JP4166446B2 - Laser processing apparatus and laser processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser processing apparatus and a laser processing method for processing, for example, an instrument panel of an automobile covering an airbag with a laser beam.
[0002]
[Prior art]
In general, an airbag for a passenger seat of an automobile is disposed inside an instrument panel. An opening is formed in the instrument panel so as to face the airbag, and a lid plate is attached to the opening. Alternatively, a rectangular frame-shaped groove is formed on the surface of the instrument panel so as to correspond to the contour of the airbag, and an open portion is defined on the inside thereof. Then, the airbag is usually covered with a lid plate or an opening portion, and when the airbag is activated, the lid plate or the opening portion is opened so that the airbag is inflated from the inside of the instrument panel to the outside. It has become.
[0003]
However, in the airbag covering structure as described above, there is a problem that the external appearance is deteriorated because the outer shape of the cover plate and the rectangular frame-shaped groove appear on the surface of the instrument panel. In addition, since the outer shape of the cover plate and the rectangular frame-shaped groove are reflected in the front window, there is a problem that it is difficult to drive.
[0004]
In order to deal with such problems, blind holes are processed at predetermined intervals on the back surface of the instrument panel by irradiation of laser light, and a square frame-shaped peripheral groove and a fragile portion as a whole corresponding to the contour of the airbag There has also been proposed a method in which an open portion is defined inside the fragile portion. In this processing method, a large number of blind holes are processed on the surface side of the panel in a state where a certain uncut thickness is secured, and the fracture strength of the fragile portion is formed to a predetermined value over the entire circumference. There is a need.
[0005]
However, since the instrument panel is not curved or has a uniform thickness at the time of molding, it has been difficult to process the instrument panel so that each blind hole is left uncut and the thickness is constant.
[0006]
In order to cope with the above problems, for example, laser processing methods disclosed in Japanese Patent Laid-Open No. 10-85966 (first prior art) and Japanese Patent Laid-Open No. 2001-38479 (second prior art) have been conventionally used. Proposed.
[0007]
In the first prior art, when a blind hole is machined by irradiating a workpiece with a laser beam, the laser beam transmitted through the blind hole is detected, and when the transmitted energy reaches a predetermined value, the blind hole is machined. Is supposed to stop. In the second prior art, when a blind hole is machined by irradiating the workpiece with laser light, the detection light is preliminarily synthesized with the laser light, and the detection light transmitted through the blind hole is detected. When the transmitted energy reaches a predetermined value, the blind hole processing is stopped.
[0008]
[Problems to be solved by the invention]
As described above, in these conventional laser processing methods, a slight laser beam or detection light transmitted through the workpiece processing part is detected, and the blind hole processing depth is set so that the uncut plate thickness is constant. Is controlling. For this reason, it is necessary to provide a sensor for detecting laser light or detection light on a supporting member such as a jig for supporting the workpiece to be processed so as to be movable integrally with the laser irradiation nozzle on the opposite side of the workpiece Therefore, the configuration of the detection apparatus is complicated and expensive. In addition, it is necessary to adjust the detection level before starting machining, and it is troublesome to detect a slight change in the thickness of the workpiece. In addition, in the first prior art, since the laser beam is transmitted through the processed portion of the workpiece, there is a possibility that a small hole is formed on the bottom surface of the blind hole-shaped processed portion or a scar remains.
[0009]
The present invention has been made paying attention to such problems existing in the prior art. Its purpose is to make the detection device simple and inexpensive to manufacture, and to reliably detect slight changes in the thickness of the instrument panel , leaving a blind hole-like processed part in a predetermined cut-off. It is an object of the present invention to provide a laser processing apparatus and a laser processing method capable of performing accurate processing while ensuring a plate thickness.
[0010]
[Means for Solving the Problems]
To achieve the above object, according to claim 1 invention, while the instrument panel made of machining head and the panel with a nozzle are relatively moved, the laser beam from the nozzle with respect to the instrument panel back surface In a laser processing apparatus that irradiates and forms blind hole-like processed parts on the instrument panel at predetermined intervals, an instrument is mounted on an instrument panel support member made of a conductor for supporting the instrument panel . Gap detecting means for fixing the panel and detecting the capacitance of the gap with reference to the instrument panel supporting member surface is provided in the processing head, and is arranged between the instrument panel supporting member and the gap detecting means. depending on the electrostatic capacitance that changes in response to the thickness of the the instrument panel Characterized by comprising control means for acceleration controlling the irradiation output of the serial laser beam.
[0011]
Therefore, according to the first aspect of the present invention, the configuration of the detection device is simple and inexpensive compared to the conventional technique in which the laser beam or the detection beam transmitted through the machined portion of the instrument panel is detected. Can be produced. In addition, a slight change in the thickness of the instrument panel can be reliably detected, and a blind hole-like processed portion can be accurately formed in a state where a predetermined uncut thickness is ensured.
[0012]
According to a second aspect of the present invention, in the first aspect of the present invention, the nozzle and the instrument panel are moved relative to each other while the predetermined distance between the instrument panel support member and the gap detecting means is constant. The laser output by pulse oscillation is controlled according to the capacitance change.
[0013]
Therefore, according to the second aspect of the present invention, the depth of the processed hole can be adjusted easily and accurately by setting the number of pulse oscillations of the laser beam in accordance with the change in capacitance. Therefore, a large number of blind hole-shaped processed portions having a certain uncut thickness can be formed at predetermined intervals on the instrument panel . For this reason, it is suitable when providing the opening part for airbags in the instrument panel which covers an airbag.
[0014]
According to a third aspect of the present invention, in the first or second aspect of the present invention, the gap detecting means is provided in a nozzle.
Therefore, according to the third aspect of the present invention, there is no need to provide the gap detecting means and the mounting portion for that purpose, the configuration is simple, and the accessibility of the nozzle to the instrument panel is improved.
[0015]
According to a fourth aspect of the invention, while relatively moving the processing head and the instrument panel with a nozzle is irradiated with laser light from the nozzles onto the instrument panel back surface, Mekuraanajo the instrument panel In the laser processing method in which the machined portions are formed at predetermined intervals, the instrument panel is fixed to an instrument panel support member made of a conductor, and a static gap of the instrument panel support member surface is defined as a reference. A capacitance is detected, and a constant cut is made at the bottom of the processing portion in accordance with the capacitance that changes in accordance with the thickness of the instrument panel disposed between the instrument panel support member and the gap detection means. The laser output by pulse oscillation is controlled so as to secure the remaining plate thickness.
[0016]
Therefore, according to the fourth aspect of the invention, the same action as that of the first aspect can be obtained.
According to a fifth aspect of the present invention, in the invention of the fourth aspect, when the machining head and the instrument panel are moved relative to each other, a pulsed intermittently oscillated pulse is oscillated at a predetermined interval so that the blind hole-shaped processed portion is provided at a predetermined interval. It is characterized by processing every other.
[0017]
Therefore, the invention described in claim 5 has the same action as the invention described in claim 2.
The invention described in claim 6 is characterized in that, in the invention described in claim 4 or 5, the processing depth is adjusted by controlling the laser output according to the number of pulses of the laser output by pulse oscillation. .
[0018]
Therefore, according to the invention described in claim 5, it is possible to obtain substantially the same operation as that described in claim 2.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, in the laser processing apparatus of this embodiment, a support member 11 made of a conductor constituting a jig is disposed on a table (not shown). On the upper surface of the support member 11, an instrument panel 12 as a work for covering the passenger seat airbag of the automobile is supported and fixed in a mounted state.
[0020]
A laser head 13 is opposed to the support member 11 so as to be able to approach and separate and tiltable, and a laser irradiation nozzle 14 projects from the lower portion thereof. Then, the support member 11 and the laser head 13 including the laser irradiation nozzle 14 are relatively moved in the lateral direction indicated by the arrow in FIG. Is moved to a predetermined processing position on the instrument panel 12.
[0021]
A laser oscillator 15 is connected to the laser head 13, and laser light pulse-oscillated to the laser head 13 is output from the laser oscillator 15 based on control of a control device 16 as control means. Then, the laser beam is guided to the laser irradiation nozzle 14, and the laser beam is intermittently irradiated from the laser irradiation nozzle 14 to the back surface of the instrument panel 12 at a predetermined interval. In this embodiment, a large number of blind hole-shaped processed portions 12a are processed on the instrument panel 12 by laser light at predetermined intervals. And as shown in FIG. 5, many processed parts form the circumferential groove l as a whole.
[0022]
That is, as shown in FIG. 3 in which W1 and W2 in FIG. 1 are enlarged, the control device 16 oscillates and outputs a reference pulse at a predetermined frequency. The reference pulse is output to the laser oscillator 15 and an on / off signal is output from the control device 16 to the laser oscillator 15. Based on these reference pulses and on / off signals, laser beams having pulse numbers P1, P2 corresponding to the on signal widths W1, W2 are intermittently output from the laser oscillator 15 to the laser head 13.
[0023]
Accordingly, the number of pulses P1 and P2 is increased or decreased according to the ON signal widths W1 and W2, and the laser output is controlled. Further, one pulse width of the laser beam and the interval between the pulses depend on the reference pulse. By setting the output pulse frequency as high as 5,000 Hz, for example, a large number of pulses are oscillated with respect to the moving speed of the nozzle 14, so that the ON signal widths W1 and W2 each act to process one hole. . And the process part 12a of the process depth L2 according to the output pulse number P1, P2 is formed on the instrument panel 12 with this laser beam.
[0024]
The base material of the laser irradiation nozzle 14 is formed of an insulating material, the first electrode 17 is formed on the inner peripheral surface thereof by coating or the like, and the second electrode 18 is also formed on the outer peripheral surface by coating or the like. Yes. A capacitance detector 19 as a detecting means is connected to the first electrode 17 and the second electrode 18. Then, during laser processing of each processing portion 12 a of the instrument panel 12, the electrostatic capacitance between the support member 11 and the laser irradiation nozzle 14 is detected by the electrostatic capacitance detector 19, and the detection result is the control device 16. Is output. Conventionally, a capacitance detector has been used to measure the gap amount between metal materials, but by interposing a non-ferrous metal material between metal materials, the electrostatic capacitance between them can be varied depending on the thickness of the non-ferrous metal material. It was clarified that the capacity changes. From this, when the plate thickness of the instrument panel 12 is changed based on the detection of the capacitance, as shown in FIG. 2, the detection is based on the capacitance corresponding to the change in the plate thickness. A voltage is obtained.
[0025]
A memory 20 is connected to the control device 16, and various data used for controlling the laser oscillator 15 by the control device 16 are stored in the memory 20. That is, the memory 20 includes processing position data of a plurality of processing parts 12a formed on the instrument panel 12, the detection voltage of the capacitance, ON signal widths W1 and W2 of ON / OFF signals, and the number of output pulses P1. , P2 is stored as a table, for example. Then, the control device 16 is based on the correlation data stored in the memory 20 when the detection result of the electrostatic capacitance is input from the electrostatic capacitance detector 19 during the laser processing of each processing portion 12a of the instrument panel 12. The ON signal widths W1 and W2 of the ON / OFF signal to the laser oscillator 15 are set. With this setting, the number of pulses P1 and P2 of the laser beam output from the laser oscillator 15 is changed, and the irradiation output of the laser beam is controlled to be increased or decreased.
[0026]
That is, as the plate thickness at the processing position on the instrument panel 12 becomes thinner, a detection voltage having a larger capacitance is output. Based on this, the ON signal widths W1 and W2 of the ON / OFF signal are set small, and the laser beam with a small number of pulses P1 and P2 is output, thereby forming the processing portion 12a having a small processing depth L2. On the contrary, as the plate thickness at the processing position on the instrument panel 12 increases, a detection voltage with a smaller capacitance is output. Based on this, the ON signal widths W1 and W2 of the ON / OFF signal are set to be large, and laser light having a large number of pulses P1 and P2 is output, thereby forming the deep processing portion 12a having the processing depth L2. That is, the machining depth L2 is adjusted according to the number of pulses. As a result, even when the plate thickness of the instrument panel 12 changes, it becomes possible to arbitrarily set the depth of each of the blind hole-shaped processed portions 12a, and as a result, a certain uncut thickness L3 is secured at the bottom. It is like that.
[0027]
The memory 20 stores program data shown in the flowchart of FIG. 4 to be described later.
Next, the operation of the laser processing apparatus configured as described above will be described based on the flowchart of FIG. In the flowchart of FIG. 4, the program stored in the memory 20 proceeds under the control of the control device 16.
[0028]
Now, laser processing is started in this laser processing apparatus. Then, first, the laser irradiation nozzle 14 is moved and arranged at a programmed position on the instrument panel 12 on the support member 11 and arranged at a predetermined interval L1 (step S1). Therefore, the predetermined distance between the laser irradiation nozzle 14 and the support member 11 is maintained at a constant value.
[0029]
In this state, the laser head 13 including the laser irradiation nozzle 14 and the support member 11 that supports the instrument panel 12 are moved relative to each other, and laser processing on the instrument panel 12 is started as shown in FIG. Step S2). In this case, in a state where laser irradiation nozzle 14 corresponding to the machining position of one hole processing portion 12a on the instrument panel 12, the capacitance by the capacitance detector 19 is detected, a plate of the instrument panel 12 A detection voltage corresponding to the thickness is input to the control device 16 (step S3).
[0030]
On signal widths W1 and W2 of the on / off signal from the control device 16 to the laser oscillator 15 are set based on the detection result of the capacitance. For this reason, the number of pulses P1 and P2 of the laser light output from the laser oscillator 15 is set according to the ON signal widths W1 and W2 (step S4). Then, the laser beams of the set pulse numbers P1 and P2 output from the laser oscillator 15 are irradiated to the instrument panel 12 from the laser irradiation nozzle 14, and a blind hole-shaped processing portion 12a is formed on the instrument panel 12 with a predetermined value. Processing is performed in a state in which the uncut plate thickness L3 is secured (step S5). In this case, if the number of pulses P1, P2 is large, a deep hole is formed, and if it is small, a shallow hole is formed. Therefore, when the detection plate thickness of the processing part 12a is thick, the set values of the pulse numbers P1 and P2 are large, and when the detection plate thickness is thin, the set values of the pulse numbers P1 and P2 are controlled to be small. The As a result, the uncut thickness L3 of the processed portion 12a can be made constant.
[0031]
As described above, when the processing of one processing portion 12a on the instrument panel 12 is completed, it is determined whether or not the next processing portion 12a exists in the processing position data in the memory 20 (step S6). . In this determination, when the next processing part 12a exists, the process returns to step S3 and the operations of steps S3 to S6 are repeated. As a result, a plurality of processed portions 12a are processed on the instrument panel 12 at predetermined intervals in a state where a certain uncut thickness L3 is secured. When the next processing portion 12a no longer exists in the processing position data, the laser processing operation for one instrument panel 12 ends (step S7).
[0032]
Therefore, according to this embodiment, the following effects can be obtained.
In this laser processing apparatus, the instrument panel 12 is electrically conductive when laser processing is performed on the blind hole-shaped processing portion 12a on the instrument panel 12 at predetermined intervals by irradiation of the laser beam from the laser irradiation nozzle 14. It supports on the support member 11 which consists of a body. In this state, the electrostatic capacity detector 19 detects the electrostatic capacity between the support member 11 and the laser irradiation nozzle 14. Based on the detection result, the control device 16 changes and controls the irradiation output of the laser light from the laser irradiation nozzle 14 every time one processing portion 12a is processed.
[0033]
For this reason, it is not necessary to provide a detector on the support member 11 side as compared with the conventional technique in which the laser beam or the detection light transmitted through the processing portion 12a of the instrument panel 12 is detected. The structure is simple and can be manufactured at low cost. Further, a slight change in the plate thickness of the instrument panel 12 can be reliably detected, and the blind hole-like processed portion 12a can be accurately processed in a state in which a predetermined cut-off plate thickness L3 is ensured. Further, since there is no need to generate transmitted light for detection, no scars remain on the instrument panel 12.
[0034]
In this laser processing apparatus, the laser beam irradiation output controlled by the control device 16 is the number of output pulses P1 and P2. For this reason, the number of output pulses P1 and P2 of the laser beam is changed based on the detection result of the electrostatic capacitance, and the blind hole-shaped processed portion 12a is cut into a predetermined cut according to the change in the plate thickness of the instrument panel 12. Processing can be performed accurately with the remaining plate thickness L3 secured.
[0035]
In this laser processing apparatus, the instrument panel 12 is a panel that covers an automobile airbag. For this reason, when the blind hole-shaped processed portion 12a is processed at predetermined intervals on the back surface of the panel covering the airbag, small holes are left on the surface side of the panel or scars remain, resulting in poor appearance. Can be suppressed, and a high-quality panel can be obtained.
[0036]
(Example of change)
In addition, this embodiment can also be changed and embodied as follows.
In the embodiment, the number of output pulses P1 and P2 is changed as the laser beam irradiation output controlled by the control device 16. On the other hand, the output energy or output frequency of the laser beam is changed as the irradiation output of the laser beam.
[0037]
In the embodiment, the instrument panel 12 that performs laser processing is an instrument panel that covers an automobile airbag. On the other hand, the present invention is applied to a panel for covering an airbag incorporated in a steering wheel or a groove processing of an industrial material other than an instrument panel in which a processing mark does not remain on the surface.
[0038]
In the embodiment, the processing position data of the plurality of processing portions 12a, the detected voltage of the capacitance, the ON signal widths W1 and W2 of the ON / OFF signal, and the correlation data of the output pulse numbers P1 and P2 are used as a table. It is remembered. These data are sequentially read out and the number of output pulses for each processing unit 12a is set. On the other hand, it is configured to calculate the number of output pulses for each processing unit 12a by calculation according to the level of the detection voltage of the capacitance.
[0039]
【The invention's effect】
As described above in detail, in the present invention, the configuration of the detection device is simple and can be manufactured at low cost, and it is possible to reliably detect a slight change in the thickness of the instrument panel. There is an effect that the processed portion can be accurately processed in a state in which a predetermined uncut thickness is ensured.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a laser processing apparatus according to an embodiment.
FIG. 2 is a characteristic diagram showing a detection voltage of capacitance according to the thickness of the instrument panel .
FIG. 3 is an explanatory diagram showing a control state of an output pulse of laser light.
4 is a flowchart showing the operation of the laser processing apparatus of FIG.
FIG. 5 is a perspective view showing a laser processing state for an instrument panel .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Support member, 12 ... Instrument panel , 12a ... Blind hole processing part, 13 ... Laser head, 14 ... Laser irradiation nozzle, 15 ... Laser oscillator, 16 ... Control apparatus as control means, 19 ... As detection means Capacitance detector, 20 ... memory, L3 ... uncut plate thickness, P1, P2 ... number of output pulses.

Claims (6)

While relatively moving the processing head and the instrument panel with a nozzle, by irradiating a laser beam from the nozzle with respect to the instrument panel back surface, formed at predetermined intervals a blind hole-like processed portion in the instrument panel In the laser processing apparatus designed to
The gap detecting means for fixing the instrument panel to an instrument panel support member made of a conductor for supporting the instrument panel and detecting the capacitance of the gap with reference to the instrument panel support member surface Control for adjusting the irradiation output of the laser beam in accordance with the electrostatic capacitance that changes in accordance with the thickness of the instrument panel disposed between the instrument panel support member and the gap detection means provided in the processing head A laser processing apparatus comprising means. Controlling laser output by pulse oscillation in accordance with a change in capacitance while relatively moving the nozzle and the instrument panel in a state where a predetermined distance between the instrument panel support member and the gap detecting means is constant. The laser processing apparatus according to claim 1, wherein the apparatus is a laser processing apparatus.   The laser processing apparatus according to claim 1, wherein the gap detection unit is provided in a nozzle. While relatively moving the processing head and the instrument panel with a nozzle, by irradiating a laser beam from the nozzle with respect to the instrument panel back surface, formed at predetermined intervals a blind hole-like processed portion in the instrument panel In the laser processing method to be performed,
The instrument panel support member made of a conductive material and fixed to the instrument panel, detects the electrostatic capacitance of the gap as a reference the instrument panel support member surface, and the instrument panel support member and said gap detection means Depending on the capacitance that changes according to the thickness of the instrument panel placed between the two, the laser output by pulse oscillation is controlled so as to ensure a certain uncut thickness at the bottom of the processed part The laser processing method characterized by the above-mentioned. 5. The laser processing method according to claim 4, wherein when the processing head and the instrument panel move relative to each other, pulsed oscillation is intermittently performed at predetermined intervals to process blind hole-shaped processing portions at predetermined intervals.   6. The laser processing method according to claim 4, wherein the processing depth is adjusted by controlling the laser output according to the number of pulses of the laser output by pulse oscillation.

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