FR2706573A1 - Device for reinforcing hollow components made of synthetic substances, particularly distributors, against deformation or stress - Google Patents

Abstract

The present invention relates to a device for reinforcing hollow components made of synthetic substance, particularly distributors, against deformation or stress. Device characterised in that it essentially consists of elements (1 and 2) projecting inside the constituent parts of the said hollow components (3 and 4) and joined together. The invention is more particularly applicable in the field of the manufacture of hollow components for accommodating or conveying fluids under low pressure and which are likely to be subjected to pressure spikes.

Description

Reinforcement device for hollow parts
in synthetic material, in particular distributors,
against deformation or stress
The present invention relates to the field of manufacturing hollow parts, in particular of synthetic material, intended for the transport or reception of fluids under pressure, and relates to a device for reinforcing such hollow parts, in particular distributors, against a deformation or stress.

 In general, hollow parts intended for the transport or reception of pressurized fluids are either made in one piece by fusible core molding or by heat blowing, or by molding two or more pieces of cooperating shape assembled between them by welding or by gluing, or even by assembly by screwing of several pieces of different materials.

 The production by molding or by heat blowing in one piece certainly allows great freedom with regard to the definition of shapes, but such an embodiment results in the production of parts with a high cost price.

 The production of parts in several parts assembled by welding allows a significant reduction in the cost, however, the mechanical strength, in particular the sealing is difficult, if not impossible to ensure, because such an assembly does not make it possible to withstand pressure peaks due to temporary overloads, in spurts. Such overloads can come, for example in the case of air distributors of heat engines, of a backfire.

 In the case of a mechanical assembly of several parts, there is also a problem of mechanical strength and sealing of the assembly.

 The present invention aims to overcome these drawbacks.

 It has, in fact, for its object a device for reinforcing hollow parts made of synthetic material, in particular distributors, against deformation or stress, characterized in that it is essentially constituted by elements projecting inside the constituent parts of said hollow parts and interconnected.

 The invention will be better understood from the description below, which relates to a preferred embodiment, given by way of nonlimiting example, and explained with reference to the appended schematic drawing, in which FIGS. 1 to 3 show, in partial sectional view, the device according to the invention.

 As shown in Figures 1 to 3 of the accompanying drawing, the device for reinforcing hollow pieces of synthetic material, in particular distributors, against deformation or stress, is essentially constituted by elements 1 and 2 projecting inside constituent parts of said hollow parts 3 and 4 and interconnected.

 The elements 1 and 2 advantageously have, at their free end part, cooperating shapes 1 ′, 2 ′ allowing their mutual accommodation and providing a space 2 "for receiving a burr of friction welding or resulting from gluing with the synthetic resin, preferably epoxy, because the plastic parts used in the production of hollow parts which may be subjected to a point pressure overload, cyclic or not, are generally assembled by friction welding or by gluing Such welding or bonding gives rise, at the joint plane, to burrs which must not extend inside the finished hollow parts.

 Thanks to the provision of the space 2 ", the burrs from the friction welding or the bonding between the elements 1 and 2 can be absorbed without protruding inside the space delimited by the parts 3 and 4 and therefore without discomfort for the fluids staying or circulating there.

 Elements 1 and 2 are advantageously in the form of domes with a circular or substantially circular section.

 However, in the case of equipping hollow parts having a relatively large distance between walls, there may be a problem of joining by welding at the level of the cooperating shapes 1 ′, 2 ′ of the elements 1, 2 due to a deformation of said elements in the shape of domes 1 and 2, the pressure being applied to the exterior of the hollow parts 3 and 4.

 To this end, according to another characteristic of the invention, the elements 1 and 2 are advantageously provided with a recess 5 opening outside the hollow parts 3 and 4 and blind near the end of the elements 1 and 2 having the cooperating forms 1 'and 2'. Such an embodiment allows, for vibration welding, to insert the support elements into the recesses 5 and thus to transfer the support force as close as possible to the surfaces to be welded, so that a deformation by buckling of elements 1 and 2 can be avoided and the welding is improved.

 However, it may happen that in particularly constrained places of hollow parts, for example the plenum of a distributor, the mechanical strength obtained by the provision of elements 1 and 2 cooperating with each other by their end part is not not sufficient to ensure an occasional cyclic or accidental overload, in particular due to a flashback.

 To this end, the invention proposes, in accordance with the embodiment according to FIG. 3, to perfect the junction by welding between the elements 1 and 2, by adding a means 6 for mechanical tightening connection of the ends of the elements 1 and 2 one on top of the other.

 According to a characteristic of the invention, the means 6 for mechanical tightening connection of the ends of the elements 1 and 2 is produced by means of a screw-nut assembly 7 the screw of which passes through a bore 8 provided in the ends of the elements 1 and 2. Thus, by fitting and tightening the nut after prior welding of the elements 1 and 2 therebetween, it is possible to perform a mechanical tightening capable of withstanding a large tearing force, thus preventing separation. elements 1 and 2.

 In accordance with another alternative embodiment of the invention, not shown in the accompanying drawing, the means 6 for mechanical tightening connection of the ends of the elements 1 and 2 can also be constituted by a screw passing through the end of one of the elements 1 or 2 and cooperating with a nut attached or embedded in the other element 2 or 1 or provided in or on an additional part such as a cover or a support part. In such a scenario, the mounting of the means 6 is facilitated by the fact that the nut is perfectly centered and maintained in the complementary element.

 It is also possible, in accordance with another alternative embodiment of the invention, not shown in the accompanying drawing, to produce the means 6 for mechanical tightening connection of the ends of the elements 1 and 2 in the form of a non-removable screw cooperating with a sunken nut or insert.

 The mechanical tightening connection means 6 can also be produced by metal or synthetic rivets or by crimping by injection of synthetic material inside the recess 5 of the elements 1 and 2 and passing through the bores 8 of their ends. By such an embodiment, it is possible to maintain the assembly of the elements 1 and 2 against high pressures, the crimping of the ends being obtained by post-shrinkage of the synthetic material constituting the crimping.

 According to another characteristic of the invention, the crimping by injection can be carried out in the form of elements for guiding and fixing a cover or the like mounted on the hollow parts. By way of example, an intake distributor can thus be provided with a style cover or even with a fixing plate for accessory elements, the fixing parts of these plate or cover then being in the form of elongated elements penetrating into the recesses 5 of the elements 1 or 2 of a part 3 or 4 and being crimped through the recesses 5 of the elements 2 or 1 of the corresponding part 4 or 3. I1 follows that upon removal following the release of the elements 1 and 2 are strongly compressed one on the other.

 Thanks to the invention, it is possible to reinforce hollow parts against possible deformation under the effect of a pressure peak and, in particular, leaktight parts intended to receive or transport fluids under low pressure.

 The invention is more particularly applicable in the field of manufacturing intake air distributors for engines, in particular internal combustion. Indeed, in this case, internal stresses which are incompatible with the guarantee of a seal at the level of the welded junctions can occur. The present invention makes it possible, by predicting the elements 1 and 2 provided on the parts 3 and 4, to improve the pressure resistance of the hollow parts, this resistance being able to be further reinforced by the provision of mechanical means cooperating with the elements 1 and 2.

 Of course, the invention is not limited to the embodiment described and shown in the accompanying drawing. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without thereby departing from the scope of protection of the invention.

Claims (11)

 1. Device for reinforcing hollow parts made of synthetic material, in particular distributors, against deformation or stress, characterized in that it is essentially constituted by elements (1 and 2) projecting inside the constituent parts said hollow parts (3 and 4) and interconnected.  2. Device according to claim 1, characterized in that the elements (1 and 2) advantageously have at their free end part cooperating shapes (1 ', 2') allowing their mutual accommodation and providing a space (2 " ) receiving a burr of friction welding or resulting from bonding with synthetic resin, preferably epoxy.  3. Device according to any one of claims 1 and 2, characterized in that the elements (1 and 2) are advantageously in the form of domes with circular or substantially circular section.  4. Device according to any one of claims 1 to 3, characterized in that the elements (1 and 2) are advantageously provided with a recess (5) opening out to the outside of the hollow parts (3 and 4) and blind near the end of the elements (1 and 2) having the cooperating shapes (1 'and 2').  5. Device according to any one of claims 1 to 4, characterized in that the elements (1 and 2) are further provided with a means (6) of mechanical clamping connection of the ends of the elements (1 and 2) one on top of the other.  6. Device according to claim 5, characterized in that the means (6) for mechanical tightening connection of the ends of the elements (1 and 2) is produced by means of a screw-nut assembly (7), the screw passes through a hole (8) provided in the ends of the elements (1 and 2).  7. Device according to claim 5, characterized in that the means (6) for mechanical tightening connection of the ends of the elements (1 and 2) consists of a screw passing through the end of one of the elements (1 or 2) and cooperating with a nut added or embedded in the other element (2 or 1) or provided in or on an additional part such as a cover or a support part.  8. Device according to claim 5, characterized in that the means (6) for mechanical tightening connection of the ends of the elements (1 and 2) is produced in the form of a non-removable screw cooperating with a sunk nut or insert.  9. Device according to claim 5, characterized in that the means (6) for mechanical tightening connection of the ends of the elements (1 and 2) is produced by metal or synthetic rivets.  10. Device according to claim 5, characterized in that the means (6) for mechanical clamping of the ends of the elements (1 and 2) is produced by crimping by injection of synthetic material inside the recess (5) elements (1 and 2) and passing through the holes (8) of their ends.  11. Device according to claim 10, characterized in that the crimping by injection is carried out in the form of elements for guiding and fixing a cover or the like mounted on the hollow parts.