FR3094061A1 - Seal between two automotive parts - Google Patents

Abstract

The invention relates to a seal (10) between two automotive parts, comprising: - a first contact part (11) provided with a sealing rib (15), - a second contact part (12) made of vis-à-vis the first contact surface so as to compress the rib, - a compression locking part (30) arranged between the two contact parts so as to limit the compression of the rib, in which the first part contact and the locking piece include sliding stops (21, 31) cooperating with each other so as to block the sliding of the locking piece relative to the first contact piece. Figure for the abstract: figure 3

Description

Gasket between two automotive parts

The present invention relates to the field of seals between vehicle parts, in particular subject to vibrations, in particular cylinder head gaskets.

It is known to use ribbed seals between vehicle parts, in particular subject to vibrations, as for example in the case of cylinder head gaskets which provide sealing between the cylinder head and the cylinder block. To ensure a seal with a ribbed seal, in particular metallic, the rib of the ribbed seal is compressed.

The joint should be designed in such a way that it does not completely crush this rib as this increases the risk of the rib cracking. Furthermore, this increases the risk of loss of elastic recovery, the elastic recovery being the ability of the joint to continue to perform its function despite more or less large openings in the joint plane. This is particularly troublesome in the case of a cylinder head gasket, where the thermomechanical stresses generate more or less large openings in the gasket face, in particular when it is made up of sheets.

To avoid this, it is known to use a positive stop or blocking piece. This blocking piece will limit the crushing of the rib under the effect of the tightening forces and any stresses. This crushing will not exceed a value depending on the geometry of the blocking piece. This blocking piece is commonly called a stopper or "stopper" (for blocker in English).

This stopper can be made in several ways, in particular in folded sheet metal, in stamped sheet metal, or in welded or free insert sheet metal.

The bent and/or stamped sheet metal solutions have rigidity drawbacks.

In welded solutions, welding generates an additional cost during the manufacture of the joint. In addition, it requires the use of compatible materials, in particular sheet metal.

Solutions with a free buffer, in the sense of not fixed by fasteners or welding, between the sheets of the joint are simpler to design because they present fewer material compatibility constraints. They also allow the use of more economical steels. However, they present a risk of movement by sliding of the stopper between the surfaces which compress it, in particular because of the vibrations to which the joint is subjected.

An object of the present invention is therefore to improve the existing seals in particular by keeping a simple design and with better reliability.

For this, a first object of the invention relates to a seal intended to ensure the seal between two automobile parts, comprising:
- a first contact piece provided with a sealing rib,
- a second contact piece facing said first contact piece and its rib, so that the rib is subjected to compression against said second contact piece when these two contact pieces are tightened towards each other,
- a compression blocking part arranged between said first contact part and said second contact part so as to allow said compression while limiting it,
wherein said first contact piece and said blocking piece include sliding abutments, the sliding abutments of said blocking piece being arranged respectively against those of said first contacting piece, so as to block the sliding of said blocking piece relative to said first contact piece.

Thus, this blocking part or stopper makes it possible to limit the compression of the rib while avoiding the risk of the blocking part slipping relative to the contact surface. The reliability of the seal is thus reinforced over time.

In addition, the use of stops to prevent slipping of the blocking part allows simple design and manufacture of the joint.

• ledit glissement est un glissement en rotation et/ou en translation ;
• la pièce de blocage est libre contre ladite première pièce de contact ; par libre on entend que bien qu’elle soit bloquée en glissement, elle est non fixée par des attaches, tels que des vis ou des rivets, par une soudure ou par de la colle ; l’invention est particulièrement utile avec une pièce de blocage libre, qui est davantage susceptible de glisser ;
• la première pièce de contact est une feuille en matériau rigide; un tel joint peut être facilement inséré entre deux pièces automobiles dont l’étanchéité doit être assurée ;
• le matériau rigide et/ou la pièce de blocage sont/est un métal ou un alliage métallique ; un tel joint est particulièrement résistant aux efforts de compression et /ou de vibrations, tels que ceux subis dans un moteur ;
• la première et/ou la deuxième pièces de contact sont/est une feuille en matériau rigide ; le joint est ainsi multicouches ; il présente une bonne étanchéité lors du serrage du joint entre deux pièces automobiles ;
• les butées en glissement sont agencées par paires, et pour chaque paire de butées en glissement :
  i) l’une des butées en glissement est agencée sur la pièce de blocage, l’autre des butées en glissement étant agencée sur ladite première pièce de contact, et
  ii) l’une des butées en glissement est une protubérance et l’autre des butées en glissement est un logement dans lequel est logée ladite protubérance ;
  cela permet une réalisation simple des butées en glissement de manière à ce qu’elles coopèrent ensemble au blocage en glissement de la pièce de blocage par rapport à la première pièce de contact ;
• selon l’alinéa précédent, dans l’une des paires de butées, la protubérance peut être de forme complémentaire et ajustée sur son pourtour aux bords du logement ; cela permet de bloquer la pièce de blocage en rotation ;
• selon l’un quelconque des deux alinéas précédents, dans l’une des paires de butées, la protubérance peut présenter un jeu entre son pourtour et les bords du logement ; cela permet une limitation des degrés de liberté de mouvements en translation, tout en laissant un certain jeu ; notamment, lorsque combiné à l’alinéa précédent, cela permet un indexage isostatique permettant une limitation des mouvements en rotation et en translation, tout en limitant des contraintes supplémentaires sur la pièce de blocage ;
• les logements sont agencés dans la pièce de blocage, et les protubérances sont agencées sur ladite première pièce de contact ; la conception de la pièce de blocage est simplifiée ; les logements peuvent notamment être des trous, notamment traversants ;
• les protubérances sont des portions découpées dans la feuille et repliées de manière saillante par rapport à ladite première pièce de contact ; c’est une manière simple de réaliser les butées en glissement ;
• le joint est un joint de culasse ; l’invention est particulièrement utile dans le cas d’un joint de culasse, où la pièce de blocage est soumise à de fortes vibrations ;
• selon l’alinéa précédent, ladite pièce de blocage peut être annulaire et agencée autour d’un orifice destiné à la communication entre un cylindre de carter-cylindres et une chambre de culasse.

Other characteristics and advantages of the present invention will appear more clearly on reading the following detailed description of an embodiment of the invention given by way of non-limiting example and illustrated by the appended drawings, in which:

• said sliding is a sliding in rotation and/or in translation;
• the blocking part is free against said first contact part; by free is meant that although it is blocked in sliding, it is not fixed by fasteners, such as screws or rivets, by welding or by glue; the invention is particularly useful with a loose blocking piece, which is more likely to slip;
• the first contact piece is a sheet of rigid material; such a seal can be easily inserted between two automotive parts whose tightness must be ensured;
• the rigid material and/or the blocking piece are/is a metal or a metal alloy; such a seal is particularly resistant to compression and/or vibration forces, such as those experienced in an engine;
• the first and/or the second contact parts are/is a sheet of rigid material; the seal is thus multi-layered; it has a good seal when tightening the seal between two automotive parts;
• the sliding stops are arranged in pairs, and for each pair of sliding stops:
  i) one of the sliding stops is arranged on the blocking piece, the other of the sliding stops being arranged on the said first contact piece, and
  ii) one of the sliding stops is a protrusion and the other of the sliding stops is a housing in which said protrusion is housed;
  this allows a simple realization of the sliding stops so that they cooperate together in the sliding blocking of the blocking part relative to the first contact part;
• according to the preceding paragraph, in one of the pairs of abutments, the protuberance can be of complementary shape and adjusted on its periphery to the edges of the housing; this makes it possible to block the blocking part in rotation;
• according to any one of the two preceding paragraphs, in one of the pairs of abutments, the protuberance may have a clearance between its periphery and the edges of the housing; this allows a limitation of the degrees of freedom of movement in translation, while leaving a certain clearance; in particular, when combined with the preceding paragraph, this allows isostatic indexing allowing a limitation of movements in rotation and in translation, while limiting additional stresses on the locking part;
• the housings are arranged in the blocking part, and the protuberances are arranged on said first contact part; the design of the blocking piece is simplified; the housings may in particular be holes, in particular through holes;
• the protuberances are portions cut out of the sheet and bent projectingly relative to said first contact piece; it is a simple way to make sliding stops;
• the gasket is a cylinder head gasket; the invention is particularly useful in the case of a cylinder head gasket, where the locking part is subjected to strong vibrations;
• according to the preceding paragraph, said blocking piece may be annular and arranged around an orifice intended for communication between a crankcase cylinder and a cylinder head chamber.

Another object of the invention is a vehicle engine comprising:
- a cylinder block having at least two cylinders,
- a cylinder head having at least two chambers,
- A seal according to the invention held in a vice between the cylinder block and the cylinder head so that each cylinder corresponds with a corresponding chamber through a corresponding orifice of the seal.

Another object of the invention is a vehicle comprising:
- a seal according to the invention tightened between two parts of this vehicle, and/or
- A motor according to the invention.

In the present application, the terms "top", "bottom", "lower", "upper" refer, unless otherwise indicated, to the orientation of the seal according to the invention or of the engine according to the invention that they are intended to have, once mounted in a vehicle.

Other characteristics and advantages of the invention will appear on reading the detailed description of the non-limiting examples which follow, for the understanding of which reference will be made to the appended drawings, among which:

: Figure 1 is a diagram of a motor according to an exemplary embodiment of the invention;

: Figure 2 is an exploded view of a seal according to an embodiment of the invention, such as that mounted on the engine of Figure 1;

: Figure 3 shows a schematic section of part of Figure 2;

: Figure 4 shows a portion of Figure 2;

: Figure 5 shows another portion of Figure 2.

FIG. 1 represents an embodiment of a vehicle engine 1 according to the invention.

This engine 1 includes:
- a cylinder block 3 having at least two cylinders 5 (only one being visible in figure 1),
- a cylinder head 2 having at least two chambers, not shown, here directly above the corresponding cylinder 5,
- a gasket 10 according to an exemplary embodiment of the invention, clamped between the cylinder block 3 and the cylinder head 2 so that each cylinder corresponds with a corresponding chamber through a communication orifice 9 corresponding to the seal 10.

In known manner, the cylinder 5 forms the chamber where the corresponding piston 4 slides.

The seal 10 is here intended to ensure the seal between the cylinder head 2 and the cylinder block 3. For this, the seal is clamped between the lower face of the cylinder head 2 and the upper face of the cylinder block 3. The tightening of the joint 10 is carried out by tightening of the cylinder head 2 against the cylinder block 3, for example by screws.

Figure 2 shows the structure of this seal 10.

In this example, seal 10 is made up of three layers:
- a first contact part, here formed by a first metal sheet 11, in particular a steel sheet,
- a second contact piece, here formed by a second metal sheet 12, in particular a steel sheet,
- a compression blocking part, hereinafter stopper 30, stopper 30 being arranged between these two sheets 11, 12.

Each of these layers has an orifice. These orifices are aligned so as to form the communication orifice 9 of the seal 10.

The first sheet 11 has two main surfaces:
- an upper surface in plane contact with the underside of the cylinder head 2, and, on the opposite,
- a lower surface, called the first contact surface 13.

The second sheet 12 also has two main surfaces:
- a lower surface in plane contact with the upper face of the cylinder block 3, and, on the opposite side,
- an upper surface, called the second contact surface 14.

Said first contact surface 13 is provided with a sealing rib 15, projecting from this first contact surface 13 towards the second sheet 12, more precisely towards the second contact surface 14.

This arrangement allows compression of the rib 15 against the second contact piece 12, the two contact surfaces 13, 14 approaching each other when the two sheets 11, 12 are clamped towards each other. , namely in the illustrated engine 1, when the cylinder head 2 is tightened on the cylinder block 3.

This compression of the rib 15 makes it possible here to achieve sealing. In particular here, the rib 15 surrounds the communication orifice 9. Thus, the tightness of the cylinder head chamber and the corresponding cylinder 5 is achieved.

However, in particular here in the engine 1, the strong vibrations to which the joint is subjected will result in strong compression vibrations on the rib 15, which can in particular generate a faster deterioration of the rib 15.

The stopper 30 is arranged in such a way as to allow said compression while limiting it, thus improving the life of the rib 15.

In general, as in this example, this stopper 30 is arranged so as to achieve a compression limit thickness of the gasket 10. For example, as here, this compression limit thickness corresponds to the thickness of the stopper 30.

For example, as here the stopper 30 can be a flat ring. In other words, its upper and lower faces are here planar. This makes it easy to determine the compression limit thickness, which therefore corresponds to the thickness of the ring forming the stopper 30.

Generally, as in this example, each sheet 11, 12 may carry a sealing rib. For example here, the second sheet 12 also has a sealing rib 16, projecting from the second contact surface 14.

The two sealing ribs 15, 16 each have a ridge, or apex. The height of a rib 15, 16 corresponds to the distance between its junction with the corresponding contact surface 13, 14 and its crest. These ridges can be, as here, facing each other, so that during compression, the ribs 15, 16 compress against each other.

In this case, the thickness e ₁ of the stopper 30 is less than the sum e ₂ of the heights of the ribs 15, 16. The stopper 30 therefore allows compression of the ribs 15, 16 against each other up to a limit thickness, which corresponds to the thickness e ₁ of the stopper 30.

According to a variant not shown, the seal may comprise a single sealing rib, which during compression compresses directly against the second contact surface. In such a case, the thickness of the bumper is less than the height of this rib.

The stopper 30 is free against said first contact surface 13, and in particular here, free between the two sheets 11, 12. 30 and the contact surfaces 13, 14.

This stopper 30 is therefore simply inserted between the two sheets 11, 12, which are fixed to each other. The stopper 30 being only maintained by its positioning between the two sheets 11, 12, which they are here fixed to each other (not shown).

According to the invention, in order to prevent the stopper 30 from sliding against the first and/or the second contact surface 13, 14, the joint 10 comprises sliding stops 21, 22, 31, 32, arranged in the example shown in pairs 17, 18.

These sliding stops are distributed between the first contact surface 13 and the stopper 30 so as to block the sliding of the latter against each other, in particular sliding in rotation and/or in translation.

Here, the joint 10 comprises two pairs 17, 18 of sliding stops. The first pair 17 and the second pair 18 are illustrated in detail in Figure 4 and Figure 5 respectively.

As illustrated in FIGS. 3 and 4, the first pair 17 comprises a sliding abutment 21 arranged on said first contact surface 13. In this example, this is a first protuberance 21 projecting downwards. This first protuberance 21 is formed by a portion cut out of the first sheet 11 and folded in a protruding manner with respect to said first contact surface 13. It can be seen in FIG. 4, a slot 23 corresponding to the zone where the first protuberance 21 has been cut out.

The first pair 17 also includes a sliding abutment 31 formed by a first housing 31, which here is formed by a through hole in the thickness of the ring forming the abutment 30.

The first protuberance 21 is housed in the first housing 31. Here, the first protuberance 21 has a clearance between its periphery and the edges 33 of the housing 31. For example, the length, and possibly the width, of the first protuberance is/are lower (s) than that (s) of the first housing 31. Thus, the first pair 17 reduces, or even blocks, the stopper 30 sliding in translation against the first sheet 11, while allowing an adjustment at least in rotation.

As illustrated in FIG. 5, the second pair 18 comprises a sliding abutment 22 arranged on said first contact surface 13. In this example, this is a second protuberance 22, also formed by a cut-out portion of the first sheet 11 and folded projectingly relative to said first contact surface 13. It can be seen in Figure 5, a slot 24 corresponding to the area where the second protrusion 22 has been cut.

The second pair 18 also includes a sliding abutment 32 formed by a second housing 32, which here is also formed by a through hole in the thickness of the ring forming the abutment 30.

The second protrusion 22 is housed in the second housing 32.

Here, the second protrusion 22 is of complementary shape and fitted on its periphery to the edges 34 of the second housing 32. For example, the length and the width of the second protrusion 32 are substantially equal to those of the second housing 32. The clearance between the second protrusion 22 and the second housing 32 may be just sufficient to allow the insertion of the second protrusion 22 into the second housing 32.

Thus, the second pair 18 blocks the stopper 30 in rotational sliding against the first sheet 11.

Thus, the first pair 17 and the second pair 18 allow isostatic indexing of the stopper 30 on the first contact surface 13. Thus, the stopper 30 is locked in rotation and in translation in the joint 10.

Here, the first pair 17 makes it possible to block the degrees of freedom in translation in the median plane of the sheets 11, 12. The reduced play, almost zero, of the second pair 18 makes it possible to block the rotation of the stopper 30 around the axis of the communication orifice 9. The presence of a clearance in the first pair 17 nevertheless facilitates the assembly of the different layers 11, 30, 12 of the gasket 10.

Furthermore, this isostatic indexing reduces the risk of additional deformations due to additional stress on the stopper 30 which would be amplified during the operation of the engine 1.

Claims (14)

Seal intended to ensure the seal between two automobile parts, comprising:
- a first contact piece (11) provided with a sealing rib (15),
- a second contact piece (12) facing said first contact piece and its rib, so that the rib is subjected to compression against said second contact piece when these two contact pieces are tight to each other,
- a blocking part (30) in compression arranged between said first contact part and said second contact part so as to allow said compression while limiting it,
wherein said first contact piece (11) and said blocking piece (30) comprise sliding abutments, the sliding abutments (31, 32) of said blocking piece being arranged respectively against those (21, 22) of said first contact piece, so as to block the sliding of said blocking piece relative to said first contact piece. Joint according to Claim 1, in which the said sliding is a sliding in rotation and/or in translation. Joint according to claim 1 or 2, in which the blocking part (30) is free against the said first contact part (11). Joint according to any of the preceding claims, in which the first contact piece (11) is a sheet of rigid material. Joint according to claim 4, in which the rigid material and/or the blocking piece (30) is/is a metal or a metal alloy. Joint according to any one of the preceding claims, in which the sliding stops are arranged in pairs (17, 18), and for each pair of sliding stops (17, 18):
- one of the sliding stops (31, 32) is arranged on the blocking part (30), the other of the sliding stops (21, 22) being arranged on the said first contact part (11), and
- One of the sliding stops is a protrusion (21, 22) and the other of the sliding stops is a housing (31, 32) in which said protrusion is housed. Joint according to Claim 6, in which in one of the pairs of abutments (18), the protuberance (22) is of complementary shape and fitted around its periphery to the edges (34) of the housing (32). Seal according to Claim 6 or 7, in which in one of the pairs of stops (17), the protrusion (21) has a clearance between its periphery and the edges (33) of the housing (31). Joint according to any one of Claims 6 to 8, in which the housings (31, 32) are arranged in the blocking part (30), and the protuberances (21, 22) are arranged on the said first contact part (11 ). Joint according to claim 9, when taken in combination with claim 4, in which the protrusions (21, 22) are portions cut out of the sheet and bent projectingly with respect to the said first contact part (11). A gasket according to any preceding claim, wherein the gasket (10) is a cylinder head gasket. Gasket according to Claim 11, in which the said blocking piece (30) is annular and arranged around an orifice (9) intended for communication between a crankcase cylinder and a cylinder head chamber. Vehicle engine (1) comprising:
- a cylinder block (3) having at least two cylinders,
- a cylinder head (2) having at least two chambers,
- A seal (10) according to claim 11 or 12 clamped between the cylinder block and the cylinder head so that each cylinder corresponds with a corresponding chamber through a corresponding orifice (9) of the seal. Motor vehicle comprising:
- a seal (10) according to one of claims 1 to 12 clamped between two parts (3, 2) of this vehicle, and/or
- a motor (1) according to claim 13.