JP2006239763A - Laser beam processing method for interior material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a fragile part in a uniform pattern when the fragile part is formed by irradiating laser beam while moving an interior material and a laser oscillator relatively by a moving means. <P>SOLUTION: An instrument panel 12 can be moved by a robot 16 and is movable relatively to a focal point (f) of the laser beam. For a process starting point B1 on an upper part line 204 of a process span, the focal point (f) is set at a motion preparation point Q1 apart toward the opposite direction to a processing direction. Moving speed of the focal point (f) is accelerated and stabilized while having the focal point (f) approach the process starting point B1. After the focal point (f) reaches the process starting point B1, processing of fine holes 202 for the fragile part 200 is started by irradiating the pulsed laser beam from the laser oscillator. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a laser beam processing method for an interior material, in which a weakened portion that is broken when the airbag is inflated is formed by a laser beam with respect to the interior material for covering a shrinking airbag, and in particular, the interior material. The present invention relates to a laser beam processing method for an interior material that performs processing while relatively moving a laser oscillator and a laser oscillator.

  2. Description of the Related Art In recent years, airbag systems have become widespread in automobile vehicles and the like, and airbags that function as air bags for impact absorbing devices are provided in the airbag systems. The airbag is folded and stored in a storage container. When a vehicle collision is detected by a sensor, the airbag is instantly inflated by gas supplied from a gas generator to absorb the impact of a driver or passenger. It functions as a cushion.

  Further, the airbag is covered with a resin interior material such as a steering wheel cover or an instrument panel, and the airbag deployment door panel is forcibly opened when the airbag is inflated. Exposed outside the storage container.

  In this case, in order to ensure the opening of the door panel, a weak portion is formed on the door panel of the interior cover by a predetermined processing pattern including, for example, a groove and a hole.

  As a method for forming the fragile portion, a processing method using a heating blade or a laser is known. As a processing method using a laser, a method is proposed in which the surface position of the interior material is measured by a distance sensor arranged at a predetermined position, and a groove having a desired depth is formed while controlling the laser output based on the measurement result. (For example, refer to Patent Document 1). In this case, the moving means may be a multi-axis robot.

JP-A-8-282420

  When forming the fragile portion by irradiating the interior material with a laser beam, the interior material is held and moved by, for example, a robot, and a constant speed along a predetermined path with respect to the position irradiated with the laser. It is good to move with. In this case, a fragile portion having a groove shape with a predetermined depth is formed by continuously irradiating a laser beam with an appropriate output, and a sewing machine including minute holes with appropriate intervals is formed by irradiating with a pulse. An eye-shaped fragile portion is formed.

  By the way, the moving means such as a robot may be slightly unstable in moving speed or moving direction immediately after the operation is started from the stop state, and is formed when the laser beam is irradiated immediately after such an operation starts. There is a concern that the groove depth of the fragile portion and the pitch of the minute holes are not uniform, or that the extending direction of the fragile portion deviates from the defined direction.

  The present invention has been made in consideration of such problems, and when forming the fragile portion by irradiating the laser beam while moving the interior material and the laser oscillator relatively by the moving means, the uniform shape is obtained. An object of the present invention is to provide a laser beam processing method for an interior material that makes it possible to obtain a fragile portion.

  The present invention processes an interior material for covering a stored airbag with a laser beam emitted from a laser oscillator, and forms a linear weak portion that breaks when the airbag is inflated. A method is provided for performing processing on a first processing start point that forms at least a part of the fragile portion using a program-movable moving means that relatively moves the interior material and the laser oscillator. A step of arranging the focal point of the laser beam at an operation preparation point separated in a direction opposite to the direction, a step of stabilizing a moving speed while bringing the focal point close to the processing start point, and the focus at the processing start point. After reaching, the laser beam is emitted from the laser oscillator to start processing the weakened portion.

  As described above, prior to the laser irradiation, the focal point is arranged at an operation preparation point separated from the machining start point in the direction opposite to the machining direction, and then the focal point approaches the machining start point. By stabilizing the moving speed, the approach area required for accelerating the moving means is secured. Therefore, when the processing start point reaches the focal point, the operation speed and the relative movement speed of the moving means are stabilized, and a fragile portion having a uniform shape can be obtained by emitting the laser beam from the laser oscillator.

  According to the laser beam machining method for an interior material according to the present invention, when forming a fragile portion by irradiating a laser beam while relatively moving the interior material and the laser oscillator by the moving means, the focal point is set as the machining start point. By operating the moving means so as to approach, the operating speed and the relative moving speed of the moving means are stabilized. Therefore, the fragile portion having a uniform shape can be obtained by starting the irradiation of the laser beam thereafter.

  Hereinafter, the laser processing method of the interior material according to the present invention will be described with reference to FIGS. The laser processing method of the interior material according to the present embodiment is applied to an instrument panel (interior material) 12 that is a thin resin plate covering an airbag stored in a dashboard portion, a steering handle central portion, a door, or the like of a vehicle. A laser processing method for forming a fragile portion 200 (see FIG. 5) that breaks when the airbag is inflated with a laser, and the laser processing system 10 shown in FIG. 1 is used.

  As shown in FIG. 1, the laser processing system 10 is provided in a processing booth 14 covered with walls on all sides, and is an articulated type in which an instrument panel 12 is held by an end effector 16a and placed at a processing position P. Laser oscillator for irradiating laser to the robot 16, the carry-in line 18 a and the carry-out line 18 b for supplying and carrying the instrument panel 12 to and from the machining booth 14, and the instrument panel 12 disposed at the machining position P 20, a non-contact distance sensor 22 that is disposed on the opposite side of the laser oscillator 20 with respect to the processing position P and detects the position of the surface 12a of the instrument panel 12, and a robot that controls the articulated robot 16. A control device 24 and a laser control device 26 that controls the laser oscillator 20 are included. A jig for accurately holding the instrument panel 12 is provided in the carry-in line 18a, and the robot 16 can accurately hold a specified portion of the loaded instrument panel 12.

  The instrument panel 12 is, for example, a thin resin molded product used for a dashboard of a vehicle. The front surface 12a is a surface that can be seen by a passenger when the vehicle is mounted, and the back surface 12b that is the opposite surface is stored. This is the surface facing the airbag. The robot 16 is a 6-axis industrial robot that can perform a program operation. When the held instrument panel 12 is moved to the processing position P, the front surface 12a is on the non-contact distance sensor 22 side, and the back surface 12b is a laser oscillator. It arrange | positions so that it may become 20 side.

  The laser oscillator 20 has a prismatic main body 20a and a thin cylindrical irradiation head 20b provided at the tip, and is horizontally installed on a support 20c. The laser generated in the main body 20a travels to the irradiation head 20b, is condensed by a lens 20d provided at the tip of the irradiation head 20b, and converges at a focal point f having a focal length F (see FIG. 2). The laser oscillator 20 may be configured to irradiate the laser beam after being refracted and reflected by a plurality of lenses and mirrors.

As the laser oscillator 20, for example, a laser oscillator such as CO ₂ , excimer, semiconductor, argon gas, or diode may be used.

  As shown in FIG. 2, the laser irradiated from the laser oscillator 20 travels along the optical axis C and converges to the position of the focal point f. Basically, the focal point f is set within the width of the thickness t of the instrument panel 12 and at the position of the depth t1 from the surface 12a. The instrument panel 12 is set so that the back surface 12b is substantially perpendicular to the optical axis C.

  The non-contact distance sensor 22 is a laser type (for example, semiconductor type) sensor that measures a surface distance L to a nearby point on the optical axis C on the surface 12 a of the instrument panel 12 and supplies it to the laser controller 26. To do.

  The laser control device 26 can recognize the position of the surface 12a of the instrument panel 12 in real time based on the surface distance L. Note that the laser that the non-contact distance sensor 22 irradiates the surface 12a is merely a weak energy laser for measurement, and unlike the laser that the laser oscillator 20 irradiates, the instrument panel 12 is not processed or deformed. Of course.

  As shown in FIG. 3, the laser control device 26 includes a sensor input unit 50 that reads the measurement result of the non-contact distance sensor 22, focal position reference data 52 that indicates a reference distance at which the instrument panel 12 should be disposed, and sensor input. A focus error calculation unit 54 that calculates a focus position error ε based on the measurement result of the non-contact distance sensor 22 obtained via the unit 50, and supplies the calculated error ε to the robot control device 24.

  The laser control device 26 further includes a laser irradiation determination unit 56 that determines the start and stop of laser irradiation based on instruction information obtained from the robot control device 24 and starts and stops the irradiation of the laser oscillator 20. The laser irradiation determination unit 56 also determines the laser irradiation time and the interval, and gives an instruction to the laser irradiation unit to irradiate the laser in a pulsed manner.

  As shown in FIG. 4, the robot control device 24 includes a carry-in / carry-out operation determination unit 100 that performs determination of the carry-in and carry-out operations of the instrument panel 12 while exchanging information with the carry-in line 18a and the carry-out line 18b, and a vulnerable unit. 200, a processing section selection unit 104 that sequentially selects sections to be processed from processing section data 102, which is information such as a path shape for each processing section, and a processing start point that is the first point of the path of each processing section data 102 A reference point specifying unit 106 that specifies Bn and an operation preparation point Qn, and an operation end point specifying unit 108 that specifies a processing end point E that is the last point of the path. The subscript n of the machining start point Bn and the operation preparation point Qn is an identifier indicating the machining order among the plurality of machining section data 102, and is identified as n = 1, 2, 3, 4, 5. Hereinafter, processing is performed in the order of the upper line 204, the lower line 208, the right line 210, the left line 212, and the center line 206, and the subscript n as an identifier corresponds to this order.

  The robot control device 24 further includes a machining section operation determination unit 110 that operates the robot 16 with the machining start point Bn and the machining end point En as the operation start and end points for the machining section selected by the machining section selection unit 104, and a predetermined section. The machining section transition operation determination unit 112 that moves the robot 16 so that the focus f coincides with the machining start point Bn corresponding to the next machining section after the machining of the machining section is completed, and the operation determination units 100 and 110, and And a robot drive unit 114 that drives the robot 16 based on the determination result of 112.

  In addition, the robot controller 24 determines the start and stop of laser irradiation based on the current position of the robot 16 in cooperation with the machining section motion determination unit 110 and gives an instruction to the laser controller 26 to start and stop the laser irradiation. And a robot position correction unit 118 that recognizes the current posture of the robot 16 and corrects the posture of the robot 16 based on the error ε obtained from the laser control device 26.

  The corrected posture obtained by the robot position correcting unit 118 is supplied to the robot driving unit 114 via the machining section motion determining unit 110, and the robot 16 takes the corrected posture.

  Each of the laser control device 26 and the robot control device 24 has a CPU (Central Processing Unit) as a main control unit, a RAM (Random Access Memory) and a ROM (Read Only Memory) as a storage unit, a driver, and the like. Each functional unit described above is realized by the CPU reading the program and executing software processing in cooperation with the storage unit or the like. Further, the function sharing between the laser control device 26 and the robot control device 24 may be different from that described above, and the laser control device 26 and the robot control device 24 may be integrated.

  Next, the weak part 200 formed in the instrument panel 12 by the laser processing system 10 will be described.

  As shown in FIG. 5, the fragile portion 200 includes a plurality of microholes 202 arranged in a so-called perforation. In the laser processing system 10, the fragile portion 200 is formed by drilling these microholes 202 with a laser. Form. The fragile portion 200 includes an upper line 204, a center line 206, and a lower line 208 that extend horizontally in parallel, and a right line 210 and a left line 212 that extend in the vertical direction at both left and right ends. The upper and lower ends of the right line 210 and the left line 212 are connected to the upper line 204 and the lower line 208 in a smooth arc shape.

  In the laser processing system 10, the upper line 204, the center line 206, the lower line 208, the right line 210 and the left line 212 are set as individual processing sections, and the processing section data 102 is stored in the robot controller 24. Stored. Among these, for example, the upper line 204 starts processing from the processing start point Bn on the left side in FIG. 5 and ends at the processing end point E on the right side.

  Moreover, the weak part 200 differs in the pitch of the micro hole 202 and the irradiation time of a laser according to a process area. Specifically, in the center line 206, the micro holes 202 are provided at intervals of a short pitch P2, and the brittleness is the highest (that is, the strength is low), and the split occurs first when the airbag is inflated.

  That is, the air bag in the vehicle is housed in the vicinity of the fragile portion 200 on the back surface 12b of the instrument panel 12, and presses the back surface 12b of the instrument panel 12 when inflating. The center line 206 is broken by contact. Thereafter, the cracks are expanded so that the micro holes 202 are connected to each other as the airbag expands, and reach the point of contact with the right line 210 and the left line 212.

  In the right line 210 and the left line 212, the micro holes 202 are provided at intervals of the pitch P1 longer than the pitch P2, and short pitch holes (not shown) are provided in the middle part of the micro holes 202, respectively. . This short pitch hole is a non-communication hole obtained by setting the laser irradiation time short. Since the right line 210 and the left line 212 are provided with short pitch holes, the fragility is relatively high, and the cracks generated at the center line 206 can be continuously advanced in the vertical direction.

  In the upper line 204 and the lower line 208, the minute holes 202 are provided at the same pitch P1 intervals as the right line 210 and the left line 212, and the short pitch holes are not provided. Have sex. Therefore, the crack progressing along the right line 210 and the left line 212 stops at the contact point with the upper line 204 and the lower line 208, but bends due to moderate fragility. In this manner, the upper region 214 sandwiched between the upper line 204 and the center line 206 opens upward, and the lower region 216 sandwiched between the lower line 208 and the center line 206 opens downward, so that the airbag is placed in the passenger compartment. Inflates and functions as a cushion for passengers. At this time, since the upper line 204 and the lower line 208 are merely bent and are not broken, the upper region 214 and the lower region 216 are not separated or scattered from the instrument panel 12.

  In addition, in FIG. 5, the micro holes 202 are schematically illustrated as having a relatively large diameter, but are actually formed to have a micro diameter (for example, 100 μm or less) that is not visible. The broken line in FIG. 5 is a virtual line added so that the weak part 200 can be easily grasped.

  As shown in FIG. 6, the machining start point B1 for the straight upper line 204 among the plurality of machining sections is set to one end (the left end in FIG. 6) of the straight line portion that forms the upper line 204, The actual machining starts from this machining start point B1 and is performed in the direction of the machining end point E1 (to the right in FIG. 6). Further, the operation preparation point Q1 is provided at a position separated from the processing start point B1 by a predetermined running distance in a direction opposite to the processing direction (that is, the left side in FIG. 6). And the machining start point B1 is defined as a run-up area T. The operation preparation point Q1 is set as a point on the extension line in the direction in which the corresponding machining section extends in the fragile portion 200 with reference to the machining start point B1, and the machining start side end in the machining section is curved. In this case, it may be provided on a tangent line with the end as a reference. In this way, by setting the operation preparation point Q1 as a point on the extended line in the direction in which the fragile portion 200 extends with the processing start point B1 as a reference, the operation directions of the robot 16 and the focus f are stabilized, and an appropriate shape is obtained. Fragile part 200 is obtained.

  The run-up area T is a section provided for stabilizing the operation speed of the robot 16 at the start of the operation and for accelerating and stabilizing the movement speed of the focal point f up to a predetermined movement speed V. It is defined corresponding to the operating characteristics of The approach area T is set corresponding to the machining start point Bn of the machining section.

  As shown in FIG. 7, the processing end point E1 for the straight upper line 204 among the plurality of processing sections is set to the other end (the right end in FIG. 7) with respect to the processing start point B1 in the linear portion. The actual machining ends at this machining end point E1. That is, the processing end point E1 coincides with the point at the arc end portion of the right line 210. At the machining end point E1, when the machining is finished, the laser irradiation is stopped and the operation of the robot 16 is stopped. Since the robot 16 moves at a constant moving speed V in order to process the upper line 204, even when stopping at the processing end point E1, the robot 16 operates somewhat due to inertia and stops within the deceleration region D.

  By the way, the machining start point B3 for the right line 210 is arranged slightly to the left of the machining start point B1 set at the upper arc end, and the operation preparation point Q3 is arranged further to the left. . Regarding the lap region Lp between the processing start point B3 and the processing end point E1, the processing is performed redundantly when processing the upper line 204 and when processing the right line 210. The length of the lap region Lp is set to at least the pitch P1 and overlaps by one pitch or more, and the upper line 204 and the right line 210 are securely connected. Thus, when the airbag expands and the right line 210 breaks, the breaking force is reliably transmitted to the upper line 204, and the upper line 204 is bent.

  This lap region Lp is also provided at the left end of the upper line 204 as shown in FIG. 6, and the processing end point E4 is provided to the right of the processing start point B1. Further, similar lap areas Lp are also provided at both ends of the lower line 208, and for these places, a lap area between one machining start point Bn and the other machining end point En in two adjacent machining sections. Lp is provided. As for the center line 206, the end part is in contact with the center part of the left line 212 and the right line 210 in a T-shape, so there is no need to provide a lap region Lp. When comprised from a section, it is good to provide the lap area | region Lp in the connection part.

  Next, a laser processing method for forming the fragile portion 200 in the instrument panel 12 using the laser processing system 10 will be described with reference to FIG. In the following description, it is assumed that processing is executed in the order of the step numbers described unless otherwise noted. In the laser processing system 10, the focal point f is fixed and the instrument panel 12 moves under the action of the robot 16. In the following description, however, the instrument panel 12 is easy to understand in comparison with the drawings. It is indicated that the focal point f moves with respect to the ment panel 12. In practice, the focal point f and the instrument panel 12 need only be configured to move relative to each other.

  First, in step S1, the robot 16 holds the instrument panel 12 conveyed by the carry-in line 18a by the end effector 16a and moves it to the processing position P under the action of the carry-in / carry-out operation determination unit 100. At this time, the direction of the instrument panel 12 is moved so that the back surface 12 b faces the laser oscillator 20.

  In step S <b> 2, the processing section selection unit 104 confirms whether there is an unprocessed section in the fragile section 200 at that time. If there is an unprocessed section, the section to be processed next is specified and the process proceeds to step S3. If it is recognized that all the processes of the fragile portion 200 have been completed, the process proceeds to step S9.

  In step S3, the reference point specifying unit 106 and the operation end point specifying unit 108 obtain a processing start point Bn, an operation preparation point Qn, and a processing end point E for a processing section to be processed next.

  In step S4, the operation of the robot 16 is defined by the machining section transition operation determination unit 112, and the instrument panel 12 is moved so that the focal point f coincides with the operation preparation point Qn. At this time, the laser beam is not irradiated. After the focal point f coincides with the operation preparation point Qn, the robot 16 is temporarily stopped.

  In step S5, the operation of the robot 16 is started, the moving means is operated so that the focal point f approaches the machining start point Bn, and the movement of the focal point f based on the operation of the robot 16 is accelerated as shown in FIG. And stabilize to maintain the specified moving speed V.

  In this case, the robot 16 has a 6-axis configuration, and the motion trajectory 220 (see FIG. 6) of the focal point f slightly deviates from the straight path of the run-up area T because the motion characteristics at the start of each axis are different. Although it may occur, the operation of each axis is stabilized in the course of time, and the focal point f accurately moves along the straight path on the approach zone T when approaching the machining start point Bn. The recent robot 16 has excellent operation characteristics, and the operation speed is stabilized relatively quickly. Therefore, it is not necessary to set the run-up area T excessively long.

  In step S6, when the focal point f reaches the processing start point Bn, a laser beam is emitted from the laser oscillator 20 to start processing the fragile portion 200 (for example, the upper line 204). At this time, since the focal point f is accurately moving at the moving speed V, the laser oscillator 20 emits a laser beam in a pulsed manner at a constant period (for example, P1 / V or P2 / V), thereby providing an instrument. The micro holes 202 can be formed in the panel 12 at a uniform pitch P1 or P2 and on an assumed path.

  Thereafter, in step S7, the processing section motion determination unit 110 defines the operation of the robot 16 and moves the instrument panel 12 at the moving speed V, thereby moving the focal point f along the processing section from the processing start point Bn. Relative movement to the processing end point En.

  In step S8, when the focal point f reaches the processing end point En, the processing section operation determination unit 110 gives an instruction to the laser control device 26 via the laser irradiation start / end instruction unit 116, and the instrument panel by the laser oscillator 20 is used. The laser irradiation to 12 is stopped. At this time, the processing for the lap region Lp is performed, and the other adjacent processing sections can be reliably connected.

  Further, the robot 16 is stopped by giving a stop command from the robot controller 24. Since the robot 16 moves somewhat due to inertia, the focal point f slightly exceeds the processing end point En and stops within the deceleration region D as shown in FIG.

  Thereafter, the process returns to step S2, and the machining is continued when an unmachined machining section remains.

  On the other hand, in step S9 (when all processing of the fragile portion 200 has been completed), the instrument panel 12 that has been processed by carrying out the robot 16 under the action of the loading / unloading operation determination unit 100 is carried out. It arrange | positions on the line 18b and carries out this instrument panel 12 to the following process.

  Thereafter, in step S10, the process waits until the unprocessed instrument panel 12 is carried in from the carry-in line 18a, and returns to step S1 when the carry-in is confirmed.

  As described above, in the laser beam machining method for the interior material according to the present embodiment, the approach region T necessary for acceleration of the robot 16 is achieved by operating the robot 16 so that the machining start point Bn approaches the focal point f. When the focal point f reaches the machining start point Bn, the focal point f based on the operation of the robot 16 has a stable moving speed V. Therefore, after the focal point f reaches the processing start point Bn, the laser holes 20 are irradiated with the laser beam, whereby the micro holes 202 are formed with a uniform pitch and shape.

  The laser processing method of the interior material according to the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations and processes can be adopted without departing from the gist of the present invention.

It is a perspective view of a laser processing system. It is a schematic top view which shows the instrument panel arrange | positioned at a non-contact distance sensor, a laser oscillator, and a process position. It is a block block diagram of a laser control apparatus. It is a block block diagram of a robot control apparatus. It is a schematic diagram of a weak part. It is a schematic diagram which shows the relationship between the process start point vicinity part in an upper line part, and a moving speed. It is a schematic diagram which shows the relationship between the process end point vicinity part in an overline part, and movement speed. It is a flowchart which shows the procedure of the laser processing method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Laser processing system 12 ... Instrument panel 12a ... Front surface 12b ... Back surface 16 ... Robot 16a ... End effector 20 ... Laser oscillator 22 ... Non-contact distance sensor 24 ... Robot control device 26 ... Laser control device 106 ... Reference point specific | specification part 108 ... Operation end point specifying unit 110 ... Processing section operation determining unit 116 ... Laser irradiation start / end instruction unit 118 ... Robot position correcting unit 200 ... Vulnerable part 202 ... Micro hole 204 ... Upper line 206 ... Center line 208 ... Lower line 210 ... Right Line 212 ... Left line 220 ... Operation trajectory Bn, B1-B5 ... Processing start point E, En, E1-E5 ... Processing end point Qn, Q1-Q4 ... Operation preparation point D ... Deceleration zone Lp ... Lap zone P1, P2 ... Pitch T ... Running area V ... Movement speed

Claims (1)

A laser beam processing method for an interior material, in which an interior material for covering a stored airbag is processed by a laser beam emitted from a laser oscillator, and a linear fragile portion that breaks when the airbag is inflated is formed. ,
Using a program-operable moving means for relatively moving the interior material and the laser oscillator,
Placing the focal point of the laser beam at an operation preparation point that is spaced apart in the direction opposite to the processing direction with respect to an initial processing start point that forms at least a part of the fragile portion;
Stabilizing the moving speed while bringing the focal point closer to the processing start point;
After the focal point reaches the processing start point, emitting the laser beam from the laser oscillator to start processing the fragile portion;
A laser beam processing method for an interior material characterized by comprising:

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