Internal combustion engine

Abstract

To provide an internal combustion engine that includes a shroud part of which shape has degrees of freedom.SOLUTION: An internal combustion engine includes: a cylinder head including a suction port; a cylinder block including a cylinder; and a plate disposed between the cylinder head and the cylinder block. The plate includes a shroud part disposed around an opening of the suction port.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an internal combustion engine.

Background Art

[0002] Conventionally, an internal combustion engine provided with a shroud portion in a combustion chamber of an internal combustion engine is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 discloses an internal combustion engine provided with a shroud in a gasoline engine. The shroud of Patent Document 1 is provided on a cylinder head of a pentroof-type combustion chamber. When a shroud is provided on the cylinder head, the shape of the shroud is restricted in consideration of the influence of die cutting and the like.

[0005] The present disclosure aims to provide an internal combustion engine provided with a shroud portion having a high degree of freedom in shape.

Means for Solving the Problems

[0006] ' The internal combustion engine according to the present disclosure includes a cylinder head having an intake port, a cylinder block having a cylinder, and a plate disposed between the cylinder head and the cylinder block, and the plate has a shroud portion disposed around an opening of the intake port.

[0007] In this internal combustion engine, the shroud is formed on a separate plate from the cylinder head. This allows the shroud to be formed without considering the effects of molding, etc., which increases the degree of freedom in the shape of the shroud. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide an internal combustion engine equipped with a shroud section that has a degree of freedom in shape. [Brief explanation of the drawing]

[0009] [Figure 1] A cross-sectional view of an internal combustion engine according to an embodiment of the present disclosure. [Figure 2] A top view of a chamber plate according to an embodiment of the present disclosure. [Figure 3] Cross-sectional view AA in Figure 2. [Figure 4] Cross-sectional view of BB in Figure 2. [Modes for carrying out the invention]

[0010] Hereinafter, one embodiment of this disclosure will be described with reference to the drawings.

[0011] As shown in Figures 1 and 2, the internal combustion engine 1 comprises a cylinder block 2, a cylinder head 4, a piston 6, a chamber plate (an example of a plate) 8, a cylinder head gasket 10, a fuel injector 12, a tangential port 14, a helical port 16, an intake valve 18, and an exhaust valve 20.

[0012] The cylinder block 2 has a cylinder 21. The cylinder head 4 is fixed above the cylinder block 2, sandwiching the cylinder head gasket 10 and the chamber plate 8. The piston 6 is housed in the cylinder 21 and slides up and down within the cylinder 21.

[0013] The internal combustion engine 1 of this embodiment is a diesel engine that injects fuel directly into the space within the cylinder 21. Furthermore, the internal combustion engine 1 of this embodiment will be described using an example in which the cylinder 21 is arranged vertically.Therefore, the upper side of the internal combustion engine 1 will be indicated as "up," the lower side as "down," the front side as "front," the rear side as "rear," the left side as "left," and the right side as "right" in the drawings.

[0014] The cylinder head 4 is equipped with a fuel injection valve 12, an intake valve 18, and an exhaust valve 20, among other components. As shown in Figure 2, in this embodiment, a first intake valve 18a, a second intake valve 18b, and two exhaust valves 20 are arranged in one cylinder.

[0015] A tangential port (an example of a first port) 14 supplies intake air to the inside of the cylinder 21. The tangential port 14 generates a swirl flow inside the cylinder 21. As shown in Figure 2, the swirl flow in this embodiment is a counterclockwise transverse vortex flowing from the tangential port 14 toward the exhaust valve 20. As shown in Figure 2, a first intake valve 18a is positioned in the tangential port 14. The tangential port 14 is connected to the inside of the cylinder 21 via an opening 14a. The umbrella portion of the first intake valve 18a is housed in the opening 14a. The opening 14a is opened and closed by the first intake valve 18a.

[0016] As shown in Figure 1, the helical port (an example of a second port) 16 is an intake port positioned alongside the tangential port 14 in the front-rear direction. The helical port 16 generates a flow within the cylinder 21 that is different from the swirl flow generated by the tangential port 14. In this embodiment, the helical port 16 generates a helical flow that flows spirally downwards inside the cylinder 21. As shown in Figure 2, a second intake valve 18b is positioned in the helical port 16. The helical port 16 is connected to the inside of the cylinder 21 via an opening 16a. The umbrella portion of the second intake valve 18b is housed in the opening 16a. The opening 16a is opened and closed by the second intake valve 18b.

[0017] As shown in Figure 1, the chamber plate 8 is positioned between the cylinder block 2 and the cylinder head 4. In other words, the chamber plate 8 is formed on the upper side inside the cylinder 21. The chamber plate 8 is a metal plate-like member such as stainless steel. A highly insulating cylinder head gasket 10 is positioned between the chamber plate 8 and the cylinder block 2. Another highly insulating cylinder head gasket 10 is positioned between the chamber plate 8 and the cylinder head 4. The cylinder head gaskets 10 are gaskets with low thermal conductivity, such as graphite, mica, a metal gasket coated with resin, or a resin gasket. These sandwich the chamber plate 8, allowing it to maintain a high temperature. As a result, the cooling loss of the internal combustion engine 1 can be reduced.

[0018] As shown in Figure 2, the chamber plate 8 has a shroud portion 8a. The shroud portion 8a is positioned around the opening 14a of the tangential port 14. More specifically, the shroud portion is positioned between the opening 14a of the tangential port 14 and the opening 16a of the helical port 16.

[0019] The shroud portion 8a includes a first wall surface 8b and a second wall surface 8c. The first wall surface 8b is formed along the right side and rear side of the opening 14a of the tangential port 14. Specifically, the first wall surface 8b extends from a point X1 located to the right of the opening 14a of the tangential port 14 to the left side along the opening 14a, and merges with the second wall surface 8c at a junction X on the right rear side of the opening 14a.

[0020] As shown in FIG. 3, the first wall surface 8b extends from the upper surface 8d to the lower surface 8e of the chamber plate 8. The lower surface of the chamber plate 8 is positioned at substantially the same height in the vertical direction as the lower surface 18c at the maximum lift position of the first intake valve 18a. Therefore, the first wall surface 8b extends to the lower surface 18c of the first intake valve 18a at the maximum lift position of the first intake valve 18a. Further, in the present embodiment, the first wall surface 8b bulges so that the space on the lower surface 8e side expands to the right side more than the upper surface 8d side. As shown in FIG. 2, the first wall surface 8b suppresses the intake air flowing from the tangential port 14 from flowing to the right rear side of the first intake valve 18a, and suppresses the swirling flow formed in the tangential port 14 from being disturbed.

[0021] The second wall surface 8c extends from a point X2, which is located at a position spaced apart from the opening 16a of the helical port 16 to the right front side (as viewed from the direction in which the cylinder 21 extends) in a top view, toward the central axis Vc of the first intake valve 18a. The second wall surface 8c joins the first wall surface 8b at a joining point X on the right rear side of the opening 14a. The second wall surface 8c is inclined more gently than the first wall surface 8b in a top view. More specifically, the inclination of the second wall surface 8c from the point X2 of the chamber plate 8 to the joining point X of the first wall surface 8b and the second wall surface 8c is gentler than the inclination of the first wall surface 8b from the point X1 of the chamber plate 8 to the joining point X of the first wall surface 8b and the second wall surface 8c.

[0022] As shown in FIG. 4, the second wall surface 8c extends from the upper surface 8d to the lower surface 8e of the chamber plate 8. A groove 8f having a U-shaped cross section or a semi-circular cross section recessed to the right side is formed in the second wall surface 8c. In the present embodiment, the groove 8f is provided on the entire surface of the second wall surface 8c.

[0023] As shown in FIG. 2, the second wall surface 8c provided on the chamber plate 8 formed on the upper side inside the cylinder 21 guides the swirling flow that swirls up to the vicinity of the second intake valve 18b toward the first intake valve 18a. Thereby, it is possible to prevent the helical flow and the swirling flow formed by the helical port 16 from interfering with each other and being disturbed, and to allow the swirling flow to flow smoothly.

[0024] Furthermore, the second wall surface 8c has a groove with a U-shaped or semicircular cross-section. As a result, the swirl flow is guided along the groove toward the first intake valve 18a without escaping downwards.

[0025] In conventional internal combustion engines equipped with a shroud on the cylinder head, it has been difficult to form grooves 8f with a U-shaped or semicircular cross-section, such as the second wall surface 8c. Specifically, in order to manufacture a shroud on the cylinder head, it is necessary to create a shape that can be molded downwards. However, the shroud portion 8a of this disclosure is provided on the chamber plate 8. This eliminates the need to consider the above-mentioned mold-making process. Therefore, there is more freedom in the shape of the shroud portion 8a. As a result, the cross-sectional shape of the second wall surface 8c can be realized.

[0026] As described above, this disclosure provides an internal combustion engine 1 equipped with a shroud portion 8a that has a degree of freedom in shape.

[0027] <Other Embodiments> Although this embodiment has been described above, this disclosure is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention. In particular, the various modifications described herein can be combined as needed.

[0028] (a) In the above embodiment, the internal combustion engine 1 was described using an example in which the cylinders 21 are arranged in the vertical direction, but the disclosure is not limited thereto. The internal combustion engine 1 may have the cylinders 21 arranged at an inclination with respect to the vertical direction. The internal combustion engine 1 may also have the cylinders 21 arranged horizontally.

[0029] (b) In the above embodiments, the chamber plate 8 was described using a metal plate-like member such as stainless steel as an example, but the disclosure is not limited thereto. The chamber plate 8 may be a plate-like member of a material other than metal, such as ceramics or resin. [Explanation of symbols]

[0030] 1: Internal combustion engine, 2: Cylinder block, 4: Cylinder head 8: Chamber Plate 8a: Shroud section, 8b: First wall surface, 8c: Second wall surface 14: Tangential port, 14a: Opening 16: Helical port, 16a: Opening 18: Intake valve, 18a: First intake valve

Claims

1. A cylinder head having an intake port, A cylinder block having a cylinder, A plate positioned between the cylinder head and the cylinder block, Equipped with, The plate has a shroud portion positioned around the opening of the intake port, The intake port has a first port that generates a swirl flow inside the cylinder, and a second port that generates a vortex flow different from the swirl flow. The shroud portion is positioned between the opening of the first port and the opening of the second port. Internal combustion engine.

2. The shroud portion includes a first wall surface formed along the opening of the first port, The internal combustion engine according to claim 1.

3. The shroud portion extends from a position spaced apart from the opening of the second port and includes a second wall surface that merges with the first wall surface. The second wall surface is inclined more gently than the first wall surface when viewed from the direction in which the cylinder extends. The internal combustion engine according to claim 2.

4. The first port is further equipped with an intake valve, The second wall surface extends toward the central axis of the intake valve when viewed from the direction in which the cylinder extends. The internal combustion engine according to claim 3.

5. The first port is further equipped with an intake valve, The first wall surface extends to the lift position of the intake valve. An internal combustion engine according to any one of claims 2 to 4.

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