JP4803347B2 - Vibration cutting equipment - Google Patents

Description

The present invention relates to a vibration cutting apparatus used for cutting the material of the mold or the like for an optical element.

  There is a technique of cutting a material such as carbide or glass, which is a difficult-to-cut material, with a tool such as diamond by cutting while vibrating the tool, which is called vibration cutting. This is because the cutting edge of the tool is finely cut at high speed by vibration, and the cutting edge generates a chip by vibration. (For example, refer to Patent Documents 1, 2, 3, etc.).

  As a result, the critical depth of cut required for normal ductile mode cutting is improved several times, and difficult-to-cut materials can be cut with high efficiency.

  In this vibration cutting process, in order to improve the processing efficiency, if the vibration frequency is increased, the above-described effect is increased, and further, the feed rate of the tool is increased in proportion to the frequency. used. Further, since this frequency exceeds the human audible range, there is also an advantage that the vibrator and the vibrator excited by the vibrator do not produce unpleasant sound.

As a method of generating such high-speed vibration at the tool edge, a standing wave is generated by exciting a member holding the tool by a piezo element or a giant magnetostrictive element, and resonating the member with bending vibration or axial vibration. It has been put to practical use as a stable vibration. In such a method, a member for holding a tool, that is, a vibrating body is fixed to a member connected to an apparatus housing, a tool stand of a processing machine, or the like at a resonance node.
JP 2000-52101 A JP 2000-218401 A Japanese Patent Laid-Open No. 9-309001

However, when the tool is vibrated at a high speed as described above, the vibrator for excitation generates heat due to electrical loss and heats the vibrator that is tightly fixed to the vibrator. To happen. This phenomenon causes the following problems.
(1) Since the vibrating body thermally expands and contracts, the position of the tool cutting edge held at the tip varies, and high-precision cutting cannot be performed.
(2) Since the vibration load also changes depending on the cutting load, the amount of heat generated by the vibrator also changes and the amount of thermal expansion of the vibrating body changes. Eventually, the position of the tool edge varies depending on the cutting conditions and the type of work material. Thus, processing reproducibility and processing versatility are impaired.
(3) Although the vibrating body is pressed and held by a screw or the like at the position of the vibration node, the holding force changes or loosens due to expansion or contraction of the vibrating body, and the resonance state is affected, and cutting is performed. The reliability as a device may be impaired.

Accordingly, an object of the present invention is to provide a vibration cutting apparatus that can efficiently achieve high machining shape accuracy and smooth surface roughness.

In order to solve the above problems, a first vibration cutting device according to the present invention includes (a) a cutting tool, (b) a vibration source for vibrating the cutting tool, and (c) a linear expansion coefficient of 6 × 10. A vibrating body that is made of a material of ⁻⁶ or less and that holds the cutting tool and transmits the vibration from the vibration source to the cutting tool as axial vibration and bending vibration; and (d) the vibrating body is subjected to axial vibration and bending. And a fixing member for fixing at a common node position in vibration. The vibration cutting apparatus further includes a cooling unit that blows a gaseous fluid onto at least a part of the vibration source. The vibration source and the vibration body have through holes that communicate with each other at the joint portion, and the cooling unit includes the through hole. A gaseous fluid is supplied from the vibration source side.

In the above apparatus, since the material for forming the vibrating body has a linear expansion coefficient of 6 × 10 ⁻⁶ or less, the thermal expansion of the vibrating body can be suppressed even if the vibration source generates heat. Therefore, the cutting tool supported by the vibrating body can be arranged with high accuracy, and high-precision cutting can be performed.
Further, in the above apparatus, since the fixing member fixes the vibrating body at a common node position in the axial vibration and the bending vibration, the resonance operation is performed by the intended axial vibration and the bending vibration while suppressing the loss of energy. Can be made. Therefore, the cutting tool can be vibrated in a target state, and highly accurate and efficient cutting can be performed.
Further, in the above apparatus, since the cooling means sprays the gaseous fluid on the vibration source, it is possible to suppress the temperature rise of the vibration source and the vibration body. Therefore, the reproducibility of the position control of the cutting tool fixed to the vibrating body can be enhanced, and high-precision cutting can be performed. Note that the gaseous fluid has an advantage that the mass is light and the vibration condition of the vibrating body is not changed. Furthermore, in the said apparatus, gaseous fluid can be flowed through a through-hole, and a vibration source and a vibrating body can be cooled directly and efficiently.

The second vibration cutting device according to the present invention is formed of (a) a cutting tool, (b) a vibration source for vibrating the cutting tool, and (c) a material containing silicon nitride as a main component, A vibrating body that holds the cutting tool and transmits the vibration from the vibration source to the cutting tool as axial vibration and bending vibration; and (d) a fixing member that fixes the vibrating body at a common node position in the axial vibration and bending vibration. With. Here, containing silicon nitride as a main component means that 50% by mass or more of the material is silicon nitride. The vibration cutting apparatus further includes a cooling unit that blows a gaseous fluid onto at least a part of the vibration source. The vibration source and the vibration body have through holes that communicate with each other at the joint portion, and the cooling unit includes the through hole. A gaseous fluid is supplied from the vibration source side.

  In the above apparatus, since the vibration member forming material is a material containing silicon nitride as a main component, the linear expansion coefficient of the vibration member forming material is extremely small, and the thermal expansion of the vibration member is suppressed even if the vibration source generates heat. And high-precision cutting is possible. In addition, a material containing silicon nitride as a main component has an advantage that a relatively large amplitude can be obtained because of its very high toughness, and an advantage that vibration at a high frequency is possible because of a large Young's modulus. There is also. In addition, an effect of suppressing a temperature rise by good thermal conductivity and an effect of preventing an adverse effect such as a damage due to a vibration load by an impact resistance are expected.

  In a specific aspect of the present invention, in the second vibration cutting apparatus, the vibrating body is formed of sialon.

A third vibration cutting apparatus according to the present invention includes (a) a cutting tool, (b) a vibration source for vibrating the cutting tool, and (c) a carbide material and holding the cutting tool. A vibration body that transmits the vibration from the vibration source to the cutting tool as an axial vibration and a bending vibration, and (d) a fixing member that fixes the vibration body at a common node position in the axial vibration and the bending vibration. The vibration cutting apparatus further includes a cooling unit that blows a gaseous fluid onto at least a part of the vibration source. The vibration source and the vibration body have through holes that communicate with each other at the joint portion, and the cooling unit includes the through hole. A gaseous fluid is supplied from the vibration source side.

  In the above apparatus, since the vibration member forming material is a super hard material, the linear expansion coefficient of the vibration member forming material is extremely small, and even if the vibration source generates heat, the thermal expansion of the vibration member can be suppressed. Precision cutting is possible. In addition, cemented carbide materials have the advantage of being able to vibrate at a high frequency because of their high Young's modulus, and are generally harder to break than ceramic materials, etc., so structural materials for holding cutting tools As highly reliable.

A fourth vibration cutting device according to the present invention is formed of (a) a cutting tool, (b) a vibration source for vibrating the cutting tool, and (c) at least one of an invar material and a stainless invar material. A vibrating body that holds the cutting tool and transmits vibration from a vibration source to the cutting tool as axial vibration and bending vibration; and (d) fixing that fixes the vibrating body at a common node position in the axial vibration and bending vibration. A member. The vibration cutting apparatus further includes a cooling unit that blows a gaseous fluid onto at least a part of the vibration source. The vibration source and the vibration body have through holes that communicate with each other at the joint portion, and the cooling unit includes the through hole. A gaseous fluid is supplied from the vibration source side.

  In the above apparatus, since the vibrating body forming material is at least one of an invar material and a stainless invar material, the linear expansion coefficient of the vibrating body forming material is extremely small, and the vibrating body does not expand even when the vibration source generates heat. This makes it possible to control with high accuracy.

In a specific aspect of the present invention, in the vibration cutting apparatus , the gaseous fluid includes a mist state. In this case, the cooling efficiency can be increased by the particles added in the form of mist, and a function such as lubrication can be added to the gaseous fluid.

In a specific aspect of the present invention, the vibration cutting apparatus further includes temperature adjusting means for adjusting the temperature of the gas fluid. In this case, the temperature of the vibration source can be controlled more precisely, the temperature of the vibrating body can be stabilized, and the temperature drift of the cutting edge position of the cutting tool can be reduced.

In a specific aspect of the present invention, the vibration cutting apparatus further includes a flow rate adjusting means for adjusting the flow rate of the gas fluid. In this case, the temperature of the vibration source can be controlled by controlling the flow rate of the gas fluid, and the temperature drift of the cutting edge position of the cutting tool can be reduced.

In a specific aspect of the present invention, in the vibration cutting apparatus , the gas fluid is dry compressed air. In this case, the gas fluid is inexpensive and easily available, and the occurrence of leakage etc. can be efficiently prevented.

In a specific aspect of the present invention, in the above-described vibration cutting apparatus , the vibrating body has a shaft-shaped outer shape, the fixing member is integrally formed with the vibrating body, and is substantially perpendicular to the shaft from the common node position of the vibrating body. It has a plate-shaped part that spreads in various directions. In this case, allows fixed without loosening precision by the plate-like portion, it is possible to realize a small stable operation of change. Further, the vibrating body can be held uniformly from the surroundings by the plate-like portion, and the fixing reliability of the vibrating body can be improved.

[First Embodiment]
Hereinafter, a vibration cutting apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating the structure of a vibration cutting apparatus that processes the optical surface of a molding die for molding an optical element such as a lens.

  As shown in FIG. 1, the vibration cutting apparatus 10 includes a vibration cutting unit 20 for cutting a workpiece W, an NC control mechanism 30 that supports the vibration cutting unit 20 with respect to the workpiece W, and an NC control mechanism 30. The stage driving device 40 that controls the operation, the vibrator driving device 50 that applies desired vibration to the vibration cutting unit 20, the gas supply device 60 that supplies a cooling gas to the vibration cutting unit 20, and the operation of the entire device. And a main controller 70 that performs overall control.

  The vibration cutting unit 20 has a cutting tool embedded in the tip of the lower chip 21 and cuts the workpiece W by the vibration of the cutting tool. Details of the vibration cutting unit 20 will be described later.

  The NC control mechanism 30 has a structure in which a column 33 is provided on a pedestal 31, and includes a head 35 that is attached to the column 33 and moves up and down in the Z direction and rotates in the θ direction. The vibration cutting unit 20 is attached to the head 35, and the chip 21 is exposed at the lower part. An XY stage 37 is provided on the pedestal 31 so as to face the vibration cutting unit 20. The XY stage 37 can support the workpiece W and move it to a desired position in the XY plane at a desired speed.

  The stage driving device 40 is capable of high-precision numerical control. By driving a motor, a position sensor, or the like built in the NC control mechanism 30 under the control of the main control device 70, the head 35 or the XY stage. 37 is operated appropriately. Thereby, the position and angle of the tip of the tip 21 of the vibration cutting unit 20 with respect to the workpiece W, and the rate of change thereof can be freely adjusted.

  The vibrator driving device 50 is for supplying electric power to a vibration source incorporated in the vibration cutting unit 20, and the tip of the chip 21 is desired under the control of the main controller 70 by a built-in oscillation circuit or PLL circuit. It can be made to vibrate with the frequency and amplitude of. As will be described in detail later, the tip of the tip 21 can bend and vibrate perpendicular to the axis, and the tip of the tip 21 is directed to the surface of the workpiece W by three-dimensional vibration. Processing is possible.

  The gas supply device 60 is for cooling the vibration cutting unit 20, and a gaseous fluid source 61 that supplies pressurized dry air (dry compressed air), and pressurized drying from the gaseous fluid source 61. A temperature adjusting unit 63 that adjusts the temperature by allowing air to pass therethrough, and a flow rate adjusting unit 65 that adjusts the flow rate of the pressurized dry air that has passed through the temperature adjusting unit 63 are provided. Here, the gaseous fluid source 61 dries air by, for example, sending air to a dryer using a thermal process, a desiccator, or the like, and pressurizes the dry air to a desired pressure with a compressor. Although not shown, the temperature adjusting unit 63 is temperature adjusting means having a flow path in which the refrigerant is circulated around and a temperature sensor provided in the middle of the flow path, and the temperature and supply amount of the refrigerant. By adjusting the pressure, the pressurized dry air passed through the flow path can be adjusted to a desired temperature. Further, the flow rate adjusting unit 65 is a flow rate adjusting means having a valve and a flow controller (not shown) so that the flow rate when supplying the temperature-controlled pressurized dry air to the vibration cutting unit 20 can be adjusted. It has become.

  FIG. 2 is a cross-sectional view illustrating the structure of the vibration cutting unit 20. The vibration cutting unit 20 includes a cutting tool 81, a vibrating body 82, an axial vibrator 83, a bending vibrator 84, a counter balance 85, and a housing 86.

  Here, the cutting tool 81 is fixed so as to be embedded in the end portion of the chip 21 that is the tip side of the vibrating body 82. The cutting tool 81 has a tip 81a as a cutting edge, and vibrates together with the vibrating body 82 as an open end of the vibrating body 82 in a resonance state. That is, the cutting tool 81 generates a vibration that is displaced in the Z direction with the vibration of the vibrating body 82 in the axial direction, and a vibration that is displaced in the XY direction with the bending vibration of the vibrating body 82.

  The vibrating body 82 has a thin outer diameter on the tip 21 side and a thick outer diameter on the root side. A first fixing flange 87, which is a plate-like portion, is formed at an appropriate location on the side surface of the vibrating body 82, and the vibrating body 82 is fixed to the housing 86 via the first fixing flange 87 with, for example, screws 93. Has been. The vibrating body 82 is oscillated by the axial vibrator 83 and enters a resonance state in which a standing wave that is locally displaced in the Z direction is formed. The vibrating body 82 is oscillated by the flexural vibrator 84 and enters a resonance state in which a standing wave is locally displaced in the XY directions. Here, the position of the first fixing flange 87 is a common node for the vibrating body 82 in the axial vibration and the flexural vibration. By fixing the first fixing flange 87 via the first fixing flange 87, the axial vibration and It is possible to prevent the bending vibration from being hindered.

  FIG. 3 illustrates the shape of the first fixing flange 87. The first fixing flange 87 shown in FIG. 3A is a perfect disk-shaped fixing member, and the outer peripheral portion is fixed to the housing 86 to seal the housing 86, and has a structure without ventilation. It has become. The first fixing flange 87 shown in FIG. 3B is a fixing member having an opening 87a, and even if the outer peripheral portion is fixed to the housing 86, the inside and outside of the housing 86 can be secured. The first fixing flange 87 shown in FIG. 3C is a fixing member having, for example, a supporting member 87b extending in three directions at an equal angle. Even if the tip of the supporting member 87b is fixed to the housing 86, the inside and outside of the housing 86 The ventilation of the can be secured.

  The axial vibrator 83 is a vibration source that is formed of a piezo element (PZT), a giant magnetostrictive element, or the like and is connected to the base side end face of the vibrating body 82. The vibrator shown in FIG. It is connected to the driving device 50. The axial vibrator 83 operates based on a drive signal from the vibrator driving device 50 and gives a longitudinal wave to the vibrating body 82 by stretching and vibrating at a high frequency. The axial vibrator 83 is displaceable in the Z direction but is not displaced in the XY direction.

  The bending vibrator 84 is a vibration source that is formed of a piezo element, a giant magnetostrictive element, or the like and is connected to the base side surface of the vibrating body 82. The bending vibrator 84 is connected to the vibrator driving device 50 of FIG. It is connected. The flexural vibrator 84 operates based on a drive signal from the vibrator driving device 50 and vibrates at a high frequency, thereby giving a transverse wave to the vibrating body 82.

  The counter balance 85 is connected to the opposite side of the vibrating body 82 with the axial vibrator 83 interposed therebetween. A second fixing flange 88 is formed at an appropriate position on the side surface of the counter balance 85, and the counter balance 85 is fixed to the housing 86 via the second fixing flange 88. The shape of the second fixing flange 88 is the same as that of the first fixing flange 87 shown in FIG. Note that the counter balance 85 is in a resonance state in which a standing wave that is vibrated by the axial vibrator 83 and locally displaced in the Z direction is formed. Here, the position of the second fixed flange 88 is a node of axial vibration for the counter balance 85, and by fixing via the second fixed flange 88, the axial vibration can be prevented from being hindered. .

  The housing 86 is a cylindrical member, and is a part that supports and fixes the vibrating body 82 and the counter balance 85 via the first and second fixing flanges 87 and 88. A first fixing flange 87 is attached to one end of the housing 86 so as to close the opening, and an air supply pipe 92 connected to the opening on the end surface is provided on the other end. The air supply pipe 92 is connected to the gas supply device 60 of FIG. 1, and is supplied with pressurized dry air set to a desired flow rate and temperature. That is, the air supply pipe 92 is a cooling means for cooling the vibration cutting unit 20 from the inside together with the gas supply device 60.

  In the vibration cutting unit 20 described above, the vibrating body 82, the axial vibrator 83, and the counter balance 85 are fixed to each other by brazing, and the axial vibrator 83 can be efficiently vibrated. Yes. Further, a through hole 91 is formed through the vibrating body 82, the axial vibrator 83, and the counter balance 85, and pressurized dry air from the air supply pipe 92 circulates therethrough. . The front end of the through hole 91 is a fine hole 91 a that branches into two or more branches, and the pressurized dry air introduced into the through hole 91 can be discharged to the end of the chip 21.

  Hereinafter, the material forming the vibrating body 82 will be described. The counter balance 85 is also formed of the same material as that of the vibrating body 82.

As the material of the vibrating body 82, a material having a linear expansion coefficient of 6 × 10 ⁻⁶ or less is used. Specifically, silicon nitride, sialon, carbide, invar material, stainless invar material, or the like is preferably used. Table 1 below shows typical examples (invar, stainless invar, carbide, silicon nitride, sialon, silicon carbide) of the material of the vibrating body 82 and comparative examples (so-called 6-4 titanium; Ti-6Al-4V). , Aluminum alloy; A5056, stainless steel; SUS304, alumina), and the physical properties of each material are also described.

Conventionally, the vibrating body 82 excited by the vibrators 83 and 84 is mainly made of stainless steel, hardened steel, aluminum, or the like. This is because although the material is relatively inexpensive, the sound speed is fast and the axial vibration can be efficiently realized. However, the linear expansion coefficient of the stainless material was as large as 13 to 17 × 10 ⁻⁶ , about 10 to 11 × 10 ^{−6 for} hardened steel, and 24 × 10 ^{−6 for} aluminum. When a vibrating body 82 (hereinafter referred to as a conventional vibrating body 82) that supports the cutting tool 81 is manufactured using such a material, if the temperature of the vibrating body 82 slightly changes, the cutting tool 81 attached to the tip of the vibrating body 82 is changed. The cutting edge position (the end of the tip 81a) fluctuated relatively greatly. For this reason, for example, when vibration cutting is started, the vibrators 83 and 84 generate heat due to electrical loss, so the temperature of the vibrators 83 and 84 gradually increases with time, and is conventionally coupled and fixed thereto. The temperature of the mold vibrating body 82 also gradually increased. As a result, the conventional vibrating body 82 was extended in length by thermal expansion and contraction as the processing progressed, and the cutting edge position of the cutting tool 81 provided at the tip was gradually changed. In such a cutting device in which the position of the cutting edge fluctuates during machining, it is difficult to create a machined shape with high precision. Cutting difficult-to-machine materials such as carbide, glass, or ceramic as workpiece W In this case, the depth of cut varies on the order of microns, and the surface roughness is not uniform.

In the present embodiment, a material having a linear expansion coefficient of 6 × 10 ⁻⁶ or less is used in order to prevent the processing accuracy from being lowered due to such thermal expansion of the vibrating body 82. That is, the present inventor uses a material having a linear expansion coefficient of 6 × 10 ⁻⁶ or less, which is about half of 10-11 × 10 ⁻⁶ of the most common hardened steel material, for the vibrating body 82. It has been found that a remarkable effect is exhibited in reducing the temperature drift of the cutting edge position of the cutting tool 81.

There are many materials with a linear expansion coefficient of 6 × 10 ⁻⁶ or less, but broadly divided into alloy materials and ceramic materials. Alloy materials are easier to process than ceramics, but their specific gravity is high and Young's modulus is low, so they are not suitable for resonating at high frequencies. Ceramic materials, on the other hand, have a Young's modulus of about 2 to 3 times that of steel, and the specific gravity is less than half, so it is light and easy to vibrate at a high frequency. It is easy to obtain a resonance frequency with high purity. That is, the Q value of the material is high, and the vibrating body 82 should be manufactured with such a material.

Hereinafter, specific materials of the vibrating body 82 will be described. The vibrating body 82 can be formed of, for example, silicon nitride or sialon. Since silicon nitride and sialon are ceramic materials having almost the same characteristics, the linear expansion coefficient at room temperature is as very small as 1.3 × 10 ⁻⁶ , which is about 1/10 of the steel material. The amount of thermal expansion and contraction is significantly reduced, and the temperature drift of the cutting edge position of the cutting tool 81 held at the tip is dramatically reduced. As a result, stable vibration and a cutting amount can be ensured, so that a highly accurate cutting surface can be obtained efficiently and with good reproducibility in the workpiece W.

  Furthermore, silicon nitride and sialon are very tough among ceramic materials, have a characteristic of being able to obtain a relatively large amplitude at a single vibration frequency with little distortion because they vibrate flexibly. Further, since the specific gravity is very light as 3.3 and the inertia force is small and the Young's modulus is as large as 300 GPa, it is easy to vibrate at a high frequency. Therefore, the load on the vibrators 83 and 84 can be reduced and the amount of generated heat can be kept low, which is very good for reducing the temperature drift of the cutting edge position of the cutting tool 81. In addition, the thermal conductivity is about stainless steel, which is relatively high for ceramics, and has a feature that it propagates without accumulating heat in the vibrating body 82 and suppresses temperature rise. Further, since silicon nitride and sialon are ceramic materials that are resistant to impacts, they are characterized by being less susceptible to cracking due to vibration loads and damage due to accidents during processing of the workpiece W.

The vibrating body 82 can be formed of, for example, a super hard material. The term “super hard material” as used herein refers to all alloys containing 80% by weight or more of tungsten carbide. Carbide material has a coefficient of linear expansion of 6 × 10 ⁻⁶ , which is about half that of steel, and has a very high rigidity and high Young's modulus, so the resonance frequency can be made relatively high. Is heavy, it is necessary to supply large energy to the vibrators 83 and 84. On the other hand, since it becomes much harder to break than when the vibrating body 82 is formed of a ceramic material, it is suitable as a structural material for holding and fixing the cutting tool 81, and the reliability of the vibrating body 82 can be increased.

The vibrating body 82 can be formed of an invar material, for example. The invar material here refers to all alloy materials in which the main component containing 50 atomic% or more is Fe and the constituent containing 10 atomic% or more is composed of at least Ni. The invar material as described above is, for example, an iron alloy containing 36 atomic% nickel, and has a linear expansion coefficient of 1 × 10 ⁻⁶ or less at room temperature. The Young's modulus is as low as about half that of steel, but by using this as the material of the vibrating body 82, thermal expansion and contraction of the vibrating body 82 is suppressed, and the temperature drift of the cutting edge position of the cutting tool 81 held at the tip is reduced. Can be suppressed.

The vibrating body 82 can be formed of, for example, a stainless invar material. As used herein, the term “stainless steel invar material” refers to all alloy materials in which the main component of 50 atomic% or more is Fe and the incidental material including 5 atomic% or more is at least one of Co, Cr, and Ni. Point to. Therefore, here, Kovar material is also included in this stainless steel invar material. The stainless steel invar material has a linear expansion coefficient of 1.3 × 10 ⁻⁶ or less at room temperature. Young's modulus is as low as about half that of steel, but by using this as a material for the vibrating body, thermal expansion and contraction of the vibrating body 82 is suppressed, and temperature drift at the cutting edge position of the cutting tool 81 held at the tip is suppressed. it can. Furthermore, the stainless steel invar material has a much higher resistance to moisture than the invar material, and has an excellent feature that rust does not occur even when subjected to a processing coolant or the like. Therefore, it is suitable as a structural material for holding and fixing the cutting tool 81. Yes.

  In the vibration cutting apparatus 10 of the first embodiment described above, pressurized dry air, which is a gaseous fluid, is supplied to the vibration cutting unit 20, and the pressurized dry air is sprayed on the vibrating body 82 and the vibrators 83 and 84. Thus, the vibrating body 82 and the vibrators 83 and 84 are air-cooled. With respect to the heat generated from the vibrators 83 and 84, by directly supplying cooling dry air for cooling to the vibrators 83 and 84 serving as the heat generator, the temperature rise of the vibrators 83 and 84 is suppressed, and the vibrator By suppressing the temperature expansion and contraction of 82, the reproducibility of the cutting edge position of the cutting tool 81 fixed to the tip can be improved, and a highly accurate cutting surface can be efficiently created. Further, when the vibrators 83 and 84 are elements that are directly driven at a high voltage, such as piezo elements, if the electrodes are covered with an insulating paint or the like outside the piezo elements, even if condensation occurs due to cooling of the gas fluid, Safe without sacrificing vibration stability. At this time, the pressurized dry air is supplied to the vibrating body 82, the axial vibrator 83, and the through hole 91 formed in the shaft center of the counter balance 85, and the pressurized dry air efficiently flows. , 84 and the temperature of the vibrating body 82 can be adjusted by the temperature and flow rate of the pressurized dry air. In this way, by adjusting the temperature of the pressurized dry air, the temperature of the vibrating body 82 is stabilized, and the temperature drift of the cutting edge position of the cutting tool 81 held at the tip thereof is reduced. Further, by adjusting the flow rate of the pressurized dry air, there is no excess or deficiency and there is no fluctuation in the supply amount, so that the temperatures of the vibrators 83 and 84 and the vibrator 82 can be controlled more stably, and the reproducibility is highly accurate. A high cutting surface can be obtained. Moreover, although the vibrators 83 and 84 and the vibrating body 82 are cooled by the pressurized dry air, the dry air can be obtained and supplied inexpensively and easily, and since there is no moisture that causes electric leakage, etc., it is safe. It is. The dry state is preferably 10% or less in terms of relative humidity because the risk of condensation is avoided.

  Note that the through hole 91 for passing pressurized dry air as described above does not need to penetrate to the forefront of the vibrating body 82, that is, instead of the pore 91a illustrated in FIG. It is also possible to have a structure in which the air is exhausted to the outside through a horizontal hole, an oblique hole or the like in the middle of the process.

  Further, in the vibration cutting unit 20 of the above-described embodiment, in order to support the vibrating body 82, the first fixed flange 87 is provided at a common node position for the axial vibration and the bending vibration of the vibrating body 82. Thereby, efficient axial vibration and flexural vibration of the vibrating body 82 can be ensured.

  That is, in this embodiment, a plate-like first fixing flange 87 integrated with the vibrating body 82 extends from the node position of the vibrating body 82 in a direction substantially perpendicular to the axial direction of the vibrating body 82, and this first fixing is performed. The flange 87 is fastened to the housing 86 with screws 93, or is strongly pressed and fixed with other parts. According to this method, (1) since the first fixing flange 87 can be firmly fixed to the housing 86, the fixing force of the vibrating body 82 is strong, and fluctuations due to loosening or the like can be suppressed almost completely. (2) Since the first fixing flange 87 is provided on the entire circumference of the vibrating body 82, the axial symmetry of the fixing point is improved, and the fixing balance of the vibrating body 82 is improved. In this case, since the balance of the fixed points depends on the geometric shape, it does not collapse. (3) The thermal expansion and contraction of the vibrating body 82 and the casing 86 and the fixing force are irrelevant, and the fixing reliability is high.

  In particular, in the case where the vibrating body 82 is not only bent and resonated but also axially resonated, both ends of the vibrating body 82 must be free-supported, and thus the vibrating body 82 is not only fixed by the first fixing flange 87. A component having a mass, that is, a counter balance 85 needs to be coupled and fixed to the opposite end face of the axial vibrator 83 coupled and fixed to the vibrating body 82, and the counter balance 85 can vibrate in the axial direction. Need to be. In the vibration cutting unit 20 of the above embodiment, the second fixed flange 88 is provided at the node position of the counter balance 85, and the integral movable parts 82, 83, 84, 85 are on the side opposite to the node position of the vibration body 82. The counter balance 85 is held at two positions with respect to the node position, and vibrations in the axial direction of the integrally movable parts 82, 83, 84, 85 can be realized without any restriction. In addition, the holding rigidity of the integrally movable parts 82, 83, 84, 85 can be made much stronger than screwing or the like, and stable and reliable axial resonance can be realized. Here, the flanges 87 and 88 are not limited to those integrated with the vibrating body 82 and the counter balance 85 and may be formed of a different material from the vibrating body 82 and the counter balance 85. In this case, the flanges 87 and 88 are fixed to the vibrating body 82 and the counter balance 85 by brazing or the like.

[Second Embodiment]
Hereinafter, the vibration cutting apparatus according to the second embodiment will be described. The vibration cutting apparatus according to the second embodiment is a partial modification of the vibration cutting apparatus according to the first embodiment. Parts that are not particularly described are common to the apparatus according to the first embodiment, and are common in the drawings. Are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 4 is a cross-sectional view illustrating the structure of the vibration cutting unit 120 in the second embodiment. In this case, the casing 86 is not provided with the air supply pipe 92 and the vibrating body 82 cannot be directly cooled. However, if the thermal expansion coefficient of the vibrating body 82 is small, the processing accuracy does not decrease. In addition, the gas supply apparatus 60 of FIG. 1 is unnecessary.

[Third Embodiment]
Hereinafter, a vibration cutting apparatus according to the third embodiment will be described. The vibration cutting device of the third embodiment is a partial modification of the vibration cutting device of the second embodiment.

  FIG. 5 is a cross-sectional view illustrating the structure of the vibration cutting unit 220 in the third embodiment. In this case, the second fixing flange 88 is not provided, and the counter balance 85 is not directly supported by the housing 86, but the axial vibration and flexural vibration of the vibrating body 82 and the counter balance 85 are ensured, and the operation The above difference does not occur. However, it is necessary to ensure the strength of the first fixing flange 87 because the second fixing flange 88 does not exist.

  In the vibration cutting unit 220 of FIG. 5, as in the first embodiment, a through-hole 91 is provided in the axial center of the integrally movable parts 82, 83, 84 (see FIG. 2) and is supplied to the housing 86. An air pipe 92 can also be provided. In this case, the integrally movable parts 82, 83, and 84 can be efficiently cooled by the gas supply device 60 of FIG.

[Fourth Embodiment]
Hereinafter, the vibration cutting apparatus according to the fourth embodiment will be described. The vibration cutting device of the fourth embodiment is a partial modification of the vibration cutting device of the first embodiment.

  FIG. 6 is a cross-sectional view illustrating the structure of the vibration cutting unit 320 in the fourth embodiment. In this case, an air supply pipe 392 is provided on the side surface of the housing 86, and the vibrators 83 and 84 can be directly cooled from the side surface, and the vibrator 82 is also directly cooled from the side surface.

[Fifth Embodiment]
The molding die according to the fifth embodiment will be described below. FIG. 7 is a diagram for explaining a molding die manufactured using the vibration cutting units 20 to 320 of the first to fourth embodiments, and FIG. 7A is a diagram illustrating a fixed die, that is, the first die 2A side. FIG. 7B is a side sectional view of the movable mold, that is, the second mold 2B. The optical surfaces 3a and 3b of both molds 2A and 2B are finished by a vibration cutting apparatus shown in FIGS. That is, the base material (material is, for example, cemented carbide) of both molds 2A and 2B is fixed on the XY stage 37 as a work W, and the vibrator driving device 50 and the like are operated so that the standing waves are generated in the vibration cutting units 20 to 320. The cutting tool 81 is vibrated at high speed while forming. In parallel with this, the stage driving device 40 is appropriately operated to arbitrarily move the tips 21 of the vibration cutting units 20 to 320 with respect to the workpiece W in a three-dimensional manner. Thereby, the optical surfaces 3a and 3b of the molds 2A and 2B are not limited to spherical surfaces and aspheric surfaces, but can be step surfaces and phase structure surfaces.

  FIG. 8 is a cross-sectional view of a lens L press-molded using the mold 2A of FIG. 7A and the mold 2B of FIG. 7B. The material of the lens L is not limited to plastic but can be glass or the like.

As described above, the present invention has been described according to the embodiment, but the present invention is not limited to the above embodiment. For example, in the gas supply device 60 of FIG. 1, instead of air, a gaseous fluid added by misting oil or other lubricating elements, an inert gas such as nitrogen gas, or the like can be used.
Further, the vibration cutting apparatus 10 in FIG. 1 incorporates a three-dimensionally movable NC control mechanism 30 and moves the vibration cutting unit 20 to a desired position. It is also possible to provide a mechanism that enables turning, and to drive the vibration cutting unit 20 by such a turning motion mechanism.

It is a block diagram explaining the vibration cutting apparatus of 1st Embodiment. It is a longitudinal cross-sectional view explaining the structure of the vibration cutting unit integrated in the vibration cutting apparatus of FIG. (A)-(c) is an end elevation which illustrates the shape of the 1st fixed flange used for the vibration cutting unit of FIG. It is a longitudinal cross-sectional view explaining the structure of the vibration cutting unit integrated in the apparatus of 2nd Embodiment. It is a longitudinal cross-sectional view explaining the structure of the vibration cutting unit incorporated in the apparatus of 3rd Embodiment. It is a longitudinal cross-sectional view explaining the structure of the vibration cutting unit integrated in the apparatus of 4th Embodiment. (A), (b) is a sectional side view of the molding die concerning a 5th embodiment. FIG. 8 is a side sectional view of a lens formed by the molding die of FIG. 7.

Explanation of symbols

  2A, 2B ... mold, 3a, 3b ... optical surface, 10 ... vibration cutting device, 20 ... vibration cutting unit, 50 ... vibrator drive device, 60 ... gas supply device, 70 ... main controller, 81 ... cutting tool, DESCRIPTION OF SYMBOLS 82 ... Vibrating body, 83 ... Axial vibrator, 84 ... Deflection vibrator, 85 ... Counter balance, 86 ... Housing, 87 ... 1st fixing flange, 88 ... 2nd fixing flange, 91 ... Through-hole, 92 ... Feeding Qi pipe

Claims (11)

Cutting tools,
A vibration source for vibrating the cutting tool;
A vibration body that is formed of a material having a linear expansion coefficient of 6 × 10 ⁻⁶ or less and that holds the cutting tool and transmits vibration from the vibration source to the cutting tool as axial vibration and bending vibration;
A fixing member that fixes the vibrating body at a common node position in the axial vibration and flexural vibration;
Cooling means for blowing a gaseous fluid to at least a part of the vibration source,
The vibration source and the vibrating body have a through hole communicating with each other at the joint portion, and the cooling means supplies the gaseous fluid from the vibration source side of the through hole. apparatus.   The vibration cutting apparatus according to claim 1, wherein the vibrator is made of a material containing silicon nitride as a main component.   The vibration cutting apparatus according to claim 2, wherein the vibrating body is formed of sialon.   The vibration cutting apparatus according to claim 1, wherein the vibrating body is made of a super hard material.   The vibration cutting apparatus according to claim 1, wherein the vibration body is formed of at least one of an invar material and a stainless invar material.   6. The vibration cutting device according to claim 1, wherein the gaseous fluid includes a mist state.   The vibration cutting apparatus according to claim 1, further comprising a temperature adjusting unit that adjusts a temperature of the gas fluid.   The vibration cutting apparatus according to claim 1, further comprising a flow rate adjusting unit that adjusts a flow rate of the gas fluid.   The vibration cutting apparatus according to claim 1, wherein the gas fluid is dry compressed air.   The vibration cutting apparatus according to claim 1, wherein the fixing member has an opening.   The vibrating body has a shaft-like outer shape, and the fixing member has a plate-like portion that is formed integrally with the vibrating body and extends from the common node position of the vibrating body in a direction substantially perpendicular to the axis. The vibration cutting device according to any one of claims 1 to 10, wherein

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