JPS624765Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylinder head gasket interposed between a cylinder block and a cylinder head of a liquid-cooled internal combustion engine.

A typical conventional cylinder head gasket has a cross-sectional shape as shown in the first drawing. The base material 1 of this cylinder head gasket is made of asbestos and is provided with combustion chamber holes 2 and coolant passage holes 3, respectively. A grommet 4 made of thin metal such as stainless steel or steel is clamped around the periphery of the combustion chamber hole 2 of the base material 1. In such prior art, since the thermal conductivity of asbestos and stainless steel is relatively low, the grommet 4 may reach an abnormally high temperature and act as an ignition source, causing the internal combustion engine to malfunction. be. Also, the cylinder block or cylinder head may melt due to the abnormally high temperature of the grommet 4, leading to destruction. Further, when the grommet 4 is crushed between the cylinder block and the cylinder head to create a gas seal, the coolant passage hole 3 must be sealed at the same time. The base material 1 and the grommet 4 are designed so that these two sealing functions can be achieved at once.
It is difficult to determine the dimensions of

Accordingly, the main object of the present invention is to provide a cylinder head gasket for a liquid-cooled internal combustion engine that has excellent heat dissipation and can simultaneously and reliably provide gas sealing and liquid sealing.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a plan view of an embodiment of the present invention,
FIG. 3 is a sectional view taken along the cutting plane line - in FIG. 2. The base material 6 of the cylinder head gasket 5 is
It is a plate-shaped body made of a metal with relatively high thermal conductivity, such as copper or aluminum. The base material 6 is provided with a combustion chamber hole 7 and a plurality of coolant passage holes 8 (four in the figure) arranged around the outer periphery of the combustion chamber hole 7. This cylinder head gasket 5 is firmly clamped between the cylinder block and the cylinder head by a bolt passing through a bolt hole 9.

The peripheral edge of the base material 6 surrounding the combustion chamber hole 7 is continuously folded back in the circumferential direction. An elastic material 20 such as asbestos is interposed in an annular shape between the protrusions 18 and 19 protruding from both the front and back end surfaces of the base material 6 . Gas sealing is achieved by squeezing the ridges 18, 19 with the end face 12 of the cylinder block and the end face 13 of the cylinder head, thereby crushing the elastic material 20. The portions of the protrusions 18 and 19 facing the combustion chamber hole 7 are curved and not sharp, so that abnormal high temperatures can be suppressed. The raised portions 18 and 19 extend in the radial direction (left-right direction in FIG. 3). Therefore, the contact area between the end surfaces 12, 13 and the raised portions 18, 19 is large. Therefore, a sealing function can be achieved with a relatively small tightening force, and heat dissipation is improved.

Surrounding the coolant passage hole 8, a sealant 11 made of, for example, silicone resin and having flexible elasticity and liquid-tightness is adhered or applied to both the front and back end surfaces of the base material 6 in an endless form. This sealant 1
1 is a raised portion 18, 1 from both the front and back end surfaces of the base material 6.
The bulge has a thickness d2 greater than the bulge thickness d3 of No. 9.

A cylinder head gasket 5 is interposed between the cylinder block and the cylinder head, and the cylinder block and the cylinder head are tightened with bolts passing through bolt holes 9. Then, the end face 12 of the cylinder block shown by the imaginary line in FIG.
and the end face 13 of the cylinder head has the raised portion 1
8 and 19, thereby sealing the combustion chamber hole 7 with gas. At this time, the sealant 11 having soft elasticity is crushed by the end surface 12 of the cylinder block and the end surface 13 of the cylinder head, and the coolant passage hole 8 is liquid-sealed.

Fins 21 are formed at the end of the base material 6 facing the coolant passage hole 8 . The formation of the fins 21 increases the surface area of the base material 6 that comes into contact with the cooling fluid, thereby promoting cooling of the cylinder head gasket 5. In addition, the fins 21 allow the coolant passage hole 8 to
Turbulent flow occurs in the coolant flowing through the cooling liquid, which also has the effect of improving the heat transfer coefficient. The fins 21 may be provided on the entire periphery of the base material 6 surrounding the coolant passage hole 8 . Further, the fins 21 may be formed so as to extend into the coolant passage holes formed in the cylinder block and the cylinder head. Furthermore, instead of the coolant passage hole 8 as shown in the figure, a plurality of small-diameter coolant liquids are provided in the portion of the base material 6 where the fins 21 are formed so as to communicate the coolant passage holes formed in the cylinder block and the cylinder head. The passage holes may be provided in a scattered manner. Further, the fins 21 may be formed with irregularities, or the surface of the base material may be roughened by shot blasting or the like.

As described above, according to the present invention, (1) heat dissipation is excellent because the base material 6 and the raised portions 18, 19 are made of a metal material with relatively high thermal conductivity. This prevents the periphery of the combustion chamber hole 7 from becoming abnormally high in temperature, thereby preventing the internal combustion engine from malfunctioning and preventing internal combustion engine failure due to abnormally high temperatures. Prevented.

(2) In addition, protrusions 18 and 19 are provided on the base material 6 surrounding the combustion chamber hole 7, protruding from both the front and back end surfaces of the base material 6,
A sealant 11 having flexible elasticity and liquid-tightness protrudes on both the front and back end surfaces of the base material 6 with a thickness greater than that of the protrusions 18 and 19 surrounding the coolant passage hole 8.
, gas sealing of the combustion chamber hole 7 and liquid sealing of the coolant passage hole 8 can be achieved simultaneously and reliably.

(3) Since the raised portions 18 and 19 extend in the radial direction, the contact area between the end surface 12 of the cylinder block and the end surface 13 of the cylinder head is large. Therefore, the sealing function can be achieved with a relatively small tightening force. In addition, heat dissipation is performed well, and the raised portions 18 and 1 facing the combustion chamber hole 7 of the base material 6 are
This prevents the curved portion of No. 9 from becoming abnormally hot and becoming an ignition source.

(4) Since the elastic material 20 is interposed between the raised parts 18 and 19, it becomes possible for the raised parts 18 and 19 to extend relatively long in the radial direction. Therefore, the raised portions 18, 19 and the end surfaces 12, 13
By bringing them into surface contact, it is possible to further improve the sealing function and heat dissipation.

(5) Due to the elastic force of the elastic material 20, the raised portion 1
8 and 19 can follow the thermal expansion and deformation of the cylinder block and cylinder head, ensuring gas sealing over a wide temperature range.

(6) Furthermore, since the elastic material 20 has elasticity, the cylinder head gasket of the present invention can be reused.

(7) Since the fins 21 are formed at the end of the base material 6 facing the coolant passage hole 8, cooling of the gasket is facilitated.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional cylinder head gasket, Fig. 2 is a plan view of an embodiment of the present invention, and Fig. 3 is a sectional view of a conventional cylinder head gasket.
The figure is a sectional view taken along the cutting plane line - in FIG. 2. 5... Cylinder head gasket, 6... Base material, 7... Combustion chamber hole, 8... Coolant passage hole, 1
8, 19...Protuberance, 11...Sealant, 21...
...Fin.

Claims (1)

[Scope of utility model registration request] This cylinder head gasket is interposed between the cylinder block and cylinder head of a liquid-cooled internal combustion engine, and the base material 6 is formed of a metal plate with relatively high thermal conductivity, and the combustion chamber of the base material 6 is The peripheral edge of the base material 6 surrounding the hole 7 is continuous in the circumferential direction, extends in the radial direction, and is folded back to form raised portions 18 and 19 that protrude from both the front and back end surfaces of the base material 6, respectively. An elastic material 20 is interposed between the raised parts 18 and 19, and surrounds the coolant passage hole 8 in an endless manner and is raised further than the raised parts 18 and 19 on both the front and back end surfaces of the base material 6 to provide elasticity and liquid tightness. 1. A cylinder head gasket for a liquid-cooled internal combustion engine, characterized in that a sealing agent 11 having properties of water is fixedly provided therein, and fins 21 are formed at an end of the base material 6 facing the coolant passage hole 8.