EP1952960B1 - Improvements made to machines for continuous production of pre-stressed or reinforced concrete pieces - Google Patents

Description

FIELD OF THE INVENTION

This patent relates to improvements introduced in machines for the continuous manufacture of prestressed or reinforced concrete parts, of the type of those which consist of a chassis movable on rails which define a manufacturing track, on which are arranged prestressed or passive active armatures, shaping the armament of the concrete parts to be obtained, being located on said frame a movable surtremium for receiving concrete, a fixed feed hopper vibrator mold, a anterior mold of retention, a vibrator mold provided with the cores for the compaction of the pieces of concrete and a posterior mold or refiner, also provided with cores to give the final shape and the smoothing of the pieces of concrete.

The improvements which are the subject of this patent relate, in concrete terms, in the first place to the fixed feed hopper of the vibrator mold and to the vibrator mold itself; second, they relate to the refiner mold, forming the final profile of the part to be manufactured; and thirdly, they relate to the side closure devices for the vibrator mold and the prior retention mold assemblies, consisting of a metal support and a piece of flexible material, which acts as a closing lip.

STATE OF THE ART

In the Spanish patent no. 428477 Referring to "Improvements for the continuous production of beams, plates and similar elements of concrete", an installation is described composed of rails anchored in the ground, between which is placed a machine equipped with the necessary hoppers on which pour the concrete and lower molds so that advancing the machine shapes the beams or the armed elements.

The machine described in the patent mentioned, already envisaged the use of three molds: a mold before or retention, a central mold or vibrator, provided with cores or walls which define the section of the pieces to obtain, and a posterior mold or refiner and she was already considering the use of two hoppers: a fixed hopper pouring concrete on the frames formed by the cables and another mobile or feed that feeds the previous one.

The refining mold is mounted on an area projecting from the frame, where are arranged metal guides to which it is coupled by means of alignment supports, and the frame is fixed on its upper area and on its front face, which allows to extract it easily.

The mold may comprise, on its rear part, a deflector plate to improve the surface finishes of the concrete slabs, when it is this product that is developed.

This machine does not completely regulate the continuous manufacture of the desired concrete parts and has drawbacks, which make its use and maximum efficiency difficult and which are mentioned below.

The fixed hopper which feeds the vibrator mold, located above the latter and separated by elastic joints which prevent the vibration of the mold is transmitted to the hopper, is formed of a rectangular upper portion shaped funnel and a lower part also rectangular, but with straight and parallel walls.

Said hopper must always be full of concrete until the central zone where the funnel-shaped upper part ends and where the right part begins, the operator having to control said level, stopping the machine if for lack of concrete the level was lower than that indicated, since the compacting of the concrete in the vibrator mold is obtained by the vibration itself and by the pressure which it confers on it the column of concrete contained in the fixed hopper and which weighs on said mold, which allows only a small margin of difference in said concrete column.

The concrete deposited in the fixed hopper gradually passes into the vibrator mold by extruding to form the prefabricated part.

According to the profile of the part to be manufactured and according to the type of concrete (degree of plasticity), the concrete of the fixed hopper does not descend uniformly, in some cases it is agglutinated, and only that of the center goes down while that which is in contact with the walls of the hopper is retained, which produces obstructions and malformations in the molding process.

To avoid this problem, it is necessary to use more fluid concrete which, because of the greater proportion of water-cement, reduces the strength of said concrete.

As explained in the previous paragraphs, the concrete that is agglutinated inside the hopper begins to harden in a few minutes, removing fluidity from the concrete that goes down to the mold, which translates into a speed reduced molding, the possibility of tears in concrete when its continuous molding and the danger that a part of the concrete that had remained agglutinated finally down to the mold and does not mouth, which forces to stop the continuous molding process with the loss of time and material that result.

Due to the considerable volumetric capacity of the vibrator mold with the fixed hopper, a significant problem arises, since when the machine arrives at the end of the runway (end of molding), the level of concrete inside the hopper must continue to to be at its high point, which forces to extract and discard or to use for other purposes, the concrete which remains inside, to carry out the cleaning of said hopper.

The implementation of the reference patent, has highlighted all these drawbacks that must be eliminated and it is this objective that seek to achieve the improvements that are the subject of this patent.

The preamble of claim 1 is disclosed by the document EP 0 803 335 A1 .

Regarding the disadvantages that arise at the end of the process, the output of the refiner mold, it is common that the manufactured parts have a smooth surface, with slight irregularities that make the finish less valuable.

It is essential that the refining mold has sufficient complements to ensure the release of the air contained in the concrete, and thus prevent hollow areas appear on the surface of the parts to obtain. These supplements significantly improve the surface finish of the pieces.

Molding machines are known which perform the lateral closure of the retention molds and vibrator using special square sectional rubbers also placed longitudinally, which exert a pressure against the molds and against the manufacturing track. These closure rubbers are pressed by cylindrical grippers (usually three or four), placed at a 45 ° inclination with respect to the track, which are actuated by strong springs, clamping pins or hydraulic systems.

In this system, in order to achieve a total efficiency of the lateral closure, the closure rubbers must be strongly squeezed, which first of all results in a strong pressure against the vibrator mold, which reduces its vibration and compaction force. since this action has a tendency to immobilize it and, secondly, by a pressure against the track, exerting an important braking force which results in the need to apply a greater power and, consequently, an increase of the energy consumed by the motor advancing the molding machine and a high wear, by friction, of the closure rubbers mentioned.

These side-closure rubbers are currently to be placed on the molding machine (one on each side), when the machine is already positioned on the production track and must be clamped, which in addition to representing an additional task, may affect the result of the vibration-compacting operation of the concrete, depending on a tightening that has been excessive or insufficient. For all these reasons, it was necessary to pay close attention to this operation of setting up said rubbers so as not to alter the quality of the manufactured or molded product.

Another type of side closure described in the US4068990 is formed essentially of a flexible plate-shaped closing lip of a length equivalent to the closure itself.

In said document, the mentioned flexible plates are fixed internally by members traversed transversely by a rotor.

DESCRIPTION OF THE IMPROVEMENTS INVOLVED IN THE INVENTION

The improvements forming the subject of the present invention are applied to machines for the continuous manufacture of prestressed or reinforced concrete pieces according to the subject-matter of claim 1. These improvements have characteristics which enable it to act on the totality of the interior space of the fixed hopper avoiding the compaction of the concrete in the peripheral zones of the hopper and allowing the work of the concrete having a low degree of humidity.

Due to the rotating action of the blades in a given direction, the concrete deposited in said hopper is stirred and in this way it is possible to ensure that the concrete does not agglutinate, is more homogeneous, and that goes down with greater ease in a vibrator mold thus avoiding unwanted early compactions.

The characteristics of this concrete clarifier and stirrer mechanism allow the machine to advance and mold at a higher speed, that it can be used for molding a drier concrete, that it allows a greater tolerance as to the level of concrete in the hopper, that it will ensure that there will be no agglutinated or compressed concrete early, which consequently would not pass into the vibratory mold, and that at the end of the manufacturing runway, when will end the molding, the level of concrete is located in the lower part of the fixed hopper, which will allow a significant saving of concrete.

Finally, the improvements which are the subject of the present invention are intended to eliminate the difficulties which currently exist with the side-locking molding machines of the retention and vibration molds.

These improvements consist in placing lateral closure devices for the vibrator mold and retention mold assemblies, formed by a metal support, longitudinally fastened externally to the vibrator mold on a first section and to the retention mold on a second section, being fixed to the longitudinal metal support mentioned, by an inclined mounting plate and screw, the corresponding flexible plate as a flat lip, which is arranged with the same inclination as the fixing plate and receives at the same time, a determined pressure because of the weight concrete itself contained in the mold vibrator.

The concrete which is being molded and compacted in the vibrator mold and the retention mold has a tendency to exit through the lower part of the sides of said vibrator and retention molds, exactly by the space between the mold and the mold. surface of the manufacturing runway.

The concrete, in its attempt to exit, puts pressure on the flexible lip, which in turn exerts pressure on the track on which it slides, forming in this way a simple and perfect closure.

This lateral closure system allows the vibrator mold full freedom to perform its function of vibrating and compacting the concrete with maximum efficiency and taking advantage of the force imparted to it by the vibrators, and at the same time offers a low slip resistance on the track, which results in the need for a lower pull force (almost zero), for the molding machine in its progression along the manufacturing track.

All of this results in better compaction of the concrete in conjunction with the consequent saving of energy, and significant savings in side closure rubbers, since the mentioned closure lips are made of a flexible and highly resistant material. wear.

These lateral closure devices molds, as they are integral with said molds and therefore the molding machine itself, eliminate the tasks of implementation of side closures as they are currently performed, the tasks that It must be done with the greatest care if one does not want to alter the result of the product to be manufactured.

GRAPHIC INFORMATION

In order to complete the current description and in order to assist in a better understanding of the features of this patent, this memo is attached, as an integral part of the latter, a set of drawings in which, by way of nonlimiting illustration, there is shown a practical embodiment of the invention.

la fig. 1

montre une vue schématique, en élévation latérale, de la totalité de la machine, dans le but d'indiquer l'emplacement du moule vibrateur, du moule de rétention et du moule affineur ;

la fig. 2

est une vue en perspective de l'ensemble de la trémie fixe équipée du dispositif clarificateur et agitateur du béton ;

la fig. 3

est une vue en plan de l'ensemble d'après la figure précédente ;

la fig. 4

est une vue frontale et en élévation du même ensemble ;

la fig. 5

est une vue en élévation latérale de l'ensemble proprement dit ;

la fig. 6

montre en perspective le mécanisme clarificateur et agitateur du béton ;

la fig. 7

est une vue en plan du mécanisme de la figure précédente ;

la fig. 8

est une vue en élévation frontale, d'après la figure 7 ;

la fig. 9

est une vue en élévation latérale, également d'après le figure 7 ;

la fig. 10

représente en perspective l'ensemble dessiné sur les figures 5 à 8, avec ses composants séparés, à la façon d'une vue éclatée ;

la fig. 11

est une vue en perspective d'une plaque de désaération et de relaxation, qui est placée à la sortie du moule affineur ou comme prolongement de ce moule ;

la fig. 12

montre en élévation latérale, partiellement sectionnée, la plaque placée à la sortie du moule affineur ;

la fig. 13

est une vue frontale correspondant à la figure précédente ; et

la fig. 14

représente, en élévation latérale et partiellement sectionnée, d'après la figure 12, la plaque de relaxation, dans une variante où elle est montée sur un prolongement du moule affineur ;

la fig. 15

est une vue, en section de la machine, montrant les nouveaux dispositifs de fermeture latérale, qui font l'objet des améliorations qui sont décrites ; et

la fig. 16

est un détail, à plus grande-échelle, de l'un de ces dispositifs de fermeture latérale.

On said drawings,

fig. 1

shows a schematic view, in side elevation, of the entire machine, for the purpose of indicating the location of the vibrator mold, the retention mold and the ripening mold;

fig. 2

is a perspective view of the entire fixed hopper equipped with the clarifier device and agitator concrete;

fig. 3

is a plan view of the set from the previous figure;

fig. 4

is a front view and elevation of the same set;

fig. 5

is a side elevation view of the assembly itself;

fig. 6

shows in perspective the clarifier and agitator mechanism of concrete;

fig. 7

is a plan view of the mechanism of the previous figure;

fig. 8

is a front elevational view, according to the figure 7 ;

fig. 9

is a side elevation, also according to the figure 7 ;

fig. 10

represents in perspective the set drawn on the Figures 5 to 8 , with its separate components, like an exploded view;

fig. 11

is a perspective view of a deaeration and relaxation plate, which is placed at the outlet of the refining mold or as an extension of this mold;

fig. 12

shows in side elevation, partially sectioned, the plate placed at the exit of the refiner mold;

fig. 13

is a frontal view corresponding to the previous figure; and

fig. 14

represents, in lateral elevation and partially sectioned, according to figure 12 the relaxation plate, in a variant where it is mounted on an extension of the refining mold;

fig. 15

is a view, in section of the machine, showing the new lateral closure devices, which are the object of the improvements which are described; and

fig. 16

is a detail, on a larger scale, of one of these lateral closure devices.

DESCRIPTION OF THE INVENTION

As can be seen in the figures referenced above, the machine for the continuous manufacture of concrete parts, shown schematically on the figure 1 , with reference (1), presents, in the first place, improvements introduced in the fixed hopper (2) and in the refining mold (5), while having a suitable retention mold (4).

The fixed hopper (2) which feeds the vibrator mold (3), is located above the latter and is separated by elastic joints which prevent the vibration of said mold (3) is transmitted to the hopper (2), which is formed of a rectangular upper portion (6) funnel-shaped and a lower portion (6a) also rectangular but with straight and parallel walls.

In this lower part (6a) of the fixed hopper (2) is located the clarifier and agitator (7) of the concrete. (See the Figures 6 to 10 ).

This assembly (7) consists of a cylindrical axis (8), located horizontally, fixed at its ends by rings (9) connected to synchronized electric geared motors (10), each of which is located at each end of said axis (8 ).

Each geared motor (10) is suitably fixed by means of its support (11), duly attached to the end walls of the lower part (6a) of the fixed hopper (2).

On the axis referenced (8) are connected blade blades (12), which are, for each of them, secured to a fastening flange (13) of semicylindrical base, for gripping said axis (8) and fixed to another flange (13 ') equivalent, located diametrically opposite and with its threshing blade (12) arranged in opposite directions.

Through screws (14) together with nuts (15) ensure the attachment of the two flanges (13).

The set of blade blades (12), fixed together in the manner described, is arranged to cover four theoretical planes arranged at 90 ° relative to each other around the cylindrical longitudinal axis (8). This arrangement ensures that the mass of concrete inside the fixed hopper (2) is stirred in a homogeneous and continuous manner, avoiding its agglutination and hardening before its passage in the vibrator mold (3).

The refining mold (5) is located towards the developed product exit zone of the machine (1).

In its upper front zone facing the exit direction of the formed parts, a relaxation and de-aeration plate has been arranged, consisting of a rectangular and horizontal plate (16) on which is located a longitudinal exhauster (17). , of trapezoidal section, with its vertical end wall and inclined in opposite directions. (See figure 11 )

Said plate (16) has its underside slightly inclined upwards (16a), in the direction of union towards the mouth (18), on which is located the exhauster (17), as it appears clearly on the figure 12 .

All this has been arranged to facilitate the exit of the air from the area of the refining mold (5) located under the plate (16) to the outside.

As an alternative practical embodiment figure (14 ) the relaxation and de-aeration plate (19), provided with a zone (19a) on its underside, slightly inclined upwards in the direction of the mouth (20), is located on the tilting extension (5a) of the refining mold (5), while the end of said mold is covered by a closure plate (21).

During the continuous production process of the concrete parts, the concrete is molded and compacted in the vibrator mold (3) and in the usual retention mold (4). During this molding and compacting time, the concrete has a tendency to exit or to flow through the lower part of the sides of said molds, that is to say, the vibrator mold (3) and the retention mold (4). flow which occurs through the small space remaining between the mold and the surface of the manufacturing track (22).

In its attempt to exit, the concrete presses on the innovative closing flexible lip (23), on which it slides, a pressure that is sufficient to form a simple and adapted closure, guaranteeing the non-exit of concrete by the sides.

These lateral closure devices (see Figures 15 and 16 ) consist of a metal support (24) arranged longitudinally and secured to the vibrator mold (3), on one section, and the retention mold (4) on another section, whose support holds a rectangular plate (23), as closing lip, made of flexible material and highly resistant to friction, whose length is equal to the two sections of the metal support (24) mentioned.

This piece (23) is joined to the metal support (24) by means of a fixing plate (25), held by screws (26).

Thanks to the closing assembly thus arranged, consisting of the metal support (24) and the flexible closing lip (23), the vibrator mold (3) acquires greater freedom to exercise its vibration function - compaction of concrete with efficiency maximum, and taking advantage of the force imparted by the vibrators.

Similarly, the low sliding resistance on the manufacturing track (22) from the mentioned flexible closing lip (23) results in the need for a lower tensile force, which can be considered as minimal, for moving the molding machine (1) in its progression along the production track (22).

In conclusion, the improvements that are described, provide better compaction of concrete, significant energy savings, as well as less wear and tear of the old side closure rubbers used to date, while also being able to do without devices for securing and closing said rubbers on the work surface, such as springs, clamping pins or hydraulic cylinders.

The closures described and which are part of the improvements which are the object of this invention, being united by means of metal supports (24) to the vibrator (3) and retention molds (4) and consequently to the machine. molding (1) itself, significantly reduce the maintenance tasks, specifically those of setting up the closures currently used, essential tasks to obtain a product developed without any alteration of its characteristics.

Claims (2)

1. Improvements made to machines for the continuous production of pieces of prestressed or reinforced concrete, of the type where the structure assembly (1) includes a fixed hopper (2), which supplies concrete to the vibrating mould (3), a standard lower retaining mould (4) and a curing mould (5) which shapes the final profile of the set piece, a relaxation and aeration board (16) which has an extractor (17) which allows air to exit from the region of said curing mould (5) being positioned on the curing mould (5), and lateral closure devices extending across the production track (22) being positioned between the vibrating mould (3) and the retaining mould (4), characterised in that said fixed hopper (2) comprises in its interior, on its lower rectangular section, an assembly (7) for clarifying and agitating the concrete, consisting of a cylindrical horizontal and longitudinal axis (8) joined by means of rings (9) at its opposing ends to respective synchronised electric reducing gears (10), attached in an appropriate manner by support elements (11) to the lower section (6a) of the fixed hopper (2), mixing blades (12) conceived as one piece of cylindrical design with the respective fixing flange (13) being attached to said axis, fixed around the axis to another, identical and diametrically opposed (13') and with its blade rotating in the other direction, such that the whole of one pair of blades in every two covers 90° zones around the axis (8), thus reaching the entirety of the space inside the fixed hopper (2), and in that the lateral closure devices comprise flexible lips (23) by way of closure elements, the length of which is equivalent to that of the closure.
2. Improvements made to machines for the continuous production of pieces of prestressed or reinforced concrete according to claim 1, characterised in that they comprise closure devices positioned on both sides, each of these consisting in a longitudinal metal element (24) of one piece with the vibrating mould (3) on its first section and of one piece with the retaining mould (4) on its second section, and in a rectangular piece (23) of identical length to the metal element (24), made of a flexible, highly friction-resistant material, which piece serves as flexible closure lip under pressure from the production track (22), the lip (23) of which is connected to its metal element (24) due to a fixing plate (25) and screws (26), and at the same time receives a specific pressure as a result of the weight of the concrete which is itself contained in said vibrating mould (3).

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