JP2002180899A - Cylinder block of semi-wet structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder block of a semi-wet structure capable of preventing the water leakage of a water jacket, and improving the fuel economy by improving the rigidity of a cylinder bore and reducing the deformation of the bore in service. SOLUTION: This cylinder block of the semi-wet structure has a block main body 17, a lower part of a cylinder liner 41 is press fitted to the main body 17, and the water jacket 16 is formed between an upper outer peripheral face of the liner and an inner wall face of the block main body 17. A straight joining face 41a is formed on a position between cylinder bores, of each cylinder liner, the joining faces of the adjacent cylinder liners are abutted on each other, and an upper part of the abutted faces is welded. As the parts between the cylinder bores are joined in plane while ensuring the necessary thickness on parts excluding the joining faces, the rigidity of the cylinder liner can be improved.

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 internal combustion engine mounted on a vehicle such as an automobile.
The present invention relates to a cylinder block having a semi-wet structure in which a lower portion of a cylinder liner is press-fitted and an upper portion thereof is wet.

[0002]

2. Description of the Related Art Conventionally, as a cylinder block of an internal combustion engine, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 11-182327. This cylinder block uses a cylinder liner connection body of an internal combustion engine which is formed by joining a plurality of cylinder liners forming an inner wall of a cylinder. By connecting the tips of the protrusions provided on the outer peripheral surface of the adjacent cylinder liner to the outer peripheral surface of the mating cylinder liner with the opposite end, all the cylinder liners are arranged around the protrusion. Joined leaving space. The space serves as a cooling water passage between adjacent cylinder liners. With such a configuration, even when the dimension between the cylinder bores is small, a cooling water passage can be provided between the cylinder liners. In addition, this cylinder liner connection body is a cast-in liner made by casting when the block main body of the cylinder block is cast.

[0003]

However, the above prior art has the following problems. (1) Since there is a gap at the interface of the cast-in, there is a possibility that the cooling water in the water jacket leaks from the cast-in portion of the cylinder liner.

(2) Since it is a cast-in liner, the thickness of the cylinder liner is not uniform and the residual stress of the liner is large. For this reason, bore deformation (deformation of the cylinder liner) during actual operation is large, friction between each cylinder bore and the piston ring is increased, and fuel consumption is deteriorated.

(3) The thickness of each cylinder liner is uniform over the entire circumference, and the liner thickness is expressed by the following equation. (Liner thickness) = (dimension between bores) / 2− (height of the protruding portion) Therefore, the liner thickness is thin over the entire circumference, and
The joint between the tip of the protruding portion and the outer peripheral surface of the mating cylinder liner is only a contact point on the circumference. Thus, the rigidity of the cylinder liner connection body (the rigidity of the cylinder bore) is small.

(4) The space around the protruding portion of each cylinder liner is a cooling water passage between the cylinder liners.
However, the space where the water channel is formed is a portion where the outer peripheral surfaces of the adjacent cylinder liners face each other, and the space is the narrowest.
Therefore, the cooling water passage formed between the cylinder bores is
It becomes a narrowed water channel, and it is not possible to supply cooling water with a sufficient flow rate and flow velocity between the cylinder bores. As a result, the temperature distribution in the circumferential direction of each cylinder bore becomes non-uniform. In particular, the temperature distribution in the upper portion of each of the cylinder bores, which has the highest temperature due to being close to the combustion chamber, becomes non-uniform, and the deformation of the cylinder bore in actual operation increases.

The present invention has been made in view of such circumstances, and has as its object to prevent water leakage of a water jacket, improve the rigidity of a cylinder bore, and reduce bore deformation during actual operation. An object of the present invention is to provide a cylinder block having a semi-wet structure with improved fuel efficiency. Also,
Another object of the present invention is to provide a cylinder block having a semi-wet structure in which the temperature distribution in the circumferential direction of the cylinder bore, particularly the temperature distribution in the circumferential direction above the cylinder bore is improved.

[0008]

The means for solving the above problems and the operation and effects thereof will be described below. The invention according to claim 1 has a block body in which a plurality of cylinders are formed, and a lower portion of a cylinder liner is press-fitted into the block body, and an upper outer peripheral surface of each cylinder liner and an inner wall surface of an outer wall of the block body. In a semi-wet structure cylinder block in which the upper part of each cylinder liner is made wet by forming a water jacket between them, a linear mating surface is formed at a portion between the cylinder bores of each cylinder liner, This is a semi-wet cylinder block configured by abutting the mating surfaces of the respective cylinder liners and joining the upper portions of the mating surfaces.

According to the present invention, since the lower portion of the cylinder liner is press-fitted into each cylinder with an interference, water leakage of the water jacket can be prevented. Also,
Since the cylinder liner is not a cast-in liner but a press-fit liner, the thickness of the cylinder liner is uniform and the residual stress is small. For this reason, the bore deformation (deformation of the cylinder liner) during operation is small, the tension of the piston ring is reduced, and the friction between each cylinder bore and the piston ring is reduced. Therefore, fuel efficiency can be improved.

[0010] In addition, linear mating surfaces are formed in portions between the cylinder bores of the respective cylinder liners, and the mating surfaces of the respective cylinder liners are abutted and joined to each other. In this way, each cylinder liner secures a necessary thickness at a portion other than the mating surface and joins the portions between the cylinder bores in a plane, so that the rigidity of the cylinder liner is improved. This also reduces bore deformation during actual operation, reduces the tension and friction, and improves fuel efficiency.

According to a second aspect of the present invention, in the cylinder block having the semi-wet structure according to the first aspect, a liner wall portion below the joint portion of each of the cylinder liners is recessed to form a water passage between bores. Is formed.

According to the present invention, an inter-bore water passage is formed below the joint of each cylinder liner by the space between adjacent cylinder liners formed by recessing the liner wall. For this reason, even if the dimension between bores is small, a waterway between bores can be formed. Further, the bore-to-bore water passage can supply cooling water having a sufficient flow rate and flow velocity between the bores of the respective cylinder liners to sufficiently cool the space between the bores. Thereby, the temperature distribution in the circumferential direction of each cylinder bore becomes uniform. In particular, the temperature distribution in the circumferential direction at the top of each cylinder bore where the temperature is highest because it is close to the combustion chamber becomes uniform. For this reason, deformation of the cylinder bore (deformation of the cylinder liner) at the time of actual operation becomes smaller, and the tension and friction are further reduced, so that the fuel efficiency is further improved.

According to a third aspect of the present invention, there is provided a cylinder block having a semi-wet structure according to the first or second aspect,
The joint portion of each of the cylinder liners is provided with at least one inter-bore communication hole for communicating the water jacket of the cylinder head fastened to the block body and the inter-bore water passage.

According to the present invention, since the communication holes between the bores are provided, the flow rate and the flow velocity of the cooling water for cooling the space between the bores of the respective cylinder liners can be sufficiently ensured. Are more uniform, and the bore deformation during operation is smaller.

The communication holes between the bores provided at the joints of the cylinder liners can be formed by drilling a path from the upper surface of the block body toward the center of the water channel between the bores. For this reason, the length of the water passage between the bores is shorter than that in a case where the water passage between the bores that directly connects the water jackets of the cylinder head and the block body is formed by drilling. This facilitates drill path processing and reduces breakage of the drill, so that the cost of drill path processing can be reduced.

According to a fourth aspect of the present invention, there is provided a cylinder block having a semi-wet structure according to any one of the first to third aspects, wherein an upper outer peripheral surface of each of the cylinder liners and an inner wall surface of an outer wall of the block body. The water jacket formed therebetween is characterized by being formed in a substantially V-shaped vertical cross section in which a lower part width is smaller than an upper part width.

According to the present invention, it is possible to secure the cooling performance of the upper part of each cylinder liner, which is higher in temperature than the lower part, and to prevent the lower part of the block body from being too cold.
As a result, the temperature distribution in the vertical direction of each cylinder liner at the time of actual operation is uniform, the straightness of the cylinder bore at the time of actual operation is improved, the friction between the cylinder bore and the piston ring is further reduced, and the fuel efficiency is further improved. I do.

According to a fifth aspect of the present invention, in the cylinder block having a semi-wet structure according to any one of the first to fourth aspects, a groove is formed above the mating surface of each of the cylinder liners. It is characterized by having.

According to the present invention, since the upper part of the mating surface of each cylinder liner has a groove shape, the mating surfaces of the cylinder liners are butted with each other and the upper part is easily joined by laser welding or the like. Can be.

According to a sixth aspect of the present invention, in the semi-wet structure cylinder block according to any one of the second to fourth aspects, the linear mating surface is provided near an upper surface of each of the cylinder liners. It is characterized by having.

According to the present invention, it is possible to sufficiently secure the volume of the water passage between the bores.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a semi-wet cylinder block embodying the present invention will be described below with reference to the drawings. In this embodiment, an example is shown in which the present invention is applied to a multi-cylinder engine mounted on a vehicle such as an automobile, for example, a four-cylinder engine. As shown in FIGS. 1 and 2, the cylinder block 14 having a semi-wet structure
Is a block body 17 having a water jacket 16
And a cylinder head 19 having a water jacket 18 therein. This cylinder head 19 is fastened to the upper surface of the block body 17. The water jacket 16 of the block body 17 is formed around four cylinder bores 30. In addition, in each of the inter-bore portions 31 to 33 which is a portion between the two adjacent cylinder bores 30, 30, inter-bore water passages 21 to 23 for communicating the water jackets 16, 18 are formed. In addition, the cylinder block 14 of the present embodiment is configured such that, for example, the entire amount of cooling water sent by a water pump (not shown)
Into the water jacket 18 of the
It flows inside. At the same time, a part of the cooling water flowing into the water jacket 18 flows into the water jacket 16 of the block body 17 through the water passages 21 to 23 between the bores.

The four cylinder bores 3 of the block body 17
Numeral 0 is constituted by the inner peripheral surfaces of the four cylinder liners 41 to 44, respectively, as shown in FIGS. Each of the cylinder liners 41 to 44 is, for example, a cast iron liner formed in a cylindrical shape by centrifugal casting or the like. Also,
The cylinder liners 41 and 44 have the same shape, and the cylinder liners 42 and 43 have the same shape.

Here, each of the cylinder liners 41 to 44 is
This will be described with reference to FIGS. Each cylinder liner 41
The lower part 45 of the to 44 has a smaller outer diameter and a smaller thickness than the upper part 46 (see FIG. 3). As shown in FIG. 3, lower portions 45 of the cylinder liners 41 to 44 are formed at lower portions of outer walls 50 of the block body 17.
Each of the small diameter holes 50a is press-fitted. Outer wall 50
Of the block body 17 has an inclined surface (inner wall surface) 50b whose inner diameter gradually decreases as going downward from the upper surface of the block body 17.
It has become. In addition, a water jacket 16 is formed between the outer peripheral surface of the upper portion 46 of each of the cylinder liners 41 to 44 and the inclined surface 50b of the outer wall 50.
The upper part 46 of 44 is wet.

As shown in FIGS. 2, 4 to 8, linear mating surfaces 41a to 44a are formed in the portions between the cylinder bores of the cylinder liners 41 to 44, respectively. That is, the cylinder liner 41 is provided with one mating surface 41a at a portion between the cylinder bores on one side. Similarly to the cylinder liner 41, the cylinder liner 44 is provided with one mating surface 44a. On the other hand, the cylinder liner 42 is provided with mating surfaces 42a, 42a at portions between the two cylinder bores on both sides. The cylinder liner 43 is also provided with two mating surfaces 43a, 43a similarly to the cylinder liner 42.

Above the mating surfaces 41a to 44a of the cylinder liners 41 to 44, grooves for welding (see grooves 41b and 42b shown in FIG. 9) are formed.
The mating surfaces 41a to 44a of the cylinder liners 41 to 44
The grooves (41b, 41b,
The four cylinder liners 41 to 44 are integrated by welding 42b) by welding or the like. In this example, the mating surfaces 41a, 42 of the cylinder liners 41, 42
a, the mating surfaces of the cylinder liners 42, 43 and the mating surfaces of the cylinder liners 43, 44 are respectively butted and joined by filler supply laser welding or the like. This welded part (joined part) is indicated by reference numeral 47 in FIG. The portions between the cylinder bores of the cylinder liners 41 to 44 are joined to each other by such welding to form the inter-bore portions 31 to 33 shown in FIG. 2.

The thickness of the upper portion 46 of each of the cylinder liners 41 to 44 is equal to the "dimension between bores" over the entire circumference except for the portions (liner wall portions) below the mating surfaces 41a to 44a.
(See FIG. 7). The “dimensions between bores” in this example are, as shown in FIGS.
This is the thickness of the narrowest part of the bore gaps 31 to 33 formed by welding two adjacent cylinder liners. Thus,
Each of the cylinder liners 41-44 has a mating surface 41a-44.
Except for the portion below a, the thickness is increased over the entire circumference to ensure sufficient rigidity.

The bore-to-bore water passages 21 to 23 are formed below the welded portions 47 of the cylinder liners 41 to 44. In order to form the water passages 21 to 23 between the bores, the liner walls (the liner walls 41c and 42c shown in FIG. 9) below the respective mating surfaces 41a to 44a are depressed. That is, the liner wall portion 41c below the mating surface 41a of the cylinder liner 41 is depressed to reduce its thickness. Similarly, the liner wall portion 42c below the mating surface 42a of the cylinder liner 42 and the liner wall portions below the mating surfaces of the cylinder liners 43 and 44 are also depressed to reduce the wall thickness. With such a configuration, each of the two liner walls 4 of the adjacent cylinder liners, for example, the cylinder liners 41 and 42,
1c, 42c, and a space is formed between the bores 2
It is 1. The same applies to the other water passages 22 and 23 between the bores. These bore-to-bore water channels 21 to 23 respectively face the water jacket 16. A tapered portion 42d for facilitating the press-fitting is formed on the outer periphery of the lower end of the lower portion 45 of each of the cylinder liners 41 to 44.

As shown in FIGS. 1 and 2, the welded portion 47 of each of the cylinder liners 41 to 44 is provided with the water jacket 18 of the cylinder head 19 and the water passages 21 to 2 between the bores.
Communication holes 51 and 52 for communicating the respective holes 3 with each other
Is provided. Each of the inter-bore communication holes 51 and 52 is formed by drill pass processing from the upper surface of the block body 17 to the center of each of the inter-bore water passages 21 to 23. FIG. 2 shows the water inlets of the inter-bore communicating holes 51 and 52 formed in the three inter-bore portions 31 to 33, respectively. The water inlets of the bore communication holes 51 and 52 communicate with the water jacket 18 via vertical holes 53 and 54 provided in the cylinder head 19 (see FIG. 1). Thus, a part of the cooling water flowing into the water jacket 18 of the cylinder head 19 is
4, communication holes 51 and 52 between bores, and water passages 21 and 2 between bores
3 to flow into the water jacket 16 of the block body 17.

Then, as shown in FIG. 3, the outer peripheral surface of the upper portion 46 of each of the cylinder liners 41 to 44 and the inclined surface 5 of the outer wall 50 are formed.
The water jacket 16 formed between the upper and lower portions of the water jacket 16 has a V-shaped vertical cross section in which the lower width is smaller than the upper width. For example, water jacket 16
The width of the lower part is less than one third of the width of the upper part.

According to the embodiment configured as described above, the following operation and effect can be obtained. (1) Since the lower portion 46 of each of the cylinder liners 41 to 44 is press-fitted into the small-diameter hole 50a of the outer wall 50 with an interference, water leakage of the water jacket 16 can be prevented.

(2) Each of the cylinder liners 41 to 44 is not a cast-in liner but a press-fit type liner. As a result, the mating surfaces 41a-4a of the cylinder liners 41-44
The liner wall portion 4a below (the liner wall portion 41c shown in FIG. 9)
Cylinder liner 41
~ 44 with uniform thickness and low residual stress. Therefore, bore deformation (deformation of the cylinder liner) during actual operation is small, the tension of the piston ring is reduced, and the friction between each cylinder bore 30 and the piston ring is reduced. Therefore, fuel efficiency can be improved.

(3) Since the upper part 46 of each of the cylinder liners 41 to 44 is made wet, the cooling performance of each cylinder bore 30 is improved, and the flow rate and flow rate of the cooling water can be reduced. Thereby, a cooling loss can be reduced.

(4) Linear mating surfaces 41a to 44a are provided between the cylinder bores of the cylinder liners 41 to 44.
Are formed, and the respective mating surfaces are abutted against each other and the upper portion thereof is joined by welding or the like. In this way, since the cylinder lies 41 to 44 secure the required thickness at portions other than the mating surfaces 41a to 44a and join the portions between the cylinder bores in a plane, the rigidity of each cylinder liner is reduced. improves. Specifically, each of the cylinder liners 41 to 4
The thickness of the upper portion 46 of the upper portion 4 is greater than half of the “dimension between bores” over the entire circumference excluding portions below the mating surfaces 41a to 44a (liner wall portions 41c and 42c shown in FIG. 9). ing. For this reason, each of the cylinder liners 41 to 4
No. 4 has a large thickness over the entire periphery except for a portion below the mating surface, so that sufficient rigidity can be secured. Accordingly, bore deformation during actual operation is reduced, the tension and friction are reduced, and fuel efficiency can be improved.

(5) Below the welded portion 47 of each of the cylinder liners 41 to 44, a liner wall portion (41c, 42) below the welded portion 47 is formed.
The space between adjacent liner walls formed by depressing c) forms water passages 21 to 23 between bores. For example, each liner wall portion 41c of the cylinder liners 41, 42,
A space is formed between 42c, and this space is the water channel 21 between the bores. For this reason, even if the dimension between bores is small, a waterway between bores can be formed.

(6) By the inter-bore water passages 21 to 23, a sufficient flow rate and flow rate of cooling water can be supplied between the bores of the cylinder liners 41 to 44 to sufficiently cool the bores. Thereby, the temperature distribution in the circumferential direction of each cylinder bore 30 becomes uniform. In particular, the temperature distribution in the circumferential direction at the top of each of the cylinder bores 30, which is at the highest temperature because it is close to the combustion chamber, becomes uniform. For this reason, the deformation of the cylinder bore 30 (deformation of the cylinder liner) at the time of actual operation becomes smaller, and the tension and friction are further reduced, so that the fuel efficiency is further improved.

(7) In the welded portion 47 of each of the cylinder liners 41 to 44, two bore communication holes 51 and 52 are provided to communicate the water jacket 18 of the cylinder head 19 and the water passages 21 to 23, respectively. ing.
Thereby, between the bores 3 of the cylinder liners 41 to 44
A sufficient flow rate and flow rate of the cooling water for cooling 1 to 33 can be secured. Therefore, the temperature distribution in the circumferential direction of each cylinder liner becomes more uniform, and the bore deformation during operation becomes smaller.

(8) The bore communication holes 51 and 52 provided in the welded portion 47 of each of the cylinder liners 41 to 44 can be formed by drill pass processing from the upper surface of the block body 17 to the center of the bore water channels 21 to 23. . For this reason, the length of the water passage between the bores is shorter than that in the case where the water passage between the bores for directly communicating the water jackets 16 and 18 of the block head 17 with the cylinder head 19 is formed by drilling.
This facilitates drill path processing and reduces breakage of the drill, so that the cost of drill path processing can be reduced.

(9) The water jacket 16 formed between the outer peripheral surface of the upper portion 46 of each of the cylinder liners 41 to 44 and the inclined surface 50b of the outer wall 50 has a lower portion whose width is substantially smaller than the upper portion. It is formed in a vertical cross section of a letter shape. Thereby, the lower part 4 of each cylinder liner 41-44
The cooling performance of the upper portion 46, which is higher than 5, can be ensured, and the lower portion of the block body can be prevented from being too cold. Therefore, each cylinder liner 41 in actual operation
44, the vertical temperature distribution becomes uniform, the straightness of each cylinder bore 30 during operation is improved, the tension and friction are further reduced, and the fuel efficiency is further improved.

(10) The water jacket 16 having a substantially V-shaped vertical cross section is formed between the outer peripheral surface of the upper portion 46 and the inclined surface 50b of the outer wall 50. For this reason, the width of the lower portion of the water jacket 16 can be reduced without using a filler as disclosed in Japanese Utility Model Laid-Open No. 57-43338 and without causing damage to a mold or the like. For example, the width of the lower part can be set to 1/3 or less of the width of the upper part. On the other hand, when casting a block body by casting a cylinder liner, if a water jacket having a thin V-shaped vertical section with a thin tip is to be formed, cracks are likely to occur in the mold, and the life of the mold is reduced. Becomes shorter.

(11) The upper portions of the mating surfaces 41a to 44a of the cylinder liners 41 to 44 are grooved (grooves 41b, 41b).
42b), the mating surfaces of the cylinder liners can be abutted against each other and the upper portion thereof can be easily joined by laser welding or the like.

(12) Linear mating surfaces 41a to 44a
Are provided near the upper surfaces of the cylinder liners 41 to 44. Thereby, the volume of the water passages 21 to 23 can be sufficiently secured.

(13) Since each of the cylinder liners 41 to 44 is a press-fit liner, there is no need to cast the liners when casting the block body 17. This allows
When the block body 17 is cast, the molten metal is not cooled by the liner, so that the ability to run the molten metal is improved.

[Modifications] While one embodiment of the present invention has been described above, the above-described embodiment can be implemented by changing its configuration as described below.

In the above embodiment, the cylinder block having a semi-wet structure according to the present invention is applied to a cylinder block of a four-cylinder engine. However, the present invention can be applied to a multi-cylinder engine other than the four-cylinder engine. That is, series 3,
The present invention is applicable to all engines such as 4, 5 cylinders, V-type 6, 8, 12 cylinders, and horizontally opposed 4, 5 cylinders.

In the above embodiment, the two bore communication holes 51, 51 are formed in the welded portions 47 of the cylinder liners 41 to 44.
Although 52 is provided, the number of communication holes between the bores may be one.

In the above-described embodiment, the communication holes 51 and 52 between the bores are provided in advance in the mating surfaces 41a to 44a of the cylinder liners 41 to 44 with grooves in which the communication holes are halved. Is also good.

In the above embodiment, the entire amount of the cooling water sent by the water pump flows into the water jacket 18 of the cylinder head 19.
The present invention is not limited to this. For example, after the entire amount of cooling water flows into the water jacket 16 side of the block body 17, the water jacket 18
The present invention can also be applied to a device configured to flow into the side.

In the above embodiment, the shapes of the mating surfaces 41a to 44a of the cylinder liners 41 to 44 are not limited to the case where all are flat. For example, one mating surface of two adjacent cylinder liners may be a convex surface, and the other may be a concave surface in surface contact with the convex surface. Further, the convex surface or the concave surface may be a convex curved surface or a concave curved surface.

[Brief description of the drawings]

FIG. 1 is a view showing a cylinder block having a semi-wet structure according to an embodiment of the present invention, and is a longitudinal sectional view showing a space between cylinder bores.

FIG. 2 is a plan view showing a block main body of the cylinder block shown in FIG.

FIG. 3 is a longitudinal sectional view showing a portion other than between the bores of the block main body shown in FIG. 2;

FIG. 4 is a plan view of a cylinder liner.

FIG. 5 is a view taken in the direction of the arrow A in FIG. 4;

FIG. 6 is a sectional view taken along the line BB of FIG. 4;

FIG. 7 is a plan view showing two adjacent cylinder liners.

FIG. 8 is a sectional view of FIG. 7;

FIG. 9 is a cross-sectional view showing a joint between two adjacent cylinder liners.

[Explanation of symbols]

13 ... engine (internal combustion engine), 14 ... cylinder block, 16, 18 ... water jacket, 17 ... block body, 19 ... cylinder head, 21 to 23 ... water passage between bores, 30 ... cylinder bore, 31 to 33 ... part between bores, 41
-44: cylinder liner, 41a-44a: linear mating surface, 41b, 42b: groove, 41c, 42c: liner wall, 45: lower part of cylinder liner, 46: upper part of cylinder liner, 47: welded part ( Joint), 50 ... outer wall,
50a: small diameter hole, 50b: inclined surface, 51, 52: communication hole between bores, 51a, 52a: water inlet, 53, 54: vertical hole.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hirofumi Michioka 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Kazunari Takenaka 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Hiroyuki Izawa 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor ▼ Kichita Kazuya 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F Term ( Reference) 3G024 AA29 AA30 CA05 DA18 FA08

Claims (6)

[Claims] 1. A block body having a plurality of cylinders formed therein, wherein a lower portion of a cylinder liner is press-fitted into the block body, and a gap is formed between an upper outer peripheral surface of each cylinder liner and an inner wall surface of an outer wall of the block body. In a cylinder block having a semi-wet structure in which a water jacket is formed and an upper portion of each cylinder liner is wet, a linear mating surface is formed at a portion between cylinder bores of each cylinder liner, and each cylinder liner is formed. A semi-wet structure cylinder block formed by abutting the mating surfaces and joining the upper portions of the mating surfaces. 2. The semi-wet structure according to claim 1, wherein a liner between the bores is formed below the joint of each of the cylinder liners by recessing a liner wall below the joint. Cylinder block. 3. The joint of each of the cylinder liners,
The cylinder having a semi-wet structure according to claim 1 or 2, wherein at least one communication hole between bores is provided for communicating a water jacket of a cylinder head fastened to the block body and the water passage between bores. block. 4. The water jacket formed between an upper outer peripheral surface of each of the cylinder liners and an inner wall surface of an outer wall of the block main body has a substantially V-shaped shape in which a lower portion has a smaller width than an upper portion. The cylinder block having a semi-wet structure according to any one of claims 1 to 3, wherein the cylinder block is formed in a vertical cross section. 5. The cylinder block having a semi-wet structure according to claim 1, wherein an upper portion of the mating surface of each of the cylinder liners has a groove shape. 6. The semi-wet cylinder block according to claim 2, wherein the linear mating surface is provided near an upper surface of each of the cylinder liners.