JP2012237571A - Non-contact temperature sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact temperature sensor which not only can prevent manufacturing man-hour and cost from increasing, productivity from reducing, and work environment from deteriorating, but also suppress sensitivity error and sensibility decrease of a sensor.SOLUTION: For example, a guiding barrel 30A of the non-contact temperature sensor has a trunk 31 composed of a long side walls 31L and 31L, short side walls 31S and 31S. The trunk 31 has non-light guide means including blades 41L1, 41L2, 41S1 and 41S2, and pores 51L1, 51L2, 51S1 and 51S2, which prevents the infrared component progressing towards an inner wall or reflected by the inner wall among radiated infrared rays IR entering the inside of the guiding barrel 30A through its opening P from reaching a reception range including a heat sensitive element for infrared detection.

Description

  The present invention relates to a non-contact temperature sensor that measures the temperature of a heat source (heating element) in a non-contact manner.

  In general, a non-contact temperature sensor for non-contact measurement of the temperature of a heat source detects a temperature rise of an infrared absorption film that absorbs infrared rays radiated from the heat source by a thermal sensor for infrared detection, and is based on the amount of heat of the emitted infrared rays. And measure the temperature of the heat source. The thermal element for infrared detection has a temperature characteristic in which the electrical characteristics change according to the amount of heat received, and not only by the amount of infrared heat absorbed by the infrared absorption film, but also by the amount of heat given to the infrared detection thermal element by the external environment. However, its electrical characteristics change. For this reason, such a non-contact temperature sensor usually detects the amount of heat flowing in and out between the external environment and the infrared detection thermal element in addition to the infrared detection thermal element, and the infrared detection thermal element. There is also provided a temperature compensating thermosensitive element for correcting the measurement result.

  As such a non-contact temperature sensor, for example, Patent Document 1 discloses a resin film in which a thermal element for detecting infrared rays is attached to the bottom side of a cylindrical holding body (for example, made of metal such as aluminum) having an opening. Infrared absorbing films are provided. In this non-contact temperature sensor, an opening portion of a cylindrical holder provided in front of the infrared absorption film is disposed so as to face a heat source (such as a heat fixing roller of a copying machine) that is a temperature detection target.

Japanese Patent No. 4415045

  Here, the cylindrical holder in the conventional non-contact temperature sensor is an infrared light guide radiated from the heat source, defines the direction of temperature detection, and the temperature detection field range (temperature detection field range in the heat source). ) To function as an infrared “guide tube”. Usually, infrared rays are radiated in all directions from each point on the surface of the heat source, and a part of them is incident on the inside from the opening of the guide tube. Of the infrared rays incident on the inside of the guide tube, there are a component that directly reaches the infrared absorbing film and a component that is reflected (including multiple reflections) by the inner wall of the guide tube and indirectly reaches the infrared absorbing film. The sum of the energy of both components is absorbed by the infrared absorption film and contributes to the temperature increase of the infrared absorption film, which may affect the sensitivity of the non-contact temperature sensor.

  Among these infrared components, the intensity (line bundle) of the infrared component reflected by the inner wall of the guide tube is affected by the reflection characteristics of the inner wall, and the reflection characteristics change depending on the surface state of the inner wall ( Fluctuations), and also fluctuates due to the occurrence of rust or dirt on the inner wall. Therefore, the infrared component reflected by the inner wall of the guide tube can be a major factor in non-contact temperature sensor sensitivity variations and aging.

  In order to suppress sensitivity errors and fluctuations due to the infrared component reflected by the inner wall of the guide tube, various methods for absorbing and not reflecting the infrared light incident on the inner wall of the guide tube have been proposed. . For example, also in the above-mentioned Patent Document 1, an anodizing treatment or anodizing treatment in which a black body absorption film (plastic, rubber, etc.) having a radiation rate of 0.94 or more is applied to the inner wall surface of a cylindrical holder that is a guide tube. A method of forming a black body absorbing film by the above is proposed (for example, refer to paragraph 0017 and paragraph 0018 of FIG. 3, FIG. 3 etc.).

  However, if the inner wall of the guide tube is treated with a black body in this manner, a plurality of problems will inevitably occur. That is, firstly, in order to perform black body treatment such as painting treatment, anodizing treatment, alumite treatment, etc. as described in Patent Document 1, these steps are required anyway. This will increase man-hours and manufacturing costs. In particular, when the non-contact temperature sensor is small, it is extremely difficult to paint the inner wall surface of the small guide cylinder. For example, in order to paint only the necessary part of the inner wall of the guide tube, each small part must be masked accurately. In addition, when the heat source becomes high temperature, the black body absorbing film is exposed to high temperature, so in order to improve its durability, for example, baking coating or the like requires high temperature and long drying time, and production As a result, the manufacturing cost is further increased. Furthermore, the coating treatment using an organic solvent is not preferable in terms of work environment and natural environment.

  Secondly, the guide tube having the black body absorbing film formed on the inner wall by the black body treatment absorbs the infrared rays incident thereon and the temperature easily rises, and as a result, the infrared radiation from the inner wall increases. A part of the incident light is incident on an infrared absorbing film provided with a heat sensitive element for detecting infrared rays and promotes the temperature rise. As a result, it causes a sensitivity error of the non-contact temperature sensor. That is, even if infrared rays are once absorbed by the black body absorbing film, the thermal energy is radiated by black body radiation, so that the effect of preventing infrared reflection on the inner wall of the guide tube may not make sense.

  Third, as described above, when the temperature of the infrared absorbing film rises due to infrared radiation from the black body absorbing film, the heat is transferred to the entire non-contact temperature sensor, thereby increasing the ambient temperature. In this case, the temperature of the infrared absorbing film and the ambient temperature (more precisely, the thermal temperature on the infrared detecting thermal element side and the thermal temperature on the temperature compensating thermal element side) are close to each other, and the difference between the two becomes small. The sensitivity of the non-contact temperature sensor is significantly reduced.

  Therefore, the present invention has been made in view of such circumstances, and can prevent an increase in man-hours and costs at the time of production, a decrease in productivity, and a deterioration of the work environment and the natural environment, and a sensitivity error. Another object of the present invention is to provide a non-contact temperature sensor that can suppress a decrease in sensitivity.

  In order to solve the above-mentioned problems, a non-contact temperature sensor according to the present invention measures the temperature of a heat source in a non-contact manner, and detects a heat quantity of infrared rays (radiated infrared rays) emitted from the heat source. And a temperature-compensating thermosensitive element for detecting the amount of heat from the external environment, and having a cylindrical shape, having an opening and a body, and defining a visual field range of temperature detection by the infrared-sensitive thermosensitive element in the heat source The guide tube is provided, and the guide tube enters the inner side (inner space) from the opening thereof and emits infrared radiation that travels toward the inner wall of the body portion and radiation reflected by the inner wall of the body portion Non-light guiding means is provided so as to prevent at least a part of the infrared rays from reaching the light receiving range including the infrared sensitive thermal element. That is, the guide tube in the non-contact temperature sensor according to the present invention has a function as an infrared light guide as a whole, and means that does not guide part of the infrared light incident on the guide tube to the light receiving range, that is, “ Non-light guiding means ”.

  The non-contact temperature sensor configured in this way is arranged so that the opening of the guide cylinder faces the heat source, and the radiant infrared rays from the heat source enter the inside (internal space) of the guide cylinder from the opening of the guide cylinder. . Of the radiant infrared light thus guided to the guide tube, the thermal energy of the light that reaches the light receiving range including the infrared detecting thermal element is applied to an appropriate infrared absorbing means (infrared absorbing film or the like). Then, based on the temperature rise of the infrared absorbing means detected by the infrared detecting thermal element and the ambient temperature detected by the temperature compensating thermal element, the amount of radiation infrared radiation and the temperature of the heat source are measured.

  At this time, the radiant infrared rays that have entered the inner side of the guide tube from the opening directly reach the light receiving range including the infrared detecting thermal element, and the remaining portion proceeds toward the inner wall of the guide tube, Alternatively, although it can be reflected by the inner wall of the guide tube, at least a part, preferably all, of the radiated infrared light is prevented from reaching the light receiving range including the infrared detecting thermal element by the non-light guiding means. Therefore, even if the black wall treatment is not applied to the inner wall of the guide tube as in the prior art, the non-uniformity and decrease in sensitivity of the non-contact temperature sensor due to the infrared component reflected by the inner wall of the guide tube and its secular variation are prevented. .

  Specifically, the non-light guiding means has a blade plate that protrudes (toward the internal space) inside the trunk portion of the guide tube, and this blade plate extends from the opening to the inside of the guide tube. It is preferable to block at least a part, preferably all, of the radiant infrared rays that are incident and travel toward the inner wall of the trunk portion and the radiant infrared rays reflected by the inner wall of the trunk portion. At this time, it is more preferable that the blade plate is provided so that the tip thereof extends toward the opening of the guide tube.

  In this way, at least a part of the radiated infrared rays that are incident on the inner side of the guide tube and reflected by the inner wall of the body portion are blocked by the blades in the path, thereby receiving light including the infrared detecting thermal element. Reaching the range is prevented. In addition, some of the infrared radiation incident on the inner and outer walls of the guide tube may be slightly absorbed by the guide tube, causing the temperature of the guide tube to rise, and the guide tube may become a secondary heat source. However, even in that case, since the vane plate of the non-light guide means can function as a sheet sink like a radiating fin, the radiant heat from the guide tube can adversely affect the sensitivity of the non-contact temperature sensor. Can be eliminated sufficiently. Further, if the slats easily reflect the radiant infrared rays, it is possible to prevent the radiant infrared rays from being absorbed by the slats and the temperature of the guide tube from rising. Furthermore, if the tip of the vane extends toward the opening of the guide tube, there is an advantage that the radiant infrared rays can be more easily blocked geometrically.

  It is also preferable that the non-light guiding means has a hole formed in the body portion of the guide tube.

  In such a configuration, a part of the radiated infrared rays that are incident on the inner side of the guide tube from the opening and reflected by the inner wall of the body portion are emitted from the hole of the non-light guide means to the outside of the guide tube and dissipated. This also prevents reaching the light receiving range including the infrared detecting thermal element. In addition, radiant infrared rays from the heat source can be incident on the inside of the guide tube from the outside through the hole, but some of the infrared rays are detected from the outside of the guide tube through the hole of the non-light guiding means. It is prevented from reaching the light receiving range including the thermal element for use, and the other part can proceed toward the inner wall of the trunk part of the guide tube or be reflected by the inner wall of the trunk part, but at least a part thereof, preferably As for all, since the course is obstructed by the vane, it is prevented from reaching the light receiving range including the infrared detecting thermal element.

  Furthermore, as described above, a part of the radiant infrared rays incident on the inner wall and the outer wall of the guide tube are slightly absorbed by the guide tube, the temperature of the guide tube rises, and the guide tube becomes a secondary heat source. Although there is a possibility, the surface of the guide tube (infrared light receiving area) is reduced and the amount of heat input to the guide tube is reduced as compared with the case where there is no hole because the guide tube has a hole. At the same time, since the substantial heat conduction path (path) in the trunk portion of the guide tube is divided and extended to increase the conduction resistance, it is difficult for the temperature rise of the guide tube to be transmitted to the sensor body. Therefore, it is possible to sufficiently eliminate the adverse effect that the conduction heat from the guide tube may have on the sensitivity of the non-contact temperature sensor.

  Still further, the vane plate of the non-light guiding means may be provided integrally with the trunk portion of the guide tube, or may be provided separately. The degree of design and production of the cylinder can be increased, and versatility can be improved. Furthermore, when the blade plate and the barrel portion of the guide tube are integrally formed, the processing and manufacturing (assembly) man-hours are reduced as compared with the case where they are formed separately, thereby further improving productivity. From the viewpoint of obtaining. Needless to say, even when both are provided separately, the conventional black body processing is unnecessary as described above.

  More specifically, when the blade plate and the barrel portion of the guide cylinder are integrally formed, an example in which the vane plate is formed from a part of the barrel portion bent toward the inner side of the guide tube (toward the internal space). At this time, the hole portion may be formed in a part of the body portion. The bending of the slats can be easily performed by a sheet metal press or the like, and thereby, the productivity can be further increased as compared with the case where the black body treatment is performed.

  Furthermore, a plurality of blades are provided along the trunk, and the amount of protrusion (overhang) from the opening of the guide tube toward the inside (internal space) of the guide tube toward the light receiving range including the infrared detecting thermal element It is also preferable that it is provided so that the amount, the extended length from the body part, and the area) are increased.

  In this way, the amount of protrusion of the blade plate near the opening of the guide cylinder arranged opposite to the heat source is made relatively small, so that the temperature detection field of view (defined by the solid angle of the heat source from the light receiving range) is defined. ) Is unnecessarily narrowed and the sensor sensitivity is prevented from being lowered, and the amount of protrusion of the blade plate on the other end side (light receiving range side) of the guide tube is relatively large. It is possible to more effectively shield most of the radiated infrared rays reflected by the inner wall of the part.

  Further, the non-light guiding means has a blade plate formed by bending a part of the body part to the outside of the guide tube (toward the external space), and a hole part formed in the body part. It may be configured. In this case, it is more preferable that the blade plate is provided so that its tip extends in a direction away from the opening of the guide tube. Furthermore, the blade plate and the hole formed by being bent outside the guide tube as described above may be mixed with the blade plate and the hole formed by bending the above-described guide tube.

  In such a configuration, at least a part of the radiated infrared rays that enter the guide tube from the opening (inner space) and travel toward the inner wall of the barrel or reflected by the inner wall of the barrel pass through the hole. Then, by being emitted to the outside and dissipating, it is prevented from reaching the light receiving range including the infrared detecting thermal element. Moreover, it can suppress that a part of infrared rays from a heat source inject into the inner side (internal space) from the outer side (external space) of a guide cylinder with a blade board. Furthermore, even when the temperature of the guide cylinder rises due to radiant infrared rays, as described above, the radiant heat from the guide cylinder is reduced by the function of the vane plate as a heat sink, and the presence of the hole portion guides the guide cylinder. The conduction heat from the cylinder is reduced. Still further, if the slats are formed to be folded inside the guide cylinder, the slats may be folded outside the guide cylinder, while the slats may interfere with each other in some cases. If it is, it is prevented that such interference arises.

  Furthermore, it is useful that the guide tube is composed of a plurality of parts having the same shape.

  In general, when manufacturing a comparatively small non-contact temperature sensor having a guide tube, as a method of forming the guide tube, a cylindrical member is joined to a substrate member, or a projecting portion punched out from the substrate member is drawn. For example, in the case of a guide tube having a long body, it is difficult to mass-produce uniform shapes with high yield and high yield, regardless of which method is used. There is a tendency. In addition, as a conventional black body treatment, there is a situation that an integrally molded product is easier to handle in order to perform a high temperature treatment using a solvent such as baking coating.

  On the other hand, the non-contact temperature sensor according to the present invention does not require a black body treatment in the guide cylinder, and is therefore highly versatile in that the method of forming the guide cylinder is not limited in the first place. In addition, if the guide tube is composed of a plurality of parts having the same shape, the design, processing, assembly, and inspection process can be further simplified, and productivity and economy can be improved. This can be further improved.

  In addition, although the shape of the guide tube is not particularly limited, a structure in which the guide tube has a rectangular tube shape and at least two adjacent trunk walls are integrally formed can be exemplified. More specifically, a part for forming one body wall is connected to or protruded from a part for forming another adjacent body wall (may be a part only for forming a blade). A rectangular guide tube can be easily obtained by using a member such as a sheet metal provided and combining a pair of bent members by fitting them together.

  Alternatively, it is also preferable to adopt a structure in which the guide tube is composed of a plurality of parts and has a base portion in which at least a part of the body portion is erected. In this case, for example, the body of the guide tube (for example, a pair of body walls facing each other) can be formed simply by cutting and bending one sheet metal (base), so that the number of parts is reduced, and A blade plate and a hole may be integrally formed on the body wall, and in addition, another blade wall may be constructed by laying or straddling another blade plate between the body walls. Good.

  Further, the guide tube has a rectangular tube shape, and an integrally formed member constituting a pair of opposing body walls in the body portion, and an integrally formed member constituting another pair of body walls facing each other in the body portion It is also preferable that these are combined. In this way, the number of parts is further reduced, and assembly is further simplified. In this case, more specifically, for example, a ceiling wall that defines the opening of the guide tube may be provided on the parts constituting the pair of body walls of the body part.

  According to the non-contact temperature sensor of the present invention, by providing the guide tube having the non-light guiding means, the radiant infrared ray emitted from the heat source and incident on the inside of the guide tube proceeds toward the inner wall of the guide tube. Or at least a part of the light reflected by the inner wall is prevented from reaching the light receiving range including the infrared detecting thermal element. Such variations and reductions in detection sensitivity due to the infrared component reflected by the inner wall of the guide tube, and variations over time can be prevented, and product reliability can be improved. Further, since the black body treatment of the guide tube is unnecessary, it is possible to sufficiently suppress the increase in man-hours and costs during production, the decrease in productivity, and the deterioration of the work environment and the natural environment. In other words, in the past, in order to restrict or suppress the infrared component incident on the infrared absorbing film, the inner wall of the guide tube was actually subjected to black body treatment, and the infrared ray was absorbed there, whereas the present invention was In the point of using the technical idea of reflecting and passing infrared rays by non-light guiding means and dissipating them, it is possible to obtain advantageous effects that are completely different from the prior art.

(A) is a top view which shows roughly the basic structure of 1st Embodiment which concerns on the non-contact temperature sensor by this invention, (B) is the sectional view on the AA line in (A). It is a perspective view which shows roughly an example of the guide cylinder with which the non-contact temperature sensor shown in FIG. 1 is equipped. FIG. 3 is a schematic cross-sectional view of a guide tube taken along line III-III in FIG. 2, showing the guide tube together with a heat source that is a detection target and another heat source that is a non-detection target. It is a schematic cross section which shows roughly an example of the guide cylinder with which 2nd Embodiment which concerns on the non-contact temperature sensor by this invention is equipped. It is a perspective view which shows roughly an example of the guide cylinder with which 3rd Embodiment which concerns on the non-contact temperature sensor by this invention is equipped. It is an expanded view of an example of the guide cylinder with which 3rd Embodiment which concerns on the non-contact temperature sensor by this invention is equipped. It is a perspective view which shows roughly an example of the guide cylinder with which 4th Embodiment which concerns on the non-contact temperature sensor by this invention is equipped. It is an expanded view of an example of the part of the guide cylinder with which 4th Embodiment which concerns on the non-contact temperature sensor by this invention is equipped. It is a perspective view which shows 5th Embodiment which concerns on the non-contact temperature sensor by this invention roughly, and is a figure which shows the state which visually recognized the non-contact temperature sensor from diagonally forward. It is a perspective view which shows 5th Embodiment which concerns on the non-contact temperature sensor by this invention roughly, and is a figure which shows the state which visually recognized the non-contact temperature sensor from diagonally back. (A), (B), and (C) are exploded perspective views of a fifth embodiment of the non-contact temperature sensor according to the present invention.

  Hereinafter, embodiments of the present invention will be described in detail. The positional relationship such as up, down, left, and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios. Furthermore, the following embodiment is an illustration for explaining the present invention, and is not intended to limit the present invention only to the embodiment. Furthermore, the present invention can be variously modified without departing from the gist thereof.

(First embodiment)
FIG. 1A is a top view schematically showing the basic structure of the first embodiment of the non-contact temperature sensor according to the present invention, and FIG. 1B is the AA line in FIG. It is sectional drawing. The non-contact temperature sensor 100 has a structure in which a support plate 13 provided with an infrared absorption film M that absorbs radiated infrared rays and generates heat is sandwiched between a base 11 of the sensor body 10 and a cover housing 12. The base 11 is formed with two bottomed recesses 21 and 22. Further, a guide tube 30 having a rectangular tube-shaped body portion 31 in which an opening P is formed is provided at a portion facing the bottomed recess 21 in the cover housing 12, and a position facing the bottomed recess 21. The upper surface (surface) of the infrared ray absorbing film M arranged in (1) is exposed to the external environment E where a heat source (not shown) exists at the bottom of the guide tube 30. Further, an infrared detecting thermal element 15 for detecting the amount of heat of the radiated infrared ray is fixed to the lower surface (rear surface) of the infrared absorbing film M in the bottomed recess 21 in the figure. Thus, the infrared detecting thermal element 15 is installed in the space V <b> 1 between the back surface of the infrared absorption film M and the bottom surface of the bottomed recess 21.

  On the other hand, the bottomed recess 22 is covered and shielded by the support plate 13 and the cover housing 12. In addition, a temperature-compensating thermosensitive element 16 that detects the amount of heat transferred from the external environment E through the heat transfer path of the sensor body 10 is fixed to the bottom surface (rear surface) of the support plate 13 in the bottomed recess 22. Yes. Thus, the temperature compensating thermosensitive element 16 is installed in the space V <b> 2 between the back surface of the support plate 13 and the bottom surface of the bottomed recess 22.

  In the non-contact temperature sensor 100 configured as described above, radiant infrared rays from a heat source (not shown) that is a detection target existing in the external environment E are emitted from the opening P of the guide tube 30 that functions as a light guide. The light enters the inside of the body portion 31 (the internal space of the guide tube 30). The radiant infrared rays that have reached the light receiving range J of the infrared absorption film M heat the infrared absorption film M, the amount of heat detected by the infrared detection thermal element 15, and the value and the temperature compensation thermal element 16 detected. Based on the calorific value, the temperature of the heat source is measured.

  Although not shown in FIGS. 1 (A) and 1 (B), a “non-light guiding means” to be described later is provided on the body 31 of the guide tube 30 of the non-contact temperature sensor 100 according to an embodiment of the present invention. Is provided.

  The material of the infrared absorption film M is not particularly limited as long as it absorbs the infrared rays emitted from the heat source and generates heat, and is a material having an absorption peak with respect to wavelength light of 4 μm to 10 μm called far infrared rays. Examples thereof include polyester, polyimide, polyethylene, polycarbonate, PPS (polyphenylene sulfide) -based resins, fluorine-based resins, silicone-based resins, and the like. Further, the infrared detecting heat sensitive element 15 and the temperature compensating heat sensitive element 16 are not particularly limited as long as the electric characteristics change according to the amount of heat received, and thermistor, thermopile, metal temperature measuring instrument having resistance temperature characteristics. A body etc. can be illustrated preferably. Furthermore, the material of the sensor body 10 is preferably a material having a high thermal conductivity and a large heat capacity, for example, aluminum.

  FIG. 2 is a perspective view schematically showing an example of the guide tube 30 provided in the non-contact temperature sensor 100 shown in FIG. In the present embodiment, the guide cylinder is denoted by reference numeral 30A.

  The guide tube 30A formed on the cover housing 12 of the sensor body 10 has a rectangular tube-shaped body 31 composed of long side walls 31L and 31L and short side walls 31S and 31S, and a part of each wall surface. However, it is bent into a plate shape inside the guide tube 30A (inside the internal space) by a simple press process or the like, and the blades 41L1, 41L1, 41L1, and 31B are respectively formed on the long side wall 31L and the short side wall 31S along the vertical direction in the figure. 41L2 and blades 41S1 and 41S2 are formed. The tip of each blade 41L1, 41L2, 41S1, 41S2 extends toward the opening P of the guide tube 30A where the radiant infrared IR from the external environment E enters, that is, obliquely upward in the figure.

  Further, holes 51L1, 51L2, 51S1, and 51S2 are formed in the portions where the blades 41L1, 41L2, 41S1, and 41S2 are hollowed out. Thus, the blades 41L1, 41L2, 41S1, 41S2 and the holes 51L1, 51L2, 51S1, 51S2 are formed at the same time. In FIG. 3 to be described later, the bending trajectories of the blades 41L1 and 41L2 are indicated by reference symbols α1 and α2, respectively.

  Further, the long side end portions 61L and 61L and the short side end portions 61S and 61S on the opening P side in the body portion 31 also have long side walls 31L and 31L and a part of the short side walls 31S and 31S inside the opening P, respectively. It is formed by being bent so as to be constricted.

  Here, FIG. 3 is a schematic cross-sectional view of the guide tube 30A taken along the line III-III in FIG. 2 (a line parallel to the short side wall 31S of the body portion 31), and the guide tube 30A is a detection target. It is a figure shown with other heat source 7B which is 7A of heat sources and a non-detection target object. As shown in the figure, the long side end portions 61L and 61L, the short side end portions 61S and 61S, and the blade plates 41L1, 41L2, 41S1, and 41S2 include the infrared detecting thermal element 15 from the opening P of the guide cylinder 30A. A protrusion amount (extension length and area from the wall surface of the body portion 31) toward the inner side (internal space) of the guide tube 30A is gradually increased toward the light receiving range J.

  The heat source 7A is, for example, a heat fixing roller of a copying machine, and infrared components are radiated from the surface to the outside in all directions (all sky directions). FIG. 3 schematically illustrates some of these infrared rays using arrows. In this state, the temperature detection visual field range Y in the heat source 7A is the long side end portion that defines the light reception range J of the infrared absorption film M provided with the infrared detection thermal element 15 and the opening range of the opening P of the guide tube 30A. It is defined geometrically from the tip positions of 61L and 61L. That is, imaginary lines Ka and Kb (two-dot chain lines in the figure, image lines) connecting the edge Ja and Jb of the light receiving range J of the infrared absorption film M and the edges Pa and Pb of the opening P far from the light receiving range, respectively. The position where the angle θ) penetrates the heat source 7A corresponds to the edges Ya and Yb of the temperature detection visual field range Y.

  Infrared rays 1200 and 1201 emitted from an arbitrary point inside the temperature detection visual field range Y of the heat source 7A at the illustrated angle are directly incident on the infrared absorption film M. On the other hand, infrared rays 1101 radiated at an angle shown in the figure from an arbitrary point inside the temperature detection visual field range Y of the heat source 7A are incident on the inner space of the guide cylinder 30A through the opening P, but the outer surface (upper surface) of the vane plate 41L2 ), Passes through the hole 51L2, and is emitted to the outside (external space) of the guide tube 30A.

  On the other hand, infrared rays 1102 radiated at an illustrated angle from an arbitrary point outside the temperature detection visual field range Y of the heat source 7A enter the inner space of the guide tube 30A through the opening P, but the inner surface (lower surface) of the blade plate 41L1. And is emitted to the outside of the guide tube 30A through the hole 51L2. Similarly, infrared rays 1103 radiated at an angle shown from an arbitrary point outside the temperature detection visual field range Y of the heat source 7A also enter the inner space of the guide cylinder 30A from the opening P. Without hitting the plate, the light passes through the hole 51L2 and is emitted to the outside of the guide tube 30A. Further, infrared rays 1104 emitted at an angle shown in the figure from an arbitrary point outside the temperature detection visual field range Y of the heat source 7A once enter the internal space of the guide tube 30A from the outside of the body portion 31 through the hole portion 51L2. However, it is reflected by the outer surface (upper surface) of the blade plate 41L2, and again passes through the hole 51L2 and is emitted to the outside of the guide tube 30A.

  Furthermore, it is assumed that infrared rays 1105 radiated at an illustrated angle from an arbitrary point of the heat source 7B that is a non-detection target are incident on the inner space of the guide cylinder 30A from the outside of the body portion 31 by grazing the upper portion of the hole portion 51L2. However, it does not reach the light receiving range J of the infrared absorbing film M.

  3 schematically shows a cross section along a line parallel to the short side wall 31S in FIG. 2, and the radiant infrared rays from the heat sources 7A and 7B and the blades and holes formed in the long side wall 31L. The relationship (action) between the radiant infrared rays in the cross section along the line parallel to the long side wall 31L in FIG. 2 and the blades and holes formed in the short side wall 31S is also described. The same applies (the same applies in FIG. 4 described later).

  That is, the infrared rays 1101, 1102, and 1103 that enter the guide tube 30A from the opening P and travel toward the inner wall of the body portion 31 are reflected by the blades 41L1, 41L2, 41S1, and 41S2 with their paths blocked, or The holes 51L1, 51L2, 51S1, and 51S2 are emitted as they are to the outside of the guide cylinder 30A, so that they do not reach the inner wall of the trunk 31 and, therefore, their radiant infrared rays 1101, 1102, and 1103 The reflection on the inner wall is prevented from reaching the light receiving range J. Further, as geometrically clear from the state shown in FIG. 3, even if a part of the radiant infrared ray that has entered the guide tube 30 </ b> A from the opening P is incident on the inner wall of the body portion 31 and reflected. Infrared rays can also be reflected from the outer surfaces (upper surfaces) of the blades 41L1, 41L2, 41S1, and 41S2, and emitted from the holes 51L1, 51L2, 51S1, 51S2, or the opening P to the outside of the guide tube 30A.

  Infrared rays 1104 and 1105 incident on the inside of the guide tube 30A from the holes 51L1, 51L2, 51S1, and 51S2 formed in the body portion 31 are also reflected by the blades 41L1, 41L2, 41S1, and 41S2 with their courses blocked. Alternatively, even if the light does not enter the blade plates 41L1, 41L2, 41S1, and 41S2, the light receiving range J is not reached.

  Thus, the blades 41L1, 41L2, 41S1, 41S2 and the hole portions 51L1, 51L2, 51S1, 51S2 constitute non-light guiding means, and thereby, toward the inner wall of the trunk portion 31 of the guide tube 30A. Or the radiant infrared rays reflected by the inner wall of the body portion 31 are prevented from reaching the light receiving range J including the infrared detecting thermal element 15. Therefore, even if the inner wall of the guide tube is not subjected to a black body treatment as in the prior art, it is possible to effectively prevent variation and decrease in sensitivity of the non-contact temperature sensor 100 and its aging due to the infrared component reflected by the inner wall of the guide tube. can do. Further, since the black body treatment is not necessary, it is possible to reliably prevent the man-hours and costs at the time of manufacturing, the decrease in productivity, and the deterioration of the work environment and the natural environment, which are the conventional problems. Furthermore, since the tips of the blades 41L1, 41L2, 41S1, and 41S2 extend upward in the drawing toward the opening P of the guide cylinder 30A, it is possible to more efficiently block the emitted infrared rays.

  In addition, some of the radiant infrared rays that are incident on the inner wall and the outer wall of the body portion 31 of the guide tube 30A may cause the temperature of the guide tube 30A to rise. Even in such a case, the blades 41L1, Since 41L2, 41S1, and 41S2 can also function as a sheet sink like a radiating fin, the radiant heat from the guide cylinder 30A is caused by the non-contact temperature sensor 100 due to the guide cylinder 30A becoming a secondary heat source. The adverse effect that can be exerted on the sensitivity can be sufficiently eliminated. Furthermore, since the blades 41L1, 41L2, 41S1, and 41S2 have a property of easily reflecting the radiant infrared rays, the radiant infrared rays are absorbed by the blade plates 41L1, 41L2, 41S1, and 41S2, and the temperature of the guide cylinder 30A is increased. It can effectively deter itself.

  Further, since the holes 51L1, 51L2, 51S1, 51S2 are formed in the guide cylinder 30A, the surface area (light-receiving area of the radiated infrared rays) of the guide cylinder 30A is reduced as compared with the case where there is no such hole, The amount of heat input to the guide cylinder 30A is reduced, and a substantial heat conduction path (path) in the body portion 31 of the guide cylinder 30A is divided and extended to increase the conduction resistance. Therefore, in this case, the temperature rise of the guide tube 30A is not easily transmitted to the sensor body 10, and as a result, it is possible to sufficiently eliminate the adverse effect that the conduction heat from the guide tube 30A can have on the sensitivity of the non-contact temperature sensor 100. It becomes. Therefore, sensitivity errors and sensitivity fluctuations of the non-contact temperature sensor 100 can be further suppressed.

  Furthermore, since the blades 41L1, 41L2, 41S1, and 41S2 are provided integrally with the body portion 31, the processing and manufacturing (assembly) man-hours can be reduced as compared with the case where the two are configured separately. This makes it possible to further improve productivity. Furthermore, since the bending of the blade plates 41L1, 41L2, 41S1, and 41S2 can be easily performed by a sheet metal press or the like, productivity is improved as compared with the case where the black tube treatment is performed on the guide tube as in the past. Further increase is possible. In addition, since the holes 51L1, 51L2, 51S1, and 51S2 can be formed simultaneously with the molding of the blade plates 41L1, 41L2, 41S1, and 41S2, productivity and economy can be further improved.

  Further, a plurality of blades 41L1, 41L2, 41S1, 41S2 are provided along the trunk portion 31, and guide from the opening P of the guide tube 30A toward the light receiving range J including the infrared detecting thermal element 15. The amount of protrusion (extension length and area) to the inside (internal space) of the cylinder 30A is gradually increased, that is, from the long side end 61L and the short side end 61S that define the opening P. In addition, since the protruding amount of the blade plates 41L1 and 41S1 is large, and the protruding amount of the blade plates 41L2 and 41S2 provided on the light receiving range J side is larger than that of the blade plates 41L1 and 41S1, the temperature detection visual field range Y The sensor sensitivity is not lowered by narrowing the sensor to an inconvenient level. In addition, this makes it possible to more effectively shield most of the radiated infrared rays reflected by the inner wall of the body portion 31 and the inner surface (lower surface) of each blade. That is, even if the inner wall of the guide cylinder 30A is not subjected to black body processing, the virtual plane G connecting the leading ends of the long side end portion 61L and the short side end portion 61S, the blade plates 41L1 and 41S1, and the blade plates 41L2 and 41S2, In other words, it functions as an ideal black body.

(Second Embodiment)
FIG. 4 is a view schematically showing an example of a guide tube provided in the second embodiment of the non-contact temperature sensor according to the present invention, and is a schematic cross-sectional view similar to FIG. The guide tube 30B is formed in the cover housing 12 (see FIG. 1) of the sensor body 10 and the rectangular tube-shaped body portion 31 is short with the long side walls 31L and 31L, like the guide tube 30A. It is comprised from the side walls 31S and 31S.

  In the guide tube 30B, a part of each wall surface of the body portion 31 is bent into a plate shape on the outside (external space side) of the guide tube 30B by a simple press process or the like, and the long side wall 31L and the short side wall Each of 31S is formed with blade plates 42L0, 42L1, and 42L2 and blade plates 42S0, 42S1, and 42S2 along the vertical direction in the figure (however, short side wall 31S and blade plate 42S0 provided there) 42S1 and 42S2 are not shown in FIG. 4 for convenience of description). Each blade 42L0, 42L1, 42L2, 42S0, 42S1, 42S2 has its tip extending in a direction away from the opening P of the guide tube 30B where the radiant infrared IR from the external environment E enters, that is, obliquely downward in the figure. ing.

  Further, holes 52L0, 52L1, 52L2, 52S0, 52S1, and 52S2 are respectively formed in the portions where the blades 42L0, 42L1, 42L2, 42S0, 42S1, and 42S2 are cut out (however, the short sides are formed). The blades 52S0, 52S1, and 52S2 provided on the wall 31S are not shown in FIG. 4 for convenience of description. Thus, the blades 42L0, 42L1, 42L2, 42S0, 42S1, 42S2 and the holes 52L0, 52L1, 52L2, 52S0, 52S1, 52S2 are formed at the same time.

  Also in the non-contact temperature sensor 100 including the guide tube 30B having such a configuration, the infrared rays 1200 and 1201 described above are directly incident on the infrared absorption film M. On the other hand, the infrared ray 1101 described above enters the internal space of the guide tube 30B from the opening P, but passes through the hole 52L2 and is emitted to the outside (external space) of the guide tube 30B without hitting the inner wall of the body portion 31. The

  On the other hand, the infrared rays 1102 described above enter the inner space of the guide tube 30B from the opening P, but pass through the hole 52L1 and are emitted to the outside of the guide tube 30B without hitting the inner wall of the body portion 31. Reflected by the inner surface (lower surface) of the plate 42L1. The infrared ray 1103 described above also enters the inner space of the guide tube 30B from the opening P, but passes through the hole 52L2 and is emitted to the outside of the guide tube 30B without hitting the inner wall of the body portion 31. Reflected by the inner surface (lower surface) of the plate 42L2. The infrared ray 1104 described above travels from the outside of the body portion 31 toward the hole portion 52L2, but is reflected by the outer surface (upper surface) of the blade plate 42L2 and moves away from the hole portion 52L2. Further, the infrared ray 1105 described above does not reach the light receiving range J of the infrared ray absorbing film M even if the infrared ray 1105 is incident on the inner space of the guide tube 30B from the outside of the trunk portion 31 by grazing the lower portion of the hole 51L1.

  That is, the infrared rays 1101, 1102, and 1103 that enter the guide tube 30B from the opening P and travel toward the inner wall of the body portion 31 are directly emitted from the holes 52L1, 52L2, 52S1, and 52S2 to the outside of the guide tube 30A. Therefore, without reaching the inner wall of the body portion 31, the radiated infrared rays 1101, 1102, 1103 are prevented from being reflected by the inner wall of the body portion 31 and reaching the light receiving range J. Further, as geometrically clear from the state shown in FIG. 4, even if a part of the radiant infrared ray that has entered the inside of the guide tube 30 </ b> B from the opening P is incident on the inner wall of the body portion 31 and reflected. Infrared rays can also be emitted to the outside of the guide tube 30B from the holes 52L1, 52L2, 52S1, and 52S2.

  Infrared rays 1104 traveling toward the inside of the guide tube 30B from the holes 52L2 and 52S2 formed in the body portion 31 are reflected by the blades 42L2 and 42S2 disposed on the course thereof, and further, the body portion 31. The infrared rays 1105 incident on the inner side of the guide tube 30B from the holes 52L1 and 52S1 formed in the laser beam do not reach the light receiving range J.

  Thus, the non-light guiding means is constituted by the blades 42L0, 42L1, 42L2, 42S0, 42S1, 42S2, and the holes 52L0, 52L1, 52L2, 52S0, 52S1, 52S2, and thereby the guide cylinder 30B. The infrared rays that travel toward the inner wall of the barrel portion 31 or are reflected by the inner wall of the barrel portion 31 and the radiant infrared rays that enter the inside from the outer side of the barrel portion 31 of the guide tube 30B are for infrared detection. Reaching the light receiving range J including the thermal element 15 is prevented. Therefore, the non-contact temperature sensor 100 having the guide cylinder 30B can also exhibit the same excellent operational effects as the non-contact temperature sensor 100 having the guide cylinder 30A described above (in order to avoid redundant description, detailed description here) Is omitted).

  Further, if the blades are formed to be bent inside the guide tube, the blades may interfere with each other in some cases, whereas the blades 42L0, 42L1, 42L2, 42S0, 42S1, and so on. Since 42S2 is bent to the outside of the guide tube 30B, interference between the blades can be suppressed.

  Here, as described above, the formation of the blade plate on the wall surface of the barrel portion 31 of the guide cylinders 30A and 30B can be easily performed by, for example, applying press working to a metal sheet-like sheet metal. In addition, it is extremely easy to produce a guide tube from a plurality of parts by bending or combining sheet metals formed by processing a blade, and an example of a practical embodiment particularly suitable for press working is described below. Will be described.

(Third embodiment)
FIG. 5A is a perspective view schematically showing an example of a guide cylinder provided in the third embodiment of the non-contact temperature sensor according to the present invention, and FIG. 5B is an exploded view of components constituting the guide cylinder. The guide cylinder 30C is formed in the cover housing 12 (see FIG. 1) of the sensor body 10 in the same manner as the guide cylinder 30A. Further, a rectangular tube-shaped body portion 33 is constituted by two substantially L-shaped walls 33L and 33L.

  The body 33 is formed with blades 43L1, 43L2, 43S1, and 43S2 along the vertical direction in the drawing. Each blade 43L1, 43L2, 43S1, and 43S2 has a tip that radiates from the external environment E. It extends toward the opening P of the guide tube 30C where the infrared ray IR is incident, that is, obliquely upward in the drawing. Further, the end portions 63L, 63L, 63S, 63S on the opening P side of the body portion 33 are also formed by being bent so that a part of the wall 33L is narrowed toward the inside of the opening P.

  The blade plates 43L1 and 43L2 are formed by bending a part of the wall 33L surface into a plate shape inside the guide tube 30C (inside the internal space) by a simple press process or the like, and the blade plate 43L1. , 43L2 are formed with holes 53L1 and 53L2 in openings. Further, as shown in FIG. 5B, the wall 33L is formed by bending the protruding arm portion of the plate member 33P at a right angle to the back side of the drawing along the dashed line in the figure, and the three protruding arm portions are end portions. It corresponds to the part 63S and the blades 43S1 and 43S2. The two bent plate members 33P and 33P are combined so as to face each other, and as shown in FIGS. 5A and 5B, the tip ends of the protruding arm portions corresponding to the blade plates 43S1 and 43S2 of the one plate member 33P. The protrusions are fitted into the fitting holes Q1 and Q2 of the other plate member 33P, respectively. Further, after the joint margin of the tip end portion of the protruding arm portion corresponding to the end portion 63S of one plate member 33P is further bent by 90 degrees, it is engaged with the end portion 63L of the other plate member 33P. Bonding or bonding is performed by an appropriate method. Thus, a hole 53S1 is defined between the end 63S and the blade plate 43S1, and a hole 53S2 is defined between the blade plates 43S1 and 43S2.

  In the non-contact temperature sensor 100 including the guide cylinder 30C configured as described above, non-light guiding means is configured by the blade plates 43L1, 43L2, 43S1, 43S2, and the holes 53L1, 53L2, 53S1, 53S2. In this way, it proceeds toward the inner wall of the trunk portion 33 of the guide cylinder 30C, or radiated infrared rays reflected by the inner wall of the trunk portion 33 and attempts to enter the inside from the outside of the trunk portion 33 of the guide cylinder 30C. The radiated infrared rays to be transmitted are prevented from reaching the light receiving range J including the infrared detecting thermal element 15. Therefore, the non-contact temperature sensor 100 having the guide cylinder 30C can also exhibit the same excellent operational effect as the non-contact temperature sensor 100 having the guide cylinder 30A described above (details here are avoided in order to avoid redundant description). Is omitted).

  Further, since the guide tube 30C is composed of a plurality of bent parts of the plate member 33P having the same shape, the design, processing, assembly, and inspection process can be greatly simplified. Since the bending does not require a complicated processing step, the productivity and economy of the non-contact temperature sensor 100 can be further improved. Furthermore, since the guide tube 30C having a rectangular tube shape can be manufactured with a small number of parts and a small number of joints, productivity can be further enhanced.

(Fourth embodiment)
FIG. 6A is a perspective view schematically showing an example of a guide cylinder provided in the fourth embodiment of the non-contact temperature sensor according to the present invention, and FIG. 6B is an exploded view of components constituting the guide cylinder. The guide tube 30D having a rectangular tube shape has the short side walls 34S and 34S erected on the cover housing 12 (base) of the sensor body 10 so as to face each other, and constitutes the long side walls 34L and 34L. End portions 64L, 64L and blades 44L1, 44L1, 44L2, 44L2 are constructed between the short side walls 34S, 34S. The short side wall 34S, 34S and the long side wall 34L, 34L constitute a body portion 34.

  Each short side wall 34S has blades 44S1 and 44S2 formed by bending a part of its surface into a plate shape inside the guide tube 30D (inside the internal space) by a simple press process or the like. It is formed along the vertical direction. Further, the blades 44L1 and 44L2 constituting the long side walls 34L and 34L are also arranged along the vertical direction in the figure. The tips of these blades 44S1, 44S2, 44L1, and 44L2 extend toward the opening P of the guide cylinder 30D where the radiant infrared IR from the external environment E enters, that is, obliquely upward in the drawing. Further, the end portions 64L, 64L, 64S, and 64S on the opening P side of the body portion 34 are also formed to be bent toward the inside of the opening P, or extend toward the inside of the opening P. It is arranged like this.

  Holes 54S1 and 54S2 are formed in the portion of the short side wall 34S where the blades 44S1 and 44S2 are cut out. In addition, a hole 54L1 is defined between the end 64L constituting the long side wall 34L and the blade plate 44L1, and a hole 55L2 is defined between the blade plates 44L1 and 44L2. Further, as shown in FIGS. 6A and 6B, the short side walls 34S, 34S are erected from a plate member 34P made of sheet metal or the like by being bent and raised along a dashed line in the drawing, Two sets of end portions 64L and both-end protrusions of plate members corresponding to the blade plates 44L1 and 44L2 are fitted into the three 3 × 4 fitting holes Q3.

  In the non-contact temperature sensor 100 including the guide cylinder 30D configured as described above, non-light guiding means is configured by the blade plates 44L1, 44L2, 44S1, 44S2, and the holes 54L1, 54L2, 54S1, 54S2. In this way, it proceeds toward the inner wall of the trunk portion 34 of the guide cylinder 30D, or radiated infrared rays reflected by the inner wall of the trunk portion 34, and enters the inner side from the outer side of the trunk portion 34 of the guide cylinder 30D. The radiated infrared rays to be transmitted are prevented from reaching the light receiving range J including the infrared detecting thermal element 15. Therefore, the non-contact temperature sensor 100 having the guide tube 30D can also exhibit the same excellent operational effect as the non-contact temperature sensor 100 having the guide tube 30A described above (details here are avoided in order to avoid redundant description). Is omitted).

  Further, since the guide tube 30D is composed of bent parts such as the plate member 34P, the design, processing, assembly, and inspection process can be greatly simplified, and the plate member 34P and the like are bent and cut out. In addition, since no complicated processing steps are required, the productivity and economy of the non-contact temperature sensor 100 can be further improved. Further, since the short side walls 34S and 34S are formed integrally with the cover housing 12 of the sensor body 10, the number of parts can be reduced while the guide tube 30D is composed of a plurality of parts for easy assembly. The productivity can be further increased.

(Fifth embodiment)
7A and 7B are perspective views schematically showing a fifth embodiment of the non-contact temperature sensor according to the present invention, and FIG. 7A is a diagram showing a state in which the non-contact temperature sensor is viewed from diagonally forward. FIG. 7B is a diagram showing a state in which the non-contact temperature sensor is viewed from obliquely behind. FIGS. 7C (A), 7C (B), and 7C (C) are exploded perspective views of the non-contact temperature sensor.

  Similar to the non-contact temperature sensor 100 shown in FIG. 1, the non-contact temperature sensor 200 includes a pedestal 11 and a cover housing 12 of the sensor body 10, and the pedestal 11 also serves as bottomed recesses 21 and 22. One concave portion is formed (see FIG. 7C (C)). In addition, a guide cylinder 30E having a rectangular tube-shaped body portion 35 in which an opening P is formed is provided at a portion facing the cover housing 12 and the bottomed recesses 21 and 22 thereon. The other components of the non-contact temperature sensor 200, such as an infrared absorption film M (not shown), the infrared detecting thermal element 15, and the temperature compensating thermal element 16, are configured in the same manner as the non-contact temperature sensor 100. . Further, the infrared detecting thermal element 15 and the temperature compensating thermal element 16 are installed so as not to be thermally interfered with in one concave portion serving as the bottomed concave portions 21 and 22.

  The guide tube 30E is composed of a cover housing 12 and another cover housing 25 provided thereon, and each of the cover housings 12 and 25 is cut and bent by an appropriate sheet metal member. This is an integrally formed member (see FIGS. 7C (A) and (B)). As shown in FIG. 7C (A), the cover housing 25 is formed by bending a strip-like member in which a rectangular hole defining the opening P of the guide cylinder 30E is bent in parallel at a plurality of locations. A ceiling wall 65 in which a rectangular hole is opened is projected. Further, the side walls erected on the cover housing 25 (base) correspond to the short side walls 35S and 35S of the body 35, and a part of each short side wall 35S is bent inward so that the vane plate 45S1 is formed. A hole 55S1 is formed in the portion where the blade 45S1 is formed.

  On the other hand, the cover housing 12 is formed by bending the protruding portions on both sides of the strip-shaped member to form the long side walls 35L and 35L of the body portion 35. Part of the blades 45L1 and 45L2 are formed by being bent inward. Further, a hole 55L2 is formed in a portion where the blade 45L2 is cut out.

  In the non-contact temperature sensor 200 including the guide cylinder 30E configured as described above, the non-light guiding means is configured by the blades 45L1, 45L2, 45S1, and the hole portions 55L2, 55S1, and thereby the guide cylinder. Infrared radiation is detected by radiant infrared rays traveling toward the inner wall of the body portion 35E of 30E or reflected by the inner wall of the body portion 35 and radiant infrared rays entering the inner side from the outer side of the body portion 35 of the guide tube 30E. Reaching the light receiving range J including the thermal element 15 for use is prevented. Therefore, the non-contact temperature sensor 200 having the guide cylinder 30E can also exhibit the same excellent operational effect as the non-contact temperature sensor 100 having the guide cylinder 30A described above (in order to avoid redundant explanation, Detailed explanation is omitted).

  In addition, since the guide tube 30E is configured by combining the cover housings 12 and 25, which are integrally formed members of the bent parts, the design, processing, assembly, and inspection processes can be greatly simplified. Thus, the productivity and economy of the non-contact temperature sensor 200 can be improved. Further, since the short side walls 35S and 35S are formed integrally with the cover casing 25, and the long side walls 35L and 35L are formed integrally with the cover casing 12 of the sensor body 10, guidance is provided. It is possible to further reduce the number of parts and further increase the productivity while making the cylinder 30E composed of a plurality of parts to make assembly extremely simple.

  Further, as shown in FIGS. 7C (A) and 7 (B), all the folding lines for folding processing in the cover housings 12 and 25 are parallel, so that there is an advantage that the press molding becomes extremely simple. Usually, when bending a sheet metal or other member sequentially, if the fold line direction changes, the member is moved and repositioned so that it matches the fold line direction for each fold, and then the next bending process is performed. In contrast, if all the folding lines are parallel, bending along one direction can be performed sequentially without changing the orientation of the member, which greatly improves the workability. be able to. Furthermore, since another cover housing 12 is disposed below the cover housing 25 of the guide cylinder 30E that is disposed closest to the heat source that is the detection target, the heat of the cover housing 25 that is relatively easily heated. However, there is an advantage that the sensor body 10 is more difficult to conduct.

  In addition, as above-mentioned, this invention is not limited to said each embodiment, A various deformation | transformation is possible in the limit which does not change the summary. For example, the guide tube may not be a square tube, may be another polygonal tube, and may be a cylinder instead of a square tube. In addition, the hole portion may or may not have a slit shape, and an appropriate hole shape can be adopted. Further, as described above, the inside of the guide tube provided in the non-contact temperature sensor according to the present invention does not need to be subjected to the same processing as that of the conventional black body processing. The black body treatment is not hindered. Still further, the guide tube may be provided with a mixture of a slat formed on the outer side and a slat formed on the inner side, even in this case, Each vane can be easily formed by pressing or the like.

  As described above, the non-contact temperature sensor of the present invention is widely and effectively used for non-contact measurement of the temperature of various other heat sources such as a detection object such as a heat fixing roller of a copying machine. can do.

  7A ... Heat source (detection target), 7B ... Heat source 7B, 10 ... Sensor body, 11 ... Base, 12 ... Cover housing (base), 13 ... Support plate, 15 ... Thermal sensing element for infrared detection, 16 ... For temperature compensation Heat sensitive element, 21, 22 ... bottomed recess, 25 ... cover housing, 30, 30A, 30B, 30C, 30D, 30E ... guide tube, 31 ... trunk, 31L, 31L ... long side wall, 31S, 31S ... short Side wall, 33 ... trunk, 33L ... wall, 33P ... plate member, 34 ... trunk, 34S ... short side wall, 34L ... long side wall, 35 ... trunk, 35L ... long side wall, 35S ... short side wall 41L1, 41L2, 41S1, 41S2 ... vane plate, 42L0, 42L1, 42L2, 42S0, 42S1, 42S2 ... vane plate, 43L1, 43L2, 43S1, 43S2 ... vane plate, 44L1, 44L2, 44S1, 44S2 ... vane plate, 45L , 45L2, 45S1 ... blades, 51L1, 51L2, 51S1, 51S2 ... holes, 52L0, 52L1, 52L2, 52S0, 52S1, 52S2 ... holes, 53L1, 53L2, 53S1, 53S2 ... holes, 54L1, 55L2, 54S1 , 54S2 ... hole, 55L2, 55S1 ... hole, 61L ... long side end, 61S ... short side end, 63L, 63S ... end, 64L, 64S ... end, 65 ... top wall, 100, 200 ... Non-contact temperature sensor, 1101, 1102, 1103, 1104, 1105, 1200, 1201 ... infrared, E ... external environment, G ... virtual surface, IR ... radiant infrared, J ... light receiving range, Ja, Jb ... edge, Ka, Kb ... Virtual line, M ... Infrared absorbing film, P ... Opening, Pa, Pb ... Edge, Q1, Q2, Q3 ... Insertion hole, V1, V2 ... Space, Y ... Temperature detection view Range, Ya, Yb ... edge, α1, α2 ... bending trajectory of, theta ... angle.

Claims (10)

A non-contact temperature sensor for non-contact measurement of the temperature of a heat source,
A thermosensitive element for detecting infrared rays for detecting the amount of infrared rays emitted from the heat source; and
A temperature-compensating thermal element that detects the amount of heat from the external environment;
A guide cylinder that has a cylindrical shape, has an opening and a body, and is provided so as to demarcate a temperature detection visual field range by the infrared detection thermal element in the heat source;
With
The guide tube is configured such that at least a part of the infrared ray that is incident on the inside of the guide tube through the opening and travels toward the inner wall of the trunk portion and the infrared ray that is reflected by the inner wall of the trunk portion is the infrared ray. Having non-light guiding means provided to prevent reaching the light receiving range including the thermal element for detection,
Non-contact temperature sensor. The non-light-guiding means has a blade plate projecting from the inside of the body portion, and the blade plate enters the guide tube from the opening and proceeds toward the inner wall of the body portion. The infrared rays, and at least a part of the infrared rays reflected by the inner wall of the body portion,
The non-contact temperature sensor according to claim 1. The non-light guide means has a hole formed in the body portion.
The non-contact temperature sensor according to claim 2. The non-light-guiding means is formed from a part of a body part in which the blade plate is bent inside the guide tube, and the hole part is formed in a part of the body part.
The non-contact temperature sensor according to claim 3. A plurality of the blade portions are provided along the trunk portion, and a protruding amount to the inside of the guide tube is increased from the opening of the guide tube toward the light receiving range.
The non-contact temperature sensor according to any one of claims 2 to 4. The non-light-guiding means includes a blade plate formed by bending a part of the body part to the outside of the guide tube, and a hole part formed in the body part.
The non-contact temperature sensor according to claim 1. The guide tube is composed of a plurality of parts having the same shape.
The non-contact temperature sensor according to claim 1. The guide tube has a rectangular tube shape, and at least two adjacent trunk walls are integrally formed.
The non-contact temperature sensor according to claim 7. The guide tube is composed of a plurality of parts, and has a base portion on which at least a part of the body portion is erected.
The non-contact temperature sensor according to claim 1. The guide tube is in the form of a square tube, and is an integrally formed member that forms a pair of opposing body walls in the body portion, and an integrally formed member that forms another pair of body walls that face each other in the body portion. Is a combination of
The non-contact temperature sensor according to claim 1.