AT513742A4 - Device for bending bracket wires for lattice girders - Google Patents

Abstract

Device (17, 42) for bending stirrup wires (2) for girder (46) or the like. With at least two along a bending stretch spaced clamping means (18, 19) for clamping the stirrup wires (2) and at least one We sentlichen across bending punch (20), which is arranged essentially between two clamping devices (18, 19) and is mounted so as to be pivotable about a pivot axis (25) extending substantially transversely to the bending step, wherein the two clamping devices (18, 18) adjacent to the bending punch (20) 19) are mounted displaceably parallel to the bending path

Description

1

The invention relates to a device for bending stirrup wires for lattice girders or the like with at least two clamping devices spaced apart along a bending path for clamping the stirrup wires and at least one bending stamper acting essentially transversely to the bending streamer, which is arranged substantially between two clamping devices and around one Essentially transversely to the bending path extending pivot axis is pivotally mounted.

It is well known in the art to use bending machines for lattice girder bending machines which have a bending punch and two ironing clamps. The initial distance of the U-clamps - the bend distance - defines the length of the wire used for a hanger. Since this length is constant during bending, one of the clamps must be movable to allow the material to bend. This type of bending has a significant disadvantage:

When bending the distance of the temple crest is increased by the immovable clamp and the stirrup vertex thus moves from its initial position on the hanger wire in the direction of end position. For this purpose, areas of the wire must first be bent and subsequently bent back to follow the movement of the punch. This work can lead to undesirable structural change of the ironing material and represents a heavy burden on the starting material.

In the case of the bending machine shown in AT 405 031 B, the bending punch can be pivoted to the extent of shortening the length of the bending stirrup wire, and thus a displacement of the bending vertex along the stirrup wire during the bending process can be prevented. In addition, since the punch can be used from various initial positions, various bow shapes can be made. Here, the fulcrum of the punch is positioned azentrisch with respect to the two ironing clamps. This allows - at the expense of symmetry - the bending of pointed stirrups, as would be possible with a centrally located pivot point. The production of thrust carriers against the feed direction is not possible with such an embodiment. 2/16 2

The object of the present invention is to remedy these deficiencies and to provide a bending device as stated at the outset, which makes it possible to form asymmetric shapes of the strap wires for lattice girders with pointed straps pointing in both directions, thereby minimizing stress on the material to be bent ,

The invention solves this problem in that the two adjacent to the bending die clamping devices are mounted displaceably parallel to the bending path. In contrast to previously known devices, in which only one of the bending punch upstream in the feed or production direction clamping device is mounted displaceably parallel to the bending path, according to the invention, both the upstream and the nachgeord-nete clamping device mounted parallel to the bending path relative to the bending punch. Accordingly, depending on the positioning of the vertex, the tips of the formed stirrups can be bent on one and the same wire both in and against the feed direction.

Thus, by means of the device according to the invention, for example, stirrup wires for lattice girders can be formed, which have outwardly pointing stirrups at both ends, so that a lattice girder made therefrom is designed as an oppositely oriented thrust support and without any use of additional stirrup wires at the ends. Until now, separate lattice girders made of stirrup wires with asymmetrically bent temples had to be used. Of course, in the case of stirrup wires with differently oriented asymmetric stirrups, the length and thus the intended use of the stirrup wire should already be approximately known during production, since cutting is only possible to a limited extent - especially in the case of a central normal carrier section with symmetrically bent stirrups.

A particularly large variety of ironing forms can be produced with the present device, when the bending die in a feed direction downstream clamping device is adjustable transversely to the bending distance. 3/16 3

In order to reduce the load on the stirrup wire further, it is advantageous if the bending punch is mounted displaceably substantially parallel to the bending path. It can thus be moved parallel to the bending path, the pivot axis of the punch, wherein it is favorable in the choice of the orientation of a bracket, when the pivot axis is moved so that the temple punch acts perpendicular to the bending vertex. This longitudinal loads of the strap can be reduced or avoided when bending.

If the bending punch is mounted displaceably independently of the clamping devices, the displacement of the bending punch to the respectively produced bow shape can be adjusted so that only or at least predominantly transverse forces act on the wire during the entire bending process. In particular, the displacement of the punch in a direction opposite to that of the movable clamping device may be useful in producing particularly pointed stirrups.

Furthermore, it is advantageous for the two clamping devices adjacent to the bending punch to be mounted so as to be displaceable independently of each other. Depending on the ironing shape to be produced, it is possible, for example, to provide different displacement speeds of the clamping devices; one of the clamping devices, in particular a clamping device adjacent to the shorter ironing leg, can be fixed while the other clamping device can remain movable.

For producing different width and long bow forms, it is useful if the distance between the clamping devices is infinitely adjustable. In addition, a feed device for clock-shaped feeding of the hanger wire may be provided, the feed rate of which is adjustable according to the distance of the clamping devices. The advancing device can also be set up so that different stirrup spacings can be realized along the stirrup wire by pushing a piece of the wire which is longer than the length of the clamping devices through the device during a stroke. 4/16 4

The invention will be explained below with reference to particularly preferred embodiments, to which it should not be limited, and with reference to the drawings. In detail in the drawing:

1A and 1B show a bending device according to the prior art when bending a right-facing bracket in a starting position or an end position /

2A and 2B, the bending device of FIG. 1A when bending a left-facing bracket in a starting position or an end position /

3A and 3B show a bending device according to the invention when bending a symmetrical bracket in a starting position or an end position;

4A and FIG. 4B show the bending device according to FIG. 3A when bending an asymmetrical, left-facing bracket in an initial position or an end position; FIG.

FIG. 5A or FIG. 5B shows the bending device according to FIG. 3A during bending of an asymmetrical, right-pointing bracket in an initial position or an end position;

6A and 6B show a variant of the bending device according to the invention when bending a symmetrical bracket in an initial position or an end position;

7A and FIG. 7B, the bending device according to FIG 6A when bending an asymmetric, left-facing bracket in a starting position or an end position.

8A and 8B show the bending device according to FIG. 6A when bending an asymmetrical, right-pointing bracket in a starting position or an end position, respectively; FIG. and

9 shows a lattice girder produced with the device according to the invention.

In Fig. 1A, a bending device 1 with a straight strap wire 2 is shown schematically. The bending device 1 comprises a front wire clamp 3 and a rear wire clamp 4. The distance between the two wire clamps 3, 4 defines a bending distance. Between the two wire clamps a bending punch 5 is arranged, which is mounted pivotably about a pivot axis 6. The bending punch 5 downstream in the feed direction 7, rear wire clamp 4 on the right side is in a fixed 5

Distance from the bending punch 5 or its pivot axis 6 is arranged. The bending of the punch 5 upstream, front wire clamp 3 on the left side, however, is mounted displaceably parallel to the bending path. In Fig. 1A, a starting position for bending a pointing to the right, in the direction of feed 7 bracket is shown. In the example shown here, the bending vertex 8 is closer to the rear wire clamp 3 than in the front wire clamp 4. The hanger wire 2 is thus from the bending vertex 8 divided into two sections 9, 10 of unequal length, a front longer section 9 on the left side and a rear, shorter section 10 on the right side. As soon as the bending punch 5 extends from the starting position shown in FIG. 1, the hanger wire 2 is bent up at the bending vertex 8 in the stamping direction 11, as shown in FIG. 1B. Since the rear wire clamp 4 is not displaceable, the bending vertex 8 follows a circular arc around the rear wire clamp 4. The bending punch 5 can be extended at most so far that it is approximately parallel to the short portion 10 of the hanger wire 2 between bending crest 8 and rear wire clamp 4 is because the force applied by the punch 5 force then no cross or Liegekraft on the short section 10 more applies. Since the length of the piece of wire clamped between the wire clamps 3, 4 remains essentially constant during the bending process, the front wire clamp 3 is displaced in the direction of the bending punch 5 when the bending punch 5 is extended, and the distance between the wire clamps 3, 4 is reduced. As shown in Fig. 1B, the bending in the direction of feed 7 can take place beyond the rear wire clamp 4, which is advantageous after the relaxation of the stirrup 12 formed by the sections 9, 10, i. after retrieving or retracting the: punch 5, a possible acute angle in the bending vertex 8 receives.

In Fig. 2A and Fig. 2B it is shown that with a known bending device 1, although an asymmetric but not completely to the left pointing bracket 13 can be formed. In this case, the bending punch 5 is attached to the hanger wire 2 that the wire section 14 left of the bending vertex 15 is shorter than the wire section 16 right of the bending vertex 15. When extending 6/16 6 of the punch 5 follows the bending vertex 15 as before a circular arc around the rear In this case, the front wire clamp 3 shifts in the best case so far in the feed direction 7, that the left, shorter wire section 14 is perpendicular to the bending section. From this end position shown in Fig. 2B further bending is no longer possible. The bracket 13 thus can not be bent over a vertical position of the shorter wire portion 14 also to the left and will return to a rightwardly inclined position of the shorter wire portion 14 during the relaxation. In addition, at the beginning of the bending operation, the bending punch 5 acts at an angle on the hanger wire 2 (see Fig. 2A), which can lead to the sliding of the bending punch 5.

FIGS. 3A to 5B schematically show an exemplary embodiment of the device 17 according to the invention. A hanger wire 2 is clamped between two clamping devices or wire clamps 18, 19. Between the wire clamps 18, 19, a bending punch 20 is arranged centrally, for example, in a starting position. The bending punch 20 has a bending head 21 with a bending mandrel 22, which is arranged on a piston 23.

The piston 23 of the punch 20 is mounted for example in a pneumatic cylinder 24 and is pneumatically driven. Of course, the piston 24 may also be hydraulically or mechanically, via a crankshaft, etc., driven. The cylinder 24 is pivotally mounted about a pivot axis 25, whereby the entire punch 20 is pivotable about the pivot axis 25. The two wire clamps 18, 19 are directly adjacent to the punch 20, so that a front wire clamp 18 is arranged upstream of the punch 20 with respect to a feed direction 7 and the other, rear wire clamp 19 is arranged downstream of the punch 20 with respect to the feed direction 7. Both wire terminals 18, 19 have two jaws 26, between which the hanger wire 2 can be held during a bending operation. The jaws 26, like the bending punch 20, pneumatically, hydraulically, mechanically or electrically driven. Furthermore, both wire clamps 18, 19 are mounted displaceably parallel to the bending path, for example, each arranged on a carriage 27, which is adapted for sliding or rolling along parallel to the bending section 7/16 7 extending rails 28 and, for example, rollers 21 'has. In this case, the same rails 28 - as shown - are used by two wire clamps 18, 19, but it can also be provided separate rail or guide body. For example, the wire clamps 18, 19 may be mounted on parallel to the bending line aligned piston.

The wire piece 29 clamped between the wire clamps 18, 19 is divided by a bending vertex 30 defined by the position of the bending mandrel 22 into a front wire section 31 in the feed direction with respect to the bending vertex 30 and a rear wire section 32.

When the bending punch 20, as in the starting position shown in FIG. 3A, acts substantially at the middle between the wire clamps 18, 19 on the hanger wire 2, the wire sections 31, 32 are approximately the same length. Upon extension of the bending punch 20 into an end position shown in FIG. 3B, the wire sections 31, 32 can thus be bent to form a symmetrical bracket 33. In order that the length of the wire piece 29 remains substantially constant, both wire clamps 18, 19 move symmetrically from both sides toward the punch 20, for example. In this case, the front wire clamp 18 moves in the feed direction 7 and the rear wire clamp 19 against the feed direction 7. The movement of the two wire terminals 18, 19 preferably takes place synchronously; but it can also be an asynchronous movement provided, for example, first only one and then only the other wire clamp shifts, or it can remain immovable a wire clamp, so that the other wire clamp shifts further accordingly. The choice of the movement sequence should be coordinated with the operation of a feed device (not shown) for feeding the straight strap wire 2 and with a removal device (not shown) for the removal of the bent strap wire 2.

The present device 17 is also particularly suitable for bending asymmetric brackets 34, 35 as illustrated in Figs. 4A to 5B. In the starting position shown in FIG. 4A for bending a bracket 34 inclined against the feed direction 7, the temple punch 20 engages at an angle on the 8/16 - 8 stirrup wire 2, so that the distance between the bending vertex 36 and bending mandrel 22 and the front wire clamp 18 is smaller than the distance between the bending vertex 36 and the rear wire clamp 19. The clamped piece of wire 29 is thus divided into a front, shorter wire section 37 and a rear, longer wire section 38. Upon extension of the punch 20 into an end position shown in Fig. 4B, the front wire clamp 18 is held, while the rear wire clamp 19 moves against the feed direction 7. The bending vertex 36 thus describes when bending a circular arc around the front, left wire clamp 18. In this case, the bending punch 20 can be extended at most so far until the short wire section 37 is arranged substantially parallel to the punch 20. Accordingly, even after a relaxation of the bracket 34, both wire sections 37, 38 - as desired - to the left or against the feed direction 7 show.

Conversely, it is of course also possible to apply the punch 20 to the hanger wire 2 so that an inclined in the feed direction 7 bracket 35 can be made. For this purpose, the bending mandrel 22 engages in the starting position shown in Fig. 5A closer to the rear wire clamp 19 on the hanger wire 2, so that the jammed wire piece 29 is divided into a front, longer wire section 39 and a rear, shorter wire section 40. When bending into the end position shown in Fig. 5B is preferably the rear, right wire clamp 18 is held so that the bending vertex 41 describes a circular arc around the held wire clamp 19 and the hanger wire 2 can be bent over it. Meanwhile, the front wire clamp 18 is released and can move in the direction of feed 7. Thus, both, the legs of an asymmetric bracket 35 forming wire sections 39, 40 may be inclined in the feed direction 7 and remain inclined even in the relaxation of the bracket 35 in the feed direction 7.

In the variant 42 of the device according to the invention shown in FIGS. 6A to 8B, the bending punch 20 is mounted displaceably parallel to the bending path, comparable to the wire clamps 18, 19. In the example shown here, the pivot axis 25 of the punch 20 is connected to a punch 9/16 9 slide 43, which is arranged on rollers 44 on a rail device 45 displaceable. The punch carriage 43 is controlled by means of a drive (not shown) and can be displaced from the central position shown in FIG. 6A both in the feed direction 7 and in the feed direction 7. All illustrated carriages, i. the slides 27 of the two wire clamps 18, 19 and the punch carriage 43 of the punch 20, can be controlled separately and independently of each other at arbitrary positions, for example by means of braking or blocking devices are held. The design of the drive and brake devices is at the discretion of those skilled in the art and can be achieved, for example, by pneumatic or hydraulic pistons, by electric motors and racks or the like.

The bending operations for a symmetrical bracket 33 (FIGS. 6A and 6B), an asymmetrical bracket 34 inclined towards the advancing direction 7 (FIGS. 7A and 7B) and an asymmetrical bracket 35 (FIGS. 8A and 8B) inclined in the advancing direction 7 are largely identical to FIGS Comparable previously with reference to FIGS. 3A to 5B bending processes, in particular as regards the control and movement of the wire terminals 18, 19, which is why - to avoid repetition - reference is made to the above statements. In contrast to the device 17 described above, however, the displacement of the bending punch 20 is added here, which will therefore be described in the following in the following.

In order to produce a symmetrical bracket 33 according to FIGS. 6A and 6B, the punch 20 or the punch carriage 43 is preferably displaced into a central position, so that the pivot axis 25 is arranged substantially vertically below the center of the clamped piece of wire 29 and the punch 20 is thus perpendicular to the hanger wire 2. In the starting position shown in Fig. 6A, the punch carriage 43 is held while the bending punch 20 extends into the end position in Fig. 6B.

In order to produce a bracket 34 which is inclined relative to the feed direction 7, the punch 20 is preferably displaced against the feed direction 7 under the bending vertex 36, so that it is arranged perpendicular to the hanger wire 2 in the initial position shown in FIG. 7A. The punch carriage 43 is held in this position while the bending punch 20 extends into the end position shown in Fig. 7B.

On the other hand, to produce a bow 35 inclined in the feed direction 7, the punch 20 is preferably displaced in the feed direction 7, so that it is arranged perpendicularly to the bow wire 2 in the starting position shown in FIG. 8A. The punch carriage 43 is held back in this position while the bending punch 20 extends into the end position shown in Fig. 8B.

Since the bending punch 20 in the starting positions shown in FIGS. 7A and 8A for producing asymmetric brackets 34, 35 can be aligned perpendicular to the bow wire 2 due to its displaceability parallel to the bending stretch, tensile forces can be avoided at the beginning of the bending operation and slipping the bending vertex 8 or sliding of the punch 20 can thus be reliably prevented.

The device 17, 42 according to the invention thus enables the production of stirrup wires 2 with symmetrical and inclined in both directions, asymmetric straps. From this, lattice girders 46, such as those shown in simplified form in FIG. 9, can be produced, which in a central region 47 are normal carriers and in the end regions 48, 49 are in each case opposite thrust carriers. Comparable static properties have hitherto only been achieved by the combination of continuous normal carriers with additional thrust carriers additionally used on the sides, which means an increased material expenditure compared to the illustrated preferred example. The inventive device 17, 42 allows a seamless combination of push and normal carrier sections in a single carrier 46 with a single, preferably continuous strap wire 50th 11/16

Claims (7)

Claims 1. A device (17, 42) for bending stirrup wires (2) for lattice girders (46) or the like with at least two clamping devices (18, 19) spaced apart along a bending path for clamping the stirrup wires (2) and at least a bending punch (20) acting essentially transversely to the bending section, which is essentially arranged between two clamping devices (18, 19) and pivotally mounted about a pivot axis (25) extending essentially transversely to the bending section, characterized in that the two are adjacent to the bending punch ( 20) adjacent clamping devices (18, 19) are mounted displaceably parallel to the bending path. 2. Device (17, 42) according to claim 1, characterized in that the bending punch (20) in a feed direction (7) downstream clamping device (19) is adjustable transversely to the bending distance. 3. Device (42) according to claim 1 or 2, characterized in that the bending punch (20) is mounted displaceably substantially parallel to the bending path. 4. Device (42) according to one of claims 1 to 3, characterized in that the bending punch (20) is mounted displaceably independently of the clamping devices (18, 19). 5. Device (17, 42) according to any one of claims 1 to 4, characterized in that the two of the bending punch (20) adjacent clamping devices (18, 19) are mounted independently of each other displaceable. 6. Device (17, 42) according to one of claims 1 to 5, characterized in that the distance between the clamping devices (18, 19) is infinitely adjustable. 7. Device (17, 42) according to any one of claims 1 to 6, characterized in that a feed device for clock-shaped feeding of the hanger wire (2) is provided. 12/16