Device and method for moulding a profiled seal on a peripheral part of a glass panel

Abstract

The invention relates to a device for moulding a profiled seal on at least one peripheral part of a glass panel, the device comprising suction units (23) for holding the glass panel to be moulded. The invention is characterised in that it comprises means (29, 31, 33) for reducing the forces transmitted to the glass panel by the suction units (23), the means being adjustable under the effect of the engagement of these units (23) with the glass panel.

Description

Device and method for molding a profiled seal on a peripheral part of a glazing unit

[0001] Some glazing intended to close bays must be fitted around their periphery with a profiled seal to ensure a watertight connection between the glazing and the bay.

[0002] This is the case, for example, in the automotive sector, where large glazing is used, most often with curved shapes.

[0003] To create the profiled seal around the periphery of these glazing units, the process is generally injection molded and then a multi-component resin is polymerized: this is often referred to as the process of "encapsulating" the glazing unit with the seal.

[0004] Patents or patent applications US5916600, US6120274 and EP3338987 describe such methods.

[0005] Current molding techniques generally consist of placing the glazing on suction cups mounted to move on a fixed part of the mold between a receiving position and a molding position, these suction cups being able to engage with the glazing by suction effect.

[0006] These suction cups can thus bring the glazing into contact with the fixed part of the mold, after which the mold is closed by means of the movable part of the mold, these two parts of the mold defining a cavity arranged on the periphery of the glazing into which the material intended to form the seal can then be injected.

[0007] This molding manufacturing process causes numerous mechanical constraints inside the glazing.

[0008] These constraints can appear in particular when the suction cups engage with the glazing by suction, when the glazing is docked on the edge of the fixed part of the mold, when the mold is closed, when the material intended to form the seal is injected (due to pressure and / or temperature), or when the glazing is detached and then ejected from the fixed part of the mold.

[0009] To reduce the stresses on the glazing, the position of each suction cup is carefully adjusted empirically, depending on the model of glazing to be encapsulated.

[0010] This adjustment, which is very time-consuming, consists, with a reference glazing, of fixing washers of varying thicknesses to the base of the support of each suction cup, so as to obtain sets of supports + suction cups with a length allowing contact which does not generate mechanical stresses between the suction cups and the glazing.

[0011] Apart from the fact that it requires a lot of time and expert labor, such an adjustment does not allow the mechanical constraints to be completely eliminated in all the glazing of a given model.

[0012] Indeed, particularly when it comes to a glazing model with a curved shape, there are significant dimensional variations from one glazing to another, due to manufacturing tolerances: these dimensional variations can typically be of the order of a millimeter.

[0013] Due to these variations, a given adjustment of the position of the mold suction cups can cause varying constraints from one glazing to another of the same model.

[0014] In some cases, and particularly for large glazing, these constraints can lead to breakage of the glass.

[0015] The present invention thus aims in particular to provide means enabling, in a simple, rapid and reliable manner, a profiled seal to be produced by molding at the periphery of a glazing unit, which makes it possible to considerably reduce – or even eliminate – the generation of mechanical stresses in the glass during the manufacturing process.

[0016] This aim of the invention is achieved in particular with a device for molding a profiled seal on at least one peripheral part of a glazing unit according to claim 1.This device comprises:- a fixed mold part,- a plurality of suction units,- means for selectively placing the suction units under vacuum so that they engage with the glazing,- a movable mold part, capable of coming into contact with the fixed mold part so as to define a molding cavity for said profiled seal,- at least one injection orifice in said cavity for a material intended to form said profiled seal,- means for reducing the forces transmitted to the glazing by the suction units, adjustable under the effect of the engagement of these units with the glazing,- said suction units each comprising a fixed support, a spring-loaded telescopic rod slidably mounted in the fixed support, a suction cup at one end of said telescopic rod and means for braking this rod.

[0017] This system allows the axial position of the suction cup to be adjusted, offering a very simple way of maintaining the suction cup in contact with the glazing without imposing any mechanical stress on it. The return spring makes it possible to obtain a suction cup that follows the dimensional variations from one glazing to another, for a given glazing model. The brake makes it possible to fix the position of the suction cup, once its self-adjusted position has been obtained by engaging with the glazing by suction. The adjustment of the position of each suction cup is thus carried out thanks to the spring, and the locking of the position thus adjusted is carried out by means of the brake.

[0018] Thanks to this device, the position of each suction unit can self-adapt to each glazing by simply placing this unit under vacuum, which eliminates the need for any tedious and non-self-adaptive prior manual adjustment of these units to the dimensional variations of a given glazing model.

[0019] In this way, the overall duration of the encapsulation glazing manufacturing process can be considerably reduced, and the risks of breakage due to excessive mechanical stresses imposed on the glass can be limited - or even eliminated.

[0020] Depending on other optional features of this device, taken alone or in combination:

[0021] - said force reduction means include deformation memory means: these means constitute an interesting alternative to the aforementioned mechanical spring and brake means;

[0022] - said deformation memory means comprise at least one vacuum ball immobilization mattress: such a mattress makes it possible to combine the functions of suction of the glazing and adaptation to dimensional variations of the glazing under the effect of the engagement of this mattress with the glazing by suction;

[0023] - said deformation memory means comprise a nail board type interface: such a board, the nails of which can move to match the shape of the glazing, constitutes an interesting alternative to the aforementioned vacuum ball mattress;

[0024] - this device includes means for centering the glazing relative to the fixed part of the mold: these centering means allow the glazing to be correctly positioned in the joint plane of the mold;

[0025] - said suction units are fixed on an ejection plate mounted movably on the fixed part of the mold between a receiving / evacuation position and a molding position: such a plate facilitates in particular the ejection of the glazing from the fixed part of the mold, once the molding of the profiled seal has been completed.

[0026] The present invention also relates to a method for molding a profiled seal on at least one peripheral part of a glazing unit, by means of a device in accordance with the above, comprising the successive steps of:- releasing the force reduction means,- placing the glazing unit on the suction units,- placing the suction units under vacuum, so that the glazing unit comes into contact with the fixed part of the mold,- actuating the movable part of the mold so as to bring it into contact with the glazing unit and to define the molding cavity of the profiled seal,- fixing said force reduction means, and- proceeding with the molding of the profiled seal on this glazing unit.

[0027] By "releasing the force reduction means" is meant here that the force reduction means are placed in a configuration that allows them to move freely in contact with the glazing. In other words, these force reduction means are placed in a disengaged configuration.

[0028] Thanks to the method according to the invention, the suction units can each come into contact with the glazing without imposing mechanical constraints on it.

[0029] Once all the suction units are in contact with the glazing, the glazing is docked on the fixed part of the mold and the moving part of the mold has come to cover the fixed part of the mold edge to edge, the force reduction means can be fixed, that is to say, locked so as to block the suction units in the positions they have acquired after having moved freely in contact with the glazing.

[0030] The method according to the invention therefore allows automatic adjustment of the positions of each of the suction units, making it possible to limit - or even eliminate - the mechanical constraints imposed by these units on the glazing.

[0031] Depending on other optional features of this process, taken alone or in combination:

[0032] - the preceding steps are implemented for a reference glazing, then the fixed positions of the force reduction means are kept to carry out the molding of the profiled seal on glazings of the same model as that of the reference glazing: in this variant of the method according to the invention, the adjustment of the positions of the suction units is carried out once and for all from a reference example of a glazing of a given model. This adjustment is then fixed and is used for all the other glazings of the same model;

[0033] - the previous steps are carried out for each glazing, then the profiled seal is molded on this glazing: in this variant of the method according to the invention, the adjustment of the positions of the suction units is carried out automatically for each glazing to be molded;

[0034] - this method comprises the step of centering the glazing relative to the fixed part of the mold, after having placed it on the suction units, and before placing them under vacuum: this step of the method according to the invention makes it possible to correctly position the glazing relative to the fixed part of the mold;

[0035] - an ejection plate is placed in a receiving / evacuation position prior to the deposition of the glazing on the suction units, and this ejection plate is placed in its molding position after having placed the suction units under vacuum, so as to bring the glazing into contact with the fixed part of the mold.

[0036] Other characteristics and advantages of the invention will emerge from reading the description which follows, with reference to the appended figures, which illustrate:

[0037] : five stages of molding by encapsulation of a glazing, according to a method of the prior art;

[0038] : a perspective view of a fixed mold part of the prior art;

[0039] : a perspective view of part of the suction units associated with the fixed mold part of the, taken in the direction of arrow F2 of this;

[0040] : a zoomed perspective view of the upper left area of ​​the ;

[0041] : two schematic views of cooperation of a suction cup with a glazing placed inside a mold of the prior art;

[0042] : a perspective view of a suction unit according to the present invention;

[0043] : an axial sectional view of the suction unit of the;

[0044] : a side view of one of the centering devices of the fixed mold part according to the invention, cooperating with a glazing;

[0045] : the different stages of a first variant of a molding process according to the invention;

[0046] : the different stages of a second variant of a molding process according to the invention;

[0047] : the different stages of yet another variant of a molding process according to the invention; and

[0048] : a perspective view of a device that can be used for yet another variant of the molding method according to the invention.

[0049] For clarity, identical or similar elements are identified by identical or similar reference signs throughout the figures.

[0050] In the following, the terms "top" and "bottom" must be understood in relation to the vertical of the place where the device and the method according to the invention are implemented, as indicated by the arrow Z in the figures.

[0051] Naturally, the invention is described in the foregoing by way of example. It is understood that those skilled in the art are able to carry out different variant embodiments of the invention without departing from the scope of the invention.

[0052] We now refer to the, on which we can see the different stages of molding by encapsulation of a glazing, according to a process of the prior art.

[0053] This molding is carried out with a mold 1 comprising a fixed part 3 and a mobile part 5, the fixed part 3 being more particularly represented in figures 2 to 4.

[0054] As is particularly visible in these figures, a plurality of suction units 7 are arranged inside the fixed mold part 3, each of these units 7 being preferably fixed on an ejection plate 9 capable of moving in translation in the vertical direction Z relative to the fixed mold part 3, between a receiving / evacuation position (high position relative to the vertical Z) and a molding position (low position relative to the vertical Z).

[0055] As can be seen in particular in Figures 3 and 4, each suction unit 7 comprises a support rod 11 fixed to the ejection plate 9, surmounted by a suction cup 13 capable of being placed under vacuum by a suitable pneumatic suction device.

[0056] It will also be noted that a plurality of electronically controlled centering fingers 15a, 15b, 15c, 15d are arranged at the periphery of the fixed mold part 3.

[0057] Referring to the, in the molding method of the prior art, the glazing to be molded 17 is first placed on the suction cups 13, the ejection plate 9 being in the high receiving position, and the glazing 17 is centered by means of the centering fingers 15a, 15b, 15c, 15d (step 1): in this position, the glazing 17 is held above the fixed mold part 3.

[0058] The suction cups 13 are then placed under vacuum and the ejection plate 9 is lowered towards its molding position (step 2), which allows the glazing 17 to be brought into contact with the edges of the fixed mold part 3, under the effect of the downward traction force produced by the suction cups 13.

[0059] One or more seals 19 arranged at the periphery of the fixed mold part 3 make it possible to compensate for the clearances due to the dimensional manufacturing tolerances of the glazing 17.

[0060] The mold is then closed by lowering the movable mold part 5 into contact with the fixed mold part 3 (step 3), which makes it possible to form the molding cavity 21 of the profiled seal for encapsulating the periphery of the glazing 17.

[0061] The multi-component material is then injected into this cavity 21, making it possible to obtain the profiled encapsulation seal 22: this material typically comprises a resin associated with a hardener, making it possible to polymerize the profiled seal.

[0062] Once this polymerization has been carried out, the mold 1 is opened by bringing the movable mold part 5 upwards, the ejection plate 9 is moved upwards into its reception / evacuation position (step 5), then after stopping the vacuuming of the suction cups 13, the glazing 17 is recovered, fitted with its peripheral encapsulation seal.

[0063] As explained above, during these different manufacturing stages, numerous mechanical constraints are imposed on the glazing 17.

[0064] These mechanical constraints are generated in particular by the suction cups 13 during the closing of the mold 1, as illustrated in the.

[0065] Figure 5a shows schematically the glazing 17 inside the closed mold 1, in a configuration where the support rod 11 of one of the suction cups 13 is slightly too long: in this particular case, the suction cup 13 imposes an upwardly directed force F3 on the glazing, thus generating undesirable mechanical stresses inside it.

[0066] Conversely, Figure 5b shows the case where the support rod 11 of the suction cup 13 is slightly too short: in this particular case, under the effect of its vacuum, the suction cup 13 imposes a downward force F4 on the glazing 17, which also generates undesirable mechanical stresses inside the glazing 17.

[0067] We now refer to Figures 6 and 6bis, which show a suction unit 23 produced in accordance with the principles of the present invention.

[0068] This suction unit 23 is shown here mounted on the ejection plate 9.

[0069] This suction unit 23 comprises a support 25 fixed by means of a spacer 27 on the ejection plate 9.

[0070] This support 25 is surmounted by a braking mechanism 29 inside which a telescopic rod 31 can slide, itself surmounted by a suction cup 13. The braking mechanism 29 is here a pneumatic mechanism; an electromechanical braking mechanism, for example by electromagnet, could also be used.

[0071] Between the braking mechanism 29 and the suction cup 13, around the telescopic rod 31, is arranged a helical spring 33 returning the suction cup 13 to the high position, that is to say away from the braking mechanism 29. This helical spring is relatively flexible because the essential aim is to reduce the forces transmitted to the glazing.

[0072] A first pipe 35 connected to a pneumatic suction unit allows the suction cup 13 to be placed under vacuum, on command.

[0073] A second pipe 37 connected to a pneumatic compression unit allows compressed air to be sent inside the braking mechanism 29.

[0074] This braking mechanism 29 may comprise bronze rings 38 surrounding the telescopic rod 31, capable of exerting a shearing force on the latter when compressed air is sent into the second pipe 37: the rod 31 is thus blocked in the presence of compressed air in the second pipe 37, and free to move in the absence of compressed air.

[0075] The molding device according to the present invention further comprises the same fixed 3 and movable 5 mold parts as those of the prior art device described above, as well as the same ejection plate 9.

[0076] The difference between the present invention and the device of the prior art lies in the fact that the suction cups 13 and their fixed support rods 11 are replaced by suction units 23 conforming to that shown in Figures 6 and 6bis.

[0077] The mode of use and the advantages of a molding device according to the present invention will be able to be understood in particular in the light of figures 8 and 9.

[0078] A first variant of the molding method according to the invention is shown, using the device of the invention.

[0079] In this first variant, the operations of mass-molding glazings of a given model (steps 11 to 15) are preceded by steps of adjusting the suction units 23 by means of a so-called reference glazing 17a, representative of a given glazing model to be mass-produced.

[0080] In the first adjustment step R1, the reference glazing 17a is placed on the suction cups 13 of the suction units 23, the ejection plate 9 being in the high receiving / evacuation position, no compressed air is injected into the braking mechanisms 29 of the telescopic rods 31 so as to disengage these mechanisms 29 and allow the free movement of the telescopic rods 31 of the suction units 23, and the suction cups 13 are placed under vacuum, so that they engage with the glazing 17a.

[0081] The ejection plate 9 is then lowered towards its molding position, so that the glazing 17a can dock on the fixed mold part 3 (step R2).

[0082] The mold 1 is then closed by lowering the movable mold part 5, and compressed air is sent into the braking mechanisms 29 of the telescopic rods 31 of the suction units 23, so as to block their movements (step R3).

[0083] These telescopic rods 31 thus remaining blocked, the movable mold part 5 is opened, the ejection plate 9 is returned to its high receiving / evacuation position, the vacuuming of the suction cups 13 is stopped, and the adjustment glazing 17a is evacuated from the device according to the invention (step R4).

[0084] The locked positions of the telescopic rods 31 of the suction units 23 are then retained for the entire remainder of the process, for the mass production of all the glazings 17b of the same model: the steps 11, 12, 13, 14, 15 of production of these glazings 17b, shown in, are then analogous to the steps 1, 2, 3, 4, 5 of the process of the prior art, shown in.

[0085] It is understood that this first variant of the method according to the invention makes it possible to adapt in a very simple manner the lengths of the suction units 23 to a reference example 17a of the glazing model 17b to be mass-produced.

[0086] This adaptation is carried out by simply placing this reference glazing 17a in contact with the suction cups 13, which can move freely until the mold 1 closes, and which are then fixed.

[0087] This makes it possible to avoid generating unwanted stresses inside the reference glazing 17a, and therefore to subsequently considerably limit the stresses generated in the glazings 17b of the same model to be mass-produced.

[0088] However, as explained above, the 17b glazings of the same model are subject to dimensional variations in manufacturing, so that despite the adjustment which has just been explained, the 17b glazings produced in series are inexorably subject to mechanical stresses generated during the manufacturing process.

[0089] To further improve this process, a second variant can be considered, in which the preliminary adjustment step with a reference glazing 17a is dispensed with, and the lengths of the suction units are adjusted for the molding of each glazing 17b of a given model.

[0090] Illustrates steps 21, 22, 23, 24, 25 of this variant of the method according to the invention.

[0091] This variant differs from the previous one in that, for each glazing 17b to be molded, steps 21, 22, 23 are implemented which are analogous to the adjustment steps R1, R2, R3 carried out with a reference glazing 17a, as explained previously.

[0092] In other words, for each glazing to be molded 17b, the freedom of movement of the telescopic rods 31 of the suction units 23 is maintained until the mold is closed, so as to eliminate the mechanical stresses generated by the suction cups in the glazing 17b.

[0093] Once the mold 1 is closed, the positions of the telescopic rods 31 are fixed by activating the braking mechanisms 29, and the material intended to form the profiled seal can then be injected into the peripheral cavity 21 defined by the two mold parts 3, 5 (step 24).

[0094] With the telescopic rods 31 thus remaining fixed, the movable mold part 5 can then be opened, the ejection plate 9 raised to its receiving / evacuation position, the suction of the suction cups 13 terminated, and the glazing 17b fitted with its peripheral profiled seal evacuated (step 25).

[0095] In either of the variants set out above, the strokes of the telescopic rods 31 and their associated suction cups 13 will be dimensioned so that the glazings 17 do not risk escaping from the zone of action of the centering fingers 15a, 15b, 15c, 15d arranged at the periphery of the fixed mold part 3, these fingers acting on the glazing 17 once it has been placed on the suction cups 13 and prior to the vacuuming of the latter, as set out above.

[0096] This situation is represented in the figure, on which we can see a centering finger 15 mounted on its actuator 41, and cooperating with a glazing 17: typically, the stroke 43 of the suction cup 13 will be provided so that the upper and lower surfaces of the glazing 17 do not leave the support zone 45 of the centering finger 15.

[0097] As will be understood in light of the above, the device and method according to the present invention allow, thanks to follower suction units 23, to automatically and perfectly adapt the positions of each of the suction cups 13 to the effective dimensions of the glazing 17 to be encapsulated with its profiled peripheral seal.

[0098] This adaptation can be carried out once and for all with a reference glazing 17a (first variant of the process according to the invention), or for each glazing 17b of a given model to be produced in series (second variant of the process according to the invention).

[0099] The method according to the invention thus makes it possible to reduce, or even eliminate, unwanted mechanical stresses inside the glazing 17, during the various stages of the molding process by encapsulation of the profiled seal at the periphery of the glazing 17.

[0100] It will further be noted that the invention makes it possible to use existing molds 1 with relatively few modifications: it is sufficient to replace the suction cups 13 and their fixed support rods 11 with suction units 23 with telescopic rods 31 as explained above.

[0101] Of course, the present invention is not limited to the embodiments described above.

[0102] It is thus possible to envisage that the suction units 23 are mounted on a fixed support, in place of the mobile ejection plate 9.

[0103] Thus, other ways of ensuring self-adaptive contact of the suction units 23 with the glazing to be molded 17 could be envisaged.

[0104] A possible variant could be to replace the suction cups 13 and their associated telescopic rods 31 with vacuum ball immobilization mattresses 47, as shown in.

[0105] Such a mattress 47 contains balls 49, and on its face intended to cooperate with the glazing 17, this mattress 47 is provided with orifices.

[0106] When this mattress 47 comes into contact with the glazing 17 (step B), it perfectly matches its shape, and retains this deformation.

[0107] The vacuuming of this mattress 47 (step C) then makes it possible to engage this mattress 47 with the glazing 17, thanks to the orifices formed in this mattress 47 and arranged opposite the glazing 17.

[0108] Due to the ability of this mattress 47 to deform and retain this deformation, this variant offers an interesting alternative to the telescopic suction units 23, also making it possible to eliminate all mechanical constraints inside the glazing 17.

[0109] Such a principle of deformation memory device could also be provided by a nail board 51, as shown in the.

[0110] As is known per se, such a nail board 51 has a large number of nails or rods 53 mounted on a support 55, and capable of moving in the same direction when applying an object having a given shape: a hand in the example shown.

[0111] Such a device would make it possible, by being applied against the glazing 17 to be molded, then by being placed under vacuum, to obtain an effect of self-adaptation to the shape of the glazing 17 and of maintaining it, similar to that obtained with a ball immobilizing mattress 47.

Claims

Device for molding a profiled seal on at least one peripheral part of a glazing (17; 17a, 17b), comprising:- a fixed mold part (3),- a plurality of suction units (23),- means for selectively placing the suction units (23) under vacuum so that they engage with the glazing (17; 17a, 17b),- a movable mold part (5), capable of coming into contact with the fixed mold part (3) so as to define a molding cavity (21) for said profiled seal,- at least one injection orifice in said cavity (21) of a material intended to form said profiled seal,characterized in that it comprises means (29, 31, 33; 47; 51) for reducing the forces transmitted to the glazing (17; 17a, 17b) by the suction units (23), adjustable under the effect of the engagement of these units (23) with the glazing (17;17a, 17b), said suction units (23) each comprising a fixed support (25), a telescopic rod (31) with a spring (33) slidably mounted in the fixed support (25), a suction cup (13) at one end of said telescopic rod (31) and braking means (29, 38) for this rod (31).; Device according to one of claims 1, in which said force reduction means comprise deformation memory means (47; 51). Device according to claim 2, wherein said deformation memory means comprise at least one vacuum ball immobilization mattress (47). Device according to one of claims 2 or 3, in which said deformation memory means comprise a nail board type interface (51). Device according to any one of claims 1 to 4, comprising means (15a, 15b, 15c, 15d) for centering the glazing (17; 17a, 17b) relative to the fixed mold part (3). Device according to any one of claims 1 to 5, wherein said suction units (23) are fixed on an ejection plate (9) mounted movably on the fixed mold part (3) between a receiving / evacuation position and a molding position. Method for molding a profiled seal on at least one peripheral part of a glazing (17; 17a, 17b), by means of a device according to any one of claims 1 to 6, comprising the successive steps of:- releasing the force reduction means (29, 31, 33; 47; 51),- placing the glazing (17; 17a, 17b) on the suction units (23),- placing the suction units (23) under vacuum, so that the glazing (17; 17a, 17b) comes into contact with the fixed mold part (3),- actuating the movable mold part (5) so as to bring it into contact with the glazing (17; 17a, 17b) and to define the molding cavity (21) of the profiled seal,- fixing said force reduction means (29, 31, 33; 47; 51), and- proceed to mold the profiled seal on this glazing. Method according to claim 7 applied to a reference glazing (17a), comprising the subsequent steps of maintaining the fixed positions of the force reduction means (29, 31, 33; 47; 51) to carry out the molding of the profiled seal on glazings (17b) of the same model as that of the reference glazing (17a). Method according to claim 7, in which the steps of this method are implemented for each glazing (17b), then the molding of the profiled seal is carried out on this glazing (17b). Method according to any one of claims 7 to 9, comprising a step consisting of centering the glazing (17; 17a, 17b) relative to the fixed part of the mold (3), after having placed it on the suction units (23), and before placing the latter under vacuum. Method according to any one of claims 7 to 10, in which an ejection plate (9) is placed in a receiving / evacuation position prior to the deposition of the glazing (17; 17a, 17b) on the suction units (23), and this ejection plate (9) is placed in its molding position after having placed the suction units (23) under vacuum, so as to bring the glazing into contact with the fixed mold part (3).

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