JPH0614126Y2 - Laminated metal gasket for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a laminated metal gasket used in an internal combustion engine, and particularly to a first and a second member butted together to obtain an inner diameter of both members. The present invention relates to a laminated metal gasket which is applied to an internal combustion engine having a structure in which different cooling water passages are communicated with each other and is interposed between the abutting surfaces of the first member and the second member and has a good sealing property. is there.

[Prior art and problems to be solved]

A gasket is inserted at the abutting surface of the cylinder block and the cylinder head of the internal combustion engine in order to bring the surfaces into close contact with each other to keep airtightness and prevent leakage of cooling water and engine oil. As this gasket, a so-called soft gasket in which an asbestos-rubber admixture is adhered with a wire core or an iron plate as a core material is generally used, but also a press-formed product of a steel plate or a laminate of a plurality of metal plates is also available. It is used.

The latter laminated metal gasket is usually used as a substrate in which a hard metal plate is used as a substrate and is sandwiched from both sides by soft metal plates (meaning a soft metal plate compared to a hard metal plate). Although it withstands a large tightening load and has excellent sealing performance and durability, the following problems tend to occur.

That is, as shown in FIG. 1, the cylinder block 01
The cylinder head 03 and the cylinder head 03 are butted against each other through a laminated metal gasket 05, the laminated metal forms a through hole 09 in the gasket 05, and a cooling water passage 02 having a large inner diameter and a cooling water passage 04 having a small inner diameter are laminated metal gaskets. When they are communicated with each other through the through hole 09 of 05, one surface of the laminated metal gasket 05 located at the step A is exposed in the cooling water passage 02 and the other surface is in contact with the cylinder head 03. Therefore, a force in the direction of arrow B acts on the laminated metal gasket 05 located at the step A due to the contact pressure with the cylinder head 03, and the soft metal plate 07 in contact with the cylinder head 03 and the cooling water passage. The deforming force (thermal stress) due to thermal expansion is generated between the soft metal plate 08 exposed inside 02, and the rigidity of the soft metal plates 07 and 08 sandwiching the hard metal plate 06 is insufficient, as shown in FIG. As described above, the laminated metal gasket 05 may be curved and the sealing performance may be deteriorated.

[Means and Actions for Solving Problems]

The present invention relates to an improvement in a laminated metal gasket for an internal combustion engine that overcomes the above problems, and a first member having a cooling water passage with a large inner diameter and a second member having a cooling water passage with a small inner diameter. Is applied to an internal combustion engine having a structure in which cooling water passages having different inner diameters formed in the both members are communicated with each other, and having a through hole corresponding to the cooling water passage, the first member and In the laminated metal gasket interposed between the butting surfaces with the second member, the inner diameter of the through hole is smaller than the inner diameter of the first cooling water passage,
A relatively soft and low-rigidity metal plate, and a hard and high-rigidity metal plate sandwiching the soft low-rigidity metal plate from both sides is a main element, and the hard and high-rigidity metal plate is at least the first A contact surface between the member, the second member and the soft low-rigidity metal plate is covered with a soft material coating, and the surface of the hard high-rigidity metal plate facing the cooling water channel is not covered with the soft material coating. It is characterized by being exposed.

In the present invention, since the main elements are a relatively soft and low-rigidity metal plate and a hard and high-rigidity metal plate sandwiching the soft and low-rigidity metal plate from both sides, the first member and the second member Even when the members are butted against each other and tightened with a large load, the soft low-rigidity metal is provided with the unevenness of the butting surface with the first member and the second member and the load concentration due to the beat portion of the hard and high-rigidity metal plate. It is possible to partially alleviate the deformation of the plate and load it on the hard and high-rigidity metal plate to obtain high sealing performance.

Further, in the present invention, since the inner diameter of the through hole of the laminated metal gasket is made smaller than the inner diameter of the cooling water passage of the first member, the protrusion of the second member smaller than the inner diameter of the cooling water passage of the first member. The hard and high-rigidity metal plate close to the second member can be brought into close contact with the mating surface to increase the abutting area between the two members, thereby improving the sealing performance between the two members.

Further, in the present invention, since the surface portion of the laminated metal gasket exposed in the cooling water passage of the first member is made of a hard and highly rigid metal plate, an unbalanced acting force acting only from one side of the laminated metal gasket is obtained. It can withstand sufficiently well and is unlikely to be deformed, and the sealing property between the soft low-rigidity metal plate and the soft high-rigidity metal plate is ensured.

Furthermore, in the present invention, at least the contact surfaces of the hard and high-rigidity metal plate with the first member, the second member and the soft low-rigidity metal plate are covered with a soft material coating. In addition to the sealing effect of the soft and high-rigidity metal plate and the soft and low-rigidity metal plate sandwiched between the metal plates, between these two metal plates and between the first member and the second member and the hard and high-rigidity metal plate. The sealing property can be further improved by the soft coating.

Moreover, in the present invention, even if the soft coating that contributes to the improvement of the sealing property has a tendency to drop off and mix into the cooling water, the surface of the hard high-rigidity metal plate facing the cooling water passage,
Since it is exposed without being covered with the soft material coating, it is prevented that the soft coating is mixed in the cooling water and adversely affects the cooling water system.

〔Example〕

An embodiment of the present invention shown in FIGS. 3 and 4 will be described below.

FIG. 3 shows the laminated metal gasket 1 for an internal combustion engine as a cross-sectional view of a main part. The gasket 1 is formed with a soft metal plate 2 and two hard metal plates 3 sandwiching the soft metal plate 2 as main elements. The laminated metal gasket 1 for internal combustion engine 1
As shown in FIG. 5, is a cylinder block 7 as a first member in which a cooling water passage 8 having a large inner diameter is formed.
And a cooling water passage (not shown) having a diameter smaller than that of the cooling water passage 8 is provided between the abutting surfaces of the cylinder head 9 and the second member.

The soft metal plate 2 of the laminated metal gasket 1 for internal combustion engine is made of stainless steel having a thickness of 0.15 mm (JIS SUS430 (ferrite type), Brinell hardness (H _B ) = 200 ± 20), and the hard metal plate 3 Is made of stainless steel with a wall thickness of 0.2 mm (JIS
SUS301H (austenitic, Brinell hardness (H _B ) =
450 ± 20, so that the soft metal plate 2 has low rigidity and the hard metal plate 3 has high rigidity.

Further, a soft material coating 4 (nitrile rubber) having a thickness of 25 μm is coated on both surfaces of the soft metal plate 3 by a galvanized coating 5 having a thickness of 2 to 5 μm (see FIG. 4). . The galvanized coating 5 is a soft material coating 4 on the surface of stainless steel.
However, it has a function of improving the sealing performance in cooperation with the soft material coating 4. It should be noted that another extremely soft metal may be used instead of zinc, or the soft material coating 4 may be omitted and only the extremely soft metal coating having a larger thickness than the galvanized coating 5 may be attached to the hard metal plate 3. You may.

The gasket 1A shown in FIG. 5 has the same structure as the gasket 1 in that the soft metal plates 2, 3 and 3 are the main elements, but one surface of one hard metal plate 3 has fine aluminum. The difference is that a silicone varnish coating 6 in which powder is dispersed is applied. Moreover, the surface 3a of the hard metal plate 3 facing the inside of the cooling water passage and projecting from the cylinder block 7 is exposed without the silicone varnish coating 6 being applied. This is a configuration adopted to prevent the hard metal plate 3 from being deformed and the silicone varnish coating 6 from being mixed into the cooling water.
The silicone varnish coating 6 is applied to the surface of the hard metal plate 3 via an extremely soft metal plating coating.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing a state in which a known laminated metal gasket is interposed between a cylinder block and a cylinder head of an internal combustion engine, and FIG. 2 is an example of the laminated metal gasket facing the fluid passage. FIG. 3 is an enlarged view of an essential portion showing a bent portion, FIG. 3 is a sectional view of an essential portion of a laminated metal gasket according to an embodiment of the present invention, FIG. 4 is an enlarged view of the essential portion, and FIG. It is a principal part sectional drawing of the laminated metal gasket which concerns. 1 ... Gasket, 2 ... Soft metal plate, 3 ... Hard metal plate, 4
... Soft material coating, 5 ... Galvanized coating, 6 ... Silicone varnish coating, 7 ... Cylinder block, 8 ... Cooling water channel, 9
…cylinder head.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-14452 (JP, A) Actually developed 49-145012 (JP, U) Actually published 45-32649 (JP, Y1) Actually published 61- 2285 (JP, Y2)

Claims (1)

[Scope of utility model registration request] 1. A first member having a large inner diameter cooling water channel formed therein and a second member having a small inner diameter cooling water channel abutted against each other, and cooling members having different inner diameters formed in the both members. Applied to an internal combustion engine having a structure in which the two communicate with each other, has a through hole corresponding to the cooling water channel, and is interposed between the abutting surfaces of the first member and the second member In the gasket, the inner diameter of the through hole is set to be smaller than the inner diameter of the first cooling water passage, and a relatively soft and low-rigidity metal plate and a hard and rigid metal plate sandwiching the soft low-rigidity metal plate from both sides. A high metal plate as a main element, the hard high-rigidity metal plate, at least the contact surface between the first member, the second member and the soft low-rigidity metal plate is covered with a soft material coating. , The hard high-rigidity metal facing the cooling water channel Surface, for an internal combustion engine laminated metal gasket, characterized in that is exposed without being covered with the soft material coating.