FR2833681A1 - Fastening for pipe and moulded component e.g. in vehicle engine compartment, comprises clip passing through slots in moulded component to engage with pipe - Google Patents

Abstract

The fastening consists of a clip, made e.g. from a metal or thermoplastic material, that passes through slots in an outer moulded cylindrical component, and engages with notches in the outer surface of a pipe (3) or tube inside it. In a variant of the design the clip can be of wire with two curved sides engaging with portions of an annular groove in the tube.

Description

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Molded part intended to be connected to a pipe
The present invention relates to a molded part intended to be connected to a pipe, a method for molding this part, a clip allowing the connection of the molded part to the pipe, a method of connecting the molded part to the pipe and the use of parts and the connection method under the hood of a motor vehicle.

 There are in many fields, devices allowing the rapid connection of a pipe (or a tubular object) to a tank, a filter or any other part used to contain or treat the fluid conveyed by the pipe. Thus, under the hood of motor vehicles for example, such devices are required in the engine or passenger compartment thermal conditioning system, in the engine air and fuel supply system, etc.

 When the pipes to be connected are based on a flexible material such as rubber, a simple metal collar enclosing the pipes (itself fitted on a tubular protuberance of the part) is enough to ensure a tight connection. However, when the piping is based on a rigid material, it is often necessary to use an additional connecting piece that is just affixed between the piece to be connected and the piping, which increases the cost of the together.

 To remedy this, simpler systems have been proposed. Thus, patent application FR 2761974 describes a non-return valve intended to be mounted between a fuel tank and its filling pipe. This valve comprises a tubular support intended to be fixed to the wall of the tank and a tubular body on which the filling pipe of the tank is fixed by fitting. The support and the tubular body are locked by means of a clip which has two pins arranged symmetrically with respect to an axial plane of the valve, each pin passing through two holes axially aligned in the support and having a curved shape in the middle, which allows it to enclose the valve body. Such a device is simple, inexpensive and makes it possible to obtain a good seal thanks to the insertion of a seal between the support and the body.

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 However, this system has drawbacks when it is extrapolated as it is for a molded part / piping system. Indeed, the openings (holes) required for the passage of the staple pins being distributed over the circumference of the part, they can only be obtained by machining (which is expensive) or during the molding of the part (by example, by injection) but with at least two release directions. In fact, the inserts used to make this type of opening are very fine parts (generally steel blades), the only contact of which with friction with the other parts of the mold can lead to rupture.

It is therefore preferred to use several inserts of simple geometry, which are inserted in a limited number of parts; in particular, we will avoid having to nest the inserts between them or having to insert them into the core (via a slot therein). In the case of the openings described above, one will therefore choose at least two inserts on either side of the central core and which therefore require two directions of demolding (that is to say leaving the mold to allow demolding of the room). However, the use of two demolding directions is expensive (since it is necessary to ensure the movement of the inserts in both directions by adequate means) and likely to lengthen the production cycle times.

In addition, demolding in two different directions is sometimes impossible given the geometry of the part (for example, if there is a relief on the part preventing movement in one of the directions).

 The object of the invention is in particular to remedy this drawback by proposing a molded part intended to be connected to a pipe by means of a clip and where the orifices intended for the insertion of the clip are made during molding and with only one demolding direction.

 To this end, the invention relates to a molded part intended to be connected to a pipe by means of a staple, comprising a projection having an internal cavity of tubular shape intended to receive by fitting, the end of the pipe, this projection comprising at least one recess intended for the insertion of at least part of the clip, and the recess or recesses being situated on the same side with respect to an axial plane of this protuberance.

 By molded part according to the present invention is meant any piece obtained by shaping in a mold, the mold being filled either by casting or by injection of the material to be molded.

 Preferably, the part is injection molded. The material to be molded can be any meltable material such as a metal, a thermoplastic polymer, etc.

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 it is advantageously a thermoplastic polymer such as a polyolefin (polyethylene or polypropylene), a polyamide, etc. It may be a homopolymer or a copolymer, which may or may not contain additives (pigments, stabilizers ...), fillers (glass fibers, talc ...) ...

 The piping intended to be connected to the part according to the present invention can be based on any known material. It can be the same type of material as that constituting the molded part, or even the same material. The present invention is particularly suitable for pipes made of thermoplastic polymer. This piping can be obtained by any known method. It is however advantageously obtained by extrusion or by injection.

 The piping intended to be connected to the part according to the present invention is generally of substantially cylindrical shape and has an external diameter close but slightly smaller than that of the internal cavity of the protuberance of the part according to the present invention, so as to be able be fitted (inserted) into it. By "substantially cylindrical" shape is meant a generally elongated shape with a section of any type, but generally circular or oval, and in particular circular. Note however that the present invention is generalized to any type of pipe section (and therefore, to any type of protrusion on the molded part), including sections provided with sharp angles such as square sections for example.

 The piping intended to be connected to the part according to the present invention may have a constant diameter over its entire length. It can also have a variable diameter and / or one or more reliefs (grooves, threads ...). It advantageously has at least one groove (hollow relief) making it possible to accommodate therein at least part of the clip so as to block the axial movement of the piping in the internal cavity of the projection when the molded part assembly / piping / clip is mounted.

 The protuberance of the part according to the invention generally has a substantially cylindrical shape. Its diameter and / or its section can be constant or variable over its length. The diameter and the relief of the protrusion are generally adapted to those of the piping to be connected with sufficient clearance to allow assembly.

 The internal cavity of the projection preferably comprises an internal stop or bead against which the piping to be connected is affixed during the connection. This stop can be of any shape. She is generally

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logement et/ou de points de fixation pour un joint d'étanchéité qui est comprimé 1 lorsque la tuyauterie est maintenue à l'intérieur de l'excroissance par l'agrafe. substantially the same shape as the internal section (ie generally circular). It advantageously comprises a groove and / or lugs serving to

housing and / or fixing points for a seal which is compressed 1 when the piping is held inside the projection by the clip.

The location of this stop is such that it allows a significant length of the piping to be inserted into the protrusion, so as to ensure a resistant connection. In general, this length is at least equal to 50% of its diameter, or even to 100% of its diameter. This length is generally not more than 2 times, preferably 1.5 times its diameter. The recesses are in this case located between the stop and the outer edge of the protrusion, generally less than 50% of the outer edge (relative to the length between the stop and this edge), or even less than 20% of the outer edge.

 Alternatively, the stop does not have a groove or protuberances and the seal is fixed to the piping (for example by insertion into a groove or by gluing on the periphery of the piping near (or at) its end or along its length) and comes into contact with the stopper during insertion.

 The protuberance of the part according to the present invention comprises at least one recess intended for the insertion of the clip. These recesses may have any shape suitable for the insertion of at least part of the clip.

Generally, this or these recesses have the form of annular sectors which, according to the invention, occupy a maximum angle of 1800 radially on the projection. The number of these recesses is generally adapted to the shape of the pins of the fastening clip. Generally, the protrusion has two recesses, since the staples used for this type of device generally have two pins or arms and the insertion of a part of each arm in the recesses may be sufficient to ensure a reliable connection.

However, the present invention also covers the case where the protrusion comprises a series of recesses intended for pins provided with "teeth". According to a particularly advantageous variant of the present invention, the protrusion comprises two recesses in the form of annular sections radially covering an angle of 180 on the protrusion. The portion of material separating these two recesses gives the assembled structure greater rigidity than in the case of a single recess alone covering the 1800s. This portion of material between the recesses generally covers a width of at least 1 % relative to the perimeter of a section of the protrusion, preferably at least 2%, or even at least 5%.

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 The thickness of the recesses (or width of slits) is generally small compared to the total length of the projection. It generally does not exceed 20% thereof, preferably 15%, or even 10% thereof, but is generally greater than 1% of this length, or even 5%. This thickness is however generally greater than mm, or even 3 mm, so that the thickness of the inserts required for their molding as well as the thickness of the clip are not too small.

 An advantage of the part according to the present invention lies in the fact that the recesses are located on the same side with respect to an axial plane of the protrusion, that is to say by a plane comprising its axis of symmetry and dividing the part into two axial halves. Indeed, such an arrangement makes it possible to mold the part with a mold comprising only a single insert to make all the recesses. Consequently, the present invention also relates to a method of molding the part as described above, which consists in molding said part by injection into a mold comprising a core intended to produce the internal cavity of the protrusion as well as an insert intended to make the recesses in this protuberance, the insert not penetrating into the core and the demolding directions of the core and of the insert being perpendicular to each other.

 The present invention also relates to a clip making it possible to connect a pipe to a part as described above. This clip comprises two pins intended to enclose the protuberance of the molded part on at least a part of its axial half not provided with recesses, this pins comprising protrusions intended to be inserted in the recesses of the protrusion and being connected between them by a connecting branch which allows the installation and removal of the clip. Preferably, the connecting branch has the shape of a handle in relief with respect to the tubular protuberance when the clip is attached to it.

 This clip can be based on any material, preferably moldable. It can be made of metal or of a thermoplastic polymer as described above. It is preferably made of a thermoplastic polymer and particularly preferably, obtained by injection of said polymer.

 Preferably, the clip according to the present invention has a uniform thickness from its ends to its connecting branch, passing through the annular protrusions.

 For mounting the clip on the protuberance / piping assembly, the protrusions of the clip are inserted in the protrusions of the projection and

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effet de clippage). the ends of the staple pins are fixed around the protrusion by any known means (bayonet, clipped part, etc.). Advantageously, the ends of the clip have a shape and dimensions such that they are fixed by themselves around the projection. To do this, the pins advantageously have a shape such that they conform to the external diameter of the protuberance and that their ends are spaced apart by less than 180, preferably less than 150, or even less than 120. Thus, the staple must be slightly deformed when the pins are placed around the protrusion (for example, the pins must be spaced at least 2%, preferably at least 5%, or even at least 10% relative to the diameter they enclose, but in any case generally less than 40%, or even less than 20% so as not to lead to their rupture) which ensures the maintenance of the clip thereafter (by a

clipping effect).

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The present invention also relates to a method for connecting a molded part according to a variant described above (that in which the internal cavity of the protrusion comprises a stop) to a pipe as described above and by means of a clip such as previously described. This process comprises the following stages: - insertion of the piping into the internal cavity of the protuberance until it comes into contact with the stop - fixing of the clip to the assembly by insertion of the protuberances of the branches of the clip in the protuberance recesses and by clipping the ends of the branches of the clip around at least part of half of the protrusion devoid of recesses.

 In this method, the piping advantageously has at least one groove in which one receives at least part of the clip so as to block the axial movement of the piping in the internal cavity of the projection.

 In addition, in this process, a sealing gasket is advantageously placed between the piping and the stop of the internal cavity of the protuberance. This seal can be either mounted on the stop (for example by insertion in a channel provided for this purpose or by fixing on lugs) or on the piping (for example by insertion in a groove or by gluing on the periphery of the piping. (or at) its end or along its length). Alternatively, the joint is simply inserted between the two. The solution which consists in protecting the stop of a groove or of lugs for fixing the joint is preferred.

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 As described above, the parts (the clip and the molded part) and the method according to the invention find their application in many fields including the automobile and in particular, for the molded parts which are located under the engine hood. Examples of such parts are the engine coolant tank and certain parts of the air intake system (manifold, filter, throttle body, etc.) and fuel, as well as the engine coolant outlet housing. .

 Consequently, the present invention also relates to the use of a molded part, a staple or a connection method as described above, under the hood of a motor vehicle. Given the temperature and the vibrational stresses prevailing at this location, we will choose, depending on the application, a suitable material. Thus, when the part is made of thermoplastic polymer, it is advantageously made of polyamide and preferably reinforced with glass fibers.

 The present invention is illustrated in a nonlimiting manner by the following figures: Figure C1: two-dimensional view of the projection of a molded part according to the prior art and intended to be connected to a pipe Figure C2: view from above this same protrusion Figure C3: cross section of this same protrusion in a plane perpendicular to the axis cutting the protrusion at its recesses Figure C4: section of this same protrusion in an axial plane Figure C5: clip according to the prior art Figure C6: top view of the clip mounted on the protrusion Figure C7: two-dimensional view of a pipe intended to be fitted into the protrusion Figure 1: two-dimensional view of the tubular protrusion of a part molded according to the invention Figure 2: top view of this same protrusion Figure 3: cross section of this same protrusion along a plane perpendicular to the axis cutting the protrusion at level water from its recesses Figure 4: section of this same protuberance in an axial plane Figure 5: staple according to the invention Figure 6: top view of the staple mounted on the protrusion

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Figures C 1 à C7 (qui illustrent un dispositif selon l'art antérieur) : Les figures CI à C4 montrent une partie de pièce selon l'art antérieur, moulée par injection et incluant une excroissance (1) ayant une cavité interne de forme tubulaire et munie de deux évidements (2). Ces évidements ont obtenus au moyen de deux inserts (fines lames d'acier) qui lors démoulage, ont été retirés du moule dans le sens indiqué par les flèches sur la figure C3. Les évidements, qui ont chacun un angle d'ouverture a de 140 , sont répartis sur la toute la circonférence de l'excroissance et il n'est donc pas possible de les obtenir par moulage au moyen d'un seul insert qui ne serait pas imbriqué dans le noyau. Figure 7: two-dimensional view of a pipe intended to be fitted in the protrusion

Figures C 1 to C7 (which illustrate a device according to the prior art): Figures CI to C4 show a part of a piece according to the prior art, injection molded and including a protrusion (1) having an internal cavity of tubular shape and provided with two recesses (2). These recesses were obtained by means of two inserts (thin steel blades) which, when removed from the mold, were removed from the mold in the direction indicated by the arrows in FIG. C3. The recesses, which each have an opening angle a of 140, are distributed over the entire circumference of the projection and it is therefore not possible to obtain them by molding by means of a single insert which would not be nested in the core.

Figure C5 shows a clip intended to be inserted (by pinching the pins) in these recesses and Figure C6 shows the clip actually inserted in these recesses.

In Figure C7, the molded part / piping / clip assembly has been assembled in accordance with the following steps: - mounting of a seal on the stop (3) provided with lugs (4) for fixing the seal (not shown) - insertion of the piping (5) in the internal cavity of the protuberance of the molded part until it comes into contact with the stop and compresses the joint - fixing of the clip on the together by inserting the clip into the recesses of the projection and into an annular groove (6) provided for this purpose in the piping.

Figures 1 to 7 (which illustrate a preferred variant of the present invention): The numbering used for the different elements is the same as for Figures CI to C7.

It is noted that the recesses (2) are this time distributed on the same side of an axial plane of the protuberance, which allows the release of the insert in a direction perpendicular to this plane.

FIG. 3 shows that the angle a is less than 90, and that the angle ss, which determines the angle which embraces all of the recesses, is equal to 1800; the demolding direction of the insert is indicated by an arrow.

FIG. 5 illustrates a particular form of the clip according to the present invention.

According to this variant, the pins of the clip comprise two protrusions

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 annulars intended to be inserted in the annular recesses formed in the projection.

In FIG. 6, it can be seen that the ends of the branches of the clip had to be moved apart when the clip was put in place since they are too close together to cross the diameter of the protrusion as they are.

In FIG. 7, the molded part / pipe / staple assembly has been assembled in accordance with the following steps: - mounting of a seal on the stop (3) provided with lugs (4) for fixing the seal (not shown) - insertion of the piping (5) in the internal cavity of the protuberance until it comes into contact with the stop and compresses the joint - fixing of the clip to the assembly by: - insertion of the annular protuberances in the recesses of the protrusion and in a part of the annular groove (6) provided for this purpose in the piping - c1ippage of the two ends of the clip around a part of the protrusion in its half axial not provided with recesses; this clipping makes it possible to at least partially compensate for the loss of angle useful for the insertion of the staples and to guarantee sufficient mechanical strength in most cases of use.

Claims (10)

CLAIMS 1 - Molded part intended to be connected to a pipe by means of a clip, characterized in that it comprises a protuberance having an internal cavity of tubular shape intended to receive by fitting, the end of the piping, this protuberance comprising at least one recess intended for the insertion of at least part of the clip, and the recess or recesses being situated on the same side with respect to an axial plane of this protuberance.  2-molded part according to claim l, characterized in that the internal cavity of the protuberance comprises a stop against which the piping to be connected is affixed during the connection.  3-molded part according to claim 2, characterized in that the stop has a groove and / or lugs serving as housing and / or fixing points for a seal.  4-molded part according to any one of the preceding claims, characterized in that the protrusion comprises two recesses having the form of annular sections radially covering an angle of 180 on the protrusion.  5-A method of molding a part according to the preceding claims, consisting of molding said part by injection into a mold comprising a core intended to produce the internal cavity of the protuberance as well as an insert intended to produce the recesses in this protuberance , the insert not penetrating into the core and the demolding directions of the core and of the insert being perpendicular to each other.  6-clip for connecting a pipe to a molded part according to claims 1 to 4, characterized in that it comprises two pins intended to enclose the protuberance of the molded part on at least part of its axial half not provided with 'recesses, this pins having protrusions intended to be inserted in the recesses of the protrusion and being connected together by a connecting branch which allows the installation and removal of the clip.  7-A method for connecting a molded part according to claims 2 or 3 to a pipe by means of a clip according to claim 6, which comprises the following steps: <Desc / Clms Page number 11>  insertion of the piping into the internal cavity of the protrusion until it comes into contact with the stopper fixing of the clip to the assembly by insertion of the protuberances of the branches of the clip in the recesses of the protrusion and by clipping the ends of the branches of the staple around at least part of half of the protrusion devoid of recesses.  8-A method according to the preceding claim, wherein the piping has at least one groove in which is housed at least part of the clip so as to block the axial movement of the piping in the internal cavity of the projection.  9-A method according to claim 7 or 8, wherein a seal is placed between the piping and the stop of the internal cavity of the projection.  10-Use of a molded part according to claims 1 to 4, a clip according to claim 6 or a connection method according to claims 7 to 9, under the hood of a motor vehicle.