EP0072779A2 - Device for applying adhesive tape to the edge of sheet material - Google Patents

Abstract

An adhesive web is to be pressed on to the edge of a shaped sheet metal part, so that the web portion on the metal part has a U-shaped cross-section. To this end, the adhesive web is first peeled off a carrier tape and is then folded with the aid of a deflecting and pre-folding roller having a profile whose cross-section is a wide V. The pre-folded web is then folded further continuously in a funnel-shaped pre-folding channel. The sheet metal part whose edge is to be covered is then introduced with that edge, within the reach of the pre-folding channel, into the folded bend of the adhesive web, and both the sheet metal part and the web thereon are conveyed together by a pair of feed and press-on rollers which press the adhesive web on the edge and sides of the sheet metal part.

Description

The invention relates to a device according to the preamble of patent claim 1.

In the sheet metal processing industry, the gluing of seam seam connections using pressure or thermosetting adhesives is widespread. So it is e.g. It is common in the automotive industry to seal fold seams on certain body parts, in particular doors, in this way and thus to prevent the risk of corrosion.

In the automotive industry and similar branches of industry, adhesives in liquid or pasty form are usually used to produce such glued seam seam connections, which are applied in the form of a bead to the sheet metal parts to be joined. This method of applying the adhesive is unsatisfactory in various ways. On the one hand, the distribution of the adhesive achieved with this is not sufficiently uniform over the entire seam, which can lead to corrosion problems, and on the other hand, adhesives in liquid or pasty form are always problematic from an occupational hygiene point of view.

In the manufacture of cans, it is e.g. US-A 3 125 056 or FR-A 2 252 147 or BE-A 444 014 also show the usual way of gluing seam seams or sealing by means of adhesive. The adhesive is applied to the flanged edges of the parts of the can body to be connected to one another, either in liquid or pasty form by extrusion or the like, or else in the form of a strip of adhesive film.

Adhesives in foils - in particular tape form such as e.g. are known under the brand names Araldit® and Redux® adhesive film (CIBA-GEIGY), not least because of their occupational hygiene advantages they are becoming more and more widespread. For gluing the seams of e.g. Car body parts, however, have so far not been used such adhesive films or only used to a very limited extent. The main reason for this is that adhesive films are tough plastic and their very low tensile strength makes machine application considerably more difficult. Additional complications arise when such adhesive film strips have to be applied to body parts whose seams have a complicated, in particular spatially curved, course. These difficulties are particularly great if the flanged edge is to be provided with adhesive on both sides, that is to say the adhesive tape has to be placed around the rank in a U-shape.

The previously known devices of the type described in the preamble of claim 1 are only suitable for processing relatively rigid and tensile adhesive tapes (not adhesive tapes).

This also applies, for example, to the apparatus with a prefolding channel and pressure rollers known from US Pat. No. 4,155,798.

The invention is based on the knowledge that the inadequate suitability of the previously known apparatuses with pre-folding channel and pressure rollers for the application of tough plastic adhesive tapes of low intrinsic rigidity and tensile strength to curved sheet metal edges is primarily due to the rigid mutual arrangement of pre-folding channel and contact pressure roll is conditional. It was also recognized that it is also important whether and how the pressure rollers are driven. For example, the apparatuses known from the aforementioned US Pat. No. 4,155,798 work with free-running pressure rollers. In other devices, such as those for seaming drawing sheets with adhesive tapes, the rollers are rigidly coupled to a drive motor.

The invention is intended to eliminate the shortcomings indicated and to provide a device of the type described in the preamble of claim 1, which is also suitable for applying adhesive tapes of low intrinsic rigidity and tensile strength to spatially curved sheet metal edges.

It has been found that the object can be achieved by training the device described in the preamble of claim 1 according to the characterizing part of claim 1.

• Fig. 1 eine perspektivische Gesamtdarstellung,
• Fig. 2 eine Detailansicht in Richtung des Pfeiles II der Fig. 1,
• Fig. 3 dieselbe Detailansicht wie Fig. 2, jedoch in einer anderen Arbeitsstellung.

The invention is explained in more detail below on the basis of an exemplary embodiment shown in the figures; show it

• 1 is an overall perspective view,
• 2 is a detailed view in the direction of arrow II of FIG. 1,
• Fig. 3 shows the same detailed view as Fig. 2, but in a different working position.

The machine shown is built on a base plate 1 and comprises: a supply reel 2 for the adhesive / carrier tape 3K / 3T, a take-up reel 4 for the carrier tape 3T separated from the adhesive tape, several deflection rollers 5 to 8, a deflection and pre-folding roller 9, a funnel-like one Folding duct 10 and a pair of pressure rollers lla / llb. With 20 a box is designated, which comprises a conventional drive consisting of an electric motor and transmission.

Each of the two rollers 11a and 11b is seated on an axle 12a or 12b, which is rotatably mounted in a housing 13 and is connected to the drive located in the box 20 via flexible and torsionally elastic shafts 14a and 14b. The axis 12b of the lower roller 11b is mounted in a swivel arm 15 (dashed lines) with the swivel axis SI, to which a pressure spring 16 (dashed lines) acts from below just before the axis 12b emerges from the housing 13 and the roller 11b upwards against the role Ila presses. The pivot axis S1 is adjusted or adjustable so that the roller axes 12a and 12b run exactly parallel to one another when the sheet metal and adhesive tape run through. For this purpose, axis S1 can be moved in the direction of arrows V + (for larger roller spacing) and V- (for smaller roller spacing) and can be fixed in the desired position. The pressure force of the spring 16 can be regulated by means known per se (not shown).

The housing 13 is articulated as a whole on the base plate 1 or the bearing block 17 of the deflecting and folding roller 9 which is firmly connected to the latter. The pivot axis S2 of this articulation runs parallel to the axes of rotation 12a or 12b of the transport and pressure rollers 11a and 11b and is also arranged such that it lies approximately in a straight line with the exit 10b of the folding duct 10 which is also fastened to the bearing block 17. The pivot axis S2 can also be slightly before or after the exit 10b of the pre-folding channel 10 i.e. are more distant or closer to the pair of rollers 11a / 11b. The central or neutral position N of the housing 13 and thus of the pair of transport and pressure rollers 11a / 11b is defined by two tension springs 18 and 19 acting in opposite directions. In this neutral position, the plane of symmetry of the pair of transport and pressure rollers coincides with that of the pre-folding channel.

The housing 13 is slidably supported on the axis S2 against the force of a spring (not shown). It can therefore be displaced as a whole in the direction of the roller axes 12a, 12b against the force of this spring. The forward shift (roller side) is limited by a stop. This arrangement is indicated in FIG. 1 by a double arrow H13-HF13, the arrow direction HF13 symbolizing the force of the spring. The spring itself and the stop are not shown for drawing reasons. The displaceability of the housing 13 can of course also be realized by other known design means.

The deflection and pre-folding roller 9 and the pre-folding channel 10 are designed such that they fold the adhesive tape 3K in a V-shape around its longitudinal axis. For this purpose, the roller 9 is flat V-shaped in profile. The V angle is preferably about 155 ° to 165 °. The V-profile of the roller 9 can also be replaced by a corresponding arc profile.

According to a preferred embodiment, the deflecting and folding roller 9, like the housing 13, can be moved backwards from the front limit stop against the force of a spring. For reasons of the drawing, this arrangement is again only symbolically indicated by a double arrow H9-HF9, HF9 symbolizing the force of the spring. In terms of construction, this arrangement can e.g. can be realized in that the roller 9 is mounted in a fork-like element, which in turn is slidably mounted in a guide mounted on the base plate 1 or the bearing block 17 against the force of a spring. The direction of advance of the deflecting and folding roller 9 does not necessarily have to run parallel to that of the housing 13. In principle, it only has to lie at an angle between the inlet and the outlet of the deflected adhesive tape 3K and enable the roller 9 to move backwards (with respect to the rollers 11a, 11b). The direction of displacement is preferably adjustable or at least adjustable.

The prefolding channel 10 is preferably attached to the bearing block 17 in an adjustable and adjustable manner. It is likewise (like the deflecting and pre-folding roller 9) essentially V-shaped in cross-section, but the V-angle decreases continuously from the band inlet end 10a to the outlet end 10b, similar to a funnel. In the apex line (connecting line of all V-vertices) the cross-section is rounded off accordingly. The V-angle is preferably approximately 90 to 100 ° at the inlet 10a and approximately 10 to 15 ° at the outlet 10b. The rounding in the crown tangentially changes into the "V". The radius of curvature of the rounding at the exit 10b is only a few millimeters, preferably approximately 3 mm. In the top view, the pre-folding duct 10 is also V-shaped, the opening angle a being approximately 70 ° C.

The effective width at the entrance 10a is approximately the same as the width of the roller 9.

The deflection rollers 6, 7 and 8 are used to return the carrier tape 3T to the take-up drum 4, which is coupled to the drive motor of the device mounted in the box 20 via a slip clutch and a chain drive located in the support arm 21. The slip clutch can also be arranged in the box 20 or immediately in front of the take-up drum 4.

• Beim Aufsetzen einer neuen Vorratsrolle 2 wird das Klebstoff-/Trägerband 3K/3T zunächst von Hand über die Umlenkrolle 5 bis zu den Rollen 6 und 9 gezogen. Dort wird das Klebstoffband 3K vom Trägerband 3T gelöst und über die Umlenk- und Vorfaltrolle 9 und den Vorfaltkanal 10 zwischen die Transport und Andrückrollen lla und llb geführt. Gleichzeitig wird das Trägerband 3T über die Umlenkrollen 6, 7 und 8 auf die Aufwickelspule 4 geführt und dort so befestigt, dass es auf dieser aufgewickelt werden kann. Die verschieden langen Weglängen zwischen der Rolle 9 und dem Rollenpaar 11a/11b einerseits und der Rolle 6 und der Aufwickelspule 4 anderseits werden dabei dadurch ausgeglichen, dass das Klebstoffband 3K entsprechend weit über das Rollenpaar lla/ llb hinaustransportiert wird, z.B. durch kurzzeitiges Einschalten des Antriebes dieser Rollen. Es kann aber auch ein Klebstoff/Trägerband 3K/3T mit einem entsprechend langen Trägerbandvorlauf verwendet werden.

The device shown is handled as follows:

• When putting on a new supply roll 2, the adhesive / carrier tape 3K / 3T is first pulled by hand over the deflection roll 5 up to the rolls 6 and 9. There, the adhesive tape 3K is detached from the carrier tape 3T and guided between the transport and pressure rollers 11a and 11b via the deflection and pre-folding roller 9 and the pre-folding channel 10. At the same time, the carrier tape 3T is guided over the deflection rollers 6, 7 and 8 onto the take-up reel 4 and fastened there so that it can be wound thereon. The different lengths of path between the roller 9 and the pair of rollers 11a / 11b on the one hand and the roller 6 and the take-up reel 4, on the other hand, is compensated for by the fact that the adhesive tape 3K is transported far beyond the pair of rollers 11a / 11b, for example by briefly switching on the drive of these rollers. However, a 3K / 3T adhesive / carrier tape with a correspondingly long carrier tape advance can also be used.

If the adhesive tape 3K is at its beginning between the transport and pressure rollers 11a and 11b and the carrier tape 3T is attached to the circumference of the take-up reel 4, the device is ready for operation.

The sheet metal part B to be edged in a U-shape with the adhesive tape 3K is now pushed with one of its corners over the tape guide and folding element 10 between the transport and pressure rollers 11a and 11b, the drive being switched on at the same time or shortly before. The transport and pressure rollers 11a and 11b pull the sheet B through with its edge and thereby press on the adhesive tape 3K. At the same time, the take-up spool 4 driven by the drive motor (box 20) via the slip clutch winds up the carrier tape 3K. The slip clutch is set so that the trains in the carrier tape 3T and in the adhesive tape 3K are approximately the same size.

The device according to the invention can be mounted in a stationary manner and the sheet metal part can be guided by hand or by means of a robot. Conversely, the sheet metal part can also be held for the application process and the device can be guided along the edge by hand, by motor on a rail or by means of a robot. The former variant is particularly suitable for smaller sheet metal parts, the latter for larger ones.

The distance Al between the pivot axis S2 of the housing 13 and a plane E defined by the axes 12a and 12b of the transport and pressure rollers 11a and 11b is decisive for the maximum permissible spatial curvature of the bleaching part B. The smaller the curvature radius of the smallest curvature of the sheet metal part, the smaller the distance A must be selected. It was found that the distance A1 ≦ 7 mm must be selected, for example, with the smallest possible sheet radius of curvature Rmin = 20 mm. With this dimensioning, sheet metal parts with a radius of curvature of 20 mm (Rmin) can just just be pulled perfectly from the rollers 11a and 11b, that is to say without clamping through the exit V-gap 10b of the pre-folding channel 10. The pair of rollers 11a / 11b assumes the position shown in FIG. 3.

Depending on the strength and direction of the sheet metal curvature, the pair of rollers 11a / 11b is more or less deflected from its central or neutral position N. The path differences on the transport and pressure rollers 11a and 11b are compensated for by the torsional elasticity of the drive shafts 14a and 14b.

The distance A2 between the deflecting and pre-folding roller 9 initiating the folding of the adhesive tape 3K and the outlet V cross section 10b of the pre-folding channel 10 is set or adjustable such that the folding increases substantially continuously over this distance (V angle continuously decreasing ) he follows. Too great a spacing would have the disadvantage that the folding initiated by the roller 9 would again be lost in front of the pre-folding duct 10 that continues the folding, or in extreme cases the tape 3K would get into the pre-folding duct 10 with a “wrong” pre-folding. In addition, an excessively large distance is also harmful because the adhesive tapes used are generally very plastic and therefore longer train distances must be avoided. If the distance A2 is too small, band distortion can occur.

The pressure roller pair 11a, 11b or the housing 13 adapts to irregularities in the sheet metal edge contours in that it can spring backwards (arrows H13-HF13, Fig. 1). The same applies to the deflection and pre-folding roller 9 (arrows H9-HF9, Fig. 1).

The device according to the invention was tested with the adhesive tapes commercially available under the names of adhesive film DLS 615 and adhesive film XB 3615 from CIBA-GEIGY, Basel. These adhesive films are those based on one-component epoxy resin with sufficient shelf life at low temperatures (refrigerator), which harden quickly at approx. 120 ° C. The films are designed so that they are sticky on one side at room temperature. The 3K tapes are approx. 16 mm wide and approx. 0.30 to 0.35 mm thick. The carrier strip 3T is made of paper and a little wider. When pulling off the supply roll 2, the carrier adheres to the stickier film side and that

Adhesive tape 3K is folded with the sticky side inwards after peeling off the carrier tape 3T and glued onto the sheet 3 by the rollers 11a and 11b.

Adhesive tapes made of DLS 615 or XB are tough plastic and have practically no inherent rigidity and only a very low tensile strength.

For the application of a tape made of DLS 615 or XB 3615 with the above-mentioned cross-section (width x thickness. = 16 x 0.30) to a sheet metal part B with radii of curvature of at least 20 mm, the machine shown was dimensioned or adjusted as follows :

Reference symbol list:

• 1 base plate
• 2 supply spools
• 3K / 3T adhesive tape with carrier tape
• 3K adhesive tape
• 3T carrier tape
• 4 take-up spool
• 5-8 pulleys
• 9 Deflection and folding roll
• 10 folding channel
• 10a entry end of 10
• 10b exit end of 10
• lla, llb transport and pressure rollers (pair)
• 12a, 12b axes
• 13 housing
• 14a, 14b flexible, torsionally elastic drive shafts
• 15 swivel arm
• 16 compression spring
• 17 bearing block
• 18th
• 19 tension springs
• 20 box with motor
• 21 support arm
• A1 distance S2-E
• A2 distance 9-10b
• A3 effective length of the pre-folding channel 10
• B sheet metal part
• E - level 12a-12b
• N middle or neutral position of 13 or 11a / 11b
• Rmin smallest radius of curvature of B
• S1 swivel axis for 15
• S2 swivel axis for 13
• a Angle of the pre-folding duct under supervision
• H9, H13, V +, V- displacement options and directions
• HF9, HF13 spring forces and directions.

Claims (12)

1.Device for the U-shaped application of an adhesive tape in the longitudinal direction around the edge of a sheet metal part, the tape guide of which has a funnel-like folding channel, from which the pre-folded tape runs between two resiliently pressed pressure rollers, which at the same time apply it to the two sides of a Press on the folded area of the sheet metal molded part, characterized in that the pressure roller pair (lla, llb) as a whole can be pivoted about a common axis (S2) which lies in a straight line which is parallel to the roller axes (12a, 12b) and at a distance with respect to the strip transport direction (A1) runs in front of this approximately in the plane of symmetry of the pre-folding channel (10), and that the pressure rollers (11a, 11b) can be driven by a motor in such a way that both rollers always have an at least approximately equal transport force on the solid bleached molded part, even if their speed differences. B) exercise. 2. Device according to claim 1, characterized in that the distance (A1) between the pivot axis (S1) of the pressure roller pair (lla, llb) and a through its axes (12a, 12b) plane (E) at least approximately with that between them Level and the output (10b) of the pre-folding channel (10) matches. 3. Device according to claim 1 or 2, characterized in that the pressure roller pair (lla, llb) is resiliently held in a neutral position (N), in which its plane of symmetry at least approximately coincides with that of the pre-folding channel (10). 4. Device according to one of the preceding claim 1, characterized in that the pre-folding channel (10) is designed as a pre-folding reel (9), which also has a slightly curved or V-shaped profile with the smallest diameter in the middle of the roll . 5. The device according to claim 4, characterized in that the profile angle of the deflecting and folding roller (9) is approximately 155 ° to 165 °. 6. Device according to one of the preceding claims, characterized in that the V-angle of the pre-folding channel (10) at the inlet (10a) is approximately 90 ° to 100 ° and at the outlet (10b) is approximately 10 ° to 15 °. 7. Device according to one of the preceding claims, characterized in that the effective passage length (A3) of the pre-folding channel (10) is approximately 0.6 to 0.8 times the effective width of the deflection and pre-folding roller (9). 8. Device according to one of the preceding claims, characterized in that the pressure rollers (lla, llb) are driven by a common motor, at least one of the two rollers (lla, llb) using a torsionally elastic element, preferably a flexible and torsionally elastic shaft (14a, 14b) is coupled to the engine. 9. Device according to one of the preceding claims, characterized in that at least one of the two axes (12a, 12b) of the pressure rollers (11a, 11b) is pivotably mounted and is pressed against the other roller by means of a spring (16), the pivot axis ( S1) is set or adjustable such that the roller axes (12a, 12b) are exactly parallel to each other at a certain roller spacing. 10.Device according to one of claims 4 to 9, characterized in that the band deflection and pre-folding roller (9) against the force (HF9) of a spring is displaceable in a direction lying between the tape inlet and the tape outlet direction. 11.Device according to claim 10, characterized in that the direction of displacement of the deflection and pre-folding roller (9) runs approximately parallel to the axes (12a, 12b) of the pressure rollers (11a, 11b). 12. Device according to one of the preceding claims, characterized in that the pressure roller pair (lla, llb) against the force (HF13) of a spring in the direction of its axes (12a, 12b) is displaceable to the rear.

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