JP7287226B2 - Machine tool and judgment method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machine tool and a determination method capable of determining removal of a relocation detection unit that detects relocation of the own machine.

Conventionally, means for monitoring the relocation of machine tools have been widely used. Japanese Patent Laid-Open No. 2002-200002 discloses a machine tool relocation detection device that detects relocation of a machine tool using a gyro sensor.
In addition, there is a technique for detecting the relocation of a machine tool by detecting a change in distance from the installation surface (floor) of the machine tool using an optical sensor.

JP 2007-334395 A

However, when the equipment relocation detection device of Patent Document 1 is removed from the machine tool to be monitored, the equipment relocation detection device cannot detect the relocation of the machine tool to be monitored, and the machine tool to be monitored cannot be detected illegally. There is a problem that it is not possible to deal with relocation or the like. Such problems are the same when using the optical sensor described above.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a machine tool capable of determining whether or not a relocation detection unit has been removed with a simple configuration, and capable of solving the above-described problems at a low cost. and to provide a determination method.

A machine tool according to the present invention is a machine tool comprising a relocation detection unit that detects relocation of its own machine, wherein the relocation detection unit has a power source, an attached portion to which the relocation detection unit is attached, and an electric circuit including the power source. and a determination unit that determines whether or not the relocation detection unit has been removed based on the voltage of the power supply.

In the present invention, the electric circuit includes the power source of the relocation detection unit and the attached portion of the relocation detection unit. Therefore, when the relocation detector is removed from the attached part, it can be detected as a voltage change of the power supply, and the determination part determines whether or not the relocation detection part has been detached based on the voltage change of the power supply.

The machine tool according to the present invention includes a voltage detection unit that detects the voltage of the power supply and outputs a notification signal when the detected voltage is equal to or less than a threshold, and the determination unit performs the determination based on the notification signal. characterized by performing

In the present invention, the electric circuit includes the voltage detection section, the power source of the relocation detection section, and the mounted section of the relocation detection section. Therefore, when the relocation detection unit is removed from the mounting part, the voltage detection unit detects a change in the voltage of the power supply and outputs a notification signal, and when the determination unit receives the notification signal, it determines that the relocation detection unit has been removed. do.

In the machine tool according to the present invention, the electric circuit includes a first connection portion that electrically connects the power source and the mounting portion, and an electrical circuit that electrically connects the mounting portion and the voltage detection portion via a fixed potential. and a second connecting portion for

In the present invention, the electric circuit includes a voltage detection section, a power supply, a mounting portion of the relocation detection section, a first connection section, and a second connection section. For example, when the attached portion is removed from the first connection portion or the second connection portion, the voltage detection portion detects a voltage change in the power supply, and the determination portion determines whether the relocation detection portion has been removed based on the detection result of the voltage detection portion. determine whether or not

The machine tool according to the present invention is characterized in that at least one of the first connecting portion and the second connecting portion is a fixing member that fixes the relocation detection portion to the attached portion.

In the present invention, at least one of the first connection portion and the second connection portion is, for example, a stud boss that fixes the relocation detection portion to the attached portion.

In the machine tool according to the present invention, the electric circuit electrically connects the power source and the mounted portion, and includes a first connection portion and a third connection portion connected in parallel to the power source, and an electrical connection to the mounted portion. and a second connection portion and a fourth connection portion that are connected to the voltage detection portion via a fixed potential.

In the present invention, the electric circuit includes a voltage detection section, a power supply, a first connection section and a third connection section connected in parallel with the power supply, a mounted section of the relocation detection section, and a mounted section connected in parallel. A second connection and a fourth connection are included. For example, when the attached portion is removed from the first connection portion and the third connection portion, or when the attached portion is removed from the second connection portion and the fourth connection portion, the voltage detection portion detects the voltage change of the power supply. Then, the determination unit determines whether or not the relocation detection unit has been removed based on the detection result of the voltage detection unit.

In the machine tool according to the present invention, the electric circuit electrically connects the power source and the attachment portion, and includes a first connection portion, a third connection portion, and a fourth connection portion that are connected in parallel with the power source, and the attachment portion. and a second connection portion electrically connected to the mounting portion and connected to the voltage detection portion via a fixed potential.

In the present invention, the electric circuit includes a voltage detection section, a power supply, a first connection section, a third connection section, and a fourth connection section connected in parallel to the power supply, a mounting section of the relocation detection section, and a mounting section. a second connection connected to the . For example, when the attached portion is removed from the first connection portion, the third connection portion, and the fourth connection portion, or when the attached portion is removed from the second connection portion, the voltage detection portion detects the voltage change of the power supply. Then, the determination unit determines whether or not the relocation detection unit has been removed based on the detection result of the voltage detection unit.

In the machine tool according to the present invention, the electric circuit includes a first connection portion that electrically connects the power source and the mounting portion, and an electrical circuit that electrically connects the mounting portion and the voltage detection portion via a fixed potential. and a second connecting portion, a third connecting portion, and a fourth connecting portion.

In the present invention, the electric circuit includes a voltage detection section, a power supply, a first connection section connected to the power supply, a mounted section of the relocation detection section, a second connection section connected in parallel with the mounted section, and a third connection section. A connecting part and a fourth connecting part are included. For example, when the attached portion is removed from the first connection portion, or when the attached portion is removed from the second, third, and fourth connection portions, the voltage detection portion detects the voltage change of the power supply. Then, the determination unit determines whether or not the relocation detection unit has been removed based on the detection result of the voltage detection unit.

In the machine tool according to the present invention, at least one of the first connection portion, the second connection portion, the third connection portion, and the fourth connection portion is a fixing member for fixing the relocation detection portion to the attached portion. It is characterized by

In the present invention, at least one of the first connection portion, the second connection portion, the third connection portion, and the fourth connection portion is, for example, a stud boss for fixing the relocation detection portion to the attached portion.

A determination method according to the present invention is a determination method for determining removal of the relocation detection unit by a machine tool having a relocation detection unit that detects relocation of the machine, wherein the machine tool includes an attached portion to which the relocation detection unit is attached, and an attached portion to which the relocation detection unit is attached. An electric circuit including a power supply included in the relocation detection unit is provided, and whether or not the relocation detection unit is removed is determined based on the voltage of the power supply.

In the present invention, the electric circuit includes the power source of the relocation detection unit and the attached portion of the relocation detection unit. Therefore, when the relocation detector is removed from the attached part, it can be detected as a voltage change of the power supply, and it is determined whether or not the relocation detector has been removed based on the voltage change of the power supply.

According to the present invention, it is possible to determine whether or not the relocation detection unit has been removed with a simple configuration, and to solve the problem that the removal of the relocation detection unit makes it impossible to deal with unauthorized relocation of the machine tool to be monitored.

1 is a schematic perspective view of a machine tool according to Embodiment 1; FIG. 1 is a schematic block diagram of a main configuration of a machine tool according to Embodiment 1; FIG. FIG. 5 is an explanatory diagram illustrating attachment of the relocation detection device in the machine tool according to Embodiment 1; 1 is a schematic circuit diagram showing a voltage detection circuit of a machine tool according to Embodiment 1; FIG. FIG. 7 is a schematic circuit diagram showing a voltage detection circuit of a machine tool according to Embodiment 2; 8 is a schematic circuit diagram showing a voltage detection circuit of a machine tool according to Embodiment 3; FIG. FIG. 11 is a schematic circuit diagram showing a voltage detection circuit of a machine tool according to Embodiment 4;

A machine tool and a determination method according to embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a perspective view schematically showing a machine tool 100 according to Embodiment 1, and FIG. 2 is a block diagram schematically showing the essential configuration of the machine tool 100 according to Embodiment 1. As shown in FIG. A machine tool 100 includes a base 1 , a machine body 2 , a machine cover 3 , an operation section 4 and a control device 10 .

A base 1 supports a machine body 2 . A machine cover 3 covers the machine body 2 . A control device 10 is attached to the rear side of the machine body 2 . The operation unit 4 has a display unit 4a, switches, buttons, a touch panel, and the like, and receives operations by an operator.

The machine body 2 includes a spindle drive mechanism 2a and a workpiece holder drive mechanism 2b. The spindle drive mechanism 2a rotates a spindle on which a tool is mounted and moves the spindle vertically, horizontally, forwards and backwards. The work holding portion driving mechanism 2b rotates the work holding portion that holds the work.

The control device 10 includes a CPU 11, a ROM 12, a RAM 13, a nonvolatile memory 14, an input/output interface (hereinafter referred to as an input/output I/F) 16, and the like. The CPU 11 reads the control program stored in the ROM 12 to the RAM 13, and controls the spindle drive mechanism 2a, the work holder drive mechanism 2b, and the like. The nonvolatile memory 14 is, for example, an EEPROM (registered trademark), an EPROM, a flash memory, or the like. A hard disk may be used instead of the nonvolatile memory 14 .

An operation signal is input from the operation unit 4 to the control device 10 via the input/output I/F 16 . Through the input/output I/F 16, a drive/stop signal is output from the control device 10 to the spindle drive mechanism 2a, the workpiece holder drive mechanism 2b, and the like.

The machine tool 100 includes a power supply 5, a power switch 6, and a relocation detection device 20 (a relocation detection unit). The power switch 6 switches the power supply 5 on/off.

The relocation detection device 20 detects whether the machine tool 100 has been illegally relocated or modified. For example, when the machine tool 100 is powered off and a vibration equal to or greater than a threshold is detected, the relocation detection device 20 transmits a signal (excess signal) indicating that the vibration value exceeds the threshold to the control device 10 .

The relocation detection device 20 includes a battery 27, a CPU 21 (determination unit), a ROM 22, a RAM 23, a nonvolatile memory 24, a voltage detection circuit 28, a vibration sensor 25, an input/output interface (hereinafter referred to as an input/output I/F) 26, and the like. have The CPU 21 reads the control program stored in the ROM 22 to the RAM 23 and executes processing for detecting relocation or modification of the machine tool 100 .

The nonvolatile memory 24 stores a threshold value for comparing vibration values detected by the vibration sensor 25 . The non-volatile memory 24 is, for example, an EEPROM (registered trademark), an EPROM, a flash memory, or the like. A hard disk may be used instead of the nonvolatile memory 24 .

Via the input/output I/F 16 , the power switch 6 inputs a signal indicating whether the power supply 5 is on or off to the control device 10 . A vibration sensor 25 detects the magnitude of vibration of the machine tool 100 . The vibration sensor 25 uses, for example, an acceleration sensor or a gyro sensor. When the vibration value detected by the vibration sensor 25 exceeds a preset threshold value, the CPU 21 outputs an excess signal to the control device 10 to that effect. Since the relocation detection device 20 has the battery 27, the above process can be executed even when the power source 5 is off.

The machine tool 100 according to the first embodiment uses the voltage detection circuit 28 to detect whether the relocation detection device 20 has been removed from the attached portion to which the relocation detection device 20 is attached. The voltage detection circuit 28 includes a metal plate 17 (attached portion) and a power supply 281 to be described later, detects the voltage of the power supply 281 and outputs the detection result to the CPU 21 . Details of the voltage detection circuit 28 will be described later. In the following, for convenience of explanation, the case where the relocation detection device 20 is provided in the control device 10 will be explained as an example.

If it is determined that the machine tool 100 has been illegally relocated or modified, the control device 10 and the relocation detection device 20 restrict the operation of the machine tool 100 thereafter. For example, when the machine tool 100 is powered off, the vibration sensor 25 detects vibration of the machine tool 100 , and if the detected vibration is greater than or equal to a threshold value, the relocation detection device 20 transmits an excess signal to the control device 10 . Upon receiving the excess signal, the control device 10 (CPU 11) outputs an instruction signal for displaying a warning to the display section 4a when the power is turned on, and prohibits the machine body 2 from operating. For example, the CPU 11 disables the drive signal for driving the spindle drive mechanism 2a or the workpiece holder drive mechanism 2b received from the operation unit 4 thereafter.

The control device 10 limits the operation of the machine tool 100 according to the excess signal output by the relocation detection device 20 . However, even if the machine tool 100 is illegally relocated or modified, the control device 10 cannot restrict the operation of the machine tool 100 unless the relocation detection device 20 outputs an excess signal. For example, if the relocation detection device 20 is detached from the machine tool 100 with illegal intent, the excess signal cannot be output from the relocation detection device 20, and the control device 10 cannot restrict the operation of the machine tool 100. . The machine tool 100 according to Embodiment 1 can deal with such problems.

FIG. 3 is an explanatory diagram for explaining attachment of the relocation detection device 20 in the machine tool 100 according to the first embodiment.
In machine tool 100 according to Embodiment 1, conductive stud bosses 171 and screws 172 are used to attach relocation detection device 20 to sheet metal 17 of control device 10 . Through holes penetrating through the substrate 29 in the thickness direction are formed at the four corners of the substrate 29 constituting the relocation detection device 20 , and screws 172 (fixing members) are inserted through the respective through holes and screwed to the stud bosses 171 . Then, the relocation detection device 20 (substrate 29 ) is fixed to the metal plate 17 . There are four stud bosses 171 : stud bosses 171 A to 171 D (fixing members), all of which are interposed between the substrate 29 and the sheet metal 17 . The substrate 29 is rectangular and insulative, and includes stud bosses 171A (first connection portion), stud bosses 171B (second connection portion), stud bosses 171C (third connection portion), and stud bosses 171D (not shown). (4th connecting portion) is energized through the metal plate 17 .

The voltage detection circuit 28 is formed on the board 29 of the relocation detection device 20 , and the voltage detection circuit 28 is a circuit including the power source 281 and the metal plate 17 as described above. The voltage detection circuit 28 detects the voltage of the power supply 281 and outputs it to the CPU 21 , and the CPU 21 determines whether the relocation detection device 20 has been removed and whether the power supply 281 is normal based on the voltage of the power supply 281 .

FIG. 4 is a schematic circuit diagram showing voltage detection circuit 28 of machine tool 100 according to the first embodiment.
The voltage detection circuit 28 further includes a reset IC 282 (voltage detection section), and the power supply 281 is composed of, for example, a 5V battery. That is, the voltage detection circuit 28 includes a power source 281 , reset IC 282 , stud bosses 171 , screws 172 and sheet metal 17 . Alternatively, instead of the power source 281, the battery 27 of the relocation detection device 20 may be used.

The anode side of the power supply 281 is branched into two at the connection node D1. One of the two is electrically connected to one end of the reset IC 282 , and the other end of the reset IC 282 is electrically connected to the first terminal 211 of the CPU 21 . The reset IC 282 is electrically connected to a conductor 283 (fixed potential) as GND.

The reset IC 282 detects the voltage of the power supply 281 and outputs a notification signal to the CPU 21 when the detected voltage is equal to or less than the threshold. For example, the reset IC 282 outputs a signal of 0 (zero) V (notification signal) to the CPU 21 when the voltage of the power supply 281 is below the threshold, and outputs a signal of 5V to the CPU 21 when the voltage of the power supply 281 exceeds the threshold. output to

The other branch of connection node D1 is electrically connected to one end of diode 284 . The other end of diode 284 is branched into two at connection node D2. One of the two is electrically connected to one end of the capacitor 285 and the other is electrically connected to the reset IC 282 . The other end of capacitor 285 is electrically connected to conductor 283 .

The cathode side of the power supply 281 is electrically connected to the stud boss 171A through the screw 172. As shown in FIG. That is, the stud boss 171A electrically connects the power source 281 and the metal plate 17. As shown in FIG. The stud boss 171A is electrically connected through the metal plate 17 to the stud boss 171B. Stud boss 171 B is electrically connected to conductor 283 . That is, the stud boss 171B is electrically connected to the reset IC 282 through the conductor 283. As shown in FIG.
In voltage detection circuit 28, current flows from power supply 281 through reset IC 282, conductor 283, stud boss 171B, sheet metal 17, and stud boss 171A in that order.

During normal operation, the capacitor 285 is charged by current from the power source 281 . Also, when the power supply 281 is turned off or the voltage detection circuit 28 is opened, the reset IC 282 is driven by power supply from the capacitor 285 . The diode 284 prevents current from flowing from the capacitor 285 to the power supply 281 side, and prevents the reset IC 282 from malfunctioning. Alternatively, the battery 27 may be used instead of the capacitor 285 .

When the notification signal is received from the reset IC 282 , the CPU 21 outputs an instruction signal to restrict the operation of the machine tool 100 to the control device 10 . The control device 10 limits the operation of the machine tool 100 when receiving the instruction signal output by the CPU 21 .
The CPU 21 is electrically connected to the conductor 283 via the second terminal 212 . Not limited to this, a GPU, a microcontroller, or the like may be used in place of the CPU 21 .

The operation of the voltage detection circuit 28 according to the first embodiment will be described below.
When the remaining amount of the power supply 281 exceeds the predetermined threshold and the relocation detection device 20 is fixed to the metal plate 17, the voltage detection circuit 28 is closed and the reset IC 282 outputs 5V to the CPU 21. The CPU 21 determines that the power supply 281 is normal based on the output from the voltage detection circuit 28 .

When the remaining amount of the power supply 281 is equal to or less than a predetermined threshold, specifically, when the power supply 281 is about to run out, or when the power supply 281 is removed, the reset IC 282 outputs 0V to the CPU 21 . Based on the output of the voltage detection circuit 28, the CPU 21 determines that the power supply 281 is abnormal. Further, the CPU 21 outputs an instruction signal for restricting the operation of the machine tool 100 to the control device 10 . The control device 10 limits the operation of the machine tool 100 according to the instruction signal output by the CPU 21 .

On the other hand, when the relocation detection device 20 is removed from the metal plate 17, at least one of the stud bosses 171A and 171B is separated from the metal plate 17, so that the voltage detection circuit 28 is opened and the reset IC 282 cannot detect the voltage of the power supply 281. Gone. Therefore, the reset IC 282 detects that the remaining amount of the power supply 281 is below the predetermined threshold, and outputs a notification signal (0 V) to the CPU 21 even if the remaining amount of the power supply 281 actually exceeds the predetermined threshold. Based on the output of the voltage detection circuit 28, the CPU 21 determines that the power supply 281 is abnormal, and outputs an instruction signal to restrict the operation of the machine tool 100 to the control device 10. FIG. The control device 10 limits the operation of the machine tool 100 according to the instruction signal output by the CPU 21 .

In this way, the machine tool 100 according to the first embodiment can be used when a third party removes the relocation detection device 20 from the metal plate 17 for the purpose of illegally relocating or remodeling the machine tool 100, or when the power source 281 is removed. When removed, it restricts operation of machine tool 100 . Therefore, unauthorized operation of the machine tool 100 can be prevented.

When a battery is used as the power source, a reset IC is used to monitor whether the battery runs out. Since the machine tool 100 according to Embodiment 1 uses the output of the reset IC 282 to detect removal of the relocation detection device 20, it can efficiently deal with unauthorized removal of the relocation detection device 20 with a simple structure and at low cost. .

The battery 27 may be used instead of the power supply 281 in the voltage detection circuit 28 without being limited to the above description. In this case, the number of parts can be reduced, and the weight and cost of the device can be reduced.

(Embodiment 2)
FIG. 5 is a schematic circuit diagram showing voltage detection circuit 28A of machine tool 100 according to the second embodiment.

Voltage detection circuit 28A includes power supply 281, reset IC 282, stud bosses 171A to 171D (screw 172), and sheet metal 17, as in the first embodiment. Alternatively, instead of the power source 281, the battery 27 of the relocation detection device 20 may be used.
Also, the connection state between the power supply 281, the reset IC 282, the diode 284, and the capacitor 285 is the same as in the first embodiment, and detailed description thereof will be omitted.

The cathode side of the power supply 281 is branched into two at a connection node D3. One of the two is electrically connected to the stud boss 171A, and the other is electrically connected to the stud boss 171B. That is, the stud bosses 171A and 171B are connected in parallel with the cathode side of the power source 281 to electrically connect the power source 281 and the metal plate 17 . The stud bosses 171A and 171B are electrically connected to the stud bosses 171C and 171D through the metal plate 17. As shown in FIG. Stud boss 171C and stud boss 171D are electrically connected to conductor 283 . The stud bosses 171C and 171D are electrically connected to the reset IC 282 through conductors 283. As shown in FIG.

In voltage detection circuit 28A, current flows from power supply 281 through reset IC 282, conductor 283, stud bosses 171C and 171D, sheet metal 17, and stud bosses 171A and 171B in this order.

The operation of the voltage detection circuit 28A according to the second embodiment will be described below.
When the remaining amount of the power supply 281 exceeds the predetermined threshold and the relocation detection device 20 is fixed to the metal plate 17, the voltage detection circuit 28A is closed and the reset IC 282 outputs 5V to the CPU 21. The CPU 21 determines that the power supply 281 is normal.

The reset IC 282 outputs 0 V to the CPU 21 when the remaining amount of the power supply 281 is equal to or less than a predetermined threshold. Based on the output of the voltage detection circuit 28A, the CPU 21 determines that the power supply 281 is abnormal. Further, the CPU 21 outputs an instruction signal for restricting the operation of the machine tool 100 to the control device 10 . The control device 10 limits the operation of the machine tool 100 according to the instruction signal from the CPU 21 .

On the other hand, when the relocation detection device 20 is removed from the metal plate 17, the voltage detection circuit 28A is in an open state, and the reset IC 282 cannot detect the voltage of the power supply 281. FIG. That is, when the stud boss 171A and stud boss 171B or the stud boss 171C and stud boss 171D are removed from the sheet metal 17, the reset IC 282 detects that the remaining amount of the power supply 281 is below a predetermined threshold, and actually the power supply 281 is A notification signal (0 V) is output to the CPU 21 even if the remaining amount exceeds the predetermined threshold. Based on the output of the voltage detection circuit 28A, the CPU 21 determines that the power supply 281 is abnormal, and outputs an instruction signal for restricting the operation of the machine tool 100 to the control device 10. FIG. The control device 10 limits the operation of the machine tool 100 according to the instruction signal from the CPU 21 .

In this manner, the machine tool 100 according to the second embodiment can be used when a third party removes the relocation detection device 20 from the metal plate 17 for the purpose of illegally relocating or remodeling the machine tool 100, or when the power supply 281 is removed. When removed, it restricts operation of machine tool 100 . Therefore, unauthorized operation of the machine tool 100 can be prevented.

Since the machine tool 100 according to Embodiment 2 uses the output of the reset IC 282 to detect removal of the relocation detection device 20, it can efficiently deal with unauthorized removal of the relocation detection device 20 with a simple structure and at low cost. .

The same reference numerals are assigned to the same parts as in the first embodiment, and detailed description thereof will be omitted.

(Embodiment 3)
FIG. 6 is a schematic circuit diagram showing voltage detection circuit 28B of machine tool 100 according to the third embodiment.

Voltage detection circuit 28B includes power supply 281, reset IC 282, stud bosses 171A to 171D (screw 172), and sheet metal 17, as in the first embodiment. Alternatively, instead of the power source 281, the battery 27 of the relocation detection device 20 may be used.
Also, the connection state between the power supply 281, the reset IC 282, the diode 284, and the capacitor 285 is the same as in the first embodiment, and detailed description thereof will be omitted.

The cathode side of the power supply 281 is branched into two at a connection node D3. One of the two is electrically connected to the stud boss 171A. The other is further branched into two at the connection node D4, one of which is electrically connected to the stud boss 171B and the other of which is electrically connected to the stud boss 171C. That is, the stud boss 171A, the stud boss 171B, and the stud boss 171C are connected in parallel with the cathode side of the power source 281 to electrically connect the power source 281 and the metal plate 17 . The stud bosses 171A to 171C are electrically connected to the stud boss 171D via the metal plate 17. As shown in FIG. Stud boss 171 D is electrically connected to conductor 283 . Stud boss 171D is electrically connected to reset IC 282 via conductor 283 .

In voltage detection circuit 28B, current flows from power supply 281 through reset IC 282, conductor 283, stud boss 171D, sheet metal 17, and stud bosses 171A-C in that order.

The operation of the voltage detection circuit 28B according to the third embodiment will be described below.
When the remaining amount of the power supply 281 exceeds a predetermined threshold and the relocation detection device 20 is fixed to the metal plate 17, the reset IC 282 outputs 5V to the CPU 21, and the CPU 21 determines that the power supply 281 is normal. .

When the remaining amount of the power supply 281 is equal to or less than a predetermined threshold, the reset IC 282 outputs 0V to the CPU 21, and the CPU 21 determines that the power supply 281 is abnormal. Further, the CPU 21 outputs an instruction signal for limiting the operation of the machine tool 100 to the control device 10 , and the control device 10 limits the operation of the machine tool 100 .

On the other hand, when the relocation detection device 20 is removed from the metal plate 17, the voltage detection circuit 28B is in an open state, and the reset IC 282 cannot detect the voltage of the power supply 281. FIG. That is, when the stud boss 171A, the stud boss 171B, the stud boss 171C, or the stud boss 171D is removed from the metal plate 17, the reset IC 282 detects that the remaining amount of the power supply 281 is below a predetermined threshold, and actually the remaining amount of the power supply 281 is A notification signal (0 V) is output to the CPU 21 even if the amount exceeds the predetermined threshold. In response to the notification signal, the CPU 21 determines that the power supply 281 is abnormal, and outputs an instruction signal to restrict the operation of the machine tool 100 to the control device 10 . Control device 10 limits the operation of machine tool 100 according to the instruction signal.

In this way, the machine tool 100 according to the third embodiment can be used when a third party removes the relocation detection device 20 from the metal plate 17 for the purpose of illegally relocating or remodeling the machine tool 100, or when the power supply 281 is removed. When removed, it restricts operation of machine tool 100 . In addition, it is possible to efficiently deal with unauthorized removal of the relocation detection device 20 with a simpler structure and at a lower cost.

Parts similar to those in the first or second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

In the above description, the case where the relocation detection device 20 is attached to the metal plate 17 using the stud bosses 171A to 171D has been described as an example, but the present invention is not limited to this. At least one of the stud bosses 171A to 171D is used to attach the relocation detection device 20 to the metal plate 17 at least one location, and the relocation detection device 20 and the metal plate 17 are electrically connected at other locations with copper wires or the like. can be

(Embodiment 4)
FIG. 7 is a schematic circuit diagram showing voltage detection circuit 28C of machine tool 100 according to the fourth embodiment.

Voltage detection circuit 28C includes power supply 281, reset IC 282, stud bosses 171A to 171D (screw 172), and metal plate 17, as in the first embodiment. Alternatively, instead of the power source 281, the battery 27 of the relocation detection device 20 may be used.
Also, the connection state between the power supply 281, the reset IC 282, the diode 284, and the capacitor 285 is the same as in the first embodiment, and detailed description thereof will be omitted.

The cathode side of power supply 281 is electrically connected to stud boss 171A. Stud boss 171A electrically connects power source 281 and sheet metal 17 . The stud boss 171A is electrically connected to the stud bosses 171B-171D through the metal plate 17. As shown in FIG. Stud bosses 171 B- 171 D are electrically connected to conductor 283 . The stud bosses 171B-171D are electrically connected to the reset IC 282 through conductors 283. As shown in FIG.

In voltage detection circuit 28C, current flows from power supply 281 through reset IC 282, conductor 283, stud bosses 171B-171D, sheet metal 17, and stud boss 171A in that order.

The operation of the voltage detection circuit 28C according to the fourth embodiment will be described below.
When the remaining amount of the power supply 281 exceeds a predetermined threshold and the relocation detection device 20 is fixed to the metal plate 17, the reset IC 282 outputs 5V to the CPU 21, and the CPU 21 determines that the power supply 281 is normal. .

When the remaining amount of the power supply 281 is equal to or less than a predetermined threshold, the reset IC 282 outputs 0V to the CPU 21, and the CPU 21 determines that the power supply 281 is abnormal. Further, the CPU 21 outputs an instruction signal for limiting the operation of the machine tool 100 to the control device 10 , and the control device 10 limits the operation of the machine tool 100 .

On the other hand, when the relocation detection device 20 is removed from the metal plate 17, the voltage detection circuit 28C is in an open state, and the reset IC 282 cannot detect the voltage of the power supply 281. FIG. That is, when the stud boss 171A or the stud bosses 171B to 171D are removed from the metal plate 17, the reset IC 282 detects that the remaining amount of the power supply 281 is below a predetermined threshold, and outputs a notification signal (0 V) to the CPU 21. do. In response to the notification signal, the CPU 21 determines that the power supply 281 is abnormal, and outputs an instruction signal to restrict the operation of the machine tool 100 to the control device 10 . Control device 10 limits the operation of machine tool 100 according to the instruction signal.

In this way, the machine tool 100 according to the fourth embodiment can be used when a third party removes the relocation detection device 20 from the metal plate 17 for the purpose of illegally relocating or remodeling the machine tool 100, or when the power source 281 is removed. When removed, it restricts operation of machine tool 100 . In addition, it is possible to efficiently deal with unauthorized removal of the relocation detection device 20 with a simpler structure and at a lower cost.

Parts similar to those of the first to third embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

In the above description, the case where the relocation detection device 20 is attached to the metal plate 17 using the stud boss 171 has been described as an example, but soldering may be used instead of this.
Also, in the above description, the case where the stud boss 171 is conductive has been described as an example, but the present invention is not limited to this. The voltage detection circuits 28, 28A to 28C and the metal plate 17 may be electrically connected by using an insulating stud boss 171 and a separate copper wire or electric wire.

17 sheet metal 20 relocation detection device 21 CPU
28, 28A to 28C voltage detection circuit 100 machine tool 171 stud boss 281 power source 282 reset IC
171A Stud boss (first connecting part)
171B Stud boss (second connecting part)
171C Stud boss (third connecting part)
171D Stud boss (4th connecting part)

Claims (8)

In a machine tool equipped with a relocation detection unit that detects relocation of its own machine,
a power supply included in the relocation detection unit;
an electrical circuit including an attached portion to which the relocation detection portion is attached and the power supply;
a voltage detection unit that detects the voltage of the power supply;
A determination unit that determines whether or not the relocation detection unit has been removed ,
A machine tool according to claim 1, wherein, when the voltage detection section becomes unable to perform the detection, the determination section determines that the relocation detection section is removed. The electrical circuit is
a first connecting portion that electrically connects the power supply and the attached portion;
2. The machine tool according to claim 1 , further comprising a second connecting portion electrically connected to said mounted portion and connected to said voltage detecting portion via a fixed potential. 3. The machine tool according to claim 2 , wherein at least one of said first connecting portion and said second connecting portion is a fixing member for fixing said relocation detecting portion to said attached portion. The electrical circuit is
a first connection portion and a third connection portion electrically connecting the power source and the attached portion and connecting in parallel from one terminal of the power source;
2. The machine tool according to claim 1 , further comprising a second connection portion and a fourth connection portion electrically connected to said mounting portion and connected to said voltage detection portion via a fixed potential. The electrical circuit is
a first connection portion, a third connection portion, and a fourth connection portion that electrically connect the power source and the attached portion and are connected in parallel from one terminal of the power source;
2. The machine tool according to claim 1 , further comprising a second connecting portion electrically connected to said mounted portion and connected to said voltage detecting portion via a fixed potential. The electrical circuit is
a first connecting portion that electrically connects the power supply and the attached portion;
2. The machine tool according to claim 1, further comprising a second connection portion, a third connection portion, and a fourth connection portion electrically connected to the mounted portion and connected to the voltage detection portion via a fixed potential. machine. At least one of the first connection portion, the second connection portion, the third connection portion, and the fourth connection portion is a fixing member for fixing the relocation detection portion to the attached portion. 7. The machine tool according to any one of Items 4 , 5 and 6 . In a determination method for determining removal of the relocation detection unit in a machine tool equipped with a relocation detection unit that detects relocation of the own machine,
The machine tool includes an electric circuit including an attached portion for attaching the relocation detection portion and a power source of the relocation detection portion,
detecting the voltage of the power supply;
A determination method , wherein when the detection is no longer possible, it is determined that the relocation detection unit is removed .

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