JPH06288274A - Output control method of internal combustion engine - Google Patents

Abstract

PURPOSE:To expand the scope of operation by deciding the number to pause the fuel injection according to the detected rotation frequency and the operating condition, and maintaining the output at an object output by pausing the fuel injection at the decided pausing number. CONSTITUTION:A fuel injection valve 5 provided near one side end of an intake maniford 4 is controlled by an electronic control device 6. To the electronic control device 6, an intake pressure signal (a) from an intake pressure sensor 13, and a rotation frequency signal (b) from a rotation frequency sensor 14 are input as the main data. And the injector final power feeding time is decided by correcting a standard injection time with various correction coefficients decided according to the engine condition. The fuel injection valve 5 is controlled by the decided power feeding time, and the fuel according to the engine load is injected from the fuel injection valve 5 to an intake system 1. The number to pause the fuel injection is decided according to the detected rotation frequency and the operating condition, and the output is maintained to the object output by pausing the fuel injection in the decided number. In such a way, the scope of operation can be expanded, and a dangerous operation can be avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine output control method for an internal combustion engine for an automobile, which is operated at a target output.

[0002]

2. Description of the Related Art Conventionally, in an automobile or the like, in order to match various performances such as torque characteristics between an engine and a transmission, a method of reducing or limiting the output of the engine so as to fit the transmission is adopted. Has been done. As an output control method of such an internal combustion engine, for example, as disclosed in Japanese Patent Laid-Open No. 59-32638, basically, the opening of a throttle valve is controlled so that the output of an engine to be regulated or more is exceeded. The engine output is controlled to keep it low so that no output is produced.

[0003]

However, in the above, in order to control the throttle valve opening, as shown in FIG. 4, the actual output in the low rotation range up to the target output Pp is reached. Since Pc does not rise to the original engine output Po, the target output P
The output Pc becomes smaller than p, the rotation range in which the engine can be operated with the original engine output is lost, and the target output Po is maintained, resulting in poor operation efficiency in the low rotation range. The present invention aims to solve such a problem.

[0004]

The present invention takes the following means in order to achieve such an object. That is, the output control method for an internal combustion engine according to the present invention detects an engine speed, detects an operating state, and sets an internal combustion engine that injects a fuel amount determined according to the detected engine speed and operating state. When the engine's original output exceeds the target output, the criterion for determining whether the engine speed is within a predetermined range and the operating state can exceed the target output is the range in which the original output of the internal combustion engine exceeds the target output. The number of times to suspend fuel injection when it is detected that the detected rotational speed and operating state are within the set range, and the rotational speed and operating state are within the range. It is characterized in that it is determined according to the detected number of revolutions and the operating condition, and the fuel injection is suspended for the determined number of suspensions to maintain the output at the target output.

[0005]

With such a structure, the output of the internal combustion engine is set as a target based on the criteria for determining that the rotational speed is within the predetermined range and that the operating state can exceed the target output. Since it is set corresponding to the range exceeding the output,
The fuel injection is not suspended outside this set range. Therefore, it is possible to operate with the output that the internal combustion engine originally has without lowering the output, and by controlling to the target output, problems do not occur in other operating regions. In addition, since fuel cut is not performed to maintain the target output, a sudden drop in output is not caused, and safety equivalent to that of an internal combustion engine that does not limit output can be secured.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. An engine 100 schematically shown in FIG. 1 is for an automobile, and an intake system 1 thereof is provided with a throttle valve 2 which opens and closes in response to an accelerator pedal (not shown), and a surge tank 3 is provided downstream thereof. It is provided.
Intake manifold 4 of intake system 1 communicating with surge tank 3
A fuel injection valve 5 is further provided near one end of the fuel injection valve 5, and the fuel injection valve 5 is controlled by the electronic control unit 6. Further, an O ₂ sensor 21 for measuring the oxygen concentration in the exhaust gas is attached to the exhaust system 20 at a position upstream of a three-way catalyst 22 arranged in a pipe line leading to a muffler (not shown). There is. This O ₂ sensor 21
Outputs a voltage signal h corresponding to the oxygen concentration.

The electronic control unit 6 is mainly composed of a microcomputer system including a central processing unit 7, a storage unit 8, an input interface 9 and an output interface 11, and the input interface 9 has Is the intake pressure signal a output from the intake pressure sensor 13 for detecting the pressure in the surge tank 3, the rotation speed signal b output from the rotation speed sensor 14 for detecting the engine speed NE, and the vehicle speed. Vehicle speed signal c output from the vehicle speed sensor 15 for detection, throttle valve 2
The throttle opening signal d output from the throttle sensor 16 for detecting the open / closed state of the engine, the water temperature signal e output from the water temperature sensor 17 for detecting the cooling water temperature of the engine, and the O ₂ sensor 21 described above. A voltage signal h or the like is input. On the other hand, the output interface 11
From the above, the fuel injection signal f is output to the fuel injection valve 5, and the ignition pulse g is output to the spark plug 18.

The electronic control unit 6 has an intake pressure signal a output from the intake pressure sensor 13 and a rotation speed signal b output from the rotation speed sensor 14 as main information, and various kinds of information are determined according to engine conditions. The fuel injection valve opening time, that is, the injector final energization time T is determined by correcting the basic injection time with the correction coefficient, and the fuel injection valve 5 is controlled according to the determined energization time to supply the fuel according to the engine load. A program for injecting from the injection valve 5 to the intake system 1 is built in. In this program, a criterion for determining that the rotation speed is within a predetermined range and that the operating state can exceed the target output is set corresponding to the range where the original output of the engine 100 exceeds the target output. However, it is detected that the detected rotational speed and operating state are within the set range, and the rotational speed and operating state are detected when the rotational speed and operating state are detected to be within the range. It is determined according to the situation, and is programmed to suspend the fuel injection for the determined number of suspensions and maintain the output at the target output.

The outline of this output control program is as shown in FIG. The effective injection time TAU is taken into consideration in consideration of various correction factors in the basic fuel injection control.
The program itself for calculating and then calculating the injector final energization time T can use a conventionally known program, and therefore illustration and description thereof are omitted. In this program, an operating range for maintaining the actual output Pc of the engine 100 at the target output Pp is set in advance, and
A map M in which the number of times fuel injection is stopped is set corresponding to the engine speed NE at the target output Pp and the throttle opening and intake pressure as elements for grasping the operating state.
Equipped with AP. Then, first in step 51,
It is determined whether or not the current engine speed NE is higher than the set engine speed range N _L and lower than the engine speed N _H , and if the engine speed NE is within this engine speed range, step If not, the process proceeds to step 54. Next, at step 52, from the throttle opening signal d output from the throttle sensor 16 and the intake pressure signal a output from the intake pressure sensor 13,
Whether the current operating state is an operating state in which the output exceeds the target output Pp is determined by the intake pressure or the throttle opening. If it is determined that the target output Pp is exceeded, the process proceeds to step 53, and if not. Moves to step 54. At step 53, the current engine speed N
The number of times fuel injection is stopped (thinned) is read from E, intake pressure PM and throttle opening TA from the map MAP,
If the value is other than the value set in the map MAP, it is determined by performing interpolation calculation. Then, in step 54, the injection is executed according to the determined number of fuel injections.

In such a configuration, the engine 100
If the engine is operating below the set rotational speed N _L ,
The control proceeds from step 51 to step 54, and the engine 100 is operated at the original output Po.
That is, as shown in FIG. 3, until the engine speed KE exceeds the speed N _L , the fuel injection is temporarily stopped and is not thinned out, and the fuel injection is performed by the calculated injector final energization time T. Performed, output Pc at that time
Delivers output in line with the original engine characteristics without any restrictions. In addition, the current engine speed NE is
If the throttle opening T or the intake pressure PM does not reach the set numerical value though the set rotational speed N _L is exceeded, for example, when traveling downhill, the control is performed in step 51 → step. The process proceeds from 52 to step 54, and as described above, the output is displayed according to the original engine characteristics.

Then, the accelerator pedal is depressed due to acceleration or the like, the throttle opening TA increases, or the intake pressure PM exceeds a set value, and the engine speed increases accordingly, and the set engine speed is increased. When the area is reached,
The control is step 51 → step 52 → step 53 →
In step 54, the number of times the fuel injection is thinned is determined, the fuel injection is stopped for that number of times, the engine output Pc is controlled to the target output Pp, and the engine output P
Keep c. That is, when the throttle valve 2 is operated in the set rotational speed range and the throttle valve 2 remains open beyond the target output Pp, or when the intake pressure PM increases, the fuel injection is performed from the normal number of times. Map M
By reducing the number of times determined based on AP, fuel injection is continued without fuel cut and output is controlled. Further thereafter, when the engine speed NE increases and exceeds the set engine speed N _H , the control _proceeds to step 51.
→ Proceeds to step 54, the fuel injection is performed a normal number of times without being thinned, and the output Pc at that time becomes the original engine output.

As described above, the output Pc of the engine 100 is controlled and maintained at the target output Pp only in a specific operating range set by the engine speed KE, the throttle opening TA and the intake pressure PM. When the rotation speed NE is lower than the rotation speed N _L and higher than the rotation speed N _H , the engine 100 is driven by the original output Po of the engine 100 to exhibit normal performance, and exceeds the performance of the transmission in a specific operation range. Without it, the output can be transmitted in a state of being sufficiently adapted to the performance.

The present invention is not limited to the embodiments described above. For example, in the above-described embodiment, the number of times the fuel injection is stopped is determined based on the preset map MAP. However, the map MAP is set using the engine speed NE, the throttle opening TA and the intake pressure PM as variables. It may be determined by calculation instead of referring to it. Besides, the configuration of each unit is not limited to the illustrated example, and various modifications can be made without departing from the spirit of the present invention.

[0014]

As described in detail above, the present invention can maintain the output at the target output in the set specific operating range, so that it can be applied to peripheral devices that do not conform to the original output characteristics of the internal combustion engine. It can be easily adapted, the range of use can be expanded, and dangerous operation resulting from non-compliance can be avoided, and sufficient safety can be ensured. Moreover, since the number of fuel injections is reduced in the specific operation range, the fuel efficiency can be improved as a whole.

[Brief description of drawings]

FIG. 1 is a schematic configuration explanatory view showing an embodiment of the present invention.

FIG. 2 is a flowchart showing a control procedure of the embodiment.

FIG. 3 is an operation explanatory view of the same embodiment.

FIG. 4 is an explanatory view of the operation of a conventional example.

[Explanation of symbols]

 1 ... Intake system 2 ... Throttle valve 5 ... Fuel injection valve 6 ... Electronic control unit 13 ... Intake pressure sensor 14 ... Rotation speed sensor 16 ... Throttle sensor

Claims (1)

[Claims] Claim: What is claimed is: 1. An internal combustion engine that detects a rotational speed, detects an operating state, and injects a fuel amount determined according to the detected rotational speed and the operating state, and operates at a set target output or less. In the output control method of (1), the criteria for determining whether the rotation speed is within a predetermined range and that the operating state can exceed the target output are set in accordance with the range in which the original output of the internal combustion engine exceeds the target output. Set, the number of revolutions detected when detecting that the detected number of revolutions and operating state is within the set range, and when detecting that the number of revolutions and operating state is within the range And an output control method for an internal combustion engine, which is determined according to operating conditions, and the fuel injection is suspended for the determined number of suspensions to maintain the output at the target output.