Ultrasonic vibration application tool and ultrasonic processing device

Abstract

An ultrasonic vibration application tool equipped with a Langevin type ultrasonic vibrator which is suitably employable for ultrasonic processing devices and which efficiently generates ultrasonic vibration includes: a cylindrical housing having a contact face on a lower or bottom part of an inner surface thereof, and a lower screw part of an outer surface thereof; a bolted Langevin type ultrasonic vibrator comprising a front mass, a rear mass and a polarized piezoelectric element arranged between both masses, in which the front mass comprises a cylindrical tool-holder and a disc-shaped bulging part provided with a contact face for fitting to the contact face of the housing; and a ring-shaped counterweight having an upper screw part on an inner peripheral surface which is screwed with the screw part of the housing.

Claims

1. An ultrasonic vibration application tool comprising a cylindrical housing having a contact face on a lower or bottom area of an inner surface thereof, and a lower screw area of an outer surface thereof; a bolted Langevin-type ultrasonic vibrator comprising a front mass, a rear mass and a polarized piezoelectric element arranged between these masses, in which the front mass comprises a cylindrical tool-holder on the lower side and a disc-shaped bulging part on the upper side which is provided with a contact face to be fitted to the contact face of the housing; and a ring-shaped counterweight having an upper screw area on an inner peripheral surface which is screwed with the screw area of the housing, in which the ring-shaped counterweight has a lower small inner diameter part having an inner diameter less than the inner diameter of screw area thereof below the screw area wherein there is a space between the inner peripheral surface of the lower small inner diameter part and the outer peripheral surface of the cylindrical tool-holder.

2. The ultrasonic vibration application tool described in claim 1, in which the distance between the edge of the inner peripheral surface of the screw area of the counterweight and the edge of the outer peripheral surface of the counterweight is in the range of 2/3 to 3/1 of the thickness of the counterweight.

3. The ultrasonic vibration application tool described in claim 1, in which the distance between the edge of the inner peripheral surface of the screw area of the counterweight and the edge of the outer peripheral surface of the counterweight is in the range of 1/1 to 2/1 of the thickness of the counterweight.

4. The ultrasonic vibration application tool described in claim 1, in which the ring-shaped counterweight has a lower small inner diameter part having an inner diameter less than the inner diameter of screw area thereof below the screw area wherein there is a space between the top surface of the lower small inner diameter part and the bottom surface of the cylindrical housing.

5. The ultrasonic vibration application tool described in claim 1, in which the contact face of the housing is a tapered face extending toward the bottom surface, and in which the contact face of the disc-shaped bulging part also is a tapered face.

6. The ultrasonic vibration application tool described in claim 1, in which the housing has a ring-shaped concave at the bottom of an inner peripheral surface thereof, wherein the ring-shaped concave has a diameter larger than the diameter of the inner peripheral surface of the housing and in which the contact face of the housing is at least one face selected from the top face and side face of the concave and the contact face of the bulging part of the front mass is a top face or a side face thereof.

7. The ultrasonic vibration application tool described in claim 1, in which the outer peripheral edge of the ring-shaped counterweight vibrates in the direction opposite to the ultrasonic vibration of the Langevin-type ultrasonic vibrator.

8. An ultrasonic processing device comprising the ultrasonic vibration application tool described in claim 1, and a tool held by the tool-holder.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 shows a structure of a representative bolted Langevin-type ultrasonic vibrator (or bolted Langevin-type ultrasonic oscillator).

(2) FIG. 2 shows a structure of an ultrasonic processing device utilizing a bolted Langevin-type ultrasonic vibrator.

(3) FIG. 3 shows a representative structure of the ultrasonic vibration application tool according to the invention.

(4) FIG. 4 is an explanatory figure for illustrating an vibration (or oscillation) mode of the ring-shaped counterweight in which the counterweight vibrates in answer to the primary axial vibration (or oscillation) generated in the ultrasonic vibration application tool of the invention which is shown in FIG. 3.

(5) FIG. 5 is an explanatory figure for illustrating an vibration (or oscillation) mode of the ring-shaped counterweight in which the counterweight vibrates in answer to the pseudo zero order vibration (or oscillation) generated in the ultrasonic vibration application tool of the invention which is shown in FIG. 3.

(6) FIG. 6 shows a structure of an ultrasonic vibration application tool of the invention which differs from that shown in FIG. 3.

(7) FIG. 7 shows a structure of an ultrasonic vibration application tool of the invention which differs from that shown in FIG. 3 and FIG. 6.

(8) FIG. 8 is a perspective view of an ultrasonic vibration application tool of the invention in which the cylindrical housing has a slit on its side wall.

(9) FIG. 9 shows an exemplary structure of an ultrasonic processing device in which an ultrasonic vibration application tool of the invention is installed. The tool is a drill.

(10) FIG. 10 shows an exemplary structure of an ultrasonic processing device in which an ultrasonic vibration application tool of the invention is installed. The tool is a spindle.

(11) FIG. 11 shows an exemplary structure of an ultrasonic processing device in which an ultrasonic vibration application tool of the invention is installed. The tool is a cutter.

EMBODIMENTS OF THE INVENTION

(12) Referring to FIGS. 3 to 11, the ultrasonic vibration application tool of the invention and an ultrasonic processing device of the invention are described below in detail.

(13) FIG. 3 is a view of a representative structure of the ultrasonic vibration application tool according to the invention. In FIG. 3, (A) shows a top view and (B) shows a sectional view sectioned along the B-B line of (A).

(14) In the FIG. 3-(B), the ultrasonic vibration application tool comprises (a) a cylindrical housing 11, (b) a Langevin-type ultrasonic vibrator 1, and (c) a ring-shaped counterweight 20, which are described below, as main constitutional members. The ultrasonic vibration application tool comprises these constitutional members.

(15) (a) A cylindrical housing having a contact face on a lower or bottom area of an inner surface thereof, and a lower screw area of an outer surface thereof;

(16) (b) A bolted Langevin-type ultrasonic vibrator comprising a front mass, a rear mass and a polarized piezoelectric element arranged between these masses, in which the front mass comprises a cylindrical tool-holder on its lower side and a disc-shaped bulging part on its upper side, which is provided with a contact face to be fitted to the contact face of the housing; and

(17) (c) A ring-shaped counterweight having an upper screw area on an inner peripheral surface which is to be screwed with the screw area of the housing.

(18) The cylindrical housing 11 shown in FIG. 3 has a contact face 21 to be fitted to the contact face of the disc-shaped bulging part above the cylindrical tool-holder on a lower or bottom area of an inner surface thereof, and a lower screw area 22 of an outer surface thereof. In the cylindrical housing 11 of FIG. 3, the contact face 11 is a tapered face extending toward the bottom surface. The screw area 22 of the cylindrical housing 11 is a male screw area and is screwed with a screw are (female screw area) of the ring-shaped counterweight described hereinafter.

(19) The Langevin-type ultrasonic vibrator 1 shown in FIG. 3 is a bolted Langevin-type ultrasonic vibrator (or oscillator) comprising a front mass having an cylindrical tool-holder 24 on its lower side and an disc-shaped bulging part 23 on its upper side which is provided with a contact area to be fitted to the contact face 20 of the cylindrical housing 11, a rear mass 3 arranged above the front mass, and a polarized piezoelectric element fixed between these masses by means of a bolt, as is in the usual manner. Thus, the Langevin-type ultrasonic vibrator installed in the ultrasonic vibration application tool of the invention comprises a conventionally used front mass which is equipped with a cylindrical tool-holder. Otherwise, the cylindrical tool-holder is connected to bottom of an individually prepared front mass. The cylindrical tool-holder may be a tool-holder having a polygonal section similar to a circular section.

(20) A variety of tool-holders to be attached to an ultrasonic processing device are already known. These tool-holders can be employed in combination with the ultrasonic vibration application tool of the invention, unless the tool-holder disturbs the function of the ultrasonic vibration application tool of the invention.

(21) The ring-shaped counterweight 20 shown in FIG. 3 has an upper screw area (female screw area) 25 on an inner peripheral surface within which the screw area 22 of the cylindrical housing 11 is screwed.

(22) The outer peripheral edge of the ring-shaped counterweight of the ultrasonic vibration application tool of the invention vibrates in the direction opposite to the direction of ultrasonic vibration generated in the Langevin-type ultrasonic vibrator.

(23) The relationship between the direction of the ultrasonic vibration (or oscillation) generated in the Langevin-type ultrasonic vibrator and the direction of the vibration (or oscillation) of the ring-shaped counterweight is described below in detail, with reference to FIG. 4 and FIG. 5.

(24) FIG. 4 illustrates the ultrasonic vibration of the Langevin-type ultrasonic vibrator 1 and the vibration of the ring-shaped counterweight 20 caused by the ultrasonic vibration of the vibrator 1, in which both vibrations are observed when the ultrasonic vibration application tool of FIG. 3 is supported (held) by a supporting fixture 26 via the cylindrical housing 11 and then electric energy is applied to the ultrasonic vibrator 1 to generate an ultrasonic vibration of the primary axle vibration mode therein. The ultrasonic vibration of primary axle vibration mode of the ultrasonic vibrator 1 is a vibration comprising reciprocal up-and-down movement from the node (indicated by black point) existing nearly at a center position of the ultrasonic vibrator 1. This movement is shown by the arrows of solid line and dotted line.

(25) The reciprocal up-and-down movement (i.e., extension and shrinkage in the vertical direction) of the Langevin-type ultrasonic vibration 1 causes the vibration (reciprocal up-and-down movement) of the peripheral edge of the ring-shaped counterweight 20 from the node at the point (indicated by a pair of black points) at which the tapered contact face of the disc-shaped bulging part 23 of the cylindrical tool holder 24 of the ultrasonic vibrator 1 is brought into contact with the tapered contact face of the cylindrical housing 11. The reciprocal movement of the peripheral edge of the ring-shaped counterweight 20 is also illustrated by the arrows of solid line and dotted line. It should be noted that the reciprocal up-and-down movement of the peripheral edge of the ring-shaped counterweight 20 is opposite to the movement of the reciprocal movement (i.e., extension and shrinkage in the vertical direction) of the ultrasonic vibration 1.

(26) Because of the reciprocal up-and-down movement of the peripheral edge of the ring-shaped counterweight 20, the transmission of the ultrasonic vibration generated in the Langevin-type ultrasonic vibrator 1 to the cylindrical housing 11 is reduced. Accordingly, the loss of the generated ultrasonic vibration to the supporting fixture via the cylindrical housing is prominently reduced, and consequently the ultrasonic vibration generated in the ultrasonic vibrator 1 is applied to the tool held by the cylindrical tool holder 24 with increased efficiency.

(27) Thus, the ultrasonic vibration is applied to the processing tool with increased efficiency. For this reason, the precision and stability of the ultrasonic processing is enhanced, and the electric energy required for the ultrasonic processing decreases.

(28) In addition, since the area of contact face of the disc-shaped bulging part 23 of the cylindrical tool holder 24 of the ultrasonic vibrator 1 as well as the area of contact face of the cylindrical housing 11 can be enlarged, in comparison with the section area of the flange utilized in the prior art ultrasonic vibrator, the Langevin-type vibrator can be more stably supported in the ultrasonic processing device. Therefore, the Langevin-type ultrasonic vibrator and the processing tool held by the vibrator can be stably supported even when the processing procedure is performed for a long term.

(29) FIG. 5 illustrates the ultrasonic vibration of the Langevin-type ultrasonic vibrator 1 and the vibration of the ring-shaped counterweight 20 caused by the ultrasonic vibration of the vibrator 1, in which both vibrations are observed when the ultrasonic vibration application tool of FIG. 3 is supported (held) by a supporting fixture 26 via the cylindrical housing 11 and then electric energy is applied to the ultrasonic vibrator 1 to generate an ultrasonic vibration of the pseudo zero-order axle vibration mode therein. The pseudo zero-order axle vibration mode of Langevin-type ultrasonic vibrator is described in WO 2017/065263A1 in which the preceding invention made by the present inventor is disclosed. Therefore, the description seen in this WO publication is included in the specification of the present application.

(30) In FIG. 5, if the vibration of pseudo zero-order axle vibration mode is generated in the Langevin-type ultrasonic vibrator by the application of electric energy, the vibration containing no node (that is the extension-shrinkage movement) within the Langevin-type ultrasonic vibrator 1 occurs, and the Langevin-type ultrasonic vibrator per se vibrates reciprocating up-and-down. This reciprocating vibration is shown by the solid line and dotted line. The reciprocal up-and-down movement of the ring-shaped counterweight 20 is opposite to the movement of the reciprocal movement of the ultrasonic vibration 1.

(31) Therefore, even in the case that the Langevin-type ultrasonic vibrator vibrates in the pseudo zero order vibration mode, the ultrasonic vibration generated in the Langevin-type ultrasonic vibrator 1 is hardly transmitted to the cylindrical housing, as a result of the vibration (i.e., reciprocating up-and-down movement) of the outer peripheral dege of the ring-shaped counterweight 20. Accordingly, the ultrasonic vibration generated in the ultrasonic vibrator 1 is applied to the processing tool held by the cylindrical tool holder 24 with increased efficiency.

(32) Thus, the ultrasonic vibration is applied to the processing tool with increased efficiency. For this reason, the precision and reliability of the ultrasonic processing are enhanced, and the electric energy required for performing the ultrasonic processing decreases.

(33) In addition, since the area of contact face of the disc-shaped bulging part 23 of the cylindrical tool holder 24 of the ultrasonic vibrator 1 as well as the area of contact face of the cylindrical housing 11 can be made large, in comparison with the section area of the flange utilized in the prior art ultrasonic vibrator, the Langevin-type vibrator can be more stably supported in the ultrasonic processing device. Therefore, the Langevin-type ultrasonic vibrator and the processing tool held by the vibrator can be well supported even in the long term processing procedure.

(34) FIG. 8 is a perspective view illustrating other constitution of the ultrasonic vibration application tool embodying the present invention, in which a slit 27 is formed on the side wall of the cylindrical housing 11. The ring-shaped counterweight is indicated by 20, while the cylindrical tool holder is indicated by 24. The ultrasonic vibration application tool is supported and fixed by the application tool-supporting equipment 26. The formation of the slit 27 on the side wall of the cylindrical housing is effective for further reducing the loss of the ultrasonic vibration generated in the vibrator to the cylindrical housing. Moreover, the narrow slit formed along the circumferential direction can work to reduce generation of thermal energy caused by the ultrasonic vibrator and to give reflection of the ultrasonic vibration.

(35) The ultrasonic vibration application tool shown in FIG. 9 has a structure in which an ultrasonic vibration application tool-supporting rotary equipment comprising motor 31, motor axle 32, rotary axle 33, electric source 34, rotary axle of rotary transmitter 36, fixed transmitter base 37, sleeve 38, rotary transmitter base 39, and bearing 30, and the ultrasonic vibration application tool of the invention equipped with a processing tool 41. The ultrasonic vibration application tool-supporting rotary equipment is conventionally utilized in the known ultrasonic processing devices.

(36) FIG. 10 illustrates an ultrasonic processing device utilizing a spindle (processing tool rotating around the center axle of the ultrasonic vibrator) in which the ultrasonic vibration application tool is placed. An ultrasonic processing device of this structure is an embodiment of the ultrasonic processing device of the invention.

(37) In the use of the ultrasonic processing device of FIG. 10, electric energy supplied from the electric source 34 is applied to the Langevin-type ultrasonic vibrator 1 via a rotary transmitter 42, 43. The ultrasonic processing device of FIG. 10 is designed for incorporating into a machining center at its head 45.

(38) FIG. 11 shows a combination of an ultrasonic vibration application tool of the invention and a cutter 44 (B), which is also utilized in the ultrasonic processing device for performing the ultrasonic processing procedure. In this procedure, the cutter reciprocates along the axle of the ultrasonic vibrator. In the use of the ultrasonic processing device of FIG. 10, either or both of the processing device and the work (i.e., subject to be processed) move lateral direction for varying the relationship of these positions, and the cutter 44 vibrates with the up-and-down motion. Thus, the ultrasonic vibrator-supporting structure does not rotate.

DESCRIPTION OF SYMBOLS

(39) 1: bolted Langevin-type ultrasonic vibrator 2: metal block (front mass) 3: metal block (rear mass) 5a, 5b, 5c, 5d: piezoelectric element 6: bolt 7a, 7b, 7c, 7d: electrode 8: flange 9: nut 10: ultrasonic grinding processing device 11: (cylindrical) housing 13: grinding means 20: ring-shaped counterweight 21: contact face 22: screw area 23: disc-shaped bulging part 24: cylindrical tool holder 25: screw area