JPH07164201A - Cutting device - Google Patents

Abstract

PURPOSE:To cut an optical glass lens with high accuracy by mounting an ultrasonic vibrator which generates ultrasonic torsional vibration with a high-frequency driving signal supplied from an oscillating device for driving, and transmitting the ultrasonic torsional vibration to a tool tip. CONSTITUTION:A cutting device 1 is composed of a bolting Langevin type electrostrictive torsional vibrator 11, an amplitude enlarge transmission hone 12, a cutting chip 13, and a high-frequency oscillator 16. The oscillator 11 is disposed inside a case provided with a cooling fan 15, and is driven by a high-frequency electric signal outputted from the oscillator 16 through a power supply connector 14, thus generating supersonic torsional vibration. The amplitude enlarge transmission hone 12 is provided with the cutting tip 13 fixed on its end part, and enlarges the amplitude of ultrasonic torsional vibration generated by the vibrator 11 and transmits it to the cutting tip 13. It is possible to cut a glass lens with high accuracy through the cutting tip 13 by the enlarged ultrasonic torsional vibration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for cutting a work made of, for example, a hard and brittle material.

[0002]

2. Description of the Related Art Conventionally, in the case of forming a shape of a work generally made of a hard and brittle material, the shape is formed by grinding and polishing. For example, in the processing of a glass lens, which is an optical component, its shape is created as a product by grinding with a CG (curve generator), sanding, and polishing.

Further, in the cutting of glass, it is impossible to apply a usual cutting method for processing a metal material, and in recent years, an attempt of cutting by ultrasonic vibration cutting has been made.

[0004]

However, in the above-mentioned conventional grinding and polishing processes, since the number of steps is large and the amount of processing is small, it takes a long time to complete one part, In addition, since switching models is complicated, there is a problem that it is not suitable for high-mix low-volume production. Especially for grinding, since a grindstone is used as a tool, there is a problem that dressing and truing must be performed on the machine. Furthermore,
Since the tool is rotated at a high speed, it is necessary to adjust the dynamic balance, and the adjustment for that purpose is complicated.

Further, in the conventional ultrasonic vibration cutting machine, since it is composed of a longitudinal vibration system and a flexural vibration system, the entire machine becomes large, and it is difficult to mount it on an NC lathe, and the spherical shape and aspherical surface are used. There is a problem that it is not suitable for lens processing that requires a shape. in addition,
Since it is composed of a longitudinal vibration system and a flexural vibration system, adjustment of the device is extremely delicate, so skill is required, and the connecting part between the longitudinal vibration system and the flexural vibration system easily generates heat, and it is an optical component. There is also a problem that it is difficult to process a certain glass lens with high accuracy.

The present invention has been made in view of the above problems, and an object of the present invention is to obtain a cutting apparatus which is small and easy to handle. In particular, it is an object to obtain a cutting device suitable for cutting an optical glass lens.

[0007]

In order to achieve the above-mentioned object, a cutting machine according to a first aspect of the present invention is provided with a driving oscillating device for outputting a high frequency driving signal, and a driving oscillating device for supplying the oscillating device. An ultrasonic vibrator that generates ultrasonic torsional vibrations by a high-frequency drive signal, a chip holding unit that holds a tool chip for cutting a work to be processed, and the chip from the ultrasonic vibrator. And a vibration transmitting means for transmitting the ultrasonic torsional vibration.

[0008]

[Function] Generally, glass materials are brittle and weak against impact force, and it is extremely difficult to perform processing by cutting metal materials, but the cutting edge of the tool is excessive in the main force direction. It becomes possible to cut glass material by applying a continuous impact force to the surface of the glass workpiece using an ultrasonic vibration cutting method of cutting while vibrating ultrasonically.

It is known that when a cutting speed is made sufficiently slower than a vibration speed of a cutting edge and a cutting condition for minute cutting is applied, a hard and brittle material such as a glass material also plastically flows. A finished surface can be obtained.

Further, by using the cutting method using ultrasonic torsional vibration, the size of the apparatus can be significantly reduced as compared with the conventional ultrasonic vibration cutting apparatus composed of a longitudinal vibration system and a flexural vibration system. Since it can be attached to a tool post such as an NC lathe, and the device itself is configured as a single unit, adjustment is extremely easy, heat is hardly generated, and the glass lens that is an optical component is highly accurate. It can be processed into

The cutting apparatus according to the first aspect of the present invention mainly comprises a drive oscillating device, an ultrasonic vibrator, a tip holding means, and a vibration transmitting means.

The drive oscillating device outputs a high frequency drive signal having a resonance frequency of the mechanical vibration system or a frequency in the vicinity thereof. The ultrasonic vibrator is excited by a high frequency driving signal supplied from the driving oscillating device to generate ultrasonic torsional vibration of a corresponding frequency, which can be constituted by, for example, a Langevin type electrostrictive torsional vibrator.

The tip holding means holds a tool tip for cutting a work to be processed. The vibration transmission means transmits the ultrasonic torsional vibration from the ultrasonic vibrator to the chip, preferably by expanding its amplitude.

In the cutting device having such a structure, since the tool tip continuously ultrasonically vibrates in the main component force direction with the work due to the torsional impact with the work due to the ultrasonic torsional vibration, good surface roughness can be obtained. Is cut with.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic configuration diagram of a cutting apparatus 1 according to an embodiment of the present invention. As shown in FIG. 1, a cutting apparatus 1 according to this embodiment includes a bolted Langevin type electrostrictive torsional vibrator 11, an amplitude amplification transmission horn 12, and
The cutting tip 13 and a high-frequency oscillator 16 are mainly included.

The vibrator 11 is a vibrator cooling fan 1
It is disposed in a case 17 provided with a No. 5 and is driven by a high frequency electric signal output from the oscillator 16 via a power feeding connector 14 to generate ultrasonic torsional vibration.

The amplitude amplification transmission horn 12 is provided below the vibrator 11, and the cutting tip 13 is fixed to the tip of the vibrator 12 by, for example, a screw, and the ultrasonic wave generated from the vibrator 11 is generated. The torsional vibration has its amplitude enlarged and is transmitted to the cutting tip 13.

In the cutting apparatus according to the present embodiment configured as described above, when a high-frequency electric signal is output from the oscillator 16, ultrasonic torsional vibration is generated from the vibrator 11 to increase the amplitude. The amplitude of the ultrasonic torsional vibration is expanded several times by the transmission horn 12, and the cutting tip 13 performs the torsional vibration by the expanded ultrasonic torsional vibration.

FIG. 2 is a schematic diagram showing a mounting portion of the cutting tip 13, (A) is a front view,
(B) is a side view. As shown in FIG. 2, the cutting tip 13 is attached to the tip notch of the amplitude amplification transmission horn 12 by a fixing screw 23, and the ultrasonic twist expanded via the amplitude amplification transmission horn 12 is performed. Vibration is generated from the center of the end surface of the horn 12 by the cutting tip 13
Arc-shaped vibration with the radius to the tip (arrow 24
Direction).

As a result, the cutting tip 13 is ultrasonically vibrated in the main component direction along with the work (not shown) to be machined, accompanied by the torsional shock caused by the ultrasonic torsional vibration. It can be cut with surface roughness.

In this case, a standing wave having a frequency substantially the same as the natural frequency of the vibrator 11 is applied to the mechanical vibration system consisting of the vibrator 11, the amplitude increasing horn 12 and the cutting tip 13. Since it is generated, this mechanical vibration system is one resonance system. Therefore, it is preferable that the amplitude expanding transmission horn 12 is fixed to the case 17 by the flange 18 at a portion corresponding to a node (a portion where the amplitude is 0) of the standing wave 19 generated in the vibration system. By fixing the vibration system to the flange 18 at the position, it is possible to transmit the ultrasonic torsional vibration to the cutting tip 13 with high efficiency without attenuating it.

In this embodiment, the resonance frequency of the vibration system under no load is about 20.4 kHz, and the amplitude at the tip of the cutting tip is about 25 μ when the output of the oscillator is 20 W.
The unit weighs 4.2 kg and the total length is 240 mm.
It is a degree. In addition to this, the resonance frequency of the vibration system under no load is about 28.1 kHz, the amplitude at the tip of the cutting tip is about 20 μm when the output of the oscillator is 15 W, and the weight of the unit is 1.7 kg. Some have a total length of about 180 mm.

FIG. 3 shows a numerically controlled lathe (NC lathe).
FIG. 2 is a schematic configuration diagram when the cutting device 1 shown in FIG. 1 is attached to FIG. As shown in FIG. 3, the NC lathe has a Z-axis moving AC servo motor 32, a Z-axis position scale 33, a carrying table 34, and an X-axis moving A.
C servo motor 35 and X-axis position scale 36
And a spindle motor 310 and a control device 311.

The transport table 34 is the cutting device 1 described above.
AC servo motor 32 for Z-axis movement
And Z along with the driving of the AC servo motor 35 for X-axis movement.
Move in the axial and X-axis directions. The Z-axis moving AC servo motor 32 and the X-axis moving AC servo motor 35 are
It is driven by the data input to the control device 311.
The Z-axis position scale 33 and the X-axis position scale 36 are located on the Z-axis and the X-axis of the transport table 34.
The position on the axis is transmitted to the control device 311.

Further, the work 37 is held by a chuck 38 attached to the tip of the lathe spindle 39 or by a employment, and the spindle motor 311 rotates the lathe spindle 39 by the data input to the control device 311.
Along with this, the work 37 also rotates.

By mounting the cutting device 1 on the NC lathe configured as described above, the transport table 3 is obtained based on the data input from the control device 311.
4 moves in the X-axis and Z-axis directions, and the work 37 is cut into a spherical or aspherical shape by a torsional impact due to ultrasonic torsional vibration of the cutting apparatus 1 held on the transport table 34. It

FIG. 4 is a shape showing the measurement result of the shape accuracy when the cutting apparatus 1 shown in FIG. 1 is attached to the NC lathe shown in FIG. 3 and the end surface of the glass material is processed into a spherical shape. It is an accuracy characteristic graph. The vertical axis represents the deviation from the ideal shape of the glass material after cutting (the 0 position is the ideal shape) [μm], and the horizontal axis is on the processed surface that passes through the center of the end surface of the glass material after cutting. The coordinate position [mm] is shown.

As a result of the shape accuracy characteristic graph shown in FIG. 4, the shape accuracy was about 3 μm (absolute value). The surface roughness was 0.09 to 0.17 μm (Ra). Further, Table 1 shows processing conditions when the end surface of the glass material is processed into a spherical shape.

[0029]

[Table 1]

Further, FIG. 5 shows that the cutting apparatus 1 shown in FIG. 1 is attached to the NC lathe shown in FIG.
It is a surface roughness-cutting speed characteristic graph which shows the relationship between the surface roughness (Ra) and the cutting speed when the end surface of the glass material is processed into a planar shape.

As can be seen from FIG. 5, the surface roughness (Ra) increases as the cutting speed increases. In addition, the surface roughness (R
It can be seen that a) is getting larger. Table 2 shows the processing conditions at that time.

[0032]

[Table 2]

Further, in FIG. 6, the cutting apparatus 1 shown in FIG. 1 is attached to the NC lathe shown in FIG.
6 is a graph showing the relationship between the number of times of machining and the flank wear width of a cutting tip when the end surface of a glass material is machined into a planar shape-a flank wear width characteristic graph. When the end surface of the glass material was processed into a planar shape using the cutting apparatus 1 according to this example, the graph shown in FIG. 6 was obtained. still,
Table 3 shows the processing conditions at that time.

[0034]

[Table 3]

[0035]

As described above, according to the present invention, since the cutting machine which generates ultrasonic torsional vibration is used, as compared with the conventional ultrasonic vibration cutting machine, the weight is about 1/9, and the size is large. It has been downsized to a general-purpose lathe turret and N
By attaching the C lathe to the tool rest, there is an effect that the spherical or aspherical surface of the glass material can be easily processed by cutting. In particular, there is an effect that it is possible to create a highly accurate and high quality finished surface for a glass material.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a cutting apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a mounting portion of a cutting tip of a cutting device according to an embodiment of the present invention, FIG.
Is a front view and (B) is a side view.

FIG. 3 is a schematic configuration diagram when the cutting device shown in the previous figure (FIG. 1) is attached to an NC lathe.

FIG. 4 is a shape accuracy characteristic graph of a glass material.

FIG. 5 is a surface roughness-cutting speed characteristic graph of a glass material.

FIG. 6 is a graph of the number of times of machining-frank wear width characteristic.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cutting processing apparatus 11 ... Electrostrictive torsional vibrator (ultrasonic vibrator) 12 ... Amplitude amplification transmission horn (vibration transmission means) 13 ... Cutting tip 16 ... High frequency oscillator ( Oscillator for driving) 32 ... AC servo motor for Z-axis movement 33 ... Z-axis position scale 34 ... Transport table 35 ... AC servo motor for X-axis movement 36 ... X-axis position scale 37・ ・ ・ Work 38 ・ ・ ・ Chuck 39 ・ ・ ・ Lathe spindle 310 ・ ・ Spindle motor 311 ・ ・ Control device

Claims (1)

[Claims] 1. A driving oscillator that outputs a high-frequency drive signal, an ultrasonic vibrator that generates ultrasonic torsional vibrations by the high-frequency drive signal supplied from the driving oscillator, and a workpiece to be machined A cutting device, comprising: a tip holding means for holding a tool tip for doing so; and a vibration transmitting means for transmitting the ultrasonic torsional vibration from the ultrasonic vibrator to the tip.