FR2550848A1 - Flap, especially for a heating or air-conditioning installation of a vehicle passenger compartment, and its manufacturing method. - Google Patents

Abstract

The invention relates to a flap, which can be used especially in a heating or air-conditioning installation of the passenger compartment of a motor vehicle, which comprises a flap body 30 made of plastic, on the edge of which there is overmoulded a sealing joint 32 made of thermoplastic elastomer, so that the portions 36, 38 of the joint 32, which are in contact with the section 44 and the faces 40 and 42 of the flap body 30, are solidly attached, over their entire extent, to the flap body by chemical compatibility of the flap-body material and of the joint material.

Description

Shutter, in particular for heating or air conditioning installation of a vehicle interior, and its manufacturing process.

The invention relates to a shutter, intended in particular to be used in a heating or air conditioning installation of the passenger compartment of a motor vehicle, for the distribution of hot or cold air to air intake vents in the passenger compartment or for adjusting a mixture of hot air and cold air flow rates in the installation, as well as the method of manufacturing this shutter.

Shutters of this type generally comprise a shutter body made of a rigid material (metal or plastic) and a seal of flexible material, such as vulcanized rubber, which is overmolded or glued to the peripheral edge of the shutter body.

To achieve good molding of the seal on the shutter body by overmolding, regularly spaced through holes are formed in the shutter body and along its peripheral edge which are filled with the material of the seal during overmolding and which are connected to two strips of flexible material forming part of the joint and each extending on one face of the shutter body along its peripheral edge, delimiting between them a groove in which is housed the edge of the body of shutter.

Such a shutter, of a type which is very widespread today, however has certain drawbacks: its manufacturing process requires a certain number of separate operations carried out on different machines, resulting in a relatively long manufacturing time and a fairly material investment. expensive. In addition, the amount of flexible material used to make the overmolded seal is relatively high, which further increases the price of the shutter.

Furthermore, since the attachment of the seal to the shutter body is purely mechanical, the free edges of the two strips of flexible material between which the peripheral edge of the shutter body is received, simply rest on the shutter body and can be lifted under the effect of an air flow when using the shutter, which produces quite significant noises.

The object of the invention is to avoid these drawbacks in a shutter of the aforementioned type. For this, it has a shutter, in particular for a heating or air conditioning installation for the passenger compartment of a motor vehicle, comprising a body made of rigid material and a seal made of flexible material, molded onto the peripheral edge of the body. of a shutter and comprising a first strip of flexible material extending substantially in the extension of the body and at least a second strip of flexible material extending on one face of the shutter body in the vicinity of its periphery, characterized in that the body of shutter is made of plastic, for example polypropylene, and] seal is of thermoplastic elastomer chemically compatible with the material of the shutter body, this chemical compatibility ensuring, during the manufacture of the shutter, the securing of said second strip of flexible material with the corresponding face of the shutter body.

This use of two compatible plastic or thermoplastic materials to form the shutter body and the seal makes it possible to secure, in a simple and safe manner, excellent attachment of the seal to the shutter body, while saving important matter.

Indeed, the shutter according to the invention differs from the prior art in that the seal is integral with the body of the shutter over the entire extent of the parts of the seal and of the shutter body which are in contact, without ac - mechanical picking, and without an edge of a seal part applied to the shutter body being able to be '# ever when using the shutter. Thanks to this total joining of the seal on the shutter body, the contact surfaces of the seal and of the shutter body are much smaller than in the prior art, and the amount of flexible material used to form the seal can be greatly reduced, on the order of 50t in volume.

The invention also provides a method of manufacturing a shutter of this type, consisting in producing a shutter body by injecting a plastic material into a mold, characterized in that it consists in then overmolding the seal. on the shutter body, for example by injection into the same mold of a thermoplastic elastomer chemically compatible with the plastic material of the shutter body.

Advantageously, the injection of the thermoplastic elastomer is made at a temperature slightly higher than the surface melting temperature of the material of the body of the shutter.

The method according to the invention therefore makes it possible to manufacture the shutter body and the seal on the same machine and automatically obtain the attachment of the seal to the shutter body, hence a significant reduction in the investment. material.

In the description which follows, given by way of example, reference is made to the appended drawings, in which - FIG. 1 is a partial sectional view of a flap edge belonging to the prior art; - Figures 2, 3 and 4 are views similar to Figure 1, but show three embodiments of a shutter according to the invention; - Figure S is a top view of part of a flap edge according to another embodiment of the invention; - Figures 6 and 7 are views similar to Figures 2 to 4, but show other embodiments of the invention.

Reference is first made to FIG. 1, representing the prior art described in the foregoing.

The shutter partially shown in section in FIG. 1 comprises a shutter body 10 which is, for example, a rectangular contour plate made of metal or plastic, and a seal 12 which is molded onto the peripheral edge of the shutter body 10 and is made of vulcanized rubber or the like.

Along its peripheral edge, the shutter body 10 includes holes 14 regularly distributed (it, when overmolding the seal 12, are filled with studs 16 of the material of this seal.

The seal 12 comprises a first flat strip 18 extending substantially in the extension of the flap body 10 and ending in a substantially cylindrical bead 19 of the tines to be applied to sealing on a wall of a heating or air conditioning installation of lthabita.:le of a motor vehicle, in which the flap is mounted. The first strip 18 is connected by an internal part 20 to two parallel strips 22 which delimit between them a groove containing the peripheral part of the flap body 10 and which are joined to one another by the studs 16.

The overmolding of the seal 12 on the flap body 10 is carried out in a rubber molding and vulcanization machine, which is different from the machine for manufacturing the flap body 10, whether this is made of metal or of material rigid plastic.

The attachment of the seal 12 to the flap body 10 is purely mechanical and is carried out by means of studs 16 between the two parallel strips 22 of the seal 12.

 As indicated in the foregoing, it may happen, during the use of the shutter, that the air flowing along the shutter lifts the free end 24 of one and / or the other of the bands 22 and the gap of the corresponding face of the body of the shutter. This results in relatively large noise in the heating or air conditioning system.

The shutter according to the invention, including various embodiments are shown in Figures 2 to 7, in particular avoids these drawbacks.

The shutter partially shown in section in FIG. 2 comprises a shutter body 30, made of rigid plastic, and a seal 32 of flexible material, which is molded onto the peripheral edge of the shutter body 30.

This seal 32 comprises a first strip 34 of flexible material, extending substantially in the extension of the flap body 30 and ending in a cylindrical bead 35. The strip 34 is connected, by an intermediate part 36, to two parallel strips 38 of flexible material delimiting a groove in which the peripheral edge of the shutter body 30 is received. Each strip 38 is integral, over its entire extent, with the part of the face 40 or 42 respectively of the shutter body on which She's spreading.

This joining of the two strips 38 on the faces 40 and 42 of the shutter body makes it possible to obtain excellent attachment of the seal 32 on the shutter body, and to reduce the width of the strips 38, which is approximately equal to the half the width of the strips 22 in the known shutter shown in FIG. 1. This reduction in the width of the strips 38 and the elimination of the studs 16 extending through the shutter body allows a reduction of approximately 505 of the total volume of the seal overmolded on the shutter body. This results in a significant saving of material and a reduction in the cost price of the component.

The face of the intermediate strip 36, which is applied against the edge 44 of the shutter body 30, is also integral with this edge over its entire extent.

According to the invention, this perfect joining of the parts in contact with the seal 32 and the flap body 30 is obtained automatically during the overmolding of the seal 32 on the flap body 3n, by using an elastomer for this seal. thermoplastic which is chemically compatible with the plastic material of the shutter body 30.

By way of example, it will be specified that the flap body 30 can be made of polypropylene, and the seal 32 of a thermoplastic elastomer based on polypropylene and an ethylene-propylene copolymer.

The method of manufacturing such a shutter consists in first carrying out the shutter body 30 by injecting the desired plastic material into a mold, then cooling to obtain the solidification of this material. Next, the thermoplastic elastomer intended to form the seal 32 is advantageously injected into the same mold, then is cooled to obtain the solidification of the seal. The mold for manufacturing the flap body 30 comprises, for example, parts which can be released so as to form around the peripheral edge of the flap body 30 a free space corresponding to the shape of the seal 32.

Preferably, the thermoplastic elastomer intended to form the seal 32 is injected into this free space at a temperature slightly higher than the surface melting temperature of the material constituting the flap body 30. The pressure and the injection temperature of the the thermoplastic elastomer in the mold makes it possible to obtain an excellent joining of the seal 32 on the shutter body 30.

A shutter according to the invention can therefore be manufactured by means of a single plastic or thermoplastic injection machine, which greatly reduces the manufacturing times and investment in material.

Referring now to Figure 3, showing an embodiment of the invention which differs from that of Figure 2 in that the seal 52 molded onto the peripheral edge of the flap body 30 comprises a single strip 54 applied to one side 4n tlii flap body 30 and secured over its entire extent with the latter.

This strip 54 is connected to the strip 56 extending in the extension of the body of the shutter by an intermediate strip 58 which is perpendicular to the two strips 54 and 56. This intermediate strip 58 is also integral with the edge 44 of the body of the shutter 30 , over its entire surface in contact with this wafer.

It will be noted that the strip 54 of the seal 52 is twice as wide as a strip 38 of the seal 32 in FIG. 2, in order to obtain substantially the same quality of attachment, in both cases, of the seal on the body. shutter.

The embodiment shown in FIG. 4 differs from that of FIG. 3 by the shape of the intermediate strip 64 of the seal 62.

This intermediate portion 64 is thicker than the intermediate portion 58 of the seal 52 and that the strips 60 and 66, and makes it possible to separate, from the edge 44 of the shutter body, the bending zone of the first strip 66 of the seal d sealing 62 relative to its solid part 60 of the shutter body 30.

This avoids any risk of tearing away from the surface of the intermediate strip 64 secured to the edge 44 of the shutter body.

The same result can be obtained with the configuration shown in FIG. 5, in which the seal 62 molded onto the shutter body 30 has the same shape as the seal 62 in FIG. 4, but where grooves 68 have been formed in the edge 44 of the shutter body 30, these grooves extending perpendicular to the plane of the shutter body 30 and opening onto the edge 44 by a constriction or narrowing 70.

During the overmolding of the seal 62, the material of the seal fills the grooves 68 and opposes any risk of tearing away from the surface of the intermediate part 64 secured to the edge 44 of the flap body.

In the embodiment shown in FIG. 6, the seal 72 comprises a strip 74 extending on the face 40 of the flap body 30 and integral over its entire extent with this, a strip 76 extending in the extension of the shutter body 30 in the same plane as the strip 74, and an intermediate strip 78, perpendicular to the strips 74 and 76, extending against the edge 44 of the shutter body, of which it is integral.

This configuration also avoids any risk of tearing off the surface of the strip 78 integral with the edge 44 of the shutter body 30.

Furthermore, the strip 76 may extend obliquely relative to the shutter body, or may be curved, so that the bead 77 is in the plane of the shutter body, as in FIG. 2.

 The embodiment shown in FIG. 7 differs from the previous ones in that the flap body 80 comprises a thinner peripheral edge 82 on which the seal 84 is molded. The strip 86 of this seal, integral with the peripheral edge 82 of the shutter body, extends to the connection 88 between the shutter body 80 and its thinner peripheral edge 82. Thus, the part 86 of the seal which is integral with the peripheral edge of the shutter body does not form a projection on the shutter body.

It will be noted that the embodiments of FIGS. 3 to 6 make it possible to obtain the same result, but on only one face of the body of the shutter, while the embodiment of FIG. 7 allows this result to be obtained in both. sides of the shutter body.

Claims (10)

Claims 1. Shutter, in particular for heating or air conditioning installation of the passenger compartment of an automobile vehicle, comprising a body made of rigid material and a seal made of flexible material, molded onto the peripheral edge of the shutter body and comprising a first strip of flexible material extending substantially in the extension of the flap body and at least a second strip of flexible material extending on one face of the flap body in the vicinity of its periphery, characterized in that the flap body (30, 80) is made of plastic, for example polypropylene, and the seal (32, 52, 62, 72, 84) is of thermoplastic elastomer chemically compatible with the material of the shutter c-orps, this chemical compatibility ensuring, during the manufacture of the shutter, the securing of said second strip (38, 54, 74, 86) with the corresponding face of the shutter body (30, 80). 2. Shutter according to claim 1, characterized in that said second strip (38, 54, 74, 86) of flexible material is integral over its entire extent with said face (40) of the shutter body (30, 80). 3. Shutter according to claim 1 or 2, wherein said first and second strips of flexible material are connected by an intermediate strip of flexible material covering the edge of the shutter body, characterized in that said intermediate strip (36, 5S, fol , 78) is integral over its entire extent with the edge (44) of the flap body. 4. Shutter according to one of claims 1 to 3, wherein the seal comprises two second strips of parallel flexible material, delimiting a groove in which is received the edge of the shutter body and each extending on one face of the body of shutter, characterized in that each second strip (38) is solid over its entire extent of the corresponding face (40, 42) of the shutter body (30). 5. Shutter according to one of claims 1 to 3, characterized in that the edge (44) of the shutter body (30) comprises, from place to place, grooves (68) perpendicular to the plane of the shutter body and opening onto the edge (44) by a narrowing (70), these grooves (68) being filled with the flexible material of the seal (62). 6. Shutter according to claim 3, characterized in that the first and second strips (74, 76; 86) of flexible material are coplanar, and said intermediate strip (78) is perpendicular thereto. 7. Shutter according to claim 3, characterized in that the first and second strips (54, 56; 60, 66) of flexible material are mutually parallel, but not coplanar and are connected perpendicularly by said intermediate strip (58, 64).  8. Shutter according to claim 7, characterized in that said intermediate strip (64) is thicker than the first and second strips (60, 66). 9. A method of manufacturing a shutter according to one of claims 1 to 8, comprising producing a shutter body by injecting a plastic material into a motlle, characterized in that it then consists in overmolding the seal (32, 52, 62, 72, 84) on the shutter body, by injection into the same mold of a thermoplastic elastomer chemically compatible with the plastic material of the shutter body. 10. The method of claim 9, characterized in that the injection of the thermoplastic elastomer is made at a temperature above the surface melting temperature of the material of the flap body.