JPS6011650A - Fuel injection device - Google Patents

Abstract

PURPOSE:To make it possible to carry out the high-responsive control of fuel injection in accordance with variations in the operating condition of an internal- combustion engine, by changing the timing of initiation of the process step of determining the amount of fuel injection in accordance with the rotational speed of the internal-combustion engine. CONSTITUTION:An MPU to which a rotating angle position signal C3 is delivered from a crank angle sensor 9 through a data input section 12, detects an engine rotational speed, and then accesses a memory 11 in order to determine the initiation timing of the next process step in accordance with the detected rotational speed. Then, the MPU receives an output signal from an air volume sensor 3 through an AD converter 8 and a data input section 12 to compute the amount of fuel injection in accordance with the engine rotational speed singal and as well to obtain the time period of fuel injection corresponding to the fuel injection amount. Thereafter, when such a condition that the sensor 9 issues a top dead center signal is detected, an injector 6 is driven by means of a data output section 13 and a down counter 14.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to (1) an improvement in a fuel injection device that controls the amount of fuel injection based on the amount of air flowing into an internal combustion engine.

Prior Art and Problems Internal combustion engines such as automotive engines have a sensor that detects the amount of incoming air, calculates the fuel injection amount based on the detection result of the sensor, and adjusts the fuel injection timing. A fuel injection device that injects an amount of fuel corresponding to the calculation result (== the amount of fuel corresponding to the calculation result) has been conventionally used. Since acceleration, deceleration characteristics, drivability, and exhaust gas transient characteristics are affected, setting their timing is an important issue.

FIG. 1(A) to CD) is an explanatory diagram of a conventional example called an asynchronous method, and FIG. 1(A) shows a top dead center signal TDC,
FIG. 5B shows the reading timing of the Senna detection results, CC) shows the calculation timing, and FIG. 1D shows the fuel injection timing.

This method reads the detection results of the two sensors and calculates the fuel injection amount based on the reading results at regular intervals T, as shown in the same figure (D) (2).
), fuel is injected for a period of time corresponding to the latest calculation result from the timing when the top dead center signal becomes "1", but it has the following drawbacks. In other words, this method reads the detection results of the senna at a fixed time T1 and calculates the fuel injection amount based on the reading results, and the delay time from the end of the calculation to the start of fuel injection varies, and the maximum Therefore, there is a drawback that it is not possible to perform injection control with good responsiveness in response to changes in the state of the internal combustion engine (for example, acceleration, deceleration, etc.).

Figures 2 (A) to CE) are explanatory diagrams of another conventional example called the synchronous method, in which Figure 2 (A) shows the top dead center signal, and Figure 2 (B) shows the crank at a constant angle (in this case (C) shows the rotation angle position signal output every time it rotates (60°).
indicates the reading timing of sensor detection results, and CD
) shows the calculation timing of the fuel injection amount, and (E) in the figure shows the fuel injection timing.

As shown in (B) to (D) in the same figure, this method starts from the time when a specific rotation angle position signal (rotation angle position signal Co in this case) (6) is detected and reads the detection results of the senna. The fuel injection amount is calculated based on the calculation result, and fuel is injected for a period corresponding to the latest calculation result from the timing when the top dead center signal becomes "1", as shown in CB in the same figure, for example. It had the following drawbacks:

The top dead center signal becomes “1” after the rotation angle position signal C9 is generated.
The time required for this to occur varies depending on the rotational speed of the internal combustion engine, and the higher the rotational speed, the shorter the above-mentioned time becomes. is always a constant time T regardless of the rotation speed
1, therefore, when the rotational speed is high, the calculation E1. E2 may not end. In such a case, the calculation results of calculations E1 and E2 will be used for the next injection H1 and H2, respectively, as shown in CE in the same figure, and the delay from the end of calculation to the start of fuel injection will be reduced. Since it takes a long time, it has the disadvantage that it is difficult to perform injection control with good response characteristics (4) according to changes in the state of the internal combustion engine. In order to improve this drawback, it is conceivable to start reading the sensor detection results when a specific rotational angular position signal before the rotational angular position signal C0 is detected, but in this case, the rotation of the internal combustion engine When the number is low, there is a drawback that it is difficult to perform injection control with good responsiveness because the delay time from the end of calculation to fuel injection becomes long.

In addition to this, fuel injection is started at the timing when the top dead center signal becomes "1", and processing for determining the fuel injection amount (reading of Senna detection results, A method has also been proposed in which fuel injection amount calculation is started and fuel is injected for a time corresponding to the calculation result from the timing when the top dead center signal becomes "1". If the time is shorter than the time required for the process to determine the fuel injection amount (for example, during idling), fuel may continue to be injected until the process is completed even though a predetermined amount of fuel has already been injected. (5) Therefore, there is a disadvantage that the twisting cost is low and raw gas is exhausted.

OBJECTS OF THE INVENTION The present invention has been made to improve the above-mentioned drawbacks, and its purpose is to enable highly responsive injection control in response to changes in the state of the internal combustion engine.

Configuration of the Invention FIG. 7 is a configuration diagram of the present invention. The sensor 100 detects the amount of air flowing into the internal combustion engine, and the calculation means 101 calculates the fuel injection amount based on the detection result of the sensor 100.

The detection means 102 detects the rotation speed of the internal combustion engine, and the timing control means 103 controls the processing start timing of the calculation means 101 based on the detection result of the detection means 102. The injection means 104 injects an amount of fuel corresponding to the calculation result of the calculation means 101 at a predetermined timing.

Embodiment of the Invention FIG. 3 is a block diagram of an embodiment of the present invention, in which 1 is an internal combustion engine, 2 is an air cleaner, 3 is an air amount sensor, 4 is a throttle chamber, 5 is an intake manifold, and 6 is an electromagnetic tube. 7 (6) is a throttle valve, 8 is an AD converter, and 9 is a top dead center signal T as shown in FIG. 4 (A) every time the crank reaches top dead center.
A crank angle sensor which outputs DC as well as rotational angular position signals C8 to C1□ every time the crank rotates by 30 degrees, as shown in FIG. 15 is an input section, 15 is a data output section, 14 is a down counter, and when the count value is "0"
The output signal is held at "1" until it becomes "1". Further, FIG. 5 is a flowchart showing the processing contents of the microprocessor 10, and the operation will be explained below with reference to FIG.

When the microprocessor 10 detects that the rotation angle position signal C5 is applied from the crank angle sensor 9 via the data input section 12 (step S'1), it starts counting the internal clock (step S2), and then , when the rotation angle position signal C1l is detected (step 85), the counting of the internal clock ends (step S4). In this case, the time between the rotation angle position signals C3 and C0 becomes shorter as the rotational speed of the internal combustion engine increases (7), so the count value corresponds to the rotational speed of the internal combustion engine.

Next, the microprocessor 10 accesses the memory 11 based on the count value (==) and determines which rotation angle position signal is detected to start the process of step S8 (step S5). In this case, the memory 11 As shown in FIG.
If ≦COU<K1, it is determined that the process of step S8 is started when the rotation angle position signal C♂ is detected. Next (step S6, the second microprocessor 10 sets the count value to "0"), and then detects the rotation angle position signal CN determined in step S5 (step S7).
), the AD converter 8, and the data input unit 12 to read the detection result of the air amount sensor 9-6 (step S
8), then calculate the fuel injection amount based on the read result (step S9), and then calculate the fuel injection time corresponding to the fuel injection amount determined in step S'9 (step 5).
10). After that, when it is detected that a top dead center signal is applied from the crank (8) tilt angle sensor 9 via the data input section 12 (step 511), the microprocessor 10 executes the fuel injection time determined in step S10. Find the value corresponding to , and set it in the down counter 14 (Step S'12).

After this, the process returns to step S1.

The down counter 14 increments its count value by 1 every time the clock signal CK is applied, and holds its output signal α at 1'' until the count value reaches 0. Fuel is continued to be injected while the signal α is "1".Therefore, in step S12, the fuel injection time (two windows) is calculated by the down counter 14 (
By setting the initial value, the amount of fuel saved in step S9 is injected into the internal combustion engine 1 (2).

As described above, in this embodiment, the timing for starting the processing in step S8 is changed according to the count values obtained in steps 81 to S4, that is, the rotational speed of the internal combustion engine (= the timing at which the process in step S8 is started, as can be seen from FIG. As shown in FIG.
Since the timing at which the process starts is delayed, the delay time from the end of calculation of the fuel injection amount to the start of injection can be reduced, and therefore, the injection has better responsiveness compared to the conventional example. can be controlled.

In the embodiment, the amount of air flowing into the internal combustion engine is detected by the air amount sensor B; however, it is of course possible to detect it by an air pressure sensor.

As described in detail, the present invention sets the start timing of the process (steps 88 to 510 in the embodiment) for determining the fuel injection amount according to the rotational speed of the internal combustion engine to LA. As a result, the delay time from the end of the above processing to the fuel injection can be shortened regardless of the rotational speed of the internal combustion engine. This has the advantage that good injection control can be performed.

(10)

[Brief explanation of drawings]

Figures 1 (CA) to (D) and Figures 2 (A) to (E) are explanatory diagrams of different conventional examples, Figure 3 is a configuration diagram of an embodiment of the present invention, and Figures 4 (A) and CB. ) are waveform diagrams of the top dead center signal 9 rotation angle position signals, FIG. 5 is a flowchart showing the processing contents of the microprocessor, FIG. 6 is a diagram showing the storage contents of the memory, and FIG. 7 is a configuration diagram of the present invention. It is. 1 is an internal combustion engine, 2 is an air cleaner, 3 is an air volume sensor,
4 is a throttle chamber, 5 is an intake manifold, 6 is a fuel injector, 7 is a throttle valve, 8
9 is an AD converter, 9 is a crank angle sensor, 10 is a microprocessor, 11 is a memory, 12 is a data input section, 13
is the data output section, 14 is the down counter, 100 is the centimeter, 101 is the performance patent applicant Fujitsu Ten Ltd. agent Patent attorney Tamamushi Kugobe (1 other person) (11) Herishiyu, \no \no 3rd Figure CI2' CI C2Cs C4Cs CG C7CB
C9Coo ClIC+2 CI 62r+nnr+
nnr+nnr+nnr+nr+Figure 5" Cs detection sI ES Count opening table 82 NOc6 interjection S3 ES Counting end S4 Access memo January 1, -O56 No cN detection S7 ES

Claims (1)

[Claims] In a fuel injection device that injects fuel corresponding to the amount of air flowing into the internal combustion engine into the internal combustion engine at a predetermined timing, the senna detects the amount of air flowing into the internal combustion engine, and the detection of the senna A calculation means for reading the result and calculating the fuel injection amount based on the read result, a detection means for detecting the rotation speed of the internal combustion engine, and controlling a processing start timing of the calculation means based on the detection result of the detection means. A fuel injection device comprising: timing control means for injecting fuel into the internal combustion engine at a predetermined timing in an amount corresponding to the calculation result of the calculation means.