Deburring tool with a sanding belt holder

Description

[0001] The invention relates to a tool with a belt holder for holding the belt according to the preamble of claim 1 and to a deburring machine according to claim 11 or 12 with such a tool.

[0002] A generic tool is known from DE 699 17 089 T2, in which a double-folded abrasive belt is inserted transversely into a slot of a spindle. By rotating the spindle, e.g., in the chuck of a drill, holes, openings, etc., can be ground. Due to the rotational movement of the transversely inserted abrasive belt, a minimum diameter of the holes or openings is required that is substantially larger than the diameter of the spindle. This tool is therefore only suitable for correspondingly large holes and openings and results in imprecise and coarse machining – also due to the rotating free ends of the transversely inserted abrasive belt.

[0003] The invention relates to the deburring of precision workpieces, such as the spaces between electrodes of multipoles, in particular quadrupoles, intended for mass spectrometers. EP 3 385 979 A1 shows, for example, in Figures 2a and 2c, a half-shell of a quadrupole for a mass spectrometer, wherein each half-shell has two electrode bars, each divided into three electrically isolated sections. This electrical separation is achieved by means of a cut produced by wire EDM. Subsequently, the surfaces of the electrode bars, shown in black in the aforementioned figures, are ground to a high precision, for example, with an accuracy of 0.1 to 1 µm. As a result of this grinding process, burrs typically form in the area of ​​the cuts and in the area of ​​edges. However, such burrs are detrimental to the measurement accuracy of the quantities measured with a mass spectrometer.Furthermore, there is a risk of injury on such ridges.

[0004] It is therefore necessary to perform deburring. Traditionally, deburring is done manually. However, manual deburring is time-consuming and therefore expensive. Furthermore, the quality of the deburring depends on the person performing the process.

[0005] The invention therefore aims to perform the deburring process, which is conventionally carried out manually, by machine.

[0006] However, this goal is thwarted by the fact that suitable deburring machines are not available.

[0007] While sanding belt holders for use in hand-held filing machines are known, such as the Poly-Strip sanding belt holder offered by joke Technology GmbH, where the sanding belt is guided back around a metal strip and clamped to the holder, replacing the sanding belt with this system is not suitable for an automated process but is designed for manual replacement.

[0008] The invention is therefore based on the objective of providing a deburring tool with a grinding belt holder that enables automatic renewal of the grinding belt in an automated process with high quality.

[0009] The invention solves this problem with the features of a deburring tool according to claim 1 and a deburring machine according to claim 11 or 12 with such a deburring tool.

[0010] The deburring tool according to the invention has a belt holder designed to hold a belt, wherein the deburring tool comprises a housing in which the belt holder can perform an alternating linear stroke. The belt holder has a forming tunnel that forms a forming channel with an inlet and an outlet for guiding the belt. The forming tunnel encloses the forming channel such that the tunnel wall forms the outer boundary of the forming channel. A belt can be fed into the inlet side of the forming channel and exits the forming channel folded centrally in the longitudinal direction. The forming channel has a round cross-section at the inlet side and a slot-like cross-section at the outlet side.

[0011] This design of the forming channel ensures that a grinding belt can be easily inserted. The curvature of the forming channel helps the grinding belt to curve along its contour. As the grinding belt is fed further into the forming channel, it undergoes further deformation until it finally emerges from the channel folded or creased lengthwise.

[0012] As a result of this folding process, a sanding belt is obtained that can be used for sanding on both sides, even if the sanding belt itself only has a top side for sanding and a bottom side that is not intended for sanding.

[0013] During the machining of a workpiece by grinding, e.g., during the deburring of a gap between electrode sections of a quadrupole mass spectrometer, the grinding belt wears down to a certain extent. To ensure consistent quality for every workpiece, the invention preferably provides that the grinding belt is replaced for each workpiece, thus enabling the production of workpieces with uniform quality.

[0014] The deburring tool according to the invention allows the abrasive belt to be pulled out and cut to a predefined length and, if necessary, subsequently pressed firmly back together. This process can be ideally automated and therefore ensures consistent quality.

[0015] According to a further development of the invention, the forming tunnel has a tubular, in particular cylindrical, section beginning at the inlet of the forming channel, which is connected to, and in particular transitions into, a funnel-shaped section that narrows towards the outlet of the forming channel and terminates with a rectangular cross-section at the outlet of the forming channel. This design simplifies the automated folding of the abrasive belt along its longitudinal axis.

[0016] A further development of the invention provides that the tubular section of the forming tunnel is formed by a tube with a cylindrical section. The round or circular opening for the abrasive belt provided in this way facilitates the trouble-free feeding of the abrasive belt into the abrasive belt holder.

[0017] According to a further development of the invention, the funnel-shaped section of the forming tunnel has two half-shells that can be screwed together. Such a design facilitates the maintenance of the deburring tool in the event of a malfunction, as the two half-shells can be separated from each other by loosening the screw connection, thereby providing access to the interior of the deburring tool.

[0018] A further development of the invention provides that a blade is arranged within the forming tunnel, particularly within the funnel-shaped section, which exits the forming channel on the outlet side. The blade only partially fills the slot-like cross-section on the outlet side of the forming channel, such that the abrasive belt wraps around one of the two longitudinal edges of the blade. Such a blade is advantageous because it stiffens the abrasive belt and, in particular, stabilizes thin abrasive belts. However, the blade is not necessary and not always useful, especially when flexibility of the abrasive belt is advantageous for specific applications.

[0019] The blade is preferably designed as a sheet metal strip of uniform thickness. The blade is either flat or curved. A flat blade can be advantageous for deburring straight edges or cuts. If the blade is curved, the bend is in the transverse direction of the blade, i.e., around its longitudinal axis, with a radius perpendicular to the plane of the sheet metal strip. This gives the sheet metal strip a trough-like shape. The radius is preferably constant across the width of the blade. Alternatively, the radius can vary across the width of the sheet metal strip. A curved blade can be advantageous for deburring bent or curved edges or cuts. The radius of the blade is adapted to the radius of the bent or curved edge or the bent or curved cut.In particular, the radius of the sword is greater than or equal to the radius of the bent or curved edge or the bent or curved cut.

[0020] Alternatively, the blade is designed with a thickness that changes in the transverse direction of the blade, i.e., perpendicular to the direction of the linear stroke, and in particular with a decreasing thickness towards one of its longitudinal edges. In this case, the blade tapers towards one of its longitudinal sides. That is, the thickness decreases in the transverse direction of the blade. This change in thickness corresponds to the change in thickness of a knife blade. Preferably, the blade has a V-shaped or triangular cross-section. The abrasive belt then lies over the pointed edge onto the two outer surfaces of the V-shape. This pointed edge is inserted into the slot or crevice to be deburred during the stroke movement. This blade contour is advantageous for secondary burr removal.

[0021] According to a further development of the invention, the abrasive belt holder can be pneumatically driven within the housing to perform an alternating stroke motion. The housing contains a first air chamber and a second air chamber, which can be pressurized, vented, and de-vented using compressed air. The two chambers are separated from each other by a movable partition, which is rigidly connected to the forming tunnel, particularly its tubular section, for example, by means of a clamping connection, a screw connection, an adhesive connection, or a welded connection. The alternating stroke motion is thus provided by a pneumatic drive. Compressed air can be fed into a drive mechanism designed with minimal structural complexity to generate the movement. Such a drive can be provided in the area of ​​the deburring tool without any electrical components. This eliminates the need for protective measures for electrical components.Furthermore, a pneumatic drive can be designed in a cost-effective manner and implemented in a space-saving way.

[0022] A further development of the invention provides that the abrasive belt holder can be electromagnetically driven within the housing for an alternating stroke movement, wherein the housing has a magnetic coil and a part of the abrasive belt holder, in particular the forming tunnel, forms the magnetic armature. Such a design is advantageous when no compressed air is available.

[0023] According to a further development of the invention, the deburring tool is housed in a machine housing that also accommodates an abrasive belt wound into a roll, wherein the abrasive belt can be fed to the inlet of the forming channel, particularly via a deflection roller. In this way, the abrasive belt roll with a large supply can be housed in the deburring tool, thus providing a large supply of abrasive belt during processing and enabling a substantially continuous processing process despite frequent belt replacement. A sufficient supply allows for frequent replacement of the abrasive belt and thus ensures deburring with consistently high quality.

[0024] A further development of the invention provides that the deburring tool includes a clamping device for clamping, pulling off, and compressing the abrasive belt and / or a cutting device comprising a cutting tool for cutting the abrasive belt. The clamping device and / or cutting device can thus be integrated into the deburring tool. These devices facilitate the automatic renewal of the abrasive belt by pulling off and cutting it.

[0025] A further development of the invention provides that the deburring tool is part of a deburring machine which has a multi-axis controllable robot arm on which the deburring tool is mounted. The deburring machine therefore comprises a robot with at least one robot arm. Thanks to the robot arm, the abrasive belt can also be used for deburring in hard-to-reach areas of workpieces in a predefined manner. This also ensures a high and consistent processing quality.

[0026] The deburring tool is alternatively part of a deburring machine that has a movable arm of a gantry machine or a movable arm of a CNC milling machine, on which the deburring tool is mounted. In these cases, the deburring machine comprises a gantry machine or a CNC milling machine, each with movable axes.

[0027] According to a further development of the invention, the deburring machine comprises a clamping device arranged outside the deburring tool for clamping, pulling off, and compressing the abrasive belt, and a cutting device arranged outside the deburring tool, which includes a cutting tool for cutting the abrasive belt. The clamping device and / or cutting device are thus provided separately from the deburring tool – unlike the variant integrated into the deburring tool described above. These devices facilitate the automatic renewal of the abrasive belt by pulling off and cutting it.

[0028] The drawing shows: Fig. 1A-E shows an embodiment of a deburring tool according to the invention in various views, namely Fig. 1A in a side view, Fig. 1B in a top view, Fig. 1C in a view along the Fig. 1BSectional plane shown, Fig. 1; in a front view, Fig. 1; in a rear view, Fig. 2; the in the Figures 1A to 1E The deburring tool shown has a grinding belt unwound from a grinding belt roll and guided through the deburring tool in a schematically depicted machine housing on a robot arm.

[0029] Figures 1A to 1E Figure 1 shows an embodiment of a deburring tool 10 according to the invention with a grinding belt holder 12, which is movably arranged in a housing 14. The grinding belt holder 12 can perform a linear stroke movement 15, the stroke being limited by two stops. Figures 1A to 1C The sanding belt holder 12 is at its left stop. The linear stroke movement is alternating, i.e., the sanding belt holder 12 moves in the Figures 1A to 1C from left to right and back again.

[0030] This alternating linear stroke motion occurs at a frequency of 5-20 strokes per second. The frequency is adjustable.

[0031] The abrasive belt holder 12 has a forming tunnel 16 which includes a forming channel 18 with an inlet 20 and an outlet 22 for the passage of a Fig. 2 The illustrated grinding belt 24 forms the inlet 20 of the forming channel 18. The inlet 20 of the forming channel 18 is also the inlet of the forming tunnel 16. Likewise, the outlet 22 of the forming channel 18 is also the outlet of the forming tunnel 16. The forming tunnel 16 forms the outer boundary of the forming channel 18.

[0032] As in Fig. 2As shown, the abrasive belt 24 is unwound from an abrasive belt roller 26 and fed to the inlet 20 of the forming channel 18 via a deflection roller 28. The deflection roller 28 can be omitted if the abrasive belt roller 26 is arranged differently. However, more than one deflection roller can also be provided to feed the abrasive belt to the inlet 20 of the forming channel 18.

[0033] The abrasive belt 24 has twice the width on the abrasive belt reel 26 as it does at the outlet 22. This is because the abrasive belt 24 is formed in the forming channel 18 and folded lengthwise in the middle, i.e., along the center line of the abrasive belt 24. This creates a fold line in the middle of the abrasive belt 24. As a result, the abrasive belt at the outlet 22 has only half the width it does on the abrasive belt reel 26.

[0034] The sanding belt 24 has a top side intended for sanding, and usually a bottom side not intended for sanding.

[0035] By folding the sanding belt 24 along its center line, the top side of the sanding belt 24, intended for sanding, points in both directions. The folded sanding belt 24 can therefore be used for sanding from either side.

[0036] The forming channel 18 has a tubular, in particular cylindrical, section 30 at its inlet 20, which transitions into a funnel-shaped section 32. The funnel-shaped section 32 has a cross-section that changes towards the outlet 22, becoming progressively narrower and changing shape from round to rectangular, so that the cross-section at the outlet 22 is slot-shaped.

[0037] When the sanding belt 24 is pushed from the entrance 20 to the exit 22, it is automatically folded over along its center line.

[0038] The tubular section 30 has fastening means 34, e.g. a screw, with which the funnel-shaped section 32 can be firmly connected to the tubular section 30.

[0039] The funnel-shaped section 32 comprises two half-shells 38, 40 which can be screwed together by means of a screw 36.

[0040] A blade 42 is preferably (though not necessarily) arranged within and / or between the two half-shells 38, 40, and thus within the forming tunnel 16, particularly within the funnel-shaped section 32, around which the grinding belt 24 can wrap. The blade 42 provides the grinding belt with additional stability and makes it possible to increase the grinding pressure. The blade 42 is preferably made of sheet steel, in particular as a strip of sheet metal with a uniform thickness.

[0041] In an alternative version not shown, the sword has a varying thickness. The sword tapers towards its upper longitudinal side. That is, in the transverse direction of the sword, or as shown in the illustrations according to the Figures 1A, 1C and 2 The thickness of the sword decreases towards the top. Preferably, the sword is then V-shaped or triangular in cross-section, with the pointed edge shown in the illustrations according to the Figures 1A, 1C and2 The upper edge of the sword is 42. The grinding belt then lies over this pointed edge onto the two outer surfaces of the V-shape.

[0042] Provided that the grinding belt 24 has sufficient stiffness and / or the grinding pressure remains below a threshold value, the sword 42 can be omitted.

[0043] The sword 42 has several bores, two of which, 44 and 46, are provided for receiving positioning pins that engage with one or both of the half-shells 38 and 40. A further bore 48 serves to guide the screw 36.

[0044] The housing 14 contains a first chamber 50 and a second chamber 52, which can be vented with compressed air. For this purpose, the first chamber 50 is connected to a compressed air connection 54, while the second chamber 52 is connected to another compressed air connection 56.

[0045] Both chambers 50, 52 are separated from each other by a partition wall 58 that can be moved in the direction of travel. The partition wall 58 is rigidly connected to the forming tunnel 16, for example by pressing or bonding or by a positive-locking connection.

[0046] The compressed air connections 54, 56 are connected via compressed air lines to a compressed air control unit (not shown), which provides ventilation and venting of the first chamber 50 and the second chamber 52 alternately according to the frequency of the stroke movement.

[0047] The partition wall 58 is sealed against the housing 14 by a ring seal 60. Furthermore, two additional ring seals 62, 64 are provided, which seal the housing 14 against the forming tunnel 16.

[0048] The housing 14 includes a housing cover 66, which is fixed to the rest of the housing 14 by means of screws 68, in particular grub screws.

[0049] Fig. 2Figure 1 shows that the deburring tool 10 is arranged in a machine housing 70, which also accommodates the abrasive belt roller 26 and the deflection roller 28. The machine housing 70 advantageously forms the end of a multi-axis controlled robot arm 72. The machine housing 70 and the robot arm 72 are in Fig. 2 only shown schematically.

[0050] The robot arm 72 allows the deburring tool 10 to be moved to almost any position on a workpiece. Compressed air or another drive, such as an electromagnetic drive, sets the abrasive belt holder 12 into an alternating linear stroke motion, causing the abrasive belt 24 to move back and forth to deburr workpieces.

[0051] Once a deburring operation is complete, the deburring tool is guided to a clamping device. There, the abrasive belt is clamped, a section of the belt is pulled from the roll, and cut off by a cutting device. The clamping device then re-clamps the abrasive belt 24 around the blade 42, thus creating a folded edge.

[0052] Overall, the invention makes it possible to provide a deburring machine with a deburring tool that enables automatic renewal of the grinding belt in an automated process to achieve high machining qualities.

[0053] The invention is preferably used for deburring multipoles, especially quadrupoles, for mass spectrometers. In particular, slots between electrode sections are deburred after the electrodes have been ground. The invention is especially useful when high-precision machined surfaces, so-called precision surfaces, must not be damaged, such as the precision surfaces of multipoles in mass spectrometers. The deburring tool according to the invention allows only the edge with the burr to be processed, as the abrasive belt is applied only to this edge and therefore acts only on this edge. The abrasive belt does not come into contact with the precision surface and therefore cannot damage it.

[0054] The invention can also be used to remove burrs that have formed after grinding drills and / or milling cutters, i.e., to deburr drills or milling cutters.

[0055] The following reference numbers are used in the figures: 10 Deburring tool 12 Grinding belt holder 14 Housing 15 Stroke movement 16 Forming tunnel 18 Forming channel 20 Inlet of forming channel and forming tunnel 22 Outlet of forming channel and forming tunnel 24 Grinding belt 26 Grinding belt roller 28 Deflection roller 30 Tubular section of forming channel 32 Funnel-shaped section of forming channel 34 Fastener 36 Screw 38 Half shell 40 Half shell 42 Blade 44 Bore 46 Bore 48 Bore 50 First chamber 52 Second chamber 54 Compressed air connection 56 Compressed air connection 58 Partition 60 Ring seal 62 Ring seal 64 Ring seal 66 Housing cover 68 Grub screws 70 Machine housing 72 Robot arm

Claims

1. Tool with an abrasive strip holder (12) designed to hold an abrasive strip (24), wherein the tool has a housing (14), characterized in that the tool is a deburring tool (10), that the abrasive strip holder (12) can perform an alternating linear reciprocating movement (15) in the housing (14), and that the abrasive strip holder (12) has a forming tunnel (16) which forms a forming channel (18) with an inlet (20) and an outlet (22) for guiding the abrasive strip (24) through, wherein the forming channel (18) is designed such that it has a round cross-section at its inlet (20) and a slit-shaped cross-section at its outlet (22) such that an abrasive strip (24) fed to its inlet (20) emerges from the outlet (22) of the forming channel (18) folded centrally in the longitudinal direction of the abrasive strip (24).

2. Deburring tool according to claim 1, characterized in that the forming tunnel (16) has a tubular, in particular cylindrical, section (30) beginning at the inlet (20) of the forming channel (18), which is connected to a funnel-shaped section (32) that narrows in the direction of the outlet (22) of the forming channel (18) and ends with a rectangular cross-section at the outlet (22) of the forming channel (18), in particular merges into this funnel-shaped section (32).

3. Deburring tool according to claim 2, characterized in that the tubular section (30) of the forming tunnel (16) is formed by a tube with a cylindrical section.

4. Deburring tool according to claim 2 or 3, characterized in that the funnel-like section (32) of the forming tunnel (16) has two half-shells (38, 40) that can be screwed together.

5. Deburring tool according to one of the preceding claims, characterized in that a blade (42) is arranged inside the forming tunnel (16), in particular inside the funnel-like section (32), which blade emerges at the outlet (22) of the forming channel (18), wherein the blade (42) only partially fills the slit-like cross-section at the outlet (22) of the forming channel (18) in such a way that the abrasive strip (24) wraps around the blade (42).

6. Deburring tool according to claim 5, characterized in that the blade (42) is formed as a sheet metal strip of uniform thickness, flat or curved, in particular curved in the transverse direction of the blade with a constant or variable radius aligned perpendicular to the plane of the sheet metal strip, or the blade (42) is designed with a thickness that changes in the transverse direction of the blade, in particular with a thickness that decreases toward one of its longitudinal edges.

7. Deburring tool according to one of the preceding claims, characterized in that the abrasive strip holder (12) can be pneumatically driven within the housing (14) for alternating reciprocating movement (15), wherein a first chamber (50) and a second chamber (52) are formed in the housing (14), which can be pressurized with compressed air and can be ventilated and vented, wherein both chambers (50, 52) are separated from each other by a movable partition wall (58) which is rigidly connected to the forming tunnel (16), in particular its tubular section (30).

8. Deburring tool according to one of the preceding claims, characterized in that the abrasive strip holder (12) can be driven electromagnetically within the housing (14) for alternating reciprocating movement (15), wherein the housing (14) has a magnetic coil and a part of the abrasive strip holder (12), in particular the forming tunnel (16), forms the magnetic armature.

9. Deburring tool according to one of the preceding claims, characterized by a machine housing (70) which also accommodates an abrasive strip (24) rolled up onto an abrasive strip roll (26), wherein the abrasive strip (24), in particular guided via a deflection pulley (28), can be fed to the inlet (20) of the forming channel (18).

10. Deburring tool according to one of the preceding claims, characterized by a clamping device for clamping, pulling off and compressing the abrasive strip (24) and / or a cutting device comprising a cutting tool for cutting off the abrasive strip (24).

11. Deburring machine with a deburring tool according to one of the preceding claims, characterized by a multi-axis controlled robot arm (72) or movable axes of a portal machine or movable axes of a CNC milling machine, on which the deburring tool (10) is arranged.

12. Deburring machine according to claim 11 or with a deburring tool according to one of the preceding claims, characterized by a clamping device arranged outside the deburring tool (10) for clamping, pulling off and compressing the abrasive strip (24) and / or a cutting device arranged outside the deburring tool (10), which has a cutting tool for cutting off the abrasive strip (24).