KR20080017281A - Laser processing device and laser processing method using same - Google Patents

Abstract

A very safe handheld laser processing device is provided to detect the relative position of a workpiece with a simple structure, and a laser processing method using the device is provided. A laser processing device comprises: a light transmitting part for transmitting a laser light(6); and a light emitting unit for receiving the laser light from the light transmitting part and projecting the laser light to a workpiece(20) to process the workpiece, wherein the light emitting unit includes: a torch body(100); a workpiece detecting probe provided at an end of the torch body; a condensing lens(2) for collecting the laser light onto a focus positioned apart from the end of the torch body; a first circuit which provides the probe with power, and calculates the distance using input signals varied based on the distance between the probe and the workpiece; a second circuit for detecting a contact between the probe and the workpiece based on signals from the probe; and a control unit(8) for controlling the generation of the laser light according to the contact between the probe and the workpiece and the distance between the probe and the workpiece.

Description

LASER PROCESSING DEVICE AND LASER PROCESSING METHOD USING SAME}

The present invention relates to a laser processing device and a laser processing method using the laser processing device, and more particularly, to a laser processing device provided with a handheld for emitting an optical unit and a laser processing using the laser processing device. It is about a method.

Welding is often performed by an operator with a handheld that emits an optical unit for temporary tack welding or the like, which is not very suitable for laser welding by automatic equipment. In this case, the laser processing device is generally equipped with a safety feature that prevents laser radiation of the part that is not required to be radiated, thereby preventing the operator from inadvertent exposure to laser radiation while simultaneously radiating high-energy emitted. To protect workers and others from the laser radiation of the laser beam, and to detect the positional relationship between the light unit and the workpiece in order to perform laser processing with a certain quality, and only if the positional relationship is within a predetermined range Makes it possible.

Contact and / or non-contact sensors for detecting the workpiece are provided with an emission light unit (referred to as "laser torch" in Japanese Patent Application Laid-Open Nos. 5-318158, 5-318159 and 2002-239771; The technique of attachment to a torch is disclosed in, for example, Japanese Patent Application Laid-Open Nos. 5-318158, 5-318159, and 2002-239771 as a method of detecting a positional relationship between a light emitting unit and a workpiece. Is disclosed.

The torch disclosed in Japanese Patent Application Laid-Open No. 5-318158 is located in a grip housing in which the radial end of the fiber which conducts the laser beam emitted by the laser oscillator is provided with a tapered nozzle at its front end. And a condenser lens is provided in front of the radiation end such that the laser beam radiated from the radiation end is collected at a point near the front end face of the nozzle, and has a circuit structure in which the laser oscillator is activated when the front end of the nozzle contacts the workpiece. As a result, the laser beam is properly focused on the workpiece.

Japanese Laid-Open Patent Application 5-318159 discloses a means for detecting the point of time when the front end of the torch comes within a predetermined distance from the workpiece in order to improve the durability of the nozzle provided at the front end of the torch, wherein the front end of the nozzle A contact sensor protruding forward from the nozzle by a required distance, and when compressed gas is injected into the nozzle, a pressure sensor that detects a point in time when the discharge pressure of the compressed gas is greater than a predetermined pressure at which the compressed gas is discharged from the front end of the nozzle. Is provided to position the front end of the nozzle at a certain distance from the workpiece, and a coil is attached to the torch to provide an inductive proximity sensor (inductive sensor) for detecting a change in the inductance of the coil, the front end of the nozzle and the workpiece An electrostatic proximity sensor (electrostatic sensor) is provided that detects a change in capacitance between. In these torches, a laser beam is generated when the front end of the torch is located at a certain distance from the workpiece.

The YAG laser torch disclosed in Japanese Patent Application Laid-Open No. 2002-239771 includes: first detection means capable of detecting non-contact or contact to detect the presence of a workpiece before processing starts; Two second detection means capable of detecting non-contact to detect the presence of the workpiece during processing; A laser radiation switch which is activated only when the presence of the workpiece is detected by the first detection means prior to the start of processing and which opens or closes the beam path shutter of the YAG laser beam; And a confirmation switch to turn on or off the YAG laser oscillator. In these torches, the laser beam is generated by pressing the laser radiation switch when the first detection means detects the presence of the workpiece. In addition, when the second detection means detects that there is no workpiece during processing, the torch is set to block the radiation of the YAG laser beam.

Japanese Laid-Open Patent Application 2002-239771 discloses that when the confirmation switch is turned on before processing, the visible light is emitted to the workpiece at the same time the YAG laser oscillator is turned on, and the visible light detector detects the reflection of the visible light before the workpiece is processed. Used as a first detection means for detecting the presence of a detector, a detector for detecting reflection of a YAG laser beam or a detector for detecting infrared and visible light generated in a portion processed during laser processing is used as the second detection means during laser processing. A torch for detecting the presence of a workpiece is disclosed.

Furthermore, a torch is disclosed in which a limit switch, which is operated when the end of the torch is pressed against the workpiece, is provided as the first detection means instead of the visible light detector. The torch is configured such that while the second detection means detects the light emitted from the workpiece during laser processing, the YAG laser beam continues to radiate even when the limit switch and the workpiece are no longer in contact with each other.

A torch is also disclosed in which an electrostatic sensor is provided as the first detection means. In this torch, depending on whether the workpiece is metal or nonmetal, before processing, the presence of the workpiece is detected and the YAG laser beam can only be emitted if the workpiece is located within the detection range of the electrostatic sensor.

A torch is also disclosed in which limit switches, electrostatic switches, and other proximity switches are provided. In this torch, the proximity sensor determines whether the workpiece is metal or nonmetal before starting processing, and then decides whether to emit the YAG laser beam by the operation of the limit switch, which YAG laser is It is emitted only if it is located within the detection range of the proximity sensor.

However, the conventional techniques described above have the following problems. In the torch disclosed in Japanese Laid-open Patent Application 5-318158, since the laser oscillator is stopped when the nozzle and the workpiece are no longer in contact with each other, continuous processing when the workpiece has a curved surface, a level difference, or the like This is impossible.

In the technique disclosed in Japanese Laid-open Patent Application 5-318159, the proximity of the torch to the workpiece is detected using a contact sensor, a pressure sensor, an induction sensor, an electrostatic sensor, or another type of sensor, and the laser oscillator is detected. Unlike the torch disclosed in Japanese Patent Application Laid-open No. 5-318158, since the workpiece is allowed later and the laser can continue to radiate even when the end of the torch is not in contact with the workpiece, the workpiece has a curved surface or a level difference Laser processing may be performed. However, in the technique disclosed in Japanese Laid-open Patent Application 5-318159, when there is a risk of unintentional radiation of the laser beam and the hand switch is turned on, safety is not necessarily maintained, and the sensor is There is a proximity to the workpiece or other object that may be detected, and accordingly the sensor detects that the torch is in proximity to the workpiece.

In the torch disclosed in Japanese Laid-Open Patent Application 2002-239771, since two types of detectors are provided, the torch has a complicated structure, and the function of the two types of sensors is difficult to adjust and maintain.

It is an object of the present invention to provide a very safe handheld laser processing device capable of detecting the relative position of a workpiece using a simple structure, and to provide a laser processing method using the laser processing device.

Laser processing device according to the present invention comprises a light transmission unit for transmitting a laser beam; And an emission light unit that receives the laser beam from the light transmission unit and emits the laser beam to the workpiece for laser processing. The emission light unit includes a torch body; A workpiece detection probe provided at the distal end of the torch body; A condenser lens for emitting a laser beam at a focal point located at a predetermined distance from the distal end of the torch body; A first circuit for powering the probe and calculating the distance by using an input of a signal that varies based on the distance between the probe and the workpiece; A second circuit for detecting contact between the probe and the workpiece based on a signal from the probe; And a control unit for controlling generation of the laser beam according to the contact state of the workpiece and the probe and the distance between the probe and the workpiece.

This configuration allows a single workpiece detection sensor to detect the presence of the workpiece prior to laser processing and to detect the distance between the workpiece detection probe and the workpiece during laser processing.

Preferably, no laser beam is generated until the control unit detects a contact between the probe and the workpiece.

Such a configuration reduces the possibility of unintentional radiation of the laser beam and makes it possible to obtain a very safe laser processing device.

The probe may be a probe of an electrostatic capacitance sensor, and the signal that changes based on the distance between the probe and the workpiece may be a detection signal of the electrostatic capacitance between the probe and the workpiece.

Further, the probe may be a probe of an overcurrent sensor, the probe may have a sensor coil, and the signal that changes based on the distance between the probe and the workpiece may be a detection signal of the impedance of the sensor coil.

Preferably, a hand switch for directing laser radiation is provided in the torch body.

In addition, a foot switch indicating laser radiation may be provided at a position near the torch body.

In addition, a safety switch for shutting down the entire device may be provided at the torch body or at a position near the torch body.

The laser processing method according to the invention consists of two stages: a laser processing preparation stage and a laser processing process stage. The laser processing preparation stage provides power to the workpiece detection probe and detects contact between the probe and the workpiece, if detected, supplies gas to the workpiece as needed using the control unit, control unit Increasing the excitation current of the laser oscillator to a level at which the required output is obtained using the < RTI ID = 0.0 > The laser processing process stage includes detecting whether the workpiece detection probe and the workpiece are located at a predetermined range of distances from each other, generating a laser to start laser processing when a laser radiation command is received from the control unit, Continuing to perform laser processing while the distance between the piece detection probe and the workpiece is within a predetermined distance range.

According to the present invention, radiation is detected by using a single workpiece detection sensor to detect contact between the workpiece detection probe and the workpiece prior to the start of laser processing and to detect the distance between the workpiece detection probe and the workpiece during laser processing. The structure of the light unit is simplified, the cost of the light emitting unit is reduced, and the durability of the light emitting unit is improved.

Embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, Embodiment 1 of this invention is described. 1 is a view showing the structure of the laser processing device according to the present invention, FIG. 2 is a view showing the structure of the torch body 100, and FIG. 3 is an example of the C / V voltage output of the electrostatic capacitance detection circuit 7. 4 shows an example of a control sequence in a preparation stage relating to laser processing by a laser processing device according to Embodiment 1 of the present invention, and FIG. 5A shows a laser processing device according to Embodiment 1 of the present invention. An example of the control sequence in the laser processing process related to the voltage is shown, and FIG. 5B is a graph illustrating an example of setting the range of detection signal levels of the C / V voltage output.

In the laser processing device of the present invention as shown in FIG. 1, the laser beam output from the laser oscillator 11 is transmitted by an optical fiber or other light transmission unit 15, and the laser beam 6 is the torch body 100. Is radiated from the end of. In the torch body 100 as shown in FIG. 2, the tapered cylindrical grip housing insulation 3 is attached to the grip housing 1 and is a sensor probe of an electrostatic capacitance sensor formed of a conductor such as a workpiece detection probe. 4 is provided at the distal end of the grip housing insulation 3. In addition, the sensor probe 4 functions as a torch. Inside the grip housing 1, the condenser lens 2 is positioned so that the central axis of the grip housing 1 and the optical axis of the laser beam coincide with each other, and are output from the laser oscillator 11 and transmitted by the light transmitting part 15. The laser beam 6 to be positioned is located at a predetermined distance from the end of the torch body 100 and is radiated to the focal point generated by the condensing lens 2. Laser processing on the workpiece 20 can be performed by positioning the workpiece 20 composed of grounded metal at a focal point (condensing position).

The torch body 100 is connected to the process gas supply unit 12, the gas control solenoid valve 13 is opened as needed during laser processing, and auxiliary gas or the like is workpiece from the end of the sensor probe 4 (torch). 20 is provided at the processed location. In addition, the torch body 100 and the laser oscillator 11 are cooled by the air-cooled cooler 14 as needed. In addition, a hand switch 5 capable of activating laser radiation is provided to the torch body 100. Thereby, the torch main body 100 is comprised.

The hand switch 5 is connected to the processing device control unit 8 as a control unit. The C / V voltage output 75 and the contact detection voltage output 76 output from the electrostatic capacitance detection circuit 7 connected to the sensor probe 4 are input to the processing device control unit 8. The foot switch 16 is provided at a position near the torch body 100, and the foot switch 16 is connected to the processing device control unit 8. Since the foot switch 16 has the same function as the hand switch 5, the operator can activate the laser radiation by using the foot switch 16 instead of the hand switch 5.

The electrostatic capacitance detection circuit 7 applies an AC signal between the sensor probe 4 and the workpiece 20 by the detection oscillator 71 to measure the electrostatic capacitance Cx, and the sensor probe 4 A first circuit that detects a varying electrostatic capacitance Cx based on the distance between the workpiece and the workpiece 20 and calculates a distance between the sensor probe 4 and the workpiece 20 based on the electrostatic capacitance Cx ; And a second circuit for detecting a contact between the sensor probe 4 and the workpiece 20 based on the signal from the sensor probe 4. Due to the AC signal applied between the sensor probe 4 and the workpiece 20 by the detection oscillator 71, the voltage induced by the electrostatic capacitance Cx between the sensor probe 4 and the workpiece 20 is It is amplified by the C / V amplifier 72 and converted by the C / V converter 73 into the C / V voltage output 75 as a DC voltage signal and output to the processing device control unit 8. As shown in FIG. 3, the electrostatic capacitance Cx varies with the distance between the sensor probe 4 and the workpiece 20, and C decreases as the distance between the sensor probe 4 and the workpiece 20 decreases. / V voltage output 75 is increased.

In the case where the substance is in contact with the sensor probe 4, the output voltage is amplified by the contact detection amplifier 74 and output as the contact detection voltage output 76 to the processing device control unit 8. At this time, when the material in contact with the sensor probe 4 is the workpiece 20, since the workpiece 20 is a metal, there is a large output voltage whose value is different from the normal output value detected during non-contact. Obtained.

The processing device control unit 8 determines the detection signal level of the C / V voltage output 75 and the contact detection voltage output 76 to determine whether to activate the laser. The detection signal level of the predetermined range of the C / V voltage output 75 and the predetermined detection signal level of the contact voltage output 76 are set according to the shape and / or material of the workpiece 20, and the contact detection voltage output When the predetermined detection signal level of 76 is set using the detection signal level of the contact detection voltage output 76, that is, the sensor probe 4 and the workpiece 20 contact each other as a reference, as described above. In the case where it is, the detection signal level of the contact detection voltage output 76 does not exceed the predetermined detection signal level if the material contacting the probe 4 with the sensor is nonmetal. Therefore, even when the sensor probe 4 is in contact with the nonmetal, it can be set so that laser radiation does not occur, whereby the operator can be protected from radiation by the laser beam, and the safety is improved. In addition, the position of the focus during laser processing uses the detection signal level of the C / V voltage output 75 to output the C / V voltage when the workpiece 20 is located at the focus of the laser beam 6 as a reference. It can be detected by setting a predetermined range of the detection signal level of 75.

The processing device control unit 8 continues to monitor the external interlock signal 9 associated with the signal or other safety measures instructing the operator to wear protective equipment, and the laser radiation command signal 10 is the internal lock. If the signal 9 is valid, it is not output to the laser oscillator 11. In this case, the display lamp 18 may emit light.

In the laser processing device of the present embodiment, when the internal lock signal 9 is not valid and the hand switch 5 (or the foot switch 16) is turned on, the processing device control unit 8 outputs the contact detection voltage output ( It is determined whether the detection signal level of 76 exceeds a predetermined value, and then it is determined whether the detection signal level of the C / V voltage output 75 is within a predetermined range. It is determined to allow laser generation, the laser radiation command signal 10 is output to the laser oscillator 11, and the laser beam 6 is emitted to the workpiece 20.

As part of preparations for laser processing, the processing device control unit 8 opens the external shutter (not shown) of the oscillator as a laser safety device, opens the gas control solenoid valve 13 as necessary, and opens the torch (sensor An auxiliary gas or the like from the probe 4 is provided to the processing position of the workpiece 20, and has a function of increasing the exciting current of the laser oscillator 11 to a level at which the required output is obtained. The safety switch 17 is also connected to the processing device control unit 8 and can shut down the entire device by pressing the safety switch 17 in an emergency or other situation. Thereby, the laser processing device of this embodiment is comprised.

The operation of the laser processing device of the present embodiment configured as described above will be described.

The hand switch 5 (or foot switch 16) is turned on with the operator in protective position or other safety measures in the proper position and, if the sensor probe 4 is positioned to contact the workpiece 20, the non- A large output voltage is detected that is different from the normal output value detected during the contact. The contact detection amplifier 74 amplifies the output voltage and outputs the result as the contact detection voltage output 76 to the processing device control unit 8, whereby the processing device control unit 8 walks before the laser processing. The presence of the piece 20 is detected. At this time, the processing device control unit 8 opens the external shutter (not shown) of the oscillator as the laser safety device, and processes auxiliary gas or the like from the torch (sensor probe 4) as necessary. In position, increases the excitation current of the laser oscillator 11 to the level at which the required output is obtained, and performs other preparations for laser processing.

When the operator separates the sensor probe 4 from contact with the workpiece 20, the electrostatic capacitance Cx changes depending on the distance between the sensor probe 4 and the workpiece 20, and the electrostatic capacitance Cx The voltage induced by is amplified by the C / V amplifier 72, converted by the CV converter 73 into the C / V voltage output 75 as a direct current voltage signal, and output to the processing device control unit 8. do. If the processing device control unit 8 detects that the detection signal level of the C / V voltage output 75 is within a predetermined range, that is, determines that the laser generation is allowed, the inner lock signal 9 is not valid. , The laser radiation command signal 10 is output to the laser oscillator 11, the laser beam 6 output from the laser oscillator 11 is input to the torch body 100 through the optical fiber or other optical transmission unit 15. .

The laser beam 6 input to the torch body 100 is focused and radiated by the condenser lens 2 at a position at a predetermined distance from the end of the torch body. In the case where the workpiece 20 is in the condensing position, the processing device control unit 8 is set such that the detection signal level of the C / V voltage output 75 is within a predetermined range. Thereby, the laser beam 6 is emitted to the workpiece 20 and laser processing is performed. In addition, the processing device control unit 8 continues to monitor the detection signal level of the C / V voltage output 75 during laser processing.

The operator turns off the hand switch 5 (or foot switch 16), or the distance between the sensor probe 4 and the workpiece 20 increases, and the detection signal level of the C / V voltage output 75 is increased. If it is outside this predetermined range, the processing device control unit 8 determines not to allow laser generation, and the output of the laser radiation command signal 10 to the laser oscillator 11 is stopped. Thereby, laser generation is stopped and laser processing is stopped,

Hereinafter, an example of the control sequence which concerns on a laser processing device which concerns on this embodiment is demonstrated.

First, the laser processing preparation stage will be described. First, the sensor probe 4 of the torch body 100 is placed in contact with the workpiece 20, and as shown in FIG. 4, the processing device control unit 8 allows the operator to place a protective gear or other The preparation for laser processing is complete with safety measures, the C / V voltage output 75 is lower than the predetermined detection signal level, and the contact detection voltage output 76 is lower than the predetermined detection signal level. Detect (the sensor probe 4 and the workpiece 20 do not contact each other) (step 1). Until the sensor probe 4 is positioned to be in contact with the workpiece 20, preparation for laser processing is not performed by the processing device control unit 8. In this configuration, even when the sensor probe 4 is located somewhat in proximity to the workpiece 20 or other object, and the C / V voltage output 75 is within a range of a predetermined detection signal level, the laser radiation command signal ( 10) is not output to the laser oscillator 11, whereby the risk of unintended radiation of the laser beam is eliminated.

The contact detection voltage output 76 is above a predetermined detection signal level, whereby the processing device control unit 8 that detects the presence of the workpiece 20 has an external shutter (not shown) of the oscillator as a laser safety device. Open, provide auxiliary gas or the like from the torch to the processing position of the workpiece as needed, increase the excitation current of the laser oscillator 11 to the level at which the required output is obtained, and perform other preparations for the laser processing (Step 2). By this, the laser processing preparation stage is completed.

The laser processing process is described below.

As shown in Fig. 5A, the operator has the protective equipment or other safety measures in the proper place (the internal signal 9 is not on (step 1), the gas check and the safety glasses check are " YES "(step 2)), the operator turns on the hand switch 5 (or foot switch 16) and works the sensor probe 4 of the torch body 100 which is in contact with the workpiece 20. Separate from the piece. At this time, as shown in FIG. 5B, the processing device control unit 8 uses the detection signal level of the C / V voltage output 75 to approach the workpiece 20 (level 1), and the distance to the workpiece 20. Determines the state (level 2) of 5 mm or more from the workpiece 20, and when the detection signal level of the C / V voltage output 75 is confirmed to be below level 1 (step 3), the laser radiation command signal ( 10 is output to the laser oscillator 11 (step 4), and the laser beam 6 is emitted to the workpiece 20 (step 5).

At every step, the external internal lock signal 9 associated with the signal or other safety measures instructing the operator to wear protective equipment is continuously monitored by the processing device control unit 8 and the external internal lock signal 9 Is not valid, the laser radiation command signal 10 is not output. At all stages, when safety switch 17 is turned on, the entire device is shut down.

When hand switch 5 (or foot switch 16) is off, that is, sensor probe 4 is disconnected from workpiece 20 and the detection signal level of C / V voltage output 75 is greater than level 2 If low, or if the sensor probe 4 is located near the workpiece 20 and the detection signal level of the C / V voltage output 75 exceeds level 1 (step 6), the laser oscillation is stopped (step 7). ). When the provision of the auxiliary gas is stopped and the laser stop state lasts longer than the predetermined time, the external shutter (not shown) of the oscillator is closed (step 8). Therefore, the laser processing preparation stage shown in FIG. 4 must be restarted to restart the laser processing.

According to the present embodiment, the sensor probe 4 which detects the contact between the torch body 100 and the workpiece 20 before laser processing starts and detects the distance between the torch body 100 and the workpiece during laser processing. By using it, the structure of the torch body 100 is simplified, the cost of the torch body 100 is reduced, and the durability of the torch 100 is improved.

First, the contact between the torch body 100 and the workpiece 20 is checked, and then the laser processor is performed only when the distance between the torch body 100 and the workpiece is within a predetermined range during laser processing. Therefore, the operation error is minimized, and at this time, a check is made as to whether the workpiece 20 is metal, and since the laser is not emitted when the workpiece 20 is not metal, the operator is not exposed to the laser beam. Laser processing provides a high degree of safety.

Hereinafter, Embodiment 2 of this invention is described. Although the workpiece detection sensor in FIG. 1 was an electrostatic capacitance sensor, the workpiece detection sensor in this embodiment is an overcurrent sensor. Another aspect of the invention is the same as that shown in FIG.

In the laser processing device of the present invention, the sensor probe of the overcurrent sensor is provided as a workpiece detection sensor in front of the handheld radiating light unit. The sensor probe houses the sensor coil, and a high frequency magnetic field is generated by applying a high frequency current to the sensor coil. When the workpiece is in the magnetic field, the magnetic flux passes through the surface of the workpiece, overcurrent flows vertically through the electromagnetic inductance, and the impedance of the sensor coil changes. The overcurrent sensor measures the distance according to the change in the oscillation state caused by this phenomenon and reduces the amplitude of the oscillation. The phase difference with respect to the reference waveform increases as the distance between the sensor coil and the workpiece decreases. The distance between the sensor probe and the workpiece is measured by detecting a change in amplitude and phase, or by rectifying the oscillation amplitude and detecting a change in direct current voltage.

In addition to using the overcurrent sensor as the workpiece detection sensor, the structural aspects, operation, and effects of the laser processing device of the present embodiment are the same as the laser processing device of the first embodiment.

According to the present invention, by using a single workpiece detection sensor to detect contact between the workpiece detection probe and the workpiece prior to the start of laser processing, the structure of the radiation light unit is simplified, the cost of the radiation light unit is reduced, and the radiation The durability of the optical unit is improved.

The processing device control unit does not output a laser radiation command signal until the operator positions the radiating light unit in contact with the workpiece, first confirms contact between the radiating light unit and the workpiece, and then the nose during laser processing. When a coal position is detected, a control sequence with two stages performing laser processing is used. Therefore, the operation error is minimized, and at this time, a check is made as to whether the workpiece 20 is metal, and since the laser is not emitted when the workpiece 20 is not metal, the operator is not exposed to the laser beam. Laser processing provides a high degree of safety.

As mentioned above, although embodiment of this invention was described, this invention is not limited to these embodiment. Various modifications to the invention are also possible within the technical scope indicated by the claims, and laser processing devices obtained by such modifications are also within the scope of the invention.

1 is a diagram showing the structure of a laser processing device according to Embodiment 1 of the present invention.

2 is a diagram illustrating the structure of the torch body 100.

3 is a graph showing an example of the C / V voltage output of the electrostatic capacitance detection circuit 7.

4 shows an example of a control sequence in a preparation step relating to laser processing by the laser processing device according to Embodiment 1 of the present invention.

5A shows an example of a control sequence in a laser processing process related to the laser processing device according to Embodiment 1 of the present invention.

5B is a diagram illustrating an example of setting a range of detection signal levels of the C / V voltage output.

* Description of the symbols for the main parts of the drawings

4: sensor probe

5: hand switch

6: laser beam

8: processing device unit

9: internal rock signal

10: laser radiation command signal

11: laser oscillator

16: foot switch

17: safety switch

20: Workpiece

75: C / V voltage output

76: contact detection voltage output

100: torch body

Claims (8)

An optical transmission unit for transmitting a laser beam; And An emission light unit which receives the laser beam from the light transmission unit and emits the laser beam to a workpiece for laser processing, The emission light unit, Torch body; A workpiece detection probe provided at the distal end of the torch body; A condenser lens that emits the laser beam at a focal point located at a predetermined distance from an end of the torch body; A first circuit for supplying power to the probe and calculating the distance by using an input of a signal that varies based on the distance between the probe and the workpiece; A second circuit for detecting a contact between the probe and the workpiece based on a signal from the probe; And And a control unit for controlling generation of the laser beam according to the contact of the workpiece with the probe and the distance between the probe and the workpiece. The method of claim 1, The laser beam is not generated until the control unit detects a contact between the probe and the workpiece. The method according to claim 1 or 2, The probe is a probe of an electrostatic capacitance sensor, And the signal varying based on the distance between the probe and the workpiece is a detection signal of an electrostatic capacitance between the probe and the workpiece. The method according to claim 1 or 2, The probe is a probe of an overcurrent sensor, The probe has a sensor coil, And the signal varying based on the distance between the probe and the workpiece is a detection signal of the impedance of the sensor coil. The method according to claim 1 or 2, A hand switch for directing laser radiation is provided in the torch body. The method according to claim 1 or 2, A foot switch for directing laser radiation is provided at a position near the torch body. The method according to claim 1 or 2, A safety switch for shutting down the entire device is provided at the torch body or at a position near the torch body. Two stages of laser processing preparation stage and laser processing process stage, The laser processing preparation stage, Providing power to a workpiece detection probe and detecting a contact between the probe and the workpiece; When detecting the contact, supplying gas to the workpiece as needed using a control unit; And Increasing the exciting current of the laser oscillator to a level at which the required output is obtained using the control unit, The laser processing process stage, Detecting that the workpiece detection probe and the workpiece are located within a predetermined range from each other; When a laser radiation command is received from the control unit, generating a laser beam to start laser processing; And Continuing to perform the laser processing while the distance between the workpiece detection probe and the workpiece is within the predetermined distance range.

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