JP2019100899A - Laser device and measurement system - Google Patents

Abstract

To provide a laser device and measurement system that can prevent damage of a laser device main body.SOLUTION: A measurement system 100 comprises: a CMM (Coordinate Measuring Machine) 8; and a laser device 1. The laser device 1 comprises: a laser device main body 10; cable that is connected to the laser device main body 10; an external force sensor 6 that detects external force to be applied to the cable; a warning signal output unit 73 that, when the external force sensor 6 detects the external force more than a threshold, outputs a warning signal Sa. The CMM 8 comprises: a table where the laser device main body 10 is placed; a supporting mechanism that supports a moving body to be irradiated with laser light to be emitted from the laser device main body 10; a drive unit 88 that drives the table or supporting mechanism so that the moving body relatively moves to the table; and a drive control unit 93 that controls the drive unit 88. The drive control unit 93 is configured to cause the drive unit 88 to suspend when receiving the warning signal Sa.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a laser device and a measurement system having the laser device.

Conventionally, to correct or inspect the spatial accuracy of positioning in a positioning apparatus capable of positioning a mobile body (probe, tool, etc.) at an arbitrary coordinate relative to a table, such as a coordinate measuring machine (CMM) or a machine tool It is known to use a laser device such as a tracking type laser interferometer (see Patent Document 1).
For example, Patent Document 1 discloses a method of performing CMM spatial accuracy correction using a tracking laser interferometer. In this method, a retroreflector as a moving body is attached to the tip of the Z spindle of the CMM, and while changing the coordinates of the retroreflector, acquisition of the coordinate values of the retroreflector by the CMM and the distance to the retroreflector by the tracking laser interferometer The measurement and the measurement are respectively performed to obtain space correction parameters.

Patent No. 4776454

In a measurement system comprising a laser device and a positioning device as described above, the following problems arise when correcting or checking the spatial accuracy of positioning.
Among the laser devices, a laser device main body that outputs and inputs laser light is placed on a table of the positioning device, and the laser device main body is connected to an apparatus installed outside the table via a cable.
However, the cable extending from the laser device body may be caught by the base of the positioning device, the support mechanism of the movable body, or the like. In this case, an excessive force may be applied to the cable connection portion of the laser device body, or the laser device body may be broken by being pulled by the cable and falling from the table.

  An object of the present invention is to provide a laser device and a measurement system capable of preventing damage to a laser device body.

  The laser device according to the present invention includes a laser device body, a cable connected to the laser device body, a sensor for detecting an external force applied to the cable or a displacement of the laser device body, and the external force for which the sensor is a threshold or more. Or a warning signal output unit that outputs a warning signal when the displacement is detected.

The laser apparatus of the present invention is used when performing correction or inspection of the positioning accuracy of a positioning apparatus which positions the moving body at an arbitrary coordinate on the table.
The positioning device is a CMM, a machine tool or the like, and the moving body is a spindle or the like on which a probe, a tool or the like is mounted.

When correction or inspection of the positioning accuracy of a moving body is performed using the laser device of the present invention, the laser device main body for inputting and outputting laser light is placed on the table of the positioning device, and the device outside the table via the cable. Connected to At this time, if an external force equal to or greater than the threshold value is applied to the laser apparatus body via the cable, or if the laser apparatus body is displaced (moved) relative to the table by the external force applied to the cable, the warning signal output unit Output a warning signal.
The positioning device that has received the warning signal can stop the movement of the table or support mechanism that is likely to be the cause of the external force. As a result, the laser device main body can be prevented from being excessively pulled by the cable, and consequently, the laser device main body can be prevented from falling from the table, and breakage of the laser device main body can be prevented.

In the laser device of the present invention, preferably, the laser device body has a panel to which a part of the cable is fixed, and the sensor detects distortion of the panel as an external force applied to the cable.
In the present invention, by appropriately setting the distortion threshold of the panel, a warning signal can be output before the laser device body actually starts moving. Thereby, breakage of the laser device can be more reliably prevented. Further, since the change in the arrangement of the laser device body with respect to the table can be prevented, it is possible to maintain the measurement accuracy of the laser device.

  In the laser device of the present invention, the sensor may be a strain sensor attached to the panel and detecting strain of the panel.

  In the laser apparatus of the present invention, the sensor may be a linear displacement sensor which is disposed to face the panel and detects a partial displacement of the panel as the distortion of the panel.

The present invention is a measurement system comprising the above-described laser device and a positioning device, wherein the positioning device is a table on which the laser device body is placed, and a laser beam emitted from the laser device body is irradiated A support mechanism for supporting the movable body, a drive unit for driving the table or the support mechanism such that the movable body moves relative to the table, and a drive control unit for controlling the drive unit; The drive control unit may stop the drive unit when the warning signal is received.
According to the measurement system of the present invention, the same effect as the laser device of the present invention described above can be obtained.

  According to the present invention, it is possible to provide a laser device and a measurement system capable of preventing damage to the laser device body.

FIG. 1 is a perspective view showing a schematic configuration of a measurement system according to a first embodiment of the present invention. FIG. 2 is a functional block diagram showing a schematic configuration of a measurement system according to the first embodiment. The perspective view which shows the laser apparatus which concerns on the said 1st Embodiment. The flowchart which demonstrates operation | movement of a laser apparatus when adjusting CMM. The side view which shows the laser apparatus which concerns on 2nd Embodiment of this invention. The top view which shows the laser apparatus which concerns on the said 2nd Embodiment. The fragmentary sectional view which shows the laser apparatus which concerns on 3rd Embodiment of this invention.

First Embodiment
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the measurement system 100 of the present embodiment includes a laser device 1 and a CMM 8 corresponding to the positioning device of the present invention. In the measurement system 100, the laser device 1 measures the distance to the retroreflector 9 in order to correct or inspect the positioning accuracy when the CMM 8 positions the retroreflector 9 which is a moving body.

[Configuration of CMM]
The configuration of CMM 8 will be briefly described with reference to FIGS. 1 and 2.
The CMM 8 includes a base 81, a table 82 provided on the base 81, a support mechanism 83 provided upright on the base 81, a drive unit 88 for driving the support mechanism 83, and a CMM control unit 90.

  The table 82 is configured to be movable in the Y direction with respect to the base 81. A workpiece is placed on the upper surface of the table 82 during normal measurement by the CMM 8, but when spatial accuracy correction or accuracy inspection is performed by the measurement system 100, the upper surface of the table 82 is replaced with the workpiece of the laser device 1. The laser device body 10 is placed.

  The support mechanism 83 slides in the Z-axis direction with respect to the slider 85, and a slider 85 slidably provided in the X-axis direction with respect to the column 84, the portal-shaped column 84 extending in the X-axis direction. And a spindle 86 which is provided. In addition, the support mechanism 83 is provided with a plurality of detectors (not shown) for detecting the positions of the slider 85 and the spindle 86.

  During normal measurement with CMM 8, a probe for measuring the contour shape of the workpiece is attached to the tip of spindle 86, but when space accuracy correction or accuracy inspection is performed by measurement system 100, the tip of spindle 86 is attached A retroreflector 9 is attached in place of the probe.

  The drive unit 88 is configured of a plurality of motors and the like that drive the table 82 and the support mechanism 83, respectively. When the drive unit 88 moves the table 82 or the support mechanism 83, the retroreflector 9 as a moving body moves relative to the table 82.

  The CMM control unit 90 is configured of, for example, a data processing apparatus 101 such as a PC, and the data processing apparatus 101 executes desired control software to realize the intended function of the CMM control unit 90. The CMM control unit 90 includes a coordinate measurement unit 91, a correction operation unit 92, a drive control unit 93, and the like.

The coordinate measurement unit 91 measures the coordinates of the retroreflector 9 from the detectors provided in the support mechanism 83. The correction operation unit 92 performs an operation for space accuracy correction based on the measurement data of the distance measurement unit 71 and the coordinate measurement unit 91. The drive control unit 93 controls the drive unit 88 to obtain the table 82 or the like. Each movement of the support mechanism 83 is controlled. Further, when receiving a warning signal Sa described later from the laser device 1, the drive control unit 93 stops the drive unit 88.

[Configuration of laser device]
The configuration of the laser device 1 will be described with reference to FIGS. 2 and 3.
The laser device 1 includes a laser device main body 10 mounted on a table 82 of the CMM 8 and a control unit 7 configured by a data processing device 101 installed outside the table 82. The laser device main body 10 includes a base 2, a support mechanism 3 installed on the base 2, a drive unit 4 for driving the support mechanism 3, a measurement head 5 supported by the support mechanism 3, and an external force sensor 6 ing.

  The base 2 is configured as a case that accommodates wiring and the like inside, and a part of the cable 23 is fixed to a panel 21 that constitutes a part of the side surface of the base 2.

The support mechanism 3 has a first support portion 31 rotatable relative to the base 2 about an axis A1 parallel to the Z direction, and a first support portion 31 rotatable about an axis A2 orthogonal to the axis A1. And 2 support portion 32. The intersection of the axis A1 and the axis A2 is a measurement reference point R by the laser device 1. Further, the support mechanism 3 is provided with a plurality of detectors (not shown) for detecting the rotation angles (the azimuth angle and the elevation angle of the measuring head 5) of the first support portion 31 and the second support portion 32.
The drive unit 4 is configured by a motor or the like that drives the first support unit 31 and the second support unit 32 around each axis, and can change the azimuth angle and the elevation angle of the measurement head 5 respectively.

The measurement head 5 is supported by the second support portion 32 of the support mechanism 3, and includes a laser interferometer 51 and an optical axis detection unit 52.
The laser interferometer 51 irradiates laser light (irradiation light) toward the direction determined by the drive unit 4 and receives laser light (reflected light) retroreflected by the retroreflector 9, and the irradiation light and reflection Detect interference light with light. Then, the laser interferometer 51 detects a change in the distance from the measurement reference point R to the retroreflector 9.
The optical axis detection unit 52 detects the amount of deviation between the optical axis of the emitted light of the laser interferometer 51 and the reflected light.

The external force sensor 6 is a sensor according to the present invention, and is a strain sensor attached to the panel 21 and detecting a strain amount F which is a magnitude of strain generated in the panel 21. The external force sensor 6 is configured as, for example, a known semiconductor strain sensor or strain gauge.
Information detected by each of the laser interferometer 51, the optical axis detection unit 52, and the external force sensor 6 is input to the control unit 7 via the cable 23 as each detection signal.

  Similar to the CMM control unit 90, the control unit 7 is configured by the data processing device 101, and the data processing device 101 executes desired control software to realize desired functions of the control unit 7. The control unit 7 includes a distance measurement unit 71, a drive control unit 72, a warning signal output unit 73, a notification unit 74, and the like.

The distance measuring unit 71 measures the distance from the measurement reference point R to the retroreflector 9 based on the detection signal output from the laser interferometer 51.
The drive control unit 72 performs feedback control of the drive unit 4 based on the detection signal output from the optical axis detection unit 52 so that the deviation amount of the optical axis between the emitted light and the reflected light becomes zero. The control signal output from the drive control unit 72 is input to the laser device body 10 via the cable 23.

  The warning signal output unit 73 outputs a warning signal Sa to the CMM control unit 90 and the notification unit 74 when the distortion amount F input from the external force sensor 6 is equal to or larger than a predetermined threshold value Sf. The threshold value Sf is, for example, a value of the distortion amount F at which the laser device main body 10 starts to move with respect to the table 82 is obtained in advance by experiment or the like, and made similar to the value or a value lower than the value. It is preferable to set.

  When the notification unit 74 receives the warning signal Sa, the display unit 102 of the data processing apparatus 101 notifies the user that the warning signal Sa has been output (the spatial accuracy correction operation of the CMM 8 has been stopped). Display on. The notification means by the notification unit 74 is not limited to the display on the display unit 102, and may be lighting of a signal light or transmission of an e-mail.

[Operation of Laser Device 1]
The basic operation of the measurement system 100 for correcting or checking the positioning accuracy of the CMM 8 is similar to that of the prior art. Briefly explained, in the CMM 8, the drive control unit 93 controls the drive unit 88 to sequentially change the coordinates of the retroreflector 9, and the coordinate measurement unit 91 measures the coordinates of the retroreflector 9 at each measurement position. On the other hand, in the laser device 1, the drive control unit 72 performs feedback control of the drive unit 4 to continue irradiating the retroreflector 9 on which the laser interferometer 51 moves with the laser light, and the distance measuring unit 71 performs retro The distance to the reflector 9 is measured. After the necessary data group is measured, the correction operation unit 92 of the CMM 8 calculates the spatial accuracy parameter based on the measured data group.

  The laser device 1 of the present embodiment starts an operation for preventing damage to the laser device main body 10 at the same time as the operation for correcting or inspecting the positioning accuracy of the CMM 8 starts. This operation will be described with reference to the flowchart shown in FIG.

  First, the external force sensor 6 starts measurement of the distortion amount F which is the magnitude of distortion generated in the panel 21 and outputs the measurement to the warning signal output unit 73 (step S1). The warning signal output unit 73 determines whether the input distortion amount F is equal to or more than a predetermined threshold value Sf (step S2).

Here, when the distortion amount F exceeds the threshold value Sf, it is considered that the following causes have occurred.
For example, when the cable 23 is caught on the base 81 or the like of the CMM 8, when the table 82 moves to change the coordinates of the retroreflector 9, an external force is applied to the cable 23 to pull the laser device body 10. At this time, an external force is also applied to the panel 21 to which a part of the cable 23 is fixed, and a distortion is generated on the panel 21 in a convex shape on the cable 23 side centering on the fixed part of the cable 23.

  In step S2, the warning signal output unit 73 outputs a warning signal Sa to the CMM 8 and the notification unit 74 when the distortion amount F is equal to or more than the threshold value Sf (step S3). On the other hand, if the distortion amount F is less than the threshold value Sf, the warning signal output unit 73 repeats step S2 until the distortion amount F becomes equal to or more than the threshold value Sf.

After the step S3, in the CMM 8, the drive control unit 93 receives the warning signal Sa and stops the drive unit 88. Thereby, when the table 82 and the support mechanism 83 are moving, the movement is stopped.
Also, after step S3, the notification unit 74 receives the warning signal Sa, and causes the display unit 102 to display a notification to the user (step S4).

  Thus, the flowchart illustrated in FIG. 4 ends. The user can restart the space accuracy correction of the CMM 8 after confirming the state of the cable 23 and the like by confirming the notification displayed on the display unit 102.

[Effect of First Embodiment]
According to the present embodiment, when an external force equal to or greater than a predetermined value is applied to the cable 23, the movement of the table 82, which has a high possibility of causing the external force applied to the cable 23, is stopped. For this reason, the laser device body 10 is prevented from being excessively pulled by the cable 23 and, consequently, the laser device body 10 is prevented from falling from the table 82. Thereby, damage to the laser device 1 can be prevented.

  In the present embodiment, the external force sensor 6 detects the distortion of the panel 21 of the laser device body 10 to detect the external force applied to the cable 23. Therefore, by setting the distortion threshold value Sf of the panel 21 appropriately, the movement of the table 82 can be stopped and the state of the cable 23 can be confirmed before the laser device body 10 actually starts to move. Thereby, breakage of the laser device 1 can be prevented more reliably. Further, the change in the arrangement of the laser device body 10 with respect to the table 82 can be prevented, and the measurement accuracy of the laser device 1 can be maintained.

  In the present embodiment, the correction operation unit 92 performs another measurement on the data measured by the distance measurement unit 71 in a period immediately before receiving the warning signal Sa as data highly likely to be affected by the external force. It can be handled separately from data. Thereby, the correction operation unit 92 can calculate the space accuracy parameter with higher reliability.

  In the present embodiment, compared to the third embodiment described later, there is no influence of the surface texture of the table 82. Therefore, the external force applied to the cable 23 can be detected with higher accuracy, and breakage of the laser device main body 10 can be prevented more reliably.

Second Embodiment
A second embodiment of the present invention will be described with reference to FIGS. 5 and 6.
The second embodiment has the same configuration as that of the first embodiment except that the configuration of the external force sensor 6A provided in the laser device main body 10A is different from that of the first embodiment. Therefore, in the following, the configuration of the external force sensor 6A will be described, and the other components will be assigned the same reference numerals and descriptions thereof will be omitted.

The external force sensor 6A is a linear displacement sensor that detects a partial displacement of the panel 21 caused by the distortion of the panel 21. The external force sensor 6A is arranged to face any part of the panel 21, preferably to face the connection part of the cable 23 in the panel 21 with respect to the base plate 22 constituting the bottom of the base 2 It is fixed via the holder 26. As the external force sensor 6A, for example, a known linear displacement sensor using a scale, a differential transformer, an electromagnetic induction, an ultrasonic wave, a capacitance or a laser can be used.
The external force sensor 6A illustrated in FIGS. 5 and 6 is a differential transformer linear displacement sensor, and both ends thereof are connected to the panel 21 and the holder 26.

The displacement amount D detected by the external force sensor 6A is input to the warning signal output unit 73 via the cable 23. The warning signal output unit 73 outputs a warning signal Sa to the CMM control unit 90 when the displacement amount D is equal to or more than the predetermined threshold Df, as in the first embodiment. The setting method of the threshold value Df is the same as the setting method of the threshold value Sf of the first embodiment.
According to the above second embodiment, the same effect as that of the first embodiment can be obtained.

Third Embodiment
A third embodiment of the present invention will be described with reference to FIG.
The third embodiment has the same configuration as that of the first embodiment except that a displacement sensor 6B is provided as a sensor of the present invention instead of the external force sensor 6 of the first embodiment. Therefore, hereinafter, the configuration of the displacement sensor 6B will be described, and the other components will be assigned the same reference numerals and descriptions thereof will be omitted.

  The displacement sensor 6B is a two-dimensional displacement sensor that detects the displacement of the laser device body 10B with respect to the table 82. The displacement sensor 6 </ b> B is installed, for example, in a recess 220 formed on the lower surface of the base plate 22 of the base 2.

  The displacement amount M detected by the displacement sensor 6B is input to the warning signal output unit 73 via the cable 23. The warning signal output unit 73 outputs a warning signal Sa to the CMM control unit 90 when the displacement amount M is equal to or more than the predetermined threshold value Mf, as in the first embodiment. The threshold value Mf is preferably set to a sufficiently small value so that the laser device body 10 does not fall off the table 82.

According to the above third embodiment, even if the laser device body 10B is pulled and moved by the cable 23, the movement of the laser device body 10B can be stopped before the laser device body 10B falls from the table 82. . As a result, it is possible to prevent the laser device body 10B from falling from the table 82.
In the third embodiment, a certain degree of movement of the laser device body 10 is permitted. If the movement of the laser device body 10 does not fall down, the spatial accuracy correction of the CMM 8 can be continued.

[Modification]
The present invention is not limited to the above-described embodiments, and modifications and the like of the scope in which the object of the present invention can be achieved are included in the present invention.

  In the above embodiment, the drive control unit 93 that has received the warning signal Sa stops the drive unit 88 that drives the table 82 and the support mechanism 83, but at least the function of driving the table 82 in the drive unit 88 By stopping it, it is possible to sufficiently prevent the laser device body 10 from falling from the table 82.

  In the above embodiment, the CMM 8 is a table moving type device, but may be a column moving type device. That is, the drive control unit 93 may be configured to stop at least the drive unit 88 that drives the column 84 when the warning signal Sa is received.

In the embodiment, the warning signal output unit 73 is configured by the data processing device 101. However, the warning signal output unit 73 may be configured by a circuit or the like included in the laser device main body 10, 10A, 10B.
Although CMM 8 is illustrated as a positioning device which constitutes a measurement system of the present invention in the above-mentioned embodiment, it is not restricted to this but may be other types of measurement devices, a machine tool, etc., for example.
The laser device of the invention is not limited to use with a positioning device such as CMM8. For example, when the cable of the laser device may be pulled by the operation of another device, the effect of the present invention is exerted by stopping the operation of the device based on a warning signal.

DESCRIPTION OF SYMBOLS 1 ... laser apparatus, 10, 10A, 10B ... laser apparatus main body, 100 ... measurement system, 101 ... data processing apparatus, 102 ... display part, 2 ... base, 21 ... panel, 22 ... base plate, 220 ... recess, 23 ... cable , 26: holder, 3: support mechanism, 31: first support portion, 32: second support portion, 4: drive portion, 5: measuring head, 51: laser interferometer, 52: optical axis detection portion, 6, 6A ... external force sensor, 6B ... displacement sensor, 7 ... control unit, 71 ... distance measurement unit, 72 ... drive control unit, 73 ... warning signal output unit, 74 ... notification unit, 8 ... CMM (positioning device), 81 ... base, 82: Table, 83: Support mechanism, 84: Column, 85: Slider, 86: Spindle, 88: Drive unit, 9: Retroreflector, 90: CMM control unit, 91: Coordinate measurement unit, 92: Correction operation unit 93 ... drive control unit, A1, A2 ... shaft, R ... reference point, Sa ... warning signal.

Claims (5)

Laser device body,
A cable connected to the laser device body;
A sensor that detects an external force applied to the cable or a displacement of the laser device body;
And a warning signal output unit that outputs a warning signal when the sensor detects the external force or the displacement that is equal to or greater than a threshold value. In the laser device according to claim 1,
The laser device body includes a panel to which a part of the cable is fixed, and the sensor detects distortion of the panel as the external force applied to the cable. In the laser device according to claim 2,
The laser device, wherein the sensor is a strain sensor attached to the panel to detect strain of the panel. In the laser device according to claim 2,
The laser device, wherein the sensor is a linear displacement sensor which is disposed to face the panel and detects a partial displacement of the panel as a distortion of the panel. A measurement system comprising the laser device according to any one of claims 1 to 4 and a positioning device,
The positioning device
A table on which the laser device body is placed;
A support mechanism for supporting a movable body to which a laser beam emitted from the laser device body is irradiated;
A driving unit that drives the table or the support mechanism such that the movable body moves relative to the table;
A drive control unit that controls the drive unit;
The measurement system, wherein the drive control unit stops the drive unit when the warning signal is received.

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