FI110174B - Apparatus for the manufacture of a concrete product - Google Patents

Abstract

The present invention relates to a method and apparatus for producing a concrete product in an extruder casting machine, continuous-casting machine or similar equipment. The concrete mix is fed in a conventional manner through a space of delineated cross section, where the continuous-section product is given its desired shape. The concrete mix being cast is compacted during the casting process to the end of removing entrapped air and achieving a constant casting quality of the product. According to the invention, at least one of the compaction movements is a direction-controlled reciprocating compaction movement having at least one translational component in the direction of the casting flow of concrete and at least one translational component perpendicular to said at least one first translational component.

Description

110174

The present invention relates to a device for producing a concrete product according to the preamble of claim 1 by means of an extrusion molding machine, a sliding molding machine or the like.

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Elongated concrete products, such as hollow core slabs, are generally manufactured by extrusion molding machines or sliding machines. The casting machine consists of a conical feed hopper 15 below which one or more feed screws are located. The Ruu-vic thread is often followed by a mold mandrel, which continues as an auxiliary mandrel to support the cavity made in the product.

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The mold mandrel has a vibrator or other compacting device for compacting the concrete to be molded into the mold and mandrel. In addition, the casting machine has an upper traction bar • · forming the top edge of the mold, and generally the mold edges «· · are formed by side traction beams. The trowels seal * * the mass to be cast and finish the cast piece. ·: Surface. Vibration can also be done using vibration in addition to or instead of • * · · 25 rubs. Extruder casting machines are \ continuous casting machines that move forward on the die surface due to the reaction force caused by the feed screws.

• · * · · I · • · ·. Extruder casting machines have been in development for a relatively long time, and the first casting machines were designed in the late 1960s 2 110174. Initially, the operation of casting machines was based on the traditional vibration technique, whereby the compaction of the concrete was achieved by various vibrations. Vibration also substantially facilitates the flow of concrete 5 in the machine. In vibration, the pulp particles receive such high velocities that the impulses of their mutual collisions are significant and cause particle displacements and thus concrete compaction. The frequency of vibration has generally been between 12.5 and 200 Hz and suitable vibrating devices are available from several manufacturers. Inventions on extruder molding machines have been based on a particular use of vibrators and, of course, on the design of the machines. As vibrators, rotary vibrators are used in which the rotating eccentric mass causes a movement in the direction of the eccentric mass of the eccentric mass, which is further transmitted to the concrete mass, on the kappa-plate attached to the vibrator. In extruder molding machines, vibrators are fixed throughout the machine, and in particular in the area of deformation and compaction of the concrete product '... · it is sought to obtain a good sealing effect on the pulp. Typically, vibrators have been used at least in a cavity mandrel, which, when vibrating inside the mass, effectively seals the concrete in all directions transverse to the flow. . binding domain by.

25 * »Instead of vibration, a casting machine has been used for compaction! '.! relatively slow movements of the various parts affecting the mass. The sealing movement is the transverse rotation of the mandrel and the deformations of the mandrel, whereby the mandrel is compacted by varying the cross-section of the mandrel. For non-circular mandrels, reciprocal rotation of the mandrel has been used for compaction. All of these devices are characterized in that the compacting of the concrete mass occurs by low-frequency mechanical movements in which the pulp particles are displaced relative to one another by the thrust caused by the movements of the machine parts and not by the collisional forces of the pulp particles.

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The compaction method described above is commonly referred to as shear compaction or shear compaction and has the advantage that the movements and displacements of the mass particles are already high at low motions, i.e. low frequency, and that the machine is noiseless.

The principle of low-frequency sealing movements is still V: developed in a device in which the hollow towers are formed • * ti.

': conical or wedge-shaped surfaces, whereby the slow casting movements of the mandrels *, ·. * 20 compact the concrete.

Compaction is done by slow * t »« ••• verrattuna movements with a stroke length of 5 - 50 mm and a frequency of 1 - *% · <t t * 10 Hz compared to vibration. The machine employs wedge-shaped or conical surfaces to provide frictional seals, which provide flow-expanding and shrinking • • constructions that form sealing spaces.

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Known vibration solutions have a number of weaknesses, although they have, in some cases, achieved a good sealing result. The biggest disadvantage is the aforementioned noise caused by the high frequency vibration itself and the uncontrolled placement of the vibrators in the various machine structures, and in particular the almost arbitrary direction of the vibration force, typically transverse to the mass flow and the machine. The unlicensed vibration force of the Hal-5 is easily directed more towards the machine structure than to the concrete, thus heavily stressing the machine. Another disadvantage of transverse vibration has been the poor flow of pulp through the machine, resulting in unnecessary pressure increase and heavy wear on parts.

10 Machines with a roller compaction principle have lower noise levels but have weaknesses in machine design, operation and casting performance.

The structures of the trenching machines are somewhat more complicated than those of the vibrating machines, and the long traversing movements result in sliding surfaces which are difficult to compact and the concrete at these points causes wear and damage. , this machine. Low Frequency Compaction only targets • * • · M mainly only large mass particles and small particles are left uncompressed, meaning that small mass particles do not · · »move into the matrix in new positions and locations · and small gas bubbles do not exit efficiently • · · mass. This problem is strongly accentuated by the new so-called. micro-proportioned concretes which do not reach their highest potential strength by current casting methods and additionally result in poor sealing.

· ·: FI 904883 discloses a casting machine in which the mandrel and feed screw are moved back and forth by means of a lever mechanism. The movement of the mandrel may be slightly • · 5 110174 rocking, but the motion of the mandrel is not used to compact the concrete. The movement of the feed screw is mainly a reciprocating, axial movement of the feed screw with a slight movement back and forth. What is disclosed in publication 5 relates only to the prevention of adherence of the concrete feed screw and not to the sealing of the concrete.

Further, on page 90 of FI 904883, lines 18 to 19 explicitly state that the movement of the feed screw is intended to prevent excessive compaction.

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Finnish patent 74648 describes a structure in which the cross-section and shape of an elastic shaped mandrel is modified to compact the concrete. This transverse deformation provides a slow sealing compression. 15 According to the publication, the mandrel itself remains free, since the longitudinal or transverse motion of the mandrel is not mentioned in the publication.

In the solution described in Finnish Patent 76514, concrete 20 is sealed with movable plates with • · · protrusions defining the lower and upper surfaces of the mold. longitudinally and transverse to the surface · '·' ·. According to the description of the publication and the figures, the shape mandrels stay in place.

It is an object of the present invention to provide a device which enables concrete to be compacted better and faster, especially for the production of high-strength concrete.

The invention is based on the use of at least one directional curved sealing movement for concreting concrete which has a directional component parallel to the casting and transverse to the casting.

According to a preferred embodiment of the invention, the concrete to be cast is subjected to at least one second sealing stroke with a frequency different from the first two-way sealing stroke. frequency of movement.

| More precisely, the device according to the invention is characterized in what is stated in the characterizing part of claim 1.

! The invention provides considerable advantages.

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The compaction is advantageously carried out at several vibration frequencies, and in particular with the use of higher vibration frequencies in addition to the low-frequency mechanical compaction, whereby the compaction effect is achieved by mass particles of all sizes. When combined with the control of • I · directional sealing and the bidirectional · sealing motion of the invention, the most effective sealing is achieved, which provides reliable concrete of the highest strength. By directing the seal 25 sufficiently in the direction of the casting into the concrete to be poured and further into the finished product, a large: part of the energy is directed towards the sealing, while at the same time directing part of the sealing movement in the transverse direction.

30 The Applicant has stated that the concurrent direction of the casting and • · v 110174: transverse abrasive sealing movement is of great importance for the final compaction of the casting. The compaction result is further improved if multiple vibration and compaction frequencies are used, but their effect is not equal to the bidirectional compaction movement. Vibration in the direction of the cast, coupled with suitable transverse movement, causes the concrete to slip easily through the nozzle, thereby minimizing wear on the parts and unnecessarily high pressure in the device. Compared to mechanical low-frequency motion, long, abrasive and abrasive movements of concrete are eliminated.

Versatile Vibration allows you to form profiles that are more difficult to cast and, if attached! Vibration of the feed screw will make concrete flow more easily in the screws and reduce wear on the screws. It is natural to make the vibration frequencies of the device adjustable, so that, at different frequencies, the device can be adjusted with different mass particles “! 20 characteristic frequencies for the best energy transfer to concrete and the most efficient vibration • • result.

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The invention will now be explained in more detail with reference to the accompanying drawings.

·. Figure 1 is a partially sectional view of a casting machine according to the invention.

Fig. 2 is a top plan view of the device of Fig. 1.

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Figure 3 shows a detail of Figure 1.

Figure 4 is a cross-sectional view of a finished product.

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The device shown in the drawings is an extruder molding machine adapted to move on carrier wheels 2 along the edges of the molding platform 1. The device is assembled on the frame 3. In this example, the casting machine has three conical feed screws 10 5. The screws 5 are mounted to the frame 3 via a rotary drive shaft 7. At the opposite end of the feed screws 5 are molded mandrels 6. A screw bar 10 passes through the screw shafts 7 and is connected to a hydraulic cylinder 11 which receives its power from the hydraulic unit 12 via a distributor 13 15. At the end of the drive shaft 7 is a variable transmission 8, by means of which the drive motors 9 of the screws 5 are connected to the screw shaft 7. At the beginning of the feed screws 5 there is a ... conical mass feeding hopper 4. After the feeding hopper 4! In the opposite direction to the casting direction, the device 20 has a top face plate 16 and a side face plate 15. The side ____: plates 15 are connected to the hydraulic cylinders 11. The top face plate 11 • is connected by a crank mechanism 20 to the actuator of the top face plate.

: | The bidirectional sealing movement of the invention is achieved by the crank mechanisms 18 and 19.1, 19.2. As shown in Figure 3, the drive shaft 7 is suspended from two fingers 18:. As the hydraulic cylinder 11 moves the drive rod 10, the drive shaft 7, the feed screw 30 and the mandrel 6 suspended on the crank mechanism 18 move forward and downward or 9,017,074 respectively upwards, resulting in a bidirectional sealing movement of the mass in the extruder. A second position of the mechanism 18 is shown in Fig. 3 by dashed lines.

This same sealing movement also takes place on the upper face plate 16 5 on the crank mechanism 19.1, 19.2, while the eccentric mechanism 20 moves the upper face plate 16 back and forth.

The device works as follows. Concrete fed to the pulp container 4 flows into feed screws 5 which are rotated by drive motor 10a 9. Rotating screws 5 push the concrete into a pressurized space which extends as a forming space delimited by mold 1, side walls 15 and top surface plate 16. In this state, the concrete is compressed between the forming mandrels 6 and the bounding walls 1, 15, 16 of the molding space and is compacted by the movement and pressure of the shaped mandrels 6 and the movable walls 15, 1 to form the desired end product, e.g. The movement of the forming mandrels 6 is achieved by hydraulic cylinders 11 which are connected to the end of the draw bar 10.

The casting machine rests on the wheels 2 on the substrate 1 being pushed by the reaction force of the mass, or the machine can be moved by a separate drive motor. The concrete mass flows from the tank 4 to the feed screws 5 which push the concrete into the forming space formed by the walls 1, 15 and 16 and provide the necessary pressure. The screws 5 can make a directional oscillation movement with the forming mandrels 6, whereby the concrete slides: easier on the surface of the screw 5 and the feed of the concrete becomes more efficient.

The screws 5 are extended by the cavity mandrels 6 which form the required cavity holes 21. Various hole shapes are shown in Figure 4. Concrete compacting is mainly effected by these cavity mandrels 6. The compaction is effected by the directional vibration of the mandrels 6, preferably by the curved bidirectional movement described herein. The mandrel may be evenly thick if the shape of the cavity allows it, since bidirectional movement also provides a transverse sealing component. In circular cavity shapes the mandrel may rotate with the screw, but in the shape cavities the mandrel must of course be non-rotatable. Of course, the sting may be tapering or expanding. Directional vibration allows for even 10 major deformations. The screws 5 are rotated through the drive shaft 7 and the mandrel 6 is moved by means of rods 10 passing through the drive shafts. In addition to the rotational movement, the screws 5 can also perform a sealing movement, whereby their movement can be combined with the movement of the rods 10.

The screws 5 are rotated via a drive belt 8 or alternatively a chain, and the drive motor is preferably a hydraulic motor, whereby its speed 20 can be easily adjusted. Alternatively, electric motors -> <> t; market and reduction gear. The hydraulic cylinders 11 and rod 10 of the mandrels give a vibratory movement directed to the mandrels, and if the screws 5 are also to be vibrated, they are locked by a pivot bearing on the rods 10 of the mandrel 6. The hydraulic cylinders 11 provide the mandrels 6 acceleration, which is advantageous to the stresses of the machine. Of course, other actuators may be used instead of hydraulic cylinders, such as eccentric mechanisms and other devices, which generally give a sinusoidal acceleration curve. 11 110174 is a normal hydraulic unit for powering hydraulically, which supplies power to the various actuators without pulse. The pulses should be phased in such a way as to balance the vibrations on the machine. The vibration frequency can be changed! 5 by controlling the distributor and adjusting the vibration force by changing the operating pressure of the actuators.

According to the present invention, the compaction movement is specifically directed vibration and not low frequency traction. As such, the 10 boundaries of oscillation and vibration vibration are difficult to determine and the appropriate vibration frequency is essentially dependent on the mass to be cast. A typical vibration frequency for concrete is 12.5 to 200 Hz. For this device, the vibration frequency of the mandrel portion has been found to be preferred at 12.5 to 50 15 Hz and in the top and side panels 5 to 10 Hz. This combination of two different frequencies is very advantageous since the vibration is directed to particles of very different sizes.

In addition to the above, the present invention has other embodiments.

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The actuators can be any sufficiently effective actuator. However, the aforementioned electrical and hydraulic • ·! / ·; 25 Raul engines. Converting a rotary motion into a periodic linear motion can be accomplished in many ways, for example by crank or eccentric mechanisms. All actuators are preferably adjustable.

30 The direction of the compaction movement can be adjusted by changing the lengths and direction of the cranks of the crank mechanism 12 110174. If the cranks are slightly inclined relative to the direction of movement, the movement is downward and, for example, the sealing effect is greater in the mandrel below the mandrel. Similarly, with the mouth-5 beveling the cranks slightly forward, the movement is directed upwards. In addition, the path drawn by the movement can be varied by varying the lengths of the cranks, and the cranks of the same mechanism may be of different lengths. If the motion control is implemented, for example, by an eccentric mechanism, the shape of the path may be modified accordingly. In addition to crank and eccentric mechanisms, other equivalent solutions, such as guide rails, can be used to provide near-arbitrary motion paths.

In the example described above, the side panels were moved only in the direction of casting, but it is conceivable that at least some of the side panels are secured to an eccentric mechanism that provides vertical or transverse movement. Other sealing movements may also be performed such that the transverse movement with respect to the direction of the casting 20 takes place horizontally. Further, an eccentric vibrator 17 can be placed inside the mold mandrels, further increasing the compaction power and facilitating the flow of the concrete mass. The compaction stroke or compaction power can be adjusted by adjusting the compaction stroke speed, stroke length, or vibration power.

Claims (5)

An apparatus for producing a controlled compressed concrete product, comprising: - at least one drive shaft (7) and an extension means (5) arranged thereto for feeding concrete into a defined cross-section (1, 6, 15). , 16), 10 - eating at least one surface defining a cross-section (1, 6, 15, 16) and which can be guided in a reciprocating compression movement to compress the concrete, and of which surfaces one is formed by eating at least a mold mandrel (6) arranged as the extension of the feeding means, and - means (11, 20) for bringing the mandrel mandrel (6) into | s / · motion and to control its (6) motion on the | 20, in that the compression movement exhibits a movement component parallel to the ingot and at least one relative to the same transverse movement component, characterized in that the means (18) for control *: the movement of the mandrel (6) comprises two stakes (18), at which the drive shaft (7), the input means (5) and the mandrel (6) are up::! suspended and through whose guiding action the mandrel (6) can be moved simultaneously in the direction of the ingot and in a relative direction to this deviating direction to effect a biphasic bi-directional movement. 110174! 16 The device of claim 1, wherein the delimited cross-section is limited by a mold (1), two side walls (15) which can be moved by means of two actuators (11), and an upper plate (16) which can be moved by means of an actuator (20), and at least one mold mandrel (6), characterized by means (19.1, 19.2) for controlling the movement of the upper disc (16) in such a way that the disc (16) can be moved in the direction of the ingot and transversely in relation to it. tili gatet. 3. Device according to claim 2, characterized by a known high frequency vibrator arranged in the mold mandrel (6). 4. Apparatus according to claim 1 or 2, characterized in that the means (18) are made of parallel stakes. 5. Device according to claim 1 or 2, characterized in - • · ·. t e c k n a d that the members (18) are made up of stakes, whose * · ·: ··: direction differs from each other. * Ml I IM I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I