JP2004106125A - Working tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tool with a high vibration speed while simply mounting the tool. <P>SOLUTION: The tip of an ultrasonic vibrator 111 is formed with a tool insertion hole 117 extending facing in the axial direction, and a tool 121 having an approximately equal resonant frequency to that of the ultrasonic vibrator 111 is inserted in the tool insertion hole 117 and fixed to a position from the adjacent to its node N3 to a loop L3 while making its rear end side in an unfixed state. This constitution constitutes this working tool 101 as a single resonance body having a plurality of resonance vibration distributions, so that the tip of the tool 121 obtains an amplitude larger than the ultrasonic vibration generated in the ultrasonic vibrator 111. The amplitude relative to the ultrasonic vibrator 111 in the fixed position of the tool 121 is smaller than the amplitude of the vibration provided to the tool 121 so as to provide sufficient rigidity even if the tool is simply mounted. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a processing tool that performs various types of ultrasonic processing such as cutting, grinding, drilling, and welding using an ultrasonic vibrator.
[0002]
[Prior art]
When performing processing using ultrasonic vibration, a tool is attached to the ultrasonic vibrator that is the drive source of ultrasonic vibration, and the tool generates high-frequency micro-vibration with a large acceleration peculiar to ultrasonic waves. The tool is caused to collide with the workpiece. Thereby, efficient processing can be performed.
[0003]
An example of a conventional machining tool utilizing such ultrasonic vibration will be described with reference to FIGS. FIG. 9 is a perspective view showing an example of a conventional processing tool utilizing ultrasonic vibration, and FIG. 10 is an exploded perspective view thereof. FIG. 11 is a perspective view showing another example of a conventional machining tool using ultrasonic vibration, and FIG. 12 is an exploded perspective view thereof. FIG. 13 is an explanatory diagram showing the longitudinal vibration section and the resonance vibration distribution of the machining tool.
[0004]
The processing tool 1 introduced here is an example of an ultrasonic drilling device that drills a minute hole in a workpiece, and has a structure in which the tool 21 is fixed to the ultrasonic vibrator 11 with a set screw type tool holder 31. belongs to.
[0005]
The ultrasonic transducer 11 includes a front horn 12, two piezoelectric elements 13, two electrodes 14, a rear horn 15, and a fastening bolt 16 (see FIG. 13). As the tool 21, a drill-shaped tool is exemplified. That is, the processing part located at the tip of the tool 21 is the drill 22. A female screw 17 is cut at the tip of the front horn 12, and a male screw 32 provided on a tool holder 31 is screwed into the female screw 17, whereby the front horn 12 and the tool holder 31 are screwed. And are screwed together. This tool holder 31 has a tool insertion hole 33. The tool 21 is inserted into the tool insertion hole 33 from the rear end side, and is fastened and fixed by a tool set screw 34 provided in the tool holder 31. Here, the machining tool 1 is configured.
[0006]
In such a structure, a high-frequency voltage corresponding to the resonance frequency of a processing tool including the ultrasonic vibrator 11, the tool holder 31, and the tool 21 is applied to two electrodes 14 from a high-frequency power supply (not shown). Thus, the two piezoelectric elements 13 repeat expansion and contraction, thereby generating ultrasonic vibration in the ultrasonic vibrator 11. Thus, the drill 22 provided at the tip of the tool 21 performs its function.
[0007]
The vibration of the ultrasonic vibrator 11 generally includes axial vibration, flexural vibration, torsional vibration, and a composite vibration of these, depending on the type of the piezoelectric element 13. The ultrasonic transducer 11 illustrated in FIGS. 9 and 10 performs axial vibration. Which vibration to select may be determined according to the type of the tool 21.
[0008]
The working tool shown in FIGS. 11 and 12 is an example of a structure in which a slot 35 is provided on the tool holder 31. The tool holder 31 illustrated in FIGS. 9 and 10 has a structure in which the tip of the tool set screw 34 is directly pressed against the tool 21 from the side of the tool 21 to fix the tool 21, whereas FIGS. In the tool holder 31 illustrated in FIG. 1, the interval between the slits 35 is narrowed by tightening the tool set screw 34, and the tool 21 is fixed by the pressing force of the tool holder 31 itself.
[0009]
Here, the vibration distribution of the processing tool 1 functioning as the ultrasonic drilling device vibrator will be described with reference to FIG. As shown in FIG. 13 showing the vibration distribution of the machining tool 1, a node (node) indicated by N is a portion where the axial vibration is 0 (zero), and the right and left sides of the node expand and contract with the phases reversed. The loop (antinode) is the maximum portion of the amplitude, and the amplitude L1 at the front end of the tool 21 is larger than the amplitude L2 at the rear end. This is because when the diameter is reduced at the node N, the vibration amplitude is increased. If the diameter is reduced from the node N portion, a desired amplitude expansion rate can be obtained by the shape and the diameter ratio, and the amplitude required for processing can be designed. 9 to 13 show the processing tool 1 configured as a half-wavelength (１ ／ wavelength) resonator, the resonator is configured with a wavelength that is an integral multiple of the half-wavelength (１ ／ wavelength). It is also possible.
[0010]
[Problems to be solved by the invention]
With the recent advances in industrial technology, attempts to effectively use ultrasonic waves have become more active than ever before, and high-value processing, that is, high difficulty such as ultrafineness, high precision, and high speed, etc. Processing is being strongly demanded. However, it is difficult to meet such a demand only by the conventional ultrasonic technology. The reason will be described below.
[0011]
As can be seen from the vibration distribution shown in FIG. 13, the amplitude of the vibration distribution of the working tool 1 is maximum at the tip of the tool 21. The vibration speed V (m / sec) of the tool 21 at this time is
V (m / sec) = 2 × π × f × a (1)
Is represented by Here, f (Hz) is the resonance frequency of the apparatus, and a (m) is the one-sided amplitude of the tip of the tool 21.
[0012]
In general, in the case of a machining tool using ultrasonic vibration such as the machining tool 1 illustrated in FIGS. 9 to 13, the higher the vibration speed V (m / sec) of the tool 21 is, the higher the efficiency and the accuracy, that is, the higher the quality. High processing is possible. Therefore, it is desirable to increase the vibration speed, but for that purpose, it is necessary to increase the resonance frequency or increase the amplitude.
[0013]
On the other hand, the vibration of the tool 21 is a reciprocating motion, and a large acceleration is generated at the top dead center and the bottom dead center of the vibration. Then, the acceleration naturally increases in proportion to the magnitude of the vibration speed V (m / sec), and this causes a large inertial force on the tool 21. To explain this with a mathematical formula, the inertia force F (N) of the tool 21 generated by the vibration is represented by the mass m (kg) of the tool 21 itself and the acceleration g (m / sec). ² ) And dominated by
F (N) = m × g (2)
Will be represented by
[0014]
From the above theory, it is necessary to vibrate the tool 21 at high speed, that is, to increase the vibration speed V (m / sec) of the tool 21 in order to perform high-efficiency and high-accuracy ultrasonic machining. As the vibration velocity V (m / sec) increases, the acceleration g (m / sec) of the tool 21 increases. ² ) Also increase sharply.
[0015]
However, as is clear from the examples shown in FIGS. 9 to 13, for example, the tool 21 is a part of the ultrasonic resonator, but is only held by the mechanical structure of the tool holder 31. For this reason, when the vibration speed V (m / sec) of the processing tool 1 is increased in order to perform high-efficiency and high-accuracy ultrasonic processing, if the holding force of the tool 21 by the tool holder 31 is weak, the tool 21 There is a problem in that the player jumps out due to his own inertial force F (N).
[0016]
For this reason, in order to vibrate the tool 21 at a slightly higher vibration velocity V (m / sec), it is necessary to hold the tool 21 strongly and make the tool as light as possible. From the above equations (1) and (2), if the vibration velocity V (m / sec) increases, the acceleration g (m / sec) of the tool 21 will increase. ² ) Increases and the inertial force F (N) generated on the tool 21 increases. To cope with this, the tool 21 needs to be strongly held, and the inertial force F (N) generated on the tool 21 at this time. This is because the mass m (kg) of the tool 21 must be reduced as much as possible in order to reduce even a little.
[0017]
Here, various methods have been proposed in the past for securely fixing the tool 21 to the ultrasonic vibrator 11, but generally, examples are shown in FIGS. 9 and 10 or FIGS. 11 and 12. The technique is widely used. These fixing methods have an advantage that the tool 21 can be easily replaced.
[0018]
However, the method illustrated in FIGS. 9 and 10 can be generally applied only to an amplitude of about a = 10 μm at a frequency of 20 kHz. In addition, if the tool set screw 34 is strongly tightened to increase the fixing force of the tool 21, there is a problem that the tool performance such as deformation, breakage, and eccentricity of the tool 21 and the processing performance are easily deteriorated.
[0019]
Further, in the method illustrated in FIGS. 11 and 12, even if the tool set screw 34 is strongly tightened, deformation, breakage, and eccentricity of the tool 21 are less likely to occur. There is a problem that the holding force of the tool 21 becomes weaker than the method illustrated. Usually, at a frequency of 20 kHz, it can be applied only to an amplitude of a = about 5 to 7 μm.
[0020]
For this reason, in order to vibrate the tool 21 at a stronger vibration velocity V (m / sec), a method of directly joining the tool holder 31 and the tool 21 using a welding technique represented by brazing or the like. Is taken. However, in this method, the material is heated at a high temperature to melt the brazing material. I have a big problem.
[0021]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a tool capable of obtaining a large vibration speed while allowing the tool to be easily mounted.
[0022]
Another object of the present invention is to provide excellent dimensional reproducibility even when a tool is remounted.
[0023]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided an ultrasonic vibrator that generates ultrasonic vibration and has a tool insertion hole provided in an axial direction from a front end portion, and a front end portion inserted into the tool insertion hole from a rear end portion. A tool having a resonance frequency substantially equal to the ultrasonic vibrator and the tool inserted into the ultrasonic vibrator, from the vicinity of the node to the loop while the rear end side is in an unfixed state. And a fastening structure fixed at a position, and configured as a single resonator having a plurality of resonance vibration distributions.
[0024]
Therefore, by merely devising the fixing position of the tool with respect to the ultrasonic vibrator by the fastening structure, the tool can obtain an amplitude larger than the amplitude of the ultrasonic vibration generated in the ultrasonic vibrator. Moreover, since the amplitude of the tool at the fixed position with respect to the ultrasonic vibrator is smaller than the amplitude of the vibration obtained in the tool, sufficient rigidity can be obtained even if the tool is simply mounted.
[0025]
According to a second aspect of the present invention, in the processing tool according to the first aspect, a cross-sectional shape of the insertion structure between the tool insertion hole and the tool has a non-circular shape.
[0026]
Therefore, since the circumferential position of the tool with respect to the tool insertion hole is uniquely determined, excellent dimensional reproducibility can be obtained when the tool is remounted.
[0027]
According to a third aspect of the present invention, there is provided an ultrasonic vibrator which generates ultrasonic vibration and has a tool insertion hole provided in an axial direction from a front end portion, and a front end portion which is inserted into the tool insertion hole from a rear end portion. A tool having a processing portion, and a fastening portion for fixing the tool inserted into the ultrasonic vibrator, the cross-sectional shape of the insertion structure between the tool insertion hole and the tool side is a non-perfect circle A machining tool that is shaped.
[0028]
Therefore, since the circumferential position of the tool with respect to the tool insertion hole is uniquely determined, excellent dimensional reproducibility can be obtained when the tool is remounted.
[0029]
According to a fourth aspect of the present invention, in the processing tool according to the second or third aspect, a polygon is selected as the non-circular shape.
[0030]
Therefore, a non-circular cross-sectional shape in the insertion structure of the tool insertion hole and the tool can be easily manufactured.
[0031]
According to a fifth aspect of the present invention, in the machining tool according to the second or third aspect, a gear shape is selected as the non-circular shape.
[0032]
Therefore, a non-circular cross-sectional shape in the insertion structure of the tool insertion hole and the tool can be easily manufactured.
[0033]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
[0034]
1 is a perspective view showing a working tool, FIG. 2 is an exploded perspective view thereof, and FIG. 3 is a perspective view showing a vibration direction of the tool. 4 is a perspective view showing another embodiment of the working tool, FIG. 5 is an exploded perspective view thereof, and FIG. 6 is a perspective view showing a vibration direction of the tool.
[0035]
The processing tool 101 of the present embodiment has a structure in which a tool 121 is fixed to an ultrasonic vibrator 111 with a tool holder 131.
[0036]
The ultrasonic transducer 111 includes a front horn 112, two piezoelectric elements 113, two electrodes 114, and a rear horn 115, which are tightened by fastening bolts 116 (see FIG. 5). They are one.
[0037]
As shown in FIG. 2, a tool insertion hole 117 extending in the axial direction is provided at the tip of the front horn 112, and the tool 121 is inserted into the tool insertion hole 117 from the rear end. .
[0038]
The tool 121 has a resonance frequency substantially equal to that of the ultrasonic vibrator 111, and a portion to be inserted into the tool insertion hole 117 is formed long. A flange 122 is formed on the tool 121, and the tool 121 is inserted into the tool insertion hole 117 to a position where the flange 122 comes into contact with the tip of the front horn 112. A processing portion 123 is integrally formed at the tip of such a tool 121.
[0039]
Here, in the processing tool 101 shown in FIGS. 1 to 3, a cubic tool for drilling a square hole is provided as the processing part 123 as the tool 121. The processed portion 123 performs a perforation process on a hard and brittle, so-called highly brittle material such as glass or ceramics by vibrating the shaft. Therefore, when such a processing part 123 is provided on the tool 121, the ultrasonic vibrator 111 for shaft vibration is used to axially vibrate the processing part 123. The ultrasonic oscillator 111 for shaft vibration is one of typical ultrasonic oscillators 111 and can be easily obtained by selecting the piezoelectric element 113.
[0040]
On the other hand, in the machining tool 101 shown in FIGS. 4 to 6, a drill bit is provided as the machining portion 123 as the tool 121. The machined portion 123, that is, the hole turning tool performs vibration cutting by performing flexural vibration. Therefore, when such a processing part 123 is provided in the tool 121, the ultrasonic vibrator 111 for bending vibration is used to cause the processing part 123 to bend and vibrate. The ultrasonic oscillator 111 for flexural vibration is one of the representative ultrasonic oscillators 111, and can be easily obtained by selecting the piezoelectric element 113.
[0041]
Next, a square shank 124 is formed on the tool 121 at a position closer to the rear end than the flange 122. This square shank 124 is shorter in length than the entire rear end portion of the flange 121 of the tool 121, and the portion of the tool 121 behind the square shank 124 maintains a cylindrical shape. The tool insertion hole 117 formed in the front horn 112 corresponding to such a square shank 124 has a shape similar to that of the square shank 124 only at the tip portion (see FIG. 5). Thereby, it can be said that a part of the cross-sectional shape in the insertion structure of the tool insertion hole 117 and the tool 121 is a non-circular shape. In the present embodiment employing the square shank 124, it can be said that a polygon is selected from among such non-circular shapes. However, as for the cross-sectional shape in the insertion structure of the tool insertion hole 117 and the tool 121, any non-circular shape can be selected, and for example, various shapes such as a gear shape, a star shape, a D-cut shape, etc. Can be selected.
[0042]
The tool 121 inserted into the tool insertion hole 117 is fixed by the tool holder 131, whereby the tool 121 is fastened to the ultrasonic vibrator 111. The form of the tool holder 131 and the structure of fixing the tool 121 by the tool holder 131 are different between the processing tool 101 shown in FIGS. 1 to 3 and the processing tool 101 shown in FIGS.
[0043]
In the machining tool 101 shown in FIGS. 1 to 3, a male screw 118 is cut in the outer peripheral axis direction of the tip of the front horn 112, and a tool holder 131 having a cap nut structure is screwed to the male screw 118. Thereby, the tool 121 is fastened to the ultrasonic vibrator 111. That is, the tool holder 131 has a female screw 132 that is screwed into the male screw 118 provided on the outer periphery of the front horn 112 (see FIG. 8). Therefore, with the tool 121 inserted into the tool insertion hole 117 until the flange 122 comes into contact with the front end of the front horn 112, the tool holder 131 is mounted from the tool 121 side, and the female screw 132 is attached to the front horn. The tool 121 is fastened to the ultrasonic vibrator 111 by being screwed into a male screw 118 formed at 112. That is, the flange 122 provided on the tool 121 is sandwiched between the tip of the front horn 112 and the tool holder 131.
[0044]
On the other hand, in the machining tool 101 shown in FIGS. 4 to 6, a female screw 119 is cut at a front end of the front horn 112 in a direction orthogonal to the axial direction. The tool 121 is fastened to the ultrasonic vibrator 111 by tightening the male screw-shaped tool holder 131. That is, with the tool 121 being inserted into the tool insertion hole 117 until the flange 122 abuts on the tip of the front horn 112, the tool holder 131 that is screwed into the female screw 119 provided on the front horn 112 is When tightened, the tip of the tool holder 131 is pressed against the tool 121, and the tool 121 is thereby fixed.
[0045]
Thus, the processing tool 101 shown in FIGS. 1 to 3 or the processing tool 101 shown in FIGS. 4 to 6 is configured.
[0046]
In order to use the processing tool 101 configured as described above, a high-frequency voltage is applied to two electrodes 114 from a high-frequency power supply (not shown). At this time, by applying a high-frequency voltage corresponding to the resonance frequency of the processing tool 101 serving as a vibration device including the ultrasonic vibrator 111, the tool holder 131, and the tool 121, the device is sandwiched between the two electrodes 114. The two piezoelectric elements 113 repeatedly expand and contract, thereby generating ultrasonic vibration.
[0047]
Here, for each of the processing tool 101 shown in FIGS. 1 to 3 and the processing tool 101 shown in FIGS. 4 to 6, an operation performed by generating ultrasonic vibration in the ultrasonic vibrator 111 will be described.
[0048]
First, in the machining tool 101 shown in FIGS. 1 to 3, a cubic tool for drilling a square hole is provided as the machining portion 123 as the tool 121. Therefore, an operation using the processing tool 101 on which the tool 121 including the processing unit 123 is mounted will be described.
[0049]
When processing hard and brittle materials, such as glass and ceramics, so-called highly brittle materials, processing methods using ultrasonic vibration have been used as one of the most efficient processing means. For example, when drilling a square hole in a highly brittle material, the shape of the processing portion 123 provided at the tip of the tool 121 may be formed into a desired square as illustrated in FIG. Then, with the ultrasonic vibrator 111 generating ultrasonic vibration in the axial direction, the processing portion 123 is applied to the workpiece made of a brittle material to supply loose abrasive grains. Then, since ultrasonic vibration is generated in the direction indicated by the arrow in FIG. 3, that is, in the axial direction of the ultrasonic vibrator 111, the loose abrasive grains are accelerated at the tip of the processing portion 123, and the high-brittle material is processed. The collision causes an infinite number of micro cracks in the workpiece, and a square hole similar to the shape of the processed portion 123 is opened. In this case, if the processing portion 123 is formed of a grindstone, the same drilling can be performed only by supplying the cutting fluid.
[0050]
Next, in the machining tool 101 shown in FIGS. 4 to 6, a drill bit is provided as the machining portion 123 as the tool 121. Therefore, an operation using the processing tool 101 on which the tool 121 including the processing unit 123 is mounted will be described.
[0051]
Vibration cutting using ultrasonic vibration is used as a means for performing high-precision and high-efficiency processing in a processing region where cutting has conventionally been difficult. Vibration cutting using such ultrasonic vibration can be usually realized by matching the vibration direction of the cutting edge with the cutting direction. Therefore, when performing vibration cutting using the processing unit 123 illustrated in FIG. 6, the ultrasonic vibrator 111 may be flexibly vibrated in a direction perpendicular to the axial direction. Hole drilling is a method of cutting the inner wall surface of a hole, and in this embodiment, it is possible to precisely cut the processed portion 123, which is a hole drilling tool, in the tangential direction of the inner wall peripheral surface of the hole. It is. At this time, the most important thing in precision drilling is to make the height of the blade of the processing portion 123, which is a drilling bit, exactly coincide with the axis of the inner peripheral surface of the non-cutting object. In particular, in the processing of small-diameter holes, problems such as deterioration of dimensional accuracy, deterioration of the quality of the cut surface, and deterioration of the tool life occur. In addition, it is necessary to control the position of the cutting edge more strictly as the machinability deteriorates, such as a material having poor machinability, a hard metal, or a hardened steel material. It's not an exaggeration.
[0052]
Here, the resonance vibration characteristics of the working tool 101 according to the present embodiment will be described with reference to FIGS. FIG. 7 is a side view of the working tool, and FIG. 8 is an explanatory diagram showing the resonance vibration distribution of the working tool along with the AA cross section in FIG. In other words, in the explanatory diagram shown in FIG. 8, the vibration state of each part generated when the processing tool 101 is ultrasonically vibrated is represented by a vibration distribution diagram, and such a vibration distribution and the internal structure of the ultrasonic vibrator 111 are described. It is explained in contrast. 7 and 8 show an example in which a drill-shaped processing portion 123 is attached to the tip of a tool 121, and an ultrasonic vibrator 111 that generates axial vibration in accordance with the drilling is used. .
[0053]
8, the dotted line indicates the vibration distribution of the ultrasonic transducer 111, and the solid line indicates the vibration distribution of the tool 121. As is clear from these vibration distributions, the ultrasonic transducer 111 has one wavelength, and the tool 121 has １ ／ wavelength. Each of the vibration distributions of the ultrasonic transducer 111 and the tool 121 is a vibration distribution in a state where the tool 121 is fastened and fixed to the ultrasonic transducer 111 with the tool holder 131, that is, in a state as the processing tool 101.
[0054]
As shown by the dotted line in FIG. 8, the axial vibration distribution of the ultrasonic transducer 111 has an axial amplitude of 0 at the node portions N1 and N2, and the amplitude at the loop portions L1, L2, and L3. It becomes maximum and its vibration distribution shows a sinusoidal curve. As described above, since the resonance frequency of the tool 121 is substantially equal to that of the ultrasonic vibrator 111, the tool 121 performs resonance ultrasonic vibration at 波長 wavelength according to the ultrasonic vibration of the ultrasonic vibrator 111. The node is N3, and the loops are L3 and L4. As is apparent from the vibration distribution between the ultrasonic vibrator 111 and the tool 121, the tool 121 is fixed to the ultrasonic vibrator 111 at the midpoint between the node N3 and the loop L3 in the vibration distribution, and joined. Will be. That is, in the case of the processing tool 101 illustrated in FIGS. 1 to 3, the tool 122 is fixed by being sandwiched between the tip of the front horn 112 and the tool holder 131. Only at this fixed position is the ultrasonic transducer 111 fixed, and the other parts are in a free state. In the case of the processing tool 101 illustrated in FIGS. 4 to 6, such a structure is such that the position at which the male screw configured as the tool holder 131 presses the tool 121 is set with respect to the ultrasonic vibrator 111 of the tool 121. This is a fixed position.
In the vibration distribution diagram shown in FIG. 8, the fixed position of the tool 121 with respect to the ultrasonic transducer 111 is shown as an intersection LN. The intersection LN, which is the fixed position of the tool 121 with respect to the ultrasonic transducer 111, can be any position as long as the position is from the vicinity of the node N3 of the tool 121 to the loop L3.
[0055]
Therefore, the tool 121 inserted into the ultrasonic transducer 111 is fixed at a position from the vicinity of the node N3 to the loop while the rear end side is in an unfixed state. Thus, in the present embodiment, there is provided a fastening structure for fixing the tool 121 inserted into the ultrasonic transducer 111 at a position from the vicinity of the node N3 to the loop L3 while keeping the rear end side in an unfixed state. I have. As a result of providing such a fastening structure, the working tool 101 of the present embodiment is configured as a single resonator having a plurality of resonance vibration distributions.
[0056]
Further, as a result of fastening the ultrasonic vibrator 111 and the tool 121 by the above-described fastening structure, in the present embodiment, the amplitude of the vibration in the ultrasonic vibrator 111 and the amplitude of the vibration in the tool 121 are the same at the intersection LN. Become. The intersection LN is substantially equal to the amplitude of the loop L1 for the ultrasonic transducer 111. On the other hand, the intersection LN is a substantially intermediate point between the node N3 and the loop L3 for the tool 3.
Thus, the tool 121 is excited by the vibrator constituted by the ultrasonic vibrator 111 and the tool holder 131 from the intersection LN as a starting point, and as a result, the machining portion provided at the tip of the tool 121 The amplitude of 123 will be larger than the loop L1 which is the maximum amplitude part of the ultrasonic transducer 111 on which the tool holder 131 is mounted. Therefore, according to the present embodiment, it is possible to increase the amplitude of the processing portion 123 provided at the tip of the tool 121 without using any special amplitude expanding means for the tool 121. Therefore, a large vibration speed can be obtained for the tool.
[0057]
In addition, in the conventional processing tool 1 which employs a conventional fastening means between the ultrasonic transducer 111 and the tool 121, for example, a fastening means as shown in FIGS. 9 to 13, the tool 21 is an entire resonator, that is, one tool. According to the present embodiment, two resonators (the ultrasonic vibrator 111 with the tool holder 131 mounted thereon and the tool 121) form independent vibration distributions while being configured as a part of one vibration distribution. Will have. As a result, the ultrasonic transducer 111 having the tool holder 131, which is two resonators having independent vibration distributions, and the tool 121 are joined at a position where the vibration amplitude is small, that is, at a position where the vibration speed is small. be able to. In addition to the vibrator, the vibration mode of the tool 121 is exactly the same as the mode in which the tool 121 resonates and vibrates independently. Within this range, efficient vibration is possible. Further, at the intersection LN, the two resonators vibrate at the same amplitude in synchronization with each other, and the acceleration increases and the holding force of the tool holder 131 increases as in the related art illustrated in FIGS. 9 to 13. The tool 121 does not jump out when the limit is exceeded. Therefore, even if the ultrasonic transducer 111 and the tool 121 are fixed by a simple joining method, vibration can be reliably transmitted to the tool 121.
[0058]
As described above, according to the present embodiment, a large vibration speed can be obtained for the tool 121 while the tool 121 can be easily mounted.
[0059]
Moreover, since the ultrasonic vibrator 111 and the tool 121 can be joined at any position, the length of the tip of the tool 121 can be set to any required length. It is not necessary to make the length of the distal end portion unnecessarily long, so that the processing tool 101 having high rigidity can be easily designed.
[0060]
Next, the mounting reproducibility of the tool 121 according to the present embodiment will be described. When the processing position accuracy is required or the processing needs to be performed with a precise dimension, a strict accuracy requirement is naturally required for the mounting reproducibility of the tool 121. On the other hand, in the present embodiment, since the square shank 124 and the tool insertion hole 117 are in a fitted state, even if the tool 121 is exchanged, it is possible to perform machining requiring strict accuracy. Processing that is fully compatible is possible.
[0061]
Here, in the present embodiment, a part of a rear end portion of the tool 121 connected to the square shank 124 has a round bar shape and is slightly smaller in diameter than the square shank 124. It is an object to avoid contact with 117 and to prevent generation of unnecessary noise due to contact between different amplitudes. Therefore, the entire area of the portion from the middle to the rear end of the tool 121 may be formed as the square shank 124 as necessary. However, this is a case where the ultrasonic vibrator 111 that vibrates axially is employed as in the processing tool 101 illustrated in FIGS. 1 to 3, and is similar to the processing tool 101 illustrated in FIGS. 4 to 6. When the ultrasonic vibrator 111 that performs flexural vibration is employed, the ultrasonic vibrator 111 is not obstructed between the tool insertion hole 117 and the rear end of the tool 121 connected to the square shank 124. A gap must be provided. However, this gap is a gap that is not visible.
[0062]
The reproducibility of the attachment of the tool 121 according to the present embodiment has been generally described above. The reproducibility of the attachment of the tool 121 is illustrated in the processing tool 101 illustrated in FIGS. 1 to 3 and in FIGS. 4 to 6. The case with the processing tool 101 will be described individually.
[0063]
First, in the machining tool 101 illustrated in FIGS. 1 to 3, a machining portion 123 for drilling a square hole is provided at the tip of the tool 121. In such a processing part 123, when the rotation angle of the square hole to be drilled and the processing position accuracy are required, or when it is necessary to perform the square hole processing with precise dimensions, the mounting reproducibility of the tool 121 is naturally reduced. Strict precision requirements come out. In this case, if the square shank 124 on the tool 121 side and the tool insertion hole 117 on the ultrasonic vibrator 111 side are in a fitted state, strict accuracy is required even if the tool 121 is replaced. Processing that is fully compatible with square hole processing becomes possible.
[0064]
Next, in the working tool 101 illustrated in FIGS. 4 to 6, a working portion 123 configured as a hole boring tool is provided at the tip of the tool 121. In such a processing section 123, the blade of the hole drill bit as the processing section 123 is worn by continuing the processing, and it is necessary to replace the blade with a new one at an appropriate time from the viewpoint of quality control. At this time, there is a case where strict demands are made on the dimensional reproducibility at the time of replacement, together with the demand for how quickly the tool can be replaced. In other words, particularly with respect to the height of the cutting edge of small-diameter drilling of so-called difficult-to-cut materials with poor machinability, very strict accuracy is desired. The position of the cutting edge was measured in a state of being enlarged, and the position was finely adjusted. However, in this case, the adjustment is extremely troublesome, and improvement has been desired from the viewpoint of productivity.
[0065]
On the other hand, in the present embodiment, since the square shank 124 on the tool 121 side and the tool insertion hole 117 on the ultrasonic vibrator 111 side are in a fitted state, the tool 121 is replaced. However, it is possible to perform processing that is sufficiently compatible with hole boring processing that requires strict accuracy. This will be described in more detail. In the machining tool 101 illustrated in FIGS. 4 to 6, since the square shank 124 and the tool insertion hole 117 are square pillars, when the tool 121 is mounted, it is used as a male screw for fixing the tool. By strongly pressing the corners of the square shank 124 with the configured tool holder 131, two rectangular surfaces corresponding to the square shank 124 and the bottom surface of the tool insertion hole 117 are strongly pressed. For this reason, if the accuracy of each part is accurate, accurate dimensional reproducibility can be obtained, and even if the tool 121 is replaced, there is no need to finely adjust the position of the blade of the drill bit as the machining part 123 again. . As a result, the complexity of finely adjusting the position of the blade of the boring tool is relieved, and the productivity is dramatically improved.
[0066]
The flange 122 provided on the tool 121 serves as a stopper when the tool 121 is inserted into the tool insertion hole 117, and functions to increase the reproducibility of the amount of protrusion of the machined portion 123, which is a boring tool. The control of the reproducibility can be controlled by another method instead of the flange 122.
[0067]
【The invention's effect】
According to the first aspect of the present invention, there is provided an ultrasonic vibrator that generates ultrasonic vibration and has a tool insertion hole provided in an axial direction from a front end portion, and a front end portion inserted into the tool insertion hole from a rear end portion. A tool having a resonance frequency substantially equal to the ultrasonic vibrator and the tool inserted into the ultrasonic vibrator, from the vicinity of the node to the loop while the rear end side is in an unfixed state. And a fastening structure to be fixed at a position, since it is a working tool configured as a single resonator having a plurality of resonance vibration distributions, it is only necessary to devise a fixing position of the tool to the ultrasonic vibrator by the fastening structure. However, the amplitude of the ultrasonic vibration generated in the ultrasonic vibrator can be larger than the amplitude of the ultrasonic vibration generated in the ultrasonic vibrator, and the amplitude at the fixed position of the tool with respect to the ultrasonic vibrator is larger than the amplitude of the vibration obtained in the tool. Because it is small, It is possible to obtain a sufficient rigidity even if easily mounted.
[0068]
According to a second aspect of the present invention, in the processing tool according to the first aspect, the cross-sectional shape of the insertion structure between the tool insertion hole and the tool is a non-circular shape, so that the position of the tool in the circumferential direction with respect to the tool insertion hole. Is uniquely determined, so that excellent dimensional reproducibility can be obtained when the tool is remounted.
[0069]
According to a third aspect of the present invention, there is provided an ultrasonic vibrator which generates ultrasonic vibration and has a tool insertion hole provided in an axial direction from a front end portion, and a front end portion which is inserted into the tool insertion hole from a rear end portion. A tool having a processing portion, and a fastening portion for fixing the tool inserted into the ultrasonic vibrator, the cross-sectional shape of the insertion structure between the tool insertion hole and the tool side is a non-perfect circle Since the processing tool has a shape, the circumferential position of the tool with respect to the tool insertion hole is uniquely determined, so that excellent dimensional reproducibility can be obtained when the tool is remounted.
[0070]
According to a fourth aspect of the present invention, in the machining tool according to the second or third aspect, since a polygon is selected as the non-circular shape, a cross-section having a non-circular shape in the insertion structure of the tool insertion hole and the tool. The shape can be easily manufactured.
[0071]
According to a fifth aspect of the present invention, in the processing tool according to the second or third aspect, since the gear shape is selected as the non-round shape, the processing tool has a non-round shape in the insertion structure of the tool insertion hole and the tool. The cross-sectional shape can be easily manufactured.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a working tool as one embodiment of the present invention.
FIG. 2 is an exploded perspective view thereof.
FIG. 3 is a perspective view showing a vibration direction of a tool.
FIG. 4 is a perspective view showing a working tool according to another embodiment of the present invention.
FIG. 5 is an exploded perspective view thereof.
FIG. 6 is a perspective view showing a vibration direction of a tool.
FIG. 7 is a side view of the working tool.
8 is an explanatory diagram showing the resonance vibration distribution of the working tool along with the AA cross section shown in FIG. 7;
FIG. 9 is a perspective view showing an example of a conventional processing tool.
FIG. 10 is an exploded perspective view thereof.
FIG. 11 is a perspective view showing another conventional example of a working tool.
FIG. 12 is an exploded perspective view thereof.
FIG. 13 is an explanatory diagram showing a longitudinal cross section of a machining tool and its resonance vibration distribution.
[Explanation of symbols]
111 ultrasonic transducer
117 Tool insertion hole
123 Processing part
121 tools
N3 node
L3 loop

Claims (5)

An ultrasonic vibrator that generates ultrasonic vibration and has a tool insertion hole from the tip end toward the axial direction,
A tool having a processing portion at the tip end portion that is inserted into the tool insertion hole from the rear end portion and has a resonance frequency substantially equal to the ultrasonic vibrator;
A fastening structure for fixing the tool inserted into the ultrasonic vibrator at a position from the vicinity of the node to the loop while keeping the rear end in an unfixed state,
And a processing tool configured as a single resonator having a plurality of resonance vibration distributions. The processing tool according to claim 1, wherein a cross-sectional shape of the insertion structure between the tool insertion hole and the tool is a non-circular shape. An ultrasonic vibrator that generates ultrasonic vibration and has a tool insertion hole from the tip end toward the axial direction,
A tool that is inserted into the tool insertion hole from the rear end and has a processing portion at the front end,
A fastening portion for fixing the tool inserted into the ultrasonic transducer,
And a cross-sectional shape of the insertion structure between the tool insertion hole and the tool side is a non-circular shape. The processing tool according to claim 2, wherein a polygon is selected as the non-circular shape. The machining tool according to claim 2, wherein a gear shape is selected as the non-circular shape.

Images