FR2795155A1 - Sealing connection of fluid conduit includes elastic ring which fits into first housing of first pipe's tubular connecting piece and second housing of sleeve - Google Patents

Abstract

Sleeve (10) has one end attached to first pipe (C) and other end to tubular connecting piece (T) of second pipe. Watertight part is deformable elastic ring (1) which fits into first housing (L1) of first pipe's tubular connecting piece (12) and second housing (L2) of sleeve (10). The ring has bead which is compressed between shoulders (19,30) of both tubular connecting pieces. An Independent claim is also included for a fuel supply circuit for automotive vehicle which includes the sealing connection.

Description

The invention relates to a sealed connection device for a fluid conduit, in particular for a motor vehicle.

Document EP-A-0 605 801 discloses a connector of the snap-on type in which the seal is provided by two O-rings separated by a spacer, these elements being attached to the interior of a housing formed in the body of the connector. .

In this type of fitting, each O-ring comes into contact with the body of the fitting mounted on one end of a first conduit on the one hand, and in contact with the external surface of the end portion of a second rigid conduit engaged in the body of the connector on the other hand. In other words, there are two diametrically opposite sealing levels for each O-ring, which can cause leakage problems when the fitting is subjected to mechanical stresses or that the fluid flowing in the fitting is at a relatively high pressure. .

As a variant, as described in document FR-A-2 740 526, it could be envisaged to bring the two O-rings and the spacer together in one piece, but the problem of leaks mentioned previously has not been resolved.

Document FR-A-2 738 893 discloses a method for producing a female end piece for connection to one end of a tubular conduit, according to which a sleeve is produced comprising a first zone for fixing to a tube and a second zone receiving a male end piece, and a seal is overmolded inside this sleeve to seal with the male end piece.

However, in this type of fitting, the overmolding of the seal in the sleeve is only possible if the inside diameter of the sleeve is sufficient to not cause problems during demolding, if this diameter is too small.

The object of the invention is to design a sealed connection device with a seal which overcomes the drawbacks inherent in the use of O-rings on the one hand, and the overmolding of a seal when the internal diameter of the conduits to be connected poses a release problem on the other hand.

To this end, the invention provides a sealed connection device for a fluid conduit, in particular for a motor vehicle, comprising a sleeve of which a first end is connected to said conduit or first conduit and of which a second end is intended to be connected to a tubular end piece or a second conduit connected to a fluid circuit, and a seal which is ensured by a ring of elastically deformable material, which is characterized in that the ring carries at least one sealing line which is situated towards a first part end of the ring to at least seal with the nozzle, and in that a second end portion of the ring is attached in a first housing formed in a first element of the connection device, so that the first end part of the ring protrudes inside the first housing and comes to be housed in a second housing nt formed in a second element of the connection device.

Advantageously, the first end part of the ring which carries the sealing line is attached by overmolding outside the first housing, while the second end part of the ring is overmolded inside this first housing.

According to a first embodiment, the second end portion of the sealing ring is attached in a first housing formed in a tubular connection insert mounted between the first conduit and the sleeve of the sealed connection device, while its first end portion is intended to be housed in a second housing formed inside said sleeve.

According to a second embodiment, the second end part of the sealing ring is attached to a housing formed inside the sleeve of the sealed connection device, while its first end part is intended to come lodge in a second housing provided in the connection insert.

According to a third embodiment, the connecting insert is eliminated and replaced by the end part of the first conduit which must be made of a rigid or semi-rigid material.

Generally, the sleeve of the sealed connection device is made from a rigid or semi-rigid plastic material, as well as the connecting insert, while the sealing ring is made of rubber or a elastically deformable elastomeric material.

A leaktight connection device according to the invention offers numerous advantages, among which there may be mentioned in particular - an improvement in tightness since a single-level seal is to be ensured with the tubular end piece or the second conduit, - a ease of assembly since the seal is not constituted by separate means which must be introduced beforehand inside the sleeve, - a gain in productivity, and - a reduced cost of implementation compared to previous solutions.

Such a sealed connection device finds application in the field of the automobile industry, in particular for fuel supply circuits. Other advantages, characteristics and details of the invention will emerge from the additional description which follows with reference to the appended drawings, given by way of example and in which - FIGS. 1 to 3 represent views in axial section of different forms of sealing rings which can be mounted in a sealed connection device according to the invention, - Figure 4 shows an exploded axial sectional view showing the various elements of a sealed connection according to a first embodiment of the invention, and - Figures 5 and 6 are views similar to that of Figure 4 but according to second and third embodiments of the invention.

Any sealed connection device necessarily includes a seal which, according to the invention, consists of an elastically deformable ring as illustrated in FIGS. 1 to 3.

In general, the ring 1 has at least one sealing line E which is constituted by a circular rib 3, for example, projecting from the internal wall of the ring 1. This sealing line E is located towards an end portion of the ring 1 for reasons which will be explained below. The ring 1 is thus generally divided into two cylindrical parts la and lb, the part 1b carrying the sealing line E.

In FIGS. 2 and 3, the two parts 1a and 1b of the ring 1 are generally separated from each other by a peripheral bead 5, knowing that it is necessary to attach more importance to the presence than to the position of this bead 5. Finally, as illustrated in FIG. 3, the part 1b of the ring 1 may have a thickness somewhat greater than that of the part 1a and this, depending on the external diameter of the element with which the sealing line E must come into sealing contact.

Such a sealing ring 1 is intended to be partly attached to a housing Ll of an element of the sealed connection device, so that the part 1b of the ring 1 which carries the sealing line E protrudes outside this accommodation Ll.

FIG. 4 illustrates a first embodiment of the sealed connection device equipped with a sealing ring according to FIG. 2, for connecting a conduit C and a rigid tubular endpiece T of a fluid circuit (not shown).

The sealed connection device R comprises a sleeve 10, a first end of which is fixed to the conduit C by a rigid tubular connecting insert 12.

One end of the connecting insert 12 has a tubular part 14 in the shape of a fir tail on which is force-fitted and sealingly the end of the conduit C, the latter being constituted by a flexible or semi-flexible pipe rigid.

The other end of the connecting insert 12 has a tubular part 16 of larger internal diameter which forms the housing L1 by delimiting an internal annular shoulder 18 with the tubular part 14.

The sealing ring 1 is molded inside the tubular part 16 so that the part 1b of the ring 1, which carries the sealing line E, protrudes outside the housing L 1 of the 'connecting insert 12 on the one hand, and that one side of the bead 5 is in contact with the end face 19 of the connecting insert 12 on the other hand.

The sleeve 10 is engaged on the connecting insert 12 and is fixed therein by snap-fastening. The latching means are for example constituted by notches 25 formed on the peripheral surface of the connecting insert 12, and by lugs 27 projecting from the internal wall of the sleeve 10, these lugs can be obtained by forming punctures in the thickener of the sleeve 10.

The inner part of the sleeve 10 has three successive housings L4, L2 and L3 of decreasing diameters which delimit between them two internal annular shoulders 30 and 32. The inside diameter of the housing L4 is slightly less than the outside diameter of the tubular part 16 of the connecting insert 12 to allow the sleeve 10 to fit on it. The inside diameter of the housing L2 is barely less than the outside diameter of the part 1b of the ring 1 to receive the latter and avoid any radial expansion of the ring 1. The inside diameter of the housing L3 is greater than the inside diameter of the part lb of the ring 1 so that the rib 3 forming the sealing line E of the ring 1 can compress radially and come into tight contact with the tip T.

When the sleeve 10 is fixed to the connecting insert 12, the end face 19 of the tubular part 16 of the insert, enters the housing L4 and comes to axially compress the bead 5 of the ring 1 on the shoulder 30 of the sleeve 10 while avoiding a radial expansion of the ring 1, and the part 1b of the sealing ring 1 is received in the housing L2 with its end face which comes to bear on the shoulder 32 of the sleeve 10 by being slightly compressed axially.

The tubular endpiece T has two parts T1 and T2 separated from each other by a flange 35. The part T1 intended to come to engage in the sleeve 10 has a peripheral projection 37 forming a bead.

To ensure the connection between the sleeve 10 and the tip T, the sleeve 10 supports a locking clip 40 which is intended to cooperate with the bead 37 of the tip T to retain it inside the sleeve 10. D ' generally, the locking clip 40 is U-shaped or jumper-shaped and has two elastically deformable tabs 42. The clip 40 is mounted in two openings 44 of the sleeve 10 so that the two tabs 42 protrude inside the sleeve 10.

Concretely, the endpiece T is introduced through its part T1 into the sleeve 10, on the side opposite to the connection insert 12. The part Tl of the endpiece T enters the housing L3 of the sleeve 10 and engages in the inside the sealing ring 1 with concomitant deformation by radial compression of the part lb which carries the sealing line E. When the bead 37 of the endpiece T passes, the two tabs 42 of the locking clip 40 move away from each other and return, by elastic return, to position themselves behind the bead 37, the collar 40 then coming substantially to bear on the end face of the sleeve 10. The endpiece T is thus immobilized axially .

The overmolded part 1a of the ring 1 seals between the connecting insert 12 and the end piece T, while the sealing line E of the part 1b and the bead 5 seals between the sleeve 10 and the tip T.

In general, the part 1b of the ring 1 which carries the sealing line E has an internal diameter smaller than that of its part 1a, and the overmolding of the ring 1 could cause problems of demolding if the ring 1 was molded entirely inside a connecting insert 12 of too small a diameter. This is why, according to the invention, the ring 1 is overmolded so that its part lb which carries the sealing line E is overmolded outside the housing Ll of the connecting insert 12. As for example, in a fuel supply circuit of a motor vehicle, the conduit C has an internal diameter of the order of 6mm, which results in an insert 12 whose part 14 connected to the conduit C has a diameter inside of the order of Smm, and of which the part 16 which receives the part 1a of the ring 1 has an internal diameter of the order of 12mm. As for the ring 1, its part 1a has an internal diameter of the order of 8mm and its part 1b has an internal diameter of the order of 7.5mm.

According to a variant of this first embodiment, the endpiece T can be replaced by the end of a rigid duct provided with a peripheral bead produced by machining.

According to a second embodiment illustrated in FIG. 5, the sealing ring 1 is not molded at one end of the connection insert 12 but inside the sleeve 10. More precisely, the part 1a of the ring 1 is molded inside the housing L2 of the sleeve 10 so that its part 1b projects outside the housing L2. In this case, the part 1b of the ring 1 is received in the housing L1 of the connection insert 12.

According to a third embodiment illustrated in Figure 6, the connecting insert 12 is removed and the sealing ring 1 is molded at the end of the conduit C. In this case, the conduit C is made of a semi-material rigid or rigid and manufactured by an injection-blowing operation for example, in order to have an increase in diameter at the end of the conduit C and an additional thickness for making the notches 25 necessary for the snap-fastening of the sleeve 10.

As a variant of this third embodiment, the sealing ring 1 can be molded into the sleeve 10, in a similar manner to the second embodiment.

 Finally, according to yet another exemplary embodiment applicable to the three aforementioned modes, the sealing ring 1 would no longer be overmolded on an element of the sealed connection device but simply attached.

Claims (16)

<U> CLAIMS </U> 1. Sealed connection device for a fluid conduit, in particular for a motor vehicle, comprising a sleeve (10), a first end of which is connected to said conduit or first conduit (C), a second end of which is intended to be connected to a tubular end piece (T) or a second conduit connected to a fluid circuit, and a seal which is ensured by a ring (1) of elastically deformable material, characterized in that the ring (1) carries at least one sealing line (E ) which is located towards a first end part (lb) of the ring (1) to at least seal with the end piece (T), and in that a second end part (la) of the ring (1) is attached to a first housing (L1; L2) formed in an element (10; 12) of the connection device, so that the first end part (lb) protrudes outside the first accommodation (L1; L2) and come and stay in a econd housing (L2; L1) formed in the element (12; 10) of the connection device. 2. A sealed connection device according to claim 1, characterized in that the first end part (lb) of the ring (1), which carries the sealing line (E), is added by overmolding on the outside. of the first accommodation (Ll; L2). 3. A sealed connection device according to claim 1 or 2, characterized in that the second end part (la) of the sealing ring (1) is attached by overmolding inside the first housing (L1; L2 ). 4. A sealed connection device according to any one of claims 1 to 3, characterized in that the first end of the sleeve (10) is connected to the first conduit (C) by a tubular connection insert (12), and in that that the second end part (la) of the sealing ring (1) is attached to the first housing (L1) which is formed at a first end of the connecting insert (12). 5. A sealed connection device according to claim 4, characterized in that the first end part (lb) of the sealing ring (1) is received in the second housing (L2) which is formed in the sleeve ( 10) to prevent its radial expansion. 6. A sealed connection device according to claim 4 or 5, characterized in that the sealing ring (1) has a peripheral bead (5) intended to be placed in axial compression on an internal annular shoulder (30) of the sleeve ( 10). 7. A sealed connection device according to claim 6, characterized in that the bead (5) of the sealing ring (1) is in contact with an annular shoulder (19) of the connecting insert (12). 8. A sealed connection device according to any one of claims 1 to 3, characterized in that the second end part (la) of the sealing ring (1) is attached to the first housing (L2) which is formed in the sleeve (10). 9. sealed connection device according to claim 8, characterized in that the first end part (lb) of the sealing ring (1) is received in the second housing (L1) which is formed at a first end of the link insert (12). 10. A sealed connection device according to claim 8 or 9, characterized in that the sealing ring (1) has a peripheral bead (5) intended to be placed in axial compression on an annular shoulder (19) of the element. connection (12). 11. A sealed connection device according to claim 10, characterized in that the bead (5) of the sealing ring (1) is in contact with an annular shoulder (30) of the sleeve (10). 12. Sealed connection device according to any one of the preceding claims, characterized in that the sleeve (10) is connected to the connection insert (12) by snap-fastening. " 13. Sealed connection device according to any one of the preceding claims, characterized in that the first conduit (C) is sealingly connected to a second end of the connection insert (12) by force fitting, for example . 14. Sealed connection device according to any one of the preceding claims, characterized in that it also comprises an elastic staple (40) in U with two elastically deformable tabs (42) which engage in two openings (44) of the sleeve (10) along a peripheral bead (37) of the tubular end piece (T) or of the second conduit for retaining the latter inside the sleeve (10). 15. Sealed connection device according to any one of the preceding claims, characterized in that the first conduit (C) and the connection insert (12) form only one piece, the sealing ring (1) being directly attached to one end of the first conduit (C). 16. Fuel supply circuit for a motor vehicle, characterized in that it comprises at least one sealed connection device as defined by any one of the preceding claims for connecting a first conduit to a nozzle or second conduit of said circuit feed.