JP2010151741A - Apparatus and method for detecting vibration - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and low-cost apparatus for detecting a vibration, capable of electrically and precisely detecting the vibration applied to a machinery being in such the state that its electric power supply is interrupted, and to provide a method for detecting the vibration. <P>SOLUTION: The apparatus for detecting the vibration, which electrically detects the vibration of the machinery 1 being in the state that its electric power supply is interrupted externally, includes: a power supply means 87 composed of a capacitor or a secondary battery; a vibration detecting means 92 for detecting the vibration whose magnitude is equal to or more than a prescribed vibration level, through a MEMS switch, when the vibration is applied to the machinery; a vibration history memory means 93 for storing the presence or absence of the vibration detected by the vibration detecting means as a vibration history, through an electric circuit; a vibration history determining means for determining a vibration occurrence on the basis of the presence or absence of the vibration history stored in the vibration history memory means, in such the state that an electric power is supplied to the machinery externally; and an activation stopping means which inhibits the operation of activating the machinery when the vibration history determining means determines the vibration occurrence. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vibration detection device and a vibration detection method, and in particular, electrically detects vibration applied to a mechanical device in a state in which power supply from the outside is cut off, and determines presence or absence of vibration after restarting power supply. About things.

  Conventionally, in machine devices such as machine tools, it is necessary to prevent duplication of machinery, resale without permission, or export to countries where export is prohibited by law. Therefore, there is a technology that uses a vibration sensor, a direction sensor, GPS, or the like in order to detect movement from the installation location of the mechanical device. In this technique, when the power supply is disconnected and the movement of the mechanical device from the installation location is detected, the mechanical device is prohibited from being activated when the power is supplied to the mechanical device again by connecting to the power supply. This technology will not be used unless the person in charge at the manufacturer or dealer removes the prohibition.

For example, the vibration detection device of Patent Document 1 includes vibration detection means, vibration history storage means, activation prohibition means, and the like. The vibration detection means includes a heel, a coil spring, a proximity switch, and the like. The vibration history storage means includes a lever and a spring. In this vibration detection device, when vibration is applied to the mechanical device in a state where the power supply is cut off, the lever locks the hook when the vibration occurs at a predetermined vibration level or higher. Vibration is detected mechanically by detecting the movement of the bag with a proximity switch.
JP 2003-35595 A

  However, since the vibration detection device is configured to mechanically detect vibration, a large number of components such as a hook, a lever, and a spring are required. Therefore, the vibration detection device becomes large and the manufacturing cost increases. This vibration detection device needs to be provided separately from the machine tool. Therefore, extra installation space is required. The sensitivity of vibration detection depends on the vibration direction of the bag. Therefore, if the vibration detection device is not installed in consideration of the vibration direction of the mechanical device, vibration is added to the mechanical device in a direction orthogonal to the vibration direction of the bag, and the vibration cannot be sufficiently detected. There's a problem.

  An object of the present invention is to provide a vibration detection device and a vibration detection method capable of electrically and highly accurately detecting vibration applied to a mechanical device in a state in which power supply is cut off. Providing a device and a vibration detection method, and the like.

  The vibration detection apparatus according to claim 1 is a vibration detection apparatus that electrically detects vibration of a mechanical device in a state where electric power supply from the outside is interrupted, and a power source means including a capacitor or a secondary battery, and a predetermined amount for the mechanical device. A vibration detecting means for detecting the vibration through the MEMS switch when vibration of a vibration level or higher is applied, and a vibration for storing the presence / absence of the vibration detected by the vibration detecting means through the electric circuit as a vibration history The history storage means, the vibration history determination means for determining the occurrence of vibration from the presence or absence of the vibration history stored in the vibration history storage means in a state where electric power is supplied to the mechanical device from the outside, and the vibration history determination means And a start / stop means for prohibiting the start-up of the mechanical device when the occurrence of vibration is determined.

  In a state where power supply to the mechanical device is cut off from the outside, power is supplied to the vibration detection means and the vibration history storage means by the power supply means including a capacitor or a secondary battery. The vibration detection means detects a vibration of a predetermined vibration level or higher added to the mechanical device via the MEMS switch. The vibration history storage means stores the presence or absence of vibration detected by the vibration detection means via the electric circuit as a vibration history.

  In a state where electric power is supplied from the outside, the vibration history determination means determines the occurrence of vibration from the presence or absence of the vibration history stored in the vibration history storage means. When it is determined by the vibration history determination means that vibration has occurred, the start / stop means prohibits starting of the mechanical device. Therefore, when vibration exceeding a predetermined vibration level occurs between the time when power supply is interrupted and the time when power is supplied again, the mechanical device is prohibited from restarting.

  According to a second aspect of the present invention, there is provided the vibration detection device according to the first aspect, wherein the vibration history storage means comprises a flip-flop, and a reset signal for supplying a reset signal to the flip-flop when the external power supply is cut off. The generation means is provided.

  According to a third aspect of the present invention, in the first aspect of the present invention, the vibration history storage means includes a photodiode turned on by the vibration detection means, a phototransistor linked to the photodiode, and a series of the phototransistor. And a connected resistor.

  The vibration detection method according to claim 4 is a vibration detection method for electrically detecting vibration of a mechanical device in a state where electric power supply from the outside is cut off, and when vibration of a predetermined vibration level or higher is applied to the mechanical device. A vibration detection step of detecting the vibration via the MEMS switch, a vibration history storage step of storing the presence / absence of the vibration detected in the vibration detection step as a vibration history via an electric circuit, and an external device to the mechanical device In a state where power is supplied, a vibration history determination step for determining the occurrence of vibration from the presence or absence of the vibration history stored in the vibration history storage step; and the mechanical device when the occurrence of vibration is determined in the vibration history determination step. And a start / stop process for prohibiting start-up.

  According to the first aspect of the present invention, since it has the above-described configuration, it is possible to reliably detect and store vibrations exceeding a predetermined vibration level added to the mechanical device even when the power supply is cut off. . Since the vibration detecting means electrically detects the vibration via the MEMS switch, the vibration can be detected with high accuracy. Since the vibration detection apparatus of the present invention can be composed of a plurality of electronic components, it can be made compact. Since the vibration detection device can be manufactured using existing electronic components, the vibration detection device can be manufactured at low cost.

  According to the invention of claim 2, the vibration history storage means includes a flip-flop, and when a power supply from the outside is cut off, a reset signal generating means for supplying a reset signal to the flip-flop is provided. The vibration history of the flip-flop can be reset by the reset signal generating means.

According to a third aspect of the present invention, the vibration history storage means includes a photodiode that is turned on by the vibration detection means, a phototransistor linked to the photodiode, and a resistor connected in series to the phototransistor. Thus, the vibration history can be stored by turning on the photodiode and keeping a predetermined current flowing through the resistor via the phototransistor.
According to invention of Claim 4, there exists an effect similar to Claim 1.

  Hereinafter, the best mode for carrying out the present invention will be described based on examples.

First, the machine tool 1 to which the vibration detection device of the present invention is applied will be described.
A machine tool 1 shown in FIG. 1 is a numerically controlled machining center capable of performing desired machining (for example, “drilling”, “cutting”, etc.) on a workpiece by moving the workpiece and the tool relative to each other. is there. The machine tool 1 (corresponding to a machine device) includes an iron base 2 that serves as a base, a machine body 3 that is fixed to the upper part of the base 2 and performs workpiece cutting, and is fixed to the base 2. A box-shaped splash cover 4 that covers the upper portion of the main body 3 and the base 2 is provided.

  As shown in FIGS. 1 and 2, the base 2 is formed in a substantially rectangular parallelepiped shape that is long in the Y-axis direction (the direction perpendicular to the plane of FIG. 1). The machine tool 1 is installed at a predetermined installation location by providing leg portions 2a capable of height adjustment at the four corners of the lower portion of the base 2 and installing these four leg portions 2a on the floor of a factory or the like. .

  The machine main body 3 and its processing area are provided inside the splash cover 4. An opening (not shown) is provided on the front surface of the splash cover 4, and a pair of sliding opening / closing doors 5 and 6 are provided in the opening.

  The open / close doors 5 and 6 are provided with rectangular glass window portions 5a and 6a, respectively, at substantially the center thereof. The open / close door 5 has a handle 5b at the right end thereof. The opening / closing door 6 has a handle 6b at the left end thereof. The opening portions are opened by opening these handle portions 5b, 6b away from each other, and the operator attaches / detaches the workpiece to / from a table (not shown) fixed to the upper portion of the base 2.

  A rectangular operation panel 80 for operating the machine tool 1 is provided on the right side of the front opening. The operation panel 80 includes a keyboard 81 having a numeric keypad and various operation switches, and a display 82. The display 82 is for displaying a setting screen or an execution operation, and is provided above the keyboard 81.

  The operator operates the keyboard 81 while checking the display 82 of the operation panel 80, thereby setting a machining program for executing machining of the workpiece, tool information, various parameters, and the like.

Next, the machine body 3 will be described.
As shown in FIG. 2, the machine body 3 includes a column 5, a spindle head 7, a spindle 9, a tool changer (ATC) 20, and a table 10. The column 5 is fixed to the upper surface of the column seat portion 4 on the rear portion of the base 2 and extends vertically upward. The spindle head 7 is provided so as to be movable up and down along the front surface of the column 5. The main shaft head 7 supports the main shaft 9 in a rotatable manner.

  The automatic tool changer 20 is provided on the right side of the spindle head 7 and automatically changes a tool holder with a tool attached to the tip of the spindle 9 based on a machining program. A table 10 is provided on the upper part of the base 2, and a workpiece is fixed to the table 10 so as to be detachable. A box-shaped control box 6 is provided on the back side of the column 5. A numerical controller 50 (see FIG. 3) for controlling the operation of the machine tool 1 is provided inside the control box 6.

Next, the moving mechanism of the table 10 will be described.
As shown in FIGS. 2 and 3, the table 10 is driven by an X-axis motor 71 and a Y-axis motor 72, which are servo motors, in the X-axis direction (the left-right direction of the machine body 3) and the Y-axis direction (the depth of the machine body 3). Direction). This moving mechanism has the following configuration. A rectangular parallelepiped support base 12 is provided below the table 10. A pair of X-axis feed guides extending along the X-axis direction are provided on the upper surface of the support base 12, and the table 10 is movably supported on the pair of X-axis feed guides.

  A support base 12 is provided on the upper portion of the base 2 and is movably supported on a pair of Y-axis feed guides extending along the longitudinal direction of the base 2. The table 10 is driven to move in the Y-axis direction along the Y-axis feed guide by a Y-axis motor 72 provided on the base 2. The table 10 is driven to move in the X-axis direction along the X-axis feed guide by an X-axis motor 71 provided on the support base 12.

  Telescopic covers 13 and 14 that contract in a telescopic manner are provided on the left and right sides of the table 10 in the X-axis feed guide. In the Y-axis feed guide, a telescopic cover 15 and a Y-axis rear cover are provided before and after the support base 12, respectively. The X-axis feed guide and the Y-axis feed guide are always covered with telescopic covers 13, 14, 15 and a Y-axis rear cover. Therefore, it is possible to prevent the chips scattered from the processing region, the splash of coolant liquid, and the like from falling on each axis feed guide.

Next, the raising / lowering mechanism of the spindle head 7 will be described.
As shown in FIG. 2, the spindle head 7 is supported by a guide rail extending in the vertical direction on the front side of the column 5 so as to be movable up and down via a linear guide. The spindle head 7 is connected to a feed screw extending in the vertical direction on the front side of the column 5 by a nut. The spindle head 7 is driven up and down in the vertical direction by rotationally driving the feed screw in the forward and reverse directions by a Z-axis motor 73 (see FIG. 2).

Next, the main shaft 9 will be described.
As shown in FIG. 2, the spindle 9 is rotationally driven by a spindle motor 74 provided on the upper part of the spindle head 7. A holder mounting hole (not shown) that increases in diameter toward the tip is provided in the tip side portion of the main shaft 9. As shown in FIG. 2, the automatic tool changer 20 grips and transports a tool magazine 21 that stores a plurality of tool holders with tools, a tool holder removed from the spindle 9, and a tool holder attached to the spindle 9. For example, a tool change arm 22 is provided. The tool magazine 21 includes a plurality of tool pots that support the tool holder and a transport mechanism that transports the tool pots within the tool magazine 21.

Next, the electrical configuration of the numerical controller 50 will be described.
As shown in FIG. 3, the numerical controller 50 includes a microcomputer including a CPU 51, a ROM 52, and a RAM 53, an input interface 54, and an input / output interface 55. A keyboard 81 of the operation panel 80 is electrically connected to the input interface 54. The ROM 52 stores various control programs. The RAM 53 is provided with a data storage area for storing display data such as various machining loads acquired during machining of the workpiece and various work memories.

  The input / output interface 55 drives an X-axis drive circuit 61, a Y-axis drive circuit 62, a Z-axis drive circuit 63, a spindle drive circuit 64 that drives the spindle motor 8, and a display 82 of the operation panel 80. CRT drive circuit 65, pump drive circuits 67 and 68 for driving pumps 75 and 76 for supplying coolant liquid to the center holes of the injection nozzle and tool, and a vibration detection circuit 85 for detecting vibration applied to the machine tool. Each is electrically connected.

  An X-axis motor 71 with an encoder 71a is connected to the X-axis drive circuit 61. An X-axis motor 72 with an encoder 72a is connected to the Y-axis drive circuit 62. A Z-axis motor 73 with an encoder 73a is connected to the Z-axis drive circuit 63. A Z-axis motor 74 with an encoder 74a is connected to the main shaft drive circuit 64.

  Based on the control signal from the CPU 51 of the numerical controller 50, the X-axis drive circuit 61, the Y-axis drive circuit 62, and the Z-axis drive circuit 63 drive the X-axis motor 71, the Y-axis motor 72, and the Z-axis motor 73, respectively. Thus, the table 10 can be moved to a desired position, and the spindle head 7 can be moved to a desired position in the height direction.

Next, the vibration detection device equipped in the machine tool 1 will be described.
The vibration detection device is a device that electrically detects vibration generated in the machine tool in a state where the external power supply is cut off. The vibration detection device includes a vibration detection circuit 85 and a vibration detection circuit 85. It is comprised with the numerical control apparatus 50 electrically connected.

  As shown in FIG. 4, the vibration detection circuit 85 is constituted on the same substrate by an AC / DC converter 86, a capacitor 87, a MEMS switch 92, a flip-flop 93, a one-shot circuit 94, and the like. . The vibration detection circuit 85 is incorporated in the control box 6 of the machine tool 1 and electrically detects and stores vibration applied to the machine tool 1 in a state where the external power supply is cut off. is there.

  The AC / DC converter 86 (hereinafter referred to as a converter) rectifies AC power supplied from an external factory power source to the vibration detection circuit 85 into, for example, DC power of 3 V to 5 V, and via a power signal line 89. This is supplied to the one-shot circuit 94, the MEMS switch 92, and the flip-flop 93. The converter 86 and the capacitor 87 are connected via a forward diode 88. The diode 88 is for preventing a backflow of current from the capacitor 87 to the converter 86 side. The converter 86 may be omitted, and direct current power rectified by a converter provided outside may be directly supplied.

  A capacitor 87 (corresponding to a power supply means) is connected to the power signal line 89 and the ground. The capacitor 87 is, for example, a large-capacity electric double layer capacitor. The capacitor 87 is charged while electric power is supplied through the converter 86. When the power supply is cut off, the capacitor 87 supplies drive power to the flip-flop 93 and the one-shot circuit 94. Instead of the capacitor 87, a secondary battery such as a nickel cadmium battery, a nickel metal hydride battery, or a lithium ion battery may be used.

  The MEMS switch 92 (corresponding to vibration detecting means) has a thin film movable electrode 92a that vibrates in response to external vibration, a capacitor side electrode 92b, and a thin film ground side electrode 92c. One end of the movable electrode 92 a is connected to the flip-flop 93. The other end of the movable electrode 92a contacts the capacitor side electrode 92b in the absence of vibration, and swings between the capacitor side electrode 92b and the ground side electrode 92c when vibration is applied.

  When a vibration of a predetermined vibration level or higher is applied, when the movable electrode 92a comes into contact with the ground side electrode 92c, the MEMS switch 92 is turned on. Therefore, the switch 92 outputs “H” level in the OFF state and outputs “L” level in the ON state. This output is input to the clock terminal CK of the flip-flop 93. In this vibration detection circuit 85, the “H” level voltage value is the power supply voltage, and the “L” level voltage value is 0V.

  The flip-flop 93 (corresponding to the vibration history storage means) stores the presence / absence of vibration detected by the MEMS switch 92 through the electric circuit as vibration history. A converter 86 is connected to the input terminal D via a diode 88. A MEMS switch 92 is connected to the clock terminal CK, a one-shot circuit 94 is connected to the reset terminal R, and an input / output interface 55 of the numerical controller 50 is connected to the output terminal Q. The flip-flop 93 outputs “H” level when the MEMS switch 92 detects vibration, and outputs “L” level when there is no vibration.

  A one-shot circuit 94 (corresponding to a reset signal generating means) resets the flip-flop 93. The input side of the one-shot circuit 94 is connected to the converter 86, and the output side is connected to the reset terminal R of the flip-flop 93. When the power supply from the converter 86 is cut off, the one-shot circuit 94 transmits a pulse signal (reset signal) to the flip-flop 93. The one-shot circuit 94 transmits a pulse signal when the CPU 51 inputs the input signal B to the one-shot circuit 94 via the amplifier 96 when the machine tool 1 is started.

Next, the operation of the vibration detection circuit 85 will be described. The description of this action includes a part of the vibration detection method.
As shown in the time chart of FIG. 5, when the power supply from the factory power supply is interrupted, the one-shot circuit 94 detects this interruption and automatically transmits a pulse signal to the reset terminal R of the flip-flop 93. , The flip-flop 93 is reset. That is, the output terminal Q becomes “L” level regardless of the immediately preceding state. The input terminal D of the flip-flop 93 is always inputted with the “H” level by the charging power of the capacitor 87 even if the power supply is cut off from the outside. The “H” level is input from the MEMS switch 92 to the clock terminal CK.

  When vibration is applied to the machine tool 1, the movable electrode 92a of the MEMS switch 92 vibrates. When this vibration exceeds a predetermined vibration level, the movable electrode 92a comes into contact with the ground-side electrode 92c. The MEMS switch 92 is turned ON, and the “L” level is transmitted to the clock terminal CK of the flip-flop 93 (corresponding to a vibration detection process). This signal becomes a trigger, and the output of the output terminal Q of the flip-flop 93 is switched from the “L” level to the “H” level. When the output of the output terminal Q becomes “H” level, even if the input signal to the clock terminal CK repeats “L⇔H”, the output of the output terminal Q is inputted with “H” level to the input terminal D. As long as it is, the “H” level state is maintained (corresponding to the vibration history storing step).

Next, the start / stop control executed by the microcomputer of the numerical controller 50 will be described based on the flowchart of FIG. In the figure, Si (i = 1, 2,...) Indicates each step. Note that the description of the start / stop control includes a description of the rest of the vibration detection method.
This start / stop control is executed when power is supplied again after the external power supply to the machine tool 1 is cut off. First, when the start / stop control is started when the power supply is started again to the machine tool 1 from which the external power supply is cut off, the machine tool 1 is first started (S1).

  Next, the output of the flip-flop 93 is confirmed (S2). Specifically, it is determined whether or not the output of the output terminal Q is at “H” level, and the occurrence of vibration is determined from the presence or absence of this vibration history. At this time, if vibration has occurred while the power supply is cut off, the output of the flip-flop 93 becomes “H” level. Therefore, in S2, it is determined whether or not the output of the flip-flop 93 is at the “H” level. If the determination is Yes, the process proceeds to S3. On the other hand, in the case of “L” level, this control is terminated and the activated state of the machine tool 1 is maintained. If it is determined that vibration has occurred (S2; Yes), the automatic operation start of the machine tool 1 is stopped in S3, and the process proceeds to S4. Note that S2 corresponds to a vibration history determination unit and a vibration history determination step, and S3 corresponds to a start / stop unit and a start / stop step.

  In S4, password input is displayed on the display 82. When the password is input by operating the keyboard 81, the process proceeds to S5. In S5, it is determined whether or not the input password is correct. When it is determined that the password is correct (S5; Yes), the process proceeds to S7. When it is determined that the password is not correct (S5; No), a warning message is displayed on the display 82 (S6), and the password input is requested again (S4).

  If the password is correct, the automatic operation start / stop of the machine tool 1 is canceled in S7, and if the warning message is displayed on the display 82, the warning message is released. Then, the process proceeds to S8, where the CPU 51 transmits the input signal B, the one-shot circuit 94 transmits a pulse signal to the flip-flop 93, and the flip-flop 93 is reset. Thereafter, this process is terminated.

Next, the operation and effect of the vibration detection apparatus described above will be described.
In a state where power supply to the machine tool 1 is cut off from the outside, power is supplied to the MEMS switch 92, the flip-flop 93, and the one-shot circuit 94 by the capacitor 87. The MEMS switch 92 detects vibrations of a predetermined vibration level or higher added to the machine tool 1. The flip-flop 93 stores the presence / absence of vibration detected by the MEMS switch 92 via an electric circuit as a vibration history.

  Therefore, even when the power supply is cut off, vibrations exceeding the predetermined vibration level added to the machine tool 1 can be reliably detected and stored. Since the MEMS switch 92 electrically detects vibration, the vibration detection circuit 85 can detect vibration with high accuracy. Since the vibration detection circuit 85 is composed of a plurality of electronic components, the vibration detection circuit 85 is small. Since the vibration detection circuit 85 can be manufactured in a small size using existing electronic components, the vibration detection circuit 85 can be manufactured at low cost.

  In a state where power is supplied from the outside, the CPU 51 determines the occurrence of vibration from the presence or absence of the vibration history stored in the flip-flop 93. When the CPU 51 determines that vibration has occurred, the CPU 51 prohibits the start of the machine tool 1. Therefore, in order to move the machine tool 1 to another location, the vibration of the predetermined vibration level or higher is caused by the movement of the machine tool 1 or the like until the electric power supply from the outside is once cut off and the electric power is supplied again. When this occurs, restart of the machine tool 1 is prohibited.

  Since the one-shot circuit 94 for supplying a pulse signal for resetting to the flip-flop 93 when the external power supply is cut off, the vibration history is stored by the flip-flop 93, and the one-shot circuit 94 The vibration history of the flip-flop 93 can be reset.

An example in which the vibration detection circuit 85 of the first embodiment is partially changed will be described. However, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIG. 7, the vibration detection circuit 85A is configured on the same substrate by an AC / DC converter 86A, a capacitor 87A, a MEMS switch 92A, a photocoupler 103, a plurality of resistors 102 and 107, and the like. Since the AC / DC converter 86A, the capacitor 87A, and the diode 88A are the same as those in the first embodiment, description thereof is omitted.

  The MEMS switch 92A (corresponding to vibration detecting means) has a thin film movable electrode 92d that can be swung by vibration, and a thin film ground electrode 92e. One end of the movable electrode 92d is connected to the cathode of the photodiode 104 and the collector of the phototransistor 106 through a power signal line. The movable electrode 92d is not in contact with the ground-side electrode 92e when no vibration is applied. When vibration of a predetermined vibration level or higher is applied to the machine tool 1, the movable electrode 92d contacts the ground side electrode 92e. The resistor 102 is for limiting the current flowing to the ground when the MEMS switch 92A is turned on.

  The photocoupler 103 includes a photodiode 104 that is turned on by the MEMS switch 92 </ b> A and a phototransistor 106 that is linked to the photodiode 104. The anode of the photodiode 104 is connected to the capacitor 87A and the diode 88A via the resistor 102. The cathode of the photodiode 104 is connected to the movable electrode 92d of the MEMS switch 92A and the collector of the phototransistor 106. A resistor 107 is connected in series to the emitter of the phototransistor 106. A numerical controller 50 is connected to the emitter of the phototransistor 106 and detects the output voltage A of the resistor 107.

Next, the operation of the vibration detection circuit 85A will be described. This description includes a part of the vibration detection method.
When vibration is applied to the machine tool 1, the movable electrode 92d of the MEMS switch 92A vibrates. When this vibration exceeds a predetermined vibration level, the movable electrode 92d comes into contact with the ground electrode 92e, and the photodiode 104 is energized and emits light. Due to the light emission of the photodiode 104, the phototransistor 106 is turned on, and the phototransistor 106 can be energized from the collector to the emitter (corresponding to a vibration detection step).

  In this state, when the movable electrode 92d is separated from the ground side electrode 92e, no current flows through the MEMS switch 92A. Here, since the phototransistor 106 is ON, this current flows between the collector and the emitter of the phototransistor 106. Therefore, when the MEMS switch is turned OFF, a closed circuit is formed from the capacitor 87A, the resistor 102, the photodiode 104, the phototransistor 106, and the resistor 107.

  Even if the MEMS switch 92A is repeatedly turned ON / OFF by vibration, the ON state of the photocoupler 103 is maintained. For this reason, the above-mentioned closed circuit is maintained even if the machine tool 1 is arranged in a stable state and vibrations are settled. In this closed circuit, the current limited by the resistors 102 and 107 flows from the capacitor 87A through the closed circuit (corresponding to the vibration history storing step). Note that the vibration history storage means includes a photodiode 104, a phototransistor 106, and a resistor 107.

  Next, the start / stop control executed by the numerical controller 50 will be described based on the flowchart of FIG. The same steps as those in the start / stop control in FIG. The description of the start / stop control includes a description of the remaining part of the vibration detection method.

In S <b> 2 </ b> A, the numerical controller 50 detects the output voltage A between the phototransistor 106 and the resistor 107. Specifically, it is determined whether or not the output voltage A is generated, and the occurrence of vibration is determined from the presence or absence of this vibration history. When vibration is generated to move the machine tool 1 to another place in a state where the power supply to the machine tool 1 is cut off, the photocoupler 103 is maintained in an ON state, and current continues to flow through the resistor 107. The output voltage A becomes “H”.
If the output voltage A is generated according to the determination of S2A (S2; Yes), the process proceeds to S3. When the output voltage A is 0 V (S2; No), this control is terminated and the activated state of the machine tool 1 is maintained.

  In S <b> 8 </ b> A, the numerical controller 50 transmits an input signal B from the CPU 51 in order to turn off the photocoupler 103. This input signal B instantaneously sets the output side of the capacitor 87 A to 0 V or below the threshold voltage of the photodiode 104 via the inverter 108. Accordingly, no current flows through the photodiode 104, the phototransistor 106 is turned off, and the photocoupler 103 is turned off. Other configurations, operations, and effects are the same as those in the first embodiment.

Next, a modified example in which the embodiment is partially modified will be described.
1] In the first and second embodiments, the vibration history storage means is not limited to the flip-flop 93, the photocoupler 103, and the resistor 107, but may electrically store the presence or absence of vibration in the machine tool 1. It ’s fine.

2] Although the first and second embodiments have been described by way of example in which the present invention is applied to the machine tool 1, the present invention can also be applied to various machine devices other than the machine tool 1.

1 is a front view of a numerically controlled machine tool according to a first embodiment of the present invention. It is a perspective view of the machine main body of a numerical control type machine tool. It is a block diagram of a numerical controller. It is a block diagram of a vibration detection circuit. It is a time chart figure explaining the operation of a vibration detection circuit. It is a flowchart figure of start stop control. 6 is a block diagram of a vibration detection circuit according to Embodiment 2. FIG. It is a flowchart figure of start stop control.

Explanation of symbols

1 Machine tool 50 Numerical control device 51 CPU
85, 85A Vibration detection circuit 87, 87A Capacitor 92, 92A MEMS switch 93 Flip-flop 94 One-shot circuit 103 Photocoupler 104 Photodiode 106 Phototransistor 107 Resistance

Claims (4)

In the vibration detection device that electrically detects the vibration of the mechanical device in a state where the power supply from the outside is cut off,
Power supply means comprising a capacitor or a secondary battery;
Vibration detection means for detecting the vibration via a MEMS switch when vibration of a predetermined vibration level or more is applied to the mechanical device;
Vibration history storage means for storing presence / absence of vibration detected by the vibration detection means as vibration history via an electric circuit;
Vibration history determination means for determining the occurrence of vibration from the presence or absence of vibration history stored in the vibration history storage means in a state where electric power is supplied to the mechanical device from the outside;
Start / stop means for prohibiting start of the mechanical device when the vibration history determination means determines the occurrence of vibration;
A vibration detection apparatus comprising: The vibration history storage means includes a flip-flop,
2. The vibration detection device according to claim 1, further comprising reset signal generating means for supplying a reset signal to the flip-flop when the external power supply is cut off.   2. The vibration history storage means includes a photodiode that is turned on by the vibration detection means, a phototransistor linked to the photodiode, and a resistor connected in series to the phototransistor. The vibration detection apparatus according to 1. In the vibration detection method for electrically detecting the vibration of the mechanical device in a state where the external power supply is cut off,
A vibration detecting step of detecting vibrations via a MEMS switch when vibrations of a predetermined vibration level or higher are applied to the mechanical device;
A vibration history storage step of storing the presence or absence of vibration detected in the vibration detection step as a vibration history via an electric circuit;
A vibration history determination step for determining the occurrence of vibration from the presence or absence of the vibration history stored in the vibration history storage step in a state where electric power is supplied to the mechanical device from the outside;
A start / stop step for prohibiting start of the mechanical device when the vibration occurrence is determined in the vibration history determination step;
A vibration detection method comprising: