CS277660B6 - Apparatus for producing bodies from concrete mixture - Google Patents

Abstract

This method and the relative means for forming blocks (10) from concrete mix at a high production rate and with high shape definition comprise a plurality of moulds (3) containing impressions (9A, 9B) each corresponding to one of the two halves into which the block (10) can be divided; these impressions are provided in their two outer flat faces so that a line (13) or bank of moulds can be formed in which two adjacent mating moulds (3) define the cavity to be filled; this line of moulds defines an upper surface (18) which comprises casting sprues and onto which the concrete mix (Z) can be poured for filling purposes. This filling is facilitated by vibrating the mould bank or line (13) for compacting purposes by usual vibrators (26) located on lower longitudinal members (1B, 1B', 1B") provided for their support. The filling is done with the aid of a tray for containing the concrete mix (Z), this tray being formed by removably locating perimetral walls (19) about the sprues (21) of the line (13) of moulds (3); the walls (19) are rested on the upper surface (18) formed by the plurality of mating moulds (3) and containing the casting sprues, and are fitted with rubber gaskets (20) for retaining the liquid component of the concrete mix (Z). <IMAGE>

Description

Technical field

The present invention relates to an apparatus for producing bodies from a concrete mixture comprising a plurality of molds provided with filling holes and mold cavities and supported on a support base equipped with a vibrating device and a device for conveying the concrete mixture to the molds.

BACKGROUND OF THE INVENTION

It is known that cement and concrete products made from a concrete mix and containing various fillers have been increasingly used more and more recently due to their sufficient hardness, low cost, high density and, in particular, the ease of forming bodies of the desired shape in other fields than in construction and these applications cover a wide range of possible applications, from decorative paving to building cladding and from sculptures and monuments to products forming parts of machines or equipment otherwise usable in mechanical engineering. Of this last field of application, the product group used as weights for providing and creating the necessary inertia masses of the machines is of particular importance. Recently, there has been an increasing demand for parts of engineering structures which are both to be sufficiently functional and sufficiently strong, while at the same time reducing the consumption of expensive materials during their manufacture; it appears that it is preferable to use concrete bodies in spite of their lower specific weight than, for example, cast iron or steel bodies, as the increase in volume is not as significant as a significant reduction in cost and cheaper production.

Typical examples of engineering products that can advantageously utilize concrete weights and loads are, for example, household washing machines and dishwashers. Washing machines shall have a carcass housing a tank with a washing drum of sufficient rigidity and of sufficient mass and inertia to ensure stability of the washing machine during washing and resistance to vibrations and oscillations caused by the rotation of the unbalanced drum contents, in particular during blasting. Dishwashers must also be loaded with additional loads to prevent the dishwasher from sliding, for example, when opening the door or removing the basket.

In these and similar cases, concrete blocks containing in particular iron or barite filler and fastened by screws or pre-assembled fastening and positioning elements are used. Concrete blocks of this type so far have relatively large dimensional deviations that are difficult to compensate for engineering products. This great inaccuracy of the products is due to the manufacturing processes used to manufacture the concrete blocks in the molds which result in irregular shapes of the blocks not only in terms of their surface quality but also in terms of their dimensions.

In the manufacture of concrete blocks by one of the known methods, the base half of the metal mold is first filled with a grained crumb concrete, then the scraper removes the excess mixture above the edges of the mold over which the scraper is guided, and then the concrete mixture in the mold recess is compressed and the whole assembly is briefly vibrated to compact the mixture, after removal of the second mold half, the formed concrete block is transferred to a conveyor belt that slowly moves through a steam tunnel to accelerate concrete hardening.

This process produces concrete blocks with a very rough surface, since the concrete mixture contains mainly sand as a filler and a semi-dry mixture is used for the production, which has to keep in contact with the mold essentially only by a point formed by outer corners of the filler grains. contacting the mixture with the mold, since in this case the formed molded body could not be removed from the metal mold. The roughness and unevenness of the concrete body surface is further increased by the fact that the concrete mixture particles remain attached to the mold and tear off from the finished body when removed and remain on the mold cavity walls, resulting not only in the formation of small depressions in the concrete body labor in mold cleaning.

Thus, in these prior art molds, concrete bodies are produced without the necessary finishing of the surface, which must be subsequently treated, and the bodies do not have exactly the same dimensions and therefore cannot be used in engineering products where the manufacturing tolerances are substantially smaller ranges.

In this known production, the required production productivity is not achieved, the products are relatively expensive and the manufacturing costs of each individual body are high, because each block or each body must be processed separately. and individually compacted by a vibrating device.

The need for individual processing of each body for compacting and vibrating the mixture results in a shorter vibration time, further reducing the quality of the concrete bodies produced. The poor quality of these products is also due to the occurrence of burrs at the joints of the two mold parts, which further increase over time as the mold wears especially on the contact surfaces between the two mold parts, which increases block handling difficulties because sharp burrs can cause injury to a worker handling these blocks, for example, when assembling the block or repairing the machine in which the block is used.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an apparatus for producing concrete bodies in molds which would enable the production of these concrete bodies to be increased whilst, in particular, substantially improving the quality of the concrete bodies produced, which should have significantly smoother surface areas. so that these concrete bodies can be used as inertia loads in washing machines or dishwashers and similar machines at low cost.

SUMMARY OF THE INVENTION

This object is achieved by a device for producing concrete bodies according to the invention, characterized in that the device comprises a group of molds comprising a series of pairs of shell mold parts, each part having a contact surface on the side facing the other part of the pair. the molding depressions, which are parts of the mold cavity, and at least one of the shell mold parts is provided with a filling opening opening into the upper surface of a row of molds which is perpendicular to the contact surfaces of the mold parts provided with the molding depressions.

In a preferred embodiment of the invention, the molds are made of plastic and are provided with positioning magnets disposed on the outside of the walls of the mold shell parts facing away from the contact surfaces with the molding depressions and the separating inserts of iron-based material held between the contact surfaces with the molding depressions magnetům.

In another preferred embodiment of the invention, the planar upper surface of the mold row is bounded by a peripheral frame provided with a seal on its underside, in particular a rubber, surrounding the mold filling holes.

In yet another preferred embodiment of the invention, the perimeter frame is supported on at least two mutually opposing piston rods of the lifting hydraulic cylinders and is slidably supported on vertical guides. In a further preferred embodiment of the invention, the plurality of molds are provided with a funnel-shaped gutter on their upper surface, disposed by means of sealing strips at the lower edges of the fill-in gutter on the upper surfaces of the plurality of molds and provided with an elongate filler mouth.

The plurality of molds are provided on their upper surface with a concrete mix container displaceable over the upper surface of the plurality of molds, wherein the concrete mix container comprises at least one removable cover plate disposed above the at least one mold filling opening.

The device according to the invention makes it possible to increase the production of concrete bodies per unit of time while achieving a substantial increase in dimensional accuracy. In particular, production is accelerated by the use of a number of plastic molds with molding recesses forming halves or other portions of the mold cavities, the molding recess of each mold corresponding in shape to the portion of the finished concrete body which is divided in the finished body by the dividing plane of the mold shell parts. Since the molds according to the invention have planar outer surfaces, they can be assembled in rows side by side, whereby a molding recess is formed in the contact surfaces of each mold part facing the adjacent mold part, which together with the mold recess in the outer side of the adjacent part is formed. The molds form a mold cavity which is then filled with a concrete mixture. The concrete mixture is preferably filled into an upper shallow container formed on the top surface of a series of molds and bounded by a peripheral frame from which the concrete mixture flows into the individual mold cavities. The filling of the molds is facilitated by the vibration of a plurality of molds by means of conventional vibrators fixed to the underside of the base plate of the mold row, which is held together by support elements.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of the block manufacturing apparatus of the present invention, the upper shallow tank of which is shown in longitudinal section; FIG. 2 is axonometric; Fig. 3 is a longitudinal sectional view of a portion of a mold assembly showing a concrete body during molding between two adjacent mold halves; Fig. 4 is an axonometric view of a mold supported on two longitudinal support members; and Figs. Fig. 5 is an axonometric view of a feed hopper, shown partially in section and deposited on a series of molds.

DETAILED DESCRIPTION OF THE INVENTION

It can be seen from Fig. 1 that the molding device according to the invention for producing concrete bodies 10 and blocks is provided with a fixed frame 1 with bearing feet IA. by which the rigid frame 8 is mounted on the floor

This rigid frame 8 comprises a robust and rigid longitudinal base plate B from which two vertical supports 1C, 1C ♦ extend.

£ fixed frame can also be formed in an alternative embodiment according to FIG. 2, two longitudinal supporting elements in the form of two longitudinal beams ^IB1. B '' on which the individual molds 6 are deposited. Each mold 6 consists of two shell parts 3A. 3B, as shown in FIGS. 2a and 4, which are connected to one another by means of connecting bolts 4, the nuts of which are supported by stiffening and distributing tapes 5 on the side flanges of the shell parts 4A, 3B. The shell parts 3A, 3B are connected together in the region of their lower edges by supporting brackets 6A, 6B made of steel profile bars, in particular of an angular profile, which are provided on their lower sides with a pair of guide lower projections 6B ', 6B ¹¹ . which are intended to guide the molding shell parts 3A, 3B and which therefore abut from the inside on the lateral surfaces of the upper flanges of the two longitudinal members IB '. IB ''.

The mold shell parts 3A, 3B are made of a plastic having low adherence to concrete, in particular made of polyethylene, polypropylene or other equivalent plastics with similar properties. These shell parts 3A, 3B can also be made of plastic which, while having a certain adhesion to concrete, is coated on its molding surfaces with a material having a very low adhesion to concrete, for example polyethylene terephthalate (PTFE).

The basic advantage of such a plastic mold 3 is that it is easy to fill its interior space with a liquid concrete mixture Z. The mold shell parts 3A, 3B have low-thickness walls that are reinforced by stiffening ribs, both mold shell parts A, B being provided with specially shaped support portions 8A. 8B, which provide comfortable support, holding and positioning means for receiving and holding the dividers 7, which also have a stiffening function. By means of these specially shaped support portions 8A, 8B of the two molding shell parts 4A, 3B, it is achieved that certain areas of the separating inserts 7 can be accessed from the outside of the made concrete block and thus serve as fastening means for fastening the concrete block or generally concrete. of the body 10 on the building structure by means of screws, bolts or similar fastening means, which is, of course, only after the concrete body 10 has been removed from the mold 3. ·

This solution is apparent from Fig. 3, which shows an exemplary embodiment of a concrete body 10 having the shape of an irregular annular body provided with a central recess formed in the manufacture of the concrete body 10 by specially shaped support portions 8A, 8B having planar, the facing surfaces facing each other and pressed from two mutually opposite sides onto the separating insert 7 disposed therebetween. After separating the first molding shell 3A from the second molding shell 3B, shown in the example of FIG. 3 to the left of the first molding shell 3A, the portion of the separator pad 7 that was previously covered by the support portions 8A, 8B is now exposed and accessible from the outside of the concrete body 10, so that the central opening so formed in the separator insert 7 can be used to insert a bolt or other fastening means for fastening the concrete body 10 to the machine structure or other object. In the manufacture of the concrete body 10 according to the invention, the separating inserts 7 are very easily placed in molds 3 between pairs of molding shell parts 3A, 3B and are held in the desired position during molding not only by conventional positioning pins or similar means fixed in the second molding shell part 3B. but also by positioning magnets 27 mounted on the outer sides of the mold shell parts 3A, 3B facing away from the mold cavity, which keep the steel cutting inserts 7 in the desired position before the cutting insert 7 is fixed by clamping between the pair of molding shell parts 3A, 3B.

A pair of molding shell parts 3A, 3B connected together by connecting bolts 4 or similar fastening means, for example also by welding, together form a mold 3, which is shown in Fig. 4 and which is provided with molding depressions 9A on two mutually opposite sides. 9B, which, when assembling the individual molds 3 into a continuous row 13, form mold cavities between adjacent molds 3 which determine the shape of the concrete body 10 to be produced.

This solution is particularly apparent from Fig. 3, which shows one molding unit consisting of a pair of molding shell parts 3A, 3B 'and another molding shell part 3B, which together with the first shell part 3A forms a molding cavity for the production of a concrete body 10. The molding unit is thus formed of two separate shell parts 3A. 3B ¹ , connected together by bolts 4.

The front and rear sides of the mold 2 may be shaped in complementary shape to the front and rear surfaces of adjacent molds 3, particularly on the contact planes where interlocking protrusions and recesses are formed or precisely positionally defined contact is ensured by inserting protruding pins 11 into the passageways. holes 12 in the flanges of the mold shell parts 3A, 3B.

Providing the mold shell parts 3A, 3B with joining means in the form of complementary protrusions and recesses is important not only to ensure a sufficiently tight contact between abutting mold shell parts 3A, 3B, and thereby avoiding the formation of protrusions along the contact surfaces between the two mold shell parts 3A, 3B along the contact surfaces, but also to ensure alignment and correct relative position of the two adjacent mold shell mold parts 3A, 3B, so as to precisely assure the shape of the mold cavity, whereby the proper engagement of the complementary fasteners is also of great importance the mechanical stiffness of the molds 3 in the transverse direction and to keep the row of molds 3 in the correct position.

It can also be seen from FIG. 4 that the individual molds 2 are supported by support brackets 6A, 6B on the longitudinal beams 1B ¹ . 1B ¹¹ and can slide on the longitudinal beams ΙΒ ', 1B''in the direction of their longitudinal axis until they come into contact with each other and gradually form a series of 13 molds 3. · This series of 13 molds 3 can be repeated several times and can also be formed a plurality of juxtaposed rows 13 of molds 3, which may eventually comprise a large number of molds 3; however, only one series of 13 molds 2 is shown in the drawings.

The number of molds 3 is essentially not limited. In practical terms, this number is limited by the reasonable length of the longitudinal base plate 1B formed integrally, as well as the total length of time required to remove the concrete bodies 10 from a variety of molds 3, which must correspond to working cycles of further operations and shift.

Each row 13 of the molds 2 is provided with an end shell member 3C which is supported by a first fixed wall 14A extending from the longitudinal base plate 1B in the example of FIG. 1 or a first support 14 supported on the support beams 1 ', 1B' '. 2. In this second example, a plurality of molds 3 are pressed together by a pressure plate 15 located at the right end of the row 13 of molds 3, by which all molds 2 are kept in close contact with each other. The pressure plate 15 is initially moved in the example of FIG. 1 by the hydraulic cylinder 16 and after maximum compression of the mold row 13, spacers 17A, 17B are inserted between the second fixed wall 14B projecting perpendicularly from the longitudinal base plate 1B and the pressure plate 15. which maintain a permanently adjusted tight contact between the molds 2, which is achieved by means of a hydraulic cylinder 16 with a piston. Upon insertion of these spacers 17A, 17B, the fluid pressure in the hydraulic cylinder 16 can be released and the piston rod of the hydraulic cylinder 16 can be withdrawn from the pressure plate 15 to the position shown in FIG. 1.

After pressing the entire row 13 of the molds 2 together, a rectangular circumferential frame 19 is provided on the upper surface 18 of the row 13 of the molds 3, provided with a rubber seal 20 on its underside. with the top surface 18 of row 13 form two shallow tray 29 for the concrete mix Z into its bottom, i.e. in the upper surface 18 of rows 13 of mold 2 j ^e provided a series of filling openings 21 and the longitudinal feed slots 21A which can flow thin concrete from into the inner mold cavities of the molds 2 for forming concrete bodies 10. The concrete mixture Z is filled up to the edge of the inner mold cavities, i.e. up to the mouth of the filling openings 21 in the plane of the upper surface 18 of the row 13 of molds 3. provided with a flat face on its upper side after being removed from the molds X.

The filling openings 21 form essentially the filling channels of the molds X, but unlike normal inlet channels, they are so short that they do not form a boss but only a planar surface on the upper side of the concrete body 10. The layer of concrete mixture Z in the shallow container 29 on the top surface 18 of the mold row 13 is processed by moving a manually or mechanically actuated lath, which sets the concrete mixture Z in motion, thereby promoting its flow through the filling holes 21 into the mold cavities of the mold 3. the entire supply of the concrete mixture Z is consumed and the molding spaces of the molds χ are filled.

In an alternative exemplary embodiment, the molding spaces of the molds X may be filled using a funnel filling trough 22 provided with rubber sealing strips 23 at the lower edges of both its side walls, through which the filling trough 22 is mounted on a series of 3D molds at the edges of the longitudinal filling slots 21A. The filling chute 22 can be moved along a series of molds 3D, performing simultaneously a scraping and wiping action, in particular if it is provided with transverse wiping plates 24, also serving as reinforcement of the filling chute 22 at the same time.

The penetration of the concrete mixture Z into the 3D molds is also facilitated by the vibration of the molds XD, so that the filling process also includes continuous or intermittent vibrations, the type of vibration used being selected depending on whether the filling is carried out manually or by machine. The longitudinally displaceable feed trough 22 moving in the direction of arrow F also has the additional advantage of being able to slide along a series of 3D molds until all the supply of concrete mixture Z in the feed trough 22 is consumed.

Because in this type of molding process, it is difficult to determine the exact amount of concrete mixture Z to fill all mold cavities XD, it is preferable to use rows containing a greater number of 3D molds than should actually be filled and fill them all at once until the Z mix is consumed.

At the same time it is necessary to understand one continuous process of gradual filling of many forms of 3D. In practice, a large number of molds X, 3D at one time are filled, even in the example with a shallow container 29, circumscribed by the peripheral frame 19, or in another example with a funnel-shaped trough 22. Particularly in the exemplary embodiment with a shallow container on the top surface 18 of the mold row 13, all molding spaces χ are filled simultaneously because the concrete mixture Z poured into the container within the rectangular peripheral frame 19 starts to flow into the filling holes 21 at once. In order to avoid incomplete filling of some molds χ with concrete mixture Z, cover plates 25A, 25B, for example of plastic, which overlap some of the filling openings 21 and do not allow the shallow container 29, i.e. the top surface 18 of the mold X series, concrete mixtures Z to penetrate into the overlapped forms χ. After the molding spaces χ in the right part of FIG. 2 are completely filled with concrete mixture Z, some of these cover plates 25A may be provided. 25B should be removed if the concrete mixture Z remains in the shallow container to gradually fill the molding spaces of the other molds 3 until the concrete mixture is completely consumed.

After all mold cavities 3 have been filled, the rectangular circumferential frame 19 which bounded the shallow container 22 is lifted by conventional lifting means, for example in this example by hydraulic cylinders 28 cooperating with vertical guides 1C, 1C ¹ and conventional securing means to prevent unwanted falling. peripheral frame 19.

When using a funnel, this covering procedure does not have the same effect, since the same result of the filling trough 22 of FIG. 5 of some molds 3 can be achieved by sliding the filling trough 22 in the direction of arrow F along a series of molds 3D. Once the 3D molds are perfectly filled with the concrete mixture Z and this perfect filling is ensured in particular by vibration, an elevated layer of material is left over the filling slots 21A and the concrete mixture Z is compacted inside the 3D molds. The concrete mixture Z is compacted by vibrations applied for 3 to 10 minutes in the vertical direction, whereby vibrations can be generated, for example, by vibrators 26 fixed to the underside of the longitudinal base plate 1B of Fig. 1 or the longitudinal beams 1B ¹ . 1B of the example of FIG. 2 and having the possibility of changing the operating mode and controlling the amplitude and frequency of the oscillations according to the desired acceleration values.

The vibrations are intended not only to compact the concrete mixture Z, but also to create a perfectly smooth surface of the concrete body 10 during molding. For the production of concrete bodies 10 of this type, a concrete mixture Z containing, in mass, is used. 40% of water, 16% of Portland cement, and the remainder being a filler with a selected grain size curve, including small pebbles, stones or gravel found in sands, iron scales and other high density minerals used to make concrete blocks; and bodies as inertial masses.

During the vibration of each mold 3, higher-weight particles P, such as aggregates in contact with the mold wall 2, are transmitted a higher kinetic energy which causes these particles P to move away from the mold surface 2 and displace them towards the center of the mold cavity. Thus, the material components containing the smallest particle size and smallest density remain on the outside of the concrete body 10 in contact with the mold surface. In this particular case, these components of the mixture mainly comprise cement and water, thus forming a surface cement slurry. After the vibration is finished, the finished concrete body 10 is removed from the mold 2 and cured. After being removed from the mold 2, the concrete body 10 has a perfectly smooth surface, has precise dimensions and shape, and in addition has an increased resistance to chemicals, while not increasing the strength, resulting from the concentration of the very low porosity and higher binder content in the surface layers. When removing the concrete bodies 10 from the molds 2, it is only necessary to remove the spacers 17A, 17B after loosening the fastening means, in particular pins or screws, or to release the pressure plate 15 on which the row 13 of the molds 2 is supported.

By this operation, the individual molds 3 are released from each other and are ready to remove the concrete bodies 10 from the mold cavities. Removal is facilitated by the extremely smooth surface area of the mold cavity and the non-stick nature of the plastic used to make the molds 3, and further ease of removal can be achieved by conventional separators and demoulding agents such as diesel, blends of vegetable oils, paraffin, wax components. other substances which can be sprayed onto the molding surface of the mold 3 before assembling the molds 3 into the row 13. It is also possible to add one of the liquefaction agents to the concrete mixture Z.

Claims (7)

PATENT CLAIMS Apparatus for the manufacture of concrete mixture bodies comprising a plurality of molds provided with filling holes and mold cavities and supported on a support base, which is equipped with a vibrating device, and a device for conveying the concrete mixture into molds, characterized in that the plurality of molds (3) comprising a series (13) of pairs of mold parts (3A, 3B) each having a contact surface on the side facing the other pair (3A, 3B) in which molding recesses (9A, 9B) are formed which are parts of the mold cavity, and at least one of the mold parts (3A, 3B) is provided with a filling opening (21) opening into an upper surface (18) of the mold row (13) perpendicular to the contact surfaces of the parts (3). 3A, 3B) of molds (3) provided with molding recesses (9A, 9B). Device according to claim 1, characterized in that the plastic molds (3) are provided with positioning magnets (27) mounted on the outside of the walls of the shell parts (3A, 3B) of the molds (3) facing away from the contact surfaces with the molding recesses. (9A, 9B), and dividers (7) of iron-based material held between the contact surfaces with the molding recesses (9A, 9B) against the positioning magnets (27). Device according to Claim 1 or 2, characterized in that the planar upper surface (18) of the row (13) of the molds (3) is bounded by a peripheral frame (19) provided with a gasket (20), in particular rubber, on its underside. surrounding the filling holes (21) of the molds (3). Device according to claim 3, characterized in that the circumferential frame (19) is supported on at least two mutually opposing piston rods of the lifting hydraulic cylinders (28) and is slidably supported on vertical guides (1C, 1C '). Device according to at least one of Claims 1 to 4, characterized in that the row (13) of the molds (3) is provided on its upper surface (18) with a funnel-shaped trough (22) mounted by means of sealing strips (23) on the lower the edges of the filling trough (22) on the upper surfaces (18) of the row (13) of the molds (3) and provided with an elongate filling mouth having a width equal to the width of the filling slots (21A) of the molds (3D). Device according to at least one of Claims 1 to 5, characterized in that the row (13) of the molds (3) is provided on its upper surface (18) with a concrete mixer (29) movable on the upper surface (18). 18) a series (13) of molds (3). Apparatus according to claim 6, characterized in that the concrete mixture container (29) comprises at least one removable cover plate (25A, 25B) disposed above the at least one filling opening (21) of the molds (3).