EP0564446A1 - Method and device for orientating straight bars - Google Patents

Abstract

Method and device for orientating straight bars of essentially oval cross-section before they are bent jointly in a bending machine. The bars (S) are first of all arranged one above the other or next to one another in an unordered position (L), in which the minor axes of the bars are at different angles. The bars are then rotated out of the unordered position about their longitudinal axis by the exertion of an approximately radial pressure on two opposite sides of the bars, into an ordered position (L') in which the minor axes of all the bars are in approximate alignment, and the bars are clamped in the ordered position. <IMAGE>

Description

The invention relates to a method and a device for aligning straight bars, which have an essentially oval cross section, before the bars are bent together in a bending machine.

When jointly bending a plurality of bars arranged one above the other or next to one another to form multi-legged reinforcement stirrups, the problem arises that considerable diameter differences occur due to the inevitable manufacturing tolerances or ribbing of the surface of the bars and that the individual bars are arranged within the layer in such a random manner are that all the bars of a layer with different diameters lie relative to the bending tools. After each bending process, the bending angles of the individual bars actually achieved differ within the layer due to the different bending geometry and the different springback caused by different material properties depending on the diameter, so that when producing reinforcement brackets with several successive bends on the same bar, the bent ends the brackets lying on top of or next to each other deviate considerably and diverge.

The object of the invention is to arrange the rods in a layer one above the other or next to one another such that when the rods are subsequently bent together, all the rods in the layer are arranged in the same way and are therefore bent with the same bending geometry. The method according to the invention is characterized in that the bars are initially arranged one above the other or next to one another in an unordered position, in which the smallest bar diameter sections have different orientations, in that the bars arranged one above the other or one next to the other from the unordered position by exercising an approximately radial direction acting pressure force on two opposite sides of the rods are rotated about their longitudinal axis in an orderly position, in which all the rods Align the position with its smallest diameter approximately, and that the rods are clamped in the orderly position.

According to a preferred method, the rods are rotated about their longitudinal axis by tangential forces acting on opposite sides of the circumference of the rods and acting in opposite directions, the direction of which changes several times.

Alternatively, the rods can be rotated about their longitudinal axis by axially extending forces acting in the same direction at several offset opposite points on the circumference of the rods, the points of application of the forces parallel to the longitudinal axis of the rods towards a stop surface defining the ends of the rods be moved.

The invention also relates to a device for carrying out the method, with a conveying device and a feeder device with which the bars can be transferred from the conveying device into a bending machine, the bending machine having a rotatable bending plate, a central bending mandrel, an eccentrically arranged bending tool and one Counterholder is equipped, characterized in that an intermediate magazine for forming an unordered position of stacked and stacked rods with different orientations of the smallest rod diameter sections is provided, that a clamping device with clamps that can be applied to the rods to exert a radially acting pressure on the rods and for Fixing the rods against displacement in their longitudinal direction is provided and that a further clamping device is provided, which can be placed on the rods, in the longitudinal direction relative to one another and in the transverse direction to the longitudinal axis the rods have sliding jaws.

The bending machine preferably has at least one bending slide which can be displaced in the direction of the longitudinal axis of the rods and which can be placed on the rods with a sliding carriage Counter holder is provided and with which the ends of the rods can be placed against a stop surface of a stop plate.

According to another feature of the invention, the bending plate of the bending machine can be controlled with an alternating sense of direction in order to press the eccentrically arranged bending tool against the bars several times and to move them away from them.

• Fig. 1a schematisch in Draufsicht eine Beschickungsvorrichtung einer Biegemaschine, zur Durchführung des Verfahrens gemäß der Erfindung;
• Fig. 1b ein Detail der Beschickungsvorrichtung in Seitenansicht bzw. in Stablängsrichtung gesehen;
• Fig. 2a eine Ansicht von Klemmzangen der Beschickungsvorrichtung vor dem Ausrichten der Stäbe, in Stablängsrichtung gesehen;
• Fig. 2b die gleiche Ansicht nach dem Ausrichten der Stäbe;
• Fig. 3a eine Ansicht der Klemmbacken vor dem Ausrichten der Stäbe, in Stablängsrichtung gesehen;
• Fig. 3b die gleiche Ansicht nach dem Ausrichten der Stäbe;
• Fig. 4 in einem weiteren Ausführungsbeispiel eine Biegemaschine zur Durchführung des erfindungsgemäffen Verfahrens;
• Fig. 5a eine schematische Darstellung des zentralen Biegedornes und des Gegenhalters der Biegemaschine vor dem Ausrichten der Stäbe, in Stablängsrichtung gesehen, und
• Fig. 5b die gleiche Darstellung nach dem Ausrichten der Stäbe.

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

• FIG. 1 a shows a schematic top view of a loading device of a bending machine for carrying out the method according to the invention;
• 1b seen a detail of the loading device in side view or in the longitudinal direction of the bar;
• 2a shows a view of clamping tongs of the loading device before aligning the rods, seen in the longitudinal direction of the rod;
• 2b shows the same view after aligning the rods;
• 3a shows a view of the clamping jaws before aligning the rods, seen in the longitudinal direction of the rod;
• 3b shows the same view after aligning the rods;
• 4 shows, in a further exemplary embodiment, a bending machine for carrying out the method according to the invention;
• Fig. 5a is a schematic representation of the central mandrel and the counter support of the bending machine before aligning the bars, seen in the longitudinal direction of the bar, and
• Fig. 5b shows the same representation after aligning the rods.

1a and 1b, a support table 1 for receiving a bundle of rods 2 is shown, which consists of several cut, straight-directed individual rods S. The rods S can have any cross-sectional shape within the scope of the invention. For the production of reinforcement brackets round rods are used, which are provided on their circumference with several ribs R (Fig. 2a) and thus have an essentially oval cross-section. In the case of bars with two opposite ribs, the bars in the area of the ribs have a largest and a smallest bar diameter which are perpendicular to one another.

A single rod S is removed from the bundle of rods 2 and is fed automatically or manually according to the arrow P 1 to an insertion device 3 adjacent to the support table 1. The insertion device 3 has at least one pair of transport rollers 4 which can be driven in both directions of rotation in accordance with the double arrow P₂, at least one transport roller per pair being displaceable in relation to the other transport roller of the pair in accordance with the double arrow P₃. The rod S is placed in the intermediate position Z1 between the open roller gap of the transport rollers 4 and after closing the gap by moving at least one transport roller according to the double arrow P₃ then using the transport rollers 4 according to the arrow P₄ in an intermediate position Z2 in a in Fig. 1b only schematically shown in cross section discharge channel 5. The outlet channel 5 is closed at the bottom by a flap 6 which can be pivoted in accordance with the double arrow P₅. Below the outlet trough 5, a plurality of screw conveyors 7, which can be driven with the aid of drive devices (not shown) according to the arrow P₆, are arranged, the axes of rotation 8 of which run perpendicular to the longitudinal axis of the outlet trough, that is to say transversely to the longitudinal direction of the rods S. The screw conveyors 7 are each supported by means of a screw bearing 9 on a frame carrier 10 extending in the longitudinal direction of the rods. The number of screw conveyors 7 and their distribution in the longitudinal direction of the rods is chosen such that the longest rod to be processed can be conveyed without problems and without undesired sag. After opening the flap 6, the rod S falls onto the screw conveyors 7 in the intermediate position Z3 and at the same time becomes in this longitudinal position by the screw conveyors 7 in this longitudinal position conveyed according to the arrow P₇ and in its transverse direction according to the arrow P₈, so that it successively assumes the intermediate positions Z3, Z4 and Z5 on the screw conveyors 7.

The movement of the rod S in its longitudinal direction is limited by a stop plate 12 provided with a stop surface 11 and extending transversely to the longitudinal direction of the rod S. The transverse movement of the rod 11 takes place until the end of the screw conveyor 7 is reached and the rods S fall into an intermediate magazine 13 lying below in the intermediate position Z6.

The intermediate magazine 13 consists essentially of a plurality of base strips 14 distributed along the longitudinal axis of the rod and side webs 15 fixedly connected to each base strip, the base strips being slidably arranged on appropriately designed bearing plates 16 in accordance with the double arrow P₉.

In the intermediate magazine 13, the rod S is held laterally once by end faces 17 of the bearing plates 16 and once by the side webs 15, the width of the opening gap of the intermediate magazine 13 being selected by the displacement of the bottom bar 14 and the height of the opening gap such that in the intermediate magazine 13 a plurality of rods are arranged one above the other and with little lateral play against the end faces 17 of the bearing plates 16 and against the side webs 15.

After the intermediate magazine 13 has been filled with the desired number of bars S, the bars are further treated by a front clamping device 18 and a rear clamping device 19, as will be described later. The front clamping device 18 consists essentially of a fixed clamp 20 and a corresponding to the double arrow P₁₀ in the direction of the fixed clamp 20 with the aid of an actuating device, not shown, movable clamp 21. The clamps 20, 21 enclose the rods located in the intermediate magazine 13 and are with Cut 22 provided. The rear clamping device 19 consists essentially of a Counter jaw 23, which is displaceable in the longitudinal direction according to the double arrow P₁₁ (Fig. 3a, Fig. 3b) with the aid of an actuating device, not shown, and from a clamping jaw 24, which once in its longitudinal direction corresponds to the double arrow P₁₂ (Fig. 3a, 3b ) with the help of an actuator, not shown, and once according to the double arrow P₁₃ in the direction of the counter jaw P₂₃ is movable with the help of another actuator, not shown. The counter jaw 23 and the clamping jaw 24 enclose the rods located in the intermediate magazine 13 and are each provided with a clamping chuck 25 which consists of a material which is softer than the rod surface, for example plastic or hard rubber, and has a clamping surface 26.

The loading device works in the following way: The individual bars S stacked one above the other in the intermediate magazine 13 in an unordered position L (FIGS. 2a, 3a) are moved by moving the movable clamping pliers 21 against the fixed clamping pliers 20 (double arrow P₁₀) and by simultaneously moving the clamping jaw 24 against the counter jaw 23 (double arrow P₁₃) loosely, but clamped without lateral play between the clamping tongs 20, 21 and the jaws 23, 24. In the disordered position L, the ribs R of the individual rods S and thus also the smallest diameter of the rods are randomly distributed, as shown by the rib axes A1, A2, A3 in different directions in FIGS. 2a and 3a. Subsequent displacement of the movable clamping pliers 21 against the fixed clamping pliers 20 (double arrow P₁ wird) is exerted by the cutting edges 22 of the clamping pliers 20, 21 on the rods S, a pressure acting from both sides. The bars S cannot avoid this pressure upwards and downwards because they rest on the base strips 14 and are also fixed by the cutting edges 22 of the clamping pliers 20, 21. The rods can only avoid this pressure by rotating according to the double arrow P₁₄ about their longitudinal axis until the respectively smallest diameter of each rod S within the position is as perpendicular as possible to the clamping surfaces 26 of the clamping chuck 25, ie the rib axes of all the rods, as denoted by the reference symbol A in FIGS. 2b and 3b, run almost parallel to the clamping surfaces 26 of the clamping chuck 25, now all the bars are in an ordered position L '.

The rotation of the rods S required to achieve the ordered position L 'about its longitudinal axis is initiated and has the effect that simultaneously with the further closing of the clamping tongs 20, 21 the counter jaw 23 with an alternating sense of direction several times in accordance with the double arrow P 1 and simultaneously the clamping jaw 23 with alternating, but each opposite sense of direction are moved back and forth several times in accordance with the double arrow P₁₂, whereby the counter jaw 23 and the jaw 24 are moved several times relative to each other.

In order to avoid lateral play between the bars and the clamping surfaces 26, the clamping jaw 24 is optionally also moved further towards the counter jaw 23. The good frictional connection between the bars S and the soft clamping surfaces 26 of the clamping chuck 25 and the opposite longitudinal displacements of the counter jaw 23 and the clamping jaw 24 exert forces on the bars S. These forces acting in opposite directions tangentially, along two opposite lines running parallel to the longitudinal axis of the rods on the circumference of the rods and cause the rotation of the rods S about their longitudinal axis according to the double arrow P₁₄. The cutting edges 22 of the clamping tongs 20, 21 prevent the rods from being displaced longitudinally as they rotate about the longitudinal axis.

After reaching the ordered position L 'encloses at least a pair of clamping arms 27 of a feeder device, not shown, the bars S located in the ordered position L' by moving the clamping arms 27 according to the double arrow P₁..

Then open the movable pliers 21 and the jaw 24, so that the rods S clamped firmly between the clamping arms 27 with the aid of the feeder device for jointly bending all the rods in a bending machine, which essentially according to FIG. 4 one according to the double arrow P₁₆ rotatable bending plate 28 with a central bending mandrel 29 and an eccentric bending block 30 and a counter-holder 31. The ordered position L 'of the bars S is inserted between the bending tools 29 and 30 such that the smallest diameters of the bars run as perpendicular as possible to the surfaces of the bending tools 29 and 30.

A bending machine for performing the method according to the invention has in a further embodiment at least one bending slide 32 which can be moved according to the arrow P₁₇ against the stop plate 12 with the aid of a displacement device, not shown. In the bending slide 32, an intermediate ring 33 which is rotatable in accordance with the double arrow P₁₈ is mounted centrally, on which the preferably cylindrical counter-holder 31 is rotatably supported in accordance with the double arrow P₁₉. In the intermediate ring 33, the bending plate 28 is rotatably mounted according to the double arrow P₁₆, which has the central cylindrical mandrel 29 and the eccentrically arranged bending stone 30. For the simultaneous bending of the bars at a further bending point, the bending machine, as shown in FIG. 4, is provided with a further bending slide 32 ', which has 32 identical elements to the bending table, so that in the following the same reference numerals but with an apostrophe are used for identical elements will.

The bending machine works in the following way: A loading device, which essentially contains all the elements of the loading device shown in FIGS. 1a and 1b, apart from the front and rear clamping devices 18 and 19, becomes an unordered layer L of one above the other or next to one another Bars S generated. The disordered position L of the bars S is inserted with the aid of the clamping arms 27, 27 'of the feeder device, not shown, in the gap formed on the one hand by the central bending mandrel 29, 29' and on the other hand by the counter-holder 31, 31 'and the bending stone 30, 30' , wherein the rib axes A1, A2, A3, A4, as shown in Fig. 5a, point randomly in any direction. The clamping arms 27, 27 'are then opened according to the double arrow P₁₅, P _15' so far that the rods S with lateral play to the clamping arms 27, 27 'are held in this position L while maintaining the superimposed arrangement.

By rotating the intermediate ring 33, 33 'in the corresponding direction of the double arrow P₁₈, P _18' , the counter-holder 31, 31 'is applied to the bars S of the disordered position L and by further rotation of the intermediate ring 33, 33' in the same direction, a corresponding Approximately radially acting pressure is exerted on the rods S from both sides. While this pressure builds up, the two bending slides 32, 32 'are simultaneously moved in the direction of the stop plate 12 in accordance with the arrow P 1, P _17' . The rods S can avoid this lateral pressure only in that they rotate according to the double arrow P₁₄ so long about their longitudinal axis until they reach a position in which the smallest diameter of each rod between the counterhold 31, 31 'and the central mandrel 29, 29 'is clamped, ie an ordered position L' is reached, in which the rib axes of all the bars, as indicated in FIG. 5b by the reference symbol A, are almost parallel to the respective surfaces of the counter-holder 31, 31 'and the central bending mandrel 29 , 29 'run. The smallest diameter of the bars S therefore run in the ordered position L 'almost perpendicular to the surfaces of the bending tools 29 and 30. The rotation of the bars S required to achieve the ordered position L' of the bars S about their longitudinal axis according to the double arrow P₁₄, P _{14 '} is due to the frictional engagement between the bars S on the one hand and the central Bending mandrel 29, 29 'and the counter-holder 31, 31' on the other hand and the above-described displacement of the bending slide 32, 32 'according to the arrow P₁₇, P _17' initiated and causes, avoiding the rods S in the longitudinal direction by the stop surface 11 is prevented .

During the displacement of the bending slide 32, 32 'according to the arrow P₁₇, P _17' act axially extending, at several offset opposite locations on the circumference of the rods attacking, same-directional forces on the rods S, the points of attack of these forces are constantly parallel with the displacement the bending slide 32, 32 'move in the direction of the stop surface 11. After reaching the ordered position L ', the clamping arms 27, 27' enclose the bars S, the bending slides 32, 32 'move according to the double arrow P₂₀, P _20' along the bars S into their bending position and the bending stones 30, 30 'bend Rotation according to the double arrow P₁₆, P _{16 '} the rods S about the central mandrels 29, 29'.

To perform the procedure after. According to a further exemplary embodiment, the bending machine shown in FIG. 4 can be used as follows according to the invention: An unordered layer L of bars S lying one above the other or next to one another is inserted into the between the central bending mandrel 29 with the aid of the clamping arms 27, 27 'of the feed device, not shown , 29 'inserted on the one hand and the counter-holder 31, 31' and the bending stone 30, 30 'on the other hand. The bending slide 32, 32 'are moved according to the double arrow P₂₀, P _20' along the longitudinal axis of the rods S in their bending position. By rotating the intermediate ring 33, 33 'in the corresponding direction of the double arrow P₁₈, P _18' , the counter-holder 31, 31 'is applied to the superimposed rods S of the disordered layer L and by further rotation of the intermediate ring 33, 33' in the same direction the bars S are firmly clamped between the counter-holder 31, 31 'and the central bending mandrel 29, 29' and at the same time a corresponding one, which acts approximately radially from both sides Pressure is exerted on the bars S of the disordered layer L.

After clamping the bars between the counter-holder 31, 31 'and the central bending mandrel 29, 29', the clamping arms 27, 27 'open by movement in accordance with the double arrow P₁₅, P _15' . The required to dodge the bars S before the lateral pressure rotation of the bars about their longitudinal axis according to the double arrow P₁₄ is initiated according to this embodiment and causes that by rotation of the bending stone 30, 30 'alternately towards the bars and away from them accordingly the double arrow P₁₆, P _{16 '} strikes the bending block 30, 30' on the rods S and shakes them.

Each time the bending stone 30, 30 'strikes the rods S, a force acts radially towards the longitudinal axis of the rods and increases the lateral pressure caused by the counter-holder 31, 31'. It has proven to be advantageous to choose the number of changes in direction as large as possible, but there is an upper limit due to the mechanical inertia of the bending plate 28, 28 '. A displacement of the bars S in their longitudinal direction is prevented according to this embodiment by frictional engagement between the clamped bar S and the counter-holder 31, 31 'with the central bending mandrel 29, 29'.

It goes without saying that the invention is not limited to the exemplary embodiments shown, but rather they can be modified in various ways within the scope of the general inventive concept. In particular, the method and the device for carrying out the method are not limited to rods with two ribs, but rather to rods with any number of ribs and, in general, to rods with any essentially oval cross-sectional geometry, in which when bending around the smallest and the largest diameter the rod has a different bending geometry and a different springback and thus different bending angles result on the bent rod. For example, the invention is also applicable to rods that are in the have an essentially rectangular cross-section with rounded corners.

A corresponding control device is provided to control the movement sequences of the devices.

Claims (11)

Method for aligning straight bars, which have an essentially oval cross section, before the bars are bent together in a bending machine, characterized in that the bars are initially in an unordered position (L), in which the smallest bar diameter sections have different orientations. or are arranged next to one another such that the rods (S) arranged one above the other or next to one another are rotated out of the disordered position (L) by applying an approximately radially acting compressive force on two opposite sides of the rods about their longitudinal axis into an ordered position (L '), in which all the bars of the layer with their smallest diameter are approximately aligned, and that the bars (S) are clamped in the ordered layer (L '). Method according to Claim 1, characterized in that the rods are set in rotation about their longitudinal axis by tangential forces acting in opposite directions on opposite sides of the circumference of the rods (S), the direction of which changes several times. A method according to claim 1, characterized in that the rods (S) are rotated about their longitudinal axis by axially extending forces acting in the same direction at several offset opposite points on the circumference of the rods, the points of application of the forces parallel to the longitudinal axis of the rods are moved in the direction of a stop surface defining the ends of the rods. A method according to claim 1, characterized in that the rods are rotated about their longitudinal axis by repeatedly acting forces directed approximately radially to the longitudinal axis of the rods and the longitudinal displacement of the rods by between the surface of the rods on the one hand and a central bending mandrel and a counterholder of the Bending machine on the other hand is prevented frictional engagement. Method according to one of claims 1 to 4, characterized in that the bars (S) are arranged in the ordered position (L ') in the bending machine in such a way that the bars with their smallest diameters run approximately perpendicular to the surfaces of the bending tools. Device for carrying out the method according to one of claims 1 to 5, with a conveyor and a feeder, with which the bars can be transferred from the conveyor into a bending machine, the bending machine having a rotatable bending plate, a central mandrel, an eccentrically arranged bending tool and is equipped with a counterholder, characterized in that an intermediate magazine (13) for forming an unordered position (L) of bars (S) arranged one above the other or next to one another with different orientations of the smallest bar diameter sections is provided, that a clamping device (18) is attached to the bars (S) attachable clamping pliers (20, 21) for exerting a radial pressure on the rods (S) and for fixing the rods (S) against displacement in their longitudinal direction is provided and that a further clamping device (19) is provided which the rods (S) can be placed in the longitudinal direction relative to each other and in the transverse direction to the longitudinal axis of the rods (S) displaceable jaws (23, 24). Apparatus according to claim 6, characterized in that the clamping pliers (20, 21) are each provided with cutting edges (22), the cutting edges of which run perpendicular to the longitudinal axis of the rods. Apparatus according to claim 6, characterized in that each clamping jaw (23, 24) is provided with a clamping chuck (25) having a clamping surface (26) which, in comparison to the material of the surface of the rods, consists of relatively soft material. Device according to one of claims 6 to 8, characterized in that the bending machine has at least one bending slide (32, 32 ') which can be displaced in the direction of the longitudinal axis of the bars and which is connected to the Rods (S) which can be placed against the counter-holder (31, 31 ') and with which the ends of the rods (S) can be placed against a stop surface (11) of a stop plate (12). Device according to one of claims 6 to 9, characterized in that the bending plate (28, 28 ') of the bending machine can be controlled with an alternating sense of direction (P₁₆, P _16' ) in order to repeatedly press the eccentrically arranged bending tool (30, 30 ') against the Press on rods (S) and move them away from them. Device according to one of claims 6 to 10, characterized in that it has a device (27, 27 ') for clamping the bars (S) in the ordered position (L') and for transferring the bars (S) between the bending tools (29 , 30) of the bending machine.

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