ES2718257B2 - Device for supplying at least one powdery substance, particularly for presses for forming ceramic pieces - Google Patents

Description

DESCRIPTION

DEVICE FOR SUPPLYING AT LEAST ONE SUBSTANCE

POWDERED, PARTICULARLY FOR FORMING PRESSES

CERAMIC PIECES

TECHNICAL FIELD OF THE INVENTION

The present invention falls within the technical field of powdery substances supply and distribution devices for the manufacture of flat ceramic articles such as wall tiles and paving tiles that require press-forming of the raw material that compose them.

BACKGROUND OF THE INVENTION

In the manufacture of flat ceramic articles, such as tiles, slabs and tiles, it is common to use shaping presses that comprise a lower bed and an upper press cross, penetrating molds made up of two semi-molds, an upper male provided with a plurality of upper compaction punches, and a lower female with a matrix of housings or alveoli, also provided with a plurality of lower compaction punches, in which a raw or semi-processed powdery substance is arranged, such as earth or clay, to from which, by means of the pressing action of the punches, compacted pieces of a material called sponge cake are formed from that moment, which are subsequently subjected to further treatments, such as glazing, decoration and firing to obtain flat ceramic items corresponding finishes.

For the production of the compacted parts, the most homogeneous possible loading of the powdery substance in the cavities of the matrix is required in order to obtain a pressed body with a density with the least possible variations, since this later affects the quality of the article. corresponding finished ceramic. In industrial practice it is very difficult to achieve a totally homogeneous load in all the cells of the matrix of the female mold.

In a stage prior to compaction and molding, the powdery substance is stored externally and it must be supplied and distributed evenly on the matrix provided with housings or receiving cells of the female molds of the press.

For this, a filling hopper of the device for supplying and distributing the powdery substance is usually used, which comprises at least one mobile cart or conveyor provided with a supporting frame and various crossbars or projections to serve as a support and move on the mold matrix. what is usually called a grill (due to its similarity to said utensil), and various elements that are used in the process of manufacturing and obtaining the cake, such as, for example and additionally, one or more scrapers, combs or blades that serve as elements dragging excess of powdery substance that may remain on the surface of the female mold, and / or a pusher that in a previous position with respect to the grill with respect to a direction of advance horizontally pushes a previously shaped sponge cake, out of the area of the alveoli in which it has been pressed, leaving the latter free to receive a new charge of substance. to powdery.

The aforementioned grid essentially consists of a perimeter frame in whose internal area a grid of various shapes (parallel linear, grids ...) is arranged substantially the same or less height or thickness than that of said perimeter frame. This grill is incorporated to the mobile cart or conveyor from above and by means of various fitting or connection means, generally by means of clamps or claws with an inverted "U" shape, in such a way that the grill is held by the effect of gravity and removably fixed to the frame bearing.

In a first stage of manufacture, the grid and the conveyor cart are positioned horizontally and superiorly in an area immediately prior to the location of the first of the cells of the female mold matrix, and in said position the externally stored powdery substance is deposited and loaded on the grill; The lower part of the grill is completely supported and flush with the upper surface of the female mold matrix, with a finish or generally flat elements or preferably in the shape of an inverted "L", called scrapers among others. denominations, made of a resistant material capable of withstanding abrasion and friction inevitably derived from friction and sliding between surfaces in direct contact.

In a second stage, the conveyor car begins its movement and advances horizontal in a direction towards and over the location of all the cells of the female mold matrix, in such a way that it positions the grid completely on said cells, whose lower compaction punch is in a raised position and flush with the surface of the matrix of the female mold. Once said position is reached by the grid and its load of powdery substance, the lower compaction punch descends, allowing the powdery substance to enter the corresponding alveoli by gravity.

In a third stage, and when the load is supplied to the cells, the conveyor carriage starts a horizontal movement back to its initial position, during which there is a removal by dragging of the excess powdery substance deposited in the previous phase on the cells and protruding from its upper edge.

This stage ends with the arrival of the conveyor car and the grid to the initial starting position in the first stage.

The supply and distribution of the powdery substance is carried out by means of the dragging of the mobile cart or conveyor that moves the loaded grid to the mold matrix and the mere action of gravity on said substance, which is deposited in a single phase and in a joint over the entire surface of all the cells, and a subsequent dragging and sweeping movement of the mobile carriage over the mold matrix.

This determines that the load as the distribution of the powdery substance over the entire alveolus is of an irregular density and homogeneity, since at present it presents irregularities in the same alveolus, as a consequence of the different quantity and density of the powdery substance in a given point differs from that of another point, depending on the quantity and density of substance that has been placed on said grate in the previous process of loading the grill from external storage and in the first stage, and the fact that the transfer to the alveoli occurs in block and unit of time on all the alveoli and on their entire surface.

DESCRIPTION OF THE INVENTION

The object of the present invention is to overcome the drawbacks of the state of technique detailed above, by means of a device for supplying at least one powdery substance, particularly for presses for forming ceramic pieces, which dispenses with the conventional grid and replaces it with means that allow a progressive supply and gradual distribution of the powdery substance by means of a continuous flow by curtain in the alveoli throughout the aforementioned second stage and with the additional difference that instead of what is referred to with the conventional method in said second stage, according to the invention the lower compaction punches are in a position of rest from the beginning of the second stage, leaving the alveoli exposed to receive the conformal powdery substance and since the conveyor carriage and the device object of the invention start the advance in the second stage, and during the entire horizontal movement phase of the itself.

With all this, a practical advantage derived from said progressive, gradual and successive loading of the cavity of the alveoli is obtained, which produces a greater homogeneity of the density of the powdery substance that remains deposited therein in a more uniform and controlled way, with a better result of the subsequent compaction to which said substance will be subjected.

BRIEF DESCRIPTION OF THE FIGURES

Aspects and embodiments of the invention are described below on the basis of schematic drawings, in which

Figure 1 is a top perspective view of the device object of the invention;

Figure 2 is a top plan view and side elevations of the device object of the invention;

Figure 3 is a top perspective view of the progressive discharge means comprising the device object of the invention and an explosion of some parts thereof;

Figure 4 is a top perspective view of the external perimeter support frame or frame of the device object of the invention, of various elements that it comprises, and an explosion of some parts thereof;

Figure 5 is a top perspective view of the device object of the invention and of a pusher comprising in one of its embodiments in position prior to it with respect to a direction of advance (A);

Figure 6 is a schematic section in side elevation of a press for forming ceramic pieces in which the device object of the invention is positioned in the first manufacturing stage;

In these figures there are references that identify the following elements:

A direction of advance

1 rack

2 receptacle

3 longitudinal linear strips

4 upper mouth of the receptacle

5 bottom outlet of receptacle

6 mounting plates for the receptacle

7 outer ribs of the receptacle

8 means of locking and unlocking the coupling plates 9 pusher

10 scrapers

11 longitudinal linear scraper inside the frame

12 plate

13 closing or lid elements

14 grooves in the upper receptacle mouth

15 through element for immobilization of the strips

16 claws or clamps

17 hopper filling device

18 upper male mold

19 lower female mold

20 press bench

21 press traverse

22 alveolus

23 longitudinal linear element of the free end of the tappet

MODES OF CARRYING OUT THE INVENTION

The device object of the invention is intended to be used in presses for the shaping of ceramic pieces that comprise at least one mobile carriage or conveyor provided with a supporting frame and various cross members or projections to serve as support and move the lower female mold die ( 19) the device itself that is the object of the present invention and other additional elements. The device for supplying at least one powdery substance, particularly presses for the shaping of ceramic pieces, the embodiment of which is shown in Figure 1, comprises a frame (1) or external perimeter frame that serves as a support inside to different elements, which are used in the process of manufacturing and obtaining the cake, such as, for example and additionally, one or more scrapers, combs or blades that serve as drag elements for excess powdery substance that may remain on the surface of the lower female mold (19), and / or a pusher that is in a anterior position with respect to the grid with respect to a direction of advance (A) of the device during its operation in the shaping press.

Inside said frame (1) there are, among others, means of progressive discharge of at least one powdery substance, configured in one or more receptacles (2), four in the embodiment shown in figure 1, which They have an upper mouth (4) with a substantially rectangular area, a lower mouth (5) whose surface is smaller than that of the mouth (4), an inverted truncated-pyramidal shape, and a height greater than the thickness or height of the frame ( 1). Said receptacle (2) or receptacles can be removable according to the embodiment shown in the figures. For this, the receptacle has connection means such as external ribs in its lower external part, in correspondence with grooves in some hooking plates (6) arranged inside the frame (1). Said hooking plates (6) in turn may have means for locking and unlocking their position and are horizontally movable on the inside of the frame (1) in order to be able to locate the receptacle (2) in different positions and enable, for example, , the use and parallel adjustment of several receptacles with different sizes of mouth (4).

The frame (1) comprises coupling means to an external conveyor element that moves the device object of the invention in the shaping press, which can be configured as shown in Figures 1 and 2 in the form of claws or clamps in the form of "U" inverted in various locations of the outer saying of said frame (1). Likewise, and according to the embodiment shown in figure 4, the frame (1) internally comprises hooking plates (6) for the receptacle (2), additional fastening means for scraping elements (11) arranged inside the frame ( 1) and in a position behind the receptacle or receptacles in a forward direction (A), to reinforce the scavenging and elimination of excess powdery substance during the operation procedure of the device in the shaping press, as well as upper closing or lid elements (13) intended to prevent the unwanted or accidental entry of powdery substance into certain areas of the device object of the invention.

The device object of the invention, the embodiment of which is shown in Figure 3, may comprise one or more longitudinal strips (3) in the mouth (4) of the receptacle (2), which are removably fixed in respective grooves (14) made in the upper ends of the mouthpiece (4), and contribute to a better distribution of the powdery substance inside the receptacle (2). In turn, said strips (3) can be immobilized with each other by means of a through element (15) that interconnects them with each other and immobilizes them in the body of the receptacle by means of threaded fastening elements that fix the through element (15) on the outside of the sides of the mouth (4) of the receptacle (2), to avoid the accidental exit of the strips (3) from the grooves (14) and also keep them equidistant from each other in their central area, for which the through element at its On the other hand, it can incorporate intermediate separating elements of greater section or diameter than the connection through holes, in such a way that they keep the strips (3) in the same position relative to each other despite the forces that may affect them during the procedure. operation of the device in the forming press.

The device object of the invention according to the embodiment shown in figure 3, incorporates in the lower mouth (5) of the receptacle (2) scraping perimeter elements (10), some or all of which have a section in the form of " L "inverted or" V "; They comprise a material capable of supporting friction and serve the purpose of adjusting and closing the perimeter of said outlet (5) with the surface of the lower female mold (19); Said scrapers (10) comprise a plate (12) preferably removable to facilitate replacement due to wear, to which the mentioned material capable of supporting friction, said material including, for example, polymers is integrally attached.

In the embodiment illustrated in Figure 5, the device object of the invention comprises a pusher element (9) with a depth equal to or greater than that of the frame (1), located outside said frame (1) and in a anterior position with with respect to a direction of advance (A). Said pusher (9) has frontally at its free end at least one longitudinal linear element (23) whose purpose is to successively move the compacted pieces or cake already shaped out of the shaping press, once each third stage of operation of the object device is finished of the invention in the shaping press, for which once said third stage is finished, the lower compaction punches rise to expose said compacted pieces or cake to the advancement of the device during an initial stage of the second stage, and then they descend for the phase of supplying and distributing powdery substance to the alveoli (22) which takes place during said second stage progressively as the device advances over each part of the cavity of the alveoli (22).

The device object of the invention whose embodiment is shown in figure 6 is fed from a filling hopper (17) that pours into it from an external storage at least one powdery substance, and once loaded onto the device it begins its advance In a shaping press comprising a lower bed (20) and an upper press cross (21), penetrating molds made up of two semi-molds, an upper male (18) provided with a plurality of upper compaction punches, and another lower female (19) with a matrix of housings or alveoli (22), also provided with a plurality of lower compaction punches, in which the device object of the invention supplies and distributes at least one powdery substance, from which by means of the subsequent pressing action of the punches, compacted pieces of the material called sponge cake are formed, which are subsequently subjected to treatments such as enamel tado, decoration and firing to obtain finished ceramic articles.

The closure or cover element or elements (13) can be removable, comprise one or more plates and present an "L" shaped section.

A method has also been provided for the operation of a device according to the embodiment described in a press for forming ceramic pieces, which comprises a first stage in which a conveyor carriage is positioned horizontally and superiorly in an area immediately prior to the location of the first of the cells of the matrix of the female mold, and in said position an externally stored powdery substance is deposited and loaded onto the powdery substance supply and distribution device; In a second stage, the conveyor carriage begins its horizontal movement and advance towards and over the location of the cells of the female mold matrix, in such a way that it gradually and successively positions the device for supplying the powdery substance on different parts of said cells. , and a third stage, in which the conveyor carriage begins a horizontal backward movement to its initial position, during which there is a removal by dragging of the excess powdery substance deposited in the previous phase on the alveoli and protruding from its top edge; said stage ends with the arrival of the conveyor carriage and the device for supplying and distributing the powdery substance to the initial starting position in the first stage, and where the lower compacting punch or punches of the press are in a lowered position at least from the phase of the second stage immediately prior to the first superposition of the mouth (5) of the receptacle (2) or receptacles on it or the cells (22), in such a way that the entry and distribution of the pulverulent substance in the corresponding alveoli (22) progressively, gradually and successively due to the combined effect of gravity and the horizontal displacement of the supply device, and a supply of said pulverulent substance by means of a constant flow by curtain.

In accordance with the foregoing, the present invention overcomes the drawbacks of the state of the art referred to above and provides an evolutionary alternative by means of an improved device and a method for the operation of said device.

Claims (14)

1. Device for supplying at least one powdery substance, particularly for presses for the shaping of ceramic pieces, of the type comprising at least one frame (1) or an external supporting perimeter frame comprising - means of progressive discharge of at least one powdery substance; - the progressive discharge means of at least one powdery substance comprise at least one receptacle element (2) with an upper mouth (4) and a lower mouth (5); - the upper mouth (4) and the lower mouth (5) of the receptacle (2) have a substantially rectangular area; the mouth (4) of the receptacle (2) has a larger surface than the lower mouth (5); -the receptacle (2) has a height that is between 40 and 150mm and is greater than the thickness or height of the frame (1); -the receptacle (2) has a substantially inverted frusto-pyramidal shape. characterized because -the receptacle (2) is removable and immobilized inside the frame (1) or external supporting perimeter frame, -in the internal part of the frame (1) or external support frame, there are hooking plates (6) for the receptacle (2), -the hooking plates (6) for the receptacle (2) have grooves in correspondence with ribs (7) on the outside of the receptacle (2), -the hooking plates (6) for the receptacle (2) are horizontally movable and comprise locking and unlocking means (8) for their fixation at any point of the horizontal plane in which they move. 2. Device according to claim 1, characterized in that -the mouth of the receptacle (2) comprises one or more linear longitudinal strips (3) removable and immobilizable in the mouth (4) of the receptacle (2), -the removable strip or strips (3) are fixed by corresponding grooves (14) at the ends of the mouth (4) of the receptacle (2), -the removable strip or strips (3) are immobilized by a through element (15) that connects said strip or strips with the sides of the mouth (4) of the receptacle (2), -the lower outlet (5) of the receptacle (2) incorporates one or more scraping perimeter elements (10) comprising a material capable of supporting friction, - at least one perimeter scraper element (10) comprises a plate (12) and the longitudinal linear element (23). Device according to claim 1, characterized in that the material capable of supporting friction is fixed integrally to the plate (12). Device according to the preceding claims 1 to 3, characterized in that at least one material comprising the perimeter scraper element or elements (10) is a polymer. Device according to claim 4, characterized in that the scraping perimeter element or elements (10) are removable. Device according to claim 5, characterized in that the perimeter scraper element (s) (10) comprise holes in correspondence with other holes included in the lower opening (5) of the receptacle (2) for their interconnection and fixing by means of through elements, particularly screws. or rivets. Device according to any of the preceding claims, characterized in that it comprises a pusher element (9) with a depth equal to or greater than that of the device as a whole, located outside the frame (1) and in an anterior position with respect to a direction of advance (A), which frontally presents in its free end a longitudinal linear element (23). Device according to any of the preceding claims, characterized in that the receptacle (2) comprises at least the longitudinal linear scraper element (11) located inside the frame (1) in a position posterior to the receptacle (2) with respect to a sense of advance (A). Device according to claim 8, characterized in that the scraper (11) is removable and is immobilized inside the frame (1). 10. Device according to any of the preceding claims, characterized in that at least a part of the interior area of the frame (1) comprises one or more closing or cover elements (13). Device according to claim 10, characterized in that the closure or cover element or elements (13) is removable. 12. Device, according to preceding claims 10 or 11, characterized in that the closing or cover element or elements (13) comprises one or more plates. 13. Device according to claim 12, characterized in that the plate or plates of the closing element or cover (13) has an "L" -shaped section. 14. Procedure for the operation of a device according to any of the preceding claims in a press for forming ceramic pieces, comprising a first stage in which a conveyor carriage is positioned horizontally and superiorly in an area immediately prior to the location of cells of a die of a female mold, and in said position an externally stored powdery substance is deposited and loaded onto a powdery substance supply and distribution device; In a second stage, the conveyor carriage begins its horizontal movement and advance towards and over the location of the cells of the female mold matrix, in such a way that it gradually and successively positions the device for supplying the powdery substance on different parts of said cells. , and a third stage, in which the conveyor carriage begins a horizontal backward movement to its initial position, during which there is a removal by dragging of the excess powdery substance deposited in the previous phase on the alveoli and protruding from its top edge; said stage ends with the arrival of the conveyor carriage and the device for supplying and distributing the powdery substance to the initial starting position in the first stage, characterized in that a lower compacting punch or punches of the press are in a lowered position at least from the phase of the second stage immediately before the first superposition of the lower outlet (5) of the receptacle (2) or receptacles on it or the cells (22), in such a way that the entry and distribution of the powdery substance in the corresponding alveoli (22) progressively, gradually and successively due to the combined effect of gravity and the horizontal advance displacement of the supply, and a supply of said powdery substance by a constant curtain flow.