EP3664945B1 - Bending machine for bending rod-shaped or tubular workpieces - Google Patents

Description

The invention relates to a bending machine for bending rod-shaped or tubular workpieces, with a bending tool which comprises a bending head with a bending disk with at least one circumferential bending groove, and also with two slide rails, each of which is provided with a shaped groove and which face each other laterally opposite longitudinal sides of the workpiece can be placed, each slide rail being attached to a support part, and in the state in which it is placed against the workpiece, the workpiece is laterally supported in an area from its tangential entry into the bending groove of the bending disc up to a point at a predetermined distance in front of it, and wherein each support part can be brought between an initial position in which the associated slide rail does not rest against the workpiece and an end position in which it is in contact with the workpiece, the other slide rail assuming its initial position when one slide rail is in contact with the workpiece .

In the DE 93 16 052.6 U1 describes a pipe bending machine that can be used to bend pipes to the left and right. Two separate slide rail devices are used on both sides of the longitudinal axis of the pipe to be treated, each of which can be moved parallel to the direction of movement of the workpiece and horizontally (perpendicular) to the workpiece. The movements of both slide rail devices are independent of one another. In addition, vertical movability of the slide rails in order to obtain fewer interfering contours is not possible with a greater bending clearance.

In a similar way are also in the pipe bending machine according to FIG EP 1 458 505 B1 or the DE 602 18 339 T2 which also allows left and right bending, slide rail devices are provided on both sides of the workpiece, which can be moved parallel to the workpiece independently of one another and perpendicular to the workpiece together. However, a vertical movement of the slide rails is not provided here either.

Another bending machine for left and right bending of elongated workpieces is in the EP 1 595 612 A1 described, in which, in turn, separate slide rails for left and right bending can be pivoted via a pivoting movement from a position lowered below the bending plane and removed from the workpiece into a raised position applied to the workpiece. In this document is for the slide rails however, no movement parallel to the workpiece and no vertical movement are provided.

The machine for bending pipe coils from the DE 1 652 817 A1 slide rails are specified that can be moved both in the vertical and in the direction of movement of the workpiece. However, a horizontal movement directed perpendicular to the workpiece is not expressly described here, only a lifting of the slide rails from the workpiece is stated.

In the case of the WO 2004/000479 A1 As shown in the bending arrangement for pipes, sliding rails which can be moved together perpendicularly to the workpiece are used in which a movement parallel to the workpiece is also possible independently of one another. In this known arrangement, however, there are clear interfering contours with only moderate bending freedom.

A bending machine of the type mentioned is from the EP 2 177 287 A2 known. There, the slide rails attached to both sides of the workpiece can be moved parallel to the workpiece, with a vertical movement or a movement directed perpendicular to the workpiece not being provided. With this known bending machine, left and right bending can also be carried out, with material from the coil and not pipe sections cut to length being processed. When bending pipes with a pipe wrench feed and a workpiece cut to length, collisions can occur in this known bending machine.

Based on this, the invention is based on the object of improving this known tube bending machine so that it has fewer interfering contours with greater bending space and can be used without problems for machines with cut workpieces as well as for material from the coil.

According to the invention, this is achieved in a bending machine of the type mentioned in that the two support parts are attached to the ends of a pivoted, two-armed lever mirror images of each other, with one of the two sliders with its shape groove against the workpiece laterally in each pivoting end position of the lever is applied.

In the invention, the slide rails are not moved via guides on which the longitudinal and transverse slides are mounted, but instead by means of a two-armed lever pivotably mounted on the machine. This allows the slide rails to be swiveled to the right and left of the bending head, which is particularly suitable for right and left Turning left proves. The slide rails can advantageously also be moved in the direction of movement of the workpiece, with the bending head also being particularly preferably arranged to be movable in the vertical and horizontal directions.

The bending machine according to the invention is particularly advantageous for bending thin-walled tubes in order to be able to bend them without an internal mandrel. It is also possible to bend aluminum pipes and stainless steel pipes without cold welding, as the clamping jaw opens horizontally before turning back at the end of the bend and no longer rests on the workpiece.

Compared to bending machines that work without a slide rail and with counter-holding rollers, the bending machine according to the invention has the advantage that the counter-holding rollers are always arranged further away from the bending center than slide rails and thus not as high a bending quality as with the bending machine according to the invention can be achieved.

In the bending machine according to the invention, a completely new concept of the arrangement of the slide rails is used, since sliding carriages with linear guides are no longer used for the infeed movement of the slide rails towards and away from the workpiece. The attachment of the slide rails to the ends of a two-armed lever allows a swiveling from right to left bending (and vice versa) quickly through a relatively quick swivel movement and thereby makes it possible to reduce idle times in the bending machine according to the invention.

The pivotability of the two-armed lever with the slide rails also enables it to be rotated into a central position in which neither of the two slide rails is in lateral contact with the workpiece, but rather both slide rails are still removed from it. Such a middle position is z. B. relevant for the last bend on a workpiece, because this allows short final straight lines to be realized on this. Because in such a middle position of the lever, the pipe wrench, which holds the workpiece, can move forward into the tool area and transfer the workpiece, which is then held by means of the bending tool and clamping jaws. The pliers can then move back without a workpiece, after which the relevant slide rail is placed on the workpiece and the last bend is produced on it.

By suitably designing the two-armed lever, it can be ensured that when one slider rests laterally against the workpiece to be treated, the other slider is brought into a starting position that is well below the bending plane and is thus in the Area of the bending plane and above the same no interfering contour due to this lowered slide rail and thus a large bending space is guaranteed.

In a preferred embodiment of the invention, the pivotably mounted lever is attached between a workpiece guide on the machine frame and the bending tool. The lever can advantageously be pivotably mounted on a bracket that is attached to the machine housing, preferably at the front of the machine frame, or also pivotably attached to the bending head and can also be moved horizontally (perpendicular to the longitudinal axis of the workpiece).

The design of the two-armed pivotable lever can take place in any suitable shape for this, but it is particularly preferably designed to be V-shaped or C-shaped.

It has proven to be particularly advantageous if the slide rails are attached to the two-armed lever inclined at an angle of 60 ° to each other, which enables a relatively short distance to be covered to swivel right and left bending (and vice versa) which also has a very positive effect on the non-productive times. On the other hand, the lever arms should also be as far apart as possible in order to ensure the greatest possible bending space.

In certain applications, however, it is also very useful to use a smaller angle of about 45 ° or, particularly preferably, 90 ° for the adjustment of the slide rails relative to one another.

Advantageously, in the invention, each slide rail on the associated support part is provided so that it can be moved parallel to the longitudinal direction of the workpiece, with the slide rail being pulled along with the movement of the workpiece in its longitudinal direction when a slide rail is in contact with the workpiece until its bending is completed, after which the slide rail is again must be returned to its original position.

For this purpose, each slide rail is advantageously seated on a tool holder attached to the associated support part, which in turn can be moved parallel to the longitudinal direction of the workpiece via a linear guide on the lever, with an adjustable stop again preferably being provided on the linear guide, by means of which a desired starting position of the slide rail can be set in Seen longitudinally, can be determined. For resetting the slide rail to its starting position after the bending has taken place, it is advantageous if each slide rail in the direction of the adjustable stop in the linear guide is spring-loaded. Instead of using an elastic spring, this can also be done using pneumatic or electrical means.

If the bending machine according to the invention is used for treating workpieces cut to length, it is particularly advantageous if the workpiece feed is provided in the form of a gripper guide.

It is also advantageous if the bending head can be moved laterally and / or vertically relative to the machine frame.

The bending machine according to the invention can be used both for processing material from the coil and for processing pipe sections cut to length. It has few interfering contours with a particularly large bending space and allows rapid switching from right to left bending (and vice versa), so that the non-productive times that occur are also only relatively short.

Fig. 1

eine Perspektivansicht einer erfindungsgemäßen Rohrbiegemaschine mit Rohrzangenführung, wobei an der vorderen Stirnseite des Maschinengestells eine Biegeeinheit mit Biegekopf und mit an einem schwenkbaren Hebel angebrachten Gleitschienen angeordnet ist;

Fig. 2

eine perspektivische Schrägansicht (von oben) auf die schwenkbare Hebeleinrichtung für die Gleitschienen mit einer Konsole zur Befestigung am Maschinengestell;

Fig. 3 bis 5

Darstellungen unterschiedlicher Positionen der die Gleitschienen tragenden Hebeleinrichtung, wie sie während des Arbeitszyklus der Biegemaschine angefahren werden (können);

Fig. 3a

in Vorderansicht und Fig. 3b in Draufsicht auf eine erfindungsgemäße Biegemaschine in einer Stellung für Linksbiegen;

Fig. 4a

eine Vorderansicht und Fig. 4b eine Draufsicht auf eine erfindungsgemäße Biegemaschine, bei welcher der die Gleitschienen tragende zweiarmige Hebel sich in einer Mittelstellung befindet, in der keine Gleitschiene gegen das zu bearbeitende Werkstück anliegt, und

Fig. 5a

eine Vorderansicht sowie Fig. 5b eine Draufsicht auf eine erfindungsgemäße Biegemaschine, die sich in einer Stellung für Rechtsbiegen befindet.

The invention is explained in more detail below in principle by way of example with reference to the drawings. Show it:

Fig. 1

a perspective view of a pipe bending machine according to the invention with a pipe wrench guide, a bending unit with a bending head and with slide rails attached to a pivotable lever being arranged on the front face of the machine frame;

Fig. 2

a perspective oblique view (from above) of the pivotable lever device for the slide rails with a console for attachment to the machine frame;

Figures 3 to 5

Representations of different positions of the lever device carrying the slide rails as they are (can) approached during the working cycle of the bending machine;

Fig. 3a

in front view and Figure 3b in a plan view of a bending machine according to the invention in a position for left-hand bending;

Figure 4a

a front view and Figure 4b a plan view of a bending machine according to the invention, in which the two-armed lever carrying the slide rails is in a central position in which no slide rail rests against the workpiece to be machined, and

Figure 5a

a front view as well Figure 5b a plan view of a bending machine according to the invention, which is in a position for right-hand bending.

In the following description of the figures, an exemplary embodiment for a pipe bending machine according to the invention is shown, the same reference numerals being used for the same parts in the various figures.

Fig. 1 shows a perspective view (from the front and obliquely from above) of a pipe bending machine 1 with a machine frame 2, on which a switch cabinet 3 with a control panel 4 and a screen 5 for operating the pipe bending machine 1 is attached to the side.

A spindle arrangement 6 with a protective hood 7 is assigned to the machine frame 2, a pipe wrench 8 being provided here for holding and advancing and also for rotating a workpiece 9 (pipe) cut to length about its longitudinal axis.

A bending unit 10 with a bending head 11 is also attached to the front face of the machine frame 2, the bending unit 10 being movable both vertically (Z-axis) and perpendicular (B-axis) to the direction of movement of the workpiece 9 (the directions of movement are in Fig. 1 illustrated by the arrow representations assigned to the bending unit 10).

In the embodiment shown here, a pivotable lever device 12 is attached to the machine frame 2, which is shown in more detail in FIG Fig. 2 is shown in a perspective view:
This lever device 12 is essentially formed by a two-armed lever 13 which is pivotably attached to a bracket 18 via a bearing pin 19, the pivot point of which simultaneously represents the pivot axis for the lever 13. Here sits how Fig. 2 shows the lever 13 on the front side of the console 18, on the rear side of which the two-armed lever 13 is connected to a servomotor 20 via a gear, via which the drive for the pivoting movements of the lever 13 is generated.

The lever 13 has on one (in Fig. 2 shown on the left) side a lever arm 16 for left bending and on its other side a lever arm 17 for right bending.

A support part 22 is formed at the end of the lever arm 16 for left-hand bending and a support part 23 is formed at the end of the lever arm 17 for right-hand bending, on each of which a linear guide 25 or 26 is attached, in each of which a displaceable tool holder 15 is seated, on which a slide rail 14 is attached via a clamp 21.

The movement of the tool holders 15 in the linear guides 25 and 26 and thus the movement of the slide rails 14 takes place in a direction parallel to the longitudinal direction of the workpiece 9 to be treated.

An adjustable stop 27 or 28 is provided in each of the linear guides 25 and 26, which is attached in the form of a rotatable nut in the embodiment shown and by means of which the starting position of the slide rail 14 of the relevant lever arm 16 or 17 can be adjusted. Such positioning is necessary because the slide rail 14 must be adapted to the position of the workpiece 9 to be bent in accordance with the bending step to be performed. In addition, this function is essential if a pipe that has been cut to length is to be bent, the end of which has already been machined (such as an end reshaping or an attached nut) and the inner contour of the slide rail 14 has a certain shape (groove, groove, etc.) .). Due to the frictional force occurring when the slide 14 rests against the workpiece 9, the slide 14 is pulled along by the workpiece 9 during the corresponding bending step until the bend is finished, after which the slide 14 must be returned to its starting position. Such a return to the initial position can be achieved by the slide 14 z. B., as in Fig. 2 shown, can be implemented via suitable biasing springs 29, but could also be suitably controlled via pneumatic or electrical means. The entire lever device 12 with the individual elements attached to it represents an assembly which could also be referred to as a pivotable support device or a counter-holder unit.

In the Figures 3a , 3b , 4a , 4b 5a and 5b, the bending machine 1 according to the invention is shown in different positions of the lever device 12, which can or must be approached during a working cycle of the bending machine 1.

So shows Fig. 3a a front view of a pipe bending machine 1 and Figure 3b a top view of this in a position intended for left-hand bending, the workpiece not being shown in both figures (as well as in the figures that follow).

The workpiece is fed to the bending unit 10 via the feed, for example a pipe wrench feed, and is threaded between a clamping jaw 30 and the bending form 31 and clamped by these. The lever device 12 then pivots up to the right (viewed in the longitudinal direction of the workpiece 9 to be treated), cf. Fig. 3a , and the slide rail 14 of the lever arm 16 for left-hand bending rests against the workpiece. During the subsequent bending process, the lever device 12 serves as a corresponding support device or counter-holder unit for the workpiece to be machined. As already mentioned, the sliding rail 14 is thereby separated from the forward moving workpiece 9 by the frictional force pulled along until the bend is completed. Then, when the slide rail 14 is lifted off the side of the workpiece 9, the support part 22 holding the slide rail 14 is pushed back into its initial position via the pretensioned spring 29.

It should be noted that a shaped groove 24 is attached to each slide rail 14 on the side facing the workpiece 9, which runs parallel to the longitudinal direction of the workpiece 9 and, when the slide rail 14 rests against the side of the workpiece 9 to be supported, comes to rest against its outer circumference . At least one (in the figures: two) bending groove 32 is also attached to the bending form 31.

In the representations of the Figure 4a and 4b the lever device 12, seen in the feed direction of the workpiece 9, has been pivoted clockwise and assumes a central position in which neither of the two lateral slide rails 14 comes to rest laterally against a workpiece 9.

This middle position, as it is in the Figure 4a and 4b is shown, is run over when switching from turning right to turning left (or vice versa). It is also essential for making a final bend on the workpiece 9 insofar as short final straight lines can be produced as a result. When the lever 13 is in this central position, the z. B. held by a pipe wrench 8 workpiece 9 moved from the front into the tool area and there between the clamping jaws 30 and the bending form 31 are received and held. The pipe wrench 8 then moves back without the workpiece 9, after which the slide rail 14 is placed laterally against this and the last bend is initiated.

Figure 5a shows the bending machine 1 in the position for right-hand bending from the front and Figure 5b shows a plan view of the lever device 12 (support device) in this position.

If a change is to be made from a position for left-hand bending to the position for right-hand bending, the bending head 11 is lowered vertically, then moved transversely to the longitudinal direction of the workpiece 9 and then positioned again in its new working position, as shown in the Figure 5a and 5b is shown. The bending head 11 is moved vertically downwards as a function of the central axis of the workpiece 9. The lever device 12 or support device pivots clockwise from right to left, viewed in the feed direction of the workpiece 9, until the into the Figures 5a and 5b The end position shown is reached, in which the slide rail 14 held on the lever arm 17 for right-hand bending can be placed laterally against the workpiece 9 and with this at the advance of which is carried along by friction in the transport direction for the execution of the bend, so that the support by this slide rail 14 is always realized over the same distance on the workpiece 9.

In the embodiments shown, the arrangement of the slide rails 14 is such that they are set at an angle of 60 ° to one another. This angle is particularly advantageous because, on the one hand, only a relatively short distance has to be covered to swivel right and left turns, which can lead to a significant reduction in non-productive times. On the other hand, the lever arms 16 and 17 are nevertheless sufficiently far apart at this angle to ensure a very large amount of bending space. However, a different size of the relative angle of incidence of the two slide rails 14 to one another would also be possible, for example larger or smaller than 90 °.

The shape of the two-armed lever 13 can be designed in any suitable manner, e.g. B. V-shaped or C-shaped (as the latter is indicated in the figure representations).

The embodiment of the lever device 12 according to the invention can also be used to advantage, in particular, for thin-walled tubes which can also be bent without an internal mandrel. The bending of aluminum pipes and stainless steel pipes without cold welding is also possible with this lever device 12.

The bending quality is increased compared to conventional bending systems, whereby the undesired non-productive times are reduced at the same time.

Claims (13)

1. A bending machine (1) for bending rod-shaped or tubular workpieces (9), comprising a bending tool which comprises a bending head (11) with a bending disk (31) comprising at least one circumferential bending groove (32), and additionally comprising two slide rails (14), each of which has a molding groove (24) and which can be placed laterally against opposing longitudinal sides of the workpiece (9), wherein each slide rail (14) is secured to a support part (15) and laterally supports the workpiece (9) in a region from where the workpiece is tangentially fed into the bending groove (32) of the bending disk (31) to a point in front of the bending groove at a specified distance therefrom when the slide rail (14) is resting against the workpiece (9), and wherein each support part (15) can be adjusted between a starting position, in which the associated slide rail (14) does not rest against the workpiece (9), and a final position, in which the slide rail (14) contacts the workpiece (9), wherein, upon contacting of one slide rail (14) with the workpiece (9), the other slide rail (14) assumes its respective starting position, characterized in that the two support parts (15) are mounted mirror-inverted to one another at the ends of a pivotably mounted, two-arm lever (13), wherein one of the two slide pieces (14) can be rested laterally against the workpiece (9) with its molding groove (24) in each final pivot position of the lever (13).
2. The bending machine as claimed in claim 1, characterized in that the pivotably mounted lever (13) is mounted between a workpiece guide (8) on the machine frame (2) and the bending tool (11).
3. The bending machine as claimed in claim 1 or 2, characterized in that the lever (13) is pivotably mounted on a bracket (18) which is fastened to the machine housing (2).
4. The bending machine as claimed in claim 1 or 2, characterized in that the lever (13) is fastened to the bending head (11) in a way that allows pivoting, and can also be moved horizontally.
5. The bending machine as claimed in any of claims 1 to 4, characterized in that the two-arm lever (13) is V-shaped or C-shaped.
6. The bending machine as claimed in any of claims 1 to 5, characterized in that the slide rails (14) are set at an angle of 60°, preferably 90°, to one another.
7. The bending machine as claimed in any of claims 1 to 6, characterized in that each slide rail (14) can be moved on the associated support part (15) in parallel to the longitudinal direction of the workpiece (9).
8. The bending machine as claimed in any of claims 1 to 7, characterized in that a servo motor (20) is associated with the lever (13) for the pivot drive.
9. The bending machine as claimed in any of claims 1 to 8, characterized in that each slide rail (14) is seated on a tool holder (15) which is attached to the associated support part (15) and which in turn can be moved in parallel to the longitudinal direction of the workpiece (9) via a linear guide (25; 26).
10. The bending machine as claimed in claim 9, characterized in that an adjustable stop (27; 28) for fixing a starting position of the slide rail (14) is provided on the linear guide (25; 26).
11. The bending machine as claimed in claim 10, characterized in that each slide rail (14) is spring-preloaded in the direction of the adjustable stop (27; 28).
12. The bending machine as claimed in any of claims 1 to 11, characterized in that the bending head (11) can be moved laterally and/or vertically relative to the machine frame (2).
13. The bending machine as claimed in any of claims 1 to 12, characterized in that a gripper guide (8) is provided for workpiece feed.

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