FR2518171A1 - HEAD GASKET FOR INTERNAL COMBUSTION ENGINE WITH COMBUSTION PRECHAMBER - Google Patents

Abstract

1. A cylinder head gasket for an internal combustion engine with an added pre-combustion chamber of the Ricardo type in which a gas-tight seal is obtained by means of metal fire rings (14) each consisting of a part associated with an opening in the gasket so as to overlap the edge of said opening and having two flanges (15, 16) in, overlapping relationship with the two faces of the gasket (13), one (16) of which flanges has been crimped and the other (15) is wider than that (16) which has been crimped, the crimped flange (16) of the fire ring being associated with a metal plate (17) engaged between it and the gasket and maintained in position by the pressure which it applies to the latter, characterised in that the width of the flange (15) facing the pre-combustion chamber completely covers the common surface area between this added Ricardo-type pre-combustion chamber and the engine block and in that the metal plate (17) which is interposed between the crimped flange (16) and the gasket has a width such that it extends over the whole of this width of the flange (15) facing the added Ricardo-type pre-combustion chamber.

Description

251817 1

  The present invention relates to a cylinder head gasket

  for an internal combustion engine with a prechamber of combustion

  tion. A cylinder head gasket is located, as shown in Figure 1 of the attached schematic drawing, between the engine block 2 and the cylinder head 3 and must fulfill several functions, including: sealing the coolant and the lubricating liquid which circulate between the engine block and the cylinder head, ensure the sealing of the combustion gas at high pressures and temperatures, adjust the available thickness between the cylinder head and engine block by acting as a clamping stop, compensate for the geometrical irregularities of the planes gasket of the cylinder head and the engine block so as to maintain contact and maintain the initial seal despite engine deformations occurring during the

operation of it.

  Usually, the sealing functions 4-of the cylinder head gasket are differentiated. The fluid-tightness, water-cooling-glycol, and lubricating oil is generally r 6 alis 6 e by the base material of the seal, consisting of asbestos cartons 4 stapled on a perforated tale 5, a metal fabric coated on both sides with a mixture of asbestos-elastomer fibers etc. The gastightness is generally achieved by "rings of fire"

  6 steel, electrogalvanised steel, stainless steel

  dable, aluminum-clad steel, etc. Modern engines having increasingly high performance for a given cubic capacity, the gas tightness is increasingly difficult to achieve, especially for diesel engines where the temperature and pressure are The latest improvements to diesel engines, in particular the addition of a supercharging system, require a new design of

rings of fire.

  Diesel engines having a fuel prechamber

  reported Ricardo type, also require a

  particular design of cylinder head gaskets.

  A conventional solution consists, as shown in Figure 2, in making a large wing of the c 8 tee of the antechamber, but having a small wing of the c 8 block tee This solution has the disadvantage of providing too different pressures between the flame front and the prechamber due to the thickness of the metal of the crimp that goes from the

single to double.

  The present invention aims to overcome these disadvantages.

  For this purpose, in the cylinder head gasket to which it relates, of the type in which the gastightness is achieved by metal fire rings each constituted by a part associated with an opening of the gasket, so as to cover the edge of the gasket. said opening, and having two wings overlapping the two faces of the seal, one of which has been crimped, the crimped wing of the fire ring is associated with a metal plate engaged 6 e between said wing and the seal, and maintained in

  place by the pressure exerted by the latter.

  The reinforcement thus produced ensures a better distribution of the pressures in the zone of the pre-combustion chamber and a better mechanical resistance to the high temperatures. In addition, the fact of having three thicknesses of metal, instead of two with a traditional fire ring, allows to better modulate the thickness where reinforcement is desired The reinforcing plate may or may not have the same thickness as the metal plate constituting the ring of fire to which it

is associated.

  The reinforcing plate may be located on the face of the gasket facing the prechamber of combustion, or on the opposite side of the gasket facing the opposite side to the

antechamber.

  According to one embodiment of the invention, the width of the reinforcing metal plate is greater than the width of the wing of the fire ring with which it is associated. Since the two wings of the fire ring are of different widths, the metal plate of

  reinforcement is associated with the shorter wing.

  This arrangement therefore makes it possible to obtain a wide wing not only of the c 8 t and of the prechamber, but also of the

  c 8 the engine block, which allows a better distribution

  contact pressure and better evacuation

  thermal conduction metal on metal.

  If, for example, in the classical solution, the thick-

  the metal constituting the ring of fire is 0.25 mm, the total thickness of the metal at the edge of the gases will be 1 0.50 mm. In the case of the invention, it is possible, for example, to use a thickness of 0.17 mm metal, both for the fire ring itself and for the metal reinforcing plate, which also makes it possible to obtain a thickness of 0.51 mm at the front of the fire to keep the same pressure of tightening, but to obtain a total thickness of 0.34 mm with respect to the prechamber out of the front of fire, instead of 0, 25 mm in the case where the ring of fire comprises only one large wing It It is therefore possible to obtain a good secondary seal around the prechamber by increasing the clamping pressure of the zone considered while maintaining the same pressure at the level of the fire front and a better possibility of modulation.

thicknesses of metal.

  Like the rings of fire, the reinforcing plates

  metal cement may be made of steel,

  galvanized, tin-plated steel, stainless steel, or aluminum-clad steel, and their thickness can range from 0.05 mm to

0.30 mm.

  A judicious choice of the metal thickness of the main fire ring and the reinforcement plate

  modulate the ratio of the clamping pressures.

  For example, if the fire ring has a thickness

2518171.

  0.15 mm and the reinforcement plate, a thickness of 0.20 mm we will have 0.50 mm of metal at the level of the main ring of fire and 0.35 mm in the area of the prechamber, a distribution from 70 to 50 in the classical solution. Depending on the needs, it is therefore possible to use a reinforcing plate of the same thickness or thickness different from that of the fire ring

with which it is associated.

  Alternatively, the part of each metal part engaged under a wing of a fire ring

is ribbed.

  According to another embodiment of the invention, in which the ring of fire covers an element such as a ribbed metal strip with one or more thicknesses or a ring which, arranged at the edge of the opening considered , is constituted by an open or closed ring

  containing, for example, asbestos, copper, brass ,.

  a refractory alloy, graphite or ceramic, the metal reinforcing plate is arranged to provide a triple thickness of metal only at the level of

  the element covered by the ring of fire.

  In any case, the invention will be well understood in

  using the following description with reference to the drawing

  schematic annexed representing, by way of non-limiting examples, several embodiments of the cylinder head gasket: Figure 3 is a sectional view of the cylinder head gasket associated with a prechamber combustion type Ricardo diesel engine; Figure 4 is an enlarged view of the seal of Figure 3; Figures 5 to 9 are views corresponding to five

  alternative embodiments of the seal of Figure 4.

  Figure 3 shows the assembly with sealing

  a Ricardo 10 system on the cylinder head of a combustion engine.

  The Ricardo contains a prechamber of combustion 12 The seal between the prechamber 10 and the block or the liner It is achieved by a cylinder head gasket 1 l This cylinder head gasket comprises a ring of fire 14 having a wide wing 15 of the 8 tee of the prechamber and a crimped short wing 16 on the side of the engine block From the c 8 té of the engine block, there is provided a metal plate 17 of reinforcement, whose end is engaged under the wing 16 of the ring of 14 This metal plate 17 is of such width that it extends over all or part of the

  width of the wing 15 with regard to the prechamber.

  In the embodiment shown, the thickness of the reinforcing plate I corresponds to the thickness of the metal fire ring 14. This thickness is, for example, 0.17 mm, which allows, thanks to the triple

  thickness at the level of the fire front, to obtain a thick

  metal thickness of 0.51 mmn, and a metal thickness of

0.34 mm with regard to the Ricardo.

  It should be noted that the contact surface between the plate 17 and the engine block 11 also favors the evacuation

  in the area under consideration.

  FIGS. 5 and 6 of the attached schematic drawing show variants of the joint of FIG. 4, in which the fire ring 14 is crimped by covering a ring of

  metallic or metalloplastic reinforcement.

  In the embodiment of FIG. 5, it is a ring 18 of the closed type, containing a certain amount damiaante 1, while, in the embodiment of FIG. 6, it is a question of an open-type ring 20 also containing asbestos 19 It should be noted that the material contained in the ring 18 or ring 20 could be different from asbestos and constituted for example by copper, brass, refractory alloy, graphite

or a ceramic.

  It should be noted that, in both cases, there is a superposition of the reinforcing plate 17 with the short wing 16 of the ring of fire only at the level of the ring.

central, respectively, 18, 20.

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  In the embodiment shown in FIG. 7, the part of the reinforcement plate 17 engaged under the wing 16 of the fire ring has a triple rib

reinforcement 21.

  FIGS. 8 and 9 show two variant embodiments of this seal, in which the fire ring 14 is crimped, in the case of FIG. 8, on a ribbed metal strip 22, and in the case of FIG. 9 on two ribbed metal strips X arranged on either side of a strip 24 In this case again, the superposition of the plate

  reinforcement 17 with the crimped wing 16 of the ring of -

  fire 14 is at band level respectively 22, 2

and 24 included in the ring.

  As can be seen from the foregoing, the invention brings a great improvement to the existing technique by providing a cylinder head gasket whose design makes it possible to better adjust the pressures by a better modulation of the zone considered. 'be of a cost price of the same level as that of the traditional cylinder head gasket, while allowing a better modulation of the thickness of the fire rings, and Stant a cost price that is not higher than

  that of traditional cylinder head gaskets.

  It goes without saying that the invention is not limited to the embodiments of this head gasket, described above as examples; it embraces :,

  contrary, all the variants and implementations

  This is particularly the case that the crimped wing of each ring of fire and the reinforcing plate could be located not from the opposite side of the prechamber, but from the side of the latter, without it being possible so far. of the frame

of the invention.

Claims (7)

CLAIMS -   1 Cylinder head gasket for internal combustion engine   with prechamber of combustion, of the type in which the 6   gas is achieved by metal fire rings.   each (14) each consisting of a part associated with an opening of the joint, so as to cover the edge of said opening, and having two wings (15, 16) overlapping the two faces of the joinm t (13), the one of the two has been crimped, characterized in that the crimped wing (16) of the fire ring is associated with a metal plate (17) engaged between said wing and the seal (13), and maintained in place by the pressure ex pressed by the latter. 2 cylinder head gasket according to claim 1, characterized in that the crimped wing (16) of each ring of fire and the reinforcing plate (17) associated therewith are situated on the face of the rotated joint of the side 6   opposite 6 to the prechamber of combustion.   3 cylinder head gasket according to claim 1, characterized in that the crimped wing (16) of each ring of fire, and the reinforcing plate (17) associated therewith are located on the face of the joint turned 6 th of cat 6 of the prechamber of combustion.   4 Head gasket according to any one of   1 to 3, characterized in that the thickness of   each reinforcing plate (X 7) is equal to the thickness   of the ring of fire (14) with which it is associated.   Head gasket according to any one of   claims t A 3 t character 6 ris 6 in that the thickness of   the reinforcing plate (17) is different from the   of the ring of fire (14) with which it is associated.   6 Head gasket according to any one of   1 to 5, characterized in that the width of   the reinforcing metal plate (17) is greater than the width of the flange (16) of the fire ring to which she is associated 6th.   7 Head gasket according to any one of   1 to 6, characterized in that the width of   the reinforcing plate (17) is equal to the width of   the non-crimped wing (15) to the right of the prechamber.   8 Head gasket according to any one of   Claims 1 to 6, characterized in that the width of   the reinforcing plate (17) is different from that of   the non-crimped wing (15) to the right of the prechamber -   9 Head gasket according to any of the   Claims 1 to 8, characterized in that the part of   each metal part (17) engaged under a wing (16) a ring of fire is ribbed.   Head gasket according to any one of   1 to 9, characterized in that, in so far as   the fire ring (14) covers an element such as a ribbed metal strip (22, 23) having one or more thicknesses or a ring (18, 20) which, disposed at the edge of the opening considered , is constituted by an open or closed ring containing, for example, asbestos, copper, brass, a refractory alloy, graphite, or a ceramic, the metal reinforcing plate (17) is arranged so as not to provide a triple thickness of metal only at the level of the 6 (18, 20, 22, 23)   covered by the ring of fire (14).