WO2012008335A1

WO2012008335A1 - Cylinder liner

Info

Publication number: WO2012008335A1
Application number: PCT/JP2011/065368
Authority: WO
Inventors: 剛門脇; 信幸國弘
Original assignee: 三菱重工業株式会社
Priority date: 2010-07-12
Filing date: 2011-07-05
Publication date: 2012-01-19
Also published as: JP2012021406A; CN103003543B; CN103003543A; KR101408624B1; KR20130029780A

Abstract

Provided is a cylinder liner, the weight of which can be reduced by decreasing the thickness. A cylinder liner (10) is provided with a plurality of first cooling bores (15) extending obliquely upward from the outer peripheral surface to the inside of the wall, and a first peripheral groove (16) formed in the center of the top surface in the thickness direction. The outlets of the first cooling bores (15) are provided in the wall surface or the bottom surface defining the first peripheral groove (16).

Description

Cylinder liner

The present invention relates to a cylinder liner applied to an internal combustion engine such as a marine diesel engine.

As a cylinder liner applied to an internal combustion engine such as a marine diesel engine, a cooling hole (hereinafter referred to as “cooling bore”) inclined with respect to a plane perpendicular to the cylinder axis is provided inside (inside the wall). Those are known (for example, see Patent Document 1).

JP-A-5-214933

However, in the cylinder liner disclosed in Patent Document 1, the compressive stress is maximized on the inner peripheral surface and the tensile stress is maximized on the outer peripheral surface, as shown in FIGS. 9 and 10. Further, in the cylinder liner disclosed in Patent Document 1, the thermal stress is increased at the peripheral edge of the outlet (woodhole) of the cooling bore (drill hole: drill hole) located on the uppermost outer peripheral surface. Therefore, in the cylinder liner disclosed in Patent Document 1, it has been difficult to reduce the wall thickness and reduce the weight.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a cylinder liner capable of reducing the thickness and reducing the weight.

The present invention employs the following means in order to solve the above problems.
The cylinder liner according to the first aspect of the present invention includes a plurality of first cooling bores that are opened obliquely upward from the outer peripheral surface toward the inside of the wall, and the first liner is provided at the center of the upper end surface in the thickness direction. In this cylinder liner, the outlet of the first cooling bore is provided on the wall surface or the bottom surface forming the first circumferential groove.

According to the cylinder liner according to the first aspect of the present invention, for example, as shown in FIG. 9, the outlet of the first cooling bore 15 is the central portion in the plate thickness direction, that is, the stress 0 (zero) point ( It is provided in the vicinity (point where neither compressive stress nor tensile stress acts) and in a place (region) where thermal stress smaller than the thermal stress on the outermost peripheral surface acts.
As a result, the thickness can be reduced to reduce the outer diameter, and the weight can be reduced.

The cylinder liner according to the second aspect of the present invention includes a plurality of first cooling bores that are opened obliquely upward from the outer peripheral surface toward the inside of the wall, and the first liner is provided at the center of the upper end surface in the plate thickness direction. A cylinder liner having a circumferential groove having a circular shape in plan view extending from the bottom surface forming the first circumferential groove toward the lower end surface along the cylinder axis from the bottom surface forming the first circumferential groove. It was made to provide in the wall surface or bottom face which forms the communicating hole to exhibit.

According to the cylinder liner according to the second aspect of the present invention, for example, as shown in FIG. 9, the outlet of the first cooling bore 15 is the central portion in the plate thickness direction, that is, the stress 0 (zero) point ( It is provided in the vicinity (point where neither compressive stress nor tensile stress acts) and in a place (region) where thermal stress smaller than the thermal stress on the outermost peripheral surface acts.
As a result, the thickness can be reduced to reduce the outer diameter, and the weight can be reduced.
Further, according to the cylinder liner according to the second aspect of the present invention, the outlet of the first cooling bore has a plan view extending from the bottom surface forming the first circumferential groove toward the lower end surface along the cylinder axis. It will be provided on the wall surface or bottom surface forming the communication hole having a circular shape. That is, the outlet of the first cooling bore is provided in a place (region) where a thermal stress smaller than the thermal stress in the first circumferential groove acts, and the longitudinal axis (center axis) of the first cooling bore As a result, the crossing angle with the plane perpendicular to the cylinder axis increases, and the stress concentration at the outlet of the first cooling bore is alleviated.
Accordingly, the thickness can be further reduced to further reduce the outer diameter, and further weight reduction can be achieved.

The cylinder liner according to the third aspect of the present invention includes a plurality of first cooling bores that are opened obliquely upward from the outer peripheral surface toward the inside of the wall, and the first liner is provided at the center of the upper end surface in the thickness direction. A cylinder liner provided with a circumferential groove, wherein the outlet of the first cooling bore has a substantially elliptical shape in plan view extending from the bottom surface forming the first circumferential groove toward the lower end surface along the cylinder axis. It was made to provide on the wall surface or bottom surface which forms the communication hole which exhibits.

According to the cylinder liner according to the third aspect of the present invention, for example, as shown in FIG. 9, the outlet of the first cooling bore 15 is the central portion in the plate thickness direction, that is, the stress 0 (zero) point ( It is provided in the vicinity (point where neither compressive stress nor tensile stress acts) and in a place (region) where thermal stress smaller than the thermal stress on the outermost peripheral surface acts.
As a result, the thickness can be reduced to reduce the outer diameter, and the weight can be reduced.
Further, according to the cylinder liner according to the third aspect of the present invention, the outlet of the first cooling bore has a plan view extending from the bottom surface forming the first circumferential groove toward the lower end surface along the cylinder axis. It will be provided on the wall surface or bottom surface forming the communication hole having a circular shape. That is, the outlet of the first cooling bore is provided in a place (region) where a thermal stress smaller than the thermal stress in the first circumferential groove acts, and the longitudinal axis (center axis) of the first cooling bore As a result, the crossing angle with the plane perpendicular to the cylinder axis increases, and the stress concentration at the outlet of the first cooling bore is alleviated.
Accordingly, the thickness can be further reduced to further reduce the outer diameter, and further weight reduction can be achieved.
Further, according to the cylinder liner according to the third aspect of the present invention, the communication hole is formed so that the shape in plan view is substantially elliptical, and the stress concentration at the outlet of the first cooling bore is further alleviated. Will be.
As a result, the thickness can be further reduced, the outer diameter can be further reduced, and the weight can be further reduced.

A cooling structure for an internal combustion engine according to a fourth aspect of the present invention includes any one of the above-described cylinder liners and a plurality of second cooling bores that are opened obliquely upward from the lower end surface toward the inside of the wall. A cooling structure for an internal combustion engine comprising a second circumferential groove on an outer peripheral portion in the plate thickness direction, and a cylinder cover disposed on the cylinder liner and closing an opening located above the cylinder liner. The inlet of the second cooling bore is provided on the wall surface or the bottom surface forming the second circumferential groove.

According to the cooling structure for an internal combustion engine according to the fourth aspect of the present invention, the cooling medium (for example, cooling water) flowing into the first circumferential groove from the outlet of the first cooling bore is, for example, in FIG. The second circumferential groove passes through a gap formed between the outer peripheral wall surface (the inner circumferential wall surface that forms the circumferential groove 25) of the convex portion 28 and the outer circumferential wall surface that forms the circumferential groove 16. After flowing into 25, it flows into the second cooling bore 24 from the inlet of the second cooling bore 24.
As a result, it is possible to eliminate the need for the cooling medium connecting hardware conventionally required to guide the cooling medium flowing out from the outlet of the first cooling bore to the inlet of the second cooling bore. It is possible to simplify the configuration of the joint portion (connection portion).
Further, since the cooling medium connection hardware can be eliminated, the outer diameter of the joint portion (connection portion) between the cylinder liner and the cylinder cover can be reduced and the weight can be reduced.

When the cooling structure of the internal combustion engine according to the fourth aspect is put on the cylinder liner, the lower end surface located on the inner peripheral side of the first circumferential groove and the second circumferential groove, A third circumferential groove is provided in the inner circumferential portion in the plate thickness direction, and the combustion gas flowing into the third circumferential groove through the space between the upper end surface of the cylinder liner and the lower end surface of the cylinder cover is It is more preferable that a gas vent passage leading to an opening provided on the outer peripheral surface of the cylinder cover is provided.

According to the cooling structure for an internal combustion engine according to such a configuration, a relief valve that is conventionally required for releasing the gas pressure at the time of abnormal combustion can be eliminated, and the configuration around the cylinder cover can be simplified. be able to.

In the internal combustion engine cooling structure according to the above configuration, it is further preferable that the gas vent passage is provided so as to pass through the vicinity of the second circumferential groove.

According to the cooling structure of the internal combustion engine according to such a configuration, the combustion gas that passes through the gas vent passage is cooled by the cooling medium that passes through the second circumferential groove.
As a result, the temperature of the combustion gas ejected from the opening provided on the outer peripheral surface of the cylinder cover can be reduced, and the safety of workers working around the internal combustion engine (for example, a ship engineer / engineer) is safe. Can be secured.

In the cooling structure for an internal combustion engine according to the above configuration, a cover outer cylinder that fits on an outer peripheral surface of the cylinder cover and forms a gas venting space with the outer peripheral surface of the cylinder cover is provided, and the gas venting space However, it is further preferable that the combustion gas ejected from the outer peripheral surface of the cylinder cover through the gas vent passage is formed to be guided downward along the outer peripheral surface of the cylinder cover.

According to the cooling structure for an internal combustion engine having such a configuration, the combustion gas ejected from the opening provided in the outer peripheral surface of the cylinder cover through the gas vent passage is guided downward along the outer peripheral surface of the cylinder cover. It is like that. That is, the combustion gas ejected from the opening provided on the outer peripheral surface of the cylinder cover is not ejected toward an operator (for example, a ship engineer / engineer) working around the internal combustion engine. Yes.
Thereby, it is possible to further ensure the safety of a worker (for example, a ship engineer / engineer) working around the internal combustion engine.

In the internal combustion engine cooling structure according to the above configuration, when the fourth circumferential groove that accommodates the O-ring along the circumferential direction is provided on the inner circumferential wall surface that forms the first circumferential groove, Engraved into the upper surface of the cylinder liner facing the bottom surface forming the bottom of the third circumferential groove on the inner circumferential side of the fourth circumferential groove along the cylinder axis toward the lower surface of the cylinder liner It is more preferable to provide a thermal dam.

According to the cooling structure for an internal combustion engine having such a configuration, the heat load of the O-ring housed in the fourth circumferential groove is reduced (about 10 ° C. in temperature) by the air layer staying in the thermal dam. It will be.
Thereby, damage to the O-ring due to heat can be prevented, the life of the O-ring can be extended, and the maintenance interval of the O-ring can be extended.

An internal combustion engine according to a fifth aspect of the present invention includes any one of the above-described cylinder liners or any one of the above-described internal combustion engine cooling structures.

According to the internal combustion engine of the fifth aspect of the present invention, the engine is provided with the cylinder liner that can reduce the wall thickness and reduce the outer diameter, and can reduce the weight. The overall size and weight can be reduced.

The cylinder liner according to the present invention has the effect of reducing the wall thickness and reducing the weight.

It is a perspective view of a cylinder liner concerning a 1st embodiment of the present invention. It is sectional drawing of the principal part which shows the cooling structure of the internal combustion engine provided with the cylinder liner which concerns on 1st Embodiment of this invention. It is a figure which expands and shows the principal part of FIG. It is a top view which shows a part of upper surface of the cylinder liner which concerns on 1st Embodiment of this invention. It is a figure which expands and shows the principal part of FIG. It is sectional drawing of the principal part which shows the cooling structure of the internal combustion engine provided with the cylinder liner which concerns on 1st Embodiment of this invention. FIG. 7 is a cross-sectional view taken along arrow VII-VII in FIG. 6. It is a perspective view of the important section showing the cylinder liner concerning a 1st embodiment of the present invention. It is a figure for demonstrating the stress which acts on the exit of the cooling bore which concerns on the past and this invention. It is a figure for demonstrating the stress which acts on the exit of the cooling bore which concerns on the past and this invention. It is sectional drawing of the principal part which shows the cooling structure of the internal combustion engine provided with the cylinder liner which concerns on 2nd Embodiment of this invention. It is a figure which expands and shows the principal part of FIG. It is a top view which shows a part of upper surface of the cylinder liner which concerns on 2nd Embodiment of this invention. It is sectional drawing of the principal part which shows the cooling structure of the internal combustion engine provided with the cylinder liner which concerns on 3rd Embodiment of this invention. It is a figure which expands and shows the principal part of FIG. It is a top view which shows a part of upper surface of the cylinder liner which concerns on 3rd Embodiment of this invention.

[First Embodiment]
Hereinafter, a cylinder liner according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 10.
FIG. 1 is a perspective view of a cylinder liner according to the present embodiment, FIG. 2 is a cross-sectional view of an essential part showing a cooling structure of an internal combustion engine provided with the cylinder liner according to the present embodiment, and FIG. 3 is an enlarged view of the essential part of FIG. FIG. 4 is a plan view showing a part of the upper surface of the cylinder liner according to the present embodiment, FIG. 5 is an enlarged view of the main part of FIG. 2, and FIG. 6 is a cylinder liner according to the present embodiment. FIG. 7 is a cross-sectional view of the main part showing the cooling structure of the internal combustion engine provided with FIG. 7, FIG. 7 is a cross-sectional view taken along the arrow VII-VII in FIG. FIG. 10 and FIG. 10 are views for explaining the stress acting on the outlet of the cooling bore according to the prior art and the present invention, respectively.

The cylinder liner according to the present invention is applied to an internal combustion engine such as a marine diesel engine, and a piston (not shown) is disposed inside the cylinder liner, and the piston slides along an inner peripheral surface thereof. It will be.
2, 3, and 5 to 8, reference numeral 11 denotes a lower water chamber 12 and an upper water chamber 13 that are fitted (attached) to the upper outer peripheral surface of the cylinder liner and between the upper outer peripheral surface of the cylinder liner. Is a liner outer cylinder (water chamber hardware). Each of the lower water chamber 12 and the upper water chamber 13 is a space (water chamber) formed in a ring shape in plan view along the circumferential direction. The lower water chamber 12 is below the upper water chamber 13 and the upper water chamber 13 is It is provided above the lower water chamber 12.

The cylinder liner 10 according to the present embodiment includes a lower cooling bore 14 and an upper cooling bore (first cooling bore) 15.
The lower cooling bore 14 is a straight hole that communicates the lower water chamber 12 and the upper water chamber 13 when the liner outer cylinder 11 is fitted to the upper outer peripheral surface of the cylinder liner 10, and extends along the circumferential direction. A plurality (14 in this embodiment) are provided. The lower cooling bore 14 has an inlet (a throat) provided on the outer peripheral surface of the cylinder liner 10 located on the upper lower side of the cylinder liner 10, and the lower cooling bore 14 has an outlet (a throat) on the upper upper side of the cylinder liner 10. The longitudinal axis (center axis) of the lower cooling bore 14 is inclined with respect to a plane perpendicular to the cylinder axis.

The upper cooling bore 15 is provided in the upper water chamber 13 and the upper surface (top surface) of the cylinder liner 10 when the liner outer cylinder 11 is fitted to the upper outer peripheral surface of the cylinder liner 10 (first) circumference. It is a linear hole that communicates with a groove (a groove that has a ring shape in plan view provided continuously along the circumferential direction), and a plurality of holes (14 in this embodiment) are provided along the circumferential direction. ing. The upper cooling bore 15 has an inlet (a mouth) provided on the outer peripheral surface of the cylinder liner 10 above the cylinder liner 10 and above the outlet of the lower cooling bore 14. (Kiguchi) is provided on the bottom surface of the circumferential groove 16 that forms the bottom of the circumferential groove 16, and the longitudinal axis (center axis) of the upper cooling bore 15 is inclined with respect to a plane perpendicular to the cylinder axis.

As shown in FIGS. 2, 3, 5, 6, and 9, the circumferential groove 16 has a U-shaped cross-sectional view, and the lower surface of the cylinder liner 10 along the cylinder axis from the upper surface of the cylinder liner 10 ( The groove is carved toward (the bottom surface), and as shown in FIG. 9 and FIG. 10, near the stress 0 (zero) point (point where neither compressive stress nor tensile stress acts) and stress It is provided on the inner periphery side from the 0 point.
As shown in FIGS. 1 to 3, 5, and 6, a circumferential groove 17 that houses an O-ring (not shown) is provided along the circumferential direction on the upper outer circumferential surface of the cylinder liner 10. Yes. As shown in FIGS. 2, 3, 5, and 6, an O-ring (not shown) is accommodated along the circumferential direction on the inner peripheral wall surface forming the circumferential groove 16 (fourth). ) Circumferential groove 18 is provided.

As shown in FIGS. 2, 3, 5, and 6, a cylinder cover 20 is disposed on the cylinder liner 10 so that an opening located above the cylinder liner 10 is closed (sealed). It has become.
2, 3, and 5, reference numeral 21 denotes a cover outer cylinder (water chamber) that fits (attaches) to the outer peripheral surface of the cylinder cover 20 and forms a water chamber 22 between the outer peripheral surface of the cylinder cover 20. Hardware). The water chamber 22 is a space formed in an annular shape in plan view along the circumferential direction, and is provided at a central portion in the axial direction (length direction) of the cylinder cover 20.

The cylinder cover 20 includes an upper cooling bore 23 and a lower cooling bore (second cooling bore) 24.
The upper cooling bore 23 is a linear hole that communicates the water chamber 22 and the upper (top) center portion of the cylinder cover 20 when the cover outer cylinder 21 is fitted to the outer peripheral surface of the cylinder cover 20. A plurality (ten in this embodiment) are provided along the circumferential direction. The upper cooling bore 23 has an inlet (a throat) provided on the upper (ceiling side) wall surface forming the water chamber 22, and the longitudinal axis (center axis) of the upper cooling bore 23 is a plane perpendicular to the cylinder axis. Leaning against.

The lower cooling bore 24 includes a (second) circumferential groove 25 provided on the lower surface (bottom surface) of the cylinder cover 20 when the cover outer cylinder 21 is fitted to the outer peripheral surface of the cylinder cover 20, A plurality of (in this embodiment, 10) linear holes are provided along the circumferential direction. The lower cooling bore 24 has an inlet (a throat) provided on the bottom surface of the circumferential groove 25 that forms the bottom of the circumferential groove 25, and an outlet (a throat) of the lower cooling bore 24 that is formed on the lower side (the water chamber 22). The longitudinal axis (center axis) of the lower cooling bore 24 is inclined with respect to a plane perpendicular to the cylinder axis.

As shown in FIGS. 2, 3, 5, and 6, the circumferential groove 25 has a U-shape in cross section, and the upper surface (top surface) of the cylinder cover 20 extends from the lower surface of the cylinder cover 20 along the cylinder axis. And is provided so as to be located outside the circumferential groove 16 when it is put on the cylinder liner 10.
In addition, a circumferential groove 26 that accommodates an O-ring (not shown) is provided on the outer peripheral surface of the cylinder cover 20 along the circumferential direction. In addition, a (third) circumferential groove 27 having a U-shape in sectional view is provided on the inner circumferential side of the circumferential groove 25 along the circumferential direction.

The inner circumferential wall surface that forms the circumferential groove 25, the lower surface of the cylinder cover 20 that continues to the wall surface, and the outer circumferential wall surface that continuously forms the circumferential groove 27 on the lower surface fit into the circumferential groove 16. A convex portion 28 is formed. The convex portion 28 has a predetermined gap (for example, 3 mm) between the outer peripheral wall surface (the inner peripheral wall surface that forms the circumferential groove 25) and the outer peripheral wall surface that forms the circumferential groove 16. A predetermined gap is formed between the lower surface (the lower surface of the cylinder cover 20) and the bottom surface forming the bottom of the circumferential groove 16, and the inner circumferential wall surface (the outer circumferential wall surface forming the circumferential groove 27). ) And the outer peripheral wall surface forming the circumferential groove 16 so as to form a predetermined gap (for example, 0.25 mm) and project downward along the cylinder axis. *

Further, a convex portion 29 that fits into the circumferential groove 25 is formed by a wall surface on the outer peripheral side that forms the circumferential groove 16, an upper surface of the cylinder liner 10 that is continuous with the wall surface, and an outer peripheral surface of the cylinder liner 10 that is continuous with the upper surface. Is formed. The protrusion 29 has a predetermined gap (for example, 3 mm) between the inner peripheral wall surface (the outer peripheral wall surface that forms the peripheral groove 16) and the inner peripheral wall surface that forms the peripheral groove 25. A predetermined gap is formed between the upper surface (the upper surface of the cylinder liner 10) and the bottom surface forming the bottom of the circumferential groove 25, and the outer peripheral wall surface (the outer peripheral surface of the cylinder liner 10) A predetermined gap (for example, 0.45 mm) is formed between the outer peripheral wall surface forming the groove 25 and protrudes upward along the cylinder axis.

As shown in FIGS. 2, 3, and 5, a gas releasing space 30 is provided along the circumferential direction on the inner peripheral side of the lower end portion of the cover outer cylinder 21. The space 30 and the circumferential groove 27 are communicated with each other through a gas vent passage 31.
The gas vent passages 31 are provided radially from the center of the cylinder cover 20 toward the outer peripheral surface at regular intervals (in the present embodiment, 45 ° intervals), and open to the bottom surface forming the bottom of the circumferential groove 27. A first passage 32 extending in the cylinder cover 20 along the cylinder axis toward the upper surface of the cylinder cover 20 and an upper end portion of the first passage 32 and an outer peripheral surface of the cylinder cover 20 are opened. A second passage 33 extending in the cylinder cover 20 along a direction orthogonal to the cylinder axis is provided.

As shown in FIGS. 6 to 8, a pipe joint 35 for connecting a cooling water supply pipe 34 (see FIGS. 6 and 7) is connected to a lower end portion of the liner outer cylinder 11 via a flange 36 and a bolt 37. Connected (attached).
The pipe joints 35 are provided radially from the center of the cylinder cover 20 toward the outer peripheral surface and at equal intervals (in the present embodiment, at intervals of 90 degrees), and one end of the pipe joint 35 is provided at the liner outer cylinder 11. The lower water chamber 12 is inserted into the lower water chamber 12 through a through-hole 38 that is formed at the lower end portion thereof and penetrates in the plate thickness direction. An opening 39 having a rectangular shape in front view (see FIG. 6) opening toward the lower water chamber 12 is provided on both side surfaces of one end of the pipe joint 35, and the cooling water supply pipe 34 and the pipe joint 35 are connected to each other. The cooling water supplied through the cylinder 39 is supplied in the circumferential direction along the outer peripheral surface of the cylinder liner 10 through the opening 39.
Note that one end (tip) side of the pipe joint 35 is closed, and cooling water flows out only from the opening 39. The cooling water supply pipe 34 and the pipe joint 35 are formed by a flange 40 provided at one end of the cooling water supply pipe 34, a flange 41 provided at the other end of the pipe joint 35, a bolt 42, and a nut 43. It is connected.

On the other hand, as shown in FIGS. 2, 3, 5, and 6, a thermal dam 44 is provided on the upper surface of the cylinder liner 10 that faces the bottom surface that forms the bottom of the circumferential groove 27. The thermal dam 44 has a U-shape in cross section, and has a circumferential groove (for example, a width of 11 mm, a depth) carved from the upper surface of the cylinder liner 10 toward the lower surface of the cylinder liner 10 along the cylinder axis. 26 mm U-shaped groove).

According to the cylinder liner 10 according to the present embodiment, for example, as shown in FIG. 9, the outlet of the first cooling bore 15 is the central portion in the plate thickness direction, that is, the stress 0 (zero) point (the compressive stress is also It is provided in the vicinity (point where no tensile stress acts) and in a place (region) where thermal stress smaller than the thermal stress on the outermost peripheral surface acts.
As a result, the thickness can be reduced to reduce the outer diameter, and the weight can be reduced.

According to the cooling structure of the internal combustion engine including the cylinder liner 10 and the cylinder cover 20 according to the present embodiment, the cooling water flowing into the circumferential groove 16 from the outlet of the upper cooling bore 15 is the outer periphery of the convex portion 28. After flowing into the circumferential groove 25 through a gap formed between the side wall surface (the inner circumferential wall surface forming the circumferential groove 25) and the outer circumferential wall surface forming the circumferential groove 16, the lower cooling The air flows into the lower cooling bore 24 from the inlet of the bore 24.
As a result, it is possible to eliminate the need for the cooling medium communication hardware conventionally required to guide the cooling water flowing out from the outlet of the upper cooling bore 15 to the inlet of the lower cooling bore 24, and the cylinder liner 10, the cylinder cover 20, It is possible to simplify the configuration of the joint portion (connection portion).
Further, since the cooling medium communication hardware can be eliminated, the outer diameter of the joint portion (connection portion) between the cylinder liner 10 and the cylinder cover 20 can be reduced, and the weight can be reduced. .

Further, according to the cooling structure for an internal combustion engine including the cylinder liner 10 and the cylinder cover 20 according to the present embodiment, the inner circumferences of the circumferential groove 16 and the circumferential groove 25 when covered on the cylinder liner 10. A circumferential groove 27 is provided in the inner circumferential portion in the plate thickness direction of the lower end surface of the cylinder cover 20 positioned on the side, and flows into the circumferential groove 27 through between the upper end surface of the cylinder liner 10 and the lower end surface of the cylinder cover 20. Since a gas vent passage 31 is provided to guide the combustion gas to an opening (exit of the second passage 33) provided on the outer peripheral surface of the cylinder cover 20, it is conventionally required to release the gas pressure during abnormal combustion. A relief valve can be eliminated, and the configuration around the cylinder cover 20 can be simplified.

Further, according to the cooling structure of the internal combustion engine including the cylinder liner 10 and the cylinder cover 20 according to the present embodiment, the gas vent passage 31 is provided so as to pass in the vicinity of the circumferential groove 25, The combustion gas passing through the gas vent passage 31 is cooled by the cooling water passing through the circumferential groove 25.
Thereby, the temperature of the combustion gas which ejects from the opening provided in the outer peripheral surface of the cylinder cover 20 can be reduced, and a worker (for example, a ship engineer / engineer) working around the internal combustion engine Safety can be ensured.

Furthermore, according to the cooling structure for an internal combustion engine including the cylinder liner 10 and the cylinder cover 20 according to the present embodiment, a gas is fitted between the outer peripheral surface of the cylinder cover 20 and between the outer peripheral surface of the cylinder cover 20. A cover outer cylinder 21 that forms a venting space 30 is provided. Combustion gas ejected from the outer peripheral surface of the cylinder cover 20 through the gas venting passage 31 through the venting passage 31 to the outer peripheral surface of the cylinder cover 20. The combustion gas ejected from the opening provided in the outer peripheral surface of the cylinder cover 20 through the gas vent passage 31 is guided downward along the outer peripheral surface of the cylinder cover 20. It is like that. That is, the combustion gas ejected from the opening provided on the outer peripheral surface of the cylinder cover 20 is not ejected toward an operator (for example, a ship engineer / engineer) working around the internal combustion engine. ing.
Thereby, it is possible to further ensure the safety of a worker (for example, a ship engineer / engineer) working around the internal combustion engine.

Furthermore, according to the cooling structure of the internal combustion engine including the cylinder liner 10 and the cylinder cover 20 according to the present embodiment, the O-ring is provided along the circumferential direction on the inner peripheral wall surface forming the peripheral groove 16. Is provided on the inner circumferential side of the circumferential groove 18 and on the upper surface of the cylinder liner 10 facing the bottom surface forming the bottom of the circumferential groove 27 along the cylinder axis. The thermal dam 44 carved toward the lower surface of the liner 10 is provided, and the heat load of the O-ring accommodated in the circumferential groove 18 is reduced (about 10 ° C. in temperature) by the air layer staying in the thermal dam 44. Will be.
Thereby, damage to the O-ring due to heat can be prevented, the life of the O-ring can be extended, and the maintenance interval of the O-ring can be extended.

According to the cylinder liner 10 according to the present embodiment or the internal combustion engine cooling structure according to the present embodiment, the thickness can be reduced to reduce the outer diameter, and the weight can be reduced. Therefore, the entire engine can be reduced in size and weight.

[Second Embodiment]
A cylinder liner according to a second embodiment of the present invention will be described with reference to FIGS. 11 is a cross-sectional view of a main part showing a cooling structure of an internal combustion engine provided with a cylinder liner according to the present embodiment, FIG. 12 is an enlarged view of the main part of FIG. 11, and FIG. 13 is a cylinder according to the present embodiment. It is a top view which shows a part of upper surface of a liner.
As shown in FIGS. 11 to 13, the cylinder liner 50 according to this embodiment is the first embodiment described above in that a communication hole (drill hole: drill hole) 51 is provided below the circumferential groove 16. Different from that. Since other components are the same as those of the first embodiment described above, description of these components is omitted here.
In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment mentioned above.

The communication hole 51 is a hole (for example, a hole having a diameter of 26 mm and a depth of 50 mm) having a circular shape in plan view extending from the bottom surface forming the bottom of the circumferential groove 16 toward the lower surface of the cylinder liner 50 along the cylinder axis. A plurality (14 in this embodiment) are provided along the circumferential direction. Further, the wall surface (inner peripheral surface) forming the communication hole 51 is provided with an outlet (a throat) of the upper cooling bore 15, and the cooling water flowing out from the outlet of the upper cooling bore 15 passes through the communication hole 51. Then, it flows into the circumferential groove 16.

According to the cylinder liner 50 according to the present embodiment, the outlet of the upper cooling bore 15 has the communication hole 51 having a circular shape in plan view extending from the bottom surface forming the circumferential groove 16 along the cylinder axis toward the lower end surface thereof. It will be provided on the wall surface to be formed. That is, the outlet of the upper cooling bore 15 is provided in a place (region) where a thermal stress smaller than the thermal stress in the circumferential groove 16 acts, and the longitudinal axis (center axis) of the upper cooling bore 15 and the cylinder axis As a result, the crossing angle with the plane perpendicular to the angle increases, and the stress concentration at the outlet of the upper cooling bore 15 is relaxed.
Accordingly, the thickness can be further reduced to further reduce the outer diameter, and further weight reduction can be achieved.
Other functions and effects are the same as those of the above-described first embodiment, and thus description thereof is omitted here.

[Third Embodiment]
A cylinder liner according to a third embodiment of the present invention will be described with reference to FIGS. 14 is a cross-sectional view of a main part showing a cooling structure of an internal combustion engine provided with a cylinder liner according to the present embodiment, FIG. 15 is an enlarged view of the main part of FIG. 14, and FIG. 16 is a cylinder according to this embodiment. It is a top view which shows a part of upper surface of a liner.
As shown in FIGS. 14 to 16, the cylinder liner 60 according to this embodiment is the second embodiment described above in that a communication hole (drill hole: drill hole) 61 is provided instead of the communication hole 51. Different from that. Since other components are the same as those of the second embodiment described above, description of these components is omitted here.
In addition, the same code | symbol is attached | subjected to the member same as embodiment mentioned above.

The communication hole 61 is a hole (for example, having a diameter of 26 mm, a depth of 26 mm in diameter) extending from the bottom surface forming the bottom of the circumferential groove 16 toward the lower surface of the cylinder liner 60 along the cylinder axis. A plurality of holes (14 holes in the present embodiment) are provided along the circumferential direction. Further, the wall surface (inner peripheral surface) forming the communication hole 61 is provided with an outlet (a throat) of the upper cooling bore 15, and the cooling water flowing out from the outlet of the upper cooling bore 15 passes through the communication hole 61. Then, it flows into the circumferential groove 16. Furthermore, the bottom surface that forms the bottom of the communication hole 61 is formed to have a hemispherical shape in cross section.

According to the cylinder liner 60 according to the present embodiment, the communication hole 61 is formed so that the shape in plan view is substantially elliptical, and the stress concentration at the outlet of the upper cooling bore 15 is further alleviated.
As a result, the thickness can be further reduced, the outer diameter can be further reduced, and the weight can be further reduced.
Other functions and effects are the same as those of the above-described second embodiment, and thus description thereof is omitted here.

The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the gist of the present invention.
For example, in the second embodiment and the third embodiment described above, the outlet of the upper cooling bore 15 is formed on the wall surface (inner peripheral surface) of the communication holes 51 and 61, but the outlet of the upper cooling bore 15 is You may make it form in the bottom face of the communicating

holes

51 and 61. FIG.

10 Cylinder liner 15 Upper cooling bore (first cooling bore)
16 (first) circumferential groove 18 (fourth) circumferential groove 20 cylinder cover 21 cover outer cylinder 24 lower cooling bore (second cooling bore)
25 (second) circumferential groove 27 (third) circumferential groove 30 Degassing space 31 Degassing passage 44 Thermal dam 50 Cylinder liner 51 Communication hole 60 Cylinder liner 61 Communication hole

Claims

A cylinder liner provided with a plurality of first cooling bores that are opened obliquely upward from the outer peripheral surface toward the inside of the wall, and provided with a first peripheral groove at the center of the upper end surface in the thickness direction,
A cylinder liner in which an outlet of the first cooling bore is provided on a wall surface or a bottom surface forming the first circumferential groove.
A cylinder liner provided with a plurality of first cooling bores that are opened obliquely upward from the outer peripheral surface toward the inside of the wall, and provided with a first peripheral groove at the center of the upper end surface in the thickness direction,
The outlet of the first cooling bore is provided on the wall surface or bottom surface forming a communication hole having a circular shape in plan view extending from the bottom surface forming the first circumferential groove toward the lower end surface along the cylinder axis. Cylinder liner.
A cylinder liner provided with a plurality of first cooling bores that are opened obliquely upward from the outer peripheral surface toward the inside of the wall, and provided with a first peripheral groove at the center of the upper end surface in the thickness direction,
The outlet of the first cooling bore is provided on a wall surface or bottom surface forming a communication hole having a substantially elliptical shape in plan view extending from the bottom surface forming the first circumferential groove toward the lower end surface along the cylinder axis. Cylinder liner.
Cylinder liner according to any one of claims 1 to 3,
Provided with a plurality of second cooling bores obliquely upward from the lower end surface toward the inside of the wall, provided with a second circumferential groove in the outer peripheral portion of the lower end surface in the plate thickness direction, and on the cylinder liner A cooling structure for an internal combustion engine comprising a cylinder cover disposed and closing an opening located above the cylinder liner,
A cooling structure for an internal combustion engine, wherein an inlet of the second cooling bore is provided on a wall surface or a bottom surface forming the second circumferential groove.
When covering the cylinder liner, a third circumferential groove is formed on the inner circumferential portion in the plate thickness direction of the lower end surface located on the inner circumferential side of the first circumferential groove and the second circumferential groove. A gas vent that guides the combustion gas that has flowed into the third circumferential groove through the gap between the upper end surface of the cylinder liner and the lower end surface of the cylinder cover to an opening provided in the outer peripheral surface of the cylinder cover. The cooling structure for an internal combustion engine according to claim 4, wherein a passage is provided.
The cooling structure for an internal combustion engine according to claim 5, wherein the gas vent passage is provided so as to pass through the vicinity of the second circumferential groove.
A cover outer cylinder that fits on an outer peripheral surface of the cylinder cover and forms a gas venting space between the cylinder cover and the outer peripheral surface of the cylinder cover, the gas venting space passing through the gas vent passage and the cylinder; The cooling structure for an internal combustion engine according to claim 5 or 6, wherein the combustion gas ejected from the outer peripheral surface of the cover is formed so as to guide downward along the outer peripheral surface of the cylinder cover.
On the inner peripheral side of the fourth peripheral groove, the inner peripheral wall surface that forms the first peripheral groove is provided with a fourth peripheral groove that accommodates the O-ring along the circumferential direction. 6. A thermal dam engraved toward the lower surface of the cylinder liner along the cylinder axis is provided on the upper surface of the cylinder liner facing the bottom surface forming the bottom of the third circumferential groove. The cooling structure for an internal combustion engine according to any one of claims 1 to 7.
An internal combustion engine comprising the cylinder liner according to any one of claims 1 to 3 or the cooling structure for the internal combustion engine according to any one of claims 4 to 8.