JP2016144839A - Cutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting device capable of preventing generation of a problem caused by carelessness of an operator or the like even when exchange work of a cutting blade is started at an arbitrary step.SOLUTION: A cutting device comprises: blade attachment/detachment means (74) which has a blade holding part (80) for holding a cutting blade (46), and attaches and detaches the cutting blade to and from a tip part of a spindle (36); input means (84) to which various commands are input; control means (86) for controlling the movement of each part; blade detection means (56, 86a, 86b) for detecting the presence or absence of the cutting blade fitted to the tip part of the spindle; and alarm means (88) for issuing a predetermined alarm. When a fitting command to fit the cutting blade to the tip part of the spindle by the blade attachment/detachment means is input to the input means, the control means executes a content of the fitting command if no cutting blade is detected by the blade detection means. If the blade detection means detects the cutting blade, the control means issues an alarm from the alarm means without executing the content of the fitting command.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a cutting apparatus including an automatic blade changer that automatically replaces a cutting blade.

  In a small and lightweight electronic device typified by a cellular phone, a device chip including an electronic circuit (device) such as an IC is indispensable. The device chip is, for example, by dividing the surface of a semiconductor wafer made of a material such as silicon with a plurality of division lines called streets, forming devices in each area, and then dividing the semiconductor wafer along the streets. Can be manufactured.

  When a plate-like workpiece such as a semiconductor wafer is divided, for example, a cutting device in which a disc-like cutting blade is attached to the tip of a spindle serving as a rotation shaft is used. If the cutting blade is rotated at a high speed and cut into the street of the work piece, and the cutting blade and the work piece are moved relative to each other in a direction parallel to the street, the work piece is cut to obtain a plurality of chips. Can be divided into

  The above-described cutting blade is replaced when worn to some extent. Thereby, the cutting capability of the cutting device is maintained in a high state. In recent years, a cutting apparatus including an automatic blade changer that automatically replaces a cutting blade has been put into practical use in order to reduce the time required for replacing the cutting blade (see, for example, Patent Document 1).

  Also, a cutting blade mounting mechanism has been proposed in which a suction port is formed in a blade mount attached to the tip of the spindle, and a negative pressure is applied from the suction port to attract and fix the cutting blade (for example, Patent Documents). 2). In this mounting mechanism, since the cutting blade can be fixed without using a member such as a nut, the cutting blade can be replaced in a shorter time.

JP-A-6-326186 JP 2002-154054 A

  In the above-mentioned cutting apparatus provided with an auto blade changer, for example, the auto blade changer may stop due to an unexpected accident. In this case, the operator must manually restart the auto blade changer and restart the cutting blade replacement operation.

  By the way, when the replacement work of the cutting blade can be resumed from an arbitrary process, a problem easily occurs due to carelessness of the operator. For example, if the replacement operation is restarted from the cutting blade mounting process with the cutting blade mounted on the spindle, the cutting blade mounted on the spindle and the newly mounted cutting blade may interfere with each other and damage the cutting device. There is.

  Therefore, the cutting blade replacement operation is limited so that it can be resumed only from the removal step of removing the cutting blade from the spindle. However, if such a restriction is provided, the spindle and the auto blade changer must be returned to the state before the replacement work before restarting the cutting blade replacement work. I need it. In addition, there has been a problem that the processes performed so far are wasted.

  The present invention has been made in view of such problems, and the purpose thereof is to prevent the occurrence of problems caused by carelessness of the operator even if the cutting blade replacement work is started from any step. It is providing the cutting device which can be performed.

  According to the present invention, a workpiece having a chuck table for holding a workpiece, a spindle that is rotationally driven, and a cutting blade that is attached to a tip portion of the spindle is cut. Cutting means; blade attaching / detaching means having a blade holding part for holding the cutting blade; and attaching / detaching the cutting blade to / from a tip of the spindle; an attaching / detaching position at which the cutting blade can be attached / detached; A moving means for relatively moving the cutting means and the blade attaching / detaching means between the separated positions separated from each other, and disposed before or after use, corresponding to the blade attaching / detaching means positioned at the separated position A blade rack capable of accommodating a plurality of the cutting blades, input means for inputting various commands, control means for controlling the movement of each part, and tip of the spindle Blade detecting means for detecting the presence or absence of the cutting blade mounted on the part, and alarm means for issuing a predetermined alarm, and the cutting blade is attached to the tip of the spindle by the blade attaching / detaching means with respect to the input means. When a mounting command indicating that the cutting blade is to be mounted is input, the control unit executes the content of the mounting command when the blade detecting unit does not detect the cutting blade, and the blade detecting unit detects the cutting blade. In such a case, there is provided a cutting device characterized in that the warning means is issued without executing the contents of the mounting command.

  In the present invention, the cutting means includes a blade mount having a disk-shaped flange portion and a boss portion protruding from the flange portion and fixed to a tip portion of the spindle, and the cutting blade is attached to the flange portion. A disk-shaped base having a contact surface to be contacted and having a through-hole into which the boss part of the blade mount is inserted at the center, and a cutting blade formed on the outer periphery of the base, The blade mount includes suction means for sucking the contact surface side of the base of the cutting blade, and the suction means opens to the support surface side of the flange portion that supports the contact surface side of the base. A suction port, a suction source for generating a negative pressure, a suction path connecting the suction port and the suction source, a pressure provided in the suction path and measuring the pressure in the suction path, and the measurement result to the control means A pressure gauge for feeding, and the control means includes the blade marker. A storage unit for storing a reference value set in correspondence with the pressure in the suction path in a state where the cutting blade is held in the head and the measurement result sent from the pressure gauge; A determination unit for determining whether or not the cutting blade is attached to the tip of the spindle from the stored reference value and the measurement result, and the blade detection means includes the pressure gauge and the storage It is preferable that it is comprised from a part and this determination part.

  A cutting apparatus according to the present invention includes blade detecting means for detecting the presence or absence of a cutting blade attached to the tip of a spindle, and alarm means for issuing an alarm, and the cutting blade is connected to the tip of the spindle with respect to input means. When a mounting command indicating that the blade is to be mounted is input, the control unit executes the content of the mounting command when the blade detecting unit does not detect the cutting blade, and when the blade detecting unit detects the cutting blade, The contents of the above are not executed and an alarm is issued by an alarm means.

  Therefore, even when a mounting command is erroneously input in a state where the cutting blade is mounted on the tip of the spindle, the cutting device is not damaged. As described above, according to the cutting device of the present invention, even if the cutting blade replacement operation is started from an arbitrary step, it is possible to prevent the occurrence of a problem due to an operator's carelessness.

It is a figure showing typically the example of composition of the cutting device concerning this embodiment. It is a disassembled perspective view which shows the structure of a cutting unit typically. It is a figure which mainly shows the cross section of a cutting unit. It is a perspective view which shows typically the structure of the periphery of an auto blade changer. 5A is a perspective view schematically showing the structure of the blade attachment / detachment unit, and FIG. 5B is a partial cross-sectional plan view schematically showing the structure of the blade attachment / detachment unit. C) is a side view of the blade attachment / detachment unit as seen from the cutting unit side. It is a block diagram which shows typically the structural example etc. of a control apparatus.

  Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram schematically illustrating a configuration example of a cutting apparatus according to the present embodiment. As shown in FIG. 1, the cutting device 2 includes a base 4 that supports each structure.

  A rectangular opening 4 a that is long in the X-axis direction (machining feed direction) is formed on the upper surface of the base 4. In this opening 4a, there are provided an X-axis moving table 6, an X-axis moving mechanism (not shown) for moving the X-axis moving table 6 in the X-axis direction, and a dustproof and drip-proof cover 8 that covers the X-axis moving mechanism. Yes.

  The X-axis movement mechanism includes a pair of X-axis guide rails (not shown) parallel to the X-axis direction, and an X-axis movement table 6 is slidably installed on the X-axis guide rails. A nut portion (not shown) is provided on the lower surface side of the X-axis moving table 6, and an X-axis ball screw (not shown) parallel to the X-axis guide rail is screwed to the nut portion.

  An X-axis pulse motor (not shown) is connected to one end of the X-axis ball screw. When the X-axis ball screw is rotated by the X-axis pulse motor, the X-axis moving table 6 moves in the X-axis direction along the X-axis guide rail.

  A chuck table 10 is provided on the upper surface of the X-axis moving table 6 for sucking and holding a plate-like workpiece (not shown) such as a semiconductor wafer, a resin substrate, or a ceramic substrate. The chuck table 10 is connected to a rotation drive source (not shown) such as a motor, and rotates around a rotation axis parallel to the Z-axis direction (vertical direction). Further, the chuck table 10 is moved in the X-axis direction by the above-described X-axis moving mechanism.

  The surface (upper surface) of the chuck table 10 is a holding surface 10a for sucking and holding a workpiece. The holding surface 10 a is connected to a suction source (not shown) through a flow path (not shown) formed inside the chuck table 10. Around the chuck table 10 is provided a clamp 12 for holding and fixing a frame (not shown) for supporting the workpiece.

  On the upper surface of the base 4, a gate-type support structure 16 that supports a cutting unit (cutting means) 14 is disposed so as to straddle the opening 4 a. A cutting unit moving mechanism (moving means) 18 that moves the cutting unit 14 in the Y-axis direction (index feed direction) and the Z-axis direction is provided on the surface side of the support structure 16.

  The cutting unit moving mechanism 18 includes a pair of Y-axis guide rails 20 arranged on the upper surface of the support structure 16 and parallel to the Y-axis direction. A Y-axis moving plate 22 constituting the cutting unit moving mechanism 18 is slidably installed on the Y-axis guide rail 20.

  A nut portion (not shown) is provided on the back side of the Y-axis moving plate 22, and a Y-axis ball screw 24 parallel to the Y-axis guide rail 20 is screwed to the nut portion. A Y-axis pulse motor (not shown) is connected to one end of the Y-axis ball screw 24. If the Y-axis ball screw 24 is rotated by the Y-axis pulse motor, the Y-axis moving plate 22 moves in the Y-axis direction along the Y-axis guide rail 20.

  A pair of Z-axis guide rails 26 parallel to the Z-axis direction are provided on the surface of the Y-axis moving plate 22. A Z-axis moving plate 28 is slidably installed on the Z-axis guide rail 26.

  A nut portion (not shown) is provided on the back side of the Z-axis moving plate 28, and a Z-axis ball screw 30 parallel to the Z-axis guide rail 26 is screwed to the nut portion. A Z-axis pulse motor 32 is connected to one end of the Z-axis ball screw 30. When the Z-axis ball screw 30 is rotated by the Z-axis pulse motor 32, the Z-axis moving plate 28 moves in the Z-axis direction along the Z-axis guide rail 26.

  A cutting unit 14 for cutting the workpiece sucked and held by the chuck table 10 is provided below the Z-axis moving plate 28. If the Y-axis moving plate 22 and the Z-axis moving plate 28 are moved as described above, the cutting unit 14 moves in the Y-axis direction and the Z-axis direction.

  FIG. 2 is an exploded perspective view schematically showing the structure of the cutting unit 14, and FIG. 3 is a view mainly showing a cross section of the cutting unit 14. As shown in FIGS. 2 and 3, the cutting unit 14 includes a spindle housing 34 fixed to the lower part of the Z-axis moving plate 28.

  Inside the spindle housing 34, an accommodation space 34a for accommodating a spindle 36 (FIG. 3) serving as a rotation shaft is formed. The spindle 36 is supported in a floating state by compressed air supplied to the accommodation space 34a.

  The tip (one end) of the spindle 36 is formed in a truncated cone shape and is exposed to the outside of the spindle housing 34. A blade mount 38 is attached to the tip of the spindle 36. On the other hand, a motor (not shown) for rotating the spindle 36 is connected to the base end side (the other end side) of the spindle 36.

  The blade mount 38 includes a disk-shaped flange portion 40 extending outward in the radial direction, and a boss portion 42 protruding from the surface side of the flange portion 40. A through hole 38a that penetrates the flange portion 40 and the boss portion 42 is formed in the center of the blade mount 38, and the tip end portion of the spindle 36 is fitted into the through hole 38a from the back surface side.

  A screw groove is provided on the outer peripheral surface of the tip of the spindle 36, and the nut 44 can be tightened. The blade mount 38 can be fixed to the spindle 36 by tightening the nut 44 at the tip of the spindle 36 with the tip of the spindle 36 fitted in the through hole 38 a of the blade mount 38.

  The outer peripheral side of the surface of the flange portion 40 is a support surface 40 a that supports the back side of the cutting blade 46. The support surface 40 a is formed in an annular shape when viewed from the Y-axis direction (axial center direction of the spindle 36), and contacts the back surface side of the cutting blade 46.

  The cutting blade 46 is a so-called hub blade, and an annular cutting blade 50 for cutting a workpiece is provided on the outer peripheral portion of a disk-shaped base (hub base) 48. The cutting blade 50 is formed to have a predetermined thickness by mixing abrasives such as diamond and CBN (Cubic Boron Nitride) with a bond material (bonding material) such as metal or resin.

  A through hole 48 a having substantially the same diameter as the boss portion 42 is formed in the center of the base 48. The cutting blade 46 is mounted on the blade mount 38 by fitting the boss portion 42 into the through hole 48 a and bringing the back surface (contact surface) 48 b of the base 48 into contact with the support surface 40 a of the flange portion 40.

  Inside the blade mount 38, a flow path (suction path) 38b for transmitting negative pressure is formed. One end side of the flow path 38b opens to the front surface side (support surface 40a side) of the flange portion 40, and serves as a suction port 40b that sucks the cutting blade 46. On the other hand, the other end side of the flow path 38b opens to the inner peripheral surface of the through hole 38a.

  A flow path (suction path) 36 a for transmitting a negative pressure is also formed inside the spindle 36. One end side of the flow path 36a opens to the outer peripheral surface of the tip portion of the spindle 38, and is connected to the other end side of the flow path 38b.

  On the other hand, the other end side of the flow path 36a generates a negative pressure via a flow path (suction flow path) 34b formed in the spindle housing 34, a pipe (suction flow path) 52 connected to the flow path 34b, and the like. The suction source 54 is connected. The pipe 52 is provided with a flow path 38b, a flow path 36a, a flow path 34b, and a pressure gauge 56 that measures the pressure inside the pipe 52.

  As described above, the cutting blade 46 is attached to the blade mount 38, and the negative pressure of the suction source 54 is applied to the back surface 48b of the base 48 through the pipe 52, the flow path 34b, the flow path 36a, the flow path 38b, and the suction port 40b. When acting on the side, the cutting blade 46 is fixed to the mount flange 40.

  As shown in FIG. 1, an auto blade changer 60 that automatically replaces the cutting blade 46 is provided at a position facing the cutting blade 46 attached to the cutting unit 14. FIG. 4 is a perspective view schematically showing the structure around the auto blade changer 60.

  As shown in FIG. 4, an auto blade changer moving mechanism (moving means) 62 that moves the auto blade changer 60 in the X-axis direction is provided below the auto blade changer 60.

  The auto blade changer moving mechanism 62 includes a pair of guide rails 64 parallel to the X-axis direction, and a moving block 66 is slidably installed on the guide rails 64. A nut portion (not shown) is provided on the lower surface side of the moving block 66, and a ball screw 68 parallel to the guide rail 64 is screwed into the nut portion.

  A pulse motor 70 is connected to one end of the ball screw 68. When the ball screw 68 is rotated by the pulse motor 70, the moving block 66 moves along the guide rail 64 in the X-axis direction.

  A casing 72 of the auto blade changer 60 is fixed to the upper part of the moving block 66. On the side of the casing 72 (on the cutting unit 14 side), a blade attaching / detaching unit (blade attaching / detaching means) for attaching the cutting blade 46 to the blade mount 38 (the tip of the spindle 36) and removing the cutting blade 46 from the tip of the spindle 36. ) 74 is provided.

  FIG. 5A is a perspective view schematically showing the structure of the blade attaching / detaching unit 74, and FIG. 5B is a partial cross-sectional plan view schematically showing the structure of the blade attaching / detaching unit 74. FIG. 5C is a side view of the blade attaching / detaching unit 74 viewed from the cutting unit 14 side.

  As shown in FIGS. 5A, 5 B, and 5 C, the blade attaching / detaching unit 74 includes an arm 76 that extends from the housing 72. A first bottom surface 78 a side of a base 78 formed in a columnar shape is fixed to the tip of the arm 76.

  A blade holding portion 80 is provided on the second bottom surface 78 b side of the base 78. The blade holding unit 80 includes a pressing pin 80a that protrudes from the center of the second bottom surface 78b, three claws 80b that are disposed around the pressing pin 80a and grip the cutting blade 46, and a coil spring that biases the pressing pin 80a. 80c.

  The auto blade changer 60 (blade attaching / detaching unit 74) and the cutting unit 14 configured as described above are relatively moved by the auto blade changer moving mechanism 62 and the cutting unit moving mechanism 18.

  Specifically, the auto blade changer 60 and the cutting unit 14 move between an attachment / detachment position where the cutting blade 46 can be attached / detached to / from the cutting unit 14 and a separation position separated from each other than the attachment / detachment position.

  As shown in FIG. 1, a blade rack 82 that can accommodate a plurality of cutting blades 46 before or after use is disposed at a position facing the auto blade changer 60 positioned at the separation position.

  The cutting blades 46 accommodated in the blade rack 82 are carried out by, for example, an auto blade changer 60 and attached to the blade mount 38. Further, the cutting blade 46 attached to the blade mount 38 is removed from the spindle by the blade holding portion 80 of the auto blade changer 60 and accommodated in the blade rack 82.

  As shown in FIG. 1, an operation panel (input means) 84 for inputting various instructions (commands) by an operator is provided on the upper surface of the base 4. In addition, each component such as the X-axis moving mechanism, the chuck table 10, the cutting unit 14, the cutting unit moving mechanism 18, the pressure gauge 56, the auto blade changer 60, the auto blade changer moving mechanism 62, and the operation panel 84 is a control device ( Control means) 86.

  FIG. 6 is a block diagram schematically illustrating a configuration example of the control device 86. In FIG. 6, a part of the connection relation regarding the control device 86 is also illustrated. In the cutting device 2 according to the present embodiment, for example, when an instruction (mounting command) for mounting the cutting blade 46 on the blade mount 38 is input to the operation panel 84, the control device 86 causes the pressure gauge 56 to 38b, the flow path 36a, the flow path 34b, and the pressure inside the piping 52 are measured.

  The control device 86 includes a storage unit 86a capable of storing various types of information, and the measurement value (measurement result) sent from the pressure gauge 56 is stored in the storage unit 86a. Further, the control device 86 includes a determination unit 86 b that determines whether or not the cutting blade 46 is attached to the blade mount 38 based on the measurement value sent from the pressure gauge 56.

  The determination unit 86b compares the measurement value sent from the pressure gauge 56 with a reference value (threshold value) for determination stored in the storage unit 86a in advance. The reference value for determination is set according to the pressure inside the flow path 38b, the flow path 36a, the flow path 34b, and the pipe 52 in a state where the cutting blade 46 is mounted on the blade mount 38.

  For example, when the measured value is larger than the reference value for determination, the determination unit 86b determines that the cutting blade 46 is not attached to the blade mount 38. On the other hand, when the measured value is equal to or less than the reference value for determination, the determination unit 86b determines that the cutting blade 46 is attached to the blade mount 38.

  As described above, the pressure gauge 56, the storage unit 86a, and the determination unit 86b function as a blade detection mechanism (blade detection unit) that detects the presence or absence of the cutting blade 46 attached to the blade mount 38.

  When it is determined that the cutting blade 46 is not attached to the blade mount 38, the control device 86 controls the cutting unit moving mechanism 18, the auto blade changer 60, and the auto blade changer moving mechanism 62, and A cutting blade 46 is attached.

  On the other hand, when it is determined that the cutting blade 46 is attached to the blade mount 38, the control device 86 issues an alarm with the alarm device (alarm means) 88 without attaching the cutting blade 46 to the blade mount 38. To emit.

  As described above, the cutting device 2 according to the present embodiment issues a warning with the blade detection mechanism (blade detection means) that detects the presence or absence of the cutting blade 46 attached to the blade mount 38 (the tip of the spindle 36). An alarm device (alarm means) 88, and when an instruction (attachment command) to attach the cutting blade 46 to the blade mount 38 is input to the operation panel (input means) 84, the control device (control means) ) 86 executes the content of the instruction when the blade detection mechanism does not detect the cutting blade 46, and issues the alarm with the alarm device 88 without executing the content of the instruction when the blade detection mechanism detects the cutting blade 46. It is configured as follows.

  Therefore, the cutting apparatus 2 will not be damaged even if an attachment instruction is erroneously input while the cutting blade 46 is attached to the blade mount 38. Thus, according to the cutting device 2 according to the present embodiment, even if the replacement operation of the cutting blade 46 is started from an arbitrary step, it is possible to prevent the occurrence of problems due to the operator's carelessness.

  Note that the configurations, methods, and the like according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention.

2 Processing device 4 Base 4a Opening 6 X-axis moving table 8 Dustproof and drip-proof cover 10 Chuck table 10a Holding surface 12 Clamp 14 Cutting unit (cutting means)
16 Support structure 18 Cutting unit moving mechanism (moving means)
20 Y-axis guide rail 22 Y-axis moving plate 24 Y-axis ball screw 26 Z-axis guide rail 28 Z-axis moving plate 30 Z-axis ball screw 32 Z-axis pulse motor 34 Spindle housing 34a Housing space 34b Flow path (suction flow path)
36 Spindle 36a Flow path (suction path)
38 Blade mount 38a Through hole 38b Flow path (suction path)
40 Flange portion 40a Support surface 40b Suction port 42 Boss portion 44 Nut 46 Cutting blade 48 Base (hub base)
48a Through hole 48b Back surface (contact surface)
50 Cutting blade 52 Piping (suction flow path)
54 Suction source 56 Pressure gauge (blade detection means)
60 Auto blade changer 62 Auto blade changer moving mechanism (moving means)
64 Guide rail 66 Moving block 68 Ball screw 70 Pulse motor 72 Case 74 Blade attachment / detachment unit (blade attachment / detachment means)
76 Arm 78 Base 78a First bottom surface 78b Second bottom surface 80 Blade holding portion 80a Press pin 80b Claw 80c Coil spring 82 Blade rack 84 Operation panel (input means)
86 Control device (control means)
86a Storage unit (blade detection means)
86b Determination unit (blade detection means)
88 Alarm device (alarm means)

Claims (2)

A chuck table for holding the workpiece;
A cutting means that has a spindle that is driven to rotate and a cutting blade that is attached to the tip of the spindle, and that cuts a workpiece held on the chuck table;
A blade attaching / detaching means having a blade holding part for holding the cutting blade, and attaching / detaching the cutting blade to / from a tip of the spindle;
A moving means for relatively moving the cutting means and the blade attaching / detaching means between an attaching / detaching position at which the cutting blade can be attached / detached and a spaced position separated from the attaching / detaching position;
A blade rack arranged corresponding to the blade attaching / detaching means positioned at the separated position and capable of accommodating a plurality of the cutting blades before or after use;
Input means for inputting various commands;
Control means for controlling the movement of each part;
Blade detecting means for detecting the presence or absence of the cutting blade attached to the tip of the spindle;
An alarm means for issuing a predetermined alarm;
When a mounting command for mounting the cutting blade to the tip of the spindle is input to the input unit by the blade attaching / detaching unit, the control unit does not detect the cutting blade by the blade detecting unit. A cutting apparatus characterized in that the contents of the mounting command are executed and the warning means is issued without executing the contents of the mounting command when the cutting blade is detected by the blade detecting means. The cutting means includes a blade mount having a disk-shaped flange portion and a boss portion protruding from the flange portion and fixed to the tip portion of the spindle,
The cutting blade is formed on a disk-shaped base having a contact surface that contacts the flange portion and having a through hole into which the boss portion of the blade mount is inserted at a central portion and an outer peripheral portion of the base. A cutting blade,
The blade mount includes suction means for sucking the contact surface side of the base of the cutting blade;
The suction means includes a suction port that opens on the support surface side of the flange portion that supports the contact surface side of the base, a suction source that generates negative pressure, and a suction port that connects the suction port and the suction source. A pressure gauge provided in the suction path and measuring the pressure in the suction path and sending the measurement result to the control means,
The control means stores a reference value set corresponding to the pressure in the suction path in a state where the cutting blade is held on the blade mount, and the measurement result sent from the pressure gauge. And a determination unit that determines whether or not the cutting blade is attached to the tip portion of the spindle from the reference value stored in the storage unit and the measurement result,
The cutting apparatus according to claim 1, wherein the blade detection unit includes the pressure gauge, the storage unit, and the determination unit.

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