WO2006018415A2

WO2006018415A2 - Sonotrode conveying unit for treating ultrasonic workpieces and method for operating a sonotrode conveying unit

Info

Publication number: WO2006018415A2
Application number: PCT/EP2005/053932
Authority: WO
Inventors: Peter Solenthaler; Georg Lang
Original assignee: Telsonic Holding Ag
Priority date: 2004-08-14
Filing date: 2005-08-10
Publication date: 2006-02-23
Also published as: WO2006018415A3; EP1776204A2

Abstract

The invention relates to a sonotrode conveying unit for treating ultrasonic workpieces, comprising a base (2), a drive (3) which is arranged in the base (2), and a converter (7) which is provided with sonotrodes (8) which are displacably coupled to the drive (3). A high-frequency generator (9) is arranged in a static manner on the base (2) in the vicinity of the drive (3) or is coupled in a mobile manner to the converter (7) and/or sonotrode (8).

Description

Sonotrode feed unit for ultrasonic workpiece machining and method for operating a sonotrode feed unit

The invention relates to a sonotrode feed unit for ultrasonic workpiece machining and in particular for ultrahigh-speed welding or riveting and to a method for operating a sonotrode feed unit.

Such sonotrode feed units are available in various designs on the market and also in printed form, for example by the company brochure "Pneumatic Ultrasonic Feed Units in Compact Design USV Series" from TELSONIC Ultrasonics These feed units comprise a suitable attachment for attachment to a machine tool - fitted base on which a feed drive - usually a pneumatic piston-cylinder drive - is seated.The ultrasonic application takes place via a so-called sonotrode, via which ultrasonic vibrations are introduced into the workpiece to be machined Ultrasound is generated by a, with the sonotrode coupled converter, which is driven with a high-frequency voltage.

As a rule, the generator for generating the high-frequency voltage is spatially separated from the sonotrode feed unit in the processing machine, the high-frequency voltage being conducted to the converter via corresponding HF cables. Here are a variety of cable plugs and sockets are used, which are basically sources of interference. Since converter and So¬ notrode move relative to the base and the processing plant by the feed relatively, the high-frequency cable must also have a corresponding excess length. Particularly in applications in which a large number of sootrode feed units are used for processing spatially limited plastic parts, the individual converters are supplied by one or a few high-frequency generators, the converters being driven partly simultaneously, partly serially by means of a corresponding HF switchover become. Such generators have a high space and cooling requirements, which in particular leads to space problems in cramped conditions.

From DE 198 105 09 a device for welding with ultrasound is known, in which a joining device has an ultrasonic transducer and a sonotrode connected thereto. A force coupler connects a carrier and a frame which carries the sonotrode and the amplitude amplifier as well as an ultrasonic transducer. DE 100 09 174 likewise shows an ultrasonic machining device and an ultrasonic machining method.

In principle, in the case of the above-described construction of such sonotrode advancing units, the problem of high-frequency shielding and detuning of the resonant circuits due to the cable capacitance increases with increasing cable length between HF generator and converter. Furthermore, the control of a plurality of converters with an RF switching unit is technically complicated. If multiple sonotrodes are used, they must be properly matched in frequency for a particular sequence of workpiece operations.

Based on this, the object of the invention is to provide a sonotrode feed unit for ultrasonic workpiece machining, for example, the less high frequency Shielding and voting problems with simple gerätetechni¬ shear concept has.

This object is achieved by the features specified in the characterizing part of claim 1 in the context of two alternative positioning concepts of the high-frequency generator. Accordingly, it may be arranged statically on the base adjacent to the drive. The HF generator is thus directly integrated into the sonotrode feed unit and is spatially significantly closer to the converter than in the prior art. To drive and supply the converter with Hochfre¬ frequency voltage so a short RF cable is enough, which is easier shielded and shows lower voting problems. For the supply of the HF generator, a simple AC mains connection or DC connection is naturally unproblematic.

The second alternative provides that the HF generator is mobile coupled to the converter and the sonotrode, so with the feed movement of converter and sonotrode is delivered to the workpiece. This achieves an optimally close spatial relationship between the converter and the high-frequency generator, which in a preferred embodiment results in the high-frequency line connection between the HF generator and the converter being substantially rigid and covered to the outside - ie cable and plug-less - is. In this case, integration of converter and HF generator into a common housing is particularly advantageous. This also enables a water and steam-proof design, e.g. in aseptic packaging machines.

A further preferred embodiment of the mobile HF generator variant is used in sonotrode feed units which are intended for longer feed lengths. For such feed units, it is known that there is a base at the base Provided longitudinal guide on which a carriage is slidably ge leads. This carriage carries the converter with sonotrode and is moved back and forth between the piston-cylinder drive between an active and a passive position, so that these components are kept clean even over longer feed lengths. The Schlit¬ th now offers the possibility to arrange the high-frequency generator dar¬, so that this enlarged unit of RF generator, converter and sonotrode stored clean and can be performed for their delivery movement for workpiece machining.

Preferably, a high-frequency line connection for supplying the converter with energy between the generator and the converter is substantially rigid and covered to the outside. The mobile coupling of the generator together with the converter and / or the sonotrode enables the use of cable connections which are not moved even in the feed phase. This prevents line breaks, disconnected switches, etc. Particularly preferably, the high-frequency generator and the converter in a common housing is arranged ange¬ integrated. On the one hand, this allows a particularly compact design. On the other hand, in addition, the cable between the converter and the generator is protected from damage to the outside.

Preferably, the housing consists of an electrical and / or of a thermally conductive material. If the housing is designed as a closed housing made of electrically conductive material, it acts as a Faraday cage and at the same time shields the high-frequency part of the feed unit. If the housing is formed of thermally conductive material, it can simultane- ously be used as a cooling element. It is also conceivable to provide the outside of the housing with cooling fins. In this context, the generator is preferably attached to the inside of an outer wall of the housing. The outer wall of the housing, to which the generator is mounted on the inside, is preferably formed supporting. This results in particular in a simple and less expensive construction. The generator housing is also the feed unit.

Particularly preferred materials in this context are metals, in particular aluminum. Among thermally conductive Materi¬ a material is typically al understood that includes mediates a specific thermal conductivity at 2O ⁰ C of more than auf¬ 10WM ^-1 K ^'1.

Due to the immobile arrangement of the generator and converter in particular connection points to converter and the generator for a feed line during the feed are rigidly arranged to each other an¬.

The generator is preferably a high-frequency generator operated with low-voltage. For ultrasonic applications, high-frequency generators are typically generators which generate a signal having a frequency of 10'000 to 50'000 Hz.

Under low voltage is typically understood a voltage of about 50VAC or 120VDC or less (definition SEV). The use of low voltage makes it possible to build a particularly compact generator that can also be easily integrated into a compact housing.

According to a further preferred embodiment, the housing is also provided with a supply line for cooling air. The cooling air is used for cooling the generator and / or the converter. Particularly advantageously, the supply line can be arranged through an opening in a piston rod of the drive for the feed unit. Since the piston rod anyway must be connected to the carriage, this allows a particularly compact introduction of the cooling air in the carriage.

It is also preferred that the feed line for the cooling air is connected to the pneumatic system of the drive, for example, directly connected to the pneumatic cylinder or connectable.

In addition, the generator and the converter are preferably arranged as close to each other as possible electrically. In particular, the secondary side of the transformer of the generator is arranged spatially closer to the converter than the primary side. In this way, particularly short high-frequency connections between generator and converter can be realized. Voting problems are lower. In addition, shorter cables can be used, which saves on production costs. In particular, the distance between secondary connections of the transformer of the generator and connections of the converter is less than 20 cm. In this way converter and generator can be particularly easily integrated in a compact housing.

The generator can furthermore be connected or connectable to a feed line and to a control line, which are arranged in a common cable. In this way, leads from the converter and the generator housing containing only an electrical line to the outside.

Preferably, the feed unit is also provided with Endlagenschal¬ tern, which serves to define the end positions of the carriage. Length measuring sensors or pressure measuring sensors are also conceivable. The Entschalterschalter and possibly electronic components for the limit switch are arranged in the housing of the generator. Such an arrangement allows a particularly compact and simple design. There is also the Possibility to use electronic components for the generator also for the limit switch. Typically, electronic components for the limit switch can be arranged on the housing for the generator, which further reduces the size of the arrangement.

The housing may also be provided with a display and / or with a control panel. This is particularly easy due to the arrangement of the generator in the housing. An operating unit on the housing is particularly intuitive for the user. In the case of large plants, fault finding is possible at a glance directly at the unit of welding.

Typically, LEDs may be provided as display indicating basic functions. More difficult to measure parameters such. Power measurements can also be measured externally. Due to the low voltage used, it is possible in a simple manner to use a measuring adapter which can be switched into the feed line and which is used, for example, in the supply line. measures the power consumption.

As a generator, of course, both a digital and an analog generator can be used.

According to a further preferred embodiment, the line connections between the converter and the generator are connected directly to connection points on the converter or to the generator, so that no sockets or plugs are required. Such a construction is readily possible in view of the rigid arrangement between converter and generator. By dispensing with plugs and sockets, the manufacture of the feed unit according to the invention can be simplified and the susceptibility to errors can be reduced. Another aspect of the invention relates to a method for operating a sonotrode feed unit. Typically, it is a sonotrode advancing unit as described above. According to the invention, during the feed phase, a high-frequency generator for operating a converter is moved together with this converter.

The converter housing may be configured to be rotatable and, at the same time, a rigid support for a potential booster to prevent bending vibrations in the system.

Further features, details and advantages of the invention will become apparent from the following description in which Ausführungs¬ examples are explained in more detail with reference to the accompanying drawings. Show it:

1 to 3 schematic side views of a sonotrodes¬ feed unit in three different Ausführungs¬ forms,

FIG. 4 a perspective view of a further embodiment of a sonotrode feed unit according to the invention,

Figure 4b perspective view of an adapter plug and

Figure 5 is an exploded view of the feed unit of Figure 4a.

The basic components of the sonotrode feed unit 1 shown there are to be explained with reference to FIG. Thus, at a base 2 via which the connection of the sonotrode Feed unit 1 to a corresponding processing plant er¬ follows, for example, a pneumatically actuated piston-cylinder drive 3 is arranged. Furthermore, extends from the base 2 of a rail-like longitudinal guide 4, on which a carriage 5 is slidably guided in Vor¬ thrust V. The carriage 5 is fixed to the piston rod 6 of the piston-cylinder drive 3. At the opposite end of the carriage 5 sits a converter 7, which converts a high-frequency voltage via appropriate piezoelectric elements into ultrasound. This is introduced into the sonotrode 8 mounted on the converter, so that when a workpiece is subjected to the sonotrode 8, a corresponding welding, riveting or the like can be carried out.

The high-frequency voltage for the converter 7 is generated by a high-frequency (HF) generator 9, which is flange-mounted in the immediate vicinity of the piston-cylinder drive 3 on the side of the base 2 facing away from the longitudinal guide 4. To transmit the high-frequency voltage from the RF generator to Kon¬ verter 7 is the shielded RF cable 10, which are provided due to the spatial proximity of the RF generator 9 to the converter 7 particularly short and with little length to compensate for Sonotroden- delivery movement can. The power supply of the HF generator 9 is gesi¬ chert via a standard power cord 11. Even a low-voltage supply is possible.

The HF generator can be operated in a so-called time mode, ie it is only switched on after delivery of the sonotrode 9 and switched off after a certain activation time. Alternative operating modes instead of a time mode for switching off are conceivable, such as switching off depending on energy, power, power and / or path. The variant of the sonotrode unit 1 'shown in FIG. 2 differs from that in FIG. 1 only in the arrangement of the HF generator 9. It sits on the carriage 5, ie it is mobile, but relative to the converter 7 in peace. In that regard, the high-frequency line connection 12 indicated by dashed lines in FIG. 2 can be placed between the HF generator 9 and converter 7 within the housing cover 13 of these two components without the use of a cable which is loose in any way and without a plug connection.

All other components of the sonotrode feed unit 1 'according to FIG. 2 are identical to the corresponding components of the embodiment according to FIG. 1 and are provided with identical reference numerals. In this respect, a further description of these parts is unnecessary.

The converter 7 is provided with connection points 15. The generator 9 is provided with connection points 16. Verbindungsleitun¬ conditions 12 between the connection points 15, 16 may be due to the arrangement of converter 7 and generator 9 in a common housing very short, typically less than 20cm long ausge¬ forms. A short length of the line connection 12 is also obtained if a secondary-side connection 17 of the transformer (not specifically shown) of the generator 9 is closer to the connection points 15 of the converter 7 than the connection of the primary side 18 of the transformer.

In the embodiment according to FIG. 3, conceptually, as in the variant according to FIG. 2, a mobile arrangement of the HF generator 9 coupled to the converter 7 is provided on the piston rod 6 of the piston-cylinder drive 3. In this case, however, converter 7 and HF generator 9 are integrated in a common housing 14 which is mounted on a longitudinal guide 4, for example ner not shown ball bushing in the feed direction V can be additionally performed. With an appropriate design of the piston-cylinder drive 3 with its piston rod 6, this additional longitudinal guide can also be omitted.

Obviously, the integration of HF generator 9 and converter 7 creates an extremely compact sonotrode unit 1 ", in which the usual high-frequency problems can be optimally reduced due to a conceivably close association of the two aforementioned components.

Incidentally, in turn, components of the embodiment according to FIG. 3, which correspond to those of FIGS. 1 and 2, are provided with identical reference numerals and require no further discussion.

In all the embodiments shown, the HF generator 9 (possibly with converter 7) consist of a correspondingly populated board (see also FIG. 5), which is inserted into a housing, preferably made of aluminum with integral cooling fins.

Figure 4a shows a perspective view of a sonotrode feed unit 1 ''', which is constructed substantially the same as the feed unit according to Figure 2. A base 2 carries a longitudinal guide 4, on which with a carriage 5 arranged in a housing 14 unit Generator 9, converter 7 and sonotrode 8 is slidably disposed. The generator 9 is connected via a feed and control cable 11 and a plug 22 with a control and power supply unit. The power supply typically supplies a low voltage of 48V. The use of low voltage allows the use of small, electrical and electronic components in the generic Tor 9 and therefore a compact design. As a result, the construction of the generator on the feed unit 1 '"is made possible.

The feed unit 1 '' 'is provided with a first pneumatic port 19 and a second pneumatic port 21 for operating a pneumatic cylinder 3. In addition, a connection 20 is provided for cooling air. The cooling air can be diverted via a branch from the compressed air system for the pneumatic drive 3 wer¬. The feed unit 1 '"is also provided with an ultrasonic test switch 24. By actuating the switch 24, the generator can be put into operation for a short time directly by the feed unit for test purposes.

The feed unit 1 '"is also provided with a displaceable limit switch 25, which defines the lower end position. Similarly, an upper limit switch (not shown) can be provided. In addition, the feed unit 1 '"is provided with a stroke limitation 26.

In Figure 4b, an adapter plug 23 is shown schematically. The adapter plug 23 is inserted between the control and power supply unit, not shown, and the plug 22. The adapter plug 23 permits the measurement of parameters, for example the power consumption of the generator 9, which can not be measured / displayed by the generator 9 itself. For reasons of cost and space it is attempted to make the generator 9 as simple as possible. Measurement arrangements for parameters which are not determined by default can thereby be outsourced in a simple manner to such a measuring adapter 23, which can be used variably for a plurality of feed units according to the invention. The adapter plug can be provided with display elements. He may also have a memory with which measurement data can be transmitted in a computer. The adapter can also be connected directly to a computer via suitable interfaces.

FIG. 5 shows an exploded view of the feed unit 1 '' 'according to FIG. 4a. FIG. 5 shows a circuit board 27 of the generator 9. In addition, the housing 14 made of aluminum is shown, which at the same time serves for receiving and holding the generator, for its protection and shielding, and in particular also for cooling.

As an alternative to the cooling flow connections 20 shown in FIGS. 4a and 5, it is also conceivable to guide cooling air from the pneumatic system through the piston rod 6 into the housing 14 (not shown).

Of course, other drives may be used instead of pneumatic drives, e.g. motor drives.

Claims

claims

1. sonotrode feed unit (1, 1 ', 1 ", 1'" for the ultrasound workpiece processing, in particular for the ultrasonic welding, comprising

a base (2),

a drive arranged on the base (2), preferably pneumatic piston-cylinder drive (3), a converter (7) with sonotrode (8) connected to the drive

(3) are motion coupled, characterized by

- A high-frequency generator (9), the

= static at the base (2) in the vicinity of the drive (3) or

= Mobile with converter (7) and / or sonotrode (8) coupled.

2. sonotrode feed unit according to claim 1, wherein a Längs¬ guide (4) on the base (2), and on the longitudinal guide (4) slidably guided slide (5) are provided by the drive (3) between an active and passive position is adjustable, characterized in that the Hochfre¬ frequency generator (9) on the carriage (5) is arranged.

3. sonotrode feed unit according to claim 1 or 2, characterized in that the high-frequency line connection (12) between the high-frequency generator (9) and converter (7) is substantially rigidly and externally covered.

4. sonotrode feed unit according to one of claims 1 to 3, characterized in that the high-frequency generator (9) and converter (7) are integrated in a common housing.

5. sonotrode feed unit according to claim 5, characterized gekenn¬ characterized in that the housing (14) is formed from electrically and / or thermally conductive material, in particular made of aluminum.

6. sonotrode feed unit according to claim 5, characterized gekenn- marked, that the generator on the inside of an outer wall of the housing (14) is attached.

7. sonotrode feed unit according to claim 6, characterized gekenn¬ characterized in that the housing (14) is provided with cooling fins.

8. sonotrode feed unit according to one of claims 1 to 7, characterized in that connection points (15, 16) for ei¬ ne line connection (12) on the converter (7) and the generator

(9) are arranged rigidly to each other during the feed.

9. Sonotrode feed unit according to one of claims 1 to 8, characterized in that the generator is a small voltage spinned high-frequency generator (9).

10. sonotrode feed unit according to one of claims 4 to 9, characterized in that the housing (14) with a supply line for cooling air for cooling the generator (9) and / or the converter (7) is provided.

11. sonotrode feed unit according to claim 10, characterized gekenn¬ characterized in that the supply line through an opening in a piston rod (6) of the drive (3) is arranged.

12. sonotrode feed unit according to one of claims 10 or 11, characterized in that the supply line with a Pneumatic system of the drive (3), in particular connected to a pneumatic cylinder or is connectable.

13. sonotrode feed unit according to one of claims 4 to 12, characterized in that the generator (9) and the Kon¬ verter (7) are arranged in the housing (14) such that the secondary side (17) of the transformer of the generator ( 9) is closer to the converter than the primary side (18) of the generator (9).

14. sonotrode feed unit according to one of claims 4 to 13, characterized in that the distance between the secondary-side terminals (16) of the transformer of the generator (9) and terminals (15) of the converter (7) is less than 20cm.

15. Sonotrode feed unit according to one of claims 1 to 14, characterized in that the generator with a feed line (11) and a control line is connected or bar¬, which are arranged in a common cable.

16 Sonotrode feed unit according to one of claims 1 to 15, characterized in that the feed unit (1) Endla¬ genschalter for defining the end position, wherein the limit switch and optionally Elektronik ten components for the limit switch in the housing (14) of the generator (9) are arranged.

17. sonotrode feed unit according to one of claims 4 to 16, characterized in that the housing (14) with a An¬ display and / or control panel (24) is provided.

18. sonotrode feed unit according to one of claims 1 to 17, characterized in that a line connection (12) between the converter (7) and generator (9) without sockets or plug directly to connection points (15, 16) of the converter (7) and / or the generator (9) is connected.

19. A method for operating a sonotrode feed unit in particular according to one of claims 1 to 18, characterized gekenn¬ characterized in that during the feed phase, a high-frequency generator (9) for operating a converter (7) together with the converter (7) is moved.

20. plug adapter for a sonotrode feed unit according to one of claims 1 to 18, characterized in that the plug-in adapter with a measuring arrangement for measuring Betriebs¬ parameters of the feed unit, in particular their Leistungs¬ recording, provided and that the plug-in adapter (23) View ver¬ means for displaying or outputting the operating parameters.