JP5721595B2 - Internal combustion engine cooling structure - Google Patents

Description

  The present invention relates to a cooling structure for an internal combustion engine applied to an internal combustion engine such as a marine diesel engine.

  As a cooling structure of an internal combustion engine applied to an internal combustion engine such as a marine diesel engine, a cooling hole (hereinafter referred to as a “boiling hole”) inclined inside a wall perpendicular to a plane perpendicular to the cylinder axis. ) Is 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 FIG. Further, in the cylinder liner disclosed in Patent Document 1, the stress is increased due to the stress concentration at the outlet (woodhole) of the bore ring hole (drilled hole: drilled 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 of the present invention is to provide a cooling structure for an internal combustion engine that can reduce the thickness of the cylinder liner and reduce the weight.

The present invention employs the following means in order to solve the above problems.
A cooling structure for an internal combustion engine according to an aspect of the present invention includes a cylinder liner that is continuous along the circumferential direction and includes a circumferential groove that is carved inward in the radial direction from the outer peripheral surface at one end. A first cooling water passage which is fitted to the outer peripheral surface of the one end portion and is formed along the circumferential direction is formed between the outer peripheral surface of the cylinder liner which forms the peripheral groove, and the cylinder during operation of the internal combustion engine. A cooling structure for an internal combustion engine comprising: a ring-shaped reinforcing metal that suppresses the outward expansion of the liner in the radial direction, wherein a cooling water hole that guides cooling water to the first cooling water passage includes the reinforcing metal Has been drilled.

According to the cooling structure for an internal combustion engine according to one aspect of the present invention, the cylinder liner is formed with a circumferential groove for cooling instead of the conventionally used bore ring hole, and is drilled in the reinforcing hardware. The cooling water guided through the cooling water hole is jetted into the circumferential groove from the outlet of the cooling water hole and collides with the outer peripheral surface of the cylinder liner forming the circumferential groove, so that the cylinder liner is cooled. .
This eliminates (eliminates) the conventionally used borehole hole and eliminates stress concentration at the exit of the borehole hole. As a result, the thickness of the cylinder liner can be reduced to reduce the weight.
Further, according to the cooling structure for an internal combustion engine according to the present invention, the outward expansion of the cylinder liner in the radial direction during operation of the internal combustion engine is suppressed (restrained) by the reinforcing hardware.
Thereby, the thickness of the cylinder liner can be further reduced, and the outer diameter of the cylinder liner, the cylinder cover, and the reinforcing hardware can be further reduced and reduced in weight.

In the cooling structure of the internal combustion engine, wherein the first coolant holes are drilled in a straight line from the lower end surface of the reinforcing hardware toward the inner circumferential surface located in the lower half of the reinforcing hardware, the A second cooling water hole for guiding the cooling water discharged from the first cooling water passage is formed in a straight line from the upper end surface of the reinforcing metal piece toward the inner peripheral surface located in the upper half of the reinforcing metal object. Has been.

  According to such a cooling structure for an internal combustion engine, the reinforcement hardware is directed from the lower end surface of the reinforcement hardware toward the inner peripheral surface located in the lower half of the reinforcement hardware or from the inner peripheral surface located in the lower half of the reinforcement hardware. The cooling water hole can be easily processed into a reinforcing metal piece simply by rotating the drill toward the lower end surface of the steel plate.

According to the cooling structure for an internal combustion engine according to another aspect of the present invention, a cylinder liner that includes a circumferential groove that is continuous in the circumferential direction and is carved inward in the radial direction from the outer peripheral surface of the one end. A first cooling water passage is formed along the circumferential direction between the outer circumferential surface of the cylinder liner that fits on the outer circumferential surface of the cylinder liner and forms the circumferential groove. An internal combustion engine cooling structure that suppresses expansion of the cylinder liner radially outward , wherein the first cooling water hole is located above the lower end surface of the reinforcement hardware. A second pipe that extends toward the end face, opens in the lower end face of the reinforcing metal piece, and is closed in the upper half of the reinforcing metal piece , and guides the cooling water to the first cooling water passage. Cold Water holes, said being drilled in a straight line toward the first plurality of locations of the inner peripheral surface of the reinforcing hardware from multiple locations of the cooling water holes, the cooling water discharged from the first cooling water passage A third cooling water hole is formed in a straight line from the upper end surface of the reinforcement hardware toward the inner peripheral surface located in the upper half of the reinforcement hardware .

  According to such a cooling structure for an internal combustion engine, the first cooling water hole can be easily machined into the reinforcing hardware simply by rotating the drill from the lower end surface to the upper end surface of the reinforcing hardware. The second cooling water hole can be easily processed into the reinforcing hardware simply by rotating the drill from the inner peripheral surface of the reinforcing hardware toward the first cooling water hole.

  An internal combustion engine according to the present invention includes any one of the cooling structures for an internal combustion engine.

  With the internal combustion engine according to the present invention, the entire engine can be reduced in size and weight.

  According to the present invention, there is an effect that the thickness of the cylinder liner can be reduced to reduce 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 which concerns on 1st Embodiment of this invention. It is a figure which expands and shows the principal part of FIG. It is the IV-IV arrow line view of FIG. It is sectional drawing of the principal part which shows the cooling structure of the internal combustion engine which concerns on 2nd Embodiment of this invention. It is a figure which expands and shows the principal part of FIG. It is a VII-VII arrow line view of FIG. It is a figure for demonstrating the stress which acts on the conventional borehole hole exit.

[First Embodiment]
Hereinafter, a cylinder liner, a cylinder cover, and a reinforcing hardware according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4.
1 is a perspective view of a cylinder liner according to the present embodiment, FIG. 2 is a cross-sectional view of a main part showing a cooling structure of an internal combustion engine according to the present embodiment, and FIG. 3 is an enlarged view of the main part of FIG. 4 is a view taken in the direction of arrows IV-IV in FIG.

The cylinder liner, cylinder cover, and reinforcing hardware according to the present invention are applied to an internal combustion engine such as a marine diesel engine, and a piston (not shown) is disposed therein, and the piston is disposed on the inner peripheral surface thereof. Will slide along.
As shown in FIG. 2 and FIG. 3, the reinforcing hardware 10 according to the present embodiment has the cylinder liner 20 in the vicinity of the joint portion between the cylinder liner 20 and the cylinder cover 40 (upper end portion (one end portion) of the cylinder liner 20). A (first) cooling water passage (cooling water flow path) that is continuous along the circumferential direction between the outer peripheral face of the cylinder liner 20 that fits on the outer peripheral face and forms the circumferential groove 21 and the lower end face of the cylinder cover 40. ) 11 and a ring-shaped (annular) member that suppresses (restrains) the cylinder liner 20 from expanding outward in the radial direction when the internal combustion engine is in operation (during warming).

  As shown in FIGS. 3 and 4, the reinforcing hardware 10 has a plurality of (first) cooling water holes 12 and (second) cooling water holes 13 along the circumferential direction (14 in this embodiment). Book). The cooling water hole 12 is a linear hole that communicates the lower end surface of the reinforcement hardware 10 and the inner peripheral surface located in the lower half of the reinforcement hardware 10, and the cooling water hole 13 is the upper end surface of the reinforcement hardware 10. And a linear hole that communicates with the inner peripheral surface located in the upper half of the reinforcing hardware 10. Further, the longitudinal axis (center axis) of the cooling water hole 12 and the longitudinal axis (center axis) of the cooling water hole 13 are each inclined with respect to a plane perpendicular to the cylinder axis.

  As shown in FIG. 1 to FIG. 3, the upper end portion of the cylinder liner 20 is continuous in the circumferential direction and is carved inward in the radial direction from the outer peripheral surface of the upper end portion of the cylinder liner 20. ), A single circumferential groove 21 having a semicircular shape in cross section is provided. Further, the upper end portion of the cylinder liner 20 that is located near the circumferential groove 21 and closer to the lower end portion (the other end portion) of the cylinder liner 20 than the circumferential groove 21 is an expansion projecting outward in the radial direction. The diameter part (projection part) 22 is provided so as to be continuous along the circumferential direction. The expanded diameter portion 22 includes a (first) curved surface 23 whose outer diameter gradually increases gradually from the lower end (other end) side of the cylinder liner 20 toward the upper end (one end) side, and a cylinder. The liner 20 is formed so as to be parallel to a (first) side surface (outer peripheral surface) 24 having a constant outer diameter from the lower end side toward the upper end side and a plane perpendicular to the cylinder axis. An upper surface (end surface) 25 is formed. The outer peripheral end of the curved surface 23 and the lower end of the side surface 24 are formed to be continuous, and the upper end of the side surface 24 and the outer peripheral end of the upper surface 25 are formed to be continuous.

  Further, on the radially inner side (inner peripheral side) of the upper surface 25, a (second) side surface (outer peripheral surface) 26 having a (substantially) constant outer diameter from the lower end side to the upper end side of the cylinder liner 20. However, it is provided so as to sandwich the circumferential groove 21. The inner peripheral end of the upper surface 25 and the lower end of the side surface 26 are formed so as to be continuous, and the upper end of the side surface 26 located on the lower end side of the cylinder liner 20 and the lower end of the circumferential groove 21 are continuous. The upper end of the circumferential groove 21 and the lower end of the side surface 26 located on the upper end side of the cylinder liner 20 are formed to be continuous.

2 and 3 is continuous with the curved surface 23, the side surface 24, and the inner peripheral end of the curved surface 23, and extends from the inner peripheral end of the curved surface 23 toward the lower end side of the cylinder liner 20. It is a water chamber hardware that forms a water chamber 32 with the outer peripheral surface of the cylinder liner 20.
2 and 3 denotes a water chamber that forms a (second) cooling water passage (cooling water flow passage) 34 continuous with the outer peripheral surface of the cylinder cover 40 along the circumferential direction. The cooling water passage 34 is a metal and is formed so as to communicate with the cooling water passage 11.
As shown by arrows in FIG. 3, the cooling water supplied into the water chamber 32 is composed of the cooling water hole 12, the cooling water passage 11 formed between the reinforcing hardware 10 and the cylinder liner 20, and the cooling water hole. 13. The cooling water passage 11 formed between the reinforcing hardware 10 and the cylinder cover 40 is sequentially passed to the cooling water passage (cooling water passage) 34.

As shown in FIG. 2, a cylinder cover 40 is disposed on the cylinder liner 20, and an opening located above the cylinder liner 20 is closed (sealed).
The cylinder cover 40 includes an upper boring hole 41 and a lower boring hole 42.
In the upper bore hole 41, the water chamber hardware (cover outer cylinder) 33 extends between the outer peripheral surface of the cylinder cover 40 located above (one side) of the reinforcing hardware 10 and the outer peripheral surface of the reinforcing hardware 10. When fitted, the first water chamber 43 provided on the outer peripheral surface of the cylinder cover 40 and the outer peripheral surface of the cylinder cover 40 located above (one side) the water chamber 43 (first). 2) are linear holes communicating with the water chamber 44, and a plurality of holes are provided along the circumferential direction of the cylinder cover 40. The longitudinal axis (center axis) of the upper borehole 41 is inclined with respect to a plane perpendicular to the cylinder axis.

The lower boring hole 42 is provided with a water chamber hardware (cover outer cylinder) 33 so as to straddle between the outer peripheral surface of the cylinder cover 40 positioned above (one side) of the reinforcing hardware 10 and the outer peripheral surface of the reinforcing hardware 10. When fitted, it is a straight hole that connects the water chamber 43 and the cooling water passage 34, and a plurality of holes are provided along the circumferential direction of the cylinder cover 40. Further, the longitudinal axis (center axis) of the lower bore ring hole 42 is inclined with respect to a plane perpendicular to the cylinder axis.
The cooling water supplied into the cooling water passage 34 passes through the lower borehole hole 42, the water chamber 43, and the upper borehole hole 41 in order, and is guided to the water chamber 44.

According to the cooling structure for an internal combustion engine including the cylinder liner 20, the cylinder cover 40, and the reinforcing hardware 10 according to the present embodiment, the cylinder liner 20 has a cooling circumferential groove instead of the conventionally used borehole hole. 21 is formed, and the cooling water guided through the cooling water hole 12 drilled in the reinforcing hardware 10 is ejected from the outlet of the cooling water hole 12 into the circumferential groove 21 to form the circumferential groove 21. The cylinder liner 20 is cooled by colliding with the outer peripheral surface of the cylinder liner 20.
This eliminates (eliminates) the conventionally used borehole hole and eliminates stress concentration at the exit of the borehole hole. As a result, the thickness of the cylinder liner 20 can be reduced and the weight can be reduced.
Further, according to the cooling structure of the internal combustion engine including the cylinder liner 20, the cylinder cover 40, and the reinforcement hardware 10 according to the present embodiment, the outward expansion of the cylinder liner 20 in the radial direction when the internal combustion engine is operated is the reinforcement hardware 10. It will be restrained (restrained).
Thereby, the thickness of the cylinder liner 20 can be further reduced, and the outer diameters of the cylinder liner 20, the cylinder cover 40, and the reinforcing hardware 10 can be further reduced and lightened.

Furthermore, according to the cooling structure of the internal combustion engine provided with the cylinder liner 20, the cylinder cover 40, and the reinforcing hardware 10 according to the present embodiment, the internal peripheral surface of the reinforcing hardware 10 when the internal combustion engine is stopped (in the cold state), A (predetermined) gap is ensured between the outer periphery of the cylinder liner 20 and the cylinder liner so that the inner peripheral surface of the reinforcing hardware 10 is in contact with the outer peripheral surface of the cylinder liner 20 when the internal combustion engine is in operation (during the warm state). The reinforcing hardware 10 is made of a metal material (for example, S25C or SS400 when the cylinder liner 20 is made of FC250) having an elastic modulus larger than that of 20.
As a result, it is possible to easily remove the reinforcing hardware 10 from the cylinder liner 20 when the internal combustion engine is stopped (in a cold state), and (gas and cooling water) during the operation of the internal combustion engine (in a warm state). The sealing property can be improved.
Note that FC250 is flake graphite cast iron (gray cast iron) with a guaranteed tensile strength of 250 N / mm ² or more, S25C is a general structural carbon steel with a carbon content of 0.25%, and SS400 is 400 N / mm ² or more. It is a general structural rolled steel with a guaranteed tensile strength.

  According to the cylinder liner 20 according to the present embodiment or the internal combustion engine including the cooling structure for the internal combustion engine according to the present embodiment, the entire engine can be reduced in size and weight.

[Second Embodiment]
A cylinder liner, cylinder cover, and reinforcement hardware according to a second embodiment of the present invention will be described with reference to FIGS.
5 is a cross-sectional view of the main part showing the cooling structure of the internal combustion engine according to the present embodiment, FIG. 6 is an enlarged view of the main part of FIG. 5, and FIG. 7 is a view taken in the direction of arrows VII-VII in FIG. .
The reinforcing hardware 50 according to the present embodiment includes a (first) cooling water hole 52 instead of the (first) cooling water hole 12 and the (second) cooling water hole 13, and (second) cooling water. The hole 53 and the (third) cooling water hole 54 are provided, and the cylinder liner 60 according to this embodiment is provided with the circumferential groove 61 instead of the circumferential groove 21 described above. Different from that of one embodiment. 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.

  As shown in FIG. 5 and FIG. 6, the reinforcing hardware 50 according to the present embodiment includes a cylinder liner 60 in the vicinity of the joint portion between the cylinder liner 60 and the cylinder cover 40 (upper end portion (one end portion) of the cylinder liner 60). A (first) cooling water passage (cooling water flow path) that is continuous along the circumferential direction between the outer peripheral face of the cylinder liner 60 that fits on the outer peripheral face and forms the circumferential groove 61 and the lower end face of the cylinder cover 40. ) 51 and a ring-shaped (annular) member that suppresses (restrains) the cylinder liner 60 from expanding outward in the radial direction when the internal combustion engine is operating (during the warm state).

  As shown in FIGS. 6 and 7, the reinforcement hardware 50 is provided with a plurality of cooling water holes 52 and a plurality of cooling water holes 54 (14 in this embodiment) along the circumferential direction. The cooling water hole 52 extends from the lower end surface of the reinforcement hardware 50 toward the upper end surface, opens at the lower end surface of the reinforcement hardware 50, and closes (is a dead end) in the upper half of the reinforcement hardware 50. The longitudinal axis (center axis) is drilled so as to be parallel to the cylinder axis. The cooling water hole 53 is a linear hole that communicates the inner peripheral surface of the reinforcing hardware 50 and the cooling water hole 52, and its longitudinal axis (center axis) is on a line that extends radially from the cylinder axis. It is drilled to be positioned. The cooling water hole 54 is a straight hole that communicates the upper end surface of the reinforcing hardware 50 and the inner peripheral surface located in the upper half of the reinforcing hardware 50, and its longitudinal axis (center axis) is the cylinder axis. It is perforated so as to be inclined with respect to a plane perpendicular to the surface.

As shown in FIG. 6 and FIG. 7, the upper end portion of the cylinder liner 60 is continuous in the circumferential direction, and is carved inward in the radial direction from the outer peripheral surface of the upper end portion of the cylinder liner 60. ), A single circumferential groove 61 having a trapezoidal cross-sectional shape is provided.
6, the cooling water supplied into the water chamber 32 is a cooling water passage 52, a cooling water hole 53, a cooling water passage formed between the reinforcement hardware 50 and the cylinder liner 60. 61, the cooling water hole 54, and the cooling water passage 61 formed between the reinforcing metal 50 and the cylinder cover 60 are sequentially passed to the cooling water passage (cooling water passage) 34.
Further, the cooling water supplied into the cooling water passage 34 passes through the lower borehole hole 42, the water chamber 43, and the upper borehole hole 41 in order, and is guided to the water chamber 44.

According to the cooling structure of the internal combustion engine provided with the cylinder liner 60, the cylinder cover 40, and the reinforcing hardware 50 according to the present embodiment, the cylinder liner 60 has a cooling peripheral groove instead of the conventionally adopted borehole hole. 61 is formed, and the cooling water guided through the cooling water holes 52 and 53 formed in the reinforcing metal fitting 50 is ejected from the outlet of the cooling water hole 53 into the circumferential groove 61. The cylinder liner 60 is cooled by colliding with the outer peripheral surface of the cylinder liner 60 to be formed.
This eliminates (eliminates) the conventionally used borehole hole and eliminates stress concentration at the exit of the borehole hole. As a result, the thickness of the cylinder liner 60 can be reduced and the weight can be reduced.
Further, according to the cooling structure for an internal combustion engine provided with the cylinder liner 60, the cylinder cover 40, and the reinforcing hardware 50 according to the present embodiment, the outward expansion of the cylinder liner 60 in the radial direction when the internal combustion engine is operated is the reinforcing hardware 50. It will be restrained (restrained).
Thereby, the thickness of the cylinder liner 60 can be further reduced, and the outer diameters of the cylinder liner 60, the cylinder cover 40, and the reinforcing hardware 50 can be further reduced and reduced in weight.

Furthermore, according to the cooling structure of the internal combustion engine provided with the cylinder liner 60, the cylinder cover 40, and the reinforcement hardware 50 according to the present embodiment, the internal peripheral surface of the reinforcement hardware 50 when the internal combustion engine is stopped (in a cold state), A (predetermined) gap is secured between the cylinder liner 60 and the outer peripheral surface of the cylinder liner 60, and the cylinder liner is arranged such that the inner peripheral surface of the reinforcing hardware 50 is in contact with the outer peripheral surface of the cylinder liner 60 when the internal combustion engine is operating (during the warm state). The reinforcing hardware 50 is made of a metal material having an elastic modulus larger than that of the elastic member 60 (for example, when the cylinder liner 60 is made of FC250, S25C or SS400).
As a result, it is possible to easily remove the reinforcing hardware 50 from the cylinder liner 60 when the internal combustion engine is stopped (in the cold state), and (gas and cooling water) during the operation of the internal combustion engine (in the warm state). The sealing property can be improved.
Note that FC250 is flake graphite cast iron (gray cast iron) with a guaranteed tensile strength of 250 N / mm ² or more, S25C is a general structural carbon steel with a carbon content of 0.25%, and SS400 is 400 N / mm ² or more. It is a general structural rolled steel with a guaranteed tensile strength.

  According to the cylinder liner 20 according to the present embodiment or the internal combustion engine including the cooling structure for the internal combustion engine according to the present embodiment, the entire engine can be reduced in size and weight.

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, the extending direction and inclination of the cooling water hole 12 and the cooling water hole 13 described in the first embodiment, the cooling water hole 52, the cooling water hole 53, and the cooling water hole 54 described in the second embodiment are as follows. It can be appropriately changed as necessary, and is not limited to those described in the first embodiment and the second embodiment.

DESCRIPTION OF SYMBOLS 10 Reinforcement hardware 11 Cooling water passage 12 Cooling water hole 20 Cylinder liner 21 Circumferential groove 50 Reinforcement hardware 51 Cooling water passage 52 (First) Cooling water hole 53 (Second) Cooling water hole 60 Cylinder liner 61 Circumferential groove

Claims (5)

A cylinder liner having a circumferential groove which is continuous along the circumferential direction and is carved inward in the radial direction from the outer peripheral surface of one end;
A first cooling water passage is formed along the circumferential direction between the outer circumferential surface of the cylinder liner that fits on the outer circumferential surface of the cylinder liner and forms the circumferential groove, and operates the internal combustion engine. A cooling structure for an internal combustion engine comprising a ring-shaped reinforcing metal that suppresses expansion of the cylinder liner to the outside in the radial direction at the time,
A first cooling water hole that guides cooling water to the first cooling water passage is formed in a straight line from the lower end surface of the reinforcing hardware toward the inner peripheral surface located in the lower half of the reinforcing hardware. And
A second cooling water hole for guiding the cooling water discharged from the first cooling water passage is drilled in a straight line from the upper end surface of the reinforcement metal to the inner peripheral surface located in the upper half of the reinforcement metal. cooling structure for an internal combustion engine, characterized in that it is set. A cylinder cover joined to the upper end of the cylinder liner;
In the vicinity of the joint between the cylinder liner and the cylinder cover, a second cooling water passage that is continuous along the circumferential direction is formed between the lower end surface of the cylinder cover and the upper end surface of the reinforcement hardware. The cooling structure for an internal combustion engine according to claim 1, wherein: A cylinder liner having a circumferential groove which is continuous along the circumferential direction and is carved inward in the radial direction from the outer peripheral surface of one end;
A first cooling water passage is formed along the circumferential direction between the outer circumferential surface of the cylinder liner that fits on the outer circumferential surface of the cylinder liner and forms the circumferential groove, and operates the internal combustion engine. A cooling structure for an internal combustion engine comprising a ring-shaped reinforcing metal that suppresses expansion of the cylinder liner to the outside in the radial direction at the time,
The first cooling water hole is formed in a straight line extending from the lower end surface of the reinforcing hardware toward the upper end surface, opening at the lower end surface of the reinforcing hardware, and closing within the upper half of the reinforcing hardware. And
The second cooling water hole for guiding the cooling water to the first cooling water passage is formed in a straight line from a plurality of locations of the first cooling water hole toward a plurality of locations on the inner peripheral surface of the reinforcing hardware. And
A third cooling water hole for guiding the cooling water discharged from the first cooling water passage is drilled in a straight line from the upper end surface of the reinforcing hardware toward the inner peripheral surface located in the upper half of the reinforcing hardware. cooling structure for an internal combustion engine, characterized in that it is set. A cylinder cover joined to the upper end of the cylinder liner;
In the vicinity of the joint between the cylinder liner and the cylinder cover, a second cooling water passage that is continuous along the circumferential direction is formed between the lower end surface of the cylinder cover and the upper end surface of the reinforcement hardware. The cooling structure for an internal combustion engine according to claim 3, wherein An internal combustion engine comprising the internal combustion engine cooling structure according to any one of claims 1 to 4 .

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