Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16J—PISTONS; CYLINDERS; SEALINGS
  • F16J15/00—Sealings
  • F16J15/16—Sealings between relatively-moving surfaces
  • F16J15/32—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings

Definitions

• connection means are used which, in a body generally attached or integral with the member, are constituted by a bore intended to receive the end of the tube, means for retaining the tube relative to the body, whether these are conventional or so-called instantaneous connections and sealing means arranged between the bore and the end of the tube to prevent any leakage of the liquid circulating in the circuit.
• these sealing means are simply constituted by an O-ring made of elastic or deformable material which fills the annular space between the bore and the external surface of the end of the tube placed in this bore.
• the O-ring is not suitable for all applications and in particular in the automotive field where manufacturers are imposing increasingly stringent requirements with regard to the sealing of the fluid circuits. And this is how the shape of the still annular seals has been profoundly modified to meet these requirements.
• a joint with a quadrilobe section and a joint with a x-section with lips, that is to say a joint which does not twist when it is put in place. places the tube in the connection member and which provides an increasing seal as a function of the pressure to which it is subjected, without however having the drawbacks of these joints, namely a significant risk of extrusion for the joints in x-section of the made of their great flexibility and a heterogeneity of stress distribution for common quadrilobe joints.
• the present invention relates to an annular seal of quadrilobe meridian section intended to be housed in the space delimited by a cylindrical housing and the external surface of a cylindrical tube substantially axial to the housing so that the lobes, each bounded by an O-shaped surface, define contact lines axially offset from the joint, on the one hand for two of them, the bore and on the other hand for the other two the tube, in which the meridian radius of the outer lobes is smaller than the meridian radius of the inner lobes.
• the distribution of stresses in the joint while the tube is mounted in the bore and the pressurized fluid circulates in the circuit is much more homogeneous than in a normal quadrilobe joint.
• the coaxiality defects between the cylindrical housing and the end of the tube which is inserted therein are much better taken into account by a seal whose flexibility is greater outside than inside, that is to say larger in the vicinity of the surface of the housing than in the vicinity of the surface of the tube.
• the ratio of the meridian radii is substantially equal to the ratio of the internal and external radii of the joint.
• substantially equal we mean an identity of more than at least 20%.
• At least one of the radial faces of the joint forming its axial ends is planar.
• only one face of such a seal is subjected to the pressure of the fluid circulating in the circuit to be sealed and only this face must be shaped like lips, that is to say that between the inner lobes and outside the joint subjected to this pressure there is a depression or a groove which gives a certain flexibility allowing the radial spacing of the lobes relative to one another.
• the other face being generally subjected only to atmospheric pressure does not have to be deformable under the same conditions.
• FIG. 1 is a meridian sectional view of a seal according to a first embodiment of the invention
• - Figure 2 is a sectional view of an alternative embodiment of Figure 1.
• the seal shown in FIG. 1 is an annular seal whose meridian section 1, substantially inscribed in a square 2 has two outer lobes 3 and 4 and two inner lobes 5 and 6.
• This seal When this seal is placed between two substantially coaxial cylindrical surfaces, that is to say a surface 7 of a housing formed in a connection member and an external surface 8 of a tube inserted in the housing 7, it bears against the surface 7 by two contact lines 9 and 10, offset from each other in the axial direction of the cylindrical surfaces 7 and 8 and by two contact lines 11 and 12 on the surface 8.
• contact lines belong to toric surfaces whose meridian radius is that of the corresponding lobes.
• the rays RI of lobes 3 and 4 are smaller than the rays R2 of lobes 5 and 6.
• the outer lobes 3 and 4 and the inner lobes 5 and 6 are separated axially by a groove 13, 14 whose depth is such that when the seal is compressed between the two surfaces 7 and 8, the quadrilateral contact of the seal with its surfaces remains preserved.
• This arrangement has the advantage in terms of the manufacture of the seal, of placing the seal of the mold into which the elastomeric material of the seal will be injected at the bottom of the grooves 13 and 14 so that any burr that may arise at this joint plane is always contained in these grooves and does not interfere with the contact of the joint with the two surfaces between which it must seal 1.
• the ratio of the radii RI, R2 is more or less 20% almost equal to the ratio of the inside diameters Dl and outside D2 of the joint.
• a joint according to the invention will have an inside diameter of 4.30 mm, an outside diameter of 8.30 mm, a radius RI equal to 0.3 mm and a radius R2 equal to 0.5 mm.
• the square in which the quadrilobic surface of the meridian section of the joint is inscribed is a square of approximately 2 mm in side.
• the joint shown in FIG. 1 also has two grooves which separate a lobe of small radius from a lobe of large radius.
• grooves 17 and 18 give the joint and in particular the outer part of this joint, that is to say on the side of the lobes of small radius, a possibility of being deform and be pressed against the surface 7 of the bore, under the effect of a pressure applied to the surfaces 15 and 16.
• the flexibility given to the lobe and therefore to the corresponding external toric portions is more or less large and at this level the seal acts at least partially as a lip seal.
• the seal may have another end face 16 which is flat as shown in FIG. 2. If the seal is put in place in applications where the seal is provided between two media without significant pressure, the two end faces 15 and 16 of the seal can be flat.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Gasket Seals (AREA)
• Cable Accessories (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8847904

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (1)

Citations (2)

• 2000
  • 2000-03-09 FR FR0003026A patent/FR2806144B1/fr not_active Expired - Fee Related
• 2001
  • 2001-03-05 WO PCT/FR2001/000639 patent/WO2001066981A1/fr active Application Filing
  • 2001-03-05 AU AU40764/01A patent/AU4076401A/en not_active Abandoned
  • 2001-03-09 AR ARP010101132A patent/AR027638A1/es unknown

Patent Citations (2)

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