JPH1030494A - Cylinder block - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent any clearance among respective liners from occurring by checking any possible deformation of each cylinder liner to be produced at a time when molten metal poured in and around these cylinder liners is solidified and contracted. SOLUTION: Four cylinder liners 19 being made up into cylindrical form are adjacently set up at each junction 23, constituting a liner constituent body 16. Each projection 24 extending over the full length of these cylinder liners 19 is formed at both sides of these junctions 23. Each of the projections 24 is extended in the same direction as each joining surface of these two junctions 23, while a flat surface being situted at the opposite side to each joining surface is paralleled with each joining surface. Each rib 25 extending over the full length of respective cylinder liners 19 is formed at each side of these four cylinder liners 19 at predetermined intervals. Height of a rib 25a being made up in a position drawn nearest to the junction 23 should be set to be higher than the other ribs 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder block for an engine, and more particularly to a cylinder block formed by arranging a plurality of cylinder liners adjacent to each other and casting the periphery of the cylinder liner with molten metal. It is.

[0002]

2. Description of the Related Art Conventionally, there has been known a cylinder block formed by casting a cylinder liner made of cast iron with an aluminum alloy or the like (for example, Japanese Patent Application Laid-Open No. Hei 5-321175). In this cylinder block, the weight of the entire block can be reduced by using only the cylinder liner made of cast iron.

FIG. 14 shows a cylinder block 10 of this type.
FIG. The cylinder block 100 includes an aluminum alloy block main body 101 and a cast iron liner structure 10 cast in the block main body 101.
2 and a water jacket 1 formed on the block body 101 so as to surround the liner structure 102.
03. The liner structure 102 is formed by joining a plurality of cylinder liners 104 having a cylindrical shape.

A plurality of bolt holes 105 are formed in the cylinder block 100, and a cylinder head (not shown) is fastened and fixed to the upper surface of the cylinder block 100 by the bolt holes 105 and bolts (not shown).

[0005]

In the cylinder block 100, a molten metal (a molten aluminum alloy) is poured around the liner structure 102 and solidified.
Each cylinder liner 104 is brought into a state of being tightly joined. Here, since each cylinder liner 104 has a cylindrical shape, the thickness of the block main body 101 near the joint portion B is partially increased (the chevron region A in FIG. 14). The melt solidifies later in time than the other portions of the melt. Therefore, the molten metal in the portion of the chevron region A moves to the direction indicated by the arrow in FIG. 14, that is, to another portion where the solidification and contraction starts earlier in time.

As a result, a lateral force F shown in FIG. 14 is applied to each cylinder liner 104 by the movement of the molten metal, and the cylinder liner 104 is deformed to have an elliptical cross section. In some cases, a gap was formed at the joint B of the liner 104. For this reason, there is a problem in that the accuracy of the shape of each cylinder bore (the inner peripheral wall of the cylinder liner 104) is reduced, and the rigidity of the liner component 102 is significantly reduced due to the gap formed in each joint B.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a cylinder block in which a plurality of cylinder liners are arranged adjacent to each other and the periphery thereof is made of molten metal. An object of the present invention is to suppress the deformation of each cylinder liner that occurs when the molten metal poured around the cylinder solidifies and contracts, and to prevent the generation of gaps between the liners.

[0008]

A first aspect of the present invention is the first aspect.
The invention relates to a liner structure formed by joining a plurality of cylinder liners so as to form a line at each joint, and a connected body formed so as to cover a side surface of the liner structure by solidifying a molten metal. In the cylinder block provided with (1) and (2), the joint portion is formed with a protruding portion extending from the side portion along the joint surface of each cylinder liner.

A second invention according to a second aspect of the invention is characterized in that, in the first invention, the projecting portion is a ridge extending in the axial direction of the cylinder liner. The first or second
According to the configuration of the invention, when the molten metal is solidified to form a connected body, the solidification contraction force of the molten metal acts on the surface of the protrusion or the ridge located on the side opposite to the joining surface. Due to this solidification shrinkage force, both joint surfaces at each joint are brought into close contact with each other.

According to a third aspect of the present invention, there is provided a liner structure formed by joining a plurality of cylinder liners so as to form a line at each joint, and a liner structure formed by solidifying molten metal. And a connecting body formed so as to cover the side surface of the cylinder liner, the side surface of the liner structure, at least a portion including a joint portion, a protrusion extending in the axial direction of the cylinder liner is formed. To that effect.

According to the above configuration, when the molten metal is solidified to form a connected body, the movement of the molten metal accompanying the solidification shrinkage is regulated by the ridges formed on the side surfaces of the liner structure. Further, the thick portion formed near the joint tends to solidify slowly, and the movement of the molten metal accompanying the solidification shrinkage increases in the thick portion. In the second invention, since the ridge is formed at least in the portion including the joint,
The movement of the molten metal is effectively suppressed.

According to a fourth aspect of the present invention, in the third aspect, at least two or more ridges are formed, and the ridge is located closer to the joint. The purpose is to make the height of the ridge higher than the height of the other ridges.

According to the above configuration, in addition to the operation of the third aspect, by making the height of the ridge located closer to the joint portion higher than the height of the other ridges,
The movement of the molten metal during solidification shrinkage is effectively suppressed.

According to a fifth aspect of the present invention, there is provided a liner structure formed by joining a plurality of cylinder liners so as to form a line at each joint, and a liner structure formed by solidifying molten metal. In the cylinder block provided with a connecting body formed so as to cover the side surfaces of the connecting body, the thickness of the connecting body at a position separated from the joint is relatively larger than the thickness of the connecting body at a position close to the joint. The purpose is to be set thick.

According to the above configuration, the thickness of the connecting body at a position separated from the joint is set relatively thick.
When the molten metal is solidified to form a connected body, the amount of the molten metal moving in a direction away from the joint is reduced.

According to a sixth aspect of the present invention, there is provided a liner structure formed by joining a plurality of cylinder liners so as to form a line at each joint, and a liner structure formed by solidifying molten metal. In the cylinder block provided with the connecting body formed so as to cover the side surface of the above, it is intended that a space through which the molten metal can enter is formed between the joined portions.

According to the above configuration, a space into which the molten metal can enter is formed between the joints, and a part of the molten metal enters and solidifies in this space. At this time, since the molten metal in the space solidifies and contracts, the molten metal is drawn into this space. As a result, the amount of molten metal moving in the direction away from the joint decreases.

According to a seventh aspect of the present invention, there is provided a liner structure formed by joining a plurality of cylinder liners so as to form a line at each joint, and a liner structure formed by solidifying molten metal. In the cylinder block provided with a coupling body formed so as to cover the upper surface and the side surface of the cylinder, an engagement portion for engaging with the coupling body covering the upper surface of the liner structure is formed at an upper portion of the joint. And

According to the above configuration, when the molten metal is solidified to form the connected body, the movement of the molten metal covering the upper surface of the liner structure is suppressed by the engaging portions formed above the respective joints. You. Therefore, the amount of the molten metal moving in the direction away from the joint decreases.

According to an eighth aspect of the present invention, there is provided a liner structure formed by joining a plurality of cylinder liners so as to form a line at each joint, and a liner structure formed by solidifying molten metal. A connection block formed so as to cover the side surfaces of the cylinder block, and a water jacket formed so as to surround the connection body. In addition, the purpose is to form a cooling water passage communicating with the water jacket, and to form a press-fit portion extending in the width direction of the cylinder liner while sandwiching the cooling water passage at its upper and lower positions.

According to the above construction, each cylinder liner is securely joined at the joint by the press-fitting portion. Further, leakage of the cooling water from the cooling water passage is suppressed by the press-fit portion,
In particular, it is possible to prevent the cooling water in the cooling water passage from reaching the mounting surface between the cylinder block and the cylinder head.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a plan view showing a cylinder block 14 for a four-cylinder engine in the present embodiment, and FIG.
FIG. 2 is a sectional view taken along line 2-2 in FIG. 1. As shown in FIGS. 1 and 2, the cylinder block 14 is
5, a liner structure 16 and a water jacket 17. As shown in FIG. 2, the upper surface of the block body 15 is processed so as to be flat,
Is a seal surface on which is mounted.

The liner structure 16 comprises four cylinder liners 19 (in FIG. 1, some cylinder liners 19 are shown).
(Only one is shown), and these liners 19 are arranged adjacent to each other in a line and joined to each other. Each cylinder liner 19 is formed in a cylindrical shape using cast iron as a material, and a cylindrical space surrounded by an inner peripheral wall thereof is a cylinder bore 19a.

As shown in FIG. 2, each cylinder bore 19a
Accommodates the piston 20 to which the piston ring 20a is attached so as to be able to reciprocate. In each cylinder bore 19a, a space above the piston 20 constitutes a part of a combustion chamber 22 for burning a mixture of fuel and air. Each of the cylinder bores 19a is formed in a highly accurate (roundness) cylindrical shape in order to maintain airtightness of an air-fuel mixture or exhaust gas generated by combustion.

FIG. 3 shows a part of the upper surface of the cylinder block 14, and FIG. 4 shows an enlarged part of FIG. In each cylinder liner 19, the other cylinder liners 19
The joining portions 23 each having a joining surface are formed at portions where the joining is performed. As shown in FIGS. 3 and 4, the joint portion 23 has protrusions 24 that extend over the entire length of the cylinder liner 19 on both sides (upper and lower sides in FIG. 3). As shown in FIG. 4, each protrusion 24 extends in the same direction as the joint surface of each joint 23. And each protrusion 2
4, a plane S parallel to each joint surface is formed at a position opposite to each joint surface. In this embodiment,
The protrusion 24 formed on each joint 23 corresponds to the protrusion of the present invention.

FIG. 5 is a sectional view taken along the line 5-5 in FIG. As shown in the figure, a concave portion 29 is formed in each joint 23 over the entire width direction (vertical direction in FIG. 1). A space K is formed between the inner walls of the concave portions 29, and a molten metal described later can enter the space K.

As shown in FIGS. 3 and 4, ribs 25 are formed on the side surface of each cylinder liner 19 at predetermined intervals so as to extend over the entire length of each cylinder liner 19. Each rib 25 is formed over the entire outer peripheral surface of the cylinder liner 19 including the side portion of the joint 23. Among these ribs 25, the rib 25 a formed at the position closest to the joint 23 is set higher than the other ribs 25.

The block body 15 is formed to have a predetermined shape by die casting. That is, the respective cylinder liners 19 are arranged adjacent to each other in a mold (not shown), and the respective cores (not shown) provided in the mold are inserted into the respective cylinder bores 19a so that the respective cylinder liners 19 are formed. It is fixed at the joint 23 in a close contact state. Then, the block main body 15 is formed by pouring molten metal (molten aluminum) into a mold and solidifying it. In the present embodiment, the molten aluminum corresponds to a molten metal for forming a connected body.

The block body 15 includes a liner structure 16.
A water jacket 17 is formed so as to surround the outer periphery of the water jacket 17. The block main body 15 and the liner structure 16 are cooled by the cooling water flowing in the water jacket 17. The water jacket 17 and the liner structure 1
6, a connecting portion 26 that forms a part of the block body 15 is formed so as to surround each cylinder liner 19. This connecting portion 26 allows each cylinder liner 1
9 are interconnected. The connecting portion 26 in the present embodiment corresponds to a connecting body of the present invention.

As shown in FIG. 4, the connecting portion 26 is formed with a thick portion 26a having a relatively large thickness on the side of each joint portion 23. As shown in FIG. 3, the thickness ta of the connecting portion 26 located on both side portions E of each cylinder liner 19 (the vertical position in FIG.
Is set to be thicker than the thickness tb at a position close to.

In the block body 15, a plurality of bolt holes 27 are formed in a portion corresponding to the outer side of the water jacket 17 as shown in FIG. As shown in FIG. 2, the cylinder head 28 is mounted on the upper surface of the cylinder block 14 via the gasket 21, and a bolt (not shown) attached to each bolt hole 27.
Is fastened and fixed.

The operation and effect of the embodiment constructed as described above will be described. In the present embodiment, when the molten metal is poured into the mold to form the block body 15, the molten metal in the thick portion 26a starts to contract toward the center of its own volume during the cooling process. As a result, as shown in FIG. 4, a solidification contraction force F1 acts on the plane S and the like as the molten metal solidifies.

Therefore, according to the present embodiment, the joining surfaces of the joining portions 23 can be brought into a more closely contacted state by the solidification contraction force F1. As a result, even when the molten metal moves along with the solidification and contraction of the molten metal as shown by the arrows in FIG. 4, the deformation of each cylinder liner 19 and the generation of the gap between the joining surfaces due to the movement of the molten metal are prevented. Can be suppressed. For this reason, it is possible to prevent a reduction in the shape accuracy of each cylinder bore 19a and a reduction in the rigidity of the liner structure 16.

According to this embodiment, each cylinder liner 1
A plurality of ribs 25 are formed on the side surface of the melt 9, and the ribs 25 can suppress the movement of the molten metal caused when the solidification and contraction occur.

Furthermore, according to the present embodiment, the height of the rib 25a formed closest to the joint 23 is set higher than the other ribs 25. Since the thickness of the connecting portion 26 is large in the vicinity of the joining portion 23, the moving amount when the molten metal solidifies and contracts is large. As described above, by locally setting the height of the rib 25 at a portion where the amount of movement of the molten metal is large, the running performance when the molten metal is poured into the mold is not significantly reduced. The movement of the molten metal at the time of solidification shrinkage can be effectively suppressed. As a result, deformation of each cylinder liner 19 and generation of a gap between the joints 23 can be reliably suppressed.

According to this embodiment, each cylinder liner 1
9, the thickness t of the connecting portion 26 at a position corresponding to both side portions E
a is set relatively thicker than other parts.
The movement of the molten metal in a direction away from the joining portion 23 occurs because the thickness of the connecting portion 26 in the vicinity of the joining portion 23 is thicker than other portions, and the solidification of the molten metal in that portion is delayed. Therefore, the connecting portions 26 on the both side portions E
The thickness tb at the position close to the joining portion 23 is made thinner than the thickness ta, so that the solidification of the molten metal in the vicinity of the position (thickness tb) is accelerated, and the influence of the molten metal shrinkage at the both side portions E is increased. It is possible to suppress the vicinity of the portion 26a. As a result, the amount of movement of the molten metal in the direction away from the joints 23 can be reduced, and deformation of the cylinder liners 19 and generation of gaps between the joints 23 due to the movement of the molten metal can be suppressed. it can.

According to the present embodiment, a concave portion 29 is formed in each joint portion 23, and a part of the molten metal poured into the mold is filled in a space K formed between the concave portions 29. Infiltrate and solidify. At this time, since the molten metal in the space K solidifies and contracts, the molten metal in the connecting portion 26 is drawn into the space K. As a result, it is possible to reduce the amount of the molten metal moving in a direction away from each of the joints 23, and to suppress deformation of each of the cylinder liners 19 and generation of a gap between each of the joints 23 due to the movement of the molten metal. be able to.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. 6 to 8, focusing on differences from the first embodiment. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

FIG. 6 is a plan view showing the upper surface of the cylinder block 14 in this embodiment. FIG. 7 is a sectional view taken along line 7-7 in FIG. 6, and FIG. 8 is a sectional view taken along line 8-8 in FIG.

As shown in FIG. 7, a concave portion 30 and a convex portion 31 are formed at the joint of each joint 23. Recess 3
0 and the protrusion 31 are formed over the entire width of the cylinder liner 19, and the protrusion 31
Are joined to each other by press-fitting. As shown in FIGS. 7 and 8, three grooves 32 extending over the entire width of the cylinder liner 19 are formed between the press-fit portions D1 and D2 of the concave portion 30 and the convex portion 31.

As shown in FIG. 6 and FIG.
6, a pair of communication holes 33 is provided at the position where the protrusion 24 was formed in the first embodiment.
The communication hole 33 is formed by solidifying a molten metal to form a block main body 15 having a shape similar to that of the block main body 15 in the first embodiment, and then performing drilling from the upper surface of the cylinder block 14. I have. FIG.
As shown in (1), each groove 32 communicates with the water jacket 17 through each communication hole 33, and forms a cooling water passage 34 between the bores. Part of the cooling water flowing through the water jacket 17 flows through the cooling water passage 34 between the bores, and cools the liner structure 16, particularly the vicinity of each joint 23, which is heated by the heat transmitted from the combustion chamber 22. The cooling water passage 34 between the bores in the present embodiment corresponds to the cooling water passage of the present invention.

According to the present embodiment configured as described above, since the structure in which the convex portion 31 is pressed into the concave portion 30 in each joint portion 23 is employed, the joining force at both joint portions 23 increases, and Deformation of the cylinder liner 19 due to the movement of the molten metal and generation of gaps between the joining surfaces can be suppressed more reliably.

Further, in the present embodiment, the convex portion 31 and the concave portion 3
Since the cooling water passage 34 between the bores is formed between the press-fitting portions D1 and D2 with zero, the leakage of the cooling water from the water passage 34 to the outside can be suppressed. In addition, according to the present embodiment, it is possible to prevent a problem that the cooling water leaks to the upper surface of the cylinder block 14 and enters the combustion chamber 22.

The inter-bore cooling water passage 3 is provided between the joints 23.
In the case where 4 is provided, it is necessary to apply an adhesive to the joint surface of the joint portion 23 to seal the water passage 34. However, according to the present embodiment, since the sealing property can be ensured by the press-fitting structure, the seal using such an adhesive is not required, and the configuration can be simplified.

Further, according to this embodiment, the inter-bore cooling water passage 34 is constituted by the plurality of grooves 32. Therefore,
Compared with the case where the inter-bore cooling water passage 34 is formed by one space, the bore rigidity can be secured, and the shape accuracy such as the roundness and straightness of the bore can be kept good.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. 9 to 13, focusing on differences from the first and second embodiments. explain. In the present embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted.

FIG. 9 shows the upper surface of the cylinder block 14 in this embodiment. FIG. 10 shows 10-10 of FIG.
FIG. 13 is a cross-sectional view taken along line 13-13 of FIG. 9. 11 is a partially enlarged view of FIG. 10, and FIG. 12 is a cross-sectional view taken along line 12-12 of FIG.

In the first and second embodiments,
The upper surface of the liner structure 16 was exposed, and the cylinder head 28 was attached to the exposed surface via the gasket 21. In contrast, in the present embodiment, FIG.
As shown in FIG. 0 and FIG. 13, the length of each cylinder liner 19 is set shorter than in the above embodiments, and the upper surface of the liner structure 16 is not exposed. That is, the upper surface of the liner structure 16 is covered with aluminum constituting a part of the connecting portion 26, similarly to the side surfaces. A connecting portion 26 (hereinafter referred to as a “connecting portion 2”
6b "), a cylinder head 28 is attached via a gasket 21.

As shown in FIGS. 11 and 12, a step portion 40 extending over the entire width of the cylinder liner 19 is formed at an upper portion of each joint portion 23. As shown in FIG. 12, concave portions 41 are formed at opposing positions on both side walls of each step portion 40, and each concave portion 41 has a predetermined length in the axial direction of the cylinder liner 19. A pair of protrusions 42 are formed facing each other. In the present embodiment, the recess 41 and the protrusion 42
Constitutes the engaging portion of the present invention.

The operation and effect of the embodiment constructed as described above will be described. In the present embodiment, the block main body 15 including the connecting portions 26 and 26b is formed by solidifying the molten metal poured into the mold as in the above embodiments. Connecting part 26 on the upper surface of joint 23
The molten metal b tends to move to both ends of the joint portion 23 as shown by arrows in FIGS. 9 and 12 during solidification and shrinkage, and the molten metal in the central portion C of the connecting portion 26b has Tensile stress acts with the movement. As a result, this connecting portion 2
Tensile stress will remain in the central part C of 6b when the molten metal solidifies, and if this tensile stress exceeds the limit strength of aluminum, cracks may occur.

However, according to the present embodiment, by providing the step portion 40 and increasing the cross-sectional area (cross-section shown in FIG. 11) of the connecting portion 26b, it is possible to suppress the occurrence of the crack as described above. . Further, by forming the protrusion 42 in the recess 41 of the step portion 40, the movement of the molten metal in the connecting portion 26b can be suppressed. Thereby, the tensile stress generated in the central portion C of the connecting portion 26 can be reduced, and the occurrence of cracks in the portion C can be suppressed. In addition, by suppressing the movement of the molten metal in the connecting portion 26b, the amount of the molten metal moving in a direction away from each joint 23 can be reduced, and the deformation of each cylinder liner 19 due to the movement of the molten metal can be reduced. And each joint 23
The generation of a gap between them can be suppressed.

The embodiments of the present invention have been described above. However, the present invention can be embodied as another embodiment described below. In this alternative embodiment, substantially the same functions and effects as those of the above embodiments can be obtained.

(1) In each of the above embodiments, the rib 25 is formed over the entire side surface of the liner structure 16. On the other hand, a configuration in which the ribs 25 are formed only in the vicinity of each joint 23 may be adopted in consideration of the improvement of the run-off property when the molten metal is poured into the mold.

(2) In the above embodiments, cast iron was selected as the material of the cylinder liner 19. On the other hand, aluminum alloy or MMC (metal matrix composite, Meta
The cylinder liner 19 may be formed by l Matrix Composite) or PMCC (Powder Metallurg Composite).

(3) In each of the above embodiments, the block body 15 is formed by die casting. On the other hand, the block main body 15 may be formed by various casting methods such as medium pressure casting and low pressure casting.

The technical ideas grasped from the above embodiments are described below together with their effects. (A) In the cylinder block according to claim 8,
The cooling water passage is formed by a plurality of grooves extending in the width direction of the cylinder liner.

According to the configuration described in (a) above, the rigidity of the bore can be improved by forming the cooling water passage with a plurality of grooves.

[0059]

According to the first aspect of the present invention, the projecting portion extending from the side of the joining portion along the joining surface of the cylinder liner is formed. Further, according to the second aspect of the present invention, the protruding portion is constituted by a ridge extending in the axial direction of the cylinder liner. The solidification contraction force of the molten metal acts on the surface of the protruding portion or the ridge located on the side opposite to the joining surface when the molten metal is solidified to form a connected body. Therefore, according to the first or second aspect of the present invention, the joint surfaces at each joint are brought into close contact with each other by the solidification contraction force. as a result,
Deformation of each cylinder liner and generation of a gap between the cylinder liners can be prevented.

According to the third aspect of the present invention,
A protrusion extending in the axial direction of the cylinder liner is formed on at least a portion including the joint on the side surface of the liner structure. Therefore, when the molten metal is solidified to form a connected body, the movement of the molten metal accompanying the solidification shrinkage can be effectively suppressed. As a result, deformation of each cylinder liner and generation of a gap between the cylinder liners can be prevented.

According to the fourth aspect of the present invention,
At least two or more ridges are formed, and the height of the ridge located closer to the joint is higher than the height of the other ridges. Therefore, in addition to the effects of the third aspect, the movement of the molten metal during solidification shrinkage can be more effectively suppressed, and deformation of each cylinder liner and generation of a gap between the cylinder liners can be prevented. it can.

According to the fifth aspect of the present invention,
The thickness of the connecting body at a position distant from the joint is relatively increased. Therefore, when the molten metal is solidified to form a connected body, the amount of the molten metal moving in a direction away from the joint is reduced. As a result, deformation of each cylinder liner and generation of a gap between the cylinder liners can be prevented.

According to the sixth aspect of the present invention,
A space through which the molten metal can enter is formed between the joined portions. When a part of the molten metal enters the space and solidifies and contracts, the molten metal is drawn into the space, so that the amount of the molten metal moving in the direction away from the joint decreases. As a result, deformation of each cylinder liner and generation of a gap between the cylinder liners can be prevented.

According to the seventh aspect of the present invention,
An engagement portion is formed at an upper portion of the joint to engage with a connector that covers the upper surface of the liner structure. Therefore, by the engagement portion,
When the molten metal is solidified to form a connected body, the movement of the molten metal covering the upper surface of the liner structure is suppressed, so that the amount of the molten metal moving in a direction away from the joint decreases. As a result, deformation of each cylinder liner and generation of a gap between the cylinder liners can be prevented. In addition, the occurrence of cracks in the molten metal covering the upper surface of the liner structure can be prevented.

According to the eighth aspect of the present invention,
Between each joint, while forming a cooling water passage communicating with the water jacket, sandwiching the cooling water passage at its upper and lower positions,
In addition, a press-fit portion extending in the width direction of the cylinder liner is formed. Therefore, since the cylinder liners are securely joined at the joining portion by the press-fit portion, deformation of the cylinder liners and generation of a gap between the cylinder liners can be prevented. In addition, it is possible to suppress the leakage of the cooling water from the cooling water passage, and in particular, to prevent the cooling water of the cooling water passage from reaching the mounting surface between the cylinder block and the cylinder head.

[Brief description of the drawings]

FIG. 1 is a plan view showing a cylinder block according to a first embodiment.

FIG. 2 is a sectional view taken along the line 2-2 in FIG. 1;

FIG. 3 is a plan view showing the vicinity of a joint.

FIG. 4 is an enlarged plan view showing the vicinity of a joint.

FIG. 5 is a sectional view taken along the line 5-5 in FIG. 1;

FIG. 6 is a plan view showing a cylinder block according to a second embodiment.

FIG. 7 is a sectional view taken along the line 7-7 in FIG. 6;

FIG. 8 is a sectional view taken along line 8-8 in FIG. 6;

FIG. 9 is a plan view showing a cylinder block according to a third embodiment.

FIG. 10 is a sectional view taken along the line 10-10 in FIG. 9;

FIG. 11 is an enlarged sectional view of a main part of FIG. 10;

FIG. 12 is a sectional view taken along the line 12-12 in FIG. 11;

FIG. 13 is a sectional view taken along the line 13-13 in FIG. 9;

FIG. 14 is a plan view showing a cylinder block according to a conventional technique.

[Explanation of symbols]

14 ... cylinder block, 15 ... block body, 16 ...
Liner component, 17 ... Water jacket, 19 ... Cylinder liner, 23 ... Joined portion, 24 ... Protrusion as protruding portion, 25 ... Rib as protruding ridge, 26, 26b ... Connecting portion as connecting body, 28 ... Cylinder Head, 34: cooling water passage between bores, 41: concave portion as an engaging portion, 42: projecting portion as an engaging portion, D1, D2: press-fit portion, K: space.

Claims (8)

[Claims] 1. A liner structure formed by joining a plurality of cylinder liners so as to form a line at each joint, and a connection formed so as to cover a side surface of the liner structure by solidifying molten metal. A cylinder block comprising a body and a body, wherein the joint portion is formed with a protrusion extending from a side portion thereof along a joint surface of each of the cylinder liners. 2. The cylinder block according to claim 1, wherein the projecting portion is a ridge extending in an axial direction of the cylinder liner. 3. A liner structure formed by joining a plurality of cylinder liners so as to form a line at each joint, and a connection formed so as to cover a side surface of the liner structure by solidifying a molten metal. A cylinder block, comprising: a body; and a side surface of the liner structure, at least a portion including the joint portion is formed with a ridge extending in an axial direction of the cylinder liner. 4. The cylinder block according to claim 3, wherein at least two or more ridges are formed, and the height of the ridge is closer to the joint. Characterized in that the height of the cylinder block is higher than the height of the other ridges. 5. A liner structure formed by joining a plurality of cylinder liners so as to form a line at each joint, and a connection formed so as to cover a side surface of the liner structure by solidifying molten metal. In the cylinder block including the body, the thickness of the connecting body at a position separated from the joint is set to be relatively thicker than the thickness of the connecting body at a position close to the joint. A cylinder block characterized by the following. 6. A liner structure formed by joining a plurality of cylinder liners so as to form a line at each joint, and a connection formed so as to cover a side surface of the liner structure by solidifying molten metal. A cylinder block comprising a body, wherein a space through which the molten metal can enter is formed between the joined portions. 7. A liner structure formed by joining a plurality of cylinder liners in a row at respective joints, and formed so as to cover an upper surface and side surfaces of the liner structure by solidifying molten metal. A cylinder block comprising: a connection body that covers an upper surface of the liner structure; and an engagement portion that engages with a connection body that covers an upper surface of the liner structure. 8. A liner structure formed by joining a plurality of cylinder liners so as to form a line at each joint, and a connection formed so as to cover a side surface of the liner structure by solidifying molten metal. A body and a water jacket formed so as to surround the periphery of the connecting body, wherein a cylinder block in which an upper surface of the connecting body serves as a mounting surface of a cylinder head is connected to the water jacket between the joints. And a press-fitting portion extending in the width direction of the cylinder liner and sandwiching the cooling water passage between upper and lower positions thereof.