JP2017087363A - Ultrasonic polishing device and ultrasonic polishing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic polishing device that can reduce heat generation caused by friction between a polishing tool and the ultrasonic polishing device without damaging a work-piece at the moment when the polishing tool contacts the work-piece.SOLUTION: The ultrasonic polishing device comprises: a driving circuit 101 that supplies driving power to a vibration generation portion 20; a power detection portion 103 that detects power values of the driving power to be supplied from the driving circuit 101 to the vibration generation portion 20; and a vibration-amplitude detection portion 105 and a frequency detection portion 107 which detect vibration amplitudes and frequencies of the ultrasonic vibration respectively detected by a vibration detection portion 40 for feedback. At the beginning of activation, the vibration generation portion 20 is driven at a vibration amplitude during non-processing smaller than a vibration amplitude during processing. If the frequencies detected by the frequency detection portion 107 change at a change rate equal to a prescribed change rate or more, the vibration amplitude during non-processing is changed to the vibration amplitude during processing. If a change rate of the vibration amplitudes detected by the vibration amplitude detection portion 105 and a change rate of the power values detected by the power detection portion 103 are equal to a prescribed rate or less, the vibration amplitude during processing is changed to the vibration amplitude during non-processing.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ultrasonic polishing apparatus and an ultrasonic polishing method for polishing a workpiece by ultrasonically vibrating a polishing tool.

  Conventionally, an ultrasonic polishing apparatus is used that vibrates a polishing tool connected to the vibration generating unit by vibrating the vibration generating unit, and polishes the workpiece by applying the ultrasonic vibrating tool to the workpiece. ing.

JP 2014-188613 A

However, the conventional ultrasonic polishing apparatus has the following problems.
(1) There is a risk of scratching at the moment when the polishing tool touches the workpiece. For example, as shown in FIGS. 5 and 6, when polishing is performed by applying a flat polishing tool 50 to the workpiece 200, the polishing tool is previously provided. 50 is ultrasonically vibrated with the amplitude at the time of polishing, and the tip side 50 a of the vibrating polishing tool 50 is brought into contact with the surface of the workpiece 200. If it is an expert, when the front end side 50a of the grinding | polishing tool 50 contact | abuts to the surface of the workpiece | work 200, as shown in FIG. Appropriate polishing can be performed by appropriately adjusting the pressing force of. However, if the person is not an expert, for example, when the tip side 50a of the polishing tool 50 is brought into contact with the surface of the workpiece 100, only a part (edge) of the tip side 50a is shown in FIG. The edge of the front end side 50a is pressed against the surface of the workpiece 200 with a strong force during polishing from the beginning without being able to adjust the pressing force to the workpiece 200. For this reason, there is a problem in that a large kinetic energy is applied to the surface of the workpiece 200 that contacts the edge, and the surface of the workpiece 200 is damaged. Once the surface of the workpiece 200 is scratched, it is necessary to return the process or re-create the work. In addition, even a skilled person is a task that uses nerves, so it has been required to reduce the burden of work over a long period of time.

(2) There is a risk of heat generation due to friction between the polishing tool and the ultrasonic polishing apparatus that holds the polishing tool. The ultrasonic polishing apparatus needs to change the shape of the polishing tool used depending on the object to be polished. Therefore, the vibration frequency is changed by changing the tool. Depending on the vibration frequency, if the vibration amplitude is continuously set to the amplitude at the time of machining from the start, there is a concern that heat generation may increase. Further, once the heat generation becomes large, the work cannot be performed until it is cooled, and there is a possibility that the work efficiency is lowered.

  The present invention has been made in view of the above points, and its object is not to damage the workpiece at the moment when the polishing tool touches the workpiece, and to generate heat due to friction between the polishing tool and the ultrasonic polishing apparatus that holds the polishing tool. It is an object to provide an ultrasonic polishing apparatus and an ultrasonic polishing method capable of reducing the above.

The present invention relates to a vibration generating part controlled by a control means, a horn part for transmitting ultrasonic vibration generated by the vibration generating part, and a work piece attached to the tip of the horn part and ultrasonically vibrated. An ultrasonic polishing apparatus comprising: a polishing tool that polishes a polishing tool; wherein the control means detects a drive circuit that supplies drive power to the vibration generator, and a power value of the drive power supplied from the drive circuit Power detection unit, and an amplitude detection unit and a frequency detection unit for detecting the amplitude and frequency of ultrasonic vibration by the vibration generation unit, respectively, the control means, at the start of the start, the vibration generation unit, Driven with a non-machining amplitude that is smaller than the machining amplitude, and when the frequency detected by the frequency detector changes at a rate of change greater than or equal to a predetermined rate of change, the amplitude of the vibration generator is not Change from the working amplitude to the machining amplitude, and on the other hand, the change in at least one of the amplitude change rate of the machining amplitude detected by the amplitude detector and the change rate of the power value detected by the power detector When the rate becomes a predetermined change rate or less, control is performed to change the amplitude of the vibration generating unit from the machining amplitude to the non-machining amplitude.
The non-machining amplitude immediately after start-up and the non-machining amplitude changed from the machining amplitude do not necessarily have to be the same, and the amplitudes of both may be different, as long as the amplitude is smaller than the machining amplitude. That's fine.
As described above, at the moment when the polishing tool touches the workpiece, only a part of the portion of the polishing tool that should contact the workpiece touches the workpiece and damages it, or the workpiece touches the workpiece with a strong force. However, in the case of the present invention, when the polishing tool touches the workpiece, the polishing tool vibrates with a small amplitude during non-machining, so that a large polishing force is not applied to the workpiece. . For this reason, even if only a part of the part of the polishing tool that should contact the workpiece touches the workpiece, the workpiece will not be damaged, and even if it touches the workpiece with a strong force, it may be excessively polished. Absent. Since the polishing tool is automatically changed to the processing amplitude during a predetermined time until the polishing tool comes into contact with the workpiece and the contact state is stabilized, the processing of the workpiece can be started smoothly. In other words, the required level of skill of the worker can be lowered.
Also, when the polishing tool is pulled away from the workpiece, it is automatically detected and changed to a non-processing amplitude that is smaller than the processing amplitude, so the polishing tool and the ultrasonic polishing device that holds it Heat generation due to friction between them can be suppressed, and power consumption can be reduced. That is, the amount of heat generated in the entire process can be suppressed, and the continuous operation time can be extended. In addition, since the amplitude is changed to the non-machining amplitude when the polishing tool is pulled away from the workpiece, there is no possibility that the workpiece is damaged or over-polished as described above when the workpiece is touched again for machining.
Here, the reason why the frequency change of the non-machining amplitude is used to detect that the polishing tool is in contact with the workpiece is as follows. That is, the inventor of the present application confirms by experiment that a change in frequency at the moment when the polishing tool touches the workpiece can be captured if the amplitude is small during non-machining, and detects this change in frequency. It was. That is, the inventor of the present application experimented that in the case of non-machining amplitude with a small amplitude (for example, a minimum amplitude), a change in the amplitude or a change in power does not show a significant change at the moment when the polishing tool touches the workpiece. Confirmed by The inventor of the present application also confirmed by experiment that no significant change in the frequency at the moment when the polishing tool touched the workpiece was observed in the processing amplitude. On the other hand, as described above, when the amplitude is small during non-machining, the frequency of detecting that the polishing tool has touched the workpiece can be detected, and the change in frequency is used for the measurement. Since the frequency varies depending on the weight and shape of the polishing tool attached to the ultrasonic polishing apparatus, the rate of change is used for the detection, not the absolute value of the frequency.
On the other hand, the reason why the change in amplitude and the change in power during processing are used to detect the removal of the polishing tool from the workpiece is as follows. That is, in the case of processing amplitude, since the change in frequency before and after the polishing tool leaves the workpiece is small, it was confirmed by experiment that it is difficult to use the frequency change for detection. On the other hand, in the case of machining amplitude, it was confirmed by experiments that the change in amplitude and the change in power before and after the polishing tool moved away from the workpiece were large enough to capture this, so we decided to use them for the detection. It is. In other words, if both the rate of change in amplitude and the rate of change in power are equal to or greater than a predetermined value, it is determined that the polishing tool is not separated from the workpiece and the amplitude during processing is continued. In the case of the present invention, when the change rate of either the amplitude change rate or the power value change rate is equal to or lower than the predetermined change rate, it is determined that the polishing tool is separated from the workpiece. In order to more accurately determine that the two have been separated, the two change rates may be determined to be separated when both of them are equal to or less than a predetermined change rate.

  That is, when both the change rate of the amplitude and the change rate of the power value are equal to or less than a predetermined change rate, the amplitude of the vibration generating unit is changed from the machining amplitude to the non-machining amplitude. It is preferable to perform the control in order to make a more reliable determination.

  Further, the present invention provides a vibration generating unit, a horn unit for transmitting ultrasonic vibration generated by the vibration generating unit, and a polishing unit that is attached to a tip of the horn unit and polishes a workpiece by ultrasonic vibration. In an ultrasonic polishing method using an ultrasonic polishing apparatus comprising a tool, at the beginning of startup, the step of driving the vibration generating unit with a non-machining amplitude smaller than a machining amplitude, and the vibration A step of changing the non-machining amplitude from the non-machining amplitude to the machining amplitude when the frequency of the generating portion changes at a rate of change greater than or equal to a predetermined rate of change at the non-machining amplitude; When the change rate of at least one of the power values for driving the vibration generating unit is equal to or less than a predetermined change rate, the non-machining amplitude is smaller than the machining amplitude. Step to change It is characterized by having, when.

  According to the present invention, it is possible to prevent the workpiece from being damaged at the moment when the polishing tool touches the workpiece, and to reduce heat generation due to friction between the polishing tool and the ultrasonic polishing apparatus that holds the polishing tool.

1 is an overall schematic configuration diagram showing an ultrasonic polishing apparatus 1. FIG. 3 is a perspective view of a main part in a state in which a workpiece 200 is polished by a polishing tool 50. FIG. FIG. 5 is a control flow diagram illustrating an example of a method for controlling the ultrasonic polishing apparatus main body 10. It is the figure which showed the measured value of each of amplitude, electric power, and frequency at the time of the ultrasonic polishing apparatus main body 10 drive, and the determination content in the control part 109 over time. FIG. 4 is a perspective view of a main part showing a state at the moment when a polishing tool 50 touches a workpiece 200. FIG. 4 is a perspective view of a main part showing a state in which a polishing tool 50 is stably in contact with a workpiece 200.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an overall schematic configuration diagram showing an ultrasonic polishing apparatus 1 according to an embodiment of the present invention. FIG. 2 is a main part perspective view showing a state in which the workpiece (workpiece) 200 is polished by the polishing tool 50 attached to the ultrasonic polishing apparatus main body 10. As shown in FIG. 1, the ultrasonic polishing apparatus 1 includes an ultrasonic polishing apparatus main body 10 and a control unit 100 that drives and controls the main body 10. The ultrasonic polishing apparatus main body 10 includes a vibration generating unit 20 whose driving is controlled by the control unit 100, a horn unit 30 for transmitting ultrasonic vibration generated by the vibration generating unit 20, and a tip of the horn unit 30. A polishing tool 50 that polishes the workpiece 200 by being attached and ultrasonically vibrated is provided.

  The vibration generating unit 20 is configured by a driving piezoelectric element (piezoelectric element layer or the like), and performs ultrasonic vibration with driving power supplied from a driving circuit 101 of the control unit 100 described below. A horn portion 30 is connected to one end of the vibration generating portion 20, and a polishing tool 50 is attached to a tool attachment portion 31 provided at the tip of the horn portion 30. As shown in FIG. 2, a slit 33 is provided at the tip surface of the tool mounting portion 31 of the horn portion 30. One end of the polishing tool 50 is inserted into the slit 33, and the upper and lower portions of the slit 33 are attached to the mounting screws. By tightening with 35, the polishing tool 50 is clamped and fixed. The polishing tool 50 used in this example has a long rectangular shape and a flat plate shape.

  A feedback vibration detecting unit 40 is connected to the other end of the vibration generating unit 20. The feedback vibration detection unit 40 is constituted by a piezoelectric element, and transmits the state of ultrasonic vibration of the vibration generation unit 20, that is, the ultrasonic polishing apparatus main body 10 to the control unit 100.

  The control means 100 includes a drive circuit 101 that supplies drive power for driving the vibration generating unit 20, a power detection unit 103 that detects a power value of the drive power in the drive circuit 101, and the feedback vibration detection unit. An amplitude detection unit 105 that receives a signal related to the state of ultrasonic vibration from 40 and detects the amplitude of the ultrasonic vibration, a frequency detection unit 107 that detects the frequency of the ultrasonic vibration, and the power detection unit The driving power value of the ultrasonic polishing apparatus main body 10 and the amplitude and frequency of ultrasonic vibration are input over time from the 103, the amplitude detecting unit 105, and the frequency detecting unit 107, respectively, and the driving circuit 101 is driven based on these input signals. And a control unit 109 that performs control.

  FIG. 3 is a control flow chart showing an example of a method for controlling the ultrasonic polishing apparatus main body 10 performed in the control means 100. As shown in the figure, first, when an on / off switch (not shown) of the ultrasonic polishing apparatus main body 10 is turned on, the control unit 109 causes the drive circuit 101 to operate the ultrasonic polishing apparatus main body 10 with an amplitude during non-processing. An operation command is output so as to do this (step ST1). Here, the non-machining amplitude means an amplitude smaller than the machining amplitude when the workpiece is actually machined, and is particularly preferably a minimum amplitude. It should be noted that the frequency is substantially the same during machining and non-machining. Specifically, the non-machining amplitude is, for example, about 0.5 to 5.0 μm, but the present invention is not limited to this value. If ultrasonic vibration is performed with such non-working amplitude, heat generation due to friction between the polishing tool 50 and the tool mounting portion 31 holding the polishing tool 50 can be suppressed, and power consumption can be reduced.

  Next, when the polishing tool 50 comes into contact with the workpiece 200 in order to process the workpiece 200, the control unit 109 detects the contact using the rate of change of the frequency of the ultrasonic vibration (step ST2). An operation command is output to the drive circuit 101 so that the amplitude of the ultrasonic vibration becomes the machining amplitude (step ST3). Specifically, the processing amplitude is, for example, about 5.0 to 50.0 μm, but the present invention is not limited to this value. In addition, after determining that the polishing tool 50 has contacted the workpiece 200, a predetermined time (for example, 0.4 second to 1.0 second) has elapsed, and the amplitude is set to be the machining amplitude. Is more preferred. The predetermined time is preferably a time close to the time from when the polishing tool 50 touches the workpiece 200 until the polishing tool 50 is brought into a normal contact state.

  As described above, in the case of the present embodiment, the moment when the polishing tool 50 touches the workpiece 200 is a non-machining amplitude with a small amplitude of the ultrasonic vibration of the polishing tool 50, so a large polishing force is not applied to the workpiece 200. Therefore, as shown in FIG. 5, even if only a part of the portion of the polishing tool 50 that should contact the workpiece 200 contacts the workpiece, the workpiece 200 can be prevented from being damaged, and the workpiece 200 can be contacted with a strong force. Even so, it is possible to prevent the fear of polishing this too much.

  Next, when the predetermined time elapses from the moment when the polishing tool 50 touches the workpiece 200, the polishing tool 50 enters a normal contact state with the workpiece 200 as shown in FIG. (Or in a short time thereafter), the amplitude of the ultrasonic vibration of the polishing tool 50 becomes the amplitude during processing. Therefore, the workpiece 200 can be polished. That is, since the polishing tool 50 is automatically changed from the non-machining amplitude to the machining amplitude during a predetermined time until the polishing tool 50 comes into contact with the workpiece 200 and the contact state is stabilized, the workpiece is smoothly smoothed. Can be started. In other words, the required level of skill of the worker can be lowered.

  While the workpiece 200 is being polished, the amplitude and power of the ultrasonic vibration constantly change as the load due to polishing changes with time. In other words, when the polishing of the workpiece 200 is stopped, that is, when the polishing tool 50 is pulled away from the workpiece 200, the amplitude and power of the ultrasonic vibration are not changed. Therefore, the control unit 109 calculates respective change rates (amplitude change rate and power change rate) from the amplitude and power value of the ultrasonic vibration input from the amplitude detection unit 105 and the power detection unit 103, respectively. When it is detected that each of the change rates is equal to or less than the predetermined change rate, it is determined that the polishing tool 50 has moved away from the workpiece 200 (step ST4), and the control unit 109 causes the drive circuit 101 to determine whether or not the processing amplitude has been exceeded. An operation command is output so as to switch to the machining amplitude (step ST1). If only one of the change rate of amplitude and the change rate of power is changed, it is determined that the polishing tool 50 is not separated from the workpiece 200, and the amplitude during processing is continued. Note that the non-machining amplitude immediately after the start-up and the non-machining amplitude changed from the machining amplitude are not necessarily the same, and both amplitudes may be different.

  In this way, when the polishing tool 50 is separated from the workpiece 200 and is not processed, this is automatically detected and changed to the non-processing amplitude smaller than the processing amplitude, so the polishing tool 50 and the tool that holds the tool are held. Heat generation due to friction between the mounting portions 31 can be suppressed, and power consumption can be reduced. That is, the amount of heat generated in the entire process can be suppressed, and the continuous operation time can be extended. In addition, when the workpiece 200 is touched again for processing again, there is no risk of the workpiece 200 being damaged or excessively polished as described above. That is, in the machining process, since it is difficult to check the contact surface during the machining, the machining is advanced while confirming the workpiece machining surface with many separations. For this reason, contact / separation is repeated, but preparation for each re-contact can be made.

  By the way, in step ST2, the frequency change of the non-machining amplitude is used for detecting that the polishing tool 50 is in contact with the workpiece 200 for the following reason. That is, the inventor of the present application finds that the change in frequency at the moment when the polishing tool 50 touches the workpiece 200 can be detected if the amplitude is small during non-machining and detects the change in frequency. . That is, the inventor of the present application confirmed by experiments that in the case of non-machining amplitude with a small amplitude, no significant change is recognized at the moment when the polishing tool 50 touches the workpiece 200 with the change in amplitude or the change in power. . In addition, the inventor of the present application also confirmed by experiments that no significant change in the frequency at the moment when the polishing tool 50 touches the workpiece 200 was observed in the processing amplitude. On the other hand, as described above, when the amplitude is small during non-machining, the frequency of detecting that the polishing tool 50 has touched the workpiece 200 can be detected, and the change in frequency is used for the measurement. Since the frequency differs depending on the weight, shape, etc. of the polishing tool 50 attached to the ultrasonic polishing apparatus main body 10, the change rate, not the absolute value of the frequency, is used for the detection.

  On the other hand, the reason why the change in amplitude and the change in power are used to detect that the polishing tool 50 has been pulled away from the workpiece 200 in step ST4 is as follows. That is, in the case of the processing amplitude, since the change in the frequency before and after the polishing tool 50 is separated from the workpiece 200 is small, it was confirmed by experiment that it is difficult to use the frequency change for the detection. On the other hand, in the case of processing amplitude, since it has been confirmed by experiments that the change in amplitude and the change in power before and after the polishing tool 50 moves away from the workpiece 200 are large enough to capture this, use these for detection. It was.

  FIG. 4 shows measured values of amplitude, power, and frequency from when the on / off switch (not shown) of the ultrasonic polishing apparatus body 10 is turned on until the workpiece 200 is polished and then the polishing tool 50 is separated from the workpiece 200. And determination contents in the control unit 109 are shown over time (at intervals of one second). In the figure, the measured value of the amplitude is shown as a bit value converted into a digital data by A / D converting the voltage converted from the measured amplitude. That is, this value itself does not indicate the amplitude itself, but the rate of change of the amplitude can be determined. The difference in amplitude is calculated by calculating the difference between the measured value measured last time (that is, measured one tenth of a second before) and the measured value measured this time. In determining whether or not the amplitude has changed, it is determined that the difference value is ± 3 or more, that is, there is a change (that is, it has changed to a predetermined change rate or more) “◯”. The measured value of power is indicated by a bit value obtained by converting the measured power value into a voltage and converting it into digital data. That is, this value itself does not indicate the power value itself, but the rate of change of the power value can be determined. The power difference is calculated by calculating the difference between the measured value measured last time (that is, measured one tenth of a second before) and the measured value measured this time. In determining whether or not the power has fluctuated, a case where the difference value is ± 4 or more is judged as “◯” with fluctuation (that is, changed to a predetermined change rate or more). The measured value of the frequency is the frequency itself, and the unit is “Hz”. The frequency difference is calculated by calculating the difference between the measured value measured four times before (that is, measured four seconds before) and the measured value measured this time. In determining whether or not the frequency has fluctuated, a case where the difference value is ± 6 or more is judged as “◯” with fluctuation (that is, changed to a predetermined change rate or more). The reason why the frequency is compared with the measurement value measured four times before and the difference is set to ± 6 or more is to prevent a determination error due to variation in the measurement value because the change rate itself is small. In FIG. 4, the description of the predetermined time after determining that the polishing tool 50 has contacted the workpiece 200 is omitted for the sake of convenience (actually, the elapsed time is between 72.3 seconds and 72.4 seconds). A predetermined time is entered).

  In FIG. 4, when the on / off switch is turned on at an elapsed time of 70.1 seconds, as described above, the ultrasonic polishing apparatus main body 10 starts ultrasonic vibration with a non-machining amplitude. At this time, the amplitude and the driving power are small and cannot be measured accurately. The measured value of the amplitude is “0” and the power is “0”. On the other hand, the frequency is about “23020 (Hz)”. In the case of this table, the polishing tool 50 comes into contact with the workpiece 200 at the elapsed time “72.0”. However, in the case of non-machining amplitude, there is a case where no significant change is observed in the amplitude and power before and after the contact. I understand. That is, as described above, in the case of non-machining amplitude, the contact cannot be detected by the amplitude and power. On the other hand, in the case of non-machining amplitude, there is a measurable change in frequency. Therefore, by measuring this change in frequency, it is measured that the polishing tool 50 has contacted the workpiece 200. In this example, it is determined that the contact has occurred three seconds after the actual contact, and after the predetermined time has elapsed, the control unit 109 outputs a command to change the amplitude from the non-machining amplitude to the machining amplitude. As a result, the amplitude shifts to machining amplitude after a predetermined time, not immediately after contact, so that the polishing tool 50 can be shifted to a stable contact state with respect to the workpiece 200 during that time, and the machining of the workpiece 200 starts smoothly. can do.

  When the amplitude becomes the amplitude during machining and machining of the workpiece 200 is started, the absolute values of the amplitude and power increase immediately after that, and the amplitude and power values constantly change during the subsequent machining of the workpiece. In the case of this table, the polishing tool 50 is separated from the workpiece 200 at the elapsed time “77.2”. However, in the case of machining amplitude, it can be seen that there is no significant change in the frequency before and after the separation. That is, as described above, in the case of machining amplitude, the separation cannot be detected at that frequency. On the other hand, in the case of processing amplitude, measurable changes occur in the amplitude and power when the polishing tool 50 is separated (obviously, there is no change). Therefore, by measuring changes in both the amplitude and power, the control unit 109 determines that the polishing tool 50 has moved away from the workpiece 200, and simultaneously outputs a command to change the amplitude to the non-machining amplitude. The reason for measuring both the amplitude and the power is that if only one of them is measured, a determination error may occur. Furthermore, in this example, in order to prevent a determination error, when the state where both the amplitude and the power are less than the predetermined change rate continues for a sufficient five seconds (elapsed time “77.7”), it is determined that they are separated. Yes. However, in the present invention, the separation may be determined using a measured value of only one of the amplitude and power.

  As described above, when the polishing of the workpiece 200 is finished or interrupted, the amplitude of the ultrasonic vibration is changed to a non-machining amplitude smaller than that during machining, so that the polishing tool 50 and the tool mounting portion 31 that holds the polishing tool 50 are retained. Heat generation due to friction between them can be suppressed, and power consumption can be reduced. When the polishing tool 50 is brought into contact with the workpiece 200 again, the process proceeds from step ST1 to step ST2, and the amplitude is changed to the machining amplitude again.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. Note that any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are exhibited. For example, in the above example, the amplitude and frequency of the ultrasonic vibration are detected using the feedback vibration detection unit. However, without using this, other than a system (for example, a bridge circuit) that automatically tracks while measuring the impedance during driving, etc. The amplitude and frequency of the ultrasonic vibration may be detected using the detection means (method). Moreover, as long as there is no contradiction in the objective, a structure, etc., the embodiment shown by the said description and each figure can combine the description content of each other. In addition, the above description and the description of each drawing can be an independent embodiment even if it is a part of it, and the embodiment of the present invention is an embodiment in which the above description and each drawing are combined. It is not limited to.

DESCRIPTION OF SYMBOLS 1 Ultrasonic polishing apparatus 10 Ultrasonic polishing apparatus main body 20 Vibration generation part 30 Horn part 31 Tool attachment part 33 Slit 35 Attachment screw 40 Feedback vibration detection part 50 Polishing tool 100 Control means 101 Drive circuit 103 Power detection part 105 Amplitude detection part 107 Frequency detection unit 109 Control unit 200 Workpiece (workpiece)

Claims (3)

A vibration generator controlled by the control means;
A horn for transmitting ultrasonic vibration generated by the vibration generator;
In an ultrasonic polishing apparatus provided with a polishing tool attached to the tip of the horn portion and polishing the workpiece by ultrasonic vibration,
The control means includes a drive circuit that supplies drive power to the vibration generating unit;
A power detection unit that detects a power value of drive power supplied from the drive circuit;
An amplitude detector and a frequency detector for detecting the amplitude and frequency of the ultrasonic vibration by the vibration generator, respectively,
The control means includes
At the start, the vibration generator is driven with a non-machining amplitude smaller than the machining amplitude.
When the frequency detected by the frequency detector changes at a change rate equal to or higher than a predetermined change rate, the amplitude of the vibration generating unit is changed from the non-machining amplitude to the machining amplitude,
On the other hand, the change rate of at least one of the amplitude change rate of the processing amplitude detected by the amplitude detection unit and the change rate of the power value detected by the power detection unit is equal to or less than a predetermined change rate. In this case, the ultrasonic polishing apparatus controls to change the amplitude of the vibration generating unit from the machining amplitude to the non-machining amplitude. The ultrasonic polishing apparatus according to claim 1,
Control that changes the amplitude of the vibration generating unit from the machining amplitude to the non-machining amplitude when both the amplitude change rate and the power value change rate are equal to or less than a predetermined change rate, respectively. An ultrasonic polishing apparatus characterized by performing. A vibration generating unit;
A horn for transmitting ultrasonic vibration generated by the vibration generator;
In an ultrasonic polishing method using an ultrasonic polishing apparatus, comprising a polishing tool attached to the tip of the horn part and polishing the workpiece by ultrasonic vibration,
At the beginning of driving, the step of driving the vibration generating unit with a non-machining amplitude smaller than the machining amplitude;
When the frequency of the vibration generating unit is changed at a change rate equal to or higher than a predetermined change rate at the non-machining amplitude, the non-machining amplitude is changed to the machining amplitude;
Compared to the machining amplitude when the rate of change in amplitude of the machining amplitude and the rate of change of at least one of the power values for driving the vibration generator are less than a predetermined rate of change. And a step of changing to a non-machining amplitude with a small amplitude.

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