JP2905936B2 - Engine control device - Google Patents

Description

The present invention relates to an engine control device.

(Prior Art) Generally, in an engine, the opening degree of a throttle valve is an important factor in fuel control, rotation speed control, and the like. In order to maintain each control accuracy at a high level, the opening of the throttle valve is generally high. It is necessary to always accurately grasp the fully-closed angle (fully-closed position) serving as a reference for the degree. Further, since the opening of the throttle valve gradually changes due to aging or the like due to long-term use, it is important to always update and set the latest value. From such a viewpoint, conventionally, when the throttle valve is at the fully closed position, it is widely practiced to sequentially learn the output of the throttle opening degree sensor at that time and store it as the latest fully closed angle information.

On the other hand, such full-closed angle learning needs to be performed for each revolution of the engine, and it is convenient to perform this at the time of deceleration of the engine. In such a case, the deceleration state is accurately determined. It is necessary. There are various methods for determining such a deceleration state. One of the methods is, for example, as disclosed in Japanese Utility Model Publication No. 54-14826, based on the charging efficiency of the engine. If is lower than a preset value set for each engine speed, a method for determining this as a deceleration state is known.

The method of determining the deceleration based on the charging efficiency will be briefly described with reference to FIG. 4. First, the charging efficiency when the throttle valve is fully closed for each rotation speed of the engine is determined in advance, and this is calculated. In addition to the closed line (that is, the throttle opening is considered to be fully closed in a lower filling efficiency region than the fully closed line), and in the actual control, A fully-closed determination line serving as a reference for deceleration determination is provided on a slightly higher filling efficiency side than the fully-closed line. If the charging efficiency at a certain engine speed is on the lower charging efficiency side than the fully closed determination line, it is determined that the vehicle is in the deceleration operation state.

(Problems to be Solved by the Invention) However, when the deceleration is determined based on the charging efficiency as described above and the fully closed angle of the throttle valve is learned at the time of deceleration, especially in a region where the engine speed is close to the idle speed. However, there is a concern that the learning accuracy is reduced for the following reasons.

That is, as shown in FIG. 4, the fully-closed line has such a characteristic that the filling efficiency decreases as the position shifts from the predetermined position (point a) corresponding to the idling speed to the high speed side. On the other hand, the charging efficiency corresponding to each engine speed when the engine is operated with no load or with load, as shown by the no-load operation line and the with-load operation line, respectively, , The charging efficiency tends to gradually increase as the position shifts to the side, and the always-loaded operation line is located on the high charging efficiency side between them. Therefore, the loaded operation line and the no-load operation line are close to each other in the low rotation speed range. b and point c
Will intersect.

Although such a phenomenon is a very important point in learning control as described later, conventionally, the detection filling efficiency is higher than that of the fully closed determination line in either the loaded operation or the no-load operation. When it is located on the low filling efficiency side, the full closing angle learning was uniformly executed, so no problem occurs in the high rotation speed range, but in the low rotation speed range, for example, in the no-load operation state is a, for example, the deceleration state at low rotational side of the engine speed ne ₂ corresponding to the point c (i.e., stock torr valve fully closed) a is the one or no-load operation (i.e., a state in which the throttle valve is slightly opened) It is difficult to determine whether or not this is the case. In some cases, this may be erroneously determined to be a deceleration operation despite the no-load operation, and the fully closed angle learning may be performed. Further, in the same manner to the no-load operating state, a deceleration state in the low rotational side of the engine speed ne ₁ corresponding to the point b (i.e., the throttle valve is fully closed) or in the non of whether or chromatic load operation is Is difficult to determine, and in some cases, the operation may be erroneously determined to be the deceleration operation despite the loaded operation, and the full closing angle learning may be performed. By performing such erroneous learning, the accuracy of the fully closed angle learning may be reduced, which may adversely affect the operation control of the engine.

Technique of this as that one way to deal with problems, and performed only in the high rotational speed side than the rotational speed ne ₂ corresponding full close angle learning point c, to prohibit it in than this lower rotational speed side However, in such a case, since the range of the number of revolutions at which the full-closed angle learning can be performed is narrow, the frequency of the learning is low, and as a result, the learning accuracy is a bottleneck. I was

Therefore, in the present invention, the possible range of the fully closed angle learning is expanded to a lower rotation side to increase the learning frequency, thereby further improving the learning accuracy.

(Means for Solving the Problems) In the present invention, as specific means for solving the problems, (I) In the invention described in claim 1, the opening degree of the throttle valve is detected and a signal corresponding thereto is detected. The opening degree detecting means for outputting, the charging efficiency detecting means for detecting the charging efficiency of the engine based on the intake air amount and the engine speed, and the detected charging efficiency detected by the charging efficiency detecting means are predicted for each engine speed. An engine control device comprising: a learning unit that sequentially learns an opening signal output from the opening detection unit as a fully closed angle of the throttle valve when the opening signal is lower than a preset set value. A connection state detection means for detecting a connection state with the drive system is provided. When the connection state detection means detects a non-connection state, learning by the learning means is performed. (II) In the invention according to the second aspect, in the invention according to the first aspect, when the connection state detecting means detects a non-connection state between the engine and its drive system. Even if the engine speed is equal to or higher than the predetermined speed, learning by the learning means is performed.

(Operation) In the invention of the present application, the following operation is obtained because of such a configuration.

(I) According to the first aspect of the invention, the charging efficiency of the engine is less than a predetermined value, and the charging efficiency is determined to be in the deceleration operation region (that is, the throttle valve is fully closed). However, if a no-load operation state of the engine is detected, the learning of the fully closed angle of the throttle valve is prohibited, and this is executed only in the loaded operation state. Is completely eliminated, for example, as compared with the case where the full-closed angle learning is performed even under the no-load operation state, so that the possible range of the full-closed angle learning is expanded.

(Ii) According to the second aspect of the present invention, even in the no-load operation state, the fully closed angle learning is executed in a region of a predetermined rotation speed or more where there is no risk of erroneous learning.
Compared with the case described in the above (i), the range in which the full-closed angle learning is possible is further expanded by the amount of the learning performed under the no-load operation state.

(Effects of the Invention) Therefore, according to the engine control device of the present invention, the following effects can be obtained.

According to the engine control device of the first aspect, the frequency of detection of the fully closed angle during learning is increased by an amount corresponding to the expansion of the possible range of the fully closed angle learning, so that more accurate learning control is possible. The effect of being squeezed can be obtained.

According to the engine control device of the second aspect, the possible range of the full-closed angle learning is further expanded and the frequency of detecting the full-closed angle is further increased as compared with the case described above. The advantage is that the angle learning can be performed if possible.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

First Embodiment FIG. 1 shows an automobile engine 1 provided with a control device according to an embodiment of the invention as set forth in claim 1 of the present application, and a control system thereof. An intake passage 3 is an exhaust passage. The intake passage 2 is provided with an air flow sensor 4 and a throttle valve 5 whose opening is detected by a throttle opening sensor 11. In addition to the water temperature sensor 6 provided in the cylinder block 1a, the engine 1 has a crank angle sensor.
10 are located. Further, the drive system of the engine 1 is provided with a brake switch 7, a clutch switch 8, and a neutral determination switch 9. The engine 1 of this embodiment is mounted on an M / T transmission type vehicle, and the clutch switch 8 is ON (that is, the clutch is depressed) and the neutral determination switch 9 is in the neutral position. Is detected (step S7 in FIG. 2), but for example, in a vehicle mounted on an A / T transmission type vehicle, only the neutral determination switch 9 is used. It is possible to determine the no-load operation state (that is, to determine the no-load operation in the neutral or parking mode).

In the engine 1 configured as described above, the fully closed angle learning of the throttle valve 5 is performed by the control unit 20 in accordance with the operating state of the engine 1 detected by the sensors. In this case, the invention described in claim 1 of the present application is applied, and when the charging efficiency of the engine is equal to or less than a predetermined value and the throttle valve 5
Is fully closed and learning is performed only when the engine 1 is in a loaded operation state.

Hereinafter, the actual operation of the fully closed angle learning will be described with reference to the flowchart of FIG. 2 and FIG.

After the start of the control, as a premise of the control, the fully closed throttle opening thidl is set to a predetermined value (k ₀ ) corresponding to the current engine water temperature (step S1).

Next, the current engine speed (Ne), TVO sensor output (thopn), airflow sensor output (vs) corresponding to the intake air amount, brake switch signal (xbrk), clutch switch 8 and neutral determination A no-load switch signal (xnld) composed of a combination of switches 9 is read (steps S2 to S7). Then, based on the air flow sensor output (VS) and the engine speed (Ne) of the detected values, the current charging efficiency (ce = VS / N)
e · K) is calculated (step S8).

Next, it is determined whether or not the current engine water temperature (thw) is higher than a predetermined value A (step S9). If (thw <A), the fully closed angle is considered in consideration of a malfunction of the thermowax. Does not transition to learning.

On the other hand, if (thw> A), then step S10
, The charging efficiency (ce) at the current engine speed Ne is compared with a preset set value (sipol) (this set value (sipol) is determined on the fully closed determination line shown in FIG. 4). Shows the filling efficiency). And ce <sipo
l, the charging efficiency corresponding to the current engine speed Ne is on the higher charging efficiency side than the fully closed determination line, and therefore, it is determined that the engine is not in the deceleration operation state. Does not transition to

On the other hand, if ce> sipol, it is determined that the engine is currently being decelerated, and then the current engine speed Ne is compared with a settable speed (ne ₁ ) that can be learned (step S11). ). The set speed ne ₁ is a speed corresponding to the intersection b between the fully closed determination line and the loaded operation line as shown in FIG. 4, and is lower than the set speed ne ₁ . Is a risk of erroneous learning as described above. Accordingly, Ne <does not enter the full-close learning side in order to avoid erroneous learning when it is ne _1, Ne> shifts the first time to the next control in the case of ne _1.

Next, in order to complete the determination of the deceleration state, it is further determined whether or not the brake is currently applied (xbrk = 1) (step S12). If xbrk ≠ 1, it is determined that the vehicle is in the deceleration region from the viewpoint of the charging efficiency but has not yet completely shifted to the deceleration operation. In this case, the process does not shift to the fully closed angle learning, When xbrk = 1, it is determined that the vehicle is completely decelerated for the first time. Then, in step S13, it is determined whether the vehicle is currently in a no-load operation state (that is, xnld =
1 is determined, and when xnld = 1 (ie, no-load operation state), fully closed angle learning is not performed, and when xnld ≠ 1 (ie, with load operation state), The transition to fully closed angle learning for the first time and the current throttle valve opening (tvop
n) is learned as the fully closed angle (thidl) (step S1)
Four).

In this way, for example, even if it is determined that the engine 1 is in the no-load operation state even if it is determined that the engine is in the deceleration operation state (that is, the throttle valve is fully closed) from the viewpoint of the engine charging efficiency, the throttle valve is opened. By prohibiting the full-closed angle learning of the degree and executing it only in the loaded operation state, the range of the minimum engine speed at which the fully-closed learning without erroneous learning is possible is set to the rotation speed ne ₂ (FIG. 4). from the lowest engine speed) in the conventional control to the rotational speed ne ₁ in which it is possible to expand the low-rotation. Therefore, as compared with the conventional case, the frequency of detecting the fully closed angle at the time of the fully closed angle learning increases by an amount corresponding to the shift of the learnable rotation speed to the low rotation side,
As a result, the learning accuracy is improved, which can contribute to the improvement of the control accuracy of the engine fuel control or the rotational speed control.

Second Embodiment Next, control in an engine control device according to an embodiment of the invention as set forth in claim 2 of the present application will be described with reference to FIG. 3. The control in this embodiment is the same as that in the first embodiment. In the control, the fully closed angle learning was completely prohibited when the engine was running with no load, but in the range where there was no risk of erroneous learning even in the no-load operation state. Increases the detection frequency of the full-close angle during full-close angle learning by performing full-close angle learning,
Thus, the control accuracy of the fully closed angle learning is further improved. That is, as a criterion of the execution of all the close angle learning, has two reference rotational speed of the rotational speed ne ₂ corresponding to the rotational speed ne ₁ and the point c which corresponds to the point b of FIG. 4, in a load-driving state during deceleration performs all close angle learning only in the rotational speed ne ₁ or more regions, the rotation speed is in the no-load operation state ne ₂
The full-closed angle learning is performed in the above-described region, thereby further increasing the detection frequency of the full-closed angle and eliminating erroneous learning.

Specifically, after determining whether or not the vehicle is in a deceleration state from the charging efficiency in step Q10 of FIG. 3, it is next determined whether or not the vehicle is in a no-load operation state (step Q11). And xnl
When d ≠ 1 (loaded operation), the rotation speed ne is less than or equal to ₁ , and when xnld = 1 (no load operation), the rotation speed ne
All close angle learning in the ₂ following regions, respectively is not performed, to allow for the first time all close angle learning in rotational speed ne ₂ or more regions in and rotational speed ne ₁ or more areas and no-load operation with a load-operation, in this case After the deceleration operation is confirmed in step Q14, the fully closed angle learning is executed (step
Q15).

With such control, erroneous learning of the fully closed angle is completely eliminated in both the loaded operation and the no-load operation.

[Brief description of the drawings]

1 is a longitudinal sectional view of an essential part of an engine provided with a control device according to a first embodiment of the present invention, FIG. 2 is a control flowchart thereof, FIG. 3 is a control flowchart of a control device according to a second embodiment, FIG. 4 is a deceleration characteristic diagram with respect to the charging efficiency. DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Intake passage 3 ... Exhaust passage 4 ... Air flow sensor 5 ... Throttle valve 6 ... Water temperature sensor 11 ... Throttle opening sensor 20 ... Control unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-196142 (JP, A) JP-A-2-161137 (JP, A) JP-A-63-223356 (JP, A) JP-A-4- 60152 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) F02D 45/00

Claims (2)

(57) [Claims] An opening degree detecting means for detecting an opening degree of a throttle valve and outputting a signal corresponding thereto, a charging efficiency detecting means for detecting an engine charging efficiency based on an intake air amount and an engine speed, When the detected charging efficiency detected by the charging efficiency detecting means is lower than a preset value set for each engine speed, the opening signal output from the opening detecting means is changed to the fully closed angle of the throttle valve. A control device for an engine, comprising: learning means for learning sequentially as a connection state, wherein a connection state detection means for detecting a connection state between the engine and its drive system is provided, and the disconnected state is detected by the connection state detection means. An engine control device characterized in that learning by the learning means is prohibited in such a case. 2. The learning means according to claim 1, wherein even when the connection state detecting means detects a disconnected state between the engine and its drive system, if the engine speed is equal to or higher than a predetermined speed. A control device for an engine, wherein learning by the engine is performed.