JP2006110972A - Ultrasonic machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic machining apparatus having a rotary tool which has high rotational accuracy and large rotating speed. <P>SOLUTION: The ultrasonic machining apparatus has a motor 1 for rotating a stainless-steel made rotary shaft 2 having a hole in the center axis, and a first pulley 11 is connected to the shaft of this motor 1. The rotary shaft 2 is provided with a second pulley 12 and a belt 13 for transferring the rotation of the motor 1. A bearing 7 is installed for supporting the rotary shaft 2 rotatably, and a stainless case 14 is provided for fixing this bearing 7. The rotary shaft 2 has a projection 15, and the first flange 16, a blade 6 on which a piezoelectric ceramic 18 is bonded and the second flange 17 are fitted, fastened with a nut 19, and further fastened with a locking nut 20. Driving wiring of drive the piezoelectric ceramic 18 includes a lead wire 22 passed through a hole 21 of the rotary shaft 2 from an ultrasonic oscillator 8 and connected to the ceramic 18. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ultrasonic processing apparatus that uses a tool that rotates glass, ceramic, silicone, cemented carbide, or the like, which is an object to be processed, and applies ultrasonic vibration to the rotating tool to perform processing.

  In order to cut a workpiece formed of a hard and brittle material such as glass, silicon, silicon nitride, or super hard metal, a cutting device having a disk-shaped blade that is a rotating tool is generally used. It is used. Further, there is a grinding apparatus provided with a rod-shaped grindstone that is a tool that rotates to grind the workpiece.

Recently, in order to process so-called difficult-to-process materials, a method of applying ultrasonic vibration to a tool or an object to be processed has been frequently used.
Such a processing method is called ultrasonic cutting, and is described in detail in Non-Patent Document 1, for example. Ultrasonic cutting has the advantages that the frictional resistance between the workpiece and the tool is reduced, so that the thermal distortion of the machined surface is reduced, the machining accuracy is increased, and the life of the cutting tool is extended. is doing.

Patent Document 1 discloses a cutting device having a configuration in which an ultrasonic vibrator is attached to a rotating shaft that rotates a disk-shaped blade. The cutting device shown in the plan view of FIG. 1 and the side view of FIG. 2 has a motor 1 for rotating a rotating shaft, and a slip ring 3 and an ultrasonic transducer 4 are connected to the rotating shaft 2. Further, a cutting tool in which the vibration transmission direction changer 5 and the blade 6 are integrated with the rotary shaft 2 is fastened and fixed by a fastening nut 10. A bearing 7 for rotatably supporting is also provided. Further, an ultrasonic oscillator 8 and a brush 9 for applying an ultrasonic alternating voltage to the ultrasonic transducer 4 are provided.
The general operation method of the above cutting apparatus is as follows. First, when the motor 1 is operated, an ultrasonic alternating voltage is applied from the ultrasonic oscillator 8 to the slip ring 3 rotating through the brush 9 almost simultaneously. The AC voltage applied to the slip ring 3 is applied to the ultrasonic vibrator 4 and the ultrasonic vibrator 4 vibrates ultrasonically. This ultrasonic vibration propagates through the rotary shaft 2 and propagates to a cutting tool in which the vibration transmission direction changer 5 and the blade 6 are integrated. This ultrasonic vibration is converted into ultrasonic vibration that vibrates in a direction in which the diameter of the blade 6 is expanded or contracted by the vibration transmission direction converter 5 and is applied to the rotating blade 6. Then, the workpiece is cut by the blade 6 to which the ultrasonic vibration is applied.

The ultrasonic grinding apparatus is described in detail in Non-Patent Document 2. The ultrasonic grinding apparatus shown in FIG. 3 also has a motor for rotating a rotary shaft, and the rotary shaft is provided with a slip ring and an ultrasonic vibrator. Further, a booster, a horn, and a diamond grindstone as a grinding tool are connected to the rotating shaft. In addition, a bearing for rotatably supporting is arranged. An ultrasonic oscillator and a brush for applying an ultrasonic alternating voltage to the ultrasonic vibrator are provided.
The general operation method of the above ultrasonic grinding apparatus is as follows. First, when the motor is operated, an ultrasonic alternating voltage is applied from an ultrasonic oscillator to a slip ring that rotates through a brush almost simultaneously. The AC voltage applied to the slip ring is applied to the ultrasonic vibrator, and the ultrasonic vibrator vibrates ultrasonically. This ultrasonic vibration propagates through the booster and horn, and then propagates to the grinding wheel, which is a grinding tool.
JP 2000-210928 A Ultrasonic Handbook Editorial Committee, “Ultrasonic Handbook”, Maruzen Co., Ltd., August 1999, p679-684 Japan Electromechanical Industry Association, "Ultrasonic Engineering", Corona Co., Ltd., 1993, p218-229

  However, when an ultrasonic vibrator is attached to the rotating shaft, the rotating shaft vibrates ultrasonically, so that the ultrasonic vibration propagates to the bearing and the bearing may be damaged. In addition, abnormal wear may occur on the rotating shaft and the bearing, or the wear may increase. Furthermore, since an ultrasonic transducer that is substantially equal to the diameter of the rotating shaft is joined to the rotating shaft, the weight increases, inertia increases, and the structure becomes unsuitable for high speed rotation. Furthermore, the rotation becomes unstable due to the shape error and weight imbalance of the ultrasonic transducer bonded to the rotating shaft, the rotating device breaks down, and the processing accuracy decreases.

An object of the present invention is to provide an ultrasonic machining apparatus having a rotary tool having a rotary shaft with high accuracy and high reliability.

  The present invention provides an ultrasonic machining apparatus having a rotating shaft for rotating a machining tool, a hole or a hole penetrating the central axis of the rotating shaft, and applying an AC voltage to the ultrasonic vibrator in the hole. Lead wires are provided for this purpose.

  The present invention is also an apparatus in which an ultrasonic machining apparatus machines a workpiece by using a disk-shaped tool.

  Furthermore, the present invention is an apparatus in which an ultrasonic processing apparatus performs machining on an object to be processed using a rod-shaped tool.

  Since the ultrasonic processing apparatus of the present invention has high rotational accuracy and can be rotated at high speed, high-accuracy and high-speed processing is possible.

FIG. 4 is a plan view including a partial cross-section showing a basic configuration showing the first embodiment. A motor 1 for rotating a stainless steel rotating shaft 2 having a hole in the shaft center is provided, and a first pulley 11 is connected to the shaft of the motor 1. The rotary shaft 2 has a second pulley 12 and a belt 13 for transmitting the rotation of the motor 1. There is a bearing 7 for rotatably supporting the rotating shaft 2, and there is a stainless case 14 for fixing the bearing 7. Only a part of the case 14 is shown in the figure. The rotary shaft 2 has a protrusion 15, and the first flange 16, the blade 6 joined with the piezoelectric ceramic 18 and the second flange 17 are fitted and tightened with a nut 19, and further tightened with a locking nut 20. . Here, the screw part of the rotating shaft 2, the nut 19 and the screw part of the locking nut 20 are omitted for the convenience of the drawing.
In addition, it is important that the hole 21 provided in the rotating shaft 2 has a symmetrical shape as much as possible with respect to the shaft center in order to maintain a rotation balance during rotation.
Further, when the lead wire 22 is fixed to the outer periphery of the rotary shaft 2, the rotation balance may be deteriorated depending on the weight and position of the lead wire 22. On the other hand, if the hole 21 is provided in the axial center of the rotating shaft 22 and the lead wire 22 is provided there, the influence of the weight and position of the lead wire 22 is reduced. This is the reason why the hole 21 is provided in the axial center portion of the rotating shaft 2.

  There is an ultrasonic oscillator 8 for applying an alternating voltage to the piezoelectric ceramic 18, and it is connected to the brush 9 by a lead wire 22. The brush 9 is electrically connected to the slip ring 3 joined to the rotating shaft 2. A hole 21 penetrating the central portion of the rotating shaft 2 is provided, and a lead wire 22 for connecting the slip ring 3 and the piezoelectric ceramic 18 is passed through the hole 21. The lead wire 22 passes through the hole 21, passes through four grooves 23 provided outside the rotating shaft 2, and is connected to the piezoelectric ceramic 18.

  FIG. 5A is a cross-sectional plan view taken along line AA of a side view (B) of the distal end portion of the rotating shaft for showing the details. In addition, the outer peripheral part of the blade 6 was omitted for convenience of drawing. FIG. 5B is a side view thereof. Four grooves 23 are provided at every 90 degrees at the tip of the rotating shaft 2. The lead wire 22 is embedded in the groove with, for example, an epoxy resin. The lead wire 22 passes through the hole of the rotating shaft 2, exits at the tip of the rotating shaft 2, passes through four grooves 23 below the tightening nut 20 and the nut 19, and is connected to the piezoelectric ceramic 18. Further, the lead wire 22 is connected to the piezoelectric ceramic 18 on the back surface through a hole in the blade.

6 is a partial sectional plan view showing details of the brush 9 and the slip ring 3 shown in FIG. A cylindrical copper alloy 25a constituting the slip ring 3 and a copper alloy 25b having a circular cross section are fixed to alumina 24 which is an insulator joined to the rotary shaft 2. Between the copper alloys 25a and 25b is a cylindrical insulating resin 26, which insulates the copper alloy 25a and the copper alloy 25b. The brush 9 is in contact with the copper alloys 25a and 25b. Further, copper alloys 25a and 25b are also provided on the back of the brush 9, and lead wires 22 are connected to the copper alloys 25a and 25b. Furthermore, the copper alloys 25a and 25b are pressed by the spring 27 in the direction of the rotation axis. The mechanism for pushing the spring 27 is omitted for convenience of drawing.
It is important to make the brush 9 and the slip ring 3 symmetrical with respect to the axis of the rotating shaft as much as possible, to reduce the distance from the axis, and to reduce the mass, in order to reduce the rotational inertia. It is.

  FIG. 7 is a plan view showing details of the blade 6 to which the piezoelectric ceramic 18 shown in FIG. 1 is bonded. A carbon fiber composite material 28 is bonded to the blade 6 by an epoxy resin on the surface contacting the piezoelectric ceramic 18 and the first and second flanges. The carbon fiber composite material 28 prevents the first and second flanges and the blade from being damaged by ultrasonic vibration. The blade hole 29 provided in the blade 6 is for passing the lead wire 22 through the piezoelectric ceramic 18 on the back surface. The front and back surfaces have exactly the same configuration.

  Next, the operation method of this cutting device will be described. First, the motor 1 is turned on, the motor 1 is rotated, this rotation is transmitted to the first pulley 11, the belt 13 and the second pulley 12, the rotating shaft 2 is rotated, and the blade 6 is rotated. At almost the same time, the ultrasonic oscillator 8 is switched on, and an AC voltage is applied to the piezoelectric ceramic 18 that is passed through the lead wire 22, the brush 9, the slip ring 3, and the lead wire 22 and is bonded to the blade 6. The blade 6 rotates and is in an ultrasonic vibration state, and cuts the workpiece.

According to the above cutting apparatus, since the ultrasonic vibration hardly propagates to the rotating shaft, the damage or wear of the bearing is almost negligibly small, so that the rotational accuracy is increased and the processing accuracy is improved. .
In addition, since no ultrasonic transducer is connected to the rotation shaft, the inertia is small, so that high-speed rotation is possible and the processing speed is improved.
Furthermore, since the rotation axis does not have an ultrasonic transducer that is difficult to have a rotation balance, the rotation accuracy is increased and the processing accuracy is improved.

  FIG. 8 is a plan view including a partial cross section showing a basic configuration showing the second embodiment. A motor 1 having a hollow shaft for rotating a stainless steel rotating shaft 2 is provided, and an output-side rotary transformer 31 is connected to the upper portion of the motor 1. A flange 32 and a rotating shaft 2 are connected to the lower part of the motor. The flange 32 and the rotating shaft 2 are provided with a hole 21 penetrating in the center. There is a bearing 7 for rotatably supporting the rotating shaft 2, and there is a stainless case 14 for fixing the bearing 7. The bearing 7 is used depending on applications such as a bearing and a hydrostatic bearing. A chuck device 34 for holding a stainless bar 33 having a diamond grindstone at the tip is connected to the tip of the rotating shaft. The stainless rod 33 is tightened by the chuck device 34. A cylindrical piezoelectric ceramic 18 is joined to the upper portion of the stainless bar 33.

  FIG. 9 is a perspective view showing details of the stainless steel rod 33 to which the piezoelectric ceramic 18 is bonded. The piezoelectric ceramic 18 is joined to the upper part of the stainless steel rod 33 by an epoxy resin. The shape of the piezoelectric ceramic 18 is cylindrical, and is polarized in the axial direction as indicated by an arrow in the figure. Silver electrodes are baked on the inner and outer surfaces of the cylinder. Furthermore, lead wires 22 are joined to the inner silver electrode and the outer silver electrode by soldering. A diamond grindstone 35 is joined to the lower part of the shaft of the stainless bar 33.

  There is an ultrasonic oscillator 8 for applying an alternating voltage to the piezoelectric ceramic 18, and the lead wire 22 is connected to the input side rotary transformer 30. The lead wire 22 from the output-side rotary transformer 31 connected to the upper part of the motor passes through the hollow shaft of the motor 1 and then passes through the hole 21 penetrating through the central portion of the rotating shaft 2 and is held by the chuck device 34. The piezoelectric ceramic 18 joined to the stainless steel bar 33 is connected.

  Next, an operation method of the surface grinding apparatus will be described. First, the motor 1 is turned on, the motor 1 is rotated, and the rotating shaft 2, the chuck device 34 and the stainless steel bar 33 are rotated. At the same time, the ultrasonic oscillator 8 is switched on, and an AC voltage is applied to the piezoelectric ceramic 18 that is passed through the lead wire 22, the input-side rotary transformer 30, the output-side rotary transformer 31, and the lead wire, and joined to the stainless steel rod 33. . The stainless steel bar 33 is rotated and ultrasonically vibrated, and the object to be processed is ground by a diamond grindstone 35 joined to the tip of the stainless steel bar 33.

According to the above surface grinding device, since ultrasonic vibration hardly propagates to the rotating shaft, the damage or wear of the bearing is so small that it can hardly be ignored, so the rotational accuracy is increased and the processing accuracy is improved. To do.
In addition, since no ultrasonic transducer is connected to the rotation shaft, the inertia is small, so that high-speed rotation is possible and the processing speed is improved.

  In the above invention, the hole of the rotating shaft passes through, but of course the hole does not need to pass through the rotating shaft if an AC voltage can be applied to the tool.

  The ultrasonic processing apparatus of the present invention can be used in various processing apparatuses that process a workpiece by rotating a tool.

It is a top view which shows the structure which shows the conventional ultrasonic cutting device. It is a side view which shows the structure which shows the conventional ultrasonic cutting device. It is a cross-sectional top view which shows the conventional ultrasonic grinding apparatus. It is a top view containing the partial cross section of the ultrasonic cutting device of the 1st structure of this invention. It is the top view and side view which show a part of rotating shaft of the 1st structure of this invention. It is a section top view showing the brush and slip ring of the 1st composition of the present invention. It is a top view which shows the braid | blade of the 1st structure of this invention. It is a top view including the partial cross section of the ultrasonic grinding apparatus of the 2nd structure of this invention. It is a perspective view which shows the grinding stone of the 2nd structure of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Rotating shaft 3 Slip ring 4 Ultrasonic vibrator 5 Vibration transmission direction changer 6 Blade 7 Bearing 8 Ultrasonic oscillator 9 Brush 10 Tightening nut 11 First pulley 12 Second pulley 13 Belt 14 Case 15 Protrusion 16 First 1 flange 17 second flange 18 piezoelectric ceramic 19 nut 20 loosening nut 21 hole 22 lead wire 23 groove 24 alumina 25 copper alloy 26 resin 27 spring 28 carbon fiber composite material 29 blade hole 30 input side rotary transformer 31 output side rotary Transformer 32 Flange 33 Stainless steel bar 34 Chuck device 35 Diamond grinding wheel

Claims (3)

In the ultrasonic processing apparatus, there is a rotating shaft, there is a hole or a hole penetrating the central axis, and a lead wire for applying an AC voltage to the ultrasonic vibrator is provided in the hole. It is a feature. The ultrasonic processing apparatus according to claim 1, wherein the ultrasonic processing apparatus is an apparatus for machining a workpiece using a disk-shaped tool. The ultrasonic processing apparatus according to claim 1, wherein the ultrasonic processing apparatus is an apparatus for machining a workpiece using a rod-shaped tool.

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