JP2005271171A - Vibration cutting device and vibration generating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration cutting tool which has small vibration damping, high durability, and a size-reducible structure. <P>SOLUTION: A vibration cutting device having an oscillator (1) for vibrating a cutting tool (101) comprises a point supporting member (202) for supporting the oscillator (1) at points, wherein the oscillator (1) has a hard region (103) in only a region which becomes a node of the vibration during vibration and is supported by the point supporting member (202). According to the present invention, the oscillator (1) is supported at points by the point supporting member (202), and therefore vibration damping can be reduced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cutting tool, and more particularly to an improvement of a vibration cutting tool that cuts by giving a circular (elliptical) orbit to the cutting tool.

  Conventionally, a vibration cutting apparatus configured to superimpose vibrations in the cutting direction and the cutting outflow direction on the cutting tool by the first and second actuators during cutting is proposed, for example, in Japanese Patent Laid-Open No. 7-68401 (Patent Document 1).

Further, in Japanese Patent Laid-Open No. 2000-52101, the body portion of the elliptical vibrator is formed in a cylindrical shape, and a predetermined sinusoidal voltage is separately input to the piezoelectric element provided on the cylindrical body portion from the control mechanism. There has been proposed an elliptical vibration cutting device configured to generate elliptical vibration in a vibrator so that a cutting tool can be elliptically vibrated to cut a work material (Patent Document 2).
JP-A-7-68401 JP 2000-52101 A

  However, the above Patent Document 1 does not disclose details of a method for fixing the vibrator so as to vibrate. In the above-mentioned Patent Document 2, there is a description that the cylindrical body portion is supported in a state in which the cylindrical body portion is separately penetrated by two support members (paragraph number 0018), but what kind of support method is specifically preferred? There was no disclosure.

  Further, according to the applicant's investigation of the device manufactured and sold by the patentee according to Patent Document 2, the cylindrical body is supported by the support member with a screw having a contact area of about φ2.5. Turned out to be.

  However, when the body portion that is a vibrator is held with such a relatively wide contact area, vibration damping of the cutting tool becomes large and vibration of a sufficiently large cutting tool cannot be obtained. On the other hand, if the contact area of a screw or the like for fixing the body part is made smaller than this, the tip of the screw will bite into the body part when screwed or vibrate, making it unusable as a product. The smaller the product, the smaller the contact area between the body and the screw. However, due to these limitations, it has been difficult to reduce the size of the product.

  Under such circumstances, it has been necessary to accept vibration attenuation by fixing the vibrator. For this reason, it is necessary to generate vibrations including the energy loss in the piezoelectric actuator. This means that a high voltage (for example, near the withstand voltage) must be applied to the piezoelectric actuator, which means that excessive heat generation and adhesive deterioration of the piezoelectric actuator are accelerated, and durability is reduced. .

  SUMMARY OF THE INVENTION In order to solve the above-described problems, an object of the present invention is to provide a vibration cutting tool having a structure with low vibration attenuation, high durability, and miniaturization.

  In order to achieve the above object, the present invention provides a vibration cutting apparatus including a vibrating body that vibrates a cutting tool, and includes a point support member that supports the vibrating body as a point, and the vibrating body is a region that becomes a vibration node during vibration. And only the area | region which is point-supported by a point support member is equipped with the hardening area | region, It is characterized by the above-mentioned.

  According to the above configuration, since the vibrating body that vibrates the cutting tool is point-supported at the vibration node, the contact area is small and vibration attenuation is suppressed, so that the vibration of the cutting tool can be increased. At this time, a relatively strong force is applied to the vibrator that is point-supported by the point support member, and the point support member bites into the vibrator if the material is a normal metal or the like. Since this region is a hardened region, deformation such as the point support member biting into the vibrating body can be suppressed. Here, since this hardening region is provided only in the region that is point-supported by the point support member and does not reach other parts of the vibration body, the elasticity of the entire vibration body is not reduced. Therefore, even if the hardened region is provided, it is possible to maintain the vibration characteristics of the vibration body to be subjected to vibration amplification.

  Here, the “cured region” refers to a region that is formed relatively hard compared to the hardness of the entire vibrator that requires a certain degree of elasticity, and there is no limitation on the form of the cured region. For example, if it is a metal, hardening processing etc. can be considered. Further, it is conceivable to form a film having a high hardness in the region or to cover it with a material having a high hardness.

  Further, “only the point-supported region” means that the vibration characteristics of the entire vibrating body are not hindered, and even if a hardened region is formed at a position deviated from the point-supported point. Any aspect that does not inhibit the characteristics falls within the scope of the claims.

  Furthermore, “point support” means that the vibrating body is supported with a sufficiently small contact area as compared with a conventional apparatus having no hardening region. For example, the diameter of the contact point at which the point supporting member supports the vibrating body is φ1. 0.5 mm or less, preferably approximately φ0.6 mm. This is because, if the diameter of the contact point is such a level, vibration attenuation caused by the contact itself is small, and the cutting tool can be downsized.

  Furthermore, it is preferable that at least the tip of the point support member that supports the vibrating body on the point of the supporting member is harder than the hardness of the hardened region provided on the vibrating body. It is considered that the point support member itself has a higher stress per unit area than point in the past, but according to this configuration, the point support member tip has a higher hardness than that of the hardened region, so wear and deformation Is suppressed.

  Specifically, the point support member is screwed to the receiving portion, and it is preferable that the screw tightening torque of the point support member is set in a range of 10 to 15 cN · m. According to the experiment conducted by the present applicant, when the screw tightening torque reaches about 10 cN · m, the mechanical Q value, which is the relative value of the vibration characteristics, becomes high, and the displacement of the vibrating body hardly occurs. Since it has been found that the mechanical Q value decreases when the torque exceeds about 15 cN · m, it is considered preferable to adjust the screw tightening torque within this range.

  The vibrating body preferably has an axisymmetric shape. In order to obtain a preferable elliptical orbit, it is desirable that the symmetry be good with respect to at least one of the two axes of the axial direction of the vibrating body and the direction perpendicular to the axis. According to this configuration, since the vibrating body has a symmetrical shape with respect to the axial direction, the symmetry of the vibrating body with respect to the axial direction can be ensured. This means, for example, that when a salai for providing a sensor or the like is provided on one side of the vibrating body, a salai having the same shape is also provided on the opposite side in the axial direction as a dummy.

  Similarly, it is preferable that the vibrating body has a symmetrical shape with respect to a plane that passes through the center of gravity and is orthogonal to the axis. As described above, in order to obtain a preferable elliptical orbit, it is desirable that the symmetry is good with respect to at least one of the two axes of the axial direction of the vibrating body and the direction perpendicular to the axis. Since the shape symmetric with respect to the plane perpendicular to the axial direction of the vibrating body is provided, symmetry with respect to the plane perpendicular to the axial direction of the vibrating body can be ensured. For example, if a special shape (such as Saray) is provided for a sensor or the like at a position offset in the axial direction from the center of gravity of the vibrating body, the same applies to a position symmetrical with respect to the axis passing through the center of gravity. This means providing a special shape.

  The present invention relates to a vibration generator that vibrates a vibration end, a vibration body having a vibration end, a vibrator provided on a vibration belly of the vibration body, a receiving portion disposed at a vibration node of the vibration body, And a point support member that supports the vibration node of the vibrating body at a point, and a hardening region is provided only in a region that is point-supported by the point support member of the vibrating body.

  According to the above configuration, when the vibrator vibrates, the vibrating body vibrates, and the vibration node is supported by the point support member. At this time, since the vibrating body is point-supported, the contact area is small and vibration damping can be suppressed. Further, since the point-supported region is a hardened region, deformation such as the point support member biting into the vibrating body can be suppressed. Here, since this hardening region is provided only in the region that is point-supported by the point support member and does not reach other parts of the vibration body, the elasticity of the entire vibration body is not reduced. Therefore, even if the hardened region is provided, it is possible to maintain the vibration characteristics of the vibration body to be subjected to vibration amplification.

  According to the present invention, since the vibrating body is point-supported by the point support member, vibration attenuation can be reduced. Further, since vibration damping can be suppressed, it is not necessary to increase the voltage applied to the piezoelectric actuator to the withstand voltage, and durability can be enhanced. Further, since the vibration characteristics are good, the cutting device can be downsized. In particular, according to the present invention, since the hardened region is provided only in the region where the point support member is in contact, it is possible to prevent the vibration body from being worn or deformed by the point support without sacrificing the vibration characteristics.

  Next, preferred embodiments for carrying out the present invention will be described with reference to the drawings.

(Embodiment 1)
Embodiment 1 of the present invention relates to a vibration cutting tool having a biaxial symmetry shape that is axisymmetric and is symmetric with respect to a plane that passes through the center of gravity perpendicular to the axis.

  FIG. 1 is an overall perspective view of the vibration cutting tool. FIG. 2 shows an enlarged perspective view of the vibrating body 1 of the present vibration cutting tool. As shown in FIG. 1, the vibration cutting tool includes a vibrating body 1 that vibrates and a vibrating body support device 2 that holds the vibrating body 1 so as to vibrate.

  The entire vibration cutting tool is attached to an alignment device such as an NC lathe. The vibrating body support device 2 includes a base 21 that holds the vibrating body 1 and an insertion portion 22 that is held by the alignment device. The receiving portion 20 serving as an arm for holding the vibrating body 1 is fixed to the mounting surface 210 of the base 21 by screwing into the screw hole 203. The receiving portion 20 is provided with an opening. The vibrating body 1 is inserted into the opening, and the vibrating body 1 is point-supported by a plurality of point support members 202 at a vibration node of the vibrating body 1. Yes.

  FIG. 3 shows a cross-sectional view of the receiving portion 20 along the AA section of FIG. As shown in FIG. 3, the receiving portion 20 is inserted through the large step horn 106 (126) of the vibrating body 1, and a portion that becomes a node of the vibration is point supported by the point support member 202. The point support member 202 is supported by a screw hole 201 provided in the receiving portion 20 and is screwed with a predetermined torque. Cured regions 103 and 124 are provided in the region of the vibrator 1 that is point-supported by the point support member 202.

  As shown in FIG. 2, the vibrating body 1 includes a front end portion 100, a body portion 110, and a rear end portion 120. The distal end portion 100 includes a large step horn 106 near the body portion 110 and a small step horn 107 beyond the body portion 110, and can amplify the vibration generated in the body portion 110 to vibrate the distal end surface 102 with a large amplitude. A step-step horn structure is provided. Similarly, the rear end portion 120 is also provided with a large step horn 126 near the body portion 110 and a small step horn 127 at the tip thereof so that vibration can be amplified. The large step horns 106 and 126 and the small step horns 107 and 127 are symmetrically provided with the same shape and the same length with respect to the center of the body portion.

  The body portion 110 has a mounting surface 111 formed by chamfering four surfaces perpendicular to the X axis and the Y axis in FIG. Piezoelectric actuators 112X are provided on two surfaces that are perpendicular to the X-axis direction (referred to as X-plane), and piezoelectric actuators 112Y are provided on two surfaces that are perpendicular to the Y-axis direction (referred to as Y-plane). Each is provided. The piezoelectric actuator 112 is manufactured by forming electrode films on both surfaces of a ferroelectric ceramic crystal such as lead zirconate titanate (PZT) by metal plating or the like. The piezoelectric actuator 112 is pasted with an adhesive. Solder plating is provided at the corners of the electrode film so that solder or the like can be easily welded, and the wiring 113 (lead wire) 114 is electrically connected by soldering or the like. A wiring 114 is welded to the contact 113 and is drawn out so that a voltage can be applied between both electrodes of the piezoelectric actuator 112. The wiring 114 is a twisted line. The piezoelectric actuator 112 is deformed by an electromechanical conversion action in response to application of an alternating voltage, and the deformation is transmitted to the body 110 as vibration.

  At the distal end portion 100, a step tool small 107 is provided with a cutting tool 101 serving as a contact member during processing. The cutting tool 101 is a chip-shaped cutting blade made of a material having high hardness such as diamond. The cutting tool 101 is supported by the tip of the small step horn 107 and is fixed so that a part of the blade protrudes from the tip surface 102.

  The large step horn 106 is provided with a dummy salai 105. A dummy salai 105X having an X surface and a dummy salai 105Y having a Y surface are provided. The dummy salai 105 is formed in order to maintain symmetry with respect to the center of gravity of the vibrating body 1.

  Similarly, the large step horn 126 is provided with a sensor salai 121. A sensor salai 121X having an X surface and a sensor salai 121Y having a Y surface are provided. Vibration sensors 122X and Y are provided on the sensor sarays 121X and 121Y. A wiring (lead wire) 123 that is a twisted wire is drawn out from both poles of the vibration sensor 122. The vibration sensors 122X and Y have the same structure as that of the piezoelectric actuator, and can convert mechanical strain on the affixed surface into a voltage corresponding to the amount of strain and output it via the wiring 123 by the electromechanical conversion action. It has become.

  4A is a sectional view of the sensor saray 121 taken along the line BB of FIG. 2, and FIG. 4B is a sectional view of the dummy saray 105 taken along the line AA of FIG. As shown in FIG. 4A, among the four surfaces of the sensor salai 121, the vibration sensor 122X is provided on one X surface, and the vibration sensor 122Y is provided on one Y surface. If one vibration sensor 122X and one Y is provided in each of the X-axis direction and the Y-axis direction, vibrations can be detected, so that a total of two vibration sensors 122X and Y are provided. Originally, the Saray that provides an adhesive surface on which the vibration sensor 122 is installed without distortion should be equal to the number of vibration sensors. However, in this embodiment, the salai 121XB is also provided on the opposite side of the salai 121XA provided with the vibration sensor 122X, and the salai 121YB is provided on the opposite side of the salai 121YA provided with the vibration sensor 122Y. The presence or absence of saray affects the displacement of the center of gravity, but since the saray 121XB and YB as dummy are provided in this way, the vibrating body 1 is configured symmetrically with respect to the axis.

  Further, as shown in FIG. 4B, the step horn large 106 is provided with four sides of dummy sarays 105 provided with no sensors. The dummy salai 105 is provided at a position symmetrical to the four-surface sensor saray 122 with respect to a plane that passes through the center of gravity of the vibrator 1 and is perpendicular to the axial direction (Z-axis direction). With this configuration, a shape that is symmetric with respect to the plane including the Y-axis direction perpendicular to the center of gravity of the vibrating body 1 is provided, and the same position as the center of gravity when all the sarays are absent. The center of gravity is located.

  Symmetry is maintained around the X, Y, and Z axes due to the presence of the dummy salais 121XB, YB, and 105, which are generated by the amplitude and phase difference of the AC voltage applied to the piezoelectric actuators 112X and Y during vibration machining. This makes it possible to greatly simplify the control of elliptical vibration.

  FIG. 5 is a simulation diagram illustrating an enlarged state of distortion when the vibrating body 1 vibrates. In FIG. 5, the darker the hatched portion, the smaller the amplitude and the thinner, the greater the vibration. The amplitude of the tip portion 102 of the vibrating body 1 is large, and the vibration of the piezoelectric actuator 112 provided at the antinode of the vibration is amplified by the two-step horn structure, and the vibration of the tip surface 102, that is, the cutting tool 101 is increased. I understand that. Further, the vibration body 1 has four vibration nodes C1 to C4. How the vibration is transmitted and where the antinode of vibration is generated and where the vibration node is formed are determined by the shape and elasticity of the vibrating body, the frequency of vibration, and the like. In this embodiment, as shown in FIG. 5, the frequency at which a vibration node is generated is applied to the piezoelectric actuator 112, and the receiving portion 20 is positioned at the vibration nodes C1 and C4 so that the vibrating body 1 is turned on. I support it.

  FIG. 9 shows a relationship between the screw tightening torque and the mechanical Q value substitute value. In this embodiment, the screw tightening torque of the point support member 202 is set in a range of 10 to 15 cN · m. It shows that the higher the mechanical Q value, the higher the degree of mechanical resonance, the higher the energy, and the greater the vibration. As shown in FIG. 9, when the screw tightening torque reaches about 10 cN · m, the mechanical Q value, which is a relative value of the vibration characteristics, increases, and when the screw tightening torque exceeds about 15 cN · m, the mechanical Q value is increased. Decreases. On the other hand, if the screw tightening torque is about 10 cN · m or less, the vibration body 1 may loosen and move during processing. It is appropriate to set the screw tightening torque of the point support member 202 in the range of 10 to 15 cN · m.

  FIG. 10 shows a relationship between the screw tip diameter and the output amplitude. The said relationship figure shows the output amplitude which appears on a front-end | tip surface when the area of the contact point supported is changed in the same vibration cutting device. In the present embodiment, the point support member 202 has a diameter of a contact point that supports the vibrating body 1 in a point of approximately φ0.6 mm. As shown in FIG. 10, in the case of φ2.5 mm used in the conventional cutting apparatus, the output amplitude is smaller than 4 μm, whereas when the contact point is φ1.5 mm or less, the output amplitude is 6 times larger than 1.5 μm. In addition, when the diameter of the contact point is φ0.6 mm as in the embodiment of the present application, the output amplitude is 8 μm or more, and the amplitude is twice or more. If the diameter of the contact point is further reduced, the output amplitude is considered to be further increased. However, the stress of the point holding member and the contact point becomes too large, and the point support member 202 bites in, resulting in inconveniences such as deformation and perforation. A reasonable diameter is around 0.6 mm.

  When the diameter of the contact point at the tip of the point support member 202 is set to φ0.6 mm, the constituent material of the vibrating body 1 is deformed by a strong stress, and the point support member 202 bites in and a hole is formed. . In order to cope with this, in the present embodiment, as shown in FIGS. 2 and 3, only the region of the vibrating body 1 that becomes a node of vibration during vibration and is point-supported by the point support member 202 is cured. Regions 103 and 124 are provided. The hardened regions 103 and 124 are formed by, for example, a partial quenching process. The hardness of the hardened region is, for example, about Hv650. By such a hardness strengthening process at the point contact portion, it is possible to suppress the disadvantage that the vibrating body 1 is pierced or deformed due to the point contact.

  In addition, a strong stress is applied to the tip of the point support member 202 that is in contact with the cured regions 103 and 124 by being screwed with the above torque. For this reason, in this embodiment, the tip of the point support member 202 is formed to be harder than the hardness of the hardened regions 103 and 124 provided in the vibrating body 1. According to the said structure, since the hardness of the front-end | tip of the point support member 202 is higher than that of the hardening area | regions 103 and 124, abrasion and a deformation | transformation are suppressed. Specifically, when the hardness of the hardened region is about Hv650, the hardness of the tip of the point support member 202 is about Hv750. By improving the hardness of the point support member 202 as described above, the point support member 202 can be prevented from being deformed and worn by point contact.

  In the above configuration, when an AC voltage having a predetermined frequency of about 20 kHz is applied to the piezoelectric actuator 112X, bending vibration is generated in the Y-axis direction of the vibrating body 1 around the contact points 104 and 125 that are point-supported by the point support member 202. Occur. When an AC voltage having the same frequency is applied to the piezoelectric actuator 112Y, flexural vibration is also generated in the X-axis direction of the vibrating body 1 around the contact points 104 and 125. If a predetermined phase difference (for example, π / 2) is provided between the AC voltage applied to the piezoelectric actuator 112X and the AC voltage applied to the piezoelectric actuator 112Y, the bending vibration in the X-axis direction and the bending vibration in the Y-axis direction are combined. As a result, elliptical (circle) vibration can be generated. The elliptical vibration generated at the antinode of the vibration of the body portion 110 is amplified by the two-step horn structure of the vibrating body 1 and causes the cutting tool 101 protruding from the tip surface 102 to vibrate in a large elliptical orbit. If the cutting tool 101 that is oscillating elliptically is brought into contact with the work material in this way, the thickness of the chip becomes thinner than normal cutting due to the action of elliptical oscillating cutting, the cutting resistance is reduced, and quenching is performed. Mirror surface machining of steel or the like is possible, and cutting heat is reduced, so that the cutting tool life is extended and machining accuracy is improved. Moreover, burrs and cracking vibrations are prevented.

  Here, in particular, according to the first embodiment, since the vibrating body 1 is point-supported with a contact diameter that is significantly smaller than that of the prior art, vibration attenuation can be suppressed with minimum energy loss. For this reason, it is possible to obtain a sufficient amplitude without applying a high voltage close to the withstand voltage to the piezoelectric actuator 112. For example, a driving voltage is sufficient at about 1/3 of the conventional voltage. Thus, the life of the piezoelectric actuator can be extended.

  In addition, since the vibration attenuation is small, the area or thickness of the piezoelectric actuator for obtaining the same output as the conventional product can be reduced to about half that of the conventional product. As a result, the vibration cutting tool can be greatly reduced in size to about 1/10. Since the vibration cutting tool can be downsized, it is possible to take advantage of the vibration cutting tool in the following applications.

  First, because the range of positioning devices such as NC lathes that can be installed has expanded, it has become possible to polish lenses without polishing and polishing small parts. In the vibration processing apparatus, since the cutting tool always has an elliptical orbit, the relative speed of the cutting tool does not become zero even when processing the center point of the lens. For this reason, in the lens mirror finish, there is no longer any portion that cannot be cut off at the center of the lens. This eliminates the need for the conventional center-bottom removal processing after cutting.

  In addition, in the processing of very thin shafts such as watch-related wheel axles, it has become possible to mirror finish the horn part by vibration cutting.

  In addition, mirror finishing can be performed by vibration cutting, so that similar finishing can be performed by one vibration cutting instead of a plurality of processes of conventional cutting, quenching, and polishing with a grindstone. For this reason, since simplification of the process and prevention of deterioration of wear due to grindstone grains can be prevented, there are many advantages in highly accurate machining, for example, machining of the horn part of the watch axle of a luxury watch.

  In addition, according to the first embodiment, the dummy salais 121 and 105 improve the symmetry of the X-axis, the Y-axis, and the Z-axis, making it easier to control the elliptical orbit. That is, if the symmetry of the vibrating body is out of order, the amplitude and phase of the AC voltage input to the piezoelectric actuators 112X and Y have to be adjusted in order to obtain a preferable elliptical trajectory. Therefore, when an alternating voltage having the same amplitude is applied to each of the piezoelectric actuators 112X and Y with a phase difference of π / 2 in principle, a beautiful elliptical orbit is obtained. For example, in the case of a conventional product having no biaxial symmetry, the mechanical Q value predicted as a completely symmetrical product is about 100% off from the actual one, whereas according to this embodiment, Due to the axial symmetry, the error can be kept within a range of several percent.

(Embodiment 2)
The second embodiment of the present invention relates to a vibration cutting tool that is further downsized than the first embodiment. FIG. 6 is an overall perspective view of the present vibration cutting tool. FIG. 7 shows an enlarged perspective view of the vibrating body 3.

  As shown in FIG. 6, the vibration cutting tool includes a structure in which a vibrating body support device 4 that holds a vibrating body 3 that vibrates is accommodated. The entire vibration cutting tool is further attached to an alignment device such as an NC lathe by an attachment member (not shown).

  The vibrating body support device 4 has a housing structure and can accommodate the vibrating body 3 therein. An opening 403 is provided on the end surface of the vibrating body support device 4, and the tip portion 300 of the vibrating body 3 projects therefrom. The vibrating body supporting device 4 has four receiving portions 401, and a point supporting device 402 is screwed on each surface to support the vibrating body 3 inside.

  As shown in FIG. 7, the vibrating body 3 includes a distal end portion 300 and a trunk portion 310. The tip portion 300 has a single step horn structure, and can amplify the vibration generated in the body portion 310 to vibrate the tip surface 302 with a large amplitude.

  A cutting tool 301 serving as a contact member during processing is provided on the distal end surface 302 of the distal end portion 300 as in the first embodiment. The cutting tool 301 is a chip-shaped cutting blade made of a material having high hardness such as diamond. The cutting tool 301 is fixed so that a part of the blade protrudes from the tip surface 302. Near the body portion 310 of the distal end portion 300 is a portion that becomes a node at the time of vibration, which is a contact point 304 of a point holding member 402 provided in the vibration body support device 4, and a peripheral region including the contact point 304 is a hardening region. 303.

  The body part 310 is chamfered on four sides to form an attachment surface 311. A piezoelectric actuator 312X is provided on the X plane, and a piezoelectric actuator 312Y is provided on the Y plane. The piezoelectric actuator 312 is attached with an adhesive. A wiring 314 is electrically connected to the contact 313 at the corner by soldering or the like, and a voltage can be applied between both electrodes of the piezoelectric actuator 312. The wiring 314 is a twisted line. The piezoelectric actuator 312 is deformed by an electromechanical conversion action in response to application of an alternating voltage, and the deformation is transmitted to the body portion 310 as vibration. The body portion 310 has a symmetric structure with respect to the axis (Z axis), and the symmetry with respect to the center of gravity of the vibration body 3 is maintained. For this reason, it has become possible to greatly simplify the control of elliptical vibration generated by the amplitude and phase difference of the AC voltage applied to the piezoelectric actuators 312X and Y during vibration processing.

  Vibration sensors 322X and Y are attached to one X surface and one Y surface of the mounting surface 311. A wiring 323 that is a twisted wire is drawn out from both poles of the vibration sensor 322. The vibration sensors 322X and Y have the same structure as that of the piezoelectric actuator, and can convert mechanical strain on the affixed surface into a voltage corresponding to the amount of strain and output it via the wiring 323 by the electromechanical conversion action. It has become.

  In addition, a contact point 325 where the point holding member 402 supported by the vibrating body support device 4 abuts is present in a region serving as a vibration node at the rear end of the body portion 310, and a peripheral region including the contact point. Is a hardened region 324.

  FIG. 8 is a simulation diagram illustrating an enlarged state of distortion when the vibrating body 3 vibrates. In FIG. 3, the darker the hatched portion, the smaller the amplitude and the thinner, the greater the vibration. It can be seen that the amplitude of the tip 302 of the vibrating body 3 is large, and the vibration of the piezoelectric actuator 312 provided at the antinode of the vibration is amplified to increase the vibration of the tip surface 302, that is, the cutting tool 301.

  Also in the second embodiment, the screw tightening torque of the point support member 402 is set in a range of 10 to 15 cN · m. It is possible to prevent the vibrating body 3 from shifting while maintaining a mechanical Q value that is somewhat high.

  Also in the second embodiment, the diameter of the contact point where the point support member 402 supports the vibrating body 3 is approximately φ0.6 mm. For this reason, the output amplitude is greatly increased as compared with the conventional case where the diameter of the contact portion is set to φ2.5 mm.

  Also in the second embodiment, the cured body 303 and 324 are provided only in the region of the vibrating body 3 that is a node of vibration during vibration and is point-supported by the point support member 402. The hardened regions 303 and 324 are formed by, for example, a partial quenching process. The hardness of the hardened region is, for example, about Hv650. By such a hardness strengthening process of the point contact portion, it is possible to suppress the inconvenience that the point support member 402 bites by the point contact and the vibrator 3 is pierced or deformed.

  Further, the tip of the point support member 402 that is screwed into contact with the cured regions 303 and 324 with the above torque is formed to be harder than the hardness of the cured regions 303 and 324 provided in the vibrating body 3. Specifically, when the hardness of the hardened regions 303 and 324 is about Hv650, the hardness of the tip of the point support member 402 is about Hv750. By improving the hardness of the point support member 402 as described above, it is possible to suppress the point support member 402 from being deformed and worn by point contact.

  In the above configuration, when an AC voltage of about 25 kHz is applied to the piezoelectric actuator 312X, bending vibration is generated in the Y-axis direction of the vibrating body 3 around the contact points 304 and 325 that are point-supported by the point support member 402. Occur. When an AC voltage having the same frequency is applied to the piezoelectric actuator 312Y, flexural vibration is also generated in the X-axis direction of the vibrating body 3 around the contact points 304 and 325. If a predetermined phase difference (for example, π / 2) is provided between the AC voltage applied to the piezoelectric actuator 312X and the AC voltage applied to the piezoelectric actuator 312Y, the flexural vibration in the X-axis direction and the flexural vibration in the Y-axis direction are combined. As a result, elliptical (circle) vibration can be generated. The elliptical vibration generated at the antinode of the vibration of the body portion 310 is amplified by the single-step step horn structure of the vibrating body 3, and the cutting tool 301 protruding from the tip surface 302 is vibrated with a large elliptical orbit. If the cutting tool 301 that is oscillating elliptically is brought into contact with the work material in this way, the thickness of the chip becomes thinner than normal cutting due to the action of elliptical oscillating cutting, the cutting resistance is reduced, and quenching is performed. Mirror surface machining of steel or the like is possible, and cutting heat is reduced, so that the cutting tool life is extended and machining accuracy is improved. Moreover, burrs and cracking vibrations are prevented. For this reason, the same effects as those of the first embodiment are also achieved in the second embodiment.

  In particular, according to the second embodiment, since it has a compact shape, it is possible to use a vibration cutting tool for various processes without selecting a lathe to be attached.

  Further, according to the second embodiment, since the vibration frequency is selected in the ultrasonic region exceeding the audible frequency band, there is an advantage that noise can be prevented.

  The present invention is not limited to the above embodiment, and can be variously modified and used.

  For example, in the above-described embodiment, the present invention is applied to a vibration cutting apparatus in which a cutting tool is provided at the tip, but the applicable product is not limited thereto. That is, the present invention can be applied to any vibration generator (tool) that amplifies vibration generated by a vibrator such as a piezoelectric actuator via a fulcrum and transmits the amplified vibration to the other end that is an action point. If the point support member of the present invention is provided in the point support structure at the fulcrum, the hardened region of the present invention is provided at the contact point of the vibrating body, and preferably the vibrating body has the axial symmetry of the present invention, a high mechanical Q value Thus, the vibration amplitude can be increased, and the advantages of the present invention can be enjoyed as they are.

  Moreover, in the said embodiment, although the point support member was screwed, it may fix by another method. Further, the number of points supported is two, but the number of points supported may be changed. Moreover, although the four contact points per one support location were used, it is not limited to this.

1 is an overall perspective view of a vibration cutting tool according to Embodiment 1. FIG. FIG. 3 is an enlarged perspective view of a vibrating body of the vibration cutting tool according to the first embodiment. It is sectional drawing in a receiving part, and sectional drawing of the AA cut surface of FIG. It is a figure which shows axial symmetry, and sectional drawing of the BB cut surface of FIG. It is a figure which shows axial symmetry, and sectional drawing of the AA cut surface of FIG. FIG. 3 is a vibration simulation diagram of the vibrating body according to the first embodiment. FIG. 4 is an overall perspective view of a vibration cutting tool according to a second embodiment. FIG. 6 is an enlarged perspective view of a vibrating body of a vibration cutting tool according to a second embodiment. FIG. 10 is a vibration simulation diagram of the vibrating body according to the second embodiment. FIG. 6 is a relationship diagram between a screw tightening torque and a mechanical Q value substitute value. The relationship figure of a screw tip diameter and output amplitude.

Explanation of symbols

  C1 to C4 ... nodes of vibration, 1, 3 ... vibrating body, 2, 4 ... vibrating body support device, 20 ... receiving portion, 21 ... base, 22 ... insertion portion, 100 ... tip portion, 101 ... cutting tool, 102 DESCRIPTION OF SYMBOLS ... Tip surface, 103 ... Hardening area, 104 ... Contact point, 105 ... Dummy salai, 106 ... Step horn large, 107 ... Step horn small, 110 ... Body part, 111 ... Mounting surface, 112 ... Piezoelectric actuator, 113 ... Contact, 114 ... Wiring (lead wire), 120 ... Rear end portion, 121 ... Salai for sensor, 122 ... Vibration sensor, 123 ... Wiring (lead wire), 124 ... Hardening region, 125 ... Contact point, 126 ... Large step horn, 127 ... Step horn small, 201 ... screw hole, 202 ... point support member (screw), 203 ... screw hole, 300 ... tip part, 301 ... cutting tool, 302 ... tip surface, 303 ... hardening region, 3 4 ... contact point, 310 ... body part, 311 ... mounting surface, 312 ... piezoelectric actuator, 313 ... contact, 314 ... wiring (lead wire), 322 ... vibration sensor, 323 ... wiring (lead wire), 324 ... hardened region, 325 ... contact point, 401 ... receiving part, 402 ... point support member (screw)

Claims (7)

In a vibration cutting apparatus including a vibrating body that vibrates a cutting tool,
Comprising a point support member for point-supporting the vibrating body;
The vibrator is provided with a hardening region only in a region that becomes a vibration node during vibration and is point-supported by the point support member.   The vibration cutting device according to claim 1, wherein a diameter of a contact point where the point support member supports the vibrating body is approximately φ0.6 mm.   2. The vibration cutting device according to claim 1, wherein at least a tip of the point support member that supports the vibration body among the support members is harder than a hardness of the hardened region provided in the vibration body. The point support member is screwed to the receiving portion,
The vibration cutting device according to claim 1, wherein a screw tightening torque of the point support member is set in a range of 10 to 15 cN · m.   The vibration cutting apparatus according to claim 1, wherein the vibrating body has an axisymmetric shape.   The vibration cutting apparatus according to claim 1, wherein the vibrating body has a symmetrical shape with respect to a plane that passes through the center of gravity and is orthogonal to the axis. In the vibration generator that vibrates the vibration end,
A vibrating body having the vibrating end;
A vibrator provided on a vibration belly of the vibrator;
A receiving portion disposed at a vibration node of the vibrating body;
A point support member provided at the receiving portion and supporting a node of vibration of the vibrating body;
A vibration generating device, wherein a hardening region is provided only in a region of the vibrating body that is point-supported by the point support member.

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