Laser processing apparatus

Abstract

To provide a laser processing device that can quickly grasp poor processing on a work-piece.SOLUTION: A laser processing device 100 comprises: a laser beam source 110 that emits a laser beam L; an XY feeding device 102 that displaces a work-piece WK relatively with respect to the laser beam source 110; and a temperature detector 115 for measuring the temperature of the work-piece WK. Further, the actuation of the laser beam source 110 is controlled by a laser driving part 116. The laser driving part 116 detects a temperature in the work-piece WK using a temperature detection signal outputted from the temperature detector 115, and determines whether the measured temperature is a temperature required after heating or not. The temperature detector 115 is supported by a support tool 111 so as to measure the temperature of a portion in the work-piece WK after the lapse of a predetermined time from the irradiation with the laser beam L.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laser processing apparatus that performs various processes on a workpiece by irradiating the workpiece with a laser beam.

Background Art

[0002] Conventionally, a laser quenching apparatus is known that heats a portion irradiated with a laser beam to an austenite state by irradiating the surface of a workpiece such as carbon steel with a laser beam and performs a quenching process. In this case, rapid cooling of the portion of the workpiece heated to the austenite state is performed automatically by heat diffusion and heat conduction to the inside and periphery of the workpiece after the laser beam has passed. For example, Patent Document 1 below discloses a laser quenching apparatus that increases or decreases the output of the laser beam according to the temperature of the heated portion of the workpiece irradiated with the laser beam.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0004] However, in the laser quenching apparatus disclosed in Patent Document 1 above, since the temperature after the laser beam is irradiated on the workpiece is unknown, it is not clear whether the rapid cooling process for the quenching process is being performed appropriately, and there is a problem that it is difficult to quickly grasp a quenching process defect.

[0005] The present invention has been made to address the above problems, and an object thereof is to provide a laser processing apparatus capable of quickly grasping a processing defect in a workpiece.

Summary of the Invention

[0006] To achieve the above object, a feature of the present invention is in a laser processing apparatus that forms an optical spot by a laser beam on the surface of a workpiece and processes the same surface.A laser light source that emits laser light, a table that detachably holds a workpiece, a light spot scanning means for relatively displacing a light spot with respect to a workpiece, and a temperature detector that outputs a temperature detection signal representing the temperature of a portion of the workpiece through which the light spot has passed , a control device that monitors the temperature of the surface of the workpiece using a temperature detection signal and detects that the temperature of the portion where the light spot has passed in the workpiece has reached a predetermined temperature, and a measurement position adjustment mechanism that changes the measurement position of the temperature by a temperature detector with respect to the workpiece and comprising The light spot scanning means is an XY feed device that relatively displaces the table and the laser light source with respect to each other. The measurement position adjustment mechanism changes the measurement position of the temperature by a temperature detector with respect to the workpiece by the operation control by the control device. The control device changes the measurement position of the temperature by a temperature detector with respect to the workpiece according to the change in the feed speed during the processing of the light spot in the workpiece is to do so.

[0007] According to the features of the present invention configured as described above, since the laser processing apparatus includes a temperature detector that detects the temperature of a portion of the workpiece through which the light spot has passed, it is possible to quickly grasp processing defects on the workpiece by checking the temperature of the irradiated portion of the laser light after being heated by the light spot. In particular, the laser processing apparatus can quickly grasp heat treatment defects on the workpiece by grasping the temperature of the irradiated portion of the laser light where no processing other than heating immediately after the light spot has passed is performed. Further, since the control device of the laser processing apparatus detects that the temperature of the portion where the light spot has passed in the workpiece has reached a predetermined temperature, it is possible to easily and accurately grasp a heat treatment defect in the workpiece. Further, since the laser processing apparatus is provided with a measurement position adjustment mechanism that changes the measurement position of the temperature by a temperature detector with respect to the workpiece, the temperature can be detected at a desired measurement position according to the specifications of the workpiece or the specifications of the laser processing. Further, since the control device of the laser processing apparatus controls the operation of the measurement position adjustment mechanism according to the feed speed of the light spot in the workpiece and changes the measurement position of the temperature with respect to the workpiece, it is possible to accurately grasp a heat treatment defect in the workpiece by changing the measurement position according to the change in the feed speed during the processing with respect to the workpiece.

[0008] In addition, for the processing using the laser light performed by the laser processing apparatus, there are surface modification treatments on the workpiece such as laser quenching, tempering, annealing or normalizing by laser, laser cladding for closely adhering different or the same kind of materials on the workpiece, laser welding for connecting two workpieces to each other, and the like.

[0009] Also, in order to achieve the above object, the features of the present invention are, in a laser processing apparatus that forms a light spot by laser light on the surface of a workpiece to perform processing on the same surface, a laser light source that emits laser light, A table that detachably holds a workpiece, a light spot scanning means for relatively displacing a light spot with respect to a workpiece, and a temperature detector that outputs a temperature detection signal representing the temperature of a portion of the workpiece through which the light spot has passed , includes a control device that controls the operation of the laser light source and monitors the temperature of the surface of the workpiece using a temperature detection signal. The light spot scanning means is an XY feed device that relatively displaces the table and the laser light source with respect to each other. The control device starts monitoring the temperature of the surface of the workpiece after a predetermined time has elapsed since irradiating the workpiece with the laser light is to do so.

[0010] According to the features of the present invention configured as described above, since the laser processing apparatus includes a temperature detector that detects the temperature of the portion of the workpiece through which the light spot has passed, it is possible to quickly grasp processing defects in the workpiece by checking the temperature of the irradiated portion of the laser beam after being heated by the light spot. In particular, the laser processing apparatus can quickly grasp heat treatment defects in the workpiece by grasping the temperature of the irradiated portion of the laser beam where no processing other than heating is performed immediately after the light spot has passed.

[0011] Also, to achieve the above object, the features of the present invention are, in a laser processing apparatus that forms a light spot by laser light on the surface of a workpiece to perform processing on the same surface, a laser light source that emits laser light, A table that detachably holds a workpiece, light spot scanning means for relatively displacing the light spot with respect to the workpiece, and a temperature detector that outputs a temperature detection signal representing the temperature of the portion of the workpiece through which the light spot has passed , a support that integrally supports the laser light source and the temperature detector so that the laser light source and the temperature detector are integrally displaced with respect to the table and comprising , the light spot scanning means is an XY feed device that relatively displaces the table and the laser light source with respect to each other this.

[0012] According to the features of the present invention configured as described above, since the laser processing apparatus includes a temperature detector that detects the temperature of the portion of the workpiece through which the light spot has passed, it is possible to quickly grasp processing defects in the workpiece by checking the temperature of the irradiated portion of the laser beam after being heated by the light spot. In particular, the laser processing apparatus can quickly grasp heat treatment defects in the workpiece by grasping the temperature of the irradiated portion of the laser beam where no processing other than heating is performed immediately after the light spot has passed.

[0013] Also, to achieve the above object, the features of the present invention are, in a laser processing apparatus that forms a light spot by laser light on the surface of a workpiece to perform processing on the same surface, a laser light source that emits laser light, A table that detachably holds a workpiece, light spot scanning means for relatively displacing the light spot with respect to the workpiece, and a temperature detector that outputs a temperature detection signal representing the temperature of the portion of the workpiece through which the light spot has passed , a Z-feed device that relatively displaces a table and a temperature detector in the Z-axis direction orthogonal to the direction of relative displacement by light spot scanning means and comprising, the light spot scanning means is an XY-feed device that relatively displaces the table and the laser light source is to do so.

[0014] According to the features of the present invention configured as described above, since the laser processing apparatus includes a temperature detector that detects the temperature of the portion of the workpiece through which the light spot has passed, it is possible to quickly grasp processing defects in the workpiece by checking the temperature of the irradiated portion of the laser beam after being heated by the light spot. In particular, the laser processing apparatus can quickly grasp heat treatment defects in the workpiece by grasping the temperature of the irradiated portion of the laser beam where no processing other than heating is performed immediately after the light spot has passed.

[0015] Also, another feature of the present invention is the above-mentioned In the laser processing apparatus, further, there is provided a control device that controls the operation of the laser light source and monitors the temperature of the surface of the workpiece using the temperature detection signal.

[0016] Also, another feature of the present invention is the above-mentioned In the laser processing apparatus, further, and includes a measurement position adjustment mechanism for changing the measurement position of the temperature detected by the temperature detector with respect to the workpiece, The measurement position adjustment mechanism is provided with an elongated support hole that extends in a direction approaching or separating from the laser light source and supports the temperature detector at these approaching or separating positions.

[0017] Also, in these cases, In the laser processing apparatus, the temperature detector is arranged on the rear side in the traveling direction of the same laser light source with respect to the laser light source and is to be displaced together with the same laser light source. According to this, Since the laser processing apparatus has the temperature detector arranged on the rear side in the traveling direction of the laser light source and displaced together with the laser light source, it is possible to accurately follow the displacement of the laser light source and measure the temperature of the workpiece.

[0018] Also, in these cases, In the laser processing apparatus, it is to include a temperature history storage unit that stores the temperature history of the portion of the workpiece through which the light spot has passed. According to this, Since the laser processing apparatus includes a temperature history storage unit that stores the temperature history of the portion of the workpiece through which the light spot has passed, it is possible to improve the traceability that leaves the processing content of the workpiece as a record and enables subsequent tracking.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0020] (Configuration of Laser Processing Apparatus 100) Hereinafter, an embodiment of a laser processing apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram schematically showing the configuration of a laser processing apparatus 100 according to the present invention. Note that the drawings referred to in this specification are schematically represented, such as exaggerating some components to facilitate understanding of the present invention. For this reason, dimensions, ratios, etc. between the respective components may be different. This laser processing apparatus 100 is a heat treatment apparatus using a laser that irradiates a workpiece WK made of a metal material such as carbon steel with a laser beam L to perform a quenching process on the surface layer by computer control (NC control).

[0021] The laser processing apparatus 100 includes a table 101. The table 101 is a plate-shaped mounting table that detachably holds the workpiece WK and is supported by an XY feed device 102. The XY feed device 102 is a mechanical device for displacing the table 101 in two axial directions, namely the illustrated X-axis direction and the illustrated Y-axis direction, which are perpendicular to each other in the same plane, by operation control by a comprehensive control device 120 described later, and is configured with a feed screw mechanism.

[0022] In this case, the feed screw mechanism includes feed screw shafts (not shown) having male threads formed thereon and extending in the illustrated X-axis direction and the illustrated Y-axis direction, respectively, and nut portions (not shown) having female threads meshing with these male threads and directly or indirectly connected to the table 101. In FIG. 1, the X-axis direction is the left-right direction, and the Y-axis direction is the depth direction of the paper surface.

[0023] Feed motors (not shown) are respectively connected to the feed screw shafts extending in the illustrated X-axis direction and the illustrated Y-axis direction in this feed mechanism. These feed motors are electric motors (servo motors in this embodiment) that rotationally drive the respective feed screw shafts in the forward rotation direction and the reverse rotation direction, and their operations are respectively controlled by the comprehensive control device 120.

[0024] Above the table 101, a laser light source 110 is provided. The laser light source 110 is an optical device for emitting and heating a laser beam L to the workpiece WK held on the table 101 and is supported by a support 111. In this embodiment, it is composed of a semiconductor laser with a wavelength of 940 nm and an output of 2 kW. This laser light source 110 is operationally controlled by the comprehensive control device 120 via a laser drive unit 116 to form a square light spot SP with a side length of 5 mm on the surface of the workpiece WK. Note that the shape and size of the light spot SP are appropriately set according to the specifications of the quenching process and are not limited to this embodiment.

[0025] The support 111 is a metal part for supporting the laser light source 110 and the temperature detector 115 above the table 101, and is configured as a plate-like body having support holes 111a, 111b as through holes through which the laser light source 110 and the temperature detector 115 pass, respectively. In this case, the support 111 supports the laser light source 110 and the temperature detector 115 in a state in which the angles of the laser light source 110 and the temperature detector 115 with respect to the surface of the table 101 can be changed. The support 111 also includes a measurement position adjustment mechanism 112 and a scale 113.

[0026] The measurement position adjustment mechanism 112 is a part for changing the measurement position MP of the temperature by the temperature detector 115, and mainly includes a support hole 111b, a lock hole 112a, and a lock screw 112b. The support hole 111b is a part for supporting the temperature detector 115 at a position close to or away from the laser light source 110, and is formed in an elongated hole extending in the Y-axis direction in the figure. This support hole 111b is formed on the rear side with respect to the traveling direction of the laser light source 110.

[0027] Lock hole 112a is a portion for fixing the position of temperature detector 115 at any position in the longitudinal direction of support hole 111b, and a through hole through which set screw 112b passes is formed in an elongated shape extending along support hole 111b. Set screw 112b is a component for fixing the position of temperature detector 115 at any position in the longitudinal direction of support hole 111b, and is composed of a male screw that screws into temperature detector 115 via lock hole 112a.

[0028] Scale 113 is a portion for grasping the amount of displacement of temperature detector 115, and is provided along support hole 111b on the outer surface of support 111. Scale 113 is indicated by a one-piece pointer 113a provided on temperature detector 115. Support 111 is supported by Z feed device 114.

[0029] The Z feed device 114 is controlled by the overall control device 120.Laser light source 110 It is a mechanical device for displacing in a Z-axis direction (vertical direction in the figure) orthogonal to the illustrated X-axis direction and the illustrated Y-axis direction respectively, and is configured with a feed screw mechanism. In this embodiment, the table 101 is displaced in the illustrated X-axis direction and the illustrated Y-axis direction with respect to the laser light source 110, and the laser light source 110 is displaced in the illustrated Z-axis direction with respect to the table 101. However, since the table 101 and the laser light source 110 only need to be configured to be relatively displaced with respect to each other, at least one of them may be configured to be displaced with respect to the other.

[0030] The temperature detector 115 is a temperature detection device that outputs a temperature detection signal, which is an electrical signal corresponding to the temperature of the portion of the surface of the workpiece WK irradiated and passed through by the light spot SP, to the laser drive unit 116. In this embodiment, the temperature detector 115 is composed of a radiation thermometer. This temperature detector 115 is supported by a support 111 on the side of the laser light source 110. In this case, as shown in FIG. 2, the temperature detector 115 is supported by the support 111 such that the temperature measurement position MP is located in the rear portion in the traveling direction of the light spot SP with respect to the portion where the light spot SP is formed on the surface of the workpiece WK.

[0031] The laser drive unit 116 is a constant current power source that functions as a driver for controlling the operation of the laser light source 110 by supplying the power supplied from an external power source (not shown) to the laser light source 110 according to the operation control of the comprehensive control device 120. This laser drive unit 116 includes a laser control unit 116a composed of a microcomputer including a CPU, a ROM, a RAM, etc. that controls the operation of the constant current power source according to an instruction from the comprehensive control device 120.

[0032] The laser control unit 116a independently controls whether or not to emit the laser beam L and the output intensity of the laser beam L, and continuously oscillates the laser beam L from the laser light source 110. Further, the laser control unit 116a stores the required temperature after heating. Here, the required temperature after heating is an ideal temperature that should change after a predetermined time has elapsed since the irradiation of the laser beam L ended in order to appropriately perform quenching treatment on the portion heated by the laser beam L. In this case, the required temperature after heating is a specific one temperature or temperature range at which the quenching treatment is properly performed. And the required temperature after heating is preset by the operator before the execution of the quenching treatment.

[0033] An operation panel 116c is connected to this laser control unit 116a. The operation panel 116c is an input / output interface dedicated to the laser control unit 116a, which includes an input device (not shown) composed of a group of switches that receives instructions from the operator and inputs them to the laser control unit 116a, and a liquid crystal display device (not shown) that displays the operating status of the laser control unit 116a.

[0034] The overall control device 120 is composed of a microcomputer including a CPU, a ROM, a RAM, etc., and comprehensively controls the overall operation of the laser processing apparatus 100. At the same time, according to a quenching processing program (so-called NC (Numerical Control) program) prepared by the operator (not shown), while emitting the laser beam L from the laser light source 110, the table 101 and the laser light source 110 are relatively displaced to control the heat treatment processing of the workpiece WK.

[0035] This overall control device 120 is respectively provided with an operation panel 121 composed of a group of operation switches for receiving an operation from the operator with respect to the overall control device 120, and a display device 122 composed of a liquid crystal display for displaying the operating status of the overall control device 120 to the operator.

[0036] (Operation of the laser processing apparatus 100) Next, the operation of the laser processing apparatus 100 configured as described above will be explained. First, an operator who performs quenching on the workpiece WK prepares the workpiece WK, sets it on the table 101, and then sets the temperature measurement position MP on the workpiece WK by the temperature detector 115.

[0037] Specifically, the operator loosens the set screw 112b in the measurement position adjustment mechanism 112 to displace the temperature detector 115 in the longitudinal direction of the support hole 111b (the Y-axis direction in the figure) to position the temperature measurement position MP on the workpiece WK by the temperature detector 115. In this case, the temperature measurement position MP on the workpiece WK is the portion where a predetermined time has elapsed after the laser beam L has been irradiated on the surface of the workpiece WK.

[0038] Here, the predetermined time from when the laser beam L is irradiated until the temperature is measured is the time from when the laser beam L is irradiated and the portion of the workpiece WK is heated until the temperature measurement is started after the irradiation of the laser beam L is completed (hereinafter, sometimes referred to as the "delay measurement time"). This delay measurement time is appropriately set according to the type of the workpiece WK. In the present embodiment, the temperature measurement position MP is set at the position where the portion irradiated with the laser beam L is located after 1 second has elapsed after the irradiation is completed (the portion displaced by about 10 mm).

[0039] After the operator identifies the temperature measurement position MP on the workpiece WK using the aiming function (optical aiming, LED aiming, or laser aiming) of the temperature detector 115, the operator tightens the set screw 112b to fix the position and posture of the temperature detector 115. Thereby, the operator can set the temperature measurement position MP on the workpiece WK by the temperature detector 115.

[0040] Next, the operator sets the quenching process conditions for the comprehensive control device 120. Specifically, the operator operates the operation panel 121 to input information such as the position of the quenching process for the workpiece WK, the output of the laser beam L, and the feed rate. Also, the operator operates the operation panel 116c to set the delay measurement time and the required temperature after heating for the laser control unit 116a respectively. In this embodiment, the operator sets 1 second as the delay measurement time and 500°C as the required temperature after heating.

[0041] Note that the operator can also input to the comprehensive control device 120 a temperature range consisting of a lower limit temperature and an upper limit temperature for the required temperature after heating, or a specific temperature and a range allowed for that specific temperature (for example, ±10°C).

[0042] Next, the operator instructs the comprehensive control device 120 to execute the quenching process. In response to this instruction, the comprehensive control device 120 starts executing the quenching process program to perform the quenching process on the workpiece WK.

[0043] Specifically, after instructing the laser control unit 116a in the laser drive unit 116 to execute the post-heating temperature monitoring program shown in FIG. 3, the comprehensive control device 120 controls the operations of the XY feed device 102 and the Z feed device 114 respectively to position the workpiece WK with respect to the laser light source 110 and instruct the laser drive unit 116 to emit the laser beam L. Then, the comprehensive control device 120 emits the laser beam L from the laser light source 110 to form an optical spot SP on the workpiece WK set on the table 101, and displaces the position of the table 101 in the X-axis direction, Y-axis direction, and Z-axis directions shown in the figure respectively to perform the quenching process on the portion indicated by the operator on the workpiece WK.

[0044] In the process of executing this quenching treatment, the laser control unit 116a executes a post-heating temperature monitoring program. The post-heating temperature monitoring program measures the temperature of the heated portion where the laser beam L is irradiated on the workpiece WK after a predetermined time has elapsed since the irradiation was completed, thereby determining whether the irradiation of the laser beam L (i.e., the heat treatment) has been appropriately performed.

[0045] Specifically, the laser control unit 116a starts the execution of the post-heating temperature monitoring program at step S100, and at step S102, starts the operation of the temperature detector 115. As a result, a temperature detection signal output by the temperature detector 115 is input to the laser control unit 116a.

[0046] Next, the laser control unit 116a executes a determination process at step S104 to determine whether the irradiation of the laser beam L has started. In this case, until the laser control unit 116a instructs the laser light source 110 to start emitting the laser beam L, it continuously determines "No" in this determination process and waits for the emission of the laser beam L. Then, when the laser control unit 116a instructs the laser light source 110 to start emitting the laser beam L, it determines "Yes" in this determination process and proceeds to step S106.

[0047] Next, the laser control unit 116a starts a measurement process of the elapsed time since the start of irradiation at step S106. Here, the elapsed time since the start of irradiation is the elapsed time since the laser light source 110 started emitting the laser beam L. Therefore, the laser control unit 116a starts measuring time using the timer function built into itself. In addition, in the case of the second and subsequent executions of the measurement process of the elapsed time since the start of irradiation by this step S106, after resetting the already executed measurement process, the measurement process is started again.

[0048] Next, the laser control unit 116a executes a determination process in step S108 as to whether or not the irradiation of the laser beam L has stopped. In this case, if the laser control unit 116a has not instructed the laser light source 110 to stop emitting the laser beam L, the laser control unit 116a determines "No" in this determination process and proceeds to step S110. On the other hand, if the laser control unit 116a has instructed the laser light source 110 to stop emitting the laser beam L, the laser control unit 116a determines "Yes" in this determination process and proceeds to step S114. That is, the determination process in step S108 is a process for detecting a temporary interruption of the laser beam L irradiating the workpiece WK or the end of the irradiation of the laser beam L (that is, the end of the quenching process).

[0049] Next, the laser control unit 116a executes a determination process in step S110 as to whether or not the elapsed time since the start of irradiation has reached a predetermined time. Specifically, the laser control unit 116a continues to determine "No" in this determination process and returns to step S108 until the elapsed time since the start of irradiation measured in step S106 reaches the previously set delay measurement time. Then, when the elapsed time since the start of irradiation reaches the delay measurement time, the laser control unit 116a determines "Yes" in this determination process and proceeds to step S112.

[0050] Next, the laser control unit 116a executes a temperature monitoring process for the portion where the irradiation of the laser beam L has been completed in step S112. The temperature monitoring process in step S112 is performed by executing the temperature monitoring subprogram shown in FIG. 4.

[0051] Specifically, the laser control unit 116a starts executing the temperature monitoring subprogram in step S200 and resets the temperature error count value to "0" in step S202. In this case, the temperature error count value is an integer value for counting the number of temperature errors in which the measured temperature by the temperature detector 115 is outside the required temperature after heating.

[0052] Next, in step S204, the laser control unit 116a determines whether or not the measured temperature of the workpiece WK has reached the required temperature after heating. Specifically, the laser control unit 116a identifies the temperature of the workpiece WK using the temperature detection signal output from the temperature detector 115, and determines whether or not this measured temperature has dropped to the required temperature after heating.

[0053] In this case, when the measured temperature is the same as the required temperature after heating (including the case where it is within a predetermined range with respect to the required temperature after heating), the laser control unit 116a determines "Yes" in this determination process and proceeds to step S212. Then, in step S212, the laser control unit 116a ends the execution of this temperature monitoring subprogram and returns to step S108 in the post-heating temperature monitoring program. Thereby, until the stop of the irradiation of the laser beam L is detected, the laser control unit 116a repeatedly executes the temperature monitoring subprogram to monitor the temperature of the portion of the workpiece WK through which the laser beam L has passed.

[0054] On the other hand, when the measured temperature is not the required temperature after heating, the laser control unit 116a determines "No" in this determination process and proceeds to step S206. In the determination process in step S204, the case where it is determined that the measured temperature has not become the required temperature after heating is a heating temperature error. The heating temperature error means that the temperature after a predetermined time has elapsed after the irradiation of the laser beam L on the workpiece WK has been completed does not drop to the temperature specified by the required temperature after heating, and is higher or lower than the required temperature after heating, indicating that there is a high possibility that the quenching process is not properly performed.

[0055] Next, in step S206, the laser control unit 116a determines whether the number of heating temperature errors has reached a predetermined number. Here, the predetermined number is set in advance in the laser control unit 116a via the integrated control device 120 by the operator. In this embodiment, the predetermined number is set to 3. When the temperature error count value is less than or equal to the predetermined value, the laser control unit 116a determines "No" in this determination process, proceeds to step S208, increments the temperature error count value (a process of adding "1"), and then returns to step S204.

[0056] On the other hand, when the temperature error count value exceeds the predetermined value, the laser control unit 116a determines "Yes" in this determination process and proceeds to step S210. That is, the process in step S206 is for determining whether the heating temperature error is a temporary error such as sudden or accidental, or a reliable error that continuously occurs.

[0057] Next, in step S210, the laser control unit 116a executes error processing. Specifically, the laser control unit 116a displays on the display device 122 and generates an alarm sound via the integrated control device 120 that a heating temperature error has occurred. Then, in step S212, the laser control unit 116a ends the execution of this temperature monitoring subprogram and returns to step S108 in the post-heating temperature monitoring program. Through the error processing in this step S210, the operator can grasp that the quenching process for the workpiece WK is not properly performed, check the state of the workpiece WK, or interrupt the quenching process.

[0058] Next, when the laser control unit 116a detects the stop of the irradiation of the laser beam L in step S108 of the post-heating temperature monitoring program, in step S114, it starts the measurement process of the elapsed time since the irradiation stop. Here, the elapsed time since the irradiation stop is the elapsed time since the laser light source 110 stopped emitting the laser beam L. Therefore, the laser control unit 116a starts the time measurement using the timer function built in itself. In addition, in the case of the second and subsequent executions of the measurement process of the elapsed time since the irradiation stop by this step S114, after resetting the already executed measurement process, the measurement process is started again.

[0059] Next, the laser control unit 116a executes a determination process in step S116 as to whether or not the irradiation of the laser beam L has stopped. In this case, when the laser control unit 116a instructs the laser light source 110 to start emitting the laser beam L, it determines "Yes" in this determination process and returns to step S106. On the other hand, when the laser control unit 116a has not given an instruction to start emitting the laser beam L to the laser light source 110, it determines "No" in this determination process and proceeds to step S118. That is, the determination process by this step S116 is a process of detecting re-irradiation of the laser beam L to the workpiece WK.

[0060] Next, the laser control unit 116a executes a determination process in step S118 as to whether or not the elapsed time since the irradiation stop has reached a predetermined time. Specifically, the laser control unit 116a continues to determine "No" in this determination process until the elapsed time since the irradiation start measured in step S114 reaches the delay measurement time set in advance, and proceeds to step S120. Then, when the elapsed time since the irradiation stop reaches the delay measurement time, the laser control unit 116a determines "Yes" in this determination process and proceeds to step S122.

[0061] Next, the laser control unit 116a executes temperature monitoring processing for the portion where the irradiation of the laser beam L has been completed in step S120. Since the temperature monitoring processing in this step S120 is performed by executing the temperature monitoring subprogram in step S112, its description is omitted. As a result, the laser control unit 116a can perform temperature monitoring after the irradiation of the laser beam L up to the last portion of the portion of the workpiece WK irradiated with the laser beam L. Then, after executing the temperature monitoring processing in this step S120, the laser control unit 116a returns to step S116.

[0062] Next, the laser control unit 116a executes determination processing as to whether or not the quenching process for the workpiece WK has ended in step S122. Specifically, if there is remaining baking processing for other portions of the workpiece WK in the quenching processing program, the laser control unit 116a determines "No" in this determination processing and returns to step S104. On the other hand, if there is no remaining baking processing for other portions of the workpiece WK in the quenching processing program, the laser control unit 116a determines "Yes" in this determination processing and proceeds to step S124.

[0063] Then, the laser control unit 116a ends the execution of the post-heating temperature monitoring program in step S124. In this case, the overall control device 120 ends the execution of the quenching processing program and ends the quenching process for the workpiece WK. Therefore, the operator removes the workpiece WK from the table 101 and ends the quenching operation.

[0064] As can be understood from the above operation description, according to the above embodiment, since the laser processing apparatus 100 includes the temperature detector 115 that detects the temperature of the portion of the workpiece WK through which the light spot SP has passed, it is possible to quickly grasp the processing defects on the workpiece WK by checking the temperature of the irradiated portion of the laser beam L after being heated by the light spot SP. In particular, the laser processing apparatus 100 can quickly grasp the heat treatment defects on the workpiece WK by grasping the temperature of the irradiated portion of the laser beam L where there is no treatment other than heating immediately after the light spot SP has passed.

[0065] Furthermore, in the implementation of the present invention, it is not limited to the above embodiment, and various changes are possible without departing from the object of the present invention. In the description of the following modification examples and the figures referred to, the same reference numerals are given to the same components as in the above embodiment, and the description thereof is omitted.

[0066] For example, in the above embodiment, the laser processing apparatus 100 is configured such that the laser control unit 116a detects a heating temperature error with respect to the workpiece WK in step S204 of the temperature monitoring subprogram. However, the laser processing apparatus 100 can also be configured such that the temperature detection result by the temperature detector 115 is displayed on the display device 122, and the operator determines whether there is a heating temperature error.

[0067] Also, in the above embodiment, when the laser processing apparatus 100 detects a heating temperature error with respect to the workpiece WK in step S210 of the temperature monitoring subprogram, it is configured to display that fact on the display device 122 and generate an alarm sound (step S210). However, the laser processing apparatus 100 may be configured to immediately interrupt the execution of the quenching process when a heating temperature error with respect to the workpiece WK is detected in step S210 of the temperature monitoring subprogram.

[0068] Also, in the above embodiment, the laser processing apparatus 100 is configured to be able to adjust the measurement position MP of the temperature on the workpiece WK by the temperature detector 115 using the measurement position adjustment mechanism 112. However, the laser processing apparatus 100 can also be configured such that the support 111 fixedly supports the temperature detector 115 and the measurement position MP of the temperature on the workpiece WK cannot be adjusted.

[0069] Also, in the above embodiment, the laser processing apparatus 100 is configured to be able to adjust the measurement position MP of the temperature on the workpiece WK by the temperature detector 115 using the measurement position adjustment mechanism 112 by manual operation by an operator. However, the laser processing apparatus 100 can be configured such that the adjustment of the measurement position MP of the temperature detector 115 by the measurement position adjustment mechanism 112 is controlled by the laser control unit 116a via a feed screw mechanism driven by an electric motor or the like. In this case, the laser control unit 116a can control the operation of the measurement position adjustment mechanism 112 according to the feed speed of the light spot SP on the workpiece WK and change the measurement position MP of the temperature by the temperature detector 115.

[0070] Also, in the above embodiment, the temperature detector 115 is supported by the support 111 that supports the laser light source 110 and is configured to be displaced integrally with the laser light source 110 with respect to the table 101. In this case, the temperature detector 115 is disposed behind the laser light source 110 in the traveling direction of the same laser light source 110. Further, the XY feed device 102 that displaces the table 101 corresponds to the light spot scanning means according to the present invention.

[0071] However, the temperature detector 115 can also be arranged at a position other than the rear side in the traveling direction of the laser light source 110 with respect to the laser light source 110. For example, the temperature detector 115 can also be arranged at the same position (positions arranged side by side in the Y-axis direction in the figure) with respect to the laser light source 110. Further, the temperature detector 115 does not necessarily have to be supported by the support tool 111 that supports the laser light source 110, and it may be supported by a support tool different from the support tool 111 that supports the laser light source 110. In this case, it is preferable that the position or the angle of the temperature detector 115 is supported so as to be changeable so that the measurement position MP follows the displacement of the laser light source 110.

[0072] Also, in the above embodiment, the temperature monitoring sub-program is configured to determine a heating temperature error when the temperature of the workpiece WK measured a plurality of times (three times) deviates from the required temperature after heating (steps S202, S206, S208). However, the temperature monitoring sub-program can also be configured to determine that there is a heating temperature error when the measured temperature by one measurement deviates from the required temperature after heating. That is, the temperature monitoring sub-program can also be configured by omitting each process of steps S202, S206, and S208.

[0073] Also, in the above embodiment, the laser processing apparatus 100 is configured such that the laser control unit 116a executes the post-heating temperature monitoring program and the temperature monitoring sub-program, respectively. That is, the laser control unit 116a corresponds to the control device according to the present invention. Thereby, the laser processing apparatus 100 can quickly perform the temperature monitoring of the workpiece WK by performing the temperature monitoring of the workpiece WK within the laser driving unit 116. However, the laser processing apparatus 100 can also be configured such that the overall control device 120 executes the post-heating temperature monitoring program and the temperature monitoring sub-program, respectively. That is, the overall control device 120 corresponds to the control device according to the present invention. In this case, the temperature detector 115 is configured to output a temperature detection signal to the overall control device 120.

[0074] Also, in the above-described embodiment, the laser processing apparatus 100 is configured not to store the history of temperature measurement of the workpiece WK in the post-heating temperature monitoring program and the temperature monitoring sub-program. However, the laser processing apparatus 100 can improve the traceability that enables the processing details of the workpiece WK to be left as a record for later tracking by executing a temperature history storage step that stores the history of temperature measurement of the workpiece WK in the post-heating temperature monitoring program and / or the temperature monitoring sub-program. In this case, as shown in FIG. 1, the laser drive unit 116 may include a temperature history storage unit 116b that stores the history of temperature measurement of the workpiece WK.

[0075] Also, in the above-described embodiment, the laser processing apparatus 100 is configured as a laser heat treatment apparatus that performs quenching treatment or tempering treatment on the surface layer of the workpiece WK. However, the laser processing apparatus 100 according to the present invention can be applied to various mechanical apparatuses that perform processing other than surface modification processing such as heat treatment on the workpiece WK, for example, laser cladding that adheres a different or the same material onto the workpiece WK, laser welding that connects two workpieces WK to each other, and the like.

Explanation of Reference Numerals

[0076] WK... Workpiece, L... Laser beam, SP... Light spot, MP... Measurement position of temperature by temperature detector, 100... Laser processing apparatus, 101... Table, 102... XY feed device, 110... Laser light source, 111... Support tool, 111a, 111b... Support holes, 112... Measurement position adjustment mechanism, 112a... Lock hole, 112b... Set screw, 113... Scale, 113a... Pointer, 114... Z feed device, 115... Temperature detector, 116... Laser drive unit, 116a... Laser control unit, 116b... Temperature history storage unit, 116c... Operation panel, 120... Integrated control device, 121... Operation panel, 122... Display device.

Claims

1. In a laser processing apparatus for forming a light spot by laser light on the surface of a workpiece and performing processing on the surface, a laser light source that emits the laser light, a table that detachably holds the workpiece, light spot scanning means for relatively displacing the light spot with respect to the workpiece, a temperature detector that outputs a temperature detection signal representing the temperature of a portion of the workpiece through which the light spot has passed, a control device that monitors the temperature of the surface of the workpiece using the temperature detection signal and detects that the temperature of the portion of the workpiece through which the light spot has passed has reached a predetermined temperature, a measurement position adjustment mechanism for changing the measurement position of the temperature by the temperature detector with respect to the workpiece, the light spot scanning means is an XY feed device that relatively displaces the table and the laser light source with respect to each other, the measurement position adjustment mechanism is one that changes the measurement position of the temperature by the temperature detector with respect to the workpiece by the operation control of the control device, the control device is a laser processing apparatus characterized in that the measurement position of the temperature by the temperature detector with respect to the workpiece is changed according to a change in the feed rate during processing of the light spot on the workpiece.

2. In a laser processing apparatus for forming a light spot by laser light on the surface of a workpiece and performing processing on the surface, a laser light source that emits the laser light, a table that detachably holds the workpiece, light spot scanning means for relatively displacing the light spot with respect to the workpiece, a temperature detector that outputs a temperature detection signal representing the temperature of a portion of the workpiece through which the light spot has passed, a control device that controls the operation of the laser light source and monitors the temperature of the surface of the workpiece using the temperature detection signal, the light spot scanning means is an XY feed device that relatively displaces the table and the laser light source with respect to each other, the control device is a laser processing apparatus characterized in that monitoring of the temperature of the surface of the workpiece is started after a predetermined time has elapsed since the laser light is irradiated on the workpiece.

3. In a laser processing apparatus for forming a light spot by laser light on the surface of a workpiece and performing processing on the surface, a laser light source that emits the laser light, a table that detachably holds the workpiece, light spot scanning means for relatively displacing the light spot with respect to the workpiece, A temperature detector that outputs a temperature detection signal representing the temperature of the portion of the workpiece through which the light spot has passed; A support that integrally supports the laser light source and the temperature detector so that the laser light source and the temperature detector are integrally displaced with respect to the table; The light spot scanning means is A laser processing apparatus, characterized in that it is an XY feed device that relatively displaces the table and the laser light source with respect to each other.

4. In a laser processing apparatus that forms a light spot by laser light on the surface of a workpiece and processes the same surface, A laser light source that emits the laser light; A table that detachably holds the workpiece; Light spot scanning means for relatively displacing the light spot with respect to the workpiece; A temperature detector that outputs a temperature detection signal representing the temperature of the portion of the workpiece through which the light spot has passed; A Z feed device that relatively displaces the table and the temperature detector in the Z-axis direction orthogonal to the direction of the relative displacement by the light spot scanning means; The light spot scanning means is A laser processing apparatus, characterized in that it is an XY feed device that relatively displaces the table and the laser light source with respect to each other.

5. In the laser processing apparatus according to claim 3 or claim 4, further, A control device that controls the operation of the laser light source and monitors the temperature of the surface of the workpiece using the temperature detection signal. A laser processing apparatus characterized by comprising.

6. In the laser processing apparatus according to any one of claims 2 to 5, further, A measurement position adjustment mechanism for changing the measurement position of the temperature by the temperature detector with respect to the workpiece; The measurement position adjustment mechanism is A laser processing apparatus, characterized in that it has an elongated support hole that extends in a direction approaching or separating from the laser light source and supports the temperature detector at these approaching or separating positions.

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