JP2017110914A - Apparatus and method of measuring surface temperature distribution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously measure surface temperature distributions in an outer peripheral direction of a measurement target object with a simple device.SOLUTION: There is provided an apparatus that receives infrared radiation light from a measurement target object 2 to measure the surface temperature of the measurement target object 2, and comprises one infrared thermal image device 11 and at least two or more infrared mirrors 12. The infrared thermal image device 11 directly receives infrared radiation light from a predetermined direct measurement rage on the surface of the measurement target object 2; the infrared mirrors 12 receive infrared radiation light from a range other than the direct measurement range on the surface of the measurement target object 2 and reflect the light toward the infrared thermal image device 11; and the infrared thermal image device 11 further receives the reflected light from the infrared mirrors 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a surface temperature distribution measuring apparatus and a measuring method for measuring a surface temperature distribution on the outer periphery of a measurement object such as a tube or a column.

  For example, in the manufacture of steel pipes, when uneven hardness in the circumferential direction occurs in a product after heat-quenching, it is necessary to identify a quenching defect in order to improve the cause and elucidate the cause. For this purpose, it is necessary to measure the temperature distribution in the entire circumference of the steel pipe.

  When trying to measure the temperature distribution from a single direction on a measured object with a curved outer periphery, many substances are measured low at a position that is not perpendicular to the measuring device due to the effect of directional emissivity. Therefore, the measurement accuracy of the temperature distribution is hindered.

  In contrast, for example, multiple infrared radiation thermometers are installed, the surface temperature of the outer circumference of the object to be measured is measured (captured) from multiple directions, and the effect of directional emissivity is suppressed by superimposing the images. Thus, it is possible to measure the temperature distribution of the entire outer periphery. However, the installation of a plurality of infrared radiation thermometers increases the cost and it is extremely difficult to synchronize the measured values of the plurality of infrared radiation thermometers with time.

  Patent Document 1 discloses a surface temperature distribution measuring device using an infrared measurement terminal connected by a plurality of optical fibers opposed to a curved surface to be measured in a normal direction.

  Patent Document 2 discloses an infrared radiation thermometer that surrounds the object to be measured with a hood so as to allow the object to be measured, and can measure the infrared temperature even if the object to be measured moves.

Japanese Patent No. 2737419 Japanese Patent No. 3437140

  However, in the case of the measuring device of Patent Document 1, a large amount of optical fibers and infrared measuring terminals are required to measure the entire circumference of the object to be measured. In the case of Patent Document 2, only the average temperature of the entire circumference of the object to be measured can be measured.

  An object of the present invention is to solve such a problem and to simultaneously measure the surface temperature distribution in the outer peripheral direction of an object to be measured with a simple apparatus.

  In order to solve the above problems, the present invention is an apparatus that receives infrared radiation from an object to be measured and measures the surface temperature of the object to be measured, and includes at least one infrared thermal imaging apparatus, Two or more infrared mirrors, the infrared thermal imaging device directly receives infrared radiation from a predetermined direct measurement range of the surface of the object to be measured, the infrared mirror, Infrared radiation from a range other than the direct measurement range is received on the surface of the object to be measured and reflected toward the infrared thermal imaging device, and the infrared thermal imaging device receives reflected light from the infrared mirror. Furthermore, the present invention provides a surface temperature distribution measuring device characterized by receiving light.

  In the surface temperature distribution measuring apparatus, each of the infrared thermal imaging device and each of the infrared mirrors has an angular range in which a directional emissivity of a measurement surface of the object to be measured is equal to an emissivity in a normal direction of the measurement surface. It is preferable that it is arranged so as to receive infrared radiation from inside.

  The two or more infrared mirrors may be configured such that the reflected light to the infrared thermal image device does not overlap the direct light directly received from the object to be measured and the reflected light from other infrared mirrors. It is preferably arranged to reach the device. Further, the two or more infrared mirrors may be arranged so as to receive infrared radiation from all angle ranges other than the range directly received by the infrared thermal imaging device.

  The present invention also relates to a method of receiving infrared radiation from a device under test and measuring the surface temperature of the device under test, comprising one infrared thermal imager and at least two infrared rays. The infrared thermal imaging device directly receives infrared radiation from a predetermined direct measurement range of the surface of the object to be measured, and the infrared mirror has a surface of the object to be measured. Receiving infrared radiation from a range other than the direct measurement range and reflecting the infrared radiation toward the infrared thermal imaging device, and causing the infrared thermal imaging device to further receive reflected light from the infrared mirror. A surface temperature distribution measuring method is provided.

  In the surface temperature distribution measuring method, in the infrared thermal imaging device and each infrared mirror, an angular range in which a directional emissivity of a measurement surface of the object to be measured is equal to an emissivity in a normal direction of the measurement surface It is preferable to arrange so as to receive infrared radiation from inside.

  Two or more infrared mirrors are used so that the reflected light to the infrared thermal imaging apparatus does not overlap the direct light directly received from the object to be measured and the reflected light from other infrared mirrors. It is preferably arranged to reach the device. Further, two or more infrared mirrors may be arranged to receive infrared radiation from all angle ranges other than the range directly received by the infrared thermal imager.

  The reflected light from the infrared mirror is inverted so as to be in the same direction as the direct light from the object to be measured, and the portion where the measurement position overlaps is deleted from the direct light and the reflected light. You may display the surface temperature of the outer periphery of a measurement object.

  According to the present invention, the temperature distribution of the entire circumference of the object to be measured can be simultaneously measured with a simple device. This makes it possible to manage performance due to temperature in various manufacturing industries.

It is a figure which shows the outline of the surface temperature distribution measuring apparatus concerning embodiment of this invention. It is a figure which shows the example of the directional emissivity for every material. It is a figure which shows the outline of the surface temperature distribution measuring apparatus concerning different embodiment of this invention. It is an example of the visible image showing the temperature distribution measured in the Example. It is a different example of the visible image showing the temperature distribution measured in the Example. It is a further different example of the visible image showing the temperature distribution measured in the Example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 schematically shows a surface temperature distribution measuring apparatus according to an embodiment of the present invention. The surface temperature distribution measuring apparatus 1 includes, for example, one infrared thermal image device 11 provided on one direction side of the measurement object 2 having a circular cross section, and substantially opposite to the infrared thermal image apparatus 11 with respect to the measurement object 2. In this embodiment, two infrared mirrors 12 are arranged on the side. Broken lines in the figure indicate infrared radiation or reflection. Hereinafter, of the surface of the DUT 2, the side facing the infrared thermal image device 11 is referred to as the front. The two infrared mirrors 12 provided on the back side of the DUT 2 make an angle of 120 ° with each other.

  As the infrared thermal image device 11, an existing device that can detect infrared energy radiated from the DUT 2 and convert it to a temperature and display it as a color image can be used. As the infrared mirror 12, an existing optical mirror capable of sufficiently reflecting infrared rays coated with a metal such as gold or silver is used. Visible light may not be reflected. As shown in FIG. 1, the infrared mirror 12 receives infrared radiation from the measurement surface where the directional emissivity described below significantly decreases from the back side of the object 2 to be measured or from the infrared thermal imaging apparatus 11. It is arranged at the position to do.

  The number and arrangement of the infrared mirrors 12 are determined by the characteristic of the directional emissivity of the DUT 2. FIG. 2 shows an example of directional emissivity. The emissivity value varies depending on the material, but in the case of material A and material B shown in FIG. 2, the emissivity is almost constant from 0 ° (normal direction) to 60 ° and slightly exceeds 60 °. However, the emissivity suddenly decreases. Therefore, when the object to be measured 2 is the material A or B, the infrared thermal imaging device 11 on the front and the infrared mirrors 12 on the outer periphery which is the measurement surface of the object to be measured 2 have normal directions facing each other. It is possible to measure stably by sharing as an angular range for measuring within 60 °, that is, within 120 ° on both sides. That is, in the case of the material A or B, the direct measurement range by the infrared thermal imager 11 is set to 60 ° on both sides across the normal direction on the front side, and the back side as in the embodiment shown in FIG. Two infrared mirrors 12 are arranged on the side at an angle of 120 °, and reflected light from these infrared mirrors 12 is photographed by the infrared thermal imager 11. Thereby, infrared radiation light outside the direct measurement range directly received by the infrared thermal imaging device 11 is received through the two infrared mirrors 12, and the surface temperature of the entire outer periphery of the DUT 2 can be measured simultaneously. On the other hand, when the emissivity rapidly decreases from around 50 °, for example, as the material C in FIG. 2, it is necessary to narrow the respective measurement ranges of the infrared thermal imaging device 11 and each infrared mirror 12. For example, four infrared mirrors 12 are arranged as shown in FIG. As a standard for determining that the emissivity is equivalent to the normal direction in order to receive infrared light stably, for example, the directional emissivity of the measurement surface of the DUT 2 is the normal direction of the measurement surface ( The emissivity in the direction of 0 ° may be 95% or more.

  A plurality of infrared mirrors 12 are arranged so that direct light directly received by the infrared thermal image device 11 and reflected light from each infrared mirror 12 reach the infrared thermal image device 11 without overlapping at least. Further, in order to easily identify the boundary between the direct light and the reflected light, or the boundary of the reflected light for each infrared mirror 12 in the case of FIG. 11 is preferably reflected.

  In this way, as shown in FIG. 1 or FIG. 3, the infrared thermal imaging device 11 can obtain an image by direct light received directly from the front side and reflected light from the plurality of infrared mirrors 12.

  The direct light and the reflected light photographed by the infrared thermal image device 11 are subjected to image processing by a control unit built in the infrared thermal image device 11. First, since the reflected light from the infrared mirror 12 becomes a mirror image, it is reversed so that the direction coincides with the direct light taken directly from the front. Next, in the obtained image, an overlapping portion obtained by photographing the same position is deleted, and the ordinate is displayed as an angle. Visible image data representing the surface temperature distribution of the entire outer periphery of the DUT 2 is obtained by arranging the images thus obtained in time series.

  As described above, according to the present embodiment, the infrared mirror 12 can be received so that infrared radiation can be received in an angular range where the emissivity is constant according to the directional emissivity characteristic of the DUT 2. By arranging and photographing the reflected light from the infrared mirror 12 together with the direct light on the front side simultaneously with the infrared thermal imaging device 11, the temperature distribution of the entire circumference of the object 2 to be measured can be measured simultaneously with a simple device configuration. can do.

  In the present invention, the DUT 2 preferably has a circular cross section, such as a cylindrical shape or a tubular shape, or a cross section having no concave portion. A prismatic shape is also applicable. Moreover, even if it is a complicated shape like a rail or a crankshaft, for example, if it is surface temperature distribution of only the part which does not have a recessed part in cross-sectional shape, it can measure by this invention.

  As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to this example. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  In the induction quenching process of the small-diameter pipe, in order to identify the position where the quenching was insufficient, the temperature distribution of the entire outer circumference of the small-diameter pipe was measured. In order to examine both the heating unevenness and the cooling unevenness, the temperature distribution of the entire circumference was measured at two places, between the coils being heated and after the cooling header. Since the directional emissivity of the steel pipe takes a substantially constant value from 0 ° to 60 °, measurement is performed from three directions as shown in FIG. 1, and two infrared mirrors are arranged. As the infrared mirror, “4-6λ plane mirror” manufactured by Edmund was used.

  About the image image | photographed with the infrared thermal image apparatus, the mirror image was reversed in the same direction as direct light, the duplication imaging | photography part was deleted, the coordinate was changed into the angle, and it arranged in time series. 4-6 is an example of the visible image after cooling showing the temperature distribution obtained in this way, a vertical axis | shaft shows the angle from a front, and a horizontal axis shows a length direction. The shading of the image indicates the temperature.

  FIG. 4 shows an example in which the temperature difference due to the angle, that is, the circumferential position is extremely small and the temperature distribution is almost constant. FIG. 5 shows an example in which the temperature unevenness slightly occurs in the vicinity of the angle of 150 ° to 200 °. FIG. 6 is an example in which remarkable temperature unevenness occurs in the vicinity of 100 ° to 250 °. The temperature unevenness discovered from FIGS. 5 and 6 occurs at a position that cannot be found by photographing only on the front side where the infrared thermal imaging device 11 is provided. The temperature on the opposite side was measured at the same time as the front side, and temperature irregularities were found. As a result, for example, a place where the water flow was not sufficiently applied at the time of cooling could be specified, and the process could be improved.

  The present invention is not limited to steel pipes and steel bars, and in various materials, it is a tubular or cylindrical member having no recess in the cross-sectional shape, a prismatic member, or a long member of the outer periphery of a portion having no recess in the cross section. Applicable to temperature measurement.

DESCRIPTION OF SYMBOLS 1 Surface temperature distribution measuring apparatus 2 Object to be measured 11 Infrared thermal imaging apparatus 12 Infrared mirror

Claims (9)

A device that receives infrared radiation from a device under test and measures the surface temperature of the device under test,
One infrared thermal imager and at least two infrared mirrors;
The infrared thermal imager directly receives infrared radiation from a predetermined direct measurement range on the surface of the object to be measured;
The infrared mirror receives infrared radiation from a range other than the direct measurement range on the surface of the object to be measured and reflects it toward the infrared thermal imaging device,
The infrared thermal imager further receives reflected light from the infrared mirror.   The infrared thermal imaging device and the infrared mirrors each receive infrared radiation from an angular range in which the directional emissivity of the measurement surface of the object to be measured is equal to the emissivity in the normal direction of the measurement surface. 2. The surface temperature distribution measuring device according to claim 1, wherein the surface temperature distribution measuring device is arranged to receive light.   The two or more infrared mirrors may be configured such that the reflected light to the infrared thermal image device does not overlap the direct light directly received from the object to be measured and the reflected light from other infrared mirrors. The surface temperature distribution measuring device according to claim 1, wherein the surface temperature distribution measuring device is arranged so as to reach the device.   The two or more infrared mirrors are arranged so as to receive infrared radiation from all angle ranges other than the range directly received by the infrared thermal imager. The surface temperature distribution measuring apparatus as described in any one of -3. A method of receiving infrared radiation from a device under test and measuring the surface temperature of the device under test,
One infrared thermal imager and at least two infrared mirrors;
The infrared thermal imaging device directly receives infrared radiation from a predetermined direct measurement range on the surface of the object to be measured,
The infrared mirror receives infrared radiation from a range other than the direct measurement range on the surface of the object to be measured and reflects it toward the infrared thermal imaging device,
A method for measuring a surface temperature distribution, wherein the infrared thermal imaging apparatus further receives reflected light from the infrared mirror.   The infrared thermal imaging apparatus and the infrared mirrors each receive infrared radiation from within an angular range in which the directional emissivity of the measurement surface of the object to be measured is equal to the emissivity in the normal direction of the measurement surface. 6. The surface temperature distribution measuring method according to claim 5, wherein the surface temperature distribution measuring method is arranged so as to receive light.   Two or more infrared mirrors are used so that the reflected light to the infrared thermal imaging apparatus does not overlap the direct light directly received from the object to be measured and the reflected light from other infrared mirrors. It arrange | positions so that an apparatus may be reached | attained, The surface temperature distribution measuring method as described in any one of Claim 5 or 6 characterized by the above-mentioned.   The two or more infrared mirrors are arranged so as to receive infrared radiation from all angle ranges other than the range directly received by the infrared thermal imager. The surface temperature distribution measuring method according to any one of the above.   The reflected light from the infrared mirror is inverted so as to be in the same direction as the direct light from the object to be measured, and the portion where the measurement position overlaps is deleted from the direct light and the reflected light. The surface temperature distribution measuring method according to any one of claims 5 to 8, wherein the surface temperature of the outer periphery of the measurement object is displayed.