Auxiliary chamber type internal combustion engine

Abstract

To provide an auxiliary chamber type internal combustion engine which can form air-fuel mixture having a high fuel concentration around a sub-combustion chamber in a main combustion chamber in which a tumble flow is formed.SOLUTION: An auxiliary chamber type internal combustion engine includes a main combustion chamber in which a tumble flow is formed, a sub-combustion chamber disposed across a partition wall from the main combustion chamber, and a fuel injection valve which injects fuel into the main combustion chamber. The fuel injection valve has a first injection injected toward the tumble flow, and a second injection injected toward the sub-combustion chamber.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a pre-chamber internal combustion engine. [Background technology]

[0002] Conventionally, a pre-combustion chamber type internal combustion engine has been known (see, for example, Patent Document 1). The pre-combustion chamber type internal combustion engine of Patent Document 1 comprises a main combustion chamber and a pre-combustion chamber, an ignition device disposed in the pre-combustion chamber, and a fuel injection valve disposed in the main combustion chamber. The pre-combustion chamber type internal combustion engine of Patent Document 1 is a passive type pre-combustion chamber type internal combustion engine that forms an air-fuel mixture in the pre-combustion chamber by supplying fuel injected from the main combustion chamber to the pre-combustion chamber. The air-fuel mixture formed in the pre-combustion chamber is ignited by an ignition device to form a flame. The flame formed in the pre-combustion chamber is injected into the main combustion chamber via a communication passage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 7255673 Summary of the Invention [Problem to be solved by the invention]

[0004] In such a passive type pre-combustion chamber internal combustion engine, it is preferable to form a fuel-rich mixture around the pre-combustion chamber and supply the mixture to the pre-combustion chamber. The pre-combustion chamber internal combustion engine of Patent Document 1 supplies fuel spray from the fuel injection valve to the outside of the pre-combustion chamber, forming a fuel-rich mixture around the pre-combustion chamber. Patent Document 1 does not disclose how fuel injection should be performed when a tumble flow is formed in the main combustion chamber.

[0005] An object of the present disclosure is to provide an internal combustion engine with a pre-combustion chamber that can form a mixture with a high fuel concentration around the pre-combustion chamber in the main combustion chamber where a tumble flow is formed. [Means for solving the problem]

[0006] The auxiliary combustion chamber type internal combustion engine according to the present disclosure comprises a main combustion chamber in which a tumble flow is formed, an auxiliary combustion chamber arranged with a partition wall between it and the main combustion chamber, and a fuel injection valve that supplies fuel to the main combustion chamber, the fuel injection valve having a first injection that is injected toward the tumble flow and a second injection that is injected toward the auxiliary combustion chamber. [Effects of the Invention]

[0007] In this pre-combustion chamber internal combustion engine, the first injection is carried by the tumble flow and supplies a fuel spray around the pre-combustion chamber. The second injection is injected toward the pre-combustion chamber and supplies a fuel spray around the pre-combustion chamber. The pre-combustion chamber internal combustion engine forms a mixture with a high fuel concentration around the pre-combustion chamber by the first injection and the second injection. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side cross-sectional view of the vicinity of a communication passage, illustrating an injection pattern of an internal combustion engine with a pre-combustion chamber according to an embodiment of the present disclosure; [Figure 2] FIG. 2 is a bottom cross-sectional view of the vicinity of a communication passage, illustrating the injection pattern of the pre-chamber type internal combustion engine according to the embodiment of the present disclosure. [Figure 3] FIG. 10 is a cross-sectional side view of the vicinity of a communication passage, illustrating an injection pattern of an internal combustion engine with a pre-combustion chamber according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the sliding direction of piston 8 is indicated as P, the side where intake valve 14 is located is indicated as intake side IN, the side where exhaust valve 16 is located is indicated as exhaust side EX, and the direction in which ridge line X1 extends is indicated as ridge line direction X.

[0010] As shown in FIG. 1, the auxiliary combustion chamber type internal combustion engine 1 includes a main combustion chamber 2, an auxiliary combustion chamber 3, a communication passage 4, an ignition device 6, a piston 8, and a fuel injection valve 9.

[0011] The main combustion chamber 2 is a space surrounded by the cylinder 10a of the cylinder block 10, the cylinder head 12, and the piston 8. In this embodiment, the main combustion chamber 2 has a pent roof shape, with two slopes formed toward the intake port 12a side and the exhaust port 12b side of the cylinder head 12. The main combustion chamber 2 is connected to the intake port 12a via an intake valve 14. The intake port 12a is connected, for example, to an intake passage (not shown). The intake port 12a in this embodiment forms a tumble flow T in the main combustion chamber 2. The main combustion chamber 2 is connected to the exhaust port 12b via an exhaust valve 16. The exhaust port 12b is connected, for example, to an exhaust passage (not shown).

[0012] The auxiliary combustion chamber 3 protrudes from the cylinder head 12 toward the main combustion chamber 2 and is separated from the main combustion chamber 2 by an auxiliary combustion chamber wall (an example of a partition wall) 5. The auxiliary combustion chamber 3 of this embodiment is located adjacent to the main combustion chamber 2 at the top of the pent roof shape, and has a space surrounded by the auxiliary combustion chamber wall 5. The center line C2 of the auxiliary combustion chamber 3 of this embodiment coincides with the center line C1 of the main combustion chamber 2.

[0013] The auxiliary combustion chamber wall 5 has a side wall 51 and a bottom wall 52. In this embodiment, the side wall 51 is formed in a cylindrical shape, and the bottom wall 52 is formed in a hollow hemispherical shape.

[0014] The communication passages 4 are provided in the auxiliary combustion chamber wall 5. As shown in Fig. 2, the communication passages 4 communicate between the main combustion chamber 2 and the auxiliary combustion chamber 3. In this embodiment, a total of eight communication passages 4 are provided: two in the direction of the ridge line X1 of the pent roof, three toward the intake side, and three toward the exhaust side.

[0015] As shown in Fig. 1, the ignition device 6 is disposed in the auxiliary combustion chamber 3. The ignition device 6 ignites the air-fuel mixture in the auxiliary combustion chamber 3 by discharging the current flowing through the ignition coil using the central electrode and the side electrode.

[0016] The piston 8 is housed in the cylinder 10a and slides within the cylinder 10a. The piston 8 surrounds the main combustion chamber 2 from below.

[0017] The fuel injection valve 9 injects fuel toward the main combustion chamber 2 and the auxiliary combustion chamber 3, forming an air-fuel mixture in the main combustion chamber 2 and the auxiliary combustion chamber 3. In this embodiment, the fuel injection valve 9 has a first fuel injection valve 9a and a second fuel injection valve 9b. The first fuel injection valve 9a is arranged on the exhaust side EX. The first fuel injection valve 9a is a direct injection type that injects fuel directly into the main combustion chamber 2. The second fuel injection valve 9b is arranged on the intake side IN. The second fuel injection valve 9b is also a direct injection type that injects fuel directly into the main combustion chamber 2. The injection amount Q1 of the first injection F1 is greater than the injection amount Q2 of the second injection F2.

[0018] The first fuel injection valve 9a injects the first injection F1. The first injection F1 is injected toward the tumble flow T. More specifically, the tumble flow T flows toward the piston 8 in the sliding direction P on the exhaust side EX. The first fuel injection valve 9a injects the first injection F1 toward the bottom dead center side of the sliding direction P of the piston 8. As a result, the first injection F1 rides on the tumble flow T flowing toward the piston 8. The first injection F1 riding on the tumble flow T flows toward the top dead center side (cylinder head 12 side) in the sliding direction P on the intake side IN, and flows around the auxiliary combustion chamber wall 5.

[0019] As shown in FIG. 2, the first fuel injection valve 9a has multiple nozzle holes and injects the first injection F1 in multiple directions. In this embodiment, the first fuel injection valve 9a has a central nozzle hole F1a that injects toward the center line C2 of the auxiliary combustion chamber 3, and two side nozzle holes F1b that are arranged on both sides of the central nozzle hole F1a and inject the first injection F1 toward the ridge line X1. In other words, the first fuel injection valve 9a forms the first injection F1 in three different directions. Of the multiple nozzle holes of the first fuel injection valve 9a, the injection amount Qm of the central nozzle hole is greater than the injection amount Qs of the other nozzle holes. In this embodiment, the injection amount Qm of the central nozzle hole F1a is greater than the injection amount Qs of the side nozzle holes F1b.

[0020] The second injection F2 injects fuel toward the auxiliary combustion chamber wall 5. The second injection F2 collides with the auxiliary combustion chamber wall 5 and the spray diffuses. The second fuel injection valve 9b injects the second injection F2 toward the center line C2 of the auxiliary combustion chamber 3.

[0021] In the auxiliary combustion chamber type internal combustion engine 1 configured as described above, the first fuel injection F1 injected from the central nozzle F1a of the first fuel injection valve 9a rides on the tumble flow and flows to the periphery of the auxiliary combustion chamber wall 5. After flowing around the periphery of the auxiliary combustion chamber wall 5, the first fuel injection F1 hits the auxiliary combustion chamber wall 5 and diffuses. The first fuel injection F1 injected from the side nozzle F1b of the first fuel injection valve 9a rides on the tumble flow and diffuses, forming an air-fuel mixture in the main combustion chamber 2 with a homogeneous air-fuel ratio.

[0022] The second injection F2 injected from the second fuel injection valve 9b collides with and diffuses on the auxiliary combustion chamber wall 5. As a result, the second injection F2 forms a mixture with a high fuel concentration around the auxiliary combustion chamber wall 5. In this embodiment, the second injection F2 is injected after the completion of the first injection F1. As a result, the fuel concentration of the mixture around the auxiliary combustion chamber wall 5 formed by the first injection F1 can be further increased by the second injection F2.

[0023] The air-fuel mixture formed around the auxiliary combustion chamber wall 5 flows into the auxiliary combustion chamber 3 through the communication passage 4. The air-fuel mixture that flows into the auxiliary combustion chamber 3 is ignited by the ignition device 6. The ignited air-fuel mixture becomes a flame. The flame passes through the communication passage 4 and is injected into the main combustion chamber 2 as a jet flame.

[0024] As described above, according to the present disclosure, it is possible to provide an auxiliary combustion chamber type internal combustion engine 1 that can form a mixture with a high fuel concentration around the auxiliary combustion chamber 3 in the main combustion chamber 2 where a tumble flow is formed.

[0025] <Other embodiments> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications are possible within the scope of the gist of the invention. In particular, the multiple modifications described in this specification can be arbitrarily combined as necessary.

[0026] In the above embodiment, the first injection F1 and the second injection F2 are formed using the first fuel injection valve 9a and the second fuel injection valve 9b, but the present disclosure is not limited to this. As shown in Fig. 3, the first injection F1 and the second injection F2 may be formed by a single fuel injection valve 9 arranged on the intake side IN. [Explanation of symbols]

[0027] 1: Pre-chamber internal combustion engine 2: Main combustion chamber 3: Auxiliary combustion chamber 4:Communication path 5: Pre-combustion chamber wall 6:Ignition device 8: Piston 9: Fuel injector 9a: First fuel injector 9b: Second fuel injector 10a: Cylinder F1: 1st injection, F2: 2nd injection

Claims

1. a main combustion chamber in which a tumble flow is formed; an auxiliary combustion chamber disposed between the main combustion chamber and the auxiliary combustion chamber via a partition wall; a fuel injection valve that injects fuel into the main combustion chamber; Equipped with The fuel injection valve A first jet of air is jetted toward the tumble flow. a second injection directed toward the auxiliary combustion chamber; having Pre-chamber internal combustion engine.

2. Further comprising a piston that slides within the cylinder; The first injection is injected toward the bottom dead center side in the sliding direction of the piston.

2. The pre-combustion chamber type internal combustion engine according to claim 1.

3. The second jet is jetted toward the partition wall.

2. The pre-chamber internal combustion engine according to claim 1.

4. The injection amount of the first injection is greater than the injection amount of the second injection.

2. The pre-chamber internal combustion engine according to claim 1.

5. The first jet is jetted from a plurality of nozzles, The injection amount of the central nozzle among the plurality of nozzles is greater than the injection amounts of the other nozzles.

2. The pre-chamber internal combustion engine according to claim 1.

6. The fuel injection valve includes a first fuel injection valve disposed on an exhaust side and a second fuel injection valve disposed on an intake side, the first fuel injector injects the first injection; The second fuel injection valve injects the second injection.

6. The pre-chamber internal combustion engine according to claim 1.

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