JP2018132476A - Radiation temperature measurement unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation temperature measurement unit having a high accuracy of temperature measurement of heat radiation of a linear measuring object.SOLUTION: A radiation temperature measurement unit 100 includes: a radiation thermometer 20 for detecting heat radiation of a linear measuring object 101; and a heat radiation condensation unit 2 for condensing the heat radiation to the radiation thermometer. The heat radiation condensation unit includes: a cylindrical mirror 50 for condensing the component along a first direction crossing the longitudinal direction of the measuring object; and a cylindrical lens 40 for condensing the component along a second direction crossing the first direction, of the heat radiation. The radiation temperature measurement unit is configured so that the heat radiation condensed by the cylindrical mirror and condensed by the cylindrical lens is guided to the radiation thermometer.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a radiation temperature measurement unit including a radiation thermometer that measures temperature by thermal radiation from an object, and more particularly to a radiation temperature measurement unit that uses a thin wire as an object to be measured.

  Conventionally, a radiation thermometer is sometimes used to measure the temperature of a linear object to be measured (for example, Patent Document 1). Further, a radiation thermometer is used in the process of preheating the core wire in the manufacture of electric wires. The core wire preheating step is a step of performing core wire preheating with a preheater on the fine metal wire before the insulating coating treatment is performed on the fine metal wire with an extruder. By preheating the core wire uniformly with respect to the thin metal wire, generation of insulation unevenness in the insulation coating process is prevented. Since the temperature of the fine metal wire changes depending on the environmental temperature, preheating temperature management of the fine metal wire is required in the core wire preheating step, and the set temperature of the preheater is appropriately adjusted. Therefore, it is required to accurately measure the temperature of the fine metal wires in the core wire preheating process. When a contact-type thermometer is used to measure the temperature of the fine metal wire, the heat of the fine metal wire is taken away by the contact, so that the obtained measured value is lower than the surface temperature of the fine metal wire. Moreover, since the thermocouple is worn by contact, temperature measurement becomes intermittent. FIG. 1 is a diagram showing an example of a conventional radiation thermometer used for measuring the temperature of a linear object to be measured. Conventionally, in order to accurately measure the temperature of the fine metal wire 301 in the process of preheating the core wire, as shown in FIG. 1, the temperature of the fine metal wire 301 is a radiation thermometer for a small area for metal having a target size 302 of about several millimeters. Measurement at 300 is performed.

JP 09-155704 A

  However, the thin metal wire 301 changes the tension during traveling, and the pass line changes vertically and horizontally. Therefore, the target size 302 of the radiation thermometer 300, i.e., may be out of the measurement area. That is, the conventional radiation thermometer has a problem that temperature measurement of a linear object to be measured cannot be performed stably.

  The present invention has been made against the background of the above-described problems, and provides a radiation temperature measurement unit aimed at improving the accuracy of temperature measurement by a radiation thermometer.

  A radiation temperature measurement unit according to the present invention includes a radiation thermometer that detects thermal radiation of a linear object to be measured, and a thermal radiation condensing unit that condenses the thermal radiation on the radiation thermometer, and the heat The radiation condensing unit includes a first optical system that condenses a component along a first direction intersecting a longitudinal direction of the object to be measured among the thermal radiation, and the first direction among the thermal radiations. A second optical system that condenses the components along the intersecting second direction, and the thermal radiation collected by the first optical system and condensed by the second optical system is the radiation temperature. It is configured to be guided to a total.

  When the object to be measured is linear, the emissivity is low, and the infrared energy radiated from a minute area is weak. According to the present invention, of the thermal radiation of the linear object to be measured, the component along the first direction is collected by the first optical system, and the component along the second direction intersecting the first direction is the first component. The light is collected by two optical systems and guided to a radiation thermometer. That is, the infrared radiation energy radiated from the length direction and the circumferential direction of the object to be measured can be effectively led to the radiation thermometer by the thermal radiation condensing unit. Furthermore, when detecting the thermal radiation of the object to be measured with a radiation thermometer, the infrared radiation energy radiated from the length direction and the circumferential direction of the object to be measured is radiated even if the position of the object to be measured fluctuates. Since the site is only slightly displaced, there is no change in the amount of effective radiant energy, and infrared radiant energy can be guided to the radiation thermometer. As described above, according to the present invention, it is possible to improve the accuracy of detection of thermal radiation of the object to be measured by the radiation thermometer.

It is a figure which shows an example of the conventional radiation thermometer used for the measurement of the temperature of a linear to-be-measured object. It is sectional drawing which shows the radiation temperature measurement unit which concerns on embodiment of this invention from the side. It is sectional drawing which shows the radiation temperature measurement unit which concerns on embodiment of this invention from upper direction. It is a figure which shows the positional relationship of the optical member in the radiation temperature measurement unit which concerns on embodiment of this invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a radiation temperature measuring unit of the invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below. In addition, the size and shape of each constituent member in the drawings are shown in an easy-to-understand manner for explanation, and may differ from the actual size and shape.

Embodiment.
FIG. 2 is a sectional view showing the radiation temperature measuring unit according to the embodiment of the present invention from the side. FIG. 3 is a sectional view showing the radiation temperature measuring unit according to the embodiment of the present invention from above. 2 and 3, some members are omitted in order to avoid complication of the drawings. The radiation temperature measurement unit 100 includes a radiation thermometer unit 1 and a heat radiation condensing unit 2. The radiation thermometer unit 1 includes a housing 10 and a radiation thermometer unit 20. The housing 10 is a box-like member as a whole, and a lid 11 is disposed on the upper surface. The radiation thermometer unit 20 is fixed to a support portion 13 formed on the side surface 12 of the housing 10. The radiation thermometer unit 20 includes a radiation thermometer 21 and an objective lens 22. Thermal radiation of the thin metal wire 101 which is a linear object to be measured having a diameter of φ0.1 mm (millimeter) to φ3.0 mm is detected by the radiation thermometer 21.

  The thermal radiation condensing unit 2 includes a holding member 30, a cylindrical lens 40 (second optical system), and a cylindrical mirror unit 50. The holding member 30 is a columnar member as a whole, and has a pair of circular planes 31 and 32 and a side surface 33 connecting the plane 31 and the plane 32. The holding member 30 is fixed to the side surface 12 of the housing 10 such that the pair of flat surfaces 31 and 32 are substantially parallel to the pair of side surfaces 14 and 15 intersecting the side surface 12 in the housing 10 of the radiation thermometer unit 1. ing. The radius of the planes 31 and 32 is 30 mm. The inside of the holding member 30 is cut out so as not to block the heat radiation of the thin metal wire 101, and an opening is formed in a portion facing the radiation thermometer 21. The length along the circumference of the side surface 33 of the opening is about ¼ of the circumference of the side surface 33.

  The cylindrical mirror unit 50 includes a support plate 51 and a cylindrical mirror 52 (first optical system). In the present embodiment, the cylindrical mirror 52 is a cylindrical plano-concave mirror, that is, a concave cylindrical mirror. The support plate 51 is a thin plate member obtained by cutting a stainless steel pipe having a diameter of 60 mm into a shape corresponding to the opening of the holding member 30. The support plate 51 has a shape in which a part of the side surface 33 of the holding member 30 is cut out, and has a size that closes the opening of the side surface 33 described above. The cylindrical mirror 52 is a kaleidoscope mirror sheet having a thickness of 0.2 mm, and is attached to the concave surface of the support plate 51. The cylindrical mirror 52 has a radius of curvature of 30 mm and a focal length of about 15 mm.

  The support plate 51 is attached to the side surface 33 by an ultra-small hinge 53 in the vicinity of the lower edge of the above-described opening of the side surface 33. The support plate 51 is supported by an ultra-small hinge 53 so as to be rotatable in a range of about 120 ° around an axis orthogonal to the pair of planes 31 and 32. The rotation range of the support plate 51 is between a closed position that closes the opening portion of the side surface 33 and constitutes a part of the side surface 33, and an open position that opens the opening portion. In FIG. 2, the cylindrical mirror unit 50 when the support plate 51 is in the closed position is indicated by a solid line, and the cylindrical mirror unit 50 when the support plate 51 is in the open position is indicated by a two-dot chain line. When the support plate 51 is positioned at the closed position, the cylindrical mirror unit 50 is configured such that the concave surfaces of the support plate 51 and the cylindrical mirror 52 face the inside of the holding member 30 and the convex surface faces the outside of the holding member 30. Has been. In the support plate 51, a pin 54 whose surface is knurled is provided at the end opposite to the end supported by the hinge 53. The user opens and closes the support plate 51 by pinching the pin 54 with a finger.

  A U-shaped cutout 31 </ b> A is formed on the flat surface 31 of the holding member 30 so as to be continuous with the above-described opening of the side surface 33. Similarly, a U-shaped notch 32 </ b> A is formed on the flat surface 32 of the holding member 30 continuously with the above-described opening of the side surface 33. The cutout portion 31 </ b> A and the cutout portion 32 </ b> A are formed at positions where the U-shaped bottom surface is substantially the same height as the optical axis OP of the cylindrical mirror 52 in the vertical direction of the radiation temperature measurement unit 100.

  The cylindrical lens 40 is a plano-convex lens, and is disposed inside the holding member 30 so that the plane faces the radiation thermometer unit 20 and the concave surface faces the cylindrical mirror unit 50 by a predetermined mounting mechanism.

  The thin metal wire 101 that is the object to be measured is arranged in the vicinity of the bottom surface of the U-shape located on the inner side of the holding member 30 in the notch 31A and the notch 32A. The fine metal wire 101 is positioned so as to intersect the optical axis OP of the cylindrical mirror 52. The distance of the metal thin wire 101 from the cylindrical mirror 52 is 18 mm to 19 mm, which is longer than the focal length F of the cylindrical mirror 52. Detection of thermal radiation of the fine metal wire 101 by the radiation thermometer 21 is performed while the fine metal wire 101 travels in the direction indicated by the arrow along the longitudinal direction.

  FIG. 4 is a diagram showing the positional relationship of the optical members in the radiation temperature measurement unit according to the embodiment of the present invention. On the optical axis OP of the cylindrical mirror 52, the cylindrical lens 40 is arranged so that its optical axis coincides with the optical axis OP. The radiation thermometer 21 is disposed on the opposite side of the cylindrical mirror 52 across the cylindrical lens 40 on the optical axis OP. The objective lens 22 is disposed between the cylindrical lens 40 and the radiation thermometer 21. With this arrangement, infrared radiation (thermal radiation) emitted from the metal thin wire 101 is reflected by the cylindrical mirror 52, refracted by the cylindrical lens 40, further refracted by the objective lens 22, and condensed on the radiation thermometer 21.

  Here, with reference to FIG.2 and FIG.3, the aspect which the thermal radiation of the metal fine wire 101 condenses on the radiation thermometer 21 is demonstrated. The thermal radiation radiated from the thin metal wire 101 is reflected by the cylindrical mirror 52. As shown in FIG. 2, out of the heat radiation radiated by the traveling metal wire 101, the vertical direction (first direction) intersecting the longitudinal direction of the metal wire 101, in other words, the vertical direction of the radiation temperature measuring unit 100. The component along is collected by the cylindrical mirror 52. On the other hand, the component along the direction (second direction) parallel to the longitudinal direction of the fine metal wire 101 in the thermal radiation radiated by the fine metal wire 101 is collected when reflected by the cylindrical mirror 52 as shown in FIG. Not lighted.

  The thermal radiation reflected by the cylindrical mirror 52 enters the cylindrical lens 40 and is transmitted therethrough. As shown in FIG. 3, when passing through the cylindrical lens 40, the component along the direction parallel to the longitudinal direction of the thin metal wire 101 in the heat radiation is condensed by the cylindrical lens 40. On the other hand, the component of the thermal radiation along the vertical direction is refracted by the wavelength refractive index of the cylindrical lens 40.

  The thermal radiation that has passed through the cylindrical lens 40 is guided to the radiation thermometer 21. That is, the thermal radiation radiated from the fine metal wire 101 is condensed by the cylindrical mirror 52 along the vertical direction, and the cylindrical lens 40 is condensed along the direction parallel to the longitudinal direction of the fine metal wire 101. Then, it is guided to the radiation thermometer 21.

  In the present embodiment, the focal length F of the cylindrical mirror 52 is determined so that the distance from the cylindrical mirror 52 to the fine metal wire 101 is longer than the focal length F of the cylindrical mirror 52, and the fine metal wire 101 is disposed. Has been. Further, the focal length of the cylindrical lens 40 is set so that the component of thermal radiation condensed by the cylindrical mirror 52 and refracted by the cylindrical lens 40 and the component of thermal radiation condensed by the cylindrical lens 40 form an image at the same position. The radiation thermometer 21 is disposed at the focal position of the cylindrical lens 40.

  The metal thin wire 101 has a low emissivity, and the infrared energy radiated from a small area is weak. According to the present embodiment, the component in the vertical direction of the thermal radiation of the fine metal wire 101 is collected by the cylindrical mirror 52, and the component parallel to the longitudinal direction of the fine metal wire 101 is collected by the cylindrical lens 40, Guided to the radiation thermometer 21. That is, the thermal radiation condensing unit 2 of the present embodiment can effectively guide the infrared radiation energy radiated from the length direction and the circumferential direction of the metal thin wire 101 as the object to be measured to the radiation thermometer 21. Further, when the radiation thermometer 21 detects the thermal radiation of the fine metal wire 101, the length of the fine metal wire 101 is changed even if the position of the fine metal wire 101 fluctuates in the vertical direction and the front-back direction (the direction along the optical axis OP). Infrared radiant energy radiated from the direction and the circumferential direction is only slightly displaced from the radiated portion, so that the amount of effective radiant energy is not changed, and the infrared radiant energy can be guided to the radiation thermometer 21. As described above, according to the present embodiment, the accuracy of temperature detection of the thin metal wire 101 by the radiation thermometer 21 can be further increased.

  The radiation thermometer 21 is arranged at the focal position of the cylindrical lens 40 having the focal length determined as described above. Therefore, the heat radiation of the thin metal wire 101 is condensed on the radiation thermometer 21 and the detection accuracy by the radiation thermometer 21 can be further improved.

  In the embodiment, a kaleidoscope mirror sheet is used for the cylindrical mirror 52, but the present invention is not limited to this. A mirror sheet, an aluminum mirror plate, a high gloss aluminum alloy plate, a stainless mirror, a plastic mirror sheet, or the like may be used for the cylindrical mirror 52.

  Further, a dielectric protective film or the like may be applied to the mirror surface of the cylindrical mirror 52. This protects the mirror surface and facilitates the removal of dirt adhering to the mirror surface.

  In the embodiment, the radius of curvature of the cylindrical mirror 52 is 30 mm, but is not limited thereto, and may be 15 mm or more.

  DESCRIPTION OF SYMBOLS 1 Radiation thermometer part, 2 Thermal radiation condensing unit, 10 Case, 11 Lid, 12 Side surface, 13 Support part, 14 Side surface, 15 Side surface, 20 Radiation thermometer unit, 21 Radiation thermometer, 22 Objective lens, 30 Holding Member, 31 plane, 31A notch, 32 plane, 32A notch, 33 side, 40 cylindrical lens, 50 cylindrical mirror unit, 51 support plate, 52 cylindrical mirror, 53 hinge, 54 pins, 100 radiation temperature measurement unit, 101 Metal thin wire, 300 Radiation thermometer, 301 Metal thin wire, 302 Target size, F Focal length, OP Optical axis.

Claims (8)

A radiation thermometer that detects thermal radiation of a linear object to be measured;
A thermal radiation condensing unit for condensing the thermal radiation on the radiation thermometer,
The thermal radiation condensing unit is
A first optical system for condensing a component of the thermal radiation along a first direction intersecting with a longitudinal direction of the object to be measured;
A second optical system that condenses a component of the thermal radiation along a second direction that intersects the first direction;
A radiation temperature measurement unit configured to guide the thermal radiation condensed by the first optical system and condensed by the second optical system to the radiation thermometer.   The radiation temperature measurement unit according to claim 1, wherein the second direction is parallel to a longitudinal direction of the object to be measured.   The thermal radiation of the object to be measured is reflected in a state where components along the first direction are collected by the first optical system, and the thermal radiation reflected by the first optical system is reflected by the second optical system. By passing through the system, the component along the first direction is refracted at the wavelength refractive index of the second optical system, and the component along the second direction is condensed and guided to the radiation thermometer. Item 3. A radiation temperature measurement unit according to Item 1 or 2.   On the optical axis of the first optical system, the second optical system is arranged so that the optical axis thereof coincides with the optical axis of the first optical system, and the radiation thermometer is arranged on the optical axis of the first optical system. The radiation temperature measurement unit according to any one of claims 1 to 3, wherein the radiation temperature measurement unit is disposed on the opposite side of the first optical system with the second optical system interposed therebetween.   The radiation temperature measurement unit according to claim 4, wherein a distance from the first optical system to the object to be measured is longer than a focal length of the first optical system.   The component of the thermal radiation that is condensed by the first optical system and refracted by the second optical system and the component of the thermal radiation that is condensed by the second optical system are imaged at the same position. The radiation temperature measurement unit according to claim 4 or 5, wherein a focal length of the second optical system is determined.   The radiation temperature measuring unit according to any one of claims 1 to 6, wherein the first optical system is a cylindrical mirror.   The radiation temperature measuring unit according to any one of claims 1 to 7, wherein the second optical system is a cylindrical lens.

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