Bending machine and bending method for a rod-shaped workpiece made of solid or tube material

Abstract

A bending machine for a rod-shaped workpiece (6) made of solid or tubular material is described, comprising: a bending head (4) for forming bends in the workpiece (6), each bend lying in a bending plane; a workpiece guide (10) arranged upstream of the bending head (4), through which the workpiece (6) is advanced along a feed axis into the bending head (4) to position a bending point in the bending head (4), and which supports the workpiece (6) during a bending operation of the bending head (4); and a gripper (8) arranged upstream of the workpiece guide (10) on the feed axis, which holds the workpiece (6) and advances it along the feed axis, wherein the workpiece guide (10) and the gripper (8) are mounted on a support arm (12) which is rotatably attached to the base frame (20) about the feed axis, such that a rotation of the support arm (12) rotates the gripper (8) and the workpiece guide (10) together to adjust the bending plane. The feed axis rotates.

Description

[0001] The invention relates to a bending machine for a rod-shaped workpiece made of solid or tubular material, comprising: a base frame, a bending head arranged at one end of the base frame for forming bends in the workpiece, each lying in a bending plane, a workpiece guide arranged upstream of the bending head, through which the workpiece is advanced along a feed axis into the bending head to position a point to be bent in the bending head, and which supports the workpiece during a bending operation of the bending head, and a clamp arranged upstream of the workpiece guide on the feed axis, which is attached to the base frame and holds the workpiece and advances it along the feed axis.

[0002] The invention further relates to a bending method for a rod-shaped workpiece made of solid or tubular material, in which bends are formed in the workpiece, each lying in a bending plane, by means of a bending head arranged at one end of a base frame, wherein the workpiece is advanced into the bending head along a feed axis by means of a workpiece guide arranged upstream of the bending head in order to position a point to be bent in the bending head, and the workpiece is supported during a bending operation of the bending head, and the workpiece is held and advanced along the feed axis by means of a clamp arranged upstream of the workpiece guide on the feed axis, which is attached to the base frame.

[0003] Such a bending machine and bending process are known from EP 1849536 A1. They serve to bend a wire at various points, with the bends potentially lying in different bending planes. The wire is held with a double clamp. To adjust the bending plane, for example, to switch from a first bend in a first bending plane to a second bend in a second bending plane, the double clamp is held on an arm that can be rotated about the feed axis, so that this rotation causes the clamp to rotate with the wire and the bending plane to be adjusted. For this rotation of the wire, the tool guide located in front of the bending head has a certain amount of play, allowing the wire to rotate about its longitudinal axis within the guide.This allows long workpieces to be processed, which would be problematic without this support during rotation if curved sections have already been formed, as their weight then acts as a lever and moves the workpiece in the no longer closed workpiece guide and may even deform or damage it.

[0004] A more technically complex bending machine is known from WO 2022 / 234608 A1, in which the clamp is attached to a multi-jointed arm in order to be able to rotate the entire clamp, which is held on the arm, around its gripping center in which the workpiece is held.

[0005] Both the generic EP 1849536 A1 and WO 2022 / 234608 A1 can only optimally support the workpiece in front of the bending head during rotation if round material is being processed.

[0006] The invention is therefore based on the objective of creating an improved and, in particular, more universally applicable workpiece holder for a bending machine or a bending process.

[0007] The invention is defined in the independent claims; the dependent claims relate to preferred embodiments.

[0008] The design features of the bending machine and the configuration of the bending process according to the independent claims solve the aforementioned problem. Where embodiments and / or advantages are described below with reference to the bending machine, this description applies equally, and in particular with regard to the achievable advantages and the measures used for the bending process. Conversely, this also applies analogously to aspects described with reference to the bending process.

[0009] The bending machine for a rod-shaped workpiece made of solid or tubular material, particularly with a non-round, e.g., rectangular, cross-section, typically has a one- or multi-part base frame. A bending head for forming bends is located at one end of this frame. These bends each lie in a bending plane, which usually needs to be adjusted during processing to allow bends in different planes. A workpiece guide is positioned upstream of the bending head. The term "upstream" refers to the direction in which the workpiece is fed between the individual bends. The workpiece is advanced into the bending head along a feed axis through the workpiece guide to position the bending point correctly within the head. The workpiece guide supports the workpiece during this advancement and optionally also during the bending operation of the bending head.A gripper, which holds the workpiece, is positioned upstream of the workpiece guide on the feed axis. It pushes the workpiece along the feed axis forward and through the workpiece guide. The workpiece guide and the gripper are mounted on a support arm, which in turn is rotatably attached to the base frame around the feed axis, so that the gripper and the tool guide are also attached to the base frame via the support arm. This means that the support arm rotates the gripper and the workpiece guide together around the feed axis when the bending plane is set, which proves to be extremely advantageous (su).

[0010] Similarly, a bending process is provided for a rod-shaped workpiece made of solid or tubular material, particularly with a non-circular, e.g., rectangular, outer cross-section, in which bends are formed in the workpiece by a bending head, e.g., arranged on the base frame, each bend lying in a bending plane. The workpiece is advanced into the bending head along a feed axis by a workpiece guide located upstream of the bending head to position the next bending point. During the bending operation of the bending head, the workpiece guide optionally also supports the workpiece. A clamp advances the workpiece along the feed axis. It is located upstream of the workpiece guide on the feed axis. The workpiece guide and the clamp are supported by a support arm that is rotatably mounted on the base frame about the feed axis.By rotating the support arm, the workpiece guide and gripper are rotated together around the feed axis to adjust the bending plane. This design necessitates that the rotational mechanism of the support arm be configured so that its rotation occurs around an axis defined by the gripping center of the gripper and a stabilizing center of the workpiece guide. Thus, the support arm rotates around the feed axis.

[0011] The use of the support arm offers the advantage for both the bending machine and the bending process that the clamp and workpiece guide remain closed during rotation, regardless of the workpiece's cross-section. During rotation, the workpiece is thus perfectly supported at multiple points spaced apart in the feed direction, both within the workpiece guide and the clamp. This multi-point support eliminates the need for a double clamp, and even non-round materials can be processed, as the material no longer rotates within a single clamp but rather with the support arm and the clamp itself. The bending machine incorporates a corresponding control unit that keeps the clamp and workpiece guide closed during rotation and drives a mechanism that rotates the support arm.Furthermore, there is no longer a restriction to round cross-sections, as the workpiece no longer needs to rotate in the workpiece guide, since the guide now rotates synchronously with the workpiece. In addition, the machining time is reduced because opening and subsequent closing of the clamp in the workpiece guide is no longer necessary for rotation. The use of the support arm, which carries both the clamp and the workpiece guide, allows for surprisingly simple adjustment of the bending plane while still optimally holding the workpiece during rotation. This is particularly advantageous when the workpiece has bends that would result in a particularly large lever arm during rotation. This is the case, for example, with very long workpieces.

[0012] Furthermore, the use of the support arm has the advantage that it can be attached to an extendable or rotatable auxiliary arm, which is extended or swung out before the workpiece is rotated. In this way, particularly with very long workpieces, the necessary maneuvering space can be created to rotate the workpiece, which has already been bent in one section and may have a wide lateral projection, in order to set the bending plane for the next bend. Such an auxiliary arm is known, for example, from EP 1849536 A1, but there it was used to pick up a workpiece from a feeding device and support it during bending.

[0013] Preferably, the support arm has a clamping drive that moves the clamping force along the support arm and relative to the workpiece guide to advance the workpiece along the feed axis. The clamping drive can, for example, include a carriage carrying the clamping force, which is movable along the support arm. In some embodiments, the carriage is moved by a spindle, in particular a ball screw drive, which is installed on the support arm. During the advancement, the workpiece guide can be opened accordingly, or it can have suitable clearance for the feed movement, so that the workpiece can be advanced by the workpiece guide in the feed direction.

[0014] To achieve a greater feed stroke, it is preferred, either alternatively or additionally, to attach the support arm to the base frame via a carriage that can move along the base frame. This movement typically occurs along the feed direction, so that the carriage provides a structure with which the workpiece can be moved in the feed direction.

[0015] There are various ways to grip the workpiece, which can be used individually or in combination. For example, the support arm can be mounted on a rocker arm or guide carriage, allowing it to move transversely to the feed axis. Another option is to attach the support arm to a swivel joint, enabling it to pivot away from the feed axis and / or rotate perpendicular to it. This allows it to be positioned in a way that allows a new workpiece to be gripped and prepared for machining.

[0016] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations given, but also in other combinations or on their own, without leaving the scope of the present invention.

[0017] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying drawings, which also disclose essential features of the invention. These exemplary embodiments serve only for illustration and are not to be interpreted as limiting. For example, a description of an exemplary embodiment with a plurality of elements or components is not to be interpreted as meaning that all of these elements or components are necessary for implementation. Rather, other exemplary embodiments may also contain alternative elements and components, fewer elements or components, or additional elements or components. Elements or components of different exemplary embodiments may be combined with one another unless otherwise specified. Modifications and variations described for one of the exemplary embodiments may also be applicable to other exemplary embodiments.To avoid repetition, identical or corresponding elements in different figures are designated with the same reference symbols and are not explained multiple times. The figures show: . Fig. 1 a perspective schematic overview of a bending machine, Fig. 2 a close-up of the bending machine Fig. 1 Figures 3 and 4 are representations similar to the Figs. 1 and 2 , however, one support arm of the bending machine is brought into a different rotational position, Figs. 5 and 6 are enlarged views of a workpiece clamp and a workpiece guide of the bending machine. Fig. 1 with different positions of the tool clamp, Fig. 7 a schematic representation of two cooperating bending machines according to Fig. 1 , Figs. 8 and 9 are modified embodiments of the bending machine of the Fig. 1 .

[0018] Fig. 1Figure 2 shows a bending machine 2, which has a bending head 4 for bending an elongated workpiece 6, in this exemplary embodiment solid material with a non-round, here rectangular, cross-section, as is provided in all exemplary embodiments. Here, a busbar is bent. The workpiece 6 is held in a clamp 8 and advanced to the bending head 4 by a workpiece guide 10, which is hereinafter also referred to as the guide. The guide 10 is positioned in front of the bending head 4, guides the busbar along the feed axis to the bending head during the advancement, and stabilizes the workpiece when the bending head 4 bends the workpiece. The guide 10 guides the workpiece when it is not yet engaged with the bending head – for example, when the workpiece is to be safely reinserted into the bending tool after being repositioned by the bending head, or when a workpiece is to be pushed forward while the bending head is in its downward position.

[0019] Guide 10 and jaws 8 are mounted on a support arm 12, which is rotatable about an axis defined by the longitudinally extended workpiece 6 in the jaws 8 and the guide 10. The jaws 8 are displaceable along the support arm 12 by means of a slide via a ball screw 14. This displacement is indicated by a double arrow, as is the rotation of the support arm 12 by a corresponding double arrow. The support arm 12 is held for this rotation in a rotary mount 16 and is particularly preferably designed such that it rotates only below (in the area shown in the diagram). Figs. 1 and 2 (position shown) of the workpiece 6 held in the clamp 8. The significance of this design will be explained below with reference to the Fig. 5 , 8 and 9 clearly, because it allows the workpiece 6 extending between the pliers 8 and the rotary holder 16 to not only be straight, as in Figs. 1 to 4depicted, but can also have bends in this section for which the support arm 12 (relative to Figs. 1 and 2 ) leaves the upper half-space free.

[0020] For the rotation of the support arm 12 about the longitudinal axis of the workpiece 6, which is also the feed axis along which the gripper 8 pushes the workpiece 6 onto the bending head 4, a rotary drive 18 is provided which rotates the support arm 12 in the rotary holder 16 about the said axis.

[0021] The support arm 12 with clamp 8 and guide 10 is arranged on a frame 20, at the end of which the bending head 4 is located. The support arm 12 is mounted on a guide carriage 22 on the frame 20, which is movable along the frame 20 via rails 24. The support arm 12 is attached to an auxiliary arm 26 via the swivel mount 16, which allows two-axis adjustment because it can pivot about an axis (not labeled) on the guide carriage 22. In this way, the support arm 12 can be moved transversely to the feed axis (longitudinal axis of the workpiece 6). Fig. 1, 2 ) be moved.

[0022] The bending head 4 can be lowered relative to a table 28 to allow the workpiece 6 to be more easily positioned in different orientations, corresponding to the desired bending planes, by rotating the support arm 12. The table 28 can also be lowered, for example, to support the workpiece 6 at a lower level if it already has at least one bend. A bending head drive 30 is designed for this purpose.

[0023] The bending machine 2 also has a control unit 32 comprising a processor, which controls the operation of the bending machine 2 and in particular controls the drives 18 and 30 as well as 14.

[0024] The Figs. 3 and 4 show the bending machine of Fig. 1 However, the support arm 12 is now different from the illustration of the Fig. 1 It has been rotated 90° counterclockwise.

[0025] As can be seen, the support arm 12 rotates the clamp 8 and the workpiece guide 10 synchronously. Thus, during this rotation process, which is necessary to set a new bending plane, the workpiece 6 is held stably in both the clamp 8 and the guide 10, without either of these elements needing to have rotatable sections, in particular a rotatable gripping section, as would otherwise be essential for the guide 10 in the illustrated case of a non-rotationally symmetrical cross-section of the workpiece 6.

[0026] The Figs. 5 and 6Figure 8 shows a further feature of the pliers 8, which can be advantageous in embodiments. The pliers 8 have two gripping sections 34a, 34b, which are spaced apart along the feed direction. In this way, they hold the workpiece 6 by two sections spaced apart in the feed direction and thus already determine the feed direction, i.e., even without the assistance of the guide 10. The guide 10 has two retaining jaws 10a, 10b, which are normally closed around the workpiece 6. This is the state of the Fig. 6However, if a bend is required that necessitates advancing the gripper very far, the control unit 32 can open the guide 10, and the front gripping section 34b, which has a correspondingly slim outer cross-section, can be pushed through the open guide 10. In this way, the gripper 8 can be positioned very far forward by the drive 14, and it is possible to place bent sections almost to the bending-head end of the gripper 8 without re-insertion, etc.

[0027] Fig. 7 shows how two bending machines according to Fig. 1Bending machine 2 and another bending machine 36 can cooperate to bend a workpiece that has been pulled from a coil supply 38 and straightened by a straightening device 40, so that a corresponding elongated workpiece is available for processing. This workpiece 6 has a front end 6a and a rear end 6b. Bending machine 2 bends the rear end 6b, and bending machine 36 bends the front end 6a. A transport robot 42 conveys the finally bent workpiece 6 away. The transfer of the workpiece between bending machines 2 and 36 is effected by appropriately driving the auxiliary arms 12 and 26, which are pivoted or positioned so that bending machine 36 can take the workpiece previously bent in bending machine 2 with its gripper.

[0028] The Figs. 8 and 9Alternative configurations are shown that allow the transfer of a workpiece from one bending machine 2 to another bending machine 2. In the illustration of the Fig. 8 The support arm 12 is not located on a carriage, but on a rotating platform. This allows a workpiece already bent at the front end 6a to be transferred from a bending machine, so that it can now be bent at the rear end 6b.

[0029] The same effect can be achieved if the support arm 12 is held on a two-axis movable table, so that a displacement in the x and y directions is possible.

Claims

1. Bending machine for a rod-shaped workpiece (6) made of solid or tubular material, in particular with a non-round, e.g. rectangular, outer cross-section, comprising: - a bending head (4) for forming bends in the workpiece (6), each of which lies in a bending plane, - a workpiece guide (10) arranged upstream of the bending head (4), through which the workpiece (6) is advanced along a feed axis into the bending head (4) to position a point to be bent in the bending head (4), and - a gripper (8) arranged upstream of the workpiece guide (10) on the feed axis, which holds the workpiece (6) and advances it along the feed axis. characterized by the fact that - the workpiece guide (10) and the gripper (8) are mounted on a support arm (12) which is rotatably attached around the feed axis, so that a rotation of the support arm (12) rotates the gripper (8) and the workpiece guide (10) together around the feed axis to adjust the bending plane.

2. Bending machine according to claim 1, characterized by the fact that the support arm (12) has a clamping drive (14) which moves the clamping device (8) along the support arm (12) and relative to the workpiece guide (10).

3. Bending machine according to claim 1 or 2, characterized by the fact that the auxiliary arm (26) is mounted on a carriage (22) which is movable on a base frame (20).

4. Bending machine according to one of the above claims, characterized by the fact that the support arm (12) is attached to a rocker arm or guide carriage (22) so that it can be moved transversely to the feed axis in order to grip a workpiece (6) in the jaws (8).

5. Bending machine according to one of the above claims, characterized by the fact that the support arm (12) is attached to a swivel joint so that it can be pivoted out of the feed axis to receive a workpiece (6) into the gripper (8).

6. Bending method for a rod-shaped workpiece (6) made of solid or tubular material, in particular with a non-round, e.g. rectangular, outer cross-section, in which bends are formed in the workpiece (6) with a bending head (4), each of which lies in a bending plane, wherein the workpiece (6) is advanced into the bending head (4) by a workpiece guide (10) arranged upstream of the bending head (4) along a feed axis in order to position a point to be bent in the bending head (4), and the workpiece (6) is held by the workpiece guide (10) and a clamp (8) arranged upstream of it on the feed axis, and is advanced by the clamp (8) along the feed axis. characterized by the fact that - the workpiece guide (10) and the gripper (8) are supported by a support arm (12) which is rotatably mounted about the feed axis and are rotated together about the feed axis by means of the support arm (12) to adjust the bending plane.

7. Bending method according to claim 6, characterized by the fact thatthe support arm (12) has a clamping drive (14) which moves the clamping device (8) along the support arm (12) and relative to the workpiece guide (10).

8. Bending method according to claim 6 or 7 characterized by the fact that the support arm (12) is attached to a carriage (22) which is movable on a base frame (20).

9. Bending method according to one of the above method claims, characterized by the fact that the support arm (12) is attached to a rocker arm or guide carriage (22) so that it can be moved transversely to the feed axis in order to grip a workpiece (6) in the jaws (8).

10. Bending method according to one of the above method claims, characterized by the fact that the support arm (12) is attached to a swivel joint so that it can be pivoted out of the feed axis to receive a workpiece (6) into the gripper (8).

Images