Cutting device

Abstract

The present application provides a cutting device capable of detecting abnormality of the shape of the outer diameter of a cutting tool. The management unit of the cutting device includes: a measurement unit that measures the light receiving amount of light emitted from a light emitting unit and received by a light receiving unit in a state where the cutting tool is located between the light emitting unit and the light receiving unit; a measured waveform forming unit that forms a measured waveform representing the shape of the outer diameter of the cutting tool based on the light receiving amount measured at a plurality of rotation angles of the cutting tool; a comparison waveform forming unit that forms a comparison waveform representing the shape of the outer diameter of the cutting tool measured by the measurement unit in the case of installation with an arbitrary eccentricity; an ideal waveform identifying unit that identifies the comparison waveform with the most matching region with the measured waveform as an ideal waveform; a difference calculation unit that calculates the area of the difference between the measured waveform and the ideal waveform; and a determination unit that determines that the shape of the cutting tool is abnormal in the case where the difference exceeds a threshold value.

Description

Technical Field

[0001] The present invention relates to a cutting device equipped with a cutting tool. Background Art

[0002] A cutting device that uses a cutting tool to cut and divide a workpiece into individual components is used (for example, see Patent Document 1). The cutting device shown in Patent Document 1 periodically performs so-called dressing, in which the cutting edge cuts into a dressing plate, in order to align the center of rotation of the cutting tool with the center of the outer edge of the cutting edge.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 10-055985

[0004] In conventional cutting devices, even trimming the cutting edge cannot eliminate deformation caused by uneven wear of the cutting tool, potentially degrading the machining quality. However, conventional cutting devices have a problem: they cannot detect abnormalities in the outer diameter shape caused by such deformation of the cutting tool. Summary of the Invention

[0005] Therefore, an object of the present invention is to provide a cutting device capable of detecting an abnormality in the shape of the outer diameter of a cutting tool.

[0006] According to one aspect of the present invention, there is provided a cutting device comprising: a chuck table for holding a workpiece; a cutting unit for cutting the workpiece held on the chuck table using a cutting tool mounted on a spindle; and a management unit for managing the cutting tool mounted on the spindle, the management unit comprising: a light emitting portion; a light receiving portion which is opposite to the light emitting portion and receives light emitted by the light emitting portion; a measuring portion which measures the amount of light emitted from the light emitting portion and received by the light receiving portion when the cutting tool is located between the light emitting portion and the light receiving portion; and a measured waveform forming portion which forms a waveform based on the amount of light received measured at a plurality of rotation angles of the cutting tool. , forming a measured waveform representing the shape of the outer diameter of the cutting tool; a comparison waveform forming part, which forms a comparison waveform representing the shape of the outer diameter of the cutting tool measured by the measuring part when the cutting tool is mounted on the spindle with an arbitrary eccentricity; an ideal waveform identifying part, which changes the eccentricity used in the comparison waveform forming part in stages to form a plurality of comparison waveforms, and identifies the comparison waveform having the largest area consistent with the measured waveform as an ideal waveform; a difference calculating part, which calculates the area of ​​the area where the difference is generated by superimposing the measured waveform and the ideal waveform; and a determination part, which determines that the shape of the cutting tool is abnormal when the difference exceeds a threshold value.

[0007] According to another aspect of the present invention, a cutting device is provided, which comprises: a chuck table for holding a workpiece; a cutting unit for cutting the workpiece held on the chuck table using a cutting tool mounted on a spindle; and a management unit for managing the cutting tool mounted on the spindle, the management unit comprising: a light emitting portion for emitting light; a light receiving portion for receiving the light emitted by the light emitting portion, which is opposite to the light emitting portion; a measuring portion for measuring the amount of light emitted from the light emitting portion and received by the light receiving portion when the cutting tool is located between the light emitting portion and the light receiving portion; a measured waveform forming portion for measuring the amount of light emitted from the light emitting portion and received by the light receiving portion based on a plurality of cutting tools. The received light amount measured by the rotation angle meter forms a measured waveform representing the shape of the outer diameter of the cutting tool; an ideal waveform forming unit, which forms an ideal waveform representing the shape of the outer diameter of the cutting tool when the cutting tool is mounted on the spindle with a certain eccentricity; a difference calculating unit, which calculates the area of ​​a region where the difference is generated by superimposing the measured waveform and the ideal waveform; and a judgment unit, which judges that the shape of the cutting tool is abnormal when the difference exceeds a threshold value, and the ideal waveform forming unit calculates the intermediate value between the maximum value and the minimum value of the measured waveform, and forms an ideal waveform with the difference between the intermediate value and the maximum value and the minimum value as the eccentricity of the cutting tool.

[0008] The present invention can detect abnormality in the shape of the outer diameter of a cutting tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a perspective view showing a configuration example of the cutting device according to the first embodiment.

[0010] Figure 2 It shows Figure 1 A three-dimensional diagram of a structural example of a cutting unit of a cutting device.

[0011] Figure 3 It shows Figure 1 A side view of a structural example of a cutting unit and a management unit of a cutting device.

[0012] Figure 4 It shows Figure 1 A graph showing an example of processing of a management unit of a cutting device.

[0013] Figure 5 It is shown in Figure 1 A top view of the shape of the outer diameter of a cutting tool used in a cutting device.

[0014] Figure 6 It shows Figure 1 A flowchart of an example of the operation flow of the cutting device.

[0015] Figure 7This is a side view showing a configuration example of a cutting unit and a management unit of a cutting device according to a second embodiment.

[0016] Figure 8 It shows Figure 7 A graph showing an example of processing of a management unit of a cutting device.

[0017] Description of labels

[0018] 1, 1-2: Cutting device; 10: Chuck worktable; 20: Cutting unit; 21: Cutting tool; 30, 30-2: Management unit; 31: Light-emitting unit; 32: Light-receiving unit; 33: Measuring unit; 34: Measured waveform forming unit; 35: Comparative waveform forming unit; 36: Ideal waveform recognition unit; 36-2: Ideal waveform forming unit; 37: Differential calculation unit; 38: Judgment unit; 100: Workpiece. DETAILED DESCRIPTION

[0019] The following describes embodiments of the present invention in detail with reference to the accompanying drawings. The present invention is not limited to the contents described in the following embodiments. In addition, the components described below include components that are easily conceivable to those skilled in the art, and components that are substantially the same. Furthermore, the structures described below may be appropriately combined. In addition, various omissions, substitutions, or modifications of the structures may be made without departing from the scope of the present invention.

[0020] (First embodiment)

[0021] A cutting device 1 according to a first embodiment of the present invention will be described with reference to the drawings. Figure 1 It is a perspective view showing a configuration example of the cutting device 1 according to the first embodiment. Figure 2 It shows Figure 1 A perspective view of a structural example of a cutting unit 20 of a cutting device 1. Figure 3 It shows Figure 1 sectional view of a structural example of the cutting unit 20 and the management unit 30 of the cutting device 1. Figure 4 It shows Figure 1 Graph showing an example of processing by the management unit 30 of the cutting device 1 . Figure 5 It is shown in Figure 1 A plan view showing the shape of the outer diameter of the cutting tool 21 used in the cutting device 1.

[0022] The cutting device 1 is a device for cutting a workpiece 100. In the first embodiment, the workpiece 100 cut by the cutting device 1 is, for example, a wafer such as a circular semiconductor wafer or an optical device wafer with silicon, sapphire, gallium, etc. as a base material. The workpiece 100 has devices 103 formed in an area divided by a plurality of predetermined dividing lines 102 formed in a grid shape on a flat front surface 101. The workpiece 100 has an adhesive tape 105 adhered to the back surface 104 on the back side of the front surface 101, and a ring frame 106 is installed on the outer edge of the adhesive tape 105. In addition, in the present invention, the workpiece 100 may also be a rectangular packaging substrate, a ceramic plate, a glass plate, etc. having a plurality of resin-sealed devices.

[0023] like Figure 1 As shown, the cutting device 1 has a chuck table 10, a cutting unit 20, and a management unit 30. The chuck table 10 uses the holding surface 11 to attract and hold the back side 104 of the workpiece 100 via the adhesive tape 105. The cutting unit 20 uses the cutting tool 21 that rotates around the axis to cut the workpiece 100 attracted and held by the chuck table 10. The cutting device 1 moves the workpiece 100 and the cutting tool 21 on the chuck table 10 relative to each other along the predetermined dividing line 102 through the X-axis moving unit 41, the Y-axis moving unit 42, and the Z-axis moving unit 43, and performs cutting along the predetermined dividing line 102. Figure 1 As shown, the cutting device 1 is a so-called facing dual-axis cutting device having two cutting units 20 (i.e., a two-spindle cutting machine).

[0024] The cutting apparatus 1 further includes a sub-chuck table 15. The sub-chuck table 15 is disposed adjacent to the chuck table 10 and holds a dressing plate 150 by suction via a holding surface 16. The dressing plate 150 is used for dressing by being cut by the cutting tool 21 to actively wear the cutting tool 21 and thereby improve machining quality.

[0025] like Figure 2 and Figure 3 As shown, the cutting unit 20 includes a cutting tool 21 , a spindle 22 , a spindle housing 23 , a tool holder 24 , a tool cover 25 , water supply nozzles 26 - 1 , 26 - 2 , and 26 - 3 , a water supply source connection portion 27 , a trough member 28 , and a lifting portion 29 .

[0026] The cutting tool 21 is fixed to the front end of the spindle 22 via the tool holder 24 and is rotated by the spindle 22 as a rotation axis, thereby cutting the workpiece 100. The cutting tool 21 is a so-called hub tool in the first embodiment. Figure 2 and Figure 3As shown, the cutting tool 21 has an annular cutting edge 21-1 and a disc-shaped base 21-2. The cutting edge 21-1 is provided on the outer periphery of the base 21-2 and protrudes from the outer periphery of the base 21-2. The cutting edge 21-1 is composed of abrasive grains such as diamond or CBN (Cubic Boron Nitride) and a binder material (bonding material) such as metal or resin, and is formed to a predetermined thickness. The base 21-2 has an insertion hole 61 (see FIG. 6 ) in the center for fixing to the tool holder 24. Figure 5 ) and is formed into an annular shape. The base 21-2 is made of a metal such as an aluminum alloy. In addition, the cutting tool 21 in the present invention is not limited to a hub tool, and can also be a so-called hubless tool consisting only of a cutting edge 21-1 having an insertion hole 61.

[0027] like Figure 3 As shown, the spindle 22 is housed in the spindle housing 23 so as to be rotatable about its axis in the Y-axis direction. The front end of the spindle 22 protrudes outward from one end of the spindle housing 23. A motor (not shown) is connected to the base end of the spindle 22 for rotating the spindle 22. The spindle 22 serves as the rotation axis of the cutting tool 21. The tool holder 24 clamps the cutting tool 21 with a circular plate-shaped flange portion, inserts the cylindrical boss portion into the insertion hole 61 and is mounted on the front end of the spindle 22, thereby mounting the cutting tool 21 on the front end of the spindle 22 in a manner that allows it to rotate about its axis.

[0028] The tool cover 25 is mounted on the front end side of the spindle housing 23, covering the top, front and rear of the cutting tool 21. The tool cover 25 has a plurality of water channels formed therein, such as Figure 2 As shown, water supply nozzles 26-1, 26-2, and 26-3 are provided at one end of the lower side of the multiple water channels, and a water supply source connection portion 27 is provided at the other end of the upper side of the multiple water channels. The water supply nozzle 26-1 supplies cutting fluid supplied from the water supply source connection portion 27 to the side of the cutting edge 21-1 of the cutting tool 21. The water supply nozzle 26-2 supplies cutting fluid supplied from the water supply source connection portion 27 to the front of the cutting edge 21-1 of the cutting tool 21. The water supply nozzle 26-3 supplies cutting fluid supplied from the water supply source connection portion 27 to the workpiece 100 in front of the cutting edge 21-1 of the cutting tool 21. The cutting fluid is, for example, pure water.

[0029] like Figure 3 As shown, the groove member 28 is formed with a groove 28-1 having a width greater than the thickness of the cutting edge 21-1 of the cutting tool 21. The groove member 28 is provided on the blade cover 25 and holds the upper end of the cutting edge 21-1 via the groove 28-1. The lifting unit 29 lifts and lowers the groove member 28.

[0030] like Figure 1 and Figure 3As shown, the management unit 30 includes a light emitting unit 31, a light receiving unit 32, and a control unit 50. The control unit 50 includes a measuring unit 33, a measured waveform forming unit 34, a comparative waveform forming unit 35, an ideal waveform identifying unit 36, a difference calculating unit 37, a determining unit 38, and a comparative waveform storing unit 39.

[0031] like Figure 3 As shown, a light-emitting unit 31 is provided on one side wall of the groove 28-1 and emits light toward the other side wall of the groove 28-1. Within the light-emitting unit 31, a light source 31-1 is optically connected via an optical fiber, etc., and emits light from the light source 31-1. A light-receiving unit 32 is provided on the other side wall of the groove 28-1, opposite the light-emitting unit 31, and receives the light emitted by the light-receiving unit 31. Within the light-receiving unit 32, a light-receiving element 32-1 is optically connected via an optical fiber, etc., and the light reaching the light-receiving unit 32 is detected by the light-receiving element 32-1.

[0032] like Figure 3 As shown, the measuring unit 33 is electrically connected to the light receiving element 32-1. When the cutting tool 21 is positioned between the light emitting unit 31 and the light receiving unit 32, the measuring unit 33 measures the amount of light emitted from the light emitting unit 31 and received by the light receiving unit 32. The measuring unit 33 is electrically connected to the control unit 50, which will be described later, and transmits information on the measured amount of light received to the control unit 50.

[0033] like Figure 4 As shown, the measured waveform forming unit 34 forms a measured waveform 71 representing the shape of the outer diameter of the cutting tool 21 based on the amount of received light measured at multiple rotation angles of the cutting tool 21. Here, the shape of the outer diameter of the cutting tool 21 refers to the planar shape of the outer edge of the cutting edge 21-1 of the cutting tool 21.

[0034] like Figure 5 As shown, the comparative waveform forming portion 35 forms the following comparative waveforms 72-1, 72-2, and 72-3: the planar shape of the outer edges 66-1, 66-2, and 66-3 of the cutting edge 21-1 of the cutting tool 21 is not abnormal in shape due to a portion being more worn than other portions, but is substantially circular, and shows that when the cutting tool 21 is mounted on the spindle 22 with an arbitrary eccentricity 67-1, 67-2, and 67-3, as shown in FIG. Figure 4 The planar shapes of the outer edges 66-1, 66-2, and 66-3 of the cutting edge 21-1 of the cutting tool 21 measured by the measuring unit 33 are shown in FIG. The ideal waveform identifying unit 36 ​​changes the eccentricities 67-1, 67-2, and 67-3 used in the comparative waveform forming unit 35 in stages to form a plurality of comparative waveforms 72-1, 72-2, and 72-3. Figure 4 As shown, the comparative waveform 72 - 2 having the largest area that matches the measured waveform 71 is identified as the ideal waveform 74 .

[0035] Here, the term "abnormal shape" for the outer edge of the cutting edge 21-1 of the cutting tool 21 refers to a deviation from a circular shape. More specifically, it refers to a region where the difference between the planar shape of the outer edge of the cutting tool 21 and the circle closest to the planar shape is superimposed exceeds a predetermined value. If the planar shape of the outer edge of the cutting tool 21 is not abnormal, the planar shape of the outer edge of the cutting tool 21 is considered normal. The predetermined value is appropriately determined based on the area of ​​the region where the difference between the planar shape of the outer edge of any cutting tool 21 with no machining quality issues and the circle closest to the planar shape is superimposed.

[0036] In addition, the eccentricity refers to the offset between the rotating axis of the main shaft 22 on which the cutting tool 21 is installed and the center of the cutting tool 21. Since the diameter of the insertion hole 61 of the cutting tool 21 is formed to be slightly larger than the diameter of the boss portion of the main shaft 21 on which the insertion hole 61 is installed, some gap is generated between the two during installation, and sometimes it is generated when the main shaft 22 rotates.

[0037] The amount of received light measured by the measuring unit 33 decreases at a rotation angle where the outer edge 62 of the cutting edge 21-1 of the cutting tool 21 protrudes radially from the rotation center of the cutting tool 21, and increases at a rotation angle where the outer edge 62 of the cutting edge 21-1 of the cutting tool 21 is recessed radially. Therefore, the measured waveform 71 represents the planar shape of the outer edge 62 of the cutting edge 21-1 of the cutting tool 21 mounted on the spindle 22. Figure 5 As shown, when the center of the cutting tool 21 is not eccentric with respect to the center of the spindle 22 and the planar shape of the outer edge 65 of the cutting edge 21-1 is not abnormal but substantially circular, the amount of light received measured by the measuring unit 33 is constant regardless of the rotation angle. Figure 5 As shown, the amount of light received measured by the measuring unit 33 is when the center of the cutting tool 21 is eccentric with respect to the center of the spindle 22 and the planar shape of the outer edges 66-1, 66-2, and 66-3 of the cutting edge 21-1 is not abnormal but is substantially circular. Figure 4 As shown, the sine waves have amplitudes 73 - 1 , 73 - 2 , and 73 - 3 corresponding to the eccentricities 67 - 1 , 67 - 2 , and 67 - 3 .

[0038] The region where the comparison waveforms 72-1, 72-2, and 72-3 agree with the measured waveform 71 is the rotation angle where the difference in light intensity from the measured waveform 71 is less than a predetermined value. The predetermined value is appropriately determined based on the difference between the measured waveform 71 and the ideal waveform 74 of any cutting tool 21 with no problem in machining quality.

[0039] The difference calculation unit 37 calculates the difference between the measured waveform 71 and the ideal waveform 74. Figure 4The area of ​​region 75 shown in FIG. This area 75 quantifies the degree to which the planar shape of the outer edge 62 of the cutting tool 21 deviates from a circle. If the difference exceeds a predetermined threshold, the determination unit 38 determines that the planar shape of the outer edge 62 of the cutting edge 21-1 of the cutting tool 21 is abnormal. The predetermined threshold is appropriately determined based on the area of ​​region 75 where the difference is found by superimposing the measured waveform 71 of any cutting tool 21 with no machining quality issues on its ideal waveform 74.

[0040] The comparison waveform storage unit 39 stores the arbitrary eccentricities 67 - 1 , 67 - 2 , and 67 - 3 in correspondence with the comparison waveforms 72 - 1 , 72 - 2 , and 72 - 3 according to the positional relationship between the cutting tool 21 and the groove-shaped member 28 .

[0041] The control unit 50 controls each component of the cutting device 1, causing the cutting device 1 to perform various operations related to machining the workpiece 100 and various operations related to determining the shape of the cutting tool 21. In the first embodiment, the control unit 50 includes a computer system. The control unit 50 includes: an arithmetic processing unit having a microprocessor such as a CPU (central processing unit); a storage device having a memory such as a ROM (read only memory) or a RAM (random access memory); and an input / output interface device. The arithmetic processing unit performs arithmetic processing according to the computer program stored in the storage device and outputs control signals for controlling the cutting device 1 to the various components of the cutting device 1 via the input / output interface device.

[0042] The functions of measured waveform forming unit 34, comparative waveform forming unit 35, ideal waveform identifying unit 36, difference calculating unit 37, and determining unit 38 are realized by executing a computer program stored in a storage device by the arithmetic processing unit of control unit 50. Comparative waveform storage unit 39 is realized by the storage device of control unit 50.

[0043] The cutting device 1 further includes a display unit 51 and a display light 52. The display unit 51 is composed of a liquid crystal display device or the like that displays the status of the machining operation and images. The display unit 51 switches the displayed image under the control of the control unit 50. The display unit 51 displays the determination result of the determination unit 38 and notifies the operator of the cutting device 1. The display light 52 is illuminated under the control of the control unit 50. By illuminating the display light 52, the operator of the cutting device 1 is informed of the determination result of the determination unit 38.

[0044] The operation of the cutting device 1 according to the first embodiment will be described. The cutting device 1 according to the first embodiment performs an operation to determine the planar shape of the outer edge 62 of the cutting edge 21-1 of the cutting tool 21 mounted on the front end of the spindle 22 after replacing the cutting tool 21, after performing trimming of the cutting tool 21, or before or during cutting processing by the cutting tool 21 (hereinafter, the operation to determine the shape of the cutting tool 21 will be omitted as appropriate).

[0045] Figure 6 It shows Figure 1 Flowchart of an example of the process of the operation of the cutting device 1. Figure 6 As shown, the cutting apparatus 1 first performs dressing (step ST11) by causing the cutting edge 21-1 of the cutting tool 21 to cut into the dressing plate 150 held by the holding surface 16 of the subchuck table 15. When the dressing is completed ("YES" in step ST12), the cutting apparatus 1 performs a shape determination operation for the cutting tool 21 (step ST13).

[0046] In the operation of determining the shape of the cutting tool 21, the control unit 50 first adjusts the vertical position of the groove-shaped member 28 using the lifting unit 29 so that the cutting tool 21 is located between the light emitting unit 31 and the light receiving unit 32. Next, while rotating the cutting tool 21 about its axis, the control unit 50 generates light using the light emitting unit 31, receives the light emitted by the light emitting unit 31 using the light receiving unit 32, and measures the amount of light received by the light receiving unit 32 using the measuring unit 33.

[0047] Then, the measured waveform forming section 34 analyzes the temporal change of the received light amount measured by the measuring section 33, as shown in FIG. Figure 4 As shown, a measured waveform 71 is formed that indicates changes in the amount of received light with respect to the rotation angle of the cutting tool 21 .

[0048] After forming the measured waveform 71, the ideal waveform recognition unit 36 ​​gradually changes the eccentricities 67-1, 67-2, and 67-3 used in the comparison waveform formation unit 35. Next, the comparison waveform formation unit 35 forms comparison waveforms 72-1, 72-2, and 72-3 based on the eccentricities 67-1, 67-2, and 67-3 determined by the ideal waveform recognition unit 36 ​​and with reference to the comparison waveform storage unit 39. Then, the ideal waveform recognition unit 36 ​​generates the comparison waveforms 72-1, 72-2, and 72-3 based on the plurality of comparison waveforms 72-1, 72-2, and 72-3 formed by the comparison waveform formation unit 35. Figure 4 As shown, the comparative waveform 72 - 2 having the largest area that matches the measured waveform 71 is identified as the ideal waveform 74 .

[0049] After identifying the ideal waveform 74, the difference calculation unit 37 calculates the area of ​​a region 75 where the difference is generated by superimposing the measured waveform 71 and the ideal waveform 74. Based on the area of ​​the region 75 calculated by the difference calculation unit 37, the determination unit 38 determines that the planar shape of the outer edge 62 of the cutting edge 21-1 of the cutting tool 21 is abnormal if the area of ​​the region 75 exceeds a predetermined threshold value, and determines that the planar shape of the outer edge 62 of the cutting edge 21-1 of the cutting tool 21 is normal if the area of ​​the region 75 is below the predetermined threshold value.

[0050] When the control unit 50 determines that the planar shape of the outer edge 62 of the cutting edge 21-1 of the cutting tool 21 is normal ("Yes" in step ST14) in the shape determination action of the cutting tool 21, the control unit 50 notifies the operator of the cutting device 1 of the determination result through the display unit 51 or the display light 52 (step ST15), thereby ending the process of a series of actions.

[0051] When the control unit 50 determines that the planar shape of the outer edge 62 of the cutting edge 21-1 of the cutting tool 21 is abnormal in shape during the shape determination operation of the cutting tool 21 ("No" in step ST14), the control unit 50 notifies the operator of the cutting device 1 of the determination result through the display unit 51 or the display light 52 (step ST16), and the process of a series of actions enters step ST17.

[0052] When the control unit 50 performs the shape determination action of the trimming and cutting tool 21 less than the specified number of times ("No" in step ST17), the process of a series of actions returns to step ST11 and repeats the shape determination action of the trimming and cutting tool 21 until the specified number of times is reached.

[0053] When the control unit 50 has performed the dressing and shape determination actions of the cutting tool 21 for a specified number of times (step ST17), it uses the display unit 51 or the display light 52 to notify the operator of the cutting device 1 that the shape abnormality of the planar shape of the outer edge 62 of the cutting edge 21-1 of the cutting tool 21 has not been resolved through the specified number of dressings (step ST18), urges the replacement of the cutting tool 21, etc., and ends the process of a series of actions.

[0054] The cutting device 1 of the first embodiment having the above-mentioned structure determines whether the planar shape of the outer edge 62 of the cutting edge 21-1 of the cutting tool 21 is normal or abnormal by quantifying the degree to which the planar shape of the outer edge 62 of the cutting edge 21-1 of the cutting tool 21 deviates from the circle, thereby achieving the effect of being able to detect that the planar shape of the outer edge 62 of the cutting edge 21-1 of the cutting tool 21 is abnormal, which cannot be detected in the technology of patent document 1 for detecting the abnormal eccentricity of the cutting tool.

[0055] [Second embodiment]

[0056] A cutting device 1 - 2 according to a second embodiment of the present invention will be described with reference to the drawings. Figure 7 It is a cross-sectional view showing a configuration example of the cutting unit 20 and the management unit 30 - 2 of the cutting apparatus 1 - 2 according to the second embodiment. Figure 8 It shows Figure 7 This is a graph showing an example of processing performed by the management unit 30-2 of the cutting device 1-2. Figure 7 and Figure 8 In the present invention, the same parts as those in the first embodiment are denoted by the same reference numerals and their description is omitted.

[0057] In the first embodiment, as Figure 7 As shown in FIG. 1 , the cutting device 1 - 2 of the second embodiment is obtained by changing the management unit 30 to a management unit 30 - 2 . Figure 7 As shown, management unit 30-2 is obtained by replacing the comparison waveform generator 35, ideal waveform identification unit 36, and comparison waveform storage unit 39 within the control unit 50 of management unit 30 with an ideal waveform generator 36-2. Ideal waveform generator 36-2 generates an ideal waveform 86 such that the planar shape of the outer edge of the cutting edge 21-1 of the cutting tool 21 is circular, not abnormal, and represents the planar shape of the outer edge of the cutting edge 21-1 of the cutting tool 21 when mounted on the spindle 22 with a certain eccentricity. The functions of ideal waveform generator 36-2 are implemented by the processing unit of control unit 50 executing a computer program stored in the storage device.

[0058] The operation of the cutting device 1-2 according to the second embodiment will be described. The operation of the cutting device 1-2 according to the second embodiment is the same as that of the cutting device 1 according to the first embodiment, except for the operation for determining the shape of the cutting tool 21. The operation for determining the shape of the cutting tool 21 according to the cutting device 1-2 according to the second embodiment is the same as that of the cutting tool 21 according to the first embodiment, before the measured waveform forming unit 34 forms the measured waveform 81.

[0059] In the shape determination operation of the cutting tool 21 of the second embodiment, as shown in FIG. Figure 8 As shown, the ideal waveform forming unit 36-2 calculates the intermediate value 84 between the maximum value 82 and the minimum value 83 of the measured waveform 81, and uses the difference 85 between the intermediate value 84 and the maximum value 82 and the minimum value 83 as the amplitude corresponding to the eccentricity of the cutting tool 21 to form a sine wave, and uses this sine wave as the ideal waveform 86.

[0060] After determining the ideal waveform 86, the difference calculation unit 37 calculates the area of ​​the region 87 where the difference is generated by superimposing the measured waveform 81 and the ideal waveform 86, similarly to the first embodiment. Then, the determination unit 38 determines that the planar shape of the outer edge of the cutting edge 21-1 of the cutting tool 21 is abnormal if the total area of ​​the region 87 where the difference is generated exceeds a predetermined threshold value, and determines that the planar shape of the outer edge of the cutting edge 21-1 of the cutting tool 21 is normal if the total area of ​​the region 87 is below the predetermined threshold value, similarly to the first embodiment.

[0061] The cutting device 1-2 of the second embodiment having the above-mentioned structure, like the cutting device 1 of the first embodiment, determines whether the planar shape of the outer edge of the cutting edge 21-1 of the cutting tool 21 is normal or abnormal by quantifying the degree to which the planar shape of the outer edge of the cutting edge 21-1 of the cutting tool 21 deviates from the circle, thereby achieving the effect of being able to detect that the planar shape of the outer edge of the cutting edge 21-1 of the cutting tool 21 is an abnormal shape.

[0062] The present invention is not limited to the above-described embodiment, and can be implemented with various modifications without departing from the spirit of the present invention.

Claims

1. A cutting device comprising: a chuck table that holds the workpiece; a cutting unit that cuts a workpiece held on the chuck table using a cutting tool mounted on a spindle; and a management unit that manages the cutting tool mounted on the spindle, This snap-in contains: luminous part; a light receiving portion, which is opposite to the light emitting portion and receives the light emitted by the light emitting portion; a measuring unit that measures an amount of light emitted from the light emitting unit and received by the light receiving unit in a state where the cutting tool is located between the light emitting unit and the light receiving unit; a measured waveform forming unit that forms a measured waveform representing a shape of an outer diameter of the cutting tool based on the amount of received light measured at a plurality of rotation angles of the cutting tool; a comparative waveform forming portion that forms a comparative waveform representing a shape of an outer diameter of the cutting tool measured by the measuring portion when the cutting tool is mounted on the spindle with an arbitrary eccentricity; an ideal waveform identifying unit that forms a plurality of comparative waveforms by gradually changing the eccentricity used in the comparative waveform forming unit, and identifies the comparative waveform having the largest area that coincides with the measured waveform as the ideal waveform; a difference calculation unit that calculates an area of ​​a region where a difference is generated by superimposing the actual waveform and the ideal waveform; and The determination unit determines that the shape of the cutting tool is abnormal when the difference exceeds a threshold value.

2. A cutting device comprising: a chuck table that holds the workpiece; a cutting unit that cuts a workpiece held on the chuck table using a cutting tool mounted on a spindle; and a management unit that manages the cutting tool mounted on the spindle, This snap-in contains: a light-emitting portion that emits light; a light receiving portion, which is opposite to the light emitting portion and receives the light emitted by the light emitting portion; a measuring unit that measures a light intensity of the light emitted from the light emitting unit and received by the light receiving unit in a state where the cutting tool is located between the light emitting unit and the light receiving unit; a measured waveform forming unit that forms a measured waveform representing the shape of the outer diameter of the cutting tool based on the received light amount measured at the rotation angle of the plurality of cutting tools; an ideal waveform forming portion for forming an ideal waveform representing the shape of the outer diameter of the cutting tool when the cutting tool is mounted on the spindle with a certain eccentricity; a difference calculation unit that calculates an area of ​​a region where a difference is generated by superimposing the actual waveform and the ideal waveform; and The determination unit determines that the shape of the cutting tool is abnormal when the difference exceeds a threshold value. The ideal waveform forming unit calculates an intermediate value between the maximum value and the minimum value of the actually measured waveform, and forms an ideal waveform using the difference between the intermediate value and the maximum value and the minimum value as the eccentricity of the cutting tool.

Images