JPH0733805B2 - Acceleration / deceleration determination device for internal combustion engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an acceleration / deceleration determination device for an internal combustion engine used for fuel injection control and the like.

<Prior Art> The following is a conventional example of an electronically controlled fuel injection device for an internal combustion engine in which an acceleration / deceleration determination device is used (see Japanese Utility Model Laid-Open No. 60-066558).

That is, the basic injection amount Tp = K × Q / N from the intake air flow rate Q detected by the air flow meter and the engine rotation speed N.
(K is a constant) and at the same time, after calculating various correction coefficients COEF mainly according to the water temperature, the air-fuel ratio feedback correction coefficient α and the correction coefficient Ts based on the battery voltage, the fuel injection amount Ti = Tp × during steady operation Calculate COEF x α + Ts.

Then, for example, in a single point injection system (hereinafter referred to as SPI method), an injection pulse signal having a pulse width corresponding to the fuel injection amount Ti is output to the fuel injection valve in synchronization with an ignition signal or the like every 1/2 revolution of the engine. Supply fuel to the engine.

Further, the acceleration judgment is performed at regular intervals (for example, 10 msec) from the rate of change of the intake throttle opening to calculate the increased injection amount during acceleration, and the increased injection amount is added to the fuel injection amount Ti to accelerate the fuel. The engine output is increased by increasing the time.

Further, the acceleration increase is also performed by interrupt injection that is performed by interrupting the injection pulse during acceleration between the normal injection pulse signals.

Also, during deceleration operation, deceleration determination is performed based on the rate of change to achieve deceleration reduction.

<Problems to be Solved by the Invention> By the way, since the acceleration determination is performed at regular intervals based on the change rate of the intake throttle opening detected by the intake throttle opening sensor, the following problems occur.

That is, since the intake throttle valve opening sensor generates a sliding noise until the intake throttle valve opening changes by about 1 ° within the fixed time, the detection / separation capability is low and the detection / separation capability is low within the fixed time.
In slow acceleration / deceleration operation that changes by ≤ °, it is not possible to accurately detect the acceleration / deceleration operation state due to the effect of the sliding noise. Therefore, in the past, the intake throttle valve was opened during the fixed time, that is, 10 msec. Degree is greater than 1 °,
For example, when the acceleration / deceleration operation state is changed by 1.6 ° or more, it is determined that the engine is in the acceleration / deceleration operation state, the erroneous determination due to the sliding noise is prevented, and the acceleration / deceleration operation state of the engine is surely detected. .

However, if the output of the intake throttle valve opening sensor is momentarily cut off, the instantaneous change causes the intake throttle valve opening degree to change by 1.6 ° or more within the fixed time, and for example, deceleration determination is made even during steady operation. There was a problem that the deceleration amount was reduced and the driving performance deteriorated.

The present invention has been made in view of such circumstances, and an internal combustion engine that can reduce the frequency of erroneous determination of acceleration / deceleration operation even if the output of load detection means such as an intake throttle valve opening sensor is momentarily cut off An object is to provide an acceleration / deceleration determination device.

<Means for Solving Problems> Therefore, according to the present invention, as shown in FIG. 1, the load detection means A for detecting the engine load, and the load for each predetermined sampling period by inputting the detection signal. The load change amount calculation means B for calculating the change amount and the load change amount calculated above are added at least once based on the fact that the load change amount is larger than the first reference value.
The first acceleration / deceleration operation start determination means C that determines that the deceleration operation has started, and the calculated load change amount is greater than a second reference value that is smaller than the first reference value at least twice consecutively. The second acceleration / deceleration operation start determination means D for determining that the acceleration / deceleration operation is started based on the above.

<Operation> As described above, when the first acceleration / deceleration operation start determination means C detects that the calculated load change amount is larger than the first reference value at least once, the rapid acceleration / deceleration operation is immediately performed. While it is determined that the deceleration operation has started, the load change amount calculated by the second acceleration / deceleration operation start determination means D is
A second value smaller than the first reference value at least twice consecutively.
Only when it is detected that the value is larger than the reference value, it is determined that the acceleration / deceleration operation is started. As a result, the frequency of erroneous acceleration / deceleration determination due to momentary interruption in the steady operation state is suppressed without impairing the rapid acceleration / deceleration property during rapid acceleration / deceleration.

<Embodiment> An embodiment of the present invention will be described below with reference to FIGS. The present embodiment will be described by taking the fuel injection control as an example.

In FIG. 2, for example, a control device 1 including a microcomputer outputs an ignition signal (rotation speed signal) output from an ignition coil 2, an intake air flow rate signal output from an air flow meter 3, and a water temperature sensor 4. Intake throttle valve opening sensor 5 as cooling water temperature signal and load detection means
And an intake throttle valve opening signal output from. The control device 1 operates according to the flowcharts shown in FIGS. 3 to 5, and outputs the injection pulse signal and the interrupt injection pulse signal to the drive circuit 7 of the fuel injection valve 6.

Here, the control device 1 constitutes a load change amount calculation means, a first acceleration / deceleration operation start determination means, and a second acceleration / deceleration operation start determination means.

Next, the operation will be described with reference to the flowcharts of FIGS.

This flow chart is started when a start signal is input every 10 msec. In addition, in the acceleration / deceleration determination (flow chart) of the present embodiment, the instantaneous interruption and the acceleration / deceleration operation start state are used by utilizing the fact that the instantaneous interruption is unlikely to occur twice consecutively (or continuously for a long time). To determine. That is, a relatively small opening change rate Δα indicating the acceleration / deceleration operation state (second
The acceleration / deceleration start operation state is determined only when the reference value) is detected twice consecutively.

On the other hand, at the start of the sudden acceleration / deceleration operation, waiting for two consecutive detections as described above,
The deterioration of drivability due to the delay in shifting to the acceleration / deceleration control becomes noticeable, and as soon as a relatively large opening change rate Δα (a first reference value described later) indicating the rapid acceleration / deceleration operation state is detected, It determines that sudden acceleration / deceleration operation has started, and makes a quick transition to acceleration / deceleration control to prevent deterioration of drivability.

In S1, the intake throttle valve opening detected by the intake throttle valve opening sensor 5 is read.

In S2, the opening change rate Δα of the intake throttle valve during the sampling period (for example, 10 msec) is calculated based on the intake throttle valve opening detected this time and the previous time.

At S3, the calculated opening change rate Δα and the second reference value (the second reference value (the reference value for absorbing the sliding noise) described above)
Compared with the standard opening of 1.6 °, and if Δα> 1.6 °, it is not possible to immediately determine whether an instantaneous interruption has occurred or the start of acceleration operation, so proceed to S4. On the other hand, when Δα ≦ 1.6 °, the process proceeds to S5 for determination in deceleration operation.

In S4, it is determined whether or not it is the first acceleration determination after the start of the acceleration operation, and if YES, the process proceeds to S6 to determine whether or not the rapid acceleration operation is started. On the other hand, in the case of NO, since it is unlikely that the instantaneous interruption will occur twice in succession (continuously for a long time), it is judged that the engine is definitely in the acceleration operation start state, and the process proceeds to S7 to shift to the acceleration operation control. move on.

In S6, the calculated opening change rate Δα is compared with the first reference value 2.4 ° as the first reference value (reference value for determining whether or not the sudden acceleration / deceleration operation is started), and Δα> When it is 2.4 °, it is judged that the rapid acceleration operation is started, and the process immediately proceeds to S7 to shift to the acceleration operation control. On the other hand, when Δα ≦ 2.4 °, it is avoided to immediately judge whether it is an instantaneous interruption or the start of acceleration operation, and the process proceeds to S8. In other words, in acceleration states other than sudden acceleration, even if the acceleration determination is delayed once, it does not significantly affect the drivability. Therefore, in order to reliably prevent the above-mentioned erroneous determination, S3 and S4 will cause a momentary interruption. And the acceleration state are discriminated.

In S7, the acceleration increase flag F _ACC is set to 1 and the fact that the vehicle is in the acceleration operation state is stored in the RAM.

In S8, the acceleration increase flag F _ACC is set to 0, and the fact that the engine is in a steady operation state is stored in the RAM.

On the other hand, in S5, the calculated opening change rate Δα is compared with the negative value of the second reference opening of 1.6 °, and when Δα <−1.6 °, it is immediately determined whether the instantaneous interruption or the deceleration operation is started. I can't, so I proceed to S9. When Δα ≧ −1.6 °, it is determined that the engine is in a steady operation state, and the process proceeds to S10, in which both the acceleration increase flag F _ACC and the deceleration decrease flag F _DEC are set to zero.

In S9, it is determined whether or not it is the first deceleration determination after the start of the deceleration operation, and if YES, the process proceeds to S11 to determine whether or not the rapid deceleration operation is started. On the other hand, in the case of NO, it is unlikely that the instantaneous interruption will occur twice consecutively (continuously for a long time), so it is judged that the engine is in the deceleration operation start state, and the process proceeds to S12 to shift to the deceleration operation control. move on.

In S11, the calculated opening change rate Δα and the first reference opening 2.4
When Δα <-2.4 °, it is judged that the sudden deceleration operation has started and the deceleration operation control should be immediately started.
Go to S12. On the other hand, when Δα ≤ -2.4 °, avoid immediately determining whether it is an instantaneous interruption or deceleration operation,
Proceed to S13. In other words, in a deceleration state other than the sudden deceleration, even if the deceleration determination is delayed once, it does not significantly affect the drivability.
The instantaneous interruption and the deceleration state are discriminated by S5 and S9.

In S12, the deceleration reduction flag F _DEC is set to 1 and the deceleration operation state is stored in the RAM.

In S13, the deceleration reduction flag F _DEC is set to 0, and the fact that the vehicle is in a steady operation state is stored in the RAM.

With this configuration, when the acceleration is determined for the first time after the acceleration / deceleration operation is started, the rapid acceleration / deceleration is performed based on the calculated opening change rate Δα and the relatively large first reference opening 2.4 ° or the negative value thereof. Deceleration judgment is made. Then, by taking advantage of the fact that there is little possibility of instantaneous interruption occurring twice, the opening change rate Δα is larger than the second reference opening of 1.6 ° which is relatively small twice or the negative of the second reference opening. When it is smaller than the value, it is determined that the acceleration / deceleration operation state is not the instantaneous interruption.

For this reason, when the output of the intake throttle valve opening sensor 5 is momentarily cut off regardless of the steady operation state, the opening change rate Δα instantaneously exceeds the second reference opening of 1.6 ° or Even if the value falls below a negative value, the first acceleration / deceleration judgment is not made unless the first reference opening of 2.4 ° or its negative value is exceeded, so the frequency of erroneous acceleration / deceleration judgment can be reduced and driving performance improved. Can be maintained. On the other hand, if the opening change rate Δα exceeds the first reference opening of 2.4 ° or a negative value thereof, it is immediately determined that the acceleration / deceleration state is in effect, and the acceleration / deceleration control is performed. Therefore, it is possible to prevent deterioration of drivability during rapid acceleration / deceleration.

Further, if the opening change rate Δα exceeds the second reference opening 1.6 ° set in the same manner as the conventional example or the negative value thereof twice in succession, the acceleration / deceleration determination is made. Acceleration / deceleration determination can be performed from a state in which the opening change rate Δα is small while completely distinguishing between the instantaneous interruption and the acceleration / deceleration start state.

Next, the acceleration increase control routine will be described with reference to the flowchart of FIG.

In S21, it is determined whether the acceleration increase flag F _ACC is 1 or 0, and F
_{When ACC} = 1, it is determined that the vehicle is in the acceleration operation state, and the process proceeds to S22, and when _FACC = 0, the routine is ended.

In S22, the map is searched for the opening change rate dependent increase coefficient A based on the calculated opening change rate Δα. The increase coefficient A is set to increase as the change rate Δα increases.

In S23, the water temperature dependent increase coefficient B is searched from the map based on the detected cooling water temperature of the engine. This increase coefficient B
Is set to decrease as the cooling water temperature increases.

In S24, the rotation-dependent increase coefficient Nc is searched from the map based on the detected rotation speed. This increase coefficient Nc is set to increase as the rotation speed increases.

In S25, the interrupt injection amount T _R is calculated by the following equation.

T _R = A × B × Nc × KQ ₂ Note that KQ ₂ is a coefficient that depends on the load (for example, intake air flow rate, basic injection amount).

The interrupt injection pulse signal corresponding to the interrupt injection amount T _R thus obtained is output to the fuel injection valve 6 via the drive circuit 7 to perform interrupt injection to increase the acceleration.

Next, the deceleration reduction control routine will be described with reference to the flowchart of FIG.

In S31, it is determined whether the speed reducer flag F _DEC is 1 or 0, and F
_{When DEC} = 1, it is determined that the vehicle is in the decelerating operation state and the routine proceeds to S32. When _FDEC = 0, the routine is ended.

In S32, the water temperature dependent deceleration reduction coefficient BD is searched from the map based on the detected cooling water temperature of the engine. This reduction coefficient BD is set to decrease as the cooling water temperature increases. The reduction coefficient BD may be the same as the increase coefficient B.

In S33, the rotation-dependent deceleration reduction coefficient ND is searched from the map based on the detected rotation speed.

In S34, the reduction gear fuel coefficient KDC is calculated by the following equation.

KDC = BD × ND × KQ ₂ The deceleration reduction fuel coefficient KDC thus obtained is used by the following formula when calculating the fuel injection amount Ti during normal injection.

Ti = Tp x α x (1 + Kmr + K _TW + ... + K _AS -KDC) + Ts where Kmr is the air-fuel ratio correction coefficient, K _TW is the water temperature increase correction coefficient, and K is
_AS is the start and post-start increase amount correction coefficient.

In this way, an injection pulse signal corresponding to the calculated fuel injection amount Ti is output to the fuel injection valve 6 via the drive circuit 7 to perform fuel injection.

In the present embodiment, the comparison with the first reference opening of 2.4 ° is made only at the first acceleration / deceleration determination after the start of acceleration / deceleration operation. It may be compared with 1 standard opening of 2.4 °, and acceleration / deceleration is judged only when the second standard opening of 1.6 ° is exceeded twice, but it is limited to 2 times. However, the number is not limited as long as the object of the present invention is achieved. The specific numerical values shown as the first reference opening and the second reference opening are not limited to these. In addition, the load includes the intake air flow rate, intake negative pressure, torque, and the like.

<Effect of the Invention> As described above, according to the present invention, when it is detected that the calculated load change amount is larger than the first reference value at least once, the rapid acceleration / deceleration operation is immediately started. On the other hand, the acceleration / deceleration operation is started only when it is detected that the calculated load change amount is larger than the second reference value smaller than the first reference value at least twice consecutively. Since it is determined that the acceleration / deceleration during sudden acceleration / deceleration is not impaired, the rate of change in opening can be greatly reduced while significantly reducing the frequency of false acceleration / deceleration determination due to momentary interruptions in steady operation. Acceleration / deceleration determination can be performed from a state in which Δα is small, and thus engine operability can be favorably maintained.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to the claims of the present invention, FIG. 2 is a configuration diagram showing an embodiment of the present invention, and FIGS. 3 to 5 are flowcharts of the same. 1 ... Control device, 2 ... Ignition coil, 5 ... Intake throttle valve opening sensor, 6 ... Fuel injection valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-279756 (JP, A) JP-A-56-132467 (JP, A) JP-A-59-90769 (JP, A)

Claims (1)

[Claims] 1. A load detecting means for detecting an engine load, a load change amount calculating means for inputting the detection signal to calculate a load change amount for each predetermined sampling period, and the calculated load change amount, A first acceleration / deceleration operation start determination means for determining that the acceleration / deceleration operation has started at least once based on the value being larger than the first reference value; and the calculated load change amount at least twice. Second acceleration / deceleration operation start determination means for determining that the acceleration / deceleration operation has started based on the fact that the acceleration / deceleration operation is continuously started and is larger than the second reference value that is smaller than the first reference value. An acceleration / deceleration determination device for an internal combustion period, which is characterized in that: