JP5877117B2 - Bit wear detector - Google Patents

Description

  The present invention relates to a bit wear detection device for detecting wear of a bit provided in a cutter head of a shield machine.

  In a shield excavator for tunnel excavation (also referred to as a tunnel excavator or a tunnel excavator), the ground is excavated with a bit provided in the cutter head by rotating the cutter head. The bit provided in the cutter head includes a roller bit (roller cutter) that rolls by excavating (crushing) the ground by receiving a reaction force from the ground according to the rotation of the cutter head, and a cutter fixed to the cutter head. There are bits (fixed bits), shell bits, and the like.

  With the recent increase in shield tunnel excavation work, maintenance of the shield machine bits has become a problem. Since excavation performance decreases when the bit is worn, it is necessary to replace the bit as appropriate according to wear. Various bit wear detection devices for detecting bit wear have been proposed in order to determine the bit replacement time.

  In Patent Document 1, as shown in FIG. 7A, the proximity switch 101 is provided on the cutter head 2, and the striker 102 is provided at a position facing the proximity switch 101 of the roller bit 3. A device for detecting the wear state of the roller bit 3 from a change in the rotational speed of the roller bit 3 has been proposed.

  In Patent Document 2, as shown in FIG. 7B, the cutter head 2 is provided with a wear detection jack 103 that can protrude and retract toward the roller bit 3, and the wear detection jack 103 is applied to the roller bit 3. An apparatus for detecting the wear state of the roller bit 3 from the amount of protrusion when the contact is made has been proposed.

  In Patent Document 3, as shown in FIG. 7C, an eddy current sensor 104 that detects a distance by forming a magnetic field toward the cutting edge of the roller bit 3 is provided in the cutter head 2. A device for detecting the wear state of the roller bit 3 from the detection signal is proposed.

Japanese Patent No. 3544190 Japanese Patent No. 3588068 JP 2003-82986 A Japanese Patent No. 3919172

  However, in each of the conventional bit wear detection devices described above, a power line that supplies power to the sensor portion that detects wear, and a signal that passes the sensed electrical signal (if the wear detection jack 103 is used, supply operating oil) Hydraulic hose) to be connected. Therefore, in the conventional bit wear detection device, it is necessary to connect the sensor portion and the analysis portion provided in the excavator main body with an electric wire or the like by adopting a slip ring or a rotary joint on the rotating shaft of the cutter head 2. is there. Since there is high-pressure (for example, about 3 atm) earth and sand water around the cutter head 2, it is necessary to adopt a special structure for the slip ring and the rotary joint, which is very expensive.

  Further, in the above-described conventional bit wear detection device, since the sensor portion is provided in an environment where high-pressure earth and sand water exists, there is a very high possibility that a stone collides with the sensor portion and breaks it. . Furthermore, for example, when a stone is sandwiched between the sensor portion and the roller bit 3, there is a high possibility of malfunction, and there is a problem in terms of reliability.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a bit wear detection device that is highly reliable and can be realized at low cost without causing damage or malfunction due to earth and sand water.

The present invention was devised to achieve the above object, and is a bit wear detection device for detecting wear of a bit provided in a cutter head of a shield machine, and the wear amount for measuring the wear amount of the bit. Measured by a measurement unit, a bit side transmission unit that transmits ultrasonic wear amount data measured by the wear amount measurement unit, and a power supply unit that supplies power to the wear amount measurement unit and the bit side transmission unit The wear amount measuring unit and the power supply unit are accommodated in a first accommodation hole formed in the bit, and formed in the bit and separated from the first accommodation hole. The bit-side transmission unit is accommodated in the second accommodation hole formed at the position, and transmitted at least by the bit-side transmission unit of the measurement unit to the excavator body disposed behind the cutter head. Wear amount Comprising an analysis unit having a body-side receiving unit that receives over data, the body-side receiving unit, wherein the shield machine cutter head side of the partition wall of the main body to receive the ultrasonic wave having propagated sediment water from the bit-side transmission unit It is the bit wear detection apparatus provided in .

  The wear amount measuring unit may include a printed circuit board on which a wiring pattern is formed on the substrate and worn along with the bit, and a disconnection detecting unit that detects disconnection of the wiring pattern of the printed circuit board.

  The bit side transmission unit may be configured to transmit the identifier of the measurement unit together with the wear amount data measured by the wear amount measurement unit.

  A plurality of the wear amount measurement units may be provided in one bit, and the plurality of wear amount measurement units may share one bit transmission unit.

  The measurement unit may be housed in a housing hole formed in the bit and sealed with resin.

  The bit is a roller bit including a shaft portion fixed to the cutter head and a ring-shaped blade portion rotatably provided around the shaft portion, and radially outward from an inner peripheral surface of the blade portion. You may make it form the said accommodation hole toward.

  The bit may be a bolt-fixed exchangeable cutter bit.

  The analysis unit further includes a control panel that outputs a control signal serving as a trigger for measuring the amount of wear, and a main body side transmission unit that transmits the control signal with ultrasonic waves, and the measurement unit outputs the control signal. A bit-side receiving unit for receiving may be provided, and the wear amount measuring unit may be configured to measure the wear amount when receiving the control signal.

  The wear amount measurement unit is configured to periodically measure the wear amount, and the bit-side transmission unit is configured to periodically transmit wear amount data measured by the wear amount measurement unit. Also good.

  ADVANTAGE OF THE INVENTION According to this invention, there is no possibility of damage or malfunction due to earth and sand water, and it is possible to provide a bit wear detection device that is highly reliable and can be realized at low cost.

(A) is a schematic block diagram of the bit abrasion detection apparatus which concerns on one embodiment of this invention, (b) is the block diagram. (A), (b) is a schematic block diagram which shows an example of the wear amount measurement part used with the bit wear detection apparatus of FIG. It is a figure which shows the roller bit in the bit abrasion detection apparatus of FIG. 1, (a) is sectional drawing of a blade part, (b) is a side view of a blade part, (c) is a fractured sectional view. It is a figure which shows the modification of the bit abrasion detection apparatus of FIG. It is a figure which shows one modification of the bit wear detection apparatus of FIG. 1, (a) is a case where a measurement part is mounted in a bolt fixed exchange type cutter bit, (b) is a case where a measurement part is mounted on a shell bit. It is a schematic block diagram. In this invention, it is a figure which shows an example of the bit which mounts a measurement part. (A)-(c) is a schematic block diagram of the conventional bit abrasion detection apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  Fig.1 (a) is a schematic block diagram of the bit abrasion detection apparatus based on this Embodiment, (b) is the block diagram.

  As shown in FIGS. 1A and 1B, the bit wear detection device 1 detects wear of a bit provided in the cutter head 2 of the shield machine 100. In the present embodiment, a case where the wear of the roller bit 3 is detected will be described.

  The bit wear detection device 1 includes a measurement unit 5 embedded in a bit (here, a roller bit 3) and an analysis unit 6 provided in the excavator main body 4 disposed behind the cutter head 2.

  First, the measurement unit 5 will be described.

  The measurement unit 5 includes at least a wear amount measurement unit 7 that measures the wear amount of the bit (here, the roller bit 3), and a bit side transmission unit that transmits the wear amount data measured by the wear amount measurement unit 7 using ultrasonic waves. 8, and a power supply unit 9 that supplies power to the wear amount measurement unit 7 and the bit-side transmission unit 8.

  As shown in FIG. 2A, the wear amount measuring unit 7 includes a printed circuit board 10 on which a wiring pattern 10b is formed on a substrate 10a and is worn together with a bit (here, a roller bit 3), and wiring of the printed circuit board 10. And a disconnection detector 11 that detects disconnection of the pattern 10b.

  Here, as the printed circuit board 10, a plurality of U-shaped wiring patterns 10 b rotated 90 degrees counterclockwise are arranged along the direction of wear, and how many wiring patterns 10 b are disconnected (illustrated). The amount of wear is measured by detecting how many wiring patterns 10b are disconnected from below. The arrangement interval along the direction of wear of the wiring pattern 10b is, for example, 1 mm to 5 mm, and can be arbitrarily set according to the required measurement accuracy.

  In addition, the wiring pattern 10b of the printed circuit board 10 is not limited to this, For example, as shown in FIG.2 (b), it is U-shaped and the length of the advancing direction (from the lower end part of the board | substrate 10a). A plurality of wiring patterns 10b each having a different distance to the bottom of the U-shape are formed, and the amount of wear is measured by detecting how many wiring patterns 10b are disconnected as in the case of FIG. It may be.

  The disconnection detection unit 11 includes, for example, a constant voltage source, an ammeter, and a switching circuit, and sequentially applies a voltage from the constant voltage source to each wiring pattern 10b using the switching circuit and measures a current value with the ammeter. When the measured current value is smaller than a preset threshold value (a value close to 0), it can be determined that a disconnection has occurred in the wiring pattern.

  Here, the wear amount measuring unit 7 is configured by the printed circuit board 10 and the disconnection detecting unit 11, but the configuration of the wear amount measuring unit 7 is not limited to this, and for example, a known thickness gauge or the like is used. It can also be used as the wear amount measuring unit 7. In this specification, the amount of wear means the degree of wear (how much the bit has been reduced due to wear), and does not mean a quantitative value such as a worn mass. The wear amount data measured by the wear amount measuring unit 7 is output to the bit side transmitting unit 8 via the control micro CPU 12.

  The bit-side transmission unit 8 modulates the data of the wear amount measured by the wear amount measurement unit 7 (AM modulation) to generate a modulation signal, and transmits the modulation signal from the modulation circuit 13 with ultrasonic waves. It consists of an ultrasonic element 14 and an ultrasonic element drive circuit 15 that drives the ultrasonic element 14.

  Here, the reason why ultrasonic waves are used as a wireless communication medium will be described.

  Typical wireless communication media include radio waves, light, sound waves, ultrasonic waves, magnetic waves, and the like. In the present invention, since radio communication is performed in earth and sand water, radio waves and light cannot be used. In addition, low-frequency sound waves cannot be expected to communicate stably due to the effect of reflection from the earth and sand, and magnetic waves have a short transmission / reception distance, and the weight of the magnetic material for generating magnetic lines is large and the power consumption increases. is there. That is, when performing wireless communication in earth and sand water, the communication using ultrasonic waves is the most stable, and depending on the output power, a transmission / reception distance of about 20 to 30 m is ensured even in consideration of irregular reflection due to earth and sand. It is possible. Therefore, in the present invention, an ultrasonic wave is used as a wireless communication medium.

  The power supply unit 9 includes a battery and a power supply circuit, and is configured to supply power to the micro CPU 12, the modulation circuit 13, and the ultrasonic element driving circuit 15. Although details will be described later, since the battery of the power supply unit 9 is embedded in the resin and cannot be replaced, at least the period of the lifetime (replacement time) of the bit to be measured in consideration of the frequency of wear measurement and power consumption. As described above, it is necessary to use a device capable of operating the measuring unit 5.

  The measuring unit 5 further includes a bit side receiving unit 16 that receives a control signal (a signal that triggers measurement of the wear amount) transmitted from the analyzing unit 6. The bit-side receiving unit 16 demodulates the ultrasonic element 14 shared with the bit-side transmitting unit 8 and a signal (modulation signal) received by the ultrasonic element 14 into a control signal, and outputs the control signal to the micro CPU 12 Circuit 17.

  The micro CPU 12 is configured to control the wear amount measuring unit 7 so as to measure the wear amount when a control signal is input from the demodulation circuit 17. As a result, the wear amount measuring unit 7 measures the wear amount only when the control signal is received.

As shown in FIG. 3 (a) ~ (c), the measurement section 5, the bit (in this case a roller bit 3) it is accommodated in the accommodation hole 18 formed is sealed with a resin (not shown).

  The roller bit 3 includes a shaft portion 3a fixed to the cutter head 2, and a ring-shaped blade portion 3b provided around the shaft portion 3a via a bearing mechanism 3c so as to be rotatable. In this embodiment, the accommodation hole 18 is formed from the inner peripheral surface of the ring-shaped blade portion 3b toward the outside in the radial direction so as not to penetrate the blade portion 3b. The accommodation hole 18 can be formed by, for example, electric discharge machining.

  Two accommodation holes 18 are formed, and the first accommodation hole 18a is indicated by a broken line in FIG. 1B (abrasion amount measurement unit 7, power supply unit 9, micro CPU 12, modulation circuit 13, and ultrasonic element drive circuit. 15 and the demodulation circuit 17. Hereinafter, these are collectively referred to as a measurement unit body 19) and sealed with resin, and the ultrasonic element 14 is accommodated in the second accommodation hole 18b.

  The first accommodation hole 18a in which the measurement unit main body 19 is accommodated is extended to a portion close to the surface of the roller bit 3, and the print of the wear amount measurement unit 7 at the tip portion (the portion closest to the surface of the roller bit 3). A substrate 10 is disposed. In addition, since the carbide | carbonized_material chip | tip 3d is provided in the blade part 3b of the roller bit 3 with the predetermined space | interval in the circumferential direction, as shown in FIG.3 (b), it is located in the middle of the adjacent carbide | carbonized_material chip | tip 3d. The first accommodation hole 18a may be formed as described above.

  Here, the reason why only the ultrasonic element 14 is accommodated in the second accommodation hole 18 b is that the ultrasonic wave transmission / reception direction (directivity) of the ultrasonic element 14 is outside the radial direction of the roller bit 3. It is necessary to arrange the element 14, and when all the measurement units 5 are accommodated in one accommodation hole 18, the printed circuit board 10 of the wear amount measurement unit 7 is always positioned in the ultrasonic wave transmission / reception direction, from the viewpoint of communication sensitivity. It is because it is not preferable.

  A groove 3e is formed between the two receiving holes 18a and 18b along the inner peripheral surface of the blade portion 3b of the roller bit 3, and the measurement unit main body 19 and the ultrasonic element 14 are connected to the groove 3e. The signal line to be received is accommodated.

  In the present embodiment, the two receiving holes 18a and 18b are formed at opposing positions (that is, positions 180 degrees rotationally symmetric with respect to the central axis), but the positions at which the receiving holes 18a and 18b are formed are particularly limited. is not.

  In the present embodiment, a case where one wear amount measuring unit 7 is provided will be described, but a plurality of wear amount measuring units 7 may be provided in one bit. For example, when three wear amount measuring units 7 are provided, as shown in FIG. 4, three first accommodation holes 18 a corresponding to the three wear amount measurement units 7 are formed, and these first accommodation holes 18 a are formed. In addition, it may be formed at substantially equal intervals along the circumferential direction of the roller bit 3 (in this case, at positions that are rotationally symmetric with respect to the central axis by 120 degrees).

In the roller bit 3, without reaction force acting on the roller bits 3 for some reason, such as when a roller bit 3 is not rolling, but there is a possibility that the circumferential direction of a part only wear increases, the measurement of the wear at a plurality of locations If this is done, it is possible to prevent detection omission in such a case.

  When a plurality of wear amount measuring units 7 are provided, the plurality of wear amount measuring units 7 can share one bit-side transmitting unit 8. At this time, it is possible to share only the ultrasonic element 14, or it is possible to share all parts of the measuring unit 5 other than the wear amount measuring unit 7.

  Next, the analysis unit 6 will be described.

  As shown in FIGS. 1A and 1B, the analysis unit 6 includes at least a main body side reception unit 20 that receives wear amount data transmitted by ultrasonic waves from the bit side transmission unit 8 of the measurement unit 5. doing.

  The main body side receiving unit 20 includes an ultrasonic element 21 and a demodulation circuit 22 that demodulates a signal (modulated signal) received by the ultrasonic element 21. In the present embodiment, the signal demodulated by the demodulation circuit 22 is input to the arithmetic device 24 such as a personal computer via the interface (I / F) 23, and the arithmetic device 24 monitors the bit wear state. Configured.

  In the shield machine 100, the high pressure earth and sand water is on the cutter head 2 side of the partition wall 4a, and the atmosphere opposite to the cutter head 2 on the partition wall 4a. Since the ultrasonic waves do not propagate efficiently in the atmosphere, in this embodiment, the ultrasonic element 21 of the main body side receiving unit 20 is provided on the cutter head 2 side of the partition wall 4a (that is, earth and sand water) and extends from the ultrasonic element 21. The signal line is configured to be connected to the demodulation circuit 22 through the partition wall 4a. The position where the ultrasonic element 21 is provided is not limited to this, and the partition wall 4a is a rigid body that allows sound waves to pass therethrough. Therefore, the ultrasonic element 21 is disposed on the side opposite to the cutter head 2 (that is, in the atmosphere) of the partition wall 4a (or the partition wall). It is also possible to prevent damage caused by earth and sand water.

  The analysis unit 6 further includes a control panel 25 that outputs a control signal serving as a trigger for measuring the amount of wear, and a main body side transmission unit 26 that transmits the control signal using ultrasonic waves.

  The control panel 25 is configured to output a control signal in response to a data request operation (for example, an operation such as pressing a switch) by an operator or the like. In the present embodiment, the control panel 25 directly outputs a modulation signal obtained by modulating the control signal. Of course, the arithmetic device 24 can output the control signal instead of the control panel 25. In this case, however, a modulation circuit is required separately.

  The main body side transmission unit 26 includes an ultrasonic element 21 shared with the main body side reception unit 20 and an ultrasonic element driving circuit 27 that drives the ultrasonic element 21.

  Next, the operation of the bit wear detection device 1 will be described.

  First, the control panel 25 of the analysis unit 6 is operated to output a control signal (modulation signal) from the control panel 25 and transmitted from the ultrasonic element 21 of the main body side transmission unit 26. The bit side receiving unit 16 that has received the control signal (modulated signal) from the main body side transmitting unit 26 by the ultrasonic element 14 demodulates the received signal by the demodulation circuit 17 and outputs the demodulated control signal to the micro CPU 12.

  The micro CPU 12 that has received the control signal controls the wear amount measuring unit 7 and measures the wear amount of the roller bit 3. In the wear amount measurement unit 7, the wear amount of the roller bit 3 is measured by detecting the disconnection of the wiring pattern 10 b by the disconnection detection unit 11. The wear amount data measured by the wear amount measurement unit 7 is modulated by the modulation circuit 13 of the bit side transmission unit 8 and transmitted from the ultrasonic element 14.

  The main body side reception unit 20 that has received the signal (modulation signal) from the bit side transmission unit 8 by the ultrasonic element 21 demodulates the received signal by the demodulation circuit 22, and the demodulated wear amount data is transmitted via the interface 23. Input to the arithmetic unit 24. The arithmetic unit 24 analyzes the wear state of the roller bit 3 based on the input wear amount data and displays it on a display device such as a display.

  In the present embodiment, the case where the wear of the roller bit 3 is detected has been described, but the present invention can also be applied to bits other than the roller bit 3.

  For example, as shown in FIG. 5 (a), the present invention can be applied to a cutter bit (fixed bit) 51 fixed to the cutter head 2 and configured to detect wear of the cutter bit 51. As shown in (b), it is also possible to apply to the shell bit 52 and to detect the wear of the shell bit 52.

  FIG. 5A shows a case where a bolt fixing type that is detachably fixed to the cutter head 2 by using a bolt 53 is used as the cutter bit 51. In such a bolt-fixed exchange type cutter bit 51, conventionally, wear and detection have not been performed because piping and wiring have been difficult, and judgment of the replacement time has been made by experience. By applying it, it is possible to easily detect wear and appropriately determine the replacement time.

  As shown in FIG. 6, the cutter head 2 is provided with a large number of bits, but it is not necessary to mount the measuring unit 5 on all the bits, and a representative bit (a bit considered to have the greatest wear). It is sufficient to mount the measuring unit 5 only on the head. As an example, three roller bits 3 indicated by thick arrows in FIG. 6 can be selected as representative bits, and the measuring unit 5 can be mounted.

  When the measuring unit 5 is mounted on a plurality of bits, the bit side transmitting unit 8 of each measuring unit 5 transmits the identifier of the measuring unit 5 together with the wear amount data measured by the wear amount measuring unit 7. It is preferable to configure so that the analysis unit 6 side (arithmetic unit 24) can determine which bit the signal is sent from the measurement unit 5 mounted on.

  The operation of the present embodiment will be described.

  In the bit wear detection device 1 according to the present embodiment, at least the wear amount measurement unit 7 that measures the wear amount of the bit and the wear amount data measured by the wear amount measurement unit 7 are ultrasonically stored inside the bit. An excavator disposed in the back of the cutter head 2 by embedding a measuring unit 5 having a bit-side transmitting unit 8 to transmit, a wear amount measuring unit 7 and a power supply unit 9 for supplying power to the bit-side transmitting unit 8 The main body 4 includes at least an analysis unit 6 having a main body side receiving unit 20 that receives wear amount data transmitted by ultrasonic waves by the bit side transmitting unit 8 of the measuring unit 5.

  By configuring in this way, it becomes possible to exchange wear amount data by wireless communication using ultrasonic waves, and it is possible to eliminate a wire portion that is likely to be submerged, so an expensive slip ring or rotary joint is provided. This eliminates the need for the bit wear detection device 1 at a lower cost than the conventional one.

  Moreover, in this Embodiment, since the measurement part 5 is embedded in the inside of a bit and earth and sand water does not contact the measurement part 5 directly, there is no possibility of damage or malfunction by earth and sand water, and its reliability is high. The bit wear detection device 1 can be realized.

  Further, in the present embodiment, the wear amount measuring unit 7 includes the printed circuit board 10 on which the wiring pattern 10b is formed on the substrate 10a and worn together with the bit, and the disconnection detecting unit that detects the disconnection of the wiring pattern 10b of the printed circuit board 10. Therefore, the wear amount can be reliably measured at low cost.

  Furthermore, in the present embodiment, the analysis unit 6 further includes a control panel 25 that outputs a control signal serving as a trigger for measuring the amount of wear, and a main body side transmission unit 26 that transmits the control signal with ultrasonic waves, The measurement unit 5 includes a bit-side reception unit 16 that receives a control signal, and the wear amount measurement unit 7 is configured to measure the wear amount when the control signal is received. This makes it possible to measure the wear amount only when necessary, and to reduce power consumption. As a result, a small and inexpensive battery can be used, and the measurement unit 5 can be reduced in size and cost.

  In this embodiment, the wear amount is measured only when necessary. However, the present invention is not limited to this, and the wear amount measuring unit 7 is configured to periodically measure the wear amount, and the bit side transmission is performed. The unit 8 may be configured to periodically transmit the wear amount data measured by the wear amount measuring unit 7 so that the wear amount is periodically and automatically measured. With this configuration, the bit side receiving unit 16 (demodulation circuit 17) of the measuring unit 5, and the control panel 25 and the main body side transmitting unit 26 (ultrasonic element driving circuit 27) of the analyzing unit 6 can be omitted. This makes it possible to further reduce the cost and size.

  The present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

  For example, when the bit wear detection device 1 of the present invention is used, it is possible to detect not only bit wear but also frame wear by embedding the measuring unit 5 in the frame of the cutter head 2.

1 Bit wear detection device 2 Cutter head 3 Roller bit (bit)
4 digging machine main body 5 measuring unit 6 analyzing unit 7 wear amount measuring unit 8 bit side transmitting unit 9 power supply unit 20 main unit side receiving unit 100 shield digging machine

Claims (9)

A bit wear detection device for detecting wear of a bit provided in a cutter head of a shield machine,
A wear amount measurement unit that measures the wear amount of the bit, a bit side transmission unit that transmits ultrasonic wear amount data measured by the wear amount measurement unit, a wear amount measurement unit, and a bit side transmission unit. A power supply unit that supplies power constitutes a measurement unit, and the wear amount measurement unit and the power supply unit are housed in a first housing hole formed in the bit, and formed in the bit. In addition, the bit side transmitter is accommodated in a second accommodation hole formed at a position away from the first accommodation hole,
The shield machine main body disposed to the rear of the cutter head, at least, Bei example an analysis unit having a body-side receiving section for receiving the data of wear amount transmitted in the bit-side transmission unit with ultrasound of the measuring unit,
The bit wear detecting device, wherein the main body side receiving unit is provided on a cutter head side of a partition wall of the excavator main body so as to receive an ultrasonic wave propagating earth water from the bit side transmitting unit . The wear amount measuring unit is
A printed circuit board on which a wiring pattern is formed and worn along with the bit;
The bit wear detection device according to claim 1, further comprising: a disconnection detection unit that detects disconnection of the wiring pattern of the printed circuit board. The bit wear detection device according to claim 1, wherein the bit side transmission unit is configured to transmit an identifier of the measurement unit together with wear amount data measured by the wear amount measurement unit. The bit wear detection device according to claim 1, wherein a plurality of wear amount measurement units are provided in one bit, and the plurality of wear amount measurement units share one bit transmission unit. . The bit wear detection device according to claim 1, wherein the measurement unit is accommodated in an accommodation hole formed in the bit and sealed with resin. The bit is a roller bit composed of a shaft portion fixed to the cutter head and a ring-shaped blade portion rotatably provided around the shaft portion,
The bit wear detection device according to claim 5, wherein the receiving hole is formed from an inner peripheral surface of the blade portion toward a radially outer side. The bit wear detection device according to claim 1, wherein the bit is a bolt-fixed exchangeable cutter bit. The analysis unit further includes a control panel that outputs a control signal serving as a trigger for measuring the amount of wear, and a main body side transmission unit that transmits the control signal with ultrasonic waves,
The measurement unit includes a bit-side reception unit that receives the control signal,
The bit wear detection device according to claim 1, wherein the wear amount measurement unit is configured to measure a wear amount when the control signal is received. The wear amount measuring unit is configured to periodically measure the wear amount,
The bit wear detection device according to any one of claims 1 to 7, wherein the bit side transmission unit is configured to periodically transmit data on the wear amount measured by the wear amount measurement unit.