DE102013108299B4 - Press frame and method for mounting a press frame and press with such a press frame - Google Patents

Abstract

Press frame, in particular for a forging press, with upper spar (1) and lower spar (2) and between upper spar (1) and lower spar (2) arranged side posts (3), said upper spar (1) and lower spar (2) with the interposition of the side stand (3 ) are tensioned against each other with tie rods (4), wherein the tie rods (4) are each formed by a plurality of flexurally elastic tension elements, which are designed as prestressing steel strands (5), wherein in the region of each side stand (3) the prestressing steel strands (5) in such a way Concentrated areas are that in each case a plurality of tie rods (4) are each provided from a plurality of prestressing steel strands (5), wherein the strands (5) are each end in receiving plates (7a, 7b) are arranged, which against clamping surfaces of upper spar (1) and Sub-spar (2) abut, wherein the receiving plates (7a, 7b) each have a plurality of holes (8) through which the strands (5) are passed, wherein the strands (5) on the receiving plates by means of mono-anchors (9), each with individual anchoring sleeves (10) are attached.

Description

The invention relates to a press frame, in particular for a forging press, with upper beam and lower beam and arranged between the upper beam and lower beam side uprights, the upper beam and lower beam are clamped with the interposition of the side stand with tie rods against each other, wherein the tie rods are each formed by a plurality of flexurally elastic tension elements.

In such a press, it may be z. B. a forging press, z. As a free-form forging press or a drop forging press act. However, the invention also includes press racks for other mechanical or hydraulic press types for cold, warm and hot forming of metals and non-metals and hydrostatic locking presses for temporary closing of forming tools during the forming process, in particular large-size presses with pressing forces of more than 1,000 kN, preferably more than 10,000 kN. In such presses, the tie rods have a great length of more than 5 m, preferably more than 10 m.

In practice, as tie rods for such presses of large design usually solid tie rods made of steel are used, which are end provided with threads and clamped with clamping nuts. The production of such massive tie rods is expensive. In addition, the assembly is particularly complicated if the tie rods long lengths of z. B. more than 10 m. The available lengths are limited so that the clamping lengths that can be realized in presses are limited in absolute terms. In addition, the attachment of the tie rods by means of threads in practice causes problems because the anchor threads of the threaded tie rods have high notch stresses on the thread root. For this reason, there is a need in practice to replace such massive tie rods with alternative solutions.

It was therefore in the DE 1,938,279 or the corresponding one US Pat. No. 3,643,592 proposed to replace the known tie rods by steel cables as bracing. The tie rods are therefore each formed by a plurality of steel cables, which should be arranged in the interior of circular tube spacers. The steel cables or tensioning cables are held in clamping plates, which are each arranged on the outside of the spars / yokes. These clamping plates have a number of at least partially conical bores, which serve to receive clamping sleeves, with which the prestressed cables are held in their prestressed position. The clamping force is transmitted via the conical clamping sleeves of the steel cables to the clamping plates. The clamping force causes a normal force over the wedge angle of the clamping sleeves of the conical bore. This normal force is many times greater than the clamping force itself. Due to the high normal forces, it is possible to transfer the clamping forces from the tensioning cables to the clamping plates even at low coefficients of friction due to the friction effect.

However, the use of steel cables, which can be carried out as spiral ropes or stranded cables, has not gained acceptance in practice. - This is where the invention starts.

Incidentally, one knows from the DE 28 18 511 a press frame in a special construction with upper spar, lower spar and arranged between the upper spar and lower spar uprights and clamping devices with a plurality of individual clamping elements and anchoring elements, the upper spar, lower spar and the stator are clamped together by the clamping elements and at least one of the spars an arcuate Umschlingungsauflager for the clamping elements having. The clamping elements are simply U-shaped or double U-shaped. The clamping elements are designed as monofilament prestressing steels in the form of round steel or strip steel or so-called tensioning cables constructed therefrom. It should also be common steel cables or tension cables can be used.

Also the DE 30 079 75 C2 describes such a press frame in a special design with double U-shaped guided adjacent clamping elements. However, construction and assembly of such press frame in a special construction are relatively complicated.

Incidentally, in the DE 22 39 147 A described a press frame, in which between the crosshead and lower beam on the one hand only to train claimed, made of high-strength steel wires existing tendons and on the other hand pressure and dimensionally stable spacers are arranged. Unlike in prestressed concrete, the clamping elements should not serve to put pressure members made of concrete or the like so under bias that the tensile stresses can absorb by reducing high pressure biases, but the pressing forces are transmitted directly through the wires between the head and lower beam.

The invention has for its object to provide a press frame of the type described above, which is characterized even at large heights and a design for very large pressing forces by a simple and inexpensive construction and a simple and inexpensive installation with high stability.

To solve this problem, the invention teaches a press frame with the features of claim 1. It is provided that the flexurally elastic tension elements are designed as prestressing steel strands. Such prestressing steel strands are preferably formed from a plurality of cold-drawn individual wires. They are preferably prestressing steel strands according to EN 10138-3, ASTM A416, ASTM A 886 and / or ASTM A882 or other comparable national and international standards and regulations. In particular, prestressing steel strands in the embodiment can be used as a seven-wire stranded wire with seven individual wires. Although such prestressing steel strands consist of several individual wires, unlike steel cables, however, not several strands are stranded to form a rope, so that the prestressing steel strands are also referred to as monostrands.

The inventive measures a press frame with high clamping force density and high dynamic load capacity is created, which is optimized even with extremely large heights (eg., 25 to 40 m and more) and a design for very large pressing forces by a simple and inexpensive construction Pressure piece cross-sections (ie side stand cross-sections) and a simple and inexpensive assembly with high stability and extreme robustness because of its inherent system redundancy.

The invention is initially based on the recognition that press racks for presses of large design can be improved in terms of cost and installation effort, if the usually used in practice massive tie rods are replaced by bending elastic tension elements. The very high production costs for massive tie rods and in particular the high assembly costs of tie rods with a length of more than 10 m are reduced by the use of flexurally elastic tension elements.

However, the invention proceeds from the recognition that this concept of flexurally elastic clamping elements can be implemented optimally if the described prestressing steel strands are used as bracing elements.

Such standardized prestressing steel strands have long been used in practice very successfully in construction, for. As in the production of prestressed concrete or in the manufacture of bridge constructions. Therefore, prestressing steel strands are available at relatively low cost as standardized stock items. Compared to conventional steel cables, prestressing steel strands are characterized by considerable advantages.

Conventional steel cables, as z. B. in the DE 1,938,279 can be proposed, can be designed as spiral ropes or stranded cables. Spiral ropes consist according to the standard of at least two layers of wires that are stranded to each other. The wires of the different layers only touch each other at the crossing points. This leads to an increased load at these points. For these reasons, such steel cables can not be so heavily loaded, as it corresponds to the sum of the strengths of the individual wires. Steel cables can alternatively be designed as stranded cables. In this case, the stranded cable can be stranded so that the direction of impact of the strands is opposite to each other in the direction of impact in the strands. Although the wires within the strands line up, the wires of adjacent strands only touch at one point. This too leads to increased stress at these points. Therefore, such stranded cables can not be so heavily loaded, as it corresponds to the sum of the strengths of the individual wires. Alternatively, a stranded rope can also be stranded so that the direction of impact of the strands is equal to the direction of impact in the strands. This avoids the punctiform contact of the wires of adjacent strands, because the wires of adjacent strands are in line contact in such a directing rope. Thus, although the increased load at the crossing points can be avoided. The wires run in this construction but at a very large angle to the cable axis, because add the impact angle of the strands and the rope. The rope axis is the direction in which the train is to be transferred. Therefore, even such rollover cables can not be so heavily loaded, as it corresponds to the sum of the strengths of the individual wires. Overall, this means that steel cables according to the standard may only be used to 45% to 50% of the strength of the individual wires. This leads to an increased space requirement in the cross section and in turn to an increased material requirement and higher costs for the Verspannelemente themselves and larger side posts with corresponding disadvantages.

These disadvantages are avoided by the use of prestressing steel strands. First of all, there is no point contact between the wire layers, the wires of adjacent strands do not touch. The angle of the wires differs at most from the simple direction of impact of the wires in the strand from the direction of pull. For this reason, prestressing steel strands can be subjected to static loads of up to 65% to 70% of the rated tensile strength of the individual wires in accordance with the relevant standards, building inspectorate approvals and other technical regulations. This reduces the required cross-sectional area, so that the material requirements and space requirements and thus the overall costs can be reduced. By the way, prestressing steel strands can be produced more cheaply than steel cables, since individual strands do not have to be stranded together in a separate production step and because prestressing steel strands also do not have to be manufactured to order. They are universally available as standardized mass-produced goods from the construction industry in excellent quality and at low cost.

The invention is therefore characterized in particular by the use of generally known prestressing steel strands for the production or clamping of a press frame.

Preference is given to using seven-wire prestressing steel strands, with six wires being turned around the somewhat thicker central wire. Preferably prestressing steel strands are used, the individual wires have a diameter of 4 mm to 8 mm, z. B. 6 mm, have. The prestressing steel strands can have a nominal diameter of 10 mm to 20 mm, z. B. 15 mm to 17 mm. Prestressing steel strands are preferably used, each having a tensile strength of more than 1,500 MPa, more preferably more than 1,700 MPa. The prestressing steel strands can each have a tensile strength of 1,500 to 2,000 MPa, z. B. 1,700 to 1,900 MPa, have. Under load, the strands can have a permissible double-voltage amplitude of more than 150 MPa, z. B. 190 MPa or more, for dynamic loads. On the endurance test bench, the monostrands endure a double-voltage amplitude of up to 250 MPa under 2 million to 10 million load changes, including their monostrand end anchorages, at a maximum stress of 45% of the strand tensile strength. In direct comparison to conventional threaded tie rods, this corresponds to a value increased by a factor of 2 to 3. Immediately to the increase in the double-voltage amplitude of the tie rods and the proportional increase of the compressive stress of the clamped together pressure pads (side stand) of the press frame is coupled. In direct interaction with the prestressing steel strands, economically optimized material utilization in the prestressed press frame can thereby be achieved. Thus, system-related overall weight and cost reduction can be achieved, which is not limited to the actual tie rods, but also affects the rest of the press frame.

According to the invention, the prestressing steel strands are each homogeneously applied to a plurality of regions, eg. B. two areas concentrated, so that then, as it were in the range of each side stand each two tie rods are provided in each case a plurality of prestressing steel strands.

According to the invention, the strands are arranged or fixed on the end side in receiving plates, these receiving plates bearing against clamping surfaces of the upper spar and the lower spar. In the area of the upper spar, at least one upper receiving plate is used at least per side stand, which rests on the upper clamping surface of the upper spar. Accordingly, a lower receiving plate is used in the region of the lower spar, which abuts as it were from below against the lower clamping surface of the lower spar. The receiving plates each have a plurality of holes through which the individual strands are passed. Consequently, the prestressing steel strands are not clamped directly against the upper beam and lower beam and consequently are not fastened directly in the upper beam or in the lower beam, but rather on the receiving plates, via which the force is transmitted from the struts into the tension elements (or vice versa). By the receiving plates and a kinking of the prestressing steel strands is prevented, so that no significant static skew and no appreciable dynamic bending stress can occur.

In principle, it is possible to clamp the prestressing steel strands directly in the perforations / bores of the receiving plates by means of conical clamping wedges by the holes in the receiving plates or clamping plates are at least partially conical. Particularly preferred, however, no direct attachment of the prestressing steel strands in the clamping plates, but the attachment is realized by means of separate anchoring devices, so that then particularly preferably receiving plates can be used with cylindrical holes. As a result, the production of these mounting plates is simplified, because it only cylindrical holes must be introduced. When anchoring the prestressing steel strands on the receiving plates can then be used in turn on known anchoring concepts and in particular commercial components that z. B. from the construction industry are known. According to the invention, work is carried out with mono-anchors, each with individual anchoring sleeves.

Consequently, within the scope of the invention, use is made of a mono-anchoring in which the individual prestressing steel strands are held in separate housings (anchoring sleeves), with the aid of corresponding clamping wedges. Such mono-anchors can be arranged in any distribution, so that the available space can be optimally utilized. In addition, handy and cheap clamping presses can be used, in addition, a different bias per strand is possible.

Compared to solutions in which mounting plates or clamping plates are themselves equipped with conical bores, the Solutions with separate anchoring devices, especially mono-anchors with separate sleeves, by various advantages. Since only cylindrical holes must be introduced into the mounting plates, these can be easily manufactured and the space can be optimally utilized. The mounting plates can be designed relatively thin, since they only need to be designed for bending stresses. The components used, in particular the clamping or anchoring sleeves, are available as cost-effective mass-produced goods from the construction industry. Particularly in combination with the prestressing steel strands (monostrands) essential to the invention, considerable cost savings can be achieved in the production of large press frames. The tension of the individual prestressing steel strands can be selectively controlled and adjusted by pulling on a free end of the prestressing steel strand until the anchoring sleeve is lifted off the receiving plate / clamping plate. This makes it possible to measure the preload of each individual strand without having to release the clamp, even though it is installed in a cavity (or sidestand). This ensures a particularly safe operation of the press.

Taking into account the fact that the prestressing steel strands z. B. an outer diameter of 15 mm to 16 mm, z. B. according to the standard 15.3 mm or 15.7 mm, may have, the receiving plate z. B. with holes with a diameter of 20 mm to 25 mm, z. B. 22 mm, equipped. When spacing and distributing the holes, the diameter or the wall thickness of the anchoring sleeves must be taken into account, at least in the case of a single anchoring. The (outer) distance of the individual holes can be z. B. be twice to four times the wall thickness of the sleeves used. The distance between the holes can be z. B. 30 mm to 60 mm.

As already described, it is intended to concentrate the prestressing steel strands in several areas per press side. The bending stresses in the clamping plates are thereby reduced because the diameter of the individual areas is smaller. It is then expedient to provide several recesses per press side in the press bars. In principle, several side stands per press side can be used. Preferably, however, in each case one common side stand per press side is used. In the side posts corresponding cavities are arranged through which the prestressing steel strands are passed. The areas in which the prestressing steel strands are concentrated and the associated cavities in the spacers are preferably non-circular but larger in one direction than in the other. The plurality of areas in which the prestressing steel strands are concentrated preferably have the same or approximately the same distance from the median plane of the press. This reduces the difference in the dynamic elongation of the bracing members due to the bending of the yokes.

As described, it is possible to pass the prestressing steel strands through the side posts by using side stands with cavities through which the prestressing steel strands pass. Alternatively, it is also within the scope of the invention to arrange the prestressing steel strands next to the side uprights.

It can be used commercially available prestressing steel strands, the z. B. can be blank. Furthermore, galvanized prestressing steel strands can be used. Alternatively, prestressing steel strands with a sheath, z. B. with a plastic sheath, z. As PE jacket, are used.

The invention also provides a method for mounting a press frame with the features of claim 8. In this case, a plurality of prestressing steel strands are passed through the upper receiving plate and the lower receiving plate and attached to the receiving plates, which rest against the respective clamping surfaces of the spars, with anchoring devices , The anchoring devices may be the mono-anchors already described or, alternatively, bundle anchors. In bundle anchoring, a plurality of strands are arranged in a certain pattern in an anchor plate and clamped together with a bundle tensioning press. The anchor plate has a plurality of conical holes whose pattern corresponds to the pattern of the clamping press. The anchoring then takes place with corresponding clamping wedges, which engage in the anchor plates.

However, within the scope of the invention, preference is given to a mono-anchorage, in which the individual prestressing steel strands are held in separate housings (anchoring sleeves), with the aid of corresponding clamping wedges. Such mono-anchors can be arranged in any distribution, so that the available space can be optimally utilized. In addition, handy and cheap clamping presses can be used, in addition, a different bias per strand is possible. In any case, both the mono-voltage and the bundle bracing are characterized by low costs and the possibility of re-tensioning. Both are highly redundant systems. The method preferably relates to the assembly in connection with the press frame described, in which the prestressing steel strands in each case homogeneous to a plurality of areas are concentrated. However, the method described can also be realized in such embodiments in which the prestressing steel strands are distributed homogeneously in the region of each side stand, so that z. B. a tie rod per side stand from each of a variety of prestressing steel strands can be constructed.

During assembly, it must be ensured that the numerous prestressing steel strands are passed through respectively corresponding (aligned) bores of the receiving plates and that the strands are guided in parallel and in particular do not intersect or twist. To ensure this, there are various possibilities within the scope of the invention. It is possible to use between the upper beam and lower beam a variety of ducts through which the prestressing steel strands are passed. For this purpose, a plurality of such cladding tubes can be combined by an auxiliary device (eg a plate) to form a bundle in a predetermined distribution. Such a bundle can be constructed by a perforated plate in the same drilling pattern as in the receiving plate. In this case, rigidly formed cladding tubes are used with a (widening in cross-section) sleeve, z. B. plastic, z. As commercial PE pipes or PVC pipes. In detail, reference is made to the figure description. Alternatively, standardized corrugated pipes made of steel strip can be used for tendons (eg according to EN 523). Another possibility is the use of standardized extruded profiles with matching hole pattern. Such extruded profiles can be produced preferably from plastics, wood-based materials or aluminum. In connection with the use of cladding tubes, it may be advantageous to fill them with suitable material, for. B. with highly viscous damping oil, z. B. to avoid vibrations of the strands. If the damping oil has a sufficiently high kinematic viscosity, the so-called aperiodic limiting case occurs, and the strand itself is subject to highly dynamic, periodic excitation, as described, for example, in US Pat. B. could occur in high-speed mechanical presses, not to vibrate.

Alternatively, the assembly of the prestressing steel strands can take place with the aid of a separate guiding device. For this purpose, a plurality of strands can first be fastened together with one end to a guide device, so that an exact positioning of the strands takes place relative to one another. Subsequently, this guide device from the upper spar to the lower beam (or vice versa) are performed with the strands attached thereto. Such a guide segment can, for. B. first attached to the upper receiving plate and are guided after retraction of the strand down. As a result, the strands are aligned exactly. Also refer to the description of the figures.

However, due to the particular simplicity, a particularly preferred mounting option is characterized in which the strands are guided one after the other from the upper spar to the lower spar (or vice versa), with no need for precise guidance. The strand is inserted into a specific hole in the upper receiving plate and by appropriate marking of the holes in the receiving plates ensures that the strand is then passed through the corresponding hole in the opposite receiving plate. The decisive factor is the fact that the strand to be inserted does not get caught between the already mounted strands and possibly exits crossed. To avoid this, the strand is equipped with a reinforcing sleeve, it is artificially thickened. Such a thickening with the aid of a reinforcing sleeve or a similar means ensures that the strand or the end of the strand on which the reinforcing sleeve is mounted, can no longer penetrate into the interstices of the already retracted strands. In this way, intersections or the like are avoided, even if the respective fitter can not see the area between the receiving plates in the area of the side stand. Further details are explained in the description of the figures. In any case, the described solution with the reinforcing sleeve is characterized by a very low production costs for the mounting aid, especially since these mounting aids are independent of the press height. The assembly is easy.

The embodiment with reinforcing sleeves can be optimized in that the reinforcing sleeves are each provided with a magnet or even magnetically formed. This embodiment has the advantage that the reinforcing sleeves can first be mounted below the upper receiving plate, since they are held by the magnetic force on the receiving plate. The prestressing steel strands can then be passed through the receiving plate and by the feed force, the reinforcing sleeve separates from the receiving plate as soon as the strand presses on the magnet. This also ensures that there is a contact between the strand and the magnet, so that the reinforcing sleeve is then held by the magnetic force on the prestressing steel strand. In this way, the reinforcing sleeve can be performed together with the prestressing steel strand through the press frame, so that it prevents over-crossing of the prestressing steel strands in the manner described. Once the magnetic reinforcing sleeve exits the bottom of the lower spar, it can easily be removed by the fitter and the stranded wire into the corresponding hole in the receiving plate be introduced. The handling is thus further improved by this magnetic design. The susceptibility to errors and the assembly time are reduced. In addition, the upper receiving plate for retracting the strands not jacked up and therefore later not be drained again. This in turn eliminates the need to re-align the plate and shortening the strands at the bottom of the press. When using magnetic reinforcing sleeves, it is convenient to arrange below the upper receiving plate an insulator plate which is provided with a plurality of apertures which receive the magnetic reinforcing sleeves. With the help of such an insulator plate, the individual reinforcing sleeves are held in spite of the magnetic forces at a distance, so that tilting of the individual sleeves is avoided. Insulator plate means that this plate made of a non-magnetizable material, eg. B. made of wood or plastic. The magnetic reinforcing sleeves can be made in various ways, so a (one-piece) sleeve of magnetic material can be made. By particularly simple production, however, an embodiment is characterized in which the reinforcing sleeve consists essentially of a tube (made of magnetizable material), to which the end face a suitable magnet is applied and then a cap is attached.

The prestressing steel strands essential to the invention are generally supplied on rolls (so-called coils). Preferably, the prestressing steel strands are withdrawn endlessly from such a coil and separated in the respective length. In principle, it is possible to separate the strands after removal from the coil and before drawing into the press. However, the separation is particularly preferably carried out only in the desired length after being drawn into the press. It is expedient to mount the coils with a coil unwinding device. The prestressing steel strands are preferably guided from above first through the upper spar or through the upper receiving plate and then through the lower spar or the lower receiving plate. Nevertheless, it is expedient not to arrange the coil and the unwinding device at the level of the upper spar, since this would be associated with very high costs. Such a coil unwinding device is preferably arranged next to the press below the upper spar and particularly preferably at the level of the sheet. The unwinding device operates with an electric or hydraulic roller system which pushes the end of the strand preferably from the center of the coil. The strand is then preferably passed through a hose (similar to a Bowden cable) up to the press or to the upper spar. The hose is attached to the output of the unwinding device and a holder on the upper beam. As a result, the strand can not fall laterally and also a slipping back of the strand from the unwinding device is prevented. Also during assembly can be made of known components from the construction industry.

Preferably, after the assembly and continuously or periodically during operation, the bias voltage is measured and thus protokoliert. For that there are different possibilities. First, a gap test can be done. Shortly after completion of the assembly and after removal of the press, it is driven by pressing load. For example, the resulting gap between the upper beam and the side stand is measured and documented. This measurement can be repeated at regular intervals. If the gap increases, there are preload losses that can then be corrected.

Alternatively, the preload can be periodically checked by measurement using a clamp with test fixture.

In another approach, the bias can be permanently controlled by providing a permanent measurement. There are also different possibilities for this. In a first alternative, a force-measuring ring can be used. For this purpose, a force measuring ring can be mounted under each anchoring device, which permanently measures the applied force of each strand. Alternatively, strain gauges (DMS) can be used. At the side stands z. B. each mounted several strain gages. With the help of a measuring amplifier, a general bias loss can be detected. By the arrangement of several DMS, z. G., Three strain gages, it is possible to more or less accurately determine the range of bias loss. A further measurement possibility consists in a natural frequency measurement of the strands, which can be done with the aid of accelerometers, acoustically, with optical sensors, lichtstroboskopisch using image analysis methods or other suitable methods. Because when the preload decreases, the fundamental frequency of the oscillating strand decreases at the same time. If the fundamental frequency of one of these strands drops below a certain minimum frequency value, retensioning is required.

In the following the invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment. Show it

1 schematically simplifies a press in the embodiment as a forging press with a press frame according to the invention,

2 an enlarged section of the object after 1 in another view in the area of the Oberholms,

3A . 3B a further enlarged section of the object after 2 in two different assembly situations,

4 an inventive prestressing steel strand in a perspective view,

5 an anchoring device for the object 3A . 3B .

6 the press frame after 1 during the assembly,

7 an assembly aid in a first embodiment,

8th an assembly aid in a second embodiment,

9A . 9B an assembly auxiliary device in a third embodiment (in a perspective side view and in a bottom view);

10A . 10B an assembly aid for a strand replacement (in a side view and in a top view during use),

11A - 11C different anchoring patterns,

12A - 12E various possibilities of bundle anchoring and mono-anchoring,

13 an alternative embodiment of the embodiments according to 9a and 9b ,

14 a reinforcing sleeve of the article after 13 ,

In the figures, a press is shown with a press frame, wherein the press frame of upper spar 1 and lower spar 2 and two on both sides of the press room arranged side uprights 3 composed. Between Oberholm 1 and lower spar 2 In the exemplary embodiment, a cross member L is guided, on which a press cylinder P supported on the upper member works. upper beam 1 and lower spar 2 are under the interposition of the side stand 3 with tie rods 4 braced against each other, with the tie rods 4 According to the invention are each formed by a plurality of flexurally elastic tension elements. These flexurally elastic tension elements are according to the invention as prestressing steel strands 5 educated. The tie rods 4 are therefore not made of solid steel anchors, but they are made up of a variety bending elastic prestressing steel strands 5 together.

These are prestressing steel strands in the exemplary embodiment 5 according to EN 10138-3, which is exemplary in 4 are shown. The prestressing steel strand 5 consists of seven cold-drawn single wires 6 together, with six wires turned around a central wire. Such prestressing steel strands 5 are used in construction.

The prestressing steel strands 5 be on the end of receiving plates 7a . 7b assembled. These are in the area of Oberholms 1 upper mounting plates 7a and in the area of the sub-spar 2 lower mounting plates 7b provided, each press side each having an upper receiving plate 7a and a lower receiving plate 7b assigned. These mounting plates 7a . 7b are also referred to as clamping plates. The mounting plates 7a . 7b each have a variety of holes 8th through which the individual prestressing steel strands pass 5 be passed. The holes 8th the mounting plates 7a . 7b are cylindrical. This will be the prestressing steel strands 5 not directly on the mounting plates 7a . 7b but it will be separate anchoring devices 9 used. In the exemplary embodiment, the mono-anchors used are preferably used 9 shown where the individual strands 5 each with individual anchoring sleeves 10 on the mounting plates 7a . 7b be attached.

3A shows the upper mounting plate 7a without the installed prestressing steel strands 5 and 3B shows this area with the installed prestressing steel strands 5 including the anchoring device 9 , Structure and mode of operation of the anchoring direction 9 can be especially in 5 detect. They are made of anchoring sleeves 10 and clamping wedges 11 Together The anchoring sleeves 10 form an open housing with an at least partially conical opening, through which the strand to be clamped 5 is passed. The fixation is done with the help of a clamping wedge 11 , The bracing is done with a monospace press, not shown. It is based on the 1 to 3 recognizable that the prestressing steel strands 5 are concentrated in two areas per press page. There are two tie rods per press side 4 provided, each consisting of prestressing steel strands 5 consist. This concentration of prestressing steel strands 5 On two areas per press side causes the bending stresses in the mounting plates 7a . 7b be reduced. It is within the scope of the invention that the prestressing steel strands 5 the individual areas by common side stand 3 or be passed through uniform cavities. Alternatively, however, also more press stands per side stand or several separate cavities are provided. Different options are in the 11A to 11C shown.

As an alternative to mono-anchoring, bundle anchors can also be used, which are also known from the construction industry. Different options are in the 12A to 12E shown, wherein the 12A . 12B and 12C show different ways of bundle anchoring and the 12D and 12E different possibilities of mono-anchors.

A particular advantage of prestressing steel strands 5 is the fact that they are available as standardized mass-produced goods from the construction industry and can be used for press construction. Another advantage is the ease of mounting such flexurally elastic clamping elements. In turn, it is possible to fall back on known components from the construction industry.

The prestressing steel strands 5 are usually rolled up as a coil 12 delivered. Such a coil 12 can first in a so-called cage 13 lifted and then solved. The cage prevents the entire coil from jumping open. The cage with the coil is then placed in an unwinding device 14 used or with an unwinding device 14 connected, wherein in such an unwinding device, the end of the coil is pushed out, for. B. is pulled out of the middle of the coil. With the help of the unwinding device, the strand can then be pushed into the area of the press. This is in 6 indicated. Particularly advantageous is the fact that the unwinding device can not be arranged at the level of the upper spar, but at the bottom or floor level. The strand 5 is through a hose 15 in the area of the Oberholms 1 guided. This hose 15 is at the exit of the unwinding device 14 and a holder 16 on the upper beam 1 attached. This allows the strand 5 do not fall off laterally, even a slipping back of the strand from the unwinding device 14 is prevented similar to the principle of a "Bowden cable". The strand is particularly preferred 5 endless from the coil 12 pulled off and first through the upper receiving plate 7a and then the lower mounting plate 7b guided and fixed. Only then is the stranded wire 5 then disconnected and the next strand can be mounted.

During assembly, make sure that the strands 5 be guided parallel to each other and do not cross or twist. There are various possibilities for this, which are exemplified by the 7 to 9 should be explained.

7 shows a first alternative in which the strands 5 with the help of ducts 17 to be mounted, which by an auxiliary device 21 are combined into a bundle. The bundle is passed through a perforated plate 21 in the same drilling pattern as in the receiving plate 7a . 7b built up.

In this case, a plurality of bundle sections are combined to form a bundle which has the desired length. The individual ducts 17 are then composed of individual pipe sections. For this reason, the individual pipe sections with appropriate sleeves 18 equipped. First, a first tube bundle section 19 assembled and left in the press. Thereafter, the next tube bundle section 19 on the thimbles 18 of the first tube bundle section 19 plugged and this unit is further drained. This process is repeated until a continuous guide for the strands 5 from the upper beam 1 to the lower beam 2 consists. Then the strands can 5 through the pipes 17 be guided exactly to their desired location. The ducts 17 remain when clamping in the press, so that also an exchange of strands 5 is possible.

8th shows a guide device 19 ' for an alternative mounting option. Also, the strands z. B. are guided through pipes, but to use less material, a movable guide is used. Also this leadership segment 19 ' arranges pipes 20 ' through a perforated plate 21 ' in the same pattern as in the receiving plate. This in 8th shown guide segment 19 ' is at the upper receiving plate 7a attached and after retraction of the strands 5 led down. This will make the strands 5 aligned. This is how the strands become 5 accurately managed and the cost of such an arrangement is lower compared with the alternative with cladding throughout the press.

By special simplicity, the in 9A . 9B illustrated preferred embodiment, in which the strands 5 be mounted one after the other, with the help of reinforcing sleeves 22 , which are placed on the ends of the strands. At the in 9A . 9B The method shown is marked by marking / marking the holes 8th in the receiving plates 7a . 7b Ensures that the fitter has a single strand 5 through aligned holes 8th in the upper receiving plate 7a and the lower receiving plate 7b pulls through and mounted there. To avoid strands 5 When passing from top to bottom, the strand is "artificially thickened" by a reinforcing sleeve 22 end to the strand 5 is put on. This reinforcement sleeve 22 Ensures that the strand can then no longer penetrate into the spaces between the already installed strands. In this way, a crossing or twisting of the strands is avoided even if the fitter the area between the upper spar 1 and lower spar 2 can not see. Because the reinforcement sleeve 22 can not be passed through the holes in the receiving plates due to their thickness, the upper receiving plate 7a initially "jacked up" enough room to attach the reinforcing sleeve 22 to accomplish. Through the existing workspace in the foundation support, the reinforcing sleeve below the lower spar 2 be taken off again, before going into the appropriate hole 8th in the lower receiving plate 7b is threaded. After passing through the lower receiving plate 7b then the mono-anchorage is attached to the stranded wire. This solution according to 9A . 9B is very inexpensive.

The in the 9a and 9b The solution shown with reinforcement sleeves can be further optimized by the reinforcement sleeves 22 be magnetically designed or equipped with magnets. This is in accordance with the training 13 and 14 directed. 14 shows an example of a reinforcing sleeve 22 , which is formed (partially) magnetically. In this embodiment, the reinforcing sleeve 22 from a piece of pipe 22a , a magnet 22b and a cap 22c , The magnet (eg neodymium disc magnet) is attached to the end of the pipe or end face 22a created and then the protective cap 22c plugged, so the magnet 22b between the front end of the pipe section 22a and the protective cap 22c is held. The use of a magnetic reinforcement sleeve 22 is in 13 indicated. A variety of reinforcing sleeves 22 be below the upper receiving plate 7a pre-assembled, with the reinforcing sleeves 22 by the magnetic force on the upper mounting plate 7a being held. In the illustrated embodiment is below the upper mounting plate 7a an insulator plate 28 arranged a variety of openings 29 in which the reinforcing sleeves 22 can be used. With the help of this insulator plate 28 An alignment of the reinforcing sleeves and at the same time it is prevented that the individual reinforcing sleeves tilt against each other due to the magnetic forces. The magnetic field of the magnets 22b gets through the steel pipe 22a guided and holds the reinforcing sleeve reliably on the receiving plate 7a , In a next assembly step, the prestressing steel strand 5 in the press frame or through the receiving plate 7a be guided. The feed force of the stranded wire 5 releases the reinforcement sleeve 22 from the receiving plate 7a , In the illustrated embodiment, it is also ensured that the reinforcing sleeve 22 only then from the receiving plate 7a triggers when the strand 5 on the magnet 22b suppressed. This ensures that a contact between the strand 5 and the magnet 22b which is the reinforcing sleeve 22 allows to attach to the strand 5 hold. Subsequently, the reinforcing sleeve 22 along with the wire 5 passed through the press frame, so that in the manner already described a crossing of the prestressing steel strands 5 is prevented. Once the reinforcement sleeve exits the bottom of the lower spar, it can easily be removed by the fitter. The strand 5 can then into the corresponding hole of the receiving plate 7b be introduced.

In principle, within the scope of the invention it is also possible to exchange a damaged strand in the assembled press. This can z. B. in the 10A . 10B illustrated assembly aid 23 be used. It is shown by way of example that a completely broken strand is to be exchanged in the middle of six other strands. This mounting aid works with a spring mechanism, namely with expanding or unfolding leaf springs 24 , This serves to insert a guide wire 25 , with which then a new strand can be pulled into the area of the missing strand. This mounting aid is with the wire 25 completely through the upper mounting plate 7a and the lower receiving plate 7b guided. It essentially consists of a core 26 (eg a hexagon) with spring elements 24 (Eg leaf springs), where the leaf springs 24 end with a connecting means 27 , z. B. a string, are connected as a guide. This device is through the upper receiving plate 7a pressed. Then fold the leaf springs 24 apart again and the cord presses when blurring the mounting aid on the surrounding strands 5 from. This is how the assembly aid becomes 23 on the guide wire 25 hanging down to the bottom and there from the lower receiving plate 7b pulled out. With the wire so introduced 25 then can the new wire 5 be confiscated.

Claims (11)

Press frame, in particular for a forging press, with upper beam ( 1 ) and sub-spar ( 2 ) and between Oberholm ( 1 ) and sub-spar ( 2 ) arranged side posts ( 3 ), whereby Oberholm ( 1 ) and sub-spar ( 2 ) with the side stands ( 3 ) with tie rods ( 4 ) are braced against each other, the tie rods ( 4 ) are each formed by a plurality of flexurally elastic tension elements, which are used as prestressing steel strands ( 5 ) are formed, wherein in the range of each side stand ( 3 ) the prestressing steel strands ( 5 ) are concentrated in a plurality of areas such that in each case a plurality of tie rods ( 4 ) each of a plurality of prestressing steel strands ( 5 ) are provided the strands ( 5 ) each end in receiving plates ( 7a . 7b ) are arranged, which against clamping surfaces of upper beam ( 1 ) and sub-spar ( 2 ), wherein the receiving plates ( 7a . 7b ) each have a plurality of holes ( 8th ) through which the strands ( 5 ) are passed, wherein the strands ( 5 ) on the mounting plates by means of mono-anchors ( 9 ) each with individual anchoring sleeves ( 10 ) are attached. Press frame according to claim 1, characterized in that the prestressing steel strands ( 5 ) are designed as strands according to EN 10138-3. Press frame according to claim 1 or 2, characterized in that the prestressing steel strands ( 5 ) from several z. B. cold drawn individual wires ( 6 ) and are preferably formed as a seven-wire strands, each of which consists of seven individual wires ( 6 ) consist. Press frame according to one of claims 1 to 3, characterized in that the individual wires ( 6 ) has a diameter of 4 mm to 8 mm, z. B. 6 mm, have. Press frame according to one of claims 1 to 4, characterized in that the prestressing steel strands ( 5 ) has a nominal diameter of 10 mm to 20 mm, z. B. 15 mm to 17 mm. Press frame according to one of claims 1 to 5, characterized in that the prestressing steel strands ( 5 ) each have a tensile strength of more than 1,500 MPa, z. B. 1,500 to 2,000 MPa, preferably more than 1,700 MPa, z. B. 1,700 to 1,900 MPa, have. Press frame according to one of claims 1 to 6, characterized in that the holes ( 8th ) of the receiving plates ( 7a . 7b ) are cylindrical. Method for mounting a press frame with upper rail and lower rail and arranged between the upper rail and lower rail side uprights, in particular according to one of claims 1 to 7, wherein upper beam ( 1 ) and sub-spar ( 2 ) with the side stands ( 3 ) are braced against each other, wherein a plurality of prestressing steel strands ( 5 ) by a against the upper clamping surface of the upper spar ( 1 ) fitting upper receiving plate ( 7a ) and one against the lower clamping surface of the sub-spar ( 2 ) fitting lower receiving plate ( 7b ) and at the receiving plates ( 7a . 7b ) by means of anchoring devices ( 9 ), wherein in the region of the upper spar a reinforcing sleeve ( 22 ) on the strand ( 5 ) and the stranded wire ( 5 ) with this reinforcing sleeve ( 22 ) in the area of the sub-spar ( 2 ), wherein the outer diameter of the reinforcing sleeve ( 22 ) greater than the outer spacing of adjacent strands ( 5 ) is formed, or first between the upper beam ( 1 ) and sub-spar ( 2 ) Cladding tubes ( 17 ), preferably a bundle of cladding tubes ( 17 ), and then the strands ( 5 ) through the ducts ( 17 ) through from the upper receiving plate ( 7a ) to the lower receiving plate ( 7b ) or a plurality of strands ( 5 ) first together on a guide device ( 19 ' ) and then the guiding device ( 19 ' ) with the strands attached thereto ( 5 ) from the upper beam ( 1 ) to the lower beam ( 2 ) to be led. Method according to claim 8, characterized in that the reinforcing sleeves ( 22 ) are equipped with a magnet and / or are magnetically formed. Method for mounting a press frame with upper rail and lower rail and arranged between the upper rail and lower rail side posts, in particular according to claim 8 or 9, wherein upper beam ( 1 ) and sub-spar ( 2 ) with the side stands ( 3 ) are braced against each other, wherein a plurality of prestressing steel strands ( 5 ) by a against the upper clamping surface of the upper spar ( 1 ) fitting upper receiving plate ( 7a ) and one against the lower clamping surface of the sub-spar ( 2 ) fitting lower receiving plate ( 7b ) and at the receiving plates ( 7a . 7b ) by means of anchoring devices ( 9 ), the prestressing steel strands ( 5 ) endlessly from a coil ( 12 ) and separated before or after being drawn into the press, the prestressing steel strands ( 5 ) of a coil ( 12 ), which is in a coil unwinding device ( 14 ) is arranged next to the press below the press upper part ( 1 ), wherein the prestressing steel strands ( 5 ) through a hose ( 15 ) are guided upward to the upper beam of the press, wherein the hose on the unwinding on the one hand and on a holder ( 16 ) Is attached to the upper spar on the other. Press, z. B. forging press, with a press frame according to one of claims 1 to 7, and with at least one pressing unit, for. B. a hydraulic press cylinder.

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