JP2009082932A - Laser beam machining apparatus and laser beam machining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining apparatus and a laser beam machining method capable of performing the laser beam machining of an object even when the profile (contour) of a surface of the object is variously changed in the radial direction. <P>SOLUTION: The laser beam machining apparatus comprises a table 21 for setting an object 10, and a machining head 31 for performing the laser beam machining of the object 10 by applying laser beam to the object 10. The table 21 is turned by a spindle motor 22, and driven in the radial direction by a feed motor 23. The machining head 31 is supported by a head driving device 30 so as to change the vertical position and the inclination. A controller 60 controls first and second motors 35, 36 by using the profile data indicating the profile in the radial direction of the object 10, and adjusts the height and the inclination of the machining head to the object 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a laser processing apparatus and a laser processing method for irradiating a processing target with laser light to perform laser processing on the processing target.

Conventionally, a laser processing apparatus that irradiates a processing target with laser light from a processing head while rotating the processing target to form fine pits, grooves, or reaction traces on the surface of the processing target is well known. Yes. In this type of laser processing apparatus, in order to deal with the surface shake of the workpiece that fluctuates up and down with rotation, for example, as shown in Patent Document 1 below, reflected light from the workpiece is used. Thus, focus servo control as during data recording and reproduction on the optical disc is performed so that the laser beam is always focused on the surface of the workpiece.
JP 2001-243663 A

  In the conventional laser processing apparatus, the focus servo function can be sufficiently exerted when the surface of the object to be processed is substantially flat like a master disk of an optical disk. However, when laser processing a workpiece having a surface profile (outer shape) that varies in the radial direction, the range of change in the height of the surface of the workpiece exceeds the range of change in the focus of laser light in focus servo control. Sometimes. In such a case, the laser beam cannot always be focused on the surface of the object to be processed, and the accuracy of laser processing deteriorates. Also, due to the surface profile that varies in the radial direction, the laser beam is not irradiated perpendicularly to the surface of the workpiece, that is, the optical axis of the laser beam is not perpendicular to the tangential direction of the surface profile, There is also a problem that accurate machining cannot be expected. Furthermore, due to the surface profile varying in the radial direction, the tangential direction of the surface profile and the moving direction of the optical machining head do not match, and the workpiece cannot be laser machined at the set radial machining pitch. There is also a problem that accurate machining cannot be expected.

  The present invention has been made to address the above problems, and its purpose is to realize high-precision machining even when laser machining a workpiece having a surface profile (outer shape) that varies in the radial direction. An object of the present invention is to provide a laser processing apparatus and a laser processing method.

  In order to achieve the above object, the present invention is characterized in that a table for setting a processing object, a processing head for irradiating the processing object set on the table with laser light and laser processing the processing object, and a table In a laser processing apparatus comprising a rotating device for rotating the workpiece and a radial feed device for moving the machining head relative to the table in the radial direction of the table, profile data representing a profile in the radial direction of the workpiece Based on this, there is provided a head adjusting means for adjusting at least one of the height and inclination of the machining head with respect to the workpiece.

  In the laser processing apparatus configured as described above, the head adjusting means adjusts the height and / or inclination of the processing head with respect to the processing target according to the profile of the processing target. Thereby, the focal position of the laser beam emitted from the machining head is always aligned with the surface of the workpiece, or the optical axis of the laser beam is always kept perpendicular to the surface of the workpiece. Therefore, even if the profile (outer shape) of the surface of the workpiece varies in the radial direction, the workpiece is processed with high accuracy by the laser beam.

  Another feature of the present invention is that a moving speed correcting means for correcting the relative moving speed of the machining head with respect to the table by the radial feeding device is provided based on the profile data. According to this, when the tangential direction of the surface profile in the radial direction in the workpiece is inclined with respect to the moving direction of the processing head, the moving speed correction means corrects the moving speed of the processing head with respect to the table. The laser beam can always be moved at a constant speed with respect to the tangential direction of the surface profile in the radial direction of the workpiece. As a result, the object to be processed can be laser processed at a set processing pitch in the radial direction.

  Another feature of the present invention is that the profile data is data prepared in advance when designing a workpiece or data generated based on data prepared in advance when designing a workpiece. There is provided first profile data acquisition means for acquiring data prepared in advance at the time of designing a workpiece and using the acquired data as profile data or generating profile data from the acquired data . According to this, when data related to the profile data is prepared at the time of designing the workpiece, the data can be used effectively, and the laser processing for performing adjustment and correction based on the profile data can be performed quickly. To be done.

  In addition, another feature of the present invention is further acquired by a three-dimensional shape measuring device that measures a three-dimensional shape of a workpiece and acquires three-dimensional shape data representing the three-dimensional shape, and a three-dimensional shape measuring device. Further, there is provided second profile data acquisition means for generating and acquiring profile data representing a radial profile of the workpiece based on the three-dimensional shape data. According to this, since profile data can be generated based on the three-dimensional shape data acquired by the three-dimensional shape measuring apparatus even if the profile data of the workpiece is not prepared in advance, adjustment based on the profile data is possible. And high-precision laser processing for correction.

  Another feature of the present invention is that the three-dimensional shape measuring apparatus measures the three-dimensional shape of the processing object in a state where the position is fixed with respect to the table and the processing object is set on the table. . According to this, since the three-dimensional shape measurement of the object to be processed is also performed in a series of steps of laser processing, the work efficiency of laser processing when the profile data of the object to be processed is not prepared in advance is improved. .

  Another feature of the present invention is that the second profile data acquisition means averages profiles at a plurality of different circumferential positions of the workpiece, and acquires profile data representing a profile in the radial direction of the workpiece. There is to do. According to this, since profile data in consideration of the entire surface of the workpiece is generated, it is possible to make the laser processing for adjustment and correction based on the profile data more accurate.

  Furthermore, in carrying out the present invention, the invention is not limited to the invention of the laser processing apparatus for laser processing the workpiece, and the invention of the laser processing method for laser processing of the workpiece and the computer program for realizing the laser processing method Can also be implemented.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall schematic diagram of a laser processing apparatus according to the embodiment. This laser processing apparatus includes a table 21 as a support member that fixes and supports the workpiece 10 and a machining head 31 that irradiates the workpiece 10 with laser light to laser process the workpiece. . The table 21 is formed in a circular shape and is driven by a spindle motor 22 and a feed motor 23.

The spindle motor 22 rotationally drives the table 21 through the rotation shaft 22a by the rotation. The spindle motor 22 incorporates an encoder 22b that detects the rotation of the motor 22, that is, the table 21, and outputs a rotation detection signal representing the rotation. This rotation detection signal is composed of an index signal Index generated every time the rotation position of the table 21 comes to one reference rotation position, and a pulse train signal that repeats a high level and a low level by a predetermined minute rotation angle and is mutually π A phase signal φ _A and a B phase signal φ _B that are out of phase by / 2. The rotation detection signal is supplied to the spindle motor control circuit 41 and the rotation angle detection circuit 42. The spindle motor control circuit 41 calculates the rotation speed of the spindle motor 22 using the rotation detection signal from the encoder 22b, and the calculated rotation speed becomes equal to the rotation speed designated by the controller 60 according to an instruction from the controller 60. Thus, the rotation of the spindle motor 22 is controlled. The rotation angle detection circuit 42 detects the rotation angle of the spindle motor 22, that is, the table 21 in accordance with an instruction from the controller 60 and supplies it to the controller 60.

  The feed motor 23 rotates the screw rod 24 to drive the table 21 in the radial direction. The screw rod 24 is connected to one end of the screw rod 24 so as to rotate integrally with the rotation shaft of the feed motor 23, and is screwed to a nut (not shown) fixed to the support member 25 at the other end. The support member 25 fixedly supports the spindle motor 22 and is only allowed to move in the radial direction of the table 21. Therefore, when the feed motor 23 rotates, the spindle motor 22, the table 21, and the support member 25 are displaced in the radial direction of the optical disk DK by the screw mechanism including the screw rod 24 and the nut.

  An encoder 23a that detects the rotation of the feed motor 23 and outputs a rotation detection signal similar to the encoder 22b is also incorporated in the feed motor 23. The rotation detection signal is output to the radial position detection circuit 43 and the feed motor control circuit 44. The radial position detection circuit 43 has a count circuit that counts the rotation detection signal from the encoder 23a, detects the radial position of the table irradiated with laser light based on the count value of the count circuit, and determines the radial position. A detection signal is output. The initial setting of the count circuit is performed in cooperation with the feed motor control circuit 44 according to an instruction from the controller 60.

  That is, at the initial stage, the controller 60 instructs the feed motor control circuit 44 to move the support member 25 to the initial position and the radial position detection circuit 43 to perform initial setting. In response to this instruction, the feed motor control circuit 44 rotates the feed motor 23 to move the support member 25 to the initial position. This initial position is a drive limit position of the support member 25 driven by the feed motor 23. The radial position detection circuit 43 continues to input the rotation detection signal from the encoder 23a while the support member 25 is moving. When the support member 25 reaches the initial position and the rotation of the feed motor 23 stops, the radial position detection circuit 43 detects the stop of the input of the rotation detection signal from the encoder 23a, and sets the count value of the built-in count circuit as “ Reset to “0”. At this time, the radius position detection circuit 43 outputs a signal for stopping the output to the feed motor control circuit 44, whereby the feed motor control circuit 44 stops outputting the drive signal to the feed motor 23.

  The feed motor control circuit 44 drives and controls the feed motor 23 according to an instruction from the controller 60 to move the irradiation position of the laser beam to a designated radial position of the table 21 or move the table 21 in the radial direction at a designated speed. . Specifically, the feed motor control circuit 44 feeds using the radial position detected by the radial position detection circuit 43 when the movement of the irradiation position of the laser beam to the radial position designated by the controller 60 is instructed. The rotation of the motor 23 is controlled, and the feed motor 23 is rotated until the detected radial position becomes equal to the radial position designated by the controller 60. When the feed motor control circuit 44 is instructed to move the irradiation position of the laser beam in the radial direction of the table at the movement speed specified by the controller 60, the radius of the table 21 is determined from the rotation detection signal from the encoder 23a. The movement speed in the direction is calculated, and the rotation of the feed motor 23 is controlled so that the calculated movement speed becomes equal to the movement speed designated by the controller 60.

  The processing head includes a laser light source, a collimating lens, a polarizing beam splitter, a quarter-wave plate, an objective lens, a convex lens, a cylindrical lens, a quadrant photodetector, a focus actuator, and the like, and laser light from the laser light source is applied to the processing object 10. Condensed light and reflected light from the workpiece 10 is received. The laser light source is driven and controlled by a light emission signal supply circuit 45 and a laser driving circuit 46 that are controlled by the controller 60. The light emission signal supply circuit 45 inputs data representing the machining pattern from the controller 60 and supplies a pulse train signal corresponding to the data to the laser drive circuit 46. The laser drive circuit 46 is controlled by the controller 60 and supplies an initial drive signal to the laser light source irrespective of the drive signal corresponding to the pulse train signal from the light emission signal supply circuit 45 or the light emission signal supply circuit 45.

  Further, the reflected light from the laser light irradiated onto the workpiece 10 is guided to and received by a four-divided photodetector. The four-divided photodetector supplies a light reception signal composed of four signals to the focus error signal generation circuit 48 via the HF signal amplification circuit 47. The focus error signal generation circuit 48 generates a focus error signal based on the light reception signal detected by the four-divided photodetector and amplified by the HF signal amplification circuit 47 and outputs the focus error signal to the focus servo circuit 49. The focus servo circuit 49 is instructed by the controller 60, generates a focus servo signal based on the focus error signal, and supplies the focus servo signal to the drive circuit 50. The drive circuit 50 drives and controls the focus actuator in the machining head 31 according to the focus servo signal, and controls the laser light to be focused on the surface of the workpiece 10. The focus actuator is provided in the processing head 31 to displace the objective lens in the optical axis direction.

  The processing head 31 is assembled to a head driving device 30 fixed above the table 21 by a support mechanism (not shown). The head driving device 30 includes a first support member 33 supported by the frame body 32 so as to be displaceable only in the vertical direction, and a first support member 33 supported by the first support member 33 so as to be rotatable about an axis whose axis is perpendicular to the paper surface. 2 support members 34. The processing head 31 is assembled and fixed to the second support member 34. The head driving device 30 includes a first motor 35 and a second motor 36. The 1st motor 35 displaces the 1st support member 33 up and down with respect to the frame 32 by the rotation via a ball screw mechanism. The second motor 36 rotates the second support member 34 about the first support member 33 around the vertical axis of the paper surface by the rotation of the second motor 36 via the gear mechanism. Encoders 35a and 36a are incorporated in the first and second motors 35 and 36, respectively. The encoders 35a and 36a output rotation detection signals similar to those of the encoders 22b and 23a.

  A height detection circuit 51 is connected to the encoder 35a, and a first motor control circuit 52 is connected to the first motor 35. The height detection circuit 51 has a count circuit that counts the rotation detection signal from the encoder 35a, and outputs a detection signal indicating the vertical height of the machining head 31 based on the count value of the count circuit. The initial setting of the count circuit is performed in cooperation with the first motor control circuit 52 according to an instruction from the controller 60. Specifically, the controller 60 instructs the first motor control circuit 52 to move the machining head 31 to the initial position and to initially set the height detection circuit 51 in the initial stage. In response to this instruction, the first motor control circuit 52 rotates the first motor 35 to move the machining head 31 to the initial position. This initial position is a drive limit position of the machining head 31 driven by the first motor 35. The height detection circuit 51 continues to input the rotation detection signal from the encoder 35a while the machining head 31 is moving. When the machining head 31 reaches the initial position and the rotation of the first motor 35 stops, the height detection circuit 51 detects the stop of the rotation detection signal input from the encoder 35a and calculates the count value of the built-in count circuit. Reset to “0”. At this time, the height detection circuit 51 outputs an output stop signal to the first motor control circuit 52, whereby the first motor control circuit 52 stops outputting the drive signal to the first motor 35.

  The first motor control circuit 52 drives and controls the first motor 35 according to an instruction from the controller 60 to move the machining head 31 up and down. Specifically, the first motor control circuit 52 uses the height detected by the height detection circuit 51 when the movement of the machining head 31 to the height specified by the controller 60 is instructed. The rotation of the motor 35 is controlled, and the first motor 35 is rotated until the detected height becomes equal to the height designated by the controller 60.

  An angle detection circuit 53 is connected to the encoder 36a, and a second motor control circuit 54 is connected to the second motor 36. The angle detection circuit 53 has a count circuit that counts the rotation detection signal from the encoder 36a, and outputs a detection signal that represents the angle of the machining head 31 around the axis in the direction perpendicular to the paper surface based on the count value of the count circuit. . The initial setting of the count circuit is performed in cooperation with the second motor control circuit 54 according to an instruction from the controller 60. Specifically, the controller 60 instructs the second motor control circuit 54 to move the machining head 31 to the initial position and to initially set the angle detection circuit 53 in the initial stage. In response to this instruction, the second motor control circuit 54 rotates the second motor 36 to rotate the machining head 31 to the initial position. This initial position is a drive limit position of the machining head 31 driven by the second motor 36. The angle detection circuit 53 continues to input a rotation detection signal from the encoder 36a while the machining head 31 is moving. When the machining head 31 reaches the initial position and the rotation of the second motor 36 stops, the angle detection circuit 53 detects the stop of the input of the rotation detection signal from the encoder 36a and sets the count value of the built-in count circuit as “ Reset to “0”. At this time, the angle detection circuit 53 outputs an output stop signal to the second motor control circuit 54, whereby the second motor control circuit 54 stops outputting the drive signal to the second motor 36.

  The second motor control circuit 52 drives and controls the second motor 36 according to an instruction from the controller 60 to rotate the processing head 31 around the vertical axis on the paper surface. Specifically, the second motor control circuit 54 uses the angle detected by the angle detection circuit 53 when the rotation of the machining head 31 to the angular position specified by the controller 60 is instructed. And the second motor 36 is rotated until the detected angle becomes equal to the angle designated by the controller 60.

  The controller 60 is configured by a computer including a CPU, a ROM, a RAM, a non-volatile memory such as a hard disk, and the like. By executing a program in accordance with an instruction from an input device 61 such as a keyboard and a mouse, the laser processing apparatus Is activated. The controller 60 is also connected with a display device 62 for visually informing the operator of the operation instructions and the operation status.

  In addition, a three-dimensional shape measuring device 70 is also connected to the controller 60. The three-dimensional shape measuring device 70 is fixed to a support mechanism (not shown) and is arranged in parallel with the head driving device 30 at a position above the table 21. The three-dimensional shape measuring apparatus 70 scans the outer surface of the processing object with laser light, that is, sequentially irradiates a minute region on the outer surface of the processing object with laser light, and based on the reflected light from the outer surface. By detecting the distance to each minute region on the outer surface, three-dimensional shape data (point cloud data) representing the shape of the outer surface is generated. Note that the three-dimensional shape data measured by the three-dimensional shape measuring apparatus 70 is expressed as coordinate values in a three-dimensional coordinate system with any fixed point of the three-dimensional shape measuring apparatus 70 as the origin.

  Next, the operation of the laser processing apparatus configured as described above will be described. First, the operator turns on a power supply (not shown) of the laser processing apparatus and starts the operation of the controller 60. The controller 60 starts execution of the main program in step S10 of FIG. 2A.

  After starting the execution of this program, the controller 60 uses the display device 62 to prompt the operator to input data necessary for processing the workpiece 10 in step S11. The operator uses the input device 61 to use a processing pitch in the radial direction, a processing pattern in the rotational direction (for example, a processing pitch in the rotational direction when creating fine pits at regular intervals), and a linear velocity of rotation of the table 21. Data representing the laser processing start radius position, the laser processing end radius position, and the like are input to the controller 60. The controller 60 stores these input data. In addition, when processing the processing target object 10 to be processed using previous data, the processing in step S11 is not necessary.

  Next, in step S12, the controller 60 sends the radial position detection circuit 43, the feed motor control circuit 44, the height detection circuit 51, the first motor control circuit 52, the angle detection circuit 53, and the second motor control circuit 54 to the An operation for initial setting processing of the radial position, height, and angle is instructed. In response to this instruction, the circuits 43, 44, 51 to 54 perform the initial setting operation described above, thereby positioning the table 21 and the machining head 31 at the initial positions, as well as the radial position detection circuit 43 and the height detection circuit. 51 and the count values for detecting the radial position, height and angle in the angle detection circuit 53 are reset to the initial value “0”, respectively. Thereafter, the radial position detection circuit 43, the height detection circuit 51, and the angle detection circuit 53 generate detection signals representing the radial position of the table 21, the height of the processing head 31, and the angle of the processing head 31 based on the count value. Output.

  Next, in step S13, the controller 60 instructs the feed motor control circuit 44 to move the table 21 to the initial radius position. The feed motor control circuit 44 rotates the feed motor 23 until the radial position detection signal input from the radial position detection circuit 43 becomes equal to the initial radial position instructed by the controller 60. As shown in FIG. 5, the initial radius position is a position where the three-dimensional shape measuring device 70 comes above the rotation center position of the table 21. The table 21 moves to this position by the process of step S13. In this state, the operator sets the workpiece 10 on the table 21.

  Next, the controller 60 uses the display device 62 to ask the operator about the necessity of measuring the three-dimensional shape of the workpiece 10. The three-dimensional shape measurement process is a process for acquiring profile data of the workpiece 10 in order to adjust the moving speed of the table 21 and the height and tilt angle of the machining head 31 in laser machining. Note that this profile data is radial data PD (representing the upper surface shape of the workpiece 10, where the height of the non-machined surface of the workpiece 10 (the lower surface when set on the table 21) is “0”. n), which will be described in detail later in the description of the profile acquisition routine. In this case, when profile data already exists as design data when the workpiece 10 is designed, the operator specifies that measurement of a three-dimensional shape is not required. On the other hand, when the profile data does not exist, the operator designates measurement of a three-dimensional shape.

  When the measurement unnecessary for the three-dimensional shape is designated, the controller 60 determines “No” in step S15 and proceeds to step S16. In step S <b> 16, the controller 60 instructs the operator to input profile data using the display device 62. This type of profile data is usually stored in a non-volatile memory such as a hard disk of the controller 60 or an external storage device. Accordingly, the operator designates the file name of the profile data stored in the nonvolatile memory or the external storage device (for example, identification data for designating the processing object 10) using the input device 61. By designating the file name, the controller 60 reads the designated profile data and writes it in the RAM or the like.

  In the acquisition of the profile data, when the profile data based on the design data of the workpiece 10 is placed on the flat plate, the intersection of the central axis of the workpiece 10 and the flat plate is the origin, In two coordinate axes, the x coordinate axis whose direction is on the plane of the flat plate and the y coordinate axis perpendicular to the coordinate axis, a plurality of height data represented by x, y coordinate values or a relation curve of y = f (x) If it is prepared as an expression, it is only necessary to input profile data. However, when the design data or the profile data based on the design data cannot be directly used, the profile data based on the design data or the design data is obtained near the central axis of the workpiece 10 when the profile data is acquired. A plurality of data represented by x, y coordinate values having an origin or a relational curve expression of y = f (x), and the coordinate conversion similar to the coordinate conversion of three-dimensional shape data to be described later is performed. When the workpiece 10 is placed on a flat plate, the data or the relational curve expression indicates that the intersection of the central axis of the workpiece 10 and the flat plate is the origin, and the direction is on the plane of the flat plate and the x coordinate axis is perpendicular to the coordinate axis. The coordinate data is converted into a plurality of data represented by two coordinate axes and a relational curve expression, and the profile data can be used.

  On the other hand, when the operator designates the measurement of the three-dimensional shape, the controller 60 determines “Yes” in step S15, and in step S17, the controller 60 determines the three-dimensional shape measurement apparatus 70 to store the processing object 10. Instructs measurement of 3D shape. In response to the measurement instruction, the three-dimensional shape measuring apparatus 70 measures the three-dimensional shape of the upper surface of the workpiece 10 and acquires three-dimensional shape data (point cloud data) representing the three-dimensional shape. , Supplied to the controller 60. The controller 60 writes the supplied three-dimensional shape data in a storage device such as a RAM. This three-dimensional shape data is represented as coordinate values by a three-dimensional coordinate system with any fixed point of the three-dimensional shape measuring apparatus 70 as the origin. This three-dimensional coordinate system is hereinafter referred to as a coordinate system M (see FIG. 6) of the three-dimensional shape measuring apparatus 70.

  After the processing in step S17, the controller 60 executes a profile acquisition routine in step S18. The profile acquisition routine is shown in detail in FIG. 3, and its execution is started in step S100. In step S101, the controller 60 converts the three-dimensional shape data based on the coordinate system M of the three-dimensional shape measuring apparatus 70 into the three-dimensional shape data based on the reference coordinate system S. As shown in FIG. 6, the reference coordinate system S is a coordinate system in which the coordinate origin is at the center of the table 21 and the Z axis is perpendicular to the plane of the table 21. A coordinate conversion function F for converting the three-dimensional shape data of the coordinate system M into the three-dimensional shape data of the reference coordinate system S is acquired in advance and stored in a nonvolatile memory such as an optical disk of the controller 60. An example of a method for obtaining the coordinate conversion function F will be described later.

  After the processing in step S101, the controller 60 initializes variables m and n to “0” in step S102. As shown in FIG. 7, the variable m designates a rotating coordinate system R (m) obtained by rotating the X and Y coordinate axes of the reference coordinate system S by a predetermined angle θ around the Z axis. In FIG. 7, the rotating coordinate systems R (0), R (1), R (2) are represented by X′-Y ′ coordinates, X ″ -Y ″ coordinates, and X ′ ″-Y ′ ″ coordinates. As shown. As shown in FIG. 8, the variable n designates the origin in the rotating coordinate system R (m) and the radial position directed outward by a predetermined distance B in the X-axis direction from the origin.

After the processing in step S102, the controller 60 in step S103, the three-dimensional shape data of the rotational coordinate system R (m) obtained by rotating the converted three-dimensional shape data of the reference coordinate system S by m · θ. Convert to θ is a predetermined positive value determined in advance, for example, a value of about 20 degrees or 30 degrees. In this case, the coordinates based on the reference coordinate system S are (x _s , y _s , z _s ), the coordinates based on the rotating coordinate system R (m) are (x _r , y _r , z _r ), and the rotation angle θ is a table. A counterclockwise direction when 21 is viewed from above is positive. The coordinate conversion is performed by executing the calculation of Equation 1 below. In the process of the first step S103, since m = 0, m · θ = 0, and the three-dimensional shape data of the reference coordinate system S is not substantially converted.

  Next, in step S104, the controller 60 selects the three-dimensional shape data (the absolute value of the Y coordinate value is equal to or less than a predetermined minimum value A from all the three-dimensional shape data converted in step S103). Point cloud data) D (x, y, z) is extracted. FIG. 8 exaggerates the area to which the point cloud data extracted by the process of step S104 belongs and shows with a dot pattern. This processing means extracting point cloud data near the vicinity of the XZ plane. In other words, it means that point cloud data representing a cross section when the workpiece is cut along the XZ plane is extracted.

Next, in Step S105, the controller 60 selects the minimum data D (x (x coordinate value−n · B) having a positive value from the extracted point group data D (x, y, z). _c , y _c , z _c ) and minimum data D (x _e , y _e , z _e ) having a negative value (X coordinate value −n · B) are extracted. As shown in FIG. 9 (A), the point group data at the closest position sandwiching the center position r0 and the positions r1, r2, r3,. Means taking out. Initially, since the variable n is set to “0”, two pieces of data D (x _c , y _c , z _c ) and D (x _e , y _e , z _e ) at the closest positions across the center position r0 Will be extracted.

Next, in step S106, the controller 60 uses the two data D (x _c , y _c , z _c ) and D (x _e , y _e , z _e ) by executing the following equation 2. The Z coordinate value Z (m, n) of the point on the straight line connecting the two points specified by the two data and corresponding to the radial position separated by the distance B is calculated by the interpolation method. And stored in the RAM (see FIG. 9B). This Z coordinate value Z (m, n) represents the height of the center position r0 of the workpiece 10 and the positions r1, r2, r3,... Separated from the center position r0 by a distance B outward in the radial direction. However, since the variable n is initially “0”, it represents the height of the center position r 0 of the workpiece 10.

  After the process of step S106, the controller 60 adds “1” to the variable n in step S107, and executes the determination process of step S108. In this determination process, it is determined whether data having an X coordinate value equal to or greater than the value n · B exists in the point cloud data D (x, y, z) extracted by the process of step S104. In this determination process, whether or not the point cloud data D (x, y, z) exists at or outside the radial position represented by the value n · B, in other words, the radially outer end of the workpiece 10 is the radius. It is determined whether it is larger than the position n · B. If the data exists, the controller 60 determines “Yes” in step S108, returns to step S105, and executes the processes of steps S105 to S108 again. By the processing of steps S105 to S108, the variable n is incremented by “1”, and Z coordinate values (heights of the workpiece 10) Z (m, 0) at a plurality of radial positions represented by the value n · B. , Z (m, 1), Z (m, 2)... Are calculated.

  If there is no point cloud data whose X coordinate value is greater than or equal to the value n · B due to the increase of the variable n, the controller 60 determines “No” in step S108 and sets the variable m in step S109. “1” is added, and the determination process of step S110 is executed. In step S110, it is determined whether the value m · θ is less than 360 degrees. This is to determine whether the rotation of the coordinate axis at each angle θ has made one rotation.

  If the value m · θ is less than 360 degrees, the controller 60 determines “Yes” in step S110, returns the variable n to the initial value “0” in step S111, and includes steps S103 to S110. Run the process again. By repeating these steps S103 to S110, point group data D () near the XZ plane in the rotational coordinate system R (0), R (1), R (2),. x, y, z) are extracted, and using these point cloud data D (x, y, z), the rotational coordinate systems R (0), R (1), R (2),. The Z coordinate value Z (m, n) for each radial position n · B in the XZ plane is calculated.

  When the value m · θ is 360 degrees or more, the controller 60 determines “No” in step S110, sets the variable n to the initial value “0” in step S112, and performs the processing in steps S113 to S115. Execute. In step S113, the controller 60 extracts the Z coordinate value Z (m, n) specified by the variable n (0, 1, 2,...), And the extracted Z coordinate value Z (m, n) is extracted. The average value is calculated, and the average value is profile data PD (n representing the height of the workpiece 10 at the radial position specified by the variable n (the central position and the radial position at a distance B from the central position). ). In the calculation of the average value, all the extracted Z coordinate values Z (m, n) are added together, and the combined value is divided by the number of all the extracted Z coordinate values Z (m, n). . The calculated profile data PD (n) is stored in the RAM and also stored in a non-volatile memory such as a hard disk together with identification data representing the workpiece 10. Note that the number of all the extracted Z coordinate values Z (m, n) is usually a number larger by “1” than the maximum value of the variable m. However, when the workpiece 10 is not completely circular, the maximum radius is different for each rotating coordinate system R (m). Therefore, in the state where the variable n is a large value, all the extracted Z coordinate values Z ( The number of m, n) is not necessarily a number that is “1” larger than the maximum value of the variable m.

  In step S114, the controller 60 adds “1” to the variable n. In step S115, the controller 60 determines whether or not the Z coordinate value Z (m, n) specified by the variable n exists. That is, it is determined whether the Z coordinate value related to the radius position specified by the current variable n exists in the Z coordinate value Z (m, n) calculated by the process of step S106. As long as the Z coordinate value exists, the controller 60 determines “Yes” in step S115, and repeatedly executes the circulation processing in steps S113 to S115. If the Z coordinate value no longer exists due to an increase in the variable n, the controller 60 determines “No” in step S115, and ends the execution of the profile acquisition routine in step S116. As a result, in this state, profile data PD (n) representing the height of the workpiece 10 at the center position and the outer radial position (n = 0, 1, 2,...) At a distance B from the center position is obtained. It is stored in RAM and non-volatile memory.

  Returning to the description of the program in FIG. 2A again, the controller 60 executes the processing of steps S19 and S20 after the input of profile data in step S16 or the execution of the profile acquisition routine in step S18. In step S19, the controller 60 supplies the laser machining start radius position input by the process of step S11 to the feed motor control circuit 44, and instructs the feed motor control circuit 44 to move the table 21. The feed motor control circuit 44 controls the feed motor 23 using the radial position detected by the radial position detection circuit 43, and the table until the detected radial position reaches the laser processing start radial position designated by the controller 50. Move 21.

  In step S20, the controller 60 calculates the rotational speed of the spindle motor 22 using the radial position r detected by the radial position detection circuit 43 and the linear velocity input in step S11. Then, the controller 60 outputs the calculated rotation speed to the spindle motor control circuit 41 to instruct the rotation of the spindle motor 22. The spindle motor control circuit 41 calculates the rotation speed of the spindle motor 22 calculated based on the rotation detection signal from the encoder 22b, and the calculated rotation speed becomes equal to the rotation speed input from the controller. The rotation of the spindle motor 22 is controlled. As a result, the spindle motor 22 starts to rotate at a rotational speed at which the linear velocity at the laser light irradiation position becomes equal to the input linear velocity.

次に、予め光ディスクなどの不揮発性メモリに記憶されていて、加工ヘッド３１の初期高さ位置からレーザ光焦点がテーブル２１の表面に合うまでの駆動距離Ｓから、前記計算した高さＨを減算して加工ヘッド３１の高さＤ（＝Ｓ−Ｈ）を求める（図１０参照）。 After the processing in steps S19 and S20, the controller 60 inputs the radial position r detected by the radial position detection circuit 43 in step S21, and uses the input radial position r and profile data PD (n). Using this, the height D and the inclination φ of the machining head 31 are calculated. In the calculation of the height D of the machining head 31, first, it corresponds to the radial position j-1, j (j is “0” or a positive integer) adjacent to the radial position r in the profile data PD (n). A pair of profile data PD (j−1) and PD (j) are extracted, and the extracted profile data PD (j−1) and PD (j) are converted into Z coordinate values z (x ₁ ) and z (x ₂ ). In this case, the values x ₁ and x ₂ represent the radial positions (X coordinate values) corresponding to the variables j−1 and j in the profile data PD (j−1) and PD (j), respectively. Then, the height H from the table 21 of the workpiece 10 at the radius position r is calculated using the interpolation method by executing the calculation of the following equation (3). When the profile data PD (n) on both sides does not exist and only the profile data PD (n) on one side exists, the profile data PD (n) on one side is set to a height H.

Next, the calculated height H is subtracted from the driving distance S that is stored in advance in a non-volatile memory such as an optical disk and from which the laser beam focus is brought into contact with the surface of the table 21 from the initial height position of the processing head 31. Thus, the height D (= SH) of the machining head 31 is obtained (see FIG. 10).

また、前記数４の演算の実行に代えて、半径位置ｒの両隣の２つ以上のプロファイルデータＰＤ(ｎ)を抽出し、最小２乗法により直線を求め、この直線の傾きを「ａ」とする。そして、tan^-1ａの演算により傾きφを計算するようにしてもよい。 The inclination φ of the machining head 31 is calculated by executing the following equation 4 using the X coordinate values x ₁ and x ₂ and the Z coordinate values z (x ₁ ) and z (x ₂ ) (see FIG. 11). ). Note that the slope φ is set to “0” when the profile data PD (n) on both sides does not exist and only the profile data PD (n) on one side exists.

Further, instead of executing the calculation of Equation 4, two or more profile data PD (n) adjacent to the radius position r are extracted, a straight line is obtained by the least square method, and the slope of this straight line is expressed as “a”. To do. Then, the inclination φ may be calculated by calculating tan ⁻¹ a.

  After calculating the height D and the inclination φ, the controller 60 outputs the calculated height D and inclination φ to the first and second motor control circuits 52 and 54 in step S22, respectively, and the machining head 31. The first and second motor control circuits 52 and 54 are instructed to change the height and inclination of the motor. The first motor control circuit 52 inputs the height detected by the height detection circuit 51 and drives the first motor 35 so that the detected height becomes equal to the height D supplied from the controller 60. Control. Thereby, the first motor 35 controls the height of the machining head 31 to be the height D supplied from the controller 60 by displacing the machining head 31 in the vertical direction. The second motor control circuit 54 inputs the angle detected by the angle detection circuit 53, and drives and controls the second motor 36 so that the detected angle becomes equal to the inclination φ supplied from the controller 60. As a result, the second motor 36 rotates the machining head 31 to control the inclination of the machining head 31 to the inclination φ supplied from the controller 60. As a result, the focal position of the laser beam moves to the surface of the workpiece 10 and the optical axis of the laser beam is perpendicular to the radial tangent of the workpiece 10.

  After the process of step S22, the controller 60 instructs the laser drive circuit 46 to start the initial irradiation of laser light in step S23. The laser drive circuit 46 supplies voltage and current to the laser light source in the processing head 31, and the laser light source emits laser light and starts irradiating the processing object 10 with laser light. However, the supply voltage to the laser light source in this case is low, and the laser light source emits laser light having an intensity lower than the intensity at which the workpiece 10 is processed by the laser light. Next, in step S24, the controller 60 instructs the focus servo circuit 49 to start focus servo. The focus servo circuit 49 supplies a drive signal for focus pulling to the drive circuit 50 to move the objective lens in the processing head 31 upward and downward, and the S-shaped signal supplied from the focus error signal generation circuit 48. A zero-cross point is detected, and from this time, a focus servo signal created from a signal supplied from the focus error signal generation circuit 48 is supplied to the drive circuit 50. As a result, the laser beam is focused on the upper surface of the workpiece 10, and thereafter, the focus servo circuit 49 uses the focus servo signal created from the focus error signal from the focus error signal generation circuit 48 to drive the drive circuit 50. Continue to drive the objective lens through.

Next, the controller 60 calculates the feed speed in the radial direction of the table 21 in step S25. The linear velocity v and machining pitch p input by the process of step S11, the radial position (radius value) r taken from the radial position detection circuit 43 by the process of step S21, and the radius position calculated by the process of step S22 By using the inclination φ of the workpiece 10 at r, the corrected radial feed speed Vr is calculated in consideration of the profile of the upper surface of the workpiece by executing the following equation (5).

  This equation 5 will be described. When the linear velocity is v and the radial position (radius value) is r, the rotational speed k of the table 21 is k = v / 2πr. On the other hand, since the reciprocal 1 / k of the rotational speed k represents the time required for one rotation of the table 21, the profile of the upper surface of the workpiece 10 is not considered by dividing the machining pitch p by the time 1 / k. The radial feed speed p · k of the table 21 is expressed as p · k = p · v / 2πr. Here, in consideration of the inclination φ at the radial position r in order to consider the profile of the upper surface of the workpiece 10, the corrected machining pitch p ′ is expressed as p · cos φ. Accordingly, the corrected radial feed speed Vr of the table 21 is p ′ · k = p · k · cosφ = p · v · cosφ / 2πr.

  After the process of step S25, the controller 60 outputs the calculated corrected radial feed speed Vr to the feed motor control circuit 44 in step S26 to instruct the start of rotation of the feed motor 23. The feed motor control circuit 44 calculates the radial feed speed of the feed motor 23 based on the rotation detection signal supplied from the encoder 23a, and the calculated radial feed speed becomes the supplied corrected radial feed speed Vr. The rotation of the feed motor 23 is controlled so as to be equal. As a result, the table 21 starts to move in the radial direction at the processing pitch p ′ obtained by correcting the processing pitch p according to the profile of the upper surface of the processing target 10.

  After the processing of step S26, the controller 60 supplies data representing the processing pattern to the light emission signal supply circuit 45 and instructs the laser driving circuit 46 to emit laser light having the processing laser light intensity. The light emission signal supply circuit 45 outputs a pulse train signal corresponding to the data representing the processed pattern supplied to the laser drive circuit 46. The laser drive circuit 46 supplies a drive signal corresponding to the pulse train signal from the light emission signal supply circuit 45 to the laser light source in the processing head 31. In this case, the output level of the drive signal is large, and the laser light source starts to emit laser light having output energy sufficient for laser processing the workpiece 10. Thereby, the workpiece 10 starts to be laser processed.

  After the process of step S27, the controller 60 repeatedly executes the circulation process including steps S28 to S32 of FIG. 2B. In step S28, the controller 60 inputs the radius position r from the radius position detection circuit 43, and determines whether the input radius position r is the end radius position input by the process of step S11. The processing in steps S29 and S30 is the same as the control processing for the height D and the inclination φ of the machining head 31 in consideration of the profile of the upper surface of the workpiece 10 in steps S21 and S22 described above. The processing in steps S31 and S32 is the same as the control processing for the moving speed in the radial direction of the table 21 in consideration of the profile of the upper surface of the workpiece 10 in steps S25 and S26 described above.

  By the circulation process composed of these steps S28 to S31, until the table 21 reaches the end radius position (until the laser irradiation position reaches the end radius position), the processing head 31 is adjusted according to the profile of the upper surface of the processing object 10. The height D and the inclination φ are continuously controlled for correction, and the moving speed of the table 21 in the radial direction is also controlled for correction. As a result, in the laser processing of the workpiece 10, the focal position of the laser beam is maintained on the surface of the workpiece 10, and the optical axis of the laser beam is maintained perpendicular to the radial tangent of the workpiece 10. It is. Further, the processing pitch is also maintained at the set pitch even if the surface inclination of the processing object 10 changes. Therefore, according to this embodiment, the workpiece 10 is laser machined regardless of the profile of the upper surface of the workpiece 10.

  When the table 21 reaches the end radius position during the circulation process including the steps S28 to S31, the controller 60 determines “Yes” in step S28 and executes the processes of steps S33 to S35. In step S33, the controller 60 instructs the laser drive circuit 46 to stop laser light irradiation and the light emission signal supply circuit 45 to stop outputting the pulse train signal. As a result, the laser drive circuit 46 stops outputting the drive signal to the laser light source in the machining head 31, and the light emission signal supply circuit 45 stops outputting the pulse train signal, so the laser light source stops emitting the laser light. To do. In step S34, the controller 60 instructs the focus servo circuit 49 to stop the focus servo. Thereby, the focus control of the objective lens in the machining head 31 by the focus servo circuit 49 is also stopped. In step S35, the controller 60 instructs the feed motor control circuit 44 to stop the feed of the table 21 in the radial direction. As a result, the feed motor control circuit 44 stops the rotation of the feed motor 23. In step S36, the controller 60 instructs the spindle motor control circuit 41 to stop the rotation of the spindle motor 22. As a result, the spindle motor control circuit 41 stops the rotation of the spindle motor 22.

  Next, in step S37, the controller 60 instructs the feed motor control circuit 44 to move the table 21 to the initial radius position in the same manner as in step S13. And the controller 60 complete | finishes execution of a program in step S38.

  Thereafter, the operator removes the workpiece 10 set on the table 21, sets a new workpiece 10, and causes the program of FIG. 2 to be executed again. In this case, if there is no change in the processing conditions in the second and subsequent processing of the processing target 10, the processing in steps S12 and S13 in FIG. 2 is skipped.

  According to the embodiment configured as described above, the processing on the workpiece 10 is performed according to the radial profile of the workpiece 10 by the processes of steps S21 and S22 in FIG. 2A and steps S29 and S30 in FIG. 2B. The height and inclination of the head 31 are adjusted. Therefore, the focal position of the laser light emitted from the processing head 31 is always adjusted to the surface of the processing object 10, and the optical axis of the laser light is always kept perpendicular to the surface of the processing object 10. As a result, even if the profile (outer shape) of the surface of the workpiece 10 varies in the radial direction, the workpiece 10 is machined with high accuracy by the laser beam.

  Further, according to the embodiment configured as described above, the processing head 31 with respect to the table 21 is processed based on the profile of the processing object 10 by the processing of steps S25 and S26 of FIG. 2A and steps S31 and S32 of FIG. 2B. The relative radial movement speed is corrected. Therefore, when the radial surface of the workpiece 10 is inclined with respect to the movement direction of the machining head 31, the movement speed of the machining head 31 relative to the table 21 is corrected. As a result, the laser beam can always be moved at a constant speed with respect to the radial surface of the workpiece 10, and the workpiece 10 is processed with high accuracy by the laser beam.

  Further, according to the embodiment configured as described above, when profile data or data corresponding to the profile data is prepared in advance at the time of designing the workpiece 10, the process of step S16 in FIG. Data is input and used. Therefore, in this case, the previously prepared data is effectively used, and laser processing for adjusting and correcting based on the profile data is quickly performed. If the data prepared in advance does not exist, profile data is acquired by using the three-dimensional shape measuring apparatus 70 by the processing in steps S17 and S18 in FIG. 2A. Therefore, also in this case, highly accurate laser processing that performs adjustment and correction based on the profile data is realized.

  Further, the three-dimensional shape measuring apparatus 70 measures the three-dimensional shape of the workpiece 10 in a state where the position is fixed with respect to the table 21 and the workpiece 10 is set on the table 21. Thereby, since the three-dimensional shape measurement of the workpiece 10 is also performed in a series of steps of laser machining, the working efficiency of the laser machining is improved when the profile data of the workpiece 10 is not prepared in advance. . In the profile acquisition routine of FIG. 3, profile data representing a profile in the radial direction of the workpiece 10 is acquired by averaging the profiles at a plurality of different circumferential positions of the workpiece 10. Therefore, profile data considering the entire surface of the workpiece 10 is generated, and it becomes possible to make the laser processing for performing adjustment and correction based on the profile data more accurate.

  Next, an example of acquiring a coordinate conversion function F for converting the three-dimensional shape data based on the coordinate system M of the three-dimensional shape measuring apparatus 70 into the three-dimensional shape data based on the reference coordinate system S will be described.

  The operator moves the table 21 to the initial radius position by executing a program (not shown) similar to the process of step S13 in FIG. 2A, and positions the three-dimensional shape measuring apparatus 70 above the rotation center of the table 21 ( (See FIG. 12). In this state, nothing is placed on the table 21. Next, the operator uses the input device 61 to execute the coordinate conversion function acquisition program of FIG. The execution of the coordinate conversion function acquisition program is started in step S200.

  After starting the execution of the coordinate conversion function acquisition program, the controller 60 starts the operation of the rotation angle detection circuit 42 in step S201. Next, in step S <b> 202, the controller 60 causes the three-dimensional shape measurement device 70 to measure the three-dimensional shape, and acquires the three-dimensional shape data measured by the three-dimensional shape measurement device 70. In this case, as shown in FIG. 12, the surface of the table 21 is three-dimensionally measured. After acquiring the three-dimensional shape data in step S202, the controller 60 calculates an expression of the plane T corresponding to the upper surface of the table 21 in step S203. Specifically, the following method is adopted. The acquired three-dimensional shape data is represented by the coordinate system M of the three-dimensional shape measuring apparatus 70.

The three-dimensional shape data in a predetermined area is extracted from all the obtained three-dimensional shape data, and is substituted into the following formula 6 plane to calculate the coefficients a, b, and c by the least square method. (Formula derivation process 1). The predetermined area is designated as an area where the X and Y coordinate values are near “0”.

  Next, three-dimensional shape data whose distance from the plane T is within a predetermined range is extracted from all the acquired three-dimensional shape data (formula derivation process 2). Then, in order to determine whether the expression derived from the three-dimensional shape data in the predetermined region previously extracted represents the plane T of the table 21, the three-dimensional shape extracted from all the three-dimensional shape data It is determined whether or not there is a predetermined number of data (expression derivation process 3). If it is equal to or greater than the predetermined number, all the three-dimensional shape data extracted later, whose distance from the plane T is within the predetermined range, are substituted into the formula of the plane T in the formula 6, and the coefficients a, b, c is calculated (formula derivation process 4).

  On the other hand, if the number is less than the predetermined number, the three-dimensional shape data of the predetermined area adjacent to the previously extracted predetermined area (area where the X and Y coordinate values are near “0”) is extracted again. Then, the formula derivation processes 2 to 4 are performed again to derive the plane T formula. This process is repeated until the number of three-dimensional shape data whose distance from the plane T derived by the expression deriving process 1 is within a predetermined range reaches a predetermined number or more. As a result, the expression of the plane T corresponding to the upper surface of the table 21 is determined.

  After the process of step S203, the controller 60 displays the reference object 80 on the display device 62 so as to be placed in step S204. The reference object 80 is an object that can define a fixed point. In this embodiment, a sphere is adopted as the reference object 80, and the fixed point is the center of the sphere. As the reference object 80, other objects such as a rectangular parallelepiped, a polyhedron, a triangular pyramid, a cone, and a cylinder may be adopted as long as they can define a fixed point. In response to the instruction to install the reference object 80, the operator places the reference object 80 away from the center of rotation of the table 21, as shown in FIG.

Next, the controller 60 initializes a variable n indicating the number of rotations of the table 21 to “0” in step S205, and repeatedly executes the circulation process including steps S206 to S212. In step S206, the controller 60 causes the three-dimensional shape measurement apparatus 70 to measure the three-dimensional shape, and acquires the three-dimensional shape data measured by the three-dimensional shape measurement apparatus 70. In step S207, the fixed point coordinates P (x _n , y _n , z _n ) of the reference object 80 are calculated using the acquired three-dimensional shape data.

This fixed point coordinate calculation process is a known method as disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-333371. For example, the feature data of the reference object 80 is input in advance, and all the obtained three-dimensional data is obtained. The three-dimensional shape data representing the outer shape of the reference object 80 is extracted. Then, a fixed point of the reference object 80 is calculated using the extracted three-dimensional shape data. As in the present embodiment, when the reference object 80 is a sphere and the fixed point is the center of the sphere, the sphere and the radius are adopted as the feature data of the reference object 80. Then, three-dimensional shape data representing the outer shape of the sphere designated by the feature data is extracted from all the obtained three-dimensional shape data, and the extracted three-dimensional shape data is substituted into the following formula 7 representing the sphere. Then, the center coordinates (a, b, c) are calculated as fixed points of the sphere using the least square method. The center coordinates (a, b, c) are set as fixed point coordinates P (x _n , y _n , z _n ).

  After the processing in step S207, the controller 60 adds “1” to the variable n in step S208, and determines in step S209 whether the value n · θ is equal to or greater than 360 degrees. Here, θ is an angle at which the table 21 is rotated in order to calculate a fixed point of the reference object 80 at a different position, and is a predetermined angle of at least less than 120 degrees. That it is less than 120 degrees is because three or more fixed points of the reference object are necessary. If the value n · θ is less than 360 degrees, the controller 60 makes a “No” determination at step S209, and designates a rotation speed representing a predetermined low speed to the spindle motor control circuit 41 at step S210. Instructs the spindle motor 22 to start rotating at a low speed. The spindle motor control circuit 41 rotates the spindle motor 22 at a low speed using the rotation detection signal from the encoder 22b according to the instruction. The low speed rotation of the spindle motor 22 is because the reference object 80 is not moved on the table 21.

After the process of step S210, the controller 60 continues to input the rotation angle from the rotation angle detection circuit 42 in step S211, and continues the determination process of step S211 until the rotation angle of the table 21 reaches the predetermined angle θ. . When the rotation angle of the table 21 reaches the predetermined angle θ, the controller 60 instructs the spindle motor control circuit 41 to end the rotation of the spindle motor 22 and stops the rotation of the spindle motor 22 in step S212. Then, the controller 60 repeatedly executes the circulation process including steps S206 to S212 described above until the value n · θ reaches 360 degrees or more. By this circulation processing, at least three fixed point coordinates P (x ₀ , y ₀ , z ₀ ), P (x ₁ , y ₁ , z ₁ ), P (x ₂ , y ₂ ) in the reference object 80 located at different positions. , z ₂ ) .. are calculated.

When the value n · θ is 360 degrees or more, the controller 60 determines “Yes” in step S209 and determines the fixed point coordinates P (x ₀ , y ₀ , z ₀ ), P (x ₁ , y ₁ , z ₁ ), P (x ₂ , y ₂ , z ₂ )... are substituted into the following equation (8) and the coefficients a, b, c are calculated using the least squares method. An expression of the plane Pt including the coordinates is derived.

Next, in step S212, the controller 60 calculates the center coordinates O (x ₀₀ , y ₀₀ , z ₀₀ ) of the circle passing through the plurality of fixed points P. In this case, as shown in FIG. 14, first, the expressions of planes P1, P2,... Perpendicular to the straight line connecting the two fixed points P and including the midpoints of the two fixed points P are expressed as all the two fixed points P. Calculate with the set of The simultaneous equations formed from the expressions of the two planes P1, P2 (and planes P1, P3, planes P2, P3...) And the plane Pt are expressed as all two planes P1, P2 (and planes P1, P3, planes). Solve for each pair of P2, P3 ...). As a result, the coordinates of the intersections of all two planes P1, P2 (and planes P1, P3, planes P2, P3,...) And the plane Pt, that is, the center coordinates of a circle passing through a plurality of fixed points P, are all obtained. Are calculated for each set of two planes P1, P2 (and planes P1, P3, planes P2, P3,...). Finally, an average value of the calculated plurality of center coordinates is calculated as a center coordinate O (x ₀₀ , y ₀₀ , z ₀₀ ).

一方、平面Ｔの式は、前記ステップＳ２０３の処理により前記数６のように定められている。したがって、前記数９の直線Ｌの式と前記数６の平面Ｔの式との連立方程式を解いて座標値ｘ,ｙ,ｚを求めれば、直線Ｌと平面Ｔとの交点Ｔoの座標値(ｘ_to,ｙ_to,ｚ_to)が計算される。この交点Ｔoは、テーブル２１の表面における回転中心であり、基準座標系Ｓにおける座標原点である。 Next, in step S213, the controller 60 parallels the normal vector of the plane Pt (a plane including a plurality of fixed points P) and passes through the central coordinate O, and the plane T (corresponding to the upper surface of the table 21). The coordinate values (x _to , y _to , z _to ) of the intersection To are calculated (see FIG. 15). In this case, the equation of the straight line L is expressed by the following equation 9 using the center coordinates O (x ₀₀ , y ₀₀ , z ₀₀ ). a, b, c are components of the normal vector of the plane Pt, and are a, b, c in the equation (8).

On the other hand, the expression of the plane T is determined as shown in Equation 6 by the process of Step S203. Therefore, if the coordinate values x, y, and z are obtained by solving simultaneous equations of the equation of the straight line L in the equation 9 and the equation of the plane T in the equation 6, the coordinate value of the intersection To of the straight line L and the plane T ( x _to , y _to , z _to ) are calculated. This intersection To is the center of rotation on the surface of the table 21 and the coordinate origin in the reference coordinate system S.

Next, in step S214, the controller 60 calculates a normal vector C _M of the plane T and two vectors A _M and B _M perpendicular to the normal vector of the plane T. In this vector calculation process, first, assuming that the expression of the plane T is a · x + b · y + c · z + 1 = 0, the normal vectors of the plane T are (a, b, c) and (−a, −b, − Therefore, a normal vector that matches the direction of the Z coordinate axis in the reference coordinate system S (that is, the vector faces the direction of the three-dimensional shape measuring apparatus 70) is selected. In this case, when the inner product is calculated with the reference vector (0, 0, 1) in the Z coordinate axis direction in the coordinate system M of the three-dimensional shape measuring apparatus 70 and the normal vector of the plane T, the sign becomes negative. The normal vector may be selected. A unit vector {1 / (a ² + b ² + c ² ) ^1/2 } · (a, b, c) of this vector is defined as a vector C _M.

Next, when the coordinate system M of the three-dimensional shape measuring apparatus 70 is rotated around the Y coordinate axis and the X coordinate axis is parallel to the plane T, a vector parallel to the X coordinate axis is assumed. In the coordinate system M of the three-dimensional shape measuring apparatus 70, the y coordinate value component of this vector is “0”, the x coordinate value component is “1”, and the z coordinate value component is e. Since this vector is perpendicular to the vector C _M , the inner product is “0”. Therefore, e is calculated from a + c · e = 0. A unit vector {1 / (1 + e ² ) ^1/2 } · (a, b, c) of this vector (1, 0, e) is defined as a vector A _M. Next, the cross product of the vector C _M and the vector A _M is calculated, and this vector is defined as B _M.

ここで、値ｇ₁₁,ｇ₁₂,ｇ₁₃,ｇ₂₁,ｇ₂₂,ｇ₂₃,ｇ₃₁,ｇ₃₂,ｇ₃₃は座標系Ｍを基準座標系Ｓに平行にするための回転行列値を示し、値ａ,ｂ,ｃは座標系Ｍの原点を基準座標系Ｓの原点に移動させるための平行移動成分を示す。 Next, in step S215, the controller 60 calculates a coordinate conversion function F for converting the three-dimensional shape data of the coordinate system M of the three-dimensional shape measuring apparatus 70 into the three-dimensional shape data of the reference coordinate system S. To do. The same three-dimensional shape data represented by the coordinate values of the coordinate system M of the three-dimensional shape measuring apparatus 70 is (x _M , y _M , z _M ), and the coordinate values of the reference coordinate system S ( x _s , y _s , z _s ), the coordinate transformation function F is expressed by the following formula 10.

Here, the values g ₁₁ , g ₁₂ , g ₁₃ , g ₂₁ , g ₂₂ , g ₂₃ , g ₃₁ , g ₃₂ , g ₃₃ indicate rotation matrix values for making the coordinate system M parallel to the reference coordinate system S. , Values a, b, and c indicate parallel movement components for moving the origin of the coordinate system M to the origin of the reference coordinate system S.

Further, the same vector represented by the vector component of the coordinate system M of the three-dimensional shape measuring apparatus 70 is (x _M , y _M , z _M ), and the one represented by the vector component of the reference coordinate system S is (x _S , y _S , z _S ), the following equation 11 is also established.

Since the vector components As, Bs, and Cs that are the vectors A, B, and C in the reference coordinate system S are (1, 0, 0), (0, 1, 0), (0, 0, 1), the number 11 (x _S , y _S , z _S ) is substituted with (1, 0, 0), (0, 1, 0), (0, 0, 1), and (x _M , y _M substitutes z _M) vector calculated in the step S124 in a _M, B _M, the vector components of C _M. As a result, nine simultaneous equations are established, and the values g ₁₁ , g ₁₂ , g ₁₃ , g ₂₁ , g ₂₂ , g ₂₃ , g ₃₁ , g ₃₂ , g ₃₃ are obtained by solving them.

Next, since the coordinate value of the intersection To, which is the origin in the reference coordinate system S, is (0, 0, 0), (x _S , y _S , z _S ) in the above equation 10 is (0, 0, 0). And (x _to , y _to , z _to ) calculated in step S213 is substituted for (x _M , y _M , z _M ). As a result, three equations are established, and the values a, b, and c in Equation 11 can be obtained by solving the simultaneous equations. Then, in the step S215, the controller 60, these values _{g 11, g 12, g 13} , g 21, g 22, g 23, g 31, g 32, g 33, a, b, and c the number of the It is stored in a non-volatile memory such as a hard disk together with the equation (10). In step S216, the execution of the coordinate conversion number acquisition program is terminated.

  As mentioned above, although embodiment of this invention was described in detail, in implementing this invention, it is not limited to the said embodiment, A various deformation | transformation is possible unless it deviates from the objective of this invention.

  For example, in the above embodiment, when the three-dimensional shape measuring device 70 is fixed above the table 21 and the profile data in the radial direction of the workpiece 10 is not input, the three-dimensional shape of the workpiece 10 is measured by the three-dimensional shape measurement. Shape data was acquired, and a profile in the radial direction of the workpiece 10 was obtained by this data processing. However, if the profile data in the radial direction of the workpiece 10 can always be prepared from the design data, the three-dimensional shape measuring device 70 may not be provided. In addition, regardless of the presence or absence of radial profile data of the workpiece 10, the three-dimensional shape data of the workpiece 10 is always acquired by three-dimensional shape measurement, and the radial profile of the workpiece 10 is obtained by this data processing. May be requested.

  Moreover, in the said embodiment, the three-dimensional shape measuring apparatus 70 was fixed above the table 21, and three-dimensional shape measurement and laser processing were implemented in a series of processes. However, instead of this, the 3D shape measuring device 70 is placed in a completely different place, the 3D shape of the workpiece 10 is measured and 3D shape data is recorded on the recording medium, or the controller 60 can download the server. After storing the three-dimensional shape data, the processing object 10 may be set on the table 21 and the three-dimensional shape data of the processing object 10 may be read from the recording medium or downloaded from the server. In this case, the workpiece 10 is set so as to be set on a table having an upper surface constituted by a plane and where the position on which the workpiece 10 is placed is determined. Then, a position corresponding to the rotation center of the table 21 is made known by a mark, a pin or the like. According to this, only the method of calculating the coordinates of the center of rotation when obtaining the coordinate transformation function F is different from the above embodiment, and the other processes are the same as in the above embodiment, and are the same as in the above embodiment. Thus, a profile in the radial direction of the workpiece 10 can be obtained.

  In the above embodiment, the X-Z plane data in a plurality of rotating coordinate systems obtained by rotating the three-dimensional shape data by a predetermined angle θ in the profile acquisition routine of FIG. In addition, the profile of the workpiece 10 is obtained based on data representing the height of the upper surface of the workpiece 10. However, if the machining accuracy of the workpiece 10 is high, a profile in the radial direction may be obtained directly from the three-dimensional shape data, and the profile data in the radial direction of the workpiece 10 may be used.

  Moreover, in the said embodiment, while adjusting the height D and inclination (phi) of the process head 31 with the profile of the process target object 10, the feed speed of the process target object 10 in the radial direction was correct | amended. However, when the workpiece 10 is close to a flat plate or does not require high machining accuracy, a part of the adjustment and correction may be omitted.

  Further, in the above embodiment, the processing head 31 is moved in the radial direction with respect to the workpiece 10 by moving the table 21 in the radial direction by the feed motor 23. However, the machining head 31 may be moved in the radial direction relative to the table 21. Therefore, instead of the table 21, the machining head 31 may be driven by a motor and moved in the radial direction with respect to the table 21.

It is the schematic which shows the whole laser processing apparatus concerning one Embodiment of this invention. It is a flowchart which shows the first half part of the main program performed by the controller of FIG. 3 is a flowchart showing a second half of a main program executed by the controller of FIG. 1. It is a flowchart which shows the detail of the profile acquisition routine of FIG. It is a flowchart which shows the coordinate transformation function acquisition program performed by the controller of FIG. It is the schematic which shows arrangement | positioning of a table, a three-dimensional shape measuring apparatus, and a process head in the state which located the table in the initial radius position. It is a figure explaining the coordinate system and reference | standard coordinate system of a three-dimensional shape measuring apparatus in the state which located the table in the initial radius position. It is a figure explaining the rotation coordinate system which rotated the reference coordinate system around the Z-axis centering on the table. It is a figure explaining extraction of the three-dimensional shape data of the XZ plane in a rotation coordinate system. (A) is a figure for demonstrating the radial position which separated by the distance B, (B) is a figure for demonstrating the interpolation calculation of the Z coordinate value in a radial position. It is a figure which shows the relationship between a radial position and the height of a process head. It is a figure for demonstrating the inclination of the processing head with respect to a radial position. It is a layout diagram of a table and a three-dimensional shape measuring device when measuring the three-dimensional shape of the table. It is a figure which shows the state which mounted the reference | standard object on the table. It is explanatory drawing of the process for calculating the center coordinate of the circle | round | yen which passes through several fixed points. It is explanatory drawing for demonstrating the plane containing several fixed points, and the plane equivalent to the upper surface of a table.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Processing object, 21 ... Table, 22 ... Spindle motor, 23 ... Feed motor, 30 ... Head drive device, 31 ... Processing head, 35, 36 ... Motor, 41 ... Spindle motor control circuit, 42 ... Rotation angle detection circuit , 43 ... Radial position detection circuit, 44 ... Feed motor control circuit, 45 ... Light emission signal supply circuit, 46 ... Laser drive circuit, 49 ... Focus servo circuit, 51 ... Height detection circuit, 53 ... Angle detection circuit, 60 ... Controller 70 ... 3D shape measuring device, 80 ... reference object

Claims (10)

A table for setting the workpiece,
A processing head for irradiating a processing target set on the table with a laser beam to laser process the processing target;
A rotating device for rotating the table;
In a laser processing apparatus comprising a radial feed device for moving the processing head relative to the table in the radial direction of the table,
A laser processing apparatus comprising: a head adjusting unit that adjusts at least one of a height and a tilt of the processing head with respect to a processing object based on profile data representing a profile in a radial direction of the processing object. . The laser processing apparatus according to claim 1, further comprising:
A laser processing apparatus comprising: a moving speed correcting unit that corrects a relative moving speed of the processing head in the radial direction with respect to the table by the radial feeding apparatus based on the profile data. The laser processing apparatus according to claim 1 or 2,
The profile data is data prepared in advance when designing a workpiece or data generated based on data prepared in advance when designing a workpiece, and further prepared in advance when designing a workpiece. A laser processing apparatus comprising: first profile data acquisition means for acquiring the data and using the acquired data as the profile data or generating the profile data from the acquired data. The laser processing apparatus according to any one of claims 1 to 3, further comprising: a three-dimensional shape measuring apparatus that measures a three-dimensional shape of a workpiece and acquires three-dimensional shape data representing the three-dimensional shape; ,
Second profile data acquisition means for generating and acquiring the profile data representing the profile in the radial direction of the workpiece based on the three-dimensional shape data acquired by the three-dimensional shape measuring apparatus is provided. A featured laser processing apparatus. In the laser processing apparatus of Claim 4,
The laser processing apparatus, wherein the three-dimensional shape measuring apparatus measures a three-dimensional shape of a processing object in a state where the position is fixed with respect to the table and the processing object is set on the table. In the laser processing apparatus according to claim 4 or 5,
The second profile data acquisition means averages profiles at a plurality of different circumferential positions of the workpiece and acquires profile data representing a profile in the radial direction of the workpiece. . Set the workpiece on the table,
The processing target is irradiated with the laser beam from the processing head while rotating the table and moving the processing head for irradiating the laser beam relative to the table in the radial direction of the table. In a laser processing method for laser processing an object,
A laser processing method, wherein at least one of a height and an inclination of the processing head with respect to a processing target is adjusted using profile data representing a profile in a radial direction of the processing target. The laser processing method according to claim 7, further comprising:
A laser processing method, wherein a relative moving speed of the processing head in the radial direction with respect to the table is corrected based on the profile data. In the laser processing method according to claim 7 or 8,
The profile data is data prepared in advance when designing a workpiece or data generated based on data prepared in advance when designing a workpiece, and further prepared in advance when designing a workpiece. The laser processing method is characterized in that the acquired data is acquired and the acquired data is used as the profile data, or the profile data is generated from the acquired data. The laser processing method according to claim 7 or 8, further comprising: measuring a three-dimensional shape of a workpiece by using a three-dimensional shape measuring device to obtain three-dimensional shape data representing the three-dimensional shape;
A laser processing method comprising: generating and acquiring the profile data representing a radial profile of the workpiece based on the acquired three-dimensional shape data.

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