JP6884363B2 - Langevin type ultrasonic vibration generator for ultrasonic processing - Google Patents

Description

The present invention relates to a Langevin type ultrasonic vibrator for ultrasonic processing and a method for supporting the same.

Ultrasonic vibrators that use a piezoelectric element as an ultrasonic source are known to have various configurations, and as a typical configuration, a pair of metal blocks and piezoelectrics fixed between these metal blocks are used. A Langevin type ultrasonic vibrator composed of elements is known. Among them, the bolt-tightened Langevin type ultrasonic vibrator, which has a structure in which the piezoelectric element is connected between a pair of metal blocks by bolts and tightened and fixed at high pressure, is capable of high-energy ultrasonic vibration, so cutting of various materials is possible. , Plastic machining, abrasive grain machining, etc. are being studied for use in ultrasonic machining, which is used by attaching to tools.

The configurations of various ultrasonic transducers including the bolt-tightened Langevin type ultrasonic transducer are already known, but just in case, the configuration of a typical bolt-tightened Langevin type ultrasonic transducer and the form of its use are attached. This will be briefly described below with reference to FIGS. 1 and 2.

FIG. 1 is a diagram showing an example of a typical structure of a bolt-tightened Langevin type ultrasonic vibrator. The bolt-tightened Langevin type ultrasonic vibrator 1 has a structure in which a piezoelectric element (eg, a piezoelectric ceramic plate) 3 is sandwiched between a pair of metal blocks 2a and 2b, and the metal blocks 2a and 2b are fastened to each other using bolts 4. Have. In FIG. 1, the arrow marked on the piezoelectric element indicates the polarization direction. The piezoelectric element 3 is connected to electrode pieces (usually, electrode pieces such as phosphor bronze) 5a and 5b used as terminals for applying electric energy.

FIG. 2 is a diagram showing a configuration example of an ultrasonic grinding machine (polishing machine) using a bolt-tightened Langevin type ultrasonic vibrator as an ultrasonic vibration source. In FIG. 2, the ultrasonic grinding apparatus 10 accommodates an ultrasonic vibrator 1 having a polishing tool 13 connected to a lower end portion via a horn 12 in a housing 11, and the ultrasonic vibrator 1 is housed in the housing 11. It is rotatably supported by a bearing 14. The rotation of the ultrasonic vibrator 1 is driven by the AC spindle motor 16 connected to the servo unit 15. In the device of FIG. 2, the electric energy for ultrasonic vibration of the ultrasonic vibrator is a contact type power supply composed of a carbon brush connected to an external electric energy supply source 17 and a slip ring 18. Supplied via equipment.

By the way, the effects expected by applying ultrasonic vibration to various tools in an ultrasonic processing apparatus are reduction of cutting resistance by the tool, improvement of sharpness, improvement of processing accuracy and the like. However, the ultrasonic processing apparatus manufactured so far and used in the actual processing work has not sufficiently obtained the expected effect. For this reason, at present, the spread of ultrasonic processing equipment has not progressed much. Therefore, in order to promote the sufficient spread of ultrasonic processing, it is said that it is necessary to improve the support rigidity of the ultrasonic vibrator and the accuracy of the support position in carrying out the ultrasonic processing work.

The inventor of the present invention has devised an improved invention of an ultrasonic vibrator, which is expected to improve the support rigidity of the ultrasonic vibrator, and has filed a patent application. For example, the latest invention among those improved inventions is disclosed in Patent Document 1.

Patent Document 1 states that a vibration complex of a tool and an ultrasonic vibrating body is supported with high stability, and a support (fixed support) of the complex of ultrasonic energy generated in the ultrasonic vibrating body. As a support structure that enables the application of vibration energy to the tool with high efficiency by suppressing the exposure to the tool to a low level, a flange is attached to the ultrasonic vibrating body equipped with the tool, and one side of the flange is attached. , A support structure that engages and supports by contacting the support surface of the fixed body prepared separately with stress applied (however, the flange of the ultrasonic vibrating body is not joined to the fluffy support surface of the fixed body. Further, the flange of the ultrasonic vibrating body that is in contact with the supporting surface of the fixed body and is engaged and supported has a structure that vibrates ultrasonically in the thickness direction of the flange when the ultrasonic vibrating body is in a vibrating state). Has been done.

Further, in Patent Document 2, a transmission horn that supports an ultrasonic vibrator and an ultrasonic vibrator and transmits ultrasonic vibration generated, a tool that is detachably attached to the tip of the transmission horn, and a transmission horn support. A flange that protrudes outward is provided on the outer diameter side of the shaft vibration node portion of the transmission horn, and a support shaft is provided on the central shaft portion of the shaft vibration node portion of the transmission horn for transmission. A configuration is disclosed in which a horn is pressed and supported on an outer cylinder by a flange and a support shaft.

International release WO2014 / 017460AI JP-A-5-77145

Yoshio Iwata et al., "Mechanical Vibrations", Mathematical Engineering Co., Ltd., May 2011, p22-p28, p152-p158

A large load is applied to the Langevin type ultrasonic vibrator used for machining. However, until now, the Langevin type ultrasonic vibrator has been designed and manufactured under no load. Therefore, when a load is applied, there is a big problem that the performance cannot be fully exhibited.

The ultrasonic processing apparatus using the new support structure of the ultrasonic transducer described in Patent Document 1 solves not a little the problems of the ultrasonic processing apparatus using the ultrasonic transducer having a conventionally known structure. It has been seen. However, it has been found that even with the ultrasonic processing apparatus using the support structure of the ultrasonic vibrator described in Patent Document 1, it is not possible to obtain an improvement in processing accuracy that is practically sufficiently satisfactory.

Depending on the method of providing the support shaft at the central shaft portion of the node portion of the shaft vibration in the transmission horn described in Patent Document 2, the node position of the shaft vibration depends on the shape of the tool attached to the tip portion of the transmission horn. Since it changes, if the tool length changes, the vibration of the ultrasonic vibrator may be reduced. Further, since the support is performed by using screws, the support rigidity may be lowered and the processing accuracy may be lowered.

Therefore, an object of the present invention is to provide a structure and a support method of a Langevin type ultrasonic vibrator suitable for ultrasonic processing, which can realize improvement in processing accuracy.

The inventor of the present invention reexamined the generation mechanism of ultrasonic vibration in the Langevin type ultrasonic vibrator for the purpose of improving the support structure of the new ultrasonic vibrator described in Patent Document 1. Then, in the examination, the support configuration shown in FIGS. 3 and 4 was considered as a model of the configuration for firmly supporting the Langevin type ultrasonic vibrator. The Langevin ultrasonic transducer 1 having the support configuration shown in FIG. 3 includes a metal front mass 2d, a phosphorus bronze electrode plate 5d, a piezoelectric element 3d polarized in the plate thickness direction, a phosphorus bronze electrode plate 5c, and a plate. Piezoelectric element 3c polarized in the thickness direction, tapered annular support frame 6b, piezoelectric element 3b polarized in the plate thickness direction, electrode plate 5b made of phosphorus bronze, piezoelectric element 3a polarized in the plate thickness direction, made of phosphorus bronze The electrode plates 5a of the above are arranged in order, and a metal rear mass 2a having a male screw is screwed into the front mass 2b and tightened. Here, the tapered annular support frame 6b has a conical shape with a small diameter on the housing side and a large diameter on the front mass side.

Considering the support rigidity and vibration characteristics of the Langevin type ultrasonic vibrator, first, regarding the support rigidity, the thickness of the tapered annular support frame 6b is 1 of the outer diameter of the piezoelectric element of the Langevin type ultrasonic vibrator. It is desirable that it is / 5 or more and 2/3 or more. Then, in order to supply the Langevin type ultrasonic vibrator with electric energy for exciting the desired magnitude of ultrasonic vibration, the total thickness of the piezoelectric elements of the Langevin type ultrasonic vibrator is a tapered annular support frame. It is desirable to make it larger than the thickness of 6b.

On the other hand, the conventional Langevin type ultrasonic vibrator is to make the flange as thin as possible so as to support the Langevin type ultrasonic vibrator so that the performance can be exhibited most with no load, and is usually the Langevin type. It is smaller than 1/10 of the outer diameter of the piezoelectric element of the ultrasonic transducer.
However, when a load is applied, the thin flange supporting the Langevin type ultrasonic vibrator is deformed, which deteriorates the processing accuracy. Also. The resonance frequency and admittance value of the Langevin type ultrasonic vibrator change greatly, and the amount of amplitude drops significantly.

Regarding the configuration of FIG. 3, the total thickness of the piezoelectric elements is 20 mm, and the diameter is 15 mm. The thickness of the tapered annular support frame 6b is 5 mm. Therefore, the thickness of the tapered annular support frame 6b is 1/3 of the outer diameter of the piezoelectric element of the Langevin type ultrasonic vibrator. The total thickness of the piezoelectric elements is four times the thickness of the tapered annular support frame 6b.

A method of supporting the Langevin type ultrasonic vibrator in the housing will be described with reference to FIG. A steel housing 11 is prepared to support the bolt-tightened Langevin ultrasonic transducer 1. A male screw is provided on the outside of the housing, and a taper for fitting with the tapered annular support frame 6b is provided on the inside of the housing 11. Then, the housing nut 21 provided with the female screw was tightened to support and fix the tapered annular support frame 6b and the housing 11 by taper fitting. To supply the electric energy to the piezoelectric element 3 of the Langevin ultrasonic transducer 1, a voltage having a predetermined frequency is applied from the ultrasonic oscillation circuit 8 provided outside the housing through the hole 19 formed in the housing 11. I tried to do it. Further, here, the numerical value indicating the dimension in FIG. 4 is in millimeters.

Here, the reason why the taper fitting and the tightening with the housing housing nut are selected as the means for supporting the ultrasonic vibrator on the housing will be described.
First, the taper fitting shown in FIGS. 5A and 5B and the straight fitting shown in FIGS. 5C and 5D will be described. Generally, the higher the required accuracy, the more taper fitting is adopted. In the case of straight connection, the clearance for fitting both parts becomes a factor of runout. Further, such vibration of the shaft portion causes the tool attached to the front mass to generate more amplified and unnecessary vibration and sound.
By the way, in the case of taper fitting, if a firm "large contact (large end alignment) is obtained and the parts are finished according to the taper standard, unnecessary vibration and sound generation can be drastically reduced.
Also, regarding maintainability, the occurrence of galling can be significantly reduced by fitting the taper. And, even if the fitting is repeated, the accuracy can be easily restored as compared with the straight fitting.
From the above features, the taper fitting was adopted.

Next, the reason why the male screw of the housing 11 and the housing nut 21 are used as means for tightening the ultrasonic vibrator to the housing will be described.
5A and 5C show the male screw of the housing 11 and the housing nut 21 as the tightening means, and FIGS. 5B and 5D show the bolt 4 through the screw hole of the housing 11 through the hole of the holding plate as the tightening means. It is a configuration that is tightened with.
First, in the case of using the housing nut 21, if the male screw shape and male screw accuracy of the housing 11 and the processing accuracy of the female screw accuracy of the housing nut 21 are improved, the error with respect to the central axis becomes small.
On the other hand, when the bolt 4 is used, there is an error due to the existence of the clearance of the holding plate. And since a plurality of bolts 4 are used, a tightening error occurs. Every time the work is repeated, an error occurs. Further, since the radius of the bolt 4 is small, the tightening force is smaller than that of the housing nut 21 even if a plurality of bolts 4 are used.
For the above reasons, taper fitting and tightening with the housing nut 21 were selected as means for supporting the Langevin type ultrasonic vibrator in the housing 11 shown in FIG. 5A.

As a means for supporting the Langevin type ultrasonic vibrator on the housing, taper fitting and tightening with a housing nut were selected. However, as shown in the schematic view of FIG. 6, the tapered annular support frame 6b has three support methods. is there.
The tapered annular support frame 6b shown in FIG. 6A has a tapered surface in contact with the housing 11 and a flat surface on the opposite side. The housing 11 has a taper so that it can be tapered and fitted with the tapered annular support frame body 6b.
The tapered annular support frame 6b shown in FIG. 6B has a tapered surface in contact with the housing nut 21, and a flat surface on the opposite side. The housing nut 21 has a taper so that the housing nut 21 can be tapered and fitted with the tapered annular support frame body 6b.
In the tapered annular support frame body 6b shown in FIG. 6C, the surface in contact with the housing 11 is tapered, and the surface in contact with the housing nut 21 is also tapered. The housing 11 and the housing nut 21 have a taper so that the housing 11 and the housing nut 21 can be tapered and fitted with the tapered annular support frame body 6b. This method is the most suitable shape for precision machining because the position accuracy can be improved by taper fitting on both sides of the tapered annular support frame body 6b.

In order to evaluate the ultrasonic vibration characteristics of the bolt-tightened Langevin type ultrasonic vibrator 1 having the shape and size shown in FIG. 3, an impedance analyzer was used in a state where the Langevin type ultrasonic vibrator 1 was unconstrained. The frequency characteristics were measured. As for the frequency characteristics, the frequency of the admittance peak indicating the resonance frequency was 29535 Hz, and the admittance value of the peak was 8.28 mS.

Further, a function synthesizer was connected to the power amplifier, and the frequency was swept at a voltage of 20 Vp-p to maximize the current at 29.39 KHz, and the current value was about 133 mA. Then, the amount of vibration displacement at the center of the front mass under that condition was measured using a leather Doppler vibrometer. The amount of vibration displacement was 14.1 μmp-p.

In FIG. 4, the tapered annular support frame 6b of the bolt-tightened Langevin ultrasonic transducer 1 and the housing are supported by tapering with the housing 11 and the housing nut 21, but the bolt-tightened Langevin type ultrasonic transducer is restrained. As for the frequency characteristics in the state, the frequency of the admittance peak indicating the resonance frequency was 29,800 Hz, and the admittance value of the peak was 10.1 mS. Normally, when the bolt-tightened Langevin ultrasonic transducer 1 is constrained, the admittance value at the resonance frequency is smaller than that in the unconstrained state, but when there is almost no effect of the constraint, various effects are exerted. Due to this, the admittance is greater when there is restraint than when there is no restraint.

Further, a function synthesizer was connected to the power amplifier, the frequency was swept at a voltage of 20 Vp-p, and the admittance was maximized at 29.66 KHz, and the admittance value was about 146 mA. Then, the amount of vibration displacement at the center of the front mass under that condition was measured using a leather Doppler vibrometer. The amount of vibration displacement was 14.1 μmp-p.

The state in which the Langevin type ultrasonic transducer in FIG. 3 was unconstrained was about 1% lower in the resonance frequency and about 22% lower in the admitance value than the Langevin type ultrasonic transducer in the constrained state in FIG. .. Further, when the function synthesizer is connected to the power amplifier and driven, the state in which the Langevin type ultrasonic vibrator in FIG. 3 is unconstrained has a current as compared with the Langevin type ultrasonic vibrator in the constrained state in FIG. Was about 10% smaller, and the amount of vibration displacement was the same.

This difference is easily caused by the temperature change of the Langevin type ultrasonic vibrator. And even in the measurement order, such a difference occurs. That is, in the state in which the Langevin type ultrasonic vibrator in FIG. 3 is unconstrained, there is almost no difference between the Langevin type ultrasonic vibrator in the restrained state in FIG.

The configuration of the Langevin type ultrasonic vibrator and the support method of the Langevin type ultrasonic vibrator of the present invention can realize support with high rigidity, and even if the Langevin type ultrasonic vibrator is repeatedly attached to and detached from the housing, the support accuracy is high. Can be maintained. Then, in the ultrasonic processing method using this, the processing accuracy can be improved.

It is a figure which shows the structure of the typical bolt-tightened Langevin type ultrasonic vibrator. It is a figure which shows the structure of the ultrasonic processing apparatus which uses the bolt-tightened Langevin type ultrasonic vibrator. It is a figure which shows the structure of the bolt tightening Langevin type ultrasonic vibrator of this invention. It is a figure which shows the structure which supported and fixed the bolt-tightened Langevin type ultrasonic vibrator of this invention to a housing by a housing nut. It is a figure explaining the comparison of straight fitting and taper fitting, and tightening by a housing nut and a bolt. It is a figure explaining the kind of taper of a taper annular support frame body. It is a figure explaining the ultrasonic cutter using this invention. It is a figure explaining the ultrasonic drill using this invention.

The Langevin type ultrasonic vibrator of the present invention and its supporting method exhibit its characteristics when a mechanical load is applied to the Langevin type ultrasonic vibrator. Further, it can be divided into an application in which the Langevin type ultrasonic vibrator is used without rotating and an application in which the Langevin type ultrasonic vibrator is used in rotation.

First, an ultrasonic cutter, which is an application that does not rotate the Langevin type ultrasonic vibrator, will be described with reference to FIG. 7. In the Langevin type ultrasonic vibrator shown in FIG. 7A, a potato screw is screwed into a steel front mass 2 in which a tapered annular support frame 6b is integrally formed, and a piezoelectric element, an electrode plate, a piezoelectric element, an electrode plate, and a piezoelectric element, an electrode plate, a piezoelectric element, and an electrode plate are screwed into the potato screw. Then, a steel rear mass is passed through and tightened with a nut 7 to form an integral body. The shape of the tapered annular support frame 6b has tapers on both sides. 7B is a perspective view of the cutter shown in the cross-sectional view of FIG. 7A. A cemented carbide cutter blade is joined to the tip of a cemented carbide or steel round bar by a method such as brazing. In addition, the cutter blade may electrodeposit diamond depending on the application.

Next, the taper of the housing 11 is matched with the taper of the tapered annular support frame 6b of the Langevin type ultrasonic transducer, and the taper of the tapered annular support frame 6b for the housing nut is matched with the taper of the housing nut and tightened. , The Langevin type ultrasonic transducer is supported and fixed to the housing.

Further, a collet is inserted into the tapered hole provided at the tip of the front mass, the collet nut is loosely tightened, then the cutter is inserted into the collet, and the tightening cutter is fixed to the Langevin type ultrasonic vibrator.

Here, the operation method of the above-mentioned ultrasonic cutter will be described. For example, in order to cut a plastic plate (not shown), an ultrasonic cutter is attached to a three-dimensional processing machine and cut into a desired shape by a program. First, the power supply of the ultrasonic oscillation circuit 8 connected to the ultrasonic cutter by a lead wire is switched on, and the ultrasonic cutter is excited with ultrasonic vibration in a desired vibration mode. After that, the 3D processing machine is switched on, the processing program is activated, and the plastic plate is cut. When the cutting is completed, the ultrasonic oscillation circuit 8 is switched off, the power of the three-dimensional processing machine is turned off, and the processing is completed.

The Langevin type ultrasonic vibrator of the present invention and the ultrasonic cutter using the support method thereof have high rigidity and high support accuracy, so that they can be used with high accuracy and for a large load.

An ultrasonic drill, which is an application for rotating a Langevin type ultrasonic vibrator, will be described with reference to FIG. Piezoelectric element, electrode plate, piezoelectric element, electrode plate are inserted in this order into the male screw of the stainless steel front mass that integrates the tapered annular support frame 6b and the male screw, and the stainless steel rear mass is screwed into the male screw to manufacture a Langevin type ultrasonic vibrator. To do.

On the other hand, the spindle is created by the following procedure. Insert two bearings between the housing and the case, then insert the outer spacer, inner spacer, and bearing, and tighten the outer spacer ring and transformer base to manufacture the spindle.

Insert two lead wires (not shown) of the Langevin type ultrasonic transducer into the housing and pass them through the holes of the transformer stand. Then, the taper of the housing and the taper of the tapered annular support frame body 6b are matched and tightened to connect them. After that, a lead wire (not shown) of the Langevin type ultrasonic vibrator and a copper wire of the rotary transformer are connected. Then, the rotating shaft is screwed into the transformer base.

Next, the rotary transformer (fixed) is adhered to the rotary transformer base (fixed) with an adhesive. After that, the rotary transformer base (fixed) is screwed to the sleeve and screwed into the housing.

Attach the motor base to the sleeve with screws, attach the coupling to the rotating shaft, attach the motor base to the sleeve, insert the motor shaft into the coupling, and fix the motor to the motor base with bolts (not shown). After that, the coupling and the motor shaft are tightened with screws. The ultrasonic spindle is manufactured by the above. Then, a collet is inserted into the tapered hole of the front mass, the collet nut is lightly tightened, and then the drill is inserted into the collet and tightened to form an ultrasonic drill.

Here, the operation method of the above-mentioned ultrasonic drill will be described. For example, in order to make a hole in a cemented carbide plate (not shown), an ultrasonic drill is attached to a three-dimensional processing machine and a hole is made at a desired position by a program. First, the power supply of the ultrasonic oscillation circuit connected to the ultrasonic drill is switched on, and the cutting fluid is discharged from the nozzle almost at the same time, and the ultrasonic drill is excited with ultrasonic vibration in a desired vibration mode. After that, the 3D processing machine is switched on, the processing program is activated, and the carbide plate is drilled. When the drilling is completed, the motor of the ultrasonic oscillator circuit and the cutting fluid supply device is switched off, and the power of the three-dimensional processing machine is turned off to finish the processing.

Grooving can be performed by replacing the ultrasonic drill with an end mill and moving the end mill in the horizontal direction while rotating the end mill. Since the Langevin type ultrasonic vibrator of the present invention has a large support rigidity, it can be processed with higher accuracy than a normal support even with a force in the horizontal direction.

The Langevin type ultrasonic vibrator of the present invention and the ultrasonic drill using the support method thereof have high rigidity and high support accuracy, so that they can be drilled with high accuracy and can be used for a large load.

As described above, the Langevin type ultrasonic vibrator of the present invention and its supporting method are suitable for ultrasonic processing in which a mechanical load is applied.

1 Bolt tightening Langevin type ultrasonic vibrator 2a Metal block (rear mass)
2b metal block (front mass)
3 piezoelectric element 4 bolt 5 phosphorus bronze electrode 6a annular support frame 6b tapered annular support frame 7 nut 8 ultrasonic oscillation circuit 10 ultrasonic grinding device 11 housing 12 horn 13 grinding tool 17 electrical energy supply source 19 hole 20 base 21 Housing nut 22 Collet nut 23 Lead wire 24 Collet

Claims (6)

A Langevin type ultrasonic vibrator composed of a pair of metal blocks consisting of an upper metal block and a lower metal block and a piezoelectric element fixed between these metal blocks is housed in a housing to generate ultrasonic vibration. It ’s a device,
The piezoelectric element of the Langevin type ultrasonic vibrator is supported and fixed on an annular support frame having a tapered surface whose diameter decreases upward.
A tapered surface whose diameter increases downward is formed on the inner lower end of the housing, which is fitted with a tapered surface on the peripheral side surface of the annular support frame, and a male screw surface is formed near the outer lower end. is being done,
And
In a state where the tapered surface of the peripheral side surface of the annular support frame and the tapered surface of the inner lower end portion of the housing face each other, a female screw surface is formed on the upper portion of the inner surface and extends to the inner peripheral side on the lower portion of the inner surface. The female threaded surface of the housing nut is the male threaded surface of the housing so that the housing nut with the reduced diameter portion forms a gap between the side surface of the lower metal block and the tip of the reduced diameter portion of the housing nut. An ultrasonic vibration generator characterized in that a Langevin type vibrator is supported and fixed in a housing by bringing the bottom surface of the annular support frame into contact with an extension portion of the housing nut. A Langevin type ultrasonic vibrator composed of a pair of metal blocks consisting of an upper metal block and a lower metal block and a piezoelectric element fixed between these metal blocks is housed in a housing to generate ultrasonic vibration. It ’s a device,
The piezoelectric element of the Langevin type ultrasonic vibrator is supported and fixed on an annular support frame having a tapered surface whose diameter decreases downward.
A male screw surface is formed near the outer lower end of the housing.
Then, using a housing nut having a reduced diameter portion in which a female screw surface is formed on the upper portion of the inner surface and a tapered surface is formed on the lower portion of the inner surface so that the diameter decreases downward, the side surface of the lower metal block is used. The Langevin type vibrator was supported and fixed in the housing by tightening the female screw surface of the housing nut to the male screw surface of the housing so that a gap was formed between the housing nut and the tip of the reduced diameter portion of the housing nut. An ultrasonic vibration generator characterized by. A Langevin type ultrasonic vibrator composed of a pair of metal blocks consisting of an upper metal block and a lower metal block and a piezoelectric element fixed between these metal blocks is housed in a housing to generate ultrasonic vibration. It ’s a device,
The piezoelectric element of the Langevin type ultrasonic vibrator has an annular surface having a tapered surface whose diameter decreases upward on the upper side surface of the peripheral edge and a tapered surface whose diameter decreases downward on the lower side surface of the peripheral edge surface. Being supported and fixed by the support frame,
The inner lower end of the housing is formed with a tapered surface whose diameter increases downward, which is fitted with the tapered surface of the upper peripheral side surface of the annular support frame, and a male screw surface is formed near the outer lower end. Is formed,
And
A housing nut with a reduced diameter portion having a female threaded surface formed on the upper side of the inner surface and a tapered surface formed on the lower side portion of the inner surface with a downwardly decreasing diameter is used to housing the female threaded surface of the housing nut. An ultrasonic vibration generator characterized in that a Langevin type vibrator is supported and fixed in a housing by tightening it on the male screw surface of the housing. The ultrasonic vibration generator according to claim 3, wherein a gap is formed between the side surface of the lower metal block and the tip end of the reduced diameter portion of the housing nut. The ultrasonic vibration generator according to any one of claims 1 to 4, wherein the thickness of the annular support frame is larger than 1/5 of the diameter of the piezoelectric element and smaller than 2/3. The ultrasonic vibration generator according to any one of claims 1 to 5 , wherein a gap is formed between the lower end portion of the housing and the base portion of the reduced diameter portion of the housing nut.

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