JP2005169615A - Ultrasonic machining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic machining device capable of making the magnitude of ultrasonic vibration applied to a tool constant irrespective of the place of the tool, and simplifying, miniaturizing the device, reducing cost, and improving reliability. <P>SOLUTION: The ultrasonic machining device is composed of a lapping machine 3 rotatably supported by a rotation spindle 4, a slurry supplying device 3 supplying abrasive grain slurry 2 to the surface of the lapping machine, and a work holder 6 rotatably holding the target work 5 polished while being contacted on the surface of the lapping machine through the abrasive grain slurry. Since the lapping machine is mounted to a supporter 18, the supporter and the ultrasonic vibration applying means 7a, 7b relatively move while contacting each other, a solid lubricant 8 is jointed to the tip of the ultrasonic vibration applying means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a machine tool for processing metal, ceramic and plastic, which uses ultrasonic vibration.

A machine tool is a machine used to make things. A machine tool is usually a machine that is defined in a narrow sense and uses a removal process such as cutting and grinding to create a desired shape. In recent years, the number of objects to be processed by machine tools has increased from difficult-to-process materials such as ceramics, titanium, and hard metals that cannot be processed by conventional machine tools or have a low processing speed. Therefore, so-called ultrasonic cutting technology for processing difficult-to-process materials by applying ultrasonic vibrations to machine tools has been widely used. It should be noted that ultrasonic cutting has the advantage that the cutting force is reduced, the frictional heat of the cutting tool is reduced, the thermal distortion of the machined surface is reduced, the life of the cutting tool is prolonged, and the machining accuracy is improved. ing. Note that the ultrasonic cutting is described in detail in Non-Patent Document 1.
Ultrasound Handbook Editorial Committee, “Ultrasound Handbook”, Maruzen Co., Ltd., August 1999, p. 679-684

  In the conventional device for applying ultrasonic vibration to a rotating or linearly moving machining device, the ultrasonic vibrator moves along with the machining device. However, depending on the position of the ultrasonic vibrator attached to the tool of the machining apparatus that rotates or linearly moves, a place where the ultrasonic vibration is large and a place where the ultrasonic vibration is small are generated, and the amount of wear differs depending on the place of the tool. As a result, unevenness in machining accuracy and changes in machining speed occurred.

  Further, since the ultrasonic vibrator is rotated together with the rotating machining device, a power feeding device such as a slip ring is required, which makes the device complicated and expensive. Further, in order to linearly move the ultrasonic vibrator together with the processing device that moves linearly, a moving cable wire for power feeding is required, and this cable wire moves, so there is a risk of disconnection.

  As an example of a conventional processing apparatus, “lapping apparatus and lapping method” described in the specification of the inventor's previous patent application (Japanese Patent Application No. 2002-1992269) shown in FIG. 7 is a lapping machine 1 pivotally supported by a rotating spindle 4, a slurry supply device 3 for supplying abrasive slurry 2 to the surface of the lapping machine 1, and a workpiece 5 to be polished on the surface of the lapping machine 1. The workpiece holder 6 is an object to be polished that is rotatably held while being brought into contact with the grain slurry 2. The lapping machine 1 is provided with ultrasonic vibration applying means 7 a and 7 b for applying ultrasonic vibration that vibrates in a direction perpendicular to the surface of the lapping machine 1 via the support 6 of the lapping machine 1. Each ultrasonic vibration applying means is preferably fixed through a contact medium such as grease in order to efficiently apply the ultrasonic vibration generated thereby to the support 6. The ultrasonic vibration applying means 7a and 7b are provided with an ultrasonic AC power supply 15 as means for supplying electric energy to each. Each ultrasonic vibration applying means and the ultrasonic AC power supply 15 are electrically connected via a slip ring 33 provided on the rotating shaft 4 of the motor 24.

  In this example, since the ultrasonic vibration applying means is attached to a fixed place of the support 6 of the lapping machine 1 to which the lapping machine 1 is attached, naturally the ultrasonic vibration at the position of the lapping machine above that position is the largest. As a result, since the magnitude of the ultrasonic vibration varies depending on the position of the lapping machine, the amount of wear and the processing speed vary depending on the position of the lapping machine. This is a problem because it affects the machining accuracy. Further, the slip ring 33 is required as means for supplying electric energy to the ultrasonic vibration applying means 7a and 7b, which causes a problem that the apparatus becomes complicated and large, and the manufacturing cost increases.

  Application of ultrasonic vibration to the cutting device is also performed. An example is shown in FIG. A part of the rotary spindle 4 of the cutting device is an ultrasonic transducer. That is, piezoelectric ceramics 12a and 12b are attached to the rotating spindle 4 to form an ultrasonic vibrator. Then, a high-frequency AC voltage is applied to the piezoelectric ceramics 12 a and 12 b from the ultrasonic AC power supply 15 through the slip ring 33. As a result, ultrasonic vibration is excited in the rotating spindle 4 and propagates to the cutting blade 19. However, since the natural frequency of the rotary spindle 4 and the natural frequency of the desired vibration mode of the cutting blade 19 generally do not coincide with each other, it is difficult to efficiently excite the desired vibration mode in the cutting blade. Further, the slip ring 33 is necessary as means for supplying electric energy to the piezoelectric ceramic, which causes a problem that the apparatus becomes complicated and large, and the manufacturing cost increases.

  Ultrasonic TECHNO (April 1998, pages 2-8, published by Nippon Kogyo Publishing Co., Ltd.) describes an ultrasonic cutting apparatus for machining small-diameter holes shown in FIG. This apparatus applies ultrasonic vibration to a drill. The drill 25 is accommodated in a drill holder 26, and the drill holder 26 is joined to rotating ultrasonic vibration applying means 7. The ultrasonic vibration applying means 7 is rotated by a rotary motor 24. An ultrasonic AC voltage is applied to the rotating ultrasonic vibration applying means 7 via the slip ring 33 by the ultrasonic AC power source 15. This ultrasonic drilling machine for machining small-diameter holes has remarkably improved machining accuracy compared to ordinary cutting due to the effect of ultrasonic vibration. However, the ultrasonic cutting apparatus for machining small-diameter holes also requires the slip ring 33, which causes a problem that the apparatus becomes complicated and large, and the manufacturing cost increases. Further, in order to increase the cutting efficiency, the natural frequency of the ultrasonic vibrator must be changed depending on the material and shape of the drill, but this is not easy.

  An object of the present invention is an apparatus that applies ultrasonic vibration to a processing apparatus that rotates or linearly moves, and the change in vibration depending on the location of the tool that requires ultrasonic vibration is small, and power is supplied to the ultrasonic vibrator. It is an object of the present invention to provide a machining apparatus that does not require a slip ring to perform the operation and that does not require a moving cable for feeding.

  The present invention provides an ultrasonic processing apparatus for processing a workpiece using ultrasonic vibration, wherein ultrasonic vibration is applied to a tool for processing the workpiece via a solid lubricant.

Preferred embodiments of the ultrasonic processing apparatus of the present invention are as follows.
(1) An ultrasonic transducer that rotates a tool for machining a workpiece and generates ultrasonic vibrations is fixed.
(2) A tool for machining a workpiece moves linearly and an ultrasonic transducer that generates ultrasonic vibration is fixed.
(3) A solid lubricant is attached to a tool for machining a workpiece.
(4) A solid lubricant is attached to the ultrasonic transducer.
(5) A fluid lubricating film exists between the solid lubricant and the tool for machining the workpiece.
(6) The frequency of the alternating voltage applied to the ultrasonic transducer is 15 kHz or more and 100 kHz or less.

  Since the ultrasonic processing apparatus of the present invention can excite ultrasonic vibrations on a tool for processing a workpiece even when an ultrasonic vibrator is fixed, power is supplied to a rotating device such as a slip ring. Since no device is required, it can be manufactured at low cost. In addition, the apparatus can be miniaturized. Furthermore, an ultrasonic transducer can be easily attached to an existing apparatus. In addition, since the ultrasonic vibrator is fixed and the tool that processes the workpiece moves, it can give the tool a uniform ultrasonic vibration that does not depend on the location of the tool when viewed as one cycle of the movement of the tool. Since it becomes possible, the effect of ultrasonic vibration becomes remarkable. Furthermore, since the ultrasonic vibrator is fixed, the cable that supplies power does not move, so a sufficiently large shape can be used, so that it is possible to supply large power to the ultrasonic vibrator, and it is powerful Since the ultrasonic vibration can be excited, the effect of the ultrasonic vibration can be sufficiently exhibited.

  First, the solid lubricant used in the present invention will be described. There are four types of solid lubricants.

  The first is a substance having a layered crystal structure, such as sulfides such as molybdenum disulfide and tungsten disulfide, and graphite. Others include fluorides such as carbon fluoride and nitrides such as boron nitride.

  The second is plastics, and engineering plastics such as PTFE have excellent mechanical properties, so when used as sliding members, they show very good lubricity, and as self-lubricating solid lubricating materials It is used a lot.

  The third is a self-lubricating composite material, and a composite material having self-lubricating properties can be obtained by compounding a solid lubricant such as molybdenum disulfide and graphite with a metal material having no lubricity.

  The fourth is a soft metal, such as low melting point lead, zinc, tin, or a thin film such as gold or silver.

  FIG. 1 is a front view showing the first embodiment. The difference from the configuration of the apparatus of FIG. 7 is that there is no slip ring and that the ultrasonic vibration applying means is fixed to the base table 10 without being attached to the support of the lapping machine.

  The lapping apparatus of FIG. 1 includes a lapping machine 1 pivotally supported by a rotating spindle 4, a slurry supply apparatus 3 that supplies abrasive slurry 2 to the surface of the lapping machine, and a workpiece 5 that is an object to be polished on the surface of the lapping machine 1. The workpiece holder 6 is rotatably held while being in contact with the abrasive slurry 2. The lapping machine 1 is attached to a support 18. Since the support 18 and the ultrasonic vibration applying means 7a and 7b move relatively in contact with each other, the solid lubricant 8 is joined to the tip portions of the ultrasonic vibration applying means 7a and 7b. Further, the ultrasonic vibration applying means 7 a and 7 b are fixed to the base table 10 using the ultrasonic transducer mounting table 9. However, the ultrasonic vibration applying means 7a and 7b are pressed against the support 18 using the spring 11 in order to make sure that they come into contact with the support 18. Further, the surface of the support 18 that comes into contact with the solid lubricant 8 is lapped to improve the contact state.

  As the ultrasonic vibration applying means 7a, a Langevin type vibrator configured by bolting piezoelectric ceramics 12a, 12b and electrode plates 13a, 13b between an upper metal member 14a and a lower metal member 14b. Is used. Note that a solid lubricant 8 is bonded to the Langevin type vibrator with an epoxy resin. Therefore, the Langevin type vibrator is configured including the solid lubricant. The solid lubricant is a composite material in which graphite is impregnated with an antimony alloy, and is SC-Carbon NC-071 manufactured by Nippon Carbon Co., Ltd.

  Each of the piezoelectric ceramics 12a and 12b is formed of, for example, a lead zirconate titanate ceramic material. Each of the electrode plates 13a and 13b is made of phosphor bronze, for example. Each of the piezoelectric ceramics 12a and 12b is polarized in the thickness direction.

  When a voltage is applied to the electrical wirings 16a and 16b by the ultrasonic AC power supply 15, the Langevin type vibrator generates longitudinal vibration in the length direction. This vibration propagates to the support 18 through the solid lubricant 8 and further propagates to the lapping machine 1.

  The solid lubricant may be joined to a support that is a work tool. At this time, it is more preferable that the surface of the ultrasonic transducer in contact with the solid lubricant is smoothed by lapping or the like.

  Examples of the ultrasonic vibration applying means include an electrostrictive vibrator and a magnetostrictive vibrator. Examples of the electrostrictive vibrator include a piezoelectric vibrator having a structure in which an electrode is attached to each surface of piezoelectric ceramic, and the Langevin vibrator. Examples of the magnetostrictive vibrator include a metal magnetostrictive vibrator and a ferrite vibrator. As the ultrasonic vibration applying means, an electrostrictive vibrator is preferably used because of its simple configuration.

  Next, a procedure for polishing a workpiece, which is an object to be polished, using the lapping apparatus of FIG. 1 will be described. First, the workpiece 5 is held and fixed (temporarily fixed) to the workpiece holder 6 using wax or the like. The workpiece holder 6 holding the workpiece 5 is placed on the surface of the lapping machine 1 such that the side surface thereof is supported by the two rollers 17. Then, the motor 24 is driven to rotate the lapping machine 1 fixed to the rotary spindle 4 connected to the motor 24. As the lapping machine 1 rotates, the work holder 6 supported by the roller 17 rotates. Almost simultaneously with the start of rotation of the lapping machine 1, the abrasive slurry 2 is dropped from the slurry supply device 3 onto the surface of the lapping machine 1. As the lapping machine 1 rotates, the abrasive slurry 2 is supplied between the workpiece 5 and the lapping machine 1. Further, at the same time when the lapping machine 1 starts to rotate, the ultrasonic alternating current power supply 15 applies ultrasonic alternating current to each of the ultrasonic vibration applying means 7a and 7b. By applying ultrasonic alternating current, each of the ultrasonic vibration applying means 7 a and 7 b propagates ultrasonic vibration to the support 18 that rotates and the lapping machine 1 through the solid lubricant 8. The surface of the workpiece 5 is polished by rotating the lapping machine 1 and the workpiece 5 held by the workpiece holder 6 via the abrasive slurry 2.

  Next, the reason why high-precision polishing can be realized with the lapping apparatus of FIG. 1 will be described. Since the ultrasonic vibrator is fixed to the base table, the vibration node can be fixed, so that the performance of the original vibrator can be exhibited. For this reason, the effect of the ultrasonic cutting process mentioned above can fully be acquired.

  Further, since the ultrasonic vibration can be propagated from the ultrasonic vibrator to the moving support tool 18 by the role of the sliding bearing of the solid lubricant, the ultrasonic vibrator is supported at 360 degrees when viewed by one rotation of the support tool. Uniform ultrasonic vibration at 360 degrees can be applied to the lapping machine placed on the support tool in contact with the tool. As a result, the lapping machine comes into uniform contact with the workpiece and wears out uniformly, so that the lapping accuracy is improved. Moreover, there is no fear of uneven wear of the lapping machine.

  Furthermore, since the ultrasonic transducer is fixed to the base table, only electric wiring is required to supply power, and no slip ring is required. For this reason, the apparatus becomes small and inexpensive. Also, the cause of failure is reduced.

  FIG. 2 is a plan view showing a configuration of an example of a cutting device having a second configuration according to the present invention. A thin ring-shaped cutting blade 19 as shown in FIG. 2 is sandwiched between a first flange 20 attached to the tip of the rotary spindle 4 and a second flange 21 fitted to the threaded portion of the rotary spindle 4 for tightening. The nut 22 is fixed by being screwed onto the threaded portion, and the cutting blade 19 is rotated to perform processing at the outer peripheral cutting portion. Then, an ultrasonic vibrator, which is an ultrasonic vibration applying means 7 in which a solid lubricant 8 is joined, is pressed by the spring 11 to the most distal portion of the rotating spindle 4. The spring 11 is attached to a fixing device 23 for fixing the ultrasonic vibrator as the ultrasonic vibration applying means 7. The fixing device 23 is attached to a base table (not shown).

  Next, a procedure for cutting a workpiece using the cutting apparatus of FIG. 2 will be described. Water is radiated to the cutting blade 19 from a nozzle (not shown). Almost simultaneously with this, a high frequency voltage is applied to the ultrasonic vibrator as the ultrasonic vibration applying means 7. As a result, the ultrasonic vibrator pressed by the spring 11 to the most distal portion of the rotating spindle 4 and joined with the solid lubricant 8 gives ultrasonic vibration to the most distal portion of the rotating spindle 4 and also generates ultrasonic vibration. The effect greatly reduces the coefficient of friction between the leading edge of the rotating spindle and the solid lubricant. Furthermore, since the friction coefficient is lowered due to the effect of the solid lubricant, there is no obstacle to the rotation of the rotating spindle. Next, electric power is supplied to the rotary motor 24 to rotate the rotary spindle 4 connected to the rotary motor 24. The ultrasonic vibration applied to the rotating spindle propagates to the cutting blade. This greatly improves the cutting speed and cutting accuracy.

  FIG. 3 is a plan view showing a configuration of an example of a cutting device having a third configuration according to the present invention. A thin ring-shaped cutting blade 19 as shown in FIG. 3 is sandwiched between a first flange 20 attached to the tip of the rotary spindle 4 and a second flange 21 fitted to the threaded portion of the rotary spindle 4 for tightening. The nut 22 is fixed by being screwed onto the threaded portion, and the cutting blade 19 is rotated to perform processing at the outer peripheral cutting portion. Then, an ultrasonic vibrator, which is the ultrasonic vibration applying means 7 to which the solid lubricant 8 is bonded, is pressed against the cutting blade 19 by the spring 11. The solid lubricant pressed against the cutting blade also prevents the cutting blade from shaking. Furthermore, since ultrasonic vibration is added to this, the frictional force is reduced. Also, the water between the cutting blade and the solid lubricant also serves as a fluid guide. The spring is attached to a fixing device 23 for fixing the ultrasonic vibrator as the ultrasonic vibration applying means 7. The fixing device 23 is attached to a base table (not shown).

  Next, a procedure for cutting a workpiece using the cutting apparatus of FIG. 3 will be described. Water is radiated to the cutting blade from a nozzle (not shown). Almost simultaneously with this, a high frequency voltage is applied to the ultrasonic transducer. As a result, the ultrasonic vibrator that is pressed against the cutting blade by the spring and joined with the solid lubricant gives ultrasonic vibration to the cutting blade, and between the cutting blade and the solid lubricant due to the effect of ultrasonic vibration. The friction coefficient is greatly reduced. Furthermore, since the friction coefficient is lowered due to the effect of the solid lubricant, the state becomes the same as that of a rolling bearing, so that there is no obstacle to the rotation of the cutting blade. In addition, the water discharged to the cutting blade by the nozzle also enters between the solid lubricant and the cutting blade, and also serves as a propagation medium that facilitates the propagation of ultrasonic waves. Furthermore, water also has a role of fluid lubrication. Next, electric power is supplied to the rotary motor, and the rotary spindle connected to the rotary motor is rotated. Since ultrasonic vibration propagates directly to the cutting blade, the cutting speed and cutting accuracy are greatly improved.

  FIG. 4 is a front view showing a configuration of an example of a drilling device having a fourth configuration according to the present invention. A hollow rotary spindle 4 is connected to a hollow rotary motor 24, and a drill chuck 25 is connected to the hollow rotary spindle 4. A solid lubricant 8 is bonded to the side opposite to the processing side of the drill 26 chucked by the drill chuck 25. Further, in order to ensure the contact state between the solid lubricant 8 and the ultrasonic vibrator as the ultrasonic vibration applying means 7, the node of the ultrasonic vibrator is supported by the support plate 27, and a rod 29 is further attached to the support plate 27. And a weight 30 is placed on the tip. Here, the linear guide 28 is used so that the rod moves only in the drilling direction.

  The solid lubricant 8 is an epoxy resin containing a solid lubricant component in which 5% by mass of spindle oil-containing graphite having an average particle diameter of 0.5 μm and 5% by mass of PTFE are mixed. The solid lubricant 8 is provided with a fluid lubricating film between the counterpart material. An ultrasonic vibrator as the ultrasonic vibration applying means 7 is brought into contact with the solid lubricant 8 joined to the drill 26 with a certain load.

  Next, a procedure for drilling a workpiece using the drill device of FIG. 4 will be described. First, a high frequency voltage is applied to the ultrasonic transducer that is the ultrasonic vibration applying means 7. As a result, ultrasonic vibration is applied to the solid lubricant bonded to the drill, which is further propagated to the drill. Although the solid lubricant and the ultrasonic vibrator are in contact with each other with a constant load, the friction coefficient is greatly reduced by the effect of the ultrasonic vibration. Furthermore, since the friction coefficient is lowered by the effect of the solid lubricant, it becomes the same state as the rolling bearing, so that it does not become an obstacle to the rotation of the drill. Next, grinding oil is given to the drill, the hollow motor is rotated, and the workpiece is processed. The drill is moved up and down by the linear motor 31. Since ultrasonic vibration propagates directly to the drill, the drilling speed is greatly improved and burrs are hardly generated.

  FIG. 5 is a perspective view showing a configuration of an example of a horizontal axis surface grinding machine of the fifth configuration of the present invention. In the horizontal axis surface grinding machine, the processing table 31 is placed on the linear guide 28 attached to the base table 10, and the table 31 is moved along its length direction. There is a grinding wheel 32 for grinding the workpiece 5 placed on the processing table 31. The grinding wheel 32 is attached to the rotary spindle 4, and the rotary spindle 4 is further connected to the rotary motor 24.

  Next, a portion using ultrasonic vibration will be described with reference to FIG. An ultrasonic vibrator as the ultrasonic vibration applying means 7 is attached to the base table 10 at a position below the grinding wheel 32. A solid lubricant 8 is bonded to the tip of the ultrasonic transducer. The solid lubricant 8 is in contact with the back surface of the processing table 31.

  Next, the procedure for surface grinding a workpiece using the horizontal axis surface grinding machine of FIG. 5 will be described. First, when a high frequency voltage is applied to the ultrasonic vibrator, ultrasonic vibration is applied to the solid lubricant, which is further propagated to the processing table. The solid lubricant and the processing table are in contact with each other by spring pressure, but the friction coefficient is greatly reduced by the effect of ultrasonic vibration. Furthermore, since the friction coefficient is lowered due to the effect of the solid lubricant, the frictional state is the same as that of a rolling bearing, so that there is no obstacle to the processing table. Next, polishing oil is applied to the workpiece, the rotary motor is rotated, the rotary spindle and the grinding wheel are rotated, and the workpiece is processed. Since the ultrasonic vibration of the processing table propagates to the workpiece, the surface grinding speed is greatly improved and the accuracy of the grinding surface is also improved.

  The ultrasonic processing apparatus of the present invention is used in a machine that produces a target shape by mainly using removal processing such as cutting and grinding.

It is a front view which shows the structure of an example of the lapping apparatus of the 1st structure of this invention. It is a top view which shows the structure of an example of the cutting device of the 2nd structure of this invention. It is a top view which shows the structure of an example of the cutting device of the 3rd structure of this invention. It is a front view which shows the structure of an example of the drill apparatus of the 4th structure of this invention. It is a perspective view which shows the structure of an example of the horizontal axis surface grinder of the 5th structure of this invention. It is sectional drawing of the processing table vicinity of a horizontal axis surface grinder. It is a front view which shows the lap | wrap apparatus using the conventional ultrasonic vibration. It is a top view which shows the cutting device using the conventional ultrasonic vibration. It is a front view which shows the drill processing apparatus using the conventional ultrasonic vibration.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lapping machine 2 Abrasive slurry 3 Slurry supply device 4 Rotating spindle 5 Work 6 Work holder 7 Ultrasonic vibration applying means 8 Solid lubricant 9 Mounting base 10 Base base 11 Spring 12 Piezoelectric ceramics 13 Electrode plate 14 Metal member 15 Ultrasonic wave AC power supply 16 Electric wiring 17 Roller 18 Support 19 Cutting blade 20 First flange 21 Second flange 22 Tightening nut 23 Fixing device 24 Rotating motor 25 Drill chuck 26 Drill 27 Support plate 28 Linear guide 29 Bar 30 Weight 31 Processing Table 32 Cutting wheel 33 Slip ring

Claims (7)

  An ultrasonic processing apparatus for processing a workpiece using ultrasonic vibration, wherein ultrasonic vibration is applied to a tool for processing the workpiece via a solid lubricant.   The ultrasonic processing apparatus according to claim 1, wherein an ultrasonic transducer that rotates a tool for processing a workpiece and generates ultrasonic vibration is fixed.   2. The ultrasonic processing apparatus according to claim 1, wherein a tool for processing the workpiece moves linearly and an ultrasonic transducer that generates ultrasonic vibration is fixed.   The ultrasonic processing apparatus according to any one of claims 1 to 3, wherein the solid lubricant is attached to a tool for processing the workpiece.   The ultrasonic processing apparatus according to claim 1, wherein the solid lubricant is attached to the ultrasonic vibrator.   6. The ultrasonic machining apparatus according to claim 1, wherein a fluid lubricating film is present between the solid lubricant and the tool for machining the workpiece. The ultrasonic processing apparatus according to any one of claims 1 to 5, wherein the frequency of the AC voltage applied to the ultrasonic transducer is 15 kHz or more and 100 kHz or less.

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