JP2004344916A - Surface processing machine and surface processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface processing machine in which the surface position of a material to be processed can be accurately detected with a simple constitution, and a surface processing method. <P>SOLUTION: A detecting piezoelectric effect element 22 is provided on the lower side of a driving piezoelectric effect element 21. A voltage value of the detecting piezoelectric effect element 22 is changed by the piezoelectric effect when slightly compressed. Therefore, if the changes of the voltage value of the detecting piezoelectric effect element 22 are monitored, the position of the surface 9a of the material 9 to be processed can be detected when a processing tool 23 is brought into contact with the surface 9a of the material 9 to be processed by elongating the driving piezoelectric effect element 21. Such a detecting piezoelectric effect element 22, for example, can be expanded/contracted about 9 μm to the full stroke. The detecting piezoelectric effect element 22, for example, is a laminated piezoelectric effect element which is formed by laminating a large number of thin piezoelectric effect films. The voltage changes can be observed with the compression of about 0.2-0.3 μm as the whole element. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface processing machine that presses a tip of a processing tool against a surface of a workpiece to form irregularities on the workpiece.
[0002]
[Prior art]
For example, a metal thin film having a large number of fine dents or protrusions of several hundreds to several tens of μm formed on its surface can efficiently reflect incident light, and is therefore used as a reflection film of a liquid crystal display device. I have. Such a reflective film is formed by rotating a roller-shaped master mold imitating a fine dent on a resin layer and pressing the same, and laminating a metal thin film on the resin layer on which the fine dent is formed. When creating a roller-shaped mother die in the shape of such a fine dent, the roller-shaped workpiece is rotated, and a processing tool with a sharp tip is intermittently pressed against the workpiece. A fine dent is formed on the surface of the workpiece.
[0003]
A surface processing machine that forms a dent on the surface of a workpiece detects the surface position of the workpiece having various thicknesses, and then forms the dent accurately to a predetermined position based on the surface position. Conventionally, the detection of the surface position of the workpiece has been performed by using the reflection of a laser beam or by detecting the in-focus position by an autofocus device (for example, Patent Document 1).
[0004]
[Patent Document 1]
JP-A-10-47916
[Problems to be solved by the invention]
However, in the reflection of a laser beam and the detection of the surface position of a workpiece using an autofocus device as described above, it is necessary to form a fine dent of several hundred μm to several tens μm such as a reflection film of a liquid crystal display device. The error was too large, and it was difficult to accurately detect the surface position of the workpiece.
[0006]
In addition, the above-described laser beam reflection and detection of the surface position of a workpiece using an autofocus device require a laser light generating device or an optical lens for detecting a focus position, and the like. This was an obstacle to miniaturization and cost reduction.
[0007]
The present invention has been made in view of the above circumstances, and has as its object to provide a surface processing machine and a surface processing method capable of accurately detecting the surface position of a workpiece with a simple configuration.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a surface processing machine that presses a tip of a processing tool against a surface of a workpiece to form irregularities on the workpiece, There is provided a surface processing machine including a piezo piezoelectric effect element for detecting that the tip of the processing tool has contacted the surface of a workpiece, coaxially with a moving direction.
[0009]
According to such a surface processing machine, the piezo piezoelectric effect element for detection is formed on the movement axis of the tip of the processing tool, so the moment when the tip of the processing tool contacts the surface of the workpiece can be detected with high accuracy. Can be detected. These piezo piezoelectric effect elements are inexpensive and show a sharp voltage change with a slight compression, so that a piezoelectric piezo effect element can be used as a processing tool without using an expensive laser device or autofocus device as in the past. By simply providing a surface processing machine, it is possible to realize a surface processing machine that is inexpensive and can accurately detect the processing origin position.
[0010]
A processing tool pressing means for pressing the processing tool against the surface of the workpiece to form irregularities on the workpiece may be provided adjacent to the piezoelectric effect element. Further, the piezo piezoelectric effect element may be processing tool pressing means for pressing the processing tool against the surface of the workpiece to form irregularities on the workpiece. By providing the processing tool pressing means adjacent to the piezoelectric element, it is possible to provide a compact and low-cost surface processing machine with a simple configuration. Further, by using such a piezoelectric effect element as a processing tool pressing means, the structure of the surface processing machine can be further simplified. The workpiece is preferably, for example, substantially cylindrical or cylindrical.
[0011]
A surface processing method in which the tip of a processing tool is pressed against the surface of a workpiece to form irregularities on the workpiece, wherein the contact of the tip of the processing tool with the surface of the workpiece is performed by a piezoelectric element. There is provided a surface processing method including a surface position detecting step of detecting by a voltage change. According to such a surface processing method, it is possible to detect a processing origin position at low cost and with high accuracy by simply providing a piezo piezoelectric effect element on a processing tool without using an expensive laser device or an autofocus device.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view schematically showing a surface processing machine of the present invention. The surface processing machine 10 is roughly divided into a processing unit 11 that processes the workpiece 9 and a control unit 12 that controls the processing unit 11. The processing unit 11 includes a moving device 15 that moves the moving body 14 along the longitudinal direction of the guide shaft 13 (the X direction in the figure), and a rotating device 17 that rotates a rotary chuck 16 that holds the workpiece 9. .
[0013]
A driving unit 19 is attached to the moving body 14 constituting the moving device 15 via a stepping motor 18 (or a servo motor). The stepping motor 18 moves the drive unit 19 up and down to perform rough positioning (coarse movement positioning device). An origin marker 25 is formed at one end of the moving body 14, and an X-axis origin sensor 26 for detecting the origin marker 25 is formed. Alternatively, a method may be used in which point processing for the origin is performed at a certain point on the axis of the workpiece 9 (a place that is not the effective use part). This method is more advantageous in terms of accuracy since it is formed on the workpiece. With the origin marker 25 and the X-axis origin sensor 26, the moving body 14 can be returned to the origin position of the moving device 15.
[0014]
The driving unit 19 includes a driving piezoelectric element 21 serving as a processing tool pressing unit, a detection piezoelectric element 22 for detecting the surface of the workpiece 9, and a processing tool 23 having a tip formed in a predetermined shape. Consists of The operation of the drive unit 19 will be described later in detail.
[0015]
The rotating chuck 16 constituting the rotating device 17 holds the workpiece 9 and rotates the workpiece 9 in the θ direction in the figure. An origin marker 27 is formed at one end of the rotating device 17, and a θ-axis origin sensor 28 for detecting the origin marker 27 is formed. The origin chuck 27 and the θ-axis origin sensor 28 can return the rotary chuck 16 to the origin position of the rotating device 17. In the case where the origin is processed and detected on the workpiece 9, feedback can be performed using a control signal without placing an origin confirmation sensor.
[0016]
The control unit 12 includes a personal computer (PC) 31 that controls the entire surface processing machine 10, a signal conversion device such as a digital-analog conversion unit (D / A conversion unit) 32, and a signal conversion device such as an analog-digital conversion. A (D / A converter) 33, a moving device driver 34, a rotating device driver 35, a piezo piezoelectric element driving driver 38, and a coarse positioning device driver 39. The D / A converter 32 sends a control signal to the stepping motor 18 and the driving piezoelectric effect element 21. The A / D converter 33 feeds back a detection signal output from the piezoelectric sensor 22 for detecting the surface of the workpiece to the D / A converter 32. A moving device driver 34, a rotating device driver 35, and a coarse positioning device driver 39 control the moving device 15, the rotating device 17, and the stepping motor 18 (coarse positioning device), respectively, according to a command from a personal computer (PC) 31. I do. Although FIG. 1 shows an example in which the PC 31 controls the D / A converter 32, the A / D converter 33, the moving device driver 34, and the rotating device driver 35, in order to speed up the exchange of control signals, The moving device driver 34 and the rotating device driver 35 may be formed as a board with a microcomputer.
[0017]
FIG. 2 is an enlarged plan view showing the drive unit. When the piezoelectric element for driving (working tool pressing means) 21 is energized by the piezoelectric effect, its length is elongated, and presses the working tool 23 against the workpiece 9 in the direction of arrow A in FIG. The driving piezo-electric effect element 21 is, for example, a stacked piezo-electric effect element formed by laminating a large number of thin piezo-electric effect films. To expand and contract by about 10 to 100 μm.
[0018]
Connecting means 41 (for example, a curable adhesive) is fixed to the lower surface of the driving piezoelectric effect element 21, and the detecting piezoelectric effect element 22 is connected to the lower side of the driving piezoelectric effect element 21 via the connecting means 41. Attached to. When the detection piezoelectric element 22 is slightly compressed, a voltage is generated and changed by the piezoelectric effect. As a result, if the change in the voltage value of the piezoelectric element for detection 22 is monitored, the moment the processing tool 23 comes into contact with the surface 9a of the workpiece 9 by extending the piezoelectric element 21 for driving, that is, The position of the surface 9a of the workpiece 9 can be detected. Such a piezoelectric element for detection 22 can expand and contract by several μm, for example, about 9 μm in full stroke. The detecting piezoelectric effect element 22 is, for example, a laminated piezoelectric effect element formed by laminating a large number of thin piezoelectric effect films, and a small voltage change can be observed with a compression of about several hundred μm as a whole element. It is.
[0019]
A processing tool fixing means 42 (for example, a chuck jig or an adhesive) is fixed to the lower surface of the detection piezoelectric element 22, and the processing tool 23 is attached to the detection piezoelectric element 22 via the processing tool fixing means 42. Attached to the lower side. The shape of the tip 23a of the processing tool 23 is like a fine dent formed corresponding to the surface 9a of the workpiece 9, and the entire processing tool 23 may be formed of a hard metal or the like. The detection piezoelectric element 22 is formed on the movement axis C of the tip 23a of the processing tool 23. Thus, the detection piezoelectric effect element 22 can reliably detect the moment when the tip 23a of the processing tool 23 contacts the surface 9a of the workpiece 9.
[0020]
Next, the operation of the surface processing machine 10 having the above-described configuration will be described with reference to FIGS. Now, it is assumed that a fine recess (dimple) 41 having a depth d, for example, 1 μm, is formed on the surface 9 a of the workpiece 9. In addition, as the workpiece 9, for example, as shown in FIG. 4, a matrix used for processing the surface of the reflective film 44 used in a reflective liquid crystal display device or the like can be given. The reflection film 44 is formed by forming a large number of extremely fine concave portions 46 smaller than the pixels 45 of the reflection type liquid crystal display device on the surface.
[0021]
The concave portion 46 forming such a reflective film 44 is, for example, a fine depression having a substantially circular or elliptical cross section with a width t of about several hundred μm to several tens μm and a depth of about several hundred μm to several tens μm. By forming a large number of such concave portions 46, the reflection film 44 can diffusely reflect incident light without unevenness. In manufacturing such a reflective film 44, the workpiece 9 is formed by pressing the workpiece 9 against the resin film to form irregularities on the surface in the step of forming a resin film that gives the concave portion 46 to the reflective film 44. Used for
[0022]
First, when starting working on the workpiece 9, the workpiece 9 is fixed to the rotary chuck 16. Next, when a personal computer (PC) 31 instructs processing preparation, the moving body 14 of the moving device 15 is moved until the X-axis origin sensor 26 detects the origin mark 25, and the moving body 14 is set at the origin position. Further, the rotating chuck 16 of the rotating device 17 is rotated until the θ axis origin sensor 28 detects the origin marker 27, and the rotating chuck 16 is set at the origin position. The workpiece 9 may be, for example, a cylindrical metal material. Alternatively, one concave portion may be processed by the drive unit 19 in a state where the workpiece 9 is set on the rotary chuck 16, and the X axis and the θ axis may be returned to the origins using the concave portions as origin markers.
[0023]
With the workpiece 9 set on the rotary chuck 16 and the moving body 14 and the rotary chuck 16 returning to the respective origin positions, the personal computer (PC) 31 is connected to the rotary chuck 16 via the D / A converter 32 as shown in FIG. As shown, the coarse movement positioning device driver 39 is operated by the PC 31 or manually, and the stepping motor 18 is moved to gradually lower the drive unit 19 toward the workpiece 9. Eventually, as shown in FIG. 3B, when the tip 23a of the processing tool 23 contacts the surface 9a of the workpiece 9, the detection piezoelectric element 22 is slightly compressed, and the voltage value changes due to the piezoelectric effect (surface). Position detection step). The change in the voltage value of the detection piezo piezoelectric effect element 22 is output to the A / D converter 33 as a landing signal M of the tip 23a of the processing tool 23.
[0024]
When the landing signal M is input from the detecting piezoelectric element 22 to the A / D converter 33, the A / D converter 33 immediately requests the D / A converter 32 to stop the stepping motor 18. The D / A converter 32 stops the stepping motor 18 and stops the drive unit 19 from lowering. Thus, the drive unit 19 can be stopped in a state where the tip 23a of the processing tool 23 is slightly in contact with the surface 9a of the workpiece 9. The personal computer (PC) 31 defines a position where the tip 23a of the processing tool 23 slightly touches the surface 9a of the workpiece 9 as an origin position.
[0025]
The personal computer (PC) 31 opens a stroke x necessary for the processing tool 23 to pierce the workpiece 9 with reference to the origin position detected by the detecting piezoelectric element 22. The controller 39 requests the drive of the stepping motor 18 (or the servo motor). As shown in FIG. 3c, the stepping motor 18 raises the drive unit 19 to open a stroke x between the tip 23a of the processing tool 23 and the surface 9a of the workpiece 9. The stroke x may be set to, for example, about several μm to several tens μm.
[0026]
The personal computer (PC) 31 stores parameters such as the drive pitch and speed of the X-axis and the θ-axis when forming the dimples 41, and the timing and the number of times, and stores them in the piezo piezoelectric element drive driver. 38, the moving device driver 34, and the rotating device driver 35 can be driven in synchronization with each other. At the same time, the A / D converter 33 stores parameters relating to the drive speed of the detection piezoelectric effect element 22, the depth of the depression, and the like. Thus, the preparation process for forming the dents (dimples) 41 in the workpiece 9 is completed.
[0027]
As described above, in the surface processing machine 10 of the present invention, since the detection piezo piezoelectric effect element 22 is formed on the movement axis C of the tip 23a of the processing tool 23, the tip 23a of the processing tool 23 is It is possible to detect the moment when it comes into contact with the surface 9a with high accuracy. Since such a piezoelectric element for detection 22 is inexpensive and shows a sharp voltage change with a slight compression, it is possible to use a processing tool 23 without using an expensive laser device or autofocus device as in the related art. Only by providing the piezo piezoelectric effect element, it is possible to realize the surface processing machine 10 capable of detecting the processing origin position with low cost and high accuracy.
[0028]
Thereafter, when the surface processing machine 10 starts the processing operation, as shown in FIG. 3D, the D / A converter 32 energizes the driving piezoelectric effect element 21 to drive the driving piezoelectric piezoelectric element by "depth d + stroke x". The effect element 21 is extended. As a result, the tip 23a of the processing tool 23 reaches the surface 9a of the workpiece 9, and at this time, a voltage signal is generated by the piezoelectric effect from the piezoelectric element 22 for detection, and the D / A is transmitted through the A / D converter 33. By setting a trigger on the conversion unit 32 and then extending the driving piezoelectric element 21 by the desired dimple depth, the work material 9 is provided with a dent (dimple) 41 having an arbitrary desired depth d. It is formed.
[0029]
The personal computer (PC) 31 controls the rotating device 17 via the rotating device driver 35 to rotate the rotating chuck 16 at a predetermined pitch in the θ direction in FIG. By performing this simultaneously or one by one, the work material 9 is provided with various recesses 41 having a depth d at predetermined intervals, such as a substantially spiral shape, a parallel shape in the X-axis direction, and a parallel shape in the θ-axis direction. It can be formed in a pattern. When the workpiece 9 is processed to a predetermined distance from the origin, the moving body 14 and the rotary chuck 16 are returned to the origin positions by the X-axis origin sensor 26 and the θ-axis origin sensor 28, and are shifted by a predetermined pitch. By performing the processing with different parameters from, and repeating this process, a large number of fine dents 41 can be accurately formed on the cylindrical workpiece 9 over the entire peripheral surface.
[0030]
It is to be noted that when the workpiece 9 is fixed to the rotary chuck 16 of the surface processing machine 10 by using the detection piezoelectric element 22 for detection, a deviation from the center is detected, and the deviation is corrected during the processing. You can also. When forming the recess 41 in the workpiece 9 with high precision, it is necessary to fix the workpiece 9 accurately to the center of rotation of the rotary chuck 16 so that the workpiece 9 does not shake during rotation. There is. When the centering of the workpiece 9 is performed, as shown in FIGS. 5A and 5B, for example, the circumferential direction θ of the workpiece 9 is divided by 45 ° and 0 ° = a, 45 ° = b ,... 315 ° = h. X1, X2,..., X6, X7 in the X-axis direction of the workpiece 9 at regular intervals, and X1-a, X1-b,. Measurement points are set at equal angles and at equal intervals, such as -g, X7-h.
[0031]
Then, using the voltage change of the piezoelectric element for detection 22 generated when the tip 23a of the processing tool 23 comes into contact with the surface 9a of the workpiece 9, the processing tool 23 pulled up to a certain height is subjected to each of the above-described measurements. X7-g, X7-h are lowered at points X1-a, X1-b,..., And X7-h, and the amount of drop of the processing tool 23 to the surface 9a of the workpiece 9 at each measurement point is measured.
[0032]
As shown in FIG. 5C, when the vertical axis represents the circumferential direction θ of the workpiece 9 and the horizontal axis represents the X-axis direction of the workpiece 9, the amount of drop at each of these measurement points is represented in a table. The deviation between the center C of the rotary shaft 9 and the rotation center of the rotary chuck 16 can be easily grasped. On the basis of the data on the mounting deviation of the workpiece 9 obtained in this manner, the stepping motor 18 is increased or decreased from a preset reference value in accordance with the amount of blurring when the workpiece 9 is processed, so that Can accurately form a concave portion having a set predetermined depth.
[0033]
The configuration of the drive unit of the surface processing machine is not limited to the above-described embodiment. For example, as shown in FIG. 6A, the detection piezoelectric piezoelectric effect element 22 and the drive piezoelectric piezoelectric element 21 A structure in which the processing tool 23 is attached via the leaf spring 51 may be adopted. Such a leaf spring 51 plays a role of preventing self-destruction due to extension of the piezoelectric effect element by applying a preload to the driving piezoelectric effect element 21 and the detection piezoelectric effect element 22.
[0034]
As shown in FIG. 6B, the driving piezo-electric effect element 21 is surrounded by a leaf spring 52, and the detecting piezo-electric effect element 22 is attached via the leaf spring 52. A configuration in which a processing tool 23 is attached to the processing tool 22 may be used. Such a leaf spring 51 also serves to prevent self-destruction due to extension of the piezoelectric effect element itself by applying a preload to the driving piezoelectric element 21.
[0035]
Further, in each of the above-described embodiments, the driving piezoelectric element 21 for processing the workpiece, the detection piezoelectric element 22 for detecting the surface of the workpiece, and the two piezoelectric elements are provided. However, it is also possible to use these two piezo-piezoelectric effect elements to perform elongation and to detect the surface of the to-be-processed material by using one piezo-piezoelectric effect element to process the work.
[0036]
【The invention's effect】
As described above in detail, according to the present invention, according to such a surface processing machine, the piezo piezoelectric effect element for detection is formed on the movement axis of the tip of the processing tool. It is possible to reliably and accurately detect the moment when the object comes into contact with the surface of the workpiece. These piezo piezoelectric effect elements are inexpensive and show a sharp voltage change with a small compression.Therefore, the piezo piezoelectric effect element can be used as a processing tool without using an expensive laser device or autofocus device as in the past. By simply providing a surface processing machine, it is possible to realize a surface processing machine that is inexpensive and can accurately detect the processing origin position.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing an outline of a surface processing machine of the present invention.
FIG. 2 is an enlarged plan view of a drive unit of the surface processing machine shown in FIG.
FIG. 3 is an explanatory diagram illustrating the operation of the surface processing machine of the present invention.
FIG. 4 is a plan view showing an example of a reflection film formed of a workpiece.
FIG. 5 is an explanatory diagram illustrating a procedure for centering a workpiece using the surface processing machine of the present invention.
FIG. 6 is a plan view showing another embodiment.
[Explanation of symbols]
9 Workpiece 9a Surface 10 Surface processing machine 18 Stepping motor 21 Piezoelectric piezoelectric element for driving (working tool pressing means)
22 Piezoelectric detecting element 23 for detection 23 Processing tool 23a Tip 41 Depression (dimple)

Claims (5)

A surface processing machine that presses a tip of a processing tool against a surface of a workpiece to form irregularities on the workpiece,
A surface processing machine comprising a piezo piezoelectric effect element for detecting that the tip of the processing tool has contacted the surface of the workpiece, coaxially with the moving direction of the tip of the processing tool. 2. The surface processing according to claim 1, further comprising a processing tool pressing unit that presses the processing tool against a surface of the workpiece to form irregularities on the workpiece, adjacent to the piezoelectric element. Machine. 2. The surface processing machine according to claim 1, wherein the piezo piezoelectric effect element is a processing tool pressing unit configured to press the processing tool against a surface of the workpiece to form irregularities on the workpiece. 3. The surface processing machine according to any one of claims 1 to 3, wherein the workpiece has a substantially cylindrical shape or a cylindrical shape. A surface processing method in which a tip of a processing tool is pressed against a surface of a workpiece to form irregularities on the workpiece,
A surface processing method comprising: a surface position detecting step of detecting, by a voltage change of a piezoelectric element, that a tip of the processing tool has contacted a surface of a workpiece.

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