EP0476245B1 - Process for making concrete products - Google Patents

Abstract

The invention relates to a process for moulding the most varied concrete products (24), in which the moulding space (20) of a mould (13) defined by mould core (14), base ring (21) and mantle (17) is filled with concrete material, which is compacted, and a top ring (43) is pressed at the top into the end of the moulding space, which top ring (43) moulds the end face of the concrete product (24). Before and/or during the pressing-in of the top ring (43), at least one opening (28) is formed in the moulding space (20), via which opening (28) the excess concrete during the pressing-in of the top ring (43) is displaced from the moulding space (20). This opening (28) is then closed again. The opening (28) is formed at the top end between the top ring (43) on the one hand and the mould core (14) or the mantle (17) on the other hand, and in fact by displacement of the mould core (14) relative to the mantle (17) with base ring (21) and concrete product (24) in such a way that the part forming the opening together with the top ring (43) lies deeper than the remaining part running flush at the top. After the top ring (43) is pressed into the predetermined length dimension of the concrete product (24), the axial relative displacement back again into the initial position takes place. <IMAGE>

Description

The invention relates to a method for producing concrete parts of the type mentioned in the preamble of claim 1.

In a known method of this type, in which the concrete is compacted by shaking and the method is therefore also called vibratory pressing method, the procedure is known as follows. The mold consists of several moving parts, namely a mold core, a mold jacket, a base ring and an upper ring that is moved down later. In addition, the shape has a vibrator, e.g. B. at least one arranged in the interior of the mandrel, on. In this known method, the top ring, which is still open at the top, is filled with concrete via a loading device, which is compacted with simultaneous vibration. Before the completion of the compression process, the mold is pulled off at the top by retracting the loading device and by a scraper ring moved therefrom. The upper ring is then moved from above with further shaking and pressed into the molding space, thereby shaping the upper end of the concrete part, in particular a pointed end there. During this press-in process, further compression takes place, which enables the tip end to be shaped. The length of the concrete part to be produced is thus achieved by further compacting the concrete. However, this further compaction of the concrete cannot be set accurately and reproducibly, since the compaction curve is strongly influenced by mixture fluctuations. The result of this is that a predetermined length of the concrete part cannot be adhered to precisely and reproducibly and that large automatic fluctuations in the mixture, particularly in the area of the water content of the concrete, do not allow a trouble-free automatic production process.

To avoid these disadvantages, especially in the production of large concrete parts, eg. B. large pipes, machines have been used in which a pivotable conveyor belt is arranged in the center above the mandrel, the concrete is fed from the loading device, this pivoting belt pivots around the mold center and in turn fills the concrete directly into the mold space. So that the upper ring can be pressed in later, the mold space is not completely filled by means of this pivotable conveyor belt. However, this is difficult because such a pivotable conveyor belt does not make it possible to fill uniformly over the entire diameter of the molding space. In addition, there are major problems when asymmetrical concrete parts, eg. B. egg profiles, rectangular profiles or the like. To be produced with different wall thicknesses; because in this case the control of this swiveling conveyor belt is extremely complex in order to achieve evenly even filling of the molding space.

In DE-A-33 23 340, a proposal is described in connection with the same problem which, in addition to the upper ring, provides a single ring which can be displaced relative to it in the extension of either the mold core wall or the mold shell, this extension being pressed onto the mold core or when the upper ring is pressed in The molded jacket is put on and then the upper ring, overlapping the extension, is pressed on. In this way, when the upper ring is pressed on, concrete should not be pressed out inwards onto the upper side of the mold core or outwards onto the upper side of the mold shell in the phase in which when the upper ring is pressed in, the mold space in this upper region is still open and concrete is pressed out of it can be. This device, as an additional element, makes the extension necessary in addition to the upper ring and leads to additional sealing problems where the extension sits on the top of the mold core or the mold shell. In this proposal, it is stated as a disadvantage that in any case concrete, which has previously been compacted, can be pressed out of the mold at the top and pressed inwards or outwards, where it can lead to contamination, malfunctions or the like.

The invention has for its object to provide a method of the type mentioned in the preamble of claim 1, by means of which molded concrete parts can be produced in exactly reproducible length and in an automated manufacturing process while maintaining small tolerances.

The object is achieved in a method of the type mentioned according to the invention by the features in the characterizing part of claim 1. The invention is based on the knowledge that the production of concrete parts with a precisely specified length by pressing in the upper ring can not be achieved or can hardly be achieved with an accompanying compression of the concrete material located in the molding space, because different densifications result from mixture fluctuations. The basic idea of the invention is therefore to more or less fully compact the concrete when filling the mold, it being possible to consciously work with longer shaking times, so that the concrete is always optimally compacted regardless of mixture fluctuations, and essentially when compaction is achieved or Completion of the verdich tion process to make the end of the concrete part to be shaped, in particular the pointed end, and the exact length of the concrete part. The production of the exact length is achieved in that when the upper sleeve is pressed in by the pressing action, a corresponding amount of excess, compacted concrete material is displaced through the at least one opening from the molding space and the exact length of the concrete is thus compacted not by compression but at least essentially by displacement Concrete material is adjusted until the specified length is reached. The term at least one opening, through which excess, at least predominantly compacted concrete can be displaced from the molding space, means any form of an opening, in particular also one which, when the upper ring is moved down, between the inside of the ring and the mold core or between the outside of the ring Upper ring and the shaped jacket is present. It is not a question of the naturally existing, in the same plane opening between the upper ring and the mold core or mold shell, which is present when the upper ring is pressed into the molding space, as long as the molding space is still open at the top during this pressing. Such an axially directed mold cavity opening, which runs flush with the flush mold core top and mold shell top, is sealed in the known method explained at the outset by pressing down the upper ring, with the aim of precisely avoiding that concrete material in this area is pressed out and onto the mold core or mold shell becomes. In the basic principle of the invention, excess, almost ready-compacted concrete is deliberately displaced out of the molding space through the at least one opening in the molding space when the upper ring is pressed in, this displaced concrete being able to be taken up and reused. The method according to the invention is suitable not only with great advantage for the production of unreinforced concrete parts, but in particular also for the production of such concrete parts, the inserts, in particular reinforcements, for. B. reinforcement cages and / or inner linings, risers or the like. Have. Especially in the manufacture of such reinforced concrete pipes or pipes with inner lining, the length of the concrete part can be reproduced exactly in relation to the length z. B. a reinforcement cage or an inner lining. It is known that concrete parts, e.g. B. pipes, which are provided with reinforcement cages or with an inner lining, due to the rigidity of the reinforcement cage or the inner lining after demolding show no signs of settlement, because the inserts are rigid in length. Conversely, concrete parts that are not reinforced or not provided with an inner lining, in particular pipes, show signs of settlement after demolding due to the elasticity of the concrete. With the method according to the invention, however, the settlement phenomenon can now be exactly compensated with the same shape, even in the case of unreinforced concrete parts, e.g. B. in that in the manufacture of the upper ring when it is pressed in, this is made to a nominal size + the corresponding addition.

It can be advantageous if the process features are used in claims 2-4. As a result, the concrete is displaced when the upper ring is pressed in and the predetermined length of the concrete part is produced where the upper ring is pressed in, so that relatively few displacements of the concrete material to be displaced occur.

A further particularly advantageous embodiment of the method results from claim 5. For an inverted shape of the upper ring, i. H. in the case of reverse muffing, the features in claims 6 and 7 are advantageous.

As a result of this axial relative displacement between the mold core on the one hand and the molded jacket with the base ring and the already formed concrete part on the other hand, a gradation and thus an annular opening is now achieved in the upper area, starting from a flat and flush course, this opening being a radial one, which is either open radially inwards if it is formed by a protruding concrete part and the lower top of the mold core, or if it is formed in the opposite direction by the moldings on the outside and by the lower mold table of the mold shell, it is directed radially outwards. Since the concrete to be displaced is only pressed onto the upper side of the mandrel or, in the event of reverse sealing, onto the upper side of the molding table, this displacement of the concrete, even large quantities of concrete, is possible quickly and easily. As a result, the method according to the invention for the production of exact concrete part lengths can also be used advantageously in the production of such concrete parts which do not have a symmetrical cross section, e.g. B. for the production of egg profiles, concrete pipes with a sole, rectangular profiles with different wall thicknesses or the like. The method according to the invention can be used for practically any type of shape and machine, without modifications or additional elements being necessary. The only prerequisite is working according to the vibratory press method, with only the manufacturing sequence being used for the method according to the invention and so the control of the individual manufacturing processes must be changed. It has been shown that large concrete parts can be easily produced with the method according to the invention in a reproducible manner and in an automatic manufacturing process, for. B. Pipes with a nominal width of 2 m and a length of 3 m. In the case of such large pipes, an automatic production process was previously impossible. With reproducible quality and exactly the same length, the method according to the invention permits an automatic production process for this. Is worked with relative displacement according to claims 5, 6 or 7, for. B. with a stationary mandrel, after at least substantially completed the filling and compaction process the shell with the base ring and concrete part is raised relative to the fixed mandrel by the predetermined amount. Then the shaped concrete part with its inner surface projects axially by this amount above the top of this mandrel, this amount specifying the height of the ring opening defined at the outset. During this upward or subsequent displacement, the upper ring is pressed on from above until the specified exact length of the concrete part is reached. Like the axial pushing up, this pressing in of the upper ring is precisely controlled via limit switches, displacement measurement or the like, so that a very precise length of the concrete part can be reproducibly achieved. As soon as the latter has been reached, the molded casing, together with the base ring and the concrete part, is lowered back to the starting position by the aforementioned amount relative to the stationary mold core, and the pressing process of the upper end of the concrete part, in particular the pointed end, is completed. The upper ring can then be lifted upwards away from the mold and the concrete part can be removed from the mold in the manner provided by the respective machine. In the case of relative displacement, it is advisable to continue shaking, as well as when the upper ring is pressed in, in order to facilitate these processes. Even after the upper ring has been pressed in and the tip end has been shaped, shaking can be continued to achieve a good shape of the tip end. It can be seen that with this relative displacement and thus the production of the annular opening in the upper region of the mold between the concrete part and the mold core or, in the case of reverse sealing, between the concrete part and the mold shell, the length of the concrete part in a certain range is independent of the length of the mold shell alone can be adjusted by specifying the degree of relative displacement and specifying the depth of immersion of the top ring in the mold space. The method according to the invention above all also enables the production of such concrete parts that are provided with reinforcement or inner lining that leads up to the upper end of the concrete part, in which case reproducible precise shaping of the tip end and production of an exact predetermined concrete part length is possible, although the upper ends of the reinforcement cages or the inner lining protrude into the end of the pointed formation.

Further advantageous refinements of the method according to the invention result from claims 8-20.

Further details and advantages of the invention emerge from the following description.

The full wording of the claims is not reproduced above solely in order to avoid unnecessary repetition, but instead is referred to only by mentioning the claim numbers, whereby all these features of the claim are to be regarded as being explicitly disclosed here and essential to the invention. All of the features mentioned in the above and the following description, as well as the features that can only be inferred from the drawing, are further components of the invention, even if they are not particularly emphasized and in particular are not mentioned in the claims.

• Fig. 1 eine schematische, teilweise geschnittene Seitenansicht einer Maschine zum Herstellen von Betonteilen, wobei in der Form links ein Betonteil mit Bewehrungen und rechts ein Betonteil mit einer Innenauskleidung gezeigt ist,
• Fig. 2 - 5 jeweils eine schematische, teilweise geschnittene Seitenansicht der Form in größerem Maßstab und in einzelnen Stadien des Herstellungsverfahrens gemäß einem ersten Ausführungsbeispiel.

The invention is explained in more detail below with reference to exemplary embodiments shown in the drawings. Show it:

• 1 is a schematic, partially sectioned side view of a machine for producing concrete parts, a concrete part with reinforcements being shown on the left and a concrete part with an inner lining on the right,
• 2-5 each show a schematic, partially sectioned side view of the mold on a larger scale and in individual stages of the manufacturing process according to a first embodiment.

For a better understanding of the invention, the basic structure of a machine 10 and its mode of operation are first explained with reference to FIG. 1, this being an exemplary embodiment of a machine 10. The machine 10 is suitable for producing concrete parts 24 of various shapes, both round and non-round, for example egg-shaped, angular or the like. Shaped concrete parts 24. The concrete parts 24 to be produced include, for example, pipes, manhole rings, shaft necks or special parts such as square or rectangular shaft elements, heating ducts, retaining wall elements, joint pieces, branches or the like. As concrete parts to be manufactured, in particular name: concrete pipes according to DIN 4032 and reinforced concrete pipes according to DIN 4035, manhole rings according to DIN 4034, as well as special parts, e.g. B. concrete parts made of fiber concrete or polymer concrete, as well as rectangular elements, square shafts or the like .. Both concrete parts 24 can be produced without inserts and with inserts. 1 such reinforcements are shown in the form of reinforcement cages in the concrete part 24 shown on the left of the center line of the form and in the form of an inner lining 37 for the concrete part on the right of the center line, this inner lining 37 representing a corrosion protection lining that the concrete part 24 on the inside as possible lining the entire height and all around. Even if this is not shown, concrete parts 24 can also be produced which, in addition to the inner lining 37, are also provided with reinforcements 36, should this be desired. Concrete parts 24 can also be produced which have neither reinforcement 36 nor an inner lining 37. The concrete parts 24 to be produced can also have ascending elements, such as crampons or the like, which are not shown here.

The machine 10 operates fully automatically. Some parts of the machine 10 are arranged under the floor. They are located in a shaft 11. This applies to a carrier 12, which is only indicated schematically and to which a mold 13 is interchangeably attached. The mold 13 has a mold core 14, which is stationary here, which is hollow on the inside and can be exchangeably fastened on at least one central vibrator (not shown further). The mandrel 14 is e.g. round and provided on its top with a circular core cover 15, which is followed by a cylindrical core wall 16 leading downwards. The interchangeable fastening of the mandrel 14 has the sense of being able to produce differently sized and / or shaped concrete parts 24 by exchanging it for another mandrel.

Part of the form 13 is also an outer, interchangeable mold jacket 17, which is also cylindrical. The molded jacket 17 carries a striving flange 18 at the top, which forms a molding table there. The mold jacket 17 surrounds the mold core 14 at a radial distance, forming a mold space 20 therebetween. In the lower area, a support ring 19 is seated on the mold core 14. At the bottom, the mold space 20 is closed off by a base ring 21, also called a sleeve, which serves to shape the lower front end of the molded part 24 and which is slipped over the mold core 14. The bottom ring 21 can e.g. after insertion on the machine side, by moving a corresponding lifting carriage downwards, together with the mold jacket 17, are moved over the mold core 14 into the lowered position in which the base ring 21 can rest on the support ring 19. This corresponds to the position shown in FIG. 2. The mold jacket 17 is pressed with its lower end against the base ring 21 on which it rests, so that the molding space 20 is closed there. The bottom ring 21 can later serve to facilitate the removal of the finished concrete part 21.

The machine 10 is provided above the shaft 11 and to the side of the mold 13 with a longitudinally displaceable loading and distribution device 30 of a known type, which is referred to below only as a loading device. The latter can be moved back and forth along a horizontal guide 31 in the direction of arrow 32, namely between the starting position shown in FIG. 1, left, and the working position indicated by dashed lines, right. In the initial position, the charging device 30 is located laterally next to the mold 13, without the latter and in particular the open end of the molding space 20 being covered by parts of the charging device 30. In the dotted working position moved to the right and forwards in the direction of arrow 32, the loading device 30 is located above the open upper end of the molding space 20, so that 30 can be filled into the latter by means of the loading device 30.

The loading device 30 has in the usual way a schematically indicated storage container 33 for the fresh concrete, further a conveyor belt 34 and underneath this a working agitator in a frame 35 which is only indicated schematically and which is not further visible.

To fill the mold 13, the charging device 30 is moved in the direction of the arrow 32 over the mold 13, fresh concrete being conveyed from the storage container 33 via the conveyor belt 34 to the mold 13 and being filled into the mold by means of the agitator in the frame 35.

The machine 10 can also have a concrete smoothing device, not shown, which either forms a separate part of the machine or is integrated in the loading device 30. The smoothing device can be moved along a horizontal plane above the form 13 filled with concrete when the loading device 30 is retracted in accordance with arrow 32 and causes the upper side to be smoothed out when retracting. The smoothing device can e.g. be integrated in the frame 35.

The machine 10 also has a press-in device 40, which is only indicated schematically and, in the exemplary embodiment shown, has a holder 42 which can be lowered in the direction of the arrow 41 and can be moved in the opposite direction by means of a drive (not particularly shown), to which an upper ring 43, also called an upper sleeve, is attached. The task of the press-in device 40 is to Filling the mold space 20 with fresh concrete and compacting when filling by running central vibrators to further compact the concrete if desired, and to give the upper end face of the concrete part 24 to be shaped the shape corresponding to the upper ring 43, in particular in the concrete part 24 thereby the upper tip end form. For this purpose, the press-in device 40 is moved into its working position indicated by dashed lines, and in this the holder 42 is pressed down into the open end of the molding space 20 together with the upper ring 43 by means of a drive (not shown) in the direction of arrow 41.

The press-in device 40 has a carrier 44, which is here approximately sled-shaped, only indicated schematically, and a holding arm 45 striving from it, on the e.g. cantilevered end of the holder 42 is arranged with the upper ring 43. The press-in device 40 can be moved in the horizontal direction according to arrow 46 by means of a drive (not particularly shown) between the starting position shown with solid lines on the left and the working position shown with dashed lines on the right. A guide 47 is used for this purpose, along which the carrier 44 can be displaced in the direction of the arrow 46. Further details can be found in DE-A-37 04 881.

As shown in FIG. 1, several ejection cylinders 25 are arranged in the shaft 11 below the base ring 21, which are operated by pressure medium, in particular consist of hydraulic cylinders and are used for lifting and lowering. The ejection cylinders 25 engage from below on the base ring 21, on which the shaped jacket 17 stands. In this embodiment, the bottom ring 21 is held and clamped on the shaped jacket 17 by means of a plurality of holders 26 which are driven by a drive 27, e.g. a hydraulic drive can be actuated.

The previously known production method for producing concrete parts 24 is described below. For this purpose, the mold 13 is brought into the starting position shown in FIG. 2. For this purpose, the mold jacket 17, seated on the base ring 21, is lowered over the mold core 14, the base ring 21 being seated on the ejection cylinders 25 located underneath. If a concrete part 24 with inlays, e.g. with reinforcements 36 (FIGS. 1-5 left half of the mold) and / or with an inner lining 37 (FIGS. 1-5 right half of the mold), the reinforcement 36 or the inner lining 37 is also introduced, these also being on the foot side stand up the bottom ring 21. The shaped jacket 17 is fixedly connected to the bottom ring 21 in the region of its lower end via the sleeve-shaped holder 26 actuated by its drive 27, specifically in the area of the outer edge of the bottom ring 21 extending outside the shaped jacket 17. The ejection cylinder 25 becomes the unit , consisting of base ring 21, shaped jacket 17 and, if desired, reinforcements 36 and inner lining 37, lowered so far into the pit 11 that the top of the shaped jacket 17, namely its flange 18 forming the forming table, is flush with the core cover 15 of the shaped core 14 completes, as shown in FIG. 2. In this lowered position, the bottom ring 21 sits on the inside on the core-side support ring 19, so that the discharge cylinders 25 are relieved, which in this position have no contact with the bottom ring 21 and the other parts fixed thereon, but are lowered somewhat further. Now, by means of the loading device 30, which moves into the position shown in dashed lines in FIG. 1, concrete is poured into the mold space 20, which is open at the top and is compacted by the rotating central vibrator while being vibrated at the same time. In this previously known manufacturing method, after filling the mold space 20 and before the completion of the compression process, the mold 13 in the upper region, where the core cover 15, the flange 18 of the mold jacket 17 and the concrete part 24 are flush with one another, by retracting the loading device 30 by means of the explained smoothing device, for example a scraper ring, just pulled off. Subsequently, with further shaking, the upper ring 43 is moved downward in the direction of arrow 41 by means of its drive (not shown further) and pressed into the open end of the molding space 20, thereby shaping the upper end face of the concrete part 24, e.g. there formed a so-called pointed end. In the known production method, this compression process of the upper ring 43 results in further compression, which only makes it possible to give the upper end of the concrete part 24 the shape corresponding to the upper ring 43, e.g. to shape a top end there. During this pressing in of the upper ring 43 and shaping of the tip end with accompanying further compression, pressing is continued until the desired length of the concrete part 24 measured in the vertical direction is reached. This length is achieved by further compacting the concrete. It has been shown that this further compaction of the concrete cannot be set accurately, e.g. the compression curve is strongly influenced by mixture fluctuations. This leads to the fact that the length of the concrete part 24 cannot be exactly adhered to and that, in the event of large mixture fluctuations, in particular in the area of the water content of the concrete, a problem-free automatic production sequence is not possible. These disadvantages explained are eliminated by the invention and the method explained below.

The state of the mold 13, which is shown in FIG. 2, is assumed below. The bottom ring 21 with the molded jacket 17 and that in the molding space 20 as far as shaped concrete part 24 sit on the support ring 19 of the mandrel 14. The upper side of the mold 13 is essentially flush, ie the concrete part 24 and the flange 18 run at least substantially within the plane of the core cover 15, which is oriented at right angles to the longitudinal central axis of the mold core 14. The filling and compression process is at least essentially complete. The form 13 has just been pulled off on the flush top.

Now, before and / or during the pressing in of the upper ring 43, at least one opening 28 is formed in the mold space 20, specifically by removing parts of the mold 13 delimiting the mold space 20. In the exemplary embodiment shown, the at least one opening 28 is formed at the upper end of the mold 13, and there between the upper end of the mold core 14 on the one hand and the upper ring 43 on the other hand (FIG. 4). This at least one opening 28 is formed before and / or during the pressing in of the upper ring 43 in that, starting from the flush end of the mandrel 15, the mandrel 17 with flange 18 and the concrete part 24, an axial relative displacement between the mandrel 14 on the one hand and the Shaped jacket 17 together with the bottom ring 21 and the concrete part 24 on the other hand in a displacement position shown in FIGS. 1 and 3 and is carried out in such a way that the top of the mold core 14, eg the core cover 15 by a predetermined dimension x deeper than the top 18 of the molded jacket 17 and the top of the concrete part 20. In this way, when the upper ring 43 moves down and is pressed in, an annular opening 28 is formed at the upper end between the upper ring 43 and the mandrel 14. When the upper ring 43 is pressed in, excess concrete, which is designated 29 in FIGS. 4 and 5, can be displaced from the molding space 20 via this annular opening 28. In the embodiment described, since the upper side of the mold core 14 is lower than the upper side 18 of the molded casing 17 and the upper side of the concrete part 24, this excess concrete is in this arrangement through the annular opening 28 inwards and onto the upper side, e.g. the core cover 15, the mandrel 14 displaced. This displacement of the excess concrete 29 continues until the exact length of the concrete part 24 is reached when the upper ring 43 is pressed in. In the concrete part 24 shown in FIGS. 1-5, which in the exemplary embodiment is provided with reinforcements 36 on the left of the center line and with an inner lining 37 in the exemplary embodiment on the right of the center line, the upper ring 43 can therefore be exactly to the predetermined length of the concrete part 24 despite these inserts be pressed in, although eg in the reinforcement 36, the inner reinforcement cage projects with its upper end into the tip end formed at this end of the concrete part 24 and extends almost to the end of the concrete part 24. This is also possible in the embodiment with the inner lining 37, which extends with its upper end to the upper end of the concrete part 24. So if concrete parts 24 are to be produced, which with inserts, e.g. Reinforcements 36 and / or inner lining 37 are to be provided, it is possible to determine the length of the concrete part 24 exactly in relation to the length of these inserts, in particular reinforcements 36 or inner lining 37. It goes without saying, however, that concrete parts 24 are also produced without any deposits. With such unreinforced concrete parts, it is possible to press the top ring 43 exactly to a length of the unreinforced concrete part that corresponds to the target length plus an added settlement dimension of the concrete part, if it can be assumed that such an unreinforced concrete part after the Manufacturing and demoulding continues. If such a settlement is not to be expected, the upper ring 43 can also be pressed into the predetermined final length of the concrete part 24 even when producing an unreinforced concrete part.

After reaching a length of the concrete part 24 generated when the upper ring 43 is pressed in, an opposite axial relative displacement between the mold core 14 on the one hand and the mold jacket 17 together with the base ring 21 held thereon and the concrete part 24 on the other hand is carried out back into an initial position, which is shown in FIG. 5 and in which the mold core 14, the mold jacket 17 with its upper flange 18 and the concrete part 24 are flush with the respective upper side again. In this starting position, the molding space 20 is closed by the upper ring 43.

In the first exemplary embodiment shown in FIGS. 1-5, the mold 13 is designed in such a way that the mold core 14 is arranged in a stationary manner and is thus also held stationary during this relative displacement. In this case, the axial relative displacement takes place in that, with respect to the stationary mandrel 14, the shaping jacket 17 together with the base ring 21 held thereon and the concrete part 24 from the flush position according to FIG. 2 by the dimension x upwards into the displacement position according to FIG. 3 and 4 and later can be moved back to the starting position according to FIG. 5. The peculiarity lies in the fact that a possibility is created only after the compaction process has been completed and in the case of at least substantially non-compactible concrete, that when the top rim is pressed in ges 43 for shaping the upper end of the concrete part 24 excess concrete, which must disappear from the mold space 20 when the upper ring 43 is pressed in, can be displaced through the opening 28 and thus the predetermined length for the concrete part 24 can be achieved when the upper ring 43 is pressed in can. In order to achieve this axial relative displacement of the mold shell 17 together with the base ring 21 and the concrete part 24 relative to the mold core 14 by the dimension x, the ejection cylinders 25 can be used, which are activated and by attacking the underside of the base ring 21 this unit relative to Lift stationary mandrel 14 by dimension x. The base ring 21 lifts off from the core-side support ring 19. For the opposite relative displacement back into the starting position, the ejection cylinders 25 can be activated in opposite directions, whereby, depending on the individual case, a relative displacement back into the starting position can also be achieved by pressing in the upper ring 43.

In another exemplary embodiment, not shown, the molded jacket 17 together with the base ring 21 and the concrete part 24 is instead held stationary, the molded core 14 then being moved relative to it in the described manner into the displacement position and back into the starting position. In this case, with the base ring 21 held stationary, the mold core 14 is moved downward by the dimension x into the displacement position according to FIG. 3 with seated parts. When the exact length of the concrete part 24 has been reached, the mold core 14 is moved in the opposite direction by the dimension x upwards again into the flush starting position according to FIG. 5.

In another embodiment of a mold 13, in which none of the elements forming the mold is stationary, the mold core 14, on the one hand, and the mold jacket 17 together with the base ring 21 and the concrete part 24, on the other hand, are relative to one another in order to reach the displacement position and to move back to the starting position described described postponed.

In the described embodiment according to FIGS. 1-5, an upper ring 43 is assumed, which according to its shape enables the manufacture of such a pointed end of the concrete part 24, the step of which is lower in the axial direction is on the outside. On the other hand, there are cases in which the upper ring 43 has an inverted shape and can form such an end on the concrete part 24 in which the axially lower step is located on the inside. In the case of such an inverted muff, the at least one opening 28 is formed in the molding space between the upper end of the molding jacket 17, 18 and the upper ring 43. In this case, before and / or during the pressing-in of the upper ring 43, the at least one opening 28 is formed in the mold space in that, starting from the flush end of the mold core 14, the mold jacket 17, 18 and the concrete part 24, an axial relative displacement between the mold core 14 on the one hand and the molded jacket 17 together with the base ring 21 and the concrete part 24 on the other hand is made in the displacement position in such a way that the molded jacket 17 with its upper side, in particular the flange 18, then runs a predetermined dimension x lower than the upper side 15 of the molded core 14 and the concrete part, so that when the upper ring 43 is pressed in between the latter, namely its outer ring area, and the mold jacket 17, 18, a corresponding ring opening is formed, through which concrete 29 has a corresponding amount to the outside and then to the top, in particular the molding table 18 , The shaped jacket 17 is displaceable. In this case, the charging device 30 is adapted accordingly, so that the scraper ring lifts upwards on the form 13 at the front and thus takes the excess concrete 29 with it.

The displaced in the described embodiment on the top 15 of the mandrel 14, excess concrete initially remains on the top 15 and is pushed during the next filling process in the manufacture of the next concrete part through the loading device 30 into the mold space 20, so that this amount of concrete 29 in each Working cycle for the production of the next concrete part 24 is used.

Even if it can be advantageous to press the upper ring 43 only after the filling and compression process has been completed, it can nevertheless be advantageous to press in the upper ring 43 and to form the at least one opening 28 by the described axial relative displacement by Dimension x should begin around the end of the filling and compression process.

When the concrete part 24 is produced, the compaction is carried out by vibrating, namely the at least one central vibrator located in the mold core 14. It can be advantageous if the concrete is fully compacted when the mold 13 is filled, with longer vibration times, so that the concrete is always optimally compacted, regardless of mixture fluctuations. Only when the compaction process has been completed can the tip end be produced by pressing in the upper ring 43 and the manufacture to the exact length dimension of the concrete part 24. This length can be inserted in a certain range regardless of the length of the molded jacket 17 by determining the relative displacement by the dimension x and by determining the depth of immersion of the upper ring 43 in the mold space 20 be put. The method is particularly advantageous in the production of concrete parts 24 in the form of reinforced concrete pipes or pipes with an inner lining 37, as shown in FIGS. 1-5, because the length of the tubular concrete part corresponds exactly to the length of the reinforcement cages 36 or the inner lining 37 can be determined.

Even if the method according to the invention has been explained above with reference to a machine 10 according to FIG. 1, this method can be used in almost all known machines which operate according to the vibratory pressing method, and this without machine changes or additional elements in the area of the mold 13 or on elsewhere are necessary. In order to work with the method according to the invention, all that is required is a change in the production sequence and the control of the individual production phases.

Another advantage of the method according to the invention, which enables the production of exact lengths of the concrete parts 24, is the production of concrete parts 24 with non-symmetrical cross sections, e.g. in the case of egg profiles, in concrete pipes with a base or the like. Due to the different walls, different amounts of concrete would normally have to be displaced in the circumferential direction in the known manufacturing process when the upper ring is pressed in.

In the method according to the invention, in which the concrete is displaced onto the upper side of the mold core 14, this is possible without any problems, because the concrete does not have to be displaced radially within the closed mold space 20, but rather because of the creation of the at least one annular opening 28 the concrete can dodge onto the top of the mandrel 14 and is only pressed out according to the displacement cross section. The method according to the invention enables a trouble-free automatic production process in the production of concrete parts 24 of various types, shapes and sizes and also for large pipes, e.g. those with a length of 3 m and a nominal width of 2 m.

During or after the relative displacement by the dimension x in the displacement position according to FIGS. 1 and 3, the upper ring 43 is pressed down by means of a drive until the exact length 1 of the concrete part 24 is reached. The axial relative displacement by the dimension x and the pressing down of the upper ring 43 are controlled precisely via limit switches or path measurements or the like, so that the length for the concrete part 24 can be reproducibly achieved exactly. As soon as the exact length is reached, the axial relative displacement by the dimension x is carried out back to the starting position according to FIG. 5 in the manner described. Then the process of shaping the upper end of the concrete part 24, in particular the tip end there, is completed. Subsequently, the upper ring 43 is moved back upward by its drive in the direction of arrow 41 and to the left in its starting position. The demolding of the manufactured concrete part 24 can then take place, which can take place differently depending on the machine type and method. E.g. De-molding takes place by activating the ejection cylinders 25, which, from below, extend the base ring 21 together with the molded jacket 17 and the molded concrete part 24 sufficiently far relative to the staitonal molded core 14, e.g. 500 mm, eject upwards, whereupon the parts mentioned can be completely removed from the mold core 14 by means of a crane or the like. Depending on the method, the concrete parts 24 produced are then removed together with the molded jacket 17. In the other case, the concrete parts 24 are immediately released and removed without a molded jacket.

Within the scope of the invention is also a procedure in which after the upper ring 43 has been pressed in to the exact length of the concrete part 24, the concrete part 24 with the molded jacket 17 and base ring 21 are then moved back into a lower position via an existing ejection carriage and then by means of the Upper ring 43 the top end of the concrete part 24 is finished pressed. The formwork removal process is then carried out in the usual manner by raising the mold jacket 17 and the discharge car, so that the concrete part 24 is completely detached and can be removed from the machine.

The concrete is compacted by shaking. This vibration is also taken in the displacement position during the axial relative movement between the mandrel 14 on the one hand and the form jacket 17 with the base ring 21 and the concrete part 24 on the other hand, furthermore when the upper ring 43 is pressed in and the excess concrete 29 is displaced from the mold space 20 and also in the axial direction Relative displacement by dimension x back to the starting position. The central vibrator is therefore switched on during these processes. Even if the exact dimension is reached when the upper ring 43 is pressed down and the closed state of the mold according to FIG. 5 is reached by a relative displacement by the dimension x, it is still possible to shake further in order to obtain a good shape of the upper end, in particular spiked to reach the concrete part 24 through the upper ring 43.

In another embodiment, not shown, one proceeds from the flush state of the mold 13 with filled and compacted concrete to form the at least an opening of the mold space 20 so that at least one element of the mold core 14 and / or the mold shell 17 and / or the base ring 21 and / or the top ring 43 is removed and this at least one opening thereafter when the required amount 29 of concrete is removed the mold space 29 has been displaced, is closed again by moving this part back in place. Such elements, which can be removed to form the at least one opening and can then be moved back into the starting position, are, for example, wall parts of the mold core 14 and / or the mold jacket 17, which can consist of flaps, slides or the like the concrete displaced through the openings created in this way is provided so that contamination of the mold 13 is avoided on the one hand and on the other hand this displaced concrete can be processed in the subsequent working cycle. In addition or instead, such a removable element that can be moved back into the starting position can also be part of the base ring 21. Finally, corresponding elements can be provided instead or simultaneously with the upper ring 43. This also realizes the basic principle according to the invention, in which, before and / or during the pressing in of the upper ring 43 in the mold space 20, at least one opening is formed through which excess concrete is displaced from the molding space 20 when the upper ring 43 is pressed in to the predetermined dimension of the concrete part 24 and then you close it again at least one opening afterwards. The invention is based on the knowledge that, after reaching a certain compaction state with the best possible compaction, regardless of mixture fluctuations, the concrete cannot be compacted further by compressing it in a closed mold space, at least not reproducibly and so that a predetermined length for the concrete part 24 is reproducibly possible. Therefore, the invention provides the basic idea of only at least substantially after the compaction process with almost full compaction has been achieved, by shaping the concrete part end, in particular spigot end, by pressing in the upper ring 43, this then pressing in the spigot end because of no further possible compaction of the concrete The predetermined length of the concrete part 24 can be produced in a simple manner by providing at least one opening 28 in the mold space 20 before and / or during the pressing in of the upper ring, through which excess concrete 29 is displaced from the mold space 20 when the upper ring 43 is pressed in until the predetermined length of the concrete part 24 is reached during this pressing-in process.

The method described is characterized in that it can be used in existing machines without the need for any additional or differently designed device parts, in particular in the area of the mold. Only the manufacturing process and thus the control of the individual manufacturing stages must be changed and adapted to it. The method makes it possible, on the one hand, to achieve the best possible compaction despite the mixture fluctuations in the concrete and, on the other hand, to always achieve exact predetermined overall lengths with regard to the concrete part to be produced, even if mixture fluctuations and compaction fluctuations should occur in the concrete.

Claims (20)

1. A method of making concrete parts (24), particularly parts of pipes, shaft rings, shaft necks or the like, in a mould (13) with a mould base (20) defined by a mould core (14), a bottom ring (21) and a mould shell (17), in which the mould space (20) is filled with concrete material (24) which is compressed and forces into the open end of the mould space a top ring (43) which bounds the mould space and which imparts to the end of the concrete part (24) a matching shape, particularly a pointed end, characterised in that before and/or during the pressing in of the top ring (43), at least one aperture (28) is formed in the mould space (20) and when the top ring (43) is pressed in, excess concrete (29) is forced out of the mould space (20) through this at least one aperture (28), after which the at least one aperture (28) is closed again.

2. A method according to Claim 1, characterised in that the at least one aperture (28) in the mould space (20) is formed by removing parts (14, 16, 17, 21, 28) which bound the mould space (20).

3. A method according to Claim 1 or 2, characterised in that the at least one aperture (28) in the mould space (20) is formed at the upper end of the mould (18).

4. A method according to one of Claims 1 to 3, characterised in that the at least one aperture (28) is formed in the mould space (20) between the top end of the mould core (14) and the top ring (43).

5. A method according to one of Claims 1 to 4, characterised in that before and/or during the pressing in of the top ring (43) the at least one aperture (28) in the mould space (20) is formed in that on the basis of the mould core (14), the mould shell (17) and the concrete part (24) in the mould space (20) being flush at the top, there is a relative axial displacement between the mould core (14) on the one hand and the mould shell (17) together with the bottom ring (21) and the concrete part (24) on the other, into a displacement position so that the top of the mould core (14), e.g. the core cover (15), extends by a given amount (x) deeper than the top (18) of the mould shell (17) and concrete part (24) and, when the top ring (43) is pressed in, an annular aperture (28) is formed between the top ring (43) and the mould core (14) to which concrete (29) can be forced inwardly and onto the top (15) of the mould core (14).

6. A method according to one of Claims 1 to 3, characterised in that the at least one aperture (28) in the mould space (20) is formed between the top end (18) of the mould shell (17) and the top ring (43).

7. A method according to Claim 6, characterised in that before and/or during pressing in of the top ring (43), the at least one aperture (28) in the mould space (20) is formed in that on the premise of the mould core (14, 15), mould shell (17, 18) and concrete part (24) finishing flush at the top in the mould space (20) there is a relative axial displacement between the mould core (14) on the one hand and the mould shell (17) with the bottom ring (21) and concrete part (24) on the other, into a displacement position so that the top of the mould shell (17), particularly with the mould table (18), extends by a certain amount (x) deeper than the top (15) of the mould core (14) and of the concrete part (24) and, when the top ring (43) is pressed in, there is formed between the latter (43) and the mould shell (17, 18) an outer annular aperture through which concrete can be displaced outwardly and onto the top (18) of the mould shell (17).

8. A method according to one of Claims 1 to 7, characterised in that once a length (I) of concrete part (24) created during pressing in of the top ring (43) is attained, there is an oppositely directed axial relative displacement between the mould core (14) on the one hand and the mould shell (17) together with the bottom ring (21) and the concrete part (24) on the other, back into a starting position in which the mould core (14), the mould shell (17) and the concrete part (24) all have their respective tops (15, 18) flush with one another.

9. A method according to one of Claims 1 to 8, characterised in that in the starting position the mould space (20) is closed by the top ring (43).

10. A method according to one of Claims 1 to 9, characterised in that the mould core (14) is kept stationary and the mould shell (17) together with the bottom ring (21) and the concrete part (24) are displaced relatively to it (14) into the displacement position and back into the starting position.

11. A method according to one of Claims 1 to 9, characterised in that the mould shell (17) together with the bottom ring (21) and the concrete part (24) are maintained stationary and the mould core (14) is displaced relatively to it (17, 21) into the displacement position and back into the starting position.

12. A method according to one of Claims 1 to 11, characterised in that the mould core (14) on the one hand as well as the mould shell (17) together with the bottom ring (21) and the concrete part (24) on the other are all displaced in relation to one another.

13. A method according to Claim 1 or 2, characterised in that to form the at least one aperture, at least one element of the mould core (14) and/or mould shell (17) and/or bottom ring (21) and/or top ring (43) is removed and upon the top ring (43) being pressed in, excess concrete is displaced from the mould space (20) through this at least one aperture and afterwards this at least one element is moved again on the spot in order to close the aperture.

14. A method according to one of Claims 1 to 13, characterised in that the pressing in of the top ring (43) and the formation of the at least one aperture (28) in the mould space (20) are started substantially towards the end of the filling and compaction process.

15. A method according to one of Claims 1 to 14, characterised in that pressing in of the top ring (43) and forming of the at least one aperture (28) start when the filling and compaction process is at least nearly completed.

16. A method according to one of Claims 1 to 15, characterised in that inserts, particularly reinforcing members (36), e.g. reinforcing baskets, inner linings (37), rising elements or the like are placed into the mould space (20).

17. A method according to one of Claims 1 to 16, characterised in that the top ring (43) is pressed in to the predetermined length (I) at the concrete part (24).

18. A method according to one of Claims 1 to 15, characterised in that the top ring (43) is pressed in to such a length of the non-reinforced concrete part (24) as corresponds to the desired length plus an allowance for settlement of the concrete parts.

19. A method according to one of Claims 1 to 18, characterised in that the concrete is compacted by riddling and in that riddling takes place also during the relative axial movement between the mould core (14) on the one hand and the mould shell (17) with the bottom ring (21) and the concrete part (24) on the other into the displacement position and also during pressing in of the top ring (43) and displacement of excess concrete (29) from the mould space (20) and also upon relative axial movement back into the starting position.

20. A method according to one of Claims 1 to 19, characterised in that riddling also takes place after the starting position is reached and while the mould space (20) is closed by means of the top ring (43).

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