FR2609928A1 - Method for moulding moulded products and moulding installations allowing implementation of the said method - Google Patents

Abstract

The invention relates to a method for manufacturing moulded products, as well as to a moulding installation allowing implementation of the said method. It will, in particular, find its application in building and construction, for moulding construction products, on a cement base, such as building blocks, or other products of similar shape. The installation 1 for pressforming such products comprises at least: - a moulding device 2, having a mould 8 whose lower surface 10 is open, - a vibration device 3, having a vibrating support table 12, - a set 4 of plates 5 for handling the moulded products. According to the method of the invention: - the mould 8 is placed on the support table 12, such that the latter is in direct contact with the lower face 10 of the mould 8, - the product or products to be obtained are moulded, - a handling plate 5 is interposed between the support table 12 and the lower face 10 of the mould 8, - the product or products obtained are released from the mould onto the said plate 5.

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 shaped construction products based on cement such as concrete blocks or others. However. the invention pcrra s apply to other areas where we find the same molding problems.

 Currently, such molding installations are known, they essentially comprise a hopper for supplying moldable material, one or more molds the shape of which corresponds to the products to be produced, a movable distribution drawer which allows, by a back and forth movement. , to feed the mold from the material contained in the feed hopper, a compaction press as well as a vibrator which make it possible to give the molded products a significant compactness in order to increase their mechanical strength.

 In such installations, the problems are numerous and come essentially from the fact that the moldable material is very abrasive, the need to vibrate the product during molding, the handling of fresh products and their drying.

 With regard to abrasion and vibration, the devices and installations known to date overcome these disadvantages by various embodiments which give good results despite the technical difficulty to be overcome.

 With regard to the handling problem, in the majority of known molding installations, flat wooden planks are used on which the products are molded directly.

Thus, after demolding, the fresh products are kept on these wooden planks and stored in drying areas.

 In fact, a process is known for manufacturing molded products based on cement, such as concrete blocks, in which, prior to molding, a wooden board is placed on the vibrator table and then, the mold, the bottom of which is open, is placed on this wooden board.

 Thus, the wooden board constitutes on the one hand the bottom of the mold and on the other hand will be used after demolding for the handling of fresh products.

 The different elements for molding being thus positioned respectively, the mold is filled with moldable material via the feed hopper and the distribution spool then vibrations are caused by the vibrator in order to make the moldable material penetrate into the mold, finally it is compacted by means of the compression pin and by vibration.

 Then, demolding is carried out according to known techniques by raising the mold, the fresh molded product then remaining on the handling wooden board.

 Such installations require a large quantity of handling wooden planks because these cannot be released, re-used only when the molded products are perfectly dry and prehensible. It is common that, in the cost of a molding installation, the wooden planks represent approximately 10 7 of the price of this being given their large number necessary. In fact, the drying required is generally around 24 hours and in installations with production rates removed, it is common to use 3 to 4,000 boards.

 In addition, the cost of the boards is important not only at the time of investment of the machine but also during service, the boards are generally considered as consumable materials.

 Indeed, since wood is a relatively soft material, and due to the abrasion of the moldable material, vibrations, and pressures exerted on the boards at the time of molding, they have a limited lifespan and must be replaced frequently periodically to always obtain a good quality product.

 In particular, as the handling wooden board serves as the mold base, it is important that it has good flatness. In addition, since the molded products are heavy, it is also important that the latter resist during handling to avoid loss of product.

 To overcome these various drawbacks, it was thought to use metal handling plates which offered the advantage of being much more resistant. However, this project was abandoned due to the additional cost that this brought on the installation. Indeed, such steel handling plates cost about 3 times more expensive than wooden planks, which has a very significant impact on the cost of investment.

 The aim of the present invention is to propose a process for the manufacture of molded products, in particular of construction based on cement, such as concrete blocks or other similar shaped products, which uses, as a handling plate, in particular traditional wooden boards, and which, by virtue of its implementation, makes 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, as traditionally, on the wooden board.

which allows on the one hand to have a better vibration during compaction, because the damping effect of the wooden board is eliminated, and on the other hand to have a better longevity of the boards, because these can no longer withstand compaction or vibration forces during molding.

 One of the aims of the present invention is to propose a process for the production of molded products in which the handling plates have only a role as a plan for laying the molded fresh products usable only during the handling of the products to transport them to the 'drying and storage area. In addition, the plates suffering much less mechanically, there will be a better presentation of the stacking and the recovery by mechanical and automatic devices during handling will be facilitated.

 Another object of the present invention is to propose a process for the manufacture of molded products which allows the production of a product with a better finish at the level of their laying plan, this advantageously having an impact on the subsequent handling of dry products: better presentation of the products during stacking, possible shifting of the products on their laying surface.

 Another object of the present invention is to provide a molding installation, in particular authorizing the implementation of the process for manufacturing molded products, in particular of cement-based construction, such as concrete blocks or other similar shaped products, according to the present. invention, whose operating cost is significantly reduced due to the better longevity of handling plates.

 Another object of the present invention is to provide a molding installation which makes it possible to obtain molded products, in particular of cement-based construction, which has a better finish and increased mechanical strength.

 Another object of the present invention is to provide a molding installation which makes it possible to make substantial gains in moldable material on the one hand by a better molding technique and on the other hand by avoiding the production of non-conforming molded products and by eliminating the losses by breakage at the time of their handling.

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

According to the invention, the process for manufacturing molded products, in particular of cement-based construction, such as concrete blocks or other similar shaped products, in particular implemented in an installation for pressing such products, comprising at least
a molding device having at least one mold whose lower face is open,
- a vibration device having a vibrating receiving table,
- a set of molded product handling plates is characterized by the fact that
- the mold is placed on the vibrating receiving table so that it is in direct contact with the underside of the mold,
- the product (s) to be obtained are molded,
- a handling plate is inserted between the vibrating receiving table and the underside of the mold,
- The product (s) thus obtained are removed from the mold on said plate.

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 underside of which is open, and a compression pestle cooperating with said mold,
- A vibration device having a vibrating receiving table, is characterized in that said vibrating receiving table substantially constitutes the bottom wall of the mold.

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

 FIG. 1 schematically represents a profile view of a molding installation allowing the implementation of the manufacturing process according to the invention.

 Figure 2 shows a front view of the installation shown in Figure 1.

 Figures 3a to 3d show the different characteristic phases of the process for manufacturing molded products according to the present invention.

 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. Nevertheless, one could envisage 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.

 Figures 1 and 2 schematically show an installation 1 for molding products, in particular cement-based construction products such as concrete blocks, which comprises at least one molding device 2, a vibration device 3, a set 4 of plates of handling 5 of the molded products.

 In addition, to allow the supply of molded material from the installation 1, the latter comprises a feed hopper 6 and a distribution drawer 7 which will allow the mouldable material to be brought to the molding device 2.

 The molding device 2 has at least one hollow mold 8 whose internal volume corresponds to the products 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.

 Furthermore, the mold 8 consists of the closed side walls and has an upper face 9 and a lower face 10 open.

 In addition, the molding device 2 will also have a compression pestle 11. The latter will be able to move vertically along the arrows 15 so that it can penetrate into the mold 8 through its upper face 9 and slide in the mold to compact the moldable material.

 As regards the vibration device 3, it has at least one vibrating receiving table 12, actuated by any means of known vibrating systems.

 In addition, the receiving table 12 will have a surface adapted to the open bottom face 10 of the mold 10. In fact, this will constitute the mold closing plate, in other words the bottom of the mold. In the case of concrete block molding, the table 12 will advantageously be flat.

 The handling plates 5 of the molded products will be placed on the assembly 4 which will be provided in such a way that, during the process, the plates 5 can be placed one by one on the upper face of the vibrating receiving table 12 Such devices are known to those skilled in the art.

 As regards the supply of moldable material, this will be kneaded beforehand and then contained in the supply hopper 6, the lower face of which will have a controlled hatch for letting the material flow as required.

 Under this hatch will be disposed the distribution drawer 7 which will be advantageously mounted to slide horizontally on a plate 13 and controlled by a drive member 14 so that the drawer 7 performs a back and forth movement between the hopper 6 and the open face 9 upper mold 8 to supply it with moldable material.

Such devices are. also known to those skilled in the art.

Such an installation 1 allows in particular the implementation of the process for manufacturing molded products according to the present invention in which the following steps are successively carried out:
the mold 8 is placed on the vibrating receiving table 12 so that it is in direct contact with the underside 10 of the mold,
- the product (s) to be obtained are molded, such as concrete blocks
for example,
- a handling plate 5 is inserted between the table
vibrating reception 12 and the underside 10 of the mold 8,
- we unmold the said product (s) on said plate 5.

As for the molding of said products, it is
carried out according to traditional phases, namely in particular
- by filling the mold 8 with moldable material by
through the feed hopper 6 and the
distribution 7,
- by vibrating the mold 8 to facilitate the introduction of
the moldable material in the mold through the table
vibrating 12,
- by compacting the moldable material in the mold 8 by
vibration and by the action of the compression pestle 11 while doing so
penetrate at the level of the upper face 9 of the mold then by exerting
compression pressure of the material.

However, unlike traditional methods in
which the handling plate 5 serves as the mold base, according to the
present invention, said products are directly molded on the
receiving table 12 of the vibration device 3 whose surface
is suitable for this purpose,
After molding, vibration and compaction of the products, we
interposes the handling plate 5; for this, the mold 8 is separated from the vibrating receiving table 12, the fresh molded product
then still being contained in the mold 8.

During this phase, the mold 8 is lifted without causing the molded fresh product or products to be removed from the mold. In this regard, in an interesting embodiment of the present invention, it is noted
the 8-pestle 11 mold assembly without causing relative movements of one relative to the other, then placed on the receiving table
vibrating 12 the said handling plate 5, finally we descend the mold assembly 8-pestle it on the said plate 5.

 Figures 3a to 3d show the different phases of the implementation of the method of the present invention.

 FIG. 3a shows, respectively positioned between them, the mold 8 disposed on the vibrating receiving table 12, the lower face 10 of the mold being closed by said table 12, and the compression pestle 11 capable of sliding in the mold 8 .

 In the first phase illustrated in FIG. 3a, the mold 8 has been previously filled with moldable material and the vibrating table is put into action, the vibrations being shown diagrammatically by the broken arrows 16.

 FIG. 3b shows the action of the compression pestle 11 which descends vertically in the mold 8 to exert a compressive force Fp to compact the moldable material in addition to the vibrations 16.

 FIG. 3c represents the phase in which the handling plate 5 is interposed between the mold 8 and the vibrating table 12.

 In this case, the action of the vibrating table is stopped in order to be able to position the plate 5 on the surface thereof. In addition, to insert the handling plate 5, the 8-pestle 11 mold assembly is raised without causing the molded fresh product or products which have just been compacted to be demolded.

 On this subject, given the compaction which has just taken place, the fresh product remains contained and maintained in the mold, and to unmold it, an external action will be necessary to drive it out of the mold, either a shock, or either a pressure.

 Consequently, to avoid any untimely demolding, according to the present invention, it is ensured to raise the mold 8-pestle 11 assembly without causing relative movements of one with respect to the other which could be sufficient to cause demolding. .

 Nevertheless, to obtain a good surface condition at the level of the upper part of the molded products, during the vertical movements of 1 mold 8-pestle 11 assembly, said pestle 11 is kept in contact with the molded product contained in the mold 8.

 it should be noted that, to allow this step, during which a handling plate 5 is inserted between the mold 8 and the top of the vibrating table 12. the installation of the invention, and more precisely the molding device 2, has a mold 8 and a compression pestle 11 provided for vertical sliding relative to the vibrating table 12; this sliding is shown diagrammatically in FIG. 3c by the arrows 17.

 In addition, the molding device 2 is such that, during the ascent of the mold 8 during the plate insertion phase, the pestle 11 follows the vertical movements of the mold without causing significant efforts on the products contained in the mold. likely to unmold it.

 In practice, according to the invention, the pestle is mounted on a counterweight type compensation system, shown schematically in phantom in Figure 3c, mechanical. hydraulic or electric.

 This compensating system 18 will make it possible to substantially annihilate the weight of the pestle 11 during the raising or lowering of the mold during the insertion phase of the handling plate 5.

 Thus, in this operation, it will suffice to reassemble the mold 8 by creating a force on the latter, marked Fm in FIG. 3c, by a jack system for example, the pestle 11 then following the movements of the mold, its weight being counterbalanced by a counterweight "P.

 However, in order to keep the pestle 11 in contact with the fresh product contained in the mold 8, so as not to alter the upper surface condition of the molded product, the compensation system 18 will make it possible to create a differential force. In other words, the weight P will be slightly less than the force Fm so that there remains a force applied downwards to keep the product and the pestle in contact. For example, a force of the order of 50 to 100 kg would be sufficient to give good results.

 Finally, the demolding phase is illustrated in Figure 3d.

The handling plate 5 being previously placed on the vibrating table 12, the latter no longer being in action, the 8-pestle mold assembly 11 is redeposited as described above, then when the mold is in contact with the handling plate 5 , the pestle 11 is immobilized vertically and the mold 8 is raised.

 FIG. 3d illustrates the ascent phase of the mold 8, the blocking of the pestle 11 being shown diagrammatically by the brake shoe marked 19.

 Then, when the product is completely removed from the mold, the pestle 11 is released and then raised to allow handling of the fresh products thus obtained. This handling will not be described in the present application because it is outside the scope thereof.

 It should be noted that, thanks to the process of the present invention, which also makes it possible to reduce the stresses and attacks on the handling plates 5, these can advantageously be produced in the form of wooden boards or the like.

 However, it is naturally possible to make handling plates of much more resistant material, however, this will unnecessarily penalize the price of 1 installation.

 Naturally, -other implementations of the present invention, within the reach of those skilled in the art, could be envisaged without departing from the scope thereof.

Claims (10)

 1. Method of manufacturing molded products, in particular of cement-based construction, such as concrete blocks or other similar shaped products, in particular used in a pressing installation (1) of such products comprising at least  a molding device (2) having at least one mold (8), the lower face (10) of which is open,  - a vibration device (3) having a vibrating receiving table (12),  - a set (4) of handling plates (5> of molded products, characterized in that  the mold (8) is placed on the vibrating receiving table 112) so that it is in direct contact with the lower face (10) of the mold (8),  - the product (s) to be obtained are molded,  - a handling plate (5) is inserted between the vibrating receiving table (12) and the underside (10) of the mold (8),  - The said product (s) obtained on said plate (5) are removed from the mold.  2. Method according to claim 1, characterized in that, to insert the handling plate (5), the mold (8) is separated from the receiving table (12), the fresh molded product being contained in the mold ( 8).  3. Method according to claim 2, characterized in that, for the insertion phase of the plate (5), the mold is lifted (8) without causing the release of the molded fresh product (s).  4. Method according to claim 3, the molding device (2) further comprising a compression pestle (11) able to penetrate at the level of the upper face (9) of the mold (8) and to slide therein, the molding of the products being carried out in particular  - by filling the mold (8) with moldable material,  - by vibrating the mold (8) to facilitate the introduction of moldable material,  - by compacting the material in the mold (8) by action of the compression pestle (11), and by vibrations, characterized in that  the mold assembly (8) -pilon (11) is raised without causing relative movements of one with respect to the other,  - the handling plate (5) is placed on the vibrating reception table (12),  - The mold assembly (8) -pilon (11) is lowered onto the said plate (5).  5. Method according to claim 4, characterized in that, during the vertical movements of the mold assembly (8) -pilon (11), to insert the handling plate (5), said pestle is kept in contact ( 11) with said molded product contained in the mold (8).  6. Molding installation (1), in particular authorizing the implementation of the process for manufacturing molded products according to claim 1, comprising at least  - a feed device (6, 7) of moldable material.  - A vibration device (3) having a vibrating reception table (12), characterized in that said reception table (12) substantially constitutes the bottom wall (10) of the mold (8).  a molding device (2) having a mold (8) whose lower face (10) is open, and a compression pestle (11) cooperating with said mold (8),  7. Installation according to claim 6, characterized in that the mold (8) and the compression pestle (11) of the molding device (2) are provided with vertical sliding relative to the vibrating table (12) and, such that when raising the mold (8), to insert the handling plate (5), the pestle (11) follows the vertical movements of the mold (8) without causing significant force on the product or products likely to unmold them.  8. Installation according to claim 7, characterized in that the pestle (11) is mounted on a compensation system (18) of the counterweight type capable of substantially annihilating the weight of the pestle (11) during the ascent or descent of the mold (8) during the insertion phase of the handling plate (5).  9. Installation according to claim 8, characterized in that the compensation system (18) nevertheless makes it possible to create a differential force in order to keep the pestle (11) in contact with the fresh product contained in the mold (8).  10. Installation according to claim 6, characterized in that it comprises handling plates (5), placed under the mold (8) after molding of the product or products, being in the form of boards made from wood.