JP2008002303A - Misfire time output or load limiting operation method of engine and its device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for restraining the deterioration of the efficiency of an engine power generation plant caused by the deterioration of the fuel consumption of an engine, by restraining reduction in a utilization factor of the engine when a misfire occurs. <P>SOLUTION: A means performs the output limiting operation of the engine on the basis of a misfire detecting result of the engine having a plurality of cylinders, and calculates a first limiting output being an output of subtracting a misfire output quantity corresponding to a misfire occurrence cylinder number from a normal operation output on the basis of a misfire detecting signal, and calculates a second limiting output on the basis of the misfire detecting signal by using an output limiting value set on the basis of the relationship between a preset misfire occurrence cylinder and a change in torsional vibration, and calculates a minimum limiting output by comparing the first limiting output with the second limiting output, and operates the engine with the minimum limiting output as a misfire-time allowable maximum output. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is applied to a power generating multi-cylinder diesel engine, a gas engine, etc., detects misfire of a multi-cylinder engine, and performs engine output limited operation based on the misfire detection result. The present invention relates to a method and an apparatus thereof.

In a multi-cylinder diesel engine or a multi-cylinder gas engine for power generation, if misfire occurs in one cylinder or a plurality of cylinders, the misfire is detected at the same time by the misfire detector in order to continue the stable operation of the engine. The operation is continued by reducing the output to a partial output at which stable operation is possible.
That is, as shown in FIG. 3 (B), which shows a change in output during a misfire of a multi-cylinder diesel engine for power generation or a multi-cylinder gas engine, in the conventional multi-cylinder engine for power generation, all cylinders are in a normal operation state and 100 When operating at% output, if a misfire occurs in 2 cylinders, reduce the operation output level to 50% output (in the case of 1 cylinder, reduce to 90% output) for stable engine operation. Yes.

  In Patent Document 1 (Japanese Patent Laid-Open No. 2002-39007), the time required for the ignition timing to change to a predetermined range from the ignition timing of each cylinder detected by a crank angle detector is set between a plurality of cylinders. To determine whether a misfire has occurred in a specific cylinder, and for the misfired cylinder, a correction to increase the fuel injection amount or a correction to delay the ignition timing by the spark plug A misfire control device for an internal combustion engine is disclosed.

JP 2002-39007 A

However, in the conventional multi-cylinder diesel engine or multi-cylinder gas engine for power generation, as described above, when a misfire occurs when all cylinders are operating normally and operating at 100% output. When a misfire occurs in the two cylinders, the operation output level is reduced to 50% output as shown in FIG. 3B to achieve stable engine operation.
In other words, in the case of a conventional engine, when a misfire occurs in one or two cylinders, the operating output level is taken into account of a reduction in the output of the misfire-occurring cylinder and a safety factor that takes into account the strength of the engine components. The engine operation is continued with the output reduced to about 50%. However, the actual maximum allowable operating output at which the engine can be stably operated when a misfire occurs in one or two cylinders is often higher than the output level of about 50% output uniquely set as described above. .

Therefore, in the case of such a conventional technique, when a misfire occurs in a multi-cylinder engine, for the purpose of continuing the stable operation of the engine, the above-mentioned allowable maximum operation output is limited more than necessary. As a result, the utilization factor of the engine is reduced, and the engine is operated at a lower output than necessary, so that the fuel consumption rate of the engine is also deteriorated, and the efficiency of the engine power plant is reduced.
Have such problems.

  In view of the problems of the prior art, the present invention reduces the engine operation output level to the maximum allowable operation output for stable operation in consideration of various requirements due to the occurrence of misfire when one or more cylinders misfire. The engine misfire output limit operation method and misfire output that can suppress the decrease in the engine utilization rate at the time of misfire and suppress the decrease in efficiency of the engine power plant due to the deterioration of the engine fuel consumption rate An object is to provide a limiting device, a misfire-time load limiting operation method, and a misfire-time load limiting device.

  The present invention achieves such an object, and detects misfire of a multi-cylinder engine by a misfire detector, and performs engine output limit operation based on the misfire detection result. In the apparatus, a first limit output that is an output obtained by subtracting a misfire output corresponding to the number of misfire occurrence cylinders from a normal operation output of the engine based on a misfire detection signal input from the misfire detector is calculated. The second limit output is calculated based on the misfire detection signal using a limit output calculation means and an output limit value set based on a relationship between a preset misfire occurrence cylinder and a change in torsional vibration of the engine. A second limit output calculating means that compares the first limit output with the second limit output and calculates a minimum limit output as an allowable maximum output during misfire. And a misfire controller for controlling the fuel control device of the engine to a fuel injection amount so as to become a limit limit output value at the time of misfire occurrence from the limit output calculating means. 1).

  Further, an invention of an apparatus for carrying out the operation method is provided for an engine configured to detect misfire of a multi-cylinder engine by a misfire detector and perform engine output limiting operation based on the misfire detection result. In the misfire output limiting device, a first limit output which is an output obtained by subtracting a misfire output corresponding to the number of misfire occurrence cylinders from a normal operation output of the engine based on a misfire detection signal input from the misfire detector. Based on the misfire detection signal, the first limit output calculating means for calculating, and using an output limit value set based on a preset relationship between a misfire-generating cylinder and a change in torsional vibration of the engine, The second limit output calculating means for calculating the limit output and the first limit output and the second limit output are compared, and the minimum limit output is calculated as the allowable maximum output at the time of misfire. And a misfire controller for controlling the fuel control device of the engine to a fuel injection amount that becomes a limit limit output value at the time of misfire occurrence from the limit output calculating means. (Claim 5).

  In the invention, specifically, the misfire controller sets an output limit value based on the misfire occurrence cylinder and the torsional vibration corresponding to the cylinder number based on a relationship between the misfire occurrence cylinder and a change in torsional vibration of the engine. The misfire-occurring cylinder / torsional vibration reference output limit value setting table, and the second limit output calculating means assigns the misfire-occurring cylinder number based on the misfire detection signal input from the misfire detector to the misfire-generating cylinder / The second limit output is calculated in correspondence with the torsional vibration reference output limit value setting table (claims 3 and 7).

In a multi-cylinder diesel engine or gas engine, when a misfire occurs in one or two cylinders of the engine, the mode (amplitude and frequency) of the torsional vibration of the crankshaft of the engine changes. Varies depending on the cylinder.
Therefore, in the event of misfire, it is necessary to change the engine output limit amount due to misfire, depending on which cylinder the misfire occurrence cylinder is in, and to set the maximum allowable operating output that can stably operate the engine in the event of misfire There is.

According to the invention, when the detection signal of the misfire occurrence cylinder is input from the misfire detector to the misfire controller, the first limit output calculation means of the misfire controller outputs the normal operation output of the engine based on the misfire detection signal. A first limit output, which is an output obtained by subtracting the misfire output corresponding to the number of misfire occurrence cylinders from is calculated.
Further, in the misfire-occurring cylinder / torsional vibration reference output limit value setting table of the misfire controller, the cylinder number of the misfiring-occurring cylinder (multiple If a misfire occurs in the cylinder, the output limit value from the normal operation output value of the engine considering the engine torsional vibration corresponding to the misfire-occurring cylinder number) is set in advance. When the detection signal of the misfire occurrence cylinder number is input from the detector, the second limit output calculation means of the misfire controller supplies the detected misfire occurrence cylinder from the misfire occurrence cylinder / torsional vibration reference output limit value setting table. Calculate the second limit output which is the output limit value of the corresponding cylinder number That.

  In the limit output calculation means of the misfire controller, the first limit output and the second limit output are compared to calculate the smaller limit output, that is, the minimum limit output, and the minimum limit output is calculated. The fuel control device of the engine is controlled to a fuel injection amount that is such an allowable maximum output value at the time of misfire as an allowable maximum output value at the time of misfire that is an allowable maximum operation output (allowable maximum operating load) at the time of misfire occurrence.

Therefore, according to this invention, when a misfire occurs, the first limit output obtained by subtracting the misfire output corresponding to the number of cylinders where misfire has occurred from the normal operation output of the engine, and the output limit value based on the torsional vibration of the engine cause misfire. The minimum limit from both the second limit output that is the output limit value corresponding to the misfire occurrence cylinder number calculated using the misfire occurrence cylinder / torsional vibration reference output limit value setting table set corresponding to the cylinder number The output is calculated, and the fuel control device of the engine is controlled so as to have a minimum limit output, that is, an allowable maximum output value at the time of misfire. Therefore, when a misfire occurs, the engine output is set to the first limit output and The vehicle can be operated up to the upper limit of the allowable maximum output value at the time of misfire considering both of the second limited outputs.
As a result, as in the prior art, it is possible to avoid restricting the output to the maximum allowable operating output more than necessary for the purpose of continuing the stable operation of the engine in the event of a misfire. The fuel consumption rate can be improved and the efficiency of the engine power plant can be improved.

In addition to this invention, the following configuration is preferable.
In other words, the misfire controller detects a power limit element other than the output drop due to the misfire-occurring cylinder and the torsional vibration of the engine when the misfire is detected, and detects a third limit based on the output limit element. The limit output calculating means compares the first limit output, the second limit output, and the third limit output when a misfire is detected, and calculates the minimum limit output as the allowable maximum output at the time of misfire. (Claims 2 and 6).
According to this configuration, in addition to the first limit output and the second limit output, the output limit element other than the output reduction by the cylinder and the torsional vibration of the engine is detected, and the third limit based on the output limit element is detected. The limit output is calculated and the allowable maximum output at the time of misfire is calculated in consideration of the three output limiting elements of the first limit output, the second limit output, and the third limit output. The detection accuracy of the upper limit value of the maximum allowable output value at the time of misfire can be improved.

  The present invention also relates to an engine misfire load limit operation method for detecting misfire of a plurality of cylinders in an engine that is operated independently and performing engine load limit operation based on the misfire detection result. The misfire generating cylinder in which the detected value of the engine load is detected by using an allowable maximum load setting table in which the allowable maximum load of the engine is set corresponding to the misfire generating cylinder number based on the signal and the engine load detection signal The engine is stopped when an allowable maximum load corresponding to the number is exceeded (Claim 4).

  Further, the invention of an apparatus for carrying out the operation method is configured to detect misfire of a plurality of cylinders by a misfire detector in an engine that is operated independently, and to perform load limit operation of the engine based on the detection result of the misfire. A load detector for detecting the engine load of the engine, and an allowable maximum load setting table in which an allowable maximum load of the engine is set corresponding to a misfire occurrence cylinder number, When the detected value of the engine load input from the load detector exceeds the allowable maximum load of the allowable maximum load setting table corresponding to the cylinder number of the misfire occurrence cylinder input from the misfire detector, the engine is stopped. A misfire controller that outputs a stop signal is provided (claim 8).

According to this invention, when a misfire occurs, the engine can be operated if the engine load is equal to or less than the maximum allowable load corresponding to the cylinder number of the misfire-occurring cylinder. It is possible to avoid stopping the engine at an allowable maximum load that is uniquely set for the purpose of continuing the engine.
Thereby, the utilization factor of an engine can be improved.

According to the present invention, when a misfire occurs, the first limit output obtained by subtracting the misfire output corresponding to the number of misfire occurrence cylinders from the normal operation output of the engine, and the output limit value based on the torsional vibration of the engine is the misfire occurrence cylinder number. The minimum limit output is obtained from both the second limit output which is the output limit value corresponding to the misfire occurrence cylinder number calculated using the misfire occurrence cylinder / torsional vibration reference output limit value setting table set corresponding to The fuel control device of the engine is controlled so that the fuel injection amount is calculated such that the minimum limit output, that is, the allowable maximum output value at the time of misfire, so that when the misfire occurs, the engine output is set to the first limit output and the second limit output. Because it can be operated up to the upper limit of the allowable maximum output value in case of misfire, taking into account both of the limited output of You can avoid performing output unnecessarily restrictive for the fuel consumption rate by can be avoided to a low load operation of unnecessarily engines can be improved, thereby improving the efficiency of the engine power plant.
Also, using the allowable maximum load setting table in which the allowable maximum load of the engine is set corresponding to the misfire-occurring cylinder number, the detected value of the engine load at the time of misfiring is the allowable maximum load corresponding to the cylinder number of the misfiring cylinder If the engine load is below the maximum allowable load corresponding to the cylinder number of the misfired cylinder, the engine can be operated when misfire occurs. It is possible to avoid stopping the engine at an allowable maximum load that is uniquely set for the purpose of continuing stable operation of the engine.
By these, the utilization factor of an engine can be improved rather than a prior art.

  Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.

FIG. 1 is a plan layout diagram showing the overall configuration of a misfire output limiting system in a multi-cylinder diesel engine for power generation according to an embodiment of the present invention, and FIG. 2 is a control block diagram at the time of misfire detection in the embodiment.
In FIG. 1, reference numeral 100 denotes an engine. In this example, a V-type multi-cylinder (8-cylinder) diesel engine for power generation is shown, but a multi-cylinder gas engine or a multi-cylinder gasoline engine may be used. 1 is a cylinder (8 cylinders) of the engine 100, 2 is a fuel injection device that injects fuel into each cylinder 1, and 4 is a fuel control device that controls the fuel injection amount and fuel injection timing of the fuel injection device 2. It is.

The above configuration is the same as that of a well-known power generation V-type multi-cylinder (8-cylinder) diesel engine.
The present invention relates to an output limiting operation method and an output limiting device when a misfire occurs in a multi-cylinder engine having the above-described configuration.

  In FIG. 1, reference numeral 5 denotes a misfire detector for detecting misfire of the engine 100. The misfire detector 5 is attached to each cylinder 1 and detects the occurrence of misfire in each cylinder 1 by detecting a change in pressure in the cylinder. 6 is a load detector for detecting the engine load. A misfire controller 5 receives a misfire occurrence detection signal in each cylinder 1 from each misfire detector 3 and an engine load detection value from the load detector 6, respectively. The misfire detection signal and engine load detection In response to the value, calculation and control as will be described later are performed, and the control signal is output to the fuel control device 4 to control the fuel control device 4.

Next, with reference to FIG. 2, a description will be given of an engine misfire output limiting operation method and apparatus according to an embodiment of the present invention.
When misfire is detected by the misfire detector 3, a misfire detection signal and a misfire occurrence cylinder number are input to an output reduction amount calculation unit 51, a misfire occurrence cylinder combination calculation unit 52, and a misfire cause output fluctuation element calculation unit 53, respectively. Is done.
The output reduction amount calculation unit 51 calculates a misfire output reduction amount corresponding to the number of misfire occurrence cylinders based on the misfire detection signal and the cylinder number of misfire occurrence and inputs it to the first output limit calculation unit 55. Reference numeral 54 denotes a rated output setting unit which sets a normal operation output when no misfire occurs.
The first output limit calculation unit 55 calculates the engine limit output at the time of misfire by subtracting the misfire output reduction amount corresponding to the number of misfire occurrence cylinders from the normal operation output set in the rated output setting unit 54. Then, this calculated value is input to the minimum limit output calculation unit 59 as the first limit output.

In the misfire occurrence cylinder combination calculation unit 52, a misfire occurrence cylinder for corresponding to a table of the misfire occurrence cylinder / torsional vibration reference output limit value setting unit 57 described later based on the misfire detection signal and the cylinder number of the misfire occurrence. Are combined and input to the second output limit calculation unit 56.
57 is a misfire-generating cylinder / torsional vibration reference output limit value setting unit. Depending on the relationship between the misfire-occurring cylinder and changes in the torsional vibration of the engine, the misfire-occurring cylinder number or multiple cylinders may be misfired experimentally or by simulation calculation. In the case of occurrence, an engine output limit value is set in consideration of the combination of the misfire occurrence cylinder number and the torsional vibration of the engine corresponding to the misfire occurrence cylinder number.
That is, as shown in the table of FIG. 4, for example, the allowable maximum load (output) (%) when a misfire occurs in 2 cylinders in a V-type 16 cylinder is a matrix with combinations of cylinder numbers (L1, R1, etc.). Is set. In FIG. 4, R is a right row cylinder, L is a left row cylinder, and the number is% relative to the rated output (rated load).

  In the second output limit calculation unit 56, the misfire generation cylinder / torsional vibration reference output limit value setting unit 57 based on the misfire generation cylinder combination (for example, L 1 and R 3) input from the misfire generation cylinder combination calculation unit 52. Then, an output limit value (for example, 60% load in the combination of L1 and R3) corresponding to the combination (for example, L1 and R3) is calculated and input to the minimum limit output calculation unit 59.

Further, the misfire-caused output fluctuation element calculation unit 53 includes a third output limiting element other than the output reduction due to the misfire-occurring cylinder, that is, the first limit output, and the output limit due to the torsional vibration of the engine, that is, the second limit output. If the third output limiting element is detected, this detection signal is input to the third limited output calculation unit 58.
The third limit output calculation unit 58 calculates a third limit output corresponding to the output limit value including the contents of the third output limit element and inputs the third limit output to the minimum limit output calculation unit 59.

The minimum limit output calculation unit 59 calculates the minimum limit output by comparing the first limit output, the second limit output, and the third limit output.
The minimum limit output is input to the fuel control device 4 as an allowable maximum output value at the time of misfire, which is an allowable maximum operation output at the time of misfire occurrence, and also input to the fuel cutoff cylinder calculation unit 60. Further, the minimum limit output is also input to a load comparison unit 61 described later.
The fuel cutoff cylinder calculation unit 60 calculates a fuel cutoff cylinder based on the misfire allowable maximum output value and the detection signal of the misfire occurrence cylinder from the misfire detector 3 and inputs it to the fuel control device 4.

In the fuel control device 4, the maximum allowable output value at the time of misfire is distributed to the normal combustion cylinders other than the fuel cutoff cylinder caused by misfire inputted from the fuel cutoff cylinder calculation unit 60, and the fuel injection for the cylinder for normal combustion is performed. The fuel injection amount of the device 5 is controlled to the fuel injection amount distributed based on the misfire-allowable maximum output value.
By comparing the first limit output, the second limit output, and the third limit output as described above and setting the minimum limit output as the maximum allowable output upon misfire, as shown in FIG. For example, even in the case of a two-cylinder misfire, the amount varies from 100% engine output to 75%, 70%, 65%, 60%, 55%, 50% depending on the amount of the first to third limit outputs. It will drive with engine power.

  In the embodiment, the misfire-caused output fluctuation element calculation unit 53 detects the third output restriction element other than the first restriction output and the second restriction output, and the contents of the third output restriction element. The means for calculating the third limit output corresponding to the output limit value incorporating the above is omitted, and the misfire-allowable maximum output value is calculated from the first limit output and the second limit output. Good.

Next, the detected value of the engine load from the load detector 6 is input to the load comparison unit 61 of the misfire controller 5.
In the load comparison unit 61, the minimum limit output calculated by the minimum limit output calculation unit 59 is used as the allowable maximum load at the time of misfire, and the detected value of the allowable maximum load and the engine load input from the load detector 6 is used. And the comparison result is input to the engine stop necessity determination unit 62.
The engine stop necessity determination unit 62 outputs an engine stop command signal to the fuel control device 4 when the detected value of the engine load exceeds an allowable maximum load corresponding to the misfire occurrence cylinder number. As a result, the engine is stopped.

  According to this embodiment, when a misfire occurs, the first limit output obtained by subtracting the misfire output corresponding to the number of cylinders with misfire from the normal operation output of the engine 100 and the output limit value based on the torsional vibration of the engine 100 are misfired. The misfire occurrence cylinder number calculated by using the misfire occurrence cylinder / torsional vibration reference output limit value setting unit (misfire occurrence cylinder / torsional vibration reference output limit value setting table) 57 of the misfire controller set corresponding to the occurrence cylinder number. The minimum limit output is calculated from both the second limit output which is the corresponding output limit value, and the fuel control amount of the engine 4 is set so that the fuel injection amount becomes the minimum limit output, that is, the allowable maximum output value at the time of misfire. Therefore, in the event of a misfire, the allowable maximum output at the time of misfire that takes into account both the first limit output and the second limit output as the output of the engine 100 It can be operated up to the upper limit.

  As a result, as in the prior art, the output is limited more than necessary with respect to the allowable maximum operation output for the purpose of continuing stable operation of the engine 100 when misfire occurs (for example, 50% output as shown in FIG. 3B). The engine 100 can be used more efficiently than the prior art, and the fuel consumption rate can be improved by avoiding operating the engine 100 at a lower load than necessary. Efficiency can be improved.

  Further, as in the above-described embodiment, in addition to the first limit output and the second limit output, the output limit element other than the output drop by the cylinder and the torsional vibration of the engine is detected and the first limit output is based on the output limit element. If the maximum allowable output at the time of misfire is calculated in consideration of the three output limiting elements of the first limited output, the second limited output, and the third limited output, It is possible to improve the accuracy of the upper limit value of the maximum allowable output value at the time of misfire.

  In addition, according to this embodiment, the detection value of the engine load is set to the cylinder of the misfire occurrence cylinder when the misfire occurs by using the allowable maximum load setting table in which the allowable maximum load of the engine is set corresponding to the misfire occurrence cylinder number. Since the engine is stopped when the maximum allowable load corresponding to the number is exceeded, the engine can be operated if the engine load is less than the maximum allowable load corresponding to the cylinder number of the misfiring cylinder when a misfire occurs. Thus, it is possible to avoid stopping the engine at an allowable maximum load or higher that is uniquely set for the purpose of continuing stable operation of the engine when misfire occurs. Thereby, the utilization factor of the engine can be further improved.

  According to the present invention, when a misfire occurs in one cylinder or a plurality of cylinders, the engine operation output level can be increased to an allowable maximum operation output for stable operation in consideration of various requirements due to the occurrence of misfire. It is possible to provide an engine misfire output limiting operation method and misfire output limiting device capable of suppressing a decrease in the engine utilization rate at the time of occurrence and suppressing an efficiency decrease in the engine power plant accompanying a deterioration in the fuel consumption rate of the engine. .

It is a plane arrangement block diagram which shows the whole structure of the output limiting system at the time of misfire in the multicylinder diesel engine for electric power generation which concerns on the Example of this invention. It is a control block diagram at the time of misfire detection in the said Example. It is an output change diagram at the time of misfire in the multi-cylinder diesel engine for electric power generation, (A) shows this invention, (B) shows a prior art. It is a table | surface which shows an example of the misfire generation cylinder / torsional vibration reference output limit value setting table in the said Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Engine 1 Cylinder 2 Fuel injection apparatus 3 Misfire detector 4 Fuel control apparatus 5 Misfire controller 6 Load detector

Claims (8)

  An engine misfire output limit operation method for detecting misfire of a multi-cylinder engine and performing engine output limit operation based on the misfire detection result, wherein misfire occurs from normal operation output based on the misfire detection signal The first limit output, which is an output obtained by subtracting the misfire output corresponding to the number of cylinders, is calculated, and the output limit value is set based on the relationship between a preset misfire occurrence cylinder and a change in torsional vibration of the engine And calculating a second limit output based on the misfire detection signal, comparing the first limit output and the second limit output when detecting the misfire, and calculating a minimum limit output, An engine misfire output limited operation method, characterized in that the engine is operated with the minimum limit output set as the maximum allowable output during misfire.   When the misfire is detected, an output limiting element other than the output drop due to the misfire-occurring cylinder and the torsional vibration of the engine is detected, a third limited output based on the output limiting element is calculated, and when the misfire is detected, The first limit output, the second limit output, and the third limit output are compared to calculate a minimum limit output, and the engine is operated with the minimum limit output set as an allowable maximum output upon misfire. The engine output limiting operation method during misfire of claim 1.   Using a misfire occurrence cylinder / torsional vibration reference output limit value setting table in which an output limit value based on the torsional vibration is set corresponding to a misfire occurrence cylinder number according to the relationship between the misfire occurrence cylinder and a change in torsional vibration of the engine 2. The engine misfire output limited operation method according to claim 1, wherein the second limited output is calculated.   An engine misfire load limit operation method for detecting misfire of a plurality of cylinders in an engine that is operated independently and performing engine load limit operation based on the detection result of misfire, comprising a detection signal of a misfire occurrence cylinder and an engine load Based on the detection signal, using the allowable maximum load setting table in which the allowable maximum load of the engine is set corresponding to the misfire occurrence cylinder number, the detected value of the engine load corresponds to the detected misfire occurrence cylinder number. An engine misfire load limiting operation method characterized by stopping the engine when an allowable maximum load is exceeded.   An engine misfire output limiting device configured to detect misfire of a multi-cylinder engine by a misfire detector and perform engine output limiting operation based on the misfire detection result, and is input from the misfire detector. A first limit output calculating means for calculating a first limit output, which is an output obtained by subtracting a misfire output corresponding to the number of misfire occurrence cylinders from the normal operation output of the engine based on a misfire detection signal; and a preset misfire A second limit output calculating means for calculating the second limit output based on the misfire detection signal using an output limit value set based on a relationship between the generation cylinder and a change in torsional vibration of the engine; A limit output calculating means for comparing the first limit output with the second limit output and calculating the minimum limit output as an allowable maximum output in case of misfire; Misfire when output limiting device for an engine is characterized in that includes a misfire controller for controlling the fuel control system of the engine misfire when the fuel injection amount such that the limit limit the output value from.   The misfire controller detects a power limiting element other than a decrease in output by the misfiring cylinder and a torsional vibration of the engine based on a misfire detection signal input from the misfire detector, and a third based on the output limiting element And a third limit output calculating means for calculating a limit output, wherein the limit output calculation means compares the first limit output, the second limit output, and the third limit output to obtain a minimum limit output. 6. The engine misfire output limiting device according to claim 5, wherein the engine is configured to calculate an allowable maximum output at the time of misfire.   The misfire controller has a misfire generating cylinder / torsion in which an output limit value based on the misfire generating cylinder and the torsional vibration is set corresponding to the misfire generating cylinder number according to the relationship between the misfire generating cylinder and a change in torsional vibration of the engine. A vibration reference output limit value setting table, wherein the second limit output calculating means assigns a misfire occurrence cylinder number based on a misfire detection signal input from the misfire detector to the misfire occurrence cylinder / torsional vibration reference output limit value setting table; 6. The engine misfire output limiting device according to claim 5, wherein the second limited output is calculated in correspondence with the engine. An engine misfire load limiter configured to detect misfire in a plurality of cylinders in a single-operated engine by a misfire detector and perform engine load limit operation based on the misfire detection result. A load detector for detecting the load, and an allowable maximum load setting table in which the allowable maximum load of the engine is set in correspondence with the misfire occurrence cylinder number, and the detected value of the engine load input from the load detector is And a misfire controller that outputs a stop signal for stopping the engine when an allowable maximum load in the allowable maximum load setting table corresponding to a cylinder number of a misfire-occurring cylinder input from the misfire detector is exceeded. An engine misfire load limiting device.

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