JPS6321702Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylinder head gasket.

To explain the conventional so-called laminate type cylinder head gasket (hereinafter referred to as gasket) with reference to Figs. 1 and 2, 1 is the crankcase, 2 is the cylinder liner, 3 is the cylinder head, 4 is the outer plate of the gasket 5, and 6 is the steel plate. 7 is an upper internal structural plate (hereinafter referred to as an upper plate) provided on the upper surface of the intermediate plate, and 8 is a lower internal structural plate (hereinafter referred to as a lower plate) provided on the lower surface of the intermediate plate. The gasket 5 is provided with a gap 9 between it and the cylinder liner 2, and a fire ring 10 is fitted into the inner peripheral edge of the outer plate 4 of the gasket 5 to fill this gap 9.
This is to prevent the compression ratio of the engine from decreasing due to an increase in dead space, and to prevent the inner peripheral edge of the outer plate 4 from being directly exposed to combustion heat. By the way, protrusions 12 and 13 are formed on both the upper and lower plates 7 and 8, concentrically with the cylinder liner bore 11, so as to protrude toward the cylinder head 3 side and the crankcase 1 side, respectively. Note that 14 indicates a hole for a tightening bolt. In this way, in the above conventional device, the protrusion 1
Since 2 and 13 are formed in one piece, when the cylinder head 3 is assembled, the stress acting on the flange 15 of the cylinder liner 2 and the shelf 16 of the crankcase 1 through the gasket 5 becomes excessive. There were problems such as cracks A and B occurring in the liner 2 and crankcase 1, deformation of the cylinder liner 2, and even impairing gas sealing performance. The present invention has been devised in view of the above, and to explain the embodiment shown in FIG.
Projections 17 and 18, which are different from the projections 2 and 13, protrude concentrically and, like the projections 12 and 13, are arranged above the cylinder liner. Further, the height of the protrusions 17 and 18 located radially outward is set to be higher in the vertical direction than the protrusions 12 and 13 located radially inward.

This embodiment uses a single protrusion 1 as in the conventional case.
2 and 13, it is formed into a double protrusion having further protrusions 17 and 18,
Moreover, the protrusions 17 and 18 are more effective than the protrusions 12 and 13.
Since the height of the cylinder liner 2 is increased, the stress concentration acting on the flange portion 15 and the shelf portion 16 can be alleviated, and therefore the bore deformation of the cylinder liner 2 can be suppressed.
The stress acting on the liner flange 19 can be set within the allowable stress range of the flange 19, and the generation of cracks as described above can be avoided, which has the effect of improving gas sealing properties.

In the above embodiment, the earrings 10 were used, but as shown in FIG. 4, they may not be used.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a conventional device, Fig. 2 is an enlarged sectional view taken along the - line in Fig. 1, Fig. 3 is a sectional view of an embodiment of the present invention, and Fig. 4 is a modification of the same embodiment. FIG. 2: Cylinder liner, 5: Gasket, 7: Upper plate, 8: Lower plate, 12, 13, 17, 18; Projection portion, 15: Flange portion, 16: Shelf portion.

Claims (1)

[Scope of utility model registration request] Protrusions with arcuate cross sections protruding toward the outer plate are provided on the upper and lower plates of the internal structure plate laminated within the outer plate of the cylinder head gasket, respectively,
A double protrusion is formed in a portion of the upper plate and the lower plate located above the cylinder liner so as to be concentric with the cylinder liner bore, and the double protrusion is formed on the radially outer side of the double protrusion. A cylinder head gasket characterized in that the protrusion is formed higher than the protrusion on the radially inward side and is disposed near the outer peripheral edge of the cylinder liner flange.