JPH082448Y2 - Engine controller - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a control device for an engine that determines the operating state of the engine according to the opening of a throttle valve and controls the fuel injection amount. .

[Conventional technology]

In recent engines, in order to improve the combustion state and reduce the fuel consumption amount, feedback control of the fuel injection amount and increase of the fuel injection amount are performed based on the operating state of the engine.
Controls such as fuel cut are being performed. Particularly in rotary engines and high-power engines, surging and backing are likely to occur due to low combustion stability in the light load region, so the operating state of the engine should be accurately determined, and based on this, It is necessary to control the fuel injection amount and the like.

By the way, the operating state of the engine can be determined according to the intake air amount of the engine, but when the intake air amount is small, this intake air amount must be detected with high accuracy using an air flow meter or a boost pressure detector. Is difficult. Therefore, in the related art, the one in which the opening degree of the throttle valve is detected and the operating state of the engine is determined based on this is often used.

On the other hand, when the throttle valve is fully closed, the opening degree of the throttle valve from a predetermined reference position, that is, the fully closed throttle valve opening degree is adjusted based on the idling speed, and therefore varies from engine to engine. . Therefore, as disclosed in, for example, Japanese Patent Laid-Open No. 56-107926, a fully closed throttle valve opening detection device for detecting the fully closed state of the throttle valve by learning is proposed for each engine. There is.

When the fully closed state of the throttle valve is detected using such a fully closed throttle valve opening detection device, the determination of the operating state of the engine is performed by determining the throttle valve opening from the fully closed state, that is, the absolute value. It is performed based on the difference between the throttle valve opening and the fully closed throttle valve opening.

[Problems to be solved by the device]

However, the intake air amount of the engine with respect to the absolute throttle valve opening is generally 2 as shown in FIG.
It has a characteristic of a quadratic curve or a sine curve.
Therefore, when the absolute throttle valve opening at the time of full closing is different, for example, the change amounts y _{1 to} y ₃ of the intake air amount with respect to the difference x between the same absolute throttle valve opening and the fully closed throttle valve opening are mutually different. Not equal.

Therefore, if the engine operating state is determined based on the throttle valve opening from the fully closed state as described above, it is difficult to improve the operating state determination accuracy. .

[Means for solving the problem]

In order to solve the above problems, an engine control device according to the present invention includes an absolute throttle valve opening detecting means for detecting an absolute throttle valve opening which is an opening from a predetermined reference position in a throttle valve, and a throttle. A fully closed throttle valve opening learning means for learning the fully closed throttle valve opening when the valve is fully closed, the detected absolute throttle valve opening, and the learned fully closed throttle valve opening. And an operating state determining means for determining the operating state of the engine according to the difference between the absolute state and the absolute value detected by the absolute throttle valve opening detecting means at least as the fully closed throttle valve opening obtained by learning is larger. A slot that performs correction to increase the difference between the throttle valve opening and the learned throttle valve opening at full closing. Torque valve opening correction means and operating state determination correction means for performing correction so that the larger the fully closed throttle valve opening obtained by learning, the smaller the threshold for operating state determination in the operating state determination means. It is characterized by having either one of.

[Action]

With the above configuration, the fully closed throttle valve opening when the throttle valve is fully closed can be accurately detected by the learning of the fully closed throttle valve opening learning means even if it varies depending on individual engines.

Then, at least when the fully closed throttle valve opening obtained by the learning by the throttle valve opening correction means is larger, the absolute throttle valve opening detected by the absolute throttle valve opening detection means and the fully closed time learned. The larger the difference from the throttle valve opening is corrected, or the larger the fully closed throttle valve opening obtained by learning is obtained by the operation state determination correction means, the more the operation state determination means determines the operation state. Since the correction is performed so that the threshold value becomes smaller, the operating state of the engine can be determined with high accuracy.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

An intake passage 12 for supplying intake air is connected to the engine body 11 as shown in FIG. An air cleaner 13, an air flow meter 14, a throttle valve 15, and a fuel injection valve 16 are sequentially provided in the intake passage 12.
This throttle valve 15 has
As the absolute throttle valve opening which is the opening from the predetermined reference position in the
A throttle valve opening sensor 17 which is an absolute throttle valve opening detecting means for detecting a rotation angle from a direction perpendicular to the longitudinal direction of the is provided.

Further, a rotation speed sensor 18 is attached to the engine body 11, and an exhaust passage 19 for discharging combustion gas is connected to the engine body 11. The exhaust passage 19 is provided with an O ₂ sensor 20 that detects the oxygen concentration in the combustion gas.

Air flow meter 14, throttle valve opening sensor 1
7, the rotation speed sensor 18, and the O ₂ sensor 20 are connected to the control device 21, and the control device 21 is connected to the fuel injection valve 16.

The control device 21 includes a fully closed throttle valve opening learning unit that learns a fully closed throttle valve opening when the throttle valve 15 is fully closed, a detected absolute throttle valve opening and a learned fully closed valve. The difference between the opening time of the throttle valve opening and the operating state determination means for determining the operating state of the engine according to the engine speed detected by the rotation speed sensor 18, and the fully closed throttle valve opening obtained by learning are The larger the value, the smaller the operating state determination threshold in the operating state determination means becomes, and the operating state determination correction means that performs correction so that the correction is performed, and the fuel based on the signals from the air flow meter 14 and the O ₂ sensor 20 is used. The fuel injection amount by the injection valve 16 is controlled.

In the above configuration, the intake air flowing into the intake passage 12 via the air cleaner 13 further circulates via the air flow meter 14, and the fuel injected from the fuel injection valve 16 is mixed to form an air-fuel mixture, which is supplied to the engine body 11. Inhaled. The air-fuel mixture sucked into the engine body 11 burns in a cylinder (not shown) of the engine body 11 to generate a rotational force, and then is discharged from the exhaust passage 19.

The fuel injection amount of the fuel injection valve 16 is controlled by the control device 21.
Is controlled as follows.

First, as shown by the solid line in FIG. 2, the learning value of the absolute throttle valve opening detected by the throttle valve opening sensor 17 and the fully closed throttle valve opening to be described later based on a preset operating state determination map. The operating state of the engine is determined based on the difference between the engine speed and the engine speed detected by the engine speed sensor 18.

The operating state of this engine is, for example, a feedback zone for injecting fuel according to the intake air amount detected by the air flow meter 14 so that the oxygen concentration in the exhaust gas detected by the O ₂ sensor 20 becomes a predetermined value. Divided into a fuel increase zone that injects fuel that is increased by a predetermined amount from the injection amount in the feedback zone, and a fuel cut zone that stops fuel injection and decelerates without generating driving force for external loads. Has been. Then, the control device 21 controls the fuel injection valve according to each operating state.
Controls the fuel injection amount by 16.

Further, in the control device 21, learning of the fully closed throttle valve opening and correction of the threshold value for operating state determination are performed according to the flowchart shown in FIG.

First, it is checked whether or not the learning condition for the fully closed throttle valve opening is satisfied, and if it is not satisfied, the routine directly returns (S11). That is, when the engine cooling water temperature is low or the air conditioner is operating, the throttle valve 15 is controlled so as not to be fully closed. Do not learn the throttle valve opening when closed.

If it is determined in S11 that the learning condition for the fully closed throttle valve opening is satisfied, the process proceeds to S12 to start the operation of the learning timer, and in S13, the throttle valve is opened until the learning timer times out. The average value TVOA of the absolute throttle valve opening output from the opening sensor 17 is obtained. That is, the influence of overshoot, vibration, etc., when the throttle valve 15 is rotated is eliminated.

Next, in S14, it is checked whether or not S11 to S13 have been performed a predetermined number of times N. If N times have not been performed, the process returns to S11, and if N times have been performed, the process proceeds to S15. In S15, S1
Further, the average value TVOB of the N absolute throttle valve opening average values TVOA calculated in 7 is calculated.

Then, in S16, it is checked whether the average value TVOB of the absolute throttle valve opening is equal to or smaller than the preset upper limit value TVO _max . If it is determined in S16 that the average value TVOB of the absolute throttle valve opening is larger than the upper limit value TVO _{max, the} process proceeds to S18, and the upper limit value TVO _max.
Set _max as the learning value for the throttle valve opening when fully closed.

At S16, the average value TVOB of the absolute throttle valve opening is
If it is determined that it is equal to or smaller than the upper limit value TVO _max , the process proceeds to S17, and the average value TVOB of the absolute throttle valve opening is set to the preset lower limit value.
Check if it is greater than or equal to TVO _min . If it is determined in S17 that the average value TVOB of the absolute throttle valve opening is smaller than the lower limit value TVO _min , the process proceeds to S19, and the lower limit value TVO _min is set as the learning value of the throttle valve opening at full closing.

If it is determined in S17 that the average value TVOB of the absolute throttle valve opening is equal to or larger than the lower limit value TVO _{min, the} process proceeds to S20 and the average value TVOB of the absolute throttle valve opening is fully closed. Set as a learning value for the hour throttle valve opening.

That is, when the average value TVOB of the absolute throttle valve opening is larger than the preset upper limit value TVO _max or smaller than the lower limit value TVO _min , the average value TVOB of the absolute throttle valve opening is an abnormal value. Therefore, the upper limit value TVO _max or the lower limit value TVO _min is set as the learning value without learning.

When the learning value of the throttle valve opening at full closing is set in S18, S19, or S20 as described above, in S21, the threshold of the operating condition determination map is determined based on the threshold correction map shown in FIG. Correct the value. That is, the larger the fully closed throttle valve opening obtained by learning, the smaller the threshold value for operating condition determination, as indicated by the broken line in FIG.

As described above, even when the intake air amount of the engine with respect to the absolute throttle valve opening changes in a quadratic curve or a sine curve, the operation state determination map according to the magnitude of the throttle valve opening in the fully closed state can be used. Since the threshold value is corrected, the driving state can be accurately determined.

In the present embodiment, the example in which the correction is performed such that the larger the fully closed throttle valve opening obtained by learning is, the smaller the threshold value of the driving state determination in the driving state determination means is described. The judgment of the state is
It is performed by comparing the threshold value of the operating state judgment with the difference between the absolute throttle valve opening and the learning value of the throttle valve opening at the time of full closing, so that the control device 21 functions as a throttle valve opening correction means. The larger the fully closed throttle valve opening obtained by learning, the larger the difference between the absolute throttle valve opening detected by the absolute throttle valve opening detection means and the learning value of the fully closed throttle valve opening. The same effect can be obtained even if correction is performed so as to increase.

Further, the determination of the operating state is not limited to the above-described three zones, but the fuel increase zone may be subdivided according to the degree of fuel increase, or the fuel cut zone may be limited to some cylinders or rotors. On the other hand, it may be subdivided into cases where fuel injection is stopped and cases where fuel injection is stopped for all cylinders or rotors.

Furthermore, as the parameter for determining the operating state, other parameters may be used instead of the engine speed.
Further, only the difference between the absolute throttle valve opening and the learning value of the fully closed throttle valve opening may be used as a parameter.

On the other hand, learning of the fully closed throttle valve opening is not limited to learning with respect to the absolute throttle valve opening, but is performed with respect to a deviation amount from a preset predetermined reference fully closed throttle valve opening, for example. But it's okay.

[Effect of device]

The engine control device according to the present invention is, as described above,
Absolute throttle valve opening detection means for detecting an absolute throttle valve opening, which is the opening of the throttle valve from a predetermined reference position, and full learning for fully closed throttle valve opening when the throttle valve is fully closed. The throttle valve opening degree learning means for closing, the operating state determining means for determining the operating state of the engine according to the difference between the detected absolute throttle valve opening degree and the learned throttle valve opening degree at full closing At the same time, the larger the fully closed throttle valve opening obtained by learning, the larger the difference between the absolute throttle valve opening detected by the absolute throttle valve opening detection means and the learned fully closed throttle valve opening. Throttle valve opening correction means that corrects to a larger value and fully closed throttle obtained by learning As lube opening is large, out of the operating condition determining correction means for correcting such threshold is reduced in the operating condition determining in operation state judgment means, it is configured to include either.

As a result, the throttle valve opening at the time of full closing when the throttle valve is fully closed is accurately detected, and at least one of the throttle valve opening correction means and the operating state determination correction means corrects it. Therefore, the operation state of the engine can be determined with high accuracy.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is an explanatory diagram showing the configuration of an engine equipped with a control device. FIG. 2 is an explanatory diagram showing a driving state determination map. FIG. 3 is a flowchart showing the operation performed by the control device. FIG. 4 is a graph showing the correction rate of the threshold value for determining the driving state. FIG. 5 is a graph showing the relationship between the absolute throttle valve opening and the intake air amount in the conventional example. Reference numeral 11 is an engine body, 15 is a throttle valve, 17 is a throttle valve opening sensor (absolute throttle valve opening detection means), 21 is a control device (throttle valve opening learning means when fully closed, operating state determination means, operating state determination) Correction means).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F02D 45/00 364 G

Claims (1)

[Scope of utility model registration request] 1. An absolute throttle valve opening detecting means for detecting an absolute throttle valve opening which is an opening of a throttle valve from a predetermined reference position, and a throttle valve opening at the time of fully closing when the throttle valve is fully closed. The throttle valve opening learning means for fully closing the engine, the operating state for judging the engine operating state according to the difference between the detected absolute throttle valve opening and the learned throttle valve opening for fully closing The determination means is provided, and at least as the fully closed throttle valve opening obtained by learning is larger, the absolute throttle valve opening detected by the absolute throttle valve opening detection means and the fully closed throttle valve opening learned. The throttle valve opening correction means that performs correction so that the difference between the One of the operating state determination correction means for performing correction so that the threshold value of the operating state determination in the operating state determination means decreases as the opening degree of the closed throttle valve increases. Control device for the engine.