JP2009195955A - High-accuracy laser beam processing and laser beam-electrolysis composite processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-accuracy laser beam processing apparatus which is innovative and highly unique by adopting a construction that can measure the shape, position, and posture of a very small workpiece and its position relative to a laser beam using a laser beam source for processing. <P>SOLUTION: The high-accuracy laser beam processing apparatus comprises a work holding error correcting means that measures the initial position of a workpiece with a measuring laser beam, measures a rotated position after the rotation of the workpiece at a predetermined angle with a work holding means, grasps a three-dimensional position of the workpiece with a control unit, and determines a processing irradiation point of the workpiece to correct a holding error of the workpiece. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a laser processing apparatus, in particular, a high-precision laser processing and electrolytic finishing processing of small-diameter shaft processing objects such as vascular dilation stents, circuit inspection contact probes, injection needles, and medical inspection probes. The present invention relates to laser processing and a combined laser / electrolytic processing apparatus.

There has been an increasing demand for surgical catheters applied to cardiac surgery and brain surgery, medical catheters such as stents, tubes, and probes for high-density electronic circuit inspection that require small diameter and high flexibility.
The market for medical catheters and tubes is about 181.9 billion yen (according to Yano Research Institute Inc., 2006), which is increasing compared to the previous year. In particular, the developing microcatheter market is expected for brain surgery. Resin, coiled small-diameter wire, knitted small-diameter wire, etc. are used for the catheter and stent material, but relatively high-rigidity stainless steel metal tubes are often used. It is necessary to form a complicated shape on the surface of the thin tube material in order to have functions such as expanding the diameter, achieving both rigidity and flexibility, cutting the skin for injection, reducing friction, and collecting blood. It is. In particular, it is very difficult to form complex shapes on the surface because a microcatheter with a diameter of 0.2 mm or less is required in brain surgery. Machining and electrical discharge machining are currently used to process medical catheters and tubes and circuit inspection probes. However, it takes an extremely long time to process complex and fine shapes. There is a problem that it cannot be made smaller. In order to solve these problems, it is conceivable to use laser machining that does not generate machining force due to non-contact machining and does not require complicated control of the workpiece and tool (electrode) gap.
When applying laser processing, it is difficult to detect the relative position between the workpiece and the tool because of non-contact processing. In addition, it is a common problem for all processing methods to hold minute parts such as catheters, stents and probes with high accuracy.

On the other hand, laser processing apparatuses that perform minute laser processing, such as removal processing, on a processing target (hereinafter also referred to as “workpiece”) with a processing laser beam are conventionally used.
As this type of laser processing equipment, in addition to the processing laser light source that emits processing laser light, the processing laser light has a wavelength different from that of the processing laser light in order to align the focus of the processing laser light and the workpiece. A laser processing apparatus having a measurement laser light source that emits light is known (see, for example, Patent Documents 1 and 2).

In the laser processing apparatus described in Patent Document 1, measurement laser light reflected by a work is incident on a photodetector through a pinhole mask, and the height of the material is measured using a confocal effect. The focal height of the processing laser is adjusted.
In the laser processing apparatus described in Patent Document 2, the measurement laser light emitted from the measurement laser light source and reflected by the workpiece is incident on the CCD camera. Then, the height in the cylinder is measured based on the result of photographing with the CCD camera and the amount of light received by the photodetector, and the irradiation position of the processing laser is adjusted based on the information.
In the laser processing apparatuses described in Patent Documents 1 and 2, a part of the optical path from the processing laser light source to the work and a part of the optical path from the measurement laser light source to the work are common.

Furthermore, the laser processing apparatus described in Patent Document 3 measures the Z-axis direction of a workpiece using a measurement laser, and measures the X- and Y-axis directions by photographing the workpiece with a CCD camera.
JP 2002-321080 A Japanese Patent Laid-Open No. 2005-161387 JP 2004-243383 A

  The laser processing apparatuses described in Patent Documents 1 and 2 use two laser sources, a processing laser and a measurement laser, and there is a problem in that both installation errors are reflected in the measurement error. In addition, basically only position information in the Z direction can be measured, and the axial posture cannot be measured.

  Further, the laser processing apparatus described in Patent Document 3 uses two laser sources, that is, a processing laser and a measurement laser, and there is a problem in that both installation errors are reflected in the measurement error. In addition, since the measurement in the X and Y axis directions is performed only at a preset reference machining point, accurate workpiece placement is required. Furthermore, the measurement of the shaft attitude cannot be performed.

Small diameter shafts such as vascular dilating stents, circuit inspection contact probes, injection needles, and medical inspection probes that are difficult to hold and transport are difficult to accurately place on a processing machine. It is very difficult to process the shape.
If the posture of the workpiece can be measured on the machine and the holding error can be corrected, it is possible to accurately irradiate the processing point on the workpiece with the laser without setting the workpiece with high accuracy.
There are many processing systems that measure the shape of a workpiece with a measuring laser and perform laser removal processing as necessary. However, since the measuring laser and the processing laser are not the same, the measurement point and the processing point are different. If processing and measurement are performed with the same light source, the measurement point and the processing point can be made the same.
Conventionally, the axial position is imaged and measured using a CCD, measuring laser, etc., and the axial position is corrected based on these data. In this case, in addition to the processing optical system, the measuring optical system, Not only does it require lighting, it causes problems such as a decrease in the movable area and an enormous system.
On the other hand, there is a problem that a heat-affected layer (HAZ), burrs and the like are generated on the surface of the material after laser processing.

The present invention provides a breakthrough by enabling measurement of the shape, position, orientation, and relative position of a laser with a single light source from a laser head that emits a processing laser and a measurement laser. It is an object to provide an accurate and unique high-precision laser processing apparatus. At this time, if the shape of the minute workpiece is known, measurement of the workpiece shape in the laser emission direction (Z-axis direction) can be omitted.
In addition, since the present invention assumes a medical part as one of the processed products, the machining amount is highly efficient by avoiding mechanical processing that generates burrs in the fine shape finishing after laser processing, An object of the present invention is to provide a high-precision laser processing apparatus that can be controlled with high accuracy and can minimize the amount of material removal necessary for finishing.

To achieve the above object, a high-precision laser processing apparatus of the present invention includes a laser processing apparatus and a spindle that supports a work holder, and a moving stage that relatively moves the laser processing apparatus and the spindle in the XYZ directions, The laser processing apparatus includes a laser oscillator, a laser head as laser beam emitting means for emitting a processing laser beam and a measurement laser beam, and a reflected light amount for measuring the reflected light amount of the measurement laser beam reflected by the workpiece. Measuring means, an imaging device capable of photographing a workpiece using reflected light of measurement laser light, an optical system for forming an optical path of processing laser light and measurement laser light emitted from a laser head, and processing Laser beam for measurement and laser beam for measurement, arranged at a position away from the workpiece with respect to the laser head in the optical axis direction of the laser beam for measurement and laser beam for measurement A reflecting plate, a moving stage, a laser oscillator, a reflected light amount measuring means, and a control means for controlling the image sensor are provided, and an initial position of the work is measured using the measurement laser beam, and the work is held by the work holding means. It is provided with a work holding error correcting means for measuring a rotational position when the angle is rotated, grasping a three-dimensional position of the work by the control means, and correcting a work holding error by obtaining a processing irradiation point of the work. It is a feature.
The high-precision laser processing apparatus of the present invention includes a spindle that supports the laser processing apparatus and the work holder, and a moving stage that relatively moves the laser processing apparatus and the spindle in the XYZ directions. A laser head as a laser beam emitting means for emitting a laser oscillator, a processing laser beam, and a measuring laser beam, an imaging device capable of photographing a workpiece using reflected light of the measuring laser beam, and a laser head The optical system for forming the optical path of the machining laser beam and measurement laser beam and the optical axis direction of the machining laser beam and measurement laser beam are arranged at a position farther from the workpiece than the laser head. And a reflector that reflects the measurement laser beam, and a control that controls the moving stage, the laser oscillator, the reflected light amount measuring means, and the image sensor. And measuring the initial position of the workpiece using the measuring laser beam and the rotation position when the workpiece is rotated by a predetermined angle by the workpiece holding means, and grasping the three-dimensional position of the workpiece by the control means. A workpiece holding error correcting means for correcting a workpiece holding error by obtaining a processing irradiation point of the workpiece is provided.

  Further, the laser / electrolytic composite machining apparatus of the present invention is the high-precision laser machining apparatus, wherein the electrolytic machining apparatus is placed on a stage on which the laser machining apparatus is placed so as to be adjacent to the laser machining apparatus. It is a feature.

The present invention has the following excellent effects.
(1) Since shape measurement is performed with a light source from a single laser head that emits a processing laser and a measurement laser, shape measurement / processing with no deviation between the measurement position and the processing position is possible.
(2) By enabling measurement of the workpiece shape, position, orientation, and relative position with the laser, the laser can be accurately measured even for workpieces with non-constant holding positions or workpieces with holding errors. Can be irradiated to any position.
(3) Since a measurement laser and a dedicated optical system are not required, the system can be dramatically reduced in size.

(4) By controlling the finishing area and the machining amount with high efficiency and high accuracy by changing the amount of electrolytic current by performing the electrolytic finishing to avoid the machining that generates burrs. Is possible. Further, by minimizing the amount of material removal necessary for finishing, it is possible to add functions such as high flexibility and expandability while maintaining high pipe rigidity.
(5) In many cases, the process of attaching / detaching the electrode to / from the workpiece is a bottleneck in electrolytic machining, especially in the case of micro workpieces. According to the laser / electrolytic sequential processing apparatus performed in step 1, this problem can be solved by making the electrolytic processing power supply and the work holding mechanism conductive.

  Hereinafter, embodiments of the high-precision laser processing and laser / electrolytic composite processing apparatus of the present invention will be described in detail with reference to the drawings. However, the present invention is not construed as being limited thereto, and Various changes, modifications, and improvements can be made based on the knowledge of those skilled in the art without departing from the scope of the invention.

[Embodiment 1]
FIGS. 1 and 2 illustrate the first embodiment, and show a case where the workpiece shape is not known.
(Schematic configuration of high-precision laser processing and laser / electrolytic composite processing equipment)
FIG. 1 is a diagram schematically showing a schematic configuration of a high-precision laser machining and laser / electrolytic complex machining apparatus according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram for explaining the laser processing apparatus of the high-precision laser processing and laser / electrolytic composite processing apparatus of FIG.

In FIG. 1, a laser processing device 4 and an electrolytic processing device 5 are placed on the moving stage 1, and a rotating stage 3 that supports a spindle 6 is placed on the moving stage 2.
A stage driver (not shown; the same applies hereinafter) moves the moving stage 1 in the Y direction (perpendicular to the paper surface), the moving stage 2 in the X and Z directions, and the rotating stage 3 It is rotated in the direction indicated by arrow R.
When the moving stage 2 on which the spindle 6 is placed is configured to move in the XYZ directions, the moving stage 1 can be a fixed stage. In short, the laser processing apparatus 4 and the electrolytic processing apparatus 5 and the spindle may be configured to be relatively movable in the XYZ directions.
The workpiece holder 11 holds a workpiece 15 which is a small diameter shaft processing object, such as a vascular expansion stent, a circuit inspection contact probe, an injection needle, a medical inspection probe, and the like, and is supported by the spindle 6. And is driven to rotate around the central axis of the spindle 6 (see arrow C in FIG. 1).

The laser head 7 of the laser processing apparatus 4 is connected to a laser oscillator 8, and the electrolytic electrode 10 of the electrolytic processing apparatus 5 and the work holder 11 of the spindle 6 are connected to a power supply 9 for electrolytic processing.
The control PC 12 constituting the control means acquires information from the stage driver, the laser oscillator 8, the electrolytic processing power source 9, and the light receiving elements 13, 99 and the image sensor 14 described later, and controls each of them.

(Laser processing equipment)
The laser processing apparatus 4 will be described with reference to FIG.
The laser processing apparatus 4 is a laser beam emitting unit that emits a processing laser beam for processing the workpiece 15 and a measuring laser beam for aligning the focal point of the processing laser beam with the workpiece 15. The laser head 7, the light receiving element 13 as a laser output fluctuation measuring means from the laser head 7, and the light receiving element 99 as a reflected light quantity measuring means for measuring the reflected light quantity of the measurement laser beam reflected by the work 15. An imaging device 14 capable of photographing the workpiece 15 using reflected light of the measurement laser light, and an optical system 16 for forming an optical path of the processing laser light and the measurement laser light emitted from the laser head 7. It has.
In addition, the laser processing device 4 is disposed at a position away from the work 15 with respect to the laser head 7 in the optical axis direction of the processing laser light and the measurement laser light, and reflects the measurement laser light. 17.

Hereinafter, the processing laser beam and the measurement laser beam are collectively expressed as “laser beam”. In the following description, the left-right direction in FIG. 1 (that is, the optical axis direction of the laser light applied to the workpiece 15) is expressed as the Z direction, the vertical direction on the paper is the Y direction, and the vertical direction is the X direction.
Further, in this embodiment, the optical axis direction of the laser light applied to the workpiece 15 is perpendicular to the processing surface, but the present invention can also be implemented by irradiating with an angle.

  The optical system 16 includes a lens 18, a mirror 19, a beam sampler 20, a beam splitter 98, light receiving elements 13 and 99, an imaging element 14, a lens 21, and an objective lens 22.

  The beam sampler 20 transmits most of the laser light emitted from the laser head 7 and guided by the lens 18 and the mirror 19 toward the objective lens 22 and reflects the remaining laser light toward the light receiving element 13. The beam sampler 20 reflects part of the measurement laser light reflected by the workpiece 15 and the reflection plate 17 toward the beam sampler 98. The objective lens 22 condenses the laser light that has passed through the lens 21 onto the work 15. The beam sampler 98 transmits part of the measurement laser light reflected by the workpiece 15 and the reflection plate 17 to the image sensor 14 and reflects it to the light receiver 99.

  The laser head 7 and the laser oscillator 8 are, for example, fiber lasers, and output the processing laser light and the measurement laser light as described above. The output of the measurement laser beam is much smaller than the output of the processing laser beam. For example, the output of the measurement laser beam is about 1/20 of the output of the processing laser beam. Further, the laser head 7 according to the present embodiment emits a processing laser beam having a stable output in order to perform appropriate processing of the workpiece 15.

  The light receiving elements 13 and 99 are composed of elements such as photodiodes and phototransistors. The light receiving elements 13 and 99 measure the variation in the output light amount from the laser head 7 and the reflected light amount of the measurement laser light reflected by the work 15 by converting the received light amount into an electric amount.

  The image sensor 14 is an image sensor such as a CCD or a CMOS. The imaging element 14 is arranged so that the position where the reflected light of the workpiece 15 forms an image is the light receiving surface of the imaging element 14 when the workpiece 15 is at the position of the focus F of the measurement laser beam.

  The reflector 17 reflects the measurement laser light when the work 15 is at a position deviated from the focus F of the measurement laser light in the X direction. As will be described later, the reflecting plate 17 is used to detect the end of the work 2 in the X and Y directions. The reflecting plate 17 of this embodiment is formed of a ceramic member or a metal member.

  In FIG. 1, a laser oscillator 8, light receiving elements 13 and 99, an image pickup element 14, an electrolytic processing power source 9, moving stages 1 and 2, and a stage driver that drives the rotary stage 3 are connected to the control PC 12. As described above, the control PC 12 performs various controls of the laser processing apparatus 4, the electrolytic processing power source 9, and the stage driver. For example, the control PC 12 outputs a laser beam emission command or a stop command to the laser head 7. Further, the control PC 12 specifies the Z-direction position of the focal point F of the measuring laser beam based on the reflected light amount measured by the light receiving element 99 and drives the moving stage 2 to move the workpiece 15 to the focal point F position. To do. In addition, the control PC 12 includes a processing state detection unit that detects a processing state of the processing object based on the change in the amount of reflected light, and controls a laser beam stop command and the like according to the processing state. Further, the control PC 12 performs a calculation for normalizing the output fluctuation of the measurement laser beam using the light amount measured by the light receiving element 13.

(Principle of detection of Z direction position of focus of laser beam for measurement)
FIG. 3 is a graph showing the relationship between the position of the work 15 shown in FIG. 1 in the Z direction and the amount of reflected light measured by the light receiving element 99.

  When the output of the measurement laser beam emitted from the laser head 7 is constant, the relationship between the reflected light amount of the measurement laser beam measured by the light receiving element 13 and the Z-direction position of the workpiece 15 is shown in FIG. As shown by a solid line G in FIG. That is, when the workpiece 15 is in the position of the focus F of the measurement laser beam in the Z direction, the amount of reflected light measured by the light receiving element 99 becomes the maximum value L, and the workpiece 15 is moved from the focus F to the objective lens 22 side or the reflector. The amount of reflected light measured by the light receiving element 99 decreases with increasing distance toward the 17 side.

  Therefore, when the output of the measurement laser beam is constant, the reflected light quantity of the measurement laser beam is measured by the light receiving element 13 while moving the workpiece 15 in the Z direction by the moving stage 2, and the maximum point M is determined. By specifying and measuring the Z-direction position of the workpiece 15 corresponding to the maximum point M, the Z-direction position of the focal point F of the measurement laser beam is detected.

(Principle of detection of X and Y direction end of work)
FIG. 4 is a diagram illustrating an example of an image captured by the image sensor 14 when the measurement laser light is reflected by the reflecting plate 17 illustrated in FIG. 1.

  In this embodiment, the measurement laser beam reflected by the reflecting plate 17 is used to detect the ends of the workpiece 15 in the X and Y directions. Hereinafter, for convenience of explanation, an X-direction end 15b (see also FIG. 2) of the rectangular parallelepiped workpiece 15 is detected as an example, and the X- and Y-direction end portions of the workpiece 15 of this embodiment are taken as an example. The detection principle will be described.

  Before detecting the X-direction end 15b of the work 15, first, the position of the focus F of the measurement laser beam in the Z direction is detected by the above-described method, and the work 15 and the focus F are aligned. That is, as shown in FIG. 2, the alignment of the surface of the work 15 and the focal point F is performed in the Z direction. In this state, a focus corresponding point F1 corresponding to the focus F is set on the video imaged by the image sensor 14 (see FIG. 4). Thereafter, the workpiece 15 is moved in the Y direction by the moving stage 1 and is disposed at a position out of the focus F in the Y direction.

  When the work 15 is out of the focus F in the Y direction, for example, the image shown in FIG. That is, a part of the measurement laser light irregularly reflected by the reflecting plate 17 is blocked by the work 15, so that the work corresponding area 15c corresponding to the work 15 on the image taken by the image sensor 14 becomes dark, and the other The area becomes brighter. In addition, since the position of the surface of the work 15 and the focal point F is aligned in the Z direction, the end corresponding line 15d corresponding to the Y direction end of the work 15 is on the image captured by the image sensor 14. Clearly identified by That is, the end 15d in the Y direction of the work 15 is detected.

  When the end corresponding line 15d is clearly specified, a distance Y1 in the Y direction between the end corresponding line 15d and the focus corresponding point F1 is calculated. That is, the distance between the Y-direction end 15d and the focal point F is calculated. Further, since the Y direction end portion 15d and the machining portion and distance of the workpiece 15 are known in advance in design, the distance in the Y direction from the focal point F to the machining portion of the workpiece 15 is calculated. Similarly, the end portion of the workpiece 15 in the X direction is also detected, and the distance in the Z direction from the focal point F to the machining site of the workpiece 15 is calculated. Further, the calculation of the distance from the focal point F to the processing part of the workpiece 15 is performed by the control PC 12.

(Work thickness measurement)
FIG. 5 is a flowchart showing a procedure for measuring the thickness of the workpiece 15 in the high-precision laser processing and laser / electrolytic composite processing apparatus shown in FIG. In the high-precision laser processing and laser / electrolytic composite processing apparatus configured as described above, the thickness of the workpiece 15 is measured as follows.

  First, the moving stage 1 and 2 move the laser device 4 and the workpiece 15 relative to each other in the X and Y directions, and the workpiece 15 is arranged at a position where the laser beam emitted from the laser head 7 is irradiated (step S1). ). Thereafter, a laser beam for measurement is emitted from the laser head 7 (step S2), and the amount of reflected light is measured by the light receiving element 99 (step S3).

  Thereafter, the work 2 is arranged in a predetermined range in the X direction, and it is determined whether or not the reflected light amount is measured at each arrangement position (step S4). Specifically, in step S4, it is determined whether or not the work 15 is arranged in a predetermined range including the position of the focal point F of the measurement laser beam in the Z direction, and the amount of reflected light is measured at each arrangement position. When the measurement is not performed within the predetermined range, the process returns to step S3.

On the other hand, when the amount of reflected light is measured within a predetermined range, the position in the Z direction of the focus F of the measurement laser beam is detected (step S6).
The Z-direction position of the focus F of the measurement laser beam at this time represents the thickness of the work 15 in the X and Y directions.

  Thereafter, the workpiece 15 is moved in the X and Y directions by the moving stages 1 and 2, and the thickness of the workpiece 15 in each X and Y direction is measured (step 7). When the height of the work 15 is detected in a certain area in the X and Y directions, a flag is set at a position where machining is determined to be necessary, and the machining position is specified (step S8). After the processing position of the workpiece 15 is specified, a laser beam for processing is emitted from the laser head 7 to the specified processing position to perform laser processing of the workpiece 15. Further, the measurement laser beam may be mixed into the processing laser beam, and the operation may be repeated up to a predetermined reflected / scattered light amount.

  In the first embodiment, step S2 is a measurement laser light emission step for emitting measurement laser light from the laser head 7, and step S3 is a characteristic of the measurement laser light reflected by the workpiece 15. This is a reflected light characteristic measurement step for measuring the amount of reflected light, which is one, and step S6 is a focus detection step for detecting the position of the focus F of the measurement laser light.

The above-described measurement of the workpiece thickness includes an XYZ position measurement process of the workpiece 15, but when strict accuracy is not required for machining of the workpiece to be machined, for example, the shape and structure of the workpiece are known in advance. In the case where it is sufficient to machine a preset machining position and machining amount, it is possible to omit the XYZ position measurement step (S3 to S6 above) and determine the focal position of the workpiece in the following manner. .
(1) After S <b> 2 in FIG. 5, the workpiece is placed at a position where it can be processed by calculating from the shape and dimensions of the workpiece.
(2) Use an optical system (arrangement of a condensing lens or the like having a long focal length) in which the irradiation laser spot change caused by the processing depth change accompanying the progress of processing does not have a fatal effect on the measurement of the residual processing thickness.
(3) The machining position and machining amount of the workpiece are determined in advance from the shape and dimensions of the workpiece, and the workpiece is appropriately moved in the X direction within a range that does not have a fatal effect on the measurement of the remaining machining thickness as the machining progresses. .

(Workpiece axis center measurement)
In order to measure the axial center of a small-diameter axial workpiece that is a workpiece in this embodiment, the workpiece 15 is moved in the X and Y directions by the moving stages 1 and 2, and the measurement laser beam is emitted from the laser head 7. The measurement laser beam reflected by the reflecting plate 17 is photographed by the image sensor 14, and the height at which the boundary between the portion where the reflected light is detected and the portion blocked by the workpiece 15 is in focus is determined. The axis center height.

(Correction of workpiece holding error)
As shown in FIG. 6, when the workpiece 15 is not accurately held with respect to the workpiece holder 11, correct processing cannot be performed even if the original processing position is irradiated with laser. Therefore, it is necessary to grasp the workpiece holding error and move the laser irradiation position.
In this embodiment, as described below, the control PC measures the initial position of the workpiece 15 using the measurement laser beam and the rotational position when the workpiece 15 is rotated by a predetermined angle by the workpiece holder 11. Is provided with means for correcting the holding error of the workpiece by grasping the three-dimensional position of the workpiece and obtaining the processing irradiation point of the workpiece 15.

As an example, as shown in FIG. 7, it is assumed that the microtubule as the work 15 is eccentric from the rotation center, that is, the rotation center s of the spindle 6.
In the measurement, the center coordinates of the microtubule are calculated from the position of the edge in the radial direction of the microtubule in consideration of the tube diameter of the microtubule. Only the center coordinates of the microtubules are shown below.
The coordinate axes X, Y, and Z are coordinate axes of the high-precision laser processing and laser / electrolytic composite processing apparatus of the present invention, and the positions yc and zc in the Y and Z directions on the coordinate axes X, Y, and Z of the rotation center s of the microtubule. Is unknown.

<Measurement 1>
As shown in FIG. 8, in the initial position of the microtubules is measured using the measurement laser beam position y ₀ and Y-direction tilt Vy of the Y-direction.
The Y-direction position y at the x point of the microtubule is
y = V _y x + y ₀ (1)
It becomes.

<Measurement 2>
As shown in FIG. 9, the microtubule is rotated 90 ° clockwise from the initial position, and the position z ₀ in the Z direction and the inclination Vz in the Z direction are measured using the measurement laser beam at the rotation position.
The z-direction position z at the x point of the microtubule is
z = V _z x + z ₀ (2)

<Measurement 3>
As shown in FIG. 10, the microtubules are rotated 180 degrees clockwise from the initial position in its rotational position, the position in the Y direction y ^- ₀ and Z direction of the Y-direction tilt V ^- a measuring laser beam y Use to measure.
The Y-direction position y ^{− at} the x point of the microtubule is
_{^{y - = V - y x +}} y - 0 (3)
And
V ^- _y = -V _{y
^{y 0 + y - 0 = y}} + y - = 2y c
There is a relationship.

When calculating the y position y _c of the rotation center of the microtubule from the equations (1) and (3),
^{_{y c = (y 0 + y}} - 0) / 2 = (y p + y - p) / 2 (4)

Next, based on FIG. 11, how to obtain the processing irradiation point of the microtubule will be described.
Y at the processing point X = _{x p,} Z coordinate values formula (1) (2) from _{y p = V y x p +} y 0
_{z p = V z x p +} z 0

The deviation from the center of rotation of the microtubule is calculated using the result of equation (4),
y ′ = (y _p −y _c )
z ′ = (z _p -y _c )
It is.
Therefore, the Y and Z coordinate values at the machining point when the microtube is rotated by the rotation angle θ are
Y = y′cos θ + z′sin θ + y _c
Z = −y′sin θ + z ′ cos θ + z _c
However, as can be seen from the above equation, the match strictly processing point in the Z-axis direction position of the focal point of the processing laser it is necessary to separately measure the z _c.

  Since the workpiece holding error can be corrected as described above, the workpiece holding mechanism has a relatively poor holding accuracy but can hold the workpiece quickly and easily, for example, a mechanism that sandwiches the workpiece between parallel plates. It is possible to apply. Furthermore, if the same mechanism is used, it is possible to hold the holder without changing the workpiece diameter even if the workpiece diameter changes.

(Electrolytic processing equipment)
The re-solidified product and heat-affected layer are present on the workpiece surface after laser processing, and the product is incomplete. To finish this, there are mechanical polishing, chemical polishing, etc., but machining microtubules with a diameter of 0.5 to several millimeters is not suitable due to the rigidity of the workpiece, In this case, there are problems such as difficulty in controlling the solution temperature and a long processing time.
In this embodiment, as shown in FIG. 1, the electrolytic processing apparatus 5 is placed on the moving stage 1 on which the laser processing apparatus 4 is placed so as to be adjacent to the laser processing apparatus 4. The workpiece 15 held in the position can be freely moved to the vicinity of the electrolytic processing tank 25 and the electrolytic electrode 10.
When the movable stage 2 on which the spindle 6 is placed is configured to be movable in the XYZ directions, the movable stage 1 can be a fixed stage. In short, the laser processing apparatus 4 and the electrolytic processing apparatus 5 What is necessary is just to be comprised so that a spindle and relative movement can be carried out to a XYZ direction.

  After the workpiece 15 is laser processed by the laser processing apparatus 4, the workpiece 15 is moved to the electrolytic processing tank 25 while being held by the workpiece holder 11. When the work holder 11 and the electrolytic electrode 10 of the spindle 6 are electrically connected to the power supply 9 for electrolytic processing, electrolytic finishing can be performed with the holding state at the time of laser processing. At that time, the relative distance between the workpiece 15 and the electrolytic electrode 10 is obtained from the measurement result at the time of laser processing and the relative position of the spindle 6 and the electrolytic electrode 10 measured in advance, and the workpiece position suitable for electrolytic processing is performed by stage control. Processing can be performed.

  Laser / electrolytic composite processing that performs electrolytic finishing after laser processing enables processing of microtubules with a diameter of 0.1 mm or less, and the amount of finishing processed compared to mechanical processing + mechanical polishing or mechanical processing + chemical polishing Therefore, the machining efficiency becomes about 10 times, it is burr-less, the residual stress can be reduced, and the residual abrasive grains can be eliminated.

The process of machining the workpiece will be described as follows.
(1) The design shape is input to the control PC 12.
(2) The work 15 is installed on the work holder 11.
(3) The work 15 is moved between the condensing optical system 16 and the reflecting plate 17.
(4) Laser measurement of workpiece holding error.
(5) Laser machining of the workpiece 15 is performed while performing stage control for machining the design shape while correcting the workpiece holding error from the measurement result and turning on / off the machining laser.
(6) The workpiece 15 is moved to the electrolytic processing rod 25. An electrolytic processing power source is conducted to the work holder 11 and the electrolytic electrode.
(7) Perform electrolytic finishing.

[Embodiment 2]
12 and 13 are for explaining the second embodiment, and show a case where the workpiece shape is known.
In the second embodiment, since the method of specifying the Z-direction position of the focal point F of the measurement laser beam based on the image information of the image sensor 14 is adopted, the optical system is different from the first embodiment described above. 16 is different, and is characterized in that the operations of (detection principle of the Z direction position of the focus of the laser beam for measurement) and (work thickness measurement) in the first embodiment can be omitted.
In the second embodiment, since (work holding error correction) (electrolytic machining apparatus) described in the first embodiment is the same, the description thereof is omitted.

  12 and 13, the optical system 16 includes a convex lens 23, a mirror 19, a beam sampler 20, an image sensor 14, a convex lens 24, and an objective lens 22.

  The beam sampler 20 transmits most of the laser light emitted from the laser head 7 and guided by the lens 18 and the mirror 19 toward the objective lens 22. Further, the beam sampler 20 reflects a part of the measurement laser light reflected by the workpiece 15 and the reflection plate 17 toward the image sensor 14. The objective lens 22 condenses the laser beam that has passed through the convex lens 24 on the work 15.

  The laser head 7 is a fiber laser, for example, and outputs the processing laser beam and the measurement laser beam as described above. The output of the measurement laser beam is much smaller than the output of the processing laser beam. For example, the output of the measurement laser beam is about 1/20 of the output of the processing laser beam. Further, the laser head 7 according to the present embodiment emits a processing laser beam having a stable output in order to perform appropriate processing of the workpiece 15.

  The image sensor 14 is an image sensor such as a CCD or a CMOS. The imaging element 14 is arranged so that the position where the reflected light of the workpiece 15 forms an image is the light receiving surface of the imaging element 14 when the workpiece 15 is at the position of the focus F of the measurement laser beam.

  The reflector 17 reflects the measurement laser light when the work 15 is at a position deviated from the focus F of the measurement laser light in the X direction. As will be described later, the reflecting plate 17 is used to detect the end of the work 2 in the X and Y directions. The reflecting plate 17 of this embodiment is formed of a ceramic member or a metal member.

  In FIG. 12, a laser oscillator 8, an image sensor 14, an electrolytic processing power source 9, a stage driver that drives the moving stages 1 and 2, and the rotary stage 3 are connected to the control PC 12. As described above, the control PC 12 performs various controls of the laser processing apparatus 4, the electrolytic processing power source 9, and the stage driver. For example, the control PC 12 outputs a laser beam emission command or a stop command to the laser head 7. Further, the control PC 12 specifies the position in the Z direction of the focal point F of the measurement laser light based on the information of the imaging element 14, drives the moving stage 2, and moves the workpiece 15 to the position of the focal point F. In addition, the control PC 12 includes a processing state detection unit that detects a processing state of the processing object based on the change in the amount of reflected light, and controls a laser beam stop command and the like according to the processing state.

(Principle of detection of X and Y direction end of work)
FIG. 4 is a diagram illustrating an example of an image captured by the image sensor 14 when the measurement laser light is reflected by the reflecting plate 17 illustrated in FIG. 12.

  In this embodiment, the measurement laser beam reflected by the reflecting plate 17 is used to detect the ends of the workpiece 15 in the X and Y directions. Hereinafter, for convenience of explanation, the X- and Y-direction end portions of the workpiece 15 of the present embodiment will be described by taking as an example the case where the X-direction end portion 15b (see also FIG. 13) of the rectangular parallelepiped workpiece 15 is detected. The detection principle will be described.

  Before detecting the X-direction end 15b of the work 15, first, the position of the focus F of the measurement laser beam in the Z direction is detected by the above-described method, and the work 15 and the focus F are aligned. That is, as shown in FIG. 13, the alignment of the surface of the work 15 and the focal point F is performed in the Z direction. In this state, a focus corresponding point F1 corresponding to the focus F is set on the video imaged by the image sensor 14 (see FIG. 4). Thereafter, the workpiece 15 is moved in the Y direction by the moving stage 1 and is disposed at a position out of the focus F in the Y direction.

  When the work 15 is out of the focus F in the Y direction, for example, the image shown in FIG. That is, a part of the measurement laser light irregularly reflected by the reflecting plate 17 is blocked by the work 15, so that the work corresponding area 15c corresponding to the work 15 on the image taken by the image sensor 14 becomes dark, and the other The area becomes brighter. In addition, since the position of the surface of the work 15 and the focal point F is aligned in the Z direction, the end corresponding line 15d corresponding to the Y direction end of the work 15 is on the image captured by the image sensor 14. Clearly identified by That is, the end 15d in the Y direction of the work 15 is detected.

  When the end corresponding line 15d is clearly specified, a distance Y1 in the Y direction between the end corresponding line 15d and the focus corresponding point F1 is calculated. That is, the distance between the Y-direction end 15d and the focal point F is calculated. Further, since the Y direction end portion 15d and the machining portion and distance of the workpiece 15 are known in advance in design, the distance in the Y direction from the focal point F to the machining portion of the workpiece 15 is calculated. Similarly, the end portion of the workpiece 15 in the X direction is also detected, and the distance in the Z direction from the focal point F to the machining site of the workpiece 15 is calculated. Further, the calculation of the distance from the focal point F to the processing part of the workpiece 15 is performed by the control PC 12.

(Workpiece Z position measurement)
In order to measure the axial center of a small-diameter axial workpiece that is a workpiece in this embodiment, the workpiece 15 is moved in the X and Y directions by the moving stages 1 and 2, and the measurement laser beam is emitted from the laser head 7. The measurement laser beam reflected by the reflecting plate 17 is photographed by the image sensor 14, and the height at which the boundary between the portion where the reflected light is detected and the portion blocked by the workpiece 15 is in focus is determined. The axis center height.

It is a figure which shows typically schematic structure of the high precision laser processing and laser-electrolytic composite processing apparatus concerning Embodiment 1 of this invention. It is explanatory drawing for demonstrating the laser processing apparatus in the high precision laser processing shown in FIG. 1, and a laser / electrolytic composite processing apparatus. It is a graph which shows the relationship between the position of the Z direction of the workpiece | work shown in FIG. 1, and the amount of reflected light measured with a light receiving element. It is a figure which shows an example of the image | video image | photographed with an image pick-up element, when the measurement laser beam is reflected by the reflecting plate shown in FIG. It is a flowchart which shows the procedure of the thickness measurement of the workpiece | work in the high precision laser processing and laser / electrolytic combined machining apparatus shown in FIG. It is explanatory drawing for demonstrating the holding | maintenance error of a workpiece | work. It is explanatory drawing for demonstrating the means to correct | amend the holding | maintenance error of a workpiece | work. It is explanatory drawing which shows the state which has a workpiece | work in an initial position. It is explanatory drawing which shows the state which has a workpiece | work in a 90 degree rotation position. It is explanatory drawing which shows the state which has a workpiece | work in a 180 degree rotation position. It is explanatory drawing for demonstrating the method of calculating | requiring a process irradiation point. It is a figure which shows typically schematic structure of the high precision laser processing and laser-electrolytic composite processing apparatus concerning Embodiment 2 of this invention. It is explanatory drawing for demonstrating the laser processing apparatus in the high precision laser processing shown in FIG. 12, and a laser / electrolytic composite processing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Moving stage 2 Moving stage 3 Rotating stage 4 Laser processing apparatus 5 Electrolytic processing apparatus 6 Spindle 7 Laser head 8 Laser oscillator 9 Power supply for electrolytic processing 10 Electrolytic electrode 11 Work holder 12 Control PC (control means)
DESCRIPTION OF SYMBOLS 13 Light receiving element 14 Image pick-up element 15 Work 16 Optical system 17 Reflector 18 Lens 19 Mirror 20 Beam sampler 21 Lens 22 Objective lens 23 Convex lens 24 Convex lens 98 Beam sampler 99 Light receiving element

Claims (3)

  A laser processing apparatus and a spindle that supports a work holder, and a moving stage that relatively moves the laser processing apparatus and the spindle in the XYZ directions, the laser processing apparatus including a laser oscillator, a processing laser beam, and a measurement laser A laser head as a laser beam emitting unit that emits light, a reflected light amount measuring unit for measuring a reflected light amount of a measurement laser beam reflected by a workpiece, and a workpiece using the reflected light of the measurement laser beam An image sensor capable of processing, an optical system for forming an optical path of the processing laser beam and the measurement laser beam emitted from the laser head, and an optical axis direction of the processing laser beam and the measurement laser beam to the laser head. On the other hand, a reflector that is arranged at a position farther from the workpiece and reflects the laser beam for measurement, the moving stage, the laser oscillator, and the reflector Control means for controlling the quantity measuring means and the image sensor, and measuring and controlling the initial position of the work using the measurement laser beam and the rotational position when the work is rotated by a predetermined angle by the work holding means. A high-precision laser processing apparatus comprising: a work holding error correcting unit that grasps a three-dimensional position of a work by means and corrects a work holding error by obtaining a processing irradiation point of the work.   A laser processing apparatus and a spindle that supports a work holder, and a moving stage that relatively moves the laser processing apparatus and the spindle in the XYZ directions, the laser processing apparatus including a laser oscillator, a processing laser beam, and a measurement laser Laser head as laser beam emitting means for emitting light, imaging device capable of photographing workpiece using reflected light of measurement laser beam, optical path of processing laser beam and measurement laser beam emitted from laser head An optical system for forming the reflector, and a reflector that reflects the measurement laser light and is disposed at a position away from the workpiece with respect to the laser head in the optical axis direction of the processing laser light and the measurement laser light. A moving stage, a laser oscillator, a reflected light amount measuring means, and a control means for controlling the image pickup device, and using a measuring laser beam The initial position of the workpiece and the rotation position when the workpiece is rotated by a predetermined angle by the workpiece holding means are measured, the three-dimensional position of the workpiece is grasped by the control means, and the processing irradiation point of the workpiece is obtained. A high-precision laser processing apparatus, comprising a workpiece holding error correcting means for correcting a holding error.   3. A high-precision laser processing apparatus according to claim 1, wherein the electrolytic processing apparatus is mounted on the stage on which the laser processing apparatus is mounted so as to be adjacent to the laser processing apparatus. Processing equipment.

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