JP5920871B2 - Laser heat treatment system - Google Patents

Description

  The present invention relates to a laser heat treatment system, and more particularly, to a laser heat treatment system provided with a control device having means for setting a heat treatment temperature according to the material of a workpiece and calculating a standard heat treatment condition based on the heat treatment temperature. .

  In recent years, a method of performing a heat treatment of a steel material using a laser beam, particularly a laser quenching method has attracted attention (see, for example, Patent Document 1). In the laser quenching method, since heat can be concentrated locally, the thermal effect on the workpiece is extremely small, and ultra-low distortion quenching is possible. For this reason, it is also suitable for applications that require high machining accuracy. In addition, there is an advantage that the cooling rate is high and baking is easy to occur.

JP 2010-255114 A

  Laser heat treatment methods such as laser quenching have many excellent features. However, there are a wide variety of conditions that should be set prior to the heat treatment, and it is not always easy to set conditions for obtaining the desired quality. Such condition setting is often made based on the experience and intuition of the operator. For this reason, the quality of the processed product varies greatly depending on the skill level of the operator. In addition, when the shape of the heat treatment region of the workpiece is complicated, for example, when there is a curved portion with a small curvature radius or a large surface unevenness, it is necessary to set conditions appropriately corresponding to the shape.

A laser heat treatment system according to the present invention relatively changes the positional relationship between a laser device that outputs laser light, a processing head for irradiating the heat treatment region of the work with the laser light, and the work and the processing head. A laser beam scanning device, and a control device having means for setting a heat treatment temperature corresponding to the material of the workpiece and calculating a standard heat treatment condition based on the heat treatment temperature, the control device comprising the heat treatment region And a correction means for changing the standard heat treatment condition on the basis of at least one of the curvature radius and the surface irregularity of the heat treatment region.
As the laser beam scanning device, it is preferable to use a robot device that can three-dimensionally move the processing head along the heat treatment region.
Examples of the heat treatment include quenching, nitriding, carburizing, annealing, tempering, and normalizing.

In the laser heat treatment system according to the present invention, it is preferable that the correction unit includes a first correction unit that decreases the scanning speed of the laser light as the radius of curvature of the heat treatment region decreases.
In addition, the standard heat treatment condition includes a standard scanning speed of the laser light, and when the radius of curvature is smaller than a predetermined threshold, it is preferable that the scanning speed is slower than the standard scanning speed.
Further, it is particularly preferable that the first correction unit lowers the output of the laser beam as the scanning speed is decreased.

In the laser heat treatment system according to the present invention, the standard heat treatment condition includes a standard focus position of the laser light, and the correction unit determines the focus position of the laser light as the surface unevenness of the heat treatment region increases. It is preferable to include a second correction unit that shifts greatly from the standard focus position. The standard focus position means a position that provides an appropriate working distance, and is not limited to a position that provides a just focus. The focal position is a position corrected by the correction means so that the proper working distance can be maintained even when the surface irregularities are present, and is not limited to the position where the just focus is achieved.
Further, it is preferable that the focal position is shifted from the standard focal position when the size of the surface irregularities is larger than a predetermined threshold.

  The laser heat treatment system according to the present invention enables selection of a preset control mode based on processing accuracy and processing speed, and the control device calculates the standard heat treatment condition according to the selected control mode. Is preferred.

The laser heat treatment system according to the present invention includes a temperature sensor that measures the temperature of the heat treatment region, and the control device performs a trial by changing the output of the laser light to a level at which no oxide film is formed in the heat treatment region. And a means for measuring the temperature of the heat treatment region in the trial, wherein the correction means changes the standard heat treatment condition or the corrected standard heat treatment condition according to the temperature measured in the trial. Correction means may be included.
Alternatively, a radiation thermometer for measuring the temperature of the heat treatment region is provided, and the control device performs a trial while forming an oxide film in the heat treatment region by lowering the output of the laser light, and the laser light in the oxide film Means for acquiring the absorption rate, and the correction means includes third correction means for changing the standard heat treatment condition or the corrected standard heat treatment condition according to the absorption rate obtained in the trial. Can do.

  The laser heat treatment system according to the present invention includes an operation unit for changing the setting of the heat treatment temperature that can be operated during heat treatment, and the correction unit is configured to perform the standard heat treatment condition or the operation based on the operation of the operation unit. It is preferable that online correction means for changing the corrected standard heat treatment condition is included.

  According to the laser heat treatment system of the present invention, even if the shape of the heat treatment region of the workpiece is complicated, the heat treatment corresponding to the shape can be performed accurately. For this reason, while being able to improve the quality of a processed product, it can suppress that a difference arises in quality by an operator's skill level.

It is a figure which shows schematic structure of the laser heat processing system which is embodiment of this invention. In the laser heat processing system which is embodiment of this invention, it is a figure which shows the relationship between processing precision, processing time, and control mode. In the laser heat processing system which is embodiment of this invention, it is a figure which shows the relationship between the shape of the heat processing area | region of a workpiece | work, and heat processing conditions. It is a flowchart which shows the control procedure by the laser heat processing system which is embodiment of this invention. It is a flowchart which shows the control procedure by the laser heat processing system which is embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiment described below is an example of the application of the present invention, and the application of the present invention is not limited to this.

  In the embodiment, quenching is exemplified as the heat treatment, and the laser quenching system 10 will be described in detail. However, the present invention is not limited to quenching as described above. Examples of the heat treatment to which the present invention can be applied include nitriding, carburizing, annealing, tempering, and normalizing in addition to quenching.

  In addition, the workpiece 100 that is quenched by the laser quenching system 10 (hereinafter sometimes simply referred to as “quenching or processing”) is not particularly limited, and according to the application classification, tool steel, bearing steel, knife steel, mechanical structure According to the component classification, such as steel for steel and spring steel, various steel materials such as carbon steel (ordinary steel), alloy steel (special steel), chrome steel, nickel chrome steel, nickel chrome molybdenum steel and manganese steel can be exemplified. Further, the shape of the quenching region 101 is not particularly limited.

FIG. 1 shows a schematic configuration of a laser hardening system 10.
The laser hardening system 10 includes a laser device 20, a processing head 30, a robot device 40, and a main controller 50. The robot apparatus 40 is a laser beam scanning apparatus that relatively changes the positional relationship between the workpiece 100 and the machining head 30. The main controller 50 is a control device that controls the operation of each component of the laser hardening system 10 and also functions as an input device and a display device.

  The laser hardening system 10 further includes a processing table 11 on which the workpiece 100 is placed, a temperature sensor 12 that measures the temperature of the workpiece 100, and the like. The processing table 11 can be appropriately changed according to the shape of the workpiece 100 and is not particularly limited. In the present embodiment, it is described that the machining head 30 is moved by the robot apparatus 40, but the workpiece 100 may be scanned with the laser beam by moving the machining table 11.

  The temperature sensor 12 is not particularly limited as long as the temperature of the quenching region 101 of the workpiece 100 can be measured in real time during the quenching process, but a radiation thermometer is preferably used from the viewpoint of measurement accuracy and the like. When a radiation thermometer is used as the temperature sensor 12, the temperature sensor 12 preferably includes the sensor fiber 13 and the sensor amplifier 14 and is mounted on the processing head 30.

  As a radiation thermometer suitable for the temperature sensor 12, the thing whose measurable temperature is about 100 degreeC-2500 degreeC can be illustrated. A plurality of radiation thermometers may be provided, such as a first thermometer corresponding to a low temperature region and a second thermometer corresponding to a high temperature region. The optical axis of the radiation thermometer is preferably set coaxially with the laser light irradiated on the workpiece 100.

The laser device 20 is not particularly limited as long as it is a device capable of outputting laser light capable of quenching the workpiece 100, and a known laser device can be applied. Examples of the suitable laser device 20 include a high-power semiconductor laser device (HDDL), a YAG laser device, a CO ₂ laser device, and the like. A laser fiber 21 is connected to the laser device 20, and laser light output from the laser device 20 is transmitted to the processing head 30 through the laser fiber 21.

  The processing head 30 is a component for irradiating the quenching region 101 of the workpiece 100 with laser light, and is disposed at a position where the workpiece 100 can be irradiated with laser light. For example, it is arranged immediately above the processing table 11. For example, a laser fiber 21 is connected to the upper portion of the processing head 30, and laser light introduced from the upper portion of the processing head 30 passes through an optical system to be described later and irradiates the workpiece 100 from the lower portion. Is done. The processing head 30 is attached to an arm portion 42 described later of the robot apparatus 40.

  The processing head 30 is equipped with an optical system (not shown) such as an XY scanner and an F-θ lens. A known form can be applied to these optical systems.

  The robot apparatus 40 moves the machining head 30 on the workpiece 100 and scans the laser beam output from the laser apparatus 20 along the quenching region 101 of the workpiece 100. The robot apparatus 40 includes a main body 41 that functions as a base and an arm 42 that extends from the main body 41. For example, the main body 41 includes a controller that operates the arm 42 in response to a control command from the main controller 50. The arm portion 42 is preferably provided with a plurality of joint portions. The arm part 42 has a wrist part, a lower arm part, and an upper arm part, for example, and can move each independently. Moreover, it is preferable that the connection part of the main-body part 41 and the arm part 42 can turn. Thereby, the process head 30 can be moved to a horizontal direction (XY direction) and an up-down direction (Z direction).

  As described above, the main controller 50 functions as an input device, a display device, and a control device. In order to realize this function, the main controller 50 includes an operation unit 51, a display unit 52, and a control unit 53. The operation unit 51 is not particularly limited as long as processing parameters can be input by an operator, and examples thereof include a keyboard, a numeric keypad, a switch, a knob, and a touch panel. The display unit 52 is not particularly limited, and a general display can be used.

  Examples of the machining parameters input by the operation unit 51 include the material of the workpiece 100. The main controller 50 stores, for example, the absorption rate of laser light corresponding to the material of the workpiece 100, and automatically derives the absorption rate from the input material information. As other processing parameters, information on the shape of the workpiece 100 including the quenching region 101 is necessary. As such information, it is preferable to use CAD data indicating the shape of the workpiece 100 including the quenching region 101. In the present system, the control mode is selected by the operator. Furthermore, the operator changes the setting of the quenching temperature during the quenching process, if necessary. These operations can be performed by operating the operation unit 51.

FIG. 2 shows the relationship between the processing accuracy and processing time and the control mode.
The control mode is set in advance based on the machining accuracy and the machining speed. The control mode M1 is suitable when high machining accuracy is required. However, in the control mode M1, the machining speed is slowed down in order to pursue high machining accuracy. On the other hand, when the shape of the quenching region 101 is simple, the control mode M3 is suitable, which enables high-speed machining. The control mode M2 is an intermediate mode between M1 and M3. The quenching condition calculation means 60 described later calculates appropriate quenching conditions based on the selected control mode.

  The control mode is not limited to M1 to M3, and more control modes can be set. The control mode 53 is automatically selected by the control unit 53 based on, for example, the degree of curvature or surface irregularity (curvature radius, size of surface irregularity) of the quenching region 101, the presence frequency of the curvature or surface irregularity, and the like. It is good also as what selects it.

  The control unit 53 includes a quenching condition calculation unit 60 and a quenching control unit 61. Thereby, quenching conditions can be set based on the processing parameters input by the operator, and the target quenching region 101 can be quenched according to the quenching conditions. The control unit 53 is an apparatus that includes, for example, a CPU, a recording unit that stores the function of each unit such as the input machining parameters and the quenching calculation unit 60, and an input / output port. It can be configured by a computer.

  The quenching calculation means 60 sets a quenching temperature T according to the material of the workpiece 100 (hereinafter, a set value of the quenching temperature T is referred to as a set temperature Ts), and the shape of the workpiece 100 including the set temperature Ts and the quenching region 101 is set. Based on the CAD data shown and the selected control mode, the standard quenching condition is calculated. The standard quenching conditions include, for example, a standard output of laser light, a standard focal position of laser light, and a standard scanning speed of laser light. The quenching calculation means 60 calculates the standard output, the standard focus position, and the standard scanning speed so that, for example, the temperature at each irradiation spot of the laser beam is constant throughout the quenching region 101. Further, not only the robot apparatus 40 but also operations of an XY scanner, a focus lens, and the like are calculated.

  The standard quenching condition calculated by the quenching calculation means 60 is, for example, constant from the quenching start point to the end point. The standard focal position is calculated with reference to any position (for example, the quenching start point) of the quenching region 101 so that the distance between the position and the processing head 30 becomes an appropriate working distance. The standard output and the standard scanning speed are calculated by, for example, the set temperature Ts and the selected control mode. That is, the quenching calculation means 60 does not consider the curvature radius or surface unevenness of the quenching region 101.

  In addition to the standard output, the standard focus position, and the standard scanning speed, the standard quenching condition includes, for example, the irradiation angle of the laser beam with respect to the quenching region 101. In the case of quenching a flat surface, the irradiation angle is generally perpendicular to the surface of the workpiece 100 or within an angle range that can be changed by an XY scanner, but a surface that intersects the thickness direction of the workpiece 100 is quenched. For example, it is preferable to move the wrist part of the arm part 42 to change the irradiation angle.

  The quenching control means 61 performs quenching by controlling the operation of each component such as the laser device 20, the processing head 30, and the robot device 40 in accordance with the standard quenching condition calculated by the quenching calculation means 60 or the corrected quenching condition described later. Run. The quenching control means 61 acquires the temperature of the quenching area 101 from the temperature sensor 12 and executes temperature feedback control for adjusting the output of the laser beam when the temperature deviates from the set temperature Ts by a predetermined temperature or more. preferable.

  The control unit 53 further includes a plurality of correction means for more accurately setting the quenching conditions according to the shape of the quenching region 101 and the like. That is, the control unit 53 corrects the standard quenching condition as necessary. Furthermore, if necessary, the corrected quenching conditions (hereinafter referred to as corrected quenching conditions) are additionally corrected.

  Examples of the correcting unit include a first correcting unit 62, a second correcting unit 63, a third correcting unit 65, and an online correcting unit 66. The first correction unit 62, the second correction unit 63, and the third correction unit 65 correct the quenching conditions before the quenching process is started, and the online correction unit 66 corrects the quenching conditions during the processing. The third correction unit 65 executes correction when a trial described later is executed by the trial execution unit 64.

  The first correction unit 62 decreases the scanning speed of the laser light as the radius of curvature R of the quenching region 101 decreases. That is, the constant standard scanning speed is corrected according to the radius of curvature R of the quenching region 101. Moreover, it is preferable that the 1st correction | amendment means 62 reduces the output of a laser beam, so that scanning speed is made slow. If there is a curved portion in the quenching area 101 and the radius of curvature is small, it is assumed that the laser beam passes or overruns the inside of the quenching area 101. The occurrence of other problems. In addition, by changing the output in accordance with the scanning speed, it is possible to prevent an overheated state from occurring at a curved portion where the scanning speed is slowed down.

  The first correction means 62 preferably slows the scanning speed according to the curvature radius R when the curvature radius R of the quenching region 101 is equal to or less than a predetermined threshold value Rz. The threshold value Rz can be determined by, for example, experiments or simulations, and can be changed according to the control modes M1 to M3. For example, Rz = 0.5 mm, 0.4 mm, and 0.3 mm can be set in the order of the control modes M1, M2, and M3. Even if the radius of curvature R is equal to or less than the threshold value Rz, the scanning speed may be changed stepwise by defining a range in which the scanning speed is constant. For example, when 0.3 mm <R ≦ 0.5 mm, it can be corrected to 75% of the standard scanning speed, and when 0.1 mm <R ≦ 0.3 mm, it can be corrected to 50% of the standard scanning speed.

  The second correction unit 63 shifts the focal position of the laser beam greatly from the standard focal position as the surface unevenness of the quenching region 101 increases. In other words, the second correction unit 63 corrects the constant standard focus position according to the surface unevenness of the quenching region 101. Thereby, even if it is a part with a large surface unevenness | corrugation, it can process by an appropriate working distance.

  The second correction unit 63 preferably shifts the focal position according to the size H of the surface irregularities when the size H of the surface irregularities of the quenching region 101 is equal to or greater than a predetermined threshold Hz. Similarly to the threshold value Rz, the threshold value Hz can be determined by experiment or simulation, and can be changed according to the control modes M1 to M3.

FIG. 3 shows the relationship between the shape of the quenching region 101 and the quenching conditions.
In the drawing, a plan view (left side of the drawing) of the quenching area 101 and a cross-sectional view (right side of the drawing) of the workpiece 100 taken along line A of the quenching area 101 are shown. In the cross-sectional view, the left-right direction of the paper surface is the thickness direction of the workpiece 100. In addition, on the right side of the cross-sectional view, a range in which the focal position is set to P0, P1, and P2 is shown.

  In the quenching region 101 illustrated in FIG. 3, there are a concave portion 102, a convex portion 103, and two curved portions 104a and 104b. There is no surface irregularity in the straight line portion 105 sandwiched between the curved portions 104a and 104b, and the quenching conditions here are the standard quenching conditions, that is, the standard focus position P0, the standard scanning speed V0, and the standard output K0.

  On the other hand, in the recess 102, only the focal position is changed to the focal position P1 shifted downward from the standard focal position P0 by the function of the second correction means 63. Further, the convex portion 103 is changed to a focal position P2 shifted upward from the standard focal position P0. Since the convex portion 103 is larger than the concave portion 102 in the size of the surface irregularities (difference from the linear portion 105) with respect to the standard focal position P0 (the linear portion 105), the amount of change in the focal position is more convex than the concave portion 102. It becomes large in the part 103. That is, | P2-P0 |> | P1-P0 |.

  Further, in the curved portions 104a and 104b, the scanning speed is made slower than the standard scanning speed V0 by the function of the first correction means 62. Since the curvature radius Rb of the curved portion 104b is smaller than the curvature radius Ra of the curved portion 104a, the scanning speed Vb at the curved portion 104b is made slower than the scanning speed Va at the curved portion 104a (Vb <Va ). Further, the output is made smaller than the standard output K0 in accordance with the decrease in the scanning speed. The output Kb in the music part 104b is made smaller than the output Ka in the music part 104a.

  The trial execution means 64 performs the trial by changing the standard output or the corrected output to a level at which no oxide film is formed in the quenching region 101, and measures the temperature of the quenching region 101 in the trial. The trial is a process for confirming that the standard quenching condition or the corrected quenching condition is appropriate, and the conditions other than the output of the laser beam are set to the same as when actually performing the quenching process.

  The trial execution means 64 preferably reduces the laser light output (for example, 1/10 of the standard output) so that the temperature of the quenching region 101 in the trial is 200 ° C. or lower, preferably 100 ° C. to 150 ° C. It is. For this reason, an oxide film is not formed in the quenching region 101, and it is possible to prevent the surface state of the quenching region 101 from being changed by the trial.

  For example, the trial can be set so that the operator can select whether or not to perform the trial. For example, when the shape of the quenching region 101 is simple, the operator can omit the trial because the standard quenching condition can be sufficiently handled. Alternatively, it may be set to automatically determine the presence or absence of a trial based on the correction amount by the correction means. For example, the trial may be performed only when the correction amount is large.

  The third correction means 65 changes the standard quenching condition or the corrected quenching condition according to the temperature of the quenching area 101 measured in the trial. For example, when the temperature of the quenching region 101 measured by the trial (hereinafter referred to as a measured temperature) deviates from a predicted temperature by a predetermined temperature or more, the third correction unit 65 determines that the measured temperature fluctuation range ΔT is within a predetermined range ( For example, the quenching condition is changed when the measured temperature exceeds ± 30 ° C. In the latter case, in the quenching region 101, it is preferable to change the quenching condition of the portion exceeding the measured temperature ± 30 ° C so as to satisfy the measured temperature ± 30 ° C.

  The correction by the third correction unit 65 may be performed by changing any of the laser beam output, the focal position, and the scanning speed. However, if the correction is slight, it is preferable to change only the output. It is. Whether or not the correction is slight can be determined by comparing the correction amount with a preset threshold value. If the correction amount exceeds the threshold value, the focus is determined according to the shape of the quenching region 101. The position and scanning speed may be changed.

  The online correction means 66 changes the standard quenching condition or the corrected quenching condition when the operator changes the set temperature Ts during the quenching process. In the present embodiment, the operation unit 51 includes a function capable of changing the set temperature Ts during the quenching process. The online correction unit 66 changes the quenching condition based on the operation of the operation unit 51. For example, when the set temperature Ts is largely changed, the quenching condition is greatly changed. This correction function is used, for example, when the operator determines that the temperature acquired by the temperature sensor 12 is lower than the actual temperature because smoke is generated from the quenching area 101 or the like. For example, the operator can change the set temperature Ts as necessary based on the color of the quenching region 101 irradiated with the laser beam.

  As with the third correction unit 65, the correction by the online correction unit 66 may be performed by changing any of the laser beam output, the focal position, and the scanning speed, but is a correction based on the operation of the operation unit 51. It is preferable to change only the output.

  It is also preferable that the trial execution means 64 is configured to perform a trial while lowering the output of the laser light and forming an oxide film in the quenching region 101 to acquire the absorption rate of the laser light in the oxide film. In the actual quenching process, the workpiece 100 becomes very high temperature, so that the temperature around the processing point (laser beam irradiation spot) also becomes high to some extent, and an oxide film may be formed on the surface of the workpiece 100. In other words, when the laser beam is scanned and quenched, an oxide film may already be formed at the next processing point. A trial for forming an oxide film is suitable for such a case.

  In this case, it is preferable to reduce the output of the laser beam so that the temperature of the quenching region 101 in the trial is preferably 200 ° C. to 300 ° C. Since the absorption rate and the emissivity are equal, the absorption rate of the oxide film in the trial can be obtained using a radiation thermometer. At this time, the optical axis of the radiation thermometer is preferably set, for example, behind the laser beam irradiation spot in the scanning direction. Alternatively, a radiation thermometer for measuring the absorption rate may be provided separately.

  In this case, the third correction unit 65 changes the standard quenching condition or the corrected quenching condition according to the absorption rate of the oxide film acquired in the trial. For example, the third correction unit 65 can change the output of the laser beam based on the absorption rate of the oxide film.

Here, an example of a control procedure when the workpiece 100 is quenched by the laser quenching system 10 having the above configuration will be described in detail with reference to FIGS. 4 and 5.
4 and 5 are flowcharts showing the control procedure. In the figure, the procedure by the operator is surrounded by a chain line, and the procedure by the control unit 53 is surrounded by a solid line.

  First, parameters required for machining are input by the operator (S10). The input parameters include the material of the workpiece 100, CAD data indicating the shape of the workpiece 100 including the quenching region 101, and a control mode (any one of M1 to M3). The operator can input these parameters by operating the operation unit 51.

  Subsequently, the absorption rate of the laser beam used for quenching is derived from the material of the input workpiece 100, and the quenching temperature is set (S11). In addition, the procedure of S11-S13 is performed by the function of the quenching condition calculating means 60. The quenching temperature corresponding to the absorption rate of the workpiece 100 is stored in advance in the storage unit of the control unit 53, for example. Then, the quenching condition calculation means 60 sets a quenching temperature corresponding to the absorption rate (determination of the set temperature Ts). Here, the absorptance may be derived in consideration of not only the material of the workpiece 100 but also the surface roughness. In addition, the control mode selected from among the plurality of control modes is set as a precondition for quenching condition calculation (S12).

  Based on the set temperature Ts, CAD data indicating the shape of the workpiece 100, and the selected control mode, the standard quenching condition is calculated (S13). The quenching calculation means 60 calculates the standard output, the standard focus position, and the standard scanning speed so that, for example, the temperature at each irradiation spot of the laser beam is constant throughout the quenching region 101.

  Next, quenching conditions are corrected in S14 to S22. S24 and S25 are steps for correcting the quenching conditions during the quenching process.

  First, in S14, based on the CAD data of the workpiece 100, it is determined whether or not the curvature radius R of the curved portion of the quenching region 101 is equal to or less than the threshold value Rz. When it is determined in S14 that the radius of curvature R is equal to or less than the threshold value Rz, the scanning speed of the laser beam is decreased as the radius of curvature R decreases (S15). That is, the movement of the arm part 42 is slowed down. On the other hand, when there is no curved portion in the quenching region 101 or when the curvature radius R of the curved portion is larger than the threshold value Rz and the curvature is gentle, the standard scanning speed is maintained and the process proceeds to the next correction step.

  In S16, as in S14, based on the CAD data, it is determined whether or not the size H of the surface unevenness of the quenched region 101 is equal to or greater than the threshold Hz. If it is determined in S16 that there are surface irregularities of the threshold Hz or higher, the focal position of the laser beam is greatly shifted from the standard focal position as the size H of the surface irregularities increases (S17). That is, the focus lens and the arm part 42 are controlled to shift the focal position downward in accordance with the depth of the concave portion and shift the focal position upward in accordance with the height of the convex portion. On the other hand, when the surface unevenness does not exist in the quenching region 101 or when the size H of the surface unevenness is smaller than the threshold Hz, the standard focus position is maintained and the process proceeds to the next correction step.

  In S18, it is determined whether or not the trial is performed. Whether or not the trial is performed is preferably selectable by an operator. When the execution is selected, the laser light output is lowered and the trial is performed (S19, S20). In the trial, the output is lowered to the extent that no oxide film is formed on the workpiece 100, and other parameters are set to be the same as those during actual quenching. Then, the temperature of the quenching region 101 is measured by the temperature sensor 12.

  Subsequently, it is determined whether or not the fluctuation width ΔT of the measured temperature in the trial is larger than a predetermined range ΔTz (S21). When it is determined in S21 that the deflection width ΔT is larger than the predetermined range ΔTz, the quenching condition is corrected (S22). For example, the quenching condition is corrected by changing the output of the laser beam. On the other hand, when the deflection width ΔT is smaller than the predetermined range ΔTz, it means that the standard quenching condition or the corrected quenching condition is appropriate, and the process proceeds to the next step without performing the correction.

  Then, the quenching process is started according to the standard quenching condition or the corrected quenching condition (S23). This procedure is executed by the function of the quenching control means 61. The robot apparatus 40 moves the machining head 30 along the quenching region 101 and the machining is automatically performed. Usually, the operator observes the machining state. When it is determined from the color of the quenching region 101 that the quenching temperature is not appropriate, the set temperature Ts can be changed by operating the operation unit 51 (S24), and the quenching condition can be changed during processing based on this operation. Correction is performed (S25). At this time, it is preferable to correct the quenching condition by changing the output of the laser beam.

  When quenching is completed in the entire quenching region 101 (S26), the entire quenching process is terminated.

  DESCRIPTION OF SYMBOLS 10 Laser hardening system, 11 Processing table, 12 Temperature sensor, 13 Sensor fiber, 14 Sensor amplifier, 20 Laser apparatus, 21 Laser fiber, 30 Processing head, 40 Robot apparatus, 41 Main body part, 42 Arm part, 50 main Controller, 51 operation unit, 52 display unit, 53 control unit, 60 quenching condition calculation unit, 61 quenching control unit, 62 first correction unit, 63 second correction unit, 64 trial execution unit, 65 third correction unit, 66 online Correction means, 100 workpiece, 101 quenching region, 102 concave portion, 103 convex portion, 104a, 104b curved portion, 105 linear portion.

Claims (5)

A laser device for outputting laser light;
A processing head for irradiating the heat treatment region of the workpiece with the laser beam;
A laser beam scanning device that relatively changes the positional relationship between the workpiece and the processing head;
A radiation thermometer for measuring the temperature of the heat treatment region;
A control device having means for calculating a standard heat treatment condition based on the heat treatment temperature and the CAD data of the work, setting a heat treatment temperature according to the material of the work;
With
The control device includes: a correction unit that changes the standard heat treatment condition based on a radius of curvature of the heat treatment region and a surface unevenness of the heat treatment region; and an oxide film is formed in the heat treatment region by reducing the output of the laser beam. Means for performing a trial while obtaining the absorption rate of the laser light in the oxide film ,
The correction means includes
Based on the CAD data, it is determined whether or not the radius of curvature of the heat treatment region is equal to or less than a predetermined threshold value Rz, and when it is determined that the radius of curvature is equal to or less than the threshold value Rz, the laser beam according to the radius of curvature. And a first correction means for reducing the output of the laser beam as the scanning speed is reduced,
Based on the CAD data, it is determined whether or not the size of the surface unevenness of the heat treatment region is greater than or equal to a predetermined threshold Hz, and when it is determined that the size of the surface unevenness is greater than or equal to the threshold Hz, the surface unevenness A second correction means for largely shifting the focal position of the laser beam from the standard focal position of the standard heat treatment condition according to the size of
Third correction means for changing the standard heat treatment condition or the corrected standard heat treatment condition in accordance with the absorption rate acquired in the trial;
A laser heat treatment system comprising: The laser heat treatment system according to claim 1,
Enables selection of preset control mode based on machining accuracy and machining speed,
The said control apparatus calculates the said standard heat processing conditions according to the said selected control mode, The laser heat processing system characterized by the above-mentioned. In the laser heat treatment system according to claim 1 or 2 ,
An operation unit for changing the setting of the heat treatment temperature that can be operated during the heat treatment,
The laser heat treatment system, wherein the correction means includes an online correction means for changing the standard heat treatment condition or the corrected standard heat treatment condition based on an operation of the operation unit by an operator. In the laser heat treatment system according to claim 3 ,
3. The laser heat treatment system according to claim 1, wherein the third correction means and the online correction means change only the output of the laser beam to change the standard heat treatment condition or the corrected standard heat treatment condition. In the laser heat treatment system according to any one of claims 1 to 4 ,
The laser heat treatment system, wherein the heat treatment is quenching, nitriding, carburizing, annealing, tempering, or normalizing.

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