JP2015151994A - gas engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a gas engine capable of improving mixture uniformity of air and fuel gas and ensuring stable combustion.SOLUTION: A gas engine 1 comprises: an agitator 17 agitating separately introduced air and fuel gas in a common channel 57 to the air and the fuel gas; cylinders 35, 36, and 37; and an intake manifold 9 that includes combustion chambers 42, 43, and 44 disposed between the agitator 17 and the cylinders 35, 36, and 37 and communicating with the agitator 17 and the cylinders 35, 36, and 37, respectively, the agitator 17 including agitation means 20 swinging and agitating mixture gas.

Description

  The present invention relates to a gas engine using fuel gas as fuel.

  In a gas engine that uses fuel gas such as LPG (liquefied petroleum gas) or LNG (liquefied natural gas) as fuel, air and fuel gas are difficult to uniformly mix due to a difference in specific gravity between air and fuel gas. As a result, the combustion within the cylinder or from cylinder to cylinder may be biased, resulting in variations in combustion. Therefore, in order to improve the degree to which air and fuel gas are uniformly mixed (mixing uniformity), Patent Document 1 discloses a structure in which a turbulence promoter having a large number of holes is arranged downstream of a fuel gas injection nozzle. In addition, a structure is disclosed in which many holes are provided in a pipe in which an injection nozzle is extended. These structures are intended to facilitate diffusion of the fuel gas as it passes through these holes and to mix with the air. In addition, the flow path in the air suction pipe is provided with a spiral fin for forward rotation and a spiral fin for reverse rotation, and the fact that air flow is disturbed between these two spiral fins makes it possible to A structure for improving the mixing uniformity is also disclosed.

  In Patent Document 2, a concave portion is provided on the surface of the cylinder head facing the combustion chamber, and fuel gas collides with the inner wall of the concave portion to generate turbulent airflow, thereby improving the mixing uniformity of air and fuel gas. And a structure in which an air intake pipe is formed in a spiral shape, and air is swirled to be supplied and mixed with fuel gas.

Japanese Patent Laid-Open No. 9-228898 JP 2002-285912 A

  However, the configurations shown in Patent Document 1 and Patent Document 2 have a problem that the structure is likely to be complicated because a structure that improves mixing uniformity is provided for each combustion chamber.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a gas engine that enables stable combustion by improving the uniformity of mixing of air and fuel gas with a simple structure. It is something that is going to be realized.

  In order to solve the above problems, the present invention provides a gas engine using fuel gas as a fuel, a mixer for mixing separately sucked air and fuel gas, and a plurality of cylinders provided with combustion chambers. And an intake manifold that is provided in common to the plurality of cylinders and communicates the mixer and the plurality of cylinders.

  In addition to the above invention, it is preferable that a stirring unit for stirring the mixed gas mixed in the mixer is provided between the mixer and the intake manifold.

  Moreover, in addition to the said invention, it is preferable that a stirring means is a blade-shaped member swirled in the state in which air and fuel gas were mixed.

  Moreover, in addition to the said invention, it is preferable that a blade | wing part-shaped material can be rotated by the flow of air and fuel gas.

1 is a right front perspective view showing a gas engine according to an embodiment of the present invention. 1 is a left rear perspective view showing a gas engine according to an embodiment of the present invention. 1 is a left front perspective view showing a part of a gas engine according to an embodiment of the present invention. It is sectional drawing which shows the structure which concerns on the cylinder head which concerns on one embodiment of this invention, and mixed gas supply. It is an external appearance perspective view which shows the 1st Example of the mixer which concerns on one embodiment of this invention. It is an external appearance perspective view which shows the 2nd Example of the mixer which concerns on one embodiment of this invention. It is an external appearance perspective view which shows the 3rd Example of the mixer which concerns on one embodiment of this invention.

  Hereinafter, a gas engine 1 according to an embodiment of the present invention will be described with reference to the drawings. The gas engine 1 of the present invention is driven by burning a gas in which air and a fuel gas are mixed (hereinafter referred to as “mixed gas”), and illustrates a case of a three-cylinder engine. I will explain.

(Overall configuration of gas engine 1)
FIG. 1 is a right front perspective view showing a gas engine 1 according to an embodiment of the present invention, and FIG. 2 is a left rear perspective view. As shown in FIGS. 1 and 2, the gas engine 1 has a structure in which other components are attached to the cylinder block 2 with the cylinder block 2 as a center. The gas engine 1 is provided with an oil pan 3 constituting a lubricating oil reservoir below the cylinder block 2, and a crankshaft pulley 4 is attached to the crankshaft 5 on the front side of the cylinder block 2. In the drawings described below, the arrangement side of the crankshaft pulley 4 is the front, the opposite side is the rear, the right side is the right when the front side is viewed from the rear, the left hand is the left, and the oil pan The direction in which the cylinder block 2 is arranged with respect to 3 is indicated as an upper side, and the opposite side is indicated as a lower side. The crankshaft 5 penetrates the cylinder block 2 in the front-rear direction, and a flywheel 6 is attached to the end opposite to the crankshaft pulley 4 (rear side). It can be rotated.

  A cylinder head 7 is disposed above the cylinder block 2, and a cylinder head cover 8 and an intake manifold 9 are attached to the upper part of the cylinder head 7 so as to be juxtaposed in the left-right direction. A mixed gas is accommodated in the intake manifold 9. A carburetor 10 as a mixer is attached to the upper rear side of the intake manifold 9 via a common channel 57 (see FIG. 4). The common flow path 57 is a flow path through which both the air mixed by the carburetor 10 and the fuel gas pass. An exhaust manifold 11 is attached to the left side surface of the cylinder head 7, and a muffler (not shown) is connected to the exhaust manifold 11. On the other hand, a spark plug 12 is disposed at the upper right side of the cylinder head 7 inside a recessed portion 8 a formed on the left side of the cylinder head cover 8. The spark plug 12 is provided corresponding to each of three cylinders, which will be described later, and is connected to an ignition coil and a power source (battery) via a connector and a wire harness (not shown), respectively.

  The carburetor 10 is connected to an air supply pipe section 13 for supplying air from the outside and a fuel gas supply pipe section 14 for supplying fuel gas. The fuel gas supply pipe section 14 is disposed so as to intersect the air supply pipe section 13 and communicated with the air supply pipe section 13 through a fuel gas suction port 15 (see FIG. 2). Therefore, in the carburetor 10, the air supplied from the air supply pipe 13 and the fuel gas supplied from the fuel gas supply pipe 14 are mixed. The fuel gas supply pipe section 14 is configured to be able to supply fuel gas into the air supply pipe section 13 from one end, and the other end is closed. A throttle valve 58 (see FIG. 4) is disposed in the common flow path 57, and the throttle valve is opened and closed by the motor 16 provided outside the common flow path 57 to supply air and fuel gas supply amounts ( Adjust the suction amount.

  An agitator 17 provided with agitation means 20 for increasing the uniformity of mixing of air and fuel gas in a common flow path 57 (see FIG. 4) for air and fuel gas between the carburetor 10 and the intake manifold 9. Is arranged. The agitator 17 is disposed in a pipe portion 18 projecting from the intake manifold 9 on the downstream side (intake manifold 9 side) of the carburetor 10. The carburetor 10 is attached to the intake manifold 9 by a flange 19a on the carburetor 10 side and a flange 19b on the intake manifold 9 side. The stirrer 17 further stirs the air and fuel gas mixed by the carburetor 10 to improve mixing uniformity. Therefore, the stirrer 17 is disposed in the common flow path 57 on the downstream side (intake manifold 9 side) from the position (fuel gas suction port 15) where the air supply pipe portion 13 and the fuel gas supply pipe portion 14 intersect. The

  The fuel gas supply pipe 14 is connected to a fuel gas supply source via a tube (not shown). As the fuel gas, LPG (liquefied petroleum gas such as propane gas) or LNG (liquefied natural gas such as city gas) can be used. The fuel gas supply source is a gas cylinder in the case of propane gas, and a gas supply pipe in the case of city gas.

(Configuration of intake manifold 9)
FIG. 3 is a left front perspective view showing a part of the gas engine 1. As shown in FIG. 3, the intake manifold 9 of the present embodiment has a container-like form surrounded by an outer shell portion 25, and is attached to the upper surface of the cylinder head 7 with a bolt or the like via a spacer 26 and a gasket 27. It is fixed. A space surrounded by the outer shell portion 25 and the gasket 27 is a mixed gas chamber 28 that stores a mixed gas of air and fuel gas. A stirrer 17 is disposed in a pipe portion 18 formed above the rear side end of the intake manifold 9, and a stirring means 20 is disposed inside the stirrer 17. A carburetor 10 (see FIG. 1) is attached above the agitator 17 in the figure.

  As an example, the gas engine 1 of the present embodiment illustrates a three-cylinder engine. The spacer 26 and the gasket 27 are provided with intake ports 30, 31, and 32 that communicate with the cylinders at positions facing the cylinders of the three cylinders. A mixed gas is supplied into each cylinder through these intake ports. Therefore, the mixed gas chamber 28 of the intake manifold 9 can supply mixed gas to all of the three cylinders. The mixed gas chamber 28 has a structure in which a mixed gas in which air and fuel gas are stirred and uniformly mixed by the carburetor 10 and the stirrer 17 is accommodated, and thereafter, the mixed gas can be supplied into each cylinder. ing.

  As shown in FIG. 3, the upper portion of the intake manifold 9 is inclined downward from the rear side (communication portion with the stirrer 17) toward the front side, and is separated from the communication portion with the stirrer 17. In accordance with this, the cross-sectional area is gradually reduced. In addition, this cross-sectional area means the area of the surface orthogonal to the arrangement direction of cylinders 35, 36, and 37 (refer FIG. 4), ie, the front-back direction. That is, since the mixed gas is supplied into the mixed gas chamber 28 from the communication portion with the stirrer 17, this cross-sectional area corresponds to the cross-sectional area of the mixed gas in the mixed gas chamber 28. In the present embodiment, the width of the intake manifold 9 in the left-right direction is substantially constant, and the height of the intake manifold 9 is gradually decreased from the communicating portion of the intake manifold 9 and the stirrer 17 toward the front end portion. The cross-sectional area is reduced.

(Configuration related to cylinder head 7 and mixed gas supply)
Next, the configuration relating to the cylinder head 7 and the mixed gas supply will be described with reference to FIG.

  4 is a cross-sectional view showing a configuration relating to the cylinder head 7 and the supply of the mixed gas, and is a vertical cross-sectional view taken along the cutting line AA of the intake manifold 9 shown in FIG. In the present embodiment, the cylinders 35, 36, and 37 are arranged in a line in the front-rear direction within the cylinder block 2. Pistons 38, 39, and 40 are disposed in each cylinder. Each of the pistons 38, 39, and 40 is connected to the crankshaft 5 (see FIG. 1) via a connecting rod 41. Spaces surrounded by the cylinders 35, 36, 37, the pistons 38, 39, 40 and the cylinder head 7 are combustion chambers 42, 43, 44. Since this structure is substantially the same as that of a conventional diesel engine, description thereof is omitted.

  The cylinder head 7 and the spacer 26 (the gasket 27 is not shown) are provided with intake ports 30, 31, 32 penetrating in the thickness direction at positions corresponding to the cylinders 35, 36, 37, respectively. Each of the intake ports 30, 31, 32 communicates with the mixed gas chamber 28 and the combustion chambers 42, 43, 44. The cylinder head 7 is provided with intake valves 45, 46, and 47 for opening and closing the intake ports 30, 31, and 32, respectively. These intake valves are released at the timing when the mixed gas is supplied to each of the combustion chambers 42, 43 and 44, and are closed at the timing of compression and exhaust. The intake valves 45, 46, 47 are driven by cams (not shown) and are opened and closed in accordance with the drive timing of the pistons 38, 39, 40.

  The cylinder head 7 is formed with exhaust ports 48, 49, 50 communicating with the combustion chambers 42, 43, 44. The exhaust ports 48, 49, 50 are connected to the exhaust manifold 11 (see FIG. 3) through exhaust connection passages 51, 52, 53 formed in the cylinder head 7. The cylinder head 7 is provided with exhaust valves 54, 55, and 56 that control the opening and closing of the exhaust ports 48, 49, and 50, respectively. The exhaust valves 54, 55, 56 are closed at the timing of supplying the mixed gas to the combustion chambers 42, 43, 44, the timing of compression and combustion, and are released at the timing of exhaust of the exhaust gas after combustion. The exhaust valves 54, 55, and 56 are driven by cams (not shown) and open and close in accordance with the drive timing of the pistons 38, 39, and 40. In the cylinder head 7, a spark plug 12 (not shown) (see FIG. 1) is disposed at a position facing the combustion chambers 42, 43, 44.

  A pipe part 18 projects from the upper part of the rear end part of the outer shell part 25 of the intake manifold 9, and a stirrer 17 equipped with stirring means 20 is inserted inside the pipe part 18, and the flange part 21 a. Is fixed so as to be sandwiched between the pipe part 18 and the air supply pipe part 13. The carburetor 10 is disposed on the upstream side of the stirrer 17, and the intake manifold 9 and the carburetor 10 are fixed to each other by a flange 19a and a flange 19b (not shown). As described above, the fuel gas supply pipe section 14 is connected to the air supply pipe section 13 of the carburetor 10, and the fuel gas can be sucked into the carburetor 10 from the fuel gas suction port 15. Yes. The flow path from the fuel gas suction port 15 to the mixed gas chamber 28 is a common flow path 57 for air and fuel gas. A throttle valve 58 is disposed between the fuel gas suction port 15 and the stirrer 17.

  As shown in FIG. 4, a cooling water flow path 59 is provided around the cylinders 35, 36, and 37 of the cylinder block 2. The cooling water channel 59 is shown in a simplified manner. Cooling water is circulated through the cooling water channel 59 by a pump (not shown).

(Driving method of gas engine 1)
Next, driving of the gas engine 1 in the present embodiment will be described with reference to FIG. FIG. 4 shows one state of the cylinders 35, 36 and 37. The cylinder 35 at the right end in the figure represents a state in which the mixed gas is sucked into the combustion chamber 42 from the mixed gas chamber 28, and the piston 38 is in a position near the bottom dead center. At this time, the intake valve 45 releases the intake port 30 and the exhaust valve 54 closes the exhaust port 48. A cylinder 36 in the center of the drawing shows a state where the mixed gas is compressed, and the piston 39 is at the top dead center position. At this time, both the intake valve 46 and the exhaust valve 55 are connected to the intake port 31 and the exhaust port 55, respectively. The exhaust port 49 is closed. Further, the cylinder 37 at the left end in the figure represents a state where exhausted exhaust gas is exhausted, and represents the middle of the movement of the piston 40 in the direction of reducing the volume of the combustion chamber 44. At this time, the intake valve 47 closes the intake port 32, and the exhaust valve 56 releases the exhaust port 50.

  The driving of the gas engine 1 described in the present embodiment is the same as that of a four-cycle engine that repeats suction, compression, combustion, and exhaust of mixed gas. explain. First, the piston 38 is moved from the top dead center to the bottom dead center. At this time, the exhaust port 48 is first closed by the exhaust valve 54, and then the intake port 30 is released by the intake valve 45. Since the combustion chamber 42 has a negative pressure relative to the pressure in the intake manifold 9 (mixed gas chamber 28), the mixed gas in the mixed gas chamber 28 is sucked into the combustion chamber 42 from the intake port 30.

  Subsequently, each of the intake port 30 and the exhaust port 48 is closed by the intake valve 45 and the exhaust valve 54, the piston 38 is moved from the bottom dead center side to the top dead center side, and the volume of the combustion chamber 42 is reduced while mixing. Compress the gas. When the piston 38 reaches the top dead center, the spark plug 12 ignites to burn the mixed gas. Then, the combustion gas in the combustion chamber 42 expands rapidly, pushes down the piston 38 to the bottom dead center side, and rotates the crankshaft 5. After reaching the bottom dead center, the piston 38 closes the intake port 30 with the intake valve 45 and releases the exhaust port 48 with the exhaust valve 54. Then, by moving the piston 38 to the top dead center side, the exhaust gas after combustion passes through the exhaust port 48 and the exhaust connection flow path 51 and is discharged from the exhaust manifold 11 to the outside.

  In the gas engine 1, pistons 38, 39, and 40 are connected to the crankshaft 5 via a connecting rod 41, and the cycle of suction, compression, ignition (combustion), and exhaust of mixed gas is controlled at an optimal timing. .

  As described above, the gas engine 1 uses fuel gas as fuel, and in order to transmit a stable rotational force to the crankshaft 5, it is important that there is no variation in combustion among the combustion chambers. For this purpose, the supplied mixed gas is required to have high mixing uniformity.

  Therefore, the mixing of air and fuel gas will be described with reference to FIGS. 4, 5, 6, and 7. First, the flow of air and fuel gas will be described with reference to FIG. When any of the three cylinders is in a suction state, for example, when the cylinder 35 is in a suction state (when the piston 38 moves from the top dead center side to the bottom dead center side), the pressure in the combustion chamber 42 is the mixed gas chamber. Since the pressure becomes negative with respect to the pressure in the gas 28, the mixed gas is sucked into the combustion chamber 42 from the mixed gas chamber 28. Then, since the pressure in the mixed gas chamber 28 becomes a negative pressure as compared with the atmosphere, an air flow from the carburetor 10 toward the mixed gas chamber 28 occurs. When an air flow is generated, the pressure in the air supply pipe unit 13 is lower than the pressure of the fuel gas in accordance with the flow velocity of the air. Due to the pressure difference, the fuel gas is supplied from the fuel gas suction port 15 to the air supply pipe unit. 13 is sucked into. Therefore, if there is an air flow, the fuel gas can be sucked into the air supply pipe section 13 even if the relative pressure of the fuel gas is low.

  As the fuel gas, LPG (liquefied petroleum gas such as propane gas) or LNG (liquefied natural gas such as city gas) is used. Since these fuel gases and air have different specific gravities, the air and the fuel gas are in a laminar flow as they are, and it is difficult to achieve a uniform mixed state. Therefore, in the present embodiment, the stirrer 17 is disposed in the common flow path 57 of air and fuel gas downstream of the fuel gas suction port 15 (intake manifold 9 side), and mixing until the stirrer 17 is reached. The gas is further swirled and turbulent by the stirrer 17 to produce a uniform mixed state. Next, the configuration of the stirrer 17 will be described with reference to FIGS. 5, 6, and 7.

(Configuration of stirrer 17)
If the mixed gas in which air and fuel gas are mixed by the carburetor 10 is further stirred by the stirrer 17, the mixing uniformity of the mixed gas can be improved. In the present embodiment, in order to generate a mixed gas in which the mixing uniformity of air and fuel gas is improved, the stirring means 20 provided in the stirrer 17 is mixed while swirling air and fuel gas. An example using a blade-like member will be described.

  5 is an external perspective view showing the first embodiment of the stirrer 17, FIG. 6 is an external perspective view showing the second embodiment, and FIG. 7 is an external perspective view showing the third embodiment. Reference is also made to FIG. As shown in FIG. 5, the stirrer 17 of the first embodiment includes a tubular main body portion 21 inserted into the pipe portion 18 provided in the intake manifold 9 (see FIG. 4) described above, and the main body portion 21. It comprises a stirring means 20 projecting from the inner peripheral wall 21b. The stirring means 20 is arranged in a common flow path 57 for air and fuel gas, and is provided by four blade-like members 60, 61, 62, 63 that project from the inner peripheral wall 21 b of the main body 21 toward the center. It is configured. By disposing the four blade-like members 60, 61, 62, and 63 in the common flow channel 57, the mixed gas passing through the stirrer 17 is swirled to improve the mixing uniformity.

  The blade-like members 60, 61, 62, and 63 are arranged at substantially the same position in the flow direction (vertical direction) of the mixed gas at equal intervals in the circumferential direction (direction along the circumference of the inner peripheral wall 21b). Each of the blade-like members 60, 61, 62, 63 is inclined so as to be twisted from the upstream side toward the downstream side. The blade-like members 60, 61, 62, 63 are smoothly rounded at the edge of the portion through which the mixed gas passes, and the fluid resistance of the blade-like members 60, 61, 62, 63 to the mixed gas can be reduced. It has a shape. The front end central portions of the blade-like members 60, 61, 62, 63 are not connected to each other, and constitute a central flow path 64. As shown in the drawing, the blade-like members 60, 61, 62, and 63 adjacent to each other in the circumferential direction are arranged so as to have regions overlapping each other at the circumferential edge when viewed from the vertical direction. Thereby, it becomes easier to swirl the mixed gas passing through the stirrer 17. These blade-shaped members are preferably molded integrally with the main body portion 21, and can be molded by, for example, aluminum die casting. Moreover, since the temperature of the supplied air and fuel gas is low, the stirring means 20 of the present embodiment is not limited to metal and may be made of resin (resin molded product).

  The fuel gas sucked from the fuel gas suction port 15 flows toward the intake manifold 9 (mixed gas chamber 28) together with air. The air and the fuel gas (mixed gas) are swirled by passing between adjacent blade-shaped members among the blade-shaped members 60, 61, 62, 63 (indicated by arrows in the figure). Further, the flow of the mixed gas is disturbed when passing through the blade-like members 60, 61, 62, 63 and when passing through the central flow path 64 to become a turbulent flow. Air and fuel gas are sufficiently agitated by the agitation means 20 configured as described above, and the combustion chambers 42 and 43 of the respective cylinders are provided as mixed gas having high mixing uniformity via the intake manifold 9 (mixed gas chamber 28). , 44 can be supplied.

  Next, the configuration of the second embodiment of the stirrer 17 will be described with reference to FIG. In contrast to the first embodiment having a central flow path 64 at the center of the tip of the blade-like members 60, 61, 62, 63, the second embodiment is configured without this central flow path 64. The same functional parts as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment. The stirrer 17 of the second embodiment is provided on a tubular main body portion 21 inserted into the pipe portion 18 provided on the intake manifold 9 (see FIG. 4) described above, and an inner peripheral wall 21b of the main body portion 21. The stirring means 20 is comprised. The stirring means 20 is disposed in a common flow path 57 for air and fuel gas, and is provided by four blade-like members 65, 66, 67, 68 that project from the inner peripheral wall 21 b of the main body 21 toward the center. It is configured.

  Each of the blade-like members 65, 66, 67, and 68 is connected so that the center portions of the tips intersect each other, and the circumference of the blade-like members 65, 66, 67, and 68 is excluded except for a portion where the tip is fixed. Those adjacent in the direction are arranged so as to have regions that overlap each other at the circumferential edge when viewed in the vertical direction. Thereby, it becomes easier to swirl the mixed gas passing through the stirrer 17. The blade-like members 65, 66, 67, and 68 are preferably formed integrally with the main body portion 21, and can be formed by, for example, aluminum die casting. Moreover, since the temperature of the supplied air and fuel gas is low, the stirring means 20 of the present embodiment is not limited to metal and may be made of resin (resin molded product). Alternatively, the blade-like members 65, 66, 67, and 68 may be formed in a separated shape, and then fixed using a fixing member (for example, a pin or a screw) at the center of the tip. The blade members 65, 66, 67, and 68 are smoothly rounded at the edge of the portion through which the mixed gas passes, and the fluid resistance of the blade members 65, 66, 67, and 68 to the mixed gas can be reduced. It has a shape.

The fuel gas sucked from the fuel gas suction port 15 flows toward the intake manifold 9 (mixed gas chamber 28) together with air, but between the adjacent blade-like members of the blade-like members 65, 66, 67, 68. A swirl flow is obtained by passing through the flow path (indicated by an arrow in the figure). This flow is turbulent and becomes turbulent when it passes through the blade-like members 65, 66, 67, 68 and when it collides with the fixed tip of each blade-like member. Air and fuel gas are sufficiently agitated by the agitation means 20 configured as described above, and the combustion chambers 42 and 43 of the respective cylinders are provided as mixed gas having high mixing uniformity via the intake manifold 9 (mixed gas chamber 28). , 44 can be supplied.

  Next, the configuration of the third embodiment of the stirrer 17 will be described with reference to FIG. In the stirrer 17 of the first and second embodiments already described, the stirrer 20 is fixed to the tubular main body 21, whereas the third embodiment stirs the main body 21. The means 20 is characterized in that it can be rotated. As shown in FIG. 7, the stirring means 20 of the third embodiment includes a beam portion 70 that crosses the main body portion 21 from the flange portion 21 a provided at the end portion of the main body portion 21, and a central portion of the beam portion 70. In the common flow path 57, it is comprised from the blade-shaped member 72,73,74,75 suspended so that rotation by the shaft member 71 was possible. The stirring means 20 of the present embodiment is shaped like a screw. However, it differs from a screw that the blade-like members 72, 73, 74, and 75 are rotated by the flow of the mixed gas.

  The blade-like members 72, 73, 74, and 75 may be configured to be rotatable with respect to the shaft member 71, or may be configured to be rotatable with respect to the beam portion 70 together with the shaft member 71. The blade-like members 72, 73, 74, 75 are rotated by the flow of the mixed gas (in the example of FIG. 7, they are rotated clockwise). Thus, when the blade-like members 72, 73, 74, and 75 are rotated by the flow of the mixed gas, the mixed gas is stirred by the blade-like members 72, 73, 74, and 75 and becomes turbulent on the downstream side. As a result, the mixing uniformity of the mixed gas is promoted.

  In FIG. 7, the blade-shaped members 72, 73, 74, and 75 are so-called cantilevered support structures in which the shaft members 71 are suspended from the beam portion 70 and are rotatably supported. A beam portion (not shown) may be further provided on the downstream side of 73, 74, and 75 to provide a both-end support structure. Moreover, it is good also as a cantilever support structure which supports the blade-shaped members 72, 73, 74, 75 on the upstream side of the downstream beam portion only on the downstream beam portion.

  As described above, the gas engine 1 using fuel gas as a fuel has a carburetor 10 as a mixer for mixing separately sucked air and fuel gas, and a plurality of cylinders 35 having combustion chambers 42, 43 and 44. , 36, 37 and an intake manifold 9 that is provided in common to the plurality of cylinders 35, 36, 37 and communicates the carburetor 10 and the plurality of cylinders 35, 36, 37.

  As described above, the gas engine 1 includes the intake manifold 9 in common to the plurality of cylinders 35, 36, and 37, and the intake manifold 9 includes the carburetor 10. Therefore, the air is provided for each combustion chamber (cylinder). The structure can be simplified, for example, the number of carburetors can be reduced as compared with a configuration including a mechanism for mixing the fuel gas and the fuel gas.

  In contrast, the conventional gas engine uses an intake manifold that supplies air and fuel gas for each of a plurality of cylinders, whereas the gas engine 1 of the present embodiment has a carburetor 10 to an intake manifold 9. The mixed gas is supplied to each of the three cylinders 35, 36, and 37 via the (mixed gas chamber 28). Therefore, once the mixed gas is accommodated in the intake manifold 9 having a large volume, it is possible to further improve the mixing uniformity in the mixed gas chamber 28.

  Further, the gas engine 1 according to the present embodiment includes a stirring unit 20 that stirs the mixed gas mixed by the carburetor 10 between the carburetor 10 and the intake manifold 9.

  By configuring the gas engine 1 as described above and further stirring the mixed gas mixed by the carburetor 10 by the stirring means 20, it becomes possible to improve the mixing uniformity of the air and the fuel gas.

  Further, as the stirring means 20, a blade-like member that swirls a mixed gas of air and fuel gas is used. As described in the first embodiment (see FIG. 5) and the second embodiment (see FIG. 6), each blade-like member is inclined while twisting from the upstream side to the downstream side, and adjacent blade-like members. When the mixed gas passes through the flow path between the two, the mixed gas is swirled and becomes a turbulent flow, thereby improving the mixing uniformity. Further, each vane-like member can be arranged at substantially the same position in the mixed gas flow direction, so that the distance from the stirring means 20 to the intake manifold 9 can be shortened. It is possible to simply increase the mixing uniformity by increasing the distance from the stirring means 20 to the intake manifold 9, but in this case, the mixed gas supply to the combustion chambers 42, 43, 44 is delayed. Can be considered.

  In the third embodiment (see FIG. 7), the stirring means 20 includes blade-like members 72, 73, 74, and 75 that can be rotated by the flow of the mixed gas. When the blade-like members 72, 73, 74, and 75 are rotated by the flow of the mixed gas, the mixed gas is stirred by the blade-like members 72, 73, 74, and 75, and the blade-like members 72, 73, 74, and 75 It becomes a turbulent flow on the downstream side, and it becomes possible to promote the mixing uniformity of the mixed gas. According to such a configuration, good mixing performance can be obtained even if the distance from the fuel gas suction port 15 to the intake manifold 9 is shortened.

  It should be noted that the present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved. For example, although the blade-shaped member of each of the above-described embodiments has a configuration of four sheets, the number of blade-shaped members is not limited to four, and for example, even if there are one or five blades, the mixed gas flow is hindered. However, it can be arbitrarily selected if sufficient mixing uniformity can be obtained. Moreover, although the blade-shaped member which comprises the stirring means 20 is arrange | positioned at equal intervals in the circumferential direction, it does not need to be equal intervals. In the present embodiment, the vane-like members are arranged at the same position in the flow direction of the mixed gas in the common channel 57, but each vane-like member is arranged to be shifted from the upstream side to the downstream side. May be. Furthermore, when the combination of four blade-like members is one set, a plurality of pairs of blade-like members may be arranged in the mixed gas flow direction.

  Moreover, although the stirring means 20 of this Embodiment is comprised with the blade-shaped member, as the stirring means, the spiral fin formed spirally in the common flow path (mixed gas flow path) of air and fuel gas Can also be arranged. The spiral fin may have a structure in which the outer circumferential end is fixed to the inner peripheral wall 21b of the main body 21 of the stirrer 17, a structure in which the spiral fin itself can be rotated by a mixed gas flow, or the like. Further, the present invention improves the mixing uniformity by making the mixed gas into a swirl flow or a turbulent flow in the mixed gas flow path. A protrusion may be arranged at 57, and a groove or the like may be formed in the inner peripheral wall 21b of the stirrer 17.

  Further, the intake manifold 9 (mixed gas chamber 28) of the present embodiment is configured such that the cylinder 36, which is separated from the arrangement position of the cylinder 35 from the arrangement position of the cylinder 35 close to the communication portion between the stirrer 17 and the intake manifold 9. Although the channel cross-sectional area of the mixed gas is gradually reduced toward the arrangement position 37, the channel cross-sectional area may not be reduced.

  Further, the gas engine 1 of the present embodiment has been described by exemplifying the case of three cylinders. However, the gas engine 1 can be applied to, for example, a two-cylinder engine or a four-cylinder engine. Intake manifold that can supply mixed gas, and a stirrer 17 that further stirs and mixes in a state where the sucked air and fuel gas are mixed, thereby suppressing variation in combustion among cylinders and stable driving A possible gas engine can be provided.

  Since air and fuel gas have different specific gravities, they tend to be layered even if they flow through a common flow path, and a uniform mixed state is often not obtained. Therefore, in the conventional gas engine, air and fuel gas are mixed by disturbing (including swirling) the flow of either air or fuel gas. On the other hand, the gas engine 1 of the present embodiment is further agitated by the agitator 17 in a state where the air and the fuel gas are mixed and supplied to the combustion chamber of each cylinder. By doing in this way, the mixed gas provided with the mixing uniformity of air and fuel gas can be supplied to each of the combustion chambers. As a result, the gas engine 1 having stable combustion characteristics with little variation in each combustion chamber can be realized.

  In addition, the gas engine 1 which concerns on embodiment of this invention is adaptable to what drives and burns the mixed gas of air and fuel gas based on a diesel engine or a gasoline engine.

  Moreover, since the gas engine 1 of the present invention uses LPG (liquefied petroleum gas), LNG (liquefied natural gas) or the like as the fuel gas, for example, generally used propane gas or city gas is used as the fuel gas. Can do. Therefore, since operation becomes possible by connecting propane gas or city gas to the fuel gas supply pipe section 14, it is effective as a power source for a portable generator or the like.

DESCRIPTION OF SYMBOLS 1 ... Gas engine 2 ... Cylinder block 7 ... Cylinder head 9 ... Intake manifold 10 ... Carburetor 11 ... Exhaust manifold 12 ... Spark plug 15 ... Fuel gas suction port 17 ... Stirrer 20 ... Stirring means 26 ... Spacer 28 ... Mixed gas chamber 30 , 31, 32 ... Intake port 35, 36, 37 ... Cylinder 38, 39, 40 ... Piston 42, 43, 44 ... Combustion chamber 45, 46, 47 ... Intake valve 48, 49, 50 ... Exhaust port 54, 55, 56 ... exhaust valve 57 ... common flow path 60, 61, 62, 63 ... blade-like member (first embodiment)
65, 66, 67, 68 ... blade-like member (second embodiment)
70: Beam portion 71: Shaft member 72, 73, 74, 75 ... Blade-like member (third embodiment)

Claims (4)

A gas engine using fuel gas as fuel,
A mixer for mixing separately sucked air and the fuel gas;
Multiple cylinders with combustion chambers;
An intake manifold that is provided in common to the plurality of cylinders and communicates the mixer and the plurality of cylinders;
have,
A gas engine characterized by that. The gas engine according to claim 1, wherein
Stirring means for stirring the mixed gas mixed in the mixer is provided between the mixer and the intake manifold.
A gas engine characterized by that. The gas engine according to claim 1 or 2,
The stirring means is a blade-like member that swirls in a state where the air and the fuel gas are mixed.
A gas engine characterized by that. The gas engine according to claim 3,
The blade-like member can be rotated by the flow of the mixed gas.
A gas engine characterized by that.

Images