JPH0680351B2 - Metal gasket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a metal gasket, in particular, a combustion gas, which is interposed at a joint surface between a cylinder head and a cylinder block forming an exterior of an internal combustion engine. The present invention relates to a metal gasket for preventing leakage of cooling water, lubricating oil and the like.

(Prior Art) A sealing function is imparted to a joint surface between a cylinder head and a cylinder block forming an exterior of an internal combustion engine by interposing a metal gasket.

Then, the metal gasket substrate is provided with combustion chamber holes at positions corresponding to the combustion chambers on the cylinder block side, and beads are provided on the outer peripheral edges of these combustion chamber holes so that combustion gas pressure and the like when the engine is in use. It has a function of compensating for the gap generated on the deck surface at the periphery of the combustion chamber hole due to.

One of the gaskets of this type is a grommet type. This is because the grommet is provided on the substrate so that the alternating load applied to the bead when the engine is operating is partially borne by the grommet and the friction generated between the cylinder block and the cylinder block is alleviated.

(Problems to be Solved by the Invention) In the above-described conventional configuration, the vibration itself generated at the time of engine operation is absorbed by the bead, and the bead has the compensating part by the grommet at the end on the combustion chamber side. This prevents bead fatigue.

However, the substrate is in direct contact with the engine, and above all, fretting occurs in the bead neck due to a difference in thermal expansion.

Therefore, the microsealant applied to the upper surface of the substrate has a drawback that it is difficult to secure the sealability for a long period of time because the microsealant is scraped off by the machining tool mark of the engine and the sealability deteriorates.

Furthermore, downsizing and weight reduction of engines have advanced in recent years,
Due to the lack of space, the bead mounting width becomes smaller, and as a result, the bead top comes into contact with the engine at an acute angle, which further promotes the above inconvenience.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a metal gasket that can reduce friction with an engine and can secure a sealing property for a long period of time.

[Structure of the Invention] (Means for Solving the Problems) A substrate 2 provided with beads and a flat compensating plate 7 having a thickness smaller than that of the substrate are laminated on the substrate. And the edge of the compensator on the side of the combustion chamber is bent on the substrate surface on the top side of the bead 4, so that the height of the bead is set lower than the bead portion of the substrate on the flat part on the combustion chamber side. In the metal gasket provided with the compensated compensating portion 5, at least one upper plate or one or more sub plates 8 in each vertical direction are brought into contact with each other while holding the substrate, and the upper sub plate and the lower sub plate The micro-seal material is applied to the surface of the compensating plate 7 or the surface of the sub-plate in each of the upper and lower directions.

(Operation) Therefore, the bead 4 provided on the substrate 2 does not directly contact the engine, but contacts the upper and lower surfaces through the sub plate 8 and the compensating plate 7, or each sub plate. At this time, since the surface of each sub-plate and compensator is coated with a micro-seal material, fretting due to the bead top can be prevented even if there is contact vibration with the engine, and as a result, the sealing effect can be maintained for a long period of time.

(Examples) Examples will be described below with reference to the drawings.

FIG. 1 is a constitutional view of an embodiment of a metal gasket according to the present invention and is shown as a sectional view.

FIG. 2 is a perspective plan view in which a part of the metal gasket is cut away, and a sectional view taken along the line XX ′ of this figure is shown in FIG.

First, the plan configuration will be described with reference to FIG. A metal gasket body 1 is composed of an elastic metal plate 2 (hereinafter referred to as a substrate).

Reference numeral 3 is a combustion chamber hole, and a plurality of holes are provided corresponding to the combustion chamber on the cylinder block side (not shown). Also, the combustion chamber hole 3
A bead 4 is provided on the periphery of the bead, and the two-dot chain line in the figure indicates the top position of the bead.

A compensating portion 5 (matte portion) is provided on the periphery of the combustion chamber hole 3 on the combustion chamber side of the bead 4 to suppress the amplitude of the substrate due to engine vibration and protect the bead from fatigue damage. .

Since the present embodiment shows a grommet type gasket, the compensating portion 5 refers to a portion where the end of the combustion chamber hole of the substrate 2 is bent and covered (described later).

In addition, a plurality of bolt holes 6 are provided on the periphery of the metal gasket body 1 , and when the metal gasket is used for fastening by interposing it on the joint surface between the cylinder head and the cylinder block, which is not shown, Insert the bolt.

First, the cross-sectional structure of the metal gasket having the above-mentioned planar structure is
It will be described with reference to the drawings.

As shown in the drawing, a compensating plate 7 is provided along the bottom surface of the substrate 2, and the compensating portion 5 is formed by bending the substrate 2 so as to wrap around the end 2a on the combustion chamber hole side.

Here, the compensator will be described. First, the height t of the compensation unit 5
Is smaller than the height T of the bead 4. This serves to prevent the bead 4 from sagging against the vibration of the engine when it is installed in the engine (when it is inserted between the cylinder head and the cylinder block). That is, when the beads are compressed by the vibration of the engine and the height of the beads is reduced (when the beads are flat), the height t of the bead 4 is less than this due to the thickness t of the compensator 5. This is because the fatigue fracture of the bead is prevented because it is not made very small. That is, the compensating section 5 serves as a stopper to prevent the bead from setting.

Reference numeral 8 denotes a sub plate, which is arranged on the upper surface of the substrate 2, so that the substrate provided with the beads comes into contact with the engine through the sub plate 8.

In short, in FIG. 1, it is explained that the compensator 7 is provided along the bottom surface of the substrate 2 and the end of the compensator is bent to form the compensator 5. In this case, it is equivalent to providing sub plates on both sides thereof.

In this case, the microsealant is applied to each surface of the sub plate 8 and the compensating plate 7 (substantially the sub plate).

Therefore, when the metal gasket shown in the above embodiment is interposed between the cylinder head and the cylinder block and fastened with bolts, the outermost sub-plate portion is applied to the engine through the film of the microsealant. I will come into contact with you.

Therefore, the micro sealant is embedded in the tool mark created during engine processing, and the movement of the bead that occurs during engine operation is received by the back surface of the secondary plate and does not directly contact the engine. The microsealant applied on the surface of the can maintain the sealing effect for a long period of time without peeling.

FIG. 3 is a cross-sectional configuration diagram of another embodiment of the present invention.
It corresponds to the position of the sectional view in the figure. The symbols in the figure are
It corresponds to FIG.

In this embodiment, in addition to the configuration shown in FIG.
Is added to the upper and lower surfaces to form a total of four sub-plates.

Also in this case, the micro-sealant is applied to each sub-plate in the same manner as described above. Other configurations are the same as in FIG.

Therefore, in this embodiment, since the engine body is in contact with each other through the upper and lower two sub plates, the contact vibration with the engine is absorbed by each sub plate, and as a result, fretting can be prevented.

Since the sealant is applied between the layers having the above-mentioned structure, it is possible to compensate for the variation in the surface pressure caused by the rigidity of the engine and to achieve a more stable sealing effect. .

[Effects of the Invention] As described above, according to the present invention, in a metal gasket in which a compensating portion is bent between a bead and a combustion chamber hole, a plurality of sub plates are provided by sandwiching a substrate. Therefore, fretting due to contact vibration with the engine can be prevented, and as a result, a metal gasket that can maintain the sealing effect for a long time can be provided.

[Brief description of drawings]

FIG. 1 is a sectional configuration diagram of an embodiment of a metal gasket according to the present invention, FIG. 2 is a partially cutaway perspective plan view for explaining a plane configuration of a metal gasket, and FIG. 3 is a sectional configuration of another embodiment. It is a figure. DESCRIPTION OF SYMBOLS 1 ... Metal gasket main body, 2 ... Substrate 3 ... Combustion chamber hole, 4 ... Bead 5 ... Compensation part, 6 ... Bolt hole 7 ... Compensation plate, 8, 9, 10 ... Sub-plate

Claims (1)

[Claims] 1. A substrate provided with a bead and a flat compensating plate having a thickness smaller than that of the substrate are laminated on the substrate, and the end of the compensating plate on the combustion chamber hole side. A metal gasket provided with a compensating portion set to be lower than the height of the bead in a flat portion on the combustion chamber side of the bead portion of the substrate by bending the edge on the substrate surface on the top side of the bead. Holding at least one upper plate or one or more sub plates in each of the upper and lower directions, and the surface of the upper sub plate and the lower compensating plate, or the surface of the sub plate in each of the upper and lower directions. A metal gasket characterized in that a microseal material is applied to the metal gasket.