WO2014168094A1

WO2014168094A1 - Ultrasonic tool

Info

Publication number: WO2014168094A1
Application number: PCT/JP2014/060004
Authority: WO
Inventors: 尚男倉田; 康有藏座
Original assignee: 本多電子株式会社
Priority date: 2013-04-09
Filing date: 2014-04-04
Publication date: 2014-10-16
Also published as: KR20140143451A; CN104254431A; CN104254431B; JP2014200591A; JP5632999B2; KR101484904B1

Abstract

The present invention addresses the problem of providing an ultrasonic tool capable of inhibiting a retaining member in a secured state from becoming unstable in relation to an attachment hole for a retaining member, even when the fastening torque of a screw member for securing the retaining member in the attachment hole is low. An ultrasonic cutter is provided with: an ultrasonic transducer having a support part (13) in which an attachment hole (31) is formed in the tip surface, and a screw hole (32) is formed in the circumferential wall of the tip section so as to pass through the attachment hole (31); a retaining member (17) having a notch groove (35) in which a cutter blade (16) can be inserted and being removably inserted in the attachment hole (31) with the cutter blade (16) inserted in the notch groove (35); and a screw member (33) which presses against the retaining member (17) inserted into the attachment hole (31) by being threaded into the screw hole (32), the retaining member (17) being pressed against the circumferential surface of the attachment hole (31) together with the cutter blade (16). The retaining member (17) contacts the circumferential surface of the attachment hole (31) at two prescribed contact positions (M) surrounding the center axis line (A) of the attachment hole (31) when the retaining member (17) is pressed between the screw member (33) and the circumferential surface of the attachment hole (31).

Description

Ultrasonic tool

The present invention relates to an ultrasonic tool to which a tip tool for machining a workpiece is attached in a replaceable manner.

Conventionally, as this type of ultrasonic tool, an ultrasonic cutter using a Langevin type vibrator is known (for example, Patent Document 1). In such an ultrasonic cutter, a cylindrical holding member having a pair of elastic pieces for holding a plate-like cutting tool is used, and the holding member is detachably fitted into a circular mounting hole formed on the tip surface of the horn. By tightening the screw member screwed to the side portion of the tip of the horn, the holding member is fixed to the mounting hole, and one elastic piece is pressed to clamp the blade.

Japanese Utility Model Publication No. 5-26295

By the way, in the ultrasonic cutter as described above, the holding member is fixed to the mounting hole by tightening with a screw member from a direction orthogonal to the axis of the holding member with the cylindrical holding member inserted into the circular mounting hole. ing. For this reason, in the site | part on the opposite side to the screw member side in a holding member, it contact | abuts only in one place with respect to the surrounding surface of an attachment hole. Therefore, when the tightening torque of the screw member is small, there is a problem that the pressing force of the screw member against the holding member is insufficient and the fixing state of the holding member with respect to the mounting hole becomes unstable.

Such a problem is not limited to the ultrasonic cutter, but is generally common to ultrasonic tools to which a tip tool other than the cutting tool is attached.
The present invention has been made paying attention to such problems existing in the prior art. The purpose is to provide an ultrasonic tool capable of suppressing the fixing state of the holding member with respect to the mounting hole from becoming unstable even when the tightening torque of the screw member for fixing the holding member to the mounting hole is small. It is to provide.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
An ultrasonic tool that solves the above problems includes an ultrasonic vibrator having a support portion formed in a peripheral wall of a tip portion with a mounting hole formed in a tip surface and a screw hole penetrating the mounting hole. A holding member that has a notch groove into which a tool can be inserted and is inserted into the attachment hole in a state where the tip tool is inserted into the notch groove, and is screwed into the screw hole to thereby attach the attachment hole. A screw member that presses the holding member inserted into the mounting hole and clamps the holding member together with the peripheral surface of the mounting hole together with the tip tool, and the holding member includes the screw member and the mounting hole. When sandwiched between the peripheral surface and the peripheral surface, the peripheral surface of the mounting hole abuts at a plurality of locations surrounding the central axis of the mounting hole.

According to this configuration, when the holding member is clamped between the screw member and the peripheral surface of the mounting hole, the holding member comes into contact with the peripheral surface of the mounting hole at a plurality of locations surrounding the central axis of the mounting hole. The contact area with respect to the peripheral surface of the mounting hole is larger than that of the conventional device that contacts the peripheral surface of the hole at only one place. For this reason, even when the tightening torque of the screw member that fixes the holding member to the mounting hole is small, it is possible to suppress the fixing state of the holding member to the mounting hole from becoming unstable.

In the ultrasonic tool, the holding member sandwiches the reference surface with respect to the peripheral surface of the mounting hole when a surface including the central axis of the mounting hole and the central axis of the screw member is used as a reference surface. It is preferable to abut on both sides.

According to this configuration, the holding member can be fixed to the mounting hole with a good balance by the screw member.
In the ultrasonic tool, the attachment hole is circular, and the portion of the holding member opposite to the screw member side is an arc surface having a larger curvature than the peripheral surface of the attachment hole, A flat surface formed by cutting out a part of the holding member so as to intersect with the reference surface is formed on the arc surface, and the holding member has a peripheral surface of the mounting hole with respect to a peripheral surface of the mounting hole. It is preferable that the contact is made on both sides of the flat surface in the direction.

According to this configuration, the holding member can be easily and well-balanced and fixed to the mounting hole by the screw member simply by cutting out a part of the holding member to form a flat surface.
In the ultrasonic tool, the flat surface is preferably perpendicular to the reference surface.

According to this configuration, the holding member can be more stably and stably fixed to the mounting hole by the screw member.
In the ultrasonic tool, when the holding member is clamped between the screw member and the peripheral surface of the mounting hole, the holding member engages with a tip portion of the screw member and It is preferable that a positioning portion for positioning is formed.

According to this configuration, it is possible to position the holding member with respect to the mounting hole by engaging the tip portion of the screw member with the positioning portion.

According to the present invention, even when the tightening torque of the screw member for fixing the holding member to the mounting hole is small, it is possible to suppress the fixing state of the holding member to the mounting hole from becoming unstable.

The side view of the ultrasonic cutter of one embodiment. The partially broken expanded side view which shows a state when a cutter blade is attached to the ultrasonic vibrator used for the ultrasonic cutter via a holding member. The disassembled perspective view which expanded the principal part of FIG. FIG. 4 is an enlarged sectional view taken along line 4-4 in FIG. 2; The principal part expanded sectional view of the ultrasonic cutter of a comparative example. The graph which shows the relationship between the fastening torque of the screw member in the ultrasonic cutter of a comparative example, and a drive current value. The graph which shows the relationship between the fastening torque of the screw member in the ultrasonic cutter of an Example, and a drive current value. The graph which shows the relationship between the fastening torque of the screw member in the ultrasonic cutter of a comparative example, and a frequency. The graph which shows the relationship between the fastening torque of the screw member in the ultrasonic cutter of an Example, and a frequency. The graph which shows the relationship between the fastening torque of the screw member and impedance in the ultrasonic cutter of a comparative example. The graph which shows the relationship between the fastening torque of the screw member and impedance in the ultrasonic cutter of an Example.

Hereinafter, an embodiment in which an ultrasonic tool is embodied as an ultrasonic cutter will be described with reference to the drawings.
As shown in FIGS. 1 and 2, an ultrasonic cutter 11 as an example of an ultrasonic tool includes a case 12 having a rectangular shape in a side view and a cylindrical support portion 13 functioning as a horn from the case 12. An ultrasonic transducer 14 accommodated in the case 12 is provided so as to be exposed. In the present embodiment, a Langevin type transducer is employed as the ultrasonic transducer 14.

A cable 15 for driving power supply is connected to the base end of the case 12, and the front end of the support portion 13 protrudes from the front end of the case 12. A substantially cylindrical holding member 17 holding a plate-like cutter blade 16 as an example of a tip tool is detachably supported on the support portion 13.

The ultrasonic vibrator 14 includes a plurality of (four in the present embodiment) sandwiched between a cylindrical first metal block 20, a cylindrical second metal block 21, and the first metal block 20 and the second metal block 21. And an annular piezoelectric element 22. In this case, both ends of the coupling bolt 23 are inserted into the first central screw hole 20 a of the first metal block 20 and the second central screw hole 21 a of the second metal block 21 with the coupling bolt 23 inserted into each piezoelectric element 22. Each is screwed.

The first metal block 20, the second metal block 21, and the piezoelectric element 22 have substantially the same outer diameter, and the piezoelectric element 22 is electrically connected to an oscillation circuit (not shown). A flange 24 having a larger diameter than that of the second metal block 21 is integrally formed on the surface of the second metal block 21 opposite to the piezoelectric element 22 side. Further, a support portion 13 having a smaller diameter than the second metal block 21 is integrally formed at the center of the surface of the flange 24 opposite to the second metal block 21 side. That is, the 2nd metal block 21, the flange 24, and the support part 13 are integrally formed mutually.

Further, an operation button 25 for driving the ultrasonic transducer 14 is provided on the side surface of the tip portion of the case 12. When the operation button 25 is pressed, AC power is supplied to the piezoelectric element 22 by an oscillation circuit (not shown), and the ultrasonic transducer 14 resonates. Thereby, the vibration of the support portion 13 is transmitted to the cutter blade 16 via the holding member 17, and the cutter blade 16 vibrates.

As shown in FIG. 3, a taper is formed at the peripheral edge of the tip of the support portion 13. A circular attachment hole 31 into which the holding member 17 can be inserted and removed is formed in the distal end surface 30 of the support portion 13. A screw hole 32 is formed in the peripheral wall at the tip of the support portion 13 so as to penetrate the mounting hole 31. A screw member 33 is screwed into the screw hole 32. A conical recess 33 a (see FIG. 4) is formed at the center of the tip surface of the screw member 33. In the present embodiment, a hexagon socket set screw is employed as the screw member 33.

As shown in FIGS. 3 and 4, a taper is formed at the peripheral edge of the tip of the substantially cylindrical holding member 17 made of metal. A cutout groove 35 that divides the tip end surface 34 into almost equal halves is formed on the tip end surface 34 of the holding member 17. The notch groove 35 extends from the distal end surface 34 of the holding member 17 to the proximal end portion 36.

The cutter blade 16 can be inserted into the notch groove 35. The portions on both sides of the holding member 17 across the notch groove 35 are a first clamping portion 37 and a second clamping portion 38, respectively. And the 1st clamping part 37 and the 2nd clamping part 38 are each elastically deformable inside by using the base end part 36 as a fulcrum.

A flat flat surface 39 having a substantially rectangular shape formed by cutting out a part of the holding member 17 is formed on the outer surface of the first clamping portion 37. The flat surface 39 extends from the distal end surface 34 of the holding member 17 to the proximal end portion 36 so as to be parallel to the cutout groove 35. A conical positioning recess 40 as an example of a positioning portion that can be engaged with the tip of the screw member 33 is formed at the center of the flat surface 39.

The portion of the second clamping portion 38 opposite to the screw member 33 side, that is, the outer surface of the second clamping portion 38 is an arc surface 38 a having a larger curvature than the peripheral surface of the mounting hole 31. A rectangular flat surface 38b formed by cutting out a part of the holding member 17 is formed on the arc surface 38a.

The flat surface 38b extends from the front end to the base end of the holding member 17 so as to be parallel to the cutout groove 35. That is, the flat surface 38 b extends over the entire length of the holding member 17. The flat surface 38b intersects the reference plane C perpendicularly when a plane including the central axis A of the mounting hole 31 and the central axis B of the screw member 33 is defined as the reference plane C.

Next, an operation when the cutter blade 16 is mounted on the support portion 13 of the ultrasonic transducer 14 will be described.
When the cutter blade 16 is attached to the support portion 13 of the ultrasonic transducer 14, first, the cutter blade 16 is inserted into the notch groove 35 of the holding member 17 to the back. Subsequently, the holding member 17 in a state where the cutter blade 16 is inserted into the notch groove 35 is inserted into the mounting hole 31 of the support portion 13. Subsequently, the holding member 17 is rotated to align the position of the positioning recess 40 with the screw hole 32. Subsequently, the screw member 33 is screwed into the screw hole 32.

Then, the tip of the screw member 33 engages with the positioning recess 40. When the screw member 33 is further screwed into the screw hole 32, the holding member 17 is clamped between the screw member 33 and the peripheral surface of the attachment hole 31. At this time, the first clamping part 37 of the holding member 17 is pressed by the screw member 33 and bent toward the second clamping part 38 side. Thereby, the cutter blade 16 is clamped by the first clamping unit 37 and the second clamping unit 38. Therefore, the holding member 17 is clamped by the screw member 33 and the peripheral surface of the attachment hole 31 together with the cutter blade 16.

At this time, as shown in FIG. 4, since the flat surface 38 b is formed on the circular arc surface 38 a that is the outer surface of the second holding portion 38 of the holding member 17, the circular arc surface 38 a is formed in the circumferential direction of the mounting hole 31. Contact is made at a contact position M that is a position on both sides of the flat surface 38b. As a result, the holding member 17 is fixed to the mounting hole 31 of the support portion 13, whereby the mounting operation of the cutter blade 16 to the support portion 13 via the holding member 17 is completed.

In this case, the two abutting positions M are both located at a location surrounding the central axis A of the mounting hole 31, and the distance from the reference plane C is the same. That is, in FIG. 4, the figure formed by sequentially connecting the center of the screw member 33 and the two contact positions M with a straight line is a substantially isosceles triangle.

Thus, when the holding member 17 is fixed to the mounting hole 31 of the support portion 13, the holding member 17 comes into contact with the peripheral surface of the mounting hole 31 at two locations surrounding the central axis A of the mounting hole 31. The contact area with respect to the peripheral surface of the mounting hole 31 is larger than that of the conventional device that contacts the peripheral surface of the base 31 only at one location. For this reason, even when the tightening torque of the screw member 33 is small, the fixing state of the holding member 17 with respect to the mounting hole 31 is prevented from becoming unstable compared to the conventional case.

According to the embodiment detailed above, the following effects are exhibited.
(1) When the holding member 17 is clamped between the screw member 33 and the peripheral surface of the mounting hole 31, the holding member 17 comes into contact with the peripheral surface of the mounting hole 31 at two locations surrounding the central axis A of the mounting hole 31. Therefore, the contact area with respect to the peripheral surface of the mounting hole 31 is wider than that of the conventional device that contacts the peripheral surface of the mounting hole 31 only at one location. For this reason, even when the tightening torque of the screw member 33 that fixes the holding member 17 is small, the fixing state of the holding member 17 with respect to the mounting hole 31 can be suppressed from becoming unstable.

(2) The holding member 17 sandwiches the reference plane C with respect to the peripheral surface of the mounting hole 31 when a plane including the central axis A of the mounting hole 31 and the central axis B of the screw member 33 is used as the reference plane C. Since they are in contact with both sides, the holding member 17 can be fixed to the mounting hole 31 with a good balance by the screw member 33.

(3) The arc surface 38 a of the holding member 17 is on both sides of a flat surface 38 b formed by cutting out a part of the arc surface 38 a with respect to the peripheral surface of the mounting hole 31 in the circumferential direction of the mounting hole 31. It is in contact. For this reason, the holding member 17 can be easily and well-balanced and fixed to the mounting hole 31 by the screw member 33 simply by cutting out a part of the arc surface 38a of the holding member 17 to form the flat surface 38b. Can do.

(4) Since the flat surface 38 b is perpendicular to the reference surface C, the holding member 17 can be more stably and stably fixed to the mounting hole 31 by the screw member 33.
(5) When the holding member 17 is clamped between the screw member 33 and the peripheral surface of the mounting hole 31, the holding member 17 is engaged with the tip of the screw member 33 to position the holding member 17. A positioning recess 40 for performing the above is formed. For this reason, the holding member 17 can be positioned with respect to the mounting hole 31 by engaging (contacting) the distal end portion of the screw member 33 with the positioning recess 40.

(Example of change)
In addition, the said embodiment can also be changed and actualized as follows.
The holding member 17 does not necessarily need to form the flat surface 39.

The holding member 17 does not necessarily need to form the positioning recess 40.
The holding member 17 does not necessarily have the flat surface 38b perpendicular to the reference surface C.
The holding member 17 is not necessarily required to contact the circumferential surface of the mounting hole 31 on both sides of the flat surface 38 b sandwiched in the circumferential direction of the mounting hole 31.

The holding member 17 may form a recess instead of the flat surface 38b. In this case, the cross-sectional shape of the recess may be an arbitrary shape such as a polygonal shape such as a triangular shape or a quadrangular shape, or a semicircular shape or a semielliptical shape.

The holding member 17 does not necessarily need to be brought into contact with the peripheral surface of the mounting hole 31 on both sides of the reference surface C.
When the holding member 17 is clamped between the screw member 33 and the peripheral surface of the mounting hole 31, the holding member 17 is brought into contact with the peripheral surface of the mounting hole 31 at three or more locations surrounding the central axis A of the mounting hole 31. You may do it.

The holding member 17 may have a polygonal column shape such as a quadrangular column shape or a hexagonal column shape, or an elliptical column shape. In this case, the shape of the attachment hole 31 is also changed according to the shape of the holding member 17.
-Instead of the cutter blade 16, a saw, a sword, a needle, or the like may be employed as a tip tool.

Hereinafter, examples and comparative examples that further embody the above-described embodiment will be described.
(Example 1)
As shown in FIG. 4, the ultrasonic cutter 11 using the holding member 17 of the above-described embodiment is taken as Example 1.

(Comparative Example 1)
As shown in FIG. 5, the ultrasonic cutter 11 using the holding member 50 obtained by omitting the flat surface 38 b in the holding member 17 of Example 1 was used as Comparative Example 1. In Comparative Example 1, the holding member 50 is in contact with the peripheral surface of the mounting hole 31 only at one place (position indicated by L in FIG. 5).

<Measurement of drive current value>
For Example 1 and Comparative Example 1 described above, the drive current value when driving each piezoelectric element 22 was measured by changing the tightening torque of the screw member 33 from 0.10 to 0.60 Nm at intervals of 0.05 Nm. . The result of Comparative Example 1 is shown in FIG. 6, and the result of Example 1 is shown in FIG.

The measurement result of the drive current value showed that the tightening torque value when the drive current value suddenly increased in Example 1 compared to Comparative Example 1. That is, in Comparative Example 1, the driving current value increases rapidly when the tightening torque is 0.35 Nm or less, and in Example 1, the driving current value increases rapidly when the tightening torque is 0.25 Nm or less. Therefore, it can be said that Example 1 has higher resistance to the weak tightening force of screw member 33 than Comparative Example 1. In general, the lower the tightening force of the screw member 33, the higher the drive current value. When the drive current value increases excessively, the oscillation circuit that supplies AC power to the piezoelectric element 22 fails.

<Frequency measurement>
For Example 1 and Comparative Example 1, the frequency of vibration of each ultrasonic transducer 14 was measured by changing the tightening torque of the screw member 33 from 0.10 to 0.60 Nm at intervals of 0.05 Nm. The result of Comparative Example 1 is shown in FIG. 8, and the result of Example 1 is shown in FIG.

As for the measurement result of the frequency, the variation in the frequency in Example 1 was smaller than that in Comparative Example 1. That is, the difference between the maximum value and the minimum value of the frequency in Example 1 was smaller than that in Comparative Example 1. Specifically, the difference between the maximum value and the minimum value of the frequency was about 1000 Hz in Comparative Example 1, whereas it was about 200 Hz in Example 1. Therefore, it can be said that the sharpness of the cutter blade 16 is more stable in Example 1 than in Comparative Example 1. In general, the greater the frequency variation, the more unstable the cutter blade 16 becomes and the sharpness decreases.

<Measurement of impedance>
For Example 1 and Comparative Example 1, the impedance when driving each piezoelectric element 22 was measured by changing the tightening torque of the screw member 33 from 0.10 to 0.60 Nm at intervals of 0.05 Nm. While the result of the comparative example 1 is shown in FIG. 10, the result of Example 1 is shown in FIG.

As for the measurement results of impedance, the variation in impedance was smaller in Example 1 than in Comparative Example 1. In other words, the difference between the maximum value and the minimum value of the impedance in Example 1 was smaller than that in Comparative Example 1. Specifically, the difference between the maximum value and the minimum value of the frequency was about 250Ω in Comparative Example 1, whereas it was about 60Ω in Example 1. Therefore, it can be said that the sharpness of the cutter blade 16 is more stable in Example 1 than in Comparative Example 1. In general, the greater the variation in impedance, the more unstable the cutter blade 16 becomes and the sharpness decreases.

<Discussion>
From the above results, it was shown that Example 1 has higher resistance to the weak tightening force of the screw member 33 and higher vibration stability of the cutter blade 16 than Comparative Example 1.

DESCRIPTION OF SYMBOLS 11 ... Ultrasonic cutter as an example of an ultrasonic tool, 13 ... Support part, 14 ... Ultrasonic vibrator, 16 ... Plate-shaped cutter blade as an example of a tip tool, 17 ... Holding member, 30 ... Tip surface, 31 DESCRIPTION OF SYMBOLS ... Mounting hole, 32 ... Screw hole, 33 ... Screw member, 35 ... Notch groove, 38a ... Arc surface, 38b ... Flat surface, 40 ... Positioning recessed part as an example of positioning part, A ... Center axis of mounting hole 31, B ... central axis of screw member 33, C ... reference plane.

Claims

An ultrasonic transducer having a support portion formed so that a mounting hole is formed in the distal end surface and a screw hole penetrates the mounting hole in the peripheral wall of the distal end portion;
A holding member that has a notch groove into which a tip tool can be inserted, and that can be inserted into and removed from the mounting hole in a state where the tip tool is inserted into the notch groove;
A screw member that presses the holding member inserted into the attachment hole by being screwed into the screw hole and clamps the holding member together with the peripheral surface of the attachment hole together with the tip tool;
When the holding member is clamped between the screw member and the peripheral surface of the mounting hole, the holding member abuts on the peripheral surface of the mounting hole at a plurality of locations surrounding the central axis of the mounting hole. Ultrasonic tool to do.
The holding member abuts on both sides of the mounting surface with respect to the peripheral surface of the mounting hole when a surface including the central axis of the mounting hole and the central axis of the screw member is used as a reference surface. The ultrasonic tool according to claim 1.
The mounting hole is circular,
The part of the holding member opposite to the screw member side is an arc surface having a larger curvature than the peripheral surface of the mounting hole,
A flat surface formed by cutting out a part of the holding member so as to intersect the reference surface is formed on the arc surface,
The ultrasonic tool according to claim 2, wherein the holding member is in contact with the peripheral surface of the mounting hole on both sides of the flat surface in the circumferential direction of the mounting hole.
The ultrasonic tool according to claim 3, wherein the flat surface is perpendicular to the reference surface.
The holding member includes a positioning portion that engages with a tip portion of the screw member and positions the holding member when the holding member is clamped between the screw member and the peripheral surface of the mounting hole. The ultrasonic tool according to any one of claims 1 to 4, wherein the ultrasonic tool is formed.