MXPA97007659A - Procedure for extruding a profiled cord frame enforma on a crystal, extrusion row for executing the procedure and productobten - Google Patents

Abstract

The object of the invention is a method for extruding a profiled cord in the form of a frame (4) made with an elastomer over the marginal zone of a glazing (1), which has one or more living angles (2). The profiled cord (4) is provided with a radially oriented sealing lip and protruding beyond the edge of the glazing (1). In the area of the angle (2), the profiled cord (4) is placed in an arc of a circle. An extrusion die (14) having an elongated slot, which is covered at the end, by a small slide (16) is used. Preferably, the small slide (16) is coupled to a guide slice (17), which rolls on the peripheral surface of the glazing (1). In this way, in the angle region, the lip (8) is continuously stretched and then shortened continuously to its initial length. The product that is obtained, encristalado for automobile, comprises especially in the angles, a frame whose lip as the rest of the cord constitutes a continuity with the linear parts neighbors

Description

PROCEDURE TO EXTRUDE A PROFILED CORD IN THE FORM OF A FRAME ON A CRUSHER, EXTRUSION ROW TO EXECUTE THE PROCEDURE AND PRODUCT OBTAINED DESCRIPTION The present invention relates to a method for extruding on the marginal zone of a plate comprising at least one angle, in particular a glazing, a profiled cord in the form of a frame, which has a lip that overflows the plate, made of an elastomer, with the help of an extrusion die; the profiled cord is placed in a circle in the area of the angle. The invention also relates to an extrusion die to carry out this process and with the product obtained. It is known to extrude frame shaped profiles made of an elastomer comprising a lip that forms a sealing shoulder radially and directly on the marginal zone of a glazing. This can be done, for example, by moving the extrusion die with the aid of a robot along the edge of the glazing. Procedures of this type are described, for example, in EP 0 421 833 A2, 0 611 672 A2 , 0 444 998 Bl and 0 479 677 Bl. The extrusion process can also be executed by displacing the glazing with the aid of a robot in relation to a fixed mounted extrusion die. Processes that operate in this manner are described in EP 0 585 129 Al, 0 634 263 Al, 0 662 384 Al and 0 707 657 Al. Known processes for extruding a profiled frame comprising a centering lip and a lip of a tightness that protrudes beyond the edge of the glazing in which, in general, a robot guides the extrusion head to the periphery of the glazing or then where a robot displaces the glazing in front of a fixed extrusion head, can be executed without difficulty, while encristalados or objects of that type in the form of plates, which are provided with the profiled frame, have round angles or a radius of at least about 20 mm. If the round radius is less than about 20 mm, or if the plate has one or more sharp angles, the known machines must then, if the extrusion speed still have to be economical, deposit in the profile angled regions in a circle arc; the axis of the profiled cord describes an arc of a circle with a radius of approximately 20 mm. This has the consequence that the sealing lip can no longer protrude in the angle region of a constant length beyond the edges of the glazing. In the case of a right angle for example, the sealing lip directly at the angle would no longer overflow the edges, but would follow an arc into the interior of the angle. In those cases, the peripheral lip whose function is that of being in support on the body around the encristalado, could not fulfill its mission. Therefore, it is necessary in the state of the art to complete, at a later stage of the procedure, the profiled frame extruded in the angle regions. According to the process described in EP 0 524 060 Al, the frame is completed by a method similar to the injection molding process. In this case, the marginal zone that must be completed, is enclosed in an injection mold, and an appropriate polymer is injected into the injection mold and hardens in the mold. This procedure did its tests, but nevertheless it is linked to an increase in labor costs due to the necessary additional procedural stages. It is also interesting in a general manner to be able to modify, in one or several places on the periphery of the glazing, the relative position of the cord of the peripheral frame and of the end of the overflowing lip. This is the case in particular if the edge of the recess where the glazing is inserted has, in certain places, a modulation, widening or narrowing, which can be interesting to follow only with the lip without the essential of the cord completely following the sinuosities of that is. So, it is essentially the lip that, thanks to its variable width in the place in question, would solve the problem. The object of the invention is to improve the method mentioned at the beginning of the present specification, in such a way that the lower lip protruding beyond the edge of the glazing is extended or completed in certain areas of the frame, without Supplementary procedure stage is necessary. This objective is achieved according to the invention due to the fact that an extrusion die is used comprising an elongated slot and a small slide which seals the end of the slot and which the small slide moves on command, in radial direction during the extrusion of the Circle arc in the angle of the plate.

The method according to the invention is therefore based on the use of an extrusion die of variable swath cross section, by the controlled modification of which the width of the sealing lip in the angle zone is continuously modified in the desired manner in the area in question, and if it is a living angle, in which the lip is lengthened before reaching the angle and then shortened again continuously to the initial length. Thus, it is possible, also in the area of right angles or even acute angles, to form the frame completely extruded at the moment of the extrusion operation in such a way that a post-molding of the sealing lip especially in the angle areas, since it is not necessary. The process according to the invention can, in principle, be ced out in the case of extrusion with the aid of an extrusion die ced along a stationary plate, as well as with the help of an extrusion die disposed in a fixed manner, at the level of which the glazing is displaced. The commanded displacement of the small slide for lengthening and shortening the slit can be done in different ways. For example, in this way, the small slide can be provided with an electric or pneumatic drive, which is controlled by the central microprocessor of the installation. Instead of this, in particular at the angles, the small slide can thus be coupled to a lateral guide slice, which rolls on the peripheral surface of the plate that must be provided with the profiled frame and displaces the small slide of the desired way, especially at the moment of the cornering. Other features and advantages of the invention will be apparent from the dependent claims and from the description below of a preferred embodiment based on the accompanying drawings. In these annexed drawings: Figure 1 shows an angle zone of a glazing comprising an extruded frame according to the state of the art; Figure 2 shows an angle zone of a glazing according to Figure 1, but with an extruded frame according to the method of the invention; Figure 3 is an elevation view of the side of an extrusion head driven by a robot comprising an extrusion die according to the invention, during the extrusion operation; and Figure 4 is a schematic view of the extrusion operation in the angle zone of the glazing. The invention is illustrated and described below, in the context of a use for encristalados, in particular encristalados for automobiles. However, the method according to the invention can, of course, also be used in the case of the extrusion of profiled frames on other objects, such as, for example, metal plates, doors, chests, etc ..., as long as those objects also present the need to modify the width of the lip, especially when they have one or several living angles and that the profiled frame is provided with a profile segment that protrudes beyond the edge of the object. The glazing 1 shown in the drawings presents, in the corner area, a living angle 2, in this case an angle of a value of 90 °. Certain glazings for automobiles are sometimes configured so as to present such a sharp angle, while its contour for the rest, describes curves having a more or less large radius. Such glazing forms of this type often occur in fixed lateral glazing. Glazing is often used which comprises two sharp angles cone glazed rear of cars; in this case, the two lower corners are in the form of usual angles, while the two upper corners are more or less quite round. In other cases, encristalados are used that are of right angles in all the corners. The method according to the invention can be used in all those cases.

In glazing 1, a layer 3 in the form of a frame made of an opaque material, generally made with an ink for cooking, is first applied to the marginal zone. In general, this ink is fired on the surface of the glass at the time of the thermal treatment to which the glazing is subjected for its bending and / or its tempering. The profiled frame 4 is then extruded on this layer 3 on the glazing at the level of the marginal zone of the glazing 1. The profiled frame 4 has a base segment 5 and a wing 7 extending perpendicular thereto. The sealing lip 8 projecting outwards beyond the glazing is joined to the wing 7. On the base segment 5, at the time of assembly, the adhesive mass with which the glazing sticks to the flange of the adhesive is applied. fixing the frame of the body window. This segment of profile 5 can also present, in principle, another cross section; if this is the case, this base segment 5 can also be completely removed and the adhesive mass is then deposited directly on the glazing, preferably on the opaque layer 3. To obtain a regular cross-section in the angle zone, the row of extrusion in its relative displacement to the periphery of the encristalado, it must describe in the angle, a circular trajectory, according to which the axis of the profiled cord describes a curve of ray R, of dimension when less than approximately 20 mm. Inevitably, the outer side 10 of the lip will thus also describe an arc of circle around the same center of circle, having as a consequence that, from the beginning of the rotation of the extrusion die, the part of the lip 8 that forms I protrude beyond the edge of the glazing, it will shorten. In the outer end angle zone 11, the lip 8 practically no longer extends to the edge of the glazing. The phenomena are the same if the edge of the opening comprises a meander whose glazing edge does not have the equivalent, while the lip moves away or approaches the body improperly. In the case of the execution of the method according to the invention, on the contrary, a shape of the adapted lip 8 is obtained and, in the case of a corner, as it appears in figure 2. Since in the angle zone, the The pivoting movement of the extrusion die and its displacement according to a circular path remain in principle unchanged; the shape and the appearance of the sections of the profile 5 and 7, in principle, are the same as in the case shown in FIG. 1. The length I of the sealing lip 8 protruding towards the outside increases, however, continuously, starting from the place where the circular and rotational movement of the extrusion die begins, until the extrusion die has traveled half the arc of a circle. In that place, the lip 8 has the length L. Then, the length of the lip 8 decreases continuously, until it has reached its original length I again at the end of the circle arc. In this way, the lip 8 in the angle region of the glazing has the shape as shown in FIG. 2, that is to say that the part of the lip which protrudes beyond the edges of the glazing, also extends into the angle zone parallel to the edge of the glazing, and only the outer outer corner of the lip, is somewhat round. Figure 3 is an elevation view of the side of an extrusion head for manufacturing the extruded profile frame according to the invention. The extrusion head comprises, inter alia, the actual spinneret body 14 comprising the calibrated spinneret orifice. , the small slide 16 that can be moved horizontally and, in the case shown, where the extrusion head is mechanically controlled, a guide slot 17 joined to the small slide 16, which rolls on the peripheral surface 18 of the glazing 1. The slit 15 'of the row hole 15, which forms the sealing lip, has a length L, which is considerably greater than the length I of the sealing lip in the region of the longitudinal edges of the glazing. The slit 15 'is sealed at its end by the small slider 16 to such an extent that the free lip slit 15' has, in the region of the rectilinear longitudinal edges of the glazing, the desired length I. The small slide 16 and the support 19 supporting the guide slide 17, which are fixed to one another in a fixed manner, are slidably mounted by means of a sliding support 20 on a horizontal guide rod 21. A pressing force it exerts by means of the helical spring 22 on the sliding device attached to the guide slide 17; the guide rail 17 is pushed against the peripheral surface 18 of the glazing 1. The fixing 23 carrying the guide rod 21 is rigidly connected to the extrusion head carrying the extrusion die. The extrusion die 14 is provided with two channels 26, 27, spaced apart from one another, through which the polymer to be extruded arrives at the orifice of the row 15, 15 '. The volume flow of the polymer can be regulated in the two channels 26, 27, independently of one another, as described in EP 0 444 998 Bl. The valves that regulate the volume flow in the two channels 26, 27 can preferably be controlled as a function of the position of the small slide 16, and in such a way that the volume flow in the channel 27 increases and the volume flow in the channel 26 decrease, as the lip groove 15 'opens further. Due to this fact, the volumetric flow rates are adapted to the mass needs of polymer different from the inside of the row orifice during the rotation of the extrusion head. Figure 4 shows, in a plan view, the sequence of the movements of the row 14 and of the small slide 16 at the moment of the extrusion of the profiled frame 4 in an angle zone of the glazing 1. It is recognized that the guide slice 17 that progresses on the peripheral surface 18, moves, at the moment of the pivoting movement of the row 14, outwards in the direction of the arrow F with the small slide 16 coupled to the guide slice; the row groove 15 'forming the lip 8 is progressively released continuously, due to this fact. As soon as the guide roller reaches the angle 2 of the glazing at the moment of the pivoting movement of the row 14 that continues, the direction of movement of the small slide 16 is reversed, thanks to the fact that the slit 15 'is shortened continuously again , until it has reached its final position at the end of the pivoting movement of the row 14. Differently from the previous procedures, especially that which is disclosed in EP 0 524 060 Bl, the method of the invention allows a product to be obtained , encristalado for automotive especially, that includes in the angles, a frame whose lip like the rest of the cord, constitutes a continuity with the neighboring linear parts. In the prior art, on the other hand, the splicing between the new molded part in the corner and the neighboring parts of the extruded profile was visible except in the case where a cosmetic correction was provided.

Claims (8)

1. CLAIMS 1.- Process for extruding on the marginal zone of a plate comprising at least one angle, in particular a glazing, of a profiled cord in the form of a frame, having a lip overflowing the plate, made with an elastomer, with the help of a row of extrusion; the profiled cord is deposited in a circle arc in the area of the angle, characterized in that it is used with an extrusion die comprising an elongated slit and a small slider that seals the end of the slit and in which the small slider is moved over Control in radial direction during the extrusion of the circle arc in the angle of the plate.
2. Method according to claim 1, characterized in that the displacement control of the small slide is carried out by means of a microprocessor which also controls the relative displacement of the extrusion die and the glazing.
3. 3. Method according to claim 1, characterized in that the control of movement of the small slide, is carried out by means of a guide slice coupled to the small slide, which progresses on the peripheral surface of the plate and is pushed against its edge peripheral.
4. 4. - Plate, especially glazed for automobile, equipped by means of extrusion according to the claim 1, with a profile shaped cord that has a lip that overflows the plate; the plate comprises at least one angle in which the cord is deposited in an arc of a circle, characterized in that, in the angle of the plate, the end of the lip moves away from the rest of the cord and in that in the angle, the lip as the rest of the cord constitutes a continuity with the neighboring linear parts.
5. 5. Device for executing the method according to claim 1, comprising an extrusion head carrying an extrusion die, a fixation device, either for the plate providing the extruded profiled cord, or for the extrusion head. , and an automatic manipulator that displaces the extrusion die and the glazing, one in relation to the other, according to a predetermined program, characterized in that the extrusion die has an elongated slit and a small slider that seals the elongated slit, small slider whose sliding movement can be commanded to lengthen and reduce the lip groove in the angle region as a function of the angular pivoting movement between the glazing and the extrusion die.
6. 6. - Device according to claim 5, characterized in that the small slide is provided with a drive that is controlled by a central micro-processor of the device.
7. 7. Device according to claim 5, characterized in that the small slide is connected to a guide rail that rolls on the peripheral surface of the plate, which is mounted slidably on a guide rod together with the small slide, parallel to the plane of exit from the row hole.
8. 8. Device according to claim 7, characterized in that the contact of the guide roll with the peripheral surface is ensured by an elastic pressure means such as a helical spring.