JP2018001186A - Device for measuring focal length in laser welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for measuring a focal length in laser welding, which can accurately and easily measure the focal length of a laser beam relative to a position where a workpiece is welded, and which enables one person to correct misalignment of a laser welding apparatus.SOLUTION: There is provided a device to be mounted on a scanner portion 1 of a laser welding apparatus, for measuring a focal length of a laser beam relative to a position where a workpiece is welded. The device comprises: a digital depth gauge 4 which has a main scale portion 2 including a front end portion 21 for abutting a welding position, and which has a slider portion 3 formed movably along the main scale portion, the slider portion including a display portion 31 for displaying a distance the slider portion is moved and displaced, as an amount of misalignment relative to a proper focal length, the slider portion also including an alarm portion 32; and an attachment portion 5 having a main body portion 51 which is disposed adjacent and parallel to the laser beam, and which stores and holds the slider portion, while allowing a rear end portion 22 of the main scale portion to move backward, the attachment portion 5 being mountable on the scanner portion at the rear end of the main body portion. The alarm portion issues alarm information when the distance the slider portion is moved and displaced reaches within a range specified relative to the proper focal length.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a laser welding focal length measurement device that is mounted on a scanner unit that irradiates a laser beam of a laser welding device and measures the focal length of the laser beam with respect to a workpiece welding position.

  In recent years, many laser welding apparatuses have been used for joining workpieces such as automobile bodies (see Patent Document 1). For example, in the laser welding apparatus 100 described in Patent Document 1, as shown in FIG. 7, a scanner unit 102 including an optical member that irradiates a laser beam 101 to a processing point of a workpiece W, and a scanner unit 102 are provided. A multi-axis robot apparatus 104 attached to the arm section tip 103, a scanner control apparatus 105 that controls the operation of the optical system members of the scanner section 102, and a robot control apparatus 106 that controls the operation of the arm section and the like of the multi-axis robot apparatus 104. And. A central processing unit 107 that outputs operation commands synchronized with the scanner control unit 105 and the robot control unit 106 is also provided.

  As shown in FIGS. 7 and 8, the scanner unit 102 includes an expander lens 1022 that moves in the optical axis direction of the laser beam output from the optical fiber 1021 and adjusts the focal length, and an expander lens. A collimating lens 1023 that condenses the laser light that has passed through 1022 and two scanning mirrors 1024 and 1025 that scan the laser light that has passed through the collimating lens 1023 on a workpiece are provided. Then, the scanner control device 105 and the robot control device 106 have the operation information so that the welding position of the workpiece W and the focal position of the laser beam 101 coincide with each other based on the design position data of the workpiece W. Is provisionally taught in advance.

  However, there may be a positional deviation between the welding position of the actual workpiece and the focal position of the laser beam due to the influence of the manufacturing error of the actual workpiece to be welded or the workpiece set deviation with respect to the receiving jig. Therefore, as a preparatory action before actual laser welding, it is measured at the provisionally taught position whether the above-mentioned positional deviation amount is within the specified value based on the actual workpiece. Work to correct the deviation is being carried out.

  For example, when laser spot welding is performed at the welding position of the body (work) of an automobile by the laser welding apparatus 100, the following work is performed as a work for correcting the positional deviation based on the actual work. . That is, as shown in FIG. 9, a simple measuring tool 108 having a predetermined length of a steel ruler 108a is attached to the scanner body 102a. Here, the scanner main body 102a emits the first guide light G1 projected coaxially with the laser light 101 and the second guide light G2 projected obliquely with respect to the first guide light G1. The position where the first guide light G1 and the second guide light G2 intersect is set as the focal position. Therefore, in the provisionally taught steel rule 108a, the scale P1 at the position where the first guide light G1 and the second guide light G2 cross each other and the scale P2 at the welding position of the work W are read, so that the work W in the actual work is measured. The positional deviation amount P3 (P2-P1) between the welding position of the laser beam 101 and the focal position of the laser beam 101 is measured.

  Further, as shown in FIGS. 9 and 10, the focal length checker M1 reads the scale P1 at the position where the first guide light G1 and the second guide light G2 intersect and the scale P2 at the welding position of the workpiece W. If the positional deviation amount P3 exceeds the specified value, the robot operator M2 is instructed to correct the position of the arm unit. The robot operator M2 operates the arm unit with the operation panel 109 of the multi-axis robot apparatus 104 so as to operate the positional deviation amount P3 within a specified value. When the focal length checker M1 confirms that the positional deviation amount P3 between the welding position of the workpiece W and the focal position of the laser beam 101 is within a specified value, the robot operator M2 The robot controller 106 performs an operation for re-teaching / storing the position. This operation is repeated for each welding position of the workpiece W.

JP 2010-214393 A

  However, the above-described misalignment correction work has the following problems. That is, [1] While the positional deviation accuracy of the focal length required by design in laser welding is within about ± 1.0 mm, the welding position of the workpiece and the laser are based on the scale of the steel rule 108a. Since this is a method of visually confirming the amount of positional deviation from the focal position of the light, measurement error of the focal length of the laser beam with respect to the welding position of the workpiece is likely to occur. [2] In this correction work, the focal length confirmer M1 And the robot operator M2 require two-man work, and there are problems such as an inevitable increase in work man-hours.

  The present invention has been made to solve the above-described problems, and can measure the focal length of the laser beam with respect to the welding position of the workpiece with high accuracy and simpleness, and can also perform the positional deviation correction work of the laser welding apparatus by one person. An object of the present invention is to provide a laser welding focal length measuring device capable of performing the following.

In order to solve the above problems, a laser welding focal length measuring apparatus according to the present invention has the following configuration.
(1) A laser welding focal length measurement device that is mounted on a scanner unit of a laser welding device and measures a focal length of laser light with respect to a welding position of a workpiece,
A main scale portion formed so that a front end portion can be brought into contact with a welding position of the workpiece, and formed so as to be movable along a front-rear direction of the main scale portion. A digital depth gauge having a display part that displays as a displacement amount with respect to the size and a slider part in which an alarm part is formed;
An accommodation holding portion is formed adjacent to and parallel to the optical axis of the laser beam to accommodate and hold the slider portion on the front end side, and the rear end portion of the main scale portion moves rearward on the rear end side. A main body portion formed with a concave groove portion that allows to be provided, and an attachment portion formed so as to be attachable to the scanner portion on the rear end side of the main body portion,
The alarm unit generates alarm information when a movement displacement amount displayed by the display unit reaches within a specified value of the focal length.

In the present invention, the main scale part formed so that the front end portion can come into contact with the welding position of the workpiece, and the main scale part is formed so as to be movable along the front-rear direction of the main scale part. A digital depth gauge having a display part for displaying as a positional deviation amount with respect to the exact size and a slider part on which an alarm part is formed, and a slider part disposed adjacent to and parallel to the optical axis of the laser beam, A storage holding portion for storing and holding is formed, and a main body portion having a recessed groove portion that allows the rear end portion of the main scale portion to move backward is formed on the rear end side. An attachment part formed so as to be attachable to the scanner part,
The alarm unit generates alarm information when the amount of displacement displayed on the display unit falls within the specified focal length, so that the temporary teaching state where the front end of the main scale unit is in contact with the welding position of the workpiece Then, the scanner part of the laser welding apparatus is moved along the longitudinal direction of the main scale part, the alarm part is confirmed to generate alarm information, and the movement of the scanner part of the laser welding apparatus is stopped. . Therefore, it is not necessary to observe the moving displacement amount displayed on the digital depth gauge display with high accuracy while the scanner unit of the laser welding device is moving, and the scanner unit of the laser welding device is stopped in response to alarm information. After that, it is only necessary to confirm whether or not the amount of movement displacement displayed on the display unit is within a prescribed value of the focal length of the laser beam. If the amount of movement displacement displayed on the display unit is within the prescribed value of the focal length of the laser beam, the position is re-taught as the normal position of the scanner unit, and the positional deviation correction of the scanner unit of the laser welding apparatus is performed. Can be performed accurately and easily. Therefore, it is possible to perform the positional deviation correction operation of the laser welding apparatus by one person while reducing human errors such as reading errors of the numbers on the display unit. Note that the alarm information generated from the alarm unit corresponds to, for example, lighting of an alarm lamp or generation of an alarm sound.
Therefore, according to the present invention, the focal length of the laser beam with respect to the welding position of the workpiece can be easily measured with high accuracy, and the position deviation correction operation of the laser welding apparatus can be performed by one person.

(2) In the laser welding focal length measuring device described in (1),
A sensor part for detecting the position of the rear end part of the main scale part is attached to the main body part of the attachment part, and the movement displacement amount of the slider part is determined by the detection signal from the sensor part as a prescribed value of the focal length. Preliminary alarm information is generated from the alarm unit of the sensor unit or the slider unit before reaching within.

In the present invention, a sensor part for detecting the position of the rear end part of the main scale part is attached to the main body part of the attachment part, and the movement displacement amount of the slider part is determined by the detection value from the sensor part as a prescribed value of the focal length. The preliminary alarm information is generated from the alarm part of the sensor part or slider part before reaching within, so the scanner part of the laser welding equipment is moved at high speed until the preliminary alarm information is generated, and the preliminary alarm information is generated. After that you can do it at low speed. For this reason, it is possible to quickly and accurately perform the action of causing the movement displacement amount displayed on the display unit to fall within the prescribed value of the focal length of the laser beam while preventing overrun of the scanner unit. Further, since overrun of the scanner unit can be prevented, damage to the laser welding focal length measuring device due to an operation error can be avoided.
As a result, the focal length of the laser beam with respect to the welding position of the workpiece can be measured more accurately and easily, and the misalignment correction operation of the laser welding apparatus can be performed more quickly and accurately by one person.

(3) In the laser welding focal length measuring device described in (2),
The sensor unit is a non-contact type magnetic sensor, and a magnetic member is attached to a rear end portion of the main scale unit.

In the present invention, the sensor unit is a non-contact type magnetic sensor, and a magnetic member is attached to the rear end portion of the main scale unit. Therefore, the main unit of the digital depth gauge is a non-ferrous material such as an aluminum alloy. Even if it is a member, the position of the rear-end part of a main scale part can be detected correctly. Further, since the sensor unit is a non-contact type, there is no fear of damage due to an erroneous operation.
As a result, the focal length of the laser beam with respect to the welding position of the workpiece can be measured with higher accuracy and ease, and the durability as a measuring device can be enhanced.

(4) In the laser welding focal length measurement device described in any one of (1) to (3),
The attachment part is formed so as to be attachable to the scanner part through a base part having a through hole through which the laser light passes, and is arranged around the optical axis of the laser light with respect to the base part. It is formed to be rotatable in the direction.

  In the present invention, the attachment portion is formed so as to be attachable to the scanner portion through a base portion having a through hole through which laser light passes, and is arranged around the optical axis of the laser light with respect to the base portion. Since it is formed so as to be rotatable in the direction, even if the position of the scanner unit is changed corresponding to the welding position of the workpiece, the attachment unit is rotated in the circumferential direction around the optical axis of the laser beam. The visibility of the display unit from the operator can be ensured without changing the focal length of the laser beam with respect to the welding position. Further, when laser welding a workpiece formed symmetrically, the focal length of the laser beam with respect to the welding position of the workpiece can be measured using the same laser welding focal length measuring device.

(5) In the laser welding focal length measuring device described in (4),
The base portion includes a flange portion that is inserted and fixed between a scanner main body of the scanner portion and a laser output side cover body.

  In the present invention, since the base portion includes a collar portion that is inserted and fixed between the scanner main body of the scanner portion and the laser output side cover body, the laser output side cover body is removed from the scanner main body of the scanner portion. The focal length of the laser beam with respect to the welding position of the workpiece can be measured without any problem. Therefore, the trouble of removing the laser output side cover body can be omitted, and damage to the optical system member housed in the scanner body which is the heart can be avoided.

  According to the present invention, it is possible to provide a laser welding focal length measuring device that can easily and accurately measure the focal length of a laser beam with respect to a welding position of a workpiece and can perform misalignment correction work of the laser welding device by one person. Can do.

It is a typical perspective view of the laser welding focal length measuring device concerning the embodiment of the present invention. It is a top view of the laser welding focal distance measuring apparatus shown in FIG. It is AA sectional drawing shown in FIG. It is a side view showing the use condition of the laser welding focal distance measuring apparatus shown in FIG. It is a control block diagram of the laser welding focal length measuring apparatus shown in FIG. It is a flowchart figure which shows the measuring method of the laser welding focal distance measuring apparatus shown in FIG. It is a schematic block diagram of the laser welding apparatus described in patent document 1. It is a specific block diagram of the scanner unit shown in FIG. It is explanatory drawing of the method of measuring the positional offset amount of the welding position of a workpiece | work and the focus position of a laser beam using the conventional simple measuring tool. FIG. 10 is an explanatory diagram of a method for correcting the positional deviation of the focal length by applying the simple measuring tool shown in FIG. 9 to the laser welding apparatus shown in FIG. 7.

  Next, a laser welding focal length measuring apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings. First, the overall structure of the laser welding focal length measuring device according to the present embodiment will be described, and then the laser welding focal length measuring device is used as the laser welding device, and the focal point of the laser beam with respect to the welding position based on the actual workpiece. A method for measuring the distance and correcting the misalignment of the scanner unit will be described in detail.

<Overall structure of laser welding focal length measuring device>
First, the overall structure of the laser welding focal length measuring apparatus according to the present embodiment will be described with reference to FIGS. FIG. 1 shows a schematic perspective view of a laser welding focal length measuring apparatus according to an embodiment of the present invention. FIG. 2 shows a top view of the laser welding focal length measuring apparatus shown in FIG. FIG. 3 is a cross-sectional view taken along the line AA shown in FIG. FIG. 4 is a side view showing a use state of the laser welding focal length measuring device shown in FIG. FIG. 5 shows a control block diagram of the laser welding focal length measuring apparatus shown in FIG.

  As shown in FIGS. 1 to 5, the laser welding focal length measurement device 10 according to the present embodiment is attached to the scanner unit 1 of the laser welding device 20 and the focal length of the laser beam RB with respect to the welding position WS of the workpiece W. It is a device that measures. The laser welding apparatus 20 will not be described in detail, but a scanner unit 1 having an optical system member that irradiates the workpiece W with the laser beam RB, and a multi-axis robot apparatus in which the scanner unit 1 is attached to the tip of the arm unit ( (Not shown), a scanner control unit (not shown) for controlling the operation of the optical system member of the scanner unit 1, and a robot control unit (not shown) for controlling the operation of the arm unit and the like of the multi-axis robot apparatus. It has.

  In the laser welding focal length measuring device 10, the main scale portion 2 formed so that the front end portion 21 can come into contact with the welding position WS of the workpiece W, and the front-rear direction F (longitudinal direction) of the main scale portion 2. A digital depth gauge 4 having a display unit 31 and a slider unit 3 on which an alarm unit 32 is formed, which is formed so as to be movable, and displays the displacement amount as a positional deviation amount with respect to the exact focal length of the laser beam. Yes.

  The front end portion 21 of the main scale portion 2 is formed in a tapered shape so as to avoid interference with the workpiece W. Further, a magnetic member 23 (for example, a magnet) is fixed to the rear end portion 22 of the main scale portion 2. The main scale unit 2 incorporates a capacitive encoder 24 for detecting the amount of displacement of the slider unit 3.

  The slider unit 3 includes a detection unit 35 that detects an electrical signal output from the encoder 24 corresponding to the amount of movement displacement of the slider unit 3 in the front-rear direction with respect to the main scale unit 2, and the movement displacement amount detected by the detection unit 35. Display unit 31 for displaying numerical values, a power switch 34, a setting unit 33 for setting the positional deviation amount with respect to the exact focal length of the laser beam to "0", and a positional deviation amount when set to "0". A storage unit 36 that stores the position of the slider unit 3, a determination unit 37 that determines that the movement displacement amount has reached within the prescribed value of the focal length, and that the movement displacement amount has reached within the prescribed value of the focal length. When the determination unit 37 determines, an alarm unit 32 that generates this alarm information is provided. The positional accuracy that can be detected by the digital depth gauge 4 is, for example, within ± 0.1 mm. The prescribed value of the focal length means an allowable value of the positional deviation amount with respect to the exact focal length. The alarm information generated from the alarm unit 32 corresponds to, for example, lighting of an alarm lamp or generation of an alarm sound.

  Further, the laser welding focal length measuring device 10 is provided with an accommodation holding portion 511 that is arranged adjacent to and parallel to the optical axis BJ of the laser beam RB, and accommodates and holds the slider portion 3 on the front end side. It has a main body portion 51 formed with a concave groove portion 512 that allows the rear end portion 22 of the main scale portion 2 to move rearward on the end side, and can be attached to the scanner portion 1 on the rear end side of the main body portion 51. The formed attachment part 5 is provided. The distance between the optical axis BJ of the laser beam RB and the main body 51 of the attachment unit 5 is preferably about 2 to 3 mm. The attachment part 5 includes a main body part 51 and a mounting part 52, and is formed in a substantially L-shaped cross section. The main body 51 and the mounting portion 52 are each formed in a substantially rectangular shape having the same width.

  A sensor unit 6 for detecting the position of the rear end portion 22 of the main scale unit 2 is attached to the main body unit 51 of the attachment unit 5, and the movement displacement amount of the slider unit 3 is determined by the detection signal from the sensor unit 6. Preliminary alarm information is generated from the alarm unit 62 or 32 of the sensor unit 6 or the slider unit 3 before reaching within the prescribed value of the focal length. The detection unit 61 of the sensor unit 6 is disposed so as not to contact the main scale unit 2.

  The sensor unit 6 is, for example, a non-contact type magnetic sensor. In this case, a magnetic member 23 (for example, a magnet) is attached to the rear end portion 22 of the main scale portion 2. Therefore, even if the main scale part 2 of the digital depth gauge 4 is a non-ferrous member such as an aluminum alloy, the position of the rear end part 22 of the main scale part 2 can be reliably detected.

  The attachment unit 5 is formed so as to be attachable to the scanner unit 1 through a base unit 7 having a through hole 71 through which the laser beam RB passes, and the optical axis BJ of the laser beam RB with respect to the base unit 7. Is formed so as to be rotatable in the circumferential direction R. Further, a through hole 522 through which the laser beam RB passes is formed in the mounting portion 52 of the attachment unit 5, and a rotation shaft portion 521 having the optical axis BJ of the laser beam RB as an axis is formed to protrude rearward. . A bearing portion 72 that supports the rotating shaft portion 521 of the attachment portion 5 is fitted to the base portion 7. Therefore, the attachment part 5 can rotate in the circumferential direction around the rotation shaft part 521 with respect to the base part 7.

  In addition, the base unit 7 includes a collar portion 73 that is inserted and fixed between the scanner main body 11 of the scanner unit 1 and the laser output side cover body 12. The collar portion 73 is formed with an insertion hole 231 through which the thumbscrew portion 13 that engages with the nut portion 112 fixed to the scanner body 11 via the collar portion 113 is inserted. The thumbscrew part 13 is inserted from the gap between the laser output side cover body 12 and the base part 7 and fastened to the nut part 112. Further, the exit portion 111 of the laser beam RB of the scanner body 11 is formed in an annular convex shape, and the rear end portion 732 of the base portion 7 is formed in a concave shape so as to be slidable with the exit portion 111.

<Measurement method of focal length>
Next, the laser welding focal length measurement device 10 is attached to the scanner unit 1 of the laser welding device 20, and the focal length of the laser beam with respect to the welding position is measured based on the actual workpiece, and the positional deviation of the scanner unit is corrected. The method will be described in detail with reference to FIG. FIG. 6 is a flowchart showing a measuring method of the laser welding focal length measuring apparatus shown in FIG.

  As shown in FIG. 6, first, the laser welding focal length measuring device 10 is mounted on the scanner unit 1 of the laser welding device 20 (step: S1). Specifically, the flange 73 of the base unit 7 is inserted and fixed between the scanner main body 11 of the scanner unit 1 and the laser output side cover body 12. Next, the front end portion 21 of the main scale portion 2 is adjusted to the exact position of the focal length of the laser beam by a setting gauge (not shown), and the numerical value of the display portion at that time is set to “0” (step: S2). ). Setting of the numerical value of the display unit to “0” (“0” point alignment) is performed by the setting unit 33 of the digital depth gauge 4. The setting gauge is a gauge that can be attached to the scanner unit 1 and can confirm the exact position of the focal length of the laser beam. Adjustment of the focal length of the laser beam RB is performed by adjusting the optical system member of the scanner unit 1.

  Next, the scanner unit 1 of the laser welding apparatus 20 is moved to the temporary teaching position, and the front end portion 21 of the main scale unit 2 is brought into contact with the welding position WS of the workpiece W (step: S3). The provisional teaching position is the position of the scanner unit 1 that is provisionally taught so that the welding position of the workpiece W and the focal position of the laser beam RB coincide with each other based on the design position data of the workpiece W or the like. The scanner unit 1 is moved by operating the operation panel of the multi-axis robot apparatus. At this time, the attachment unit 5 may be rotated around the optical axis BJ of the laser beam RB while the scanner unit 1 is fixed so that the display unit 31 of the digital depth gauge 4 can be easily viewed from the operator. The main scale 2 is preferably brought into contact with the welding position WS of the workpiece W substantially vertically.

  Next, the slider part 3 is moved along the front-rear direction F of the main part 2 from the temporary teaching state in which the front end part 21 of the main part 2 is brought into contact with the welding position WS of the workpiece W (step: S4). . Until the preliminary alarm sounds, the moving speed of the slider unit 3 may be high (for example, about 1 to 2 m / s). Next, when the preliminary alarm sounds, the movement displacement amount of the display unit 31 is read and compared with the prescribed value of the focal length, and further moved so that the movement displacement amount of the display unit 31 is within the prescribed value of the focal length. (Step: S5). The moving speed of the slider part 3 at this time is good to make it low speed (for example, about 0.1-0.2 m / s) in consideration of the inertia of the arm part etc. of a multi-axis robot apparatus. Note that within the prescribed value of the focal length of the laser beam RB is, for example, within ± 1 mm of the exact focal length.

  Next, when this alarm sounds, the scanner unit 1 of the laser welding apparatus 20 is immediately stopped (step: S6). Next, it is confirmed whether or not the numerical value of the movement displacement amount displayed on the display unit 31 is within a specified value of the focal length of the laser beam RB (step: S7). If the numerical value of the movement displacement amount displayed on the display unit 31 is within the prescribed value of the focal length of the laser beam RB, the position is set as the normal position of the scanner unit with respect to the actual workpiece, and the operation panel is connected to the laser welding apparatus 20. Is re-taught and stored (step: S8).

  On the other hand, if the numerical value of the movement displacement amount displayed on the display unit 31 exceeds the prescribed value of the focal length of the laser beam RB, the positional deviation of the scanner unit 1 is detected while observing the movement displacement amount of the display unit 31. Correction is made (step: S9). Then, again, it is confirmed whether or not the numerical value of the movement displacement amount displayed on the display unit 31 is within the prescribed value of the focal length of the laser beam RB (step: S7), and the movement displacement amount displayed on the display unit 31. Is within the specified value of the focal length of the laser beam RB, the position is regarded as the normal position of the scanner unit with respect to the actual workpiece, and the laser welding apparatus 20 is operated to re-teach and store it by operating the operation panel (step: S8).

  By repeating the operations in steps S3 to S9 described above for the next welding position, it is possible to correct the positional deviation of the focal length of the laser beam with respect to all the welding positions of the actual workpiece.

<Effect>
As described above in detail, according to the laser welding focal length measuring apparatus 10 according to the present embodiment, the main scale portion 2 formed so that the front end portion 21 can come into contact with the welding position WS of the workpiece W, and the book A slider formed with a display unit 31 and an alarm unit 32 that are formed to be movable along the front-rear direction F of the scale unit 2 and display the amount of displacement as a positional deviation amount with respect to the exact focal length of the laser beam RB. A digital depth gauge 4 having a portion 3 and a storage holding portion 511 which is disposed adjacent to and parallel to the optical axis BJ of the laser beam RB, and stores and holds the slider portion 3 on the front end side, is formed on the rear end side. The main scale part 2 has a main body part 51 formed with a concave groove part 512 that allows the rear end part 22 to move backward, and is formed so as to be attachable to the scanner part 1 on the rear end side of the main body part 51. An attachment unit 5;
The alarm unit 32 generates alarm information when the movement displacement amount displayed on the display unit 31 reaches within the prescribed value of the focal length, so the front end portion 21 of the main scale unit 2 is set to the welding position WS of the workpiece W. From the contacted temporary teaching state, the scanner unit 1 of the laser welding device 20 is moved along the front-rear direction F of the main scale unit 2 to confirm that alarm information is generated from the alarm unit 32, and the laser welding device The movement of the 20 scanner units 1 may be stopped. Therefore, during the movement of the scanner unit 1 of the laser welding apparatus 20, it is not necessary to visually observe the moving displacement amount displayed on the display unit 31 of the digital depth gauge 4 with high accuracy, and the laser welding apparatus 20 receives the alarm information. After the scanner unit 1 is stopped, it is only necessary to confirm whether or not the movement displacement amount displayed on the display unit 31 is within the prescribed value of the focal length of the laser beam. If the movement displacement amount displayed on the display unit 31 is within the prescribed value of the focal length of the laser beam, the position is re-taught as the normal position of the scanner unit 1, and the scanner unit 1 of the laser welding apparatus 20 is re-taught. It is possible to easily correct the misalignment with high accuracy. Therefore, it is possible to perform the positional deviation correction operation of the laser welding apparatus 20 by one person while reducing human errors such as reading errors of the numbers on the display unit 31. The alarm information generated from the alarm unit 32 corresponds to, for example, lighting of an alarm lamp or generation of an alarm sound.
Therefore, according to the present embodiment, the focal distance of the laser beam RB with respect to the welding position WS of the workpiece W can be measured with high accuracy and easily, and the positional deviation correction work of the laser welding apparatus 20 can be performed by one person.

Further, according to the present embodiment, the sensor unit 6 that detects the position of the rear end portion 22 of the main scale unit 2 is attached to the main body unit 51 of the attachment unit 5, and the slider unit is detected by a detection signal from the sensor unit 6. Since the preliminary alarm information is generated from the alarm unit 62 or 32 of the sensor unit 6 or the slider unit 3 before the movement displacement amount of 3 reaches within the prescribed value of the focal length, the movement of the scanner unit 1 of the laser welding apparatus 20 is performed. The preliminary alarm information is generated at high speed, and the preliminary alarm information is generated at low speed. Therefore, it is possible to quickly and accurately perform the action of causing the movement displacement amount displayed on the display unit 31 to fall within the prescribed value of the focal length of the laser beam RB while preventing overrun of the scanner unit 1. In addition, since overrun of the scanner unit 1 can be prevented, damage to the laser welding focal length measurement device 10 due to an operation error can be avoided.
As a result, the focal length of the laser beam RB with respect to the welding position WS of the workpiece W can be measured with higher accuracy and ease, and the positional deviation correction operation of the laser welding apparatus 20 can be performed more quickly and accurately by one person.

According to the present embodiment, the sensor unit 6 is a non-contact type magnetic sensor, and the magnetic member 23 is attached to the rear end 22 of the main scale unit 2. Even if the main scale portion 2 is a non-ferrous member such as an aluminum alloy, the position of the rear end portion 22 of the main scale portion 2 can be accurately detected. Further, since the sensor unit 6 is a non-contact type, there is no fear of damage due to an erroneous operation.
As a result, the focal length of the laser beam RB with respect to the welding position WS of the workpiece W can be measured more accurately and easily, and the durability as a measuring device can be further improved.

  Further, according to the present embodiment, the attachment unit 5 is formed to be attachable to the scanner unit 1 through the base unit 7 having the through hole 71 through which the laser beam RB passes, and is attached to the base unit 7. Since it is formed so as to be rotatable in the circumferential direction R around the optical axis BJ of the laser beam RB, even if the position of the scanner unit 1 is changed corresponding to the welding position WS of the workpiece W, the attachment unit 5 is laser By rotating in the circumferential direction R about the optical axis BJ of the light RB, the visibility of the display unit 31 from the operator is ensured without changing the focal length of the laser beam RB with respect to the welding position WS of the workpiece W. can do. Further, when laser welding is performed on the workpiece W formed symmetrically, the focal length of the laser beam RB with respect to the welding position WS of the workpiece W can be measured using the same laser welding focal length measuring device 10.

  Further, according to the present embodiment, the base unit 7 includes the collar portion 73 that is inserted and fixed between the scanner body 11 of the scanner unit 1 and the laser output side cover body 12. The focal length of the laser beam RB with respect to the welding position WS of the workpiece W can be measured without removing the laser output side cover body 12 from the scanner body 11. Therefore, the trouble of removing the laser output side cover body 12 can be omitted, and damage to the optical system member housed in the scanner body 11 that is the heart can be avoided.

In addition, it cannot be overemphasized that this embodiment can be changed in the range which does not change the summary of this invention.
For example, in the present embodiment, the attachment unit 5 is formed so as to be attachable to the scanner unit 1 via the base unit 7 having the through hole 71 through which the laser beam RB passes, and the laser beam is applied to the base unit 7. Although it is formed so as to be rotatable in the circumferential direction R around the optical axis BJ of RB, it is not necessarily formed so as to be attachable to the scanner unit 1 via the base unit 7. For example, the attachment unit 5 may be directly attached to the scanner unit 1.

  INDUSTRIAL APPLICABILITY The present invention can be used as a laser welding focal length measurement device that is mounted on a scanner unit that irradiates laser light of a laser welding device and measures the focal length of laser light with respect to a workpiece welding position.

DESCRIPTION OF SYMBOLS 1 Scanner part 2 Main scale part 3 Slider part 4 Digital depth gauge 5 Attachment part 6 Sensor part 7 Base part 10 Laser welding focal distance measuring device 11 Scanner main body 12 Laser output side cover body 20 Laser welding apparatus 21 Front end part 22 Rear end part 23 Magnetic member 31 Display unit 32, 62 Alarm unit 51 Main body unit 61 Detection unit 71 Through hole 73 Gutter part 511 Storage holding part 512 Groove part RB Laser beam BJ Optical axis W Work WS Welding position

Claims (5)

A laser welding focal length measurement device that is mounted on a scanner unit of a laser welding device and measures a focal length of laser light with respect to a workpiece welding position,
A main scale portion formed so that a front end portion can be brought into contact with a welding position of the workpiece, and formed so as to be movable along a front-rear direction of the main scale portion. A digital depth gauge having a display part that displays as a displacement amount with respect to the size and a slider part in which an alarm part is formed;
An accommodation holding portion is formed adjacent to and parallel to the optical axis of the laser beam to accommodate and hold the slider portion on the front end side, and the rear end portion of the main scale portion moves rearward on the rear end side. A main body portion formed with a concave groove portion that allows to be provided, and an attachment portion formed so as to be attachable to the scanner portion on the rear end side of the main body portion,
The laser welding focal length measuring device, wherein the alarm unit generates alarm information when a movement displacement amount displayed by the display unit reaches within a prescribed value of the focal length. In the laser welding focal length measuring device according to claim 1,
A sensor part for detecting the position of the rear end part of the main scale part is attached to the main body part of the attachment part, and the movement displacement amount of the slider part is determined by the detection signal from the sensor part as a prescribed value of the focal length. The laser welding focal length measuring device is characterized in that preliminary alarm information is generated from the alarm unit of the sensor unit or the slider unit before reaching within. In the laser welding focal length measuring device according to claim 2,
The laser welding focal length measuring device, wherein the sensor unit is a non-contact type magnetic sensor, and a magnetic member is attached to a rear end portion of the main scale unit. In the laser welding focal length measuring device according to any one of claims 1 to 3,
The attachment part is formed so as to be attachable to the scanner part through a base part having a through hole through which the laser light passes, and is arranged around the optical axis of the laser light with respect to the base part. A laser welding focal length measuring device characterized by being formed to be rotatable in a direction. In the laser welding focal length measuring device according to claim 4,
The laser beam focal length measuring apparatus according to claim 1, wherein the base portion includes a flange portion that is inserted and fixed between a scanner body of the scanner portion and a laser output side cover body.

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