JP7241295B2 - Servo motor drive device, galvano drive device, and laser processing device - Google Patents

Description

The present invention relates to a servo motor driving device, a galvano driving device in which a galvano scanner is driven by the servo motor, and a laser processing apparatus provided with the galvano driving device.

A laser processing apparatus performs two-dimensional scanning of a laser beam output from a laser light source with a galvanometer scanner to mark characters, symbols, figures, etc. on a surface to be processed, or to perform drilling, cutting, and the like.

In the galvanometer scanner, the galvanometer mirror is rotated based on the rotation of the output shaft of the servomotor, and the laser beam is scanned on the XY plane. The output shaft of the servomotor is supported by a bearing (ball bearing) provided inside the case of the servomotor.

Abrasion of the bearing hinders smooth rotation of the output shaft of the servomotor, and in the galvanometer scanner, hinders smooth rotation of the galvanomirror, resulting in a decrease in scanning accuracy.
Therefore, by performing feedback control based on the deviation between the target rotational position (angle) of the galvano mirror and the actual rotational position (angle), the actual rotational position is matched with the target rotational position. A servo motor driving device has been proposed which is controlled in such a way as to

Patent Documents 1 to 6 are known as prior art documents related to such a servo motor driving device.

JP-A-2003-23792 Japanese Patent Application Laid-Open No. 2007-32712 Japanese Patent Application Laid-Open No. 2003-191083 JP 2013-167777 A JP-A-04-127980 JP-A-09-38787

In the servo motor drive device having the feedback control function as described above, since the deviation of the rotational position of the output shaft due to wear of the bearing is corrected, it is difficult to determine the fine degree of wear of the bearing.

Therefore, if the deviation between the target rotational position and the actual rotational position of the output shaft becomes large while feedback control is being performed, the servomotor needs to be replaced. As a result, for example, if the servomotor needs to be replaced while the galvanometer scanner is in operation in a laser processing apparatus, work efficiency is reduced due to the repair work.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and its object is to provide a servomotor drive device, a galvanometer drive device, and a laser processing device that can detect wear of a drive motor bearing at an early stage. .

A galvano-driving device for solving the above-mentioned problems comprises galvano-driving means for rotating a galvano-mirror by rotation of an output shaft of a drive motor, and causing the galvano-driving means to rotate the galvano-mirror to a preset rotational position. drive control means for outputting a drive signal; rotation state detection means for detecting the rotation state of the galvanomirror based on the drive signal and outputting a rotation state signal; and detection of the drive signal and the rotation state signal. In the galvanometer drive device having a feedback control section that corrects the drive signal and supplies it to the drive motor so as to correct the deviation, the drive control means has a determination mode for outputting a drive signal for determination, wear detecting means for detecting the degree of wear of the bearing of the output shaft based on the rotational state of the galvanomirror based on the drive signal for determination; It is characterized by comprising switching means for supplying a signal only to the wear detection means.

With this configuration, since the operation of the feedback control section is disabled in the determination mode, it is possible to detect the fine degree of wear of the bearing of the drive motor from the rotation state signal.
Further, in the above galvanometer drive device, the drive control means outputs a determination drive signal for rotating the entire effective rotation range of the galvanometer mirror in the determination mode, and the wear detection means outputs the determination drive signal. It is preferable to detect the degree of wear over the entire effective rotation range of the galvanomirror based on the rotation state signal based on the drive signal.

With this configuration, the degree of wear can be detected over the entire effective rotation range of the galvanomirror in the judgment mode.
Further, in the above galvanometer drive device, the drive control means outputs a determination drive signal for repeatedly rotating the galvanometer mirror in the determination mode, and the wear detection means rotates based on the determination drive signal. It is preferable to detect the degree of wear of the bearing of the output shaft based on the dynamic state signal.

With this configuration, the galvanomirror is repeatedly rotated and the rotation state signal and the reference value are compared, thereby improving the detection accuracy of the degree of wear.
Further, in the above galvanometer drive device, the drive control means outputs a determination drive signal for repeatedly rotating the galvanometer mirror in the reciprocating direction in the determination mode, and the wear detection means outputs the determination drive signal It is preferable to detect the degree of wear of the bearing of the output shaft over the reciprocating direction of the galvanomirror based on the rotational state signal based on.

With this configuration, it is possible to detect the degree of wear of the bearing of the output shaft when the galvanomirror moves forward and backward, thereby improving the detection accuracy of the degree of wear.
Further, in the above galvanometer drive device, it is preferable that the drive control means outputs a trapezoidal wave as the determination drive signal.

With this configuration, the torque for rotating the galvanomirror is gradually increased over time and then gradually decreased to generate the rotation state signal, thereby improving the detection accuracy of slight wear.

Further, in the above galvanometer drive device, the drive control means outputs a drive position signal for rotating the galvanometer mirror to a preset rotation position as the drive signal, and outputs a drive signal for determination as the drive signal for determination. A driving position monitor (observation) signal is output, and the wear detection means detects the rotational position of the galvanomirror based on the driving position monitor (observation) signal for determination as the rotational state signal and a current position signal obtained in advance. It is preferable to detect the degree of wear of the bearing of the output shaft by comparing with a set reference value.

With this configuration, since the operation of the feedback control section is disabled in the determination mode, it is possible to detect the fine degree of wear of the bearing of the drive motor from the current position signal.
Further, in the galvanometer driving device described above, it is preferable that the drive control means shifts to the determination mode following power-on.

With this configuration, the degree of wear can be detected when the galvanometer drive device is started up, so the galvanometer drive device and the laser processing apparatus are prevented from operating in a state where wear is progressing.
Further, in the above galvanometer drive device, the drive control means shifts to the determination mode when power is shut down, and the wear detection means includes storage means for storing detection results in the determination mode, and when the power is turned on again. and an output means for outputting the detection result stored in the storage means.

With this configuration, when the power is shut down, the mode is shifted to the determination mode, the detection result is stored in the storage means, and when the power is turned on again, the detection result is output by the output means, so the galvanometer driving device in a state where wear has progressed. operation can be prevented.

Further, the galvanometer drive device described above includes temperature detection means for outputting a current temperature signal obtained by detecting the temperature of the drive motor to the wear detection means, and the wear detection means detects the current temperature based on the current temperature signal. Preferably, either the position signal or the reference value is temperature-corrected.

With this configuration, even if the viscosity of the bearing grease changes due to a change in the temperature of the drive motor, the detection accuracy of the degree of wear of the bearing does not deteriorate.
A laser processing apparatus for solving the above problems irradiates a laser beam emitted from a laser light source onto a surface to be processed through a galvanometer mirror rotated by the galvanometer driving device according to any one of the above. Characterized by

With this configuration, since the operation of the feedback control section is disabled in the determination mode, it is possible to detect the fine degree of wear of the bearing of the drive motor from the current position signal. Prediction of the replacement timing of the drive motor is facilitated, and replacement of the drive motor can be performed at a time other than when the laser processing apparatus is in operation.

A servo motor driving device for solving the above problems comprises a servo motor, a servo motor driving means for driving the servo motor, a drive control means for outputting a driving signal to the servo motor driving means, and the Rotational state detection means for detecting the rotational state of the output shaft of the servo motor and outputting a rotational state signal; and Correcting the drive signal so as to correct a deviation between the drive signal and the rotational state signal. and a feedback control unit for supplying the servomotor with a feedback control unit, wherein the drive control unit has a determination mode for outputting a determination drive signal, and rotates the servomotor based on the determination drive signal. wear detection means for detecting the degree of wear of the bearing of the output shaft based on the state; and switching means for invalidating the operation of the feedback control section in the judgment mode and supplying the rotation state signal only to the wear detection means. characterized by comprising

With this configuration, since the operation of the feedback control section is disabled in the determination mode, it is possible to detect the fine degree of wear of the bearing of the servomotor from the rotation state signal.

According to the servo motor driving device, the galvano driving device, and the laser processing device of the present invention, wear of the bearing of the driving motor can be detected early.

1 is a block diagram showing a laser processing apparatus according to a first embodiment; FIG. FIG. 2 is a block diagram showing the configuration during normal operation of the laser processing apparatus of the first embodiment; FIG. 2 is a block diagram showing the configuration of the laser processing apparatus according to the first embodiment at the time of wear determination; FIG. 4 is an explanatory diagram showing the rotation range of the output shaft of the drive motor; FIG. 5 is an explanatory diagram showing the rotation range of the output shaft of the drive motor in the determination mode; FIG. 5 is an explanatory diagram showing the rotation operation of the output shaft of the drive motor in the determination mode; FIG. 4 is an explanatory diagram showing a driving position monitor (observation) signal for judgment; Explanatory drawing which shows the present position signal at the time of determination mode. FIG. 5 is an explanatory diagram showing the rotation operation of the output shaft of the drive motor in the determination mode; FIG. 4 is an explanatory diagram showing a driving position monitor (observation) signal for judgment; 4 is a flow chart showing the operation of the laser processing apparatus; 4 is a flow chart showing the operation of the laser processing apparatus; The block diagram which shows the laser processing apparatus of 2nd embodiment. FIG. 10 is a block diagram showing the configuration during normal operation of the laser processing apparatus of the second embodiment; The block diagram which shows the structure at the time of wear determination of the laser processing apparatus of 2nd embodiment.

(First embodiment)
A first embodiment of a servo motor driving device for controlling the operation of a galvanometer driving device mounted on a laser processing apparatus will be described below with reference to the drawings.

FIG. 1 shows an example of a block diagram of a laser processing apparatus. The galvanomirror 1 is rotated based on the rotation of the output shaft 3 of the drive motor 2, and irradiates the laser beam L supplied from the laser light source 17 toward the processing surface of the workpiece. The drive motor 2 has an output shaft 3 rotatably supported by a bearing such as a ball bearing provided in a case, and the rotation angle and rotation speed of the output shaft 3 are controlled based on the current supplied to the coil 4. .

A drive control means 5 for controlling the laser processing operation outputs a drive position signal dp for controlling the rotational position of the galvanomirror 1 to the amplifier 7 and the integrator 8 via the adder 6 . The drive position signal dp is also output to a switch 11, which will be described later. The amplifier 7 amplifies the drive position signal dp and outputs it to the adder 9 , and the integrator 8 integrates the voltage value of the drive position signal dp and outputs it to the adder 9 .

The adder 9 adds the voltage signals output from the amplifier 7 , the integrator 8 and the speed detection means 10 described later and outputs the result to the switch 11 .
A switch 11 is switched and controlled based on a control signal cs1 output from the drive control means 5, and converts either the output signal of the adder 9 or the drive position signal dp to a V/I converter (voltage current converter) 12. output to The drive position signal dp and the output signal of the adder 9 are voltage signals. supply as

The output shaft 3 of the drive motor 2 is rotated at a rotation speed and a rotation angle based on the drive current di. Then, the galvanomirror 1 is rotated based on the rotation of the output shaft 3 .
The drive motor 2 is provided with position detection means 13 for detecting the rotational position (rotational angle) of the output shaft 3 , that is, the rotational angle of the galvanomirror 1 . The position detection means 13 detects the rotation angle of the galvanomirror 1 and converts it into a current position signal rt which is a voltage signal. The current position signal rt is a rotational state signal obtained by detecting the actual rotational state of the galvanomirror 1 .

A current position signal rt output from the position detection means 13 is output to the speed detection means 10 and the switch 14 . The speed detection means 10 generates a voltage signal indicating the rotation speed of the galvanomirror 1 by differentiating the current position signal rt, and outputs the voltage signal to the adder 9 .

The switch 14 is switched and controlled based on the control signal cs2 output from the drive control means 5, and outputs the current position signal rt output from the position detection means 13 to either the adder 6 or the wear detection means 15. . The control signal cs2 is output from the drive control means 5 in the judgment mode for judging the wear of the bearing of the drive motor 2. When the control signal cs2 is inputted, the switch 14 outputs the current position signal rt to the wear detection means. 15 only.

When the current position signal rt is input through the switch 14, the wear detection means 15 compares the current position signal rt with a preset reference value, and wears the bearing of the drive motor 2 based on the comparison result. to detect wear.

The drive control means 5 is set to be in a determination mode when the laser processing apparatus is started up or shut down, and outputs a predetermined drive position monitor (observation) signal dpc for determination in the determination mode.

The reference value set in the wear detection means 15 is a numerical value corresponding to the current position signal rt in a state of no wear when the drive motor 2 is operated based on the determination drive position monitor (observation) signal dpc. The wear detection means 15 detects the error between the reference value and the current position signal rt.

FIG. 4 shows an example of the rotation operation of the output shaft 3 of the drive motor 2 and the galvanomirror 1 which operate based on the determination drive position monitor (observation) signal dpc in the determination mode. Normally, the galvanomirror 1 can reciprocate at a constant rotation limit angle α1, and the effective rotation range α2, which is the rotation range of the output shaft 3 of the drive motor 2 according to the specifications, is greater than the rotation limit angle α1. A narrow range is set, and the galvanomirror 1 is controlled to reciprocate within the effective rotation range α2.

In the determination mode, the drive position monitor (observation) signal dpc for determination is used to reciprocate the output shaft 3 within the range of the rotation limit angle α1, and the current position signal rt in this state is input to the wear detection means 15. Detect the degree of wear. Further, as shown in FIG. 5, the degree of wear may be detected by reciprocating rotation within a range of an arbitrary determination angle α3 narrower than the rotation limit angle α1.

In the determination mode, the output shaft 3 and the galvanomirror 1 are repeatedly rotated by the driving position monitor (observation) signal dpc for determination, and the degree of wear is detected by the wear detection means 15 based on the current position signal rt in that case.

Specifically, for example, as shown in FIG. 6, the galvanomirror 1 is reciprocatingly rotated within the range of the rotation limit angle α1 to perform the repeated rotation operation. At this time, when rotating from the origin position x to the maximum rotation position y, the degree of wear is detected based on the current position signal rt of the galvanomirror 1 .

At this time, for example, as shown in FIG. 7, during the forward movement from the origin position x to the maximum rotation position y, the rotational speed of the galvanomirror 1 increases parabolically. A signal dpc is output, and a current position signal rt as shown in FIG.

The wear detection means 15 determines the degree of wear based on the current position signal rt1 during the forward movement of the galvanomirror 1, and does not determine the degree of wear based on the current position signal rt2 during the return movement.
FIG. 9 shows a case where the galvanomirror 1 is reciprocated and the degree of wear is determined based on the current position signal rt during forward movement and backward movement. In this case, for example, the current position signal rt when the output shaft 3 moves forward from the origin position x to the maximum rotation position y and when it moves back from the maximum rotation position y to the origin position x is the wear detection means 15. to determine the degree of wear.

At this time, the driving position monitor (observation) signal dpc for determination is output from the drive control means 5 as a signal whose voltage level transitions in a trapezoidal shape, as shown in FIG.
As shown in FIG. 1, the drive motor 2 is provided with temperature detection means 16 . The temperature detection means 16 outputs a current temperature signal tm obtained by detecting the temperature of the drive motor 2 to the wear detection means 15 .

The wear detection means 15 temperature-corrects the reference value based on the current temperature signal tm, and detects the degree of wear by comparing the corrected reference value with the current position signal rt.
The viscosity of the grease with which the bearing of the output shaft of the drive motor 2 is filled changes with temperature. Therefore, when the degree of wear is determined after turning on the power of the laser processing apparatus, the temperature of the drive motor 2 is low, so the viscosity of the grease is high. Further, when the degree of wear is determined following the start of the shutdown processing of the laser processing apparatus, the temperature of the drive motor 2 is high, so the viscosity of the grease is low.

The wear detecting means 15 corrects the reference value based on the change in the temperature of the driving motor 2, thereby eliminating the influence of the viscosity of the grease when detecting the degree of friction by comparing the current position signal rt and the reference value. works like

Next, the operation of the laser processing apparatus and the galvanometer driving apparatus configured as described above will be described.
The judgment mode for judging the degree of wear of the bearings of the drive motor 2 is performed when the power of the laser processing apparatus is turned on or after the start of shutdown processing.

FIG. 11 illustrates the case of entering decision mode following power up. As shown in the figure, when the laser processing apparatus is powered on, the determination mode is started and the wear detection means 15 performs a determination operation of the degree of wear (step 1), and the determination result is displayed on the display device. be. After that, the operation shifts to normal operation, and the operation of the galvanomirror 1 is controlled by the drive motor 2 (step 2).

During the judgment operation of step 1, as shown in FIG. The determination drive position monitor (observation) signal dpc is the signal shown in FIG. 7 or FIG. Then, the driving position monitor (observation) signal dpc for judgment is converted into the driving current di by the V/I converter 12 and supplied to the driving motor 2 .

The drive motor 2 rotates the output shaft 3 based on the supply of the drive current di, and rotates the galvanomirror 1 based on the rotation of the output shaft 3 . At this time, the drive position monitor (observation) signal dpc for determination causes the galvanomirror 1 to reciprocate within the effective rotation range α2 or any determination angle α3 narrower than the effective rotation range α2.

The position detection means 13 outputs a current position signal rt obtained by detecting the rotation angle of the galvanomirror 1 to the switch 14 . In the determination mode, the switch 14 is switched to the wear detecting means 15 side, and the current position signal rt is output to the wear detecting means 15. FIG.

When the current position signal rt is input, the wear detection means 15 compares the current position signal rt with a preset reference value, detects the comparison result, and outputs it to display means or the like. The operator can confirm the degree of wear of the bearing of the drive motor 2 by confirming the comparison result.

In the normal operation of step 2, the switch 11 is switched to the adder 9 side and the switch 14 is switched to the adder 6 side, as shown in FIG. In this state, when the drive position signal dp is output from the drive control means 5 to the adder 6, the drive position signal dp passes through the amplifier 7, the integrator 8, the adder 9 and the switch 11 to V/I. It is supplied to converter 12 .

The V/I converter 12 generates a drive current di based on the sum of the output signals of the amplifier 7 and the integrator 8 and supplies the drive current di to the coil 4 of the drive motor 2 . The driving motor 2 rotates the output shaft 3 based on the supply of the driving current di, and rotates the galvanomirror 1 .

When the galvanomirror 1 rotates, the position detection means 13 generates a current position signal rt obtained by converting the rotation position (rotation angle) of the galvanomirror 1 into a voltage, which is output to the speed detection means 10 and the switch 14. be done.

The speed detection means 10 generates a voltage signal corresponding to the rotational speed of the output shaft 3 based on the current position signal rt and outputs it to the adder 9 . Also, the current position signal rt is output to the adder 6 via the switch 14 .

Through such an operation, feedback control is performed so that the rotation angle and rotation speed of the galvanomirror 1 match the rotation angle and rotation speed according to the driving position signal dp.
FIG. 12 shows a case where the judgment mode is started when the power of the laser processing apparatus is shut down. When the laser processing apparatus is powered on, it shifts to normal operation, and the drive motor 2 controls the operation of the galvanomirror 1 (step 11).

When the normal operation is finished and the shutdown operation is started (step 12), the determination mode is started and the wear detection means 15 performs the wear degree determination operation (step 13). The determination operation of step 13 is the same as the operation of step 1 shown in FIG.

When the determination operation is completed, for example, the determination result is stored in a storage unit (storage means) provided in advance in the wear detection means 15, and when the power is turned on again, the power supply is cut off so that it can be confirmed on the display unit (output means) or the like. .

The laser processing apparatus and the galvanometer driving apparatus as described above can provide the following effects.
(1) In the determination mode, the switches 11 and 14 are switched to provide feedback for correcting the deviation between the drive position signal dp output from the drive control means 5 and the current position signal rt detected by the position detection means 13. Control is stopped. In this state, the degree of wear of the bearing of the output shaft 3 of the drive motor 2 is detected by the wear detecting means 15 based on comparison between the current position signal rt and a preset reference value. Therefore, it becomes easy to confirm the fine degree of wear.

(2) Since the fine degree of wear can be confirmed, it becomes easy to predict the optimal replacement timing of the drive motor 2 . Therefore, there is no need to stop the operation of the laser processing apparatus and replace the drive motor 2 during normal operation, so that working efficiency can be improved.

(3) In the determination mode, the drive position monitor (observation) signal dpc for determination output from the drive control means 5 rotates the galvanomirror 1 over the entire effective rotation range α2. Therefore, the degree of wear can be detected over the entire effective rotation range α2 of the galvanomirror 1 .

(4) By repeatedly rotating the galvanomirror 1 within the effective rotation range α2 or the determination angle α3 according to the determination drive position monitor (observation) signal dpc output from the drive control means 5, the wear degree determination accuracy can be improved. can be improved.

(5) The galvanomirror 1 is repetitively rotated back and forth within the effective rotation range α2 or the determination angle α3 by the determination drive position monitor (observation) signal dpc output from the drive control means 5, and forward movement and return movement are performed. Wear determination can be performed based on the current position signal rt at time. Therefore, since it is possible to detect wear that is difficult to detect by determining wear only during forward movement or return movement, it is possible to improve the accuracy of determining the degree of wear.

(6) When the galvanomirror 1 is repetitively rotated back and forth within the effective rotation range α2 or the determination angle α3, the drive position monitor (observation) signal dpc for determination is a trapezoidal wave. Therefore, the torque for rotating the galvanometer mirror 1 can be gradually increased over time from a small torque and then gradually decreased, and this can be repeated, so that even minor wear can be detected with high accuracy. can.

(7) After turning on the power of the laser processing device, the degree of wear can be checked before the laser processing device is put into operation by shifting to the determination mode and performing wear determination. Therefore, it is possible to prevent the production of defective products by preventing the laser processing in a state where wear has progressed.

(8) At the start of shutdown of the laser processing apparatus, it is possible to shift to the determination mode to perform wear determination and store the determination result in the wear detection means 15 . Then, when the laser processing apparatus is operated next time, the determination result can be displayed on the display unit or the like based on power-on, so that the laser processing apparatus can be prevented from operating in a state where wear has progressed.

(9) By outputting the temperature signal of the drive motor 2 detected by the temperature detection means to the wear detection means 15, the wear determination by the wear detection means 15 can be temperature-corrected. That is, when the temperature of the drive motor 2 does not rise in the wear determination performed after the power is turned on, or when the temperature of the drive motor 2 rises in the wear determination at the time of shutdown, the viscosity of the grease in the bearing varies with temperature. When comparing the current position signal rt with the reference value, the wear detecting means 15 corrects the reference value so as to correspond to the viscosity change of the grease, and compares the corrected reference value with the current position signal rt to detect wear. Judgment can be made. Therefore, the accuracy of wear determination can be improved.

(Second embodiment)
13 to 15 show a second embodiment of the laser processing apparatus. In this embodiment, a rotation state signal for detecting the rotation state of the galvanomirror 1 is generated based on the current value flowing through the coil 4 of the drive motor 2 in the judgment mode. The same components as in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 13, the output signal of switch 11 is output to V/I converter 12 via adder 21 . A drive current di output from the V/I converter 12 is supplied to the I/V converter 22 via the coil 4 .

The I/V converter 22 converts the current value of the drive current di into a voltage signal to generate a rotation state signal rs, and outputs the voltage signal to the switch 23 . The switch 23 is switched and controlled based on the control signal cs3 output from the drive control means 5, outputs the rotation state signal rs to the adder 21 in normal operation, and outputs the rotation state signal rs to the adder 21 in the judgment mode. Output to means 15 .

A current position signal rt output from the position detection means 13 is output only to the adder 6 . In the judgment mode, the drive current monitor (observation) signal dpi for judgment set in advance from the drive control means 5 is output to the adder 21 via the switch 11 . The drive current monitor (observation) signal dpi for determination is a signal for supplying a constant current to the coil 4 of the drive motor 2 to rotate the output shaft 3 with a constant torque. Other configurations are the same as those of the first embodiment.

In the laser processing apparatus configured as described above, the drive position signal dp is output from the drive control means 5 to the adder 6 during normal operation, as shown in FIG. A drive current di based on the drive position signal dp is supplied to the coil 4 of the drive motor 2, and the galvanomirror 1 is rotated by the operation of the drive motor 2. FIG.

The rotating state of the galvanomirror 1 is detected by the position detecting means 13 and output as the current position signal rt. Then, the current position signal rt is supplied to the adder 6, and a voltage signal corresponding to the rotation speed of the output shaft 3 detected based on the current position signal rt is output to the adder 9.

Through such an operation, feedback control is performed so that the rotation angle and rotation speed of the galvanomirror 1 match the rotation angle and rotation speed according to the driving position signal dp.
Also, the current value of the driving current di is converted into a voltage signal by the I/V converter 22 and output to the adder 21 . Therefore, feedback control is performed so as to suppress fluctuations in the drive current di.

As shown in FIG. 15, in the determination mode, the switches 11 and 23 are switched to output the driving current monitor (observation) signal dpi for determination to the V/I converter 12 via the switch 11 and the adder 21. be done. Then, the coil 4 of the drive motor 2 is supplied with the drive current di based on the determination drive current monitor (observation) signal dpi, the output shaft 3 of the drive motor 2 rotates, and the galvanomirror 1 rotates.

Here, if the bearing of the output shaft 3 is worn, the output shaft 3 will not rotate smoothly. Then, the drive current di input to the I/V converter 22 does not become a constant current, and ripples occur.

The I/V converter 22 outputs the rotation state signal rs based on the variation of the drive current di to the wear detection means 15 via the switch 23 . The wear detection means 15 determines the fluctuation of the drive current di, that is, the degree of wear of the output shaft 3, based on the rotation state signal rs.

The laser processing apparatus and the galvanometer driving apparatus as described above can provide the following effects.
(1) In the determination mode, the switches 11 and 23 are switched to provide feedback for correcting the deviation between the drive position signal dp output from the drive control means 5 and the current position signal rt detected by the position detection means 13. Control is stopped. Then, the drive motor 2 is driven with a constant current based on the determination drive current monitor (observation) signal dpi output from the drive control means 5 . In this state, the degree of wear of the bearing of the output shaft 3 of the drive motor 2 is detected based on the rotation state signal rs obtained by detecting the variation of the drive current di by the wear detection means 15 . Therefore, it becomes easy to confirm the fine degree of wear.

(2) The same effect as in the first embodiment can be obtained by confirming the fine degree of wear based on the rotational state signal rs that detects the fluctuation of the driving current di.
Note that the above embodiment may be modified as follows.

The wear detection means 15 may add temperature correction to the current position signal rt output from the position detection means 13 and compare the corrected current position signal with a reference value to detect the degree of wear.

- The drive current monitor (observation) signal dpi for determination need not be a constant current. The wear detection means 15 may detect the difference between the current supplied to the coil 4 of the drive motor 2 and the current actually flowing through the coil 4 based on the determination drive current monitor (observation) signal dpi.

- In the first and second embodiments, the switch 11 is inserted in the rear stage of the V/I converter 12, and the drive position monitor (observation) signal dpc for judgment or the drive current monitor (observation) signal dpi for judgment is A current signal that is directly supplied to the coil 4 may be used.

・The servo motor drive device of the above embodiment is an arm control device for FA robots, an angle control device for inspection tables and the like, a movement control device for mounting tables such as machine tools, a joint control device for robots, and a rotation control device for surveillance cameras. It can be used as a control device for controlling devices, plotters, and stamping machines with three axes in the XYZ directions.

DESCRIPTION OF SYMBOLS 1... Galvano mirror, 2... Servo motor (drive motor), 3... Output shaft, 5... Drive control means (galvano drive means), 6, 9... Feedback control part (adder), 7... Feedback control part (amplifier) , 8... Feedback control section (integrator) 11, 14... Switching means (switching device) 13... Rotation state detecting means (position detecting means) 15... Wear detecting means 16... Temperature detecting means 17... Laser light source 22 rotation state detection means (I/V converter) L laser light dp drive signal (drive position signal) dpc drive signal for determination (drive position monitor (observation) signal for determination); dpi: drive signal for determination (drive current monitor (observation) signal for determination), rt: rotation state signal (current position signal), rs: rotation state signal, tm: current temperature signal, α2: effective rotation range.

Claims (11)

Galvanometer drive means for rotating the galvanometer mirror by rotation of the output shaft of the drive motor;
drive control means for outputting a drive signal to the galvanometer drive means for rotating the galvanometer mirror to a preset rotation position;
rotation state detection means for detecting the rotation state of the galvanomirror based on the drive signal and outputting a rotation state signal;
A galvanometer drive device comprising a feedback control unit that corrects the drive signal and supplies the drive signal to the drive motor so as to correct a deviation between the drive signal and the rotation state signal,
The drive control means has a determination mode for outputting a drive signal for determination,
wear detection means for detecting the degree of wear of the bearing of the output shaft based on the rotational state of the galvanomirror based on the drive signal for determination;
a first switch that disables the operation of the feedback control section by being switched and controlled based on a first control signal output from the drive control means in the determination mode; a second switch that supplies the rotation state signal only to the wear detection means by being switched and controlled based on the output second control signal ;
In the determination mode, the galvano drive means drives the drive motor with a constant current based on the determination drive signal, and the wear detection means responds to the determination drive signal output by the rotational state detection means. a galvano-driving device , wherein the degree of wear of a bearing of the output shaft is detected based on a rotational state signal obtained by detecting the rotational state of the galvano-mirror. In the galvanometer drive device according to claim 1,
The drive control means, in the determination mode, outputs a determination drive signal for rotating the entire effective rotation range of the galvanomirror,
The galvanometer driving device, wherein the wear detection means detects the degree of wear over the entire effective rotation range of the galvanometer mirror based on a rotation state signal based on the drive signal for determination. In the galvano drive device according to claim 1 or 2,
The drive control means outputs a determination drive signal for repeatedly rotating the galvanomirror in the determination mode,
The galvanometer drive device, wherein the wear detection means detects the degree of wear of the bearing of the output shaft based on the rotational state signal based on the determination drive signal. In the galvanometer driving device according to claim 3,
The drive control means, in the determination mode, outputs a determination drive signal for repeatedly rotating the galvanomirror in a reciprocating direction,
The galvanometer driving device, wherein the wear detection means detects the degree of wear of the bearing of the output shaft over the reciprocating direction of the galvanometer mirror based on the rotational state signal based on the determination drive signal. In the galvanometer driving device according to claim 4,
The galvanometer drive device, wherein the drive control means outputs a trapezoidal wave as the determination drive signal. In the galvanometer driving device according to any one of claims 1 to 5,
The drive control means outputs a drive position signal for rotating the galvanomirror to a preset rotation position as the drive signal, and outputs a drive position monitor (observation) signal for determination as the drive signal for determination. death,
The wear detecting means compares a current position signal obtained by detecting the rotational position of the galvanomirror based on the drive position monitor (observation) signal for determination as the rotational state signal with a preset reference value. 1. A galvanometer driving device characterized by detecting the degree of wear of a bearing of said output shaft. In the galvanometer driving device according to any one of claims 1 to 6,
The galvanometer drive device, wherein the drive control means shifts to the determination mode following power-on. In the galvanometer driving device according to any one of claims 1 to 6,
The drive control means transitions to the determination mode when power is shut down,
The wear detection means is
a storage means for storing detection results in the determination mode;
and output means for outputting the detection result stored in the storage means when the power is turned on again. In the galvanometer driving device according to claim 6,
temperature detection means for outputting a current temperature signal obtained by detecting the temperature of the drive motor to the wear detection means;
The galvano-driving device, wherein the wear detecting means temperature-corrects either the current position signal or the reference value based on the current temperature signal. A laser processing apparatus, characterized in that a laser beam emitted from a laser light source is irradiated onto a surface to be processed through a galvanometer mirror rotated by the galvanometer driving device according to any one of claims 1 to 9. . a servo motor;
servo motor driving means for driving the servo motor;
drive control means for outputting a drive signal to the servo motor drive means;
rotation state detection means for detecting the rotation state of the output shaft of the servomotor based on the drive signal and outputting a rotation state signal;
A servo motor driving device comprising a feedback control unit that corrects the driving signal and supplies the driving signal to the servo motor so as to correct the deviation between the driving signal and the rotation state signal,
The drive control means has a determination mode for outputting a drive signal for determination,
wear detection means for detecting the degree of wear of the bearing of the output shaft based on the rotational state of the servomotor based on the determination drive signal;
a first switch that disables the operation of the feedback control section by being controlled based on a first control signal output from the drive control means in the determination mode; and an output from the drive control means in the determination mode. a second switch for supplying the rotation state signal only to the wear detection means by being switched and controlled based on a second control signal ;
In the determination mode, the servomotor drive means drives the servomotor with a constant current based on the determination drive signal, and the wear detection means drives the determination drive signal output by the rotational state detection means. and detecting the degree of wear of a bearing of the output shaft based on a rotation state signal obtained by detecting the rotation state of the servomotor based on the servomotor driving device.

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