JPS63280834A - Control for electrical equipment of internal combustion engine - Google Patents

Abstract

PURPOSE:To control the energizing time to a proper value by setting the value which is obtained by subtracting a prescribed time from the energizing time for the electrical equipment such as fuel injection valve, as the counting value of a counter, and by outputting an energizing completion signal after the lapse of a prescribed time from the completion of counting by the counter. CONSTITUTION:During the operation of an engine 1, an ECU 5 calculates the fuel injection time (energizing time) on the basis of the output signals of an intake pipe absolute pressure sensor 8, engine revolution speed sensor 11, etc. The calculated energizing time is counted by a counter, and a fuel injection starting instruction is outputted into a fuel injection valve 6. An interruption signal is generated on the completion of counting by the counter, and an instruction for suspending the fuel injection is outputted according to the interruption signal. In this case, the difference which is obtained by subtracting a prescribed time from the above-described energizing time is set as the count value of the counter, and the fuel injection stop instruction is outputted after the lapse of a prescribed time from the time of generation of the interruption signal.

Description

FIELD OF THE INVENTION The present invention relates to a method for controlling an electrical device of an internal combustion engine, and more particularly to a control force method for controlling the energization time of an electrical device in response to an interrupt signal.

(Prior Art and its Problems) A conventional control method for an electrical device that controls the operation of an internal combustion engine, such as a fuel injection valve, is to measure the energizing time of the electrical device, and to determine the end of the energizing time. A time counter that generates an interrupt signal at time r, and calculates the energization time according to the operating state of the internal combustion engine, nIj, ! Outputting a timekeeping start command for the 1 o'clock counter and controlling the electric device;
There is a device in which side control is performed by a central processing unit that outputs a command to start one cycle and outputs a command to end the cycle of the electric device in response to the interrupt signal from the time counter.

However, since the central processing unit usually handles arithmetic processing (for controlling electrical equipment) as well as many arithmetic processing for other controls, there is a specific system that does not accept interrupt signals. (hereinafter referred to as the "interrupt-prohibited section"). Therefore, if the time when an interrupt signal from the time counter is generated falls within the interrupt-prohibited section, the interrupt is disabled until the interrupt-prohibited section is canceled. The input signal is not received, and the output of the command to end the energization of the electrical device is delayed by this waiting time.As a result, the energization time of the electrical device is substantially extended, and the actual There is a problem in that the energizing time cannot be controlled to the desired energizing time set according to the operating state of the internal combustion engine.

For example, when the electrical device is a fuel injection valve, the injection time of the fuel, that is, the injection amount becomes larger than the appropriate amount, resulting in a decrease in engine drivability and fuel efficiency.

(Object of the Invention) The present invention has been made in order to solve the problems of the prior art described above, and is capable of controlling the energization time of an electrical device to an appropriate value even when the central processing unit has an interrupt-prohibited section. It is an object of the present invention to provide a method for controlling an electric device for an internal combustion engine, thereby making it possible to improve drivability, fuel efficiency, etc.

(Means for Solving the Problems) In order to achieve the above object, the present invention calculates the energization time of an electric device that controls the operation of the internal combustion engine according to the operating state of the internal combustion engine by a calculation processing means, The calculated energization time is set to Ni by the time counter, and the arithmetic processing means outputs a command to start energizing the electric device, and when the time counter ends, an interrupt signal is generated, and the interrupt signal is In the method for controlling an electrical device of an internal combustion engine, the arithmetic processing means outputs an energization termination command for the electrical device in response to the energization time, and the difference obtained by subtracting a predetermined time from the energization time is set as the count value of the time counter. and the energization end command is output after the predetermined time has elapsed from the generation of the interrupt signal of the time counter.

(Example) Hereinafter, one example of the present invention will be described based on the accompanying drawings.

FIG. 1 is an overall configuration diagram of a fuel supply control device to which the control method of the present invention is applied.
Tl+) sensor 4 is connected, and outputs an electric signal corresponding to the opening degree of the throttle valve 3 to supply it to an electronic control unit (hereinafter referred to as rEcUJ) 5.

A fuel injection valve (hereinafter referred to as "injector J") 6 as an electrical device is provided for each cylinder between the engine 1 and the throttle valve 3 and slightly upstream of the intake valve (not shown) in the intake pipe 2. (only shown), each injector is connected to a fuel pump (not shown) and electrically connected to an ECU 3, and a valve opening time Tour for fuel injection is controlled by a signal from the ECU 3.

On the other hand, an intake pipe absolute pressure (PH^) sensor 8 is provided immediately downstream of the throttle valve 3 via a pipe 7, and the absolute pressure signal converted into an electrical signal by this absolute pressure sensor 8 is sent to the ECU 3. Supplied.

Further, an intake air temperature (T^) sensor 9 is attached downstream thereof, detects the intake air temperature, outputs a corresponding electric signal, and supplies the signal to the ECU 3.

The temperature of the engine cooling water installed in the main body of the engine ("l
'w) The sensor IO is composed of a thermistor or the like, detects the engine coolant temperature, and supplies a corresponding temperature signal to the ECU 3. An engine rotational speed (Ne) sensor 11 and a cylinder discrimination (CYL) sensor 12 are attached around a camshaft or crankshaft (not shown) of the engine 1. The engine speed sensor 11 is located at 18 on the engine crankshaft.
The cylinder discrimination sensor 12 outputs a predetermined control signal pulse (hereinafter referred to as rTDC signal pulse) at a predetermined crank angle position for each 0 degree rotation, and a cylinder discrimination signal pulse (hereinafter referred to as rC: YL signal) at a predetermined crank angle position of a specific cylinder. These signal pulses are supplied to the ECU 3.

The three-way catalyst 14 is disposed in the exhaust pipe 13 of the engine 1, and purifies components such as HC, Go, and NOx in the exhaust gas. The o2 sensor 15 is installed on the upstream side of the three-way catalyst 14 in the exhaust pipe 13, detects the oxygen concentration in the exhaust gas, outputs a signal according to the detected value, and supplies the signal to the ECU 3.

Further, a sensor 16 for detecting engine operating parameter values such as atmospheric pressure and battery voltage is connected to the ECU 3, and a detected value signal thereof is supplied.

The ECU 3 determines engine operating states such as a fuel cut (fuel cutoff) operating range, an acceleration range, and a deceleration range based on the above-mentioned various engine operating parameter signals, and also determines the above-mentioned T I according to the determined engine operating state. )
The injection time TOLIT for which the corresponding injector 6 should be opened in synchronization with the C signal pulse is calculated based on the following equation.

TOUT=Ti XKI+2...(1) Here, T
i is the base fjtJ value of the injection time of the injector 6,
It is determined according to the engine rotation speed Ne and the intake pipe absolute pressure PB^.

K+ and NI2 are a correction coefficient and a correction variable, respectively, and the engine operating parameter signals from the various sensors mentioned above are used to optimize engine starting characteristics, exhaust gas characteristics, fuel efficiency characteristics, acceleration characteristics, etc. according to engine operating conditions. It is calculated based on a predetermined calculation formula so that the

As described above, the IE CU 5 supplies the injector 6 with a drive signal to open the injector 6 based on the fuel injection time 1110' 0 +IT determined in ().

FIG. 2 is a block diagram showing the circuit configuration inside the ECU 3 shown in FIG. 1, in which the output signal from the engine rotation speed sensor 11 shown in FIG.
As a signal pulse, the interrupt control circuit 502 outputs 1γ and is supplied to a central processing unit (hereinafter referred to as rcPUJ) 503 as an arithmetic processing means. Connected to the interrupt control circuit 502 is a timer (31 o'clock counter) 504, which is composed of an up counter and whose operation is controlled by the CPU 303. The timer 504 supplies the callan 1 to value to the interrupt control circuit 502 and the CPU 303, and the interrupt control circuit 50
2 supplies an interrupt signal to the CPU 303 when the timer 504 finishes counting (counts up). Also, timer 50
4, unless the operation is stopped by the CPU 304,
It has a function to reset the count value to 0 at the same time as the count up L2 and automatically start counting again.

The waveform shaping circuit 501 is also connected to a Me counter 505. The Me counter 505 measures the time interval from the input of the previous TDC signal pulse from the engine rotation speed sensor 11 to the input of the current TDC signal pulse, and its count value Me is the reciprocal of the engine rotation speed Ne. Proportional. Me counter 505 supplies this count value Me to CPU 503 via data bus 506.

The output signals from each sensor such as the throttle valve opening sensor 4, intake pipe absolute pressure sensor 8, 02 sensor 15, etc. in FIG. The signal is supplied to the A/D converter 509, where it is further converted into a digital signal, and then supplied to the CPU 303 via the data bus 506.

After the signal from the cylinder discrimination sensor I2 is waveform-shaped by the waveform shaping circuit 510, it is sent to the CPU 3 as a CYL signal pulse.
03()(provided.

The CPU 303 is further connected to a read-only memory (hereinafter referred to as "FROM") 511, a random access memory (hereinafter referred to as "RAMJ") 512, and a drive circuit 513 via a data bus 506. RAM512 is C
The calculation result in P U 503 is temporarily stored, and R
OM5]1 is a control program executed by the CP LJ503, and is a basic injection time T of the fuel injection valve 6 to be read based on the intake pipe absolute pressure PB^ and the engine speed Ne.
1 map etc. is memorized.

According to the control program stored in the ROM 511, the CPU 303 calculates the fuel injection time 'ouv of the injector 6 according to the various engine operating parameter signals described above, and sets the timer set value Tset of the timer 504 according to the calculation result. In addition to setting and starting the operation, injections corresponding to the input TDC signal pulse should be performed among the #1 to #3 injectors 61 to 63 disposed in the first to third cylinders, respectively. A control signal to select the injector 6 and open it is supplied to the drive circuit 513.The CPU 503 also outputs an interrupt signal output from the interrupt control circuit 502 when the timer 504 counts up to a predetermined interrupt prohibition period. This 211-included signal selects the injector 6 that should end injection among the plurality of injectors 6 that are injecting, and supplies a control signal to the drive circuit 513 to close the valve. The drive circuit 513 supplies a drive signal to open the corresponding injector 6 from when the valve opening control signal is manually input until when the valve closing control signal is input.

3 and 4 are flowcharts of the fuel supply control program according to the present invention, and these flowcharts will be explained with reference to the timing charts of FIGS. 6 and 5 and FIGS.

FIG. 3 shows a control program for controlling the selection and energization (valve opening) of the injector 6, and this program is executed every time an rDC signal pulse occurs and when the TDC signal pulse occurs. It is executed simultaneously with the completion of the TOUT calculation.

First, in step 301, it is determined whether the number of bits of the injector port in the on state is two. The injector port serving as this flag has the same number of bits as the number of cylinders, and as will be described later, when the injector 6 is in the open state, the corresponding bit is maintained in the on state. Therefore, the number of bits of injector ports that are in the on state represents the number of injectors 6 that are currently injecting fuel. If the answer to step 301 is negative (No), that is, there are not two injectors 6 currently injecting, step 3
The process proceeds to step 02, and it is determined whether the number of bits of the injector port in the on state is one. This answer is negative (
No), that is, when all the bits of the injector ports are in the OFF state, it is determined that all injectors 6 have stopped fuel injection, and the next steps 303 to 303 are performed.
In step 306, control is executed when there is no lap, that is, when fuel injection is performed from only one injector 6. FIG. 5 shows a timing chart when there is no lap.

First, in step 303, the injector on bit as a flag is updated. This update is performed by determining the cylinder in which injection should be performed this time from the CYL signal pulse that has already been input ((a) in Figure 5) and the rDC signal pulse that has been input this time ((b) in Figure 5). This is done by turning on the injector on bit that corresponds to the cylinder that has been activated. The injector on bit has the same number of bits as the number of cylinders, similar to the above-mentioned injector port and the below-mentioned injector off bit, and the on state of the bit is maintained until the next update.

For example, as shown in FIGS. 5(a) and (b), after the generation of the CYL signal pulse, the first to
When fuel injection is performed in the order of the third cylinder, when the first 1N]C signal pulse is input immediately after each CYL signal pulse is generated.

It is determined that the cylinder to be injected this time is the first cylinder,
The corresponding bit of the injector on bit,
In other words, when the #1 bit turns on, the injector
The on bit is updated ((e) in Figure 5), and henceforth T
Each time a DC signal pulse is generated, it is updated sequentially from #2 to #3 to #l, . . .

Next, the process proceeds to step 304, where the bit of the injector port corresponding to the injector on bit turned on in step 303 is turned on ((h) in FIG. 5), and at the same time, the corresponding injector is turned on. A control signal for energizing 6 is output to the drive circuit 513. This causes the injector 6 to start injecting fuel ((d) in FIG. 5).

For example, in step 303, the injector on
When the #l bit of the bit is turned on, the #l bit of the injector port is turned on, and a control signal that energizes the #1 injector 61 is output, thereby starting fuel injection to the corresponding first cylinder. be done.

Next, the process proceeds to step 305, where the injection time TOυT that has already been calculated is set to the timer set value Tset of the timer 504.
The complement of the difference between and the predetermined time ΔTi (TOUT−ΔTi)−
' is set to +-1, and then in step 306 timer 50
4 is started ((e) in FIG. 5), and this program is ended.

0; j predetermined time Δ'"j is set to a value slightly larger than the longest time of the interrupt prohibition period of the CPU 503.

Further, the timer set value TseL of the timer 504 is set as the complement of the difference between the injection time T o LI T and the predetermined time ΔTi because the timer 504 is composed of an up counter.

FIG. 4 shows a control program for controlling de-energization (valve closing) of the injector 6. In this program, the timer 504 counts up, that is, the count value reaches the overflow value 'Of, and the interrupt control circuit 502 is activated. It is executed at the same time as the CPU 303 accepts the interrupt signal to be output.In other words, when the timer 504 counts up, the CPU 3
If it does not correspond to the interrupt-prohibited section of CPU 503, this program is executed at the same time as the count-up, and if it corresponds to the interrupt-prohibited section of the CPU 503, it is executed at the same time as the cancellation ((c) in Fig. 5). (e)).

First, in step 401, the current timer read value '''
Read read. This timer read value T read is the count value of the timer 504 that is reset to O at the same time as the count up and starts counting again, that is, the timer 50
This shows the elapsed time after the count-up of 4 ((e) in FIG. 5).

Next, the process proceeds to step 7I02, and the timer read value T reFld read out in step 401 is determined for the predetermined period Δ'
It is determined whether it is larger than T' i. This answer is negative (
NO), that is, if 'I' read≦△1゛1 is established and the predetermined time ΔT i has not elapsed after the timer 504 counts up, the process returns to step 401, and the answer to step 402 is i7 constant (Yes). ) is repeated until steps 401 and 402 are reached.

The answer to step 402 is 11 (Yes), that is, l' r
ead>Δ'I''i is established, and when the predetermined time has elapsed after the timer 504 counts up, the process proceeds to step 103.

In this step 403, an injector off bit as a flag is updated corresponding to the injector 6 for which fuel injection is to be completed this time. This update involves, for example, detecting the on state of the injector boat and turning off the injector off bit corresponding to pin 1, which is the bit that is in the on state and where fuel injection is started first. carried out by. Since only one injector 6 is injecting when there is no lapping, the bit of the injector off bit to be updated is the injector off bit updated in step 303 of FIG. Corresponds to the on bit (D in Figure 5)
, (g)).

Next, the process proceeds to step 40/I, where the bit of the injector port corresponding to the bit of the injector off bit updated in step 401 is turned off ((h) in FIG. 5), and at the same time, the bit of the injector boat corresponding to A control signal to de-energize 6 is output to the drive circuit 513. As a result, fuel injection from the injector 6 is stopped (fifth
Figure (d)). For example, when the #l bit of the injector off bit is turned off in step 403, the #l bit of the injector boat is turned off, and the #1 bit of the injector port is turned off.
The drive circuit 513 sends a control signal to deenergize the injector 61.
((g) and (h) in Figure 5), fuel injection to the corresponding first cylinder is stopped (((g) and (h) in Figure 5).
d)).

In this way, at the same time as the start of fuel injection, the timer set value of the timer 504 that starts counting the injection time is
The difference between the desired injection time '0υt' and the predetermined time ΔTi is set as t (step 305), and the fuel injection is stopped after a predetermined time nIj has elapsed from the time the timer 504 counts up (step 404). In addition, since the predetermined time ΔTj is set to a value larger than the maximum time of the interrupt prohibition period of the CPU 503 as described above,
If the count-up time of the timer 504 corresponds to the interrupt-prohibited 1-hi period, the count-up value and the predetermined time ΔT
By ensuring that the interrupt prohibition is canceled before i passes through, the interrupt signal is not accepted by the CPU 503 ((c) and (e) in FIG. 5).

Therefore, there is no delay in the output of the control signal for deenergizing the injector 6, and the desired injection time 'I''OU
At T, the injector 6 starts injecting.

Next, in step 405, the operation of the timer 504 is stopped ((e) in FIG. 5), and the process proceeds to step 106 to check whether all injector boats are in the OFF state, that is, all injectors 6 stop fuel injection. Determine whether or not the device is in a state where the When there is no lapping, all injectors 6 immediately after the - injector 6 completes injection.
Since fuel injection is stopped, the answer to step 406 is iq constant (Yes), and the program ends.

By repeating the above-described execution during non-lap, the actual injection times of the plurality of injector lids 61 to 63 are sequentially controlled to the set injection time TOUT.

Returning to the control program of FIG. 3, if the answer to step 302 is 1 (Yes), that is, one bit of the injector boat is already in the on state, one injector 6 is continuing fuel injection. It is determined that there is, and in the next steps 307 to 311, control is executed during one lap, that is, when fuel injection is performed in parallel from the two injectors 6. FIG. 6 shows a timing chart during one lap. First, in step 307, the injector is turned on in response to the 'I'' DC signal pulse inputted this time, similar to step 303 in the case of no lap.・
The bit is updated, and then the process proceeds to step 308, in which the bit of the injector boat is turned on corresponding to the injector on bit updated in step 307, and at the same time, the control signal for energizing the corresponding injector 6 is sent to the drive circuit. 513 to start fuel injection from the injector 6 ((b), (d), (f), (in FIG. 6)).
h)).

Next, the process proceeds to step 309, where the currently operating timer 504
The timer read value T read is read. During one lap, the timer 504 is set at the time of the previous loop, that is, the previous T.
The energization time of the injector 6 that started injection when the DC signal pulse was input is measured, and the timer read value "rr"
ead corresponds to the time until the timer 504 counts up. For example, the TD input during this loop
If the C signal pulse corresponds to the #1 injector 61, the timer read value Tread at this time is the count up of the timer 504 that measures the energization time of the #3 injector 63 whose injection was started during the previous loop. The values corresponding to the time up to ((d) and (e) in Fig. 6) are shown.

Next, the process proceeds to step 310, and the timer read value T read out in step 309 from the injection time 1'OUT set for the injector 6 where fuel injection has started this time.
The complement of read (Tread)-' and the predetermined time Δ
subtract twice 'ri' and set the difference in the first timer set wait term Twait1. Double predetermined time ΔT
i is a predetermined time ΔT applied when the injector 6, which started fuel injection in the previous loop, is deenergized.
This is because it is necessary to also subtract i minutes.

Next, in step 311, the first timer set wait term Twait+ set in step 310 is also set in a second timer set wait term Twait2, which will be described later, and the program ends. That is, during one lap, the timer 504 is activated as in the case of two laps, which will be described later.
Only the setting and storage of the timer set value Tset is executed by this program, and the operation of the timer 504 is controlled by the control program shown in FIG.

Next, the timer 504, which was counting the energization time of the injector 6 during which fuel injection was started in the previous loop of the control program shown in FIG. 3, counts up, and the interrupt signal is
When the PU 303 is accepted, execution of the control program shown in FIG. 4 is started.

First, steps 401 and 402 are executed. The timer read value Tread read in step 401 is l
During the lap, 11η of the control program in Figure 3
This corresponds to the injector 6 that started fuel injection during the second loop.

If the answer to step 402 is affirmative (Yes), that is, the timer 50
After the count-up of 4, when the predetermined time ΔTi has elapsed, the process proceeds to step 403, and the injector off bit is updated. That is, during one lap, the injector 6 whose energization was started during the previous loop of the control program in FIG. 3 corresponds to the one that should finish injection, so the injector off bit is updated corresponding to this injector 6 do.

For example, if injection from #1 injector 61 is started during the current loop of the control program shown in FIG.
Injector 6 where injection was started during the previous loop
, that is, the injector corresponding to #3 injector 63
Bit #3 of the OFF bits is updated to OFF ((g) in FIG. 6).

Next, the process proceeds to step 404, in which the injector boat corresponding to the injector off bit updated in step 402 is turned off, and at the same time, a control signal is output to de-energize the corresponding injector 6, and the fuel injection of the injector 6 is performed. ((d) and (h) in Figure 6).

Next, step 405 is executed, the timer 504 is stopped, and step 406 is executed. l
At the time of wrapping, the answer to step 406 is negative (No
), the process advances to step 407.

In this step 407, the timer set value ]'set of the timer 504 is set to the first value set in step 310 of FIG.
Set the complement of the timer set wait term Twait+ of
Next, in step 408, the operation of the timer 504 is started ((e) in FIG. 6), and in step 409, the second timer set in step 31+ of FIG. Timer set wait term TwaiL
2 and exit this program.

As shown in -1=, during one lap, fuel injection is started from the corresponding injector 6 at the same time as the TDC signal pulse force is applied, and the time until the count up of the currently operating timer 504 is set to the timer read value. Read as Tread, injection time of the relevant injector 6 "I" 0
0 to the complement of the timer read value (Tread)-',
TOLI is calculated by subtracting twice the predetermined time ΔTi.
T - (Tread) -'-2Δ'"i)1' w
Store it as a it, l. Furthermore, after the start of injection from the injector 6, (Tread)-'+Δ'I
``When i elapses'' two-note difference (GO0UT-(Tread)-
'-2ΔTi) is set in the timer 504 and restarted. After this reactivation, the timer 504 counts up when the timer set time (T0LIT-(Tread)-'-2ΔTi) has elapsed, and the fuel injection from the injector 6 is stopped after the predetermined time ΔTi has elapsed.

That is, the injection time of the injector 6 is the time from the start of injection until the timer 504 is restarted ((Tread)-'
+△Ti), timer set time (T 0LIT - (T
read) −′−2Δ′ “j) and the predetermined time ΔTi
Therefore, if, IJ lit is set to the set injection time pQTour. In addition, as in the case of no lap described in 1);j, the fuel injection of the injector 6 is terminated when the predetermined time ΔTi has elapsed after the timer 504 counts up, so the CPU
Regardless of whether or not it falls under the 303 interrupt prohibited section,
Injection time of injector 6 desired injection time 'rOUT
can be controlled.

Thereafter, by repeating the same execution, the injection time of each injector 61 to 63 is sequentially adjusted to the desired injection time TO.
Controlled by UT.

Returning to the control program of FIG. 3, the answer to step 301 is 17 (Yes), that is, 2
When the bits are already in the on state, it is determined that the two injectors 6 are continuing fuel injection, and the process proceeds to the next steps 312 to 315. Control is executed when fuel injection is performed in parallel. FIG. 7 shows a timing chart for these two laps.

First, in step 312, the injector on bit is updated in accordance with the TDC signal pulse input this time, as in the case of no wrap and 1 wrap (step 303 and step 307), and then the injector on bit is updated in step 312. Step 313 and step 304 and step 30
Similarly to 8, the bit of the injector boat corresponding to the updated injector on bit is turned on, a control signal is output to energize the corresponding injector 6, and fuel injection of the corresponding injector 6 is started. ((b), (d), (f), (h) in Figure 7).

Next, proceed to step 3+4 and set the current timer read value 'I
' Read read. The timer read value Tread at the time of the second lap is the timer read value Tread at the time of the loop before the previous time, that is, the value Tread from the time before the previous time.
This corresponds to the time until the count-up of the timer 504, which measures the energization time of the injector 6 when fuel injection is started when the DC signal pulse is input ((d) in FIG. 7).

Next, the process proceeds to step 315, and from the already calculated injection time TOUT, the complement (Tread) of the timer read value T read read out in step 314, the first timer set in step 409 of FIG. The value obtained by subtracting the set wait term ``I''waitx and three times the predetermined time Δ1゛1 is calculated as the second timer set wait term Twaitx.
Set to z and exit this program. At this time, the first timer set wait term Twaif,+ is the value of the second timer set wait term 'I''wait2 that was set in step 315 during the previous loop, as is clear from step 409 in FIG. 4, which will be described later. (d in Figure 7)
)). Next, the timer 504 counts up and an interrupt signal is accepted by the CPU 303, thereby starting execution of the control program shown in FIG.

First, steps 40+ and 402 are executed. The timer read value T read read in step 401 corresponds to the injector 6 for which fuel injection was started during the previous loop of the control program shown in FIG. 3 at the time of step. The answer to step 402 determines Bi (Y
es), that is, when the predetermined time ΔT i has elapsed after the timer 504 counts up, the process proceeds to step 403;
Update injector off bit. That is, at the time of step, the injector 6 whose fuel injection was started first corresponds to the one whose fuel injection was started during the previous loop of the control program shown in FIG. - Bits are updated. For example, if the fuel injection of the #l injector 61 is started during the current loop of the control program shown in FIG. Bit #2 of the OFF bits is updated to OFF ((g) in FIG. 7).

Next, as in the case of no lap and 1 lap mentioned above,
Turn off the injector boat bit corresponding to the updated injector off bit (h) in Figure 7.
), the fuel injection of the corresponding injector 6 is ended (step 404) ((C) in FIG. 7), and the operation of the timer 504 is stopped (step 405) ((e) in FIG. 7).
Furthermore, step 406 is executed.

At step time, the answer to step 406 is negative (
No), the process proceeds to step 407, where the first timer set wait term Twait+ is set to the timer set value 1' s
The timer 504 is set as e t. As is clear from step 315 in FIG. 3 and step 409 in FIG.
The second timer set wait term Twait set in 15
Equal to 2. Next, the timer 504 is restarted (step 408) ((e) in FIG. 7), and the second timer set wait term Twait2 set in step 315 is set in the current loop of the control program in FIG. 3 (l'). The program shifts to the timer set wait term Twait+ of timer set Twait+ (step 409) and ends this program.

As described above, at the time of stepping, fuel injection is started from the corresponding injector 6 at the same time as the human power of the TDC signal pulse, and the time until the count-up of the currently operating timer 504 is read out as the timer read value Tread. Injection time of injector 6 1'0IJT
, the complement of the timer read value ('read) -', the first timer set wait term Twait set as the timer set value for the injector 6 whose injection was started when the previous TDC signal pulse was input, +, and a predetermined predetermined value. time Δ
Time after subtracting 3 times Ti (Tot+τ-(Trea
d) -'-Twait, 1-3Δ1゛i)
Store it as tl. Furthermore, after the injection of the injector 6 starts ((Tread)-'-+-Δ'I" i
) elapses, the timer 504 is re-activated, and after this re-activation, the above-mentioned time (Ta
ut -(Tread)-'-"l'wait+-
3ΔTi) is set in the timer 504 and activated again. After this repeated operation, the timer set time ("I"0IJT - (Tread) -' -Twa
itl-3ΔTi), the timer 504 counts up, and after a predetermined time Δ′I″i has elapsed, fuel injection from the injector 6 is stopped. That is, the injection time of the injector 6 is determined by the timer 504 from the start of injection. time until re-activation (('rread)-'10ΔTi), time from re-activation of timer 504 to re-activation (Twai
t++ΔTi), the time from the timer 504's repeated activation to its count-up ('"our - (']" re
ad) -' -Twait+-3ΔTi) and the predetermined time is the sum of T1, so the set injection time 1''O
Controlled by UT. In addition, the fact that the injection time of the injector 6 can be controlled to the desired injection time TOUT regardless of whether or not the count-up time of the timer 504 corresponds to the interrupt-prohibited period of the CPU 503 is that the injection time of the injector 6 can be controlled to the desired injection time TOUT. This is similar to the case when lapping.

In addition, in this embodiment, an example was shown in which one timer is used as a time counter and a 3v4 fuel injection valve is controlled as an electric device, but the present invention is not limited to this, and the present invention The type and number of can be implemented in various ways.

In particular, as in this embodiment, if the (=J) standby time of a plurality of electrical devices is controlled by a single time counter, the cost of the control device can be reduced by reducing the precision of the time counter. It becomes possible.

(Effects of the Invention) As described in detail, the present invention measures the current time of an electrical device and uses the count value of the 31 o'clock counter that generates an interrupt (J) when the count up is reached. Set 5, +, obtained by subtracting a predetermined time from the desired zero time of
);jThe arithmetic processing means outputs an energization termination command for the electric device after a predetermined time has elapsed. Therefore, even if the arithmetic processing means has a τjth interrupt-prohibited period in which it receives an interrupt signal, by setting the predetermined time nij to a value larger than the longest time of the interrupt-prohibited period, The energization time of the device can be controlled to the desired value set,
As a result, it is possible to improve the drivability, fuel efficiency, etc. of the internal combustion engine. Moreover, if the time counter is 11'L-, the number of installations thereof will be reduced compared to the conventional one, and therefore it will be possible to reduce the cost of the control device.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an overall +1 force diagram of a fuel supply control device to which the control force method of the present invention is applied;
Figure 2 shows the inside of electronic control unit 1~ in Figure 1 (
FIG. 3 is a flow chart of a control program for controlling selection and energization of injectors according to the present invention; FIG. 4 is a flow chart of a control program for controlling de-energization of injectors according to the present invention; FIGS. 5 to 7 are timing charts showing fuel injection timing, tearing counter operation timing, etc. corresponding to mutually different fuel injection states. ■...Internal combustion engine, 5...Electronic control unit (ECU), 6...Injector (electrical device), 1
1... Engine rotation speed (Ne) sensor, 12... Cylinder discrimination (CYL) sensor, 502... Interrupt control circuit,
503... Central processing unit (CPU) (arithmetic processing means), 504... Timer (crying time counter), 513...
・Drive circuit.

Claims (1)

[Claims] 1. The energizing time of the electric device that controls the operation of the internal combustion engine is calculated by a calculation processing means according to the operating state of the internal combustion engine, and the calculated energization time is measured by a time counter, and the electric power is An internal combustion engine that outputs a command to start energizing a device, generates an interrupt signal when the time counter ends, and outputs a command to end energization of the electrical device from the arithmetic processing means in response to the interrupt signal. In the method for controlling an electrical device, the difference obtained by subtracting a predetermined time from the energization time is set as the count value of the time counter, and the control is performed after the predetermined time elapses from the generation of the interrupt signal of the time counter. A method for controlling an electrical device of an internal combustion engine, the method comprising outputting an energization termination command.