EP1862235B1 - Mandrel for bending tool with varying bending direction - Google Patents

Abstract

Bending tool comprises a mandrel having two interlocking shafts (9, 10) which slide against each other and each having a rotating roller (14, 15) on the front ends forming the roll bending of a profile (3) with alternating bending during the bending process.

Description

The invention relates to a mandrel shank alternating bending tool according to the preamble of claim 1 for 2D or 3D roll bending of open, semi-open or closed hollow sections and tubes with changing bending directions during the rolling bending process.

It is known to use a so-called Dornschaft bending tool for effective rolling bending of open and closed hollow sections and normal profiles on bending machines.

With the generic, going back to the same applicant Patent Application DE-A1-10123265 ( EP-A3-1 256,394 ) discloses a Dornschaft- bending tool, which is designed for bending open or closed hollow profiles and a mandrel shank, which is by means of a conveyor in the interior of the hollow profile and executable, wherein the mandrel shaft during the bending process on a bending line between At least two oppositely directed, applying the bending pressure rollers, wherein the mandrel shaft is formed at least in the region of the bending line high pressure resistant and wear-resistant and / or lubricated by a lubricant.

Such a mandrel shank tool leads in the interior of the profile to be bent during the bending process and in particular in a region between an arranged roller center roller and a support roller.

In addition, an impermissible radially inwardly or laterally and inwardly inwardly and outwardly directed deformation of the hollow profile during the bending process is avoided.
It is preferably adapted in its shape to the profile to be bent and is held by a mandrel which is fixed in a mandrel station.

During the bending process, therefore, the profile-mandrel shank tool remains in said area to support the profile to be bent in the interior.

The actual bending in novel bending machines of a profile is achieved in that in addition to the bending task still takes place an additional rolling of the profile in the bending zone.
In this bending process, a Auswalzfließeffekt in the outer area of the profile superimposed on the bending process, in a reduced form, the rolling flow effect is also on the inside of the profile. This so-called roll bending process generates high frictional or friction forces with possibly very high resistance to movement of the profile to be bent, which can lead to the destruction of the profile or at least excessive surface damage to the interior of the profile to be bent. Due to poor sliding properties on the mandrel shaft, the bending quality is also badly affected.

Thus, the larger bending radius is generally formed on the side of the profile on which the rolling roller exerts the greatest force on the material surface and thus larger Auswalzkräfte arise.

A disadvantage of such a mandrel shank tool is that a rolling bending operation with changing bending directions is not possible during the bending process, since the bending rolls are always on the same bending line with the mandrel shank on both sides in order to carry out the desired rolling deflection.

Also, any other bending machine uses such a mandrel shank, such as core-stretch bending machines, where it is important to always keep the mandrel shank in the bending line.

The invention is therefore based on the object, on the basis of a mandrel shaft tool of the type mentioned in such a way that a cost-effective roll bending of profiles in different bending directions during the bending process is executable.

To achieve the object, the invention proposes a mandrel shank alternating bending tool with the features of claim 1.

With the given technical teaching according to the invention, therefore, the essential advantage is achieved that the split mandrel shaft by means of a displacement of the two individual shafts against each other forms a change in the bending direction of the profile during the rolling bending process.

If in the following a bending of a profile is referred to as alternating bending, it is thus to be understood as meaning the changing of the bending direction of the profile to be bent during the rolling bending process in one plane.

With the object of the present invention, such a bending change is feasible without the profile to be bent in the bending device must be rotated over the profile cross-section.

In the previous bending process, the bending range is limited to symmetrical profile cross-sectional formations, such as round tubes, square or rectangular tubes with closed profiles.

In cross-section asymmetric thin-walled, open or closed profiles a change bending is not yet feasible.

This problem is solved by the present invention.

In one embodiment of the invention, a mandrel shank alternating bending tool is formed as a divided in its axially extending longitudinal direction mandrel tool, wherein the two individual mandrel shafts are mutually displaceable and positively connected to each other.

During the bending process, a roller of the split mandrel shank alternating bending tool arranged laterally on the mandrel shank is displaceably positioned offset relative to the bending line of the bending roller and thus forms a so-called free surface.

The other side of the split mandrel shaft is arranged such that the center line of the roller disposed thereon is aligned with the bending line of the bending roller, whereby a substantially smaller roller bearing surface is formed.

The two rolling rollers arranged on the outer side surfaces of the profile thus serve merely to produce the necessary pressing or rolling pressure, in order to carry out a rolling out of the lateral material wall of the profile.
This rolling is carried out primarily on the small tool rolls on the inside of the profile.

The bending of the profile is produced in that one of the two laterally arranged on the mandrel shank tool tool rolls is axially offset from the bending line of the rolling rolls, with a bending of the profile always takes place in the direction of the mandrel shank side of the tool, which is a displacement of the roll to the bending line the rolling roller has, that is, the free surface is now exactly in the bending line

This is due to the fact that a roller assembly in alignment with the bending line of the roller produces a higher surface pressure, whereby the profile arranged therebetween is more strongly rolled out and thus bent.

By an axial displacement of the two Dornschafthälften a change in the bending direction is initiated.

Here, the profile material is rolled with a modified surface pressure, since the roll is positioned offset to the bending line of the rolling roll, that is, that the free surface has a reduced surface pressure.

Of course, such a system effect in the above-described Y-axis, for example, by a 90 ° rotation of the mandrel shank alternating bending tool in the Z-axis executable.

The two Einzeischäfte the mandrel shaft alternating bending tool according to the invention are driven by a linear mandrel drive individually linearly displaceable.

It is preferably provided that a Z-roller arranged on the underside of the profile in the Z-direction, by means of a corresponding oblique position of its axis of rotation, conically tapers the profile wall on the underside of the profile.

This conical Auswalzung takes place in that the arranged below the profile Z-roll is pivotable in its axis of rotation.

Such conical Auswalzung the profile wall on the underside of the profile is required because due to the plane-parallel Auswalzung the lateral profile walls of the profile, the material has a change in length in the direction of the X-axis and the Y-axis.

The change in length of the profile in the direction of the X-axis leads to a corresponding bending behavior of the profile when the Auswalzung is performed on the side profile walls with mutually different surface pressures.

The change in length in the direction of the Y-axis due to the executed Auswalzung continues in the profile wall of the profile bottom. This means that the material is conically rolled by a corresponding conical Auswalzvorgang the profile wall on the bottom profile side in the direction of the Y-axis.

The lying on the underside profile edge on the profile side, which is rolled with a larger surface pressure, thus has the greatest penetration depth of the Z-roll.

The conical Auswalzung the lower profile wall in the direction of the Y-axis now takes place with a decreasing depth of penetration of the Z-roll to zero, the Zero point is determined by the outer profile edge of the overall profile in the direction of the Y axis.

In the execution of a profile with a laterally angled flange, it is necessary that this flange is rolled conically according to the lower profile wall.

For this purpose, it is provided that for generating the required surface pressure above the flange, a pivotally mounted flange roller is rotatably arranged, which extends with its lateral surface over the width of the flange.

In an alternate roll bending operation of a profile having such a flange, the skew of the flange roll and the Z roll located on the underside of the profile is the same, with the maximum depth of penetration of the flange roll in the flange surface corresponding to the remaining penetration depth during rolling of the lower profile wall.

To generate the necessary surface pressure for Auswalzung the profile bottom is provided to form the individual mandrel shanks of the split mandrel shank alternating bending tool on its side directed to the underside of the profile side, each with a counter-roller to the Z-roller to the appropriate Auswalzkraft for Auswalzung the material on to form the lower profile page.

The forces occurring in the direction of the Y-axis are held by an additionally arranged, rotatably mounted double Z-roll, which is arranged above the open profile.

For a closed profile only a single Z-roll is required, the lateral surface extends over the entire width of the profile.

In addition, it is provided to arrange these two vertical counter rollers in a closed profile system on the upwardly directed side of the two mandrel shafts to the upwardly directed wall of the profile also to roll with a correspondingly assigned, further one-piece Z-roll.
The primary Auswalzung takes place here also on the inside of the lower profile side.

It is thus possible for the first time to perform a rolling bend of an open or semi-open profile with alternating bending direction without rotation of the profile in the profile cross-section, due to the Auswalzung the corresponding material walls, the profile is stress-free and dimensionally stable.

In the following, the invention will be explained in more detail with reference to drawings illustrating several execution paths. Here are the drawings and their description of preferred features and advantages of the invention.

Figur 1:

schematisiert eine Draufsicht einer Anordnung von Walzrollen in der Biegelinie einer Walzbiegemaschine mit einem eingesetzten Dornschaft-Wechselbiege-Werkzeug;

Figur 2:

schematisiert eine Hauptansicht einer Walzbiegemaschine mit gleicher Anordnung wie Figur 1 mit einem eingesetzten Dornschaft-Wechselbiege-Werkzeug;

Figur 3:

schematisiert eine beispielhafte Anordnung der Rollen einer Wechsel-Walz-Biegemaschine

It shows:

FIG. 1:

schematically shows a plan view of an arrangement of rolling rolls in the bending line of a roll bending machine with a mandrel shaft alternating bending tool used;

FIG. 2:

schematically a main view of a roll bending machine with the same arrangement as FIG. 1 with an inserted mandrel shank bending tool;

FIG. 3:

schematically illustrates an exemplary arrangement of the roles of a change-rolling-bending machine

In FIG. 1 is a section of an exchange roll bending machine shown, which consists of a six-roller system in the embodiment shown.

Of course, the number of rollers and arrangement changes according to a changed profile cross-section.

The profile 3 to be bent is formed in the above-mentioned embodiment as an open, thin-walled U-profile 3, which has a further radially outwardly angled flange 20 at one of the two arranged in the Z-axis 13 U-leg 22.

The two U-legs 21, 22 are supported on their outer lateral surfaces by two arranged rolling rollers 1, 2 of the same diameter, which rotate in the direction of rotation 6, 7 during the rolling bending process and a corresponding Auswalzkraft for rolling the U-legs 21, 22 of the profile 3 in the direction of the Y-axis 4 form.
The Auswalzung is primarily carried out by the small rollers 14, 15 in the mandrel shank bending tool.

The Auswalzkraft on the U-legs 21, 22 is formed according to the so-called Actio / Reactio principle, wherein the adjustable distance in the direction of the Y-axis 4 of the two rolls 1, 2 is a measure of the surface pressure.

In the cavity of the profile 3, two mandrel shanks 9, 10 of a divided in the direction of the X-axis mandrel shaft alternating bending tool are arranged, which are mutually displaceable in the direction of the X-axis 5.

At the respective front free end, the mandrel shanks 9, 10 have a roller 14, 15 arranged in the direction of the Z-axis on the radially outwardly directed side surface 31, 31 ', which is mounted in rotation and has a projection to the side surface of the two mandrel shanks 9 , 10 trains.

These rollers 14, 15 are each fixed by means of locking screws 16, 16 '.

The two mandrel shanks 9, 10 are displaceable by means of a Dornschaftantriebes not shown in the direction of the X-axis 5, wherein one of the two mandrel shafts 9, 10 offset by a predetermined amount in the direction of the X-axis to the bending line in the direction of the Y-axis 4 of the laterally arranged and rotatably mounted roller 1, 2 is arranged.

As a result, the mantle surface of the rolling roll 1, 2 with respect to the side surface of the U-leg 21, 22 forms an open surface 11 having a width which is twice the distance between the bending line 4 of the rolling roll 1, 2 and the protruding edge 32 , 32 'of the remote side surface 31, 31' of the mandrel shaft 9, 10 is defined.

The thereto arranged opposite mandrel shaft 9, 10 has only a linear roller surface 12, which is formed due to the aligned in the Y direction arrangement of the roller 14, 15 with the bending line 4 of the rolling roller 1, 2.

This roller surface 12 thus forms an area of the largest possible Auswalzkraft.

In addition is out FIG. 1 it can be seen that the mandrel shanks 9, 10 each have a counter-roller 17, 18 rotatably mounted in the direction of the Y-axis, which are designed to produce a necessary rolling-out force for rolling out the lower profiled surface 23 of the profile 3 during roll bending.

By running in the direction of the X-axis displacement of the two mandrel shafts 9, 10, the open profile 3 bends in the bending direction 8, 8 '.

The bending direction 8, 8 'is directly dependent on the Auswalzkraft on the side surface of the profile 3.
This means that the profile 3 bends in the direction of the mandrel shaft 9, 10, which forms a free surface 11 on the side surface of the U-leg 21, 22 with the arranged roller roller 1, 2, as by the axial displacement of the roller 14, 15th to the bending line 4 a reduced Auswalzkraft is formed.

This reduced Auswalzkraft forms an equally reduced material elongation of the U-leg 21, 22 of the profile 3 from.

This in FIG. 2 shown mandrel shaft alternating bending tool shows that the two mandrel shafts 9, 10 by means of a pointing to their lateral Surfaces 24, 25 have a positive connection in the direction of the X-axis 5.

Of course, this positive connection can also have other shapes, such as a dovetail guide.

On the underside of the profile 3, in each case a counter-roller 17, 18 mounted in rotation on the underside of the mandrel shaft 9, 10 are arranged in opposite arrangement to the Z-roller 19.

This counter-roller 17, 18 forms with the rotatably mounted Z-roller 19, the necessary surface pressure to also auswalzen the lower profile surface 23 during the rolling bending process.

For such a Auswalzvorgang the lower profile surface 23, it is necessary that the below the profile 3 in the direction of the Z-axis rotatably mounted Z-roll performs a pivoting movement in the direction of arrow 26.

This pivotal movement of the Z-roller 19 forms a conical material thickness of the lower profile surface 23, since due to the Auswalzvorgangs on the lateral U-legs 21, 22, the material thickness change in the direction of the lower profile surface 23 continues and this starting from the profile edge between the U-leg 21st , 22 and bottom profile surface absorbs the same depth of impression and then let each run out to zero - depending on the bending direction.

The pressure force of the Z-roller 19 is received by a above the profile 3 rotatably arranged Z-roller 33, 34.

In FIG. 3 a schematic representation of an alternating rolling-bending device is shown with a six-roller system, wherein the oppositely rotatably arranged rolling rollers 1, 2 are assigned a lower and two upper Z-rollers.

In addition, a flange roller 39 is additionally arranged above the rolling roller 1, which has the required surface pressure with the side surface of the below arranged rolling roller 1 forms and the material wall of the angled flange 20 conically rolls.

To carry out the entire change-roll bending operation, two support rollers 35, 36 upstream of the rolling rolls 1, 2 and two bending rolls 37, 38 downstream of the rolling rolls are required.

In a further preferred embodiment of the invention, it is quite possible that the mandrel shank alternating bending tool according to the invention also forms a reciprocal bend in the direction of the Z-axis 13.

drawing Legend

1

Rolling roller, bending roller

2

Rolling roller, bending roller

3

profile

4

Y-axis = bending line

5

X-axis = direction of passage of the profile to be bent

6

direction of rotation

7

direction of rotation

8th

Bending direction 8 '

9

Dornschaft, left

10

Dornschaft, right

11

Open space 11 '

12

roller plane

13

Z-axis

14

Roller, left, roller, vertically rotatable / aligned to the bending line (4) arranged role

15

Roller, right, roller, vertically rotatable / aligned to the bending line (4) arranged role

16

Locking screw 16 '

17

Counter role, left

18

Counter role, right

19

Z-roll, Z-roll

20

flange

21

U-thighs, right

22

U-thighs, left

23

lower profile surface

24

Contact surface, right, facing each other surface

25

Contact surface, left, facing each other surface

26

arrow

27

arrow

28

paragraph

29

Zero point 29 '

30

Maximum point 30 '

31

Side surface 31 '

32

protruding edge 32 '

33

Z-roll above

34

Z-roll above

35

Support roller, left

36

Support roller, right

37

Bending roller, left

38

Bending roller, right

39

flanged

Claims (12)

1. A mandrel shaft alternating bending tool for bending open and/or closed hollow profiles (3), containing a mandrel shaft tool, which is insertable into and retractable from the inner chamber of a hollow profile using a conveyance apparatus, the mandrel shaft being located during the bending procedure on a bending line between at least two rolling rolls (1, 2), which are oriented opposite to one another and apply the bending pressure, characterized in that the mandrel shaft has two individual mandrel shafts (9, 10) positively connected to one another, which are displaceable in relation to one another in the direction of an X axis (5) of the mandrel shaft (9, 10) and each have a rotatably mounted roll (14, 15) in the direction situated radially outward on their front free ends, which primarily implements the roll-bending of the profile (3) with alternating bending direction during the bending procedure.
2. The mandrel shaft alternating bending tool according to Claim 1, characterized in that the two individual mandrel shafts (9, 10) each have a counter roll (17, 18) mounted so it is rotatable in the direction of a Y axis (4) on their free end, which implements the rolling-out force for rolling out the lower profile face (23) with a Z roll (19) situated rotatably mounted below the lower profile face (23) of the profile (3).
3. The mandrel shaft alternating bending tool according to Claim 1 or 2, characterized in that upon a displacement of the two individual mandrel shafts (9, 10) to one another, the roll (14, 15) rotatably mounted in the direction of a Z axis (13) implements an offset to the bending line (4) of the rolling roll (14, 15) in the direction of the X axis (5).
4. The mandrel shaft alternating bending tool according to one of preceding Claims 1 through 3, characterized in that the mandrel shaft (9, 10) has a recess having a runout face on its lateral face lying radially outward, the vertically rotatably mounted roll (14, 15) projecting out of the surface of the recess and resting on the inner surface of the profile (3) implemented having U-legs (21, 22).
5. The mandrel shaft alternating bending tool according to one of preceding Claims 1 through 4, characterized in that the rolling roll (1, 2) implements a free face (11), which has a reduced rolling-out force, with the mandrel shaft (9, 10) situated offset in the area of the assigned bending line (4).
6. The mandrel shaft alternating bending tool according to one of preceding Claims 1 through 5, characterized in that the rolling roll (1, 2) has a higher rolling-out force with the roll (14, 15) situated aligned to the bending line (4) than the roll (14, 15) situated offset.
7. The mandrel shaft alternating bending tool according to one of preceding Claims 1 through 6, characterized in that the profile (3) implements a bending direction (8) in the direction of the Y axis (4) which runs in the direction with the roll (14, 15) situated offset.
8. The mandrel shaft alternating bending tool according to one of preceding Claims 1 through 7, characterized in that the surface pressure generated by the rolling roll (1, 2) and the roll (14, 15) situated vertically rotatably implements rolling out of the U-legs (21, 22) of the profile (3) in accordance with the surface pressure force primarily on the interior side of the U-legs (21, 22).
9. The mandrel shaft alternating bending tool according to one of preceding Claims 1 through 8, characterized in that the rolling roll (1, 2) has a recess (28) having a cover fastened thereon using appropriate fasteners, the cover being situated at a distance to the bending roll (1, 2) and the gap resulting therefrom being implemented for frictional guiding of a flange (20) of the profile (3) angled radially outward.
10. The mandrel shaft alternating bending tool according to one of preceding Claims 1 through 9, characterized in that the Z roll (19) situated below the lower profile face (23) executes a pivot movement in the arrow direction (26) to roll out the lower profile material at a conical material thickness.
11. The mandrel shaft alternating bending tool according to one of preceding Claims 1 through 10, characterized in that the outside material edge of the profile (3) implements a zero point (29, 29') and/or a maximum point (30, 30') of the penetration depth, the Z roll (19) implementing the required conical rolling out procedure of the lower profile face (23) between the maximum point (30, 30') and the zero point (29, 29').
12. The mandrel shaft alternating bending tool according to one of preceding Claims 1 through 10, characterized in that the Z rolls (33, 34) situated above the profile (3) are implemented to absorb the generated pressure force of the lower Z roll (19), these being opposed upon change of the bending direction in the direction of the X axis (5).

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