Patent Application
20220266409
Applicant claims priority under 35 U.S.C. § 119 of German Application No. 10 2021 104 526.6 filed Feb. 25, 2021, the disclosure of which is incorporated by reference.
The invention relates to a deburring tool comprising a grinding belt holder for holding the grinding belt as well as a deburring machine comprising such a deburring tool.
The invention deals with the deburring of precision workpieces, such as, for example, of intermediate spaces between electrodes of multipoles, in particular quadrupoles, which are provided for mass spectrometers. EP 3 385 979 A1 shows, for example in
It is thus necessary to perform a deburring. The deburring usually takes place manually. However, the manual deburring is time-consuming and thus cost-intensive. Moreover, the quality of the deburring is dependent on that person, who performs the deburring process.
The invention thus aims at mechanically performing the deburring process, which is usually performed manually.
However, the fact that suitable deburring machines are not available runs contrary to this aim.
Grinding belt holders are in fact known, which can be used in manual filing machines, for example the grinding belt holder offered by the joke Technology GmbH under the name Poly-Strip, in the case of which the grinding belt is returned around a metal strip and is clamped to the grinding belt holder. However, the replacement of the grinding belt is not suitable for an automated process in the case of this system, but is designed for a manual replacement.
Another grinding belt device is disclosed in DE 699 17 089 T2. A wafer material edge end part polishing device is disclosed in JP 08001494 A.
The invention is thus based on the object of providing a deburring tool comprising a grinding belt bolder, which provides for an automatic replacement of the grinding belt in an automated process with high quality.
These and other objects are solved by means of the features of a deburring tool according to one aspect of the invention as well as a deburring machine according to other aspects of the invention comprising such a deburring tool.
The deburring tool according to the invention has a grinding belt holder, which is formed so as to hold a grinding belt, wherein the deburring tool comprises a housing, in which the grinding belt holder can alternatingly carry out a linear stroking or lifting movement. The grinding belt holder thereby has a forming tunnel, which forms a forming duct comprising an input and an output for the guide-through of the grinding belt. The forming tunnel thereby encloses the forming duct in such a way that the tunnel wall forms the outer limitation of the forming duct. A grinding belt, which, folded in the center in the longitudinal direction of the grinding belt, escapes on the output side of the forming duct, can be supplied on the input side of the forming duct. The forming duct has a round cross section on the input side and a slit-like cross section on the output side.
This design of the forming duct ensures that a grinding belt can be inserted without any problems into the forming duct. The rounding of the forming duct contributes to the grinding belt being curved, following the rounding. During the further advancement of the grinding belt into the forming duct, a further formation of the grinding belt takes place, until it finally escapes at the output of the forming duct, folded or bent, respectively, in the longitudinal direction of the grinding belt.
As a result of this folding process, a grinding belt is obtained, which can be used on both sides for grinding, even if the grinding belt per se only provides a top side for grinding and a bottom side, which is not provided for grinding.
As part of a machining of a workpiece by means of grinding, for example as part of a deburring of an intermediate space between electrode sections of a quadrupole of a mass spectrometer, the grinding belt wears to a certain extent. So that the same quality can be attained in the case of every workpiece, however, the invention preferably provides that the grinding belt is replaced for each workpiece, so that workpieces with consistent quality can be produced.
The deburring tool according to the invention makes it possible to pull out a predefined piece of the grinding belt and to cut it off and to optionally subsequently firmly press together the grinding belt again. This process can be performed in an automated manner in an ideal way and thus ensures consistent quality.
According to a further development of the invention, the forming tunnel has a tubular, in particular cylindrical section, which starts at the input of the forming duct and which is connected to a funnel-like section, which narrows in the direction of the output of the forming duct and which ends with a rectangular cross section at the output of the forming duct, in particular merges into this funnel-like section. This design simplifies the automated folding of the grinding belt along its longitudinal axis.
A further development of the invention provides that the tubular section of the forming tunnel is formed by a tube comprising a cylindrical section. The round or circular guide-through, respectively, for the grinding belt, which is provided in this way, facilitates the destruction-free supply of the grinding belt into the grinding belt holder.
According to a further development of the invention, the funnel-like section of the forming tunnel has two half shells, which can be screwed together. A construction of this type facilitates the maintenance of the deburring tool in the event of an interference, in that the two half shells can be separated from one another by releasing the screw-connection, whereby the interior of the deburring tool becomes accessible.
A further development of the invention provides that a (sword-like) bracing, which escapes at the forming duct on the output side, is arranged within the forming tunnel, in particular within the funnel-like section. The bracing thereby only partially fills the slit-like cross section at the forming duct on the output side, namely in such a way that the grinding belt places itself around one of the two longitudinal edges of the bracing. A bracing of this type is advantageous because it reinforces the grinding belt and in particular stabilizes thin grinding belts. However, the bracing is not necessary and is not expedient in all cases, in particular when a flexibility of the grinding belt is advantageous for special applications.
The bracing is preferably formed as sheet metal strip with consistent thickness. The bracing is formed in a flat or bent manner. A flat formation of the bracing can be advantageous for the deburring of straight edges or cuts. If the bracing is bent, the bending takes place in the transverse direction of the bracing, i.e. about its longitudinal axis, with a radius, which is aligned perpendicular to the plane of the sheet metal strip. The sheet metal strip thus obtains a trough-like shape. The radius is thereby preferably constant over the width of the bracing. In the alternative, the radius is variable over the width of the sheet metal strip. A bent formation of the bracing can be advantageous for the deburring of bent or curved edges or cuts. The radius of the bracing is adapted to the radius of the bent or curved edge or of the bent or curved cut, respectively. The radius of the bracing is in particular greater than the or equal to the radius of the bent or curved edge or of the bent or curved cut, respectively.
In the alternative, the bracing is formed with a thickness varying in the transverse direction of the bracing, i.e. transverse to the direction of the linear stroking or lifting movement, in particular a thickness decreasing towards one of its longitudinal edges. The bracing thereby tapers towards one of its longitudinal sides. This means that the thickness decreases in the transverse direction of the bracing. This thickness variation corresponds to the thickness variation of a knife blade. The bracing preferably has a V-shaped or triangular cross section, respectively. The grinding belt then places itself onto the two outer surfaces of the V shape via the pointed edge. This pointed edge is inserted into the slit or gap, which is to be deburred, by carrying out the stroking or lifting movement. This bracing contour is advantageous for the secondary burr removal.
According to a further development of the invention, the grinding belt holder can be driven pneumatically within the housing to carry out an alternating stroking or lifting movement. A first air chamber and a second air chamber, to which compressed air can be applied and which can be ventilated as well as purged, are thereby formed in the housing. Both chambers are thereby separated from one another by means of a displaceable separating wall, which is rigidly connected to the forming tunnel, in particular its tubular section, for example by means of a clamping connection, a screw connection, an adhesive connection, or a welded connection. The alternating stroking or lifting movement is thus provided by means of a pneumatic drive. For this purpose, compressed air can be guided into a drive mechanism, which is formed with little design effort, in order to create the movement. A drive of this type can be provided without electrical system in the region of the deburring tool. Protective measures thus become expendable for electrical components. A pneumatic drive can further be solved in a cost-efficient manner with regard to design and can be implemented in a space-saving manner.
A further development of the invention provides that the grinding belt holder can be driven electromagnetically within the housing to carry out the alternating stroking or lifting movement, wherein the housing has a magnetic coil, and a part of the grinding belt holder, in particular the forming tunnel, forms the magnetic armature. A design of this type is advantageous when no compressed air is available.
According to a further development of the invention, the deburring tool is accommodated in a machine housing, which also accommodates a grinding belt, which is rolled up to form a grinding belt roll, wherein the grinding belt can be supplied to the input of the forming duct, in particular via a deflection roller. The grinding belt roll can be accommodated with large stock in the deburring tool in this way, whereby a large stock of grinding belt is available during the machining, and an essentially continuous machining process can be performed in spite of frequent replacement of the grinding belt. A sufficient stock provides for a frequent replacement of the grinding belt and thus ensures a deburring with consistently high quality.
A further development of the invention provides that the deburring tool has a clamping means for clamping, removing, and pressing together the grinding belt and/or a cut-off means, which has a cutting tool for cutting off the grinding belt. The clamping means and/or cut-off means can thus be integrated in the deburring tool. These means facilitate the automatic replacement of the grinding belt by means of removing and cutting off the grinding belt.
A further development of the invention provides that the deburring tool is part of a deburring machine, which has a multiaxially controllable robot arm, at which the deburring tool is arranged. The deburring machine thus comprises a robot comprising at least one robot arm. Thanks to the robot arm, the grinding belt for deburring can also be inserted at places of workpieces, which are difficult to access, namely in a predefined manner. A high and consistent processing quality is likewise ensured thereby.
In the alternative, the deburring tool can be part of a deburring machine, which has a movable arm of a portal machine or a movable arm of a CNC milling machine, at which the deburring tool is arranged. In these cases, the deburring machine comprises a portal machine or a CNC milling machine, in each case comprising movable axes.
According to a further development of the invention the deburring machine comprises a clamping means, which is arranged outside of the deburring tool, for clamping, removing, and pressing together the grinding belt, and a cut-off means, which is arranged outside of the deburring tool and which has a cutting tool for cutting off the grinding belt. In contrast to the above-described alternative, which is integrated in the deburring tool, the clamping means and/or cut-off means are thus provided separately from the deburring tool These means facilitate the automatic replacement of the grinding belt by means of removing and cutting off the grinding belt.
Further developments of the invention follow from the claims, the description, and the drawings. The above-mentioned advantages of features and of combinations of several features are exemplary and can take effect alternatively or cumulatively, without the advantageous having to mandatorily be attained by embodiments according to the invention. Further features can be gathered from the drawings, in particular the illustrated geometries and the relative dimensions of several components to one another as well as the relative arrangement and operative connection thereof. The combination of features of different designs of the invention or of features from different claims is likewise possible, notwithstanding the selected dependencies of the claims, and is hereby proposed. This also relates to such features, which are illustrated in separate drawings or which are mentioned in the description thereof. These features can also be combined with features of different claims. Features listed in claims can likewise be foregone for further embodiments of the invention.
Thus, other objects and features of the invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.
In the drawings,
The grinding belt holder 12 has a forming tunnel 16, which forms a forming duct 18 comprising an input 20 and an output 22 for the guide-through of a grinding belt 24 illustrated in
As shown in
On the grinding belt roll 26, the grinding belt 24 has twice the width as at the output 22. This is so because the grinding belt 24 is formed in the forming duct 18 and is thereby folded in the center in the longitudinal direction of the grinding belt 24, i.e. along the center line of the grinding belt 24. This means that a folding edge is created in the center in the longitudinal direction of the grinding belt 24. This has the result that, at the output 22, the grinding belt only still has half the width as on the grinding belt roll 26.
The grinding belt 24 has a top side, which is provided for grinding, as well as usually a bottom side, which is not provided for grinding.
By folding the grinding belt 24 along its center line, the top side of the grinding belt 24, which is provided for grinding, faces in both directions. The folded grinding belt 24 can thus be used for grinding from both sides.
At its input 20, the forming duct 18 has a tubular, in particular cylindrical section 30, which merges into a funnel-like section 32. The funnel-like section 32 has a cross section, which changes to the output 22 and which increasingly constricts on the one hand and changes the shape from round to rectangular on the other hand, so that the cross section is formed in a slit-like manner at the output 22.
If the grinding belt 24 is pushed through from the input 20 to the output 22, it is folded over automatically along its center line.
The tubular section 30 has fastening means 34, for example a screw, by means of which the funnel-like section 32 can be firmly connected to the tubular section 30.
The funnel-like section 32 comprises two half shells 38, 40, which can be screwed together by means of a screw 36.
A bracing 42 is preferably (albeit not necessarily) arranged within and/or between the two half shells 38, 40 and thus within the forming tunnel 16, in particular within the funnel-like section 32, around which the grinding belt 24 can place itself. The bracing 42 provides additional stability to the grinding belt and makes it possible to increase the grinding pressure. The bracing 42 is preferably formed from sheet steel, in particular formed as sheet metal strip with consistent thickness.
In a non-illustrated alternative, the bracing is formed with varying thickness. The bracing thereby tapers towards its upper longitudinal side. This means that the thickness of the bracing decreases in the transverse direction of the bracing or towards the top in the illustrations according to
If the grinding belt 24 has sufficient stiffness and/or the grinding pressure remains below a threshold value, the bracing 42 can be forgone.
The bracing 32 has several bores, wherein two bores 44, 46 are provided for receiving positioning pins, which engage with one or both of the half shells 38, 40. A further bore 48 serves for the guide-through of the screw 36.
A first chamber 50 and a second chamber 52, which can be ventilated with compressed air, are provided in the housing 14. For this purpose, the first chamber 50 is connected to a compressed air connection 54, while the second chamber 52 is connected to a further compressed air connection 56.
Both chambers 50, 52 are separated from one another by means of a separating wall 58, which can be displaced in the stroke or lifting direction. The separating wall 58 is rigidly connected to the forming tunnel 16, for example by means of pressing or adhesion or by means of a positive connection.
The compressed air connections 54, 56 are connected to a compressed air control unit (not illustrated) via compressed air lines, which ensure a ventilation and purging of the first chamber 50 and of the second chamber 52, namely alternatingly according to the frequency of the stroking or lifting movement.
The separating wall 58 is sealed against the housing 14 by means of an annular seal 60. Two further annular seals 62, 64, which seal the housing 14 against the forming tunnel 16, are further provided.
The housing 14 includes a housing cover 66, which is fixed to the remaining housing 14 by means of screws 68, in particular grub screws.
The deburring tool 10 can be guided towards virtually any positions of a workpiece by means of the robot arm 72. The grinding belt holder 12 is set into an alternating linear stroking or lifting movement by means of compressed air or another drive, for example an electromagnetic drive, so that the grinding belt 24 is moved back and forth in order to debur workpieces.
As soon as a deburring process is completed, the deburring tool is guided to a clamping means. The grinding belt is clamped there, a piece of the grinding belt is removed from the roll and is cut off by means of a cut-off means. The grinding belt 24 is subsequently clamped again around the bracing 32 by means of the clamping means and is thus provided with a folding edge.
As a whole, the invention makes it possible to provide a deburring machine which comprises a deburring tool and which provides for an automatic replacement of the grinding belt in an automated process in order to obtain high machining qualities.
The invention is in fact preferably used during the deburring of multipoles, in particular quadrupoles, for mass spectrometers. In particular slits between electrode sections are thereby deburred after the grinding of the electrodes. The invention is preferably used when surfaces, which are machined in a highly precise manner, so-called precision surfaces, must not be damaged, such as, for example, the machined precision surfaces of multipoles of mass spectrometers. The deburring tool according to the invention provides for a machining of only the edge with the burr, in that the grinding belt is placed only onto this edge and thus only acts on this edge. The grinding belt thereby does not come into contact with the precision surface and can thus not damage it.
However, the invention can also be used to remove burrs created during the grinding of drills and/or milling cutters, i.e. to debur drills or milling cutters, respectively.
Although only a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.
The following reference numerals are used in the figures:
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2021 104 526.6 | Feb 2021 | DE | national |
