EP1763412B1 - Flanging devce with a tilting system - Google Patents

Abstract

The invention relates to a tilting system which comprises a tilting unit having an actuator. Said actuator has a slide which can be moved to and fro in a direction of displacement. The front of the slide is provided with a tilting molding segment for shaping the flared flange of a metal sheet.

Description

The invention relates to the handling of workpieces when performing machining operations, in particular during beading.

Beading, also called folding, falls within the scope of the non-cutting forming technique. This refers to the folding of an angled edge or a flanged flange of an outer sheet or a skin over an inner sheet or a skeleton. Sense of flanging is, if necessary, using adhesive at least two sheet metal parts or skin and skeletons firmly together. In automotive engineering, the process is mostly used on vehicle components such as hood, door, rear flap, rear compartment lid and roof.

When flanging the contour of the component is determined. One differentiates between inside and outside flanging. When external flanging the outer contour of the component such. B. hood, door, rear flap, and rear space ceiling set. In the case of inner beading, the contour of window cut-outs such as roof or door is determined.

Beading has a decisive influence on the quality of installation of the components in the body in terms of gap and drop. Beading is often done in two to three steps. This is called tilting, pre and crimping.

There are several different crimping systems. In one embodiment, the production part is moved in a special holding device, the so-called "crimping", against a stationary tool. In another embodiment, the manufacturing part is fixed in a mold and the tools move. It is also known to crimp with a movable and rotatable roller, this is called "Rollbördeln".

Crimping devices are in the broader sense driven pressing tools. The equipment is often driven hydraulically, pneumatically or electrically. Preferably, for reasons of the necessary pressing pressure of the plunger, which provides the working stroke, moved hydraulically. Beading jaws can be moved hydraulically, pneumatically or electrically via servo motors.

A crimping bed often forms the receptacle for the outer skin and skeleton. It is the exact 3D shape of the outer skin and thus a prerequisite for the required Fallungsqualität. The bed is considered a basis or zero reference and requires no post-processing or training.

The crimping jaws or rabbets result in their working position an open or fully closed ring. At the crimping jaws or creasing the actual forming takes place, since therein the flange positions are pre-worked for pre and crimping. In a two-stage crimper, the rows of jaws are arranged one above the other, in a single-stage, only one row of jaws is mounted either for pre- or finish crimping. Criterion for the one or two-stage is the cycle time of the manufacturing cell in connection with the drive of the device. Frequently, two-stage flanging devices are used.

For two-stage systems, pre- and finish flanging jaws are used one after the other. Due to the hydraulic lifting of the plunger, the flanging flange is folded over at the creasing blocks.

The two components, the skeleton and the skin, are positioned using the constrained guides and locating bolts after the basic alignment holes (ASKF). Hold-downs can secure the form-fitting contact with the skeleton on the outer skin immediately before the crimping process. With a hold-down device, the framework is pressed onto the skin before and during the crimping process and thus in the form of the crimping bed. This minimizes scaling errors and ensures the desired overlap of the flanging flange over the framework.

The EP 0 820 822 A1 and the WO 97/43165 show such machine tools that are used for folding or crimping of sheets.

In these machine tools, it is disadvantageous that they are expensive and complicated. Furthermore, beading can only be done after a precise adjustment of the different parts of the machine tool, so that optimum results are achieved.

The US Pat. No. 6,487,888 B1 shows a crimping press, which has a base and a movable nest on which a to be crimped Workpiece is received. A nest carrier carries the nest, with both nest and nest support movably mounted on the base. A laterally displaceable crimping jaw is mounted to the base and reciprocable between an extended position and a retracted position. These similar devices are in the EP 1 402 968 A1 , which forms the basis for the preamble of claim 1, and in the US Pat. No. 6,182,492 B1 shown.

The JP 59 110 427 shows a Vorbördeleinrichtung, in which a pre-crimping is initiated by vertically moving a crimping bed against a fixed metal skin.

The invention is intended to simplify the handling of workpieces when carrying out machining operations and to improve the work result.

This object is solved by the subject matter of the independent claim. Advantageous developments emerge from the dependent claims.

The invention does not provide for a complicated flanging device or modified hold-down as would be conceivable in order to achieve a better working result. Rather, a simplification of the tilting devices previously used is provided. For this purpose, at least one standard drive element and a slide, which has a Ankippformbacken directly on its front, used. Thus, the flange of a metal skin is processed. As drive elements, for example, pneumatic cylinders, hydraulic cylinders, an armature of a coil or a spindle of an electric drive can be used. These drive elements can be operated without additional gearbox or without the intervention of a large-scale toggle mechanism.

It has been found that the invention facilitates and improves tipping, in which only "critical areas" are processed on a separate tilting device (first stage). The pre-crimping and finish crimping then takes place on the actual crimping press (second and third stages) and processes the complete crimp flange of the outer contour.

"Critical areas" can be present in sections with very small radii, large opening angles (greater than approx. 116 °) and also in parts where, unlike a given crimping position, the flanging flange must be crimped. An undesirable material thrust in the crimping press is avoided with the invention.

In addition, there is the possibility that a joining of the skeleton in the skin by means of "overhead" or robot is not given for radii or flange flanges angle of less than about 116 ° and unfavorable shape curve on the outline, also depending on the position of the component in the crimp , Even in such areas, it has been proven to tilt according to the invention.

The invention avoids complicated built tilting units, which involve elaborate and rotated in three axes weldments. These designs require very complex designs and CAD studies and have not been proven.

According to the invention brackets are provided for holding the tilting unit, which are part of the crimping bed. In particular, cast-in consoles have proven themselves. Guideways for the slides can be produced in one clamping already during the shaping of the flanging bed. The invention thus makes it possible to provide tilting devices which are particularly easy to produce and which are considerably more cost-effective than those of the prior art. A cost saving of up to 40% per tilting device can be expected.

This is particularly noticeable because many tilting devices provide numerous tilting units, often between six and ten. In the case of the extensive tilting devices of the prior art, this number could often not be provided for lack of space, so that a worse result with fewer tilting devices had to be accepted.

The invention is embodied in a machine tool designed as a processing device, which has the tilting unit. With the tilting unit, a beading edge of a sheet metal skin is locally bent, for example, at a point that would tip in a non-intentional direction during subsequent beading. In addition, a tilting unit is provided at a location where particularly small bending radii are to be generated.

The invention enables a cheap and less complex overall construction. With the invention, a standardization of the Ankippeinheiten within a tilting system is possible. These systems are no longer component-dependent and model-to-model.

With the tilting system, the skin is tilted in a simple manner in the region of the crimping flange and thus a desired overlap of the crimping flange, e.g. ensured over the skeleton.

The tilting systems are attached to mechanically less complicated constructions. The mechanical design specifications allow a low construction height and width. The assembly is very easy due to the small size of the system. Ankippantriebe that are mounted on a far over the crimping cantilever frame, no longer need to be provided.

With the tilting system, the skin is tilted in a simple manner in the region of the flanging flange and thus ensures a desired overlap of the flanging flange, for example via the framework.

Hereinafter, a conceivable crimping process with a machine tool according to the invention will be described.

All tilting units of the tilting device are in the home position, i. in the rear end position.

The two components, skeleton and skin, are inserted and positioned using the constrained guides, locating and locking pins after the basic alignment bores (ASKF). The framework is pressed by means of tensioners into the skin and thus also into the bed of the tilting device. In the critical areas hold-downs pivot precisely into the root of the flanged edge of the outer skin and hold it firmly in the sense of a chamfering jaw. By the pneumatic cylinder, the slide is then driven with the attached mold jaws against the flare flange to the end position. The necessary dimensional adjustment takes place via a threaded spindle on the piston rod. The pneumatic cylinder, the hold-downs and centerings return to the basic position. Thus, the tilting is completed and the part is taken out of the device and placed in the crimping press for further processing.

Figur 1

zeigt einen Teilbereich einer erfindungs-gemäßen Werkzeugmaschine in der Seitenansicht,

Figur 2

zeigt einen Teilbereich eines zu bördelnden Stahlblechs und

Figur 3

zeigt einen weiteren Teilbereich der erfindungsgemäßen Werkzeugmaschine aus Figur 1.

The invention is illustrated in the drawing using an exemplary embodiment.

FIG. 1

shows a partial region of a machine tool according to the invention in a side view,

FIG. 2

shows a portion of a steel sheet to be flanged and

FIG. 3

shows a further portion of the machine tool according to the invention FIG. 1 ,

FIG. 1 shows a Verkzeugmaschine invention with a tilting device 1 in a view from the side. The tilting device 1 is divided into a hemming bed 2 with a cast-on bracket 17 for a slide 7, in a welded construction 3 for receiving a pneumatic cylinder 5, in a fitting 9, in a guide 4 and in a piston rod with an adjusting unit 6.

On the hemming bed 2 a sheet steel skin 14 is placed. The welded construction 3 constitutes a support for the pneumatic cylinder 5 and is fastened to the console 17 designed as a sprue.

A machined top 13 of the bracket 17 serves as a support for the guide 4 of the slider 7, which is connected to the piston rod 6 of the pneumatic cylinder 5. At the front of the slider 7, a mold jaws 9 is provided.

FIG. 2 and FIG. 3 illustrate the forming of a flange 10 of the steel sheet skin 14th

How to get in FIG. 2 sees, the flare flange 10 of the steel sheet skin 14 is bent to an angle of more than 116 ° before the actuation of the tilting unit 1. After tilting the flare flange 10 is bent further, to an acute angle of about 70 °. This condition is shown by a dashed line.

FIG. 3 illustrates the effect of the mold jaw 9 at a displacement along the displacement direction 8. How to FIG. 3 Especially good is the front of the mold baking 9 edited so that the desired angular position of the crimping flange 10 is achieved after a stroke of the mold jaw 9. It wears the in FIG. 1 not shown down device 11 to an optimum Bördelergebnis.

With the invention omitted sliding force amplifier knee lever on any actuators, whereby the tilting unit 1 according to the invention can be performed in a particularly small space and with direct force.

The machine tool according to the invention can be produced particularly easily.

On cast steel crimping bed 2, mounting surfaces for guiding the slides 9 are cast in the region of the tilting devices or tilting units to be provided corresponding to the number of "critical areas" of the sheet steel skin 14. The number of tilting units is to be determined depending on the component. These mounting surfaces are incorporated directly in the shaping of the crimping bed 2, which brings in relation to the previous production only a small additional effort with it. Guide rails with emergency running properties are mounted on these mounting surfaces. Also mounting surfaces for the welded construction for receiving the pneumatic cylinder are the same processed on the sprue or on the console 17. The slide 9 and the hold-down 11 are manufactured according to CAD / CAM data.

With the in FIG. 1 shown pneumatic cylinder 5 can be easily tilt forces of more than 4500 N generate. The necessary thrust force is determined depending on the component. The smallest possible angle of the flange 10 is sought. In the crimping device according to the invention is a ensures exact pitching or tilting, resulting in a precise flanging edge course. For this purpose, a shaped piece in the form of a hold-down 11 is pressed into the so-called "root" 12.

In the root 12, this hold-down 11 prevents the tilting unintentional rolling or pulling the steel sheet skin, whereby the emergence of bulges is counteracted. The hold-down 11 can be operated with a pivoting cylinder, not shown here, with a hydraulic cylinder, with a pneumatic cylinder, electrically or any kind of mechanical actuation. The corresponding contact pressure is determined according to the respective requirements. The installation of the hold-down can be both inside and outside of the crimping 2. In addition, it is conceivable to incorporate the fulcrum or the attachment point of the hold 11 immediately into the casting mold of the crimping bed 2. Finally, a welded construction as a supporting component of the hold-down drive is conceivable.

LIST OF REFERENCE NUMBERS

1

tilting unit

2

flanging

3

Welded construction, holder pneumatic cylinder

4

Guide the slider

5

pneumatic cylinder

6

Piston rod of the pneumatic cylinder with adjustment unit

7

pusher

8th

displacement direction

9

forming jaws

10

bead flange

11

Stripper plate

12

Root area of the flare flange

13

Guide surface of the slider on the cast console

14

sheet metal part

17

console

Claims (13)

1. Machine tool comprising a flanging bed (2), which is intended to receive a sheet metal skin (14), and at least one tilting unit (1),
   wherein the tilting unit (1) has the following features:

   - an actuator (5) having a slide (7) that is reciprocable in a direction of displacement (8),

   - fitted on the front of the slide (7) is a tilting forming die (9) for forming a border flange (10) of the sheet metal skin (14),

   - the front of the tilting forming die (9) is designed such that the border flange (10) is bendable by means of a displacement of the tilting forming die (9),

   characterized in that the tilting unit (1) is supported on brackets (17) that are integrally cast directly onto the bordering bed (2).
2. Machine tool according to claim 1,
   characterized in that
   the actuator (5) comprises a pneumatic cylinder.
3. Machine tool according to claim 1,
   characterized in that
   the actuator (5) comprises a hydraulic cylinder.
4. Machine tool according to claim 1,
   characterized in that
   the actuator (5) comprises an armature of a coil.
5. Machine tool according to claim 1,
   characterized in that
   the actuator (5) comprises a spindle of an electric drive.
6. Machine tool according to one of claims 1 to 5,
   characterized in that
   an additional gear drive, a power transmission device or a power assistance device is provided.
7. Machine tool according to one of claims 1 to 6,
   characterized in that
   for the actuator (5) a holder in the form of a welded structure (3) is provided.
8. Machine tool according to claim 7,
   characterized in that
   for the actuator (5) the welded structure (3) comprises a casting.
9. Machine tool according to one of the preceding claims,
   wherein in the region of the tilting unit (1) a holding-down device (11) for the sheet metal skin (14) is provided.
10. Machine tool according to one of the preceding claims,
    characterized in that
    mounting surfaces for guide strips for the slide (9) are integrally cast in the bordering bed (2).
11. Machine tool according to one of the preceding claims,
    characterized in that
    at least one holding-down device (11) for the sheet metal skin (14) is provided in the bordering bed (2).
12. Machine tool according to one of the preceding claims,
    characterized in that
    a holding-down device (11) for the sheet metal skin (14) is provided externally on the bordering bed (2).
13. Machine tool according to claim 11 or claim 12,
    characterized in that
    the fastening point of the holding-down device (11) is integrally cast on the bordering bed (2).

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