JPH03213257A - Ultrasonic polishing device - Google Patents

Abstract

PURPOSE:To remarkably heighten a polishing effect by installing a longitudinal vibrating means, which forces a flexural vibrator into the longitudinal vibration, a flexural vibrating means or a combined flexural vibrating means for making the flexural vibrator into the flexural vibration, respectively. CONSTITUTION:A flexural vibrator 20 fitted with an abrasive tool 56 is made into a longitudinal vibration 72 with a longitudinal vibrating means 66 and simultaneously into a flexural vibration 71 with a flexural vibrating means 61. Owing to a combined coupling vibration in both axial and flexural directions like this, vibrations of both parallel and rectangular components are made to act on various machining surfaces whereby these surfaces are effectively polished. In addition, with each vibro-strength is controlled, an optimum vibrating state from roughing to finishing is thus securable.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ultrasonic polishing apparatus suitable for polishing an object to be polished, such as a mold, whose surface to be polished exists in each direction.

BACKGROUND OF THE INVENTION Polishing of molds and the like using tools such as ultrasonically vibrating grindstones is widely used due to its effective polishing action.

An example of such a polishing device is a φ type consisting of an ultrasonic oscillator and a vertical vibrator, and the tip of the vertical vibrator is compatible with a sintered diamond grindstone, an electroplated diamond file, a resin grindstone, Tools made of brass, wood, bamboo, etc. can be attached as needed.

An example of such a vertical vibrator and tool is shown in FIG. In the figure, vibrator 1 is a vertical vibrator that vibrates in the axial direction.
Two annular electrostrictive elements 2 are placed one on top of the other with an electrode plate 3 in between, and are fastened together from both sides by a common electrode plate 11, a metal material 4, and a metal material 6 having a stepped portion 5 using a center bolt or the like. This is what I did. At the tip 7 of the vibrator l,
A female thread is provided on the shaft, and the tool 8 has a step 9,
At its output end, there is a grindstone 10 made of sintered diamond or the like.
are fixed by silver soldering. A male thread is provided at the large diameter end of the tool 8, and is screwed into a female thread provided at the tip 7 of the vibrator l. And tool 8
A variety of tools are prepared, and depending on the object to be machined, the screws mentioned above can be removed and replaced with the necessary tools.

When the vibrator l is driven by an ultrasonic oscillator (not shown) at a resonant frequency that includes the tool 8, the vibration generated by the electrostrictive element 2 resonates over the entire length, and the grinding wheel 10 is moved to the stepped portions 5 and 9.
The amplitude is expanded by, for example, 30Kh in the axial direction.
Ultrasonic vibration is performed at an amplitude of 20 μm P-P to 30 μm P-P at z as shown by the arrow.

Hold the vibrator 1 diagonally as shown in FIG.
When rubbing 2, the surface is effectively polished by ultrasonic vibration.

When a grindstone that vibrates ultrasonically in the axial direction is applied obliquely to the polishing surface in this manner, it is effectively polished, and this is used for rough polishing. Naturally, a large amount of polishing cannot be expected during finishing processing in which polishing is performed by vibrating parallel to the polishing surface.

Therefore, it is inconvenient for rough polishing on items where the polishing part is narrow and diagonal vibration cannot be applied.
For example, the side surface 15 of the narrow groove 14 of the mold 13 shown in FIG.
When polishing, the vibration direction of the whetstone becomes parallel to the polishing surface, which reduces the polishing effect. That is, vibrations parallel to the polished surface alone are not suitable for rough polishing of rough surfaces such as electrical discharge machined surfaces and cutter marks.

Therefore, a polishing device in which a polishing tool is provided at the output end of a flexurally vibrating vibrator and the tool is resonantly vibrated in a direction perpendicular to the axis has already been proposed in Japanese Patent Application No. 62-153020 (Japanese Unexamined Patent Publication No. 63-31).
(Refer to Publication No. 8248) proposed by the present applicant.

An example of the above-mentioned flexure vibrator and tool is shown in FIGS. 11 to 14, although the means for attaching the tool are somewhat different.

The deflection oscillator 20 is sandwiched between metal materials 21 and 22 from both sides at its large diameter part, and has electrodes 26 and 27 provided with an insulating part 25 left on the negative side and a full-surface electrode 28 on the other side in the thickness direction. Two annular electrostrictive elements 23.
24 has its electrodes 26 and 27 facing each other, and electrode plates 29,
30.

Further, a common electrode plate 31 is inserted between the electrostrictive element 23 and the metal material 21, and they are integrally tightened by a bolt 33 at the center of the shaft to form a deflection vibrator, and the small diameter output end of the metal material 22 A male thread 32 is provided in the section.

The tool 35, which is provided with a left-handed male thread 33 at its end, has a sintered diamond grindstone 39 further connected by silver soldering to the end of a plate 38 which is fitted into a slit 37 and joined by silver soldering. The fastening ring 42 has a right female thread 34 and a left male thread 36 on its inner periphery, a spanner hook 41 on its outer periphery, a tool 35 with a left male thread 33 on its end, and a tool 35 provided on the output end of the vibrator 20. It is tightly fastened with a left-hand male screw 32 with the circumferential angle aligned.

When driving voltages with deflection resonance frequencies whose phases are reversed to each other are applied to the electrode plates 29 and 30 using the common electrode plate 31 as a common terminal, the grinding wheel 39 resonates with the deflection vibration distribution shown in FIG. 11(b), and the tip of the grindstone 39 As shown by arrow 40, it vibrates greatly in the direction perpendicular to the axis.

As shown in FIG.
The polishing is effectively performed by ultrasonic vibrations acting perpendicularly to the polishing surface 46 of. Furthermore, when the grindstone 39 is applied diagonally to the polishing surface 46 and rubbed in parallel, the vertical component of the vibration that hits the polishing surface 46 diagonally acts, similar to the example shown in FIG. Polishing is performed.

Problems to be Solved by the Invention Although the use of a flexible vibrator that overcomes the drawbacks of vertical vibrators is effective for rough machining of groove sides, etc.
It cannot be used for finishing processes where vibration parallel to the polished surface is suitable.

Means for Solving the Problem A flexural vibrator to which a polishing tool is attached is caused to vibrate longitudinally and flexibly. In addition, each vibration intensity is controlled to the optimal compound vibration depending on the workpiece.

The working tool is effectively polished by combined vibration in the axial direction and the deflection direction, with parallel and perpendicular components of vibration acting on various machined surfaces.

Furthermore, by controlling the respective vibration intensities, optimum vibration conditions can be obtained from rough machining to finishing machining.

Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 to 7. This embodiment can also be achieved using the conventional deflection vibrator and tool described in FIG. 11 by changing the driving method thereof.

FIG. 1 shows the flexible oscillator 2o of FIG. 11 cited as a conventional example and a tool 56 provided with a sintered diamond 58, which are fastened together by a fastening ring 60 with left and right threads. The shape is the same as the conventional tool 8 shown in FIG. 8. Since the deflection vibrator 20 is the same as the conventional example, a description thereof will be omitted.

The flexural vibration means is driven by a high frequency power source 63 adjusted to the flexural resonance frequency. In other words, the output Lance 61
When voltages with opposite phases are applied to the electrode plate 29.30 by the secondary coil of Figure 2 (a) shows the total length including the tool.
A vibration distribution in the deflection mode occurs as shown in FIG.

Next, the longitudinal vibration means is driven by a high frequency power source 69 having a longitudinal resonance frequency. That is, when a voltage is applied to the center tap 65 of the secondary coil 64 of the transformer 61 via the output transformer 66, the same mode voltage is applied to the electrode plates 29 and 30, so that the electrostrictive elements 23 and 24 are expanded simultaneously in both the upper and lower directions. Since it is vertical, longitudinal vibration in the axial direction is generated, and a vibration distribution in the longitudinal mode as shown in FIG. 2(b) is generated, and the grinding wheel 5
The tip of 8 vibrates in the axial direction.

Each resonance frequency can be changed by changing the tool 56 or by changing the grinding wheel 5.
Since the frequencies of the high-frequency power sources 63 and 69 change as the power source 8 wears or loads are applied, it is preferable that the frequencies of the high-frequency power sources 63 and 69 be able to oscillate by tracking their respective resonance frequencies. Since each oscillation frequency oscillates independently, there is no relationship between frequency and phase, and the composite complex vibration changes in a random direction. The composite vibration at the output end is a combination of the flexural vibration 71 and the longitudinal vibration 72, and by controlling the amplitude of each vibration, the shape of the envelope of the vibration trajectory can be changed to a third
As shown in the figure, the shape can be a straight line, rectangle, or square, and is appropriately selected depending on the shape of the workpiece and the details of processing.

What is shown in FIG. 4 is a second embodiment of the present invention, which includes deflection drive electrostrictive elements 83, 84, and longitudinal drive electrostrictive elements 87.
A vibrator 80 is constituted by a metal member 88, which is sandwiched between metal members 81 and 82 and fastened together with bolts. The electrostrictive elements 83 and 84 are the same as the electrostrictive elements 23 and 24 (Fig. 1) that have electrodes on one side divided into two by an insulating part 25, and the electrostrictive elements 87 and 88 have electrodes on both sides that are normally used. It is an annular electrostrictive element with

A high frequency power source 92 drives the flexural vibration means.

That is, the electrode plates 85° 86 are connected via the output transformer 91.
Applying drive voltages with opposite phases to each other causes flexural vibration. Further, the high frequency power source 94 drives the longitudinal vibration means. That is, a driving voltage for longitudinal vibration is applied to the electrode plate 89 through the output transformer 93. By individually providing electrostrictive elements for each mode as in this example, it is possible to obtain a vibration output that is functionally similar to that shown in FIG. 1 but has a high power in part.

Furthermore, what is shown in FIGS. 5 and 6 is a third embodiment of the present invention. First, a vibrator that generates longitudinal vibration together with a compound flexural vibration that is a combination of a first flexural vibration and a second flexural vibration that is driven in a direction perpendicular to the first flexural vibration with a phase difference of 90 degrees from each other. Its drive circuit is shown. That is, it is driven by a longitudinal vibration means and a composite deflection vibration means.

The electrostrictive elements 101 and 102 that generate the first flexural vibration have electrodes divided into upper and lower halves on one surface, and electrode plates 108 and 1
It is energized by 09. And an electrostrictive element 103,1 that generates a second flexural vibration in a direction perpendicular to the first flexural vibration.
04 is an electrode plate 1 with electrodes divided into left and right sides on one side.
10. energized by ill. They are common electrode 1
12° 113 and sandwiched between metal members 105 and 106 and fastened together by a center bolt 107 to form a composite deflection vibrator 100. When the voltage whose phase is inverted by the output transformer 114 from the high-frequency power supply 115 for driving deflection vibration is applied to the electrode plates 108 and 109, it drives the electrostrictive elements 101 and 102 upside down and generates the first deflection vibration in the vertical direction. generate.

A portion of the power source 115 is shifted 90 degrees out of phase by a phase shifter 117, and then passed through an output transformer 116 to the electrode plate 110. i
ll is applied to the electrostrictive elements 103 and 104 to reversely drive them left and right to generate a second deflection vibration in the left and right direction.

The high frequency power supply 119 for longitudinal vibration drive is connected to the output transformer 118.
is connected to the intermediate tap of the secondary winding with a deflection m6 quadrance 114°116, and all electrode plates 108, 10
9. Since LIO and 111 are driven in the same phase, longitudinal vibration in the axial direction is excited.

A tool 120 holding a cylindrical grindstone 122 is firmly fastened to the output end of the vibrator 100 by a fastening nut 123 having left and right internal threads.

FIG. 7 shows the vibration state of the tool 120 and its tip.

At the tip of the grindstone 122, a first flexural vibration 125. A second flexural vibration 126 occurs, but since they are synchronized with a phase difference of 90 degrees, the vibration mode becomes a circular vibration 127 as shown in FIG. 7(C), and a longitudinal vibration 128 that is not synchronized with them. This generates a cylindrical complex vibration that vibrates in random directions.

Further, if the dimensions of the tool are considerably different in the horizontal and vertical directions, the first and second deflection resonance frequencies will be far apart, making it difficult to generate the circular vibration 127.

However, in such a case, a good effect can be achieved by tracking each resonance frequency individually and independently.

Such a grindstone and vibration mode are useful for polishing a portion of a K-shaped corner.

In the above embodiment, in the case of side surface polishing of deep grooves, both the longitudinal vibration and the deflection vibration are strongly adjusted, and after the rough machining, the deflection component is gradually reduced while finishing is carried out. In polishing the bottom surface of a deep groove, after rough machining using both vibration components, the vertical component is reduced toward finishing, and polishing is performed using the deflection component.

Compound vibration of compound deflection vibration (circular vibration) and longitudinal vibration using a round bar (cylindrical) grindstone is effective for machining round holes, R corner sides, and round hole bottoms. Similar to the upper side, the flexural vibration component acts auxiliarily on the side surface, and the longitudinal vibration component acts auxiliarily on the bottom surface, increasing the polishing effect.

In this way, the effect is the same even if the longitudinal and flexural resonance frequencies of the vibrator do not match, and the composite vibration of the longitudinal vibration component and the flexural vibration component perpendicular to it is a composite vibration if the vibration frequencies are different. Although the direction changes randomly, the random vibration direction change does not adversely affect the polishing effect.

Therefore, the tool has a large degree of freedom in its dimension.
This can greatly simplify the configuration of the vibration system.

According to such a wrapper, the vibration of the grindstone contains many components in the direction perpendicular to the polishing surface, so it is suitable for polishing hard and brittle materials such as cemented carbide and ceramics.

Effects of the Invention As described above, the present invention provides a flexural vibrator provided with a polishing tool, a longitudinal vibration means for vertically vibrating the flexural vibrator, and a flexural oscillating means or compound flexural vibration for flexurally vibrating the flexural vibrator. Compared to the conventional polishing action using only vertical or flexural vibration, the combined vibration with perpendicular vibration can significantly increase the polishing effect. By controlling the amplitudes of the longitudinal and deflection components to optimal values according to the processing situation, it is possible to perform effective polishing from rough polishing to finishing.

[Brief explanation of drawings]

Fig. 1 is a side view showing the first embodiment of the present invention, Fig. 2 is a waveform diagram showing the relationship between vibration distribution in the flexural mode and vibration distribution in the longitudinal mode, and Fig. 3 is an envelope of various vibration trajectories. FIG. 4 is a side view showing the second embodiment of the present invention, FIG. 5 is a side view showing the third embodiment of the present invention, and FIG. 6 is a perspective view of the electrode plate. Fig. 7 is a perspective view showing the tool and its vibration state, Fig. 8 is a perspective view showing an example of the conventional method, Fig. 9 is a front view showing a flat surface being polished, and Fig. 10 is a groove being polished. 11 is a side view showing another conventional example, FIG. 12 is a side view with a part of the fastening part cut away, and FIG. 13 is a perspective view of the electrode plate. FIG. 14 is a perspective view of the electrostrictive element, and FIG. 15 is a side view of the electrostrictive element in a polished state. 20.80,100...Flexible vibrator, 56,120
... Polishing tool, 66.93,118 ... Longitudinal vibration means, 61.91 ... Flexural vibration means, 114,116.
...Complex deflection vibration means applicant: Taga Electric Co., Ltd., %, 3 Figures (a) (b) (C) (d) (e), :% is Figure 3'' (short), %, 72 Figure (pull) Jzu, M

Claims (1)

[Claims] 1. The present invention is characterized by comprising a flexural vibrator provided with a polishing tool, a longitudinal oscillating means for vertically vibrating the flexural oscillator, and a flexural oscillating means for flexurally vibrating the flexural vibrator. Ultrasonic polishing equipment. 2. Ultrasonic polishing characterized by comprising a flexural vibrator provided with a polishing tool, a longitudinal oscillating means for longitudinally vibrating the flexural oscillator, and a compound flexural oscillating means for vibrating the flexural oscillator in a compound flexural vibration. Device.