WO2017025069A1

WO2017025069A1 - Device for deburring work pieces by means of ultrasound

Info

Publication number: WO2017025069A1
Application number: PCT/DE2015/100499
Authority: WO
Inventors: Thomas Dreyer
Original assignee: Weber Ultrasonics Gmbh
Priority date: 2015-08-07
Filing date: 2015-11-24
Publication date: 2017-02-16
Also published as: CH712990B1; TW201706072A; DE202015104150U1

Abstract

The invention relates to a device for deburring work pieces by means of ultrasound, having: at least one ultrasound converter (4); at least one sonotrode (6), which is mechanically connected to the ultrasound converter (4) in order to transmit vibrations, wherein at least one vibrating sonotrode surface (6') of the sonotrode (6) can be immersed in a tank which can be filled or is filled with a liquid; characterized in that the ultrasound converter (4) and the sonotrode (6') are designed as a common, handheld device.

Description

Device for deburring workpieces with ultrasound

description

The invention relates to a device for deburring of workpieces with U ltraschall according to the preamble of claim 1 and a corresponding system for deburring of workpieces with ultrasound. Such a device typically comprises a ultrasonic transducer and a sonotrode mechanically connected to transmit the vibrations to the ultrasonic transducer. The sonotrode can be immersed in a liquid tank with at least one vibrating sonotrode surface.

In a variety of technical applications, it is necessary to free workpieces of undesirable burrs, for example by means of electrochemical or thermal processes or high pressure water jet method.

In addition, it is possible to deburr workpieces by means of ultrasound. A corresponding device for deburring workpieces by means of ultrasound is described in the German patent application no. 10 2015 106 343.3 of the Applicant Weber Ultrasonics GmbH of April 24, 2015.

A disadvantage of the cited prior art is that the prior art devices are relatively large and expensive and are designed more for a series treatment of the workpieces. Deburring individual workpieces or merely sections of individual workpieces is associated with a disproportionately large (cost) effort.

The present invention is therefore based on the object to propose an alternative device for deburring of workpieces, which is inexpensive and easy to use.

This object is achieved by a device having the features of claim 1 and by a system having the features of claim 14. Advantageous embodiments of the device according to the invention can be found in the claims 2 to 13. A further advantageous embodiment of the system can be found in claim 15. H iermit the wording of all claims is explicitly incorporated by reference in the description.

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

at least one ultrasonic transducer and

at least one sonotrode, which is mechanically connected to transmit the vibrations with the U ltraschallwandler, wherein the sonotrode is immersed with at least one oscillating sonotrodes surface in a liquid-filled or filled tank.

It is essential that ultrasonic transducer and sonotrode are designed as a common, hand-held device.

From applications for ultrasonic welding, it is generally known that cavitation occurs. This occurs preferentially on defects of the surface, since there microscopic glass bubbles adhere to the immersion in the liquid. This can therefore be the case in particular on burrs and in boreholes. According to the Applicant, this effect can be used 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 workpiece to be deburred is to be briefly exposed to intensive ultrasound-induced cavitation in order to perform deburring. The underlying process of deburring with U ltraschall is in the German patent application N r. 10 2015 106 343.3 of the applicant Weber U ltrasonics GmbH of 24 April 2015, the content of which is hereby explicitly incorporated by reference.

Particularly 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 in motion by the introduction of high-frequency mechanical vibrations (ultrasound). They typically do the connection of the ultrasonic generator to the workpiece forth and initiate the vibrations in this.

The reason for the intensive cavitation is the significantly higher amplitude of the mechanical deflection than usual sound transducers for the cleaning technique with sonotrodes.

The device according to the invention thus differs in essential aspects from previously known devices: Ultrasonic transducer and sonotrode are designed as a hand-held device, i. H. in that the ultrasonic transducer and the sonotrode are formed as a common element which is manually guided by a user during the deburring of workpieces with ultrasound. Ultrasonic transducers and sonotrode are rigidly connected to transmit the mechanical vibrations from the ultrasonic transducer to the sonotrode.

This results in particular in the advantages that the device can be used individually and ultrasound can also be applied to ultrasonically difficult to reach areas of a workpiece to be deburred with the hand-held device and thus be freed from interfering burrs. Another advantage is that the design of U ltraschallwandler and sonotrode as a hand-held device allows a compact and cost-effective implementation, which is also suitable for occasional and individual uses. In particular in hard to reach areas, such as holes or angles, it is possible with the hand-held device in a simple manner to remove unwanted burrs and to rework these areas locally to the desired result. In a preferred embodiment of the invention is a mechanical

Transformer (booster) arranged to increase or decrease the mechanical amplitude between the ultrasonic transducer and the sonotrode. The transformer preferably acts as a reinforcing element and can thus lead to a higher amplitude of the mechanical deflection of the sonotrode, which in turn leads to an increased generation of cavitation in the liquid and thereby to an increased deburring. The use of such In principle, transformers are already known from applications for ultrasonic welding.

According to one embodiment of the invention, the device comprises a spacer for setting a constant distance between the at least one oscillating sonotrode surface and the workpiece to be deburred. By means of the spacer it can be ensured that the intense cavitation occurring on the vibrating sonotrode surface leads to the removal of burrs on the surface of the workpiece. Advantageously, the spacer is adjustable such that the constant distance of said sonotrode surface from the workpiece is at least 0.1 mm, but smaller or at most the same size as an acoustic wavelength in the liquid. With the spacer can therefore be ensured that neither the workpiece is damaged by the sonotrode even with the hand-held device, nor that due to a large distance between the sonotrode and the workpiece to be deburred only a deficient deburring occurs.

A further preferred embodiment comprises a monitoring device which is designed to continuously monitor compliance with a constant distance of the sonotrode surface from the workpiece. In this case, the monitoring device can be designed with a feedback device for a user. Preferably, a signal is sent to the user when the distance between the sonotrode surface and the workpiece to be deburred lies outside a desired, preferably presettable, region.

A further advantageous embodiment of the device comprises a weight balance for the hand-held device. The weight compensation is provided to compensate for the weight of the hand-held device (at least U ltraschallwandler and sonotrode). The weight compensation is carried out by an opposite force that can be generated by, for example, a counterweight, a spring or an active drive. Without external influence, the weight balance sets a balanced resting position. The weight of the hand-held device of the device can depend on the frequency range of the U ltraschallwandlers and thus the size of U ltraschallwandlers in a kilogram range. Here it is for a user for a stress-free and controlled use of the device advantageous if the weight compensation of the hand-held device is compensated.

In another preferred embodiment of the device, the sonotrode is arranged replaceably. Preferably, sonotrode and / or the transformer and / or the ultrasonic transducer are interchangeably arranged. H hereby has the advantage that with a base unit by the change of said parts different U ltraschall frequency ranges can be covered. Furthermore, the device can be adapted, for example, to different dimensions or geometries of the workpieces to be deburred and / or to different types of burrs, by means of the exchangeable sonotrode.

In a further preferred embodiment, the hand-held device is formed liquid-tight. Preferably, the device comprises a housing for the ultrasonic transducer, wherein the sonotrode and the housing are connected to each other in a liquid-tight manner. This results in the advantage that the sonotrode or the hand-held device can be immersed in the liquid without causing damage to the device. Even liquid splashes or the like can not cause damage to the device.

In a further preferred embodiment, the device has a grip region which is ergonomically tapered. A user can thus handle the handheld device more easily. Preferably, the device comprises a housing for the ultrasonic transducer, which housing is ergonomically tapered in the grip area. The U ltraschallwandler is thus arranged in the housing, so that in a simple manner, a grip area on the U ltraschallwandler can be provided, which makes the handling comfortable for the user and allows a controlled guidance during deburring.

In a further advantageous embodiment of the invention, a button or switch for activating the ultrasonic vibrations is arranged on the hand-held device of the device. The button or switch is connected to the U ltraschallgenerator. By means of the push-button or switch, an acti- v the U ltraschallgenerators, which supplies the ultrasonic transducer with electrical energy to stimulate the U ltraschallwandler to mechanical vibrations. The activation of the ultrasound can thus be done by a user directly to the hand-held device.

In an advantageous development, the device comprises active cooling for the ultrasonic transducer, in particular preferably compressed-air cooling or a fan integrated in the hand-held device.

In a further advantageous embodiment, the device comprises at least one ultrasonic generator which is designed to supply the ultrasonic transducer with electrical energy in order to excite the ultrasonic transducer to produce mechanical oscillations. The ultrasound generator excites the ultrasound transducer to vibrate mechanically, with the ultrasound transducer also causing the sonotrode to vibrate in the ultrasonic frequency range.

Preferably, the ultrasonic generator is configured 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.

The hand-held Entgratungsvorrichtung may be particularly advantageous for deburring holes. For this purpose, a long and narrow sonotrode is preferably introduced into the bore so that the cavitation bubbles can remove the burrs in the interior of the bore. The hand-held deburring device is also particularly suitable for deburring other difficult to reach areas of workpieces.

Another aspect of the invention relates to a system for deburring workpieces with ultrasound. The system comprises at least one device according to the invention for deburring workpieces with ultrasound, a U ltraschallgenerator which is designed to supply the ultrasonic transducer with electrical energy to excite the ultrasonic transducer to mechanical vibrations, and a tank which can be filled or filled with a liquid, so that the sonotrode with at least one oscillating sonotrodes surface is immersed in the liquid or immersed. The device for deburring Workpieces with U ltraschall of the system is immersed with the sonotrode in the liquid of the tank and preferably guided along at a defined distance at the areas to be deburred of the workpiece so that the intense cavitation occurring there leads to the removal of the burrs.

In another advantageous embodiment of the system for deburring workpieces with ultrasound, the device for deburring of workpieces with U ltraschall with a U ltraschallgenerator for generating a U ltraschallfrequenz is formed. Accordingly, the system comprises at least one corresponding device for deburring workpieces with ultrasound and 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. The liquid is preferably a cleaning medium, as known from previously known methods for cleaning with ultrasound.

The device for deburring workpieces with U ltraschall of the system is immersed with the sonotrode in the liquid of the tank and preferably guided along at a defined distance at the areas to be deburred of the workpiece so that the intense cavitation occurring there leads to the removal of the burrs.

Further preferred features and embodiments of the device according to the invention and of the system according to the invention are explained below on the basis of exemplary embodiments and the figures. Showing:

Figure 1 with the partial figures a, b and c, a first embodiment of a device according to the invention;

Figure 2 with the partial illustrations a, b and c, a second embodiment of a device according to the invention with spacers.

In FIGS. 1 and 2, the same reference numerals designate the same or equivalent elements. All dimensions are to be understood as examples and do not include any limitation beyond the scope of the claims. 1 shows a schematic representation of a first embodiment of the device according to the invention in three views a, b and c.

Figure 1 a shows a device with a hand-held device 1 and a weight compensation 10. The device comprises a housing 5, in which a U ltraschallwandler 4 for converting electrical vibrations into mechanical vibrations and a booster (transformer) 3 arranged to increase the mechanical deflection are shown in Figure 1 c. The housing 5 is formed with an ergonomically shaped grip area 8. On the housing 5, a sonotrode 6 is arranged with a vibration-emitting surface of the sonotrode (vibrating sonotrode surface) 6 '. The individual components 4-6 are connected to each other by screw connections and thus interchangeable.

The U ltraschallwandler 4 is connected via the cable 7 in signal-effective connection with an ultrasonic generator (not shown) and is supplied by this with electrical energy. In this case, the U ltraschallgenerator has a control which regulates the mechanical amplitude of U ltraschallwandlers 4 and allows adjustment of this amplitude in a range of, for example, 10 to 100% based on a maximum mechanical amplitude. The U ltraschallwandler 4 is present - without limitation - designed for a maximum oscillation frequency in the range of 35 kHz. Such ultrasonic generators are known to the person skilled in the art and are used, for example, in installations for ultrasonic welding.

The sonotrode 6 is immersed in a tank filled with liquid medium (not shown). When the sonotrode 6 is operated ultrasonically, intensive cavitation occurs on the surface of the sonotrode 6 in the region of at least the sonotrode surface 6 '. If the sonotrode 6 is now guided along with the sonotrode surface 6 'at a (defined) distance on the areas of a workpiece to be deburred, the intense cavitation occurring there leads to the removal of the burrs.

FIG. 1b shows the device from FIG. 1a in a view rotated by 90 degrees. The weight balance 10 is arranged on the hand-held device 1 so that the weight of the hand-held device 1 is compensated and the cable 7 is not loaded on train. The counterweight 10 is presently designed as a counterweight.

FIG. 1 c shows a sectional view through the planes A - A shown in FIG. 1 a. The device comprises a sonotrode 6 and a ultrasonic transducer 4 as a handheld device 1. A transformer or booster 3 is connected between the sonotrode 6 and the ultrasonic transducer 4 Increasing the mechanical deflection arranged. As can be seen in Figure 1 c, the U ltraschallwandler 4 is arranged in the housing 5, that the housing 5 forms a handle for the hand-held device 1. The housing 5 is ergonomically tapered in a central region 8, so that a user can comfortably grasp and guide the hand-held device.

Figure 2a shows a schematic representation of a second embodiment. FIG. 2b shows the view from FIG. 2a rotated by 90 degrees. FIG. 2c shows a sectional view of the second exemplary embodiment through the plane A-A indicated in FIG. 2a. In order to avoid repetition, the following will focus on the differences between the figures.

The device comprises a hand-held device 1 a sonotrode 6 and an ultrasonic transducer 4. Between sonotrode 6 and U ltraschallwandler 4 a transformer (booster) 3 is arranged to increase the mechanical deflection. As can be seen in Figure 2c, the U ltraschallwandler 4 is arranged in the housing 5, that the housing 5 forms a handle for the hand-held device 1. The housing 5 is ergonomically tapered in a central region 8, so that a user can comfortably grasp and guide the hand-held device.

The U ltraschallwandler 4 is present - without limitation - designed for a maximum oscillation frequency in the range of 20 kHz.

On the hand-held device (1) of the device, a button (1 1) for activating the ultrasonic vibrations is arranged. The button (1 1) is connected via the cable 7 with the U ltraschallgenerator (not shown). By means of the Tasters (1 1) is an activation of U ltraschalls by a user directly on the hand-held device (1) possible.

The device additionally comprises a spacer 12. This embodiment is particularly suitable for the deburring of holes. The spacer 12 rests with the surface 12 'on a workpiece and thus ensures a maximum penetration depth into the bore. This avoids damage to the workpiece.

The spacer 12 can also be arranged on the device 1 in such a way that a constant distance between the surface of the sonotrode 6 'emitting the vibrations and the workpiece is at least 0.1 mm and is at most equal to an acoustic wavelength in the liquid.

Claims

claims

1 . Apparatus for deburring workpieces with ultrasound, comprising: at least one ultrasonic transducer (4);

at least one sonotrode (6) which is mechanically connected to transmit the vibrations to the ultrasonic transducer (4), the sonotrode (6) having at least one oscillating sonotrode surface (6 ') being immersed in a tank that can be filled or filled with a liquid;

characterized,

the ultrasonic transducer (4) and sonotrode (6 ') are designed as a common, hand-held device (1).

2. Apparatus according to claim 1,

characterized,

in that a mechanical transformer (3) is mounted between the ultrasonic transducer (4) and the sonotrode (6) in order to increase or decrease the mechanical amplitude.

3. Device according to one of the preceding claims,

characterized,

in that the device comprises a spacer (12) for setting a constant distance between the at least one vibrating sonotrode surface (6 ') and the workpiece to be deburred.

4. Apparatus according to claim 3,

characterized,

in that the spacer is adjustable such that the constant distance of the at least one vibrating sonotrode surface (6 ') from the workpiece is at least approximately 0.1 mm and corresponds at the most to approximately one acoustic wavelength in the liquid.

5. Device according to one of the preceding claims, characterized

in that the device comprises a monitoring device which is designed to continuously monitor compliance with a constant distance of the sonotrode surface (6 ') from the workpiece.

6. Device according to one of the preceding claims,

characterized,

in that the device comprises a weight balance (10) for the hand-held device.

7. Device according to one of the preceding claims,

characterized,

that the sonotrode (6) is interchangeable, preferably, that the sonotrode (6) and / or the transformer (3) and / or the U ltraschallwandler (4) are arranged interchangeably.

8. Device according to one of the preceding claims,

characterized,

in that the hand-held device (1) is liquid-tight, in particular preferred that the device comprises a housing (5) for the ultrasonic transducer (4) and the sonotrode (6) and housing (5) are made liquid-tight.

9. Device according to one of the preceding claims,

characterized,

in that the device has a grip area (8) which is ergonomically designed, in particular tapered, preferably that the device comprises a housing (5) for the ultrasonic transducer (4) and the housing (5) is ergonomically designed in the grip area (8). especially rejuvenated.

10. Device according to one of the preceding claims, characterized

in that the device comprises active cooling for the ultrasonic transducer (4), in particular preferably compressed-air cooling.

1 1. Device according to one of the preceding claims,

characterized,

in that the device comprises a button (1 1) for activating the ultrasonic vibrations, which button (11) is preferably arranged on the hand-held device (1).

12. Device according to one of the preceding claims,

characterized,

in that the device additionally comprises at least one ultrasonic generator which is designed to supply the ultrasonic transducer (4) with electrical energy in order to excite the ultrasonic transducer (4) to produce mechanical oscillations.

13. Device according to claim 12,

characterized,

in that the ultrasonic generator is designed to generate a 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.

14. System for deburring workpieces with ultrasound, comprising:

at least one device for deburring workpieces with ultrasound according to one of claims 1 to 1 1,

a U ltraschallgenerator which is designed to supply the U ltraschallwandlers (4) with electrical energy to the ultrasonic transducer (4) to stimulate mechanical vibrations and

a tank, which receives the workpiece and can be filled or filled with a liquid, so that the sonotrode (6) with at least one oscillating sonotrodesurface (6 ') dips into the liquid or is submersible. System for deburring workpieces with ultrasound, comprising: at least one device for deburring workpieces with ultrasound according to claim 12 or 13 and

a tank, which receives the workpiece and can be filled or filled with a liquid, so that the sonotrode (6) with at least one oscillating sonotrodesurface (6 ') dips into the liquid or is submersible.