CN105881194A - Machining Device - Google Patents

Abstract

The present invention provides a processing device capable of properly detecting abnormalities in processing. The processing device has: a vibration signal generating unit (58) that generates a vibration signal corresponding to the vibration of the processing tool (50); and a control unit (38) that determines the state of the processing tool based on the vibration signal generated by the vibration signal generating unit , The vibration signal generation unit includes: an ultrasonic vibrator (60), which is arranged on the tool mounter (48), and generates a voltage as a vibration signal corresponding to the vibration of the processing tool; and a transmission unit (62), which is connected to the ultrasonic vibrator , the voltage is sent to the control unit, the control unit has: a storage unit (38a), which stores the reference signal and the determination object signal; The state of the tool.

Description

Processing device

technical field

The present invention relates to a processing device for processing a plate-shaped workpiece.

Background technique

In the manufacturing process of semiconductor devices represented by IC, LSI, etc., there are cases where a grinding tool with a plurality of grindstones fixed on a disc-shaped base is used, and a semiconductor wafer made of a semiconductor material such as silicon, etc. Machined (ground) thinner. In addition, the protruding electrodes of the semiconductor wafer and the sealing resin of the package substrate, etc. are processed (cut, whirled) to be flat by using a cutting tool having a cutting edge (tip) fixed to a disc-shaped base.

In such a machining process, if tool wear, sudden machining load changes, and other abnormalities occur, the workpiece cannot be properly machined. Therefore, it is necessary to determine the occurrence of abnormality by a method such as a method of distinguishing sounds during machining by a skilled worker or a method of monitoring the current of a motor used for rotating the tool (for example, refer to Patent Document 1).

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2011-143516

However, the method of distinguishing the sound during processing requires a skilled operator, so there is a difficulty in versatility, and since it is based on the feeling, there is a difference in judgment. On the other hand, the method of monitoring the current of the motor can reduce the difference in judgment compared with the method of distinguishing the sound during machining, but it has a certain degree of measurement error, so it is not suitable for detection of minute abnormalities.

Contents of the invention

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a processing device capable of appropriately detecting abnormalities during processing.

The present invention provides a processing device, which includes: a chuck table, which holds a workpiece; and a processing unit, which processes the workpiece held on the chuck table, and the processing unit has: a spindle, which A tool mount is fixed at the end and is rotatably supported on the spindle housing; The device is characterized in that it has: a vibration signal generation unit that generates a vibration signal corresponding to the vibration of the processing tool; and a control unit that determines the state of the processing tool based on the vibration signal generated by the vibration signal generation unit. The signal generating unit includes: an ultrasonic vibrator, which is arranged on the tool mounter, generates a voltage, and the voltage becomes the vibration signal corresponding to the vibration of the processing tool; and a transmission unit, which is connected to the ultrasonic vibrator, and transmits the voltage For the control unit, the transmission unit includes: a first coil unit arranged on the side of the tool mounter; and a second coil unit opposite to the first coil unit and arranged on the side of the spindle housing, the control The unit has: a storage unit that stores a reference signal corresponding to a vibration signal generated by the vibration of the processing tool accompanying the rotation of the spindle, and a determination target signal corresponding to the vibration signal caused by the workpiece accompanying the rotation of the main shaft. a vibration signal corresponding to the vibration of the processing tool that occurs during processing; and a determination unit that determines the state of the processing tool based on a signal obtained by removing the reference signal from the determination target signal.

In addition, the present invention is preferably configured such that the control unit further includes an analyzing unit that performs Fourier transform on a waveform corresponding to a temporal change of the vibration signal to divide the vibration into frequency components.

In addition, the present invention is preferably configured such that the storage unit further stores an abnormality determination signal corresponding to a vibration signal generated by the vibration of the processing tool when an abnormality occurs during processing, and the determination unit removes the abnormality determination signal from the determination object signal. A signal obtained from the reference signal is compared with the abnormality determination signal to determine the presence or absence of an abnormality in processing.

The effect of the invention

The processing device of the present invention has: a vibration signal generating unit that generates a vibration signal corresponding to the vibration of the processing tool; and a control unit that determines the state of the processing tool based on the vibration signal generated by the vibration signal generating unit, so that An abnormality that occurs due to the vibration of the processing tool.

Description of drawings

FIG. 1 is a diagram schematically showing a configuration example of a grinding device.

Fig. 2 is an exploded perspective view schematically showing the structure of the grinding unit.

Fig. 3 is an exploded perspective view schematically showing the structure of the grinding unit.

Fig. 4 is a diagram schematically showing a cross section of a grinding unit and the like.

(A) of FIG. 5 is a graph showing an example of the waveform (waveform in the time domain) of the voltage transmitted to the control device, and (B) of FIG. 5 is a graph showing a waveform (waveform in the frequency domain) after Fourier transform. Example graph.

(A) of FIG. 6 is a graph showing an example of a reference signal, (B) of FIG. 6 is a graph showing an example of a signal to be determined, and (C) of FIG. 6 shows that the reference signal has been removed from the signal to be determined. An example graph of the resulting signal.

Fig. 7 is a diagram schematically showing a configuration example of a turning device.

Label description

2: Grinding device (processing device), 4: Abutment, 4a: Opening, 6: Transfer mechanism, 8a, 8b: Material box, 10: Positioning mechanism, 12: Loading mechanism, 14: Turntable, 16: Chuck Table, 16a: holding surface, 18: support structure, 20: Z-axis moving mechanism, 22: Z-axis guide rail, 24: Z-axis moving plate, 26: Z-axis ball screw, 28: Z-axis pulse motor, 30: support Parts, 32: grinding unit (processing unit), 34: carrying out mechanism, 36: cleaning unit, 38: control device (control unit), 38a: storage unit (storage unit), 38b: analysis unit (analysis unit), 38c : judging part (determining unit), 40: spindle housing, 42: spindle, 44: fixture, 46: cover assembly, 46a: opening, 48: wheel mounter (tool mounter), 48a: upper surface, 48b: lower Surface, 48c: Opening, 50: Grinding wheel (processing tool), 52: Wheel base, 52a: Upper surface, 52b: Lower surface, 52c: Internal thread portion, 54: Grinding stone (grinding stone), 58 : Vibration signal generation device (vibration signal generation unit), 60: Ultrasonic vibrator, 62: Transmission path (transmission unit), 64: 1st inductor (1st coil unit), 66: 2nd inductor (2nd coil unit ), 70: turning device (processing device), 72: chuck table, 72a: holding surface, 74: turning unit (processing unit), 76: spindle housing, 78: spindle, 80: cover assembly, 80a: opening, 82 : Wheel setter (tool setter), 84: Turning wheel (processing tool), 86: Wheel base, 88: Bit (cutting edge), 90: Vibration signal generating device (vibration signal generating unit), 92: Ultrasonic Vibrator, 94: transmission path (transmission unit), 96: first inductor (first coil unit), 98: second inductor (second coil unit), 100: control device (control unit), 100a: storage unit (storage means), 100b: analyzing unit (analyzing unit), 100c: judging unit (judging unit), 11: workpiece.

detailed description

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram schematically showing a configuration example of a grinding apparatus according to the present embodiment. As shown in FIG. 1, the grinding apparatus (processing apparatus) 2 has the base 4 which supports each structure. An opening 4 a is formed on the front end side of the upper surface of the base 4 , and a conveying mechanism 6 for conveying a workpiece 11 (see FIG. 4 ) to be processed is provided in the opening 4 a.

In addition, magazines 8 a and 8 b capable of accommodating the workpiece 11 are placed in a region further in front of the opening 4 a. The workpiece 11 is, for example, a disk-shaped semiconductor wafer, a resin substrate, a ceramic substrate, a packaging substrate, or the like. However, the workpiece 11 is not limited thereto, and a plate-shaped object of any material and shape may be used as the workpiece 11 .

A positioning mechanism 10 for positioning the workpiece 11 is provided behind the placement area where the magazine 8a is placed and the opening 4a. The positioning mechanism 10 is conveyed by the conveyance mechanism 6 from the magazine 8 a, for example, and positions the center of the workpiece 11 placed on the positioning mechanism 10 .

At the rear of the positioning mechanism 10, a carry-in mechanism 12 for sucking and holding the workpiece 11 and capable of turning it is provided. A turntable 14 that rotates within a predetermined angular range around a rotation axis parallel to the vertical direction (Z-axis direction) is provided behind the carry-in mechanism 12 . A plurality of (three in this embodiment) chuck tables 16 for sucking and holding the workpiece 11 are provided on the upper surface of the turntable 14 at substantially equal angular intervals.

The workpiece 11 positioned by the positioning mechanism 10 is carried in by the carrying-in mechanism 12 to the chuck table 16 positioned at the forward carrying-in and carrying-out position. The turn table 14 is rotated in a predetermined rotation direction, and the chuck table 16 is sequentially positioned at the loading and unloading position, the first grinding position, and the second grinding position.

Each chuck table 16 is connected to a rotational drive source (not shown) such as a motor, and rotates around a rotational axis parallel to the vertical direction. The upper surface of each chuck table 16 serves as a holding surface 16 a for sucking and holding the workpiece 11 . This holding surface 16 a is connected to a suction source (not shown) through a flow path (not shown) formed inside the chuck table 16 . The workpiece 11 carried into the chuck table 16 is sucked by the negative pressure of the suction source acting on the holding surface 16a.

Behind the turntable 14, two support structures 18 formed in a column shape are erected substantially vertically. A Z-axis moving mechanism 20 is provided on the front side of each support structure 18 . The Z-axis moving mechanism 20 has a pair of Z-axis guide rails 22 disposed on the front surface of the supporting structure 18 and parallel to the Z-axis direction. A Z-axis moving plate 24 is slidably provided on the Z-axis guide rail 22 .

A nut portion (not shown) is provided on the rear side (back side) of the Z-axis moving plate 24 , and the nut portion is screwed with a Z-axis ball screw 26 parallel to the Z-axis guide rail 22 . A Z-axis pulse motor 28 is connected to one end of the Z-axis ball screw 26 . By rotating the Z-axis ball screw 26 by the Z-axis pulse motor 28 , the Z-axis moving plate 24 moves in the Z-axis direction along the Z-axis guide rail 22 .

A support 30 is fixed to the front surface (front surface) of each Z-axis moving plate 24 . A grinding unit (machining unit) 32 for grinding the workpiece 11 is supported on each support 30 . The workpiece 11 positioned at the first grinding position or the second grinding position together with the chuck table 16 is ground by each grinding unit 32 . Details of the grinding unit 32 will be described later.

At a position adjacent to the carry-in mechanism 12 , a carry-out mechanism 34 is provided that sucks and holds the ground workpiece 11 and enables it to rotate. In front of the carry-out mechanism 34 and behind the opening 4a, a cleaning unit 36 for cleaning the ground workpiece 11 is provided. The workpiece 11 cleaned by the cleaning unit 36 is conveyed by the conveyance mechanism 6 and stored in, for example, the magazine 8b.

The components and control devices (control unit) of the conveying mechanism 6, the positioning mechanism 10, the loading mechanism 12, the rotary table 14, the chuck table 16, the Z-axis moving mechanism 20, the grinding assembly 32, the carrying-out mechanism 34, the cleaning assembly 36, etc. )38 connections. The control device 38 controls the operation of each part so that the workpiece 11 can be ground appropriately.

2 and 3 are exploded perspective views schematically showing the structure of the grinding unit 32 , and FIG. 4 is a diagram schematically showing a cross section of the grinding unit 32 and the like. In addition, in FIG. 2 , FIG. 3 and FIG. 4 , a part of the structure of the grinding assembly 32 is omitted.

The grinding unit 32 has a cylindrical spindle housing 40 . The spindle housing 40 accommodates a spindle 42 that rotates around the Z axis. The lower end portion of the spindle 42 protrudes outward from the spindle housing 40 . A rotational drive source (not shown) such as a motor that rotates the main shaft 42 is connected to the upper end side of the main shaft 42 .

A disk-shaped cover assembly 46 is fixed to the lower end portion of the spindle housing 40 via a fixing tool 44 . A circular opening 46 a penetrating in the vertical direction is formed at the center of the cover assembly 46 , and the lower end portion of the main shaft 42 is inserted through the opening 46 a.

A disc-shaped wheel mount (tool mount) 48 is detachably fixed to the lower end of the spindle 42 , and a grinding wheel (processing tool) 50 is attached to the lower surface 48 b side of the wheel mount 48 . The grinding wheel 50 includes a cylindrical wheel base 52 formed of metal materials such as aluminum and stainless steel; 54.

On the upper surface 52a side of the wheel base 52, a plurality of (four in this embodiment) internal thread portions 52c are formed on the inner peripheral surface of the recessed portion to be threaded (thread grooves). On the other hand, a plurality of (four in this embodiment) openings penetrating from the upper surface 48 a to the lower surface 48 b in the wheel mount 48 are formed at positions corresponding to the internally threaded portion 52 c of the wheel mount 48 . 48c. The grinding wheel 50 is detachably fixed to the lower surface 48b side of the wheel mounter 48 by screwing and fixing the external thread 56 into the internal thread portion 52c through the opening 48c.

As shown in FIG. 4 , in a state where the workpiece 11 is sucked and held on the chuck table 16, the chuck table 16 and the grinding wheel 50 are mutually rotated, and the grinding fluid such as pure water is supplied while grinding The stone 54 can grind the workpiece 11 by contacting the upper surface of the workpiece 11 .

The grinding unit 32 is provided with a vibration detection mechanism for detecting the vibration of the grinding wheel 50 . The vibration detection mechanism includes a vibration signal generation device (vibration signal generation unit) 58 ( FIG. 4 ) that generates a vibration signal corresponding to the vibration of the grinding wheel 50 .

The vibration signal generator 58 has a plurality of (four in this embodiment) ultrasonic vibrators 60 fixed inside the wheel mounter 48 . The ultrasonic vibrator 60 is formed of materials such as barium titanate (BaTiO3), lead metatitanate (Pb(Zi, Ti)O3), lithium niobate (LiNbO3), lithium tantalate (LiTaO3), etc., and the grinding wheel 50 The vibration is converted into a voltage (vibration signal).

The ultrasonic vibrator 60 is configured to resonate with vibration of a predetermined frequency. Therefore, the vibration frequency detectable by the vibration detection means is determined based on the resonance frequency of the ultrasonic vibrator 60 . Therefore, by replacing the ultrasonic vibrator 60 together with the wheel mounter 48, it is possible to optimize vibration detection according to the type (material, size, weight, etc.) mechanism.

For example, when the resonance frequency of the ultrasonic vibrator 60 is any one of 50kHz to 100kHz, 100kHz to 300kHz, and 300kHz to 500kHz, the frequency range of 50kHz to 500kHz can be appropriately detected by appropriately replacing the three types of wheel mounters 48. vibration.

In addition, a plurality of ultrasonic transducers 60 having different resonant frequencies may be installed in one wheel mount 48 so that vibrations in a wide frequency range can be detected without replacing the wheel mount 48 . For example, if three types of ultrasonic transducers 60 with resonant frequencies of 50kHz to 100kHz, 100kHz to 300kHz, and 300kHz to 500kHz are installed on one wheel mounter 48, it is possible to detect 50kHz to 50kHz without replacing the wheel mounter 48. Vibration in the frequency range of 500kHz.

Here, the plurality of ultrasonic vibrators 60 are preferably arranged symmetrically about the axis of the main shaft 42 . Thereby, the vibration of the grinding wheel 50 can be detected with high precision. In addition, the number, arrangement, shape, etc. of the ultrasonic transducers 60 are not limited to those shown in FIGS. 3 and 4 . For example, one ultrasonic vibrator 60 may be provided on the wheel mounter 48 .

A non-contact transmission path (transmission unit) 62 ( FIG. 4 ) for transmitting a voltage generated by the ultrasonic vibrator 60 is connected to the ultrasonic vibrator 60 . The transmission path 62 includes a first inductor (first coil unit) 64 connected to the ultrasonic vibrator 60 and a second inductor (second coil unit) 66 facing the first inductor 64 at a predetermined interval.

The first inductor 64 and the second inductor 66 represent annular coils around which lead wires are wound, and are respectively fixed to the upper surface 48 a side of the wheel mount 48 and the lower surface side of the cover assembly 46 .

As described above, the first inductor 64 and the second inductor 66 face each other and are magnetically coupled. Therefore, the voltage generated by the ultrasonic vibrator 60 is transmitted to the second inductor 66 side by mutual induction between the first inductor 64 and the second inductor 66 .

The second inductor 66 is connected to the control device 38 through wiring or the like. The control device 38 determines the vibration state of the grinding wheel 50 based on the voltage transmitted from the second inductor 66 .

Specifically, the control device 38 includes: a storage unit (storage unit) 38a that stores information such as the voltage (vibration signal) transmitted from the second inductor 66; A waveform (waveform in the time domain) corresponding to the temporal change of the voltage (vibration signal) transmitted at an arbitrary unit time is subjected to spectrum analysis by Fourier transform (for example, high-speed Fourier transform); and it is determined that the grinding wheel 50 The judging section (judgment unit) 38c of the state of the

In addition, the time required for grinding an arbitrary thickness of the workpiece 11 (each grinding thickness), the time required for grinding one workpiece 11 (each Workpiece) and so on. The details of each part of the control device 38 will be described later.

(A) of FIG. 5 is a graph showing an example of the waveform (waveform in the time domain) of the voltage transmitted to the control device 38, and (B) in FIG. 5 shows a waveform after Fourier transform (waveform in the frequency domain). An example graph of . 5(A), the vertical axis represents voltage (V), and the horizontal axis represents time (t), and in FIG. 5(B), the vertical axis represents amplitude and the horizontal axis represents frequency (f).

If the waveform of the voltage (vibration signal) from the vibration signal generating device 58 is Fourier transformed by the analysis unit 38b of the control device 38, the vibration of the grinding wheel 50 is divided into As the main frequency component, it is possible to easily analyze abnormalities that occur during grinding. Thereby, abnormality during grinding can be detected accurately in real time.

Hereinafter, the abnormality detection flow performed by the grinding apparatus 2 of this embodiment is demonstrated. First, as a pre-processing of detection, a reference signal acquisition step of acquiring a reference signal corresponding to the background level is performed. In this reference signal acquisition step, first, the grinding wheel 50 is rotated in a state where there is no abnormality in each part.

As a result, a voltage (vibration signal) generated by the vibration of the grinding wheel 50 accompanying the rotation of the main shaft 42 is generated from the ultrasonic vibrator 60 . A waveform (waveform in a time region) corresponding to the temporal change of the generated voltage is stored in the storage unit 38 a of the control device 38 .

Next, the analysis unit 38b of the control device 38 reads out the waveform of the voltage stored in the storage unit 38a, and performs Fourier transform (fast Fourier transform). As a result, the waveform of the voltage (vibration signal) in the time domain is converted into a reference signal (waveform in the frequency domain). (A) of FIG. 6 is a graph showing an example of a reference signal. The obtained reference signal is stored in the storage unit 38a.

After the reference signal acquisition step, the actual detection step starts. In the actual detection procedure, first, a determination target signal acquisition step of grinding the workpiece 11 to acquire a determination target signal as a determination target is performed. In this determination target signal acquisition step, first, the grinding wheel 50 is rotated to grind the workpiece 11 .

As a result, a voltage (vibration signal) generated by the vibration of the grinding wheel 50 accompanying the grinding of the workpiece 11 is generated from the ultrasonic vibrator 60 . A waveform (waveform in a time region) corresponding to the temporal change of the generated voltage is stored in the storage unit 38 a of the control device 38 .

Next, the analysis unit 38b of the control device 38 reads out the waveform of the voltage stored in the storage unit 38a, and performs Fourier transform (fast Fourier transform). As a result, the waveform of the voltage (vibration signal) in the time domain is converted into a determination target signal (waveform in the frequency domain). (B) of FIG. 6 is a graph showing an example of a determination target signal. The obtained determination target signal is stored in the storage unit 38a.

After the determination target signal acquisition step, a comparison determination step of comparing the determination target signal with the reference signal to determine the state of the grinding wheel 50 is implemented. In this comparison and determination step, first, the determination unit 38c reads the reference signal and the determination target signal stored in the storage unit 38a, and removes the reference signal from the determination target signal.

Specifically, the signal strength (amplitude) of the reference signal is subtracted (subtracted) from the signal strength (amplitude) of the determination target signal over the entire frequency range of the detection target. In this case, in order to appropriately remove the reference signal from the determination target signal, the signal strength (amplitude) of the determination target signal or the reference signal may be multiplied by an arbitrary value.

(C) of FIG. 6 is a graph showing an example of a signal obtained by removing a reference signal from a determination target signal. In this way, by removing the reference signal from the determination target signal, the state of the grinding wheel 50 can be appropriately determined, and an abnormality during grinding can be detected.

Specifically, for example, the presence or absence of an abnormality during grinding can be determined by comparing a signal obtained by subtracting a reference signal from a determination target signal with an abnormality determination signal stored in advance in the storage unit 38a. That is, when a part or all of the vibration pattern (vibration component) in the abnormality determination signal coincides with the vibration pattern in the signal obtained by removing the reference signal from the determination target signal, the determination unit 38c determines that the vibration pattern corresponding to the abnormality determination signal has occurred. An exception corresponding to the vibration pattern.

In addition, the abnormality determination signal is obtained by performing Fourier transform (high-speed Fourier transform) on the waveform of the voltage (vibration signal) caused by the vibration of the grinding wheel 50 when the grinding abnormality occurs in the analysis unit 38b. .

As described above, the grinding device (processing device) 2 of the present embodiment has: a vibration signal generating device (vibration signal generating unit) 58 that generates a vibration signal corresponding to the vibration of the grinding wheel 50; and a control device (control unit) 38 , which determines the state of the grinding wheel 50 based on the vibration signal generated by the vibration signal generating device 58, and therefore can appropriately detect abnormalities that occur with the vibration of the grinding wheel 50.

In addition, in the grinding machine 2 of the present embodiment, the Fourier transform is performed on the waveform (waveform in the time domain) corresponding to the temporal change of the voltage (vibration signal), so compared with directly performing the Fourier transform on the voltage (vibration signal) In the case of analysis, it is easy to analyze an abnormality that occurs during grinding. Thereby, abnormality during grinding can be detected with high precision.

In addition, this invention is not limited to the content of the said embodiment, Various changes can be made and implemented. For example, in the above-described embodiments, the voltage (vibration signal) was Fourier transformed, but the voltage may be analyzed as it is without Fourier transform.

In addition, by utilizing the configuration of the above-described embodiment, it is also possible to automate the arrangement of the reference height index for the grinding wheel (processing tool) 50 . In this configuration, for example, the control device 38 gradually lowers the grinding wheel 50 and brings the lower end of the grinding wheel 50 into contact with the holding surface 16 a of the chuck table 16 .

Furthermore, the control device 38 detects the contact of the grinding wheel 50 with the chuck table 16 based on the voltage (vibration signal) generated by the ultrasonic vibrator 60, and sets the height of the grinding wheel 50 at this time as a reference height. In addition, when the contact of the grinding wheel 50 and the chuck table 16 is detected, the control device 38 stops the descent of the grinding wheel 50 .

In addition, in the above-mentioned embodiment, the grinding device 2 for grinding the workpiece 11 was described, but the processing device of the present invention may be a grinding device for grinding the workpiece 11 . The basic structure of the grinding device (processing device) is the same as that of the grinding device 2 . However, in the polishing device, a polishing pad (processing tool) provided with a polishing cloth on the lower surface side is used instead of the grinding wheel 50 .

In addition, the machining apparatus of the present invention may be a turning apparatus that turns (whirling) the workpiece 11 . Fig. 7 is a diagram schematically showing a configuration example of a turning device. As shown in FIG. 7 , the turning device (processing device) 70 has a chuck table 72 that suction-holds the workpiece 11 . A horizontal movement mechanism (not shown) is provided below the chuck table 72, and the chuck table 72 moves in the horizontal direction by the horizontal movement mechanism.

The upper surface of the chuck table 72 serves as a holding surface 72 a for suction holding the workpiece 11 . The holding surface 72 a is connected to a suction source (not shown) through a flow path (not shown) formed inside the chuck table 72 . The workpiece 11 carried into the chuck table 72 is sucked by the negative pressure of the suction source acting on the holding surface 72a.

A turning unit (machining unit) 74 that turns (turns) the workpiece 11 is arranged above the chuck table 72 . The structure of the turning unit 74 is similar to that of the grinding unit 32 of the above-mentioned embodiment.

The turning unit 74 has a cylindrical spindle housing 76 . The spindle housing 76 accommodates a spindle 78 that rotates around the Z axis. The lower end of the main shaft 78 protrudes outward from the main shaft housing 76 . A rotational drive source (not shown) such as a motor that rotates the main shaft 78 is connected to the upper end side of the main shaft 78 .

A disk-shaped cover assembly 80 is fixed to the lower end of the spindle housing 76 . A circular opening 80 a penetrating in the vertical direction is formed at the center of the cover assembly 80 , and the lower end portion of the main shaft 78 is inserted through the opening 80 a.

A disc-shaped wheel mount (tool mount) 82 is detachably fixed to the lower end of the main shaft 78 , and a turning wheel (processing tool) 84 is attached to the lower surface side of the wheel mount 82 . The turning wheel 84 includes: a cylindrical wheel base 86 made of metal materials such as aluminum and stainless steel;

As shown in FIG. 7 , the turning wheel 84 is rotated while the workpiece 11 is sucked and held on the chuck table 72, the chuck table 72 is moved in the horizontal direction, and the bit 88 is brought into contact with the upper surface of the workpiece 11. surface, so that the workpiece 11 can be turned.

The turning unit 74 is provided with a vibration detection mechanism for detecting the vibration of the turning wheel 84 . The vibration detection mechanism includes a vibration signal generation device (vibration signal generation unit) 90 that generates a vibration signal corresponding to the vibration of the lathe 84 .

The vibration signal generating device 90 has a plurality of ultrasonic vibrators 92 fixed inside the wheel mount 82 . In addition, the number of ultrasonic vibrators 92 provided on the wheel mounter 82 may be one.

A non-contact transmission path (transmission unit) 94 for transmitting a voltage generated by the ultrasonic vibrator 92 is connected to the ultrasonic vibrator 92 . The transmission path 94 includes: a first inductor (first coil unit) 96 connected to the ultrasonic vibrator 60; and a second inductor (second coil unit) 98 facing the first inductor 96 at a predetermined interval. .

The first inductor 96 and the second inductor 98 represent annular coils around which lead wires are wound, and are respectively fixed to the upper surface side of the wheel mounter 82 and the lower surface side of the cover assembly 80 .

As described above, the first inductor 96 and the second inductor 98 face each other and are magnetically coupled. Therefore, the voltage generated by the ultrasonic vibrator 92 is transmitted to the second inductor 98 side by mutual induction between the first inductor 96 and the second inductor 98 .

The second inductor 98 is connected to the control device 100 through wiring or the like. The control device 100 determines the vibration state of the lathe wheel 84 based on the voltage transmitted from the second inductor 98 .

Specifically, the control device 100 includes: a storage unit (storage unit) 100a that stores information such as the voltage (vibration signal) transmitted from the second inductor 98; Spectrum analysis is performed on a waveform (waveform in a time region) corresponding to a temporal variation of a voltage (vibration signal) transmitted at an arbitrary unit time by Fourier transform (for example, a high-speed Fourier transform); and the state of the whirling wheel 84 is determined The judging section (judging unit) 100c. In addition, the functions of the storage unit 100a, the analysis unit 100b, and the determination unit 100c are the same as those of the storage unit 38a, the analysis unit 38b, and the determination unit 38c in the above-mentioned embodiment.

The turning device (processing device) 70 constituted as above also has: a vibration signal generating device (vibration signal generating unit) 90 that generates a vibration signal corresponding to the vibration of the turning wheel (processing tool) 84; and a control device (control unit) 100 , which determines the state of the gouging wheel 84 based on the vibration signal generated by the vibration signal generating device 90 , and therefore can appropriately detect abnormalities that occur with the vibration of the gouging wheel 84 .

In addition, the structure, method, etc. of the said embodiment can be suitably changed and implemented in the range which does not deviate from the object of this invention.

Claims (3)

1. A machining device comprising: a chuck table holding an object to be processed; and a processing unit processing the object to be processed held on the chuck table, the processing unit having: a main shaft whose end A tool mounter is fixed on the part and is rotatably supported on the spindle housing; and a processing tool is provided with a grinding stone, a grinding cloth or a bit on the lower surface side and is mounted on the tool mounter, The processing device is characterized in that it has: a vibration signal generating unit that generates a vibration signal corresponding to the vibration of the processing tool; and a control unit that determines the state of the processing tool based on the vibration signal generated by the vibration signal generating unit, The vibration signal generation unit includes: an ultrasonic vibrator disposed on the tool mounter to generate a voltage that becomes the vibration signal corresponding to the vibration of the processing tool; and a transmission unit, which is connected to the ultrasonic vibrator, and transmits the voltage to the control unit, The delivery unit includes: a first coil unit provided on the tool mount side; and a second coil unit disposed on the side of the main shaft housing, facing the first coil unit at a distance, The control unit has: a storage unit that stores a reference signal corresponding to a vibration signal generated by the vibration of the processing tool accompanying the rotation of the spindle, and a judgment object signal corresponding to the vibration signal generated by the machining of the workpiece. The vibration signal corresponding to the vibration of the processing tool; and A judging unit that judges the state of the machining tool based on a signal obtained by removing the reference signal from the judging target signal. 2. The processing device according to claim 1, characterized in that, The control unit further includes an analysis unit that performs Fourier transform on a waveform corresponding to a time change of the vibration signal, and divides the vibration into frequency components. 3. The processing device according to claim 1 or 2, characterized in that, The storage unit also stores an abnormality determination signal corresponding to a vibration signal generated by vibration of the processing tool when an abnormality occurs during processing, The judging means compares a signal obtained by removing the reference signal from the judging target signal with the abnormality judging signal, thereby judging the presence or absence of an abnormality in processing.