JPS63170543A - Acceleration/deceleration judging device for internal combustion engine - Google Patents

Abstract

PURPOSE:To achieve the reduction in false judgement, by providing the first acceleration/deceleration judging means which compares the load variation with the first reference value to judge acceleration/deceleration, and the second acceleration/ deceleration judging means which compares the load variation with the second reference value being smaller than the first reference value to judge acceleration/ deceleration. CONSTITUTION:An engine load is detected by a load detecting means A, and the load variation for each prescribed sampling period is calculated by a load variation calculating means B. On the basis of this load variation, whether or not acceleration/ deceleration operation has been started is judged by an acceleration/deceleration operation start judging means C, and based on this judgement, the load variation is compared with the first reference value, at the initial stage of acceleration/deceleration operation start, and acceleration/deceleration is judged by the first acceleration/ deceleration judging means D. After completion of the judgement, the load variation is compared with the second reference value being smaller than the first reference value, and the judgement is carried out by the second acceleration/deceleration judging means E. Thus, the frequency of false judgement can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) 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 system for an internal combustion engine in which an acceleration/deceleration determination device is used (see Utility Model Application No. 60-066558).

That is, from the intake air flow MQ detected by an air flow meter etc. and the engine rotation speed N, the basic injection amount Tp=KxQ
/N (K is a constant), as well as various correction coefficients C0EF mainly depending on water temperature, air-fuel ratio feedback correction coefficient α, and correction coefficient Ts depending on battery voltage, fuel injection amount Ti = during steady operation. TpxcO
Calculate EFxα+Ts.

For example, in a single point injection system (hereinafter referred to as SP1 system), an injection pulse signal with a pulse width corresponding to the fuel injection lTi is output to the fuel injection valve in synchronization with an ignition signal etc. every A rotation of the engine. Supply fuel.

Furthermore, acceleration is determined based on the rate of change of the intake throttle valve opening for a certain period of time (
For example, by calculating the increased injection amount during acceleration every 10 m5ec) and adding the increased injection amount to the fuel injection amount Ti, the amount of fuel is increased during acceleration and the engine output is increased.

Further, the increase in fuel consumption during acceleration is also performed by interrupt injection, which is performed by inserting an injection pulse during acceleration into a normal injection pulse signal.

Also, during deceleration operation, deceleration determination is made based on the rate of change to reduce the amount of deceleration.

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

In other words, the intake throttle valve opening sensor generates sliding noise until the intake throttle valve opening changes by about 1° within the certain period of time, so its detection and resolution ability is low.
During a slow acceleration operation where the change rate is less than .degree., there is a problem that the acceleration operation state cannot be accurately detected from the rate of change, and an appropriate increase in amount during acceleration cannot be achieved.

For this reason, in the past, the fixed time, that is, 10 m
Acceleration is determined when the intake throttle valve opening changes, for example, by 1.6° or more during 5ec, which can prevent erroneous acceleration determinations due to the sliding noise, and also prevents acceleration during sudden acceleration. It can be used for acceleration during accelerated driving.

However, when the output of the intake throttle valve opening sensor momentarily interrupts, the intake throttle valve opening changes by more than 1.6° within the certain period of time due to this instantaneous interruption, and even during steady operation, deceleration judgment is made. This resulted in a reduction in deceleration, resulting in a problem of deterioration of driving performance.

The present invention has been made in view of the above-mentioned circumstances, and provides an internal combustion engine capable of reducing the frequency of erroneous determination of acceleration/deceleration operation even if the output of a load detection means such as an intake throttle valve opening sensor is momentarily cut off. The purpose of this invention is to provide an acceleration/deceleration determination device.

<Means for Solving the Problems> For this reason, the present invention, as shown in FIG. A load change amount calculation means B that calculates the amount of change, an acceleration/deceleration operation start determination means C that determines whether acceleration/deceleration operation has started based on the calculated load change amount, and classification/deceleration operation Based on the determination result of the start determination means C, at the beginning of acceleration/deceleration operation, a first acceleration/deceleration operation is performed that compares the calculated load change amount with a first reference value to determine whether acceleration/deceleration operation is to be performed. After the determination by the first acceleration/deceleration determination means based on the determination results of the deceleration determination means and the acceleration/deceleration operation start determination means C is smaller than the calculated load change amount and the first reference value. A second acceleration/deceleration determining means E is provided which compares the driving speed with a second reference value and determines whether or not acceleration/deceleration operation is being performed.

<Effect> In this way, when determining the initial stage of acceleration/deceleration operation,
Acceleration/deceleration is determined by comparing the calculated load change rate with a relatively large first reference value, and thereafter acceleration/deceleration is determined by comparing the load change rate with a relatively small second reference value. I decided to do this.

<Example> An example of the present invention will be described below based on FIGS. 2 to 5. Note that this embodiment will be explained by taking fuel injection control as an example.

In FIG. 2, a control device 1 consisting of a microcomputer, for example, receives an ignition signal (rotational 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. Cooling water temperature signal, intake throttle valve opening sensor 5 as load detection means
The intake throttle valve opening signal output from the intake throttle valve is inputted. The control device 1 operates according to the flowcharts shown in FIGS. 3 to 5, and outputs an injection pulse signal and an interrupt injection pulse signal to the drive circuit 7 of the fuel injection valve 6.

Here, the control device R1 constitutes a load change amount calculation means, an acceleration/deceleration operation start determination means, and first and second acceleration/deceleration determination means.

Next, the operation will be explained according to the flowcharts shown in FIGS. 3 to 5.

This flowchart is activated by inputting an activation signal every 1Qmsec.

At Sl, the intake throttle valve opening detected by the intake throttle valve opening sensor 5 is read.

In S2, the intake throttle valve opening degree change rate Δα during the sampling period (for example, 10 m5ec) is calculated based on the intake throttle valve opening degrees detected this time and the previous time.

In S3, the calculated opening degree change rate Δα is compared with a second reference opening degree of 1.6° as a second reference value, and when Δα>1.6, it is determined that acceleration operation has started, and the process proceeds to S4. ,Δ
When α≦1.6°, the process advances to S5.

In S4, it is determined whether or not this is the first acceleration determination after the start of acceleration driving. If YES, the process advances to S6; if NO, that is, if it is the second or subsequent acceleration determination, the process advances to S7.

In S6, the calculated opening degree change rate Δα is compared with the first reference opening degree of 2.4° as the first reference value, and Δα>2.4° is determined.
When Δα≦2.4°, the process proceeds to S7, and when Δα≦2.4°, the process proceeds to S8.

In S7, the acceleration increase flag F ACC is set to 1,
The fact that it is in an accelerated driving state is stored in the RAM.

In S8, the acceleration increase flag F ACC is set to O,
Store in RAM that it is in a steady operating state.

On the other hand, in S5, the calculated opening degree change rate Δα is compared with the negative value of the second reference opening degree of 1.6°, and when Δα<−1.6°, it is determined that deceleration operation has started, Proceed to S9 and Δ
When α≧−1.6°, it is determined that the operating state is steady, and the process proceeds to SIO, where both the acceleration increase flag FACC and the deceleration decrease flag FDEe are set to 0.

In S9, it is determined whether or not this is the first deceleration determination after the start of deceleration driving. If YES, the process proceeds to Sll; if NO, that is, if it is the second or subsequent deceleration determination, the process proceeds to S12.

In Sll, the calculated opening degree change rate Δα is compared with the negative value of the first reference opening degree of 2.4°, and when Δα<-2.4°, the process proceeds to S12 and the calculation is performed to determine that Δα≧-2.4°. In some cases, the process proceeds to S13.

In S12, the deceleration reduction flag FI, ! . is set to l, and the fact that it is in a deceleration driving state is stored in the RAM.

In step 313, the deceleration reduction flag FIlEc is set to O, and the steady state of operation is stored in the RAM.

In this way, at the time of the first acceleration determination after the start of acceleration/deceleration operation, the acceleration is based on the calculated opening change rate Δα and the relatively large first reference opening of 2.4° or its negative value.・Deceleration judgment is made. Then, in the second and subsequent acceleration/deceleration determinations, acceleration/deceleration determinations are made based on the relatively small second reference opening degree of 1.6° or its negative value.

Therefore, if the output of the intake throttle valve opening sensor 5 is momentarily interrupted despite the steady operating state, the calculated opening change rate Δα momentarily exceeds the second reference opening 1.6°. Or even if it is less than the negative value, the first standard interval is 2.4
Since the initial acceleration/deceleration determination is not made unless the acceleration/deceleration exceeds .degree. or its negative value, the frequency of erroneous acceleration/deceleration determinations can be reduced and good driving performance can be maintained. In addition, since the second and subsequent acceleration/deceleration judgments are made based on the second standard opening of 1.6°, which is set in the same way as in the conventional example, the opening change rate Δα is small. Acceleration/deceleration judgment can be made.

Next, the acceleration increase control routine will be explained according to the flowchart shown in FIG.

In S21, it is determined whether the acceleration increase flag F'Acc is 1 or O. When Face=1, it is determined that the accelerating operation is in progress, and the process proceeds to S22, and when Facc=O, the routine is ended.

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

In S23, a water temperature dependent increase coefficient B is searched from the map based on the detected engine cooling water temperature.

This increase coefficient B is set to decrease as the cooling water temperature increases.

In S24, a 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 rotational speed increases.

In S25, the interrupt injection ITR is calculated using the following equation.

'l', l = A
It is a coefficient that depends on .

An interrupt injection pulse signal corresponding to the interrupt injection amount T11 obtained in this way is sent to the fuel injection valve 6 via the drive circuit 7.
output to perform interrupt injection to increase the amount of fuel for acceleration.

Next, the deceleration reduction control routine will be explained according to the flowchart of FIG.

In S31, it is determined whether the deceleration reduction flag F_DEC is 1 or 0. When FDEC=1, it is determined that the vehicle is in a deceleration driving state and the process proceeds to S32, and when Fotc=0, the routine is ended.

In S32, based on the detected engine cooling water temperature,
Search the map for the water temperature dependent deceleration loss coefficient BD. This reduction coefficient BD is set to decrease as the cooling water temperature increases. Note that this reduction coefficient BD may be the same as the increase coefficient B.

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

In S34, the deceleration reduction fuel coefficient KDC is calculated using the following equation.

KDC=BDxNDxKQ.

The deceleration reduction fuel coefficient KDC obtained in this way is used when calculating the fuel injection amount Ti during normal injection using the following formula.

T i ='rp XcrX (1+ K,, + to -(
@+-10Kas-KDC)+Ts In addition, K,, 1 is an air-fuel ratio correction coefficient, KTW is a water temperature increase correction coefficient, and KAS is a starting and post-starting increase correction coefficient.

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

In this embodiment, the first reference opening degree of 2.4° is compared only at the first acceleration/deceleration determination after the start of acceleration/deceleration operation, but for example, the first and second acceleration/deceleration determinations Sometimes, the opening degree may be compared with the first standard opening degree of 2.4°. In addition, the load is the intake air flow rate.

Examples include intake negative pressure and torque.

<Effects of the Invention> As explained above, the present invention compares the calculated load change rate with a relatively large first reference value at the beginning of acceleration/deceleration operation, and then compares the calculated load change rate with a relatively small second reference value. Therefore, even if the load change rate exceeds the second reference value due to a momentary interruption during steady operation, acceleration/deceleration determination will not be made unless the load change rate exceeds the first reference value. Therefore, the frequency of erroneous acceleration/deceleration determinations can be reduced, and acceleration/deceleration determinations can be made based on the second reference value while maintaining good driving performance.

[Brief explanation of the drawing]

FIG. 1 is a diagram corresponding to claims of the present invention, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIGS. 3 to 5 are flowcharts of the same. l...Control device 2...Ignition coil 5...
Intake throttle valve opening sensor 6...Fuel injection valve Patent applicant Japan Electronics Co., Ltd. Representative Patent attorney Fujio Sasashima Figure 4 Figure 5

Claims (1)

[Claims] load detection means for detecting the engine load; load change amount calculation means for inputting the detection signal and calculating the load change amount for each predetermined sampling period; and acceleration/deceleration operation based on the calculated load change amount. Acceleration/deceleration start determining means determines whether the acceleration/deceleration start has been started, and based on the determination result of the acceleration/deceleration start determining means, the calculated load change amount and the first a first acceleration/deceleration operation determination means that compares with a reference value and determines whether or not acceleration/deceleration operation is being performed; and a determination by the first acceleration/deceleration determination means based on the determination result of the acceleration/deceleration operation start determination means. After completion, the method further comprises second acceleration/deceleration determining means for comparing the calculated load change amount with a second reference value smaller than the first reference value and determining whether or not acceleration/deceleration operation is being performed. An acceleration/deceleration determination device for an internal combustion engine, characterized by: