EP3285937A1

EP3285937A1 - Device and method for deburring components by means of ultrasound

Info

Publication number: EP3285937A1
Application number: EP16716032.4A
Authority: EP
Inventors: Thomas Dreyer
Original assignee: Weber Ultrasonics AG
Current assignee: Weber Ultrasonics AG
Priority date: 2015-04-24
Filing date: 2016-04-11
Publication date: 2018-02-28
Also published as: TWI669186B; CN107666970A; JP2018516770A; DE102015106343A1; TW201701995A; WO2016169800A1; US20180354003A1

Abstract

A method is disclosed for deflashing components or workpieces (7) with ultrasound by using at least one sonotrode (6), having the following method steps: a) supplying at least one ultrasonic transducer (4) with electrical energy by means of at least one ultrasound generator (2) so that the ultrasonic transducer (4) is caused to vibrate mechanically; b) transmitting the vibrations to the sonotrode (6) that is mechanically connected to the ultrasonic transducer (4); c) immersing the sonotrode (6) with at least one vibrating sonotrode surface (6') into a fluid (M) so that cavitation is generated in the fluid (M) in the area of this sonotrode surface (6') by the mechanical vibrations of the sonotrode (6); d) arranging a workpiece (7) to be deburred in the vicinity of this sonotrode surface (6') by which means the workpiece (7) is deburred on at least one point, side, or surface opposite the sonotrode surface (6'). Furthermore, a device is disclosed for deburring components or workpieces (7) using ultrasound.

Description

Device and method for deburring components by means of ultrasound

Description

The invention relates to a method for deburring components or workpieces with ultrasound using ultrasound and at least one device for deburring components using ultrasound.

Conventional methods for deburring components or workpieces are based on a mechanical removal of an undesired burr by means of a corresponding cutting tool. To others, burrs are removed electrochemically or thermally. Also the use of high pressure water jet methods is known.

The invention is based on the object of specifying an alternative, effective and efficient method for deburring components or workpieces and a corresponding device. The terms "part" and "part" are used as synonyms below.

This object is achieved by a method having the features of claim 1, by a device having the features of claim 1, and by using a sonotrode known from ultrasonic welding applications according to claim 22.

Advantageous embodiments of the method and the device are the subject of dependent claims.

A method according to the invention for deburring components with ultrasound using at least one sonotrode contains at least the following method steps:

a) supplying at least one U ltraschallwandlers with electrical energy by means of at least one U ltraschallgenerators, so that the U ltraschallwandler is excited to mechanical vibrations; b) transmitting the vibrations to the sonotrode mechanically connected to the ultrasonic transducer;

c) immersing the sonotrode with at least one vibrating sonotrode surface in a liquid so that cavitation in the liquid is produced by the mechanical vibrations of the sonotrode in the region of this sonotrode surface; and

d) placing a workpiece to be deburred in the vicinity of the sonotrode surface, whereby the workpiece is deburred on at least one side or surface opposite the sonotrode surface.

An apparatus according to the invention for deburring components with ultrasound comprises:

a) at least one ultrasonic transducer;

b) at least one ultrasonic generator, which is designed to supply the ultrasonic transducer with electrical energy in order to excite the ultrasonic transducer to mechanical vibrations;

c) at least one sonotrode, which is mechanically connected to transmit the vibrations with the ultrasonic transducer;

d) a tank which can be filled or filled with a liquid so that the sonotrode is immersed or immersed in the liquid with at least one vibrating sonotrode surface; and

d) a device for defined arrangement of a workpiece to be deburred at a location in the vicinity of this Sonotrodenfläche.

In principle, it is known from applications for cleaning components in an ultrasonic bath with a liquid or a liquid medium that the cavitation occurring there in the liquid can damage the surfaces to be cleaned components. These damages are caused by cavitation bubbles collapsing on the surface. These cavitation bubbles occur preferentially on defects of the surface, since there stick microscopic gas bubbles on immersion in the liquid. Especially on burrs and in boreholes this can be the case. According to the applicant, this can be exploited for deburring metallic components by means of targeted cavitation action, since the energy released during the collapse of the individual gas bubbles cancels any existing burrs. In this case, the component to be deburred (workpiece) is intended for short-term intensive ultrasound-induced cavitation. be set to perform a deburring. The cavitation intensity occurring in conventional ultrasonic cleaning baths is insufficient according to the Applicant, so that an increased cavitation intensity, as realized in the subject matter of the invention, is necessary.

It is also known in principle that very intense cavitation can be achieved on the surface of sonotrodes vibrating with ultrasonic frequency, which dip into a liquid medium. Sonotrodes are generally tools for ultrasonic welding, which are set by the introduction of high-frequency mechanical vibrations (ultrasound) in vibration. They connect the ultrasonic generator to the workpiece and introduce the vibrations into it. The heat generated by the resulting friction leads to melting and bonding of the workpiece. Sonotrodes are the only component of an ultrasonic welding machine in direct contact with the welding part.

The reason for this intensive cavitation is the significantly higher amplitude of the mechanical deflection compared to conventional sound transducers for the cleaning technique with sonotrodes. Such high amplitudes can be achieved or enhanced by using correspondingly suitable sound transducers, amplifying elements (boosters, also referred to below as transformers) and suitable geometries of the sonotrode. This is basically known from applications for ultrasonic welding.

According to the invention, at least one sonotrode is thus introduced or introduced into a container (tank) filled with a (cleaning) liquid. Furthermore, this sonotrode according to an embodiment of the invention of an ultrasonic transducer with an ultrasonic frequency between 10 and 50 kHz, preferably about 18 kHz to about 35 kHz, most preferably about 20 kHz to about 30 kHz, operate, so that intense cavitation close to a oscillating surface of the sonotrode (also referred to herein as Sonotrodenfläche) pronounced.

A corresponding embodiment of the device provides that the ultrasonic generator is designed to generate an ultrasonic frequency of the oscillations of at least about 10 kHz and at most about 50 kHz, preferably about 18 kHz to about 35 kHz, most preferably about 20 kHz to about

30 kHz.

The workpiece to be deburred is now positioned manually or by a special device (i.e., means for defining a workpiece to be deburred) at a defined distance with respect to that vibrating surface, so that the intense cavitation occurring there will result in the removal of burrs. The positioning is advantageously carried out or adjustable so that the minimum distance to the vibrating surface is at least 0.1 mm, but it is smaller or at most the same size as an acoustic wavelength in the cleaning medium or in the (cleaning) liquid.

A corresponding design of the device provides that a distance of the workpiece from the sonotrode surface is adjustable so that it is at least about 0.1 mm and at most about one acoustic wavelength of the liquid corresponds, preferably by a corresponding adjustability of the device.

In a development of the method according to the invention, it can be provided that a mechanical transformer is mounted between the ultrasonic transducer and the sonotrode to increase or decrease the mechanical amplitude.

Accordingly, it can be provided in a development of the device that a mechanical transformer for increasing or decreasing the mechanical amplitude between the ultrasonic transducer and the sonotrode is mounted.

In a further development of the invention, a device may further be provided which leads the workpieces to be deburred continuously or discontinuously over the oscillating sonotrode surface, preferably approximately parallel thereto. This can advantageously be realized by providing a drag chain or other suitable transport system. A feature is the maintenance of a constant, but adjustable distance to the vibrating surface of the sonotrode, which is preferably continuously monitored. In a corresponding development of the device can be provided that the device is designed in the form of a transport device for continuous or discontinuous feeding of workpieces by means of adjustable distance to the oscillating surface of the sonotrode. This may comprise a monitoring device, which is designed to continuously monitor compliance with a constant distance from the sonotrode surface.

In yet another embodiment of the method according to the invention, it can be provided that a lifting movement is carried out substantially perpendicular to the sonotrode surface by means of the transport device or the transport system, so that positioning of the workpieces over the oscillating surface is achieved.

In a corresponding development of the device can be provided that the transport device is designed to perform a lifting movement substantially perpendicular to the sonotrode surface.

A further advantageous embodiment of the device comprises a receiving device for the workpieces to be deburred, which is guided by a positioning device to the oscillating surface of the sonotrode or is feasible. Again, a device for maintaining a constant distance to the oscillating surface of the sonotrode may be provided. This device can be designed for ultrasonic distance measurement, for optical distance measurement, for inductive distance measurement or for distance measurement via the path or stroke, without the invention being limited thereto.

In a particularly advantageous development of the method according to the invention, provision can be made for more than one sonotrode to be introduced into the liquid and excited to oscillate so that more than one side of the workpiece is simultaneously subjected to ultrasound or can be acted upon.

In terms of apparatus, it can accordingly be provided that more than one sonotrode is arranged and introduced into the liquid or can be introduced and excited to oscillate or excite such that more than one side of the workpiece can be subjected to ultrasound at the same time. In yet another development of the method according to the invention, provision may be made for a plurality of sonotrodes having at least partially different dimensions and / or geometries to be used for the respective probe surface.

Furthermore, an adaptation to changed workpiece dimensions can be achieved by changing sonotrodes with radiating surfaces of different geometry. It can also be provided on the side of the device that a plurality of sonotrodes are provided which have at least partially different dimensions of their respective sonotrodes.

In a further development of the device can be provided that a

Oscillation system, comprising the ultrasonic transducer, the sonotrode and, where appropriate, the transformer is fixed in a region of minimal mechanical deflection (vibration node) to the tank, preferably in the region of that vibration node, which is closest to the Sonotrodenfläche. As a result, the immersion depth of the vibration system or the sonotrode can be minimized in the liquid, which can be beneficial to the required liquid volume and tank size.

In another embodiment of the device can be provided that a plurality of vibration systems, each comprising the ultrasonic transducer, the sonotrode and possibly the transformer is fixed in each case in a region of minimal mechanical deflection of the tank, so that the respective Sonotrodenflächen are arranged at different locations relative to the location, so that more than one side of the workpiece to be deburred can be sonicated.

In yet another development of the device can be provided that the means for arranging the workpiece or workpieces is designed such that a point to be deburred of the workpiece is not covered and freely immersed in the liquid to allow the most efficient deburring. Below are further properties and advantages of the invention under Bezugnah me rubbed on the drawing.

Fig. 1 shows schematically a first embodiment of the device according to the invention;

Fig. 2 shows schematically the location-dependent vibration curve in an ultrasonic vibration system with a sonotrode;

Fig. 3 shows schematically a second embodiment of the device according to the invention;

Fig. 4 shows schematically a third embodiment of the device according to the invention;

Fig. 5 shows a possible arrangement meh eral horns according to a further embodiment of the device according to the invention; and

Fig. 6 shows differently shaped sonotrodes for use in a device according to the invention.

In Fig. 1, an embodiment of the device according to the invention is shown schematically. In a filled with liquid Reinigungsmedu m M Tan K 1 U ltraschallschwingsystem 3 is mounted. The ultrasonic vibrating system 3 comprises an ultrasonic transducer (or converter) 4 for converting electrical vibrations into mechanical vibrations, a booster 5 for increasing the mechanical deflection, and a sonotrode 6. Reference numeral 6 denotes an oscillatory vibration Loud surface of the sonotrode (alternatively referred to as "sonotrode vibrating surface" or "sonotrode surface"). The individual components 4-6 of the oscillating system 3 are connected to each other (not shown) screw connections and thus interchangeable. The converter 4 is in operative connection with a U ltraschallgenerator 2 and you rch this supplied with electrical energy. In this case, the ultrasound generator 2 has a control which regulates the mechanical amplitude of the converter 4 and a setting of this amplitude in a range of, for example, 1 0 to 1 00%. based on a maximum mechanical amplitude allows. Such U ltraschallgeneratoren are known in the art and are used for example in facilities for ultrasonic welding m.

To be deburred workpiece 7 is shown in FIG. 1 at a distance of at least 0, 1 mm and at most one acoustic wavelength of the cleaning liquid M at the abstrah loin surface 6 'of the sonotrode position iert and sonicated for a certain time, which depends on the nature of Workpiece 7 and the existing amount of burrs, etc. depends and can be determined, for example, from appropriate preliminary tests.

FIG. 2 shows the structure of the exemplary oscillating system 3 from FIG. 1 to r Illustrated again. Also shown is the principal location-dependent amplitude curve of the axial mechanical deflection x (t) of the respective components 4-6 of the oscillating system 3, from which the amplification described follows: The amplitude n from the converter 4 to r sonotrode 6. Continue to exist in areas where the deflection kung disappears, so-called nodes K, x (K) = 0. It is now particularly advantageous to fasten this oscillating system 3 precisely in these knot points K to further components of the device. Advantageously, a flange (not shown) for fixing the oscillating system 3 to the tank 1 of Fig. 1 in a d ieser Knotenpun k K be attached (see Fig. 1).

Notwithstanding the illustration in Fig. 1 can also be provided to secure the oscillating system 3 in the region of the uppermost (foremost) Kots knots K according to FIG. Thus, the immersion depth into the medium M can be minimized, which can have a favorable effect on the required volume of liquid.

A further advantageous embodiment of the device according to the invention is shown in Fig. 3. In this case, the tank 1 together with the oscillating system 3 is expanded by a device 8 (transport device) for a continuous transport of workpieces 7. The transport device 8 may, for example, comprise a link chain u in which the individual workpieces 7 are hung or suspended. This link chain can be driven by a drive device 9, for example driven rollers or toothed wheels, continuously or discontinuously. ierlich be moved over the vibrating surface 6 'or parallel to this. The transport device 8 further comprises a device by means of which the distance of the workpieces 7 to the sonotrode surface 6 'is adjustable, as symbolized in FIG. 3 by vertical double arrows. The device may be designed for continuous monitoring and adjustment of this distance.

A further advantageous embodiment of the device according to the invention is shown in Figure 4. Here is located above the tank 1 with inventive vibration system 3, a further device 10 for receiving a plurality of workpieces 7. This device 10 may be, for example, a basket, a product carrier or another, the geometry of the workpieces adapted carrier. Advantageously, the carrier or the device 10 is designed so that the surface to be deburred of the workpieces 7 is not covered and can dive freely into the cleaning medium M. The goods carrier or the device 10 is further connected to a lifting and transport mechanism 11, through which the goods carrier or the device 10 can be immersed in the cleaning medium M, as shown. Furthermore, the lifting mechanism 11 preferably has the property that the distance of the workpieces 7 to the sonotrode surface 6 'is selectively adjustable, as symbolized in Figure 4 by a vertical double arrow.

Without further illustration, combinations or juxtapositions of the embodiments disclosed in FIGS. 1, 3 and 4 for larger devices are also possible for the person skilled in the art and therefore also part of the present invention.

Depending on the geometry of the components or workpieces 7, simultaneous deburring of a plurality of component surfaces or surfaces of the workpieces 7 may be advantageous for time and / or cost reasons. For this purpose, for example, the arrangement of a plurality of sonotrodes 6a-6c shown in FIG. 5 is highly advantageous. For example, three sonotrodes 6a, 6b and 6c can be mounted on a tank 1 in such a way that, at the same time, three sides of a workpiece 7 can be deburred according to the invention. The sonotrodes 6a-6c used need not be identical. A further advantageous embodiment of the device according to the invention is shown in Fig. 6, in which different U ltraschallsonotroden 6 d to 6 f are shown with different union dimensions and geometries of the radiating surfaces. In the context of the present invention, these sonotrodes 6d-6f are preferably interchangeable in a device according to the invention, so that the device can be designed to be adaptable to, for example, different dimensions or geometries of the workpieces to be deburred 7 and / or different types of barbs ,

Claims

claims

1. A method for deburring workpieces (7) with ultrasound using at least one sonotrode (6; 6a, 6b, 6c), comprising the following method steps:

a) supplying at least one ultrasonic transducer (4) with electrical energy by means of at least one ultrasonic generator (2), so that the ultrasonic transducer (4) is excited to mechanical vibrations;

b) transmitting the vibrations to the sonotrode (6) mechanically connected to the ultrasound transducer (4);

c) immersing the sonotrode (6) with at least one oscillating sonotrode surface (6 ') in a liquid (M), so that cavitation in the liquid (M) is caused by the mechanical vibrations of the sonotrode (6) in the region of this sonotrode surface (6'). is produced;

d) arranging a workpiece to be deburred (7) in the vicinity of the Sonotrodenflache (6 '), whereby the workpiece (7) on at least one of these sonotrode surface (6') opposite side or surface is deburred.

2. The method of claim 1, wherein a generated ultrasonic frequency of the vibrations is at least about 10 kHz and at most about 50 kHz, preferably about 18 kHz to about 35 kHz, most preferably about 20 kHz to about 30 kHz.

3. The method of claim 1 or 2, wherein a distance of the workpiece (7) from the Sonotrodenfläche (6 ') is selected such that it is at least about 0.1 mm and at most about one acoustic wavelength of the liquid (M) ,

4. The method according to any one of claims 1 to 3, wherein a mechanical transformer (5) for increasing or decreasing the mechanical amplitude between the ultrasonic transducer (4) and the sonotrode (6) is mounted.

5. The method according to any one of claims 1 to 4 with a continuous or discontinuous feeding of workpieces (7) by means of a transport device (8; 11) with adjustable distance to Sonotrodenflache (6 '), in which preferably the workpieces (7) in one area be performed approximately parallel to Sonotrodenflache (6 ').

6. The method of claim 4, wherein by means of the transport device (11) a lifting movement substantially perpendicular to the Sonotrodenflache (6 ') is performed, so that a positioning of the workpieces (7) over the Sonotrodenflache (6') is achieved.

7. The method according to any one of claims 1 to 6, wherein a maintenance of a constant distance to the sonotrode surface (6 ') is continuously monitored.

8. The method according to any one of claims 1 to 7, wherein more than one Sonotrode (6a, 6b, 6c) are introduced into the liquid (M) and excited to vibrate, that at the same time more than one side of the workpiece (7 ) is applied with ultrasound.

9. The method according to any one of claims 1 to 7, wherein a plurality of sonotrodes (6d, 6e, 6f) are used with at least partially different dimensions of the respective sonotrode surface (6 ').

10. An apparatus for deburring workpieces (7) with ultrasound, comprising:

a) at least one ultrasonic transducer (4);

b) at least one ultrasonic generator (2), which is designed to supply the ultrasonic transducer (4) with electrical energy in order to excite the ultrasonic transducer (4) to mechanical vibrations;

c) at least one sonotrode (6), which is mechanically connected to transmit the vibrations with the ultrasonic transducer (4);

d) a tank (1) which can be filled or filled with a liquid (M), so that the sonotrode (6) with at least one oscillating sonotrode surface (6 ') is immersed in the liquid (M) or can be immersed; and d) a device (8, 9, 10, 11) for the defined arrangement of a workpiece (7) to be deburred at a location in the vicinity of this sonotrode surface (6 ').

11. The apparatus of claim 10, wherein the ultrasonic generator (2) is adapted to generate an ultrasonic frequency of the vibrations of at least about 10 kHz and at most about 50 kHz, preferably about 18 kHz to about 35 kHz, most preferably about 20 kHz to about 30 kHz.

12. The apparatus of claim 10 or 11, wherein a distance of the workpiece (7) from the Sonotrodenflache (6 ') is adjustable so that it is at least about 0.1 mm and at most about one acoustic wavelength of the liquid (M) , preferably by a corresponding adjustability of the device (8, 9, 10, 11).

A device according to any one of claims 10 to 12, wherein a mechanical transformer (5) is mounted to increase or decrease the mechanical amplitude between the ultrasonic transducer (4) and the sonotrode (6).

14. Device according to one of claims 10 to 13, wherein the device in the form of a transport device (8; 11) for continuous or discontinuous feeding of workpieces (7) with adjustable distance to Sono trodenfläche (6 ') is formed.

15. The apparatus of claim 14, wherein the transport device (11) for performing a lifting movement substantially perpendicular to the Sonotroden- surface (6 ') is formed or wherein the transport device (8) for carrying out a movement substantially parallel to the Sonotrodenfläche (6 ') is formed.

16. Device according to one of claims 10 to 15, with a monitoring device, which is designed for continuous monitoring of compliance with a constant distance of the workpiece (7) to Sonotrodenfläche (6 ').

17. Device according to one of claims 10 to 16, in which more than one sonotrode (6) are arranged and introduced into the liquid (M) or introduced and excited to vibrate or excitable, that at the same time more than one side of the workpiece (7 ) can be acted upon by ultrasound.

Device according to any one of Claims 10 to 17, in which a plurality of sonotrodes (6a, 6b, 6c; 6d, 6e, 6f) are provided which at least partially have different dimensions of their respective sonotrode surface (6 ').

19. Device according to one of claims 10 to 18, wherein a vibrating system (3) comprising the ultrasonic transducer (4), the sonotrode (6) and optionally the transformer (5) according to claim 13, in a region (K) of minimal mechanical Deflection (x (t)) is fixed to the tank (1), preferably in the region of a vibration node (K), which is the Sonotrodenflache (6 ') closest.

20. Device according to one of claims 10 to 19, wherein a plurality of oscillating systems (3), each comprising the ultrasonic transducer (4), the sonotrode (6) and possibly the transformer (5) according to claim 13, each in a range ( K) minimum mechanical deflection (x (t)) is fixed to the tank (1), so that the respective sonotrode surfaces (6 ') are arranged at different locations relative to the location.

21. Device according to one of claims 10 to 20, wherein the device (8, 9, 10, 11) for arranging the workpiece (7) or the workpieces (7) is designed such that a location of the workpiece to be deburred (7 ) is not covered and is freely immersed in the liquid (M).

22. Use of a sonotrode (6; 6a, 6b, 6c; 6d, 6e, 6f) for deburring workpieces (7), preferably according to a method according to one of claims 1 to 9.