WO2007122155A1

WO2007122155A1 - Device for producing moulded concrete blocks

Info

Publication number: WO2007122155A1
Application number: PCT/EP2007/053771
Authority: WO
Inventors: Rudolf Braungardt; Holger Stichel
Original assignee: Kobra Formen Gmbh
Priority date: 2006-04-21
Filing date: 2007-04-18
Publication date: 2007-11-01
Also published as: DE102006027908A1

Abstract

The invention relates to a device for producing moulded concrete blocks in a moulding machine by actuating a vibration device on a concrete mixture that has been introduced into cavities (FN) of a mould (FE). According to the invention, said device is equipped with an upper stop (oA) which reduces the deflection upwards for the upward movement stage of the vibrational movement of the mould comprising the concrete mixture.

Description

Device for producing concrete blocks.

The invention relates to a device for producing concrete blocks.

Common devices for the production of concrete blocks work on the principle of compaction and solidification of a humid concrete amount by the action of shaking forces. For this purpose, a mold is held with one or more mold cavities in a molding machine and placed on a horizontal surface and pressed. The underlay closes the lower openings of the mold nests. The upper openings of the mold cavities are usually closed by pressure plates of a Auflastvorrichtung which rest on the concrete amount, and sink with increasing compression of the concrete amount during a shaking deeper into the mold cavities. After solidification of the concrete amount, the mold is raised vertically relative to the support and the still moist concrete blocks are removed from the mold through the lower openings of the mold cavity.

During the shaking process, shape, underlay and amount of concrete in the mold cavities are stimulated by a vibrating device to vertical vibratory movements, which also continue attenuated by the concrete amount in the pressure plates of the ballast. Form, underlay and concrete quantity lead apart from the compression of the concrete amount as a vibrating group uniform jarring movements. In addition to the mass of the oscillating group and the shape of the excitation by the vibrator, the manner of holding the mold in the molding machine is of essential importance for the course of the vibrating movements. These parameters determine a basic form of a periodic shaking motion by time course and amplitude. A typical design of vibrators includes one or preferably a plurality of unbalance shakers, which stimulate shaking movements with the rotational frequency of rotating imbalance masses. The oscillating group can be suspended in a spring system including the unbalance shaker and execute substantially harmonic vibrations as shaking movements. Such a device is known for example from DE 203 01 954 U1.

Because of fast and high compression are often used devices with so-called shock vibration as Rüttelanregung, the pad is supported on support strips in a rest position and beat between the support strips beating strips periodically from below against the surface, causing them from the support strips lifts an upward movement section to goes through to a vertex and hits in the subsequent downward portion of the vertical shaking motion on the one stop for the downward movement forming support strips.

Preferably, the form containing the mold cavity is held by elastic, in particular rubber-elastic elements in the molding machine, which is given on the one hand a better vibration of the mold in the shaking movement and on the other hand less transmission of vibrations to the molding machine. From DE 27 10 643 A1, a relatively soft suspension of the mold in a machine table of a molding machine with a thick rubber strip between the mold and a surrounding frame is known. EP 0 730 936 B1 describes an apparatus in which a mold is divided into a mold insert with mold cavities and a mold frame, the mold insert being substantially immovably clamped in the mold machine and elastic damping material between intermeshing protrusions and depressions of mold insert and mold frame is inserted. DD 236896 A1 describes an arrangement for the production of concrete blocks and precast concrete parts. An oscillating table and concrete part mass is supported by springs on a foundation vibrating and excitable by means of an eccentric drive to vibrate. The vertical movement of the vibrating table is limited by adjustable stops, which achieve an intended shock effect by rhythmic shocks.

From EP 076703431 a mold for the mechanical production of concrete moldings is known in which are provided in a two-part upper mold pressure medium chambers, by means of which in mold cavities dipping plunger are supported vertically damped during a Vorverdichtungsschritts and abut vertically against stops during a final compression step, so that during precompression and final compaction, the stamping device shows a different pressure behavior on the upper concrete surface. In a mold known from WO 2005/009703 A2, a stamp device is suspended by means of swing bushings on a load-bearing device and can be moved vertically against fixed stops.

The invention has for its object to provide a further improved apparatus for the production of concrete blocks.

The invention is described in claim 1. The dependent claims contain advantageous refinements and developments of the invention.

Surprisingly, by the first stop means, which comprises a stop in the upward movement portion of the shaking movement of the mold, the base and the concrete amount Forming vibration group, further improve the compaction and solidification of the concrete amount.

In a preferred embodiment, second stop means are provided in addition to the first stop means, which form a stop for the oscillating group in the downwardly directed movement portion of the vibrating vibration in a conventional manner. For the formation of the second stop means can be used on the known from the prior art embodiments. The second stop means preferably act directly on the base, in particular a vibrating table, with a stone board optionally inserted between them and the underside of the mold.

In a first variant, the first stop means form a stop acting on the mold or the base, the mold and base for the invention being considered to be rigidly connected to one another and, if appropriate, different deflections of the mold and base and any occasional lifting of the mold from the mold Underlay in Rüttelbetrieb as not essential to the invention phenomena out of consideration. Preferably, the first stop means act on the pad placed on the pad and pressed against this, so that when striking the mold their contact pressure reinforced to the pad and in particular a lifting of the mold is avoided by the pad.

In the case of a device according to EP 0 730 936 B1, in which the mold comprises a mold frame which can be clamped in a molding machine and a mold frame held therein, and the mold insert is held vertically elastically damped to a limited extent in the mold frame, the first stop means can advantageously be used as machine-side stops on the mold frame or in a preferred embodiment as mold-internal stop elements between the mold frame and mold insert act directly on the movement of the mold insert relative to the mold frame.

The pad is in particular a combination of vibrating table and stone board in use, the stone board is removed in deposit production with the demoulded from the mold precast concrete blocks from the molding machine and replaced by an empty board for the next production cycle. In multi-layer production, the board can be omitted as part of the base or remain in the machine.

The assumed firm mutual position and joint shaking movement of the mold and pad can be given by pressing the mold on the pad on the machine frame of the molding machine or by a direct connection of form and vibrating table, in particular in the latter case, the vibrating device also directly on the Form and indirectly via the said direct connection can act on the substrate.

The first stop means may be provided in the vibrating device itself, in particular in the case of direct action of the vibrating device on the mold. For this purpose, the vibrating device is advantageously firmly connected to the molding machine assumed to be immovable, preferably to the machine frame of the molding machine. The vibrating device can advantageously comprise a plurality of vibrating actuators arranged horizontally outside the region of the mold cavities. The first and / or the second stop means can advantageously be integrated into the structure of the Rüttelaktuatoren. In another advantageous variant, the first stop means act on the pressure plates usually present on the top of the concrete amount in the mold cavities. The pressure plates are for this purpose advantageously relative to the Auflastvorrichtung by a small amount, which is smaller than the amplitude of the shaking without the other stop means, vertically displaceable, preferably against a restoring force, which may be applied in particular by a spring or elastically deformable material as a force. The means for applying the restoring force are dimensioned such that the static force exerted on the printing plates during operation on the printing plates, the printing plates are vertically spaced from the stops and only upon excitation of the pad to Rüttelschwingungen which are transmitted via the concrete amount to the printing plates in that the pressure plates are displaced relative to the abutment surfaces provided on the loading device and strike against them, taking advantage of the fact that the mass inertia of the opposite to the printing plates much heavier Auflastvorrichtung briefly significantly higher forces between printing plates and Auflastvorrichtung can act. Advantageously, a phase delay of the maximum acceleration forces acting on the concrete quantity from below and from above occurs.

In yet another embodiment, it can be advantageously provided to limit or cancel the upward acceleration force acting on the shape and / or amount of concrete by the vibrating device through the first stop means in the time course of the acceleration.

The upper stop according to the invention is fundamentally different from additionally possible safety devices which limit destruction of the device as a result of too great exceptional deflections. In the upper stop according to the invention is an upward movement compared to the determined by vibration parameters of the device and permissible degree of deflection reduced to a smaller degree.

The invention is illustrated below with reference to preferred embodiments with reference to the figures still in detail. Showing:

1 is a schematic sectional sketch of a known device,

2 shows a qualitative course of movement to FIG. 1,

3 shows a first embodiment of a device with upper stop,

4 shows another embodiment with upper stop,

5 shows a qualitative movement sequence to FIG. 3 or FIG. 4,

Fig. 6 shows an embodiment with printing plate stop.

In Fig. 1, a section of a known device is schematically outlined in a sectional side view. The mold is made up of a mold frame FR and a mold insert FE, which engage in the manner known from EPO 730 936 B1 with projections VE and recesses VR with the interposition of damping elements DM of preferably elastically biased damping material. Form frame FR and mold insert FE are vertically movable relative to each other in the context of deformability of the damping material under the action of vertical vibration forces. The degree of mobility is typically in the range between 0.5 mm and 1, 5 mm. The forming frame FR is provided with a holding flange FL in the machine frame. frame of a molding machine and adopted for the following considerations as immovable with respect to the machine frame, so that a vertical movement of the mold insert relative to the mold frame is also a movement of the mold insert relative to the machine frame. A vertical mobility of the mold insert may result to a small extent from a deflection of the mold frame FR and / or mold insert.

The mold insert has one or more mold cavities FN which are delimited by mold cavity walls NW and which are open at the bottom and at the top and have a cross section which is essentially constant in the vertical z direction.

The molding machine includes in the machine frame fixed position support rails TR, which are elongated perpendicular to the plane and form a support plane for a stone board SB as a base under the mold insert FE. The mold insert is pressed by indicated, acting from the machine frame on the flange FL on the mold frame FR clamping means BA against the stone board down.

Between the support strips TR run blow bars SL a vibrating device, which are offset in their outlined lower position with their upper edges against the support plane of the support bars down and periodically vibrate vertically during shaking during a shaking with a vibration frequency (SR) and in the movement to Beat against the stone board SB at the top and lift it off the support strips and stimulate vertical shaking movements SF. In this case, the damping elements are elastically deformed in addition to the static contact force by dynamic shaking forces and exert a restoring force on the mold insert and stone board down. The mold nests filled with moist concrete quantity BG are normally closed by pressure plates DP of a load-bearing device. The printing plates dive with little lateral play in the upper openings of the mold cavities and press on the top of the concrete amount. The printing plates are bolted to mounting plates AP, which are arranged at the lower ends of stamp tubes ST and vertically spaced therefrom by a load-bearing body carrying all dies and printing plates. The loading device containing the pressure plates, mounting plates, die tubes and load bodies is vertically displaceable in the forming machine and retracts downward as the concrete amount is compressed during a shaking operation. The loader is usually pushed down by pneumatic or hydraulic means.

The rocking motion SF imposed on the stone board and the mold insert also acts on the concrete amount BG, which rests directly on the stone board. A transfer of the shaking movement of the stone board on the printing plates and the Auflastvorrichtung takes place on the concrete amount and thus only in a damped by the concrete amount reduced level.

For the stone board and assumed with this during the Rüttelvorgangs in solid mutual position mold insert results in a qualitatively indicated in Fig. 2 course of the movement z (t) in the vertical direction over time t.

Starting from the rest position zθ sketched in FIG. 1 with the stone board resting on the support slats, the blow bars SL strike the stone board from below during rocking and accelerate the stone board, mold insert and concrete quantity against their weight and against the contact pressure between the mold insert and the mold frame contrary to the Loading force of Auflastvorrichtung upwards. The said forces have a restoring effect on the here also summarized as oscillating group designated form insert, stone board and concrete amount, which oscillate in a first upward movement section up to a maximum vertical deflection Az and then pass into a second downward movement section. The support strips form for the downward movement of the oscillating group a stop on which the stone board SB abuts at a time tA in the vertical starting position zθ. The vibrating oscillation repeats itself with the possibly also variable period of time TP of the vibrating device. The oscillating movement and the vertical accelerations, which are particularly high at times tS and tA, cause a rapid high compression of the concrete quantity. At a typical vibration frequency of 50 Hz, a shaking process is completed in about 10-15 seconds.

According to the invention, first stop means are provided, which, in the case of the shaking movement of the mold or insert FE, the bottom forming cavity bottom pad SB and the concrete element BG, comprise a stop for the first upwardly directed moving section, hereinafter also referred to as designated upper stop form. Second stop means for the downward movement portion of the oscillating group on the type of support strips TR of FIG. 1 or in another known per se embodiment may preferably be additionally provided.

According to the sequence of motions of the shape schematically sketched in FIG. 3 as a new movement sequence ZR (t), in a first preferred embodiment the oscillation movement is limited upward to a reduced maximum deflection Rz which is smaller than the maximum deflection Az sketched in FIG the upward movement through such an upper stop at a reduced deflection Rz is stopped. For comparison, the movement sequence from FIG. 2 is entered above the reduced deflection Rz with a broken line.

For a comparative consideration of the sequence of movements of the known arrangement of FIG. 1 with the course of movement according to FIG. 3, a shock vibration excitation by means of blow bars is assumed for FIG. 3 as well. Starting from the rest position with stone board resting on the support strips, a first upwardly directed movement section is again initiated at time t1 by the impact strips striking the underside of the stone board, which stops at time tz when the upper limit stop is reached at the predetermined reduced maximum deflection Rz becomes. At a time t3, the oscillating group is again accelerated downwards in a downwardly directed movement section, until the stone board abuts on the support strips as a lower stop at the time t4. The movement sequence is repeated with the period TP of the Rüttelanregung.

The movement sequences according to FIGS. 2 and 3 are idealized in order to illustrate the principle of operation. In the real world, transitions may be less abrupt and / or accompanied by overshoot or rebound movements.

In the sequence of movement of FIG. 3 with the upper stop occurs in particular at time t2, at time t3 u. In contrast, a lesser degree, a rapid change in the movement deviating from the approximately the upper vertex approximately harmonic waveform of FIG. 2, whereby higher frequency components occur increasingly and a rearrangement of the particles of different particle sizes in the concrete amount is favored. This leads to an effective compression of the concrete amount, which is economically advantageous by shorter cycle times and / or lower cost composition of the concrete amount and / or can lead to improved quality concrete blocks.

In Fig. 3, a variant is arranged by the drawn with a broken line movement section US, in which no lower stop is provided and the swinging group passes through a lower return point.

In Fig. 4 is a first example for realizing an upper stop during the upward movement portion of the shaking movement of the oscillating group based on the sketched in Fig. 1 known device based on an enlarged section of the interlocking projections VE on the mold insert FE and recesses VR on the mold frame shown. While in the known device, the upwardly facing surface of the projection VE and the downwardly facing surface of the recess are substantially parallel to each other and include a plate-shaped damping element between them and given the vertical relative movement of the mold frame and mold insert by the elastic deformability of the damping element 4, it is provided in the example of FIG. 4 that surfaces of projection VE and recess VR are vertically opposite each other at a small distance equal to the maximum reduced deflection Rz, and a relative movement of mold insert is relatively upward from the sketched rest position is limited to the mold frame by this small distance, which is smaller than the vertical component of the maximum deformability of the damping element relative to its initial position, said vertical component of the deformability in particular equal to the maximum Auslenkbark it can be AZ. In Fig. 4 is the Distance between the damping element between them enclosing surfaces of projection VE and recess VR denoted by DD.

The first stop means for forming the upper stop can in the example sketched in Fig. 4 z. B. be given by an upper stop surface OA1 and / or OA2 on the mold frame and a counter stop surface GA1 or GA2 on the mold insert. For the realization in detail, many variants are possible and familiar to the expert.

For the example of Fig. 4, the sequence of movement of Fig. 3 represents the limited by the additional upper stop movement sequence of the mold insert relative to the mold frame.

FIG. 5 schematically illustrates another embodiment for achieving an upper stop and a movement sequence of the type sketched in FIG. For the vibrating device, a plurality of vibrating actuators RA arranged horizontally outside of the surface area occupied by the mold cavities are provided, which are supported on the machine frame MR of the molding machine and act directly on the edge region RB of a mold FO and impose a vertical vibrating motion on the mold. It is shown only a section of the device with a Rüttelaktuator. The shape is not divided into a mold frame and a mold insert or in such a subdivision is no vertical mobility assumed between mold insert and mold frame.

As a support in this example, a stone board is provided as in Fig. 1 and a vibrating table RT, wherein the vibrating table is connected via releasable connecting elements with the mold and clamped under clamping of the stone board against the underside of the mold. The form by the Rüttelaktuatoren forced vertical shaking is transmitted via the connecting elements indirectly on the vibrating table and on this and the stone board on the concrete amount.

The vertical movement of the mold is defined by a lower stop and an upper stop, e.g. B. the edge region of the mold on vertically opposed surfaces OA and UA of a relative to the machine frame vertically fixed stop assembly as the first and second stop means in the vertical movement limited up and down. The maximum reduced deflection of the mold against the machine frame by the dimension Rz is illustrated in FIG. 5 by the gap Rz against the upper abutment OA at the lower abutment UA in the resting position. The vertical range of motion of the vibrating actuators RA is advantageously extended up and down beyond the stops. The sequence of movements sketched in FIG. 3 represents in the example according to FIG. 5 the movement sequence of the form FO.

The connecting elements VE are advantageously designed to be quickly detachable, in order to allow a quick and easy demoulding of the compacted concrete blocks from the mold cavities down by conventional relative vertical movement of the mold against the pad.

The arrangement and design of the connecting elements VE and the stops OA, UA is only schematically to understand functionally. In particular, the stop surfaces can also be integrated in the Rüttelaktuatoren itself.

A partially different mode of action is shown by the device according to FIG. 6, which is subdivided into a left and a right half of the figure, temporally displaced schematically represent movement situation within a period of Rüttelanregung.

The device has, as already described, a mold FO seated on a stone board SB or, correspondingly, preferably a mold insert FE with one or more mold cavities FN, which are filled with concrete amount BG and closed at the top by pressure plates DP resting on the concrete amount. The printing plates are bolted to mounting plates AP, which are connected via stamp tubes ST with a load-bearing body AK.

The peculiarity of this device is that the pressure plates relative to the Auflastkörper against a rest position, which is taken under the action of the static Auflastkraft and shown in the left half of the figure, under the effect of higher vertical forces between the pressure plate DP and load body AK by a small amount accordingly a further reduced maximum deflection in the direction of Auflastkörpers are displaced and after the displacement relative to the Auflastkörper push this small measure against the first stop means to form an upper stop.

In Fig. 6 as an implementation example, an embodiment is sketched in which the punch tube SST is connected to the mounting plate AP via an elastically deformable element ZE and outlined in the left half of the figure, the lower edge of the punch tube to the small displacement Rz 'of the pressure plate is vertically spaced. The elastically deformable element ZE in this position transmits the static load force from the load body to the pressure plate and the concrete amount. Under the static Auflastkraft is thereby by the weight of Auflastkörper and punch tubes and optionally an additional from the machine frame distributed to the Auflastkörper acting on all printing plates or mounting plates understood vertical force, which is typically applied via hydraulic cylinders. In addition, the static force exerted by the pressure plate on the amount of concrete contains the weight of pressure plate and die plate, but which is low compared to the other above-mentioned static forces. The elastically deformable element ZE is preferably elastically deformed so that the static Auflastkraft still causes no additional deformation, but that a significantly higher force of the pressure plate or mounting plate in the direction of the load body AK to deformation or further deformation of the elastic element to the stop the lower end of the stamp tube to the mounting plate.

In a first movement phase of a period of shaking movement z. B. by impact of the blow bars on the underside of the stone board, the stone board with the form of high speeded up. The accelerating force introduced into the concrete amount on the stone board also dampens the pressure plate DP and accelerates it upwards. Due to the inertia of the load-bearing body and the punch tubes and possibly the resistance of a force-supporting hydraulic fluid in the Auflastvorrichtung occurs in this phase, an increased vertical force between the pressure plate DP or mounting plate AP and load body AK or stamp tube ST, resulting in a vertical relative displacement of these components under deformation of the elastic element ZE up to the stop of the mounting plate to the underside of the stamp tube in the outlined in the right half of the figure position. Advantageously, the mass inertia of the ram tubes and the load-bearing body does not cause an appreciable upward displacement of these components, even if, as usual, the hydraulic force means pressing down on the load-bearing device are open to a hydraulic fluid source with a predetermined fluid pressure. When the mounting plate touches the lower end of the stamp tube, this is due to the inertia of the mass load body and stamp tubes, and optionally the resistance of a hydraulic fluid in the loading device temporarily a sudden excessive force on the top of the concrete amount.

In the subsequent downward movement, the mounting plate is lifted by the elastic element ZE again from the bottom of the stamp tube. The downward movement can again run against a lower stop, which is pressed by the inertia of the concrete amount this abruptly with increased force on the stone board. Due to the inertia of the Auflastkörpers with punch tubes the elastic element is again deformed at the stop of the lower end of the punch tube ST on the mounting plate, in turn, a sudden increase in the force of the pressure plate on the top of the concrete amount occurs during sudden - stop the downward movement of the pressure plate.

The short-term power increases on impact of the blow bars on the stone board and the impact of the stone board on the support strips as a lower stop on the one hand and in the above-described attacks of mounting plate and lower end of the punch rod on the other hand advantageously advantageously offset in time and advantageously act when attacking the mounting plate the punch tube occurring force peaks on the printing plates directly on top of the concrete amount.

For the relative displaceability of pressure plates and load-bearing body against the restoring force of an elastic element acting between them, different embodiments are possible, deviating from the sketched embodiment. In particular, a spring arrangement, in particular a disc spring arrangement or a spring disc pack, can be used for the elastic element. The elastic element can also be arranged inside the stamp tube. be net. The stop is not necessarily given between the top of the mounting plate and the lower end of the stamp tube. The relative displacement of pressure plate and load body is also applicable to other Rüttelanregungen as the shock vibration.

The features indicated above and in the claims, as well as the features which can be seen in the figures, can be implemented advantageously both individually and in various combinations. The invention is not limited to the exemplary embodiments described, but can be modified in many ways within the scope of expert knowledge. In particular, the first stop means for the upper stop can also be realized in a device without the second stop means for the lower stop.

Claims

Claims:

An apparatus for producing concrete blocks in a molding machine by compacting a concrete amount having a shape containing one or more of the concrete amount receiving upwardly and downwardly open

Having mold cavities and placed on a mold cavity bottom final pad and pressed against this, with a vibrator, by means of which a vibrationally held in the molding machine vibrating group, which includes the pad, the mold and the concrete amount, can be excited to vertical Rüttelschwingungen, and with insertable into the upper openings and pressing on the concrete amount pressure plates, characterized in that first stop means are provided, which forms a stop for the movement of the oscillating group in the upward movement portion of the Rüttelschwingung.

2. Device according to claim 1, characterized in that the first stop means act on the mold.

3. Apparatus according to claim 1 or 2, characterized in that the mold contains a mold frame and a mold insert held therein, in which the mold cavities are formed.

4. Apparatus according to claim 3, characterized in that the first stop means act on the mold frame.

5. The device according to claim 3, characterized in that the mold insert against the mold frame via elastic damping means is supported relative to this movable and that the first stop means between see mold insert and mold frame act and limit the relative mobility to a level which is less than the limited by the damping means degree of mobility.

6. Apparatus according to claim 1, characterized in that the first

Slings act on the an upper opening of a mold cavity occluding pressure plate.

7. Apparatus according to claim 6, characterized in that the pressure plate is coupled to a load body and is movable relative to this vertically and that the first stop means limit this relative vertical movement.

8. Device according to one of claims 1 to 7, characterized in that second stop means are present, which a mechanical

Form stop for the oscillating group in the downward movement portion of the vibration.

9. Apparatus according to claim 8, characterized in that the second stop means act on the pad.