JP2022154571A - internal combustion engine - Google Patents

Abstract

To provide an internal combustion engine which can facilitate mixing of a gas fuel with air in an intake passage to improve combustion efficiency.SOLUTION: An engine 1 includes: an intake manifold 10 having an intake passage 20 which supplies intake air to a combustion chamber 2a; and an injector which is installed at the intake manifold 10 and jets a gas fuel to the intake passage 20. A branch pipe 13 is provided with multiple collision walls 17A, 17B. The collision walls 17A, 17B are provided at the downstream side of a fuel injection port 15a in a direction that the intake air flows.SELECTED DRAWING: Figure 3

Description

The present invention relates to internal combustion engines.

BACKGROUND ART Conventionally, an automobile engine driven by gas fuel is known (see Patent Document 1). This automobile engine is retrofitted between an engine body and an intake manifold, and includes an adapter having a connection passage for connecting an intake passage of the intake manifold to a combustion chamber of the engine body, and gas fuel can be injected into the connection passage of the adapter. It has an injector mounted on the adapter as well.

The gaseous fuel injected from the injector is mixed with the air flowing from the intake passage of the intake manifold in the connection passage of the adapter to form an air-fuel mixture, which is supplied to the combustion chamber through the intake port.

JP-A-2018-13098

However, in the conventional automobile engine, since the gas fuel injected into the air is gas fuel, the gas fuel forms a belt-like gas layer (laminar flow) in the intake passage. Therefore, it may become difficult to promote mixing of air and gas fuel, and combustion efficiency may deteriorate.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an internal combustion engine capable of promoting mixing of gaseous fuel and air in an intake passage and improving combustion efficiency. .

The present invention includes an intake passage portion having an intake passage for supplying intake air to a combustion chamber, and a fuel injection valve installed in the intake passage portion and having a fuel injection port for injecting gaseous fuel into the intake passage. The internal combustion engine is characterized in that a plurality of protrusions are provided in the intake passage, and the protrusions are provided downstream of the fuel injection port in a direction in which intake air flows. .

As described above, according to the present invention, it is possible to promote mixing of gaseous fuel and air in the intake passage, thereby improving combustion efficiency.

FIG. 1 is a left side view of an internal combustion engine according to one embodiment of the invention. FIG. 2 is a rear view of the internal combustion engine according to one embodiment of the invention. FIG. 3 is a cross-sectional view taken along the line III--III in FIG. FIG. 4 is a sectional view taken along the IV-IV direction in FIG. FIG. 5 shows another arrangement state of the collision wall of the internal combustion engine according to one embodiment of the present invention, and corresponds to a cross-sectional view taken along the direction of arrows III--III in FIG.

An internal combustion engine according to an embodiment of the present invention has an intake passage portion having an intake passage that supplies intake air to a combustion chamber, and a fuel injection port that is installed in the intake passage portion and injects gas fuel into the intake passage. An internal combustion engine including a fuel injection valve, an intake passage portion is provided with a plurality of protrusions, and the protrusions are provided downstream of a fuel injection port in a direction in which intake air flows.

As a result, the internal combustion engine according to the embodiment of the present invention can promote mixing of gaseous fuel and air in the intake passage, and can improve combustion efficiency.

An internal combustion engine according to one embodiment of the present invention will be described below with reference to the drawings.
1 to 5 are diagrams showing an internal combustion engine according to one embodiment of the present invention.

1 to 5, the vertical, front, rear, left, and right directions are based on the internal combustion engine mounted on the vehicle, the front-rear direction of the vehicle (straight direction) is the front-rear direction, the left-right direction of the vehicle (the width direction of the vehicle) is the left-right direction, The vertical direction of the vehicle (height direction of the vehicle) is defined as the vertical direction.

First, the configuration will be explained.
In FIG. 1 , an engine 1 as an internal combustion engine mounted on a vehicle has a cylinder block 2 . The cylinder block 2 is provided with cylinders 2A (see FIG. 4) arranged in the vehicle width direction and a crankshaft 2S extending in the vehicle width direction. The engine 1 of this embodiment is a lateral engine of FF (front engine/front drive) type.

The engine 1 of this embodiment is an in-line three-cylinder engine in which three cylinders 2A are arranged in the axial direction (vehicle width direction) of a crankshaft 2S. However, the engine 1 is not limited to an in-line three-cylinder engine, and may be, for example, a V-type engine, and the number of cylinders is not limited to three.

As shown in FIG. 4, a piston 8 is housed in the cylinder 2A, and the piston 8 can reciprocate vertically with respect to the cylinder 2A. The piston 8 is connected to the crankshaft 2S via a connecting rod (not shown), and the vertical motion of the piston 8 is converted into rotational motion of the crankshaft 2S via the connecting rod.

A cylinder head 3 is provided above the cylinder block 2 . The cylinder head 3 has an intake port 4 (see FIGS. 3 and 4), an exhaust port (not shown), an intake valve and an exhaust valve (not shown) that open and close the intake port 4 and the exhaust port, respectively. An intake port 4 and an exhaust port are provided for each cylinder 2A.

As shown in FIG. 3, the intake port 4 has an intake inlet 4a that opens into the intake side wall 3a of the cylinder head 3, and intake outlets 4b and 4c that open into the combustion chamber 2a of the cylinder 2A. It extends from the intake inlet 4a to the intake outlets 4b, 4c.

As shown in FIG. 4, the combustion chamber 2a is defined by a space surrounded by the cylinder 2A, the bottom wall surface of the cylinder head 3, and the upper end surface of the piston 8. As shown in FIG.

The intake ports 4b and 4c are provided for each cylinder 2A, and the intake port 4 supplies the intake air taken from the intake port 4a to the cylinder 2A from the intake ports 4b and 4c.

The exhaust port discharges the exhaust gas burned in the combustion chamber 2a from the cylinder 2A to an exhaust pipe (not shown).

As shown in FIGS. 1 and 2, a cylinder head cover 6 is provided above the cylinder head 3 . An intake shaft, an exhaust shaft, and the like are installed inside the cylinder head cover 6 . The intake shaft and the exhaust shaft have intake cams and exhaust cams (not shown) that drive intake valves and exhaust valves, respectively.

An oil pan 7 is provided below the cylinder block 2 and oil for lubricating the engine 1 is stored in the oil pan 7 .

The engine 1 is provided with an intake manifold 10 . The intake manifold 10 includes a surge tank 11 and three branch pipes 12, 13, 14.

The upstream ends of the branch pipes 12 , 13 , 14 are connected to the surge tank 11 , and the downstream ends of the branch pipes 12 , 13 , 14 are connected to the cylinder head 3 .

A plurality of branch pipes 12 , 13 , 14 are arranged side by side in the axial direction of the crankshaft 2</b>S between the cylinder head 3 and the surge tank 11 .

Here, upstream and downstream refer to upstream and downstream with respect to the flow direction Wo of the intake air (see FIG. 3). For example, the intake port 4 side of the surge tank 11 is the downstream side in the intake air flow direction Wo, and the surge tank 11 side of the intake port 4 is the upstream side in the intake air flow direction Wo.

A throttle body (not shown) is connected to the upstream end of the surge tank 11 . A throttle valve (not shown) is accommodated in the throttle body, and the throttle valve adjusts the amount of intake air supplied to the intake manifold 10 by adjusting the opening of an intake passage inside the throttle body.

An air cleaner (not shown) for cleaning intake air is provided upstream of the throttle body. An intake passage 20 is formed inside the intake manifold 10 including the surge tank 11 and the branch pipes 12 , 13 , 14 .

The intake air purified by the air cleaner flows from the throttle body through the intake passage 20 of the intake manifold 10, and then is supplied to the cylinder 2A through the plurality of intake ports 4 of the cylinder head 3.

As shown in FIG. 2, injectors 15A, 15B and 15C as fuel injection valves are provided downstream of the branch pipes 12, 13 and 14, respectively. A delivery pipe 16 is provided in the cylinder head 3, and the delivery pipe 16 is connected to injectors 15A, 15B, and 15C.

Gas fuel stored in a gas fuel tank (not shown) is supplied to the delivery pipe 16 through a fuel pipe (not shown). The delivery pipe 16 distributes the gas fuel supplied from the gas fuel tank to the injectors 15A, 15B, 15C. As the gas fuel, for example, natural gas such as CNG (Compressed Natural Gas) or LPG (Liquefied Petroleum Gas) is used.

Linear portions 12A, 13A, and 14A are provided downstream of the branch pipes 12, 13, and 14, and the linear portions 12A, 13A, and 14A extend linearly in the front-rear direction. That is, as shown in the linear portion 13A of the branch pipe 13 in FIG. 4, the linear portions 12A, 13A, and 14A extend linearly in the front-rear direction. Injectors 15A, 15B, 15C are attached to linear portions 12A, 13A, 14A.

3 and 4 show the configuration of the branch pipe 13 installed between the branch pipe 12 and the branch pipe 14 in the vehicle width direction. Since the branch pipes 12 and 14 have the same configuration as the branch pipe 13, a detailed description thereof will be omitted.

A straight portion 13A of the branch pipe 13 is provided with a fuel injection port 15a. The fuel injection port 15a is composed of an opening formed in the branch pipe 13, and the gas fuel injected from the fuel injection port 15a is supplied to the intake passage 20 from the fuel injection port 15a. The branch pipe 13 of this embodiment is integrally provided with the fuel injection port 15a of the injector 15 .

The fuel injection port 15a is not limited to the opening formed in the branch pipe 13, and the fuel injection port formed at the tip of the injector 15, that is, the injector 15 protruding from the branch pipe 13 into the intake passage 20. It may also consist of its own fuel injection port.

The gaseous fuel supplied to the intake passage 20 is mixed with the intake air flowing through the intake passage 20, supplied from the intake port 4a to the intake port 4, and then supplied to the combustion chamber 2a from the intake ports 4b and 4c.

As shown in FIG. 4, a spark plug mounting hole 3b is formed in the cylinder head 3 so as to be positioned above each cylinder 2A, and a spark plug (not shown) is mounted in the spark plug mounting hole 3b.

The spark plug ignites the air-fuel mixture supplied to the combustion chamber 2a when the piston 8 rises near the top dead center. As a result, the air-fuel mixture is combusted, and energy for rotating the crankshaft 2S can be obtained. The cylinder head 3 and the intake manifold 10 of this embodiment form an intake passage.

As shown in FIGS. 3 and 4, the inner peripheral surface of the upper wall 13a of the straight portion 13A of the branch pipe 13 and the upper surface 4d of the intake port 4 are provided with a plurality of collision walls 17A and 17B. 17A and 17B protrude downward from the upper wall 13a of the linear portion 13A and the upper surface 4d of the intake port 4. As shown in FIG.

As shown in FIG. 3, the collision walls 17A and 17B are provided downstream of the fuel injection port 15a in the direction Wo in which the intake air flows. In other words, the collision walls 17A and 17B are provided on the intake port 4 side with respect to the fuel injection port 15a.

The collision walls 17A and 17B are arranged side by side in the intake air flow direction L and separated from each other in the intake air flow direction Wo with a certain gap therebetween. The collision walls 17A and 17B extend in the intake air flow direction Wo such that the intake air flow direction Wo is the longitudinal direction.

The collision walls 17A and 17B are located on one side (right side) in the vehicle width direction and on the vehicle width direction with respect to imaginary lines L1 and L2 connecting the fuel injection port 15a of the injector 15 and the intake outlets 4b and 4c of the intake port 4. is provided on the other side (left side) of the

The collision walls 17A, 17B are installed so as to separate from the imaginary lines L1, L2 as they go from the upstream ends 17a, 17b toward the downstream ends 17c, 17d in the intake air flow direction Wo.

That is, the collision walls 17A and 17B, which are adjacent to each other along the direction Wo of the intake air, are imaginary such that the upstream ends 17a and 17b approach the imaginary lines L1 and L2, and the downstream ends 17c and 17d move away from the imaginary lines L1 and L2. It is inclined with respect to lines L1 and L2.

Collision walls 17A and 17B of this embodiment constitute projections and plate members. Incidentally, the collision walls 17A and 17B of the present embodiment may be formed integrally with the branch pipe 13, or may be attached to the branch pipe 13 as separate parts.

As shown in FIG. 3, a pair of guide walls 18A and 18B are provided on the linear portion 13A of the branch pipe 13, and the guide walls 18A and 18B extend from the inner peripheral surface of the upper wall 13a of the linear portion 13A. It protrudes downward.

The guide walls 18A and 18B are provided on the upstream side of the fuel injection port 15a in the intake air flow direction Wo, and are installed so as to be adjacent to each other along the intake air flow direction Wo.

Adjacent guide walls 18A and 18B approach each other from upstream ends 18a and 18b in the intake air flow direction Wo toward downstream ends 18c and 18d.

That is, the guide walls 18A, 18B are arranged in such a manner that the width of the upstream ends 18a, 18b (the distance in the vehicle width direction) increases from the upstream ends 18a, 18b toward the downstream ends 18c, 18d in the intake air flow direction Wo. The widths (distance in the vehicle width direction) of 18c and 18d are gradually narrowed, and the downstream ends 18c and 18d sandwich the fuel injection port 15a.

Next, the action of the engine 1 of this embodiment will be described.
The branch pipes 12 and 14 are provided with collision walls 17A and 17B and guide walls 18A and 18B having the same structure as the branch pipe 13. The operation of the engine 1 will be explained using the branch pipe 13. FIG.

The engine 1 of this embodiment includes an intake manifold 10 having an intake passage 20 that supplies intake air to the combustion chamber 2a, and an injector 15 that is installed in the intake manifold 10 and injects gas fuel into the intake passage 20. .

A plurality of collision walls 17A, 17B are provided in the branch pipes 12, 13, 14, and the collision walls 17A, 17B are provided downstream of the fuel injection port 15a in the direction in which the intake air flows.

As a result, gas fuel and intake air injected from the fuel injection port 15a of the injector 15 (hereafter, gas fuel and intake air are referred to as an airflow G) flow between the collision walls 17A and 17B as shown in FIG. while colliding with the upstream ends 17a, 17b of the colliding walls 17A, 17B.

The airflow G that collides with the upstream ends 17a and 17b of the collision walls 17A and 17B passes between the upstream ends 17a and 17b of the collision walls 17A and 17B and the downstream ends 17c and 17d of the collision walls 17A and 17B. Out through the gap.

As a result, turbulence is generated in the airflow G, and the turbulence promotes mixing of gaseous fuel and intake air, thereby improving combustion efficiency.

Moreover, since the plurality of collision walls 17A and 17B are provided in the branch pipe 13, the number of collisions of the airflow G against the collision walls 17A and 17B can be increased, and the chances of generating turbulence can be increased. Therefore, the mixing of the gaseous fuel and the intake air can be promoted more effectively, and the combustion efficiency can be improved more effectively.

The engine 1 of this embodiment also has a cylinder head 3, and the cylinder head 3 has an intake port 4 including a plurality of intake outlets 4b and 4c opening into the combustion chamber 2a.

In addition, the plurality of collision walls 17A and 17B are located on one side (right side) in the vehicle width direction with respect to imaginary lines L1 and L2 connecting the fuel injection port 15a of the injector 15 and the intake ports 4b and 4c. It is provided on the other side (left side) in the vehicle width direction.

In the branch pipe 13, imaginary lines L1 and L2 connecting the fuel injection port 15a of the injector 15 and the intake ports 4b and 4c are main paths through which the gas fuel injected from the fuel injection port 15a and the intake air flow.

Therefore, by providing collision walls 17A and 17B on one side in the vehicle width direction and the other side in the vehicle width direction with respect to the main paths (virtual lines L1 and L2), the flow of gas fuel and intake air is obstructed. While preventing this, the airflow G can collide with the collision walls 17A and 17B to generate turbulence.

Therefore, the mixing of the gas fuel and the intake air can be promoted more effectively, the mixing of the gas fuel and the intake air and the intake efficiency can be compatible, and the combustion efficiency can be improved more effectively.

Further, according to the engine 1 of the present embodiment, the collision walls 17A and 17B are made of plate members. The collision walls 17A, 17B extend in the intake air flow direction Wo so that the intake air flow direction Wo is the longitudinal direction, and extend from upstream ends 17a, 17b to downstream ends 17c, 17d in the intake air flow direction Wo. are installed so as to separate from the virtual lines L1 and L2 as they go toward.

This makes it easier for the airflow G to collide with the upstream ends 17a and 17b of the collision walls 17A and 17B, ie, the corners of the collision walls 17A and 17B, and to separate the airflow G from the collision walls 17A and 17B.

Therefore, turbulence can be easily generated in the airflow G, and mixing of gaseous fuel and intake air can be promoted more effectively. As a result, combustion efficiency can be improved more effectively.

Further, according to the engine 1 of this embodiment, the branch pipe 13 is provided with a pair of guide walls 18A and 18B. They are installed side by side along the direction Wo in which the intake air flows on the upstream side.

In addition, the adjacent guide walls 18A, 18B approach each other from the upstream ends 18a, 18b toward the downstream ends 18c, 18d in the intake air flow direction Wo.

As a result, between the guide walls 18A and 18B, the flow velocity of the intake air W (see FIG. 3) flowing from the upstream ends 18a and 18b of the guide walls 18A and 18B toward the downstream ends 18c and 18d is increased, and the airflow G can increase the impact when it collides with the collision walls 17A and 17B.

Therefore, the mixing of the gaseous fuel and the intake air can be promoted more effectively, and the combustion efficiency can be improved more effectively.

The collision walls 17A and 17B are installed so as to separate from the imaginary lines L1 and L2 as they go from the upstream ends 17a and 17b toward the downstream ends 17c and 17d in the flow direction Wo of the intake air, but as shown in FIG. Alternatively, they may be installed so as to approach the imaginary lines L1 and L2 from the upstream ends 17a and 17b toward the downstream ends 17c and 17d in the flow direction Wo of the intake air.

Even in this way, the airflow G flowing between the collision walls 17A and 17B can collide with the corners of the upstream ends 17a and 17b of the collision walls 17A and 17B to generate turbulence. Therefore, the turbulent flow promotes mixing of gaseous fuel and intake air, thereby improving combustion efficiency.

Note that in the engine 1 of this embodiment, the collision walls 17A and 17B are arranged in the vehicle width direction with respect to virtual lines L1 and L2 connecting the fuel injection port 15a of the injector 15 and the intake outlets 4b and 4c of the intake port 4. The collision wall is provided on one side (right side) and the other side (left side) in the vehicle width direction, but the collision wall is either one side (right side) in the vehicle width direction or the other side (left side) in the vehicle width direction may be provided on the side.

Even in this way, it is possible to cause the airflow G to collide with the collision wall 17A or the collision wall 17B to generate turbulence while preventing the flow of the gaseous fuel and the intake air from being obstructed.

Therefore, the mixing of the gas fuel and the intake air can be promoted more effectively, the mixing of the gas fuel and the intake air and the intake efficiency can be compatible, and the combustion efficiency can be improved more effectively.

Note that the engine 1 of this embodiment may be a bi-fuel engine that uses both a liquid fuel such as gasoline and a gas fuel.

Although embodiments of the present invention have been disclosed, it will be apparent that modifications may be made by those skilled in the art without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

1... Engine (internal combustion engine), 2a... Combustion chamber, 3... Cylinder head (intake passage), 4... Intake port (intake passage), 4b, 4c... Intake outlet, 10 ... intake manifold (intake passage), 15 ... injector (fuel injection valve), 15a ... fuel injection port, 17A, 17B ... collision wall (projection, plate member), 17a, 17b ...upstream end (upstream end of the plate member in the direction in which intake air flows), 17c, 17d... downstream end (downstream end in the direction in which intake air flows), 18A, 18B... guide wall, 18a, 18b...Upstream end (upstream end of guide wall in flow direction of intake air), 18c, 18d...Downstream end (upstream end of guide wall in flow direction of intake air), L1, L2... Fuel injection An imaginary line connecting the mouth and the intake outlet

Claims (5)

An internal combustion engine comprising: an intake passage portion having an intake passage for supplying intake air to a combustion chamber; and a fuel injection valve installed in the intake passage portion and having a fuel injection port for injecting gas fuel into the intake passage. hand,
A plurality of protrusions are provided in the intake passage,
The internal combustion engine, wherein the protrusion is provided downstream of the fuel injection port in a direction in which intake air flows. Having a cylinder head including the intake passage,
The cylinder head has an intake port including the intake passage,
The intake port has a plurality of intake outlets opening into the combustion chamber,
2. The method according to claim 1, wherein the plurality of protrusions are provided on at least one side or the other side with respect to an imaginary line connecting the fuel injection port and the intake port. internal combustion engine. The plurality of protrusions are made of a plate-like member,
The plate-shaped member extends in the direction in which the intake air flows so that the direction in which the intake air flows in the intake passage is the longitudinal direction, and
3. The internal combustion engine according to claim 2, wherein the plate-like member is installed so as to separate from the imaginary line from the upstream end toward the downstream end in the direction in which the intake air flows. The plurality of protrusions are made of a plate-like member,
The plate-shaped member extends in the direction in which the intake air flows so that the direction in which the intake air flows in the intake passage is the longitudinal direction, and
3. The internal combustion engine according to claim 2, wherein the plate-shaped member is installed so as to approach the imaginary line from the upstream end toward the downstream end in the flow direction of the intake air. A pair of guide walls are provided in the intake passage,
The pair of guide walls are installed so as to be adjacent to each other along the direction of flow of intake air on the upstream side of the fuel injection port in the direction of flow of intake air,
5. The internal combustion engine according to any one of claims 1 to 4, wherein the pair of guide walls are arranged such that the adjacent guide walls approach each other from the upstream end toward the downstream end in the flow direction of the intake air. institution.

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