JPH03175135A - Cylinder head gasket of internal combustion engine - Google Patents

Abstract

PURPOSE:To make effective use of intake air by providing the grommet portion of a cylinder head gasket with a ring when mounting the gasket to the cylinder head, the upper end edge of the ring being on the same plane as the inner peripheral face of the bore of the cylinder head in such a manner as complementing a chamfered portion. CONSTITUTION:A heat resistant metal is enviromentally selected for forming a ring 2, and the ring 2 may be fixed to a gasket 1 along a grommet portion 1a using a proper adhesive or may be arranged as shown in figure during assembly without being fixed to the gasket. As shown the upper end edge portion of the bore of a cylinder block 3 is chamfered and the ring 2 is in contact with and engaged with the chamfered portion 3a. At the edge portion of the cylinder block 3 the inner peripheral face 3b of the bore is continued to the ring 2 in such a manner as complementing the notched chamfered portion 3a of the cylinder block 3, and so the ring 2 and the chamfered portion 3b are on the same plane. When the cylinder block 3 and the ring 2 are assembled the chamfered portion 3a is therefore not exposed to a combustion chamber and a space formed by notching is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cylinder block of an internal combustion engine, or a cylinder head gasket installed between a cylinder liner and a cylinder head.

[Prior Art and Problems to be Solved by the Invention] Generally, the upper edge of the cylinder bore side of the cylinder block and cylinder liner that constitutes an internal combustion engine is designed to prevent burrs from forming when forming the bore, and to prevent assembly when installing the piston. Has been chamfered to improve its properties. however,
In an internal combustion engine equipped with a cylinder block or cylinder liner having a chamfered portion, the chamfered space in the combustion chamber structure defined by the piston, cylinder head, and cylinder block (or cylinder liner) is
The wasted space that is not converted into the kinetic energy of the piston (
This is not preferable from the point of view of effective use of the air (or mixture) taken into the combustion chamber.

In addition, this space was a factor that deteriorated the precision in terms of strict compression ratio control. In view of this problem, the present invention is equipped with a cylinder block and cylinder liner in which the upper edge of the bore is chamfered. In internal combustion engines,
The present invention provides a cylinder head gasket structure that allows effective use of air (or mixture) taken into a combustion chamber.

Although the prior art related to cylinder head gaskets is not directly related to the present invention, it is known that the grommet part (annular part) of the gasket is covered with a heat-resistant ceramic material in order to improve its durability. (Refer to Utility Model Publication No. 63-21700).

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a cylinder head gasket for an internal combustion engine in which a chamfer is formed on the upper edge of the bore of a cylinder block or a cylinder liner with both bottoms of the combustion chamber. A cylinder for an internal combustion engine, characterized in that the grommet portion of the cylinder head gasket is provided with a ring that complements the chamfered portion and makes the upper edge flush with the inner peripheral surface of the bore when the gasket is installed. A head gasket is provided.

[For production]

When assembling the cylinder head, the ring provided on the grommet part of the cylinder head gasket complements the chamfered part of the cylinder block, leaving it essentially without a chamfer. This eliminates the space that was previously used for air intake, allowing for effective use of intake air.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings, taking as an example a cylinder block with a chamfered portion.

FIG. 1 is a partially sectional perspective view of a cylinder head gasket 1 according to the present invention, in which 1a indicates a grommet portion located around the cylinder bore, and 2 is a ring provided along the grommet portion 1a. The ring 2 is made of a heat-resistant metal material depending on the environment in which it is used, and may be fixed to the gasket 1 using a suitable adhesive as shown in the figure, or when assembled without being fixed, as shown in the figure. It is also possible to impose a certain arrangement relationship.

FIG. 2 shows a longitudinal section of an internal combustion engine equipped with the above-mentioned cylinder head gasket 1 and ring 2. In the figure, 3 is a cylinder block, 4 is a cylinder head, and 5 is a cylinder block 3. A piston 6 is a piston ring attached to the piston 4, which reciprocates within a bore formed in the piston.

As shown in the figure, the upper edge of the bore of the cylinder block 3 is chamfered, and the ring 2 mentioned above is in contact with and engages with this chamfer 3a.

The ring 2 has a shape that complements the cutout chamfered portion 3a of the cylinder block 3, so that the inner circumferential surface 3b of the bore is continuous even at the edge portion of the cylinder block 3, so that the ring 2 is flush with the chamfered portion 3a of the cylinder block 3. Therefore, in the assembled state, this chamfered portion 3a is not exposed to the combustion chamber, and the space created by the cutout disappears.

FIG. 3 shows a cross section of a ring-equipped cylinder head gasket 7 different from the embodiment described above.

In this embodiment, the ring 9 provided along the grommet portion 8a of the cylinder head gasket 8 is integrally attached when the gasket 8 is manufactured. In this case, the gasket 8 is made of a laminated material such as asbestos, and the ring 9 is provided with a flange portion 9a that is sandwiched between the laminated materials for integration with the gasket 8, so that the ring 9 has a so-called sand inch structure. with cylinder head gasket 7
is provided. Of course, also in this embodiment, the ring 9
The body itself is made of a heat-resistant metal material, and its shape is such that it complements the chamfered portion 3a of the cylinder block 3 (Fig. 2) and continues the bore inner circumferential surface 3b. In the embodiment, as shown in FIG.
It is formed into a substantially trapezoidal shape except for a.

Although the embodiments of the present invention have been described above with application to a cylinder block having a chamfered portion, the present invention naturally applies to an internal combustion engine in which a cylinder liner is attached to a cylinder block and a chamfered portion is provided on the upper edge of the bore of the liner. It is also applicable to

〔Effect of the invention〕

As explained above, according to the present invention, a chamfered space is created by complementing the chamfered part in a cylinder block having a chamfered upper edge part of the bore, or a cylinder head gasket attached to a cylinder head. By providing the vanishing ring, the air (or mixture) taken into the combustion chamber can be used effectively, improving combustion and improving the accuracy of engine compression ratio control. In addition, since the grommet portion of the cylinder head gasket is protected by the ring, the durability of the gasket is improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a partial cross section of the cylinder head gasket and ring, FIG. 2 is a partial vertical cross section showing the gasket and ring shown in FIG. FIG. 2 is a cross-sectional perspective view of a cylinder head gasket with a ring as an example. 1.8...Cylinder head gasket, 2.9...
Ring, 3...Cylinder block, 3a...
- Chamfered part, 4... Cylinder head. 4...Cylinder head

Claims (1)

[Claims] 1. A cylinder head gasket for an internal combustion engine in which a chamfer is formed on the upper edge of a bore of a cylinder block or cylinder liner defining a combustion chamber, wherein the gasket is attached to a grommet portion of the cylinder head gasket. A cylinder head gasket for an internal combustion engine, further comprising a ring that complements the chamfer and makes the upper edge flush with the inner peripheral surface of the bore.