JPS62271942A - Control device in internal combustion engine - Google Patents

Abstract

PURPOSE:To aim at enhancing the restarting ability of an engine, by calculating a residual amount of fuel fed upon missing of engine start from the number of cycles of ignition during a previous start of the engine, and by determining an increment of fuel for the present engine starting in accordance with the thus calculated value. CONSTITUTION:A control device 5 is connected with a rotational angle detector 2, an intake-air amount detector 3, a starter drive switch 4, an ignition switch 4A and the like, and computes an optimum ignition timing and an optimum fuel injection amount in accordance with the operating condition of an internal combustion engine to control an ignition device 6 and a fuel injection value 8. When a starter switch 4 is turned on so that the engine is on starting, the control device 5 counts the number of cycles of ignition, and stores the thus counted value in memory if the rotational speed of engine does not exceed a predetermined value, that is, if the start of the engine is missed. During the next starting of the engine, the control device 5 computes an increment of fuel for starting of the engine in accordance with the residual amount of fuel which is fed during the previous missed starting of the engine.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention detects the engine condition at the time of starting the engine and adjusts the air-fuel ratio at the time of starting, thereby improving startability, especially restartability. This invention relates to an internal combustion engine control device that can be used.

[Conventional technology]

Conventionally, for example, if an engine is restarted immediately after starting incorrectly,
The fuel supply system makes the same judgment as when starting normally and increases the starting amount sufficiently. Therefore, the remaining fuel from the previous time and the fuel from the restart are added to the intake pipe at the time of restart, resulting in excessive concentration and deterioration of restartability.

Therefore, in order to improve restartability, for example,
As shown in Publication No. 185844, the engine cooling water temperature immediately before the previous engine stop (THWE) is used to control the restart.
The final fuel injection amount control is performed by comparing the current starting cooling water temperature (THW) and determining the difference (ΔTHW = THWE - THW), and calculating the fuel injection amount correction value corresponding to ΔTHW determined in advance by experiment. It has been proposed to control the air-fuel ratio to an appropriate value by adding it to the value.

[Problem that the invention seeks to solve]

However, since the state of the engine at the time of startup is determined by the amount of change ΔTHW in the engine cooling water temperature, the elapsed time from the previous engine stop to the current start can be determined by the amount of change ΔTHW in the cooling water temperature. , it is not possible to determine the previous operating state. For example, it is not possible to determine whether the previous operating state was such that the engine failed to start and stopped, whether the engine stopped after idling, or whether the engine stopped after running.

However, the previous operating state of the engine greatly affects the current startability. If the internal combustion engine cannot start and stops, the fuel in the intake pipe of the internal combustion engine is still being injected and is not burning.
The fuel accumulates, resulting in what is commonly called a "manifold wet" condition.Therefore, when restarting, the amount of fuel is increased again, resulting in excessive fuel concentration, deteriorating startability.Furthermore, exhaust gas purification characteristics also deteriorate.

Therefore, in order to solve the above-mentioned problems, the present invention calculates the residual amount of fuel supplied at the time of the previous start error from the number of ignitions that occurred during the previous start period, and This internal combustion engine control device is capable of dramatically improving engine startability, especially restartability, by determining the fuel increase value for the current engine start, thereby increasing the fuel amount according to the previous engine operating state. The purpose is to provide

[Means for solving problems]

Therefore, in the present invention, in a device that controls the amount of fuel supplied according to the operating state of an internal combustion engine, a non-volatile storage means for storing the number of ignitions that occurred during the engine startup period each time the engine is started; At the time of starting, a determining means reads out from the storage means the number of ignitions that occurred during at least the previous starting period, and determines whether the number of ignitions is within a set range; The present invention is characterized by comprising a correction means for determining a fuel increase value at the time of starting the engine in accordance with at least a previous ignition number value.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a system configuration diagram using a control device according to the present invention. 1 is a 4-cycle internal combustion engine, 2 is an electromagnetic rotation angle detector that detects an angle signal synchronized with the rotation of the engine's crankshaft, and 3 is a sensor that measures the amount of intake air required by the engine using, for example, the opening of a vane. A moving vane type intake air amount detector that detects and converts it into a voltage value, 4A is an ignition switch that supplies power to each device, 4 is a starter drive switch that drives the starter motor to start the engine, and 5 is a digital control The device is connected to a rotation angle detector 2, an intake air amount detector 3, and a starter drive switch 4, and calculates and determines the optimal ignition timing and optimal fuel injection amount according to the operating state of the internal combustion engine. Reference numeral 6 is an ignition device that is connected to the control device 5 and generates a high voltage so as to ignite at the determined ignition timing, 7 is a spark plug, and 8 is connected to the control device 5 and controls the determined injection amount by the valve opening time. It is a fuel injection solenoid valve.

FIG. 2 shows a block diagram of the control device 5.

51 is a waveform shaping circuit that is connected to the rotation angle detector 2 and shapes the output waveform from the rotation angle detector 2 using a comparator;
52 is a stabilized power supply circuit, ignition switch 4A
The battery voltage received via the stabilizer is stabilized and provided to the control device 5.

The control device 53 is composed of a microcomputer, specifically a CPU 53A that calculates the optimum ignition timing and fuel injection amount according to various operating conditions, a CPU 53A that manually processes the rotation signal from the waveform shaping circuit 51, and Quantity detector 3
An input circuit 53 that performs A/D conversion processing on analog signals from
B. An output circuit 53C1 that receives control values such as ignition timing and fuel injection amount calculated by the CPU 53A and processes the output at a predetermined timing. A first memory 53E1 including ROM and RAM and EEPROM or power backup RAM. It includes a non-volatile rewritable second memory 53F such as.

Next, the operation of this embodiment will be explained using flowcharts. FIG. 3(A) shows a process for calculating the amount of residual fuel remaining in the intake pipe of the internal combustion engine without being combusted, from the number of ignitions during the starting operation.

First, when the ignition switch 4A is turned on and power is supplied to the control device 5, an initialization process (not shown) resets the starter flag 5TF=0 and the counters C and l for counting the number of ignitions. And Figure 3 (A
) is started in the main routine that is processed at high speed or in the timer processing at predetermined short time intervals (step 1).
01).

First, if the starter switch 4 is still in the OFF state, steps 102, 106, 110, and 111 are followed, and C,=O
Therefore, no special processing is performed.

When the starter switch 4 is turned on and the engine is starting, the ignition flag IGF=1 is set every time the CPU 53A executes the ignition process (see the ignition process routine in Figure 4), so the count up of the counter CM is increased each time. (CM"-CN+1) is executed (step 102
．． 103.104).

At that time, the ignition flag IGF=O is returned (step 1
05).

Also, once the starter isochi 4 is turned from ON to OFF after the starting operation.
When it becomes FF, if the current start has failed, that is, the engine rotational speed N is below N0, and the counter count value C is added to the previous count value T0 stored in the non-volatile second memory 53F. , is added (TM-TN+
C) l) and rewrites and stores the value TN in the second memory 53F (steps 102, 106, and 110). Thereafter, the count value of the counter is reset to 0.4 (CM=O) (step 111).

In addition, once the starter switch 4 turns from ON to OFF after the starting operation, and the starting is successful at that point, the engine rotational speed N is set to the set value N'o (for example, No =
400-600 rpm) (step 106). Therefore, when the engine is started, the fuel is combusted and the residual fuel accumulated in the intake pipe is also reduced, so the count value Cs of the counter is significantly decreased (CCN''-CHK, where K>1) (step 107). After starting,
If the engine stalls at a time shorter than the set elapsed time T0, a NO determination is made in step 108, and the process then proceeds to steps 102, 106, and 110, where the engine stalls.
The count value Cal of the counter decreased by the knob 107 is added to the integrated value T.

On the other hand, if it is determined that the engine continues to operate for a predetermined elapsed time or more after starting, and the residual fuel accumulated in the intake pipe is substantially exhausted, the answer is YES in step 108, and the engine is stored in the second memory 53F. The stored memory value T,
Reset (TN=0). Therefore, generally, the accumulated value T8 is 0 at the time of the first starting operation.

To summarize the above with reference to (a) to (d) in Figure 3 (B), if you make multiple starting errors as in (a) and (b), turn off the ignition switch each time. O
Regardless of whether it is turned on or off, the total value T8 of the count values CM obtained during those multiple times is stored in the second memory 5.
If the engine is set to 3F and once the engine starts successfully as shown in (c), but stalls within the set elapsed time T0,
A value T, which is subtracted according to the engine operating period after a successful start, is set, and if the engine operating period after a successful start is longer than the set elapsed time T, as in (d), a second value is set. The value T in the memory 53F is reset and set again from the initial state at the next startup.

Next, FIG. 4 shows the ignition processing routine, in which a predetermined ignition calculation is performed, and each time the ignition output control is performed, the ignition flag IG is
Set F (TCP=1).

FIG. 5 shows the starter ON interrupt routine that is started when the starter switch is turned on. When the integrated value TN stored in the second memory 53F is within a range smaller than the set value α (step 201), the routine starts in step 202. Proceed to RO in advance
Based on the correction map stored in M, that is, the map in which the correction coefficient fTN of the increase at the time of starting is stored for the integrated value T8 (i.e., the value correlated to the residual fuel in the intake pipe).
Find the correction coefficient fTN according to the integrated value T, and use it as RA
Temporarily hold in M. Furthermore, when the integrated value T is larger than the set value α, it can be determined that there is a very large amount of residual fuel, so f
By setting tn=1, the increase correction at the time of starting is not performed (steps 201 and 203).

Note that the process in step 201 can be omitted by appropriately setting the value of the set elapsed time T0 in FIG. 3.

In addition, FIG. 6 shows a fuel injection routine, in which the basic injection amount Tp is calculated based on the intake air amount of the engine, the engine rotational speed, etc. (step 301), and then the correction coefficient r for the increase in cooling water temperature is calculated. The basic injection amount Tp is corrected in consideration of various correction coefficients such as the correction coefficient rtn for the starting amount increase shown in FIG. (Step 303).

Note that the process shown in FIG. 5 may be performed as part of the fuel injection routine shown in FIG. 6.

By the way, in the above embodiment, the amount of fuel remaining in the intake pipe is calculated using the integrated value T stored in the second memory 53F.
However, as shown in Fig. 7, it is more accurate to make a judgment based on multiple parameters such as the integrated value T as another example and the cooling water temperature T, 1 as another engine parameter. calculations can be made. In this example, the integrated value TN and the cooling water temperature T. The starting increase coefficient fTN is set using a two-dimensional map of T. , To, the increase coefficient "1.l" is determined.

In addition, according to this embodiment, the cooling water temperature T. When the temperature is relatively high, there is little manifold wetness, so the correction is made small, and on the other hand, when the temperature is low, the manifold is completely wet, so the correction is made more.

〔Effect of the invention〕

As described above, according to the present invention, the amount of fuel supplied at the time of the previous start error is calculated from at least the value of the number of ignitions that occurred during the previous start period, and the amount of fuel supplied at the time of the current engine start is increased according to the calculated value. Since the value is determined, the starting amount can be increased according to the previous engine operating state, and the engine restartability can be significantly improved.

[Brief explanation of the drawing]

1 to 7 show one embodiment of the present invention, FIG. 1 is a block diagram showing the overall configuration of the device of the present invention, FIG. 2 is a detailed block diagram of the control device in FIG. 1, and FIG. -FIG. 7 are diagrams for explaining the operation of the present invention. 1... Internal combustion engine, 2... Rotation angle detector, 3...
Intake air amount detector, 4...Starter drive switch,
4A... Ignition switch, 5... Control device, 53E... First memory, 53F... Second memory. Representative Patent Attorney Takashi Okabe 4c Figure 1 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] A device for controlling the amount of fuel supplied according to the operating state of an internal combustion engine includes a non-volatile storage means that stores the number of ignitions that occurred during the starting period each time the engine is started, and a non-volatile storage means that stores the number of ignitions that occurred during the engine startup period. a determining means for reading the ignition number value that occurred during the starting period from the storage means and determining whether the ignition number value is within a set range; An internal combustion engine control device comprising: a correction means for determining a fuel increase value at the time of starting the engine.