JP2007009745A - Cooling structure of water-cooled engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure of a water-cooled engine capable of avoiding the sealability of a head gasket from being impaired which is caused when all the periphery of a cylinder bore is not cooled uniformly. <P>SOLUTION: This engine comprises a water jacket 24 around the cylinder bore 20. A cooling water hole 39 for introducing the cooling water from the outside into the water jacket is formed in the cylinder block of the engine. A semi-spherical lattice member 45 is installed between the cooling water hole 39 and the outer peripheral wall of a cylinder liner 26a facing the cooling water hole. The lattice member 45 is disposed so that its meshes E face the cooling water hole 39. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cooling structure for a water-cooled engine.

  The water-cooled engine is formed with a water jacket for circulating cooling water around the cylinder bore. In such a water-cooled engine, the water pump is driven to circulate the cooling water in the water jacket so that heat is taken away from the cylinder bore that becomes hot as the air-fuel mixture burns, and the engine is kept at an appropriate temperature. I have to.

Generally, an engine is configured by assembling a cylinder head via a head gasket on an upper portion of a cylinder block. In such an engine, the vicinity of the upper end portion of the cylinder block on which the cylinder head is placed, that is, the vicinity of the upper end portion of the cylinder bore in which the combustion chamber is formed becomes the highest temperature as the air-fuel mixture burns. As a result, the dimensional change due to thermal expansion is larger in the vicinity of the upper end portion of the outer peripheral wall of the cylinder bore than in other portions (the center portion, the lower end portion, etc.), and the size due to thermal contraction when cooled by that amount. Changes tend to be large. For this reason, the surface pressure acting on the head gasket is likely to be uneven due to thermal contraction when the outer peripheral wall of the cylinder bore is cooled, and as a result, the sealing performance of the head gasket may be impaired. In addition, in order to suppress that the outer peripheral wall of a cylinder bore is locally subcooled, the structure which prevents the cooling water from a cooling water hole from being directly applied to the outer peripheral wall of a cylinder is described in patent document 1 or patent document 2 Has been. Patent Document 1 describes a configuration in which a bottomed cylindrical body having a plurality of holes formed through its peripheral wall is fitted into a cooling water hole. Patent Document 2 describes a configuration in which a triangular pillar-shaped boss portion is provided between the cooling water hole and the outer peripheral wall of the cylinder bore, and the ridge line portion of the boss portion is disposed toward the cooling water hole. Has been.
JP-A-9-68041 JP 2002-115600 A

  By the way, according to the configuration described in Patent Document 1, since the bottom wall of the bottomed cylindrical body fitted in the cooling water hole is in contact with the outer peripheral wall of the cylinder bore, the bottom of the bottomed cylindrical body is cooled by the cooling water. As the wall is cooled, the contact portion of the bottom wall may be locally subcooled. Further, according to the configuration described in Patent Document 2, since the cooling water easily stays on the cylinder bore side of the boss portion, the cooling effect is reduced in the staying portion as compared with other portions, and the outer peripheral wall of the cylinder bore In this case, there is a possibility that a portion that is not locally cooled, that is, a so-called heat spot is generated. Therefore, according to the configuration of each of the above documents, the cooling water introduced from the cooling water hole can be prevented from being directly applied to the outer peripheral wall of the cylinder bore, but the entire periphery of the cylinder bore can be uniformly cooled. Is hard to say. Therefore, when the position of the cooling water hole is set near the upper end of the cylinder bore, it is extremely difficult to keep the surface pressure acting on the head gasket uniform, and as a result, the sealing performance of the head gasket is impaired. There was a fear.

  The present invention has been made in view of the above problems, and an object of the present invention is to avoid the deterioration of the sealing performance of the head gasket due to the fact that the entire periphery of the cylinder bore is not cooled uniformly. The object is to provide a cooling structure for a water-cooled engine.

  In order to achieve the above object, the invention according to claim 1 includes a cylinder block in which a water jacket is formed around a cylinder bore, and a cooling water hole is provided in an outer wall of the water jacket. A cooling structure of a water-cooled engine in which a cylinder head is assembled to a part via a head gasket, and a lattice member is provided between the cooling water hole and an inner wall of the water jacket facing the cooling water hole, The gist is that at least a part of the lattice of the lattice member is disposed so as to face the cooling water hole.

  According to the configuration, the lattice member is provided between the cooling water hole and the inner wall of the water jacket facing the cooling water hole, and at least a part of the lattice of the lattice member is disposed so as to face the cooling water hole. Yes. In this case, the cooling water introduced from the cooling water hole passes through the lattice of the lattice member, so that the momentum is weakened and reaches the inner wall of the water jacket, that is, the outer peripheral wall of the cylinder bore. In this way, by preventing the cooling water introduced from the cooling water hole from directly contacting the outer peripheral wall of the cylinder bore, the outer peripheral wall of the cylinder bore is locally supercooled by the cooling water from the cooling water hole. Can be suppressed. Therefore, even if the position of the cooling water hole is set in the vicinity of the end of the cylinder bore on the cylinder head side, the thermal contraction caused by the local overcooling of the outer peripheral wall of the cylinder bore can be minimized. Therefore, it is possible to prevent the surface pressure acting on the head gasket from becoming non-uniform due to the entire periphery of the cylinder bore not being cooled uniformly, and the sealing performance of the head gasket can be prevented from being impaired. .

The gist of the invention of claim 2 is that, in the invention of claim 1, the lattice member has a convex hemispherical shape with respect to the inner wall of the water jacket.
According to this configuration, the cooling water introduced from the cooling water holes is dispersed not only in the vertical direction with respect to the inner wall of the water jacket, that is, the outer peripheral wall of the cylinder bore, but also in a wide range centering on the same direction. Can be supplied to. Thus, it is possible to smoothly supply the cooling water introduced into the water jacket around the cylinder bore while preventing the cooling water from the cooling water hole from directly contacting the outer peripheral wall of the cylinder bore. Therefore, by adopting the grid member according to claim 2, the periphery of the cylinder bore is cooled more uniformly, so that the surface pressure acting on the head gasket can be made more uniform. It can be further avoided that the sealing performance is impaired.

The gist of the invention described in claim 3 is that, in the invention described in claim 1 or 2, the lattice member is composed of a net in which wire rods orthogonal to each other alternately rise and fall.
According to the configuration, the flow rate of the cooling water passing through the lattice member can be appropriately adjusted by forming the lattice member using the meshes having different mesh sizes. Further, in this case, since a net that is inexpensive and easy to form is adopted as a material for forming the lattice member, the cost for manufacturing the lattice member can be kept low.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the cylinder block includes a cylinder liner portion defining a cylinder bore and a cylinder outer wall portion, and the cylinder liner portion. A water jacket is formed between the outer peripheral surface of the cylinder and the inner peripheral surface of the cylinder outer wall, and seal members are respectively provided at the end on the cylinder head side and the end on the opposite side between the outer peripheral surface and the inner peripheral surface. The gist is to intervene.

  According to this configuration, when a cooling water hole for introducing cooling water from the outside is formed in the cylinder outer wall, even if the hole position is set corresponding to the upper part of the cylinder bore, the end of the water jacket on the cylinder head side It is possible to prevent the influence of the pressure of the cooling water introduced from the cooling water hole as much as possible on the sealing member interposed between the two. Thereby, in the split-type cylinder block divided | segmented on the boundary of a water jacket, the sealing performance in the cylinder head side edge part of a water jacket can be prevented from being impaired.

Hereinafter, an embodiment in which the present invention is embodied in a cooling structure for an in-vehicle gasoline engine (hereinafter referred to as an engine) will be described with reference to FIGS.
As shown in FIG. 1, the engine 11 includes a cylinder block 12 and a cylinder head 16 that is assembled to the upper portion of the engine block 11 via a head gasket 15. A head cover (not shown) is attached above the cylinder head 16, and an oil pan (not shown) is attached below the cylinder block 12.

Next, the configuration of the cylinder block 12 will be described with reference to FIGS.
As shown in FIG. 2, in the cylinder block 12, four cylinder bores 20 are provided in the upper part, and a crankcase part 21 is provided in the lower part. The crankcase portion 21 forms a crankcase together with an oil pan attached below the crankcase portion 21. A flat upper deck 22 on which the cylinder head 16 shown in FIG. 1 is placed is provided at the top of the cylinder block 12.

  As shown in FIG. 3, the cylinder block 12 includes a water jacket 24 around each cylinder bore 20. The water jacket 24 is formed in a substantially annular shape so as to surround the outer peripheral surface of each cylinder bore 20 while avoiding a connection portion between adjacent cylinder bores 20. The cylinder block 12 is divided into two structures shown below with a region forming the water jacket 24 as a boundary.

  As shown in FIG. 4, the cylinder block 12 is divided into a cylinder liner portion 25 that defines the cylinder bore 20 and a cylinder block body 30 that forms the outer wall of the water jacket 24. The cylinder liner portion 25 includes a cylinder coupling body 26 in which four cylinder liners 26a are integrally coupled, and the upper deck 22 provided on the upper portion thereof. The cylinder coupling body 26 is integrally formed so that cylindrical cylinder liners 26a serving as the respective cylinders are linearly arranged and their outer peripheral surfaces are connected to each other.

  An upper deck 22 constituting the top of the cylinder block 12 is integrally formed at the upper end of the cylinder coupling body 26. The upper deck 22 has a flat plate shape, and the cylinder head 16 is placed on the upper surface of the upper deck 22 via the head gasket 15 (see FIG. 1). In the upper deck 22, a plurality of fastening holes 27 used for fastening the cylinder liner portion 25 and the cylinder block body 30 and a plurality of cooling water passages 28 communicating with the water jacket 24 are formed at predetermined positions. A support projection 29 is provided around the lower end of the cylinder coupling body 26 along the outer peripheral surface of each cylinder liner 26a.

  On the other hand, the cylinder block main body 30 includes a crankcase portion 21 and a cylinder outer wall portion 31 that surrounds the outer periphery of the cylinder coupling body 26. The cylinder block body 30 has a shape in which a cylinder outer wall portion 31 protrudes from an upper portion of the crankcase portion 21, and a plurality of reinforcing ribs 33 are formed on the outer periphery thereof so as to extend vertically and horizontally.

  The cylinder outer wall portion 31 has an opposing surface disposed on the inner side thereof so as to oppose the outer peripheral surface of the cylinder coupling body 26, and is formed in a substantially rectangular frame shape as a whole. A flange portion 35 is provided at the upper end portion of the cylinder outer wall portion 31, and the upper surface of the flange portion 35 is an upper receiving surface 35 a that abuts and supports the lower surface of the upper deck 22 of the cylinder liner portion 25. A fastening hole 37 used for fastening the cylinder liner portion 25 and the cylinder block body 30 is opened at a position corresponding to the fastening hole 27 of the upper deck 22 in the upper receiving surface 35a.

  As shown in FIGS. 4 and 6, a cooling water hole 39 for introducing cooling water from the outside into the water jacket 24 is provided on the side wall of the cylinder outer wall portion 31. The cooling water hole 39 is formed so as to communicate the outside and the inside of the cylinder outer wall portion 31, and the hole position is the upper end portion in the axial direction of the cylinder outer wall portion 31, that is, the upper end in the axial direction of the cylinder liner portion 25. It is set at a position corresponding to the part. The cooling water hole 39 is connected to a water pump (not shown) attached to the outer portion of the engine 11 through a cooling water pipe or the like. Therefore, in the engine 11, the water pump is driven by obtaining the rotational force of the crankshaft 10 (see FIG. 1), so that the cooling water discharged from the water pump is supplied to the water jacket 24 from the cooling water hole 39. It has come to be.

Next, the configuration of the head gasket 15 and the cylinder head 16 will be described.
As shown in FIGS. 5 and 6, the cylinder head 16 is used for fastening with the intake / exhaust passages 61 and 62 communicating with the combustion chamber 60 formed at the upper end portion of the cylinder bore 20 and the cylinder block 12. Fastening holes 67 and the like are formed. Further, a water jacket 64 is formed in the cylinder head 16 so as to avoid these intake / exhaust passages 61 and 62, the fastening holes 67 and the like, and a cooling water passage 68 communicating with the water jacket 64 is provided in the cylinder head 16. It is opened on the lower surface of.

  Between the cylinder head 16 and the cylinder liner portion 25 constituting the cylinder block 12, a head gasket 15 is interposed as a sealing member that closes the gap between the cylinder head 16 and the cylinder block 12 in an airtight and liquid-tight manner. The head gasket 15 has a hole 57 used for fastening the cylinder head 16 and the cylinder block 12, and a hole 58 for communicating the cooling water passage 68 of the cylinder head 16 and the cooling water passage 28 of the cylinder block 12. It is transparent.

The cylinder block 12, the head gasket 15 and the cylinder head 16 configured as described above are assembled by the fastening structure shown in FIG.
As shown in the figure, a fastening hole 67 of the cylinder head 16, a hole 57 of the head gasket 15, a fastening hole 27 of the upper deck 22, and a fastening hole 37 of the cylinder block body 30 are arranged coaxially. A head bolt 77 inserted from above the fastening hole 67 of the cylinder head 16 is inserted into the hole 57 of the head gasket 15 and the fastening hole 27 of the upper deck 22 and fastened to the fastening hole 37 of the cylinder block body 30. Yes. The cylinder liner portion 25 is assembled to the cylinder block body 30 through the fastening with the head bolt 77, and the head gasket 15 and the cylinder head 16 are assembled to the upper portion of the upper deck 22.

  In this state where the cylinder liner portion 25 is assembled to the cylinder block main body 30, the cylinder coupling body 26 of the cylinder liner portion 25 is inserted inside the cylinder outer wall portion 31 of the cylinder block main body 30. Further, the lower surface of the upper deck 22 is abutted and supported by the upper receiving surface 35 a of the cylinder outer wall portion 31 at the upper end portion of the cylinder liner portion 25, and the tip surface of the support protrusion 29 is the inner peripheral surface of the cylinder outer wall portion 31 at the lower end portion. Is supported by contact. And while the inner peripheral surface of the cylinder outer wall part 31 and the outer peripheral surface of the cylinder coupling body 26 are arranged facing each other, between the inner peripheral surface of the cylinder outer wall part 31 and the outer peripheral surface of the cylinder coupling body 26, A water jacket 24 is formed.

  Further, a seal is provided between the lower surface of the upper deck 22 and the upper receiving surface 35 a of the cylinder outer wall portion 31 and between the tip surface of the support projection 29 of the cylinder coupling body 26 and the inner peripheral surface of the cylinder outer wall portion 31. Members 41 and 42 are interposed. By these seal members 41 and 42, sealing performance is ensured at the end portion of the water jacket 24 on the cylinder head 16 side and the end portion on the opposite side of the crankcase portion 21 side.

  In the assembled state as described above, the cooling water passage 68 of the cylinder head 16, the hole 58 of the head gasket 15, and the cooling water passage 28 of the cylinder block 12 are communicated with each other. Thus, when the cooling water is supplied through the cooling water hole 39, the cooling water is introduced into the water jacket 24 of the cylinder block 12, and the cooling water passage 28 of the upper deck 22 and the hole 58 of the head gasket 15 are provided. After passing, the water jacket 64 of the cylinder head 16 is also introduced through the cooling water passage 68. In this way, the coolant is circulated through both the cylinder block 12 and the cylinder head 16, so that each part that becomes hot by driving the engine 11 is cooled.

  Further, since the surface pressure acting on both surfaces of the head gasket 15 is increased through the fastening with the head bolt 77, the sealing performance of the head gasket 15 is sufficiently exerted, and the cylinder head 16 and the cylinder liner portion 25 are separated. These gaps are more airtight and liquid tightly closed. However, especially when the engine 11 is driven, as shown in FIG. 6, the vicinity of the combustion chamber 60, that is, the vicinity of the upper end of the cylinder liner portion 25, has a higher temperature than other portions. The head 16 and the cylinder liner portion 25 have large dimensional changes due to thermal expansion in the vicinity of their boundary portions. Accordingly, the dimensional change due to thermal contraction when cooled by cooling water tends to be large, and it becomes difficult to maintain a high surface pressure acting on the head gasket 15 uniformly. May not be fully exhibited.

  Therefore, in the present embodiment, the cooling water hole 39 and the inner wall of the water jacket 24 facing the cooling water hole 39, more specifically, the cooling water hole 39 and the outer peripheral wall of the cylinder liner 26a disposed closest to the cooling water hole 39 are provided. Between the two, a lattice member 45 having a hemispherical shape is provided.

Next, the configuration of the lattice member 45 and its arrangement will be described with reference to FIGS.
As shown in FIGS. 7 and 8, the lattice member 45 is made of a metal net made by alternately crossing a plurality of wire rods 46 at right angles. The lattice member 45 is formed by stamping a metal net into a predetermined shape into a hemispherical shape. The lattice member 45 formed in this way is arranged so that the convex side faces the outer peripheral wall of the cylinder liner 26a, and the opening of the cooling water hole 39 is closed from the water jacket 24 side. Further, in this case, the lattice member 45 is disposed such that the central axis C1 thereof coincides with the central axis C2 of the cooling water hole 39.

  The lattice member 45 has an opening edge 45 a opposite to the convex side fixed to the inner peripheral wall of the cylinder outer wall 31. In this case, examples of the fixing method of the lattice member 45 include welding and supporting and fixing with a fixing tool such as a bracket. Thus, in the state where the lattice member 45 is disposed, the mesh E located around the central axis C <b> 1 of the lattice member 45 is disposed so as to face the cooling water hole 39. Therefore, the cooling water introduced from the cooling water hole 39 reaches the outer peripheral wall of the cylinder liner 26a after passing through the mesh E of the lattice member 45.

Subsequently, the operation of the lattice member 45 will be described with reference to FIGS. 9 and 10.
As shown in FIGS. 9 and 10, the cooling water discharged from the water pump passes through the cooling water hole 39 with a predetermined discharge pressure and is introduced into the water jacket 24. Here, since the lattice member 45 is disposed between the cooling water hole 39 and the outer peripheral wall of the cylinder liner 26a disposed opposite thereto, the cooling water introduced from the cooling water hole 39 is By passing through the mesh E of the lattice member 45, the momentum is weakened and reaches the outer peripheral wall of the cylinder liner 26a. In other words, the portion of the outer peripheral wall of the cylinder liner 26a facing the cooling water hole 39, in this embodiment, in the vicinity of the upper end of the cylinder liner 26a, the cooling water from the cooling water hole 39 is weakened. Local cooling by the cooling water from the cooling water hole 39 is suppressed. Therefore, near the upper end of the cylinder liner 26a, the dimensional change due to thermal expansion is large as described above. However, since local supercooling is suppressed, the size change due to thermal contraction is minimized. It is done. Therefore, the local pressure acting on the head gasket 15 due to the dimensional change due to the heat shrinkage is prevented from being locally reduced, and the sealing performance of the head gasket 15 is suitably maintained.

  Further, in this case, the cooling water introduced from the cooling water hole 39 passes through the mesh E of the lattice member 45 so that the cooling water is not only perpendicular to the outer peripheral wall of the cylinder liner 26a but also has a wide range centering on the same direction. And is supplied to the water jacket 24. As a result, the cooling water introduced into the water jacket 24 is smoothly supplied to the periphery of the cylinder liner 26a, so that a portion that is locally supercooled by the cooling water from the cooling water hole 39 is generated, or the cooling water is It is restrained that a heat spot is generated by staying. As a result, since the periphery of the cylinder liner 26a is more uniformly cooled, the surface pressure acting on the head gasket 15 is further prevented from being locally reduced, and the sealing performance of the head gasket 15 is more favorable. Will be maintained.

According to the above embodiment, the following effects can be obtained.
(1) A lattice member 45 is provided between the cooling water hole 39 and the outer peripheral wall of the cylinder liner 26 a facing the cooling water hole 39, and the mesh E of the lattice member 45 is disposed so as to face the cooling water hole 39. Has been. In this case, the cooling water introduced from the cooling water hole 39 passes through the mesh E of the lattice member 45, so that the momentum is weakened so that the cooling water reaches the inner wall of the water jacket 24, that is, the outer wall of the cylinder liner 26a. become. In this way, the cooling water introduced from the cooling water hole 39 is not directly applied to the outer peripheral wall of the cylinder liner 26 a, so that the outer peripheral wall of the cylinder liner 26 a is localized by the cooling water from the cooling water hole 39. It is possible to suppress overcooling. Therefore, even if the position of the cooling water hole 39 is set in the vicinity of the end of the cylinder bore 20 on the cylinder head 16 side, the thermal contraction caused by locally overcooling the outer peripheral wall of the cylinder liner 26a can be minimized. . Therefore, it is possible to prevent the surface pressure acting on the head gasket 15 from becoming non-uniform due to the entire periphery of the cylinder bore 20 being not uniformly cooled, so that the sealing performance of the head gasket 15 is not impaired. be able to.

  Further, as in the present embodiment, the cylinder block 12 is a divided cylinder block that is divided with the region where the water jacket 24 is formed as a boundary, and the hole position of the cooling water hole 39 is the upper end in the axial direction of the cylinder outer wall portion 31. In the case where it is set to the portion, the influence of the pressure of the cooling water introduced from the cooling water hole 39 can be prevented from reaching the sealing member 41 as much as possible. Therefore, by providing the lattice member 45 between the cooling water hole 39 and the outer peripheral wall of the cylinder liner 26a opposite to the cooling water hole 39, the sealing performance at the end of the water jacket 24 on the cylinder head 16 side is not impaired. Can do.

  (2) The lattice member 45 is formed in a hemispherical shape, and is disposed with its convex side facing the outer peripheral wall of the cylinder liner 26a. In this case, the cooling water introduced from the cooling water holes 39 is dispersed not only in the direction perpendicular to the inner wall of the water jacket 24, that is, the outer peripheral wall of the cylinder liner 26a, but also in a wide range centering on the same direction. The jacket 24 can be supplied. This makes it possible to smoothly supply the cooling water introduced into the water jacket 24 around the cylinder bore 20 while preventing the cooling water from the cooling water holes 39 from directly contacting the outer peripheral wall of the cylinder liner 26a. . Therefore, since the periphery of the cylinder bore 20 is cooled more uniformly, the surface pressure acting on the head gasket 15 can be made more uniform, and the sealing performance of the head gasket 15 can be further prevented from being impaired. Will be able to.

  (3) The lattice member 45 is formed by a net formed by alternately raising and lowering a plurality of wire rods. In this case, the flow rate of the cooling water passing through the lattice member 45 can be appropriately adjusted by forming the lattice member 45 using a mesh having a different mesh size. In addition, since a net that is inexpensive and easy to form is used as a material for forming the lattice member 45, the cost for manufacturing the lattice member 45 can be kept low.

In addition, you may change the said embodiment as follows.
In the present embodiment, the lattice member 45 has a hemispherical shape, but the shape may be changed to, for example, a substantially box shape, a U-shaped cross section, or a flat plate shape.

  In the present embodiment, the entire lattice member 45 is formed by a net, but only a portion facing the cooling water hole 39 may be partially formed by a net. In that case, portions that do not face the cooling water holes 39 may be partially formed by a net.

  In the present embodiment, the lattice member 45 is entirely formed of a mesh, but if the lattice member 45 is provided with a plurality of holes at locations facing the cooling water holes 39, the lattice member 45 may be formed using a structural material other than the mesh. The member 45 may be formed. In this case, examples of the shape of the hole include a slit-like hole (pore), a circular hole, and a polygonal hole.

In the present embodiment, the lattice member 45 is formed of a metal net, but the lattice member 45 may be formed using a cloth or resin net.
In the present embodiment, the lattice member 45 is disposed so that the central axis C1 thereof coincides with the central axis C2 of the cooling water hole 39, but part of the mesh E of the lattice member 45 is the cooling water. If they are arranged to face the holes 39, the center axes C <b> 1 and C <b> 2 of the lattice member 45 and the cooling water holes 39 do not have to coincide with each other.

  In the present embodiment, the split cylinder block 12 is used in the engine 11, but the cylinder block 12 may be changed to a cylinder block in which the cylinder liner portion 25 and the cylinder block body 30 are integrally formed. Good.

The perspective view which shows the whole structure of the water-cooled engine in this embodiment. The perspective view of the cylinder block which also makes the principal part of a water-cooled engine. The top view of a cylinder block similarly. The disassembled perspective view which similarly shows the division | segmentation structure of a cylinder block. AA sectional drawing of FIG. BB sectional drawing of FIG. The top view which shows the structure and arrangement | positioning aspect of a lattice member. The side view which shows the structure of a lattice member, and its arrangement | positioning aspect. Sectional drawing which shows the flow of the cooling water which passes a grating | lattice member. Sectional drawing which shows the flow of the cooling water which passes a grating | lattice member.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Engine, 12 ... Cylinder block, 15 ... Head gasket, 16 ... Cylinder head, 20 ... Cylinder bore, 24 ... Water jacket, 25 ... Cylinder liner part, 31 ... Cylinder outer wall part, 39 ... Cooling water hole, 41, 42 ... Seal member, 45... Lattice member, 46.

Claims (4)

A water-cooled engine having a water jacket formed around a cylinder bore, a cylinder block provided with a cooling water hole on the outer wall of the water jacket, and a cylinder head assembled to the end of the cylinder block via a head gasket. A cooling structure,
A lattice member is provided between the cooling water hole and the inner wall of the water jacket facing the cooling water hole, and at least a part of the lattice of the lattice member is disposed to face the cooling water hole. A cooling structure for a water-cooled engine characterized by The cooling structure for a water-cooled engine according to claim 1,
The cooling structure for a water-cooled engine, wherein the lattice member has a convex hemispherical shape with respect to the inner wall of the water jacket. The cooling structure for a water-cooled engine according to claim 1 or 2,
The lattice member is composed of a net in which wire rods orthogonal to each other are alternately raised and lowered. The cooling structure for a water-cooled engine according to any one of claims 1 to 3,
The cylinder block includes a cylinder liner portion and a cylinder outer wall portion that define a cylinder bore, and forms a water jacket between an outer peripheral surface of the cylinder liner portion and an inner peripheral surface of the cylinder outer wall portion, and these outer peripheral surfaces. A cooling structure for a water-cooled engine, characterized in that a seal member is interposed between an end on the cylinder head side and an end on the opposite side between the inner peripheral surface.

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