JP3700588B2 - Cylinder block superstructure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an upper structure of a cylinder block of an internal combustion engine.
[0002]
[Prior art]
A cylinder block of a multi-cylinder internal combustion engine is required to make the wall temperature around the cylinder bore uniform, suppress bore deformation from a perfect circle, suppress piston sliding friction, and improve fuel efficiency.
Because of this requirement,
A structure for passing cooling water through the cylinder head gasket (Japanese Patent Laid-Open No. 10-103522),
・ A slit is formed between the cylinder bores in the cylinder block to create an open deck structure, and cooling water is passed through the slit.
Such a structure has been proposed.
[0003]
[Problems to be solved by the invention]
However, the conventional proposed structure has the following problems.
・ When cooling water is passed through the cylinder head gasket, it is difficult to create a cooling water passage between the narrow bores of the cylinder head gasket. When the cooling water passage is formed, the size of the portion between the bores is increased and the cylinder block length is increased.
・ When making an open deck structure by forming slits between cylinder bores in the cylinder block,
(B) The gasket seal width cannot be taken.
(B) When the combustion pressure is applied, the bore is deformed so that it expands laterally in the direction perpendicular to the longitudinal direction of the cylinder block, and excessive stress is generated at the part between the bores (the connecting part of the connecting liner). The bore expansion was suppressed by doing, but the bore wall becomes thicker,
(C) If the open deck structure is stopped to solve the expansion of the bore wall and the liner is connected to the block outer periphery and the closed deck structure, the water jacket structure that takes into account the removal of the core in casting is costly. Invite up
There were problems such as.
An object of the present invention is to provide an upper structure of a cylinder block that can make the temperature of the cylinder bore portion uniform.
A further object of the present invention is to provide a cylinder block capable of uniformizing the temperature of the cylinder bore without causing problems such as lowering of the sealing performance of the cylinder head gasket, expansion of the bore due to the open deck structure, and deterioration of castability due to the closed deck. It is to provide a superstructure.
[0004]
[Means for Solving the Problems]
The present invention for achieving the above object is as follows.
(1) A cylinder block having a cooling water passage opened upward and having no cooling water passage formed between the bores;
Separated from the cylinder block and disposed on the upper surface of the cylinder block, the cooling water is passed through the bore hole, the portion between the bore holes, the water hole formed at the portion between the bore holes, and at least the portion between the bore holes. A plate with grooves,
Consists of
The cylinder block is fastened to the cylinder head by placing a cylinder head gasket on the plate,
The upper surface of the plate is a flat surface in close contact with the cylinder head gasket, and the cylinder block and the plate are sealed with a liquid gasket,
The groove formed in the plate is formed in the lower surface of the plate, and the groove formed in the plate communicates with the cooling water passage and the water hole of the cylinder block and cools from the cooling water passage of the cylinder block. Flowing water through the groove to the water hole,
Superstructure of cylinder block.
(2) The upper structure of the cylinder block according to (1), wherein the thickness of the plate is 2 mm or more and 5 mm or less.
[0005]
In the upper structure of the cylinder block of the above (1), a plate is arranged on the cylinder block and under the cylinder head gasket, and a groove for passing cooling water is formed in this plate at least at the portion between the bore holes. The difficult part between the bore holes can be cooled with cooling water, and the temperature of the cylinder bore can be made uniform in the bore circumferential direction.
Also, since the groove is formed on the lower surface of the plate, the upper surface of the plate can be a flat surface that is in close contact with the cylinder head gasket, and the sealing performance of the cylinder head gasket does not deteriorate despite the presence of the plate. .
In addition, since the plate is placed on the open deck cylinder block, lateral expansion due to the combustion pressure of the cylinder bore is suppressed by the plate, and deformation of the bore hole is suppressed without increasing the thickness of the liner. Can do.
Further, since the cylinder block can be manufactured separately from the plate, it can be cast as a cylinder block with an open deck structure, the core can be easily removed, and the manufacturing cost can be reduced compared to a cylinder block with a closed deck structure.
The superstructure of the cylinder block (2) above, the thickness of the plates, since it is 2mm or more, the surface pressure of the gasket can be given a uniform load, also because it is 5mm or less, the piston top dead It is possible to prevent the piston ring position from being applied to the plate 15 at a point.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Below, the upper structure of the cylinder block of this invention Example is demonstrated with reference to FIGS.
As shown in FIGS. 1 to 5, the upper structure 10 of the cylinder block according to the embodiment of the present invention includes a cylinder block 11 and a plate 15.
The cylinder block 11 has a cooling water passage 12 opened upward.
The plate 15 is separated from the cylinder block 11 and is disposed on the upper surface of the cylinder block 11. The plate 15 is composed of a plate having a bore hole 13 and a groove 16 through which cooling water passes through at least the portion 14 between the bore holes.
The cylinder block 11 is fastened to the cylinder head 18 with a cylinder head gasket 17 disposed on the plate 15 and a cylinder head 18 disposed thereon.
[0007]
Desirably, the groove 16 formed in the plate 15 is formed on the lower surface 15a of the plate 15 (surface that contacts the cylinder block 11), and the upper surface 15b of the plate 15 (surface that contacts the cylinder head gasket 17) is the cylinder. The flat surface is in close contact with the head gasket 17. However, the groove 16 may be formed inside the plate by stacking two plates 15, or the groove 16 may be formed on the upper surface of the plate 15.
The groove 16 formed in the plate 15 guides the cooling water from the cooling water passage 12 of the cylinder block 11 to the portion between the bore holes and passes through the water holes 19 formed in the plate 15 to the water jacket in the cylinder head 18. Shed.
[0008]
The thickness of the plate 15 is equal to or greater than the thickness having rigidity for making the surface pressure of the gasket portion uniform (for example, 2 mm or more), and the piston ring position does not cover the plate 15 at the piston top dead center (for example, 5 mm or less). ). By tuning the thickness of the plate 15, a uniform load can be applied to the cylinder head gasket 17 part.
The plate 15 is made of a rolled steel plate. The plate 15 is attached to the upper portion of the cylinder block 11 before the bore hole of the cylinder block 11 is processed into a perfect circle, and is processed to have the same diameter when the circular hole of the bore hole of the cylinder block 11 is processed. Since the plate 15 is a separate part from the cylinder block 11, the groove 16 of the plate 15 can be processed relatively easily such as etching and laser processing before being attached to the cylinder block 11.
[0009]
The space between the cylinder block 11 and the plate 15 is sealed with a liquid gasket or an O-ring (which may be made of rubber). When the upper surface of the die-cast cylinder block is sealed with a liquid gasket, it can be sealed without considering the cast hole.
The sealing surface of the plate 15 with the cylinder head gasket 17 can improve the flatness of the plate 15 because the plate 15 is a separate part from the cylinder block 11, which is advantageous for sealing.
When the cylinder head gasket 17 is replaced, it is possible to replace only the cylinder head gasket 17 while the plate 15 remains in the assembly with the cylinder block 11.
[0010]
Next, the operation of the upper structure 10 of the cylinder block according to the embodiment of the present invention will be described. In the above cylinder block superstructure 10, the plate 15 is disposed on the cylinder block 11 and below the cylinder head gasket 17, and the groove 16 through which cooling water passes at least in the portion 14 between the bore holes is formed on the plate 15. In addition, the portion 14 between the bore holes, which has conventionally been difficult to cool, can be cooled with cooling water, and the temperature of the cylinder bore portion can be made uniform in the bore circumferential direction. This cooling structure is capable of cooling without forming the cooling water passage 12 at the portion between the bore holes of the cylinder block 11 with respect to the liner-connected bore (siamese bore) having a small width at the portion between the bore holes. Especially effective.
[0011]
When the groove 16 is formed on the lower surface of the plate 15 (the surface on the side in contact with the cylinder block), the upper surface of the plate 15 can be a flat surface (a flat surface without grooves) that is in close contact with the cylinder head gasket 17. Even though the plate 15 is interposed, the sealing performance between the cylinder block 11 and the cylinder head gasket 17 can be maintained high.
[0012]
Further, since the plate 15 is disposed on the cylinder block 11 having the open deck structure, the lateral expansion of the cylinder bore 13 due to the combustion pressure is suppressed by the plate 15, and the bore hole can be formed without increasing the thickness of the liner. 13 deformations can be suppressed.
Further, since the cylinder block 11 can be manufactured separately from the plate 15, it can be cast as a cylinder block having an open deck structure, the core can be easily removed, and the manufacturing cost can be reduced as compared with a cylinder block having a closed deck structure.
Further, since the plate 15 can be formed separately from the cylinder block 11, there is no need for reworking such as removing a cast hole from the contact surface with the cylinder head gasket 17 by using a rolled steel plate. A sufficiently high sealing property can be obtained by using a liquid gasket for sealing the contact surface.
[0013]
【The invention's effect】
According to the upper structure of the cylinder block of claim 1, the plate is arranged on the cylinder block and under the cylinder head gasket, and the groove for passing the cooling water is formed in this plate at least in the portion between the bore holes. This makes it possible to cool the portion between the bore holes that has been difficult to cool with cooling water, and to uniformize the temperature of the cylinder bore portion in the bore circumferential direction.
Also, since the groove is formed on the lower surface of the plate, the upper surface of the plate can be a flat surface that is in close contact with the cylinder head gasket, and the sealing performance of the cylinder head gasket does not deteriorate despite the presence of the plate. The effect is obtained.
In addition, since the plate is placed on the open deck cylinder block, lateral expansion due to the combustion pressure of the cylinder bore is suppressed by the plate, and deformation of the bore hole is suppressed without increasing the thickness of the liner. Can do.
Further, since the cylinder block can be manufactured separately from the plate, it can be cast as a cylinder block with an open deck structure, the core can be easily removed, and the manufacturing cost can be reduced compared to a cylinder block with a closed deck structure.
According to the superstructure of a cylinder block according to claim 2, the thickness of the plates, since it is 2mm or more, the surface pressure of the gasket can be given a uniform load, also because it is 5mm or less, the piston It is possible to prevent the piston ring position from being applied to the plate 15 at the dead point.
[Brief description of the drawings]
FIG. 1 is a sectional view of an upper structure of a cylinder block according to an embodiment of the present invention.
FIG. 2 is a perspective view of an upper structure plate of a cylinder block according to an embodiment of the present invention.
FIG. 3 is a bottom view of the upper structure plate of the cylinder block according to the embodiment of the present invention.
4 is a cross-sectional view taken along line AA in FIG.
5 is a cross-sectional view taken along line BB in FIG. 3. FIG.
[Explanation of symbols]
10 Cylinder block superstructure 11 Cylinder block 12 Cooling water passage 13 Bore hole 14 Bore hole portion 15 Plate 16 Groove 17 Cylinder head gasket 18 Cylinder head 19 Water hole

Claims (2)

A cylinder block having a cooling water passage opened upward and having no cooling water passage formed between the bores;
Separated from the cylinder block and disposed on the upper surface of the cylinder block, the cooling water is passed through the bore hole, the portion between the bore holes, the water hole formed at the portion between the bore holes, and at least the portion between the bore holes. A plate with grooves,
Consists of
The cylinder block is fastened to the cylinder head by placing a cylinder head gasket on the plate,
The upper surface of the plate is a flat surface in close contact with the cylinder head gasket, and the cylinder block and the plate are sealed with a liquid gasket,
The groove formed in the plate is formed in the lower surface of the plate, and the groove formed in the plate communicates with the cooling water passage and the water hole of the cylinder block and cools from the cooling water passage of the cylinder block. Flowing water through the groove to the water hole,
Superstructure of cylinder block.   The upper structure of a cylinder block according to claim 1, wherein the thickness of the plate is 2 mm or more and 5 mm or less.

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