JPH1071513A - Ultrasonic micro hole drilling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a lowering of machining speed as much as possible in drilling a micro hole whose length is extremely large compared with diameter so as to be capable of mass production of product having such micro holes in an ultrasonic micro hole drilling device, which drills or grind micro holes in a workpiece made of difficult machining material such as fine ceramics while giving ultrasonic vibration such as vertical vibration or twisting vibration to a drill for machining. SOLUTION: This ultrasonic micro hole drilling device is constituted in such a way that a machining head 1 is provided at an end of an arm 43, which can freely swing taking an eccentric cam 51 as a fulcrum, and a ball screw nut 42, which is threadedly engaged with a screw shaft 41, is connected to the other end of the arm 43, and the arm 43 is made to swing by rotating the screw shaft 41, giving specified feeding amount to the machining head 1 and on the other hand, giving high frequency small wave swing to the arm 43 taking the ball screw nut 42 as a fulcrum for giving low frequency vertical vibration to the machining head 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic wave for forming a fine hole in a difficult-to-cut material such as fine ceramics or applying an ultrasonic vibration such as a longitudinal vibration or a torsional vibration to a machining drill. The present invention relates to a micro-hole processing device.

[0002]

2. Description of the Related Art In recent years, an ultrasonic processing device has been mainly used for processing fine holes in difficult-to-cut materials such as fine ceramics and fine carbon. As a conventional ultrasonic processing device used for such purpose, A processing head equipped with a processing drill having a small diameter (for example, a diameter of about 0.07 to 0.1 mm) and having an ultrasonic vibrator for applying ultrasonic vibration of 20 kHz or more to the drill;
Generally, a feed mechanism that supports the processing head on the apparatus column and moves the work at a predetermined feed speed with respect to the work is generally used.

In such a processing apparatus, the drill and the workpiece are brought into contact with an appropriate processing pressure, and a cooling / grinding process in which abrasive grains are dispersed is provided at a contact position between the processing surface of the work and the drill. When a liquid (hereinafter, slurry) is supplied, and ultrasonic vibration is applied to the drill by the ultrasonic vibrator in this state, kinetic energy is given to the abrasive grains by the longitudinal vibration or torsional vibration of the drill caused by the application. In addition, a fine hole is formed in the work as the drill advances, or a pilot hole of the fine hole already formed in the work can be ground.

[0004]

However, in the case of processing a fine hole having a markedly different ratio between the hole diameter and the hole length, such as a fine hole opened in a zirconia ferrule or the like which is a connector for connecting an optical fiber cable. When the drill goes into the work as the machining progresses, it becomes gradually difficult to discharge the grinding powder from the fine holes, and the aforementioned slurry can be sufficiently supplied to the tip of the drill. Disappears. For this reason, there has been a problem that the processing speed of such fine holes has to be slowed down as the amount of penetration of the drill into the work increases, and the production efficiency is significantly reduced.

The present invention has been made in view of such a problem, and an object of the present invention is to process fine holes in which the ratio of the length of the hole to the diameter of the hole is extremely large.
It is an object of the present invention to provide an ultrasonic micro-hole processing apparatus suitable for mass production of a product having such micro-holes, while minimizing a reduction in the processing speed.

[0006]

In order to achieve the above object, an ultrasonic micro-hole machining apparatus according to the present invention comprises an ultrasonic vibrator for mounting a work drill and applying ultrasonic vibration to the drill. A processing head having: a head moving means for supporting the processing head so as to be able to move up and down with respect to the apparatus column; a screw shaft arranged in parallel with the direction in which the processing head is moved up and down with respect to the apparatus column; A nut member screwed to the arm, an arm eccentrically supported by an eccentric cam as a fulcrum, one end of which is connected to the head moving means and the other end of which is connected to the nut member, and rotating the screw shaft. The nut feed member is moved up and down as appropriate to move the machining head back and forth with respect to the workpiece, and the eccentric cam is rotated, and the arm supported by the eccentric cam is moved to the It is characterized in being configured to end the bets member side from the head vibration motor for swinging fulcrum.

According to such technical means, when the eccentric cam is rotated by the head vibration motor, the arm oscillatably supported by the eccentric cam is small and continuous with the end on the nut member side as a fulcrum. The processing head supported by the head moving means repeatedly vibrates up and down with a small amplitude due to the swing of the arm.

On the other hand, when the screw shaft is rotated by the head feed motor and the nut member screwed to the screw shaft is moved up and down, the arm having one end connected to the nut member swings around the eccentric cam as a fulcrum. The processing head connected to the other end of the arm can be freely moved forward and backward with respect to the work.

Accordingly, if the machining head is gradually lowered with respect to the workpiece by rotating the head feed motor while rotating the eccentric cam by the above-mentioned head vibration motor, the machining drill can move the workpiece with small vertical vibrations. The grinding powder is efficiently discharged from the fine holes during the processing, and the slurry can be sufficiently supplied to the tip of the drill, so that the processing speed of the fine holes for the work is improved.

Further, by controlling the rotation direction and the amount of rotation of the head feed motor, the amount of advance and retreat of the processing head with respect to the workpiece and the speed of movement thereof can be freely adjusted, so that the processing of the fine holes is progressing. Even during the process, the working drill can be instantaneously and regularly pulled out from the fine hole, and thereby the efficiency of discharging the grinding powder from the fine hole and the efficiency of supplying the slurry to the tip of the drill can be improved.

Further, in the present invention, it is preferable to provide a cam moving means for changing the engagement position of the eccentric cam with the arm along the longitudinal direction of the arm. With this configuration, by changing the engagement position of the eccentric cam with respect to the arm, the swing width of the arm caused by the rotation of the eccentric cam can be freely adjusted. Vertical vibration of the optimum amplitude can be given to the processing head.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an ultrasonic micro-hole machining apparatus according to the present invention. FIG. 1 shows a first embodiment of an ultrasonic microhole processing apparatus to which the present invention is applied. In the figure, reference numeral 1 denotes a drill 10 for machining.
Is a processing column on which the processing head 1 is supported so as to be able to move up and down with respect to the work mounting table 3. A built-in head feed mechanism 4 and a vibration generating mechanism 5 for applying a small vertical vibration to the processing head 1 are incorporated.

First, the processing head 1 includes an ultrasonic vibrator 11 through which the processing drill 10 passes. The ultrasonic vibrator 11 includes a piezoelectric element 11a, a front plate (horn) 11b sandwiching the piezoelectric element 11a, and And a backing plate 11c. Further, the machining drill 10 and the ultrasonic vibrator 11 are supported on a housing 13 of the machining head 1 via a rotary bearing 12, and are rotated by a servo motor 14 provided coaxially with the machining drill 10. Both directions can be given.

Further, the processing head 1 configured as described above
Is fixed to a slide head 20 and is supported by the device column 2 via a slide bearing 21. That is,
The slide head 20 and the slide bearing 21 constitute a head moving unit of the present invention. The slide bearing 21 moves along the vertical direction of the machining head 1 to the apparatus column 2.
Fixed rail 21a fixed to the
and a slider 21b that can freely move along the line a. The slide head 20 is fixed to the slider 21b. In addition, a linear ball bearing or an air slide bearing can be used as the slide bearing.

On the other hand, the head feed mechanism 4 built in the apparatus column 2 is screwed to a screw shaft 41 of a ball screw device provided in a direction parallel to the vertical direction of the processing head. A ball screw nut 42, an arm 43 swingably disposed via an eccentric pin 52 erected on an eccentric cam 51 described later, and a head feed motor connected to the screw shaft via a coupling 44 And one end of the arm 43 is connected to the slider 21b of the slide bearing 21 described above, while the other end is connected to the ball screw nut 42 via a cam follower (not shown). .

Accordingly, in the head feed mechanism 4, when the head feed motor 45 is rotated to give a predetermined rotation direction and rotation amount to the screw shaft 41, the screw shaft 41
A ball screw nut 42 screwed up or down on the screw shaft 41 by a predetermined distance moves up and down, and an arm 43 having one end connected to the ball screw nut 42 swings around the eccentric pin 52 as a fulcrum. Since the slider 21b is connected to the other end of the arm 43, in the processing apparatus of this embodiment, when the head feeding motor 45 is rotated, the slider 21b moves up or down on the apparatus column 2 together with the processing head 1. Then, the processing head 1 moves forward and backward with respect to the work mounting table 3.

At this time, since the feed amount of the processing head 1 to the work mount 3 is proportional to the movement amount of the ball screw nut 42, in this embodiment, the rotation direction and the rotation amount of the head feed motor 44 are adjusted. By doing so, the processing head 1 can be moved forward and backward by an arbitrary feed amount.

The vibration generating mechanism 5 includes an eccentric cam 51 having an eccentric pin 52 engaged with the arm 43.
And a support 53 for rotatably supporting the eccentric cam 51.
And a slide bearing 54 for horizontally moving the eccentric cam together with the support base 53 in accordance with the rotational position of the eccentric cam, and rotating the eccentric cam 51 at a predetermined rotation speed via a timing belt 56. Head vibration motor 55
It is composed of

In such a vibration generating mechanism 5, FIG.
As shown in FIG. 3, when the head vibration motor 55 is rotated to give a predetermined number of rotations to the eccentric cam 51, the eccentric pin 52 revolves around the rotation axis of the eccentric cam 51, and the eccentric pin 51 revolves. The arm 43 engaging with 52 swings little by little. At this time, one end 43a of the arm 43 is connected to a ball screw nut 42, and the vertical movement of the ball screw nut 42 is restrained by the screw shaft 41.
The other end 43b connected to 1b is swung.

Therefore, when the head vibration motor 55 is rotated, the arm 43 swings little by little about one end connected to the ball screw nut 42, and the slider 21b
A vertical vibration of a frequency corresponding to the number of rotations of the eccentric cam 51 is generated in the processing head 1 held at the position. At this time, the vibration generated in the processing head 1 can be made into a low frequency vibration of, for example, about 0 to 100 Hz by adjusting the rotation speed of the head vibration motor 55.

Incidentally, since the eccentric pin 52 is engaged with the arm and the eccentric cam 51 is supported by a support base, when the vibration generating mechanism 5 is observed from the outside as shown in FIG. The eccentric pin 52 only moves up and down in accordance with the rotation of the eccentric cam 51, and the eccentric cam 51 is guided by the slide bearing 54 and reciprocates in the horizontal direction together with the support 53.

In the ultrasonic micro-hole processing apparatus of the present embodiment configured as described above, the head feed motor 45 is rotated to lower the processing head 1 toward the work mounting table 3 and to mount the work. The working drill 10 is brought into contact with a work (not shown) fixed to the table 3 at an appropriate working pressure, and slurry is supplied to a contact position between the work and the working drill 10 in this state. Processing head 1
When a drive signal is applied to the ultrasonic vibrator 11 to apply ultrasonic vibration of 20 kHz or more to the processing drill 10, the workpiece is crushed by the movement of the abrasive grains accompanying the vibration of the processing drill 10, and Drill 10 for machining with feed
Penetrates into the work to form fine holes in the work.

At this time, in the processing apparatus of this embodiment, the head vibration motor 55 is rotated together with the feed of the processing head 1 by the head feed motor 45, so that the processing head 1 itself vibrates up and down at a low frequency. Since such vibration is superimposed on the ultrasonic vibration of the processing drill 10, the grinding powder generated by the processing is smoothly discharged from the fine holes, and the slurry is smoothly supplied to the fine holes. The processing speed can be improved.

FIG. 4 is a process diagram showing an example of the fine hole processing performed by the processing apparatus of the present embodiment from the relationship between the stroke amount of the processing head 1 and time. At the start of processing, first, the head vibration motor 55 is rotated to start applying low-frequency vibration to the processing head 1, and at the same time, ultrasonic vibration is applied to the processing drill 10. By rotating, the processing head 1 is set at the processing start position. When the processing head 1 reaches the processing start position, the head feeding motor 45 is rotated at a low speed to slowly lower the processing head 1 at a processing speed suitable for the work, and the processing drill 1 for the work is used.
Initiate a 0 cut.

After a certain period of time has elapsed from the start of processing, the head feed motor 45 is reversed at a high speed while the rotation of the head vibration motor 55 and the application of ultrasonic vibrations are maintained, and the processing head 1 is raised. After the tip of the drill 10 is temporarily pulled out of the work, the head feed motor 45 is immediately rotated forward at high speed, and the drill 1 is fed again to the original processing position. When the processing drill 10 is pulled out of the work at high speed in this manner, while the grinding powder is discharged from the fine hole being processed with the drawing, when the processing drill 10 is inserted again into the fine hole of the work, The slurry can be sufficiently supplied to the depth of the fine holes, and the processing speed can be significantly improved.

Such a temporary pulling-out operation of the machining drill 10 is repeatedly performed every elapse of a predetermined time. When the tip of the machining drill 10 reaches the machining end position, the head feeding motor 45 is reversed at a high speed to pull out the processing drill 10 from the work, and the processing of the fine holes is completed.

As described above, in the first embodiment, the eccentric cam 51 reciprocates in the horizontal direction together with the support 53 in accordance with the rotation of the eccentric cam 51, whereby the arm 43 swings. 5, the slit 4 into which the eccentric pin 52 is movably engaged as shown in FIG.
6 can be formed on the arm 43 so that the eccentric pin 52 can move in the slit 46 in accordance with the rotation of the eccentric cam 51. With this configuration, the support 53 of the eccentric cam 51 can be fixed to the apparatus column 2, and there is no need to support the support 53 by the slide bearing 54 as shown in FIG.

FIG. 6 shows a second embodiment of an ultrasonic micro-hole processing apparatus to which the present invention is applied. This embodiment is obtained by improving the vibration generating mechanism 5 in the first embodiment described above, so that the amplitude of the vertical vibration applied to the processing head 1 by the vibration generating mechanism 5 can be freely adjusted. It is.

More specifically, a screw shaft 60 is screwed into a support 53 supporting the eccentric cam 51, and the screw shaft 60 is rotated by an amplitude adjusting motor 61, whereby the eccentric cam 51 is rotated.
The arm 43 is configured to be able to move its engagement position along the longitudinal direction of the arm 43. Further, in this configuration, since the horizontal position of the support base 53 is restricted by the screw shaft 60, a slit 46 is formed in the arm 43 and the eccentric cam is formed as in the processing apparatus shown in FIG. The eccentric pin 52 is configured to be able to move in the slit 46 in accordance with the rotation of 51. The other configuration is the same as that of the first embodiment, and the description is omitted here.

When the engaging position of the eccentric cam 51 with respect to the arm 43 is changed along the longitudinal direction of the arm 43, the end of the arm 43 connected to the ball screw nut 42 and the arm 43 are inserted into the arm 43. Since the distance to the eccentric pin 52 changes, the head vibration motor 5
The swing width of the arm 43 caused by the rotation of the arm 5 changes.

Therefore, in the processing apparatus of the second embodiment,
By rotating the amplitude adjustment motor 61 and appropriately changing the engagement position of the eccentric cam 51 with the arm 43, the amplitude of the low-frequency vertical vibration given to the processing head by the head vibration motor can be arbitrarily adjusted. ,
Appropriate vertical vibrations that match the processing conditions at that time can be given to the processing head based on the state of grinding powder discharge and slurry supply during processing of the workpiece, and the processing speed can be improved accordingly. It is.

FIGS. 7 and 8 show a head feed mechanism 4 and a vibration generating mechanism 5 of an ultrasonic micro-hole machining apparatus according to a third embodiment. In the vibration generating mechanism 5 according to the first embodiment, the support 53 supporting the rotation of the eccentric cam 51 is used.
Is mounted on a slide bearing 54, and the support table 53 is reciprocated in the horizontal direction with the rotation of the eccentric cam 51, thereby preventing the arm 43 from reciprocating in the horizontal direction. In the third embodiment, the arm 43
The slide bearings 70 and 71 are provided at both ends of the arm 43, and one end of the arm 43 is connected to the slide head 20 and the other end is connected to the ball screw nut 42 via the slide bearings 70 and 71. The horizontal reciprocating motion generated in the arm 43 is prevented from propagating to the slide head 20 and the ball screw nut 42.

More specifically, the track rail 70a of the slide bearing 70 is fixed via a bracket 72 to the slider 21b of the slide bearing 21 to which the slide head 20 is fixed, and the track rail 7
One end of an arm 43 is rotatably supported via a bracket 73 on a slider 70b which can move freely along the line 0a. Here, the track rail 70a is disposed so that its longitudinal direction coincides with the direction perpendicular to the vertical direction of the slide head 20.

On the other hand, a fixed rail 74a of a slide bearing 74 is provided in the device column 2 in parallel with the screw shaft 41. A slider 74b moving on the fixed rail is connected to the slide bearing 71 via a bracket 75. Track rails 71a, 71a are fixed. Here, the track rails 71a, 71a are arranged so that the longitudinal direction thereof coincides with the direction orthogonal to the elevating direction of the ball screw nut 42, and sandwich the ball screw nut 42. The ball screw nut 42 is fixed to the slider 74b. When the ball screw nut 42 moves up and down with the rotation of the screw shaft 41, the slider 74b and the track rails 71a, 71 fixed to the slider 74b.
a is moved up and down together with the ball screw nut 42.

Further, as shown in FIG. 8, a connecting member 76 divided into two branches is fixed to the end of the arm 43 located on the ball screw nut 42 side. 77 is rotatably supported by a pair of brackets 78, 78, and each bracket 78 is fixed to a slider 71b which can move freely along the track rail 71a.

Since the processing head 1 fixed to the slide head 20 is completely the same as that of the first embodiment, its description is omitted here.

According to the ultrasonic micro-hole machining apparatus of the third embodiment configured as described above, when the motor 55 is driven to rotate the eccentric cam 51, the arm is provided in the same manner as in the first embodiment. Reference numeral 43 repeatedly swings with the end on the ball screw nut 42 side as a fulcrum. Since the horizontal component of the swinging motion is absorbed by the slide bearings 70 and 71, only the movement in the vertical direction is limited. The light is transmitted to the slide head 20 via the slide bearing 70 and the bracket 72. Thereby, a low frequency vibration corresponding to the rotation speed of the motor can be more smoothly applied to the processing head 1 fixed to the slide head 20, and the processing can be performed with the feed amount corresponding to the elevation of the ball screw nut. The head can be moved up and down.

[0038]

As described above, according to the ultrasonic micro-hole machining apparatus of the present invention, the discharge of cutting / grinding powder and the supply of slurry during the machining of a work can be performed more smoothly than the conventional apparatus. Since it is performed, even when processing a fine hole having a significantly large ratio of the hole length to the hole diameter, a reduction in the processing speed can be prevented as much as possible, and a product having such a fine hole can be efficiently produced. It becomes possible to produce.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a first embodiment of an ultrasonic microhole processing apparatus according to the present invention.

FIG. 2 is a first schematic diagram illustrating swinging of an arm due to rotation of an eccentric cam.

FIG. 3 is a second schematic view showing swinging of an arm due to rotation of an eccentric cam.

FIG. 4 is a process chart showing the progress of microhole processing by the ultrasonic microhole processing apparatus of the present invention.

FIG. 5 is a schematic view showing a modified example of the ultrasonic microhole processing apparatus of the first embodiment.

FIG. 6 is a schematic view showing a second embodiment of the ultrasonic microhole machining apparatus according to the present invention.

FIG. 7 is a front view showing a head feed mechanism and a vibration generating mechanism of an ultrasonic microhole machining apparatus according to a third embodiment.

FIG. 8 is a plan view showing a head feed mechanism and a vibration generating mechanism of an ultrasonic micro-hole machining apparatus according to a third embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Processing head, 2 ... Device column, 10 ... Drill for processing, 11 ... Ultrasonic vibrator, 41 ... Screw shaft, 42 ... Ball screw nut, 43 ... Arm, 45 ... Head feed motor, 51 ... Eccentric cam, 55 ... Head vibration motor

Claims (2)

[Claims] 1. A processing head having a work processing drill mounted thereon and having an ultrasonic vibrator for applying ultrasonic vibration to the drill, and a head movement for supporting the processing head vertically with respect to an apparatus column. Means, a screw shaft disposed in parallel with the vertical direction of the machining head with respect to the device column, a nut member screwed to the screw shaft, and a rocking support with the eccentric cam as a fulcrum. An arm connected to the head moving means and having the other end connected to the nut member; and a head feed motor for rotating the screw shaft to appropriately raise and lower the nut member and advance and retreat the processing head with respect to the workpiece. And a head vibration motor that rotates the eccentric cam and swings the arm supported by the eccentric cam with its end on the nut member side as a fulcrum. And an ultrasonic micro-hole processing apparatus. 2. The ultrasonic micro-hole machining apparatus according to claim 1, further comprising a cam moving means for changing an engagement position of the eccentric cam with respect to the arm along a longitudinal direction of the arm. Ultrasonic micro hole processing equipment.