JP2000045838A - Control device for gas fuel engine - Google Patents

Control device for gas fuel engine

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Publication number
JP2000045838A
JP2000045838A JP10220862A JP22086298A JP2000045838A JP 2000045838 A JP2000045838 A JP 2000045838A JP 10220862 A JP10220862 A JP 10220862A JP 22086298 A JP22086298 A JP 22086298A JP 2000045838 A JP2000045838 A JP 2000045838A
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Japan
Prior art keywords
fuel
state
value
pulse width
correction value
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JP10220862A
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Japanese (ja)
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JP3781903B2 (en
Inventor
Masahiro Sato
正博 佐藤
Original Assignee
Hitachi Car Eng Co Ltd
Hitachi Ltd
株式会社日立カーエンジニアリング
株式会社日立製作所
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Priority to JP22086298A priority Critical patent/JP3781903B2/en
Publication of JP2000045838A publication Critical patent/JP2000045838A/en
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Publication of JP3781903B2 publication Critical patent/JP3781903B2/en
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/10Internal combustion engine [ICE] based vehicles
    • Y02T10/30Use of alternative fuels, e.g. biofuels
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/10Internal combustion engine [ICE] based vehicles
    • Y02T10/40Engine management systems

Abstract

(57) [Summary] (Modifications) [Problem] A gas that can set the injection amount of gaseous fuel that can maintain the best operation state even if the pressure or temperature of gaseous fuel changes according to the operating environment or operating state of the engine. A control device for a fuel engine is provided. SOLUTION: The basic pulse width calculating means 21 for gaseous fuel, the fuel state pulse correction value calculating means 28, the air-fuel ratio correction value calculating means 25, and the injection pulse width calculating means for correcting the basic injection pulse width based on these correction values. 22; the fuel state pulse correction value calculating means includes a fuel state value calculating means 27 which uses the temperature and / or pressure of the gaseous fuel as a fuel state value, and a pulse width correction value calculating means 28 based on the fuel state value. In addition, a fuel system abnormal state determination unit 32 is provided, and when a fuel system abnormality occurs, the fuel state pulse width correction value is changed according to the calculation result from the fixed fuel state value calculation unit 30 or the fixed pulse width correction value calculation unit 31, and the fuel injection is performed. Output to the pulse width calculation means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control apparatus for a gaseous fuel engine, and more particularly, to the correction of an injection pulse width of a gaseous fuel injected from an injector based on the pressure and temperature of gaseous fuel supplied to the engine. The present invention relates to a control device for a gaseous fuel engine to be controlled.

[0002]

2. Description of the Related Art In recent years, various regulations such as exhaust gas regulations and fuel efficiency regulations have been set for automobile engines.
In particular, the regulations tend to be further strengthened from the viewpoint of environmental protection requirements. On the other hand, the current fuel for automobile engines is mainly liquid fuel such as gasoline and light oil,
Due to concerns about the shortage of liquid fuel supply and soaring prices in the future due to the limitation of reserves, automobiles using alternative energy are being developed. Typical vehicles using the alternative energy include electric vehicles, hybrid vehicles of liquid fuel and electricity, and gas vehicles using alcohol or gas (natural gas, propane gas, hydrogen gas, etc.) as fuel. However, at present, automobiles using natural gas are one step ahead in the development of infrastructure such as fuel supply facilities and equipment for supplying them, or in terms of cost.

[0003] Since natural gas vehicles use methane gas as the main fuel, exhaust gas emissions can be reduced as compared with conventional liquid fuel vehicles. Furthermore, by using an MPI (multipoint injection system) that injects fuel with the injection method being independent for each cylinder,
Optimum air-fuel ratio control is possible, and it is possible to improve driving performance such as exhaust gas performance, fuel consumption performance, power performance, driving performance, etc., and to divert the conventional engine control system for liquid (gasoline) fuel. This is generally possible, and has the effect that the manufacturing cost can be suppressed.

[0004] This is in conformity with the environmental protection requirements (eg, exhaust gas regulations, fuel efficiency regulations, etc.) surrounding automobiles in recent years, which are continually being strengthened, and are greatly expected in the future.

[0005]

Incidentally, in a vehicle using a gaseous fuel such as a natural gas vehicle, it is necessary to set the filling pressure to a high pressure when filling the fuel cylinder with natural gas. Therefore, it is important to consider the safety of handling. As an example in consideration of the safety, there is a technique described in Japanese Patent Application Laid-Open No. 7-189789. As for the safety of handling of an automobile engine using the natural gas according to the technology, consideration is given to the case where the pressure (fuel pressure) of the natural gas fuel rises abnormally or the emergency of the automobile (collision). It is known to provide a means for limiting (cutting off) the supply of fuel to the engine.

Further, since gaseous fuel is gaseous, its properties vary depending on the fuel state such as temperature and pressure. Therefore, the fuel injection amount is corrected based on the change in fuel state. In addition, it is necessary to control the engine to the optimum air-fuel ratio, and to control the engine to the optimum air-fuel ratio, it is necessary to accurately detect the fuel state of the gaseous fuel. However, for example, in the case of disconnection of the detection sensor, a shift during use of the characteristics of the detection sensor, or an increase in pressure amplitude due to a failure of the regulator for adjusting the fuel pressure, it may be impossible to detect the fuel state. . In the case where such detection is not possible, it has not been possible to determine an emergency in the past, so that normal fuel injection control had to be performed without restricting (stopping) the fuel supply.

In the engine of a natural gas automobile,
Normally, as shown in the schematic diagram of FIG.
1 = about 17 (16.8: 80% methane)
In this state, the flammable range (misfire limit) is wide on the air-fuel ratio lean side of the stoichiometric air-fuel ratio L1, but the flammable range (misfire limit) is narrow on the rich side. During the operation of the engine, the actual air-fuel ratio of the engine is different from the stoichiometric air-fuel ratio L1 of the gaseous fuel by a change in the fuel state (fuel pressure or fuel temperature) or the operating state (transient / steady state) depending on the operating environment. Changes within the range of the arrow a due to the change in the fuel pressure based on the change in the pressure, and in some cases, the driving performance deteriorates. In particular, when the actual air-fuel ratio moves to a richer side than the stoichiometric air-fuel ratio L1, the flammable range is narrow, which may cause a misfire or the like.

Further, as described above, when it becomes impossible to detect the fuel state such as disconnection of the detection sensor, the event control is performed in the undetectable state. Misfire (worst case: engine stall, unable to start) due to the air-fuel ratio moving to the rich side due to increase etc.
There is a danger of reaching. The present invention has been made in view of the above-described problems, and has as its object the gaseous fuel, the change in pressure and temperature due to the operating environment of the engine,
Alternatively, even if the pressure changes due to a change in the operating state during a transient or steady state of the engine, it is possible to set an injection amount (injection pulse width) of the gaseous fuel that can maintain the best operating state without causing the engine to misfire or the like. A control device for a gaseous fuel engine is provided.

[0009]

In order to achieve the above object,
The control device of the gaseous fuel engine of the present invention basically includes:
Basic pulse width calculating means for calculating a basic injection pulse width of gaseous fuel, fuel state pulse correction value calculating means for calculating a fuel state pulse width correction value, and air-fuel ratio correction value calculating means for calculating an air-fuel ratio correction value, An injection pulse width calculating means for correcting the basic injection pulse width based on the fuel state pulse width correction value and the air-fuel ratio correction value to calculate an injection pulse width of gaseous fuel, wherein the fuel state pulse correction value calculating means But,
A fuel state value calculating means for calculating the temperature and / or pressure of the gaseous fuel as a fuel state value; and a pulse width correction value calculating means for calculating a pulse width correction value based on the fuel state value; Fuel system abnormal state determination means, fixed fuel state value calculation means for fixing the fuel state value to a predetermined value, and fixed pulse width correction value calculation means for fixing the fuel state pulse width correction value to a predetermined value. In the event of an abnormality in the fuel system, the fuel state pulse width correction value is changed according to the calculation result from the fixed fuel state value calculation means or the fixed pulse width correction value calculation means, and the result is output to the injection pulse width calculation means. I have.

In a specific aspect of the control apparatus for a gaseous fuel engine according to the present invention, the fixed fuel state value calculating means or the fixed pulse width correction value calculating means determines the fuel state of the fuel system abnormal state determining means. A predetermined fixed combustion state value or a predetermined fixed pulse width correction value is calculated based on the degree of the abnormal value, and the fixed combustion state value or the fixed combustion state value or the normal state of the fuel state system is set so as to shift the air-fuel ratio of the engine to the lean side. It is characterized in that the fixed pulse width correction value is calculated.

In another specific aspect of the control apparatus for a gaseous fuel engine according to the present invention, the abnormal fuel state judging means stores an abnormal fuel state value in a memory when the abnormal fuel state is detected. It is characterized by comprising a storage means, and judging an abnormality in the fuel system based on the stored abnormal fuel state value. The control apparatus for a gaseous fuel engine according to the present invention configured as described above calculates the temperature and / or pressure of the gaseous fuel as the fuel state value by the fuel state value calculating means when the fuel system is normal, and calculates the pulse width correction value. Means for calculating a pulse width correction value based on the fuel state value, outputting the pulse width correction value to the injection pulse width calculation means, and correcting the basic injection pulse width to calculate the injection pulse width of the gaseous fuel. The fuel injection valve injects gaseous fuel with the calculated injection pulse width. If the fuel system is abnormal (fuel pressure, fuel temperature, etc.), the fuel system abnormal state determination means The abnormality is determined, and the fixed fuel state value calculation means or the fixed pulse width correction value calculation means calculates a predetermined fuel state value or a pulse width correction value such that the air-fuel ratio of the engine shifts to a lean side. Since the basic injection pulse width is corrected by the fixed pulse width correction value to calculate the gas injection pulse width, combustion is stabilized even when the fuel system including the fuel state cannot be detected becomes abnormal. Can continue.

Further, in another specific embodiment of the control apparatus for a gaseous fuel engine according to the present invention, the fuel system abnormal state determining means determines whether or not the temperature of the gaseous fuel is within a predetermined range.
Alternatively, the abnormality of the fuel system is determined based on the relationship between the cooling water temperature, the intake air temperature, and the gas fuel temperature during a predetermined period after the start,
When the detected temperature value of the gaseous fuel is normal, a temperature deviation between the cooling water temperature or the intake air temperature and the gaseous fuel temperature during a predetermined period after the engine is started is calculated, and when the temperature deviation is equal to or more than the predetermined value, A fuel temperature deviation correction value is calculated based on the temperature deviation, and the fuel temperature deviation correction is performed on the fuel temperature detection value. The fuel system is determined by whether the detected pressure is smoothed and whether the pressure after the smoothing process is within a predetermined range or whether the amplitude of the detected pressure is within a predetermined range. It is characterized by judging the abnormality of.

[0013] Further, the fuel system abnormal state judging means is connected to an external warning means such as an abnormality alarm device or an external diagnostic device, and performs output control to the external warning means when the fuel state is abnormal. The abnormal value storage means of the fuel system abnormal state determination means stores the abnormality detection history of the fuel state for each abnormality detection of the gaseous fuel state, and erases the history at the time of the abnormality detection of the fuel state in response to an erase request from the external diagnostic device. It is characterized by:

Still further, in the control apparatus for a gaseous fuel engine according to the present invention, the fuel system abnormal state determining means may determine whether the pressure value after the smoothing process is abnormal or not in the fuel pipe of the engine. By shutting off the fuel supply to the fuel injection valve by the arranged fuel cut-off valve, it is possible to limit (cut off) the fuel supply only during abnormal conditions (such as when the fuel pressure rises abnormally), thus improving reliability. Is improved.

In addition, the control device is connected to an external alarm device (warning lamp, buzzer, etc.) or an external diagnostic device (self-diagnosis checking device, etc.) to warn the driver and to operate the diagnosis result. By doing so, it is possible to avoid the driver from the danger state and to issue an early warning of the failure state, thereby improving reliability and serviceability.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a control device for a gaseous fuel engine according to the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall configuration diagram of an engine system including a control device for a gaseous fuel engine according to the present embodiment.

The engine system shown in FIG. 1 includes an engine 1. Each cylinder of the engine 1 includes a piston 1a, a cylinder 1b, and a combustion chamber 1c formed by the piston 1a and the cylinder 1b. An intake pipe 4 and an exhaust pipe 5 are connected to an upper part of the chamber 1c, and a spark plug 7 is arranged. An intake valve 2a and an exhaust valve 2b are arranged at a connection portion between the intake pipe 4 and the exhaust pipe 5, and an injector 18 for injecting fuel is mounted on the intake pipe 4.

In the air supply system, the air cleaner 3
Air that has entered through the throttle valve 6 is drawn into the cylinder (combustion chamber 1c) of the engine. The gaseous fuel supply system includes a fuel cylinder 20 filled with gaseous fuel at a high pressure and stored, a pressure regulating valve (regulator) 16 for adjusting fuel pressure of fuel injection, the injector 18 for injecting fuel, the fuel cylinder 20 and the regulator. 16, a low-pressure pipe 17 that connects the regulator 16 and the injector 18, and a shut-off valve 11, 1 that is installed on the cylinder side and the regulator 16 side of the high-pressure pipe 15.
2 and a low-pressure pipe 17, and gaseous fuel from the fuel cylinder 20 is guided to a regulator 16 through a high-pressure pipe 15 in which shut-off valves 11 and 12 are arranged, and the pressure is regulated by the regulator 16. Thus, the fuel is injected from the injector 18 into the intake pipe 4.

The low-pressure pipe 17 has a fuel state (fuel temperature,
A fuel temperature sensor 13 and a fuel pressure sensor 14 for detecting fuel pressure) are arranged, and the high-pressure pipe 15 is not shown in the drawing.
A high-pressure-compatible fuel pressure sensor that detects abnormal fuel pressure in the high-pressure pipe 15 is provided. Sensors for detecting information on the operating state of the engine 1 include an intake air amount detection sensor 19 for measuring a mass flow rate of intake air, a water temperature sensor 8 for measuring a cooling water temperature of the engine, and an intake air temperature sensor 9 for measuring an intake air temperature. A crank angle sensor for detecting a crank angle and a throttle sensor for detecting a throttle angle are also disposed in the engine 1, although not shown in the drawings.

The detection signals of the respective detection sensors are inputted to a control unit 10 which controls the engine speed from the signal of the crank angle sensor and the intake / intake air from the throttle sensor and the intake air amount detection sensor 19. The engine load is calculated from the intake air amount and the engine speed, and based on these various information,
An optimum fuel injection pulse width, a fuel injection timing, an ignition timing, and the like to be supplied to the engine 1 are calculated, fuel is injected by an injector 18 as a fuel injection valve, and an ignition plug (not shown) is energized / cut off by an ignition coil (not shown). 7, the mixture is ignited. A diagnostic device 19 is arranged outside the control unit 10, and both can communicate with each other via communication means such as serial communication.

FIG. 2 is a control block diagram of the control unit (control unit 10) for the gaseous fuel engine according to the present embodiment. The control block shows the calculation state of the fuel injection amount (pulse) injected from the injector 18. FIG. The gaseous fuel injected from the injector 18 is:
The procedure is performed by calculating an injection pulse width for fuel injection. The procedure is performed by an intake air amount / engine speed calculating means 20 using detection from an intake amount detection sensor 19 and a crank angle sensor (not shown). An intake air amount of the engine and an engine speed are calculated based on the signal.

The basic pulse width calculating means 21 calculates a basic injection pulse width for fuel injection (a required injection pulse width per cylinder obtained from the intake air amount) from the intake air amount and the engine speed. The calculation of the basic fuel injection pulse width is
The pulse calculation method for gasoline is used. The injection pulse width calculating means 22 calculates the air-fuel ratio correction value (described later in detail) calculated by the air-fuel ratio correction value calculating means 25 based on the calculated basic fuel injection pulse width, and calculates the fuel state pulse correction value calculating means 26. The injection fuel pulse width is calculated by correcting with a pulse width correction value (details will be described later). The injector driving means 23 includes:
The valve opening timing of the injector 18 is set based on the calculated injection fuel pulse width.

The operating state detecting means 24 calculates the engine water temperature and the throttle angle based on the detection signals from the water temperature sensor 8 and the throttle angle sensor 6a. The air-fuel ratio correction value calculating means 25 calculates the engine water temperature and the throttle angle based on the calculated values. An air-fuel ratio correction value (for example, an air-fuel ratio adjustment value such as a water temperature correction amount or an acceleration / deceleration correction amount) is calculated and output to the injection pulse width calculation means 22. In the present embodiment, the description of the air-fuel ratio feedback control and the air-fuel ratio learning control using the O 2 sensor is omitted, but the control can be included in the air-fuel ratio correction value calculating means 25. .

Next, the fuel state pulse correction value calculating means 26
Will be described. Fuel state pulse correction value calculating means 2
The fuel state value calculation means 27 calculates the temperature and pressure of the gaseous fuel based on the detection signals from the fuel temperature sensor 13 and the fuel pressure sensor 14. The pulse correction value calculating means 28 calculates a fuel temperature correction coefficient from a relationship with a basic fuel temperature (basic fuel temperature) (for example, a calculation result of an arithmetic expression: √ (input fuel temperature value) / √ (basic fuel temperature value)). And the basic fuel pressure (basic fuel pressure)
(For example, a calculation formula: (calculation result from (basic fuel pressure value) / (input fuel pressure value))) and a fuel pressure correction coefficient,
The results of these multiplications are calculated as pulse width correction values.

The calculated pulse width correction value is supplied to the switching means 2
9 to the injection pulse width calculating means 22;
The basic pulse width of the gaseous fuel injection calculated by the basic pulse width calculation means 21 is corrected by the pulse width correction value and the air-fuel ratio correction value calculated by the air-fuel ratio correction value calculation means 25, and finally the injector The injection pulse width of the liquid fuel injected at 18 is calculated.

As shown in FIG. 3, the correction of the basic pulse width by the injection pulse width calculating means 22 is performed based on the stoichiometric air-fuel ratio L1 of the gaseous fuel and the fuel state (fuel pressure and fuel temperature) depending on the operating environment. Or the fuel pressure change based on the change in the operating state (transient / steady state), the air-fuel ratio becomes the arrow a.
However, the variation is corrected by the pulse correction value calculated based on the fuel temperature and the fuel pressure, and converged to the stoichiometric air-fuel ratio L1.

The fixed fuel state value calculation means 30, fixed pulse width correction value calculation means 31, fuel system abnormal state determination means 32, and warning generation means 34 of the fuel state pulse correction value calculation means 26 are the main components of this embodiment. Determining the abnormal state of the fuel temperature and fuel pressure of the gaseous fuel and fixing the combustion state value for correction and / or the pulse width correction value, that is, If it is determined that the determination result of the fuel temperature or the fuel pressure of the gaseous fuel is abnormal, the fixed fuel state value calculation means 30 determines the fuel state detection value, and the fixed pulse width correction value calculation means 31 determines the pulse width correction value. The value is fixed (shifted to a value that can be shifted in the lean direction).

The fuel system abnormal state judging means 32 receives the signals detected by the water temperature sensor 8 and the intake air amount detecting sensor 19, and calculates the fuel temperature and the fuel pressure of the gaseous fuel calculated by the fuel state value calculating means 27. It is determined whether or not the fuel system is abnormal on the basis of the fuel state value in comparison with the abnormal value stored in the abnormal value storage means 33. This determination can be made in a plurality of stages based on the fuel state value, and the determination result is output to the fixed fuel state value calculation means 30 and the fixed pulse width correction value calculation means 31.

The fixed fuel state value calculating means 30 calculates specific fixed fuel state values (fixed fuel pressure correction coefficient, fixed fuel temperature correction coefficient) based on the determination of the plurality of stages by the fuel system abnormal state determining means 32. The fixed pulse width correction value calculating means 31 calculates a fixed pulse width correction value from a specific fixed fuel state value calculated by the fixed fuel state value calculating means 30 or the fixed pulse width correction value A specific fixed pulse width correction value is calculated based on the determination of the plurality of stages and output to the switching means 29.

On the other hand, when it is determined that the fuel system is abnormal, the fuel system abnormal state determining means 32 outputs the signal to the switching means 29 so that the pulse correction value from the pulse correction value calculating means 28 to the injection pulse width calculating means 22 is output. The pulse width correction value is switched to the fixed pulse width correction value from the fixed pulse width correction value calculation means 31. The switching of the fixed pulse width correction value by the switching means 29 based on the abnormality of the fuel system is to shift the air-fuel ratio in the engine 1 to the lean side. That is, as shown in FIG. 3, the stoichiometric air-fuel ratio L1 (about 17 (16.
8: 80% methane)), while the air-fuel ratio is leaner
The flammable range (misfire limit) is wide, but the flammable range (misfire limit) is narrow on the rich side. In the operation of the engine, if the event control is performed while the fuel state cannot be detected, the air-fuel ratio rich due to the increase in the gas density at low temperatures,
Alternatively, there is a danger of misfiring (at worst, engine stall or start-up impossible) due to rich air-fuel ratio due to excessive injection amount when fuel pressure rises.

The fixed fuel state value calculation means 30 and the fixed pulse width correction value calculation means 31 of the fuel system correction means 26 fix the fuel state value and the pulse width correction value, so that the air-fuel ratio L1 can be reduced. By shifting to the fuel ratio L2, it is possible to secure a margin for misfire in the air-fuel ratio rich state. The required amount of the fixed predetermined value depends on the structure of the engine. Therefore, it is necessary to obtain a predetermined fixed value for each engine system by an adaptation operation. , Low water temperature / high water temperature, etc.) to change the air-fuel ratio L for each engine system.
It is possible to further reduce the air-fuel ratio deviation from 2 (the width of the arrow b in FIG. 3).

Only one of the fixed fuel state value calculating means 30 and the fixed pulse width correction value calculating means 31 may be employed in order to reduce the calculation load and memory capacity of the control unit 10. When the abnormality in the fuel system is determined, the abnormal condition of the fuel system is output to the alarm transmitting device 34 to activate the external alarm 34a and the external diagnostic device 19.

Next, the fuel state abnormality detecting means will be described. FIG. 4 is a control flowchart showing an example of the abnormality detection means of the fuel temperature system.
This is a routine executed in a fixed time task. First, in step 35, a signal from the fuel temperature sensor 13 is read, and
In step 36, it is determined whether or not the input value of the voltage is within the predetermined range. Step 36 is for diagnosing the electrical connection state of the fuel temperature sensor 13. If the power supply voltage of the A / D converter for reading the input value is assumed to be 5V, the sensor signal will be the sensor characteristic or the regulator structure. Although it depends on (the structure that allows the cooling water temperature to pass through the inside of the regulator), the input value is about 1 V to 4
It falls within the range of about V. The determination values are 0.5 V and 4.5 V.
, And it is determined that the result of the electrical connection (voltage check) is OK, and the process proceeds to step 39 which is the next diagnosis item.

In step 36, if the input value is out of the predetermined range, that is, if the connection state of the vehicle harness connecting the fuel temperature sensor 13 and the control unit 10 is disconnected (harness disconnected, connector disconnected) or short-circuited (top Drop
If it is determined that the state is (landfall), it is determined in step 38 that the result of the electrical connection (voltage check) is NG, and the process proceeds to step 45, where the NG information (history) of the fuel temperature system is obtained. At the same time as setting the NG flag and fixing the fuel temperature input value or the pulse correction value as described above in step 46, the control routine ends.

After step 39, it is functionally determined whether or not the fuel temperature information is normal. In step 39, it is determined whether or not the fuel temperature has just been started (or a predetermined time after the start). The reason for setting the predetermined time after the start is that there is a risk that the fuel temperature detected by the fuel temperature sensor when measuring the fuel temperature is the pipe wall temperature. This is to measure the fuel temperature.

If it is not within the predetermined time after starting, step 4
In step 4, the fuel temperature NG flag is cleared, and the control routine ends. If it is determined in step 39 that the time is within the predetermined time after the start, the process proceeds to step 40, in which an intake temperature sensor signal and a coolant temperature sensor signal, which are other engine-related temperature information, are read. Here, the sensor characteristics of the intake air temperature sensor, the water temperature sensor, and the fuel temperature sensor may be different, the temperature information is normalized, and the respective temperatures are compared in the next step 41. In step 41, the diagnosis is performed on the premise that the temperatures immediately after the start are substantially the same (converge to the outside air temperature).

If the values are the same in step 41, it is determined that the temperature characteristic is OK in step 42, and the routine proceeds to step 44, where the fuel temperature NG flag is cleared, and this routine ends. However, if the temperatures do not match in step 41, the fuel temperature system (function check) is set to NG in step 43, and the routine is terminated via steps 45 and 46 described above.

Here, the start mode may be a restart immediately after the engine is stopped, and at this time, there is a risk of erroneous diagnosis in the present diagnosis. In addition, it is necessary to consider the characteristic variation of the temperature sensor in the temperature coincidence determination, and it is necessary to provide a sufficient margin for the predetermined determination value. In this case, the characteristic abnormality of the fuel temperature sensor (the characteristic abnormality There is a risk of overlooking the situation where the characteristics are shifted even if they do not go.

As means for solving this, step 4
1 can be replaced by the flow shown in FIG. 5 (the flow is located between steps 40 and 42 in FIG. 4). When the process of step 40 in the flow of FIG.
At 0, it is determined whether the intake air temperature matches the cooling water temperature. The determination is made based on whether or not the cooling water temperature is within ± X ° C. If not, it is determined that the mode is the restart mode, and the process proceeds to step 44. If the intake air temperature is within the cooling water temperature ± X ° C., it is determined that the engine is not in the restart mode, and it is determined whether the fuel temperature is within the cooling water temperature ± X ° C. If not, the process proceeds to step 43 as a characteristic abnormality of the fuel temperature sensor 13 and executes an NG process.

If yes, the process proceeds to step 52. In step 52, the difference between the fuel temperature and the water temperature is determined, and in step 53, it is determined whether the difference is equal to or greater than a predetermined value. If it is within the predetermined value, the process returns to step 42 in FIG. If not, it is not in a state where the pulse correction calculation based on the fuel temperature is not possible, but it is determined that the fuel temperature sensor characteristics are deviated, and the routine proceeds to step 54, where the fuel temperature is determined based on the deviation of step 53. A correction coefficient for the correction is calculated (the correction coefficient is calculated by the fuel state value calculating means 27 in FIG. 2).
Or it is reflected on the pulse correction value calculation means 28). In this way, the abnormality determination of the fuel temperature system and the correction of the fuel temperature correction are executed.

FIG. 6 is a flowchart showing an example of the means for detecting abnormality of the fuel pressure system. This flowchart is a routine executed in a fixed time task. In step 55, a signal from the fuel pressure sensor is read, and in step 56, it is determined whether or not a voltage input value is within a predetermined range. Step 56 is a step in which the fuel pressure sensor 14
In the case where the power supply voltage of the A / D converter for reading the input value is assumed to be 5 V, the sensor signal depends on the sensor characteristics and the regulator adjustment pressure. In the actual use fuel pressure range, the input value falls within a range of about 1V to about 4V. The judgment value is 0.5
V and 4.5 V, and within this range, the electrical connection (voltage check) result is determined as OK in step 57, and
The process proceeds to step 59, which is the next diagnostic item.

In step 56, if the input value is out of the predetermined range, that is, if the connection state of the vehicle harness connecting the fuel pressure sensor 14 and the control unit 10 is disconnected (harness disconnected, connector disconnected) or shorted (top If it is determined that the state is “drop, land drop”, step 58
Assuming that the result of the electrical connection (voltage check) is NG, in step 69 an NG flag, which is NG information (history) of the fuel temperature system, is set. In step 70, the fuel pressure input value is fixed as described above. Alternatively, the pulse correction value is fixed, and the control routine ends.

In step 59, the signal of the fuel pressure sensor 14 is subjected to a smoothing process, here a weighted average process. At step 60, the smoothed input fuel pressure is set to a safe range (a preset fuel pressure range).
To determine if they are inside. Outside the safe range
An abnormal rise / fall in fuel pressure means that the vehicle (engine) is in a dangerous state. An abnormal rise in fuel pressure means an increase in fuel pressure in the fuel system piping due to overfilling, etc. It can be considered as a fuel leak due to.

The purpose of smoothing is to prevent erroneous determination at the time of abnormality determination due to pressure noise (instantaneous pressure vibration or ripple) due to gaseous fuel. And stable diagnosis is possible.
FIG. 7 is a comparison diagram of the input value and the smoothed value of the fuel pressure, the electrical connection (voltage check), and the like, and shows the state of the fuel pressure abnormality determination.

If the smoothed input fuel pressure value is within the safe range, the routine proceeds to step 61, where there is no fuel pressure abnormality (O
K). If the smoothed input fuel pressure value is out of the safe range in step 60, the process proceeds to step 62, where the NG information (history) of the fuel pressure system is determined in step 69 as the fuel pressure NG (fuel pressure abnormality). At the same time as setting the NG flag and fixing the fuel pressure input value or the pulse correction value as described above in step 70, the control routine ends.

After it is determined in step 61 that there is no abnormality in the fuel pressure (OK), the process proceeds to step 63, in which the input value of the fuel pressure (the one for which the smoothing process in step 59 has not been performed) is fetched. Use to calculate the maximum and minimum values. FIG. 8 shows details of the calculation of the maximum value and the minimum value of the fuel pressure. The maximum value and the minimum value are updated at regular time intervals T. Although details of the updating means are omitted, the input new value is compared with the maximum value / minimum value for each fuel pressure input, and if the input new value> the maximum value, the input new value is replaced as the maximum value, and the input new value ≦ maximum. If the input new value is smaller than the minimum value, the maximum value is held. If the input new value is smaller than the minimum value, the maximum value is held. Each time the period T elapses, the maximum value-minimum value is obtained, and this is set as the fuel temperature amplitude (step 64 in FIG. 6).
Equivalent).

After calculating the fuel pressure amplitude, the maximum value / minimum value is initialized, and the initial value is the first input value immediately after the start of the next T. The fuel pressure amplitude is compared with a predetermined value (judgment amplitude value) (step 65 in FIG. 6). If the fuel pressure amplitude is larger than the predetermined value, it is determined that the fuel pressure system is NG (amplitude abnormal) ((step 67 in FIG. 6)).
Then, the fuel pressure NG flag is set at the point A (step 69 in FIG. 6).

Referring back to FIG. 6, step 70
Then, the fuel pressure input value or the pulse correction value is fixed as described above, and the control routine ends. If the amplitude is within the predetermined range in step 65, it is determined in step 66 that there is no abnormal amplitude (OK). In step 68, the fuel pressure NG flag is cleared, and the routine ends.

As described above, the fuel system diagnosis is performed, and the fixed input value / fixed pulse correction value is obtained. The content of the fixed input value / fixed pulse correction value in the fuel pulse width calculation is as follows.
This will be described with reference to the flowchart of FIG. The flowchart is a routine executed in a fixed time task. The contents are basically the same as those of the control block diagram of FIG.
1, 84.

First, at step 75, the intake air amount and the engine speed are fetched, and at step 76, the basic pulse width which is the basic of the injection pulse is calculated. In step 77,
An operation state based on various sensor information such as a water temperature and a throttle opening is taken in, and in step 78, various correction coefficients serving as air-fuel ratio correction coefficients are calculated. Next, at step 79, a fuel state represented by the temperature (fuel temperature) and pressure (fuel pressure) of the gaseous fuel is fetched. In step 80, the fuel system information (NG flag) is read. If the NG flag is 0, the fuel temperature correction correction coefficient calculated in step 54 in FIG. 5 is read in step 82. In step 83, step 79 The calculation of the pulse correction value is executed based on the fuel information and the fuel temperature correction correction coefficient in step 82.

If it is determined in step 81 that the fuel system NG flag is 1, the process proceeds to step 84, where
Thus, a preset pulse correction value at the time of abnormality in the fuel state is read. In step 85, the basic pulse width in step 76 is calculated by using either the fuel state pulse correction value in step 83 or the abnormal fuel state pulse correction value in step 84 and various correction coefficients (air-fuel ratio correction coefficient) in step 78. By performing the correction, the injection pulse width of the gaseous fuel is calculated, and the routine proceeds to step 86. In step 86, the injector drive pulse width is set based on the gaseous fuel injection pulse width, and the routine ends.
Thereby, fuel injection by the injector 18 is performed.

Next, a warning means for the driver will be described with reference to FIG. 10, and an output to an external diagnostic device for service at a dealer or the like will be described with reference to FIG. FIG. 10 shows an example in which a warning lamp is used as a warning means.
Then, the fuel system NG flag is read and the routine proceeds to step 91. In step 91, it is determined whether or not the fuel system is NG. If the flag of the fuel system NG = 0, that is, if the determination is NO, the present routine is terminated, but the flag of the fuel system NG = 1. If so, the process proceeds to step 92, in which the warning lamp is driven (lit) to warn the driver that there is an abnormality in the fuel system.

FIG. 11 shows the control unit 10.
It relates to control between the external diagnostic device 19 installed outside the control unit and the control unit 10, and the connection between the two is performed via communication means such as serial communication. First, in step 95, it is determined whether there is a request for output of a diagnosis result from the external diagnosis device. Normally, it is assumed that the operation of requesting the output of a diagnosis result is performed by the operation of a service person such as a dealer from the external diagnosis device.

In step 95, if there is no output request from the external diagnostic device, this routine is terminated. If there is an output request at step 95, the process proceeds to step 96, and at step 96, the fuel system NG
The flag is read out and NG is sent to the external diagnostic device in step 97.
Outputs flag information. On the side of the external diagnostic apparatus, the code is converted into a human-readable error code (which can be read even without a conversion table for converting what is abnormal), for example, a language such as "fuel system error" and displayed on the screen. .

In the present embodiment, the output of the abnormal code to the external diagnostic device has been described. However, from a global perspective, there are many countries where the service system is inadequate and the external diagnostic device is not well-equipped. There is also. In such a case, it is also effective to display an abnormality by lighting or blinking a lamp in the instrument panel. Further, the flowcharts of FIGS. 12 to 16 show a state in which the NG information in the flowchart of FIG. 4 or FIG. 6 is subdivided and an abnormal code is output which is adapted to each NG information. 12 is obtained by subdividing step 38 of the flowchart of FIG. 4 into step 100, and adding a fuel temperature system voltage check item. FIG. 13 is subdividing step 43 of FIG. The item of fuel temperature system function check is added.

The flowchart of FIG. 14 is obtained by subdividing Step 58 of the flowchart of FIG. 6 into Step 102 and adding a fuel pressure system voltage check item.
FIG. 15 is a fragmentation of step 62 of FIG.
The item 03 is added with a check item for a fuel pressure system abnormal pressure check, and the step 104 in FIG. 16 is further added with a check item for a fuel pressure system abnormal amplitude check.

In the above description, when the fuel system is abnormal, the means for correcting the pulse width is mainly used. However, in each fuel system diagnosis, in order to prevent a vehicle fire or the like, only the fuel pressure abnormality is measured. It is desirable to stop (cut off) the fuel supply to the fuel cell, and it is necessary to take this into account. FIG. 17 is a flow chart of stopping the fuel supply when the fuel pressure is abnormal, and corresponds to step 1 in the flow chart of FIG.
Step 105 is provided as a step located between 03 and 69. At step 105, it is determined whether or not the fuel system pressure is abnormal NG (fuel system pressure abnormality flag = 1). If the fuel system pressure is OK (the fuel system pressure abnormality flag = 0), the process proceeds to step 69. If the fuel system pressure is abnormal NG (the fuel system pressure abnormality flag = 1), the process proceeds to step 106. In step 106, the fuel supply is prohibited (cut off), and in step 107, the shutoff valve 11.12 in the fuel pipe is driven to prohibit (cut off) the fuel supply. Thus, safety can be improved, but means for inhibiting injection by the injector 18 can be further provided.

Next, the means for deleting the NG information (flag) will be described. The purpose of providing the NG information (flag) erasing means is that if the NG information (flag) remains after repair at a dealer or the like, the diagnosis result will not be updated unless the diagnosis is performed again, and the serviceability may be impaired. Because there is a nature. FIG. 18 is a flowchart showing an example of the means for deleting the NG information (flag), which means that the NG information (flag) is cleared only by the external diagnostic device. That is, when the flowchart is adopted, step 44 in FIG. 4 or step 6 in FIG.
8 is invalid.

It has been described that the processing is executed between the external diagnostic apparatus and the control unit 10 through communication means such as serial communication. However, in step 110, there is a request to delete the diagnostic result from the external diagnostic apparatus. It is determined whether or not it is. As a matter of course, the deletion request is premised on that a service person working using the external diagnostic device inputs the deletion request. If there is no erasure request, the NG information (flag) is retained, but if there is an erasure request, the process proceeds to step 111 where the various fuel state NG information (flag) is erased (cleared).
I do.

Here, another embodiment regarding the serviceability will be described. In the engine operation control, basically, if the diagnosis of the fuel system abnormality is executed again and the result of the diagnosis is OK, it is a problem to clear the NG information (flag) and turn off the warning lamp. Although there is no such case, if an NG determination is made after the NG is once detected (for example, in a state where the connector of the vehicle harness of the fuel temperature sensor or the fuel pressure sensor is considered to be in poor contact), the NG determination is made as follows.
The possibility of reoccurrence is high and not only gives the driver an uneasy feeling, but even if the vehicle enters a dealer etc. in this state (with the warning lamp turned off), the diagnosis results are cleared, so check, There is a high risk that serviceability will be impaired due to lack of clues for repairs.

In order to solve the above problem, even if the warning lamp is turned on / off according to a real-time diagnosis result, NG information (flag) is left in the control device as a history of fuel system abnormality NG. Propose that. The flowchart of FIG. 19 shows an example of the above-mentioned proposal. In step 115, the NG flag in the previous and current fuel system abnormality diagnosis routines is read out.
It is determined whether or not the G flag is 1. Step 11
In step 6, if the previous NG flag is 0, step 110
Then, if the NG flag is 1 in step 116, the process proceeds to step 117 to determine whether the current NG flag is also 1 or not. In this step 117, the current NG flag is set to 1
In this case, the lamp lighting state is maintained as it is, and the current N
If the G flag is 0, the process proceeds to step 118, where the lamp is turned off.

Thereafter, the routine proceeds to step 110, where it is determined whether or not there is a request (clear) for deleting NG information (flag) in response to a request from the external diagnostic device. If there is no deletion request, the routine is terminated.
Proceeding to step 111, a process for deleting (clearing) various fuel NG flags is executed in step 111. As a result, the fuel system abnormality diagnosis is executed again, and
In the case of K, even if the lamp is turned off, the diagnosis history can be retained, so that the serviceability can be improved.

As described above, one embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and may be designed without departing from the spirit of the present invention described in the appended claims. Can be variously changed. For example, in the above embodiment, the gaseous fuel is described as natural gas, but other gaseous fuels can be applied to the present invention without any inconvenience.

[0064]

As can be understood from the above description, in the control apparatus for a gaseous fuel engine according to the present invention, when the fuel system is abnormal, the fuel system abnormal state judging means judges the abnormality and outputs a pulse signal. The width correction value is changed to a predetermined fixed value such that the air-fuel ratio of the engine shifts to the lean side, and the basic injection pulse width is corrected by the fixed pulse width correction value to calculate the gas injection pulse width. Therefore, even when the fuel system including the fuel state detection failure becomes abnormal, the combustion can be continued in a stable state. As a result, driving performance deteriorates,
By reducing the exhaust performance and the like, and by connecting the fuel system abnormal state determination means and an external diagnostic device,
Serviceability (workability) at the dealer can be improved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an engine system including a control device for a gaseous fuel engine according to an embodiment of the present invention.

FIG. 2 is a control block diagram of a control device of the gaseous fuel engine of FIG. 1;

FIG. 3 is a diagram showing a relationship between an air-fuel ratio and a combustion stability of the gaseous fuel engine of FIG. 1;

FIG. 4 is a control flowchart showing detection of an abnormality in a fuel temperature system of the control device for a gaseous fuel engine in FIG. 1;

FIG. 5 is a control flowchart for determining a characteristic abnormality or the like of the fuel temperature sensor in the control flowchart of FIG. 4;

FIG. 6 is a control flowchart showing abnormality detection of a fuel pressure system of the control device for the gaseous fuel engine of FIG. 1;

FIG. 7 is a comparison diagram of an input value and a smoothed value of a fuel pressure, an electrical connection (voltage check), and the like of the control device of the gaseous fuel engine of FIG.

FIG. 8 is a timing chart of the determination of the fuel pressure amplitude of the control device for the gaseous fuel engine of FIG. 1;

FIG. 9 is a main control flowchart as a basis of the control device for the gaseous fuel engine in FIG. 1;

FIG. 10 is a control flowchart showing driving of an alarm lamp of the control device for the gaseous fuel engine of FIG. 1;

FIG. 11 is a control flowchart showing control of the control unit for the gaseous fuel engine in FIG. 1 with an external diagnostic device.

FIG. 12 is a fragmented NG of the control flowchart of FIG. 4;
9 is a control flowchart of information (fuel temperature voltage).

FIG. 13 is a fragmented NG of the control flowchart of FIG. 4;
9 is a control flowchart of information (fuel temperature system function check).

14 is a fragmented NG of the control flowchart of FIG.
9 is a control flowchart of information (fuel pressure voltage).

FIG. 15 is a fragmented NG of the control flowchart of FIG. 6;
9 is a control flowchart of information (fuel pressure system fuel pressure abnormality).

FIG. 16 is a fragmented NG of the control flowchart of FIG. 6;
9 is a control flowchart of information (fuel pressure system amplitude abnormality).

FIG. 17 is a control flowchart for stopping fuel supply based on NG information (fuel pressure system fuel pressure abnormality) in the control flowchart of FIG. 15;

18 is a control flowchart for erasing a diagnosis result in the control of the control device for the gaseous fuel engine in FIG. 1 with an external diagnosis device.

FIG. 19 is a control flowchart of turning off an alarm lamp of a control device of the gaseous fuel engine of FIG. 1 and erasing a diagnosis result of an external diagnosis device.

[Explanation of symbols]

 Reference Signs List 1 engine 2a intake valve 2b exhaust valve 3 air cleaner 4 intake pipe 5 exhaust pipe 8 water temperature sensor 9 intake temperature sensor 10 control unit 11 fuel cutoff valve 12 fuel cutoff valve 13 fuel temperature sensor 14 fuel pressure sensor 16 regulator 18 injector 19 external diagnostic device 21 Basic pulse width calculation means 22 Injection pulse width calculation means 25 Air-fuel ratio correction value calculation means 26 Fuel state pulse correction value calculation means 27 Fuel state value calculation means 28 Pulse width correction value calculation means 29 Switching means 30 Fixed fuel state value calculation means 31 Fixed pulse width correction value calculating means 32 Fuel system abnormal state determining means 33 Abnormal value recording means 34a Alarm

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) F02M 21/02 F02M 21/02 V 301 301R F-term (Reference) 3G084 AA05 BA09 BA13 BA33 DA28 EB02 EB06 EB22 EB25 EC03 FA00 FA36 3G092 AA01 AB08 BA04 BB02 BB10 CA01 CB05 DE04S EA07 EA08 EA09 EA11 EA13 EA17 EA19 EA28 EB01 EB04 EB06 EB08 EC09 FA15 FB02 FB03 FB05 FB06 FB07 HA01Z HA04Z HA03Z01 H03H01 H03B01 JB10 LB01 LB06 MA01 MA11 MA24 NA01 NA06 NA08 NB02 NB06 NB11 NC01 NE00 NE14 NE15 NE16 NE17 NE19 NE23 PA01Z PA10Z PA11Z PA18Z PB01Z PB08Z PE01Z PE03Z PE08Z PF16Z

Claims (13)

[Claims]
1. A basic pulse width calculating means for calculating a basic injection pulse width of gaseous fuel, a fuel state pulse correction value calculating means for calculating a fuel state pulse width correction value, and an air-fuel ratio correction for calculating an air-fuel ratio correction value. A gas fuel engine comprising: value calculation means; and injection pulse width calculation means for correcting the basic injection pulse width based on the fuel state pulse width correction value and the air-fuel ratio correction value to calculate a gas fuel injection pulse width. In the above control device, the fuel state pulse correction value calculating means includes a fuel state value calculating means for calculating the temperature and / or pressure of the gaseous fuel as a fuel state value, and a pulse for calculating a pulse width correction value based on the fuel state value. With a width correction value calculating means, a fuel system abnormal state determining means for determining an abnormal state of the fuel system, a fixed fuel state value calculating means for fixing the fuel state value to a predetermined value,
Fixed pulse width correction value calculation means for fixing the fuel state pulse width correction value to a predetermined value, and when the fuel system is abnormal, the fuel is calculated based on the calculation result from the fixed fuel state value calculation means or the fixed pulse width correction value calculation means. A control device for a gaseous fuel engine, wherein a state pulse width correction value is changed and output to said injection pulse width calculation means.
2. The fuel state pulse correction value calculating means,
2. The fuel cell system according to claim 1, further comprising: a switching unit that switches between the pulse width correction value and the fixed pulse width correction based on an output signal of the fuel system abnormal state determination unit and outputs the switching value to the injection pulse width calculation unit. A control device for a gaseous fuel engine according to claim 1.
3. The fixed fuel state value calculating means or the fixed pulse width correction value calculating means, wherein a predetermined fixed combustion state value or a predetermined fixed combustion state value is determined based on a fuel state abnormal value degree of the fuel system abnormal state determining means. The control device for a gaseous fuel engine according to claim 1, wherein the control device calculates a pulse width correction value.
4. The fixed fuel state value calculation means or the fixed pulse width correction value calculation means calculates the fixed combustion state value or the fixed pulse width correction value so as to shift an air-fuel ratio of an engine to a lean side with respect to a normal state of a fuel state system. 4. The control device for a gaseous fuel engine according to claim 3, wherein the controller calculates a fixed pulse width correction value.
5. An abnormal fuel condition judging means includes abnormal value storage means for storing an abnormal fuel state value in a memory when detecting an abnormal fuel state, and detecting abnormalities in the fuel system based on the stored abnormal fuel state value. The control device for a gaseous fuel engine according to claim 1, wherein
6. The fuel system abnormality state determining means determines whether the temperature of the gaseous fuel is within a predetermined range, or
3. The control apparatus for a gaseous fuel engine according to claim 1, wherein an abnormality in the fuel system is determined based on a relationship among a cooling water temperature, an intake air temperature, and a gaseous fuel temperature during a predetermined period after starting.
7. The fuel system abnormal state determining means calculates a temperature deviation between a cooling water temperature or an intake air temperature and a gas fuel temperature during a predetermined period after starting the engine, when the detected temperature value of the gas fuel is normal. When the temperature deviation is equal to or more than a predetermined value, a fuel temperature deviation correction value is calculated based on the temperature deviation,
7. The control apparatus according to claim 6, wherein a fuel temperature deviation correction is performed on the detected fuel temperature value.
8. The fuel system abnormal state determining means determines whether or not the detected pressure of the gaseous fuel is within a predetermined range and smoothes the detected pressure so that the pressure after the smoothing processing is within a predetermined range. 3. The control apparatus for a gaseous fuel engine according to claim 1, wherein the abnormality of the fuel system is determined based on whether or not there is, or whether or not the amplitude of the detected pressure is within a predetermined range.
9. The fuel system abnormality state determination unit is connected to an external warning unit such as an abnormality alarm unit or an external diagnosis unit.
3. The control device for a gaseous fuel engine according to claim 1, wherein output control to external warning means is performed when the fuel state is abnormal.
10. The gaseous fuel according to claim 5, wherein the abnormal value storage means of the fuel system abnormal state determination means stores a fuel state abnormality detection history for each gaseous fuel state abnormality detection. Engine control device.
11. The gas according to claim 5, wherein the abnormal value storage means of the fuel system abnormal state determination means deletes the history of the detection of the fuel state abnormality in response to an erase request from an external diagnostic device. Control unit for fuel engine.
12. The fuel system abnormal state determining means executes the determining means again, and when the determination result is normal,
3. The control device for a gaseous fuel engine according to claim 1, wherein only output permission to the external abnormality warning device is prohibited.
13. The control device according to claim 1, wherein the fuel system abnormal state determination means determines that the pressure value after the smoothing processing is abnormal, and determines that the fuel system has a fuel cutoff valve disposed in a fuel pipe of the engine. 3. The control device for a gaseous fuel engine according to claim 1, wherein the fuel supply to the injection valve is shut off.
JP22086298A 1998-08-04 1998-08-04 Control device for gaseous fuel engine Expired - Fee Related JP3781903B2 (en)

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Application Number Priority Date Filing Date Title
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Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP22086298A JP3781903B2 (en) 1998-08-04 1998-08-04 Control device for gaseous fuel engine

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100475333B1 (en) * 2001-12-26 2005-03-10 씨멘스 오토모티브 주식회사 A liquid gas injection system for car
KR100475342B1 (en) * 2001-12-26 2005-03-10 씨멘스 오토모티브 주식회사 A liquid gas injection system for car
JP2006029096A (en) * 2004-07-12 2006-02-02 Yanmar Co Ltd Pressure accumulating fuel injector
JP2007170327A (en) * 2005-12-26 2007-07-05 Hitachi Ltd Fuel supply system for internal combustion engine

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100475333B1 (en) * 2001-12-26 2005-03-10 씨멘스 오토모티브 주식회사 A liquid gas injection system for car
KR100475342B1 (en) * 2001-12-26 2005-03-10 씨멘스 오토모티브 주식회사 A liquid gas injection system for car
JP2006029096A (en) * 2004-07-12 2006-02-02 Yanmar Co Ltd Pressure accumulating fuel injector
JP2007170327A (en) * 2005-12-26 2007-07-05 Hitachi Ltd Fuel supply system for internal combustion engine

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