MX2008005285A - Machine for cambering, forming, folding or bending bars, wires or extruded shapes and method using same - Google Patents

Abstract

The invention concerns a machine for cambering, forming, folding or bending a bar, a wire or an extruded shape comprising a bending form (7, 21) provided with a clamping system, with a device for orienting the tube (1) and a bending jaw (8). The invention is characterized in that:the bending jaw (8) is prismatic and machined to the tube radius (1) on at least one of its surfaces (9, 10);the kinematics of the displacement of the bending jaw (8) in a peripheral area (11) at the bending form (7, 21) is provided by any combination of at least two, rectilinear or rotating, movements;the bending jaw (8) is steerable in rotation about a median axis (12) perpendicular to the bending plane;the bending jaw (8) is mobile in the vertical direction to provide multiple bending operations.

Description

MACHINE FOR ARCHING, CONFORMING, FOLDING OR CURVING BARS, WIRES OR PROFILES AND PROCEDURE USING THE SAME FIELD OF THE INVENTION The invention relates to a machine for arching, shaping, folding or bending bars, wires or profiles. BACKGROUND OF THE INVENTION Chairs, dryers, chandeliers, showcases and numerous objects are made with rods, tubes or elbowed profiles, sometimes folded into the three dimensions in complex shapes. These forms are realized by means of machines of curvado that deform the elements without breaking them, conserving a minimum crushing. These bending machines are increasingly sophisticated to make parts that are always more complicated, in a reproducible, automated way, and at high production rates. It is often necessary to make two curvatures on a tube, a bar or a profile, sometimes more, in different planes, which is obtained by decoupling the tube after each stage, then repositioning after an axial rotation. Traditionally, bending machines have different bending heads that allow deformations of the elements in the three dimensions in two Ref .: 191502 or several stages according to the needs. In the case of complete automation of these machines, it is essential to reposition the element to be deformed in the machine after each bending, this operation is carried out by the orientation heads placed between the bending elements or by the bending heads that they allow multiple deformations such as those described in EP 1 272 293 of the same applicant. In some cases it is desirable to carry out deformations of the tubes, wires, profiles or bars in several planes and optimally without the reactivation by an orientation device that causes a loss of time and possible problems of placement in the machine, classically the machines of curved according to the prior art are of two types, the machines for the extension and the machines for the winding. These two categories of machines, which will be described in more detail in the description, present common defects: - frequent marking of the tube by the curved jaws on the machine, - the difficulty of carrying out multiple bends in the case of very short distances, including null, between the curvatures, - the impossibility of making pieces whose curved parts interfere with the machine or with the tools due to a single direction of the curvature; - the difficulty of making the curvatures on the tubes that carry accessories fixed on the perimeter. BRIEF DESCRIPTION OF THE INVENTION The object of the invention is thus to solve these main difficulties by proposing a bending machine having a bending head of a novel type. The present invention relates to a machine for arching, shaping, folding or bending a tube, a bar, a wire or a profile carrying a shape of curvature that has a securing system, an orientation device of the tube and curved jaws, characterized in that: - the bending jaws are prismatic and machined to the diameter of the tube on at least one of its surfaces, - the kinematics of displacement of the bending jaws in an area peripheral to the shape of the curvature is ensured for any combination of at least two movements, rectilinear or rotary, - the bending jaws can be oriented in rotation about an intermediate axis perpendicular to the plane of the curvature, - the bending jaws can be moved in the vertical direction to allow placement to the right or left of the tube to be bent as well as the overlapping of various shapes or diameters. The bending jaws may be displaced in a peripheral area with respect to the shape of the curvature so that they are applied on the tube to be curved in multiple configurations. The advantages of the bending machine according to the invention are multiple, it is possible to make a curvature on a tube in both directions in the body of a same piece, a same piece can be manufactured with curvatures of large angles, small angles and short segments, - the accessories do not present any impediment to the curving on the piece; - the surface of a fragile piece, for example of a light alloy, of a tube or profile, is not marked, - the quality of the curvature is excellent and this for all the contemplated configurations. Other characteristics and advantages of the invention will be apparent from the description that will be given immediately with respect to the appended figures that are given as non-limiting examples. BRIEF DESCRIPTION OF THE FIGURES Figure 1 represents a curving machine for extension, according to prior art. Figure 2 illustrates a bending machine for the winding according to the prior art. Figure 3 illustrates the two essential elements of the invention, the shape of the curvature and the curved jaws. Figure 4 shows the space of the horizontal plane in which the bending jaws can be displaced in the course of bending operations. Figure 5 and Figure 6 show the possible displacements of the bending jaws in the rotation and along the vertical axis. Figure 7, Figure 8 and Figure 9 illustrate a classic bending operation in the clockwise direction. Figure 10 and Figure 11 present a bending operation in the counterclockwise direction. Figure 12 and Figure 13 show the development of a wide-angle curvature on the machine according to the invention. Figure 14 and Figure 15 represent the curvature of a tube that bears attached parts. Figure 16, Figure 17 and Figure 18 show a curvature with curved jaws in two stages that allow a minimum straight segment, even null, between two curvatures. Fig. 19, Fig. 20 and Fig. 21 show the particular displacement of the bending jaws in the case of the bending of a brittle tube. Figure 22, figure 23, figure 24, figure 25, figure 26 and figure 27, illustrate different bending sequences of a fragile tube carrying an attached piece. Figure 28 represents a variant of the invention. DETAILED DESCRIPTION OF THE INVENTION To facilitate reading, it is used in the later description of the term "tube" to designate in general a piece that can be a bar, a wire, a profile or a tube before bending. To simplify the representations in the figures 19 to 27, the movements are presented in a horizontal plane, these realizations are of course reproducible in all work planes. In a conventional manner, a bending machine according to the invention has a frame that supports the shape of the bend, a fastening device that allows the support of the tube during its entire conformation and a device for orienting the tube. To facilitate the understanding of the invention, figures 3 to 28 do not present, in a schematic manner, more than the essential elements of the invention, that is to say the shape of the curvature and the curved jaws. The prior art of the bending technique is known under two main forms, a technique called "for extension" shown on figure 1, and a technique called "for winding" illustrated on figure 2. According to the technique "for the extension "the tube 1 is flanged on the shape of the curvature 2 and driven in rotation by the latter. The tube 1 is maintained in the course of bending by a strip 3 which can be fixed or sliding. This machine has several drawbacks especially due to the fact that for the segments between the reduced curvatures the jaws must be machined to the shape of the preceding curvature, due to the fact that the bending head is unidirectional and thus the curvature is not realizable anymore. that in a clockwise or counterclockwise direction, and by the fact that the jaws before ensuring that they do not slide the tube in the course of the bend, they can print marks on it, more particularly in the case of light alloys. According to the technique "by winding", whose representation is provided on figure 2, the tube 1 is flanged on the fixed part and a mobile member carried by the head 4, for example a roller 5, winds the tube on the fixed form 6. As for the prior art, the short segments between the curvatures are difficult or not feasible and a labeling of the tube by the roller that moves in the rotation at the time of the curvature is frequent. The two essential elements of the bending machine according to the invention are schematized on FIG. 3. The shape of the curvature 7 is double in this representation and the bending jaws 8 have a particular prismatic shape. The shape of the curvature can be symmetric or non-symmetric. According to a variant of the invention illustrated in FIG. 28, the use of a simple curvature shape with a particular securing device is also contemplated. As shown in FIG. 3, the shape of the double curvature 7 allows bending in the clockwise direction or in the counterclockwise direction according to the position of the bending jaws 8. The tube that is will deform is placed in the center of the double shape and is kept inside it. The curved jaws 8 are prismatic and machined to the radius of the tube on at least one of their surfaces. Advantageously, the jaws will be machined on their two lateral surfaces 9, 10 so as to allow bending in the two possible directions in the plane of the shape of the bend. The inner shape of the jaws 8 is generally concave and advantageously of a shape complementary to the dimensions adapted to expose the semicircle of the shape of the curvature. By thus configuring the curved jaws 8, it is possible to place the shape of the curvature even closer and thus make successive curvatures with very short straight segments. The curved jaws according to the invention also have the particular feature that they can be arranged according to very numerous configurations: in the plane passing through the two forms of curvature, the kinematic characteristics of displacement of the jaws 8 are located in a peripheral area 11 presented with the strokes on figure 4, this displacement is ensured by the combination of at least two movements, rectilinear or rotary, the bending jaws 8 can also be oriented in rotation about an axis 12 crossing it in its middle part and located perpendicularly to the plane of the two forms and thus with respect to the plane of the curvature, as shown on FIG. 5, the curved jaws 8 are movable in the vertical direction, along the axis 12, to allow multiple curvatures, such as those illustrated on the Figure 6. In summary, the curved jaws 8 can move in the three dimensions around the shape of the curvature and adopt a multitude of positions to perform the curvatures. Figures 7 to 27 illustrate in particular cases the curvatures and the specific embodiments. Figures 7 to 9 show a clockwise curvature with a fixation of the bending jaws very close to the shape of the curvature. Figures 10 and 11 show the position of the jaws 8 for a counterclockwise curvature and the position of the jaws 8 at the end of the curvature. Figures 12 and 13 show a displacement of the jaws 8 of the curvature along the axis of the tube 1, the winding around the shape is a more pronounced consequence. Figures 14 and 15 show an example of the curvature taking into account an annex piece 13 placed on the tube, the annex parts that can be carried by the tubes before the curvature are for example flanges, valves, couplings, etc., in In this example, the jaws 8 retain their position with respect to the parts attached to the entire length of the curvature, describing an arc of a circle. Figures 16 to 18 illustrate a bending that uses the bending jaws 14 in two stages that allow applying a load on the preceding bending in order to respect a minimum straight segment between the bends. A cavity carried in the form of a curvature in the case of chained or flanged bends can also be provided. According to the invention, the jaws can move in rotation around their intermediate axis 12 and along this same vertical axis, in fact it is advantageous to place different machined shapes on the sides of the jaws so that different curvatures are made with the same jaws . Advantageously, a means for uncoupling the unused part (s) of the jaws could be contemplated to perform the following curvature. Thus, as shown on FIGS. 16 to 18, curved jaws of two stages 14 could have a step 15 used in a first bend and a second step 16, in the vertical direction, used for a second bend one. once removed from stage 15, the tube is reoriented and the jaws 14 moved upwards. This withdrawal of one or several stages can be carried out in different ways, for example by the rotation of the stage around an axis 18. By combining the different possibilities of displacement of the bending jaws with those of jaws that use several zones, they are accessible very numerous curvatures with a single piece. According to the invention, the bending machine can have jaws that have at least one retractable surface, and the retractable surface is retracted by tilting or rotating around a joint placed on the jaws themselves. Figures 19 to 21 present a variant of the invention in which the behavior of the tube in the curvature does not tolerate the free winding of the tube, for example in the case where there is a risk that there are gaps or in the case of a thin-walled tube, in this situation it is advantageous to produce very long curved jaws 19 which allow the maintenance of the tube 1 during the course of the curvature. In this example, the curved jaws 19 operate a tilting movement with respect to the tangent of the bend bend so that there is no sliding of these bending jaws with respect to the curved tube. According to the invention, the jaws can move in an area peripheral to the shape of the double curvature, this is particularly advantageous in the case where the obstacles are on the piece to be made and the curvature must be particularly pronounced. In this situation represented by figures 22 to 27 it is possible to move the jaws and execute the bending by successive sequences of reduced angles, these sequences are determined by the developed length that authorizes the length of the jaws of the curvature. The invention also relates to a method of bending a tube, using a machine such as that described above in which the jaws are displaced at least once on the tube in the course of the operation of the shaping. The jaws may be displaced in a peripheral area 11 according to the shape of the curvature. To perform different curvatures, the jaws can be displaced in a vertical direction or in rotation around a vertical axis that crosses it, perpendicular to the plane of the curvature, or according to a combination of the preceding movements. An example of the displacement of the jaws in the course of the curvature is illustrated on figures 22 to 27, figures 22 and 23 represent the curvature of the first sector of a tube 1 carrying an obstacle 20, figures 24 and 25 represent the decoupling of the jaws 8 and their repositioning on the tube after the obstacle 20. Finally figures 26 and 27 illustrate the curvature of the second sector. An important variant of the invention is shown on FIG. 28. This variant consists in providing a simple, symmetric or non-symmetrical, stepped or non-stepped shape of the curvature 21, with a device for securing the tube 1 mounted on a rocker 22 and having two clamping jaws that can be straight or having a stepped or non-stepped shape 23 and 24. The curving jaws 23 and 24 can be equipped themselves with curved shapes, so that the possible combinations can be multiplied . As for the examples which refer to a double curvature shape, the bending jaws 8 are prismatic and machined to the radius of the tube on at least one of their surfaces, the kinematics of displacement of the bending jaws is made in a peripheral area with respect to the shape of the curvature and the jaws can be oriented at the same time in the rotation and are movable on a vertical axis. All the possibilities described in the preceding examples with a double curvature form remain valid with this specific securing system. This variant allows the use of a single form of curvature operating in one direction or in another variant according to the desired direction or radius of curvature, the clamping jaws 23 and 24 authorize an alternative securing to the right or to the left and the device of inclination allows to completely retract the jaws without operating on the work area and authorizing the realization of curvatures of up to 180s. The rocker 22 carries two hands that ensure the guide of the rocker and its trajectory in a form 25. Such form 25 carries arms in such a way as to ensure precisely the desired displacement. The rocker 22 is driven by a set of berbiquí, hands and square gears that slide in a groove of the rocker arm. In the representation of FIG. 28, the rocker 22 is tilted to the right, the inoperative clamping jaws 23 are located below the working area, ie below the plane of the curvature, the active clamping jaws 24 are kept closing the tube 1 on the shape of the curvature 21 while the curving jaws 8 bend during the course of their displacement towards the peripheral space of the shape of the curvature 21. Such deformation can be operated at 1802. Many others are possible. variants for the bending machineFor example, a shaping of the simple or convex bending jaws 8 can be envisaged with one or more surfaces, such surfaces can be articulated in different ways on the jaws, and jaws with several steps can be provided without going beyond the reach of the jaws. the invention. Different means can be contemplated that allow the movement of the jaws in the peripheral zone to the shape of the curvature and its orientation in space. The tubes, rods, wires or profiles may be of varying sizes and nature without departing from the scope of the present invention. It is very evident that more complex curvatures than those described in the examples can be contemplated, especially with the multiple repositioning of the jaws during the course of forming an element. The machine that carries the characteristics of the invention can be, on the other hand, commanded numerically or not.

Of course, the invention is not limited to the embodiments described and represented as examples, but it also includes all technical equivalents as well as their combinations. It is noted that in relation to this date the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (14)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A machine for arching, shaping, folding or bending a tube, a bar, a wire or a profile that bears a shape of the curvature , comprising a fastening system, a tube orientation device and curved jaws, characterized in that: - the bending jaws are prismatic and are machined to the radius of the tube on at least one of its surfaces, - the displacement kinematics of the bending jaws in an area peripheral to the shape of the bend is ensured by any combination of at least two movements, rectilinear or rotary, - the bending jaws can be oriented in rotation about an intermediate axis perpendicular to the plane of curvature. the curvature, - the bending jaws can be moved in the vertical direction to allow multiple bends. The machine according to claim 1, characterized in that the bending jaws can be displaced in an area peripheral to the shape of the curvature so that the tube to be bent is subjected to multiple configurations. 3. The machine according to claim 2, characterized in that the tube to be shaped carries at least one annex piece. 4. The machine in accordance with the claim 2, characterized in that the bending jaws present at least one surface machined on another step in the vertical direction that allows another curvature. The machine according to claim 4, characterized in that in another step of the jaws that can be used for another curvature, it is placed in front of the tube on which the curvature is going to be made, a means of vertical displacement and / or a means of displacement in the rotation of the jaws with respect to the shape of the curvature. The machine according to claim 4, characterized in that the bending jaws have at least one step that can be retracted. The machine according to claim 6, characterized in that the step that can be retracted is retracted by tilting or rotating around a joint placed on the jaws. 8. The machine according to any of the preceding claims, characterized in that the shape of the curvature is double. 9. The machine according to any of claims 1 to 7, characterized in that the shape of the curvature is simple or double and the device for securing the tube on the shape of the curvature is carried by a rocker. 10. The machine according to claim 9, characterized in that the rocker arm has two jaws that can secure the tube alternately on each side of the shape of the curvature and in such a way that when the jaws are clamped on the tube, the other jaws are located below the plane of curvature of the tube. The machine according to claim 10, characterized in that the two jaws are equipped themselves with curved shapes. 12. A method of bending a tube, characterized in that it employs a machine according to claim 1, wherein the bending jaws are displaced at least once on the tube in the course of the shaping operation. The method of curvature of a tube according to claim 12, characterized in that the bending jaws can be displaced in a peripheral area with respect to the shape of the curvature. The method of curvature of a tube according to claim 12 or 13, characterized in that the bending jaws are displaced in a vertical direction or in rotation about a vertical axis running through it, or in accordance with a combination of the two preceding movements.