EP0885100B1 - Loading device for a plate press - Google Patents

Abstract

PCT No. PCT/DE97/02628 Sec. 371 Date Jul. 13, 1998 Sec. 102(e) Date Jul. 13, 1998 PCT Filed Nov. 11, 1997 PCT Pub. No. WO98/22268 PCT Pub. Date May 28, 1998A loading device for a plate press, composed of two loading supports which can be displaced perpendicular to a conveyance direction. Each loading support has at least one holding device with a conveyor belt which travels in the direction of conveyance. A workpiece to be processed is placed on the upper reach of the conveyor belt and is deposited by the conveyor belt in or on the press. The conveyor belt is moved in such a way that the relative speed of its upper reach in relation to a workpiece being conveyed is equal to zero for all states of movement of the assigned loading supports. As a result, no frictional movement occurs between the conveyor belt and workpieces being carried thereby.

Description

Field of the Invention

The invention relates to the field of processing workpieces in a plate press, especially the loading of this plate press for the production of tempered chipboard. Interested in this especially how to place such a workpiece, so for example the chipboard to be machined in the press, since the transfer from the feeder to the press must be done that the workpiece to be machined on the press occupies the most precisely defined position. Usually this will thereby achieved that the workpiece to be machined is not full-surface is placed on the press, but first with an edge and then with the other edge to create bubble-like effects avoid causing the workpiece to blur on the press lead and thus deteriorate the exact positioning mentioned or make it impossible.

Various systems are known to achieve this.

State of the art

DE 28 47 273 C3 is a generic loading device described, provided in the terminal blocks as holding devices are in the storage position of the workpiece to be processed opened and pulled outwards so that the workpiece down into the press (usually on the lower heating plate) can fall. The ones opened when the workpiece is placed down This should prevent or at least prevent friction from occurring can be minimized by providing additional casters on which the workpiece to be machined moves apart the loading spars are put down.

Another system (DE 35 03 156 C1) provides for additional ones Holding devices, e.g. Terminal strips to be omitted here the workpiece to be machined lies directly on the loading bars on which are provided with holes through which during of the transport process, the workpiece to be machined is sucked in and via the air flow during the depositing process upwards to the workpiece is blown so that the workpiece is on an air cushion swims.

From DE 39 14 866 a similar system is known, in which the Loading device consists of belt transports, which in the Press room are retracted so that the workpiece to be processed on the longitudinal edges of the belts of this belt transport system worn and promoted in the press. When dropping the Work piece in the press, the two conveyor belts pulled outside so that the workpiece is down on the lower heating plate can fall. To prevent the workpiece from the left or from the right conveyor belt due to uncontrolled friction one side or the other will be moved to the inside these conveyors rolls up so that the Friction between belt transport and workpiece is reduced. However, this system is very complex, since large masses (conveyor devices) need to be moved quickly, whichever is appropriate great acceleration with corresponding effort and suitable facilities are required for this.

From DE-A-28 25 206 a loading device is known with the help of which a layer package is placed in a hot press and removed again can. Two taped devices are used to carry out this process, the speed of the top of the tapes being either by a Motor drive or kept constant by jamming with respect to the press is so that the positioning of the layer package during the filing process remains fixed. This requires separate devices, for example a holder in the form of a suction bar or a separate motor for moving the Conveyor belt according to the extension speed.

The loading devices described have in common that despite of the additional facilities mentioned is insufficient or insufficient ensures that there is no sliding friction between the Workpiece and the one used for conveying and storing specific system that grips under the workpiece and this wearing. With the three systems mentioned at the beginning, it is necessary that the workpiece is always placed on one side, so that do not form air pockets on which the workpiece can blur. With all known systems, this has the consequence that the charging bars moved outwards one after the other when the workpiece was put down have to be, i.e. only then can the second loading spar its release movement begins when the first loading spar has already left the area of the workpiece and this with the corresponding edge has reached the press. This in turn means that the second loading spar is still the full release route must return to the other side of the workpiece on the lower To drop the heating plate. Depending on the machine effort to Allowing these processes to run as quickly as possible remains a certain time range in which the workpiece with its one edge area is in contact with the hot heating plate, whereas the other edge area still undercut by the second loading spar and held above the hot plate. Especially at specific machining processes, for example during pressing of resin-impregnated papers that form a layer package however, it is very desirable to minimize this period hold, since otherwise processes take place in this layer package (e.g. precondensation), that affect the uniform quality of the workpiece.

Subject of the invention

The invention is therefore based on the task, the generic Feed device so that when placing the Workpiece, for example a layer package on the heating plate, no sliding friction occurs, this feed device should continue be mechanically simple.

According to the invention, this object is according to the characterizing part of claim 1 solved.

By designing the holding devices as "small" conveyor belts it is guaranteed that no relative friction between the upper run of these conveyor belts and the bottom of each workpiece to be machined occurs, so that consequently none Incorrect positioning when placing the workpiece on the press may occur. According to a particularly advantageous development this solution is provided, these conveyor belts mechanically with the Coupling movement of the loading spars so that the peripheral speed the two pulleys that carry the conveyor belt, is chosen so that the movement of the loading spars upper run of the conveyor belts at the same speed in the opposite direction moves, so consequently the absolute speed a point on the conveyor belt and thus also the Relative speed, based on the workpiece at rest Is zero.

The solution according to the invention makes it possible in particular for the two To control loading spars so that when you put down the workpiece on the lower heating plate of the press cause that from the reasons described above required tilt-like laying movement the workpiece is laterally minimized on the press, so that the desired full-surface contact of the underside of the workpiece with the heating plate in the shortest possible time.

Brief description of the preferred embodiment :

Fig. 1

eine schematische Aufsicht auf die erfindunsgemäße Beschickungsvorrichtung,

Fig. 2

eine Teilaufsicht auf einen Eckbereich der Beschikkungsvorrichtung nach Fig. 1,

Fig. 3

einen Vertikalschnitt durch einen Teilbereich der Beschickungsvorrichtung,

Fig. 4

einen Vertikalschnitt durch die Presse mit der erfindungsgemäßen Beschickungsvorrichtung kurz vor dem Ablegen des Werkstückes auf der unteren Heizplatte und

Fig. 5

einen Vertikalschnitt entsprechend Fig. 4, beim Eintragen des Werkstückes in die Presse.

The solution according to the invention will now be explained with reference to drawings. Show it:

Fig. 1

2 shows a schematic view of the loading device according to the invention,

Fig. 2

2 shows a partial view of a corner area of the charging device according to FIG. 1,

Fig. 3

a vertical section through a portion of the loading device,

Fig. 4

a vertical section through the press with the loading device according to the invention shortly before placing the workpiece on the lower heating plate and

Fig. 5

a vertical section corresponding to FIG. 4, when entering the workpiece in the press.

Description of the preferred embodiment :

The loading device according to the invention is used for loading a press 10 (Fig. 4.5), of which only the lower part with the lower heating plate 1 is shown. To this lower heating plate should the workpiece 8 from its position outside the press promoted and stored there as precisely as possible. For this is initially a holding frame 2 is provided, which in its Press moved position to both sides of the lower heating plate 1 extends and on which the loading device with its individual Components is held.

The main components of this loading device are two slidable parallel to the long sides of the holding frame 2 Loading bars 3A, 3B. 1 is the loading spar 3A shown extended, i.e. it does not protrude the lower heating plate 1, whereas the loading handle 3B is retracted is shown, i.e. it protrudes over the lower heating plate 1. For guidance the loading bars 3A, 3B are in a known manner with the holding frame 2 connected by two tubes or rods R, which are stored in corresponding receptacles S of the holding frame. The rods R of the loading bars 3A, 3B contribute to their Inside the press pointing end holding devices on which the workpiece 8 to be machined rests when both loading spars are in the retracted position (Fig. 5), in the the workpiece 8 also from a loading station into the press 10 can transport.

The holding devices consist of several conveyor belts 4, the upper run over the feed bars 3A, 3B. For this is on the narrow side of the loading spars pointing outwards 3A, 3B, a deflection roller 4A is provided, on the one pointing inwards The end of the loading bars 3A, 3B are the conveyor belts 4 over a common drive shaft 5 out. To drive this Drive shaft 5 is a rack 6A, 6B at the front end 2A mounted with a gear 7A, 7B at the end of the drive shaft 5A, 5B combs. The function of this drive is illustrated in Fig. 3:

The diameter of the gear 7 is chosen so that the conveyor belts 4 against the movement of the loading spars 2 with the same Promote speed as the loading spars face outwards move so that the movement of the loading bars 3A, 3B to none Friction between the upper run of the conveyor belts 4 and Bottom of the workpiece 8 leads, regardless of which Speed or direction the loading bars move.

A typical sequence of movements of the loading device according to the invention is as follows:

First, the holding frame 2 is outside of the press in a loading station, where the loading bars 3A, 3B under the workpiece drive in to this from other conveyors, for example a roller conveyor.

Then the holding frame 2 is inserted into the press 10 until it occupies the desired position in which the workpiece 8 is above the lower heating plate 1 is held by the retracted Loading bars 3A, 3B, this position is in Fig. 5 shown.

Then the workpiece 8 is placed on the lower heating plate 1 in that the two loading spars with a slight delay 3A, 3B are extended (large arrows in FIG. 4), whereby according to the above-described positive coupling of the drive the conveyor belts 4 the upper run of these conveyor belts in the moves in the opposite direction (small arrows) with the same speed at which the loading bars extend be so that between the upper run of the conveyor belts on the one hand and the underside of the workpiece 8 no relative movement and thus can also form no friction. In the illustrated embodiment 4 the loading spar 3B hurries slightly ahead of the feeder spar 3A, so that the long side on the right in FIG. 4 of the workpiece 8 already placed on the lower heating plate 1 while the corresponding left side edge is still just in the End region of the conveyor belts 4 held above the heating plate 1 becomes. It can be clearly seen from FIG. 4 that with the corresponding Extension speed of the two loading bars Time between putting down the right side edge and putting it down the left side edge of the workpiece 8 is kept to a minimum can be.

The exemplary embodiment shown is for mechanical positive coupling the conveyor belts 4 with their associated loading bars 3A, 3B preferred the rack and gear combination described, however, it is just as possible to do this using a designed process Chain with sprockets or with belts and pulleys to reach.

Claims (4)

1. Loading apparatus for a plate press, comprising conveying means which engage beneath the workpiece (8) to be treated on both sides, for which purpose said apparatus has a fork-like supporting frame (2), which is displaceable in the direction of conveyance onto the plate press, and on which frame there are disposed two feed bars (3A, 3B) which are displaceable perpendicularly relative to the direction of conveyance and each have at least two retaining means (4A, 4B) whereby the workpiece is retained in the region of its two sides relative to the direction of conveyance and deposited into the plate press, characterised in that the retaining means comprise conveyor belts (4), conveying rolls or conveying rollers, which are disposed in the direction of displacement of the associated feed bars (3A, 3B), and on the upper runs of which belts/upper sides of which rolls or rollers the workpiece (8) rests in the position where the feed bars (3A, 3B) are retracted into the plate press, and in that the conveyor belts/conveying rolls/conveying rollers are mechanically forcibly linked to the movement of the associated feed bar (3A, 3B) in such a manner that the relative speed of the respective upper runs/respective upper sides, relative to the workpiece (8), is equal to zero in all of the positions of movement of its associated feed bar (3A, 3B).
2. Loading apparatus according to claim 1, characterised in that, for the forcible linkage, a toothed rod (6A, 6B) is provided which is attached to the front end (2A) of the supporting frame (2) of the feed bars (3A, 3B), and which meshes with a toothed wheel (7) which is securedly connected to the common drive shaft (5A, 5B) for the conveyor belts (4) of a feed bar (3A, 3B).
3. Loading apparatus according to claim 1, characterised in that the conveyor belts (4) travel on two guide rollers (4A, 4B) which are retained on each side of the associated feed bar (3A, 3B), one of said guide rollers sitting on the drive shaft (S).
4. Method of operating a loading apparatus for a plate press comprising conveying means which engage beneath the workpiece to be treated, and to which belong two feed bars which are displaceable perpendicularly relative to the direction of conveyance and which each include at least two conveyor belts/conveying rolls or conveying rollers as the retaining means, on the upper runs of which belts/upper sides of which rolls or rollers the workpiece (8) to be treated rests in the position where the feed bars (3A, 3B) are retracted, wherein the workpiece (8) to be treated is deposited in the press (10) in such a manner that the two feed bars (3A, 3B) are actuated with a time lag therebetween which is of such a magnitude that both feed bars (3A, 3B) extend virtually simultaneously, while the conveyor belts (4) of both feed bars (3A, 3B) engage beneath the workpiece (8).

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