EP2036626B1 - Perforation device - Google Patents

Abstract

The method involves subjecting the flow medium to a test pressure alternative to the working pressure. The test pressure is set to a value, in which the punching stamp of the punching device lies on the plate (2) while avoiding a significant intrusion on the surface. A sensor detects the resulting position of the piston and by which the signal so obtained is used to detect whether the perforation device is missing a stamp. An independent claim is included for a perforation device for perforation of the reinforcement element of an interior lining element of a motor vehicle, with a punching device.

Description

The invention relates to a perforation device, comprising at least one punching device for an optionally deformed plate, a tool lower part with a workpiece holder having at least one opening, a tool upper part, which is lockable above the plate and carries at least one punch, which on the piston rod of an in a cylinder is arranged by introducing a reciprocable piston-type fluid, wherein a signal-emitting sensor is provided for detecting defective punching operations, and wherein the fluid is exposed to a working pressure sufficient to produce a punch hole in the plate.

Technical area

Such a perforating device is e.g. needed for the production of openings in the support elements of the interior trim elements of motor vehicles, in order to relate these with a directly fitting decoration fabric. Usually such decorative fabrics, which can also serve to improve the feel, bonded to the support elements, which can lead to blistering especially in the area of undercuts. There is therefore a desire to create perforations in the support elements, by the trapped air quantities at. Need to escape.

State of the art

It is already known to produce such openings by means of drills. This is associated with a considerable amount of work.

A perforation device of the type mentioned is from the DE 39 03 555 A1 known. It makes it possible to create punched holes in poorly visible places of body panels and at the same time to check whether the respective desired punched hole actually originated or not. For this purpose, a sensor is arranged in the tip of the punch, which is suitable to detect light reflections of the sheet or a pressure drop in a fluid emerging from the punch. However, the sensors used in each case are so large as to be able to use such a device in the present field, because the perforations produced by the punch on the top of the decorative fabric after its bonding with the reinforcing element recognizable. They are therefore not useful in the present field of application.

Presentation of the invention

The object of the invention is to further develop such a perforation device in such a way that it is reliably indicated whether a perforation has occurred or not and that the holes can be made so small that they form a reinforcing element after the decorative fabric has been bonded do not map on its top.

This object is achieved according to a method according to claim 1 and an apparatus according to claim 2.

The separation of the sensor from the punch makes it possible to make it almost arbitrarily small and to use commercially available needle-thin designs. The invention is based on the recognition that it is completely sufficient for the purpose sought to indicate whether all punches are still available or not, because as long as the punches are available, arises at the working pressure, which is at least four times the test pressure , Advantageously, at least five times, in the existing of an organic material plate of 1 to 4 mm thickness inevitably a hole of sufficient flow permeability for any trapped gas or a vacuum, which ensures that the later glued decoration fabric is free from bubbles with the plate. If, on the other hand, at least one puncturing punch is broken off, which can happen, then the breaking off of this puncturing punch is reliably indicated before the production of further carrier elements which would be defective. The broken punch can thus be replaced in good time and the perforating be used again without errors. If the sensor cooperates with a shutdown automatic, it is even ensured that the replacement of the broken punch is performed reliably and that no defective parts can be delivered at all.

The plate is used in the further description with regard to the relevant field of application of the invention as well as a synonym for the reinforcing element. For the return of the punch into its initial position, the fluid can be fed into the space bounding the back of the piston chamber of the working cylinder, the return pressure can correspond to the working pressure.

The punches can be kept as small as absolutely necessary for the punching process for mechanical reasons. Diameters of 0.5 to 2.00 mm can easily be achieved by perforating conventional reinforcing elements made from polypropylene, ABS, hardboard or composite materials.

It has proven to be advantageous if the test pressure is adjustable to a value of 0.5 to 1.2 bar. With such a low value, unwanted penetration into the surface of the reinforcing element is not to be feared and at the same time it is ensured that all punches bear with their front side so firmly against the surface that it can be recognized by the sensor whether a punch is missing. In such a case, the piston and the piston rod in the cylinder displaces by a value of at least 8 mm, which can be reliably detected and displayed.

The sensor is particularly well protected against conceivable external influences within the cylinder. Its preferred mounting position is therefore within the cylinder.

According to claim 1, the sensor is arranged in the cylinder opposite the piston at the upper end of the cylinder. At this point, a relative displacement of the piston when feeding the test pressure, which signals a missing or canceled punch, particularly well visible. If a sharp needle is used in place of the punch, the same effect is produced.

The sensor is arranged according to claim 1, the upper end face of the piston opposite in the cylinder. He is there particularly easily interchangeable in case of disturbances.

In principle, all distance sensors that are available on the market can be considered as sensors. Induction sensors have proven particularly suitable because of their reliability and their easy controllability.

In general, the perforation device comprises a plurality of punching devices, which are distributed over the top of the reinforcing element, that a direct, bubble-free concern of the decorative fabric in the subsequent sticking is securely excluded. The individual punching device has such a small cross-section that the mutual distances can be made small. Even critical undercuts can be safely concealed. Any resulting burrs point to the bottom and do not appear there disturbing.

The punching devices are associated with the surface of the reinforcing element to be perforated in the portion to be perforated substantially perpendicular. As a result, a secure perforation is achieved while avoiding unnecessary risks related to the bending or the canceling of punches.

The piston / cylinder units contained in the punching devices may be time displaced with the fluid during operation in order to reduce the forces that are effective in the tool at the same time. The size of the tumblers can be reduced. The control of the individual piston / cylinder units can be done in a very fast rhythm and possibly overlapping, to continue to obtain short cycle times with low reaction forces.

The perforation device is particularly suitable for perforating a three-dimensionally deformed reinforcing element of an interior trim element of a motor vehicle.

Brief description of the drawing

An exemplary embodiment of the invention is illustrated in the accompanying drawings. It will be explained in more detail below.

• Fig. 1 eine beispielhafte Perforationsvorrichtung in perspektivischer Ansicht von oben.
• Fig. 2 eine Stanzvorrichtung der in Fig. 1 gezeigten Perforationsvorrichtung in längsgeschnittener Darstellung während der bestimmungsgemäßen Verwendung.

Show it:

• Fig. 1 an exemplary perforation in a perspective view from above.
• Fig. 2 a punching device of in Fig. 1 shown perforation device in longitudinal section during the intended use.

Embodiment of the invention

In the Fig. 1 Perforating device shown comprises at least one punching device 1 for an optionally deformed plate 2, which is here a reinforcing element for the sidewall lining of the interior of a motor vehicle, a tool base with a workpiece holder 3, which has an opening 4, a tool upper part 5, the can be locked above the plate 2 and which carries a punch 6, which is arranged on the piston rod 7 in a cylinder 8 by introducing a druckbeauschlagbaren fluid back and forth piston 9, wherein a signal-emitting sensor 10 is provided for detecting faulty punching operations and wherein the Fluid is acted upon by a working pressure, which is sufficient to produce a punched hole in the plate 2. It is provided that the fluid can be acted upon as an alternative to the working pressure with a test pressure, wherein the test pressure is adjustable to a value at which the punch 6 of the punching device 1, while avoiding a significant penetration of the surface 11 of the reinforcing element 2, wherein the sensor 10 is adapted to detect the resulting position of the piston 9 and wherein the signal obtained thereby is used to evaluate the punching operation. De Sensor finally determines whether the punch 6 is still available or not: If it is canceled, then the piston moves away when applying the test pressure as far as the sensor 10, that this is reliably detected and displayed as an error. The missing punch 6 can therefore be replaced in good time before the further production of defective parts. In conjunction with automatic shutdown, the invention enables even jam free production.

In Fig. 1 a plurality of punching devices is distributed over the surface of the reinforcing member to be perforated so that blistering when laminating a decorative fabric on the top is safely avoided. The individual punching devices are therefore preferably arranged in the region of undercuts. A vacuum may be applied to the holes produced by the punching devices during lamination in order to bring the decoration material into direct contact contact with the reinforcing element during lamination.

The test pressure is adjustable to a value of 0.5 to 1.2 bar, suitably to a value of 1 bar, while the working pressure is usually 6 bar. Such pressures are widely available in compressed air networks.

In Fig. 1 It can also be seen that the punching devices 1 are assigned to the surface of the plate 2 to be perforated substantially perpendicularly in the portion to be perforated. Damage to the punch 6 is thereby prevented and ensures a secure punching.

The piston / cylinder units 8.1 contained in the punching devices 1 can be displaced in time with the fluid in order to reduce the forces acting on the tool during the stamping process.

In Fig. 1 It is shown that the sensor 10 is arranged in the cylinder 8, opposite to the piston 9 at the upper end of the cylinder 8 and the upper end face of the piston 8 opposite. In addition to a particularly reliable function, this ensures easy replacement. The sensor 10 is designed as an induction sensor.

The piston / cylinder unit is bolted to the upper tool 5 and thus easily replaceable. It contains at the front end of the piston rod 7 a thread onto which a union nut can be screwed with a bore through which the punch 6 can be passed. By tightening the nut a firm contact pressure of the provided at the rear end with a thickening punch results in the front end of the cylinder rod 7 and doing a defined assignment to this. In the assembled state, the punch 6 is guided in the projecting area by a screwed onto the cylinder 8 guide sleeve, which surrounds him with little play and ensures that the punch 6 can not be canceled in the shown, retracted state.

The piston / cylinder unit is pressurized with compressed air, both for the forward and the backward movement and for the feeding of the test pressure.

It can exceed the diameter of the punches by 50 to 200% in order to avoid mutual contact, if there is a lateral deflection during the inclined penetration of the punches in the reinforcing element, which can lead to the cancellation of the punches 5. On the other hand, a too large formation of the openings is not useful, because this can lead to the springs of the punch in the vicinity of the opening surrounding parts of the reinforcing element and as a result of a qualitatively unsatisfactory punching process. In the direction of the lower end, the diameter of the openings 4 may be stepped or conically widened in order to avoid clogging by the punching waste and to obtain the openings self-cleaning.

Claims (8)

1. Method for recognising whether a die is missing in a perforation device, in which the perforation device comprises at least one punching device (1) for an optionally shaped plate (2), as well as a lower tool part with a seat (3), which has at least one opening (4), an upper tool part (5), which can be locked above the plate (2) and which carries at least one punching die (6), which is arranged on the piston rod (7) of a piston (9), which can be moved back and forth in a cylinder (8) by the introduction of a pressurisable fluid medium, a signal-emitting sensor (10) being provided to detect faulty punching processes and the fluid medium being capable of subjection to a working pressure which is sufficient to produce a punched hole in the plate (2), characterise in that the flow means is subjected to a test pressure as an alternative to the working pressure, the test pressure being set at a value, al which the punching die (6) of the punching device (1) rests on the surface (11) of th plate (2) avoiding significant penetration, the sensor (10) detecting the position of the piston (9) resulting thus and in which the signal thus obtained is used to recognise whether a die is missing in the perforation device.
2. Perforation device comprising at least one punching device (1) for an optionally shaped plate (2), as well as a lower tool part with a seat (3), which has at least one opening (4), an upper tool part (5), which is locked above the plate (2) and which carries at least one punching die (6), which is arranged on the piston rod (7) of a piston (9), which is moved back and forth in a cylinder (8) by the introduction of a pressurised fluid medium, a signal-emitting sensor (10) being subjected to a working pressure which is sufficient to produce a punched hole in the plate (2) and the fluid medium being capable of subjection to a test pressure as an alternative to the working pressure, characterised in that, when the device is used, the test pressure is set at a value at which the punching die (6) of the punching device (1) rests on the surface (11) of the plate (2) avoiding significant penetration, in that the sensor (10) detects the position of the piston (9) resulting thus, in that the signal obtained in the process is used to evaluate the punching process, in that the sensor (10) is arranged opposing the upper end face of the piston (8) at the upper end in the cylinder (8).
3. Perforation device according to claim 2, characterised in that the test pressure is set at a value of 0.5 to 1.2 bar.
4. Perforation device according to either of claims 2 or 3, characterised in that the sensor (10) is an induction sensor.
5. Perforation device according to any one of claims 2 to 4, characterised in that it comprises a plurality of punching devices (1).
6. Perforation device according to claim 5, characterised in that the punching devices (1) are associated substantially perpendicularly with the surface of the plate (2) to be perforated in the part region to be perforated.
7. Perforation device according to claim 5 or 6, characterised in that the piston/cylinder unit (8.1) contained in the punching devices (1) can be subjected to pressure with the fluid medium with a time lag.
8. Use of the perforation device according to any one of claims 2 tc 7 for perforating the reinforcement element (2) of an interior trim element of a motor vehicle.

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