JP2002103102A - Working apparatus and working method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working apparatus and a working method in which working error caused by the thermal displacement of a working tool generated by heat generation associated with the drive of an actuator by performing the working by giving vibration to the working tool by the actuator are reduced, and the working accuracy and productivity are improved. SOLUTION: In performing the worming by giving vibration to the working tool 4 by driving the actuator of two drive systems 2a and 2b orthogonal to each other in a vibration-cutting unit 1, the heat generated by the drive of the actuator is reduced by circulating cooling refrigerant within the drive systems 2a and 2b by a cooling device 24. Temperature change of the drive systems 2a and 2b associated with heat generation by the drive of the actuator is measured by a plurality of temperature sensors 21 and detected by a temperature detector 20, the temperature information is fed back to the cooling device 24 via a control device 23, and the temperature and the flow rate of the refrigerant are controlled to correct the temperature. The working accuracy is improved by reducing the working error caused by the thermal displacement at a position of a blade tip of the working tool 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing apparatus and a processing method for applying ultrasonic vibration or elliptical vibration to a processing tool by using an actuator such as a piezoelectric element or a magnetostrictive element. The present invention relates to a processing apparatus and a processing method for suppressing a processing error due to thermal displacement of a cutting edge position of a processing tool caused by heat generation.

[0002]

2. Description of the Related Art Hard-cutting is performed by a vibration cutting method in which an actuator such as a piezoelectric element or a magnetostrictive element imparts a motion such as an elliptical vibration or the like due to a combination of ultrasonic vibration or linear motion in one or more directions to a processing tool. Work of materials can be performed, and the life of a cutting tool, which is a processing tool, is improved.

[0003]

In recent years, there has been an increasing demand for high-precision processing in sub-micron units, as represented by die processing of optical element parts. However, in the vibration system in the vibration cutting method as described above, since the actuator is vibrated at a frequency of several hundreds Hz or more, the actuator generates a large amount of heat. Deterioration was caused. Also,
If the heat generation is too large, the amount of displacement exceeds the allowable amount of the structure of the vibration cutting device, and the device structure may be damaged.

Accordingly, the present invention has been made in view of the above-mentioned unsolved problems of the prior art, and generates heat accompanying the driving of an actuator when machining is performed by applying vibration to a processing tool by the actuator. An object of the present invention is to provide a processing apparatus and a processing method capable of suppressing or reducing a processing error due to a thermal displacement of a cutting edge position of a processing tool caused by the above, and improving processing accuracy and productivity.

[0005]

In order to achieve the above object, a machining apparatus according to the present invention is a machining apparatus for imparting vibration to a machining tool by an actuator. Means is provided.

In the processing apparatus of the present invention, it is preferable that the cooling means includes a refrigerant flow path provided in a structure holding the actuator for flowing a refrigerant and a circulating means for circulating the refrigerant. .

In the processing apparatus of the present invention, a temperature detecting means for detecting a temperature change accompanying the driving of the actuator and a control means for controlling the cooling means based on the temperature information detected by the temperature detecting means. It is preferable to further provide.

In the processing apparatus according to the present invention, the cooling means and the temperature detecting means are provided independently for at least two or more parts, respectively, and the control means controls each part detected by the temperature detecting means. It is preferable to control the cooling means corresponding to each part based on the temperature information.

In the processing apparatus according to the present invention, the actuator includes a functional solid element such as a piezoelectric element and a magnetostrictive element;
Alternatively, it is possible to use a member that uses an electromagnetic force, and it is preferable that the member holding the actuator and / or the processing tool is formed of a low thermal expansion material.

Further, according to the working method of the present invention, in a working method of working by applying vibration to a working tool by an actuator, a temperature-controlled coolant is circulated through a coolant channel provided in a structure holding the actuator. It is characterized in that heat generated by driving the actuator is cooled.

In the processing method of the present invention, a temperature change accompanying the driving of the actuator is detected, and the temperature and the circulation flow rate of the refrigerant are controlled based on the detected temperature information, so that the heat generated by driving the actuator is controlled. Is preferably cooled.

In the machining method of the present invention, a temperature change accompanying the driving of the actuator is detected in at least two or more parts, and the temperature of the refrigerant is individually determined for each part based on the detected temperature information of each part. And control the circulation flow rate,
It is preferable to cool each part.

[0013]

According to the processing apparatus and the processing method of the present invention, when vibration is applied to a processing tool by an actuator to perform processing, heat generated by driving the actuator is cooled to correct the temperature. By measuring the temperature change due to the heat generated by the drive and controlling the cooling means based on the measurement result to correct the temperature, the deterioration of the processing accuracy due to the thermal displacement of the processing tool is reduced, and the processing accuracy and productivity are reduced. Improve.

Further, a temperature change accompanying the driving of the actuator is detected in at least two or more parts, and the temperature and the circulation flow rate of the refrigerant are individually controlled for each part based on the detected temperature information of each part. By cooling and temperature-correcting each part, the temperature distribution can be suppressed, the thermal displacement of the processing tool can be further reduced, and the processing accuracy and productivity can be further improved.

[0015]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing the configuration of a vibration cutting device of the present invention, FIG. 2 is a schematic diagram of a vibration cutting unit in the vibration cutting device of the present invention, and FIG.
It is the schematic of the drive system in the vibration cutting apparatus of this invention.

The vibration cutting apparatus shown in FIG. 1 has a dimensional accuracy of 0.3 μm or less and a 0.1 μm
In order to obtain the following surface roughness, 10 is
A work table 12 for holding a work 11 is provided on the upper surface of the XY table, and the work 11 held on the work table 12 is configured to be movable in the XY directions. Is provided with a Z-axis slider 14 that can move in the Z direction along the frame 13, and the Z-axis slider 14 is attached with the vibration cutting unit 1 having a machining tool (bite) 4 at a lower portion. I have. The vibration cutting unit 1 is provided with two orthogonal drive systems: a Z-direction drive system 2a that generates a Z-direction linear vibration and a drive system 2b that generates an X-direction linear motion. With this configuration, when machining the work 11, XY
The work 11 is moved in the XY directions by the table 10,
The vibration cutting unit 1 is moved up and down by the Z-axis slider 14 in the Z direction.
And the position of the machining tool 4 is controlled.

Reference numeral 15 denotes an oscillating device for driving the driving systems 2a and 2b of the vibration cutting unit 1 to draw an arbitrary tool trajectory on the machining tool 4. The signal generated from the oscillating device 15 is an amplifier. As a drive current amplified by 16 and forming an arbitrary waveform, the drive system 2
a and 2b to drive the vibration cutting unit 1. Reference numeral 20 denotes a temperature detecting device, which is provided on a temperature sensor 21 such as a plurality of thermocouple thermometers installed in the vibration cutting unit 1 (three are provided in each of the driving systems 2a and 2b in FIG. 1). Connected and temperature sensor 2
1, the temperature inside the vibration cutting unit 1 is measured and detected. A control device 23 controls the cooling devices 24 (24a, 24b) based on temperature data inside the vibration cutting unit 1 measured and detected by the temperature detection device 20. The cooling device 24 (24a, 24b) supplies a coolant for cooling the inside of the vibration cutting unit 1 to a cooling pipe 25.
(25a, 25b) to supply it to the vibration cutting unit 1 and circulate through each drive system 2a, 2b to cool the vibration cutting unit 1 and each drive system 2a, 2b, and to control the temperature and flow rate of the refrigerant. Is controlled and adjusted by the controller 23 based on the temperature data inside the vibration cutting unit 1. The cooling pipes 25 (25a, 25b) are connected to the drive systems 2a, 2b of the vibration cutting unit 1 from the Z-axis slider 14 through the inside of the processing device, respectively.
2b, a refrigerant flow path 27 branched into a plurality of systems (in FIG. 3, three systems,
7a, 27b, and 27c).

The vibration cutting unit 1 has two orthogonal drive systems, a Z-direction drive system 2a for generating Z-direction linear motion and a drive system 2b for generating X-direction linear motion. As shown in FIG. 2, the systems 2a and 2b are connected to the vibration transmitting mechanism 3 via elastic hinges 6a and 6b, respectively, and the machining tool 4 is attached to the distal end of the vibration transmitting mechanism 3 via the tool holder 5. ing. The orthogonal drive system 2a in the Z direction and the drive system 2b in the X direction are each driven at an arbitrary frequency and stroke by a signal from the oscillation device 15 to generate linear motion in the Z and X directions, respectively. These linear motions are transmitted to the vibration transmission mechanism 3 via the elastic hinges 6a and 6b, and the processing tool 4 attached to the tip of the vibration transmission mechanism 3 draws an elliptical locus in the XZ plane. And the cutting is performed by the elliptical vibration.

Next, the drive system 2 (2
a) and 2b) will be described in more detail with reference to FIG. The drive system 2a in the Z direction will be described as an example, but the drive system 2b in the X direction has the same structure.

In FIG. 3, an actuator 30 composed of a magnetostrictive element as a drive source of vibration is held by a fixing member 33 having high thermal conductivity attached to a drive shaft housing 32 and connected to the drive 30 connected to the actuator 30. The rod 31 extends downward through the fixed member 33 and the drive shaft housing 32 so as to be movable in the Z direction, and is guided by a drive rod guide 34 made of an elastic hinge so as not to be affected by friction. Further, a heat conductive sheet 35 is inserted between the actuator 30 and the fixing member 33 so that there is no gap between the actuator 30 and the fixing member 33. In the drive shaft housing 32, three systems of refrigerant flow paths 27a, 27b, 27c are formed independently so as to surround the actuator 30 and the fixing member 33, and the refrigerant flow paths 27a and 27c are respectively formed in the drive shaft housing 32. The refrigerant flow paths 27b are disposed at upper and lower portions in the Z direction, and are disposed so as to surround the side portion of the fixing member 33. These refrigerant flow paths 27a, 27b, and 27c are arranged according to the required cooling degree. Thus, the cooling refrigerant can be circulated by changing the flow rate of the cooling refrigerant separately, and appropriate cooling can be performed for each refrigerant flow path. The temperature sensors 21a, 21b and 21c such as thermocouple thermometers indicate that the degree of heat generation accompanying the driving of the
Since the temperature is different depending on the position of the actuator 30, the driving system 2 a is disposed at each position of the fixing member 33 so that the temperature of the upper and lower portions and the side portion of the actuator 30 can be measured. Temperature sensor 21
The temperature information detected by the temperature detection device 20 by measuring the temperature of each part by a, 21b, and 21c is:
It is sent to the control device 23. The drive shaft housing 32 constitutes a main structure together with the vibration transmission mechanism 3, the tool holder 5, and the like.
The effect of heat generation of 0 is reduced.

The actuator 30 used in this embodiment is
It utilizes a magnetostrictive element, and is driven by a current having an arbitrary waveform generated from the oscillation device 15 and the amplifier 16. In addition, as the actuator, a functional solid element such as a piezoelectric element can be used in addition to the magnetostrictive element.
Further, a device using electromagnetic force or the like can also be used.

In the vibration cutting apparatus configured as described above, when processing a work, the work 11 is set on the work table 12 and the X and Y tables 10
The vibration cutting unit 1 is moved in the Y direction, moved up and down in the Z direction by the Z-axis slider 14, and the position of the workpiece 11 and the processing tool 4 is controlled by three-axis control. The actuators 30 respectively provided inside the drive systems 2a and 2b of the vibration cutting unit 1 are driven by currents having arbitrary waveforms generated from the oscillation device 15 and the amplifier 16, and the drive systems 2a and 2b respectively It is driven at a predetermined frequency and stroke to generate linear motion vibrations in the Z and X directions, respectively. These linear vibrations are generated by the drive rod 3
1 and the vibration transmission mechanism 3 via the elastic hinges 6a and 6b.
And vibrates the machining tool 4 attached to the tip of the vibration transmission mechanism 3 so as to draw an elliptical locus in the XZ plane, and performs cutting by the elliptical vibration.

If the driving systems 2a and 2b provided with the actuator 30 are not cooled during such cutting, the temperature rises by several tens of degrees in a short time due to the heat generated by driving the actuator 30. Due to this temperature rise, the temperature of the vibration cutting unit 1 also increases, and the vibration cutting unit 1
Due to the thermal expansion, the position of the cutting edge of the working tool 4 is displaced by several tens of μm due to thermal displacement, so that high-precision cutting cannot be performed. Therefore, the processing tool 4 caused by the heat generated by the driving of the actuator 30
In order to suppress and reduce the thermal displacement of the cutting edge position, it is necessary to cool the heat generated by driving the actuator 30. Moreover, since the degree of heat generation due to the driving of the actuator 30 varies depending on the location of the actuator 30,
In the drive system 2 (2a, 2b), the temperature detecting device 20 measures and detects the temperatures of three locations where the temperature sensors 21a, 21b, 21c are installed, respectively, and the control device 23, which has received the detected temperature information, Based on the temperature information, the cooling device 24 (24a, 24b) is controlled to adjust the flow rate of the cooling refrigerant according to the required degree of cooling using the independent refrigerant flow paths 27a, 27b, 27c. Then, a required flow rate of the refrigerant flows through each of the refrigerant flow paths to cool each part. As described above, the temperature inside the vibration cutting unit 1 is measured and detected by the temperature sensor 21 and the temperature detection device 20, and the temperature information is fed back to the cooling devices 24 (24 a, 24 b) by the control device 23 for cooling. Vibration cutting unit 1 by controlling and adjusting the temperature and flow rate of refrigerant
Cool inside. In this way, the rise in temperature is suppressed,
Furthermore, by eliminating the temperature distribution, it is possible to suppress or reduce the thermal displacement of the cutting edge position of the machining tool 4 caused by the heat generated by driving the actuator 30, and to reduce the deterioration of machining accuracy due to the thermal displacement.

In the above-described embodiment, the temperature in the vibration cutting unit 1 is measured by the temperature detecting device 20 and the control device 23, and the temperature information is fed back to perform cooling. When the vibration cutting unit 1 is driven under the same conditions as the driving conditions for which it has become clear, finding appropriate cooling conditions enables cooling under constant conditions without performing temperature control by temperature measurement and feedback. It is also possible.

Next, a description will be given of a temperature change accompanying the driving of the actuator of the driving system with reference to FIG. FIG. 4 shows the results of an experiment on the temperature change of the heat generation accompanying the driving of the actuator. As an actual example of the temperature change of the drive system, the temperature sensor 2 installed near the guide portion of the drive rod 31 is shown.
1c shows a temperature history measured according to FIG. 3 (FIG. 3).

The driving conditions are a driving frequency of 500 Hz and a driving stroke of ± 10 μm. In order to drive the actuator 30 under necessary conditions, several tens of watts of electric power are required, but its heat capacity is small and heat generation is remarkable.

In FIG. 4, when the actuator is driven without cooling, the temperature rises according to the operation time, and after 2 hours, the temperature rises by 40 ° C. or more.
Since then, the temperature has continued to rise. On the other hand, using the cooling means according to the present invention, a flow rate of 1.5 L
When the temperature was corrected by circulating the refrigerant under the conditions of / min and the liquid temperature of 19 ° C., the temperature was found to be substantially stable after 60 minutes. According to this experimental result, by cooling the drive system, the temperature of the drive system can be stabilized even if the drive system generates heat by driving the actuator, and the thermal displacement of the cutting edge position of the processing tool caused by the heat generated by the drive of the actuator. It can be seen that the machining error due to thermal displacement can be suppressed, and the deterioration of machining accuracy can be reduced.

[0029]

As described above, according to the present invention,
When machining by applying vibration to the processing tool, the temperature change due to the heat generated due to the drive of the actuator is measured by cooling the temperature generated by the drive of the actuator and correcting the temperature. By performing the temperature correction by controlling the cooling means, it is possible to reduce the deterioration of the processing accuracy due to the thermal displacement of the processing tool, and it is possible to improve the processing accuracy and the productivity.

Further, a temperature change accompanying the driving of the actuator is detected in at least two or more parts, and the temperature and circulation flow rate of the refrigerant are individually controlled for each part based on the detected temperature information of each part. By cooling and temperature-correcting each part, the temperature distribution can be suppressed, the thermal displacement of the processing tool can be further reduced, and the processing accuracy and productivity can be further improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a configuration of a vibration cutting apparatus according to the present invention.

FIG. 2 is a schematic view of a vibration cutting unit in the vibration cutting apparatus of the present invention.

FIG. 3 is a schematic view of a drive system in the vibration cutting apparatus of the present invention.

FIG. 4 is a graph showing a temperature history due to heat generated by driving an actuator of a drive system in the vibration cutting apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vibration cutting unit 2 Drive system 2a Drive system in Z direction 2b Drive system in X direction 3 Vibration transmission mechanism 4 Processing tool 5 Tool holder 6 (a, b) Elastic hinge 10 XY table 11 Work 12 Work table 13 Frame 14 Z Axis slider 15 Oscillator 16 Amplifier 17 Input cable 20 Temperature detector 21 (a, b, c) Temperature sensor 23 Controller 24 (a, b) Cooling device 25 (a, b) Cooling pipe 27 (a, b, c) Refrigerant flow path 30 Actuator 31 Drive rod 32 Drive shaft housing 33 Fixed member 34 Drive rod guide

Claims (10)

[Claims] 1. A machining apparatus for machining a machining tool by applying vibration to the machining tool by an actuator, comprising: a cooling unit for cooling heat generated by driving the actuator. 2. The cooling device according to claim 1, wherein the cooling means includes a refrigerant flow path provided in a structure holding the actuator for flowing a refrigerant and a circulating means for circulating the refrigerant. Processing equipment. 3. The apparatus according to claim 1, further comprising: a temperature detecting unit configured to detect a temperature change caused by driving the actuator; and a control unit configured to control the cooling unit based on temperature information detected by the temperature detecting unit. Claim 1.
Or the processing apparatus according to 2. 4. The cooling means and the temperature detecting means are provided independently for at least two or more parts, respectively, and the control means based on temperature information of each part detected by the temperature detecting means. 4. The processing apparatus according to claim 3, wherein each of the cooling means corresponding to each part is controlled. 5. The actuator according to claim 1, wherein the actuator is formed of a functional solid element such as a piezoelectric element or a magnetostrictive element, or an actuator using an electromagnetic force. Processing equipment. 6. The processing apparatus according to claim 1, wherein the member holding the actuator and / or the processing tool is formed of a low thermal expansion material. 7. In a machining method for machining by applying vibration to a machining tool with an actuator, a coolant whose temperature is controlled is circulated through a coolant flow path provided in a structure holding the actuator, and heat generated by driving the actuator is provided. Processing method characterized by cooling. 8. A method according to claim 1, wherein a temperature change associated with driving of said actuator is detected, a temperature of a refrigerant and a circulating flow rate are controlled based on the detected temperature information, and heat generated by driving of said actuator is cooled. The processing method according to claim 7, wherein 9. A temperature change caused by driving the actuator is detected in at least two or more portions, and the temperature and circulation flow rate of the refrigerant are individually controlled for each portion based on the detected temperature information of each portion. 9. The processing method according to claim 8, wherein cooling is performed for each part. 10. The actuator according to claim 7, wherein the actuator comprises a functional solid element such as a piezoelectric element or a magnetostrictive element, or an element using electromagnetic force.
The processing method according to any one of the above.