DE3011171A1 - Veneer pressed and bonded onto three=dimensionally fluted surface - by progressive moulding with tools then distributed pressure on pressing membrane - Google Patents

Abstract

The parent patent describes a method of fitting a decorative facing, esp. a veneer, round a workpiece possessing throats or fluting; this decorative layer is placed, with adhesive beneath it, onto the workpiece, the laminated structure is then placed below a flexible membrane and shaping tools force the membrane and decorative coating into the flutings of the workpiece. The membrane is then pressurised, so that the bonded joint is formed by the adhesive and sets. In the patent of addition, the method is improved for use on a workpiece where flutings oriented in different directions or planes meet at a corner or intersection. In a first step the membrane and veneer are pressed by a single tool at the intersection, causing a bulge to form on either side of the tool; in the second step further tools are pressed down onto membrane and veneer to transform the bulges into a series of undulations. Finally, distributed pressure is applied to the membrane thus flattening the veneer onto the three-dimensional workpiece and forming the bonding. A neat fit of veneer onto a three-dimensionally shaped workpiece is obtained.

Description

Method and device for occupying a

Workpiece with recesses with a continuous decorative layer, especially a veneer Description The invention relates to a Method for covering a workpiece having grooves with a continuous one Decorative layer, in particular a veneer according to the preamble of claim 1 as well as a device for its implementation.

Such a method and a corresponding device is in the earlier application P 30 Ol 904.6 described. With the method according to the older one Registration can be the surface of a workpiece and at the same time also in this provided grooves running through to the edge of the workpiece very well when used only cover a single continuous decorative layer. However, if you want workpieces with curved or intersecting grooves using a single one If the decorative layer is to be covered continuously, this is only possible in the case of slightly curved recesses possible; in the case of more arched recesses or recessed recesses form in the joint area, i.e. at the point of penetration of the intersecting Fillets, or folds in the strongly curved sections of the fillets and bumps. The veneer is hollow in places, it can also be the formation of creases and the breaking of the veneer occur in the named places.

The present invention is intended to provide a method according to the preamble of claim 1 are developed so that even with more arched or receding Fillets in the joint area or more strongly curved fillet sections a clean covering of the workpiece .ke using a single decorative layer guaranteed both for the main surface and for the grooves of the workpiece is.

This object is achieved according to the invention by a method according to Claim 1.

In the method according to the invention, excess material is the Decorative layer away from the joint area or the curved area into adjacent ones Sections of the fillets depressed. This material initially forms corrugations, which then later, when the membrane is pressurized, compressing the material the decorative layer are permanently pushed away. This critical process of upsetting takes place in the vicinity and not directly in the method according to the invention in the joint area of the grooves, in which the material of the decorative layer, usually veneer, anyway, must be relatively strongly deformed in order for it to be adapts itself to the surface of the workpiece in a clean, form-fitting manner. In addition, that will Excess material of the decorative layer distributed on two sides, so that one in each of the resulting corrugations only with half of the excess material must be finished. The latter two effects contribute to the fact that one is now (For the first time the clean veneering of cassette parts for doors or furniture under Can use a single piece of veneer in a membrane molding press, while so far corresponding grooves have only been made using milled precious wood profile rods was able to produce cleanly shaped in the area of the penetration edges.

Advantageous developments of the invention are in subordinate Claims stated.

With the method according to claim 2 one can anisotropy of the the decorative layer material used. The excess material will predominantly displaced in the direction in which the decorative layer material easier can be compressed and compressed.

A device for carrying out the method according to the invention, as indicated in claim 3, on the one hand ensures the formation of a plurality small corrugations, which are arranged between the individual at a distance Form preforming tools and easily pushed away by applying pressure to the membrane can be, at the same time such a device can also be flexible and optional for a symmetrical or asymmetrical displacement of excess decorative layer material because the preforming tools are not mechanically coupled.

The preform tools can, for. B. more independent of the piston rods Compressed air working cylinder be worn, which has a freely programmable control can be pressurized in the desired sequence.

With the development of the invention according to claim 4 it is achieved that generated by the preform tool engaging at the penetration edge primary corrugations without opposing strong forces and without heavy material stress can be broken down into two smaller secondary corrugations. These can then be special easily pushed away by upsetting material. The development of the invention according to claim 5 serves the same purpose.

With the development of the invention according to claim 6 it is achieved that the decorative layer does not receive any sharp kinks due to the preforming tools which it tends to break. For the same reason, further training is also the Invention according to claim 7 advantageous.

A device according to claim 8 is particularly flexible and can using one and the same standard components for use the preforming tools for a wide variety of workpiece shapes. By the axial position of each of the preform tools can be ascertained when the considered preform tool with the relative movement between the frame-fixed Tool plate and the moving workpiece in contact with the membrane and the decorative layer comes. For different types of workpiece, only the tool plate needs to be specific adapted separate part are kept ready.

The tool plate can be set up and roasted very quickly make when the fixation of the spring cylinder on her as specified in claim 9 he follows.

In a device according to claim 10, the spring cylinders are in the tool plate well centered even after frequent changes; the centering does not need to be done via the external thread of the spring cylinder.

The development of the invention according to claim 11 enables a special easy adjustment of the axial position of the spring cylinder according to specified values, which are written, for example, at each of the receiving openings in the tool plate could be.

With the development of the invention according to claim 12, one becomes special receive great freedom in the design of the deformation dynamics of the decorative layer, because the various molds are too far apart Points of the press closing path brought into contact with the membrane and the decorative layer Nevertheless, only one spring cylinder that can be used in a uniform manner is required.

In a device according to claim 13 you can for the Pre-forming of membrane and decorative layer in the joint area between grooves or - in the case of curved groove sections, spring cylinders are also used for carrying of preform strips, which allow the membrane and decorative layer to be pressed in get into the straight fillets or fillet sections.

The invention is explained below with the aid of exemplary embodiments Explained in more detail with reference to the accompanying drawing. In this show: Fig. 1: a perspective view of a corner of a cassette-shaped workpiece; FIG. 2: the workpiece according to FIG. 1 after a piece of veneer has been placed on it; Fig. 3: that Workpiece shown in Fig. 2 after pressing down the corner of the veneer by a preform pin engaging in the joint area of the grooves; Fig. 4: the in Fig. 3 workpiece shown after the further deformation of the veneer piece in the joint area through further preform pins and preform strips; FIG. 5: the workpiece shown in FIG. 4 after pressing and upsetting the corrugations of the piece of veneer using a pressurized membrane of a membrane molding press; Fig. 6: a schematic Representation of the veneer preforming in the manufacturing steps shown in FIGS. 2 to 5; Fig. 7: a representation similar to FIG. 6, but with a manufacturing method is shown in which the displacement of excess veneer material is preferred takes place on one side of the joint area; Fig. 8: a plan view of a Cassette-shaped door panel with grooves all around; Fig. 9: a top view on a Werk'eugplatte for receiving preform tools, which are used for continuous Covering the door panel according to FIG. 8 using a single piece of veneer is used; FIG. 10: a longitudinal section through the tool plate according to FIG. 9 the line X-X there on an enlarged scale with preforming tools used; and FIG. 11: a schematic end view of a membrane molding press with a die plate 9 and 10, in which the membrane, an upper press plate and one of this worn sealing frame are shown in section and other press parts have broken away.

Fig. 1 shows a corner of a cassette-shaped rectangular workpiece 10 with two concavely curved grooves 12 and 14 running along the edges. These provide a concavely arched penetration edge 16 at their joint.

A continuous surface of the workpiece 10 is denoted by 18. A base 20 of the workpiece 10 is later used for clamping after veneering in a frame, e.g. B.

a door frame. The workpiece 10 is made of a chipboard by Milling of the grooves 12 and 14 made.

For reasons of manufacturing costs and the time required for large-scale production it is important that the surface 18 and the flutes 12 and 14 be used a common piece of veneer and can cover the grooves in one operation so does not have to veneer separately or by placing precious wood profile rods must produce.

To apply the veneer, first the surface 18 and the grooves 12 and -14 and possibly also the back of a piece of veneer 22 coated with adhesive. Then the veneer piece 22 is on the surface 18 launched. This state is shown in FIG. The size of the piece of veneer 22 is dimensioned so that the protruding over the surface 18 edges for covering the grooves 12 and 14 are sufficient.

Now the workpiece 10, which is not shown in detail in detail Glue joint and veneer piece 22 existing layer structure in a membrane molding press introduced in such a way that the tabran lies over the piece of veneer 22.

Various preforming tools are arranged behind this membrane, which the membrane and the veneer before the membrane is pressurized Pre-adjust to the shape of the workpiece before then pressurizing the membrane creates a 100% positive fit between the veneer and the workpiece will. For the sake of clarity, reference is made below to FIG FIGS. 3 to 6 show the preforming of the veneer by the preforming tools schematically explained without the membrane lying between these tools and the veneer is shown separately.

A first step in the preforming of the veneer is shown in FIG. A preform pin 24 with a spherical lower end portion is in the plane the penetration edge 16 has been driven from above against the veneer piece 22 until the latter is placed against the penetration edge 16.

Since the veneer piece 22 has a finite bending stiffness, it arises on both sides of the penetration edge 16 in each case a corrugation 26 and 28, whose Size in the drawing is exaggerated.

Fig. 4 shows the end of the veneer preform. More preform pins 30 and 32 have been moved down at the places where the corrugations 26 and 28 had their belly. Preform strips 34 and 36 have the protruding edges of the veneer piece 22 is pressed into the grooves 12 and 14. The corrugations 26 and 28 are now divided into two smaller corrugations 38, 40 and 42, 44, respectively. These four corrugations now contain all of the excess veneer material, which when pressing the edges of the veneer piece 22 from the initial plane in the roughly speaking frusto-pyramidal, predetermined by the grooves 12 and 14 Shape accrues.

If now the veneer piece 22 by applying strong pressure 3 and 4, not shown, lying between it and the preforming tools The membrane is pressed down against the workpiece 10, so the veneer material compressed in the area of the corrugations 38 to 44 and lays form-fittingly against the Recesses 12 and 14, as well as the edges of the veneer piece 22, which now occupy the recesses 12 to 14. This compression of material is proportionate small and is survived by the veneer material without damage.

The finished veneered workpiece is shown in FIG.

Slight local thickening of the veneer at the points which were previously the corrugations 38 to 44 are indicated by hatched veneer areas 46 indicated. They disappear when the grooves are then sanded over of the veneered workpiece completely.

Before this blending, about the base 20 are still protruding Parts of the veneer piece 22 separated with a sharp knife. You can see that the edges between the flutes 12 and 14 and the surface 18 and the penetrating edge 16- are also clearly reproduced in the veneered workpiece.

Fig. 6 shows the manufacturing steps using the same reference numerals according to FIGS. 2 to 5 again schematically in partial representations a) to d). These partial representations are side views of the workpiece and the preforming tools seen perpendicular to an angled coordinate x (see. Fig. 5). One recognises 6 shows the distribution of the excess veneer material particularly well four small corrugations, which then slightly by pressurizing the membrane can be pushed away under local material compression.

Many veneers can be folded lengthways and vertically these are compressed to different degrees.

As a rule, compression in the longitudinal direction of the fibers is only possible with larger ones Forces and to a lesser extent possible. It is advantageous to distribute accordingly also the excess at the joint between two intersecting grooves Veneer material asymmetrically on the two grooves, so that a larger one Share on the groove, which is perpendicular to the grain of the veneer runs or (in the case of grooves that are not perpendicular to one another or longitudinal direction of the fibers of the veneer not parallel to one of the grooves) this comes closer in the perpendicular direction.

A manufacturing process that takes this anisotropy of the veneer material into account will now be described with reference to FIG. 7, which, like FIG. 6, is a developed one Representation of the edge of the workpiece 10 and having the grooves 12, 14 of the preform tool assembly, also showing the angled coordinate x of Fig. 5 is used. Parts already described above correspond to parts are again provided with the same reference numerals.

Fig. 7a shows a workpiece 10 as the initial state again with a placed on it Veneer piece 22.

In Fig. 7b is against the part of the right in the drawing protruding edge of the veneer piece 22, the preform strip 36 and the preform pin 32 just moved in to prevent the veneer from buckling at these points 22 to prevent the formation of the corrugation 28 of FIG. 6 when the preform pin later 24 is lowered.

The preform strip 36 and the preform pin 32 thus serve in one first part of the veneer preform as a support for the veneer.

7c shows the shape of the veneer after the preform pin has been lowered 24 and at the same time slightly advancing the preform pin 32. To the left the penetration edge 16 has now formed a large corrugation 48.

Small corrugations 50 and 52 lie between the preform pin 24 and the preform pin 32 or the preform pin 32 and the preform bar 36.

In Fig. 7d, the preform pin 32 and the preform bar 36 are complete drove down. In addition, the pre shape pin 30, the compared to FIG. 6 shortened preform strip 34 and a further lying therebetween Preform pin 54 has been delivered against the corrugation 48 in such a way that you Path difference of the initial shape of the corrugation 48 takes into account. That is what happens Divide the corrugation 48 into smaller corrugations 56, 58, 60 uniformly at all locations.

7e shows the state after completion of the veneer preforming. Man recognizes that the excess veneer material with respect to the penetration edge 16 is distributed asymmetrically, namely in three larger corrugations 56, 58, 60 for Left and in two smaller corrugations 50, 52 to the right of the penetration edge 16.

In the next manufacturing step, which is shown in Fig. 7f Finished product leads, then the corrugations 50, 52, 56, 58 and 60 are pushed away, in each case without the veneer material being subjected to excessive compression or that the veneer is hollow in places or forms folds. The bigger ones Corrugations can therefore be pushed away without damaging the veneer because the veneer is compressed in the direction perpendicular to the grain, in which is given a higher compressibility.

Fig. 8 shows schematically a door panel 62 with one lying on the edge concave inwardly curved groove 64, two lying below in the drawing perpendicular to these adjoining grooves 66, 68 and one of their ends connecting curved groove 70. These grooves form at their joints arcuate penetration ridges 72, 74, 76 and 78. A center line of the grooves, on which the preforming tools are to be applied is shown in phantom in FIG reproduced at 80.

9 shows a tool plate 82 for receiving preform tools. The center line 80 is again drawn in dash-dotted lines as a reference line. at the corners of the center line 80 and in the vicinity thereof as well as at the curved ones Sections of the groove 70 are each counter-drilled receiving openings 84 for Preform tools provided. The actual preforming tools are load-bearing in these Spring cylinder 86 can be used, as will now be described in more detail with reference to FIG. 10 target.

The spring cylinder 86 have an external thread Housing 88 in which the spring chamber, not shown in detail, is formed and in which a plunger 90, which is biased outward by the spring, is guided. In the outside of the housing 88 is milled a groove 92, the bottom with a Setting scale 94 is provided. An upper thread runs on the external thread of the housing 88 knurled threaded ring 96 and a lower knurled counter-threaded edge 98. The The threaded ring 96 is positively seated in the counterbore 100 of the associated tool receiving opening 84 a; the counter-threaded ring 98 is fixed against the underside of the tool plate 82 screwed into the lower end of the plunger 90 can be a rounded print head 102 are screwed in; instead, a screw can be used at the end of the ram 104, a fastening section 106 of a preform strip 108 can also be fastened, the second end of which is correspondingly carried by another spring cylinder.

The spring cylinders 86 all have the same construction and the same fully extended position of the plunger 90. The time of engagement of the preform tool they carry (print head 102 or preform ~ bar 108) in the event of a relative movement between the tool plate and the workpiece is about the axial position of the Spring cylinder 86 on the tool plate 82 adjustable: the upper threaded rings 96 are adjusted using the setting scale 94 set to the desired path difference. This can be next to each of the receiving openings 84 is written on the top of the tool plate 82 be. Then the spring cylinders 86 together with those already attached to them Print heads 102 pushed through the receiving openings 84 from above.

The counter-threaded rings 98 are now placed onto the housing 88 from below and screwed against the underside of the tool plate 82. On those spring cylinders 86, which; To carry preform strips, the preform strips are now screwed on.

It can be seen that using the tool plate 82, as they -above has been described, the preform tools can be scaffolded very quickly and without errors can. A single universal type of spring cylinder is for the most diverse workpiece shapes usable. Only the tool board, which is also made from chipboard can be, since it only needs to absorb small forces, is for every type of workpiece to be made individually, but this does not cause great costs. Through different axial adjustment of the various spring cylinders one can see the dynamics of the veneer and membrane preforming is very easy to optimally match the respective groove geometry vote.

Fig. 11 shows schematically the arrangement of the tool plate 82 and of the preform tools carried by the spring cylinders 86 in a membrane molding press.

The tool plate 82 is attached to a support frame via stud bolts 108 110 attached, which is adjustable via threaded spindles 112 from an upper heated Press plate 114 is carried. On the press plate 114 is at the same time a Sealing frame 116 fastened in a fluid-tight manner. On the upper press plate 114 an elastic and flexible rubber membrane 120 is suspended via springs 118, which the sealing frame 116 and the set of preforming tools housed therein surrounds. The upper press plate 114 is in turn fixed from one behind the other Frame plates 122 carried by the press and penetrated through an opening 124 of the same.

A lower heated press platen 126 is off the piston rods 128 three press lock cylinders carried. Rests on it by strips or positioning pins the workpiece provided with the veneer piece 22 is aligned with the preforming tools 10, e.g. B. the door panel 62.

When the press is closed, the preforming tools come from the penetration edges 72 to 78 of the grooves progressively in contact with the membrane and veneer and create small corrugations in the vicinity of the penetration edges, as described in detail above. After the press has closed completely delimits the diaphragm 120 together with the upper press plate 114 and the sealing frame 116 a pressure chamber to which compressed air is applied via a line 130. The high pressure behind the membrane makes the membrane and veneer strong against it pressed the workpiece, the corrugations of the veneer compressing the veneer material be pushed away, as has already been described in detail above. After setting the press is opened again under the influence of pressure and heat and the finished veneered workpiece removed.

Claims (13)

Claims r>. $ 5). Method for covering a workpiece with grooves with a continuous decorative layer, in particular a veneer, in which a) the decorative layer with the interposition of an adhesive layer on the workpiece is applied, b) the layer structure thus obtained under a flexible membrane is placed and the membrane together with the underlying decorative layer underneath Use of preforming tools pressed into the grooves of the workpiece is, and c) the membrane is pressurized and the glue line under the pressurization thus obtained is caused to set, according to patent application P 30 ol 904.6, characterized in that in the case of a workpiece with intersecting Grooves or with curved grooves d) Membrane and decorative layer first in the area of the joint between the grooves or in the area of curvature a separate preform tool assembly are pressed against the workpiece and only afterwards in the area of the grooves themselves by further preforming tools are pressed against the workpiece, and e) when the membrane is pressurized Material of the decorative layer displaced into the area of the grooves under local Compression is brought into surface contact with the workpiece and in this state is glued to the workpiece. 2. The method according to claim 1, wherein the decorative layer is a veneer is used, characterized in that excess material of the veneer from the joint area between the grooves or the Curvature area the grooves is so asymmetrically displaced that a larger part of the excess Veneer material to that of the grooves or to that groove portion is displaced towards which or which of the two grooves or grooves is closest. Groove sections perpendicular to the grain of the veneer. 3. Apparatus for performing the method according to claim 1 or 2, characterized in that the separate preform tool assembly comprises a plurality having spaced preform tools (24, 30, 32, 54, 102) which can be moved independently of one another. 4. Apparatus according to claim 3, characterized in that a set of preforming tools (30, 32) is arranged at bulges of corrugations (26, 28), which are assigned to the joint area (16) or the area of curvature Preform tool (24) are generated. 5. Apparatus according to claim 4, characterized in that with the separate preform tool assembly (24, 30, 32) from the joint area (16) or the curvature area displaced material of the decorative layer in the area of the grooves (12, 14) each have a plurality of substantially equal corrugations (38 - 44) is generated. 6. Device according to one of claims 3 to 5, characterized in that that the preform tools (24, 30, 32) of the separate preform tool assembly pins have with a rounded end portion. 7. Device according to one of claims 3 to 6, there- by characterized in that the grooves (12, 14) themselves assigned preform strips (34, 36) on their facing area (16) or the bent area End have a rounded end section. 8. Device according to one of claims 3 to 7, characterized in that that the preforming tools (102) are carried by the same spring cylinders (86), which in different axial positions with a Werkzeagplatte receiving them (82) can be locked. 9. Apparatus according to claim 8, characterized in that the spring cylinder (86) have an externally threaded housing (88) on which two threaded rings (96, 98) engaging on different sides of the tool plate (82) to run. 10. Apparatus according to claim 9, characterized in that the upper (96) of the threaded rings in a complementary counterbore (100) of the receiving opening (84) of the tool plate (82) is seated. 11. The device according to claim 9 or 10, characterized against ~ draws, that in the outside of the housing (88) of the spring cylinder (86) one with a scale (94) provided groove (92) is milled. 12. Device according to one of claims 8 to 11, characterized in that that the spring travel of the spring cylinder (86) is a multiple of the height of the grooves (12, 14) is. 13. Device according to one of claims 8 to 12, characterized in that that with the ends of the plunger (90) of the spring cylinder (86) either pin-shaped print heads (102) or fastening sections (106) of preform strips (108) are detachably connected.