WO2007129599A1

WO2007129599A1 - Gas fuel internal combustion engine

Info

Publication number: WO2007129599A1
Application number: PCT/JP2007/059113
Authority: WO
Inventors: Ryuichi Yamashita; Hiromitsu Matsumoto
Original assignee: Yamaha Hatsudoki Kabushiki Kaisha
Priority date: 2006-05-01
Filing date: 2007-04-26
Publication date: 2007-11-15
Also published as: JPWO2007129599A1

Abstract

A gas fuel internal combustion engine comprises the downstream end openings (4d) of a fuel feed passage (4c) opening to a combustion chamber (18). Each downstream end opening (4d) is opened and closed by a poppet valve type fuel feed valve (20) in which an umbrella-like valve plate (20b) is formed at one end of a valve stem (20a).

Description

Specification

Gas fuel internal combustion engine

Technical field

The present invention relates to a crankcase compression type two-stroke (two-cycle) gas fuel internal combustion engine.

Background art

[0002] A crankcase compression type two-cycle internal combustion engine may include a fuel injection valve that directly supplies fuel into a cylinder from the viewpoint of improving fuel efficiency by suppressing fuel blow-through. This fuel injection valve generally injects high-pressure gasoline fuel from an injection nozzle (see, for example, Patent Document 1).

[0003] On the other hand, in the two-cycle internal combustion engine, a gas fuel may be used in order to reduce fuel costs. In this case, it is conceivable to inject and supply the gas fuel into the cylinder by the fuel injection valve.

Patent Document 1: Japanese Patent Laid-Open No. 10-252479

Disclosure of the invention

Problems to be solved by the invention

[0004] By the way, when a structure for injecting and supplying gas fuel from the injection nozzle of the conventional fuel injection valve is employed, the required amount of gas fuel may not be supplied in a short time due to its structure. Conceivable. As a result, there is a risk that sufficient output performance may not be obtained at high loads due to a decrease in charging efficiency, and fuel consumption and exhaust gas properties may deteriorate.

[0005] The present invention has been made in view of the above-described conventional situation. When gas fuel is supplied into the combustion chamber, output performance at high load can be improved, and fuel consumption and exhaust gas properties can be improved. The purpose is to provide a two-stroke gas-fueled internal combustion engine that can be compressed.

Means for solving the problem

[0006] The invention of claim 1 is a crank chamber compression type two-stroke gas fuel internal combustion engine, wherein a plurality of downstream end openings are provided in the combustion chamber of the fuel supply passage, and the respective downstream end openings are respectively provided. Opened and closed by a poppet valve type fuel supply valve that has an umbrella-shaped valve plate formed at one end of the valve stem It is characterized by that.

[0007] The invention of claim 2 is the vent roof according to claim 1, wherein the combustion chamber has an exhaust port side slope located on the exhaust port side and an anti exhaust port side slope located on the anti exhaust port side. The fuel supply valve is arranged in parallel on any one of the slopes.

[0008] The invention of claim 3 is characterized in that, in claim 2, the fuel supply valve is disposed on the slope on the anti-exhaust port side.

[0009] The invention of claim 4 is characterized in that, in claim 3, a spark plug is disposed on the exhaust port side slope of the combustion chamber.

[0010] The invention of claim 5 is characterized in that, in claim 4, the radius of the combustion chamber is A, the distance perpendicular to the cylinder axis from the center of the fuel supply valve to the electrode portion of the adjacent spark plug is B, When the distance perpendicular to the cylinder axis from the center of the combustion chamber to the electrode portion of the ignition plug is C, the ignition plug is arranged at a position of AZB≥1.5 and AZC≥2.0. It is.

[0011] The invention of claim 6 is the invention according to claim 4, wherein the spark plug is disposed so as to be positioned inside a line connecting the center of each fuel supply valve and the center of the exhaust port when viewed in the cylinder axial direction. Being characterized by that! /

[0012] In a seventh aspect of the present invention, in the first aspect, in the fuel supply passage, a pressure accumulating chamber common to a plurality of downstream end openings is formed at a portion upstream of and adjacent to each downstream end opening. It is characterized by that.

[0013] The invention of claim 8 is characterized in that, in claim 1, an independent pressure accumulating chamber is formed for each downstream end opening in each downstream end opening of the fuel supply passage.

The invention's effect

[0014] According to the gas fuel internal combustion engine of the first aspect of the present invention, a plurality of downstream end openings that open to the combustion chamber of the fuel supply passage are provided, and each downstream end opening is provided with an umbrella-shaped valve plate on the valve shaft. Since it is opened and closed by a so-called poppet valve type fuel supply valve, the opening can be opened and closed without any trouble even when the fuel supply passage and its downstream end opening are made large in diameter, and it is necessary in a short period of time. A sufficient amount of gas fuel can be supplied uniformly throughout the combustion chamber. This As a result, charging efficiency can be improved, output performance at high loads can be improved, and fuel consumption and exhaust gas properties can be improved.

[0015] In the invention of claim 2, the combustion chamber is of a pent roof type having an exhaust port side slope and an anti-exhaust port side slope, and the fuel supply valve is arranged in parallel on any of the slopes. Each fuel supply valve can be driven to open and close by, for example, one camshaft. The scavenging efficiency of the already burned gas can be improved by making the combustion chamber a pent roof type.

[0016] In the invention of claim 3, since the fuel supply valve is disposed on the inclined surface on the anti-exhaust port side, by supplying fuel to the anti-exhaust port side of the combustion chamber having a relatively high fresh air ratio, G (new Gas + residual gas) ZF (fuel) ratio can be reduced, and good combustion can be performed.

[0017] In the invention of claim 4, since the spark plug is arranged on the exhaust port side slope, an electric spark can be generated at a position facing the fuel supply valve, and stable ignition can be obtained. Can get rapid combustion. That is, because of the structure of the two-cycle internal combustion engine, the GZF ratio in the entire combustion chamber increases as described above during partial load operation. By aligning all or part of the open period of the fuel supply valve with the exhaust port closing period, the gas fuel that has been ejected even when partly loaded is not affected by the scavenging air. Can be retained. In the present invention, since the spark plug is provided on the side facing the fuel supply valve, a spark can be generated toward the stagnant fuel, and stable ignition and rapid combustion can be realized.

[0018] In the invention of claim 5, since the spark plug is disposed at a position of AZB≥1.5 and A / C≥2.0, that is, the spark plug is disposed close to the fuel supply valve. It is possible to reliably ignite the gas fuel staying in the vicinity.

[0019] In the invention of claim 6, since the spark plug is disposed inside the line connecting the center of each fuel supply valve and the center of the exhaust port, the adjacent fuel supply valve force is ejected between the valves. Electric sparks can be generated at the center of the combined gas fuel, and combustion at low loads can be stabilized. That is, in the two-cycle internal combustion engine as described above, the GZF ratio becomes large during partial load operation, but all or part of the open period of the fuel supply valve can be matched with the exhaust port closed period. The gas fuel can be retained around the fuel supply valve. In this case, the gas fuel is synthesized at the location where the fuel supply valve is adjacent to the fuel supply valve. The part flows deflected toward the exhaust port. In the present invention, since the ignition plug is positioned at the center of the deflected flow, combustion at low load is stabilized.

[0020] In the invention of claim 7, since the common pressure accumulating chamber is provided in the vicinity of the upstream side of each downstream end opening of the fuel supply passage, the high pressure gas fuel is stored in the pressure accumulating chamber. An amount of gas fuel can be supplied, and a good mixture can be generated. In addition, each fuel supply valve shares one pressure accumulating chamber, and the structure of the fuel supply passage can be simplified.

[0021] In the invention of claim 8, since an independent pressure accumulating chamber is provided for each downstream end opening in each downstream end opening of the fuel supply passage, the high pressure gas fuel is stored in each accumulating chamber, so that a short period of time can be obtained. Therefore, the required amount of gas fuel can be supplied and a good air-fuel mixture can be generated.

[0022] Further, since an independent pressure accumulating chamber is provided for each fuel supply valve, the volume downstream of the flow control valve can be reduced by reducing the pressure accumulating chamber per cylinder and reducing the fuel supply passage. The controllability of the fuel flow rate can be improved. In particular, it is possible to improve the followability in situations such as fuel cut during deceleration and subsequent re-calo speed, and to improve exhaust gas properties and operating performance. Brief Description of Drawings

FIG. 1 is a cross-sectional view for explaining a gas fuel internal combustion engine according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a cylinder head of the gas fuel internal combustion engine.

FIG. 3 is a bottom view of the cylinder head of the gas fuel internal combustion engine.

4] A configuration diagram of a gas fuel supply device of the gas fuel internal combustion engine.

FIG. 5 is a bottom view of a cylinder head showing an arrangement position of a spark plug according to another embodiment of the above embodiment.

FIG. 6 is a cross-sectional view for explaining a gas fuel internal combustion engine according to a second embodiment of the present invention.

FIG. 7 is a sectional view of a cylinder head of the gas fuel internal combustion engine.

FIG. 8 is a bottom view of the cylinder head of the gas fuel internal combustion engine.

Explanation of symbols

[0024] 1 gas fuel internal combustion engine

3c Exhaust port 4 Cylinder head

4a Combustion recess

4 Exhaust port side slope

4a '' Anti-exhaust port side slope

4c Fuel supply passage

4d Downstream end opening

4f, ί 'pressure storage chamber

18 Combustion chamber

20 Fuel supply valve

20a Valve stem

20b valve plate

35 Spark plug

a Cylinder axis

b Exhaust port center line

d tie

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 to 4 are views for explaining a crankcase compression type two-stroke gas fuel internal combustion engine according to a first embodiment of the present invention. FIG. 1 is a cross-sectional view of the gas fuel internal combustion engine. 2 is a sectional view of the main part of the cylinder head, FIG. 3 is a bottom view of the cylinder head, and FIG. 4 is a configuration diagram of the gas fuel supply device.

In the figure, reference numeral 1 denotes a crank chamber compression type two-stroke gas fuel internal combustion engine. This gas fuel internal combustion engine 1 has the following schematic structure. A cylinder block 3 is bolted to the upper joint surface 2b of the upper and lower split crankcase 2 and a cylinder head 4 is bolted to the upper joint surface 3a of the cylinder block 3.

[0028] A crankshaft 5 is disposed in the crank chamber 2a of the crankcase 2 and a piston 6 is disposed in a cylinder bore 3b of the cylinder block 3. The piston 6 is connected to the crankshaft 5 by a connecting rod 7. It is connected to the crankpin 5a. [0029] The crankcase 2 is formed with an intake passage 2c communicating with the crank chamber 2a. A throttle body 12 containing a throttle valve 11 is connected to the intake passage 2c via a reed valve 10 for preventing backflow. An air cleaner 13 is connected to the upstream side of the throttle body 12.

The throttle body 12 is equipped with a solenoid type fuel injection valve 14. The fuel injection valve 14 is arranged so that the injection port 14a injects and supplies fuel from the downstream side of the throttle valve 11 to the back of the reed valve 10. A fuel rail 15 for supplying gasoline fuel is connected to the fuel injection valve 14. The fuel injection valve 14 is used to supply gasoline fuel as an auxiliary to main gas fuel described later, and is not necessarily provided.

[0031] An exhaust port 3c is formed on the side wall of the cylinder block 3 opposite to the intake passage 2c. A plurality of scavenging ports 3d for introducing the air or air-fuel mixture compressed in the crank chamber 2a into the cylinder bore 3b is formed in the side wall of the intake passage 2c of the cylinder block 3. The cylinder side opening of each scavenging port 3d is arranged on the opposite side of the cylinder bore 3b from the exhaust port 3c.

[0032] A combustion recess 4a is formed in the lower mating surface portion of the cylinder head 4 facing the cylinder bore 3b. The combustion recess 4a is located on the exhaust port side inclined surface 4a 'formed on the exhaust port 3c side with a straight line c orthogonal to the cylinder axis a and parallel to the crankshaft, and on the anti-exhaust port side. It is a pent roof type having an anti-exhaust port side slope 4a '' formed as described above. A space surrounded by the combustion recess 4a and the top surface 6a of the piston 6 near the top dead center and the cylinder bore 3b is a combustion chamber 18.

The cylinder head 4 is formed with a fuel supply passage 4 c that communicates with the combustion chamber 18. The fuel supply passage 4c has two downstream end openings 4d and 4d that open to the anti-exhaust port side slope 4a '' of the combustion recess 4a and one upstream end opening that opens to the anti-exhaust port side wall surface of the cylinder head 4. Has 4e. The upstream end opening 4e is closed by a plate 4g, thereby forming a common pressure accumulating chamber 4f in the two downstream end openings 4d and 4d. A gas fuel supply pipe 40 (to be described later) is connected to the pressure accumulating chamber 4f through a connection hole 4i of the plate 4g. [0034] Specifically, the fuel supply passage 4c is branched from the pressure accumulating chamber 4f extending obliquely downward toward the combustion chamber 18 following the upstream end opening 4e into two branch passages 4h and 4h, and the downstream ends. It communicates with the opening 4d. Therefore, the pressure accumulating chamber 4f is connected to both the branch passages 4h and 4h, is shared by the two downstream end openings 4d and 4d, and has a capacity capable of securing a necessary fuel amount at the maximum load. .

[0035] The downstream end openings 4d, 4d that open to the anti-exhaust port side inclined surface 4a '' of the cylinder head 4 have two fuel supply valves 20, 20 that open and close the openings 4d, 4d in the crankshaft direction. Are arranged in parallel. On the other hand, a pair of spark plugs 35, 35 are arranged in parallel in the crankshaft direction on the exhaust port side inclined surface 4a '.

Each ignition plug 35 and each fuel supply valve 20 are arranged so as to form an inclination angle of about 20 degrees with respect to the cylinder axis a when viewed in the crankshaft direction (see FIG. 2). When viewed in the direction of the axis a, the cylinder is disposed on both sides of a straight line c extending through the cylinder axis a, perpendicular to the center line b of the exhaust port 3c, and extending in the crankshaft direction. Specifically, each ignition plug 35 is mounted on the cylinder head 4 so that its electrodes 35a, 35a are close to or coincide with the straight line c, and each downstream end opening 4d is slightly smaller than the straight line c. It is placed at a position away from the anti-exhaust port (see Fig. 3).

Further, as shown in FIG. 3, each spark plug 35 has a combustion chamber 18 radius A, and a cylinder axis perpendicular distance from the center of the fuel supply valve 20 to the electrode 35a of the adjacent spark plug 35. When the separation is B, and the above-mentioned combustion chamber center (cylinder axis a) force is C, the distance perpendicular to the cylinder axis to the electrode part 35a of the spark plug 35 is C, the positions are AZB≥1.5 and AZC≥2.0. ing. Here, setting AZB and AZC to 1.5, 2.0 or more means that the electrode 35a of the spark plug 35 is as close as possible to the center of the fuel supply valve 20. Therefore, it is preferable that the spark plug 35 be close to the fuel supply valve 20 within a range in which interference between the screw hole of the spark plug 35 and the downstream end opening 4d can be avoided and a necessary strength can be ensured.

[0038] The fuel supply valve 20 is a so-called poppet valve type in which an umbrella-shaped valve plate 20b that is in contact with the periphery of the downstream end opening 4d is formed integrally with the lower end of the valve shaft 20a.

The valve shaft 20a extends through the branch passage 4h toward the valve chamber 27 of the cylinder head 4, and is slid by a cylindrical valve guide member 25 press-fitted into the cylinder head 4. It is guided freely. A retainer 21 is attached to the upper end portion of the valve shaft 20a, and a valve spring 22 is disposed between the retainer 21 and the cylinder head 4 to urge the fuel supply valve 20 in a normally closing direction. . Furthermore, a valve lifter 21a is attached to the upper end of the valve shaft 20a, and the valve lifter 21a is slidably supported by the cylinder head 4.

A head cover 8 that forms the above-described valve operating chamber 27 with the cylinder head 4 is mounted on the upper surface of the cylinder head 4. A camshaft 31 that opens and closes each fuel supply valve 20 is accommodated in the valve operating chamber 27. The camshaft 31 is disposed in parallel with the crankshaft 5 and is rotationally driven by the crankshaft 5 via a timing belt (not shown).

The gas fuel internal combustion engine 1 includes a gas fuel supply device that supplies gas fuel to the combustion chamber 18. As shown in FIG. 4, this gas fuel supply apparatus has a fuel tank 41 and its upstream end connected to the discharge port 41a of the fuel tank 41, and the downstream end is a plate of the upstream end opening 4e of the fuel supply passage 4c. And a gas fuel supply pipe 40 connected to 4 g.

[0042] In the gas fuel supply pipe 40, the upstream side force also includes a manual valve 42, a fuel filter 43, a pressure sensor 44, a shut-off valve 45, a pressure regulator 46, a flow control valve 47, and a check valve 4 8 in this order. It is installed. In addition, a shutoff valve 49 and a fuel pressure sensor 50 are connected to the discharge port 41a of the fuel tank 41, and a fuel supply port 52 is connected via a check valve 51. The check valve 48 prevents a flow from the combustion supply passage 4c side to the fuel tank 41 side, and is disposed in the vicinity of the upstream end opening 4e of the fuel supply passage 4c.

[0043] Detection signals from the pressure sensors 44 and 50 are input to the ECU 53, and the ECU 53 is configured to control the shut-off valves 45 and 49 and the flow control valve 47 based on these detection signals. ing. The shut-off valves 45 and 49 are configured to close when the main switch is turned off or when the vehicle falls.

Here, as the flow control valve 47, a proportional control valve for controlling the opening area, an injector valve for controlling the valve opening time, or the like can be adopted. When an injector valve is used, the check valve 48 is not necessary because the valve itself has a check valve function. [0045] The flow rate control valve 47 is not limited to the one interposed in the middle of the gas fuel supply pipe 40. For example, the flow control valve 47 may be directly attached to the cylinder head 4 and supply gas fuel to the pressure accumulating chamber 4f. good.

[0046] According to the present embodiment, two downstream end openings 4d of the fuel supply passage 4c communicating with the combustion chamber 18 are provided, and the respective downstream end openings 4d are opened and closed by the poppet valve type fuel supply valves 20 and 20, respectively. As a result, even when the fuel supply passage 4c and the downstream end opening 4d have a large diameter, they can be opened and closed without any problem, and the required amount of gas fuel can be uniformly supplied throughout the combustion chamber 18 in a short period of time. it can. As a result, the charging efficiency can be improved, the output performance at high loads can be improved, and the fuel consumption and exhaust gas properties can be improved.

[0047] Here, it is possible to form one opening having a size corresponding to the total opening area of the two downstream end openings 4d, 4d, and the opening can be opened and closed by one fuel supply valve. In such a case, the fuel supply valve increases in size and weight, which is disadvantageous for supplying a necessary amount of fuel in a short period of time at high load.

[0048] In the present embodiment, the combustion recess 4a constituting the combustion chamber 18 is of a pent roof type having an exhaust port side inclined surface 4a 'and an anti-exhaust port side inclined surface 4a' ', and the anti exhaust port side Since the fuel supply valves 20 are arranged in parallel on the slope 4a ′ ′, each fuel supply valve 20 can be driven to open and close by one cam shaft 31. Further, by making the combustion chamber 18 a pent roof type, the scavenging efficiency of the already burned gas can be improved.

[0049] Since each of the fuel supply valves 20 is arranged on the anti-exhaust port side slope 4a '', fuel can be supplied to the anti-exhaust port side of the combustion chamber 18 having a relatively high fresh air ratio, and good combustion is achieved. Can be performed.

[0050] In the present embodiment, since the pair of spark plugs 35 are arranged on the exhaust port side inclined surface 4a ', an electric spark can be generated at a position facing each fuel supply valve 20, and stable ignition is achieved. As well as rapid combustion. That is, because of the structure of the two-cycle internal combustion engine, the GZF ratio in the entire combustion chamber 18 becomes large during partial load operation. By making all or part of the opening period of the fuel supply valve 20 coincide with the exhaust port closing period, the injected gas fuel is affected by the scavenging air, and even in the case of partial load, the fuel supply valve Gas fuel can be retained in the vicinity. In this embodiment, each ignition Since the plugs 35 are respectively provided so as to face the fuel supply valve 20, stable ignition and rapid combustion can be realized.

[0051] In the present embodiment, the electrode portion 35a of the spark plug 35 is as close as possible to the center of the fuel supply valve 20, so that the gas staying around the fuel supply valve 20 is retained. The fuel can be reliably ignited.

In the present embodiment, since the common pressure accumulating chamber 4f is formed near the upstream side of each downstream end opening 4d of the fuel supply passage 4c of the cylinder head 4, the high pressure gas fuel is stored in the pressure accumulating chamber 4f. Thus, a necessary amount of gas fuel can be supplied in a short period of time, and a good air-fuel mixture can be generated. Further, the structure of the fuel supply passage 4c can be simplified.

In the above embodiment, the case where the pair of spark plugs 35 are arranged so as to face each fuel supply valve 20 has been described. However, in the present invention, as shown in FIG. May be positioned inside lines d and d connecting the center of each fuel supply valve 20 and the center line b of the exhaust port when viewed in the direction of the cylinder axis a. In this case, an electric spark can be placed at the center of the portion where the gas fuels spouted from the adjacent fuel supply valves 20, 20 merge, and combustion at low loads can be stabilized. . That is, the two-cycle internal combustion engine has a large GZF ratio during partial load operation, but by making all or part of the open period of the fuel supply valve 20 coincide with the closed period of the exhaust port, Is less susceptible to the scavenging flow and tends to stay around the fuel supply valve. And the flow of gas fuel is synthesized at the location where each fuel supply valve 20 is adjacent, and a part is deflected to the exhaust port side. In the present embodiment, since the spark plug 35 is positioned at the center of the deflected flow, combustion at a low load can be stabilized.

In the above embodiment, the case where the fuel supply is performed by opening and closing the two fuel supply valves has been described as an example. However, in the present invention, the fuel supply is performed by the three fuel supply valves. May be. In this case, one fuel supply valve is arranged on the center line b of the exhaust port 3c and on the side opposite to the exhaust port from the straight line, and the fuel supply valves are arranged on both sides of the fuel supply valve. It becomes. Even in this case, the required amount of gas fuel can be supplied into the combustion chamber in a short period of time, and the same effect as in the above embodiment can be obtained.

FIGS. 6 to 8 are views for explaining a second embodiment of the present invention, in which FIGS. The same reference numerals indicate the same or corresponding parts.

In the second embodiment, an independent pressure accumulating chamber 4 is formed for each fuel supply valve 20. Specifically, the cylinder head 4 is formed with two cylindrical pressure accumulating chambers 4f and 4f ′ extending upward so as to surround the valve shafts 20a and 20a, following the downstream end openings 4d and 4d. Two fuel passages 4h and 4h are formed so as to communicate with the respective accumulator chambers 4 in the middle. The fuel passages 4h and 4h are connected to the branch portions 40a and 40a of the gas fuel supply pipe 40 through two connection holes 4i and 4i formed in a common plate 4g.

[0057] In the second embodiment, since the independent pressure accumulating chamber 4 is provided for each fuel supply valve 20, the accumulator chamber per cylinder has a small capacity and the fuel passage 4h has a small diameter. The volume downstream of the flow control valve 47 can be made small, and the controllability of the fuel flow rate can be improved. In particular, followability is improved even in situations such as fuel cut during deceleration and subsequent re-acceleration, which has the effect of preventing emission of unburned gas and improving exhaust gas properties and operating performance.

In each of the above embodiments, the fuel supply valve 20 is driven to open and close by the camshaft 31, but in the present invention, the fuel supply valve 20 may be driven to open and close by an actuator such as a solenoid valve. In this case, the degree of freedom in controlling the opening / closing timing of the fuel supply valve 20 can be greatly improved.

Claims

The scope of the claims

[1] Crank chamber compression type two-stroke gas fuel internal combustion engine, provided with a plurality of downstream end openings that open into the combustion chamber of the fuel supply passage, and each downstream end opening is umbrella-shaped at one end of the valve shaft A gas fuel internal combustion engine, which is opened and closed by a poppet valve type fuel supply valve formed by forming a valve plate.

[2] In Claim 1, the combustion chamber is of a pent roof type having an exhaust port side slope located on the exhaust port side and an anti exhaust port side slope located on the anti exhaust port side, and the fuel supply A gas-fueled internal combustion engine, characterized in that the valve is arranged in parallel with any one of the slopes.

[3] The gas fuel internal combustion engine according to claim 2, wherein the fuel supply valve is arranged on the slope opposite to the exhaust port!

[4] In Claim 3, an ignition plug is arranged on the exhaust port side slope of the combustion chamber.

V, a gas fueled internal combustion engine.

[5] In Claim 4, the radius of the combustion chamber is A, the distance perpendicular to the cylinder axis from the center of the fuel supply valve to the electrode portion of the adjacent ignition plug is B, the electrode of the ignition plug from the center of the combustion chamber When the distance perpendicular to the cylinder axis is C, the spark plug is A / B≥l.

5. A gas-fueled internal combustion engine characterized by being arranged at a position of A / C≥2.0.

[6] In Claim 4, the spark plug is disposed so as to be positioned inside a line connecting the center of each fuel supply valve and the center of the exhaust port when viewed in the cylinder axial direction. A gas-fueled internal combustion engine.

[7] The gas fuel according to claim 1, wherein a common pressure accumulating chamber is formed in a plurality of downstream end openings in a portion of the fuel supply passage upstream and in the vicinity of each downstream end opening. Internal combustion engine.

8. The gas fuel internal combustion engine according to claim 1, wherein an independent pressure accumulating chamber is formed at each downstream end opening in each downstream end opening of the fuel supply passage.