JP5166005B2 - Power probe - Google Patents

Description

  The present invention relates to a power probe that detects the output of a laser beam, and in particular, has a high laser resistance.

  It is the most important task to detect the output power in the control of the laser oscillator. As a method for detecting the output power, there are a method using photoelectric conversion, a method using optical-thermal conversion, a method of detecting thermal energy, and the like. In the method of detecting from one light, photons are captured and converted into electricity or heat, so that amplification is relatively easy and sensitivity is high. On the other hand, it is not suitable for measuring too much energy. The other method of detecting the thermal energy detects the laser beam as heat, so that the sensitivity is low and the measured value changes depending on the balance between heat dissipation and heat absorption, and high-precision measurement is difficult. On the other hand, it is simple and suitable for measuring laser light having relatively large energy. Conventionally, as an output measuring device for a carbon dioxide laser that outputs a relatively large energy, for example, the surface of the light receiving unit is subjected to high-absorbance coding for the wavelength light of the laser beam to be measured, and the light receiving unit The temperature rise is measured with a bimetal thermometer (see, for example, Non-Patent Document 1).

Laser beam measurement and optical component evaluation technology-Towards standardization of laser processing-March 1991 Laser Thermal Processing Study Group Working Group

  Conventionally, the detailed configuration of the laser light absorbing portion has not been described, but according to the analysis and investigation by the present inventors, the surface of the base material portion made of Al is coated with an alumite portion as a laser light absorbing portion. It has been found that This power probe is a type of calorimeter that absorbs laser light at the anodized part, disperses the absorbed heat throughout the base part, measures the temperature rise value with a bimetal thermometer, and displays it as power. ing. However, when a strong laser beam is irradiated to the anodized part and the anodized part is heated to 600 to 700 ° C., the surface of the base material part immediately below the anodized part of the irradiated part is melted, resulting in laser damage. Thus, since the melting temperature of the base material portion is low, the conventional power probe has a problem that the laser resistance is low.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a power probe having high laser resistance.

Further, the present invention provides a base material made of Al which is one of pure aluminum (JIS1000 series), Al—Mg alloy (JIS5052), JIS2000 series, JIS3000 series, JIS4000 series, JIS5000 series, JIS6000 series, and JIS7000 series. And pure aluminum (JIS 1000 series), Al-Mg alloy (JIS 5052), JIS 2000 series, JIS 3000 series, JIS 4000 series, JIS 5000 series, JIS 6000 series, JIS 7000 series disposed on the base part. a high melting point than the melting point of some Al, and pure aluminum (JIS1000 series), Al-Mg alloy (JIS5052), JIS2000 series, JIS3000 series, JIS4000 series, JIS5000 series, JIS6000 series, any of JIS7000 series Big That has a higher melting point than the melting point of Al, and a heat conducting portion made by a material having less than three times the thermal conductivity of 0.5 times or more the thermal conductivity of Al, the substrate of the heat conducting portion The laser light absorber portion formed on a different surface from the surface where the portion is disposed, and the thermal energy absorbed by the laser light absorber portion and conducted to the base material portion through the heat conducting portion are measured. A temperature sensing element and a display unit for displaying the magnitude of thermal energy measured by the temperature sensing element are provided.

Moreover, the power probe of the present invention is made of Al which is one of pure aluminum (JIS1000 series), Al—Mg alloy (JIS5052), JIS2000 series, JIS3000 series, JIS4000 series, JIS5000 series, JIS6000 series, JIS7000 series . And a pure aluminum (JIS 1000 series), Al-Mg alloy (JIS 5052), JIS 2000 series, JIS 3000 series, JIS 4000 series, JIS 5000 series, JIS 6000 series, JIS 7000 series disposed on the base section. a high melting point than the melting point of Al is either, and pure aluminum (JIS1000 series), Al-Mg alloy (JIS5052), JIS2000 series, JIS3000 series, JIS4000 series, JIS5000 series, JIS6000 series, JIS700 Has a higher melting point than the melting point of Al is either system, and a heat conducting portion made by a material having less than three times the thermal conductivity of 0.5 times or more the thermal conductivity of Al, heat The laser light absorber formed on a surface different from the surface on which the base material portion of the conductive portion is disposed, and the heat absorbed by the laser light absorber portion and conducted to the base material portion through the heat conducting portion Since the temperature measuring body for measuring the temperature of the energy and the display unit for displaying the magnitude of the heat energy measured by the temperature measuring body are provided, it is possible to achieve high laser resistance and to reduce the weight.

Embodiment 1 FIG.
Embodiments of the present invention will be described below. FIG. 1 is a cross-sectional view showing a configuration of a laser power probe according to Embodiment 1 of the present invention, and FIG. 2 is a diagram for explaining problems of a conventional power probe. In the figure, a base material portion 2 made of Cu, for example, of a material having a melting point higher than the melting point of Al and having a thermal conductivity of 0.5 to 3 times the thermal conductivity of Al. A laser light absorber portion 1 formed on the base material portion 2, a display portion 4 for displaying the magnitude of thermal energy measured by a temperature measuring body, which will be described later, and a base material portion 2 and a display portion 4. And a temperature measuring body 5 which is disposed at a substantially central portion of the base material portion 2 from the display portion 4 and is disposed through the rod portion 3. ing.

  Next, the detailed configuration of each part will be described. First, although the base material part 2 has shown the example which consists of Cu, it has a melting point higher than the melting point of Al, and it is 0.5 to 3 times the thermal conductivity of Al. Any material may be used as long as it has a material. This is because the temperature that can withstand laser light irradiation cannot be sufficiently obtained with Al, and therefore it is necessary to have a melting point higher than the melting point of Al. Further, if the thermal conductivity is too low no matter how high the melting point, it is difficult to accurately measure the temperature with the side temperature body 5 because the heat from the laser light absorber 1 is not conducted. For this reason, it is necessary to have a thermal conductivity of about 0.5 times or more of the thermal conductivity of Al. Further, if the thermal conductivity is too high no matter how high the melting point, heat is further conducted from the base material portion 2 to the outside, and it becomes difficult to accurately measure the temperature with the side temperature body 5. For this reason, it is necessary to have a thermal conductivity of about 3 times or less of the thermal conductivity of Al. Specifically, when pure aluminum (JIS1000 series: melting temperature 646 to 657 ° C., thermal conductivity 0.56 cal / ° C. · cm · sec) is used, 0.28 to 1.68 cal / ° C. · cm · sec. In the case of an Al—Mg-based alloy (JIS 5052: melting temperature 607 to 649 ° C., thermal conductivity 0.33 cal / ° C. · cm · sec) generally used most frequently, It is necessary to have a thermal conductivity of 17 to 0.99 cal / ° C. · cm · sec. In addition, when using JIS 2000, 3000, 4000, 5000, 6000, and 7000 series aluminum, it is necessary to have a thermal conductivity of 0.5 to 3 times the thermal conductivity of each aluminum. Needless to say.

Further, it is conceivable that the temperature measuring element 5 uses, for example, a bimetal, a thermocouple, a resistance temperature detector, a thermistor, or the like. Needless to say, the laser light absorber 1 may be made of a material capable of absorbing the irradiated laser light, and various materials are used in accordance with the irradiated laser light. Here, the case where a carbon dioxide laser having a wavelength of 10.6 μm is used as the irradiated laser beam will be described. In the case of this carbon dioxide laser, it is considered that alumina (Al ₂ O ₃ ) is appropriate as the laser light absorber portion 1 because of its high absorption rate. This is because alumina is considered to have a high absorption rate of a carbon dioxide laser and can perform highly accurate measurement. Since the base material part 2 is made of Cu, alumina can be made by, for example, thermal spraying. Various thermal spraying methods can be used for the thermal spraying process.

  And it is difficult to form the film thickness of the alumina produced by the thermal spraying process with a uniform film thickness from the characteristics of the manufacturing method. And the film thickness formed by a thermal spraying process is formed with a film thickness of about 10 μm or more, and the film thickness distributed on the average is 100 μm or more. Further, the maximum film thickness formed by the thermal spraying method is about several hundred μm. In the first embodiment, if the thickness of the laser light absorber portion 1 is thick and the heat retention is too large, the heat conducted to the base material portion 2 is reduced, and the heat energy can be measured with high accuracy. Disappear. Therefore, it is considered that the thickness distribution of the laser light absorber 1 is appropriately 10 μm to 200 μm from the viewpoint of manufacturing and the viewpoint of heat retention. And the display part 4 is specifically comprised by the signal transmission part, the calculating part which performs conversion from temperature to power, a power value with a display means, etc., and the thermal energy measured by the temperature measuring body The size is displayed.

  Next, a method for measuring the power of the laser beam in the power probe of the first embodiment configured as described above will be described. First, when carbon dioxide laser light (not shown) is irradiated onto the laser light absorbing section 1, almost 100% of the carbon dioxide laser light is absorbed by the laser light absorbing section 1 as heat. Then, the carbon dioxide laser light absorbed by the laser beam absorber 1 is absorbed and dispersed as thermal energy in the underlying base material 2 to raise the temperature of the underlying substrate 2. The temperature change at this time is transmitted to the display unit 4 by the temperature measuring body 5 and displayed as a laser output (power). Thus, even if it measures a laser beam, since the base material part 2 is comprised with Cu, the base material part 2 does not produce a fusion | melting to about 1000-1100 degreeC. On the other hand, since the alumina constituting the laser light absorber 1 has a melting point of about 2000 ° C., laser damage does not occur until the irradiated portion reaches about 1000 ° C.

  Here, the point that a conventional laser power probe is damaged by laser light irradiation will be described with reference to FIG. First, when the laser beam 7 is irradiated to the laser beam absorber 12 (FIG. 2A), the laser beam absorber 12 made of alumite starts to rise in temperature (up to several hundred degrees C) ( FIG. 2 (b)). Further, when the laser beam 7 is continuously irradiated, the temperature raising unit 8 spreads from the laser beam absorber unit 12 to the base material unit 60 made of Al by the thermal diffusion 10, and the laser beam absorber unit 12 is covered. The irradiation part is heated to 600 ° C. or more, and a high temperature part 9 is generated (FIG. 2C). When the laser beam 7 is further continuously irradiated, the high temperature portion 9 of 600 ° C. or more spreads toward the base material portion 60 (FIG. 2D). And since the melting point of the base material part 60 is about 600-660 degreeC, the base material part 60 produces melting. On the other hand, since the melting point of alumina constituting the laser light absorber 12 is about 2000 ° C., laser damage does not occur if the irradiated portion is about 600 ° C. However, the laser light absorber portion 12 immediately above the base material portion 60 that has melted is cracked due to thermal stress and the like with the base material portion 60, and the peeling portion 11 is generated in the laser light absorber portion 12. A possibility arises (FIG. 2 (e)).

  In the laser power probe of the first embodiment configured as described above, since the base material portion is changed from Al to Cu, the base material portion does not melt up to about 1000 to 1100 ° C. On the other hand, since alumina constituting the laser light absorber has a melting point of about 2000 ° C., laser damage does not occur until the irradiated portion is about 1000 ° C. Moreover, since the thermal conductivity of Cu is almost twice that of Al, the base material portion made of Cu is basically less likely to raise the temperature than the base material portion made of Al. It also has the advantage of. According to the research by the inventors, the laser damage threshold of the power probe for laser is about 2.5 KW to 5.5 by changing the base part made of Al to the base part made of Cu. It was confirmed that it improved to 0 KW. The size of the base part of the power probe used at this time was a cylinder formed with a diameter of 90 mm and a height of 50 mm. The laser beam was irradiated for 20 seconds with a beam diameter of about 10 mm. As a result, it is possible to easily obtain a laser power probe excellent in laser resistance.

Embodiment 2. FIG.
FIG. 3 is a cross-sectional view showing a configuration of a laser power probe according to Embodiment 2 of the present invention. In the figure, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. A base material portion 6 made of Al, a melting point higher than the melting point of Al disposed on the base material portion 6 and 0.5 to 3 times the thermal conductivity of Al A thin heat conducting portion 20 made of, for example, Cu of a material having a thermal conductivity of 2 and a laser light absorber 1 is provided thereon. Next, unlike Embodiment 1, in this Embodiment 2, the base material part 6 was comprised with Al, and the heat conductive part 20 comprised with Cu was formed. This will be described below based on the specific heat and specific gravity of Cu and Al shown in Table 1.

  As is apparent from Table 1 above, Cu having a heat capacity equivalent to that of Al is about 2.36 times that of Al by weight and about 0.72 times that of Al by volume. For example, the weight of a power probe having a laser light power of 10 KW is about 1 kg when the base member 60 is formed of Al. On the other hand, when configured as in the first embodiment, the weight of the base material portion 2 is about 2.3 kg. This difference causes a great inconvenience in workability when an operator measures the laser beam with a power probe. Therefore, in this Embodiment 2, the increase in weight is suppressed and the weight of the power probe is reduced by forming the heat conduction part 20 made of Cu on the Al base part 6 having a small specific gravity. Can be achieved. In the second embodiment, for example, plate-like Cu having a thickness of 5 mm is used as the heat conducting portion 20, and about 100 μm of alumina is formed thereon by thermal spraying. However, the thickness of Cu is not particularly limited as long as it is approximately 1 mm or more, but if it is too thin, warpage occurs when the laser light absorber 1 (alumina) is formed by thermal spraying, which is not preferable. Therefore, it is considered that the thickness is preferably about 2 mm to 5 mm from the viewpoint of flatness and weight reduction of the substrate.

  The power probe for a laser according to the second embodiment configured as described above can reduce the weight because the base material portion is made of Al, and the upper portion thereof is higher than the melting point of Al. Since the heat conduction part made of a material having a melting point and having a heat conductivity of 0.5 to 3 times the heat conductivity of Al is disposed, the first embodiment described above is provided. Similarly to the above, it is possible to easily obtain a laser power probe having excellent laser resistance.

Embodiment 3 FIG.
FIG. 4 is a cross-sectional view showing a configuration of a laser power probe according to Embodiment 3 of the present invention. In the figure, the same parts as those in the above embodiments are denoted by the same reference numerals, and description thereof is omitted. In this Embodiment 3, the display part 4 is directly installed in the base material part 6 without passing through a rod part. When a bimetal thermometer is used for the temperature measuring body, a predetermined length is required. Therefore, as shown in the above embodiments, the temperature measuring body 5 is displayed through the hollow rod portion 3. It was necessary to connect to part 4. However, with such a configuration, there are cases in which the entire length of the power probe becomes long and inconvenience occurs. In the third embodiment, by configuring the temperature measuring element 13 with a thermocouple, the rod portion is not particularly required and can be included in the base material portion 6. For this reason, the display unit 4 can be directly connected to the base member 6, and a compact laser power probe can be obtained. In addition, since the temperature of the base material portion 6 is increased by laser irradiation, it is actually preferable to dispose a heat shield portion that is thermally shielded by ceramics or the like between the base material portion 6 and the display portion 4. . Needless to say, the temperature measuring element is not limited to the thermocouple, and the above-described temperature measuring resistor, thermistor, or the like can be used. Furthermore, although the third embodiment has been described based on the configuration of the second embodiment, it goes without saying that it may be used in an example in which the base material portion is configured with Cu as in the first embodiment.

In each of the above embodiments, the carbon dioxide laser beam is shown as an example of the laser beam. However, the present invention is not limited to this, and for example, a YAG laser beam and other laser beams can be used similarly. Needless to say, the same effect can be obtained.
Moreover, although the example which comprises a laser beam absorber part by a thermal spraying alumina was shown, it is not restricted to this, The laser beam absorber part should just select the member which can absorb the laser beam irradiated, if carbon dioxide laser light, in addition, for example, mullite _{(3Al 2 O 3 · 2SiO 2} ) and steatite (MgO · SiO ₂₎ it is possible to form such by thermal spraying, to the same effect Is possible.

Further, in each of the above embodiments, Cu is used as a material having a melting point higher than the melting point of Al and having a thermal conductivity of 0.5 to 3 times the thermal conductivity of Al. Although an example was shown, it is not restricted to this, For example, brass, gold | metal | money etc. can also be used and there can exist the same effect.
Moreover, although the example which provides a laser beam absorber part only in the single side | surface of a base material part was shown, it is not restricted to this, For example, you may form a laser beam absorber part in the both surfaces or the whole surface of a base material part. Needless to say, the same effect can be obtained. Further, by forming the laser light absorber portion on a plurality of surfaces, it becomes possible to measure laser light on a plurality of surfaces, and even if one surface of the laser light absorber portion deteriorates, the other surface It becomes possible to measure by irradiating the laser beam with the laser beam absorber.

It is sectional drawing which shows the structure of the power probe for lasers of Embodiment 1 of this invention. It is sectional drawing for demonstrating the laser damage of the conventional power probe for lasers. It is sectional drawing which shows the structure of the power probe for lasers of Embodiment 2 of this invention. It is sectional drawing which shows the structure of the power probe for lasers of Embodiment 3 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Laser light absorber part, 2,6 Base material part, 4 Display part, 5,13 Temperature measuring body.

Claims (3)

A base part made of Al which is pure aluminum (JIS1000 series), Al-Mg alloy (JIS5052), JIS2000 series, JIS3000 series, JIS4000 series, JIS5000 series, JIS6000 series, JIS7000 series, and the above base From the melting point of Al, which is one of pure aluminum (JIS1000 series), Al-Mg alloy (JIS5052), JIS2000 series, JIS3000 series, JIS4000 series, JIS5000 series, JIS6000 series, and JIS7000 series, which is disposed on the part The heat of Al which has a high melting point and is pure aluminum (JIS1000 series), Al-Mg alloy (JIS5052), JIS2000 series, JIS3000 series, JIS4000 series, JIS5000 series, JIS6000 series, JIS7000 series Conductivity Laser light absorption formed on a surface different from the surface on which the base material portion of the heat conducting portion is disposed, and a heat conducting portion made of a material having a thermal conductivity of 0.5 to 3 times A body part, a temperature measuring element that measures the thermal energy absorbed by the laser light absorber part and conducted to the base material part via the heat conducting part, and the thermal energy measured by the temperature measuring object. A power probe comprising a display unit for displaying the size of the power probe. The power probe according to claim 1, wherein the laser light absorber is composed of sprayed alumina as a main component. The power probe according to claim 2 , wherein the thickness of the laser light absorber is 10 μm to 200 μm.

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