EP1779006A2

EP1779006A2 - Static seal

Info

Publication number: EP1779006A2
Application number: EP05791007A
Authority: EP
Inventors: Pascal Rogeon; Bernard Lambert; Stéphane LAMOUCHE
Original assignee: Federal Mogul Sealing Systems SAS
Current assignee: Solyem SAS
Priority date: 2004-08-02
Filing date: 2005-07-21
Publication date: 2007-05-02
Also published as: MX2007000795A; FR2873777A1; US20080309027A1; KR20070041766A; WO2006024735A3; FR2873777B1; WO2006024735A2; CA2577143A1; BRPI0513785A

Abstract

The invention relates to a static seal of the type that comprises a support (3). According to the invention, a layer of elastomer is cold-deposited on at least one face of the support and subsequently shaped, with the optional formation of threads or ribs (7), in a heated mould which is also used for curing. The support is characterised in that not all of the surface thereof is covered with the elastomer and the non-covered zones perform a function other than sealing.

Description

Sealing gasket

The present invention relates to a sealing gasket. The seal in question can be used in particular in the automotive field, in order to achieve a seal between a stationary part and a cover, for example of oil tank, cylinder head, oil pump, pump water, at a timing case, to form an intake manifold gasket, or to allow the assembly of electrodes of a fuel cell.

To date, there are different types of static seals. A first seal is made of pure elastomer. Such a seal has the advantage of being cheap, and to have damping properties. However, this seal has no mechanical strength before assembly, and the center distance of the screw openings are not controlled, which complicates the handling and assembly. In addition, such a seal does not benefit from compression limits, and does not ensure a fixed dimension between the elements to be sealed, otherwise using spacers reported, which can result in risk of bursting in. tight position.

A second seal is made from a silicone paste deposited directly on the container to be sealed. This type of seal is used in particular for the cylinder head lids. In this case, the bead is deposited by a robot on an assembly line. The advantage of such a seal is that it is cheap, its essential disadvantages being that it is destroyed when the cover with which it is associated is removed, and that it is difficult to redeposit a new similar seal. Another type of seal is constituted by a cardboard support (fibers and elastomer) manufactured by papermaking techniques. Such seals are frequently used to seal oil trays, and sometimes cylinder head covers. Such a seal has the advantage of being cheap, but to provide a very average seal. Another type of seal is a coated metal type seal. It is a strip of metallic material, such as a stainless steel or not, with a thickness of the order of 0.2 to 0.4 mm, which has at least one continuous rib to ensure a constraint sealing. To protect the steel, this metal strip is coated with a layer of a few microns of elastomer, such as a nitrile or a fluoro-type elastomer forming a surface sealing layer. Such a seal is a reasonable cost, offers good sealing qualities, but requires, for its implementation, important implementation means (coating line).

US-A-4,625,979 relates to a cylinder head gasket comprising a core consisting of several laminated layers, for example a metal core coated on its two faces by two fibrous layers, based on glass fibers or asbestos, agglomerated with a polymer. The fluid passage openings are surrounded by silicone sealing cords of constant height, deposited by screen printing and each bordered on each side by a stiffer rib, intended to limit the creep of the silicone cord in period Clamping.

The document WO-99/13248 relates to a static sealing gasket comprising a metal core made of mild steel, each face of which is coated with a layer of elastomer deposited cold, the assembly being placed in a heated mold intended to achieve the shaping of the elastomer and vulcanization, possibly with ribs or sealing threads.

The various seals known in the state of the art aim to ensure exclusively a sealing function. The object of the invention is to provide a gasket providing not only a sealing function, but also at least one other function while being obtained in a simple manner.

For this purpose, the gasket that it concerns, of the type comprising a support on at least one side of which is deposited cold a layer of elastomer, which is then shaped, with possible formation of nets or ribs, in a mold heated, where also vulcanization is carried out, is characterized in that the support is not coated over its entire surface by elastomer, the uncoated areas fulfilling a function other than a sealing function. According to one embodiment of this seal, the support is constituted by a perforated support, such as a perforated support, or woven delimiting meshes, the non-coated areas of elastomer playing, the role of filter.

Thus, the seal performs the sealing functions around certain openings that it comprises, the zone or areas not coated with elastomer, leaving visible the perforated support which acts as a filter, for example for an oil circuit, water or air. According to another embodiment of this seal, the support is constituted by a metal plate of generally rectangular shape, forming an electrode of a fuel cell, the central portion of which is not coated with elastomer and whose peripheral zone is coated on at least one side with elastomer, with openings for the passage of fluids and clamping bolts.

The supports act as an electrode, alternately anodes and cathodes, the peripheral zone comprising the elastomer sealing between two adjacent plates, this peripheral zone allowing the passage with sealing of screws and fluids.

According to another possibility, the support is constituted by a semi-permeable membrane, intended to be placed between an anode and a cathode of a fuel cell, the central part of the membrane not being coated with elastomer and the zone peripheral being coated with elastomer on at least one face, for sealing against at least one adjacent electrode, anode or cathode.

According to another embodiment of this seal, the support consists of an electrically conductive reinforcement comprising at least one non-elastomer coated zone, intended for electrical connection, the remainder of the elastomer-coated surface providing electrical insulation. and sealing.

It may be, for example to achieve the electrical connection of a sealed housing, through the joint frame.

According to another embodiment adapted for example to the sealing of printed circuits, in the electronic field, the support is constituted by an electrically insulating armature, such as a synthetic material, comprising at least one non-elastomer coated zone. , the remainder of the surface being coated with elastomer and sealing and participating in electrical insulation. According to another embodiment of this seal, the support comprises at least one zone not coated with elastomer, comprising a deformation in three dimensions. The deformation may correspond, for example to a stamped channel, to serve as fixing ancillary parts, or to serve as fluid deflector. The thickness of the elastomer layer is between 0 and

2 mm after molding. The thickness of the elastomer layer can be constant, or may be variable on the same face of the joint, or may vary from face to face, if both sides are coated.

According to one possibility, the seal comprises threads or ribs protruding from the elastomer layer with a height of between 0.05 and 2 mm.

The nets may be continuous, discontinuous, and their height may be constant or not. Thus, according to one possibility, the height of a thread is variable along the length thereof, and / or the height of the threads is different from one thread to another or on both sides of the joint, if both sides are coated.

According to one characteristic of the invention, the elastomer covers the edge of the support with or without formation of a bead. It can be a simple covering to ensure the protection of the wafer, or a bead that has sealing properties. According to another characteristic of the invention, the support comprises grooves on one or less of its faces, favoring the anchoring of the elastomer.

In any case, the invention will be better understood from the description which follows, with reference to the appended schematic drawing showing, by way of non-limiting examples, several embodiments of this seal.

Figure 1 is a flat view of a seal providing a filtration function.

Figure 2 is a plan view of an electrode of a fuel cell. Figure 3 is a partial sectional view, on an enlarged scale and in an exploded position of several constituent elements of a fuel cell.

Figure 4 is a view of the elements of Figure 3 in the assembled position.

Figure 5 is a sectional view of a membrane of a fuel cell.

Figure 6 is a perspective view of an element providing an electrical connection function.

Figure 7 is a sectional view of a joint portion having a fluid distribution channel. Figure 8 is a sectional view of a seal also having a fluid distribution channel. Figure 9 is a perspective view of a seal having a deformed portion in three dimensions.

Figures 10 and 11 are two sectional views of the edge of two joints with overlap of the edge with elastomer. Figures 12 and 13 are two partial sectional views of the central portion of a seal, wherein the elastomer is anchored in a groove.

FIG. 1 represents a seal 2 comprising a support 3 constituted by a woven mesh, or a perforated support, this support being able to be made of various types of materials, in particular stainless steel, aluminum, plastic material. On at least one of the two faces of the support 3 is deposited an elastomer layer 4 whose thickness varies, after molding, between 0 and 2 mm. The support comprises holes 5 for the passage of clamping screws, as well as other holes 6 for the passage of fluids, the holes for the fluid passage being surrounded at at least one face of the support by a thread 7 , the height of the threads being between 0.05 and 2 mm, from the elastomer layer. It should be noted that the perforated support 3 remains visible in an area not covered with elastomer, this area serving as a filter for the passage of fluids such as oil, air or water.

Fig. 2 shows a fuel cell electrode. This electrode is constituted by a plate 8 whose central portion is not coated with elastomer. Elastomer 9 is present in the peripheral zone, on each face of the plate. In this peripheral zone are provided holes 10 for the passage of clamping screws, as well as holes 12 for the passage of fluids. As shown in FIGS. 3 and 4, the elastomer layers comprise threads 13 promoting sealing. The thickness of the elastomer layer can vary between 0 and 2 mm per face, and the height of the threads with respect to the elastomer layer between 0.05 and 2 mm.

It is possible to have elastomer layers of different heights on both faces, as is apparent from FIGS. 3 and 4, and to have an elastomer layer whose height is not constant on the same face, as is apparent from these same figures.

The height of the nets 13, when they exist, can be constant or progressive.

In FIGS. 3 and 4, the elastomer layers are shaped to ensure the tight attachment of a semipermeable membrane 14. It should be noted that in FIGS. 3 and 4, one of the plates constitutes an anode A while the other constitutes a cathode C.

FIG. 5 represents a variant in which the membrane 14 itself serves as a support, the central part of the membrane not being coated with elastomer, and its two faces being coated with elastomer 9 in the two peripheral zones.

FIG. 6 shows a seal 15, comprising a support constituted by a conductive metal reinforcement 16, coated on both sides with an elastomer layer 17, having sealing threads 18. The metal is not completely coated with elastomer to provide an electrical connector function on a sealed housing.

According to the same principle, to achieve sealing in printed circuits, the armature of the seal is then insulating and made for example of synthetic material and overmolding elastomer ensures sealing and participates in electrical insulation.

FIG. 7 represents a seal comprising a support 19 coated locally on its two faces with two layers of elastomer 20 and 22. The elastomer layer 22 is discontinuous, and contains a channel 23 intended to form a distribution channel. fluid. FIG. 8 represents a seal comprising a support 24, coated on two of its faces and locally with elastomer layers 25 and 26. In a zone not coated with elastomer, the support 24 comprises a stamp 27 forming a distribution channel. fluid.

As indicated above, the elastomer layer has a thickness varying between 0 and 2 mm per face, with the possibility of asymmetry of the thickness on both sides, as shown in FIG. 8, with or without the presence of threads. , with a height of between 0.05 and 2 mm with respect to the surface of the elastomer layer.

FIG. 9 represents a seal comprising a three-dimensional stamped support 29, in a zone not coated with elastomer 30. The deformed part may serve as a fluid deflector, or for attaching ancillary parts.

An elastomer layer may be deposited on one or both sides, with an elastomer layer of thickness between 0 and 2 mm per face, with a possibility of dissymmetry of the thickness on one side and on the other , and with the possibility of nets on one or the other face.

Different embodiments can be implemented. It can be proceeded to a precut of the support, the deposition on the support of a layer allowing the adhesion of the elastomer, the cold deposition of the elastomer on at least one face of the support, the molding of the elastomer hot with vulcanization thereof and the partial or total cutting of the seal.

The shaping of the support by deformation of it if the support is metallic, can intervene during the precut of it, during the molding of the elastomer, or during the partial or total cutting of the seal.

FIGS. 10 and 11 show a seal comprising a support 34, the wafer of which is covered by an elastomer layer 35.

In the embodiment shown in FIG. 10, the wafer of the support 34 is simply coated with a layer 35 extending the elastomer layers 36 extending on either side of the support.

In the embodiment shown in FIG. 11, the elastomer layer 36 partially covering the one and the other side of the support 34, is extended at the level of the wafer by a cord 37, of greater thickness than of the support and the two layers of elastomer 36.

FIGS. 12 and 13 show two support sections 38 each showing a groove 39 into which the elastomer layer 40 penetrates. In the case of the seal of FIG. 13, the elastomer layer is flush with the two faces of the support, while in the embodiment of FIG. 14, the two elastomer layers protrude from the two faces of the support 38. The depth of the grooves is between 0 and 1 mm, while the thickness of the elastomer layer overflowing with each face of the support 38 is between 0 and 0.05 mm in the embodiment of Figure 14. The penetration of the elastomer in the grooves 39 promotes the attachment thereof on the support.

As is apparent from the foregoing, the invention provides a great improvement to the existing technique by providing a simple structure static seal, having functions other than the only sealing function.

It goes without saying that the invention is not limited to the embodiments of this seal described above as examples, it encompasses all variants.

Claims

1. A static sealing gasket, of the type comprising a support (3, 8, 14, 16, 19, 24, 29, 34, 38) on at least one side of which is deposited cold a layer of elastomer, which is then shaped, with possible formation of threads or ribs (7, 13, 18, 28), in a heated mold, where vulcanization is also performed, characterized in that the support is not coated on its entire surface by elastomer, the uncoated areas fulfilling a function other than a sealing function.

2. Joint according to claim 1, characterized in that the support is constituted by a perforated support (3), such as a perforated support, or woven delimiting meshes, the non-coated areas of elastomer (4), playing the role of filter.

3. Joint according to claim 1, characterized in that the support is constituted by a metal plate (8) of generally rectangular shape, forming an electrode of a fuel cell, whose central portion is not coated with elastomer and the peripheral region of which is coated on at least one side with elastomer (9), with openings (10, 12) being provided for the passage of fluids and clamping bolts.

4. Joint according to claim 1, characterized in that the support is constituted by a semipermeable membrane (14), intended to be placed between an anode (A) and a cathode (C) of a fuel cell, the central part of the membrane not being coated with elastomer and the peripheral zone being coated with elastomer (9) on at least one face, in order to ensure the sealing vis-à-vis at least one electrode , anode or adjacent cathode.

5. Joint according to claim 1, characterized in that the support is constituted by an electrically conductive reinforcement (16) comprising at least one uncoated area of elastomer, for the electrical connection, the rest of the surface coated with elastomer (17) providing electrical insulation and sealing.

6. Joint according to claim 1, characterized in that the support is constituted by an electrically insulating armature, such as synthetic material, comprising at least one uncoated elastomer zone, the rest of the surface being coated with elastomer and sealing and participating in electrical insulation.

7. Joint according to claim 1, characterized in that the support (29) comprises at least one uncoated area of elastomer, comprising a three-dimensional deformation.

8. Seal according to one of claims 1 to 7, characterized in that a zone (23) undeformed and not coated with elastomer and disposed between areas (22) coated with elastomer, or a zone (27) deformed and not coated with elastomer serve as fluid distribution channels.

9. Joint according to one of claims 1 to 8, characterized in that the thickness of the elastomer layer is between 0 and 2 mm, after molding.

10. Joint according to claim 9, characterized in that the thickness of the elastomer layer is variable on the same face of the seal, or may vary from one face to the other, if both sides are coated.

11. Seal according to one of claims 1 to 10, characterized in that it comprises threads or ribs protruding from the elastomer layer with a height of between 0.05 and 2 mm.

12. Seal according to claim 11, characterized in that the height of a net is variable along the length thereof, and / or the height of the nets is different from one net to another or on both sides of the net. joint, if both sides are coated.

13. Joint according to one of claims 1 to 12, characterized in that the elastomer covers the edge of the support with or without formation of a bead (37).

14. Joint according to one of claims 1 to 13, characterized in that the support comprises grooves (39) on one or less of its faces, promoting the anchoring of the elastomer.