DE102004003682A1 - Method for hot-flow forming and a device for carrying out the method - Google Patents

Abstract

Disclosed is a method for hot flow forming and bending closed, half-open, and open profiled members. Said method uses a bending machine comprising at least two rollers (17, 18) which are disposed across from each other in the feeding direction of the bending profiled member and behind which at least one milling roller (14) and an opposite central roller (11) are arranged at an axial distance in the feeding direction, said at least one milling roller (14) and central roller (11) jointly embodying a roll bending zone for the profiled member that is to be shaped. At least one bending roller (13) which can be moved against and away from the profiled member that is to be bent is arranged at the discharge end. In order to be able to shape thin-walled and sensitive open, half-open, and closed profiled members, at least the rollers (11, 14) located in the roll bending zone are heated.

Description

object of the invention is a method for hot forging bending and an apparatus for carrying out the same Method according to the preamble of claims 1 and 11.

From older registrations the same applicant is known, with so-called four-roller bending machines also sensitive and thin-walled, closed, semi-open and open profiles to bend.

The Bending is in the form of two- or three-dimensional Shapes.

at the transformation of profiles z. B. of magnesium alloys or else for high-strength steels has turned out that a pure cold-forming bending is not sufficient. Due to the high strength of the material to be formed and a related brittleness Conditionally, the formability is sufficient not enough to reshape the profile satisfactorily. For certain Deformation breaks the profile, rips or becomes in another Way damaged, so it was not possible so far was to bend such delicate profiles.

Especially in thin-walled Profiles, it has been found that these profiles for buckling tend and reshaping was previously not possible.

Of the The invention is therefore based on the object, a novel method for bending deformation of thin-walled and sensitive, open, semi-open and closed profiles to propose, which works reliable.

to solution The object is the invention by a method according to the technical teaching of claim 1.

Essential is that at least arranged in the bending roll zone rollers are heated.

In A preferred embodiment of the invention is intended that there are arranged and opposing roles that are at the opposite Walls of the Create profile, are heated accordingly.

Though will in the following description for at least one of these two Rolls of the term "rolling roll" used but is not literal to understand, because these roles have functionally no longer exclusively a Auswalzaufgabe, but they serve additionally the shape guide of the profile in the bending roll zone. The actual bend of the profile takes place at a distance between the rear in the inlet direction Bending roller and at least one at a distance in the inlet direction front arranged support roller.

The However, the invention is not limited to the heated arrangement of rolling rolls limited in the area of the bending roll zone. It can of course also more roles are heated, especially in the inlet direction arranged in front of the bending roll zone support roller and the opposite Counter role, which is a support opposite of the profile to be bent the front in the inlet direction bending roll allows.

Instead of The described four-roller bending machine can therefore also other roller bending machines heated running become. The invention will therefore be given by way of example only with reference to a four-roller bending machine explained. However, the technical teaching of the invention applies to all known Bending process.

For training heating there are also different embodiments, which comprises all of the subject matter of the present invention should be.

In A first preferred embodiment of the invention is provided that in the Biegewalzzone oppositely arranged rolling rollers (namely the upper roller and the opposite center roller) electrically conductive (high-current) formed are. For this purpose contributes each rolling roller has an external current-carrying Cloak, which is radially inward is electrically insulated from an inner support by an insulating ring, the carrier in a conventional manner rotatably connected to the shaft.

The opposing Role is formed in the same way. Will now be a relatively high Power of z. B. 1000 to 2000 amps on a given role, then a series of differently running current paths result, which extend at least partially through the profile to be bent. Due to corresponding resistance heating, the profile becomes highly effective heated specifically only in the bending roll zone. These rungs go - as stated - partially through the profile to be bent. Partially run the current paths but also inward towards one in the area of the bending roll zone held spike shaft, over whose mandrel also a part of the current flows is discharged to the outside. Thereby the resistance heating takes place also in the interior of the profile.

One further current flow takes place through the opposing ones Rolls directly under electrical interposition of the conductive profile, so that only the bending roll zone concentrated and with high efficiency is heated with very high temperatures.

at the transformation of thin-walled Magnesium profiles or magnesium alloy profiles are used here Temperatures in the bending roll zone of about 150 to 200 ° C generated.

at The transformation of high-strength steel sheet profiles, however, are Temperatures in the range between 700 and 900 ° C preferred.

Important in this embodiment is that concentrates only in the bending roll zone a relative high warming takes place. This warming will preferably generated by said current flow resistance heater.

hereupon However, the invention is not limited. The invention can also Provide that the opposite rollers with known heating cartridges are equipped, which are the rolling rolls Preheat.

As well Is it possible, Insert heating coils in the opposite rolling rolls, these too over to heat up a corresponding current flow.

Next the mentioned resistance current flow heating and the heating with individual heating elements is in a further development of the invention provided that the rolling rolls heated by other heating means be such. B. by liquid heating means, which are passed into the interior of the rolling rolls, by hot air heating means, which act directly on the rollers, by infrared or inductive warming the rolling rolls.

As well can These rolling rolls are heated by means of laser energy. All mentioned heating methods can also be combined with each other.

The Invention is not limited to the heating of the rolling roller and the this respect the bending roll zone opposite Central role limited.

In a development of the invention, it is provided that also vertically to the two mentioned Rollers provided, so-called vertical rollers additionally heated are. It will be here all Heating method applied as described above. The named vertical rollers lie against the side wall of the to be bent profile and lead there the heat concentrates in the profile to be bent in the side wall.

Especially if the previously mentioned current flow heating is used, there are also current flow paths, which extend over the Vertical rollers extend.

The Invention is not limited to the heating of rolling rolls in the area limited to the bending roll zone, but it is provided in a continuing education that in the Inlet direction of the front lying rollers are heated. It deals this is the supporting role and the supporting role opposing Counter role, in turn, both at the opposite walls of the profile.

Also These two roles can be over all heating mechanisms described above are heated. The heating in This area then corresponds to a preheating of the profile, which then finally concentrated heated and heated in the bending roll zone. This significantly improves the transformation of sensitive profiles.

By the controlled arrangement of current paths that result that are the opposite ones Apply rolling rolls to the profile in an electrically conductive manner in the bending-rolled zone, result in precisely defined current paths, so that it through the application the current possible is to precisely regulate the temperature in the bending roll zone to + -1 ° C.

to Control will be appropriate temperature sensors to each other opposite Rolling rollers arranged, which regulate the flow of current through the arrangement regulate.

In a development of the invention, it is also provided that on the inlet side of the profile, namely in the area of the machine bridge one further preheating takes place. This preheating can consist of a heating channel, in the interior of which a number arranged by several heating stations arranged one behind the other are.

These Heating stations can provide in any way a predefined heating of the profile.

It However, it is preferred that each heating station as radiant heating (IR heater) is formed. In addition to the radiant heating can, however even other heating mechanisms are used, such. B. induction heaters and preferably other non-contact Heating method.

With The given technical teaching has the advantage that also very sensitive magnesium and magnesium alloys or aluminum-magnesium alloys even with thin-walled wall thickness can be safely transformed for the first time without it becoming one Breakage or buckling of the profile comes.

to support the profile of the inside is inserted in the interior of the profile Dornschaft carried, which is attached to a mandrel bar.

in this connection it is preferred if arranged at the front end of a link chain is that supporting runs in the interior of the profile and extends out of the bending zone into the area of the bending roller, so as to offer the bender a corresponding counter bearing.

In order to becomes a support of the profile opposite achieved the bending role, so that the bending roller is not the profile still afterwards can deform.

Here It is provided in a development of the invention that the Dornschaft is heated. As already stated, takes place the heating is preferred over the described Stromflussheizung.

For heating However, the spike shaft can also all other previously mentioned heating mechanisms individually and / or used in combination with one another, in particular one Radiant heating, a liquid heating, a laser heating and the like more.

Of the Subject of the present invention does not arise only from the subject matter of the individual claims, but also from the combination the individual claims among themselves.

All in the documents, including Summary of information and features, in particular the spatial training shown in the drawings as claimed essential to the invention, as far as they individually or in Combination opposite the prior art are new.

in the Below, the invention will be described with reference to only one embodiment illustrative drawings closer explained. Here are more from the drawings and their description Essential to the invention features and advantages of the invention.

It demonstrate:

1 : Schematically represented perspective view of a hot-formed sheet bending machine according to the invention

2 : An enlarged partial view of the bending head in section

3 : the representation of the hot-flow forming machine according to 1 with more details

4 : a section along the line IV-IV in 3

5 : a section along the line VV in 3

In 1 is a machine bridge 1 shown on the a number of successively arranged guide stations 3 . 4 . 5 is attached. At the rear of the machine bridge is a mandrel holding station 2 for the holder of 2 mandrels 6 . 7 arranged.

The leadership stations 3 . 4 . 5 serve both to guide the mandrel bars 6 . 7 as well as to guide a profile, not shown, reshaping 21 ,

In a manner not shown is this profile 21 in a gripping head 8th clamped, with a push carriage 9 connected is.

The slide carriage 9 is about drives 10 in the longitudinal direction of the machine bridge 1 driven method so as to reshape the profile 21 in the bending head 70 insert.

From the 2 and 3 go further details.

The 3 shows that it is essential in one embodiment that the profile to be reshaped 21 a heating channel 30 assigned.

This heating channel consists of a series of heating stations arranged one behind the other 31 . 32 . 33 , of which each heating station has multiple emitters 34 . 35 having.

Further, in the heating channel 30 still leadership roles 37 arranged, which are oscillating and with the help of spring elements 38 against the profile to be reshaped 21 be employed.

The section through the half-channel 30 is in 4 shown. There, the individual, previously mentioned parts are drawn in section.

Instead of 2 thorn bars 6 . 7 - as in 1 shown here - here is only a single thorn pole 6 used.

Based on 2 and 3 Now, the new bending head according to the invention 70 explained in more detail.

It essentially consists of a central role 11 on a rotation axis 12 is rotatably mounted and, for example, in the direction of arrow 29 is driven in rotation.

The middle role 11 lies - opposite the bending profile - a rolling roller 14 opposite, so that through these two rolling rollers 11 . 14 a bending roll zone 40 for the profile to be reshaped 21 . 21 ' is defined.

So can the roller 14 be driven and in addition works the push slide 9 in the direction of the longitudinal axis of the profile 21 to this by the bending roll zone 40 through push.

In the interior of the hollow profile is in this case in the region of the bending roll zone 40 a spike shaft 25 arranged, which preferably consists of several elements.

The rear end of the mandrel shaft 25 is by a first support element 26 formed, which in the space between a support roller 17 and one to the opposing counterpart 18 is arranged.

In the area of the bending roll zone 40 forms the spine shaft 25 a second support element 27 which is a denting or a collapse of the profile in the area of the bending roll zone 40 prevented.

In the area forward is the mandrel shaft 25 with a link chain 28 connected, which consists of individual, articulated members which rest against the inner wall of the hollow profile, wherein the link chain 28 into the area of the bending roller 13 leads.

The bending roller 13 is designed to pivot and can in any way on the profile to be bent 21 ' be delivered so as to achieve a defined bend.

The bending of the profile to be reshaped is thus preferably effected by the action of the bending roller 13 on the profile to be reshaped 21 , whereby a corresponding back pressure of the spaced behind the support roller 17 is reached.

However, the forming (a hot-flow bending) takes place in the area of the bending-rolled zone 40 ,

The 5 shows that in the area of the bending roll zone 40 Still further rolling rolls can be arranged, which rest against the upper and lower side wall of the profile. The vertical rollers 15 . 16 are in 5 shown.

sense This vertical rollers is, in addition to the profile in the area to guide the side wall and to prevent a break-out in this area.

Incidentally, it is not shown in detail that also in the area of the support and the counter role 17 . 18 again in vertical plane to this vertical rollers 19 . 20 can be arranged, as in 2 is indicated.

The entire profile 21 By the way, it is on a support table 22 on to prevent the profile from sinking.

By the way, the bending head has a bottom 23 and an upper lid 24 on.

Now important is the electric current heating in the area of the bending roll zone 40 as they are based on the 2 is shown in more detail.

First, it can be seen that the upper roller 14 on a push slide 65 is rotatably mounted, which is formed in the direction of the profile to be bent and wegstellbar.

At this push carriage 25 Now, the one pole of a current flow source is applied, while the other pole of the current flow source is electrically conductive with the opposite center roller 11 is connected.

It therefore comes to the formation of the current paths 55 - 64 , which are listed in detail in the drawing with the current paths A1 to A10.

For example, the current path A1 extends from the center roller 11 over the electrically conductive jacket 41 on the surface of the profile 21 and is there in the form of the current path 62 (A8) and flows over the profile.

Of the Rung A3 turns into Rung A4. The current path A5 goes in the current path A6 over. The current path A7 merges into the current path A8. The current path A9 goes into the current path A10 over.

All Rungs are interconnected and electrically conductive with each other connected.

By initiating a relatively large current through the electrically conductive jacket 41 the rolling roller 14 on the electrically conductive profile 21 flows, and from this profile on the electrically leit capable coat 41 the central role 11 result in concentrated high-energy heating zones in the bending roll zone 40 , so that the sensitive profile is concentrated heated only in the area of this forming zone.

It is also shown that the same heating mechanisms with the current paths also in the region of vertical rollers arranged perpendicular thereto 15 . 16 can be arranged.

It is also shown that the mandrel shaft 25 is electrically conductive, wherein the support elements 26 . 27 are also electrically conductive and the current then finally on the mandrel 6 is derived to the rear.

The 2 shows, by the way, that the support role 17 and the counter-roll 18 are electrically heated in the same way, with a corresponding current flow over the thrust carriage 66 is initiated and the opposite pole, for example, electrically conductive with the mantle of the counter-roller 18 connected is.

It then results in the current paths 45 - 54 with the designations B1 to B10 in the drawing.

Again, there is a manifold branching of the current paths, this Stromflussbeheizung in the area of the support role 17 and the counter-roll 18 as preheating for the actual heating in the bending roll zone 40 is to be considered.

Again, it may be provided that perpendicular thereto vertical rolling rolls 19 . 20 are arranged, which can be heated in the same way.

The bending roller 13 Incidentally, it is also on a push carriage 67 stored, but with the bending roller 13 not heated.

As already mentioned, there is every role heated by current flow heating 11 . 14 . 17 . 18 . 15 . 16 . 19 . 20 from an electrically conductive jacket 41 , which has an electrically insulating insulating ring 43 from an optionally conductive carrier 42 isolated. is. The respective carrier 42 is then each with the wave 44 rotatably connected.

to 3 is also noted that the outlet end of the heating channel 30 with a cover plate 39 is provided to an impermissible escape of the heat developed there from the heating channel 30 to prevent.

Of the entire heater is a suitably sized transformer assigned, which provides the corresponding power services.

The essential difference of the hot-flow forming process according to the invention for cold-flow bending is that during cold-flow forming, the bending rolls require a certain penetration depth into the material of the profile to be formed, in order to achieve a microstructure flow. This microstructure flow is achieved by a rolling effect and this achieved by a certain penetration depth of the profile cross-section in the profile to be reshaped. Here is a significant difference to the novel hot flow bending according to the invention, because - as previously shown - the actual rolling rolls, namely the center roll 11 and the rolling roll 14 make no actual Auswalzung the profile more, but only assume a support function and a power line.

Due to the resistance heating in the rolling bending zone 40 a heating in the structure of the profile to be formed is generated in order to make the structure bendable. A corresponding magnesium profile would not be deformable at room temperatures. Here, the aforementioned twisted heating in the bending-rolling zone is made possible to make the structure of the magnesium alloy flowable, and a deformation in the area between the bending roller 13 and the support roller spaced therefrom 17 to enable.

On a high strength steel material, this means that this High strength steel material in the bending roll zone in the temperature range between 700 to 1000 ° C must be heated to also a microstructure flow in the bending roll zone to enable and thus for the first time to achieve the transformation of this profile.

1

machines bridge

2

Dorn holding station

3

transfer station

4

transfer station

5

transfer station

6

mandrel

7

mandrel

8th

chuck

9

Traverse frame

10

drive

11

Central role

12

axis of rotation

13

bending roller 13 ' 13 ''

14

roller

15

Vertical roller

16

Vertical roller

17

supporting role

18

counter-roller

19

Vertical roller

20

Vertical roller

21

profile 21 '

22

support table

23

ground (Bending head)

24

cover

25

spike shaft

26

support element (Rear)

27

support element (Front)

28

link chain

29

arrow

30

heating duct

31

heating station

32

heating station

33

heating station

34

spotlight (above)

35

spotlight (laterally)

36

Guide (slide carriage

9 )

37

leadership

38

spring element

39

End plate

40

Roll-bending zone

41

coat

42

carrier

43

insulation

44

wave

45

current path B1

46

current path B2

47

current path B3

48

current path B4

49

current path B5

50

current path B6

51

current path B7

52

current path B8

53

current path B9

54

current path B10

55

current path A1

56

current path A2

57

current path A3

58

current path A4

59

current path A5

60

current path A6

61

current path A7

62

current path A8

63

current path A9

64

current path A10

65

Traverse frame

66

Traverse frame

67

Traverse frame

68

69

70

bending head

Claims (19)

Method for hot-flow forming bending of thin-walled closed, semi-open or open profiles with a bending machine consisting of at least two in the direction of entry of the bending profile ( 21 . 21 ' ) Opposite arranged rollers ( 17 . 18 ) behind which in the inlet direction at an axial distance at least one roller ( 14 ) and an opposing middle roll ( 11 ), which together form a bending roll zone ( 40 ) for the profile to be reshaped ( 21 . 21 ' ) form, wherein at least one against the profile to be bent and wegstellbare bending roll on the outlet side ( 13 ), characterized in that at least in the bending roll zone ( 40 ) arranged rollers ( 11 . 14 ) are heated. Method according to claim 1, characterized in that that also other roles of the bending machine are heated. Method according to claim 1 or 2, characterized that arranged in the inlet direction in front of the bending roll zone support roller and the opposite Counter role, which is a support opposite of the profile to be bent are heated in the inlet direction forward bending roll. Method according to one of claims 1 to 3, characterized in that arranged in the bending roll zone, oppositely arranged rolling rollers are formed electrically conductive and are traversed by a high current through the reshaped profile ( 21 . 21 ' ) runs at least in the region of the bending roll zone. Method according to one of claims 1 to 4, characterized that the applied current also to the inside of the reshaping Profile on the arranged in the interior of the bending roll zone mandrel shaft is directed. Method according to one of claims 1 to 5, characterized that the rolls by a liquid Heating means are heated. Method according to one of claims 1 to 6, characterized that the rolls by electrically heated cartridges and / or Heating coils are heated. Method according to one of claims 1 to 7, characterized that the rollers by radiant heating and / or by inductive warming be heated. Method according to one of claims 1 to 8, characterized that also further, arranged perpendicular to the heated rollers and heated in the bending roll zone arranged vertical rolling are. Method according to one of claims 1 to 8, characterized in that on the inlet side of the profile, namely in the region of the machine bridge, a preheating takes place. Apparatus for hot-flow forming bending of thin-walled closed, semi-open or open profiles with a bending machine consisting of at least two in the direction of entry of the bending profile ( 21 . 21 ' ) Opposite arranged rollers ( 17 . 18 ) behind which at an axial distance in the inlet direction at least one roller ( 14 ) and an opposing middle roll ( 11 ), which together form a bending roll zone ( 40 ) for the profile to be reshaped ( 21 . 21 ' ) form, wherein at least one against the profile to be bent and wegstellbare bending roll on the outlet side ( 13 ), characterized in that at least in the bending roll zone ( 40 ) arranged rollers ( 11 . 14 ) are heated. Device according to claim 11, characterized in that that they are exercising of the method according to one or more of claims 1 to 10 is determined. Device according to one of claims 10 or 11, characterized in that the heated bending roll zone ( 40 ) at least from the rotationally driven center roller ( 11 ), the rolling roller ( 14 ) is opposite Device according to one of claims 10 or 13, characterized in that the profile to be reshaped ( 21 . 21 ' ) through the bending roll zone ( 40 ) is additionally pushed through. Device according to one of claims 10 or 14, characterized in that the mandrel shaft ( 25 ) in the area of the bending roll zone ( 40 ) is heated and a support element ( 27 ) forms for the interior of the profile. Apparatus according to claim 15, characterized in that at the front of the mandrel shaft ( 25 ) a link chain ( 28 ), which consists of individual, hingedly interconnected members which bear against the inner wall of the hollow profile, wherein the link chain ( 28 ) into the area of the bending roller ( 13 ) leads. Device according to one of claims 10 or 16, characterized in that in the region of the bending roll zone ( 40 ) Vertical Rollers ( 15 . 16 ) are arranged, which bear against the upper and lower side wall of the profile. Apparatus according to claim 17, characterized in that the vertical rolling rolls ( 15 . 16 ) are heated. Device according to one of claims 10 or 18, characterized in that a current through the electrically conductive sheath ( 41 ) of the rolling roll ( 14 ) via the electrically conductive profile ( 21 ) flows, and from there to the electrically conductive sheath ( 41 ) the middle role ( 11 ) is derived.