BLADE CHANGER UNIT

Abstract

Blade changing unit (7) for attaching a cutting blade (21) to and removing the cutting blade (21) from a hub (242) extending in an axial direction of an attachment (24) fixed to a distal end of a spindle (23) of a machining device (1), wherein the cutting blade (21) has a circular base (212) having a centrally defined insertion hole (211) and a cutting edge (213) arranged on an outer circumferential edge section of the circular base (212), wherein the blade changing unit (7) comprises: an electrically conductive holder (825) for holding the cutting blade (21); a movement unit (84) for moving the blade changer unit (7); and a control unit (100) for controlling the movement unit (84) and detecting a line between the holder (825) and the hub (242), wherein the control unit (100) comprises: a computer (102) for calculating a center of the attachment (24) from coordinates at which the line between the holder (825) and the hub (242) is detected when the motion unit (84) is controlled to bring the holder (825) into contact with the attachment (24) at least three points, and an attachment / removal control (103) for attaching and removing the cutting blade (21), while a center of the holder (825) is aligned with the center of the attachment (24) calculated by the computer (102).

Description

TECHNICAL BACKGROUNDTechnical field

[0001] The present invention relates to a blade changer unit that detects the center of an attachment to align the blade changer unit and the attachment with each other in a machining apparatus having a mechanism for automatically changing cutting blades. Description of related technology

[0002] For cutting workpieces such as semiconductor wafers or the like, a cutting device comprising cutting blades is used as a processing device (see, for example, JP 2016-144838A). In order for the cutting device to operate continuously, cutting blades must be automatically supplied to the cutting device as consumable tools.

[0003] The cutting device disclosed in JP 2016-144838A comprises a blade frame for holding a plurality of cutting blades and a blade changer unit for changing cutting blades on a cutting unit.

[0004] Further prior art helpful for understanding the present invention can be found in the following documents: JP H06- 285 735 A relates to a tool changing unit for a grinding device. JP 2011- 98 401 A relates to a blade attachment assisting tool capable of attaching an annular blade to a tool attachment. PRESENTATION OF THE INVENTION

[0005] The blade changing unit of the cutting device disclosed in JP 2016-144838A needs to perform a process of aligning the center of an attachment and the center of a holder that holds a cutting blade in the blade changing unit with each other in order to properly attach and detach cutting blades.

[0006] Even after the conventional cutting device performs the above positional alignment, the center of the attachment and the center of the holder in the blade changer unit may become positionally misaligned due to the effect of heat, collision of parts, etc. In the event of such positional misalignment, the center of the attachment and the center of the holder must be adjusted into alignment with each other.

[0007] However, the blade changer unit disclosed in JP 2016-144838A requires the operator to perform a laborious and time-consuming process involving visual and tactile senses to determine the position of the center of attachment.

[0008] It is therefore an object of the present invention to provide a blade changing unit capable of easily determining the position of an attachment to which a cutting blade is to be attached.

[0009] According to one aspect of the present invention, a blade changer unit is provided for attaching a cutting blade to and detaching the cutting blade from a hub extending in an axial direction from an attachment fixed to a distal end of a spindle of a machining device, wherein the cutting blade has a circular base with a central insertion hole defined therein and a cutting edge arranged on an outer peripheral edge portion of the circular base, wherein the blade changer unit comprises an electrically conductive holder for holding the cutting blade, a moving unit for moving the blade changer unit, and a control unit for controlling the moving unit and detecting a conduction between the holder and the hub, wherein the control unit comprises a calculator for calculating a center of the attachment from coordinates at which the conduction between the holder and the hub is detected,when the movement unit is controlled to bring the holder into contact with the attachment at at least three points, and has an attachment / detachment control for attaching and detaching the cutting blade while a center of the holder is aligned with the center of the attachment calculated by the computer.

[0010] Preferably, the attachment has a bearing flange projecting outward in a radial direction from a rear end of the hub in an axial direction thereof to support the cutting blade, the spindle has an axial direction as a Y-axis direction, the computer calculates coordinates in the Y-axis direction of the hub from the coordinates at which the line between the holder and the hub is detected when the holder is brought into contact with the hub or a distal end of the bearing flange at at least one point, and the attachment / detachment controller attaches or detaches the cutting blade in alignment with the coordinates in the Y-axis direction of the hub calculated by the computer.

[0011] According to another aspect of the present invention, a blade changer unit is provided for attaching a cutting blade, the cutting blade having a circular base having an insertion hole defined centrally therein and a cutting edge defined on an outer peripheral portion of the circular base, to and detaching the cutting blade from a hub extending in an axial direction from an attachment fixed to a distal end of a spindle of a machining device, the blade changer unit comprising an electrically conductive holder for holding an electrically conductive receptacle having an opening larger than the hub, a moving unit for moving the blade changer unit, and a control unit for controlling the moving unit and detecting conduction between the holder and the hub.wherein the control unit comprises a computer for calculating a center of attachment from coordinates at which the line between the holder and the hub is detected when the movement unit is controlled to bring the receiving device held by the holder into contact with the attachment at at least three points, and an attachment / detachment control for attaching and detaching the cutting blade while a center of the holder is aligned with the center of attachment calculated by the computer.

[0012] Preferably, the attachment has a bearing flange protruding outward in a radial direction from a rear end of the hub in an axial direction thereof for supporting the cutting blade, the spindle has an axial direction as a Y-axis direction, the computer calculates coordinates in the Y-axis direction of the hub from the coordinates at which the line between the holder and the hub is detected when the receiving device is brought into contact with the hub or a distal end of the bearing flange at at least one point, and the attachment / detachment controller attaches and detaches the cutting blade in alignment with the coordinates in the Y-axis direction of the hub calculated by the computer.

[0013] Preferably, the receiving device comprises the cutting blade.

[0014] According to the present invention, the blade changing unit is capable of easily determining the position of the center of attachment to which a cutting blade is to be attached.

[0015] The above and other objects, features and advantages of the present invention and the mode for carrying them out will become more apparent and the invention itself will be best understood by studying the following description and the appended claims with reference to the attached drawings which show preferred embodiments of the invention. SHORT DESCRIPTION OF THE FIGURES Fig. 1 is a perspective view exemplifying the structure of a cutting device having a blade changing unit according to a first embodiment of the present invention; Fig. 2 is an exploded perspective view of a cutting unit of the Fig. 1 shown cutting device; Fig. 3 is an exploded perspective view showing, by way of example, the structure of the blade changer unit of the Fig. 1; Fig. 4 is a perspective view illustrating an example of the structure of a blade storage device of the Fig. 3 represents the blade changer unit; Fig. Figure 5 is a perspective view showing the manner in which the Fig. 4 The blade storage shown holds several cutting blades; Fig. 6 is a perspective view exemplifying the structure of a blade attaching / detaching unit of the Fig. 3 represents the blade changer unit; Fig. 7 is a perspective view exemplifying the structure of a blade clamping device of the Fig. 6; Fig. 8 is a perspective view exemplifying the structure of a nut holder of the Fig. 6; Fig. Fig. 9 is a side view showing, by way of example, the structure of a conductive position detection unit of the Fig. 6; Fig. 10 is a perspective view showing the manner in which grippers of the blade clamping device and an outer peripheral surface of a hub are engaged with each other in a position calculation process for calculating the position of the central axis of an attachment of the Fig. 3 shown blade changer unit are kept in contact; Fig. Fig. 11 is another perspective view showing the manner in which grippers of the blade clamping device and the outer peripheral surface of a hub are engaged with each other in the position calculation process for calculating the position of the central axis of the attachment of the Fig. 3 shown blade changer unit are kept in contact; Fig. 12 is a view schematically showing the manner in which the grippers of the blade clamping device and the outer peripheral surface of the hub are engaged in the position calculation process for calculating the position of the central axis of the attachment of the Fig. 3 shown blade changer unit are held in contact at a first contact point; Fig. 13 is a view schematically showing the manner in which the grippers of the blade clamping device and the outer peripheral surface of the hub are engaged in the position calculation process for calculating the position of the central axis of the attachment of the Fig. 3 shown blade changer unit are kept in contact at a second contact point; Fig. 14 is a view schematically showing the manner in which the grippers of the blade clamping device and the outer peripheral surface of the hub are engaged in the position calculation process for calculating the position of the central axis of the attachment of the Fig. 3 shown blade changer unit are kept in contact at a third contact point; Fig. 15 is a perspective view showing the manner in which the grippers of the blade clamping device and a distal end face of the hub are engaged in a position calculation process for calculating the position of a distal end face of the attachment of the Fig. 3 shown blade changer unit are kept in contact with each other; Fig. 16 is a view schematically showing the positional relationship between the grippers of the blade clamping device and the hub when attaching or detaching a blade on the basis of the position of the central axis of attachment obtained by the position calculation process for calculating the position of attachment of the blade clamping device shown in Fig. 3 shown blade changer unit; Fig. 17 is a side view illustrating the manner in which grippers of a blade chuck and a bearing flange of an attachment are kept in contact with each other in a position calculating process for calculating the position of a distal end surface of the attachment of a blade changer unit according to a modification of the first embodiment; Fig. 18 is a perspective view illustrating the manner in which grippers of a blade clamping device hold an electrically conductive receiving device in a position calculating process for calculating the position of the central axis of an attachment of a blade changer unit according to a second embodiment of the present invention; Fig. 19 is a perspective view illustrating the manner in which a boss is inserted into an opening in a receiving device in the position calculating process for calculating the position of the central axis of attachment of the blade changer unit according to the second embodiment; Fig. 20 is another perspective view illustrating the manner in which the hub is inserted into the opening in the receiving device in the position calculating process for calculating the position of the central axis of attachment of the blade changer unit according to the second embodiment; Fig. 21 is a view schematically illustrating the manner in which an inner peripheral surface of the receiving means defining the opening is held in contact with an outer peripheral surface of the hub at a first contact point in the position calculating process for calculating the position of the central axis of attachment of the blade changer unit according to the second embodiment; Fig. 22 is a view schematically illustrating the manner in which the inner peripheral surface of the receiving means defining the opening is held in contact with an outer peripheral surface of the hub at a second contact point in the position calculating process for calculating the position of the central axis of attachment of the blade changer unit according to the second embodiment; Fig. 23 is a view schematically illustrating the manner in which the inner peripheral surface of the receiving means defining the opening is held in contact with an outer peripheral surface of the hub at a third contact point in the position calculating process for calculating the position of the central axis of attachment of the blade changer unit according to the second embodiment; Fig. 24 is a perspective view illustrating the manner in which the receiving means and a distal end surface of the hub are kept in contact in a position calculating process for calculating the position of a distal end surface of the attachment of the blade changer unit according to the second embodiment; Fig. 25 is a side view illustrating the manner in which a receiving means held by a blade chuck and a bearing flange of an attachment are held in contact with each other in a position calculating process for calculating the position of a distal end surface of the attachment of a blade changer unit according to a first modification of the second embodiment; Fig. 26 is a side view exemplifying the structure of a position detection unit of a blade attachment / detachment unit of a blade changer unit according to a second modification of the second embodiment; Fig. 27 is a side view of an attachment of a cutting device having the blade changing unit according to the second modification of the second embodiment; Fig. 28 is a side view of a cutting blade of the cutting device having the blade changing unit according to the second modification of the second embodiment; Fig. 29 is a side view illustrating the manner in which a boss of the attachment of the cutting device having the blade changer unit according to the second modification of the second embodiment is inserted into an insertion hole in the cutting blade; and Fig. 30 is a perspective view exemplifying the structure of a blade chuck of a blade attaching / detaching unit of a blade changer unit according to a modification of the first embodiment and the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Preferred embodiments of the present invention will be described in detail hereinafter with reference to the drawings. The present invention is not limited to the details of the embodiments described below. The components described below cover those that could be easily envisioned by those skilled in the art and those that are substantially identical to those described above. Furthermore, the arrangements described below can be used in appropriate combinations. Various omissions, substitutions, or changes to the arrangements may be made without departing from the scope of the present invention. [First embodiment]

[0017] A blade changer unit according to a first embodiment of the present invention will be described below with reference to the drawings. Fig. 1 illustrates in perspective, by way of example, the structure of a cutting device having the blade changing unit according to the first embodiment of the present invention. Fig. 2 shows in an exploded perspective a cutting unit of the Fig. 1 shows the cutting device. Fig. 3 shows in an exploded perspective the structure of the blade changer unit of the Fig. 1 shows the cutting device. (cutting device)

[0018] The blade changing unit designated by 7 according to the first embodiment is accommodated in the cutting device designated by 1, which in Fig. 1 is shown as a machining device. The cutting device 1 is a device for cutting, ie machining, a workpiece 200 which is in Fig. 1. According to the first embodiment, the workpiece 200 is in the form of a wafer, such as a disk-shaped semiconductor wafer made of silicon, sapphire, gallium, or the like. The workpiece 200 has a front side 201 divided into a grid of regions by a grid of provided dividing lines 202, and a plurality of components 203 formed in each of the regions.

[0019] According to the present embodiment, the workpiece 200 may be what is commonly referred to as a TAIKO (registered trademark) wafer, which has a thin central region and a thicker region at its outer peripheral portion, or a rectangular package substrate, a ceramic substrate, or a ferrite substrate having a plurality of plastic-encapsulated components thereon, a substrate containing nickel and / or iron, or the like. According to the first embodiment, the workpiece 200 has a back surface 204 adhered to an adhesive tape 206 having an outer peripheral edge portion to which an annular frame 205 is attached, so that the workpiece 200 is supported on the annular frame 205.

[0020] The Fig. 1 is a device for holding the workpiece 200 on a clamping table 10 and for cutting, ie machining, the workpiece 200 with a cutting blade 21 along the intended dividing lines 202. As in Fig. 1, the cutting device 1 includes the chuck table 10 that holds the workpiece 200 on a holding surface 11 thereof under suction, a pair of cutting units 20 that each cuts the workpiece 200 held on the chuck table 10 with the cutting blade 21, an image pickup unit 30 that picks up an image of the workpiece 200 held on the chuck table 10, and the blade changer unit 7.

[0021] As in Fig. 1, the cutting device 1 also includes at least one X-axis movement unit (not shown) for machining the chuck table 10 in an X-axis direction parallel to a horizontal direction, a Y-axis movement unit 40 for indexing the cutting unit 20 in a Y-axis direction parallel to a horizontal direction and perpendicular to the X-axis direction, and a pair of Z-axis movement units 50 for cutting the respective cutting units 20 in a Z-axis direction parallel to a vertical direction and perpendicular to both the X-axis direction and the Y-axis direction. As shown in Fig. 1, the cutting device 1 is a two-spindle dividing device, that is, what is commonly referred to as a facing double type cutting device, which has the two cutting units 20.

[0022] The chuck table 10 is disk-shaped, and the holding surface 11 thereof for holding the workpiece 22 thereon is made of a porous ceramic or the like. The chuck table 10 is movable by the X-axis moving unit along the X-axis direction between a machining area 63 under the cutting unit 20 and a loading / unloading area 64 spaced from the machining area 63, where the workpiece 200 is loaded into and unloaded from the chuck table 10. The chuck table 10 is also rotatable about a central axis parallel to the Z-axis direction by a rotary actuator (not shown). The chuck table 10 is connected to a vacuum suction source (not shown) and attracts and holds the workpiece 200 under a vacuum developed by the vacuum suction source. According to the first embodiment, the clamping table 10 attracts and holds the back side 204 of the workpiece 200 with the adhesive tape 206 arranged therebetween. As shown in Fig. 1, a plurality of clamps 12 for clamping the annular frame 205 are arranged around the clamping table 10.

[0023] Each of the cutting units 20 acts as a cutting means, with the cutting blade 21 removably attached thereto for cutting the workpiece 200 held on the chuck table 10. The cutting unit 20 is movable relative to the workpiece 200 held on the chuck table 10 in the Y-axis direction by the Y-axis moving unit 40 and in the Z-axis direction by the Z-axis moving unit 50.

[0024] As in Fig. As shown in Fig. 1, one of the cutting units 20 is supported on a column 4 of a gantry-shaped support frame 3 mounted on the device body 2, via the Y-axis moving unit 40 and one of the Z-axis moving units 50. Similarly, the other cutting unit 20 is supported on another column 5 of the support frame 3 via the Y-axis moving unit 40 and the other Z-axis moving unit 50. The support frame 3 also includes a horizontal beam 6 connecting the respective upper end portions of the columns 4 and 5.

[0025] The Y-axis movement unit 40 and the Z-axis movement units 50 enable the cutting units 20 to position their cutting blades 21 at desired positions above the holding surface 11 of the clamping table 10.

[0026] As in Fig. 2, each of the cutting units 20 includes a spindle housing 22 movable in the Y-axis direction and the Z-axis direction by the Y-axis moving unit 40 and the Z-axis moving unit 50, respectively, a spindle 23 rotatably disposed in the spindle housing 22 and rotatable about its own central axis by an electric motor, not shown, and an attachment 24 attached to a distal end portion of the spindle 23.The cutting unit 20 also includes a fixing screw 26 extending through a washer 25 and a through hole 241 defined centrally in the attachment 24 and screwed into a threaded hole 231 defined in a distal end surface of the spindle 23 to attach the attachment 24 to the distal end portion of the spindle 23, the cutting blade 21 attached to the attachment 24, and a fixing nut 27 that fixes the cutting blade 21 to the attachment 24 while centering the cutting blade 21 between itself and the attachment 24.

[0027] The attachment 24 is fixed to the distal end portion of the spindle 23. The attachment 24 includes a hollow cylindrical hub 242 and a bearing flange 243 disposed on the hub 242 at one end thereof, i.e., an axial rear end thereof, closer to the spindle housing 22. The hub 242 extends along axial directions of the attachment 24 and has an outer diameter that substantially corresponds, along its entire length, to the inner diameter of an insertion hole 211 defined in the cutting blade 21. That the outer diameter of the hub 242 is substantially the same as the inner diameter of the insertion hole 211 means that the outer diameter and the inner diameter are equal to each other to the extent that an outer peripheral surface of the hub 242 and an inner peripheral surface of the cutting blade defining the insertion hole 211 are capable of contacting each other at at least several contact points.

[0028] The bearing flange 243 has an annular shape projecting outward in a radial direction from the end of the hub 242 closest to the spindle housing 22, said annular shape having an outer diameter larger than the outer diameter of the hub 242. The bearing flange 243 supports the cutting blade 21 at an outer peripheral portion 244 thereof at its distal end. The hub 242 and the bearing flange 243 are arranged coaxially with each other. The hub 242 of the attachment 24 has another end portion remote from the spindle housing 22, which has an outer peripheral surface 245 with an external thread.

[0029] The cutting blade 21 is in the form of an ultra-thin grindstone having a substantially ring shape. According to the first embodiment, the cutting blade 21 is what is commonly referred to as a hub blade, which includes an annular circular base 212 made of an electrically conductive material and having the insertion hole 211 defined centrally therein, and an annular cutting edge 213 disposed at an outer peripheral edge portion of the circular base 211 and cutting the workpiece 200. The insertion hole 211 defined in the annular base 212 is a hole through which the other end portion of the hub 242 extends to attach the cutting blade 21 to the attachment 24. The cutting edge 213 is made of diamond, cubic boron nitride (CBN), or the like, and a bonding material, i.e.a binder made of metal, plastic, or the like, and has a predetermined thickness. According to the present invention, the cutting blade 21 may be a disc blade having only the cutting edge 213.

[0030] The cutting blade 21 thus configured is fitted over the hollow cylindrical hub 242 of the attachment 24, which extends through the insertion hole 211 in the circular base 212. The cutting blade 21 is gripped and secured in position between the bearing flange 243 of the attachment 24 and the fastening nut 27, which is screwed over the externally threaded outer peripheral surface 245 of the hub 242.

[0031] The spindle 23 of the cutting unit 20, the attachment 24, and the cutting blade 21 have a central axis 246 parallel to the Y-axis direction. According to the first embodiment, at least the spindle 23 and the attachment 24 are made of an electrically conductive material, i.e., a metal according to the first embodiment. According to the first embodiment, the central axis 246 of the spindle 23, the attachment 24, and the cutting blade 21 extends parallel to the Y-axis direction.

[0032] The image pickup unit 30 is attached to one of the cutting units 20 for joint movement therewith. The image pickup unit 30 includes an image pickup device for capturing an image of a region to be divided of the workpiece 200 held on the chuck table 10 before the workpiece 200 is cut. The image pickup device may be, for example, a charge-coupled device (CCD) imaging sensor or a complementary metal oxide silicon (CMOS) imaging sensor. The image pickup unit 30 captures an image of the workpiece 200 held on the chuck table 10 for use in an alignment process for positioning the workpiece 200 and the cutting blade 21 in alignment with each other, and outputs the captured image to a control unit 100 for the blade changer unit 7.

[0033] The X-axis movement unit moves the chuck table 10 in the X-axis direction as a machining feed direction, thereby machining the chuck table 10 and the cutting units 20 relative to each other along the X-axis direction. The Y-axis movement unit 40 moves the cutting units 20 in the Y-axis direction as an index feed direction, thereby indexing the chuck table 10 and the cutting units 20 relative to each other along the Y-axis direction. The Z-axis movement unit 50 moves the cutting units 20 in the Z-axis direction as a cutting feed direction, thereby cutting the chuck table 10 and the cutting units 20 relative to each other along the Z-axis direction.

[0034] Each of the X-axis moving unit 40 and the Y-axis moving unit 40 and the Z-axis moving unit 50 includes a known ball screw rotatable about its own central axis, a known electric motor for rotating the ball screw about its own central axis, and a pair of guide rails on which the chuck table 10 or the cutting units 20 are movably supported for movement in the X-axis direction, the Y-axis direction, or the Z-axis direction.

[0035] The cutting device 1 further includes an X-axis direction position detection unit (not shown) for detecting the position of the chuck table 10 in the X-axis direction, a Y-axis direction position detection unit (not shown) for detecting the positions of the cutting units 20 in the Y-axis direction, and a Z-axis direction position detection unit (not shown) for detecting the positions of the cutting units 20 in the Z-axis direction. Each of the X-axis direction position detection unit and the Y-axis direction position detection unit may include a linear scale parallel to the X-axis direction or the Y-axis direction and a reading head. The Z-axis direction position detection unit can detect the positions of the cutting units 20 in the Z-axis direction based on pulses of the electric motors.The X-axis direction position detection unit, the Y-axis direction position detection unit, and the Z-axis direction position detection unit output the position of the chuck table 10 in the X-axis direction and the positions of the cutting units 20 in the Y-axis direction and the Z-axis direction to the control unit 100. According to the first embodiment, the positions of components of the cutting device 1 in the X-axis direction, the Y-axis direction, and the Z-axis direction are determined as positions relative to predetermined reference positions (not shown).

[0036] The cutting device 1 also includes a cassette elevator 60 for placing a cassette 61 accommodating workpieces 200 to be cut and which have been cut thereon and for moving the cassette 61 in the Z-axis direction, a cleaning unit 62 for cleaning workpieces 200 which have been cut, and an unillustrated feeding unit for loading and unloading workpieces into and from the cassette 61 and feeding workpieces 200. (blade changer unit)

[0037] The blade changer unit 7 attaches or detaches a cutting blade 21 to the hub 242 of the attachment 24 fixed to the distal end portion of the spindle 23 of each of the cutting units 20 positioned in an attachment / detachment position. The attachment / detachment position is a predetermined position in the X-axis direction, the Y-axis direction, and the Z-axis direction at which each of the cutting units 20 is positioned for attaching or detaching a cutting blade 21 with the blade changer unit 7.

[0038] As in Fig. 1, the blade changer unit 7 is arranged behind the support frame 3 in a position which is further from the loading / unloading area 64 than the processing area 63. As shown in Fig. 3, the blade changing unit 7 comprises blade storages 70 for holding cutting blades 21 to be replaced and which have been replaced, blade attachment / detachment units 80 for attaching cutting blades 21 to and detaching cutting blades 21 from the spindles 23 of the respective cutting units 20 and for conveying cutting blades 21 between the blade storages 70 and the cutting units 20, and the control unit 100.

[0039] According to the first embodiment, the blade storage units 70 and the blade attachment / detachment units 80 are associated with each other in pairs and are also associated with the cutting units 20 in pairs. In other words, the blade changer unit 7 includes a pair of blade storage units 70 and a pair of blade attachment / detachment units 80.

[0040] According to the first embodiment, one of the blade storages 70 holds a plurality of cutting blades 21 to be attached to and detached from the spindle 23 of one of the cutting units 20. One of the blade attachment / detachment units 80 attaches or detaches a cutting blade 21 to one of the cutting units 20 and conveys cutting blades 21 between one of the blade storages 70 and one of the cutting units 20. According to the first embodiment, the other of the blade storages 70 holds a plurality of cutting blades 21 to be attached to and detached from the spindle 23 of the other of the cutting units 20. The other of the blade attaching / detaching units 80 attaches or detaches a cutting blade 21 to the other of the cutting units 20 and conveys cutting blades 21 between the other of the blade storages 70 and the other of the cutting units 20.

[0041] The cutting blades 21 held by each of the blade storages 70 include cutting blades that are not yet in use, cutting blades that have already been used but are still usable because their useful life has not yet ended, and cutting blades of one type and / or of different types.

[0042] Next, each of the components of the blade changer unit 7 will be described below. (blade storage)

[0043] Fig. Figure 4 shows in a perspective view the structure of one of the blade storage units of the Fig. 3 shows the blade changer unit 7. Fig. Figure 5 shows in perspective the way in which the Fig. 4 shows a blade storage 70 which holds several cutting blades 21.

[0044] The blade storage 70 holds replacement cutting blades 21 to be attached to the respective cutting unit 20 and replaced cutting blades 21 that have been removed from the corresponding cutting unit 20. Since the two blade storages 70 are structurally identical to each other, only the blade storage 70 that is located on the far side in Fig. 3 is described as a representative. Those parts of the other blade storage 70 that are identical to those of the representative blade storage 70 are designated by identical reference numerals and will not be described in detail below.

[0045] As in Fig. 3 and Fig. 4, the blade storage 70 includes a post 71 disposed on the device body 2, and a support member 73 attached to an upper end portion of the post 71 by a rotary shaft 72. The support member 73 is arranged along the Y-axis direction in a relationship directed toward the corresponding blade attachment / detachment unit 80. The support member 73 includes a plurality of (i.e., four in the first embodiment) blade holders 74 concentrically disposed on a surface side thereof directed toward the corresponding blade attachment / detachment unit 80, for holding a plurality of (i.e., four in the first embodiment) cutting blades 21 to be attached to and detached from the corresponding cutting unit 20.

[0046] Each of the blade holders 74 holds a cutting blade 21 thereon. The blade holder 74 includes a hollow cylindrical blade fitting member 741 to be inserted into the insertion hole 211 in the cutting blade 21, and a plurality of positioning members 742 disposed on the outer peripheral surface of the blade fitting member 741 for positioning the cutting blade 21 after the blade fitting member 741 is inserted into the insertion hole 211 thereof. Each of the positioning members 742 includes a ball capable of projecting from and retracting into the outer peripheral surface of the blade fitting member 741, and a spring for normally biasing the ball radially outward.When the cutting blade 21 is placed on the blade holder 74, the ball fits against an inner edge of the circular base 212 until a radially inward force acting on the ball reaches a predetermined value, thereby performing a positioning function to position the cutting blade 21 on the blade holder 74.

[0047] The blade storage 70 constructed in this way holds cutting blades as in Fig. 5. Specifically, when the blade fitting member 741 is inserted into the insertion hole 211 in the circular base 212 of the cutting blade 21, the ball retracts into the blade fitting member 741. When the cutting blade 21 slides over the ball, the ball springs back and protrudes from the outer peripheral surface of the blade fitting member 741, fitting against the inner edge of the circular base 212 to thereby hold the cutting blade 21, as shown in Fig. 5. According to the first embodiment, the blade fitting element 741 has a central axis 743 parallel to the Y-axis direction.

[0048] The rotary shaft 72, by which the support member 73 is attached to the upper end portion of the post 71, has one end disposed at the upper end portion of the post 71 and the other end coupled to a rear side of the support member 73. The end of the rotary shaft 72 disposed at the upper end portion of the post 71 is coupled to the drive shaft of an electric motor 75 disposed in the post 71. The support member 73 is intermittently rotatable about the central axis of the rotary shaft 72 by the rotary shaft 72. When the support member 73 is intermittently rotated by the rotary shaft 72, the support member 73 selectively positions one of the blade holders 74 after another at a predetermined transfer position 744 on their circulation path. (Blade attachment / removal unit)

[0049] Fig. Fig. 6 is a perspective view illustrating the structure of the blade attachment / detachment unit 80 of the Fig. 3 shows the blade changer unit 7. Fig. 7 shows in a perspective view an example of the structure of a blade clamping device of the Fig. 6 shows the blade attachment / detachment unit 80. Fig. Figure 8 shows in a perspective view the structure of a nut holder of the Fig. 6 shows the blade attachment / detachment unit 80.

[0050] Since the two blade attachment / detachment units 80 are structurally identical to each other, only the blade attachment / detachment unit 80 shown in Fig. 3 on the far side will be described as a representative. Those parts of the other blade attachment / detachment unit 80 that are identical to those of the representative blade storage 70 are designated by identical reference numerals and will not be described in detail below.

[0051] As in Fig. As shown in Figure 6, the blade attachment / detachment unit 80 includes a unit body 81, blade clamps 82, a nut holder 83, and a moving unit 84 that movably supports the unit body 81. According to the first embodiment, the blade attachment / detachment unit 80 includes two blade clamps 82 and a nut holder 83.

[0052] The blade clamps 82 and the nut holder 83 are mounted on the unit body 81 and have respective central axes 821 and 831 that are angularly spaced from each other and extend parallel to each other. According to the first embodiment, the central axes 821 of the blade clamps 82 and the central axis 831 of the nut holder 83 extend parallel to the Y-axis direction.

[0053] The blade clamping devices 82 hold respective cutting blades 21 thereon. As in Fig. 7, each of the blade clamping devices 82 includes a housing 822 fixed to the unit body 81 and having a hollow cylindrical shape, a disk-shaped support base 824 attached to a distal end of the housing 822 by an arm 823, and a plurality of grippers 825 attached to the support base 824.

[0054] The grippers 825 are circumferentially spaced from each other at an outer edge portion of an end surface of the support base 824 facing the blade holders 74 of the corresponding blade storage 70. According to the first embodiment, there are three grippers 825 arranged at circumferentially equally spaced intervals on the outer edge portion of the end surface of the support base 824. The grippers 825 are radially movable on the end surface of the support base 824 by a drive mechanism (not shown) housed in the support base 824. When the grippers 825 are moved radially inward toward each other, they grip the outer peripheral surface of the circular base 212 of a cutting blade 21. When the grippers 825 are moved radially outward away from each other, they release the cutting blade 21. The grippers 825 are made of an electrically conductive material, e.g., a metal in the first embodiment.The grippers 825 act as electrically conductive holders for holding a cutting blade 21.

[0055] The nut holder 83 attaches a fastening nut 27 to a hub 242 and removes a fastening nut 27 therefrom. As shown in Fig. 8, the nut holder 83 includes a housing 832 fixed to the unit body 81 and having a hollow cylindrical shape, a spindle 833 housed in the housing 832 and rotatable about a central axis 831 parallel to the Y-axis direction, a disk-shaped support base 834 fixed to one end of the spindle 833, and a plurality of grippers 835 attached to the support base 834.

[0056] The spindle 833 has one end that projects from the housing 832 toward the corresponding blade storage 70. The spindle 833 has another end that is coupled to an electric motor (not shown) for rotating the spindle 833 about its own central axis.

[0057] The grippers 835 are spaced apart from each other in a circumferential direction at an outer edge portion of an end surface of the support base 824 facing the blade holders 74 of the corresponding blade storage 70. According to the first embodiment, there are four grippers 835 arranged at equally spaced intervals in the circumferential direction on the outer edge portion of the end surface of the support base 834. The grippers 835 are movable in a radial direction on the end surface of the support base 834 by a drive mechanism (not shown) housed in the support base 834. When the grippers 835 are moved inward toward each other in the radial direction, they grip the outer peripheral surface of a fastening nut 27. When the grippers 835 are moved outward away from each other in a radial direction, they release the fastening nut 27. The grippers 835 are made of an electrically conductive material, e.g., a metal in the first embodiment.The grippers 835 act as electrically conductive holders for holding a fastening nut 27.

[0058] The fixing unit 84 moves the unit body 81, that is, the blade clamps 82 and the nut holder 83, along the X-axis direction, the Y-axis direction, and the Z-axis direction. The moving unit 84 moves each of the blade clamps 82 between a position where a cutting blade 21 can be attached to and detached from the blade holder 74 at the transfer position 744 of the corresponding blade storage 70, and a position where the cutting blade 21 can be attached to and detached from the hub 242 of the attachment 24 of the cutting unit 20 at the attachment / detachment position. The moving unit 84 moves the nut holder 83 to a position where a fixing nut 27 can be attached to and detached from the hub 242 of the attachment 24 of the cutting unit 20 at the attachment / detachment position. The movement unit 84 has at least one ball screw, an electric motor and guide rails.

[0059] The blade changer unit 7 further includes a changer unit side position detecting unit (not shown) for detecting the positions in the X-axis direction and the positions in the Z-axis direction of the central axes of at least the blade chucks 82 and the nut holder 83, and the positions in the Y-axis direction of flat surfaces 827 of the grippers 825 of the blade chucks 82 for contacting an end surface of the circular base 212 of a cutting blade 21, and the positions in the Y-axis direction of the grippers 835 of the nut holder 83. (Conductive position detection unit)

[0060] Each of the blade attachment / detachment units 80 of the blade changer unit 7 has a Fig. 9 has a conductive position detection unit 90 for detecting the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the hub 242 of each cutting unit 20 positioned at the attachment / detachment position, and also for detecting the position in the Y-axis direction of a distal end surface 247 of the hub 242. Fig. Figure 9 shows an example of the structure of the detection unit 90 of the conductive position of the Fig. 6 shows the blade attachment / detachment unit 80.

[0061] As in Fig. As shown in Figure 9, the conductive position detection unit 90 includes a power supply (not shown), a conduction detection unit 92, and a selector switch 93. The power supply supplies direct current (DC) electric power to the attachment 24 and the grippers 825 of one of the two blade chucks 82 through the spindle 23 of the corresponding cutting unit 20. The selector switch 93 selects one of the two blade chucks 82 to select the grippers 825 to which the power supply is to supply the DC electric power. The power detection unit 92 detects an electric current that flows when the blade chuck 82, to which the power supply supplies the DC electric power, and the attachment 24 of the spindle 23 contact each other, and outputs a signal to the control unit 100 indicating the detection of the electric current.

[0062] When the conduction detection unit 92 detects an electric current that flows when the blade chuck 82, to which the power supply supplies the DC electric power, and the attachment 24 of the spindle 23 contact each other, the conductive position detection unit 90 can detect the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the attachment 24 of the cutting unit 20 in the attachment / detachment position, and also detect the position in the Y-axis direction of the distal end surface 247 of the hub 242 of the attachment 24.

[0063] According to the first embodiment, the conductive position detection unit 90 includes the selector switch 93 and can detect the above-referenced positions of the attachment 24 by bringing the grippers 825 of a selected one of the two blade chucks 82 into contact with the attachment 24. However, according to the present invention, the conductive position detection unit 90 may not include the selector switch 93 and can detect the above-referenced positions of the attachment 24 by bringing the grippers 825 of one of the blade chucks 82, to which the power supply supplies DC electric power, into contact with the attachment 24.According to the present invention, moreover, the conductive position detection unit 90 can detect the above-referenced positions of the attachment 24 by bringing the grippers 835 of the nut holder 83, to which an unillustrated power supply supplies electric power, into contact with the attachment 24.

[0064] The control unit 100 controls the various units of the blade changer unit 7 to enable the blade changer unit 7 to attach and detach cutting blades 21 to the cutting units 20. The control unit 100 also detects electrical conduction between the grippers 825 and 835 and the hubs 242 based on detection signals from the conduction detection unit 92 of the conductive position detection unit 90 of the blade changer unit 7. The control unit 100 further controls the various units of the cutting device 1 to enable the cutting device 1 to process the workpiece 200.The control unit 100 is a computer including an arithmetic processing device including a microprocessor such as a central processing unit (CPU), a storage device including a memory such as a read-only memory (ROM) or a random access memory (RAM), and an input / output interface device. The arithmetic processing device of the control unit 100 performs arithmetic processing operations according to computer programs stored in the storage device and outputs control signals for controlling the cutting device 1 and the blade changer unit 7 through the input / output interface device to the units referred to above, the cutting device 1 and the blade changer unit 7.

[0065] The control unit 100 is provided with a Fig. 1, which includes a liquid crystal display device for displaying workpiece processing states and images, and an input unit used by the operator to input information about processing contents. The input unit includes a touch panel on the display unit 101 and / or an external input device such as a keyboard or the like.

[0066] As in Fig. 1, the control unit 100 includes, for example, a computer 102 and an attachment / detachment controller 103. The computer 102 calculates the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the attachment 24 from detection signals from the position detection units at the time the line detection unit 92 detects an electric line when the movement unit 84 is controlled to bring the grippers 825 of a blade clamp 82 into contact with the attachment 24 at at least three contact points.The calculator 102 also calculates the position in the Y-axis direction of the distal end surface 247 of the hub 242 of the attachment 24 from detection signals from the position detection units at the time the line detection unit 92 detects an electric line when the moving unit 84 is controlled to bring the grippers 825 of the blade chuck 82 into contact with the distal end surface 247 at least at one contact point.

[0067] The attachment / detachment controller 103 attaches or detaches a cutting blade 21 to the hub 242 of a cutting unit 20 at the position of the central axis 246 of the attachment 24 and the central axis 821 of the blade attachment 82 calculated by the computer 102. The attachment / detachment controller 103 also attaches or detaches a cutting blade 21 to the hub 242 of a cutting unit 20 at the position in the Y-axis direction of the distal end surface 247 of the hub 242 calculated by the computer 102.

[0068] The functions of the calculator 102 and the attachment / detachment controller 103 are realized when the arithmetic processing device performs arithmetic processing operations according to computer programs stored in the storage device of the control unit 100. The storage device of the control unit 100 stores the X-axis position and the Z-axis position of the central axis 743 of the blade holder 74 at the transfer position 744 of each blade storage 70, and also stores the Y-axis position of the blade fitting member 741 of the blade holder 74 at the transfer position 744 of each blade storage 70.The storage device of the control unit 100 further stores the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the hub 242 of the attachment 24 of each cutting unit 20 positioned at the attachment / detachment position, and also stores the position in the Y-axis direction of the distal end surface 247 of the hub 242 of the attachment 24 of each cutting unit 20 positioned at the attachment / detachment position. (Cutting device machining process)

[0069] A machining operation of the cutting device 1 of the above structure will be described below. During the machining operation, the operator registers information about machining contents in the control unit 100, loads the workpieces 200 to be cut into the cassette 61, and places the cassette 61 on an upper surface of the cassette elevator 60. During the machining operation, the operator further places the cutting blade 21 on the blade holders 74 of each of the blade storages 70 of the blade changer unit 7.

[0070] Thereafter, the cutting device 1 begins the machining process in response to a command from the operator to start the machining process. When the cutting device 1 has started the machining process, the control unit 100 controls the feed unit to convey a workpiece 200 from within the cassette 61 to the chuck table 10 in the loading / unloading area 74, where the back side 204 of the workpiece 200 supported on the annular frame 205 by the adhesive belt 206 is held under suction on the holding surface 11 of the chuck table 10, and controls the clamps 12 to clamp the annular frame 205.

[0071] The control unit 100 controls the X-axis movement unit to move the chuck table 10 toward the machining area 63, controls the image pickup unit 30 to capture an image of the workpiece 200, and performs an alignment process for positioning the workpiece 200 and the cutting unit 20 in alignment with each other based on the image captured by the image pickup unit 30. Then, the control unit 100 moves the workpiece 200 and the cutting units 20 relative to each other along the designated dividing lines 202 and causes the cutting blades 21 to cut the workpiece 200 along the designated dividing lines 202 into individual component chips carrying the respective components 203.Thereafter, the control unit 100 controls the cleaning unit 62 to clean the workpiece 200 divided into the component chips 203, and then controls the feeding unit to pick up the workpiece 200 back into the cassette 61. Thereafter, the control unit 100 controls the cutting units 20 to cut the workpieces 200 taken out of the cassette 61 one by one, and ends the machining process when all the workpieces 200 have been cut from the cassette 61. (Cutting blade attachment / removal process)

[0072] Next, an operation of the blade changer unit 7 of the cutting device 1 of the above structure for attaching / detaching a cutting blade 21 will be described below. According to the first embodiment, the control unit 100 proceeds to attach and detach a cutting blade 21 when it judges that the cutting blade 21 of at least one of the cutting units 20 has reached a blade change timing while the cutting device 1 is in a machining operation. The blade change timing refers to a timing for changing the cutting blade 21 of each of the cutting units 20.The blade replacement time is reached each time the cutting blade 21 has cut a predetermined number of workpieces 200, for example, or when the measured outer diameter of the cutting blade 21 becomes smaller than a predetermined numerical value, and is registered as part of the machining content information in the control unit 100. Furthermore, according to the present invention, the blade replacement time may be a time while one workpiece 200 is being machined, or may be when one workpiece 200 is replaced while multiple workpieces 200 are being machined consecutively.

[0073] The cutting blade 21 attachment and detachment operation of the blade changer unit 7 of the cutting device 1 refers to a method of removing the cutting blade 21 from a cutting unit 20 and attaching a cutting blade 21 held by a blade stocker 70 to the cutting unit 20. In other words, the cutting blade 21 attachment and detachment operation refers to an operation of replacing the cutting blade 21 attached to a cutting unit 20 with a cutting blade 21 held by a blade stocker 70.

[0074] In the process of attaching and detaching the cutting blade 21, the attachment / detachment controller 103 of the control unit 100 stops rotation of the spindle 23 of a cutting unit 20 that has reached a blade replacement time and controls the Y-axis moving unit 40 and the corresponding Z-axis moving unit 50 to position the cutting unit 20 that has reached the blade replacement time at the attachment / detachment position. Furthermore, in the process of attaching and detaching a cutting blade 21, the attachment / detachment controller 103 controls the electric motor 75 of the blade storage 70 corresponding to the cutting unit 20 that has reached the blade replacement time to position a cutting blade 21 to be attached to the cutting unit 20 that has reached the blade replacement time at the transfer position 744.

[0075] In the process of attaching and detaching the cutting blade 21, the attachment / detachment controller 103 controls an operation of the moving unit 84 of the corresponding blade attachment / detachment unit 80 based on the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the attachment 24 of the cutting unit 20 at the attachment / detachment position, the position of the distal end surface 247 of the attachment 24 of the cutting unit 20 in the Y-axis direction at the attachment / detachment position, the positions stored in the storage device, and the detection signals from the position detection units.

[0076] In the process of attaching and detaching the cutting blade 21, the attachment / detachment controller 103 controls the moving unit 84 to position one of the blade attachments 82 at a position where the grippers 825 of the blade attachment 82 grip the cutting blade 21 held on the blade holder 74 at the transfer position 744 on the blade stocker 70. The attachment / detachment controller 103 controls the blade attachment 82 to cause the grippers 825 thereof to grip the cutting blade 21 held on the blade holder 74 at the transfer position 744 on the blade stocker 70.

[0077] The attachment / detachment controller 103 controls the movement unit 84 to move the blade attachment / detachment unit 80 toward the cutting unit 20 at the attachment / detachment position and to position the nut holder 83 at a position where the grippers 835 thereof can grip the fastening nut 27 of the cutting unit 20 at the attachment / detachment position. The attachment / detachment controller 103 controls the nut holder 83 to cause the grippers 835 thereof to grip the fastening nut 27 and rotate the spindle 833 thereof about the central axis 831 in a direction to remove the fastening nut 27 from the outer peripheral surface 245 with an external thread of the hub 242. The attachment / detachment controller 103 controls the nut holder 83 to rotate the spindle 833 until the fastening nut 27 is released from the outer peripheral surface 245 with the external thread, after which the attachment / detachment controller 103 stops rotating the spindle 833.The attachment / detachment controller 103 controls the moving unit 84 to move the other blade chuck 82 toward the cutting unit 20 at the attachment / detachment position and to position the other blade chuck 82 at a position where the grippers 825 thereof can grip the cutting blade 21 attached to the cutting unit 20 from which the fixing nut 27 has been removed.

[0078] The attachment / detachment controller 103 controls the other blade chuck 82 to cause the grippers 825 thereof to grip the cutting blade 21 of the cutting unit 20 from which the fastening nut 27 has been removed. The attachment / detachment controller 103 controls the moving unit 84 to move the cutting blade 21 gripped by the other blade chuck 82 along the Y-axis direction away from the attachment 24 of the cutting unit 20 from which the fastening nut 27 has been removed, while pulling the hub 242 of the attachment 24 of the cutting unit 20 from which the fastening nut 27 has been removed out of the insertion hole 211 in the cutting blade 21 gripped by the other blade chuck 82.

[0079] The attachment / detachment controller 103 controls the moving unit 84 to move the one blade clamp 82 toward the cutting unit 20 from which the fastening nut 27 and the cutting blade 21 have been removed, and to position the one blade clamp 82 at a position where the gripped cutting blade 21 is disposed adjacent to and spaced apart from the attachment 24 of the cutting unit 20 from which the fastening nut 27 and the cutting blade 21 have been removed in the Y-axis direction. At this time, the attachment / detachment controller 103 positions the one blade clamp 82 at a position where the central axis 821 thereof is coaxial with, that is, in line with, the central axis 246 of the attachment 24 of the cutting unit 20 from which the fastening nut 27 and the cutting blade 21 have been removed.

[0080] The attachment / detachment controller 103 controls the moving unit 84 to move the one blade chuck 82 along the Y-axis direction toward the cutting unit 20 from which the fixing nut 27 and the cutting blade 21 have been removed, and to insert the boss 242 of the attachment 24 of the cutting unit 20 from which the fixing nut 27 and the cutting blade 21 have been removed into the insertion hole 211 in the cutting blade 21 gripped by the one blade chuck 82. The attachment / detachment controller 103 controls the moving unit 84 to position the one blade chuck 82 at a position where the circular base 212 of the cutting blade 21 gripped by the one blade chuck 82 contacts the other edge portion 242 of the bearing flange 243 of the attachment 24, and releases the grippers 825 of the one blade chuck 82 from the cutting blade 21.

[0081] The attachment / detachment controller 103 controls the moving unit 84 to move the one blade clamping device 82 away from the hub 242 of the attachment 24 of the cutting unit 20 to which the cutting blade 21 has been attached, and to position the nut holder 83 at a position where the fastening nut 27 gripped by the nut holder 83 can be screwed via the outer peripheral surface 245 with the external thread of the hub 242 of the attachment 24 of the cutting unit 20 to which the cutting blade 21 has been attached. The attachment / detachment controller 103 controls the nut holder 83 to rotate the spindle 833 thereof about the central axis 831 in a direction to arrange the fastening nut 27 on the outer peripheral surface 245 with the external thread while gripping the fastening nut 27 with the grippers 835.The attachment / detachment controller 103 controls the nut holder 83 to rotate the spindle 833 thereof until the fastening nut 27 is screwed over the outer peripheral surface 245 with the external thread, and thereafter to stop rotating the spindle 833, and releases the grippers 835 of the nut holder 83 from the fastening nut 27.

[0082] The attachment / detachment controller 103 controls the movement unit 84 to move the blade attachment / detachment unit 80 toward the blade storage 70 and position the other blade clamp 82 at a position where the gripped cutting blade 21 is located adjacent to the blade holder 74 at the transfer position 744 and spaced therefrom in the Y-axis direction. At this time, the attachment / detachment controller 103 positions the other blade clamp 82 at a position where the central axis 821 thereof is coaxial with, that is, in line with, the central axis 745 of the blade fitting member 741 of the blade holder 74 at the transfer position 744.

[0083] The attachment / detachment controller 103 controls the movement unit 84 to bring the other blade clamp 82 close to the blade holder 74 along the Y-axis direction at the transfer position 744 and insert the blade fitting member 741 into the insertion hole 211 in the cutting blade 21 gripped by the other blade clamp 82. The attachment / detachment controller 103 controls the movement unit 84 to position the other blade clamp 82 at a position where the circular base 212 of the cutting blade 21 gripped by the other blade clamp 82 contacts the blade holder 74 at the transfer position 744, and releases the grippers 825 of the other blade clamp 82 from the cutting blade 21.

[0084] The attachment / detachment controller 103 controls the movement unit 84 to move the blade attachment / detachment unit 80 to a standby position, and thereafter terminates the operation for attaching 24 and detaching the cutting blade 21. As described above, the attachment / detachment controller 103 of the control unit 100 aligns the central axis 246 of the hub 242 of the attachment with the central axes 821 of the blade chucks 82 and attaches a cutting blade 21 to the attachment 24 and detaches a cutting blade 21 therefrom. (Mounting position calculation process)

[0085] Next, an operation of the blade changer unit 7 of the cutting device 1 of the above structure for calculating the position of the hub 242 of the attachment 24 will be described below. According to the first embodiment, the control unit 100 executes the operation for calculating the position of the attachment 24 when it judges that a position calculation time point for calculating the position of the hub 242 of the attachment 24 of at least one of the cutting units 20 has been reached. The position calculation time point refers to a time point for calculating the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the hub 242 of the attachment 24 of each cutting unit 20 at the attachment / detachment position, and also for calculating the position of the distal end surface 247 of the hub 242 in the Y-axis direction.The position calculation timing is reached each time the cutting blade 21 has cut a predetermined number of workpieces 200, preferably immediately before each cutting blade 21 is to be replaced, and is stored as part of the machining content information in the control unit 100. Furthermore, according to the present invention, the position calculation timing can be performed at any time by the operator controlling the input unit.

[0086] In the attachment position calculation process, first, the calculator 102 of the control unit 100 performs a process for calculating the position of the central axis 246 of the attachment 24 of the cutting unit 20 at the attachment / detachment position. Fig. Figure 10 is a perspective view showing the manner in which the grippers of the blade clamping device and the outer peripheral surface of the hub are engaged in a position calculation process for calculating the position of the central axis of the attachment of the Fig. 3 shown blade changer unit are kept in contact with each other. Fig. Figure 11 is a perspective view showing the manner in which the grippers of the blade clamping device and the outer peripheral surface of the hub are engaged in the position calculation process for calculating the position of the central axis of the attachment of the Fig. 3 shown blade changer unit are kept in contact with each other. Fig. Figure 12 schematically illustrates the manner in which the grippers of the blade clamping device and the outer peripheral surface of the hub are engaged in the position calculation process for calculating the position of the central axis of the attachment of the Fig. 3 are held in contact with each other at a first contact point. Fig. Figure 13 schematically illustrates the manner in which the grippers of the blade clamping device and the outer peripheral surface of the hub are engaged in the position calculation process for calculating the position of the central axis of the attachment of the Fig. 3 are kept in contact with each other at a second contact point. Fig. Figure 14 schematically illustrates the manner in which the grippers of the blade clamping device and the outer peripheral surface of the hub are engaged in the position calculation process for calculating the position of the central axis of the attachment of the Fig. 3 are kept in contact with each other at a third contact point.

[0087] In the position calculation process for calculating the position of the central axis 246 of the attachment 24, the computer 102 of the control unit 100 stops rotating the spindle 23 of the cutting unit 20 that has reached the position calculation time point, and controls the Y-axis moving unit 40 and the corresponding Z-axis moving unit 50 to position the cutting unit 20 that has reached the position calculation time point at the attachment / detachment position.In the position calculation process for calculating the position of the central axis 246 of the attachment 24, as in the process for attaching and detaching a cutting blade 21, the calculator 102 of the control unit 100 removes the fixing nut 27 and the cutting blade 21 from the cutting unit 20 that has reached the position calculation time point, brings the grippers 825 of the blade chuck 82, to which electric power is supplied from the power supply, into contact with the hub 242 of the attachment 24 of the cutting unit 20 at the attachment / detachment position, as shown in FIG. Fig. 10 and Fig. 11, and calculates the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the hub 242 of the attachment 24 of the cutting unit 20 at the attachment / detachment position.

[0088] In the position calculation process for calculating the position of the attachment 24, the computer 102 controls an operation of the moving unit 84 of the corresponding blade attachment / detachment unit 80 based on the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the attachment 24 of the cutting unit 20 at the attachment / detachment position, the position in the Y-axis direction of the distal end surface 247 of the attachment 24 of the cutting unit 20 at the attachment / detachment position, the positions being stored in the storage device, and the detection signals from the position detection units.

[0089] To calculate the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the hub 242 of the attachment 24 of the cutting unit 20 at the attachment / detachment position, the computer 102 controls the moving unit 84 to move the blade attachment / detachment unit 80 to keep the grippers 825 of one of the blade chucks 82 that has not yet gripped a cutting blade 21 away from each other, and to position the grippers 825 close to the outer peripheral surface of the hub 242 of the attachment 24 of the cutting unit 20 from which the fastening nut 27 and the cutting blade 21 have been removed, so that the outer peripheral surface of the hub 242 and the blade chuck 82 can be brought into contact with each other through fine adjustments.While electrical power is supplied from the power supply to the grippers 825 of one of the blade clamping devices 82, the computer 102 controls the moving unit 84 to move one of the blade clamping devices 82 in a first direction 111 perpendicular to the central axis 821 (see . Fig. 12). According to the first embodiment, the first direction 111 is illustrated as an upward direction along the Z-axis direction. However, the present invention is not limited to such a direction.

[0090] Then the grippers 825 touch, as in Fig. 12, the outer peripheral surface of the hub 242 at a first contact point 121. The computer 102 detects, based on the detection signals from the line detection unit 92, that the grippers 825 have touched the outer peripheral surface of the hub 242 at the first contact point 121 and stops moving the blade attachment / detachment unit 80 of the movement unit 84. The computer 102 calculates the position in the X-axis direction and the position in the Z-axis direction of the central axis 821 (hereinafter referred to as 821-1) at the time the grippers 825 have touched the outer peripheral surface of the hub 242 at the first contact point 121 based on the detection signals from the position detection units, and temporarily stores the calculated positions in the storage device. Fig. 12, Fig. 13 and Fig. 14, the outer peripheral surface of the hub 242 is schematically represented by a circle with a solid line, whereas a circle inscribed in the grippers 825 is schematically represented by a circle with a dash-double-dotted line.

[0091] While electrical power is supplied from the power supply to the grippers 825 of one of the blade clamping devices 82, the computer 102 controls the movement unit 84 to move one of the blade clamping devices 82 in a second direction 112 perpendicular to the central axis 821 and different from the first direction 111 (see Fig. 13). According to the first embodiment, the second direction 112 is illustrated as a downward direction along the Z-axis direction. However, the present invention is not limited to such a direction.

[0092] Then touch as in Fig. 13, the grippers 825 contact the outer peripheral surface of the hub 242 at a second contact point 122 different from the first contact point 121. The computer 102 recognizes, based on the detection signals from the line detection unit 92, that the grippers 825 have contacted the outer peripheral surface of the hub 242 at the second contact point 122, and stops moving the blade attachment / detachment unit 80 of the movement unit 84. The computer 102 calculates the position in the X-axis direction and the position in the Z-axis direction of the central axis 821 (hereinafter referred to as 821-2) at the time the grippers 825 have contacted the outer peripheral surface of the hub 242 at the second contact point 122, based on the detection signals from the position detection units, and stores the calculated Positions temporarily in the storage device.

[0093] While electrical power is supplied from the power supply to the grippers 825 to one of the blade clamping devices 82, the computer 102 controls the moving unit 84 to move one of the blade clamping devices 82 in a third direction 113 perpendicular to the central axis 821 and different from the first direction 111 and the second direction 112 (see Fig. 14). According to the first embodiment, the third direction 113 is illustrated as a direction parallel to the X-axis direction. However, the present invention is not limited to such a direction.

[0094] Then the grippers 825 touch, as in Fig. 14, the outer peripheral surface of the hub 242 at a third contact point 123. The computer 102 recognizes, based on the detection signals from the line detection unit 92, that the grippers 825 have touched the outer peripheral surface of the hub 242 at the third contact point 123, and stops moving the blade attachment / detachment unit 80 of the moving unit 84. The third contact point 123 is different from both the first contact point 121 and the second contact point 122. The computer 102 calculates the position in the X-axis direction and the position in the Z-axis direction of the central axis 821 (hereinafter referred to as 821-3) at the time the grippers 825 have touched the outer peripheral surface of the hub 242 at the third contact point 123, based on the detection signals from the position detection units and temporarily stores the calculated positions in the storage device.

[0095] Based on the positions in the X-axis direction and the positions in the Z-axis direction of the central axes 821-1, 821-2, and 821-3, the calculator 102 calculates the position in the X-axis direction and the position in the Z-axis direction of the center of a circle passing through the central axes 821-1, 821-2, and 821-3 as the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the hub 242 of the attachment 24 of the cutting unit 20, and stores the calculated positions as the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the hub 242 of the attachment 24 of a new cutting unit 20 in the storage device.

[0096] In this way, in the position calculation process for calculating the central axis 246 of the attachment 24, the calculator 102 calculates the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the hub 242 of the attachment 24 from the positions in the X-axis direction and the positions in the Z-axis direction of the central axes 821-1, 821-2, and 821-3 represented by coordinates at which the line detection unit 92 has detected an electric line at the time when the grippers 825 at the three contact points 121, 122, and 123 touch the outer peripheral surface of the hub 242 of the attachment 24, as shown in Fig. 12, Fig. 13 and Fig. 14. According to the first embodiment, in the position calculation process for calculating the central axis 246 of the attachment 24, the calculator 102 brings the grippers 825 into contact with the outer peripheral surface of the hub 242 of the attachment 24 at the three contact points 121, 122, and 123. However, according to the present invention, the grippers 825 may be brought into contact with the outer peripheral surface of the hub 242 of the attachment 24 at least at the three contact points 121, 122, and 123.

[0097] According to the first embodiment, in the position calculation process for calculating the position of the attachment, the calculator 102 of the control unit 100 next executes a position calculation process for calculating the position of the distal end surface 247 of the hub 242 of the attachment 24 of the cutting unit 20 at the attachment / detachment position. Fig. Fig. 15 is a perspective view showing the manner in which the grippers of the blade clamping device and a distal end face of the hub are engaged in a position calculation process for calculating the position of the distal end face of the attachment of the Fig. 3 shown blade changer unit are kept in contact with each other. Fig. Fig. 16 schematically shows the positional relationship between the grippers of the blade clamping device and the hub when attaching or detaching a blade on the basis of the position of the central axis of attachment obtained by the position calculation process for calculating the position of attachment of the blade clamping device shown in Fig. 3 shown blade changer unit.

[0098] In the position calculation process for calculating the position of the distal end surface 247 of the hub 242 of the attachment 24, the computer 102 of the control unit 100 controls the moving unit 84 to move the blade attachment / detachment unit 80 to position one of the blade chucks 82 at a position where the flat surfaces 827 of the grippers 825 are located in the Y-axis direction adjacent to the distal end surface 247 of the hub 242 of the attachment 24 of the cutting unit 20 from which the fixing nut 27 and the cutting blade 21 have been removed.While the grippers 825 of one of the blade chucks 82 are spaced apart from each other and an electric power is supplied thereto from the power supply, the computer 102 controls the moving unit 84 to bring one of the blade chucks 82 along the Y-axis direction to the vicinity of the distal end surface 247 of the hub 242 of the attachment 24 of the cutting unit 20 from which the fixing nut 27 and the cutting blade 21 have been removed.

[0099] Then touch as in Fig. 15, the flat surfaces 827 of the grippers 825 touch the distal end surface 247 of the hub 242. The computer 102 detects, based on the detection signals from the line detection unit 92, that the flat surfaces 827 of the grippers 825 have touched the distal end surface 247 of the hub 242, and stops moving the blade attachment / detachment unit 80 of the movement unit 84. The computer 102 calculates the position in the Y-axis direction of the flat surfaces 827 at the time the flat surfaces 827 of the grippers 825 touched the distal end surface 247 of the hub 242, based on the detection signals from the position detection units, and stores the calculated position as the position in the Y-axis direction of the distal end surface 247 of the hub. 242 the attachment 24 of a new cutting unit 20 in the storage device.

[0100] Thus, in the position calculation process for calculating the position of the distal end surface 247 of the hub 242 of the attachment 24, the calculator 102 calculates the position in the Y-axis direction of the distal end surface 247 of the hub 242 of the attachment 24 from the position in the Y-axis direction of the flat surfaces 827 represented by coordinates at which the line detection unit 92 has detected an electric line at the time the grippers 825 touch the distal end surface 247 of the hub 242 of the attachment 24 at a contact point. According to the first embodiment, in the position calculation process for calculating the position of the distal end surface 247 of the hub 242 of the attachment 24, the calculator 102 brings the grippers 825 into contact with the distal end surface 247 of the hub 242 of the attachment 24 at a contact point.According to the present invention, the grippers 825 can be brought into contact with the distal end surface 247 of the hub 242 of the attachment 24 at at least one contact point. The attachment / detachment controller 103 of the control unit 100 controls the blade attachment / detachment unit 80 to align the central axis 821 of the blade chuck 82 with the central axis 246 of the attachment 24, as shown in FIG. Fig. 16, based on the calculated position in the X-axis direction and the calculated position in the Z-axis direction of the central axis 246 and the position in the Y-axis direction of the distal end surface 247 of the hub 242, whereupon cutting blades 21 are removed and attached. In Fig. 16, the outer peripheral surface of the hub 242 is schematically indicated by a circle with a solid line, whereas a circle inscribed in the grippers 825 is schematically indicated by a circle with a dash-double-dotted line.

[0101] The blade changer unit 7 according to the first embodiment can easily detect the positions where the grippers 825 and the attachment 24 contact each other based on the detection signals from the line detection unit 92 generated when the attachment 24 is supplied with electric power from the power supply by the grippers 825 of the blade clamping device 82 and the spindle 23. Consequently, the blade changer unit 7 according to the first embodiment is able to easily determine the position of the attachment 24 to which the cutting blade 21 is to be attached.

[0102] Moreover, the blade changer unit 7 according to the first embodiment can easily determine the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the hub 242 of the attachment 24 of the cutting unit 20 at the attachment / detachment position by bringing the grippers 825 of the blade chuck 82 into contact with the outer peripheral surface of the hub 242 of the attachment 24 of the cutting unit 20 at the attachment / detachment position at at least the three contact points 121, 122, and 123.

[0103] Moreover, the blade changer unit 7 according to the first embodiment can easily determine the position in the Y-axis direction of the distal end surface 247 of the hub 242 of the attachment 24 of the cutting unit 20 at the attachment / detachment position by bringing the grippers 825 of the blade chuck 82 into contact at least one contact point with the distal end surface 247 of the hub 242 of the attachment 24 of the cutting unit 20 at the attachment / detachment position. [Modification]

[0104] A blade changer unit according to a modification of the first embodiment will be described hereinafter with reference to the drawings. Fig. 17 is a side view illustrating the manner in which grippers of a blade clamp and a bearing flange of an attachment are held in contact with each other in a position calculation process for calculating the position of a distal end surface of the attachment of a blade changer unit according to the modification of the first embodiment. Those parts of the blade changer unit according to the modification that are identical to those of the blade changer unit according to the first embodiment are denoted by identical reference numerals and will not be described in detail below.

[0105] The blade changer unit designated by 7 according to the modification of the first embodiment is the same as the blade changer unit 7 according to the first embodiment except that a position calculation process for calculating the position of the distal end surface 247 of the hub 242 of the attachment 24 in a position calculation process for calculating the position of the attachment 24 is different from the position calculation process according to the first embodiment.In the position calculation process for calculating the position of the distal end surface 247 of the hub 242 of the attachment 24, the blade changer unit 7 according to the modification of the first embodiment brings the flat surfaces 827 of the grippers 825 of the blade clamp 82 into contact with the outer edge portion 244 of the distal end of the bearing flange 243 of the attachment 24 of the cutting unit 20 at the attachment / detachment position, calculates the position in the Y-axis direction of the outer edge portion 244 of the bearing flange 243, and calculates the position in the Y-axis direction of the distal end surface 247 of the hub 242.

[0106] The blade changer unit 7 according to the modification of the first embodiment, as with the first embodiment, can easily detect the positions where the grippers 825 and the attachment 24 contact each other based on the detection signals from the conduction detection unit 92 generated when the attachment 24 is supplied with electric power from the power supply via the grippers 825 of the blade chuck 82 and the spindle 23. Consequently, the blade changer unit 7 according to the modification of the first embodiment, as with the first embodiment, is capable of easily determining the position of the attachment 24 to which a cutting blade 21 is to be attached.According to the present invention, the grippers 835 of the nut holder 83 can be brought into contact with the attachment 24 in the same manner as the first embodiment and the modification, and the position of the attachment 24 referred to above can be calculated. [Second embodiment]

[0107] A blade changer unit according to a second embodiment of the present invention will be described below with reference to the drawings. Fig. 18 is a perspective view illustrating the manner in which grippers of a blade clamping device hold an electrically conductive receiving device in a position calculating process for calculating the position of attachment of the blade changer unit according to the second embodiment of the present invention. Fig. 19 is a perspective view illustrating the manner in which a hub is inserted into an opening in a receiving device in the position calculating process for calculating the position of the central axis of attachment of the blade changer unit according to the second embodiment. Fig. 20 is a perspective view showing the manner in which the hub is inserted into the opening in the receiving device in the position calculating process for calculating the position of the central axis of attachment of the blade changer unit according to the second embodiment. Fig. 21 schematically illustrates the manner in which an edge of the receiving means defining the opening is held in contact with an outer peripheral surface of the hub at a first contact point in the position calculating process for calculating the position of the central axis of attachment of the blade changer unit according to the second embodiment. Fig. 22 schematically illustrates the manner in which the edge of the receiving means defining the opening is held in contact with the outer peripheral surface of the hub at a second contact point in the position calculation process for calculating the position of the central axis of attachment of the blade changer unit according to the second embodiment. Fig. 23 schematically illustrates the manner in which the edge of the receiving means defining the opening is held in contact with the outer peripheral surface of the hub at a third contact point in the position calculation process for calculating the position of the central axis of attachment of the blade changer unit according to the second embodiment. Fig. Fig. 24 is a perspective view of the manner in which the receiving device and a distal end surface of the hub are held in contact with each other in a position calculation process for calculating the position of a distal end surface of the blade changer unit attachment according to the second embodiment. Fig. 18 to 24, those parts which are identical to those according to the first embodiment are designated by the same reference numerals and will not be described in detail below.

[0108] The blade changing unit, designated by 7, according to the second embodiment is the same as the blade changing unit 7 according to the first embodiment except that the grippers 825 of the blade clamping device 82 hold an electrically conductive receiving device 300 in a position calculation process for calculating the position of the attachment 24 and bring the electrically conductive receiving device 300 into contact with the outer peripheral surface of the distal end face 247 of the attachment 242, as shown in Fig. 18 is shown.

[0109] In the position calculation process for calculating the position of the attachment 24, the blade changer unit 7 according to the second embodiment causes the blade clamping device 82, which does not grip the cutting blade 21 removed from the cutting unit 20, to hold the receiving device 300, as shown in Fig. 18. The receiving device 300 is made of an electrically conductive material, ie, a metal according to the second embodiment, and has an annular shape with an opening 301 defined centrally therein. The opening 301 has an inner diameter that is larger than the outer diameter of the hub 242.

[0110] According to the second embodiment, in the position calculation process for calculating the central axis 246 of the attachment 24 of the cutting unit 20 at the attachment / detachment position, the computer 102 of the control unit 100 controls the movement unit 84 to move the blade attachment / detachment unit 80 to position the blade chuck 82 gripping the receiving device 300 at a position where the blade chuck 82 is located adjacent in the Y-axis direction to the hub 242 of the attachment 24 of the cutting unit 20 from which the fixing nut 27 and the cutting blade 21 have been removed.At this time, the computer 102 positions the cutting unit 20 and the blade chuck 82 at a position where they are coaxial with each other based on the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 at the attachment / detachment position, the cutting unit 20 and the blade chuck 82, which positions are stored in the storage device. While supplying electric power from the power supply to the grippers 825 of the blade chuck 82 gripping the receptacle 300, the computer 102 controls the moving unit 84 to bring the blade chuck 82 gripping the receptacle 300 close to the cutting unit 20 along the Y-axis direction, inserting the hub 242 into the opening 301 of the receptacle 300, as shown in FIG. Fig. 19, and to stop the blade clamping device 82 at a position where the attachment 24 and the receiving device 300 are spaced apart from each other and do not contact each other.

[0111] While electric power is supplied from the power supply to the grippers 825 of the blade clamping device 82 gripping the receiving device 300, the computer 102 controls the moving unit 84 to move the blade clamping device 82 gripping the receiving device 300 sequentially in the first direction 111, the second direction 112 and the third direction 113 perpendicular to the central axis 821 in the same manner as in the first embodiment, as shown in Fig. 20 is shown.

[0112] When the moving unit 84 moves the blade clamping device 82 in the first direction 111, as shown in Fig. 21, an inner peripheral surface of the receiving device 300, which defines the opening 301, contacts the outer peripheral surface of the hub 242 at the first contact point 121. As in the first embodiment, the calculator 102 calculates the position in the X-axis direction and the position in the Z-axis direction of the central axis 821-1 at the time when the inner peripheral surface of the receiving device 300, which defines the opening 301, has contacted the outer peripheral surface of the hub 242 at the first contact point 121, and temporarily stores the calculated positions in the storage device. In Fig. 21, Fig. 22 and Fig. 23, the outer peripheral surface of the hub 242 is schematically represented by a circle with a solid line, whereas an outer profile of the receiving device 300 is schematically represented by circles with a dash-double-dotted line.

[0113] While electrical power is supplied from the power supply to the grippers 825 of the blade clamping device 82 gripping the receiving device 300, the computer 102 controls the movement unit 84 to move the blade clamping device 82 gripping the receiving device 300 in the second direction 112. Then, as in Fig. 22, the inner peripheral surface of the receiving device 300 defining the opening 301 contacts the outer peripheral surface of the hub 242 at the second contact point 122. As in the first embodiment, the calculator 102 calculates the position in the X-axis direction and the position in the Z-axis direction of the central axis 821-2 at the time point when the inner peripheral surface of the receiving device 300 defining the opening 301 has contacted the outer peripheral surface of the hub 242 at the second contact point 122, and temporarily stores the calculated positions in the storage device.

[0114] While the power supply is supplying electrical power to the grippers 825 of the blade clamping device 82 gripping the receiving device 300, the computer controls the movement unit 84 to move the blade clamping device 82 gripping the receiving device 300 in the third direction 113. Then, as shown in Fig. 23, the inner peripheral surface of the receiving device 300 defining the opening 301 contacts the outer peripheral surface of the hub 242 at the third contact point 123. As in the first embodiment, the calculator 102 calculates the position in the X-axis direction and the position in the Z-axis direction of the central axis 821-3 at the time when the inner peripheral surface of the receiving device 300 defining the opening 301 has contacted the outer peripheral surface of the hub 242 at the third contact point 123, and temporarily stores the calculated positions in the storage device.

[0115] As in the first embodiment, the calculator 102 calculates the position in the X-axis direction and the position in the Z-axis direction of the center of the circle passing through the central axes 821-1, 821-2, and 821-3 as the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the hub 242 of the attachment 24 of the cutting unit 20, and stores the calculated positions as the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the hub 242 of the attachment 24 of a new cutting unit 20 in the cutting device.In this way, in the position calculation process for calculating the central axis 246 of the attachment 24, the calculator 102 calculates the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the hub 242 of the attachment 24 from the positions in the X-axis direction and the positions in the Z-axis direction of the central axes 821-1, 821-2, and 821-3 represented by coordinates at which the line detection unit 92 detected an electric line at the time the pickup device 300 touches the outer peripheral surface of the hub 242 of the attachment 24 at the three contact points 121, 122, and 123, as shown in FIG. Fig. 21, Fig. 22 and Fig. 23. According to the second embodiment, in the position calculation process for calculating the central axis 246 of the attachment 24, the calculator 102 brings the receiving device 300 into contact with the outer peripheral surface of the hub 242 of the attachment 24 at the three contact points 121, 122, and 123. However, according to the present invention, the receiving device 300 may be brought into contact with the outer peripheral surface of the hub 242 of the attachment 24 at at least three contact points.

[0116] According to the second embodiment, in the position calculation process for calculating the position of the distal end surface 247 of the hub 242 of the attachment 24 of the cutting unit 20 at the attachment / detachment position, the calculator 102 of the control unit 100 controls the moving unit 84 to move the blade attachment / detachment unit 80 to position the blade chuck 82 gripping the receptacle 300 at a position where the receptacle 300 is located adjacent in the Y-axis direction to the distal end surface 247 of the hub 242 of the attachment 24 of the cutting unit 20 from which the fixing nut 27 and the cutting blade 21 have been removed.

[0117] While supplying electric power from the power supply to the grippers 825 of the blade chuck 82, the computer 102 controls the moving unit 84 to move the blade chuck 82 gripping the receiving device 300 along the Y-axis direction close to the distal end surface 247 of the hub 242 of the attachment 24 of the cutting unit 20 from which the fixing nut 27 and the cutting blade 21 have been removed.

[0118] Then touched, as in Fig. 24, the receiving device 300, the distal end surface 247 of the hub 242. As in the first embodiment, the calculator 102 calculates the position in the Y-axis direction of the distal end surface 247 of the hub 242 of the attachment 24 of a new cutting unit 20 and stores the calculated position in the storage device. Thus, in the position calculation process for calculating the position of the distal end surface 247 of the hub 242 of the attachment 24, the calculator 102 calculates the position in the Y-axis direction of the distal end surface 247 of the hub 242 of the attachment 24 from the position in the Y-axis direction represented by coordinates at which the line detection unit 92 detected an electric line at the time point at which the pickup device 300 detected the distal end surface 247 of the hub 242 of the attachment 24 at a contact point.

[0119] According to the second embodiment, in the position calculation process for calculating the position of the distal end surface 247 of the hub 242 of the attachment 24, the computer 102 brings the receiving device 300 into contact with the distal end surface 247 of the hub 242 of the attachment 24 at a contact point. However, according to the present invention, the receiving device 300 may be brought into contact with the distal end surface 247 of the hub 242 of the attachment 24 at at least one contact point.Then, the attachment / detachment controller 103 of the control unit 100 controls the blade attachment / detachment unit 80 to align the central axis 821 of the blade chuck 82 with the central axis 246 of the attachment 24 based on the calculated position in the X-axis direction and the calculated position in the Z-axis direction of the central axis 246 and the position in the Y-axis direction of the distal end surface 247 of the hub 242, whereupon cutting blades 21 are detached and attached.

[0120] The blade changer unit 7 according to the second embodiment can easily detect the position where the receiving device 300 gripped by the grippers 825 and the attachment 24 contact each other based on the detection signals from the conduction detection unit 92 generated when the attachment 24 is supplied with electric power from the power supply via the receiving device 300, the grippers 825 of the blade clamping device 82, and the spindle 23. Consequently, the blade changer unit 7 according to the second embodiment is capable of easily determining the position of the attachment 24 to which a cutting blade 21 is to be attached. [First modification]

[0121] A blade changer unit according to a first modification of the second embodiment will be described hereinafter with reference to the drawings. Fig. 25 is a side view illustrating the manner in which a receiving device gripped by a blade clamping device and a bearing flange of an attachment are held in contact with each other in a position calculation process for calculating the position of a distal end surface of the attachment of the blade changer unit according to the first modification of the second embodiment. Fig. 25, those parts of the blade changer unit according to the first modification which are identical to those of the blade changer unit according to the second embodiment are designated by like reference numerals and will not be described in detail below.

[0122] The blade changer unit, designated by 7, according to the first modification of the second embodiment is the same as the blade changer unit 7 according to the second embodiment, except that a position calculation process for calculating the position of the distal end surface 247 of the hub 242 of the attachment 24 in a position calculation process for calculating the position of the attachment 24 is different from the position calculation process according to the second embodiment. As shown in Fig. 25, in the position calculation process for calculating the position of the attachment 24, the blade changer unit according to the first modification of the second embodiment brings the receiver 300 gripped by the grippers 825 of the blade chuck 82 into contact with the outer edge portion 244 of the bearing flange 243 of the attachment 24 of the cutting unit 20 at the attachment / detachment position, calculates the position in the Y-axis direction of the outer edge portion 244 of the bearing flange 243, and calculates the position in the Y-axis direction of the distal end surface 247 of the hub 242.

[0123] The blade changer unit 7 according to the first modification of the second embodiment, as in the second embodiment, can easily detect the position where the receiver 300 gripped by the grippers 825 and the attachment 24 contact each other based on the detection signals from the conduction detection unit 92 generated when the attachment 24 is supplied with electric power from the power supply via the receiver 300, the grippers 825 of the blade clamp 82, and the spindle 23. Consequently, the blade changer unit 7 according to the first modification of the second embodiment, as in the second embodiment, is capable of easily determining the position of the attachment 24 to which a cutting blade 21 is to be attached. [Second modification]

[0124] A blade changer unit according to a second modification of the second embodiment will be described hereinafter with reference to the drawings. Fig. 26 is a side view showing an example of the structure of a position detecting unit of a blade attaching / detaching unit of the blade changing unit according to the second modification of the second embodiment. Fig. 27 is a side view showing an attachment of a cutting device having the blade changing unit according to the second modification of the second embodiment. Fig. 28 is a side view showing a cutting blade of the cutting device having the blade changing unit according to the second modification of the second embodiment. Fig. Fig. 29 is a side view showing the manner in which a hub of the cutting device attachment having the blade changer unit according to the second modification of the second embodiment is inserted into an insertion hole in the cutting blade. Fig. 26, Fig. 27, Fig. 28 and Fig. 29, those parts of the blade changer unit according to the second modification which are identical to those of the blade changer unit according to the second embodiment are denoted by identical reference numerals and will not be described in detail below.

[0125] The blade changing unit, designated by 7, according to the second modification of the second embodiment is the same as the blade changing unit 7 according to the second embodiment except that the cutting blade 21 is used as the receiving device 300 from the blade chucking device 82 as shown in Fig. 26, is gripped while the position detecting operation for detecting the position of the attachment 24 is carried out, and the outer peripheral surface 245 with the external thread of the hub 242 of the attachment 24 has an outer diameter 245-1 which is smaller than an outer diameter 242-1 of one end of the hub 242, as shown in Fig. 27 is shown. In Fig. 26, only one blade clamping device 82 is shown, the selector switch 93 being omitted from the illustration.

[0126] According to the second modification of the second embodiment, the insertion hole 211 in the Fig. 28 has a diameter on an inner side which is substantially equal to the outer diameter 242-1 of the end of the hub 242 of the attachment 24 and is larger than the outer diameter 245-1 of the outer peripheral surface 245 with the external thread of the hub 242. According to the second modification of the second embodiment, in the position calculation process for calculating the position of the central axis 246 of the hub 242 of the attachment 24, as shown in Fig. 29, the outer peripheral surface 245 having the external thread of the hub 242 of the attachment 24 is inserted into the insertion hole 211 in the cutting blade 21 without contacting the inner peripheral surface of the cutting blade 21 defining the insertion hole 211. Thereafter, the cutting blade 21 is sequentially moved in the first direction 111, the second direction 112, and the third direction 113, as in the second embodiment, and the position in the X-axis direction and the position in the Z-axis direction of the central axis 246 of the hub 242 are calculated.

[0127] Moreover, according to the second modification of the second embodiment, in the position calculation process for calculating the position of the distal end surface 247 of the hub 242 of the attachment 24, in the position calculation process for calculating the position of the attachment 24, the circular base 212 of the cutting blade 21, etc., is brought into contact with the distal end surface 247 of the hub 242 or the outer edge portion 244 of the bearing flange 243, and the position in the Y-axis direction of the distal end surface 247 of the hub 242 is calculated.

[0128] The blade changer unit according to the second modification of the second embodiment can, as in the second embodiment, easily detect the position where the cutting blade 21 gripped by the grippers 825 and the attachment 24 contact each other based on the detection signals from the conduction detection unit 92 generated when the attachment 24 is supplied with electric power from the power supply via the cutting blade 21, the grippers 825 of the blade chuck 82, and the spindle 23. Consequently, the blade changer unit 7 according to the first modification of the second embodiment is capable of easily determining the position of the attachment 24 to which a cutting blade 21 is to be attached, as in the first embodiment.

[0129] Furthermore, since the blade changer unit 7 according to the second modification of the second embodiment determines the position of the attachment 24 by bringing the cutting blade 21 gripped by the grippers 825 into contact with the attachment 24, the position of the attachment 24 can be determined without using a special receiver, and the position of the attachment 24 can be determined while cutting blades 21 are being attached and detached. Furthermore, according to the present invention, the above-described position of the attachment 24 can be calculated by bringing the receiver 300 of the nut holder 83 gripped by the grippers 835 into contact with the attachment 24 in the same manner as in the second embodiment and the first and second modifications thereof. [Modification]

[0130] A blade changer unit according to a modification of the first embodiment and the second embodiment will be described hereinafter with reference to the drawings. Fig. 30 is a perspective view illustrating, by way of example, the structure of a blade clamping device of a blade attaching / detaching unit of the blade changing unit according to the modification of the first embodiment and the second embodiment. Fig. 30, those parts of the blade changer unit according to the modification which are identical to those of the blade changer units according to the first embodiment and the second embodiment are denoted by identical reference numerals and will not be described in detail below.

[0131] The blade changing unit, designated by 7, according to the modification is the same as the blade changing units according to the first embodiment and the second embodiment, except that the blade clamping device 82 has a different structure. As shown in Fig. As shown in Fig. 30, the blade clamping device, designated by 82-1, of the blade attachment / detachment unit 80 of the blade changer unit 7 according to the modification includes a support base 824 having an end surface facing the blade holder 74 and the attachment 24 of the cutting unit 20, and two suction grooves 828 defined therein, which are connected to a suction source, and an entry hole 829 defined therein for receiving the hub 242, which enters the entry hole 829 when the cutting unit 20 is attached and detached. The suction grooves 828 and the entry hole 829 are recessed from the end surface of the support base 824.

[0132] According to the modification, the two suction grooves 828 have an annular shape and are positioned coaxially with the end surface. When a negative pressure from the suction source acts in the suction grooves 828, the cutting blade 21 is held under suction against the end surface of the support base 824. The entry hole 829 is defined centrally in the end surface of the support base 824, coaxially therewith.

[0133] The blade changing unit 7 according to the modification is capable of easily determining the position of the attachment 24 to which a cutting blade 21 is to be attached, as in the first embodiment and the second embodiment, since the attachment 24 is supplied with electric power from the power supply through the blade chuck 82-1 and the spindle 23.

[0134] The present invention is not limited to the details of the preferred embodiments described above. The scope of the invention is defined by the appended claims, and all changes and modifications that fall within the equivalent scope of the claims are therefore encompassed by the invention.

Claims

[1] Blade changer unit (7) for attaching a cutting blade (21) to and detaching the cutting blade (21) from a hub (242) extending in an axial direction of an attachment (24) fixed to a distal end of a spindle (23) of a machining device (1), wherein the cutting blade (21) has a circular base (212) having an insertion hole (211) defined centrally therein and a cutting edge (213) arranged on an outer peripheral edge portion of the circular base (212), the blade changer unit (7) comprising: an electrically conductive holder (825) for holding the cutting blade (21); a moving unit (84) for moving the blade changer unit (7); and a control unit (100) for controlling the movement unit (84) and detecting a line between the holder (825) and the hub (242), wherein the control unit (100) comprises: a calculator (102) for calculating a center of the attachment (24) from coordinates at which the line between the holder (825) and the hub (242) is detected when the movement unit (84) is controlled to bring the holder (825) into contact with the attachment (24) at at least three points, and an attachment / detachment control (103) for attaching and detaching the cutting blade (21) while a center of the holder (825) is aligned with the center of the attachment (24) calculated by the computer (102). [2] Blade changer unit (7) according to claim 1, wherein the attachment (24) has a bearing flange (243) projecting outward in a radial direction from a rear end of the attachment (24) in an axial direction thereof to support the cutting blade (21), the spindle (23) has an axial direction as a Y-axis direction, the calculator (102) calculates coordinates in the Y-axis direction of the hub (242) from the coordinates at which the line between the holder (825) and the hub (242) is detected when the holder (825) is brought into contact with the hub (242) or a distal end of the bearing flange (243) at least at one point, and the attachment / detachment control (103) attaches and detaches the cutting blade (21) in an alignment with the coordinates calculated by the computer (102) in the Y-axis direction of the hub (242). [3] Blade changer unit (7) for attaching a cutting blade (21) to and detaching the cutting blade (21) from a hub (242) extending in an axial direction of an attachment (24) fixed to a distal end of a spindle (23) of a machining device (1), wherein the cutting blade (21) has a circular base (212) having an insertion hole (211) defined centrally therein and a cutting edge (213) arranged on an outer peripheral edge portion of the circular base (212), the blade changer unit (7) comprising: an electrically conductive holder (825) for holding an electrically conductive device having an opening larger than the hub (242); a moving unit (84) for moving the blade changer unit (7); and a control unit (100) for controlling the movement unit (84) and detecting a line between the holder (825) and the hub (242), wherein the control unit (100) comprises: a computer (102) for calculating a center of the attachment (24) from coordinates at which the line between the holder (825) and the hub (242) is detected when the moving unit (84) is controlled to bring the device held by the holder (825) into contact with the attachment (24) at at least three points, and an attachment / detachment control (103) for attaching and detaching the cutting blade (21) while a center of the holder (825) is aligned with the center of the attachment (24) calculated by the computer (102). [4] Blade changer unit (7) according to claim 3, wherein the attachment (24) has a bearing flange (243) projecting outward in a radial direction from a rear end of the hub (242) in an axial direction thereof for supporting the cutting blade (21), the spindle (23) having an axial direction as a Y-axis direction, the calculator (102) calculates coordinates in the Y-axis direction of the hub (242) from the coordinates at which the line between the holder (825) and the hub (242) is detected when the device is brought into contact with the hub (242) or a distal end of the bearing flange (243) at at least one point, and the attachment / detachment controller (103) attaches and detaches the cutting blade (21) in alignment with the coordinates calculated by the computer (102) in the X-axis direction of the hub (242). [5] Blade changing unit (7) according to claim 3 or 4, wherein the device comprises the cutting blade (21).

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