Cutting tool

Abstract

A cutting tool according to the embodiments of the present disclosure comprises a body part that is to be provided in a processing space of a machine tool, a sensor that is provided to the body part, a wireless communication circuit that transmits the output of the sensor, and a first power reception antenna circuit that receives power supply radio waves transmitted from a power transmission antenna provided in the processing space and outputs electrical power.

Description

cutting tools

[0001] The present disclosure relates to cutting tools.

[0002] Patent Document 1 discloses a cutting tool including a main body, a sensor disposed in the main body, a wireless communication unit that transmits information indicating the output of the sensor to an external device, and a battery that supplies power to each device. The battery is housed in a battery housing, which is a space provided in the main body. This cutting tool can monitor the state of the cutting tool during machining using the sensor and transmit the state to an external device.

[0003] International Publication No. 2022 / 230149

[0004] A cutting tool according to an embodiment of the present disclosure comprises a main body disposed in a machining space of a machine tool, a sensor provided in the main body, a wireless communication circuit that transmits the output of the sensor, and a first power receiving antenna circuit that receives power supply radio waves transmitted from a power transmitting antenna provided in the machining space and outputs power.

[0005] FIG. 1 is a diagram showing the overall configuration of a cutting processing system in which a cutting tool according to an embodiment is used. FIG. 2 is a functional block diagram showing an example configuration of a cutting tool according to this embodiment. FIG. 3A is a diagram showing the appearance of the cutting tool. FIG. 3B is a cross-sectional view taken along line B-B in FIG. 3A. FIG. 4 is an enlarged view of a main portion of FIG. 3A. FIG. 5 is an enlarged view of a main portion of FIG. 3B. FIG. 6 is a diagram showing a circuit board and a rectenna when viewed from the front from the Z2 direction. FIG. 7 is a block diagram showing a portion of a cutting tool according to a modified example. FIG. 8 is an external view showing a portion of the cutting tool according to this modified example. FIG. 9 is a cross-sectional view showing a portion of the cutting tool according to this modified example. FIG. 10 is an external view showing a portion of the cutting tool according to this modified example.

[0006] [Problem to be Solved by the Present Disclosure] In the cutting tool with the conventional sensor described above, when the battery power is consumed and depleted, it is necessary to replace it with a new battery. In this case, the old battery must be removed from the battery housing and a new battery must be installed, making it difficult to replace the battery during machining. Therefore, if the machining time is long and the battery power is depleted during machining, there is a risk that it will not be possible to monitor the state of the cutting process thereafter. It is desirable to be able to appropriately monitor the state of the cutting process even when the machining time is long.

[0007] Effect of the Present Disclosure According to the present disclosure, the state during processing can be appropriately monitored.

[0008] First, the contents of the embodiments will be listed and described. [Outline of the Embodiments] (1) A cutting tool according to an embodiment of the present disclosure includes a main body disposed in a machining space of a machine tool, a sensor provided in the main body, a wireless communication circuit that transmits an output of the sensor, and a first power receiving antenna circuit that receives radio waves for power supply transmitted from a power transmitting antenna provided in the machining space and outputs electric power.

[0009] According to the above configuration, the first power receiving antenna circuit receives power radio waves transmitted from the power transmitting antenna provided in the machining space, enabling wireless power supply within the machining space. Therefore, the cutting tool can receive power even during machining, and the sensor output can be transmitted continuously even for long machining times. As a result, the cutting process status (the cutting tool status) can be appropriately monitored during machining.

[0010] (2) The cutting tool of (1) may further include a power storage unit that stores the power. In this case, even if the power supply radio wave from the power transmission antenna is temporarily interrupted or temporarily unable to be received, the power stored in the power storage unit allows the sensor output to continue to be transmitted.

[0011] (3) In the cutting tool described in (1) or (2) above, when the main body includes a cutting tip and a rod-shaped shank to which the cutting tip is attached, the sensor, the wireless communication circuit, and the first power receiving antenna circuit may be arranged on the shank from the end along the longitudinal direction of the shank in the following order: sensor, wireless communication circuit, and first power receiving antenna circuit. In this case, the sensor can be arranged closest to the cutting tip, which is the processing point, thereby improving sensitivity. Furthermore, the first power receiving antenna circuit is not arranged between the sensor and the wireless communication circuit, so the sensor and the wireless communication circuit can be arranged relatively close to each other. As a result, the distance of the line transmitting the sensor output to the wireless communication circuit can be shortened, thereby improving noise resistance.

[0012] (4) In the cutting tool of (3), when the shank has a recess that opens on a side surface of the shank and a lid that closes the opening of the recess, the wireless communication circuit and the first power receiving antenna circuit may be housed in a housing space defined by the recess and the lid. In this case, the wireless communication circuit and the first power receiving antenna circuit can be disposed on the shank without being exposed to the outside.

[0013] (5) In the cutting tool of (4), the cover may be made of a material that is permeable to radio waves transmitted and received from the wireless communication circuit and the power supply radio waves. In this case, the cover can be prevented from interfering with the transmission and reception of radio waves from the wireless communication circuit and the reception of radio waves for power supply.

[0014] (6) In the cutting tool of (5), when the wireless communication circuit has a transmitting / receiving antenna and the first power receiving antenna circuit has a power receiving antenna, the power receiving antenna and the transmitting / receiving antenna may be arranged opposite to the cover, in which case radio waves from the wireless communication circuit can be transmitted and received appropriately through the cover.

[0015] (7) In the cutting tool of (4), the cover may include a window that connects the accommodation space to the outside, and a window cover that is made of a material that is permeable to radio waves transmitted and received from the wireless communication circuit and the power supply radio waves and that closes the window. In this case, the window cover can be prevented from interfering with the transmission and reception of radio waves from the wireless communication circuit and the reception of radio waves for power supply.

[0016] (8) In the cutting tool of (7), when the wireless communication circuit has a transmitting / receiving antenna and the first power receiving antenna circuit has a power receiving antenna, the power receiving antenna and the transmitting / receiving antenna may be arranged opposite to the window cover, in which case radio waves from the wireless communication circuit can be transmitted and received and radio waves for power supply can be appropriately received through the window cover.

[0017] (9) In the cutting tool of (8), the power receiving antenna and the power transmitting / receiving antenna may be disposed close to each other. In this case, the window portion and the window cover can be made relatively small.

[0018] (10) The cutting tool according to any one of (1) to (9) may further include a second power receiving antenna circuit that receives power supply radio waves transmitted from a power transmitting antenna provided in the machining space and outputs power, and a combining circuit that combines the power output from the first power receiving antenna circuit and the power output from the second power receiving antenna circuit. In this case, by differentiating the receiving frequency band of the first power receiving antenna circuit from the receiving frequency band of the second power receiving antenna circuit, power supply radio waves of two different frequency bands can be received. Furthermore, by making the receiving frequency band of the first power receiving antenna circuit and the receiving frequency band of the second power receiving antenna circuit the same, the power receiving efficiency can be improved by combining the outputs of both circuits.

[0019] (11) In the cutting tool of (10), if the main body includes a rod-shaped shank having three recesses opening on a side surface of the shank and three lids closing the openings of the three recesses, the wireless communication circuit, the first power receiving antenna circuit, and the second power receiving antenna circuit may be individually housed in three housing spaces defined by the three recesses and the three lids. In this case, housing each circuit individually in the three housing spaces can prevent mutual interference when the circuits transmit and receive radio waves.

[0020] [Details of the embodiment] Preferred embodiments will be described below with reference to the drawings. Note that at least some of the embodiments described below may be combined in any manner. [Regarding the cutting system] Fig. 1 is a diagram showing the overall configuration of a cutting system in which a cutting tool according to an embodiment is used. In Fig. 1, the cutting system 1 includes a cutting tool 4, a machine tool 2, and a power supply device 6.

[0021] The machine tool 2 is, for example, an NC lathe. The machine tool 2 has a bed 2a and a housing 2b. The housing 2b is disposed above the bed 2a. The interior of the housing 2b is a machining space S. In other words, the housing 2b defines the machining space S above the bed 2a.

[0022] A headstock, a chuck for gripping a workpiece, and the like (not shown) are arranged in the machining space S. A turret 2c is also arranged in the machining space S. A cutting tool 4 is held by the turret 2c. The cutting tool 4 is a tool for performing cutting on the workpiece gripped by the chuck. The cutting tool 4 in this embodiment has a sensor that can monitor the state of the cutting (state of the cutting tool 4) and transmit it to the outside.

[0023] The housing 2b has a housing main body 2b1 and an opening / closing door 2b2. The housing main body 2b1 is fixed to the upper surface of the bed 2a. On the other hand, the opening / closing door 2b2 is movable laterally relative to the bed 2a as shown by the arrow in FIG. 1. The opening / closing door 2b2 is in a closed state in the position shown in FIG. 1. The opening / closing door 2b2 moves laterally from the closed state to an open state. When the opening / closing door 2b2 is in an open state, each element arranged in the machining space S is exposed to the outside. When the operator prepares for machining or removes a machined workpiece, the opening / closing door 2b2 is in an open state. When the opening / closing door 2b2 is in a closed state, the operator of the machine tool 2 cannot access the machining space S. Therefore, when the machine tool 2 is performing machining, the opening / closing door 2b2 is in a closed state.

[0024] The power supply device 6 has a function of wirelessly supplying power to the cutting tool 4. The power supply device 6 includes a power transmitting antenna 8 and a control device 10. The control device 10 has a function of controlling power supply by the power transmitting antenna 8. The control device 10 generates a power supply signal based on power supplied from the power source 100 and supplies the signal to the power transmitting antenna 8. The power transmitting antenna 8 is provided in the machining space S. The power transmitting antenna 8 transmits the power supply signal provided by the control device 10 to the cutting tool 4 as a power supply radio wave.

[0025] [Regarding the Cutting Tool] Figure 2 is a functional block diagram showing an example configuration of a cutting tool 4 according to this embodiment. As shown in Figure 2, the cutting tool 4 has a main body 12, a strain sensor 14, a strain sensor 16, a wireless communication circuit 18, a rectenna 20, and a power storage unit 22. The main body 12 has a shank 12a and a cutting tip 12b. The shank 12a is a metal member in the shape of a rectangular pillar that is held by a turret 2c of the machine tool 2. The cutting tip 12b is a cutting tool that cuts a workpiece by coming into contact with the workpiece. The cutting tip 12b is detachably attached to the end of the shank 12a.

[0026] The strain sensors 14, 16, the wireless communication circuit 18, the rectenna 20, and the power storage unit 22 are provided on the shank 12a. The strain sensors 14, 16 are attached to the shank 12a and detect the state of the cutting tool 4. The strain sensors 14, 16 measure the strain of the shank 12a as the state of the cutting tool 4. The strain sensors 14, 16 include a strain gauge and the like. When power is supplied from the charge control circuit 24, the strain sensors 14, 16 provide an output to the wireless communication circuit 18 that corresponds to the current strain of the shank 12a. The output of the strain sensors 14, 16 indicates the strain of the shank 12a.

[0027] The rectenna 20 has a power receiving antenna 20a and a rectifier circuit 20b. The power receiving antenna 20a receives radio waves from the power feeding device 6. The power receiving antenna 20a provides the power of the received radio waves to the rectifier circuit 20b. The rectifier circuit 20b rectifies the power provided by the power receiving antenna 20a, converts it into DC power, and outputs it. The DC power output by the rectifier circuit 20b is provided to the sensors 14, 16 and the wireless communication circuit 18. In other words, the rectenna 20 constitutes a power receiving antenna circuit that receives power feeding radio waves transmitted from the power transmitting antenna 8 provided in the machining space S and outputs DC power. The DC power output by the rectenna 20 is provided to the charge control circuit 24.

[0028] The charge control circuit 24 has functions of converting the DC power output by the rectenna 20 to a predetermined voltage, controlling the charging and discharging of the power storage unit 22, and providing the DC power from the rectenna 20 and the DC power from the power storage unit 22 to the sensors 14, 16 and the wireless communication circuit 18. When DC power is provided from the rectenna 20, the charge control circuit 24 provides DC power to the sensors 14, 16, the wireless communication circuit 18, and the power storage unit 22. When DC power is not provided from the rectenna 20, the charge control circuit 24 provides the power stored in the power storage unit 22 to the sensors 14, 16, and the wireless communication circuit 18. The power storage unit 22 stores the DC power provided via the charge control circuit 24. The power storage unit 22 discharges the stored power based on the control of the charge control circuit 24. In this embodiment, the power storage unit 22 is a storage battery (secondary battery). The power storage unit 22 may also be a capacitor.

[0029] The charge control circuit 24 also has a function of detecting the remaining amount of electricity stored in the power storage unit 22. The charge control circuit 24 detects the voltage of a line 24a connecting the charge control circuit 24 and the power storage unit 22 as the remaining amount of electricity stored in the power storage unit 22. In other words, the charge control circuit 24 functions as a sensor that detects the remaining amount of electricity stored in the power storage unit 22. The charge control circuit 24 provides information indicating the voltage of the line 24a to the wireless communication circuit 18. In this way, the output of the charge control circuit 24 as a sensor indicates the remaining amount of electricity stored in the power storage unit 22.

[0030] The wireless communication circuit 18 has a transmitting / receiving antenna 18a and functions to communicate wirelessly with a receiver or the like outside the machining space S. The wireless communication circuit 18 communicates wirelessly with the receiver, for example, via Bluetooth (registered trademark). Therefore, the wireless communication circuit 18 communicates wirelessly using a frequency band including 2.4 GHz. The wireless communication circuit 18 wirelessly transmits the output of each sensor. The sensor output includes strain information based on the output of the strain sensor 14 and the strain sensor 16, and remaining charge information based on the output of the charge control circuit 24. The remaining charge information indicates the remaining charge amount of the power storage unit 22. The remaining charge amount is expressed as a numerical value. The temperature information, strain information, and remaining charge information are stored in the same packet, for example, and transmitted at predetermined time intervals. When DC power is supplied from the charge control circuit 24, the wireless communication circuit 18 establishes a communication connection with the receiver and begins wireless communication.

[0031] As described above, the cutting tool 4 operates the sensor and the wireless communication circuit 18 based on the power supplied from the power supply device 6, and transmits the output of the sensor.

[0032] Fig. 3A is a diagram showing the appearance of the cutting tool 4. Fig. 3A is a diagram showing the first surface 4a of the cutting tool 4 as viewed from the front. In the following description, in each figure, three mutually orthogonal directions are referred to as the X direction, Y direction, and Z direction. As shown in Fig. 1, one of the X directions is referred to as the X1 direction, and the direction opposite to the X1 direction is referred to as the X2 direction. One of the Y directions is referred to as the Y1 direction, and the direction opposite to the Y1 direction is referred to as the Y2 direction. One of the Z directions is referred to as the Z1 direction, and the direction opposite to the Z1 direction is referred to as the Z2 direction.

[0033] As shown in FIG. 3A, the longitudinal direction of the cutting tool 4 is along the X direction. The first surface 4a is one side surface of the cutting tool 4. The first surface 4a is a surface of the cutting tool 4 that is parallel to the X-Y plane and faces the Z1 direction. As described above, the main body 12 of the cutting tool 4 has a shank 12a and a cutting tip 12b. The cutting tip 12b is attached to the end of the shank 12a on the X1 direction side. The rake face 12b1 of the cutting tip 12b faces the Y1 direction. The lateral relief face 12b2 of the cutting tip 12b faces the Z1 direction.

[0034] Figure 3B is a cross-sectional view taken along line B-B in Figure 3A. As shown in Figures 3A and 3B, the shank 12a has a first recess 30 and a lid portion 32. The first recess 30 opens to the first surface 4a. The lid portion 32 is a rectangular plate-shaped member. The lid portion 32 is provided at the opening 30a of the first recess 30. The outer edge of the lid portion 32 runs along the inner edge of the opening 30a. The lid portion 32 is fitted into the inner edge of the opening 30a and fixed to the opening 30a. In this way, the lid portion 32 closes the opening 30a. The outer surface 32a of the lid portion 32 forms part of the first surface 4a.

[0035] The first surface 4a has an outer surface 32a of the lid portion 32 and a flat surface 34. The flat surface 34 is the surface portion of the first surface 4a excluding the first recess 30 and facing the Z1 direction. The flat surface 34 and the outer surface 32a are flush. The first recess 30 is recessed in the Z2 direction relative to the flat surface 34. When the first surface 4a is viewed from the front, the first recess 30 has a rectangular shape with its long sides aligned along the X direction. Therefore, the lid portion 32 also has a rectangular shape with its long sides aligned along the X direction.

[0036] The wireless communication circuit 18, the charge control circuit 24, the rectenna 20, and the power storage unit 22 are housed in the housing space S1. The housing space S1 is a space defined by the first recess 30 and the lid 32.

[0037] The lid portion 32 closes the opening 30a to prevent coolant and other liquids from entering the storage space S1 during machining. As shown in Figures 3A and 3B, the lid portion 32 includes a lid main body 33a, a window portion 33b, and a window cover 33c. The lid main body 33a is a rectangular plate-shaped metal member. The outer edge of the lid main body 33a follows the inner edge of the opening 30a. The lid main body 33a is fitted into the inner edge of the opening 30a and fixed to the opening 30a.

[0038] The window portion 33b is provided in the lid main body 33a. The window portion 33b is a rectangular hole that connects the storage space S1 with the outside. The window portion 33b has a rectangular shape with its long sides aligned with the X direction. The window cover 33c is a rectangular plate-shaped member. The window cover 33c is formed using a material such as resin that is permeable to radio waves transmitted and received from the wireless communication circuit 18 and radio waves for power supply. The outer edge of the window cover 33c runs along the inner edge of the window portion 33b. The window cover 33c is fitted into the inner edge of the window portion 33b and fixed to the window portion 33b.

[0039] The gap between the outer edge of the lid body 33a and the inner edge of the opening 30a, and the gap between the outer edge of the window lid 33c and the inner edge of the window 33b are sealed, respectively, thereby preventing the coolant liquid and the like from entering the storage space S1.

[0040] As shown in FIG. 3A, the strain sensor 14 and the strain sensor 16 are provided near the end of the shank 12a in the X1 direction. The strain sensor 14 is provided on the second surface 4b side. The second surface 4b is one side surface of the cutting tool 4. The second surface 4b is a surface of the cutting tool 4 that is parallel to the X-Z plane and faces the Y2 direction. A second recess 36 is provided on the second surface 4b side of the shank 12a. The second recess 36 opens to the second surface 4b. The second recess 36 is closed by a sensor lid 38. The strain sensor 14 is accommodated in an accommodation space S2. The accommodation space S2 is a space defined by the second recess 36 and the sensor lid 38.

[0041] The strain sensor 16 is provided on the third surface 4c side. The third surface 4c is one side surface of the cutting tool 4. The third surface 4c is a surface of the cutting tool 4 that is parallel to the XY plane and faces the Z2 direction. As shown in FIG. 3B , a third recess 40 is provided on the third surface 4c side of the shank 12a. The third recess 40 opens to the third surface 4c. The third recess 40 is closed by a sensor lid 42. The strain sensor 16 is housed in an accommodation space S3. The accommodation space S3 is a space defined by the third recess 40 and the sensor lid 42.

[0042] The accommodation space S2 and the accommodation space S1 are connected by a communication passage (not shown) formed by a groove or a through-hole provided in the shank 12a. Similarly, the accommodation space S3 and the accommodation space S1 are connected by a communication passage provided in the shank 12a. The strain sensors 14 and 16 are connected to the wireless communication circuit 18 and the charge control circuit 24 in the accommodation space S1 by lines passing through the communication passage. These lines supply power to the strain sensors 14 and 16 and transmit the outputs of the strain sensors 14 and 16 to the wireless communication circuit 18.

[0043] [Regarding the arrangement of each circuit] Fig. 4 is an enlarged view of a main portion of Fig. 3A. Fig. 5 is an enlarged view of a main portion of Fig. 3B. Fig. 4 shows a state in which the lid portion 32 is removed. The two-dot chain line L in Fig. 4 indicates the outline of the window portion 33b (window lid 33c) when the first surface 4a is viewed from the front.

[0044] The housing space S1 accommodates a circuit board 45 and a rectenna 20. The circuit board 45 and the rectenna 20 are arranged side by side along the X direction. The circuit board 45 is arranged closer to the X1 direction within the housing space S1. The rectenna 20 is arranged closer to the X2 direction within the housing space S1.

[0045] The circuit board 45 includes a substrate body 46, a first circuit chip 50, and a second circuit chip 52. The first circuit chip 50 and the second circuit chip 52 are mounted on a first surface 46a of the substrate body 46. The first surface 46a is the surface of the substrate body 46 facing the Z1 direction. The second circuit chip 52 is a circuit chip that includes the charge control circuit 24. The first circuit chip 50 is a circuit chip that configures the wireless communication circuit 18.

[0046] The first circuit chip 50 has a chip surface 50a facing the Z1 direction. A transmitting and receiving antenna 18a is provided on the chip surface 50a. The wireless communication circuit 18 is composed of the first circuit chip 50 and the transmitting and receiving antenna 18a. The transmitting and receiving antenna 18a includes a substrate and an antenna element mounted on the substrate. The transmitting and receiving antenna 18a is provided near the edge of the chip surface 50a on the X2 direction side. Therefore, the transmitting and receiving antenna 18a is disposed in close proximity to the rectenna 20.

[0047] Fig. 6 is a diagram showing the circuit board 45 and the rectenna 20 when viewed from the front in the Z2 direction. As shown in Figs. 5 and 6, the power storage unit 22 is attached to the second surface 46b of the board main body 46. The second surface 46b is the surface of the board main body 46 that faces the Z2 direction. The power storage unit 22 is connected to a connection terminal (not shown) or the like provided on the board main body 46.

[0048] 4 and 5, the rectenna 20 includes the power receiving antenna 20a and a third circuit chip 56. The third circuit chip 56 is a circuit chip that includes the rectifier circuit 20b. The third circuit chip 56 is mounted on a first surface 54a of an antenna substrate 54 of the power receiving antenna 20a. The first surface 54a is the surface of the antenna substrate 54 that faces the Z1 direction.

[0049] The power receiving antenna 20a includes the above-mentioned antenna substrate 54, a pair of antenna elements 58, and a pair of feeder lines 60. The pair of antenna elements 58 are conductor patterns made of copper foil or the like mounted on the first surface 54a. The pair of antenna elements 58 are rectangular or linear and extend in a row along the X direction. The pair of feeder lines 60 are conductor patterns made of copper foil or the like mounted on the second surface 54b. The second surface 54b is the surface of the antenna substrate 54 facing the Z2 direction. The pair of feeder lines 60 are provided at positions corresponding to the pair of antenna elements 58 in the X-Y plane.

[0050] The pair of power feed lines 60 and the pair of antenna elements 58 are connected by vias or the like provided in the antenna substrate 54. The power receiving antenna 20a receives power-feeding radio waves by the pair of antenna elements 58 and outputs power from the pair of power feed lines 60. The power from the power feed lines 60 is supplied to the rectifier circuit 20b included in the third circuit chip 56.

[0051] Rectenna 20 and circuit board 45 are fixed within accommodation space S1. Rectenna 20 and circuit board 45 may be packaged in a shape that can be fixed within accommodation space S1 and fixed within accommodation space S1 as a package, or may be fixed within accommodation space S1 by a bracket or the like.

[0052] As such, the shank 12a of this embodiment has a first recess 30 that opens to the first surface 4a of the shank 12a and a lid portion 32 that covers the opening 30a of the first recess 30, and the first circuit chip 50 (wireless communication circuit 18) and the rectenna 20 are accommodated in the accommodation space S1 defined by the first recess 30 and the lid portion 32, so that the first circuit chip 50 and the rectenna 20 can be placed on the shank 12a without being exposed to the outside.

[0053] 5, the pair of antenna elements 58 are mounted on the first surface 54a as described above. The transmitting and receiving antenna 18a is provided on the chip surface 50a. Therefore, the pair of antenna elements 58 and the transmitting and receiving antenna 18a are disposed opposite the lid portion 32.

[0054] More specifically, as shown in FIG. 4 , the pair of antenna elements 58 and the transmitting / receiving antenna 18a are disposed within the range of the window portion 33b (window cover 33c) when viewed from the front from the first surface 4a. Therefore, the pair of antenna elements 58 and the transmitting / receiving antenna 18a are disposed opposite the window cover 33c. Here, as described above, the window cover 33c is formed of a material that is permeable to radio waves. Therefore, the window cover 33c can be prevented from interfering with the transmission and reception of radio waves from the transmitting / receiving antenna 18a and the reception of power supply radio waves by the pair of antenna elements 58. Furthermore, by disposing the pair of antenna elements 58 and the transmitting / receiving antenna 18a opposite the window cover 33c, radio waves can be appropriately transmitted and received through the window cover 33c.

[0055] Furthermore, in this embodiment, the transmitting and receiving antenna 18a is disposed in close proximity to the rectenna 20 (the pair of antenna elements 58). Therefore, the window 33b and the window cover 33c can be made smaller than when, for example, the transmitting and receiving antenna 18a is provided closer to the edge of the chip surface 50a on the X1 direction side, or when the circuit board 45 and the rectenna 20 are disposed with a space in the X direction.

[0056] In the cutting tool 4 configured as described above, the strain sensor 14 (strain sensor 16), the first circuit chip 50 (wireless communication circuit 18), and the rectenna 20 are arranged on the shank 12a from the end on the X1 direction side along the longitudinal direction (X direction) of the shank 12a in the following order: strain sensor 14 (strain sensor 16), first circuit chip 50, and rectenna 20. In this case, the strain sensor 14 (strain sensor 16) can be arranged closest to the cutting tip 12b, which is the machining point, thereby improving sensitivity. Furthermore, the rectenna 20 is not arranged between the sensors 14, 16 and the first circuit chip 50 (wireless communication circuit 18), so the sensors 14, 16 and the first circuit chip 50 can be arranged relatively close to each other. As a result, the length of the line for transmitting the output of the sensors 14, 16 to the wireless communication circuit 18 can be shortened, thereby improving noise resistance.

[0057] According to this embodiment, the rectenna 20 is provided to receive radio waves for power supply transmitted from the power transmission antenna 8 provided in the machining space S, thereby enabling wireless power supply within the machining space S. Therefore, the cutting tool 4 can receive power even during machining, and the outputs of the sensors 14 and 16 can be transmitted continuously even if the machining time is long. As a result, the state of the cutting process can be appropriately monitored.

[0058] Furthermore, the cutting tool 4 of this embodiment is equipped with a power storage unit 22 that stores the power output by the rectenna 20. Therefore, even if the power supply radio waves from the power transmission antenna 8 are temporarily interrupted or temporarily unable to be received, the power stored in the power storage unit 22 can be used to continue transmitting the outputs of the sensors 14 and 16.

[0059] 7 is a block diagram showing a portion of a cutting tool 4 according to a modified example. This modified example differs from the above embodiment in that it includes a plurality of rectennas (first rectenna 70 and second rectenna 72).

[0060] 7 , first rectenna 70 has a power receiving antenna 70a and a rectifier circuit 70b. Second rectenna 72 has a power receiving antenna 72a and a rectifier circuit 72b. Rectifier circuits 70b and 72b are connected to a combining circuit 74. Therefore, the DC power output by first rectenna 70 and second rectenna 72 is provided to combining circuit 74. Combiner circuit 74 combines the power output by first rectenna 70 and the power output by second rectenna 72, and provides the combined power to charge control circuit 24.

[0061] Fig. 8 is an external view showing a portion of the cutting tool 4 according to this modified example. Fig. 9 is a cross-sectional view showing a portion of the cutting tool 4 according to this modified example. Fig. 8 is a front view of the first surface 4a. Fig. 9 is a cross-sectional view along the X-Y plane. As shown in Figs. 8 and 9, the shank 12a of this example has a fourth recess 62, a cover portion 64, a fifth recess 66, and a cover portion 68 in addition to the first recess 30 and the cover portion 32.

[0062] The fourth recess 62 and the fifth recess 66 are arranged side by side in the X direction together with the first recess 30. The fourth recess 62 and the fifth recess 66 are open to the first surface 4a. The fourth recess 62 and the fifth recess 66 are recessed in the Z2 direction relative to the flat surface portion 34. The fourth recess 62 and the fifth recess 66 have a rectangular shape when the first surface 4a is viewed from the front.

[0063] The lid portion 64 is a rectangular plate-shaped member. The lid portion 64 is provided in the opening 62a of the fourth recess 62. The outer edge of the lid portion 64 follows the inner edge of the opening 62a. The lid portion 64 is fitted into the inner edge of the opening 62a and fixed to the opening 62a. In this way, the lid portion 64 closes the opening 62a. The outer surface 64a of the lid portion 64 forms part of the first surface 4a.

[0064] The lid portion 68 is a rectangular plate-shaped member. The lid portion 68 is provided in the opening 66a of the fifth recess 66. The outer edge of the lid portion 68 follows the inner edge of the opening 66a. The lid portion 68 is fitted into the inner edge of the opening 66a and fixed to the opening 66a. In this way, the lid portion 68 closes the opening 66a. The outer surface 68a of the lid portion 68 forms part of the first surface 4a.

[0065] The first rectenna 70 is accommodated in the accommodation space S4. The accommodation space S4 is a space defined by the fourth recess 62 and the lid portion 64. The second rectenna 72 is accommodated in the accommodation space S5. The accommodation space S5 is a space defined by the fifth recess 66 and the lid portion 68.

[0066] 8 and 9, the lid portion 64 includes a lid main body 65a, a window portion 65b, and a window cover 65c. The lid main body 65a is a rectangular plate-shaped metal member. The outer edge of the lid main body 65a is aligned with the inner edge of the opening 62a. The lid main body 65a is fitted into the inner edge of the opening 62a and fixed to the opening 62a.

[0067] The window 65b is provided in the lid main body 65a. The window 65b is a rectangular hole that connects the storage space S4 with the outside. The window 65b has a rectangular shape. The window cover 65c is a rectangular plate-shaped member. The window cover 65c is formed using a material such as resin that is permeable to the power supply radio waves received by the first rectenna 70. The outer edge of the window cover 65c runs along the inner edge of the window 65b. The window cover 65c is fitted into the inner edge of the window 65b and fixed to the window 65b.

[0068] The gap between the outer edge of the lid body 65a and the inner edge of the opening 62a, and the gap between the outer edge of the window cover 65c and the inner edge of the window 65b are sealed, respectively. This prevents coolant and other liquids from entering the storage space S4. The lid 68 includes a lid body 69a, a window 69b, and a window cover 69c. The lid 68 has the same configuration as the lid 64, so a description thereof will be omitted here.

[0069] The accommodation space S1 and the accommodation space S4 are in communication with each other through a communication passage (not shown) formed by a groove or a through-hole provided in the shank 12a. Similarly, the accommodation space S1 and the accommodation space S5 are in communication with each other through a communication passage formed by a groove or a through-hole provided in the shank 12a. The first rectenna 70 and the second rectenna 72 are connected to the circuit board 45 in the accommodation space S1 by lines passing through the communication passage.

[0070] Fig. 10 is an external view showing a portion of the cutting tool 4 according to this modified example. Fig. 10 shows a state in which the lids 32, 64, and 68 have been removed. In Fig. 10, a two-dot chain line L1 indicates the outline of the window 33b. A two-dot chain line L2 indicates the outline of the window 65b. A two-dot chain line L3 indicates the outline of the window 69b.

[0071] In this example, the accommodation space S1 accommodates only a circuit board 45. In this example, the circuit board 45 includes a fourth circuit chip 53 in addition to a first circuit chip 50 and a second circuit chip 52. The fourth circuit chip 53 is a circuit chip that includes a composite circuit 74.

[0072] 10 and 9, the first rectenna 70 includes the power receiving antenna 70a and a fifth circuit chip 76. The fifth circuit chip 76 is a circuit chip that includes the rectifier circuit 70b. The fifth circuit chip 76 is mounted on a first surface 78a of an antenna substrate 78 of the power receiving antenna 70a. The first surface 78a is the surface of the antenna substrate 78 that faces the Z1 direction.

[0073] The power receiving antenna 70a includes the above-described antenna substrate 78 and an antenna element 80. The antenna element 80 is a conductor pattern such as copper foil mounted on the first surface 78a. The antenna element 80 is formed in a loop shape and constitutes a loop antenna.

[0074] The second rectenna 72 includes the above-described power receiving antenna 72a and a sixth circuit chip 82. The sixth circuit chip 82 is a circuit chip that includes a rectifier circuit 72b. The power receiving antenna 72a includes an antenna substrate 84 and an antenna element 86. The configuration of the second rectenna 72 is similar to the configuration of the first rectenna 70, so a description thereof will be omitted here.

[0075] 10, the transmitting and receiving antenna 18a of the circuit board 45 is disposed inside the two-dot chain line L1. Therefore, the transmitting and receiving antenna 18a is disposed within the range of the window portion 33b (window cover 33c) when viewed from the front from the first surface 4a.

[0076] Furthermore, the antenna element 80 is disposed inside the two-dot chain line L2. Therefore, the antenna element 80 is disposed within the range of the window portion 65b (window cover 65c) when viewed from the front from the first surface 4a. Similarly, the antenna element 86 is disposed inside the two-dot chain line L3. Therefore, the antenna element 86 is disposed within the range of the window portion 69b (window cover 69c) when viewed from the front from the first surface 4a.

[0077] In this modification, the window covers 33c, 65c, and 69c are also made of a material that allows radio waves to pass through. This prevents the window covers 33c, 65c, and 69c from interfering with the transmission and reception of the antennas. Furthermore, the transmitting and receiving antenna 18a and the antenna elements 80 and 86 are disposed opposite the window covers 33c, 65c, and 69c, allowing radio waves to be transmitted and received appropriately through the window covers 33c, 65c, and 69c.

[0078] Furthermore, in this modification, cutting tool 4 includes second rectenna 72 in addition to first rectenna 70. Therefore, for example, by differentiating the receiving frequency band of first rectenna 70 from the receiving frequency band of second rectenna 72, it is possible to receive power supply radio waves of two frequency bands. Furthermore, if the receiving frequency band of first rectenna 70 is the same as the receiving frequency band of second rectenna 72, it is possible to improve power receiving efficiency by combining the outputs of both circuits 70, 72. Note that, although this modification illustrates an example in which two rectennas are provided, a greater number of rectennas, such as three or four, may also be provided.

[0079] In addition, in this modified example, the circuit board 45, the first rectenna 70, and the second rectenna 72 are individually housed in three housing spaces S1, S4, and S5, so that mutual interference can be suppressed when each circuit transmits and receives radio waves.

[0080] [Others] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. For example, in the above embodiment, the cover 32 includes a metal cover body 33a and a window cover 33c covering the window 33b, and the window cover 33c is made of a material that transmits radio waves, such as resin. However, the entire cover 32 may be made of a material that transmits radio waves, such as resin. In this case, the cover 32 can be prevented from interfering with the transmission and reception of radio waves from the transmitting and receiving antenna 18a and the reception of power supply radio waves by the pair of antenna elements 58. Furthermore, because the pair of antenna elements 58 and the transmitting and receiving antenna 18a are disposed opposite the window 33b, radio waves can be appropriately transmitted and received through the window cover 33c.

[0081] In addition, in each of the above embodiments, an example has been given of using a strain sensor as a sensor to detect the state of the cutting tool 4, but in addition to a strain sensor, a temperature sensor or an acceleration sensor may also be used to detect the state of the cutting process (the state of the cutting tool 4).

[0082] The scope of the present invention is defined by the claims, not by the meaning described above, and is intended to include meanings equivalent to the claims and all modifications within the scope thereof.

[0083] REFERENCE SIGNS LIST 1 Cutting processing system 2 Machine tool 2a Bed 2b Housing 2b1 Housing body 2b2 Openable / closable door 2c Turret 4 Cutting tool 4a First surface 4b Second surface 4c Third surface 6 Power supply device 8 Power transmission antenna 10 Control device 12 Main body 12a Shank 12b Cutting tip 12b1 Rake face 12b2 Side relief surface 14 Strain sensor 16 Strain sensor 18 Wireless communication circuit 18a Transmitting / receiving antenna 20 Rectenna 20a Power receiving antenna 20b Rectifier circuit 22 Power storage unit 24 Charging control circuit 24a Line 30 First recess 30a Opening 32 Lid 32a Outer surface 33a Lid body 33b Window 33c Window cover 34 Flat portion 36 Second recess 38 Sensor lid 40 Third recess 42 Sensor lid 45 Circuit board 46 Board body 46a First surface 46b Second surface 50 First circuit chip 50a Chip surface 52 Second circuit chip 54 Antenna board 54a First surface 54b Second surface 56 Third circuit chip 58 Antenna element 60 Power supply line 62 Fourth recess 62a Opening 64 Lid 64a Outer surface 65a Lid body 65b Window 65bb Window 65c Window cover 66 Fifth recess 66a Opening 68 Lid 68a Outer surface 69a Lid body 69b Window 69c Window cover 70 First rectenna 70a Power receiving antenna 70b Rectifier circuit 72 Second rectenna 72a Power receiving antenna 72b Rectifier circuit 74 Combiner circuit 76 Fifth circuit chip 76a First surface 78 Antenna substrate 78a First surface 80 Antenna element 82 Sixth circuit chip 84 Antenna substrate 86 Antenna element 100 Power supply L Two-dot chain line L1 Two-dot chain line L2 Two-dot chain line L3 Two-dot chain line S Machining space S1 Housing space S2 Housing space S3 Housing space S4 Housing space S5 Housing space

Claims

1. A cutting tool comprising: a main body portion to be placed in a machining space of a machine tool; a sensor provided in the main body portion; a wireless communication circuit that transmits the output of the sensor; and a first power receiving antenna circuit that receives power supply radio waves transmitted from a power transmitting antenna provided in the machining space and outputs power.

2. The cutting tool according to claim 1, further comprising a power storage unit that stores the electric power.

3. A cutting tool as described in claim 1 or claim 2, wherein the main body comprises a cutting tip and a rod-shaped shank to whose end the cutting tip is attached, and the sensor, the wireless communication circuit and the first receiving antenna circuit are arranged on the shank from the end side along the longitudinal direction of the shank in the order of the sensor, the wireless communication circuit and the first receiving antenna circuit.

4. A cutting tool as described in claim 3, wherein the shank has a recess opening into a side surface of the shank and a lid covering the opening of the recess, and the wireless communication circuit and the first power receiving antenna circuit are housed in a storage space defined by the recess and the lid.

5. The cutting tool according to claim 4, wherein the cover is made of a material that is permeable to radio waves transmitted and received from the wireless communication circuit and to radio waves for power supply.

6. The cutting tool according to claim 5, wherein the wireless communication circuit has a transmitting / receiving antenna, the first power receiving antenna circuit has a power receiving antenna, and the power receiving antenna and the transmitting / receiving antenna are arranged opposite to the cover portion.

7. A cutting tool as described in claim 4, wherein the cover portion comprises: a window portion communicating the storage space with the outside; and a window cover made of a material that is permeable to radio waves transmitted and received from the wireless communication circuit and to radio waves for power supply, and that covers the window portion.

8. The cutting tool according to claim 7, wherein the wireless communication circuit has a transmitting / receiving antenna, the first power receiving antenna circuit has a power receiving antenna, and the power receiving antenna and the transmitting / receiving antenna are arranged opposite the window cover.

9. The cutting tool according to claim 8, wherein the power receiving antenna and the power transmitting / receiving antenna are arranged in close proximity to each other.

10. A cutting tool as described in any one of claims 1 to 9, further comprising: a second power receiving antenna circuit that receives power supply radio waves transmitted from a power transmitting antenna provided in the machining space and outputs electric power; and a combining circuit that combines the power output by the first power receiving antenna circuit and the power output by the second power receiving antenna circuit.

11. The cutting tool according to claim 10, wherein the main body comprises a rod-shaped shank, the shank having three recesses opening into a side surface of the shank and three lid portions covering the three openings of the three recesses, and the wireless communication circuit, the first receiving antenna circuit and the second receiving antenna circuit are individually housed in three storage spaces defined by the three recesses and the three lid portions.

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