JPH032770Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a gasket for internal combustion engines, and in particular,
This invention relates to a gasket in which a grommet is fitted around the periphery of the opening of the gasket.

[Conventional technology]

As is well known, this type of gasket, as illustrated in FIG. It has a structure in which a grommet G is fitted.

This gasket is used by being installed between predetermined flange surfaces F, F, but the distance between the flange surfaces F, F changes due to vibrations during operation of the internal combustion engine. On the other hand, the contact surface of the grommet G with the flange surface F is caused by the restoring force A in the sheet thickness direction of the gasket body S to generate a sealing effect.
A stress is applied that tends to deform the sheet outward in the thickness direction.

Therefore, due to the vibration of the flange surface, the grommet G performs a pendulum or open-legged motion in which its outer peripheral edge side vibrates, using the opening side end position P in contact with the flange surface F as a fulcrum, and the grommet G moves in the vicinity of position P. It was easy to crack.

In particular, when the opening H is a cylinder bore opening in a cylinder head gasket or an opening in an exhaust manifold gasket, the grommet tends to seize on the flange surface, so the grommet G is integrated with the flange surface F. This caused the vibration in the shape, making the occurrence of cracks near position P even more significant.

In addition, attempts have been made to counter the corrosion of grommets caused by fluid flowing inside the opening by improving the quality of the material forming the grommet and increasing its wall thickness, and by coating it with a protective film to delay the effects of corrosion. We are responding by means of doing so. However, such means cause deterioration in processing accuracy and increase in cost.

[Problem that the invention attempts to solve]

The object of the present invention is to provide a gasket that reliably prevents the grommet from cracking as described above, prevents the grommet from being corroded by fluid, and ensures a more reliable sealing action.

[Means to solve the problem]

The gasket according to the present invention has a grommet made of a thin metal plate fitted around the opening of the gasket body.

The surface of the grommet is plated with a base plating made of nickel or nickel alloy plating, and lead plating is applied on top of the base plating.

[Effect]

Lead plating is attached to the surface of the grommet through a base plating made of nickel or nickel alloy plating, which has better adhesion to various metals, and ensures the adhesion of the lead plating to the grommet surface. This prevents the lead plating from peeling off even when high temperatures and intermittent high internal pressures are applied to cylinder head gaskets and exhaust manifold gaskets.

The lead plating acts as a buffer member between the grommet and the flange surface when the distance between the flange surfaces changes due to vibration, and also acts as a member to prevent seizure between the two. Lead plating is also
For changes in the distance between flange surfaces due to vibration,
The lead plating is expanded or contracted between the flange surface and the grommet to provide a more reliable seal.

Corrosive effects from the fluid flowing through the opening are inhibited by the chemically stable lead plating and the grommet will not corrode.

〔Example〕

As shown in FIG. 2, the gasket according to the present invention includes a sheet-like gasket main body 1 having a planar shape corresponding to the applied flange surface F, and a predetermined opening 2 of the fluid flow opening of the gasket main body 1. It is composed of a grommet 3 fitted along the inner peripheral edge.

The gasket body 1 is made of a well-known sheet material for gaskets, such as a graphite sheet or an asbestos joint sheet, and the grommet 3 is also made of a well-known sheet metal material for grommets, such as a stainless steel plate or a steel plate. Ru.

A soft and chemically stable lead plating 4 is provided on the surface of the grommet 3. Lead plating 4 is
It is attached to the grommet 3 via a base plating 5 made of nickel or nickel alloy plating that has good adhesion to various metals.

Base plating 5 between grommet 3 and lead plating 4
The presence of the
To prevent lead plating 4 from peeling off.

The gasket of the present invention formed in this way is
When installed between the flange surfaces F and F, as shown in FIG. 3, lead plating 4 is interposed between each joint surface of the flange surface F and the grommet 3, preventing the grommet from seizing on the flange surface. It also functions as a kind of buffer member.

When the flange surface F separates from the grommet 3 due to vibration, the lead plating 4 expands as shown by the dashed line in FIG. 3, and conversely, when the flange surface F approaches the grommet 3, it contracts. Thick and always seal between grommet and flange surface.

By intervening the lead plating 4, essentially,
The grommet 3 will be held in a predetermined arrangement position and in a predetermined configuration independently of the vibrations of the flange surface F, although in practice the grommet also has a damped pendular or splayed movement. however,
This pendulum or split-leg movement of the grommet is different from that in which the fulcrum corresponds to the vibration of the flange surface F, as compared to the conventional case where the fulcrum is the opening side end position P, as shown by the broken line in FIG. Diffused range (Pw)
The bending stress is not concentrated at one point.

There is no particular limitation on the thickness of each plating, but when used as an opening for the cylinder bore of a cylinder head gasket, lead plating should be 2.
It has been found through long-term experiments that it is sufficient to have a thickness of ~10 μm, and that the thickness of the base plating is sufficient to substantially cover the grommet surface, and that a thickness of 2 μm or less is sufficient.

[Effect of idea]

According to the present invention, by attaching lead plating to the surface of the grommet via the base plating,
Lead plating can be reliably attached to the grommet surface, even when high temperatures and intermittent high internal pressures are applied, such as at the openings of cylinder head gaskets and exhaust manifold gaskets.
This can reliably prevent lead plating from peeling off.

In addition, since the lead plating is always interposed between the grommet and the flange surface, it can act as a buffer member between the grommet and the flange surface, and can prevent the grommet from seizing on the flange surface. It is possible to prevent cracking of the grommet due to vibration of the flange surface, and to achieve more reliable sealing.

In addition, the grommet is protected against corrosive effects from fluids by a chemically stable lead plating, which improves the corrosion resistance of the grommet.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view for explaining the location where cracks occur in a conventional gasket. FIG. 2 is a partial sectional view of a gasket according to an embodiment of the present invention. FIG. 3 is a schematic enlarged partial sectional view for explaining the movement of the embodiment shown in FIG. 1 when it is worn. 1... Gasket body, 2... Opening, 3...
Grommet, 4... Lead plating, 5... Base plating.

Claims (1)

[Scope of utility model registration request] This gasket has a grommet 3 made of a thin metal plate material fitted around the periphery of an opening 2 of a gasket body 1, and the surface of the grommet 3 is plated with lead 4 via a base plating 5 made of nickel or nickel alloy plating. A gasket characterized by: