KR930002079B1 - Fuel control device - Google Patents

Abstract

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Description

Fuel controller

1 is a block diagram of a fuel control device according to an embodiment of the present invention.

2A and 2B are block diagrams showing the configuration of the control circuit in the embodiment of FIG. 1, respectively.

3 is a circuit diagram of a power amplifier and a power amplifier stop circuit provided inside the control circuit of FIGS. 2A and 2B.

4A, 4B, and 4C are flowcharts showing the flow of CPU operation in the control circuits of FIGS. 2A and 2B, respectively.

Fig. 5 is a timing chart showing the relationship between the crank angle detector and the detection rotation speed for explaining the operation of the misfire detection means in the embodiment.

6 is a block diagram of a conventional fuel control device.

* Explanation of symbols for the main parts of the drawings

1: engine 11: crank angle detector

20: control circuit 51 to 56: fuel injection valve

200: microprocessor (CPU)

The present invention relates to a fuel control device for detecting extinguishing of an internal combustion engine and stopping fuel supply to a specific fire extinguisher.

Recently, an electronically controlled fuel injector that is rapidly installed in a vehicle is a device for making a mixer supplied to an engine fuel chamber, and converts the engine revolutions or intakes into an electrical signal and processes it with a microcomputer to generate a signal representing an optimum air-fuel ratio. This signal controls the valve opening time of the fuel injection valve electronically driven to adjust the air-fuel ratio, thereby maintaining the engine operating state to the maximum.

In this type of electronically controlled fuel injection device, an exhaust purification device (catalyst) is generally provided in the exhaust passage. For example, as an exhaust purification device, a three-way catalytic device that simultaneously performs oxidation of Co and Hc and reduction of Nox is used. In this case, the set air-fuel ratio is set to a value near the theoretical air-fuel ratio to efficiently reduce harmful components in the exhaust gas.

By the way, in the above-described electronically controlled fuel injector, when combustion occurs in a cylinder due to component failure, poor contact of wiring, malfunction, etc., and fire extinguishing occurs, a mixture of unburned fuel and air is transferred to the catalytic device. As a result of the rapid chemical reaction in the catalyst device, the temperature of the catalyst device is greatly increased, resulting in deterioration of the catalyst device and the discharge of harmful components in the exhaust gas into the atmosphere, or when the vehicle is stopped. If dry grass or the like comes into contact with the device, there is an inconvenience of a fire.

In order to prevent this, for example, Japanese Patent Laid-Open No. 63-63933 discloses determining fire extinguishing as a result of detection of pressure in a cylinder of an internal combustion engine.

A conventional fuel control device is shown in the block diagram of FIG. 6, in which 200 is a microprocessor (hereinafter referred to as a CPU), 208 is a drive pulse width counter, and 209 is a power amplifier (drive circuit). And 51 to 56 are electronic fuel injection valves.

Next, the operation will be described. The CPU 200 outputs a digital signal corresponding to the valve opening time of the electronic fuel injection valves 51 to 56 to the drive pulse width counter 208.

The drive pulse width counter 208 down counts this digital signal, converts the digital signal into a pulse signal having a pulse duration width, and outputs the pulse signal to the power medium width section 209.

The power amplifier 209 amplifies the output of the drive pulse width counter 208 to drive the electronic fuel injection valves 51 to 56 to supply fuel to the engine.

Since the conventional fuel control device is configured as described above, even if the fuel supply to the fire extinguishing cylinder is to be stopped, the driving circuit of the electronic fuel injection valves 51 to 56 of each cylinder, that is, the power amplifier 209 is shared and grouped together. It is impossible to stop the fuel supply of only the fire extinguishing cylinder, and the fuel supply of the fire extinguishing cylinder which can be burned normally cannot be stopped together.

For this reason, there is a problem that the fuel supply to the cylinder of the engine is stopped and the engine must be stopped even though the engine has the ability to drive itself to the repair shop.

The present invention has been made to solve the above problems, and to obtain a fuel control device that can accurately detect the engine's fire extinguishing cylinder, can provide a fuel supply, prevent catalyst deterioration and fire risk. The purpose. In addition, the present invention, at least two electronic fuel injection valves open at the same time for each cylinder and open, and if the extinguishing cylinder of the internal combustion engine supplying fuel is detected, the drive of the electronic fuel injection valve of the extinguishing cylinder is stopped, and when extinguishing occurs It is an object of the present invention to obtain a fuel injector capable of preventing the deterioration of the catalyst, the emission of harmful gases, the risk of fire, and the self-driving to the repair shop.

The fuel control device according to the present invention includes fire extinguishing detection means for calculating information corresponding to the rotational speed at a predetermined crank angle period corresponding to each cylinder of the engine, and detecting the extinguishing state of the engine by the amount of change or rate of change of the information, and extinguishing is confirmed In the old cylinder, a control circuit for stopping fuel supply is provided.

In the present invention, the fire extinguishing detecting means calculates information corresponding to the engine rotational speed at any predetermined crank angle period, detects the fire extinguishing cylinder of the engine by the amount of change or the rate of change of the information, and detects the fire extinguishing cylinder to the control circuit. The fire extinguishing cylinder acts to stop the fuel supply.

In addition, the fuel control apparatus of the present invention includes fire extinguishing detection means for detecting extinguishing of a cylinder for supplying fuel by simultaneously driving and opening at least two or more electronic fuel injection valves; The fuel supply is stopped by stopping the operation and opening of the valve of the electronic fuel injection valve only in the extinguished cylinder.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, the engine 1 is a four-cycle spark-ignition engine mounted on an automobile, and takes in combustion air through the air cleaner 2, the intake pipe 3, and the throttle valve 4. As shown in FIG. Electronic fuel injection valves 51 to 56 are opened and operated at the output of the control circuit 20 to supply fuel to each cylinder.

The exhaust gas after combustion is discharged to the atmosphere via the exhaust manifold 6, the exhaust pipe 7, and the like.

The intake pipe 3 is provided with an intake air amount detector 8 which detects the intake air amount sucked into the engine 1 and outputs an analog voltage corresponding to the intake air amount.

In addition, a thermistor type intake air temperature sensor 9 which detects the intake air temperature and outputs an analog voltage corresponding to the intake air temperature is provided.

The engine 1 is provided with a thermistor type water temperature sensor 10 that detects the cooling water temperature and outputs an analog voltage (analog detection signal) according to the cooling water temperature. The crank angle detector 11 is provided with an engine 1. Detect the rotational speed of the crankshaft and output the pulse signal of the frequency according to the rotational speed.

The throttle valve is also provided with an idle switch 12 for detecting that the throttle valve opening degree is equal to or less than a set value.

The control circuit 20 is a circuit for calculating the fuel injection amount based on the detection signals of the intake air amount detector 8, the intake air temperature sensor 9, the water temperature sensor 10, the crank angle detector 11, and the idle switch 12. The fuel injection amount is adjusted by controlling the valve opening time of the electronic fuel injection valves 51 to 56.

Next, the control circuit 20 of FIGS. 2A and 2B will be described. First, in FIG. 2A, 200 is a microprocessor (hereinafter referred to as a CPU) for calculating the fuel injection amount. 201 is a rotation speed counter which is a rotation speed counter which counts the engine rotation speed by the signal from the crank angle detector 11.

The rotation speed counter 201 sends an insertion command signal to the insertion control unit 202 in synchronization with engine rotation.

When the insertion control unit 202 receives this signal, the insertion control unit 202 outputs an insertion signal to the CPU 200 via the common bus 212.

The digital input port 203 transmits a digital signal such as a starter signal from the starter switch 13 to turn on / off the operation of a starter (not shown) to the CPU 200.

The analog input port 204 is composed of an analog multiplexer and an AD converter. Each of the signals from the intake air amount detector 8, the intake air temperature detector 9, and the water temperature sensor 10 for cooling is converted to the AD 200 in order. ) To read.

The output signals of the rotation speed counter 201, the insertion control unit 202, the digital input port 203, and the analog input port 204 are transmitted to the CPU 200 via the common bus 212.

205 is a power supply circuit, and is connected to the battery 14 via the key switch 15. 206 is a random access memory (hereinafter referred to as RAM) capable of reading and writing. 207 is a read-only memory (hereinafter referred to as ROM) that stores programs, various constants, and the like.

208 is a counter for controlling fuel injection time including a register. The counter 208 includes a down counter. The counter 208 is a digital signal indicating a valve opening time of the electronic fuel injection valves 51 to 56 calculated by the CPU 200, that is, a fuel injection amount. It converts into the pulse signal of the pulse time width which gives the valve opening time of the fuel injection valves 5l-56.

209 is a power amplifier for driving the electronic fuel injection valves 51 to 56. 211 is a rudder, which measures elapsed time and transmits it to the CPU 200.

The rotation speed counter 201 measures the predetermined crank angle cycle time of the engine by the output of the crank angle detector 10, and supplies an insertion command signal to the insertion control unit 202 at the end of the measurement.

The insertion control unit 202 generates an insertion signal in response to the signal, and causes the CPU 200 to execute an insertion processing routine for calculating the fuel injection amount.

FIG. 4A shows a schematic flowchart of the CPU 200. The functions of the CPU 200 are explained based on this flowchart and the operation of the entire structure is described.

When the key switch 15 and the starter switch 13 are turned on, and the engine 1 is started, the arithmetic processing of the main routine is started at the start of step S0, and the initialization process is executed at step S1. In step S2), the digital value corresponding to the cooling water temperature from the analog input port 204 is read.

In step S3, the fuel correction amount K is calculated as a result, and the result is stored in RMA206. When step S3 is complete | finished, it returns to step S2.

Normally, the CPU 200 repeatedly executes the processing of the main routine of steps 1 (S2 and S3) in FIG. 4A according to the control program.

When the insertion signal from the insertion control unit 202 is input, the CPU 200 stops the processing even if the main routine is in process and moves to the insertion processing routine of step S40 shown in FIG. 4C.

In step S41, the predetermined crank angle period read by the rotation speed counter 201 is read. The predetermined crank angle is set every 120 degrees in this embodiment. Then, in step S42

In this embodiment, the number of revolutions is calculated and stored in the RAM 206 by the phosphorus operation.

Next, in step S43, it is checked whether or not it is an operating state for detecting fire extinguishing. This is, for example, the steady state detection means for detecting whether the engine is in a rapid acceleration state by the amount of change in the intake air, the output signal of the idle switch 12, the neutral switch signal not shown here, and the idle relative detection means composed of the vehicle speed signal. The output is checked and the digestion is detected only in the normal or idle state of the organ.

If it is determined in the fire extinguishing detection operation state in step S43, the flow advances to step S14, and if it is determined out of the fire extinguishing detection operation state, the flow advances to step S47.

In step S44, the previous rotational speed stored in the RAM 200 and the change amount of the rotational speed are calculated in the step S42 during the last insertion process. In step S45, a magnitude comparison between the amount of change and a predetermined determination value is performed.

If the amount of change is larger than the determination value on the rotation lowering side, the flow advances to step S46. If the cylinder misfire plug is stored in the RAM 206, and if the amount of change is smaller than the determination value or larger on the rotation rising side, step S46. Does not process and proceeds to step S47 as is.

The contents of step S46 from step S44 will be described in more detail with reference to FIG. 5. For example, as shown in FIG. 5 (b) at the time of insertion timing A, it is compared with the change amount of rotation speed (this time-the previous time).

Here, if extinguishing has occurred due to the combustion of the # 2 cylinder now, the engine cannot output one torque, and the rotational speed is significantly smaller than the previous rotational speed and exceeds the determination value.

As shown in Fig. 5 (a), the crank angle detector corresponding to the # 1 cylinder, for example, has a longer H level period than the corresponding to the # 2 through # 6 cylinder so that each cylinder can be identified. Since the cylinder in which the digestion is detected can be identified, in step S46, the extinguishing plug of the characteristic cylinder is set and stored in the RAM 206. The extinguishing means is constituted as described above.

Moreover, as shown in FIG. 5 (f)-FIG. 5 (h) (only the part corresponded to the electromagnetic injection valves 51-53), the electromagnetic injection valves 51-56 are FIG. 5 (c). As shown in Fig. 5E, the cylinder identification signal is used to open the valve in the exhaust process of each cylinder.

Next, in step S47 of FIG. 4C, the analog input port 204 receives the signal indicating the amount of intake air.

Next, in step S48, the basic fuel molecular weight determined by the engine speed and the intake air amount is calculated.

Next, in step S49, the correction amount for fuel injection determined by the main routine is read from the RAM 206, and a correction operation for the injection amount (injection time width) for determining the air-fuel ratio is performed.

Next, in step S50, the presence or absence of a fire extinguishing plug in the cylinder to be injected at this time is checked, and the fire extinguishing plug is set, and the flow proceeds to step S52. If the fire extinguishing plug is not set, the injection amount is changed in step S51. It sets to the counter, opens the electromagnetic injection valve of the cylinder in an exhaust process, and returns to a main routine by following step S52. A schematic function of the microprocessor 200 is as described above.

In this embodiment, in step S44 of FIG. 4C, in step S46, the amount of change in rotational speed (this rotational speed-the previous rotational speed) is calculated and compared with the judgment value. The same effect can be obtained even if the amount of change of information corresponding to the number is calculated, and the rate of change = (this rotational speed-the lower rotational speed) is calculated for this rotational speed and compared with the judgment value.

In the above embodiment, the rotational speed was calculated at a crank angle of 120 degrees, and the combustion process in which the generation of torque during combustion was very remarkable (for example, TDC (top dead center) to ATDC (after top dead center) 30 °) was calculated. Doing arithmetic with a house can detect fire extinguishing more clearly.

Referring now to the control circuit of FIG. 2B, portions having similar reference numerals as in FIG. 2A have similar configurations and functions, and thus description thereof will be omitted.

The power amplifiers 209 are provided corresponding to each of the electronic fuel injection valves 51 to 56, and six of them are driven simultaneously by the output of the same counter 208.

210 is an electric power amplification part stop circuit, and has the function of stopping the power amplification part 209 of the electronic fuel injection valve of a fire extinguisher by the command from CPU200, and stopping the drive of an electronic fuel injection valve. This can be easily achieved with a circuit as shown in FIG. In FIG. 3, 2090 is a transistor that constitutes the main body of the power amplifier 209, the base of which is connected to the power supply through the resistors R1 and R2, and the counter is connected to the resistors R1 and R2. The output of 208 is input and the emitter is grounded and the collector is connected to the electronic fuel injection valve 51.

In addition, 2100 is a transistor which forms the main body of the power amplifier stop circuit 210, and the main power of the CPU 200 is supplied to the base of the transistor 210 via a resistor R3. The emitter of the transistor 210 is grounded, and the collector is connected to the base of the phase transistor 2090.

The power medium width stop circuit 210 is configured in this manner so that when the transistor 2100 is being driven by an instruction from the CPU 200, the transistor 2100 is driven even when the transistor 2090 is driven by the output from the counter 208. The power amplification and driving of the transistor 2090 are stopped.

Here, the description is returned to the second degree. In FIG. 2B, 211 is a timer which measures the elapsed time and transmits it to the CPU 200. FIG.

The rotation speed counter 201 measures the engine rotation speed by the output of the crank angle detector 11, and supplies an insertion command signal to the insertion control unit 202 at the end of the measurement.

The insertion control unit 202 generates an insertion signal in response to the signal, and causes the CPU 200 to execute an insertion processing routine for calculating the fuel injection amount.

16 is an output from a fire extinguishing detector not shown here, and the fire extinguishing is detected for each cylinder at the internal pressure of the combustion process of each cylinder, for example, in the manner disclosed in Japanese Patent Laid-Open No. 63-63933.

Next, the operation will be described. 4A shows a schematic flowchart of the CPU 200. The functions of the CPU 200 will be described based on this flowchart, and the operation of the entire configuration will be described.

When the key switch 15 and the starter switch 13 are turned on and the engine 1 is started, the arithmetic processing of the main routine is started at the start of step S0, and the initialization process is executed at step S1, and the step is executed. In S2, the dry digital value is read into the cooling water temperature from the analog input port 204.

In step S3, the fuel correction amount is calculated as a result, and the result is stored in the RAM 206. FIG. When step S3 is complete | finished, it returns to step S2.

Normally, the CPU 200 repeatedly executes the processing of the main routines of steps S2 to S3 in FIG. 4A according to the control program. When the insertion signal from the insertion control unit 202 is input, the CPU 200 immediately stops the processing even when the main routine is in process and moves to the insertion processing routine of step S40 shown in FIG. 4C.

In step S41, a signal indicating the engine speed from the speed counter 201 is received, and in step S42, a signal indicating the amount of intake air is received from the analog input port 204.

Next, in step S43, the basic fuel injection amount determined by the engine speed, the intake air amount and the constant is calculated. Next, in step S44, the fuel injection correction amount obtained in step S3 as the main routine is read out from the RAM 206, and the injection amount for determining the air-fuel ratio is corrected.

Next, in step S45, the output 16 from the extinguishing detector (not shown here) determines whether or not the current combustion cylinder is in the extinguishing state. If it is the extinguishing partner, the process proceeds to step S46 and corresponds to the extinguishing. A cylinder plug (digestion cylinder plug) is set, and if it is not in the extinguishing state at step S45, the flow proceeds directly to step S47.

In step S47, it is checked whether the fire extinguishing cylinder plug is set, and if there is a fire extinguishing cylinder, the power amplification part stop circuit 2100 of the electronic fuel injection valve 51 of the cylinder corresponding to the extinguishing cylinder plug is operated to operate the transistor. By turning on 2100, the base of the transistor 2090 is set to the ground potential, and the power amplifier 209 having the transistor 2090 is deactivated so that fuel is not supplied to the fire extinguisher.

In step S48, the injection amount is set in the counter 208, and the solenoid injection valve of the cylinder of fire extinguishing object is driven to open the valve.

If there is no fire extinguishing cylinder in step S47, the flow proceeds directly to step S49 to drive the electronic fuel injection valve to open the valve.

Next, the flow advances to step S50 to return to the main routine.

Further, in the above embodiment, the six fuel cylinders are driven simultaneously by six-cylinder engines, but the same effect can be obtained even when applied to a system driven by two groups of three.

As described above, according to the present invention, the crank angle of the engine is detected by the crank angle detector, and information corresponding to the number of revolutions is calculated at a predetermined crank angle period corresponding to each cylinder of the engine, and the amount of change or rate of change of the information is used to extinguish the engine. And the fuel supply is stopped in the cylinder in which the extinguishing is confirmed, and thus the fuel leakage of the combustion is prevented, and the effect of preventing the deterioration of the catalytic device, the emission of harmful exhaust gas, or the fire of the vehicle is obtained. .

In addition, since the digestion can be detected when the organ is in a steady state or idle, the detection of digestion is prevented and the digestion can be accurately detected.

In addition, according to the present invention, an electronic fuel injection valve is provided for each ring of the multi-cylinder internal combustion engine, and at least two electromagnetic injection valves are simultaneously driven to open the valve. The opening of the drive valve only for the electronic fuel injection valve of the fire extinguisher according to the detection output is configured to stop the deterioration of the catalytic device, the emission of harmful exhaust gas, or the fire of the vehicle, which prevents unburned fuel from leaking. The effect of driving to the repair shop by itself is obtained.

Claims (1)

A power amplification unit for driving and opening at least two electronic fuel injection valves installed at each cylinder of the multi-cylinder internal combustion engine at the same time to supply fuel; and detecting the extinguishing cylinder of the internal combustion engine and the electronic capability of the extinguishing cylinder according to the detection capability. And a power amplification stop circuit for stopping the operation of the power amplification section corresponding to the fire extinguishing cylinder to stop driving opening of the fuel injection valve only.