JP2007319922A - Laser beam machining apparatus and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining apparatus and a method therefor which enable the machining position in laser beam machining to be discriminated. <P>SOLUTION: Upon the formation of weld beads 100, marks 101 showing the weld beads 100 and the welding order of the weld beads 100 are drawn by laser beam. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laser processing apparatus and a method thereof.

In recent years, laser welding has come to be used for welding using a robot. As such a welding technique, by attaching a laser irradiation device for irradiating laser light to the tip of a robot arm (manipulator), moving the robot arm, and further changing the direction of laser light irradiation from the laser irradiation device, There is a technique for welding a predetermined welding point while moving a laser beam (see, for example, Patent Document 1). Such welding is called remote welding because the workpiece and the laser irradiation apparatus are further away from each other.
JP 2005-177862 A

  By the way, in such remote welding, since the work head that is the final irradiation source of the laser beam and the work are separated, the laser irradiation is performed when the position of the weld bead on the work is displaced. There was a problem that it was difficult to understand the relationship between the original position and angle and the misaligned weld bead. In particular, in the case where there are a plurality of welding points on the same workpiece, it may be unclear which welding instruction (teaching position) the shifted welding point is based on.

  Accordingly, an object of the present invention is to provide a laser processing apparatus and method capable of identifying each of a plurality of processing positions when processing a laser beam on a workpiece from a distant position. is there.

  In order to achieve the above object, the present invention provides a laser irradiation means having a movable mirror for changing the irradiation direction of laser light, a moving means for moving the laser irradiation means, and a route taught in advance. And moving the moving means and the reflecting mirror to irradiate the laser beam on the workpiece at a machining position, and at least the reflection so that a mark for identifying the machining condition is drawn on the workpiece by the laser beam. And a control means for controlling the mirror.

  Further, the present invention for achieving the above object is a processing having a laser irradiation means having a reflecting mirror movable to change the irradiation direction of the laser light, and a moving means for moving the laser irradiation means. A laser processing method using an apparatus, wherein a mark for identifying a predetermined processing condition is drawn by the laser beam.

  According to the present invention, since the mark for identifying the processing condition is drawn by the laser, the condition can be identified for each processing position from the laser irradiation mark actually irradiated with the laser. When there are a plurality of machining positions, the difference in machining conditions at each machining position can be distinguished. Also, for example, if a mark that can identify the machining position is drawn as the machining condition, even if there is a deviation in the laser irradiation position itself, it is possible to determine which machining position is misaligned. It is possible to determine after the work.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram for explaining a configuration of a remote welding system (hereinafter simply referred to as a system) to which the present invention is applied.

  In the illustrated system, the welding jig is not directly in contact with the workpiece, but is welded from a place away from the workpiece using a laser beam, as compared with conventional spot welding or the like. For this reason, such welding is called remote welding.

  This system includes a robot 1, a robot controller 2 that controls the robot 1 in accordance with instructions from a control device 4 to be described later, a scanner head 6 (laser irradiating means) that is provided at the arm tip of the robot 1 and irradiates laser light. An optical fiber cable 5 (hereinafter abbreviated as optical fiber 5) for guiding laser light from a laser oscillator 3 serving as a laser light source to a scanner head 6, and an operation instruction of the robot 1, a scanner head 6, and a control device 4 for controlling the laser oscillator 3 ( Control means).

  Here, the control device 4 is, for example, a computer, and includes a central processing unit, a storage device, and the like. The control device 4 controls formation of a weld bead in the normal mode (first mode) and formation of a mark for identifying a welding spot for the test mode (second mode).

  The laser oscillator 3 uses a YAG laser oscillator to guide the laser light through the optical fiber 5.

  The robot 1 is a general multi-axis robot (also referred to as a multi-joint robot or the like), and changes its posture according to the data of the operation path given by the teaching work, that is, the scanner head 6. Can be moved in various directions. The movement range of the laser irradiation is shown as 7 in the figure.

  FIG. 2 is an explanatory diagram for explaining the internal configuration of the scanner head 6.

  As shown in the figure, the scanner head 6 includes an optical fiber 5, an optical fiber holding unit 12 that holds the optical fiber, a fiber position changing mechanism 13, a fiber actuator control device 14, a collimator lens 16, a fixed mirror 17, and a condensing distance variable lens. 19, a first lens 110, a second lens 111, a condensing distance variable lens actuator 112, a laser scanning mirror 113 (reflecting mirror), a mirror actuator 114, and a mirror control device 115. In the drawing, reference numeral 15 indicates a laser beam.

  In this scanner head 6, the laser light 15 that has passed through the collimating lens 16 passes through the fixed mirror 17, the condensing distance variable lens 19, the first lens 110, and the second condensing lens 111, and further, the laser scanning mirror 113. It is reflected by and emitted.

  The laser scanning mirror 113 can be freely rotated by a mirror actuator 114, and the mirror control device 115 is rotated based on the focal speed data taught in advance. The mirror control device 115 calculates the rotational angular velocity of the laser scanning mirror 113 for obtaining the focal velocity from the focal velocity data, and performs laser scanning so as to obtain the taught (or commanded) focal velocity. The mirror 113 is controlled.

  Further, the fiber actuator controller 14 controls the fiber position changing mechanism 13 in accordance with the laser irradiation distance 116 from the scanner head 6 to the workpiece 117 in the welding path, and changes the position of the laser emission end 61 of the optical fiber 5. The laser focus position in the welding path is adjusted. Further, the condensing distance varying lens 19 is a laser focal length when the laser irradiation distance from the scanner head 6 to the workpiece is greatly changed, such as when the installation position of the laser welding apparatus itself is changed or when the workpiece is changed. The position can be moved for alignment. The condensing distance varying lens 19 is fixed during the welding operation, and the focal length during the welding operation is changed only by changing the position of the laser emission end 61 of the optical fiber 5 as described above. Alternatively, the focusing of the laser beam may be performed by moving the position of the condensing distance varying lens 19 during the welding operation.

  As described above, in this laser welding apparatus, it is possible to irradiate laser light in various directions by the movement of the laser scanning mirror 113 together with the movement of the scanner head 6 by the robot 1.

  The irradiation range of the laser beam by the scanner head 6 is a three-dimensional range as indicated by reference numeral 7 in FIG. That is, the position of the XY direction can be changed by the reflecting mirror 11, and the direction of the Z direction can be changed by changing the position of the conflict point by the lens group 12.

  Therefore, at the time of laser welding, a combined speed of the operating speed (robot speed) of the robot 1 that moves the scanner head 6 by the movement of the robot 1 and the moving speed (focus speed) of the laser focus position by the laser scanning mirror 113. (Welding point speed).

  The control device 4 stores in advance teaching data that is an operation path of the robot 1 and instructs the robot controller 2 to operate according to the teaching data. Specifically, the teaching data corresponds to, for example, an operation path of the robot during the welding operation (that is, a path for moving the scanner head 6), an operation speed of the robot 1 during the operation path, and an operation path of the robot 1. The focus speed by the laser scanning mirror 113, the order of the welding points to be welded by irradiating the laser beam during this operation path, and the welding conditions.

  The welding conditions include welding point speed, which is the combined speed of the robot speed and the focal speed, laser output value, laser irradiation start position and laser irradiation end position for each welding point in normal operation (first mode), and test mode ( Mark data for forming different marks on the workpiece for each welding point in the second mode).

  In the normal mode, the laser irradiation start position and the laser irradiation end position at one welding point (one processing position) correspond to the current position of the robot acquired from the encoder (not shown) of each axis of the robot 1. The laser corresponding to the current rotation angle of the laser scanning mirror 113 acquired from the encoder (not shown) of the mirror actuator 114 so that the welding point to be welded at the current position has a predetermined bead shape. The irradiation position is calculated in real time, laser irradiation is started when the laser irradiation start point is reached, and laser irradiation is ended when the laser irradiation end point is reached.

  On the other hand, in the test mode, for the laser irradiation start position, a start instruction is input corresponding to the current position of the robot acquired from the encoder (not shown) of each axis of the robot 1 as in the normal mode. At this time, a mark pattern corresponding to the order of the welding points at that position is read out, and laser light is irradiated so as to become the mark. The laser irradiation end point is the time when the drawing of the mark is finished. At this time, the laser end point is controlled so as not to be later than the laser irradiation start at the next welding point taught in advance. That is, the time for drawing the mark in the test mode is set to be shorter than the time for performing laser irradiation on one welding point (processing position) in the normal mode.

  Here, the mark pattern will be described.

  FIG. 3 is an explanatory diagram for explaining an example of a mark pattern.

  First, FIG. 3A schematically shows a state of a normal weld bead. In this figure, a normal weld bead 100 is linear. Moreover, the welding points are arranged in the order of 1 to 3. In the figure, the waveform shown below the weld bead indicates the laser irradiation time (same in each figure). In the normal mode, as shown in FIG. 3 (a1), the laser beam is applied to the workpiece during the formation of the weld bead.

  In the mark pattern example 1, as shown in FIG. 3B, for example, the order of the welding points is indicated by the number of points near the weld bead 100 as the mark 101.

  As a specific method for indicating the order of welding points by the number of points in this way, for example, the operations of the scanner head 6 and the mirror actuator 114 (that is, controlling the movement of the mirror 113) are in the normal mode. In the same manner, from the time when the scanner head 6 reaches the laser irradiation position to each welding point in the normal mode to the time when the welding at the welding point is finished (FIG. 3 (b2)), FIG. 3 (b1). ), The mirror actuator 114 is operated by the number of points in the order of the welding points, and the mirror 113 is slightly swung in a direction different from the bead formation direction. Specifically, the direction different from the bead forming direction is, for example, that the mirrors are swung by the number corresponding to the welding order perpendicular to the bead forming direction. Thereby, the point which becomes the order of a welding point is drawn by the side of a welding bead. The swing angle of the mirror 113 is determined according to the distance from the scanner head 6 to the work 117.

  Even in this test mode, the time required for forming the weld bead and the mark pattern is the time from the point at which the laser irradiation position is reached in the normal mode to the point at which the welding at the welding point ends, that is, the weld bead in the normal mode. It is preferable to match the formation time. This is because if the time required to form each weld bead is different between the normal mode and the test mode, the weld point position in the test mode is shifted.

  In the mark pattern example 1, the drawn dot-shaped mark 101 is not actually a perfect circular point, but may have a shape in which wrinkles extend from the weld bead. The shape may be any shape as long as it can be identified. For example, instead of a point, a straight line extending in another direction that can be identified from the weld bead in the normal mode may be used.

  Next, an example of another mark pattern is shown in FIG.

  This mark pattern example 2 is used as a mark 102 from the time when the scanner head 6 reaches the laser irradiation position to each welding point in the normal mode to the time when the welding at that welding point ends ((FIG. 3 ( c2)), as shown in FIG. 3 (c1), a number indicating the welding order is drawn at the weld bead formation position in the normal mode (weld bead 100 indicated by a dotted line in the drawing).

  As a specific method in this case, for example, a weld bead pattern for a test mode is prepared in advance (stored in a storage device or the like in the control device 4), and instead of the weld bead pattern in the normal mode. Then, the operation of the mirror actuator 114 is controlled so as to draw the number pattern for the test mode (that is, the movement of the mirror 113 is controlled).

  In this pattern example 2, the weld bead is not formed in the normal mode, but instead, a number indicating the order of each welding point is drawn, so that the visibility is good. Also in the case of this pattern example 2, as shown in FIG. 3 (c2), the time during which the mark pattern is drawn is set to be the same as the time during which the weld bead is formed in the normal mode.

  Still another example of the mark pattern is shown in FIG.

  In this mark pattern example 3, as the mark 103, the time from the time when the scanner head 6 reaches the laser irradiation position to each welding point in the normal mode to the time when the welding at the welding point ends is determined from this time. In a short time, as shown in FIG. 3 (c1), a number indicating the welding order is drawn.

  As a specific method in this case, for example, a weld bead pattern for a test mode is prepared in advance (stored in a storage device or the like in the control device 4), and instead of the weld bead pattern in the normal mode. Then, the operation of the mirror actuator 114 is controlled so as to draw the number pattern for the test mode (that is, the movement of the mirror 113 is controlled). In the case of Example 3, the park pattern 103 may be smaller because it is necessary to draw a number earlier than the mark 102 of Example 2.

  Even in this mark pattern example 3, the weld bead is not formed in the normal mode, but instead, a number indicating the order of each welding point is drawn, so that the visibility is good. Further, in this mark pattern example 3, the time for drawing each mark 103 is earlier than the time for forming the weld bead in the normal mode as shown in FIG. 3 (d2). For this reason, by making the robot operation faster than the normal mode and increasing the overall speed, it is possible to prevent the welding point from being shifted between the normal mode and the test mode, and to confirm the welding position early. It becomes possible.

  Still another example of the mark pattern is shown in FIG.

  This mark pattern example 4 is used as a mark 104 from the time when the scanner head 6 reaches the laser irradiation position to each welding point in the normal mode to the time when the welding at the welding point is finished ((FIG. 3 ( In e2)), different shapes are drawn for each order in order to identify the welding order.

  As a specific method in this case, for example, welding bead patterns having a plurality of shapes are prepared in advance for the test mode (stored in a storage device in the control device 4), and welding in the normal mode is performed. Instead of the bead pattern, the operation of the mirror actuator 114 is controlled so as to draw this test mode pattern (that is, the movement of the mirror 113 is controlled).

  Also in this mark pattern example 4, the formation of the weld bead in the normal mode is not performed, but instead, each order is indicated by a figure with a different shape, so that the “welding order of each welding point can be confused. In addition, it is possible to identify the welding order itself by associating the welding order with the figure to be drawn in advance.

  The mark pattern can have various shapes other than those described above, and may be any shape that can identify the order in which the welding points are welded, and is limited to the shape described above. It is not a thing. Further, when the number of welding points increases, it is only necessary to identify adjacent welding points, and it is not always necessary to individually identify all of the plurality of welding points on one workpiece.

  In such a test mode, the laser output value (also referred to as laser intensity) may be weaker than in the normal mode. For example, it may be less than half, 1/10, or the like, and a mark (scratch) to the extent that the number of points drawn by the laser beam on the work can be determined. In addition, the workpiece when executing the test mode is not particularly limited, but for example, when an actual workpiece is used as a test piece, it is preferable because a deviation of the welding point can be seen in consideration of the workpiece shape and the like. Of course, it goes without saying that various test pieces other than the actual workpiece may be used as the workpiece used in the test mode.

  FIG. 4 is an explanatory diagram for explaining the operation of the present embodiment. FIG. 4A shows a case where no mark pattern is applied, and FIG. 4B shows a case where a mark pattern is applied according to the present embodiment.

  In the illustrated example, for the workpiece 200, the illustrated No. Remote welding is performed from 1 to 7.

  4 (a) and 4 (b) are welding point positions where a to g indicated by a dashed line in the figure on the workpiece 200 are planned. Welding order No. 1 to 7 correspond in the order of the planned welding points a to g. On the other hand, A to G indicated by solid lines are weld beads in which welding work is actually performed.

  As can be seen from the figure, the weld beads A to G on which the welding operation was actually performed are shifted from the planned welding points a to g. When such a shift occurs, when no mark pattern is given as shown in FIG. 2 and No. 3, since the welding points are close to each other, the weld beads B and C are No. 3. 2 and No. It is not possible to determine in which order of 3 was hit.

  On the other hand, as shown in FIG. 4 (b), when welding is performed in the test mode and a mark pattern for identifying the welding order is given, each welding bead has a mark 101 for identifying the welding order. Is attached. Therefore, by seeing this mark pattern, the weld beads B and C are No. 2 and No. It is possible to determine in which order 3 was hit. In the illustrated weld beads B and C, the weld bead B is No. No. 3, welding bead C is No. It can be seen that this corresponds to 2. The same applies to weld beads E and F. No. 6, weld bead F is No. It can be seen that this corresponds to 5.

  As described above, according to the present embodiment, since the mark pattern for identifying the order corresponding to the order in which the welding points are applied is drawn by the laser beam, the weld bead actually welded is drawn. It is possible to easily determine the welding order from the traces. Since the order of the welding points can be known from the traces welded in the world, it is possible to determine which order of welding points is shifted in the adjacent welding points and the like after a plurality of welding operations. .

  Although the embodiment to which the present invention is applied has been described above, the present invention is not limited to such an embodiment. For example, although the above-described embodiment has been described by taking welding as an example, it can be used for cutting, marking, and other laser processing using laser light in addition to welding.

  Moreover, although embodiment mentioned above decided to provide the mark which shows the order of a welding point, for example, the coordinate value (or identification symbol etc. corresponding to a coordinate value) for showing a welding position is used as a mark in addition to this. In addition, a mark corresponding to a welding condition or the like may be drawn so that a welding point (processing position) can be identified, and various marks can be drawn. it can.

  In the present invention, not only a mark for identifying a processing position is drawn by a laser, but also other processing conditions may be marked. This is because, for example, the laser scanning speed (moving speed of the laser scanning mirror, the moving speed of the robot itself, etc.) by each bead, or the intensity of the laser when the laser intensity itself is changed, can be identified. Different marks may be drawn corresponding to these conditions (or the contents of those conditions may be drawn directly).

  Thereby, it becomes possible to immediately recognize that the welding conditions are different for each welding position.

  The present invention can be used for laser welding and laser processing.

It is the schematic for demonstrating the structure of the remote welding system to which this invention is applied. It is explanatory drawing for demonstrating the structure inside a scanner head. It is explanatory drawing for demonstrating the example of a mark pattern. It is explanatory drawing for demonstrating the effect | action by this embodiment, (a) shows the case where a mark pattern is not attached, (b) shows the case where a mark pattern is attached according to this embodiment.

Explanation of symbols

1 ... Robot,
2 ... Robot controller,
3 ... Laser oscillator,
4 ... Control device,
5 ... Optical fiber cable,
6: Scanner head.

Claims (10)

A laser irradiation means comprising a reflecting mirror movable to change the irradiation direction of the laser light;
Moving means for moving the laser irradiation means;
The moving means and the reflecting mirror are moved in order to irradiate the laser beam on the workpiece in a previously taught path and machining position, and a mark for identifying the machining condition is drawn on the workpiece by the laser beam. And a control means for controlling at least the reflecting mirror.   The laser processing apparatus according to claim 1, wherein the mark is a mark for identifying a processing position.   The laser processing apparatus according to claim 2, wherein the mark corresponds to a processing order at the processing position and is different for each processing order.   The control means draws the mark in a first mode in which the moving means and the reflecting mirror are moved in order to perform predetermined processing by irradiating the laser beam onto the workpiece in the path and in the order. The laser processing apparatus according to claim 1, wherein the second mode can be switched.   The laser processing apparatus according to claim 4, wherein a time for performing laser irradiation on one processing position in the first mode is the same as a time for drawing the mark in the second mode.   The laser processing apparatus according to claim 3, wherein the mark is a number of points corresponding to the order.   The laser processing apparatus according to claim 3, wherein the marks have different shapes corresponding to the order. A laser irradiation means comprising a reflecting mirror movable to change the irradiation direction of the laser light;
A laser processing method using a processing device having a moving means for moving the laser irradiation means,
A laser processing method, wherein a mark for identifying a predetermined processing condition is drawn by the laser beam.   The laser processing method according to claim 8, wherein the mark is a mark for identifying a processing position.   The laser processing method according to claim 9, wherein the marks have different shapes corresponding to the processing order of the processing positions.

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