阅读说明：本技术 燃料喷射控制装置、燃料喷射控制方法 (Fuel injection control device and fuel injection control method ) 是由 板羽史博 向原修 饭塚智 于 2019-02-01 设计创作，主要内容包括：本发明提供一种燃料喷射控制装置,其控制内燃机的燃料喷射阀,该燃料喷射控制装置可以实现与燃料喷射阀的劣化程度相应的喷射量控制,效率高、可靠性高。本发明为一种燃料喷射控制装置,其控制内燃机的燃料喷射阀,该燃料喷射控制装置的特征在于,具备：劣化判定部,其判定所述燃料喷射阀的劣化状态；喷射量学习部,其学习所述燃料喷射阀的喷射量；以及学习频次变更部,其根据所述燃料喷射阀的劣化状态来变更所述喷射量学习部的学习频次。(The invention provides a fuel injection control device for controlling a fuel injection valve of an internal combustion engine, which can realize injection quantity control according to the deterioration degree of the fuel injection valve, and has high efficiency and high reliability. The present invention is a fuel injection control device that controls a fuel injection valve of an internal combustion engine, the fuel injection control device including: a deterioration determination unit that determines a deterioration state of the fuel injection valve; an injection amount learning unit that learns an injection amount of the fuel injection valve; and a learning frequency changing unit that changes a learning frequency of the injection amount learning unit according to a deterioration state of the fuel injection valve.)

1. A fuel injection control device that controls a fuel injection valve of an internal combustion engine, the fuel injection control device being characterized by comprising:

a deterioration determination unit that determines a deterioration state of the fuel injection valve;

an injection amount learning unit that learns an injection amount of the fuel injection valve; and

and a learning frequency changing unit that changes a learning frequency of the injection amount learning unit according to a deterioration state of the fuel injection valve.

2. The fuel injection control apparatus according to claim 1,

the degradation determination unit determines that the fuel injection valve is in the adaptation period when an integrated value of the injection count number of the fuel injection valve is less than a predetermined threshold value,

the learning frequency changing unit increases the learning frequency of the injection amount learning unit.

3. The fuel injection control apparatus according to claim 1,

the degradation determination portion determines that the fuel injection valve has not degraded when an integrated value of the injection count number of the fuel injection valve is within a predetermined range,

the learning frequency changing unit reduces the learning frequency of the injection amount learning unit.

4. The fuel injection control apparatus according to claim 1,

the degradation determination unit determines that the fuel injection valve has degraded when an integrated value of the injection count number of the fuel injection valve exceeds a predetermined threshold value,

the learning frequency changing unit increases the learning frequency of the injection amount learning unit.

5. The fuel injection control apparatus according to any one of claims 2 to 4,

the degradation determination unit changes the number of injection counts of the fuel injection valve according to a drive current value of the fuel injection valve.

6. The fuel injection control apparatus according to any one of claims 2 to 4,

the degradation determination portion changes the injection count number of the fuel injection valve in accordance with a combustion pressure in the internal combustion engine.

7. The fuel injection control apparatus according to any one of claims 2 to 4,

the degradation determination unit changes the number of injection counts of the fuel injection valve according to an injection pulse width of the fuel injection valve.

8. The fuel injection control apparatus according to any one of claims 2 to 4,

the degradation determination unit changes the number of injection counts of the fuel injection valve according to a travel distance of a vehicle on which the internal combustion engine is mounted or a rotation speed of the internal combustion engine.

9. A fuel injection control method of controlling a fuel injection valve of an internal combustion engine, characterized by comprising:

counting the number of injections by the fuel injection valve;

a step (b) of estimating a deterioration state of the fuel injection valve from the number of injections counted in the step (a); and

and (c) correcting the injection quantity of the fuel injection valve based on the degradation state of the fuel injection valve estimated in the step (b).

10. The fuel injection control method according to claim 9,

when the integrated value of the number of injections counted in the step (a) exceeds a predetermined threshold, it is determined that the fuel injection valve is deteriorated, and the injection pulse width and the drive current waveform of the fuel injection valve are corrected according to the state of deterioration.

11. The fuel injection control method according to claim 9 or 10,

in the step (a), the count number of the number of injections is changed according to the drive current value of the fuel injection valve.

12. The fuel injection control method according to claim 9 or 10,

in the step (a), the count number of the number of injections is changed in accordance with a combustion pressure in the internal combustion engine.

13. The fuel injection control method according to claim 9 or 10,

in the step (a), the count number of the number of injections is changed according to an injection pulse width of the fuel injection valve.

14. The fuel injection control method according to claim 9 or 10,

in the step (a), the count number of the number of injections is changed according to a travel distance of a vehicle equipped with the internal combustion engine or a rotation speed of the internal combustion engine.

Technical Field

The present invention relates to a fuel injection control device for controlling a fuel injection valve of an internal combustion engine and a control method thereof, and particularly to a technique effective in increasing efficiency of the internal combustion engine.

Background

In recent years, due to the enhancement of fuel efficiency and emission control of automobiles, it has been required to simultaneously achieve low fuel consumption and high power of an internal combustion engine and to adapt the internal combustion engine to a wide operating range. As one of the means for achieving this, it is required to expand the dynamic range of the fuel injection valve.

In order to expand the dynamic range of the fuel injection valve, it is necessary to improve the dynamic flow characteristics while ensuring the conventional static flow characteristics. As a method for improving the flow characteristics, it is known to reduce the minimum injection amount by half-lift control.

This half-lift control is known to perform high-precision control in a state (hereinafter referred to as a half-lift region) before a valve element provided in a fuel injection valve completely reaches a valve opening position (hereinafter referred to as a full lift), but the variation in injection amount in the half-lift region is increased due to individual differences of the fuel injection valves. Therefore, various techniques for detecting individual differences generated in each fuel injection valve have been proposed in the art.

As a background art in this field, for example, there is a technology as in patent document 1. Patent document 1 discloses a technique for indirectly detecting an individual difference in relation to a valve opening operation of a fuel injection valve (specifically, a time at which a valve element is in a valve-opened state) based on electrical characteristics. Similarly, it is disclosed that the individual difference in the valve closing operation of the fuel injection valve is detected based on the electrical characteristics.

Further, the fatigue permanent deformation of the spring, the deterioration with time due to the grinding of the movable core surface, and the like also cause the variation in the injection amount of the fuel injection valve. Therefore, it is possible to correct the injection quantity variation due to the deterioration of each fuel injection valve by performing individual difference learning when the predetermined condition is satisfied and reflecting the learning result in the subsequent injection quantity control. For this individual difference learning, for example, a technique of measuring a closing time of a fuel injection valve in a state where an engine state is stable such as idling is known.

Disclosure of Invention

Problems to be solved by the invention

However, the individual difference learning described in patent document 1 is assumed to be a case where the fuel injection valve is good in the market, and the individual difference learning is performed 1 time after the engine is started. That is, since the individual difference learning is performed after the engine is started and the learning result is reflected in the subsequent injection amount control, the injection amount correction cannot be performed if the learning condition is not satisfied.

As a result, an output difference occurs between cylinders of the engine, and thus torque fluctuation increases, which may cause problems such as poor fuel efficiency and increased engine vibration.

Further, in the case where the individual difference learning is not completed, the half-lift control cannot be performed in the region where the extremely small injection is required, and the exhaust performance may be caused to deteriorate.

In general, the individual difference learning of the fuel injection valve is performed by actually starting the engine in an engine assembly line or a vehicle assembly line. In addition, even when the fuel injection valve is replaced with a new one in the market, the engine is started to perform learning. Therefore, the individual difference learning performed during operation desirably employs the learning frequency in consideration of the deterioration of the fuel injection valve.

Therefore, an object of the present invention is to provide a fuel injection control device and a control method thereof, which control a fuel injection valve of an internal combustion engine, can realize injection amount control according to the degree of deterioration of the fuel injection valve, and has high efficiency and high reliability.

Means for solving the problems

In order to solve the above problem, the present invention provides a fuel injection control device for controlling a fuel injection valve of an internal combustion engine, the fuel injection control device including: a deterioration determination unit that determines a deterioration state of the fuel injection valve; an injection amount learning unit that learns an injection amount of the fuel injection valve; and a learning frequency changing unit that changes a learning frequency of the injection amount learning unit according to a deterioration state of the fuel injection valve.

Further, the present invention is a fuel injection control method of controlling a fuel injection valve of an internal combustion engine, the fuel injection control method comprising: counting the number of injections by the fuel injection valve; a step (b) of estimating a deterioration state of the fuel injection valve from the number of injections counted in the step (a); and (c) correcting the injection quantity of the fuel injection valve based on the degradation state of the fuel injection valve estimated in the step (b).

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to realize a fuel injection control device that controls a fuel injection valve of an internal combustion engine, that can realize injection amount control according to the degree of deterioration of the fuel injection valve, that is high in efficiency and that is high in reliability, and a control method thereof.

This can suppress problems such as poor fuel efficiency and engine vibration caused by deterioration of the fuel injection valve.

Problems, configurations, and effects other than those described above will be apparent from the following description of the embodiments.

Drawings

Fig. 1 is an overall configuration diagram showing a basic configuration of an internal combustion engine according to an embodiment of the present invention.

Fig. 2 is a basic configuration diagram of the fuel injection control device 127 in fig. 1.

Fig. 3 is a diagram showing a configuration example of the fuel injection valve 105 in fig. 1.

Fig. 4 is a diagram showing an example of individual difference learning of the fuel injection valves.

Fig. 5 is a diagram showing an operation example of the injection counter.

Fig. 6 is a diagram showing an example of the operation timing of the injection counter.

Fig. 7 is a diagram showing a relationship between a deterioration state of the fuel injection valve and the number of injections.

Fig. 8 is a flowchart showing a control method (control flow) from the deterioration degree determination to the individual difference learning implementation.

Fig. 9 is a diagram showing a degradation state estimation method based on the drive current of the fuel injection valve.

Fig. 10 is a diagram illustrating a degradation state estimation method based on the fuel pressure in the combustion chamber.

Fig. 11 is a diagram showing a degradation state estimation method based on an injection pulse width of a fuel injection valve.

Fig. 12 is a diagram illustrating a degradation state estimation method based on the engine speed.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted for redundant parts.