JP3400190B2 - Gas engine ignition timing controller - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition timing control device for suppressing torque fluctuation in a region where fuel supply is temporarily insufficient in a gas engine.

[0002]

2. Description of the Related Art In a gas engine that uses CNG, LPG, or the like as fuel, the fuel supply to the gas engine is temporarily insufficient due to a sudden change in the intake throttle valve opening. It may give you a feeling of strangeness.

As a measure against such a problem, Japanese Unexamined Patent Publication (Kokai) No. 2-252955 discloses an LPG engine having a slow fuel supply system and a main fuel supply system, and a fuel in a connecting region between these two fuel supply systems. In order to prevent a sudden change in the supply amount and the air-fuel ratio, it has been proposed to perform a smoothing process with a relatively large smoothness with respect to the calculation parameter of the fuel amount in this joint region. Such a procedure is effective in a system having only one regulator, such as a passenger car.

[0004]

However, such control is not always effective for gas engines of large and medium-sized commercial vehicles and the like.

That is, in the case of a large or medium-sized commercial vehicle or the like, one regulator cannot sufficiently supply the fuel, so that the main regulator and the sub regulator may be provided in parallel. As a result, fuel is supplied only from the main regulator in areas where a large amount of fuel with a low load is not required, and auxiliary in addition to the main regulator in addition to the main regulator in an area that requires a large amount of fuel with a medium to high load. Fuel is supplied.

In this case, if the operation of the sub-regulator is delayed in the connecting region where the fuel supply shifts from the main regulator to the sub-regulator, an appropriate air-fuel mixture cannot be formed during the delayed period, and the torque momentarily drops.

This situation is as shown in FIG. Here, when the air flow rate Ga reaches Ga1 and the fuel supply from the main regulator reaches a ceiling, the discharge pressure Pfm of the main regulator begins to decrease, but the air flow rate becomes Ga2 and the discharge pressure Pfm of the main regulator becomes the discharge pressure Pfs of the sub-regulator. In the connecting region up to the lower limit, the fuel is not sufficiently supplied from the sub-regulator and the fuel supply becomes insufficient as a whole.

On the other hand, even if the air-fuel ratio control as disclosed in JP-A-2-252955 is applied, there is no guarantee that the flow rate characteristics of the two regulators are optimum, and if there is a difference between these characteristics, the regulator It is unavoidable that the fuel supply from the plant will be insufficient, and a sufficient effect cannot be expected.

Therefore, an object of the present invention is to provide a control device which is effective as a countermeasure against the instability of the fuel supply of a gas engine of a large or medium-sized commercial vehicle having a plurality of such regulators.

[0010]

A first aspect of the present invention is to provide a means for generating a mixture of gas fuel and air, an intake throttle valve for controlling intake of the mixture into a combustion chamber, and an inside of the combustion chamber. In a gas engine having means for igniting the air-fuel mixture, as shown in FIG. 11, engine rotation speed detection means 51 for detecting the rotation speed of the engine, means 52 for detecting the load state of the engine, and A reference target ignition timing determining means 53 for determining a reference target ignition timing based on the engine rotation speed obtained from the engine rotation speed detecting means 51 and the load state of the engine obtained from the means 52 for detecting the load state of the engine; Intake throttle valve opening detection means 54 for detecting the opening degree of the intake throttle valve, and a neutral state detection for detecting whether the engine is autonomously rotating with being disconnected from the drive system. Means 55, judging means 56 for judging whether or not to store the operating state from the data obtained from the intake throttle valve opening detecting means 54 and the neutral state detecting means 55, and the air-fuel ratio from the residual oxygen concentration in the exhaust gas. It is obtained from the air-fuel ratio detecting means 57 for detecting the state, the air-fuel ratio state storing means 58 for storing the change of the air-fuel ratio obtained from the air-fuel ratio detecting means 57 at a constant time and at a constant interval, and the engine rotation speed detecting means 51. The engine rotation state storage means 59 for storing changes in the engine rotation speed at fixed intervals and the air-fuel ratio variation degree determination means 60 for determining the variation degree of the data stored in the air-fuel ratio state storage means 58.
And an engine speed variation degree determining means 61 for determining a variation degree of data obtained from the engine rotation state storing means 59, an air-fuel ratio variation degree determining means 60 and an engine rotation rate variation degree determining means 61. An ignition timing learning correction value determining means 62 for learning and determining an ignition timing learning correction value from the determined fluctuation degree, and an ignition timing determining means 63 for determining a target ignition timing from the reference target ignition timing and the ignition timing learning correction value. Prepared

In a second aspect of the invention, means for generating a mixture of gas fuel and air, an intake throttle valve for adjusting the intake of this mixture into the combustion chamber, and ignition of the mixture in the combustion chamber. In the gas engine including the means, as shown in FIG. 12, an engine rotation speed detecting means 51 for detecting the rotation speed of the engine, a means 52 for detecting the load state of the engine, and the engine rotation speed detecting means 51. Reference target ignition timing determining means 53 for determining a reference target ignition timing from the engine load speed obtained from the engine rotation speed and the engine load status detecting means 52.
An intake throttle valve opening detecting means 54 for detecting the opening degree of the intake throttle valve of the engine; a neutral state detecting means 55 for detecting whether the engine is autonomously rotated by being disconnected from the drive system; Judging means 56 for judging whether or not to store the operating state from the data obtained from the throttle valve opening detecting means 54 and the neutral state detecting means 55.
An air-fuel ratio detecting means 57 for detecting the air-fuel ratio state from the residual oxygen concentration in the exhaust gas; An ignition timing learning correction value is learned from the air-fuel ratio fluctuation degree judging means 60 for judging the fluctuation degree of the data stored in the air-fuel ratio state storing means 58 and the fluctuation degree judged by the air-fuel ratio fluctuation degree judging means 60. An ignition timing learning correction value determining means 62 for determining and an ignition timing determining means 63 for determining a target ignition timing from the reference target ignition timing and the ignition timing learning correction value are provided.

In a third aspect of the present invention, means for generating a mixture of gas fuel and air, an intake throttle valve for controlling intake of the mixture into the combustion chamber, and ignition of the mixture in the combustion chamber. In a gas engine provided with means, as shown in FIG. 13, an engine rotation speed detecting means 51 for detecting the rotation speed of the engine, a means 52 for detecting a load state of the engine, and the engine rotation speed detecting means 51. Reference target ignition timing determining means 53 for determining a reference target ignition timing from the engine load speed obtained from the engine rotation speed and the engine load status detecting means 52.
An intake throttle valve opening detecting means 54 for detecting the opening degree of the intake throttle valve of the engine; a neutral state detecting means 55 for detecting whether the engine is autonomously rotated by being disconnected from the drive system; Judging means 56 for judging whether or not to store the operating state from the data obtained from the throttle valve opening detecting means 54 and the neutral state detecting means 55.
And an engine rotation state storage means 59 for storing changes in the engine rotation speed obtained from the engine rotation speed detection means 51 at fixed intervals for a certain period of time, and a fluctuation degree of data obtained from the engine rotation state storage means 59. Engine speed variation degree determining means 61, ignition timing learning correction value determining means 62 for learning and determining an ignition timing learning correction value from the variation degree determined by the engine speed variation degree determining means 61, and the reference. An ignition timing determining means 63 for determining the target ignition timing from the target ignition timing and the ignition timing learning correction value is provided.

A fourth aspect of the present invention is the air conditioner according to the first or second aspect, wherein the lean peak value of the air-fuel ratio within a fixed time is obtained as the degree of variation determined by the air-fuel ratio variation determining means 60. The fuel ratio variation determination means 60 is provided.

A fifth aspect of the present invention is the engine speed variation determining means 61 according to the first or third aspect of the invention.
The engine rotation speed fluctuation determining means 61 is provided for obtaining the magnitude of the drop in the engine rotation speed as the fluctuation determined by the above.

[0015]

In the first aspect of the invention, if the determination means 56 determines that the operating state is to be stored based on the data obtained from the intake throttle valve opening detection means 54 and the neutral state detection means 55, the air-fuel ratio state is determined. The storage unit 58 stores the air-fuel ratio change of the exhaust gas obtained from the air-fuel ratio detection unit 57, and the engine rotation state storage unit 59 stores the engine rotation speed detection unit 51.
The changes in the engine speed obtained from the above are stored at fixed intervals for a fixed time. Next, the air-fuel ratio variation determination means 60 determines the variation degree of the data stored in the air-fuel ratio state storage means 58, and the engine rotation speed variation determination means 6
1 determines the fluctuation degree of the data obtained from the engine rotation state storage means 59. Next, the ignition timing learning correction value is learned and determined by the ignition timing learning correction value determining means 62 from this degree of variation. The correction based on the ignition timing learning correction value is corrected based on the engine rotational speed detected by the engine rotational speed detecting means 51 and the engine load state detected by the means 52 for detecting the load state of the engine, and the reference target ignition timing determining means 53 is provided. The target ignition timing is finally determined by the ignition timing determining means 63 by performing the reference target ignition timing determined by.

In the second aspect of the invention, the determining means 56 is the intake throttle valve opening detecting means 54 and the neutral state detecting means 5.
If it is determined from the data obtained from 5 that the operating state is to be stored, the air-fuel ratio state storage means 58 stores the change in the air-fuel ratio of the exhaust gas obtained from the air-fuel ratio detection means 57 at fixed intervals for a fixed time. Next, the air-fuel ratio fluctuation degree determination means 60
Determines the fluctuation degree of the data stored in the air-fuel ratio state storage means 58. Next, the ignition timing learning correction value is learned and determined by the ignition timing learning correction value determining means 62 from this degree of variation. The correction based on the ignition timing learning correction value is corrected based on the engine rotational speed detected by the engine rotational speed detecting means 51 and the engine load state detected by the means 52 for detecting the load state of the engine, and the reference target ignition timing determining means 53 is provided. The target ignition timing is finally determined by the ignition timing determining means 63 by performing the reference target ignition timing determined by.

In the third aspect of the invention, the judging means 56 is the intake throttle valve opening detecting means 54 and the neutral state detecting means 5.
If it is determined from the data obtained from No. 5 that the operating state is to be stored, the engine rotation state storage means 59 changes the engine rotation speed obtained from the engine rotation speed detection means 51 with a fixed time interval. Memorize with. Next,
The engine rotation speed fluctuation degree judging means 61 judges the fluctuation degree of the data obtained from the engine rotation state storage means 59. Next, the ignition timing learning correction value is learned and determined by the ignition timing learning correction value determining means 62 from this degree of variation.
The correction based on the ignition timing learning correction value is corrected based on the engine rotational speed detected by the engine rotational speed detecting means 51 and the engine load state detected by the means 52 for detecting the load state of the engine, and the reference target ignition timing determining means 53 is provided.
By performing the reference target ignition timing determined by
Finally, the ignition timing determination means 63 determines the target ignition timing.

According to a fourth aspect of the present invention, in the first or second aspect of the invention, the degree of variation determined by the air-fuel ratio variation determining means 60 is obtained by obtaining a lean peak value of the exhaust air-fuel ratio within a certain period of time. And

In a fifth aspect of the invention, in the first or third aspect of the invention, the magnitude of the drop in the engine rotation speed is obtained and used as the fluctuation degree determined by the engine rotation speed fluctuation determining means 61.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a system diagram showing the entire ignition timing control device of this embodiment. FIG. 2 is a configuration diagram showing the fuel supply system of this embodiment.

An intake throttle valve 22 is provided in the intake passage 31 of the gas engine 1. The intake throttle valve 22 is linked with an accelerator pedal (not shown), and the intake air amount is controlled according to the throttle valve opening TVO. Here, the throttle valve opening TVO is detected by the intake throttle valve opening sensor 22.

A mixer 11 is provided upstream of the intake throttle valve 22. The fuel is a fuel tank 17 in this mixture 11.
From the fuel supply pipe 28.

The fuel supply path 28 is provided with a sub-regulator 16 in parallel with the main regulator 14 as a regulator for controlling the pressure of the supplied fuel. The fuel introduced from the fuel tank 17 is depressurized by the main regulator 14 or the sub-regulator 16 to a predetermined primary pressure. Here, the reference pressure is guided to the main regulator 14 and the sub regulator 16 from the intake passage 31 by the reference pressure introducing pipe 29, and the main regulator 14 and the sub regulator 1
The primary pressure of 4 is maintained at a predetermined pressure difference from the pressure of the intake passage 31.

Further, a fuel injection solenoid valve 12 and fuel cutoff valves 13 and 15 are provided in the fuel supply passage 28, and the fuel supply amount is appropriately controlled according to the operating condition. The fuel thus guided to the mixer 11 is sucked in accordance with the negative pressure generated in the venturi portion 40 of the air-fuel mixture 11 in proportion to the amount of intake air to be sucked, and the air-fuel mixture with the intake air is generated. .

An ignition plug 7 for igniting the air-fuel mixture near the compression top dead center is installed above the engine combustion chamber 33 in the gas engine 1.

Here, the ignition plug 7 is controlled by the control unit 2 so as to ignite with an optimum ignition timing according to the operating state. Particularly in the present invention, the control unit 2 corrects the ignition timing based on the fluctuation of the engine rotation speed Ne and the fluctuation of the exhaust air-fuel ratio LMD, and suppresses the rapid fluctuation of the torque. Specifically, the control unit 2 controls conduction of the power switch 5 at an appropriate timing and applies a high voltage from the ignition coil 6 to the ignition plug 7.

The control unit 2 includes a CPU,
It is composed of a microcomputer such as ROM, RAM, and an input / output interface. The control unit 2 controls the operation of the entire system, and receives signals from the engine speed sensor 9, the air-fuel ratio sensor 10, the intake pipe pressure sensor 18, and the like.

Here, the engine rotation speed sensor 9 indicates the engine rotation speed Ne, the intake pipe pressure sensor 18 indicates the intake pipe negative pressure Pim as the load detecting means, and the air-fuel ratio sensor 10 indicates the exhaust gas exhaust gas from the residual oxygen concentration in the exhaust gas. The fuel ratio LMD is detected respectively. Also, from the neutral switch 25,
A signal is input indicating whether the transmission is in the neutral state, that is, whether the engine is in the state of being separated from the drive system and rotating autonomously.

Next, the ignition timing control by the control unit 2 will be described with reference to FIGS. 3 and 4.

FIG. 3 shows the state of turbulence of the engine speed Ne and the air-fuel ratio LMD, which is learned and recorded, and the ignition timing learning correction value is determined from these values. Therefore, the fluctuation degree of the engine speed Ne and the air-fuel ratio LMD is determined. It is a flowchart which shows the procedure to set.

Here, first, at step 1, it is judged from the signal from the neutral switch whether the transmission is in the neutral state, and if it is judged that the transmission is in the neutral state, at step 2, the intake throttle valve opening TVO is read. Can be started. Further, in step 3, the change rate ΔTVO of the intake throttle valve opening TVO is calculated in the control unit 2.

Next, at step 4, it is judged whether or not the intake throttle valve opening change rate ΔTVO exceeds a predetermined opening change rate ΔTTVO, and the intake throttle valve opening TVO rapidly changes in the neutral state, and the intake throttle Valve opening change rate ΔT
If the VO exceeds the predetermined opening change rate ΔTTVO, it is confirmed in step 5 that the control unit 2 is in a state where new data can be fetched, and then the control unit 2 is in the operating state as in steps 6 to 8. Start recording. In this case, the gas engine is in a state of racing with no load, and if the operation enters such a so-called empty running state, the air-fuel ratio L
The coefficient for determining the ignition timing learning correction value is calculated in advance from the state of the MD and the change in the engine rotation speed Ne.

Specifically, in step 6, the engine speed Ne from the engine speed sensor 9
In step 7, the air-fuel ratio sensor 10 outputs the air-fuel ratio LMD.
Are read into the control unit 2 respectively,
Will be recorded. This is continued until the predetermined learning time TMEM elapses from the start of recording as in step 8.

During the transitional period when the gas engine 1 enters the racing state, such as during the learning time TMEM, the fuel supply amount is temporarily insufficient because the intake air amount to the gas engine 1 rapidly increases. However, the air-fuel ratio LMD and the engine rotation speed Ne are disturbed. In particular, as in the present embodiment, such a phenomenon is likely to occur in the connecting region where the fuel supply from the main regulator 14 becomes the limit and the fuel supply from the sub-regulator 16 starts.

FIG. 5 shows an example of changes in the air-fuel ratio LMD and engine speed Ne during such racing. Here, the air-fuel ratio LMD is near its maximum value LMDpeak, and the engine speed N
It can be seen that e is disturbed in the vicinity of A shown in FIG. Here, FIG. 6 is an enlarged view of a portion A in FIG. 5, in which the engine speed Ne is the maximum value Nettop.
It is shown that the value has fallen to the minimum value Nebot.

After the recording for the predetermined learning time TMEM is completed, in the control unit 2, from these recordings, in step 9, the engine speed N
The difference ΔNe between the rotation speeds of the maximum value Netop and the minimum value Nebot of e is equal to the air-fuel ratio LM in step 10.
The lean peak value LMDpeak of D is obtained, respectively.

Further, in step 11, the engine rotation speed fluctuation coefficient Kne is calculated from the engine rotation speed drop ΔNe thus obtained, and in step 12, LMDpeak is calculated from the air-fuel ratio fluctuation coefficient. Klmd is determined respectively. These are coefficients used to calculate the ignition timing learning correction value ITg.

FIG. 7 shows the engine rotation speed fluctuation coefficient Kn.
FIG. 8 shows an example of the determination table of e, and FIG. 8 shows an example of the determination table of the air-fuel ratio fluctuation coefficient Klmd. The data of such a determination table is stored in the ROM in the control unit 2.

On the other hand, FIG. 4 is a flow chart showing the procedure of ignition timing control.

Here, first, at step 21, the engine speed Ne from the crank angle sensor 9 is
In step 22, the intake pipe negative pressure Pim is read from the intake pipe pressure sensor 18 as a numerical value indicating the load state of the engine.

Further, in step 23, the reference target ignition timing IT ₀ corresponding to these values is retrieved from the reference target ignition timing map stored in the ROM in the control unit 2 in advance. Further, in step 24, the reference learning map data LB corresponding to the engine rotation speed Ne and the intake pipe negative pressure Pim is retrieved from the reference learning ignition timing map stored in the ROM in the control unit 2 in advance. An example of this reference learning ignition timing map is shown in FIG.

The ignition timing learning correction value ITg is calculated in step 2
5, the reference learning map data LB is obtained as the product of the already-obtained engine rotation speed fluctuation coefficient Kne and the air-fuel ratio fluctuation coefficient Klmd. That is, ITg = LB × Kne × Klmd.

Further, in step 26, the target ignition timing IT is obtained by adding the ignition timing learning correction value ITg to the reference target ignition timing IT ₀ .

The ignition timing signal is sent in step 27.
It is output according to this target ignition timing IT. As a result, the ignition timing is appropriately adjusted by a correction value that has been learned and corrected in advance, and torque fluctuations are suppressed even in a joint region where the fuel supply amount is temporarily insufficient, and drivability is ensured.

Next, the specific operation will be described in more detail.

First, the operation state is changed from steps 1 to 4 in FIG.
When a predetermined condition as described in 1) is satisfied, that is, when the engine is idle, the control unit 2
The data for ignition timing correction is collected and the coefficient for correction is determined. Specifically, the engine rotation speed fluctuation value ΔNe and the lean peak value LMDpe of the air-fuel ratio.
ak is obtained, and the engine rotation speed fluctuation coefficient Kne and the air-fuel ratio fluctuation coefficient Klmd are determined from these. Here, the engine rotation speed fluctuation coefficient Kne and the air-fuel ratio fluctuation coefficient Klmd are set so that the correction value of the ignition timing appropriately increases as ΔNe and LMDpeak increase, as shown in FIGS. It is set so that the timing can be appropriately accelerated. That is, the ignition timing is advanced as the disturbance of the engine rotation speed and the air-fuel ratio becomes larger with reference to the time when the engine is idle.

The determination of the ignition timing during operation is specifically as follows. First, the reference target ignition timing IT _{0, which} is set corresponding to the engine speed Ne and the intake pipe negative pressure Pim, is set. As described above, the ignition timing learning correction value ITg calculated as the product of the reference learning map data LB, the engine rotation speed fluctuation coefficient Kne, and the air-fuel ratio fluctuation coefficient Klmd with respect to IT ₀ determined in accordance with the operating state. Is added to set the target ignition timing IT. In this way, the actual ignition is performed by the target ignition timing IT from the reference target ignition timing IT ₀ by the ignition timing learning correction value I
It is performed at a timing that is faster than Tg. By doing so, even if the fuel supply from the sub-regulator 16 is delayed and the intake air-fuel mixture becomes temporarily lean in the connection region, a sufficient combustion time can be secured, so that a temporary decrease in engine torque is minimized. It is suppressed to the limit.

Further, the engine rotation speed fluctuation coefficient Kne
Since the determination of the air-fuel ratio fluctuation coefficient Klmd is performed every time the engine is emptied, the ignition timing learning correction is performed each time the engine is emptied, even if the fuel discharge amount characteristic of the regulator changes with time. The value ITg is corrected and the appropriate target ignition timing IT is maintained.

In an operating state in which the ignition timing correction is unnecessary, such as when the engine rotation speed is low, the reference learning map data LB determined from the engine rotation speed Ne and the intake pipe pressure Pim becomes 0, so ignition learning is performed. Correction value I
Tg also becomes 0, and the ignition timing is not automatically corrected.

[0051]

According to the first aspect of the present invention, the ignition timing learning correction value is learned and determined in advance from the degree of change in the air-fuel ratio of exhaust gas and the degree of change in engine speed when the operating condition meets a predetermined condition. Since the reference target ignition timing is corrected with this ignition timing learning correction value, the ignition timing is appropriately accelerated in the region where the fuel supply amount of the engine is temporarily insufficient, and the torque during operation is temporarily reduced. It is suppressed and the drivability is improved. Also, the learning decision of the ignition timing learning correction value is
Since the operation is repeated any number of times when the predetermined operating condition is met, the target ignition timing is always appropriately corrected and the torque fluctuation is suppressed to the minimum even if the fuel discharge amount characteristic of the regulator or the like changes with time.

In the second aspect of the invention, the ignition timing learning correction value is learned and determined from the degree of change in the air-fuel ratio of the exhaust gas when the operating condition matches a predetermined condition, and the reference target ignition is set based on this ignition timing learning correction value. Since the timing is corrected, the ignition timing is appropriately advanced in the region where the fuel supply amount of the engine is temporarily insufficient, the temporary reduction of the torque during operation is suppressed, and the drivability is improved. Further, since the learning determination of the ignition timing learning correction value is made any number of times when the predetermined operating condition is met, the target ignition timing is always appropriately corrected even if the fuel discharge amount characteristic of the regulator changes with time. Torque fluctuations are minimized.

According to a third aspect of the present invention, an ignition timing learning correction value is learned and determined from the degree of change of the engine speed when the operating condition matches a predetermined condition, and the reference target ignition timing is determined by this ignition timing learning correction value. Therefore, the ignition timing is appropriately accelerated in the region where the fuel supply amount of the engine is temporarily insufficient, the temporary decrease in the torque during operation is suppressed, and the drivability is improved. Further, the learning determination of the ignition timing learning correction value is made any number of times when the predetermined operating condition is met, so that the target ignition timing is always properly corrected even if the fuel discharge amount characteristic of the regulator or the like changes with time. Torque fluctuations are minimized.

In the fourth aspect of the present invention, the lean peak value of the air-fuel ratio within a fixed time is obtained as the fluctuation degree determined by the air-fuel ratio fluctuation degree determining means, so that the fluctuation degree of the air-fuel ratio can be clearly grasped, and the ignition The time learning correction value can be appropriately and easily determined.

In the fifth aspect of the invention, since the magnitude of the drop in the engine rotation speed is obtained as the variation determined by the engine rotation speed variation determining means, the variation in the engine rotation speed can be clearly grasped and the ignition timing The learning correction value can be determined appropriately and easily.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a fuel supply system of the same.

FIG. 3 is a flow chart showing a procedure for similarly determining the ignition timing learning correction value.

FIG. 4 is a flowchart showing the contents of the ignition timing control.

FIG. 5 is an explanatory diagram showing changes in air-fuel ratio and engine rotation speed during racing of the gas engine.

FIG. 6 is an enlarged view of a portion A in FIG.

FIG. 7 is an explanatory diagram showing a determination table of an engine rotation speed fluctuation coefficient Kne.

FIG. 8 is an explanatory diagram showing a determination table of an air-fuel ratio fluctuation coefficient Klmd.

FIG. 9 is an explanatory diagram showing a reference learning ignition timing map.

FIG. 10 is a characteristic diagram showing a relationship between an air flow rate Ga and a fuel discharge amount Gf of a two-regulator system.

FIG. 11 is a configuration diagram of the first invention.

FIG. 12 is a configuration diagram of a second invention.

FIG. 13 is a configuration diagram of a third invention.

[Explanation of symbols]

51 Engine rotation speed detection means 52 means for detecting load condition of engine 53 Reference Target Ignition Timing Determining Means 54 Intake throttle valve opening detection means 55 Neutral state detection means 56 Judgment means 57 Air-fuel ratio detection means 58 air-fuel ratio state storage means 59 engine rotation state storage means 60 Air-fuel ratio variation determination means 61 Engine Rotational Speed Fluctuation Determining Means 62 Ignition timing learning correction value determining means 63 Ignition timing determination means

Continuation of the front page (56) Reference JP-A-2-252955 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02P 5/15 F02M 21/02 311

Claims (5)

(57) [Claims] 1. A means for generating an air-fuel mixture of gas fuel and air, an intake throttle valve for controlling intake of the air-fuel mixture into a combustion chamber, and means for igniting the air-fuel mixture in the combustion chamber. In the gas engine, an engine rotation speed detecting means for detecting the rotation speed of the engine, a means for detecting the load state of the engine, an engine rotation speed obtained from the engine rotation speed detecting means, and a load state of the engine are detected. Reference target ignition timing determining means for determining a reference target ignition timing from the load state of the engine obtained from the means, intake throttle valve opening detection means for detecting the opening of the intake throttle valve of the engine, and the engine is a drive system. It is obtained from the neutral state detecting means for detecting whether the vehicle is separated and autonomously rotating, and the intake throttle valve opening detecting means and the neutral state detecting means. Determination means to determine whether to store the operating state from the stored data, air-fuel ratio detection means to detect the air-fuel ratio state from the residual oxygen concentration in the exhaust, the change in the air-fuel ratio obtained from the air-fuel ratio detection means The air-fuel ratio state storage means for storing the change of the engine rotation speed obtained from the engine rotation speed detection means at a constant time constant interval, and the air-fuel ratio state An air-fuel ratio variation determining means for determining the variation of the data stored in the storage means, an engine rotation speed variation determining means for determining the variation of the data obtained from the engine rotation state storage means, and the air-fuel ratio Ignition timing learning correction value determination for learning and determining ignition timing learning correction value from the fluctuation degree determined by the fluctuation degree determining means and the engine speed fluctuation degree determining means Stage and the reference target ignition timing and the ignition timing learning correction value ignition timing control device for a gas engine, wherein the ignition timing determining means for determining a target ignition timing, by comprising from. 2. A means for generating an air-fuel mixture of gas fuel and air, an intake throttle valve for controlling intake of the air-fuel mixture into a combustion chamber, and a means for igniting the air-fuel mixture in the combustion chamber. In the gas engine, an engine rotation speed detecting means for detecting the rotation speed of the engine, a means for detecting the load state of the engine, an engine rotation speed obtained from the engine rotation speed detecting means, and a load state of the engine are detected. Reference target ignition timing determining means for determining a reference target ignition timing from the load state of the engine obtained from the means, intake throttle valve opening detection means for detecting the opening of the intake throttle valve of the engine, and the engine is a drive system. It is obtained from the neutral state detecting means for detecting whether the vehicle is separated and autonomously rotating, and the intake throttle valve opening detecting means and the neutral state detecting means. Determination means for determining whether to store the operating state from the stored data, an air-fuel ratio detection means for detecting the air-fuel ratio state from the residual oxygen concentration in the exhaust, and a change in the air-fuel ratio obtained from the air-fuel ratio detection means Is stored at constant intervals for a certain period of time, an air-fuel ratio state determination means for determining the degree of variation of the data stored in the air-fuel ratio state storage means, and the air-fuel ratio variation degree determination means. The ignition timing learning correction value determining means for learning and determining the ignition timing learning correction value from the fluctuation degree, and the ignition timing determining means for determining the target ignition timing from the reference target ignition timing and the ignition timing learning correction value. An ignition timing control device for a gas engine, which is characterized in that: 3. A means for producing a mixture of gas fuel and air, an intake throttle valve for controlling intake of the mixture into a combustion chamber, and a means for igniting the mixture in the combustion chamber. In the gas engine, an engine rotation speed detecting means for detecting the rotation speed of the engine, a means for detecting the load state of the engine, an engine rotation speed obtained from the engine rotation speed detecting means and a load state of the engine are detected. Reference target ignition timing determining means for determining a reference target ignition timing from the load state of the engine obtained from the means; intake throttle valve opening detecting means for detecting the opening of the intake throttle valve of the engine; It is obtained from the neutral state detecting means for detecting whether the vehicle is separated and autonomously rotating, and the intake throttle valve opening detecting means and the neutral state detecting means. Determination means for determining whether or not to store the operating state from the stored data, engine rotation state storage means for storing changes in the engine rotation speed obtained from the engine rotation speed detection means at fixed intervals for a fixed time, An engine rotation speed variation determination unit that determines the variation of the data obtained from the engine rotation state storage unit, and an ignition timing learning correction value is learned and determined from the variation determined by the engine rotation speed variation determination unit. An ignition timing control device for a gas engine, comprising: an ignition timing learning correction value determining means; and an ignition timing determining means for determining a target ignition timing from the reference ignition target timing and the ignition timing learning correction value. 4. The air-fuel ratio variation determining means for determining a lean peak value of the air-fuel ratio within a fixed time as the variation determined by the air-fuel ratio variation determining means. Alternatively, the ignition timing control device for the gas engine according to claim 2. 5. The engine rotation speed variation determining means for determining the magnitude of a drop in the engine rotation speed as the variation determined by the engine rotation speed variation determining means is provided. The ignition timing control device for a gas engine according to claim 3.