JP2022105620A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine capable of suppressing interference of a flame and efficiently performing combustion.

SOLUTION: An internal combustion engine includes a combustion chamber 50 comprising a main chamber 51 in which a main ignition plug 61 is disposed and an auxiliary chamber 52 in which an auxiliary ignition plug 62 is disposed. An inner cylindrical part 41 to which the main ignition plug 61 is mounted is disposed in a central upper part of the main chamber 51, and the auxiliary chamber 52 is disposed in the vicinity of the inner cylindrical part 41. A communication passage 46 communicating the auxiliary chamber 52 with the main chamber 51 is provided. The inner cylindrical part 41 is opened downwardly, and the communication passage 46 is opened on a wall surface on the main chamber 51 side in the radial direction toward a wall surface of a cylinder 21.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to an internal combustion engine.

Conventionally, as an internal combustion engine having a sub chamber in a combustion chamber, the one described in Patent Document 1 is known. The internal combustion engine described in Patent Document 1 includes a main chamber which is a main combustion chamber, a sub chamber which has a smaller volume than the main chamber and is provided adjacent to the main chamber, and a main chamber and a sub chamber on the wall surface of the sub chamber. It has a jet hole that is a communication passage that communicates with the chamber, and a sub-chamber ignition means that can arbitrarily set the ignition timing in the sub-chamber.

Further, the internal combustion engine described in Patent Document 1 includes a main chamber ignition means in which the ignition timing can be arbitrarily set in the main chamber, and an ignition timing control means for controlling the ignition timings of the sub chamber ignition means and the main chamber ignition means. According to the operating conditions, the ignition timing control means controls the main chamber ignition by the main chamber ignition means and then the sub-chamber ignition by the sub-chamber ignition means.

As a result, the intensity of the torch flame ejected from the sub chamber is generally determined by the pressure difference between the main chamber and the sub chamber, but the internal combustion engine described in Patent Document 1 is mainly used before ignition of the sub chamber depending on the operating conditions. By performing chamber ignition, the pressure in the main chamber can be increased, and a torch flame of optimum strength can be obtained according to the operating conditions.

Japanese Unexamined Patent Publication No. 2007-255370

However, in the internal combustion engine described in Patent Document 1, since the spark plugs in the main chamber and the spark plugs in the sub chamber are arranged apart from each other, the spark plugs from the spark plugs in the sub chamber and the spark plugs in the main chamber are separated from each other. There was a problem that the flame that had spread from the spark plug collided with each other and interfered with each other, making it impossible to burn efficiently.

The present invention has been made by paying attention to the above-mentioned problems, and an object of the present invention is to provide an internal combustion engine capable of suppressing flame interference and efficiently performing combustion.

The internal combustion engine according to the present invention is an internal combustion engine having a combustion chamber including a main chamber in which a main spark plug is arranged and a sub chamber in which a sub-spark plug is arranged. A cylindrical portion to which a spark plug is mounted is arranged, the sub chamber is arranged in the vicinity of the cylindrical portion, and a communication passage connecting the sub chamber and the main chamber is provided, and the cylindrical portion faces downward. The continuous passage is characterized by opening on the wall surface on the main chamber side in the radial direction toward the cylinder wall surface.

As described above, according to the above invention, the interference of the flame can be suppressed and the combustion can be efficiently performed.

FIG. 1 is a vertical sectional view of a combustion chamber of an internal combustion engine according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a combustion chamber of an internal combustion engine according to an embodiment of the present invention. FIG. 3 is a vertical sectional view of an auxiliary chamber member of an internal combustion engine according to an embodiment of the present invention. FIG. 4 is a cross-sectional view of an auxiliary chamber member of an internal combustion engine according to an embodiment of the present invention. FIG. 5 is a bottom view of an auxiliary chamber member of an internal combustion engine according to an embodiment of the present invention.

An internal combustion engine according to an embodiment of the present invention is an internal combustion engine having a combustion chamber including a main chamber in which a main spark plug is arranged and a sub chamber in which a sub-spark plug is arranged, and is located in the center of the main chamber. A cylindrical part to which a main spark plug is mounted is arranged at the upper part, a sub chamber is arranged in the vicinity of the cylindrical portion, and a communication passage connecting the sub chamber and the main chamber is provided, and the cylindrical portion opens downward. However, the continuous passage is characterized in that it opens on the wall surface on the main chamber side in the radial direction toward the cylinder wall surface. As a result, the internal combustion engine according to the embodiment of the present invention can suppress the interference of flames and can efficiently perform combustion.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. 1 to 5 are diagrams illustrating an embodiment of an internal combustion engine according to the present invention.

As shown in FIGS. 1 and 2, the internal combustion engine 10 according to an embodiment of the present invention includes a cylinder block 20 and a cylinder head 30. A cylindrical cylinder 21 is formed in the cylinder block 20, and the cylinder 21 is provided with a piston 22.

A combustion chamber 50 is formed above the cylinder 21 in the cylinder head 30, and an intake port 34 and an exhaust port 35 communicate with the combustion chamber 50. The cylinder head 30 includes an intake valve 36 and an exhaust valve 37.

The intake valve 36 opens and closes between the combustion chamber 50 and the intake port 34 at a predetermined timing. The exhaust valve 37 opens and closes between the combustion chamber 50 and the exhaust port 35 at a predetermined timing.

The internal combustion engine 10 includes a connecting rod, a crankshaft, etc. (not shown), and performs a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke while the piston 22 makes two reciprocations in the cylinder 21. It is configured as a 4-cycle spark ignition type internal combustion engine that ignites a mixture of gasoline and the like during a compression stroke and an expansion stroke.

The internal combustion engine 10 is mounted on a vehicle (not shown), and a piston is reciprocated by burning a mixture of fuel and air in a combustion chamber 50, and a crankshaft is rotated via a connecting rod to rotate the vehicle. It is designed to generate a driving force to drive the engine.

In this embodiment, the combustion chamber 50 is composed of a main chamber 51 which is a main combustion chamber and a sub chamber 52 whose volume is smaller than that of the main chamber 51. The upper surface of the main chamber 51 is formed in a roof-shaped disk shape. The upper surface of the main chamber 51 is composed of a cylinder head 30.

A main spark plug 61 is arranged in the upper part of the center of the main chamber 51. An annular (torus-shaped) sub-chamber 52 is formed around the main spark plug 61, and the sub-chamber 52 is adjacent to the upper part of the central portion of the main chamber 51. A sub-spark plug 62 is arranged in the sub-chamber 52.

Specifically, the internal combustion engine 10 includes a sub-chamber member 40 that forms the sub-chamber 52. The sub chamber member 40 is fixed to the cylinder head 30 on the upper surface of the center of the combustion chamber 50. A main spark plug 61 is provided in the center of the sub chamber member 40. Further, a sub-spark plug 62 is integrally provided around the main spark plug 61 in the sub-chamber member 40.

As shown in FIGS. 3, 4, and 5, the sub-chamber member 40 includes a cylindrical inner cylinder portion 41 and a tubular outer cylinder portion 42 located on the outer peripheral side of the inner cylinder portion 41. There is. The internal space of the inner cylinder portion 41 constitutes the main spark plug mounting hole 44. As shown in FIG. 1, a main spark plug 61 is mounted in the main spark plug mounting hole 44. The electrode 61A of the main spark plug 61 is exposed in the main chamber 51 of the combustion chamber 50.

In FIGS. 3, 4, and 5, the annular space between the inner cylinder portion 41 and the outer cylinder portion 42 constitutes the sub chamber 52. A sub-spark plug 62 is provided in the sub-chamber 52. The sub-spark plug 62 is arranged above the main spark plug 61 in the vertical direction, and the electrode 62A of the sub-spark plug 62 is located above the sub chamber 52. The sub-spark plug 62 is attached to the sub-chamber member 40 in parallel with the main spark plug 61.

The sub-chamber member 40 has a hemispherical portion 43 having a hemispherical shape as a whole, and the hemisphere portion 43 is provided at the lower ends of the inner cylinder portion 41 and the outer cylinder portion 42, and closes the sub-chamber 52 from below. There is. The above-mentioned main spark plug mounting hole 44 penetrates the hemisphere portion 43 and leads to the main chamber 51.

The hemisphere portion 43 is provided with a plurality of communication passages 46, and the communication passages 46 communicate the sub chamber 52 and the main chamber 51. The sub chamber member 40 is fixed to the cylinder head 30 by screwing or the like.

The communication passage 46 is open on the outer surface of the hemisphere portion 43, that is, on the wall surface on the main chamber 51 side in the radial direction toward the wall surface of the cylinder 21. Specifically, the communication passage 46 is opened on the wall surface on the main chamber 51 side so as to be inclined in the circumferential direction with respect to the radial direction toward the wall surface of the cylinder 21.

The communication passage 46 opens on the inner surface of the hemisphere portion 43, that is, on the wall surface on the side of the sub chamber 52, inclined in the circumferential direction with respect to the radial direction toward the center of the main spark plug 61 as shown by an arrow C in FIG. is doing.

The operation by the internal combustion engine according to the embodiment of the present invention configured as described above will be described.

During the compression stroke of the internal combustion engine 10, as shown in FIG. 4, the air-fuel mixture flows into the sub chamber 52 through the communication passage 46. As shown by the arrow C, the opening on the side of the sub chamber 52 of the communication passage 46 is inclined in the circumferential direction with respect to the radial direction toward the center of the main spark plug 61 (see FIG. 2).

Therefore, the air-fuel mixture that has flowed into the sub-chamber 52 during the compression stroke forms a swirling flow that swirls in the annular sub-chamber 52 as shown by the arrow D. Then, by the start of the combustion stroke of the internal combustion engine 10, the main chamber 51 and the sub chamber 52 of the combustion chamber 50 are filled with a mixture of air and combustion.

During the combustion stroke of the internal combustion engine 10, as shown in FIGS. 1 and 3, the flame generated in the main chamber 51 due to the ignition of the main spark plug 61 propagates mainly downward as shown by the arrow A. .. On the other hand, the flame generated by the ignition of the sub-spark plug 62 in the sub-chamber 52 is ejected from the opening of the communication passage 46 as shown by the arrow B and propagates toward the wall surface of the cylinder 21 (see FIG. 1).

Specifically, as shown by an arrow B in FIG. 5, the flame generated by the ignition of the sub-spark plug 62 in the sub-chamber 52 is inclined in the circumferential direction with respect to the radial direction toward the wall surface of the cylinder 21 (see FIG. 1). Propagate in the direction of

As described above, in the present embodiment, the main spark plug 61 is arranged in the upper center of the main chamber 51, the sub-chamber 52 is formed in an annular shape around the main spark plug 61, and the sub-spark plug is in the sub-chamber 52. 62 was placed.

As a result, since the main spark plug 61 and the sub-spark plug 62 are arranged close to each other, the interference of the flame can be suppressed and the combustion can be efficiently performed.

Further, in the present embodiment, the internal combustion engine 10 includes a communication passage 46 that connects the sub chamber 52 and the main room 51, and the communication passage 46 is on the wall surface on the main room 51 side in the radial direction toward the wall surface of the cylinder 21. It is open to the air.

As a result, the flame generated by the ignition of the sub-spark plug 62 in the sub-chamber 52 can be injected from the communication passage 46 toward the wall surface of the cylinder 21 of the main chamber 51. Further, the air-fuel mixture directly under the sub chamber 52 can be ignited by the main spark plug 61. Therefore, the flame nucleus at the initial stage of combustion can be enlarged, and the combustion speed can be improved.

Further, in the present embodiment, the communication passage 46 is opened on the wall surface on the main chamber 51 side so as to be inclined in the circumferential direction with respect to the radial direction toward the wall surface of the cylinder 21.

As a result, the flame generated by the ignition of the sub-spark plug 62 in the sub-chamber 52 can be injected from the communication passage 46 toward the wall surface and the circumferential direction of the cylinder 21 of the main chamber 51. Therefore, a swirling flow can be generated in the main chamber 51 during the combustion stroke, and combustion can be efficiently performed.

Further, in the present embodiment, the communication passage 46 is opened on the wall surface on the side of the sub chamber 52 so as to be inclined in the circumferential direction with respect to the radial direction toward the center of the main spark plug 61.

As a result, a swirling flow of the air-fuel mixture can be generated in the sub chamber 52 during the compression stroke. Therefore, it becomes easy to take in the air-fuel mixture into the sub-chamber 52. In addition, the scavenging performance in the sub chamber 52 can be improved.

Further, in the present embodiment, the internal combustion engine 10 includes a sub-chamber member 40 forming the sub-chamber 52, a main spark plug 61 is provided in the center of the sub-chamber member 40, and the periphery of the main spark plug 61 in the sub-chamber member 40. The sub-spark plug 62 is integrally provided in the.

As a result, both the main spark plug 61 and the sub-spark plug 62 can be integrally provided in the sub-chamber member 40, so that it is not necessary to newly add an installation location for the sub-spark plug 62. Manufacturing cost can be reduced.

Further, since both the main spark plug 61 and the sub-spark plug 62 can be replaced by removing the sub-chamber member 40, the replacement work of the main spark plug 61 and the sub-spark plug 62 can be easily performed. Maintainability can be improved.

Further, in this embodiment, the sub-chamber member 40 is provided on the cylinder head 30 constituting the upper surface of the main chamber 51, and the sub-spark plug 62 is attached to the sub-chamber member 40 in parallel with the main spark plug 61. ..

As a result, the sub chamber 52 can be configured by the sub chamber member 40 in a narrow portion sandwiched between the intake valve 36 and the exhaust valve 37 in the cylinder head 30, and both the main spark plug 61 and the sub spark plug 62 can be formed. It can be arranged compactly.

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

10 Internal combustion engine 30 Cylinder head 40 Sub-chamber member 46 Co-passage 50 Combustion chamber 51 Main chamber 52 Sub-chamber 61 Main spark plug 62 Sub-ignition plug

Claims (5)

An internal combustion engine having a combustion chamber consisting of a main chamber in which a main spark plug is arranged and a sub chamber in which a sub-spark plug is arranged.
A cylindrical portion to which the main spark plug is mounted is placed in the upper part of the center of the main chamber.
The sub-chamber is arranged close to the cylindrical portion, and the sub-chamber is arranged.
A communication passage connecting the sub-room and the main room is provided.
The cylindrical portion opens downward and
The internal combustion engine is characterized in that the communication passage is opened in the wall surface on the main chamber side in the radial direction toward the cylinder wall surface. The internal combustion engine according to claim 1, wherein the communication passage is opened on the wall surface on the main chamber side so as to be inclined in the circumferential direction with respect to the radial direction toward the cylinder wall surface. A sub-chamber member forming the sub-chamber is provided.
The cylindrical portion is provided in the center of the sub-chamber member, and the cylinder portion is provided.
The internal combustion engine according to claim 1, wherein the sub-spark plug is integrally provided around the cylindrical portion of the sub-chamber member. The sub chamber member is provided on a cylinder head constituting the upper surface of the main chamber.
The internal combustion engine according to claim 3, wherein the sub-spark plug is attached to the sub-chamber member in parallel with the main spark plug. The sub-chamber is formed in an annular shape around the cylindrical portion.
The internal combustion engine according to claim 3, wherein the communication passage is opened on the wall surface on the side of the sub chamber so as to be inclined in the circumferential direction with respect to the radial direction toward the center of the main spark plug.

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