FR2618094A1 - Process for the manufacture of moulded products and moulding plant enabling the said process to be used - Google Patents

Abstract

The invention relates to a process for the manufacture of moulded products and to a moulding plant enabling the process to be used. It will find its application especially in the field of building and construction for the moulding of cement-based structural products such as breeze blocks or other similar formed products. The pressing plant 1 for such products comprises at least: - a feeding device 18, 19 of mouldable material, - a moulding device 16 which has at least one mould 20 whose lower face 22 is open, and a mould reception table 25, - a set of plates for handling 14 moulded products, - a vibration device 17 whose upper part forms the reception table 25 which is horizontally retractable under the action of the handling plates 14. According to the process of the invention: - the products are moulded on the reception table 25, - a handling plate 14 is then substituted for the said reception table 25, - finally, the said product(s) obtained is(are) demoulded on the said plate 14.

Description

 The invention relates to a process for manufacturing molded products as well as to a molding installation authorizing in particular the implementation of said process.

 The invention will particularly find its application in the field of construction and building for manufacturing construction products of cement-based forms such as blocks commonly called concrete blocks. or other products. however, the invention may be applied to other fields where the same specific molding problems are found.

 Nowadays, the manufacture of such molded elements is becoming more and more mechanized and automated in order to increase production and reduce the cost price of such products. Thus, systemized installations are known which include in particular an actual molding station which makes it possible to obtain fresh molded products from the raw material, a drying station in which the fresh molded products are stored until they set, and finally a so-called palletizing station "in which the dried molded products are taken up to group them in particular on handling pallets.

 Different transfers between the stations are also carried out automatically, in particular by means of handling ferries or all other transport systems adapted to the products and the location of the different work stations.

 The heart of such an installation for manufacturing molded products is the actual molding installation. In this regard, various types of installation are known but are not entirely satisfactory in terms of the long-term reliability of the installation.

 One type of known molding installation consists essentially of a hopper for supplying moldable materials.

one or more molds whose shape corresponds to the products to be produced, a movable dispensing drawer which allows, by a back and forth movement, to feed the mold from the material contained in the feed hopper, a pestle compaction as well as a vibrator which make it possible to give the molded products a significant compactness in order to increase their mechanical resistance.

 In this type of installation, flat wooden planks are generally used on which the products are molded directly. In this regard, these boards are placed directly under the mold during molding. Then, after demolding, the fresh products are also kept on these same wooden boards and stored in the said drying areas.

 One of the particular problems of this type of installation comes precisely from these wooden boards constituting on the one hand the bottom of the mold and on the other hand serving after demolding by the handling of fresh products.

 In fact, during the implementation of the process for manufacturing molded products, the boards receive numerous mechanical shocks generated in particular due to the abrasion of the moldable material, vibrations, and pressures exerted on the boards at the time of molding.

 However, the life of the boards is very limited, and they must be replaced frequently periodically to obtain a product always of good quality, the latter depending in particular on the flatness and the mechanical condition of said wooden boards.

 In addition, frequent replacement of the boards significantly increases the cost price of the molding installation and consequently of the molded product.

 The object of the present invention is to provide a method and an installation for manufacturing molded products, in particular intended for construction, the products being for example made from cement, such as concrete blocks or other similar shaped products, which use as handling plates, in particular traditional wooden boards, but which, thanks to the specific steps of the present invention, make it possible to prevent premature wear of said boards while giving better results in terms of the quality of the molded product.

 One of the aims of the present invention is to propose a process for manufacturing molded products in which the molding is not carried out directly on the board which will be used for handling, this making it possible to increase their longevity because it does not cash more mechanical forces during the manufacture of the molding of the product.

 Another object of the present invention is to provide a method of manufacturing molded products in which the molding is not carried out, as traditionally, on the wooden board, which makes it possible to have better vibration during compaction.

in particular by eliminating the damping effects due to the said wooden board.

 Another object of the present invention is to provide a molding installation, in particular authorizing the implementation of the method for manufacturing molded products of the invention, the cost of which is significantly reduced due to the increase in duration. life of handling plates.

 Another object of the present invention is to provide a molding installation which can on the one hand be supplied with handling plates, for example from the front, and on the other hand which allows the evacuation of the products molded on the said plate by the same side, that is to say also from the front.

 Thus, we will decrease the complexity of making 1 installation and we will also allow easier maintenance of the installation, access from the rear then being cleared.

 Other objects and advantages of the present invention will appear during the description which follows which is however given only for information and which is not intended to limit it.

According to 1 invention, the method of manufacturing molded products, in particular of cement-based construction, such as blocks commonly called concrete blocks or other products, in particular used in a plant for pressing such products comprising at least
- a molding device, having at least one mold, the underside of which is open, and a mold receiving table,
- A set of handling plates for molded products, said process is characterized by the fact that one or more products are obtained by placing the mold on the receiving table so that it is in direct contact with the underside of the mold, and that at the end of the molding phase, a handling plate is substituted for said receiving table and then the product (s) obtained on said plate are removed from the mold.

The molding installation, in particular authorizing the implementation of the process for manufacturing molded products according to the present invention, comprising at least
- a device for supplying moldable material,
a molding device having a mold, the lower face of which is open, and a compression pestle cooperating with said mold,
- A vibration device having a vibration table, is characterized in that said vibration table substantially constitutes said mold reception table.

 The present invention will be better understood on reading the following description accompanied by the drawings which form an integral part thereof.

 Figure 1 schematically shows a top view of a complete installation for manufacturing molded products, in particular of cement-based construction such as concrete blocks, which essentially comprises a molding station, a drying station and a palletizing station.

 FIG. 2 shows a schematic front view of the molding station in FIG. 1.

 FIG. 3 shows a profile view of the molding device as shown in FIG. 2.

 FIGS. 4a to Xe successively show the different characteristic phases of the process for manufacturing molded products according to the present invention implemented in the molding station as notably shown in FIGS. 2 and 3.

 The present invention relates to a process for manufacturing molded products as well as a molding installation allowing the implementation of said process.

 The invention will in particular allow the molding of cement-based construction products, such as concrete blocks or other similar shaped products. However, one could consider using the present invention on the one hand in other fields where molding poses similar problems and / or on the other hand with other moldable materials than cement.

 Figure 1 schematically shows the top view of a complete installation for manufacturing molded products. The example shown applies in particular to concrete blocks.

Such complete installations of this type are currently known to those skilled in the art. The present invention relates essentially to the actual molding station which integrates perfectly into installations of known type,
The general installation in FIG. 1 shows the different work stations, namely, in 1: the actual molding installation, in 2: the product storage and drying area, in 3: a palletizing plant for dried molded products.

 The various transfers between stations 1, 2 and 3 are carried out by a ferry on the ground; which allows in particular to take the fresh molded products out of the molding station 1 and then place them on the drying area 2. This ferry also allows when the products are dry, to take them back from this storage area to direct them towards the palletizing machine 3.

 Furthermore, between the molding installation 1 and the axis of the ferry 4, a handling system 5, which in particular allows the conveying of the fresh products which have just been molded, is completed by an elevator device 6, which makes it possible to place the different products in a column according to a technique known to those skilled in the art.

 Similarly, the palletizing device 3 is connected to the transporter (by a conveyor 7, terminated by a descending device 8 whose operation is similar to the above-mentioned device 6 but reverse.

 The pallets are removed from the device 3 by a conveyor 9 constructed using techniques known to those skilled in the art. This conveyor 9 therefore sends the pallets formed with the dried molded products for storage and dispatch thereof.

 Finally, at the output of the palletizing device 3, a recovery system 10 is also provided for handling plates, which, it should be remembered, are used to authorize the handling of fresh products from item 1 to the palletizing item 3, via the drying area 2.

 This post. provided according to the techniques known to 1 person skilled in the art, in particular makes it possible to clean the handling plates, then to turn them over and place them in a waiting store 11 from which they will then be removed for the needs of the installation molding 1 and directed towards them via the conveyor 12.

Said general installation as illustrated in Figure 1 allows in particular the course of the following cycle
- molding of fresh products in the molding installation 1,
- handling of fresh products 13 on a handling plate 14 via 1 conveyor 5 to the lift device 6,
- recovery of this elevator 6 when it is completely filled by the transporter 4 and storage of the said products in the different spans of the storage area 2,
- recovery of products when they are dry in storage area 2 by the ferry 4,
formation of pallets of dried molded products, the boards 14 on which the dry products 15 are then placed are taken up one by one by means of the elevator 8 and directed by the conveyor 7 to the palletizing device 3,
- evacuation of the pallets formed by the conveyor 9,
- recovery of the boards 14 at the level of the device 10 and put on hold in the store 11 for a future use; these are then recycled via the conveyor 12.

 That said, the area which we are concerned with concerns the molding installation 1 proper and its operating process, which is why we will describe it in more detail. The details of the other positions, being generally known to those skilled in the art, are outside the scope of the present invention.

 Figures 2 and 3 schematically show an installation 1 for molding products, in particular cement construction products such as concrete blocks, which comprises at least one molding device, a vibration device 17, a set of product handling plates 14 mold.

 In addition, to allow the supply of molded material from the installation 1, the latter comprises a feed hopper 18 and a distribution slide 19 which will allow the moldable material to be brought to the molding device 16.

 The molding device 16 has at least one hollow mold 20 whose internal volume corresponds to the product to be molded. In this regard, the mold can allow the production of one or more products simultaneously according to the dimensions of the latter. In addition, the mold 20 consists of closed side walls and has an upper face 21 and a lower face 22 open.

 Furthermore, the molding device 16 will also have a compression pestle 23 which will in particular be able to move vertically along the arrows 24 so that it can penetrate into the mold 20 by its upper face 21 and slide in the mold to compact the moldable material.

 As regards the vibration device 17, it has at least one vibration table 25 actuated by any means of known vibrating system such as striker, motorized mechanical vibrator. Additional characteristics of the vibration device will be described later.

 According to a characteristic of the present invention, said vibration table 25 constitutes substantially the mold reception table. In this regard, it will have a surface adapted to the lower open surface 22 of the mold 20 and will constitute the closing plate of the mold, in other words the bottom of the mold.

 As regards the handling plates 14 of the molded products, they will advantageously consist of wooden boards for example. These will be brought by the spotted conveyor 12 and then evacuated by the identified conveyor 5.

 With regard to the supply of moldable material, this will be kneaded beforehand and then contained in the supply hopper 18, the lower face of which will have a controlled hatch to allow the material to slide as required.

 Under this hatch will be disposed the distribution drawer 19 which will be advantageously mounted to slide horizontally on a plate 26 and controlled by a drive member 27 so that the drawer 19 performs a back and forth movement between the hopper 18 and the open face 21 upper part of the mold 20 to supply it with moldable material. Such devices are also known to those skilled in the art.

 The various structural elements of the molding installation 1 having been specified in particular, let us now examine the different stages of the process for manufacturing molded products according to the present invention.

 The mold 20 is placed and applied on the reception table 25, in other words the upper part of the vibration device 17, so that the latter is in direct contact with the lower face 22 of the mold. Then, the product (s) to be obtained are molded directly on the reception table.

 At the end of the molding phase, a handling plate 14 is substituted for said receiving table 25 and then the product (s) obtained on said plate 14 are removed from the mold.

As regards the actual molding phase, it is carried out in a traditional manner, that is to say in particular:
by filling the mold 20 with moldable material via the feed hopper 18 and the distribution slide 19,
- by vibrating the mold 20 to facilitate the introduction of the moldable material into the mold by means of the vibration device 17,
- By compacting the moldable material in the mold 20 by vibration and action of the compression pestle 23 by making it penetrate at the upper face 21 of the mold and then maintaining a contact pressure with the material.

 Thus, thanks to the present invention, unlike traditional methods in which the handling plate 14 serves as the mold base, said products are directly molded on the receiving table 25 whose surface is adapted for this purpose.

 Better quality of the product is thus obtained by increased vibration due to the absence of the handling plate during molding and the life of the plates is increased, which no longer withstand compression and other forces during molding.

 In fact, according to the present invention, it is only after molding, vibration and compaction of the products that the handling plate 14 is replaced by the reception table 25, table 25 which has undergone all the efforts and which is provided for. this effect without considerably increasing the cost of the installation.

 To replace the table 25 with the plate 14, according to the present invention, at the end of the compaction phase, the compression pestle 23 is kept in contact with the molded product contained in the mold 20 and the 'compression effect to facilitate substitution and pressure on the mold 20 which had the role of applying the mold 20 on the table 25 and compressing the receiving table 25 on the vibrating table 17, before the molding phase.

 Furthermore, prior to the substitution of the receiving table 25 by the handling plate 14, the vibration is stopped at the end of the compaction phase.

 As regards the said product reception table, we have seen that the upper part of the vibrating table 25 was used. In addition, this reception table 25 is mounted on elastic means shown diagrammatically in FIGS. 4 by the pins 28 acting in the opposite direction of the compression force of the pestle 23.

 More specifically, the vibrating table is mounted on suspension pads which, once released by the mold 20, raise the assembly of the receiving table, mold, products and pestle. The tables are then transferred without significant effort.

 FIGS. 4a to 4e show the different successive phases of the substitution of the receiving table 25 by the handling plate 1i, after the compacting phase, to rest the fresh products 13 which have just been molded on said plate 14 and authorize their handling traditionally.

 To allow this substitution, the receiving table 25, substantially constituted by the upper part of the vibration device 17, has means for retracting under the action of the handling plate 14.

 Furthermore, the reception table 25 also has means for guiding horizontal translation.

 With regard to the production of said retractable means and of said guide means, these will be produced according to traditional methods of sliding organs known to those skilled in the art.

 FIG. 4a schematically shows the mold 20, the vibration device 17, the receiving plate 25 and the handling plate 14 respectively positioned with respect to each other during the molding and compacting phase.

 At the end of the compacting phase, the effect of the pestle 23 is released and the molded product is decompressed. This will allow the substitution of the receiving table 25 by the handling board 14, as shown in FIG. figure ib, by reducing the effects of friction.

 This substitution is caused by the translation of the handling plate 14 which pushes the receiving table 25 in the opposite direction to disengage it from the vibrating table and insert the handling plate 14 between the mold and the vibration device 17.

 In this respect, to facilitate substitution, the handling plate 14 has a thickness substantially identical to that of the retractable receiving table 25 and an area sufficient to close the lower open face 22 of the mold 20.

 FIG. 4c shows the release of the fresh product 13 from the handling plate 14. During the release phase, the pestle 23 is held in position and there is vertical sliding of the mold 20 relative to the latter.

 Figure Ad shows the fresh product 13 removed from the mold, the pestle 23 and the mold raised. From this moment, the handling plate 14 supporting the fresh product or products 13 can be removed from the machine. For this, the reception table 25 is actuated so that it can return to its initial position above the vibration device 17. It is moved in a reverse movement to that of the substitution phase.

FIG. 1e shows the phase of evacuation of the handling plate 14 on the conveyor 5, the return to the initial position of the plate 25 and the return of the mold 20 in direct contact with it,
Thanks to the process of the present invention and to the installation for implementing the said process, the molding, proper, of the products is therefore carried out independently of the traditional handling plates. Thus, a better result is obtained and the lifespan of the handling plates is increased, which is why they can advantageously be made of wood without prejudice to their longevity. However, any other material could also be considered.

 Furthermore, another advantage of the present invention resides in the maintenance and troubleshooting of the machine made easier by the fact that the admission of handling plates and their evacuation with fresh molded products are done in the same way. side of the molding installation.

 In this regard, the molding installation 1 comprises a device for supplying handling plates 1s, capable of placing a handling plate 14 under the mold 20 at the front of the installation, then capable of extracting from the front. of the installation, the said handling plate 14 on which the molded products 13 have been removed from the mold.

 it should be noted that, during the admission of the handling plates 14 under the product which has just been molded, the reception table 25 retracts towards the rear of the molding device 20 as is particularly illustrated in Figures 4b to d.

 Naturally, other implementations of the present invention, within the reach of those skilled in the art, could have been envisaged without departing from the scope of the invention. In particular, those skilled in the art will adapt the devices known in the field according to the needs and criteria of the method of the invention.

Claims (10)

 1. Method for manufacturing molded products, in particular cement-based construction, such as blocks commonly called concrete blocks or other products, in particular used in a pressing installation (1) of such products comprising at least  a molding device (16) having at least one mold (20) whose lower face (22) is open, and a table for receiving (25) the mold,  - A set of handling plates (14) of the molded products, process characterized by the fact that the product (s) to be obtained is molded by placing the mold (20) on the receiving table (25) so that the latter either in direct contact with the underside of the mold (22), and at the end of the molding phase, a handling plate (14) is substituted for said receiving table (25) and then the mold is removed from the mold or the said products obtained on the plate (14).  2. A method of manufacturing molded products according to claim 1, the molding device (16) further comprising a compression pestle (23) adapted to penetrate at the upper face (21) of the mold (20) and to slide. in this, the molding of the products being carried out in particular by filling the mold (20) with moldable material and then compacting the material in the mold (20) by the action of the compression pestle, characterized in that at the after the compaction phase, the compression pestle (23) is kept in contact with the molded product contained in the mold (20) and the compression effect and the pressure on the mold 20 are stopped to allow the substitution of said table (25) by said plate (14).  3. A method of manufacturing molded products according to claim 2, characterized in that the receiving table (25) is mounted on elastic means (28) acting in the opposite direction of the compressive force of the pestle (23) .  4. A method of manufacturing molded products according to claim 1, the molding installation (1) further comprising a vibration device (17) having a vibrating table (25), characterized in that one uses as table product reception the upper part of the vibrating table (25).  5. A method of manufacturing molded products according to claim 4, the mold (20) being vibrated via the vibration device (17) during the compaction phase, characterized in that the vibration is stopped at the end of the compaction phase prior to the substitution of the receiving table (25) by the handling plate (14).  6. Molding installation, in particular authorizing the implementation of the manufacturing process for molded products according to claim 1, comprising at least  - a feed device (18, 19) of moldable material,  a molding device (16) having a mold (20) whose lower face (22) is open, and a compression pestle (23) cooperating with said mold (20),  - A vibration device (17) having a vibration table (25), characterized in that said vibration table (25) substantially constitutes said mold reception table (20).  7. Molding installation according to claim 6, characterized in that the receiving table (25), constituted by the upper part of the vibration device (17), has means for retracting under the action of the plate handling (14).  8. Molding installation according to claim 7, characterized in that the receiving table (25) has means for guiding horizontal translation.  9. Molding installation according to claim 7, characterized in that the handling table (14) has a thickness substantially identical to that of the receiving table (25) retractable and a sufficient surface to close the open face (22) bottom of the mold (20).  10. Molding installation according to claim 6, characterized in that it comprises a device for supplying handling plates, capable of having, from the front of the installation, a handling plate (14) under the mold (20), during this phase the receiving table (25) retracting towards the rear of the molding device (20), then able to extract, by the front of the installation, said handling plate ( 14) on which the molded products have been removed from the mold (13)