JPH0828228A - Fluid path structure in cylinder block - Google Patents

Abstract

PURPOSE:To prevent fluid from leaking from a fluid path such as an oil path, etc., formed in the cylinder block of an internal combustion engine. CONSTITUTION:A cast iron cylinder liner block BL inserted in a cylinder block main body 1 made of aluminum alloy is integrally provided with a bearing part 27 for supporting a crankshaft Sc thereunder. An oil path 33 for connecting a main gallery 7m to a semicircular bearing hole 14 formed in the cylinder bock main body 1 is bored in an aluminum alloy inserted in a through hole 31 which is formed in such a state as penetrating through the bearing part 27. Because the oil passage 33 faces to the aluminum alloy over its whole length so as not to pass the interface with the cast iron, even if the aluminum alloy and the cast iron expand/contract at different heat expansion rates due to temperature change in the internal combustion engine, oil leakage from the interface can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid passage structure in a cylinder block made by casting a different material member made of a material different from that of the cylinder block body into a cylinder block body made of a light alloy.

[0002]

2. Description of the Related Art Conventionally, the cylinder block body of an internal combustion engine is formed by die casting of aluminum alloy,
A cast iron cylinder liner block is cast inside the cylinder block body (Japanese Patent Laid-Open No. 5-180066).
(See the official gazette).

[0003]

By the way, an oil passage for lubricating the crankshaft is formed in such a cylinder block, and the oil passage is usually formed from a main gallery formed in an aluminum alloy cylinder block main body from a cast iron. Made through a bearing portion formed in a cylinder liner block made of steel and communicates with the outer circumference of the crankshaft.

However, as described above, when the oil passage is formed across the cylinder block body made of aluminum alloy and the cylinder liner block made of cast iron, both of them are caused by the difference in the coefficient of thermal expansion between the aluminum alloy and the cast iron. There is a problem that a gap is likely to occur at the interface of the oil and oil leakage occurs from the gap.

The present invention has been made in view of the above circumstances, and in a cylinder block made of a light alloy cylinder block body in which different material members are cast, fluid leakage from a fluid passage formed therein is prevented. The purpose is to prevent.

[0006]

In order to achieve the above-mentioned object, the invention described in claim 1 is a cylinder block body made of a light alloy, in which a dissimilar material member formed of a material different from that of the cylinder block body is provided. In a cylinder block formed by casting, a fluid passage is formed in the light alloy cast in a through hole formed in a member of different material so as not to face the member of different material.

The invention according to claim 2 is a cylinder block body made of a light alloy, in which a different material member made of a material different from that of the cylinder block body is cast around, and The fluid passage is formed so as not to face the alloy cylinder block body.

According to a third aspect of the present invention, in addition to the structure of the first or second aspect, the different material member is a cylinder liner block integrally provided with a bearing portion for supporting a crankshaft. The fluid passage formed in the portion is an oil passage for lubricating the crankshaft.

Further, in the invention described in claim 4, in addition to the structure of claim 2, a plurality of bearing portions for supporting the crankshaft by the different material member and a reinforcing connecting portion for mutually connecting the bearing portions. It is a cylinder liner block equipped with
The fluid passage as an oil passage for lubricating the crankshaft is formed in the bearing portion and the reinforcing connection portion.

According to a fifth aspect of the present invention, in a cylinder block made by casting a cylinder liner block made of a material different from that of the cylinder block body in a light alloy cylinder block body, the cylinder liner block is a crank. A plurality of bearing portions that support the shaft are integrally provided, and an oil passage that lubricates the crankshaft is formed in the plurality of bearing caps that are coupled to these bearing portions and the reinforcing connection portion that mutually couples the bearing caps. It is characterized by

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 show a first embodiment of the present invention. FIG. 1 is a plan view of a cylinder block, FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1, and FIG. FIG. 3 is an enlarged sectional view taken along line 3-3, and FIG. 4 is a sectional view of the cylinder liner block corresponding to FIG.

In-line four-cylinder internal combustion engine cylinder block B
_C is a quadruple wet type cylinder liner block B
_The cylinder block body 1 having _L (dissimilar material member) is an open deck type, and the main body of the cylinder block body 1 is die cast aluminum alloy.

The cylinder block body 1 has its assembly
Pa part, that is, cylinder barrel part 1 _UAnd the lower
Part, that is, the crankcase part 1_LAnd consists of
Linda barrel part 1_UThe cylinder block body 1
Four barrel holes 3 that open to the side 2 are opened,
Cast iron, which has a lower coefficient of thermal expansion than aluminum alloy, is placed inside the reel hole 3.
Wet type cylinder liner block B_LLa
The inner parts 4 ... Are cast-molded integrally. Each liner part 4
A piston (not shown) is slidably fitted in each
A cylinder bore 21 is formed.

A water jacket 5 which opens to the deck surface 2 is formed between the outer wall surface of the four wet type cylinder liner blocks B _L and the inner wall surface of the barrel hole 3, and in the water jacket 5 is usually formed. The cooling water is circulated as in.

Further oil passage 7 to the outer wall of the cylinder barrel 1 _U, through the cylinder head (not shown) thereon deck surface 2 of the bolt holes 6 ... and lubricants for bolted
... is drilled.

The crankcase portion 1 _L constituting the lower portion of the cylinder block body 1 has left and right skirt walls 8 extending integrally downward from the lower portion of the cylinder barrel portion 1 _U ,
9 and both longitudinal end walls 10, 1 of the cylinder barrel 1 _U
A plurality of bearing walls 13 extending downward from the constricted portion 12 between the one and the four liner portions 4 and connecting the left and right skirt walls 8 and 9 integrally, and each bearing wall 13 ... The bearing portions 27 of the cylinder liner block _BL are cast into the inside of the cylinder. Each of the bearing portions 27 has a semicircular bearing hole 14 for supporting the crankshaft Sc, and each of the pair of bolt holes 15 formed on the lower surface thereof has the semicircular bearing hole 14 ... A bolt for connecting a bearing cap (not shown) that supports the crankshaft Sc in cooperation with each other is screwed.

Next, the structure of the four-piece wet type cylinder liner block _BL made of cast iron which is integrally formed in the aluminum alloy cylinder block body 1 during die casting of the cylinder block B _C will be described in detail. To do.

The quadruple wet type cylinder liner block _BL has four liner portions 4 ... And five bearing portions 27 .. The adjacent liner portions 4 ... Are connected to each other through a so-called Siamese. The three central bearings 27 ... are 2 on the left and 2 on the right, respectively.
.. are integrally connected to the lower part of the boundary walls 20 .. Also, the two bearing parts 27, 27 at both ends
Are integrally connected to the lower portions of both end walls in the longitudinal direction of the liner portions 4 ... by one left and right connecting portions 28, 28, respectively.

A seal flange 22 is integrally provided on the outer periphery of the lower portion of the liner portion 4 in a substantially horizontal direction in a direction substantially orthogonal to the cylinder axis, and the upper surface of the seal flange 22 is a flat seal surface 22. Formed in ₁ . Further, above the seal flange 22, on the outer periphery of the liner portions 4 ...
, 24 ... are integrally projected vertically and horizontally, and these ribs 23
24 are formed lower than the seal flange 22. Further, below the seal flange 22 of the liner portion 4, two upper and lower heat absorbing fins 29 sandwiched between two adjacent connecting portions 28, and substantially the entire length of the outer periphery of the cylinder liner block _BL. Three small ribs 30 for reinforcement extending ... Are integrally projected.

As is apparent from FIG. 4, through holes 31 are formed in the respective bearing portions 27 ... Of the cylinder liner block _BL.
... is formed. Therefore, the cylinder liner block _BL
When casting the steel into the cylinder block body 1, the bearing wall 1
Part of the molten aluminum alloy that constitutes 3 ...
… Inflows into. Then, in the portion of the aluminum alloy that has flowed into the through hole 31, the oil passage 33 extending from the main gallery 7m, which is one of the oil passages of the cylinder block Bc, to the oil groove 32 of the semicircular bearing hole 14 ... A passage) is drilled.

The lubricating oil supplied from the main gallery 7m passes through the oil passages 33 ... And the semicircular bearing holes 14 ...
Reaching the oil groove 32 of the crankshaft Sc supported by the oil groove 32.
Lubricate the outer periphery of. At this time, since the entire length of the oil passages 33 faces the aluminum alloy and does not pass through the interface with the cast iron, the temperature of the cylinder block Bc changes and the aluminum alloy and the cast iron expand and contract at different thermal expansion rates. However, there is no risk of oil leakage from the interface.

Next, a second embodiment of the present invention will be described with reference to FIG.

In the second embodiment, the lower end of the liner portions 4 ... And the bearing portion 2 are provided on one side wall of the cylinder liner block B _L.
The upper end of 7 ... Is integrally connected by a bulging portion 34, and the bulging portion 34 forms a main gallery 7m. The main gallery 7m communicates with the oil grooves 32 of the semicircular bearing holes 14 through the oil passages 33 that penetrate the inside of the bearings 27.

Thus, according to the second embodiment, the oil passage 3
Since the entire length of 3 faces cast iron and does not pass through the interface with the aluminum alloy, even if the cylinder block Bc changes in temperature and the aluminum alloy and cast iron expand and contract at different thermal expansion coefficients, There is no risk of oil leakage. Also,
The lower ends of the liner portions 4 ... And the upper ends of the bearing portions 27.
Cylinder liner block B _L
The rigidity of can be increased.

Next, a third embodiment of the present invention will be described with reference to FIG.

In the third embodiment, the five bearing portions 27 ... Of the cylinder liner block _BL are connected by a cylindrical reinforcing connecting portion 35 ... An oil passage 38 (fluid passage) formed so as to penetrate through the inside in the axial direction communicates with the oil passages 33 that reach the semicircular bearing holes 14 ...

Also in the third embodiment, similarly to the second embodiment, it is possible to prevent the oil leakage from the oil passages 38, 33 ... And the bearing portion 27 is provided by the reinforcing connecting portions 35.
It is possible to increase the rigidity of.

Next, a fourth embodiment of the present invention will be described with reference to FIG.

In the fourth embodiment, five bearing caps made of cast iron for supporting the crankshaft Sc in cooperation with the semicircular bearing holes 14 of the five bearing portions 27 of the cylinder liner block B _L. 36 ... is a cylindrical reinforcing connecting portion 37 integrated with them.
The oil passages 39 (fluid passages), which are connected by ... And are formed so as to penetrate through the inside of these reinforcing connection portions 37 in the axial direction, pass through the inside of the respective bearing caps 36. It communicates with the oil passage 33 which reaches 14 ...

According to the fourth embodiment, the oil passages 39 and 3 are also
Since 3 faces only the cast iron and does not cross the interface between the cast iron and the aluminum alloy, oil leakage does not occur from the interface due to the difference in thermal expansion coefficient between the two. Moreover, the rigidity of the bearing caps 26 can be increased by the reinforcing connecting portions 37.

Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various design changes can be made.

For example, the fluid passage in the inventions of claims 1 and 2 is not limited to the passage for the lubricating oil, but may be the passage for other fluid such as cooling water.

In the embodiment, the cylinder block body is made of aluminum alloy and the cylinder liner block is made of cast iron, but the materials are not limited to those of the embodiment.

Although the cylinder liner block for four cylinders is illustrated in the embodiment, the present invention can be applied to other cylinder liner blocks for multiple cylinders and single cylinders.

Furthermore, although the cylinder liner block is of the wet type in the embodiment, it is of course applicable to the dry type.

[0037]

As described above, according to the first aspect of the present invention, the through hole is formed in the light alloy cylinder block body, and the different material member that has been cast around is formed in the through hole. Since the fluid passage is formed in the cast light alloy so as not to come into contact with the different material member, the fluid passage does not pass through the interface between the light alloy and the different material, which ensures the fluid leakage from the interface. Can be prevented.

According to the invention described in claim 2,
Since the fluid passage is formed in the dissimilar material member cast inside the light alloy cylinder block body so as not to face the light alloy cylinder block body, the fluid passage passes through the interface between the light alloy and the dissimilar material. By doing so, it is possible to reliably prevent fluid leakage from the interface.

According to the invention described in claim 3,
Since the dissimilar material member is a cylinder liner block integrally provided with a bearing portion for supporting the crankshaft, and the fluid passage formed in the bearing portion is an oil passage for lubricating the crankshaft, there is no occurrence of lubricating oil leakage. The crankshaft can be reliably lubricated.

According to the invention described in claim 4,
A cylinder liner block in which a member of different material is integrally provided with a plurality of bearing portions for supporting the crankshaft and a reinforcing connecting portion for connecting the bearing portions to each other, and an oil for lubricating the crankshaft at the bearing portion and the reinforcing connecting portion. Since the fluid passage is formed as the passage, not only can the crankshaft be reliably lubricated without the occurrence of lubricating oil leakage, but also the rigidity of the bearing portion can be increased by the reinforcing connection portion.

According to the invention described in claim 5,
A cylinder liner block cast in a light alloy cylinder block body integrally includes a plurality of bearing portions for supporting a crankshaft, and a plurality of bearing caps coupled to these bearing portions and the bearing caps are mutually connected. Since the oil passage that lubricates the crankshaft is formed in the reinforcing connection part that is connected to
Not only can the crankshaft be reliably lubricated while preventing leakage of lubricating oil from the interface between the light alloy and the dissimilar material, but the rigidity of the bearing cap can be increased by the reinforcing connection portion.

[Brief description of drawings]

FIG. 1 is a plan view of a cylinder block according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG.

3 is an enlarged sectional view taken along line 3-3 of FIG.

FIG. 4 is a sectional view of a cylinder liner block corresponding to FIG.

FIG. 5 is a diagram corresponding to FIG. 4 according to a second embodiment of the present invention.

FIG. 6 is a perspective view of a cylinder liner block according to a third embodiment of the present invention.

FIG. 7 is a perspective view of a cylinder liner block according to a fourth embodiment of the present invention.

[Explanation of symbols]

1 Cylinder Block Main Body 27 Bearing Part 31 Through Hole 33 Oil Path (Fluid Path) 35 Reinforcement Connection Section 36 Bearing Cap 37 Reinforcement Connection Section 38 Oil Path (Fluid Path) 39 Oil Path (Fluid Path) B _L Cylinder Liner Block (Dissimilar Material Material) Sc Crankshaft

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiyoshi Furumori 1-4-1 Chuo, Wako City, Saitama Stock Company Honda R & D Co., Ltd.

Claims (5)

[Claims] 1. A cylinder block body (1) made of a light alloy.
In a cylinder block in which a dissimilar material member ( _BL ) made of a material different from that of the cylinder block body (1) is cast, a casting is performed in a through hole (31) formed in the dissimilar material member ( _BL ). A fluid passage structure in a cylinder block, characterized in that a fluid passage (33) is formed in the enclosed light alloy so as not to face the different material member (B _L ). 2. A cylinder block body (1) made of a light alloy.
In a cylinder block in which a different material member ( _BL ) formed of a material different from that of the cylinder block body (1) is cast, the different material member ( _BL ) is made of a light alloy cylinder block body (1). A fluid passage structure in a cylinder block, characterized in that fluid passages (33, 38) are formed so as not to face them. 3. The cylinder liner block, wherein the dissimilar material member (B _L ) is integrally provided with a bearing portion (27) for supporting the crankshaft (Sc), and a fluid passage formed in the bearing portion (27). (33, 38) is an oil passage that lubricates the crankshaft (Sc), 3.
The fluid passage structure in the described cylinder block. 4. The plurality of bearing members (27) for supporting the crankshaft (Sc) by the different material member ( _BL ) and a reinforcing connecting portion (35) for connecting the bearing portions (27) to each other are integrated. Cylinder liner block provided for the crankshaft (Sc) in the bearing portion (27) and the reinforcing connection portion (35).
The fluid passage structure in a cylinder block according to claim 2, wherein the fluid passage (33, 38) is formed as an oil passage for lubricating the. 5. A cylinder block body (1) made of a light alloy.
In a cylinder block in which a cylinder liner block ( _BL ) formed of a material different from that of the cylinder block body (1) is cast, the cylinder liner block ( _BL ) is a crankshaft (Sc).
A plurality of bearing portions (27) for supporting
An oil passage (33,) for lubricating the crankshaft (Sc) to a plurality of bearing caps (36) coupled to these bearing portions (27) and a reinforcing coupling portion (37) coupling the bearing caps (36) to each other. 39) A fluid passage structure in a cylinder block, characterized in that