CN113446126A

CN113446126A - Water jacket

Info

Publication number: CN113446126A
Application number: CN202110208411.XA
Authority: CN
Inventors: 大田笃志; 山崎信; 伊藤裕亮; 竹形徳之; 柴田一雄
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2020-03-25
Filing date: 2021-02-25
Publication date: 2021-09-28
Anticipated expiration: 2041-02-25
Also published as: JP2021156164A; CN113446126B; JP6977088B2

Abstract

The invention provides a water jacket which can further improve the cooling performance and restrain the excessive supply of cooling liquid. The water jacket (4) of the present invention is provided with: a cooling passage (4c) through which a cooling liquid flows and which is defined between a cylinder block inner wall (4a) and an outer wall (4b), the cylinder block inner wall (4a) covering a cylinder liner (2) of a cylinder block (1) integrally formed with the internal combustion engine, the outer wall (4b) facing the cylinder block inner wall (4 a); a spacer (9) which is disposed on the top dead center side of a piston (5) moving in a cylinder liner (2) with a gap in a cooling passage (4c) so as to partition a 1 st space (7) in the cooling passage (4 c); and a plurality of protruding strips (10) that are provided on the cylinder block inner wall (4a) so as to be positioned in the 1 st space (7) and that extend in the direction of the center axis of the cylinder liner (2).

Description

Water jacket

Technical Field

The present invention relates to a water jacket for cooling a cylinder liner of an internal combustion engine.

Background

Conventionally, a water jacket is known in which a plurality of concave portions are provided at positions corresponding to the upper portion of a cylinder liner to increase cooling capacity (see, for example, patent document 1).

Further, it is also known to arrange a spacer in a water jacket that cools a plurality of cylinder liners, and uniformly cool the water jacket of the plurality of cylinder liners (for example, see patent document 2).

Documents of the prior art

Patent document 1: japanese Kokai publication Hei-5-30443

Patent document 2: japanese patent laid-open publication No. 2002-30989

Disclosure of Invention

Problems to be solved by the invention

The purpose of the present invention is to provide a water jacket that can further improve cooling performance and suppress excessive supply of coolant.

Means for solving the problems

To achieve the above object, the present invention provides a water jacket having:

a cooling passage through which a coolant flows and which is defined between a cylinder block inner wall that covers a cylinder liner integrally formed with a cylinder block of an internal combustion engine and a cylinder block outer wall that faces the cylinder block inner wall;

a spacer disposed at a top dead center side of a piston moving in the cylinder liner with a space in the cooling passage to define a 1 st space in the cooling passage; and

and a plurality of protruding portions provided on the cylinder block inner wall so as to be located in the 1 st space and extending in the direction of the center axis of the cylinder liner.

According to the present invention, the coolant can be intensively flowed to the upper portion of the cylinder liner, and the heat transfer efficiency due to collision of the coolant with the protruding strip portion can be improved. This can reduce the wall surface temperature of the cylinder liner on the top dead center side, which is likely to increase in temperature, and can effectively suppress knocking.

In addition, with the spacer, the flow of the coolant to be flowed in the central portion of the cylinder liner can be prevented or suppressed, unnecessary cooling of the central portion of the cylinder liner can be suppressed, a cooling loss caused by the supply of an excessive amount of coolant can be suppressed or prevented, and a mechanical loss caused by an unnecessary temperature change of the cylinder liner can be improved.

In the present invention, it is preferable that the distance between the protruding strip and the adjacent protruding strip is set to be larger than the width of the protruding strip.

According to the present invention, by setting the interval between the protrusions to be larger than the width of the protrusions, the coolant can be prevented from staying in the recesses between the protrusions, and the coolant can be maintained at an appropriate flow rate.

In the present invention, the spacer may be configured by a space holding body capable of allowing the coolant to flow at a flow rate smaller than that of the 1 st space.

According to the present invention, a high heat insulating function can be obtained by applying the space holding body having the gap inside. Further, the flow rate of the coolant can be adjusted by selecting the material of the void retaining member.

In the present invention, the spacer may be configured by the space retainer disposed on the cylinder block inner wall side and a resin support member disposed on the cylinder block outer wall side and supporting the space retainer.

According to the present invention, the void retaining body can be reliably held, and the spacer can be easily attached to the cooling passage, thereby improving the ease of assembly of the spacer.

Further, in the present invention, it is preferable that the spacer is configured to: the cooling passage has the 1 st space at a position corresponding to a top dead center of a piston moving forward and backward in the cylinder liner, and has the 2 nd space at a position corresponding to a bottom dead center of the piston, and the 2 nd space is also supplied with a cooling liquid.

According to the present invention, the piston can be actively cooled at the top dead center and the bottom dead center where the moving speed of the piston becomes slow.

Drawings

Fig. 1 is an explanatory view showing a cylinder block provided with a water jacket according to an embodiment of the invention.

Fig. 2 is an explanatory view showing a spacer of the water jacket of the present embodiment in cross section.

Fig. 3 is an enlarged explanatory view of the protruding portion of the water jacket according to the present embodiment.

Fig. 4 is an explanatory view of a water jacket showing another embodiment of the invention in cross section.

Description of the reference symbols

1: a cylinder block;

2: a cylinder liner;

3: a cylinder block main body;

4: a water jacket;

4 a: an inner wall of the cylinder block;

4 b: an outer wall of the cylinder block;

4 c: a cooling passage;

5: a piston;

5 a: a piston pin;

6: connecting rods:

7: 1 st space;

8: a 2 nd space;

9: a spacer;

9 a: a void-retaining body;

9 b: a support;

10: and a protruding strip portion.

Detailed Description

A cylinder block of an internal combustion engine provided with a water jacket of an embodiment of the present invention is explained with reference to the drawings.

[ Structure of Cylinder Block ]

Referring to fig. 1, a cylinder block 1 of an internal combustion engine according to the present embodiment includes: four cylinder liners 2; a cylinder block body 3 that holds the cylinder liner 2; and a water jacket 4 provided to the cylinder block body 3 so as to cover a side surface of the cylinder liner 2.

Referring to fig. 2, a piston 5 is disposed in the cylinder liner 2, and the piston 5 is connected via a piston pin 5a and slides between a top dead center indicated by a one-dot chain line and a bottom dead center indicated by a two-dot chain line via a connecting rod 6. A combustion chamber is defined by the cylinder liner 2 and the piston 5.

The water jacket 4 is provided with a cooling passage 4c, the cooling passage 4c being defined by: a cylinder block inner wall 4a that covers the cylinder liner 2; and a block outer wall 4b formed radially outward of the cylinder liner 2 so as to face the block inner wall 4a with a gap therebetween. In the water jacket 4, spacers 9 are inserted so as to form gaps on the top dead center side and the bottom dead center side, respectively, so that the 1 st space 7 is dividedly formed on the top dead center side and the 2 nd space 8 is dividedly formed on the bottom dead center side. Inside the water jacket 4, the coolant (cooling water) flows in a manner along the arrangement direction of the cylinder liners 2.

The spacer 9 is composed of a space retainer 4a disposed on the cylinder block inner wall 4a side and a resin support 9b disposed on the cylinder block outer wall 4b side and supporting the space retainer 9 a. The material of the void retaining body 9a may be a porous material, a fiber aggregate, or the like, as long as it is a material that allows the coolant to flow slightly through the internal voids.

Referring to fig. 2 and 3, the water jacket 4 is provided with a plurality of protruding portions 10 so as to be positioned on the cylinder block inner wall 4a of the space 7 of the cylinder liner 1, and the plurality of protruding portions 10 extend in the central axis direction of the cylinder liner 2. Referring to fig. 3, the interval between adjacent protrusions 10 is set to be larger than the width of the protrusions 10. In the present embodiment, the protruding portions 10 are set to have a protruding height of 0.25mm, a width of 0.5mm to 2.0mm, and a spacing of 2.5mm to 7.5 mm. The projection of the present invention is not limited to this value, and is preferably set as appropriate according to the type of internal combustion engine, the shape of the water jacket, and the like.

[ Effect of Water jacket ]

According to the water jacket 4 of the present embodiment, the coolant flows intensively to the upper portion of the cylinder liner 2, and the heat transfer efficiency by the coolant colliding against the protruding strip portions 10 can be improved. Thereby, the wall surface temperature on the top dead center side of the cylinder liner 2, the temperature of which is likely to rise, can be reduced, and knocking can be effectively suppressed.

Further, by the spacer 9, the flow of the cooling liquid to be flowed through the central portion of the cylinder liner 2 can be prevented or suppressed, unnecessary cooling of the central portion of the cylinder liner 2 can be suppressed, a cooling loss due to excessive supply of the cooling liquid can be suppressed or prevented, and a mechanical loss due to unnecessary temperature variation of the cylinder liner 2 can be improved.

In the present embodiment, by setting the interval between adjacent protrusions 10 to be larger than the width of the protrusions 10, the coolant can be prevented from staying in the recesses between the protrusions 10, and an appropriate flow rate of the coolant can be maintained.

In the present embodiment, since the spacer 9 is partially composed of the space-retaining body 9a such as a porous body that can flow a small amount of the coolant, the coolant can flow at a flow rate smaller than the 1 st space 7 and the 2 nd space 8. By using the space holding body 9a for the spacer 9 in this way, a high heat insulating function can be obtained by having a gap inside. The flow rate of the coolant can be adjusted by appropriately selecting the material, structure, and the like of the space holding body 9 a.

In addition, in the present embodiment, the spacer 9 is configured by the space retainer 9a disposed on the cylinder block inner wall 4a side and the resin support 9b disposed on the cylinder block outer wall 4b side and supporting the space retainer 9a, and therefore, even if a material such as sponge, which is relatively difficult to maintain in shape, is selected as the space retainer 9a, the space retainer 9a can be reliably held by the support 9b, and can be easily attached to the cooling passage 4c, and the assemblability of the compartment spacer 9 can be improved.

In addition, in the present embodiment, the spacer 9 is configured to: in the cooling passage 4c, a 1 st space 7 is provided at a position corresponding to the top dead center of the piston 5 which advances and retracts in the cylinder liner 2, a 2 nd space 8 is provided at a position corresponding to the bottom dead center of the piston 5, and the cooling liquid flows through the 2 nd space 8. This makes it possible to actively cool the piston 5 with the coolant at the top dead center and the bottom dead center where the moving speed of the piston 5 is slow.

[ other embodiments ]

In the present embodiment, the structure in which the spacer 9 is disposed so as to form the second space 8 with a gap also in the cooling passage 4c at a position corresponding to the bottom dead center has been described, but the water jacket of the present invention is not limited to this, and for example, as in another embodiment shown in fig. 4, the spacer 9 is disposed so as to have no gap on the bottom dead center side in the cooling passage 4c, and the 2 nd space is omitted.

The following leasing effect of the invention can thus also be achieved: the flow velocity of the coolant flowing in the upper portion of the cylinder liner 2 is increased, the heat transfer efficiency at which the coolant collides with the ridge portion 10 is improved, and the wall surface temperature on the top dead center side of the cylinder liner 2, at which the temperature is likely to rise, can be reduced, so that knocking can be effectively suppressed. The effect of the present invention, that is, the wall surface temperature on the top dead center side can be reduced and knocking can be effectively suppressed, can be obtained.

Further, in the present embodiment, the spacer 9 using one kind of the space holding body 9a has been described, but the spacer of the present invention is not limited thereto, and the spacer may be configured by using a plurality of kinds of the space holding bodies. The spacer of the present invention may have no support member or may be constituted only by a support member, and is configured to completely block the flow of the coolant in the spacer. Further, the number of cylinder liners 2 may be one or two or more.

Claims

1. A water jacket, having:

2. The water jacket according to claim 1,

the interval between the protruding strip and the adjacent protruding strip is set to be larger than the width of the protruding strip.

3. The water jacket according to claim 1 or 2,

at least a part of the spacer is constituted by a space-retaining body capable of allowing the coolant to flow at a flow rate smaller than that of the 1 st space.

4. The water jacket according to claim 3,

the spacer is configured by the space retainer disposed on the cylinder block inner wall side and a resin support body disposed on the cylinder block outer wall side and supporting the space retainer.

5. The water jacket according to any one of claims 1 to 4,

the spacer is configured to: so that the cooling passage has the 1 st space at a position corresponding to the top dead center of a piston moving forward and backward in the cylinder liner and the 2 nd space at a position corresponding to the bottom dead center of the piston,

the 2 nd space is also supplied with the cooling liquid.