JPH08519Y2 - Cylinder head gasket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a cylinder head gasket.

2. Description of the Related Art A structure in which a reinforcing ring surrounding a cylinder hole is provided, and the sealing surface pressure is held by the reinforcing ring is known as disclosed in, for example, Japanese Utility Model Laid-Open No. 56-30657.

Problems to be Solved by the Invention While the cylinder head gasket secures the sealing surface pressure by the tightening load of the tightening bolts, it has to cope with the increase of the heat load with the recent increase in the output of the internal combustion engine. This increase in heat load is manifested as fatigue and fatigue of the gasket near the exhaust port and the narrow space between the cylinder holes.

In order to prevent fatigue and fatigue due to heat load, it is conceivable to dispose a double reinforcing ring as described in the above publication, but on the other hand, the double reinforcing ring results in a necessary sealing surface for each part. A corresponding clamping load is required to ensure pressure.

That is, if the tightening load is partially concentrated on a portion having a large heat load, the tightening load does not need to be increased (the tightening bolt should be increased). Since the tightening load must be applied to unnecessary portions for securing, the bolts must be correspondingly large, which is unsuitable for the recent downsizing of internal combustion engines.

Further, it is inevitable in the art to use a single reinforcing ring instead of the conventional example, but the countermeasure against the heat load is a partial problem around the cylinder hole (reinforcing ring), whereas the seal is used. Ensuring surface pressure is an overall (uniform) problem, so a reasonable material reinforcement ring must be selected to accommodate the increased heat load that cannot be predicted with conventional internal combustion engines, thus reducing manufacturing costs. On the other hand, since it is related to the balance between the partial problem and the overall problem as described above, the problem similar to the above-mentioned conventional example using the double reinforcing ring occurs, and it cannot be said to be the solution.

Means for Solving the Problems A reinforcing ring surrounding a cylinder hole is provided, and the reinforcing ring is formed by joining end portions of a plurality of ring members to each other, and is arranged in a region of high heat load in the ring members. The ring member is made of a material having higher heat resistance than the materials of other ring members.

Embodiments The drawings show an embodiment of a cylinder head gasket according to the present invention, in which A is a cylinder head gasket, 1 is a cylinder hole provided in the body 2 of the gasket A, and 3 is a grommet forming the cylinder hole 1, respectively. .

Reference numeral 4 is a reinforcing ring housed in the grommet 3 and surrounding the cylinder hole 1. The reinforcing ring 4 is the first ring member 5
And the second ring member 6 are welded to each other at their both ends, and the first ring member 5 is a region having a high heat load such as a region a near the exhaust port or a narrow region b between the cylinder holes 1 and 1. It is to be distributed to.

The second ring member 6 of the embodiment is made of mild steel, and the first ring member 5 is made of stainless steel.

When the second ring member 6 is made of stainless steel in consideration of compatibility with an internal combustion engine, the first ring member 5 may be made of Incoloy or Inconel having heat resistance strength higher than that of the stainless steel.

Even if the same stainless steel is used, the second ring member 6
If stainless steel (304) is used for the first ring member 5
For this, stainless steel (316) or stainless steel (321) may be used.

The structure of the main body 2 may be either metal laminated type or metal graphite.

When the base material sheet is formed of a metal laminated type, a folded portion formed by folding the outer plate is used instead of the grommet 3.

The reinforcing ring is configured by joining a ring member arranged in a region having a high heat load and another ring member. Since each ring member is made of a different material, reinforcement based on a difference in thermal expansion coefficient is made. Although it is assumed that the ring will be deformed as soon as possible, the entire length of the reinforcing ring is not long enough to cause thermal expansion and deformation.

Effect of the Invention As described above, the present invention has a ring member made of a material having a high heat resistance partially disposed in a high heat load region.
A gasket having heat resistant strength can be provided without impairing the uniformity of the seal.

[Brief description of drawings]

1 is a plan view, FIG. 2 is a sectional view, and FIG. 3 is a partially cutaway plan view showing a seal ring taken out from the gasket. is there. 1 ... Cylinder hole, 4 ... Reinforcing ring, 5 ... First ring member, 6 ... Second ring member

Claims (1)

[Scope of utility model registration request] 1. A reinforcing ring surrounding a cylinder hole,
The reinforcing ring is formed by joining end portions of a plurality of ring members to each other, and the ring member arranged in a region where the heat load in the ring members is high is made of a material having higher heat resistance than that of other ring members. Configured cylinder head gasket.