] An engine characterized in that the gear position of a transmission connected to the engine is detected and the fuel injection amount is controlled so that the engine torque characteristic is commensurate with the allowable torque of the transmission at the gear position. Fuel injection amount control method.